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Sample records for activated dissociation cad

  1. Application of matrix calculation 1: Design and adjustment of a tandem mass spectrometer for Collision-Activated Dissociation (CAD)

    NASA Astrophysics Data System (ADS)

    1982-02-01

    A matrix representation of the ion optics of the analyzing stage has been used in a computer model of a tandem mass spectrometer with simultaneous detection for CAD. The matrix algorithm of this model is discussed here as an elegant way of describing the ion optics in a first-order approximation. The accuracy of the calculations is illustrated by comparing calculated and measured adjustments of the instrument under normal experiment conditions. The ion-optical possibilities with respect to transmission, mass resolution influence of several ion optical parameters on the shape and position of the mass focal plane is discussed. The experimental values of mass range, mass resolution and ion transmission agree very well with the calculations. Moreover, the computer model appears to be a useful tool for giving clear insight into the operation of the rather complex ion optics of the instrument. The calculations have been further developed towards higher accuracy, making possible automatic focusing of the mass focal plane onto the detector.

  2. Effects of Peptide Backbone Amide-to-Ester Bond Substitution on the Cleavage Frequency in Electron Capture Dissociation and Collision-Activated Dissociation

    NASA Astrophysics Data System (ADS)

    Kjeldsen, Frank; Zubarev, Roman A.

    2011-08-01

    Probing the mechanism of electron capture dissociation on variously modified model peptide polycations has resulted in discovering many ways to prevent or reduce {{N}} - {{{C}}_α } bond fragmentation. Here we report on a rare finding of how to increase the backbone bond dissociation rate. In a number of model peptides, amide-to-ester backbone bond substitution increased the frequency of {{O}} - {{{C}}_α } bond cleavage (an analogue of {{N}} - {{{C}}_α } bonds in normal peptides) by several times, at the expense of reduced frequency of cleavages of the neighboring {{N}} - {{{C}}_α } bonds. In contrast, the ester linkage was only marginally broken in collisional dissociation. These results further highlight the complementarity of the reaction mechanisms in electron capture dissociation (ECD) and collision-activated dissociation (CAD). It is proposed that the effects of amide-to-ester bond substitution on fragmentation are mainly due to the differences in product ion stability (ECD, CAD) as well as proton affinity (CAD). This proposal is substantiated by calculations using density functional theory. The implications of these results in relation to the current understanding of the mechanisms of electron capture dissociation and electron transfer dissociation are discussed.

  3. Supplemental activation method for high-efficiency electron-transfer dissociation of doubly protonated peptide precursors.

    PubMed

    Swaney, Danielle L; McAlister, Graeme C; Wirtala, Matthew; Schwartz, Jae C; Syka, John E P; Coon, Joshua J

    2007-01-15

    Electron-transfer dissociation (ETD) delivers the unique attributes of electron capture dissociation to mass spectrometers that utilize radio frequency trapping-type devices (e.g., quadrupole ion traps). The method has generated significant interest because of its compatibility with chromatography and its ability to: (1) preserve traditionally labile post-translational modifications (PTMs) and (2) randomly cleave the backbone bonds of highly charged peptide and protein precursor ions. ETD, however, has shown limited applicability to doubly protonated peptide precursors, [M + 2H]2+, the charge and type of peptide most frequently encountered in "bottom-up" proteomics. Here we describe a supplemental collisional activation (CAD) method that targets the nondissociated (intact) electron-transfer (ET) product species ([M + 2H]+*) to improve ETD efficiency for doubly protonated peptides (ETcaD). A systematic study of supplementary activation conditions revealed that low-energy CAD of the ET product population leads to the near-exclusive generation of c- and z-type fragment ions with relatively high efficiency (77 +/- 8%). Compared to those formed directly via ETD, the fragment ions were found to comprise increased relative amounts of the odd-electron c-type ions (c+*) and the even-electron z-type ions (z+). A large-scale analysis of 755 doubly charged tryptic peptides was conducted to compare the method (ETcaD) to ion trap CAD and ETD. ETcaD produced a median sequence coverage of 89%-a significant improvement over ETD (63%) and ion trap CAD (77%).

  4. Aberrant caspase-activated DNase (CAD) transcripts in human hepatoma cells.

    PubMed

    Hsieh, S Y; Liaw, S F; Lee, S N; Hsieh, P S; Lin, K H; Chu, C M; Liaw, Y F

    2003-01-27

    The gene of caspase-activated DNase (CAD), the key enzyme for nucleosome cleavage during apoptosis, is mapped at chromosome 1p36, a region usually associated with hemizygous deletions in human cancers, particularly in hepatoma (HCC). It is tempting to speculate that CAD plays a tumour-suppressive role in hepatocarcinogenesis. To address this, we examined the CAD transcripts in six human HCC cell lines, one liver tissue from a non-HCC subject, and peripheral blood leukocytes (PBL) from three healthy individuals. Alternatively spliced CAD transcripts with fusion of exon 1 to exon 7 were isolated in most of the examined samples including HCC cells and normal controls. However, relatively abundant alternatively spliced CAD transcripts with fusion of exon 2 to exon 6 or 7, in which the corresponding domain directing CAD interaction with ICAD was preserved, were found only in poorly differentiated Mahlavu and SK-Hep1 cells. Interestingly, an abnormal CAD transcript with its exon 3 replaced by a truncated transposable Alu repeat was isolated in Hep3B cells, indicative of the implication of an Alu-mediated genomic mutation. Moreover, mis-sense mutations in the CAD genes were identified in all six HCC cell lines. Upon UV-induced apoptosis, DNA fragmentation efficiency was found to be intact, partially reduced and remarkably reduced in Huh7 and J328, Hep3B and HepG2, and Mahlavu cells, respectively. That mutations and aberrantly spliced transcripts for the CAD gene are frequently present in human HCC cells, especially in poorly differentiated HCC cells, suggests a significant role of CAD in human hepatocarcinogenesis.

  5. Higher-energy Collision-activated Dissociation Without a Dedicated Collision Cell*

    PubMed Central

    McAlister, Graeme C.; Phanstiel, Douglas H.; Brumbaugh, Justin; Westphall, Michael S.; Coon, Joshua J.

    2011-01-01

    Beam-type collisional activation dissociation (HCD) offers many advantages over resonant excitation collision-activated dissociation, including improved identification of phosphorylated peptides and compatibility with isobaric tag-based quantitation (e.g. tandem mass tag (TMT) and iTRAQ). However, HCD typically requires specially designed and dedicated collision cells. Here we demonstrate that HCD can be performed in the ion injection pathway of a mass spectrometer with a standard atmospheric inlet (iHCD). Testing this method on complex peptide mixtures revealed similar identification rates to collision-activated dissociation (2883 versus 2730 IDs for iHCD/CAD, respectively) and precursor-product-conversion efficiency comparable to that achieved within a dedicated collision cell. Compared with pulsed-q dissociation, a quadrupole ion trap-based method that retains low-mass isobaric tag reporter ions, iHCD yielded isobaric tag for relative and absolute quantification reporter ions 10-fold more intense. This method involves no additional hardware and can theoretically be implemented on any mass spectrometer with an atmospheric inlet. PMID:21393638

  6. Comparison of sustained off-resonance irradiation collisionally activated dissociation and multipole storage-assisted dissociation for top-down protein analysis.

    PubMed

    Keller, Karin M; Brodbelt, Jennifer S; Hettich, Robert L; Van Berkel, Gary J

    2004-04-01

    Tandem mass spectrometric data acquired for small (8-18 kDa) intact proteins by sustained off-resonance irradiation collisionally activated dissociation (SORI-CAD) and multipole storage-assisted dissociation (MSAD) were compared, and the results indicate that the two activation methods do not always provide the same fragmentation patterns. In MSAD experiments, the charge state distribution made available by the ionization conditions may dictate the range of fragment ions that can be generated. In addition, conditions of high space charge within the hexapole impair transmission and/or trapping of high m/z species, which can result in loss of important precursor and product ions. Finally, the non-resonant nature of activation in MSAD can provide access to secondary dissociation processes that are not available by SORI. Because of these considerations, MSAD is less reliable than SORI for generating sequence tag data. However, it appears that MSAD samples 'preferred' cleavage processes (i.e. those occurring at D and P residues) just as well as SORI, which implies that MSAD data may be somewhat more compatible with search algorithms that utilize unprocessed fragment ion masses.

  7. Comparison of sustained off-resonance irradiation collisionally activated dissociation and multipole storage-assisted dissociation for top-down protein analysis

    SciTech Connect

    Keller, Karin M; Brodbelt, Jennifer S; Hettich, Robert {Bob} L; Van Berkel, Gary J

    2004-01-01

    Tandem mass spectrometric data acquired for small (8--18 kDa) intact proteins by sustained off-resonance irradiation collisionally activated dissociation (SORI-CAD) and multipole storage-assisted dissociation (MSAD) were compared, and the results indicate that the two activation methods do not always provide the same fragmentation patterns. In MSAD experiments, the charge state distribution made available by the ionization conditions may dictate the range of fragment ions that can be generated. In addition, conditions of high space charge within the hexapole impair transmission and/or trapping of high m/z species, which can result in loss of important precursor and product ions. Finally, the non-resonant nature of activation in MSAD can provide access to secondary dissociation processes that are not available by SORI. Because of these considerations, MSAD is less reliable than SORI for generating sequence tag data. However, it appears that MSAD samples 'preferred' cleavage processes (i.e. those occurring at D and P residues) just as well as SORI, which implies that MSAD data may be somewhat more compatible with search algorithms that utilize unprocessed fragment ion masses.

  8. De Novo Sequencing of Heparan Sulfate Oligosaccharides by Electron-Activated Dissociation

    PubMed Central

    Huang, Yu; Yu, Xiang; Mao, Yang; Costello, Catherine E.; Zaia, Joseph; Lin, Cheng

    2014-01-01

    Structural characterization of highly sulfated glycosaminoglycans (GAGs) by collisionally activated dissociation (CAD) is challenging because of the extensive sulfate losses mediated by free protons. While removal of the free protons may be achieved through the use of derivatization, metal cation adducts, and/or electrospray supercharging reagents, these steps add complexity to the experimental workflow. It is therefore desirable to develop an analytical approach for GAG sequencing that does not require derivatization or addition of reagents to the electrospray solution. Electron detachment dissociation (EDD) can produce extensive and informative fragmentation for GAGs without the need to remove free protons from the precursor ions. However, EDD is an inefficient process, often requiring consumption of large sample quantities (typically several micrograms), particularly for highly sulfated GAG ions. Here, we report that with improved instrumentation, optimization of the ionization and ion transfer parameters, and enhanced EDD efficiency, it is possible to generate highly informative EDD spectra of highly sulfated GAGs on the liquid chromatography (LC) time-scale, with consumption of only a few nanograms of sample. We further show that negative electron transfer dissociation (NETD) is an even more effective fragmentation technique for GAG sequencing, producing fewer sulfate losses while consuming smaller amount of samples. Finally, a simple algorithm was developed for de novo HS sequencing based on their high resolution tandem mass spectra. These results demonstrate the potential of EDD and NETD as sensitive analytical tools for detailed, high-throughput, de novo structural analyses of highly sulfated GAGs. PMID:24224699

  9. An Analysis of Computer Aided Design (CAD) Packages Used at MSFC for the Recent Initiative to Integrate Engineering Activities

    NASA Technical Reports Server (NTRS)

    Smith, Leigh M.; Parker, Nelson C. (Technical Monitor)

    2002-01-01

    This paper analyzes the use of Computer Aided Design (CAD) packages at NASA's Marshall Space Flight Center (MSFC). It examines the effectiveness of recent efforts to standardize CAD practices across MSFC engineering activities. An assessment of the roles played by management, designers, analysts, and manufacturers in this initiative will be explored. Finally, solutions are presented for better integration of CAD across MSFC in the future.

  10. Activated Dissociation of HCl on Au(111).

    PubMed

    Shirhatti, Pranav R; Geweke, Jan; Steinsiek, Christoph; Bartels, Christof; Rahinov, Igor; Auerbach, Daniel J; Wodtke, Alec M

    2016-04-01

    We report zero-coverage reaction probabilities (S0) for HCl dissociative adsorption on Au(111) obtained by the seeded molecular beam hot-nozzle method. For measurements at normal incidence with mean translational energies ranging from 0.94 to 2.56 eV (nozzle temperatures 296 to 1060 K), S0 increased from 6 × 10(-6) to 2 × 10(-2). S0 also increased with increasing nozzle temperature for fixed incidence energy associated with the motion normal to the surface. Accounting for the influence of the vibrational state population and translational energy distributions in the incident beam, we are able to compare the experimental results to recent theoretical predictions. These calculations, performed employing 6-D quantum dynamics on an electronically adiabatic potential energy surface obtained using density functional theory at the level of the generalized gradient approximation and the static surface approximation, severely overestimate the reaction probabilities when compared with our experimental results. We discuss some possible reasons for this large disagreement. PMID:26990513

  11. Low-energy collisionally activated dissociation of pentose-borate complexes

    NASA Astrophysics Data System (ADS)

    Pepi, Federico; Garzoli, Stefania; Tata, Alessandra; Giacomello, Pierluigi

    2010-01-01

    Pentose-borate 1:1 complexes were generated in the ESI source of a triple quadrupole and ion trap mass spectrometer by electrospray ionization of Na2B4O7 and pentose (arabinose, lyxose, ribose, xylose) 2:1 solution in CH3CN/H2O. The study of their low-energy collisionally activated dissociation (CAD) demonstrated that ribose and lyxose are preferentially complexed at the C2-C3 cis-diol function whereas arabinose and xylose are esterified at the C1-C2 hydroxyl groups. No evidence was found of the stronger affinity for ribose to borate. The ribose probiotic rule can be explained by considering its peculiar capability, among the investigated pentoses, to almost totally complex the borate anion at the C2-C3 hydroxyl group, thus enabling the subsequent stages of nucleotide assembly, such as phosphorylation and linkage to the nucleobases. Finally, the differences observed in the pentose-borate complex CAD spectra can be used for the mass spectrometric discrimination of isomeric pentoses in complex mixtures.

  12. Sweet! Candy Bar Activity Teaches CAD, Math, and Graphics

    ERIC Educational Resources Information Center

    Granlund, George

    2009-01-01

    By far, the tastiest technology learning activity that the author's students work on is the development of the design of a chocolate candy bar. This article describes how the author implemented the candy bar activity. The activity gives students an opportunity to design a product and to take it from concept through to production.

  13. Activation of TRPC6 channels promotes endocannabinoid biosynthesis in neuronal CAD cells

    PubMed Central

    Bardell, Tamera K.; Barker, Eric L.

    2010-01-01

    Calcium influx activates biosynthesis of the endogenous cannabinoids 2-arachidonyl glycerol (2-AG) and anandamide (AEA). The calcium channel involved with endocannabinoid synthesis and release in neurons is still unknown. The canonical TRP (TRPC) channels are calcium-permeable channels that are a homology-based subdivision of the broader class of TRP channels. TRPC3, 6, and 7 are G-protein-gated nonselective cation channels that have been localized to lipid rafts and shown to colocalize with caveolin 1. Because endocannabinoid synthesis has been found to occur “on demand” in a calcium-dependent manner and has been linked to lipid rafts, we explored the potential role of transient receptor potential (TRP) channels in this process. Previously, we observed that after metabolism AEA and arachidonic acid (ArA) can be recycled into new endocannabinoid molecules. Consistent with these previous findings, we found that Cath.a differentiated (CAD) cells pretreated with radiolabeled ArA exhibited a robust increase in 2-AG release in response to TRPC stimulation with the diacylglycerol (DAG) analogue, 1-oleoyl-2-acetyl-sn-glycerol (OAG). Furthermore, cells pretreated with [3H]AEA produced a significant amount of AEA and 2-AG upon stimulation of TRPC channels. This process was not mediated through protein kinase C activation. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that only TRPC6 was present in the CAD cells. siRNA-induced knockdown of TRPC6 in the CAD cells abolished OAG-stimulated production of the endocannabionids. This evidence suggests that TRPC6 may be capable of promoting endocannabinoid synthesis in neuronal cells. PMID:20466028

  14. Minimizing base loss and internal fragmentation in collisionally activated dissociation of multiply deprotonated RNA.

    PubMed

    Taucher, Monika; Rieder, Ulrike; Breuker, Kathrin

    2010-02-01

    In recent years, new classes of nonprotein-coding ribonucleic acids (ncRNAs) with important cellular functions have been discovered. Of particular interest for biomolecular research and pharmaceutical developments are small ncRNAs that are involved in gene regulation, such as small interfering RNAs (21-28 nt), pre-microRNAs (70-80 nt), or riboswitches (34-200 nt). De novo sequencing of RNA by top-down mass spectrometry has so far been limited to RNA consisting of up to approximately 20 nt. We report here complete sequence coverage for 34 nt RNA (10.9 kDa), along with 30 out of 32 possible complementary ion pairs from collisionally activated dissociation (CAD) experiments. The key to minimizing undesired base loss and internal fragmentation is to minimize the internal energy of fragment ions from primary backbone cleavage. This can be achieved by collisional cooling of primary fragment ions and selection of precursor ions of relatively low negative net charge (about -0.2/nt).

  15. Electron Transfer Dissociation of Oligonucleotide Cations.

    PubMed

    Smith, Suncerae I; Brodbelt, Jennifer S

    2009-06-01

    Electron transfer dissociation (ETD) of multi-protonated 6 - 20-mer oligonucleotides and 12- and 14-mer duplexes is compared to collision activated dissociation (CAD). ETD causes efficient charge reduction of the multi-protonated oligonucleotides in addition to limited backbone cleavages to yield sequence ions of low abundance. Subsequent CAD of the charge-reduced oligonucleotides formed upon electron transfer, in a net process termed electron transfer collision activated dissociation (ETcaD), results in rich fragmentation in terms of w, a, z, and d products, with a marked decrease in the abundance of base loss ions and internal fragments. Complete sequencing was possible for nearly all oligonucleotides studied. ETcaD of an oligonucleotide duplex resulted in specific backbone cleavages, with conservation of weaker non-covalent bonds. PMID:20161288

  16. Enantioselective Collision-Activated Dissociation of Gas-Phase Tryptophan Induced by Chiral Recognition of Protonated uc(l)-Alanine Peptides

    NASA Astrophysics Data System (ADS)

    Fujihara, Akimasa; Matsuyama, Hiroki; Tajiri, Michiko; Wada, Yoshinao; Hayakawa, Shigeo

    2016-06-01

    Enantioselective dissociation in the gas phase is important for enantiomeric enrichment and chiral transmission processes in molecular clouds regarding the origin of homochirality in biomolecules. Enantioselective collision-activated dissociation (CAD) of tryptophan (Trp) and the chiral recognition ability of uc(l)-alanine peptides (uc(l)-Ala n ; n = 2-4) were examined using a linear ion trap mass spectrometer. CAD spectra of gas-phase heterochiral H+(uc(d)-Trp)(uc(l)-Ala n ) and homochiral H+(uc(l)-Trp)(uc(l)-Ala n ) noncovalent complexes were obtained as a function of the peptide size n. The H2O-elimination product was observed in CAD spectra of both heterochiral and homochiral complexes for n = 2 and 4, and in homochiral H+(uc(l)-Trp)(uc(l)-Ala3), indicating that the proton is attached to the uc(l)-alanine peptide, and H2O loss occurs from H+(uc(l)-Ala n ) in the noncovalent complexes. H2O loss did not occur in heterochiral H+(uc(d)-Trp)(uc(l)-Ala3), where NH3 loss and (H2O + CO) loss were the primary dissociation pathways. In heterochiral H+(uc(d)-Trp)(uc(l)-Ala3), the protonation site is the amino group of uc(d)-Trp, and NH3 loss and (H2O + CO) loss occur from H+(uc(d)-Trp). uc(l)-Ala peptides recognize uc(d)-Trp through protonation of the amino group for peptide size n = 3. NH3 loss and (H2O + CO) loss from H+(uc(d)-Trp) proceeds via enantioselective CAD in gas-phase heterochiral H+(uc(d)-Trp)(uc(l)-Ala3) at room temperature, whereas uc(l)-Trp dissociation was not observed in homochiral H+(uc(l)-Trp)(uc(l)-Ala3). These results suggest that enantioselective dissociation induced by chiral recognition of uc(l)-Ala peptides through protonation could play an important role in enantiomeric enrichment and chiral transmission processes of amino acids.

  17. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

    PubMed Central

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

    2014-01-01

    Background In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the “Emotional Part” (EP) and the “Apparently Normal Part” (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Results Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. Conclusion DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are

  18. Expression of cadR Enhances its Specific Activity for Cd Detoxification and Accumulation in Arabidopsis.

    PubMed

    Li, Jingrui; Wei, Xuezhi; Yu, Pengli; Deng, Xin; Xu, Wenxiu; Ma, Mi; Zhang, Haiyan

    2016-08-01

    Cadmium (Cd) is a transition metal that is highly toxic in biological systems. Anthropogenic emissions of Cd have increased biogeochemical cycling and the amount of Cd in the biosphere. Here we studied the utility of a bacterial Cd-binding protein, CadR, for the remediation of Cd contamination. CadR was successfully targeted to chloroplasts using a constitutive Cauliflower mosaic virus (CaMV) 35S promoter or a shoot-specific Chl a/b-binding protein 2 gene (CAB2) promoter and an RbcS (small subunit of the Rubisco complex) transit peptide. Under short-term (2 d) exposure to Cd, the cadR transgenic plants showed up to a 2.9-fold Cd accumulation in roots compared with untransformed plants. Under medium term (7 d) exposure to Cd, the concentrations of Cd in leaves began to increase but there were no differences between the wild type and the cadR transgenic plants. Under long-term (16 d) exposure to Cd, the cadR transgenic plants accumulated greater amounts of Cd in leaves than the untransformed plants. Total Cd accumulation (µg per plant) in shoots and roots of the plants expressing cadR were significantly higher (up to 3.5-fold in shoots and 5.2-fold in roots) than those of the untransformed plants. We also found that targeting CadR to chloroplasts facilitated chloroplastic metal homeostasis and Chl b accumulation. Our results demonstrate that manipulating chelating capacity in chloroplasts or in the cytoplasm may be effective in modifying both the accumulation of and resistance to Cd.

  19. Expression of cadR Enhances its Specific Activity for Cd Detoxification and Accumulation in Arabidopsis.

    PubMed

    Li, Jingrui; Wei, Xuezhi; Yu, Pengli; Deng, Xin; Xu, Wenxiu; Ma, Mi; Zhang, Haiyan

    2016-08-01

    Cadmium (Cd) is a transition metal that is highly toxic in biological systems. Anthropogenic emissions of Cd have increased biogeochemical cycling and the amount of Cd in the biosphere. Here we studied the utility of a bacterial Cd-binding protein, CadR, for the remediation of Cd contamination. CadR was successfully targeted to chloroplasts using a constitutive Cauliflower mosaic virus (CaMV) 35S promoter or a shoot-specific Chl a/b-binding protein 2 gene (CAB2) promoter and an RbcS (small subunit of the Rubisco complex) transit peptide. Under short-term (2 d) exposure to Cd, the cadR transgenic plants showed up to a 2.9-fold Cd accumulation in roots compared with untransformed plants. Under medium term (7 d) exposure to Cd, the concentrations of Cd in leaves began to increase but there were no differences between the wild type and the cadR transgenic plants. Under long-term (16 d) exposure to Cd, the cadR transgenic plants accumulated greater amounts of Cd in leaves than the untransformed plants. Total Cd accumulation (µg per plant) in shoots and roots of the plants expressing cadR were significantly higher (up to 3.5-fold in shoots and 5.2-fold in roots) than those of the untransformed plants. We also found that targeting CadR to chloroplasts facilitated chloroplastic metal homeostasis and Chl b accumulation. Our results demonstrate that manipulating chelating capacity in chloroplasts or in the cytoplasm may be effective in modifying both the accumulation of and resistance to Cd. PMID:27382127

  20. Switchgrass PviCAD1: Understanding residues important for substrate preferences and activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin is a major component of plant cell walls and is a complex aromatic heteropolymer. Reducing lignin content improves conversion efficiency into liquid fuels, and enzymes involved in lignin biosynthesis are attractive targets for bioengineering. Cinnamyl alcohol dehydrogenase (CAD) catalyzes t...

  1. Immersive CAD

    SciTech Connect

    Ames, A.L.

    1999-02-01

    This paper documents development of a capability for performing shape-changing editing operations on solid model representations in an immersive environment. The capability includes part- and assembly-level operations, with part modeling supporting topology-invariant and topology-changing modifications. A discussion of various design considerations in developing an immersive capability is included, along with discussion of a prototype implementation we have developed and explored. The project investigated approaches to providing both topology-invariant and topology-changing editing. A prototype environment was developed to test the approaches and determine the usefulness of immersive editing. The prototype showed exciting potential in redefining the CAD interface. It is fun to use. Editing is much faster and friendlier than traditional feature-based CAD software. The prototype algorithms did not reliably provide a sufficient frame rate for complex geometries, but has provided the necessary roadmap for development of a production capability.

  2. Differentiation of regioisomeric aromatic ketocarboxylic acids by positive mode atmospheric pressure chemical ionization collision-activated dissociation tandem mass spectrometry in a linear quadrupole ion trap mass spectrometer.

    PubMed

    Amundson, Lucas M; Owen, Benjamin C; Gallardo, Vanessa A; Habicht, Steven C; Fu, Mingkun; Shea, Ryan C; Mossman, Allen B; Kenttämaa, Hilkka I

    2011-04-01

    Positive-mode atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS(n)) was tested for the differentiation of regioisomeric aromatic ketocarboxylic acids. Each analyte forms exclusively an abundant protonated molecule upon ionization via positive-mode APCI in a commercial linear quadrupole ion trap (LQIT) mass spectrometer. Energy-resolved collision-activated dissociation (CAD) experiments carried out on the protonated analytes revealed fragmentation patterns that varied based on the location of the functional groups. Unambiguous differentiation between the regioisomers was achieved in each case by observing different fragmentation patterns, different relative abundances of ion-molecule reaction products, or different relative abundances of fragment ions formed at different collision energies. The mechanisms of some of the reactions were examined by H/D exchange reactions and molecular orbital calculations.

  3. Metastable atom-activated dissociation mass spectrometry of phosphorylated and sulfonated peptides in negative ion mode.

    PubMed

    Cook, Shannon L; Jackson, Glen P

    2011-06-01

    The dissociation behavior of phosphorylated and sulfonated peptide anions was explored using metastable atom-activated dissociation mass spectrometry (MAD-MS) and collision-induced dissociation (CID). A beam of high kinetic energy helium (He) metastable atoms was exposed to isolated phosphorylated and sulfonated peptides in the 3- and 2- charge states. Unlike CID, where phosphate losses are dominant, the major dissociation channels observed using MAD were C(α) - C peptide backbone cleavages and neutral losses of CO(2), H(2)O, and [CO(2) + H(2)O] from the charge reduced (oxidized) product ion, consistent with an electron detachment dissociation (EDD) mechanism such as Penning ionization. Regardless of charge state or modification, MAD provides ample backbone cleavages with little modification loss, which allows for unambiguous PTM site determination. The relative abundance of certain fragment ions in MAD is also demonstrated to be somewhat sensitive to the number and location of deprotonation sites, with backbone cleavage somewhat favored adjacent to deprotonated sites like aspartic acid residues. MAD provides a complementary dissociation technique to CID, ECD, ETD, and EDD for peptide sequencing and modification identification. MAD offers the unique ability to analyze highly acidic peptides that contain few to no basic amino acids in either negative or positive ion mode.

  4. Isotherm-Based Thermodynamic Models for Solute Activities of Organic Acids with Consideration of Partial Dissociation.

    PubMed

    Nandy, Lucy; Ohm, Peter B; Dutcher, Cari S

    2016-06-23

    Organic acids make up a significant fraction of the organic mass in atmospheric aerosol particles. The calculation of gas-liquid-solid equilibrium partitioning of the organic acid is therefore critical for accurate determination of atmospheric aerosol physicochemical properties and processes such as new particle formation and activation to cloud condensation nuclei. Previously, an adsorption isotherm-based statistical thermodynamic model was developed for capturing solute concentration-activity relationships for multicomponent aqueous solutions over the entire concentration range (Dutcher et al. J. Phys. Chem. C/A 2011, 2012, 2013), with model parameters for energies of adsorption successfully related to dipole-dipole electrostatic forces in solute-solvent and solvent-solvent interactions for both electrolytes and organics (Ohm et al. J. Phys. Chem. A 2015). However, careful attention is needed for weakly dissociating semivolatile organic acids. Dicarboxylic acids, such as malonic acid and glutaric acid are treated here as a mixture of nondissociated organic solute (HA) and dissociated solute (H(+) + A(-)). It was found that the apparent dissociation was greater than that predicted by known dissociation constants alone, emphasizing the effect of dissociation on osmotic and activity coefficient predictions. To avoid additional parametrization from the mixture approach, an expression was used to relate the Debye-Hückel hard-core collision diameter to the adjustable solute-solvent intermolecular distance. An improved reference state treatment for electrolyte-organic aqueous mixtures, such as that observed here with partial dissociation, has also been proposed. This work results in predictive correlations for estimation of organic acid and water activities for which there is little or no activity data.

  5. Isotherm-Based Thermodynamic Models for Solute Activities of Organic Acids with Consideration of Partial Dissociation.

    PubMed

    Nandy, Lucy; Ohm, Peter B; Dutcher, Cari S

    2016-06-23

    Organic acids make up a significant fraction of the organic mass in atmospheric aerosol particles. The calculation of gas-liquid-solid equilibrium partitioning of the organic acid is therefore critical for accurate determination of atmospheric aerosol physicochemical properties and processes such as new particle formation and activation to cloud condensation nuclei. Previously, an adsorption isotherm-based statistical thermodynamic model was developed for capturing solute concentration-activity relationships for multicomponent aqueous solutions over the entire concentration range (Dutcher et al. J. Phys. Chem. C/A 2011, 2012, 2013), with model parameters for energies of adsorption successfully related to dipole-dipole electrostatic forces in solute-solvent and solvent-solvent interactions for both electrolytes and organics (Ohm et al. J. Phys. Chem. A 2015). However, careful attention is needed for weakly dissociating semivolatile organic acids. Dicarboxylic acids, such as malonic acid and glutaric acid are treated here as a mixture of nondissociated organic solute (HA) and dissociated solute (H(+) + A(-)). It was found that the apparent dissociation was greater than that predicted by known dissociation constants alone, emphasizing the effect of dissociation on osmotic and activity coefficient predictions. To avoid additional parametrization from the mixture approach, an expression was used to relate the Debye-Hückel hard-core collision diameter to the adjustable solute-solvent intermolecular distance. An improved reference state treatment for electrolyte-organic aqueous mixtures, such as that observed here with partial dissociation, has also been proposed. This work results in predictive correlations for estimation of organic acid and water activities for which there is little or no activity data. PMID:27222917

  6. CAD: Designs on Business.

    ERIC Educational Resources Information Center

    Milburn, Ken

    1988-01-01

    Provides a general review of the field of Computer-Aided Design Software including specific reviews of "Autosketch,""Generic CADD,""Drafix 1 Plus,""FastCAD," and "Autocad Release 9." Brief articles include "Blueprint for Generation,""CAD for Every Department,""Ideas Sketched in Glass,""CAD on the MAC," and "A CAD Package Sampler." (CW)

  7. Westinghouse Idaho Nuclear Company, Inc. (WINCO) CAD activities at the Idaho Chemical Processing Plant (ICPP) (Idaho Engineering Laboratory)

    SciTech Connect

    Jensen, B.

    1989-04-18

    June 1985 -- The drafting manager obtained approval to implement a cad system at the ICPP. He formed a committee to evaluate the various cad systems and recommend a system that would most benefit the ICPP. A PC'' (personal computer) based system using Autocad software was recommended in lieu of the much more expensive main frame based systems.

  8. Westinghouse Idaho Nuclear Company, Inc. (WINCO) CAD activities at the Idaho Chemical Processing Plant (ICPP) (Idaho Engineering Laboratory)

    SciTech Connect

    Jensen, B.

    1989-04-18

    June 1985 -- The drafting manager obtained approval to implement a cad system at the ICPP. He formed a committee to evaluate the various cad systems and recommend a system that would most benefit the ICPP. A ``PC`` (personal computer) based system using Autocad software was recommended in lieu of the much more expensive main frame based systems.

  9. A Unified Kinetics and Equilibrium Experiment: Rate Law, Activation Energy, and Equilibrium Constant for the Dissociation of Ferroin

    ERIC Educational Resources Information Center

    Sattar, Simeen

    2011-01-01

    Tris(1,10-phenanthroline)iron(II) is the basis of a suite of four experiments spanning 5 weeks. Students determine the rate law, activation energy, and equilibrium constant for the dissociation of the complex ion in acid solution and base dissociation constant for phenanthroline. The focus on one chemical system simplifies a daunting set of…

  10. Noise-activated dissociation of soft elastic contacts.

    PubMed

    Chaudhury, M K; Goohpattader, P S

    2012-12-01

    Adhesive forces are capable of deforming a soft elastic object when it comes in contact with a flat rigid substrate. The contact is in stable equilibrium if the total energy of the system arising from the elastic and surface forces exhibits a minimum at a zero or at a slightly negative load. However, as the system is continually unloaded, the energy barrier decreases and it eventually disappears, thus leading to a ballistic separation of the contact. While this type of contact splitting has received wide recognition, what has not been much appreciated with these types of soft adhesion problems is that rupture of a contact can also occur at any finite sub critical load in the presence of a noise. The soft contact problems are unique in that the noise can be athermal, whereas the metastable and stable states of the thermodynamic potential can arise from the competition of the elastic and the interfacial energies of the system. Analysis based on Kramers' theory and simulations based on Langevin dynamics show that the contact rupture dynamics is amenable to an Eyring's form of a force and noise-induced escape of a particle from a potential well that is generic to various types of colloidal and macromolecular processes. These ideas are useful in understanding the results of a recent experiment involving the noise-activated rolling dynamics of a rigid sphere on a surface, where it is pinned by soft micro-fibrillar contacts.

  11. Evaluation of a Novel Approach for Peptide Sequencing: Laser-induced Acoustic Desorption Combined with P(OCH3)2+ Chemical Ionization and Collision-activated Dissociation in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Somuramasami, Jayalakshmi; Kenttämaa, Hilkka I.

    2007-01-01

    A novel mass spectrometric method has been developed for obtaining sequence information on small peptides. The peptides are desorbed as intact neutral molecules into a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR) by means of laser-induced acoustic desorption (LIAD). Reactions of the neutral peptides with the dimethoxyphosphenium ion, P(OCH3)2+, occur predominantly by addition of the peptide to P(OCH3)2+ followed by the loss of two methanol molecules, thus yielding product ions with the composition (peptide + P − 2H)+. Upon sustained off-resonance irradiation for collision-activated dissociation (SORI-CAD), the (peptide + P − 2H)+ ions undergo successive losses of CO and NH = CHR or H2O, CO, and NH = CHR to yield sequence-related fragment ions in addition to the regular an- and bn-type ions. Under the same conditions, SORI-CAD of the analogous protonated peptides predominantly yields the regular an- and bn-type ions. The mechanisms of the reactions of peptides with P(OCH3)2+ and the dissociation of the (peptide + P − 2H)+ ions were examined by using model peptides and molecular orbital calculations. PMID:17157527

  12. DSL ligand endocytosis physically dissociates Notch1 heterodimers before activating proteolysis can occur.

    PubMed

    Nichols, James T; Miyamoto, Alison; Olsen, Samantha L; D'Souza, Brendan; Yao, Christine; Weinmaster, Gerry

    2007-02-12

    Cleavage of Notch by furin is required to generate a mature, cell surface heterodimeric receptor that can be proteolytically activated to release its intracellular domain, which functions in signal transduction. Current models propose that ligand binding to heterodimeric Notch (hNotch) induces a disintegrin and metalloprotease (ADAM) proteolytic release of the Notch extracellular domain (NECD), which is subsequently shed and/or endocytosed by DSL ligand cells. We provide evidence for NECD release and internalization by DSL ligand cells, which, surprisingly, did not require ADAM activity. However, losses in either hNotch formation or ligand endocytosis significantly decreased NECD transfer to DSL ligand cells, as well as signaling in Notch cells. Because endocytosis-defective ligands bind hNotch, but do not dissociate it, additional forces beyond those produced through ligand binding must function to disrupt the intramolecular interactions that keep hNotch intact and inactive. Based on our findings, we propose that mechanical forces generated during DSL ligand endocytosis function to physically dissociate hNotch, and that dissociation is a necessary step in Notch activation.

  13. Measuring internal energy deposition in collisional activation using hydrated ion nanocalorimetry to obtain peptide dissociation energies and entropies.

    PubMed

    Demireva, Maria; Williams, Evan R

    2010-07-01

    The internal energy deposited in both on- and off-resonance collisional activation in Fourier transform ion cyclotron resonance mass spectrometry is measured with ion nanocalorimetry and is used to obtain information about the dissociation energy and entropy of a protonated peptide. Activation of Na(+)(H(2)O)(30) results in sequential loss of water molecules, and the internal energy of the activated ion can be obtained from the abundances of the product ions. Information about internal energy deposition in on-resonance collisional activation of protonated peptides is inferred from dissociation data obtained under identical conditions for hydrated ions that have similar m/z and degrees-of-freedom. From experimental internal energy deposition curves and Rice-Ramsperger-Kassel-Marcus (RRKM) theory, dissociation data as a function of collision energy for protonated leucine enkephalin, which has a comparable m/z and degrees-of-freedom as Na(+)(H(2)O)(30), are modeled. The threshold dissociation energies and entropies are correlated for data acquired at a single time point, resulting in a relatively wide range of threshold dissociation energies (1.1 to 1.7 eV) that can fit these data. However, this range of values could be significantly reduced by fitting data acquired at different dissociation times. By measuring the internal energy of an activated ion, the number of fitting parameters necessary to obtain information about the dissociation parameters by modeling these data is reduced and could result in improved accuracy for such methods.

  14. Teaching for CAD Expertise

    ERIC Educational Resources Information Center

    Chester, Ivan

    2007-01-01

    CAD (Computer Aided Design) has now become an integral part of Technology Education. The recent introduction of highly sophisticated, low-cost CAD software and CAM hardware capable of running on desktop computers has accelerated this trend. There is now quite widespread introduction of solid modeling CAD software into secondary schools but how…

  15. Rheb Protein Binds CAD (Carbamoyl-phosphate Synthetase 2, Aspartate Transcarbamoylase, and Dihydroorotase) Protein in a GTP- and Effector Domain-dependent Manner and Influences Its Cellular Localization and Carbamoyl-phosphate Synthetase (CPSase) Activity*

    PubMed Central

    Sato, Tatsuhiro; Akasu, Hitomi; Shimono, Wataru; Matsu, Chisa; Fujiwara, Yuki; Shibagaki, Yoshio; Heard, Jeffrey J.; Tamanoi, Fuyuhiko; Hattori, Seisuke

    2015-01-01

    Rheb small GTPases, which consist of Rheb1 and Rheb2 (also known as RhebL1) in mammalian cells, are unique members of the Ras superfamily and play central roles in regulating protein synthesis and cell growth by activating mTOR. To gain further insight into the function of Rheb, we carried out a search for Rheb-binding proteins and found that Rheb binds to CAD protein (carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase), a multifunctional enzyme required for the de novo synthesis of pyrimidine nucleotides. CAD binding is more pronounced with Rheb2 than with Rheb1. Rheb binds CAD in a GTP- and effector domain-dependent manner. The region of CAD where Rheb binds is located at the C-terminal region of the carbamoyl-phosphate synthetase domain and not in the dihydroorotase and aspartate transcarbamoylase domains. Rheb stimulated carbamoyl-phosphate synthetase activity of CAD in vitro. In addition, an elevated level of intracellular UTP pyrimidine nucleotide was observed in Tsc2-deficient cells, which was attenuated by knocking down of Rheb. Immunostaining analysis showed that expression of Rheb leads to increased accumulation of CAD on lysosomes. Both a farnesyltransferase inhibitor that blocks membrane association of Rheb and knockdown of Rheb mislocalized CAD. These results establish CAD as a downstream effector of Rheb and suggest a possible role of Rheb in regulating de novo pyrimidine nucleotide synthesis. PMID:25422319

  16. The temporal dynamics of metacognition: Dissociating task-related activity from later metacognitive processes.

    PubMed

    Desender, Kobe; Van Opstal, Filip; Hughes, Gethin; Van den Bussche, Eva

    2016-02-01

    In recent years, neuroscience research spent much effort in revealing brain activity related to metacognition. Despite this endeavor, it remains unclear exactly when metacognitive experiences develop during task performance. To investigate this, the current study used EEG to temporally and spatially dissociate task-related activity from metacognitive activity. In a masked priming paradigm, metacognitive experiences of difficulty were induced by manipulating congruency between prime and target. As expected, participants more frequently rated incongruent trials as difficult and congruent trials as easy, while being completely unable to perceive the masked primes. Results showed that both the N2 and the P3 ERP components were modulated by congruency, but that only the P3 modulation interacted with metacognitive experiences. Single-trial analysis additionally showed that the magnitude of the P3 modulation by congruency accurately predicted the metacognitive response. Source localization indicated that the N2 task-related activity originated in the ACC, whereas the P3-interplay between task-related activation and metacognitive experiences originated from the precuneus. We conclude that task-related activity can be dissociated from later metacognitive processing.

  17. Effective coordination number: A simple indicator of activation energies for NO dissociation on Rh(100) surfaces

    SciTech Connect

    Ghosh, Prasenjit; Pushpa, Raghani; Gironcoli, Stefano de

    2009-12-15

    We have used density-functional theory to compute the activation energy for the dissociation of NO on two physical and two hypothetical systems: unstrained and strained Rh(100) surfaces and monolayers of Rh atoms on strained and unstrained MgO(100) surfaces. We find that the activation energy, relative to the gas phase, is reduced when a monolayer of Rh is placed on MgO, due both to the chemical nature of the substrate and the strain imposed by the substrate. The former effect is the dominant one, though both effects are of the same order of magnitude. We find that both effects are encapsulated in a simple quantity which we term as the 'effective coordination number'(n{sub e}); the activation energy is found to vary linearly with n{sub e}. We have compared the performance of n{sub e} as a predictor of activation energy of NO dissociation on the above-mentioned Rh surfaces with the two well-established indicators, namely, the position of the d-band center and the coadsorption energy of N and O. We find that for the present systems n{sub e} performs as well as the other two indicators.

  18. Amygdala activity contributes to the dissociative effect of cannabis on pain perception.

    PubMed

    Lee, Michael C; Ploner, Markus; Wiech, Katja; Bingel, Ulrike; Wanigasekera, Vishvarani; Brooks, Jonathan; Menon, David K; Tracey, Irene

    2013-01-01

    Cannabis is reported to be remarkably effective for the relief of otherwise intractable pain. However, the bases for pain relief afforded by this psychotropic agent are debatable. Nonetheless, the frontal-limbic distribution of cannabinoid receptors in the brain suggests that cannabis may target preferentially the affective qualities of pain. This central mechanism of action may be relevant to cannabinoid analgesia in humans, but has yet to be demonstrated. Here, we employed functional magnetic resonance imaging to investigate the effects of delta-9-tetrahydrocannabinol (THC), a naturally occurring cannabinoid, on brain activity related to cutaneous ongoing pain and hyperalgesia that were temporarily induced by capsaicin in healthy volunteers. On average, THC reduced the reported unpleasantness, but not the intensity of ongoing pain and hyperalgesia: the specific analgesic effect on hyperalgesia was substantiated by diminished activity in the anterior mid cingulate cortex. In individuals, the drug-induced reduction in the unpleasantness of hyperalgesia was positively correlated with right amygdala activity. THC also reduced functional connectivity between the amygdala and primary sensorimotor areas during the ongoing-pain state. Critically, the reduction in sensory-limbic functional connectivity was positively correlated with the difference in drug effects on the unpleasantness and the intensity of ongoing pain. Peripheral mechanisms alone cannot account for the dissociative effects of THC on the pain that was observed. Instead, the data reveal that amygdala activity contributes to interindividual response to cannabinoid analgesia, and suggest that dissociative effects of THC in the brain are relevant to pain relief in humans. PMID:23273106

  19. Sensorimotor semantics on the spot: brain activity dissociates between conceptual categories within 150 ms.

    PubMed

    Moseley, Rachel L; Pulvermüller, Friedemann; Shtyrov, Yury

    2013-01-01

    Although semantic processing has traditionally been associated with brain responses maximal at 350-400 ms, recent studies reported that words of different semantic types elicit topographically distinct brain responses substantially earlier, at 100-200 ms. These earlier responses have, however, been achieved using insufficiently precise source localisation techniques, therefore casting doubt on reported differences in brain generators. Here, we used high-density MEG-EEG recordings in combination with individual MRI images and state-of-the-art source reconstruction techniques to compare localised early activations elicited by words from different semantic categories in different cortical areas. Reliable neurophysiological word-category dissociations emerged bilaterally at ~ 150 ms, at which point action-related words most strongly activated frontocentral motor areas and visual object-words occipitotemporal cortex. These data now show that different cortical areas are activated rapidly by words with different meanings and that aspects of their category-specific semantics is reflected by dissociating neurophysiological sources in motor and visual brain systems.

  20. Alkaline phosphatase isoenzyme activities in rheumatoid arthritis: hepatobiliary enzyme dissociation and relation to disease activity.

    PubMed Central

    Aida, S

    1993-01-01

    OBJECTIVES--Hyperphosphatasaemia has been observed occasionally in patients with rheumatoid arthritis (RA), and it has been suggested that the serum alkaline phosphatase (ALP) level is related to the activity of the disease. Therefore, the relationship between serum ALP and RA was studied. METHODS--The serum activities of hepatobiliary enzymes (ALP isoenzymes, gamma-glutamyltranspeptidase (GTP), leucine aminopeptidase (LAP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT)), immunoglobulins, RA haemagglutinin test (RAHA), C reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were observed in 288 patients with rheumatoid arthritis. RESULTS--Serum biliary ALP (ALP1) activity was detected in 31.6% of the patients. In patients positive for ALP1 the respective values of total ALP (ALPt) (p < 0.001), liver ALP (ALP2) (p < 0.001), bone ALP (ALP3) (p < 0.05), gamma-GTP (p < 0.001), LAP (p < 0.001), immunoglobulins IgG (p < 0.01), IgA (p < 0.01), and IgM (p < 0.01), RAHA (p < 0.001), CRP (p < 0.001), ESR (p < 0.001), and articular index (p < 0.001) were significantly higher than in patients who did not have ALP1. Significant Spearman's rank correlations (rs) were demonstrated between serum ALP2 level and the respective values of ALPt (rs = 0.9128, p < 0.001), ALP1 (rs = 0.4443, p < 0.001), ALP3 (rs = 0.5898, p < 0.001), gamma-GTP (rs = 0.2903, p < 0.001), LAP (rs = 0.3093, p < 0.001), IgA (rs = 0.2299, p < 0.01), IgM (rs = 0.1773, p < 0.05), RAHA (rs = 0.2420, p < 0.01), CRP (rs = 0.3532, p < 0.001), ESR (rs = 0.4006, p < 0.001). the articular index (rs = 0.4006, p < 0.001). However, no significant difference or correlation was noted for either AST or ALT. In many patients who showed abnormal hyperphosphatasaemia, hepatobiliary enzyme dissociation was observed: levels of ALPt (in 12.8%), ALP1 (in 31.6%), ALP2 (18.8%), gamma-GTP (in 4.3%), and LAP (in 19.3%) were abnormally high, but both AST and ALT were within normal limits. CONCLUSION

  1. Dissociation of muscle sympathetic nerve activity and leg vascular resistance in humans

    NASA Technical Reports Server (NTRS)

    Shoemaker, J. K.; Herr, M. D.; Sinoway, L. I.

    2000-01-01

    We examined the hypothesis that the increase in inactive leg vascular resistance during forearm metaboreflex activation is dissociated from muscle sympathetic nerve activity (MSNA). MSNA (microneurography), femoral artery mean blood velocity (FAMBV, Doppler), mean arterial pressure (MAP), and heart rate (HR) were assessed during fatiguing static handgrip exercise (SHG, 2 min) followed by posthandgrip ischemia (PHI, 2 min). Whereas both MAP and MSNA increase during SHG, the transition from SHG to PHI is characterized by a transient reduction in MAP but sustained elevation in MSNA, facilitating separation of these factors in vivo. Femoral artery vascular resistance (FAVR) was calculated (MAP/MBV). MSNA increased by 59 +/- 20% above baseline during SHG (P < 0.05) and was 58 +/- 18 and 78 +/- 18% above baseline at 10 and 20 s of PHI, respectively (P < 0.05 vs. baseline). Compared with baseline, FAVR increased 51 +/- 22% during SHG (P < 0.0001) but returned to baseline levels during the first 30 s of PHI, reflecting the changes in MAP (P < 0.005) and not MSNA. It was concluded that control of leg muscle vascular resistance is sensitive to changes in arterial pressure and can be dissociated from sympathetic factors.

  2. Dissociated sequential activity and stimulus encoding in the dorsomedial striatum during spatial working memory

    PubMed Central

    Akhlaghpour, Hessameddin; Wiskerke, Joost; Choi, Jung Yoon; Taliaferro, Joshua P; Au, Jennifer; Witten, Ilana B

    2016-01-01

    Several lines of evidence suggest that the striatum has an important role in spatial working memory. The neural dynamics in the striatum have been described in tasks with short delay periods (1–4 s), but remain largely uncharacterized for tasks with longer delay periods. We collected and analyzed single unit recordings from the dorsomedial striatum of rats performing a spatial working memory task with delays up to 10 s. We found that neurons were activated sequentially, with the sequences spanning the entire delay period. Surprisingly, this sequential activity was dissociated from stimulus encoding activity, which was present in the same neurons, but preferentially appeared towards the onset of the delay period. These observations contrast with descriptions of sequential dynamics during similar tasks in other brains areas, and clarify the contribution of the striatum to spatial working memory. DOI: http://dx.doi.org/10.7554/eLife.19507.001 PMID:27636864

  3. Bond dissociation free energy as a general parameter for flavonoid radical scavenging activity.

    PubMed

    Stepanić, Višnja; Gall Trošelj, Koraljka; Lučić, Bono; Marković, Zoran; Amić, Dragan

    2013-11-15

    Notwithstanding multiple mechanisms of radical scavenging (RS), measured RS activities (RSA) of flavonoids are usually related to O-H bond dissociation enthalpy (BDE) for hydrogen atom transfer (HAT). For 12 flavonoids the reaction free energies were calculated for: (1) HAT, (2) single electron transfer-proton transfer (SET-PT) and (3) sequential proton loss electron transfer (SPLET) in gas and aqueous phases. Aqueous free energies, like bond dissociation (BDFEaq), ionisation (IFEaq) and deprotonation (ΔGdeprot,aq) free energies were estimated using thermochemical cycles. While in gas HAT is a RS mechanism (BDFEg

  4. Pyruvate dehydrogenase kinase isoform 2 activity stimulated by speeding up the rate of dissociation of ADP.

    PubMed

    Bao, Haiying; Kasten, Shane A; Yan, Xiaohua; Hiromasa, Yasuaki; Roche, Thomas E

    2004-10-26

    Pyruvate dehydrogenase kinase 2 (PDK2) activity is stimulated by NADH and NADH plus acetyl-CoA via the reduction and reductive acetylation of the lipoyl groups of the dihydrolipoyl acetyltransferase (E2) component. Elevated K(+) and Cl(-) were needed for significant stimulation. Stimulation substantially increased both k(cat) and the K(m) for ATP; the fractional stimulation increased with the level of ATP. With an E2 structure lacking the pyruvate dehydrogenase (E1) binding domain, stimulation of PDK2 was retained, the K(m) for E1 decreased, and the equilibrium dissociation constant for ATP increased but remained much lower than the K(m) for ATP. Stimulation of PDK2 activity greatly reduced the fraction of bound ADP. These results fit an ordered reaction mechanism with ATP binding before E1 and stimulation increasing the rate of dissociation of ADP. Conversion of all of the lipoyl groups in the E2 60mer to the oxidized form (E2(ox)) greatly reduced k(cat) and the K(m) of PDK2 for ATP. Retention over an extended period of time of a low portion of reduced lipoyl groups maintains E2 in a state that supported much higher PDK2 activity than short-term (5 min) reduction of a large portion of lipoyl groups of E2(ox), but reduction of E2(ox) produced a larger fold stimulation. Reduction and to a greater extent reductive acetylation increased PDK2 binding to E2; conversion to E2(ox) did not significantly hinder binding. We suggest that passing even limited reducing equivalents among lipoyl groups maintains E2 lipoyl domains in a conformation that aids kinase function. PMID:15491151

  5. Evaluating Active Methane Hydrate Dissociation Along the Washington Margin in Response to Bottom Water Warming

    NASA Astrophysics Data System (ADS)

    Whorley, T. L.; Solomon, E. A.; Torres, M. E.; Johnson, H. P.; Berg, R. D.; Philip, B. T.

    2015-12-01

    Water column temperature data acquired on the upper continental slope (UCS) of the Washington (WA) section of the Cascadia margin shows gradual warming of bottom water at the upper limit of the methane hydrate stability zone (MHSZ) over the last 4 decades. Thermal models based on these records predict downslope retreat of the MHSZ by ~1-2 km (~40 m in depth), potentially destabilizing methane hydrate and releasing CH4into the sediment and water column. To test for contemporaneous methane hydrate dissociation along the UCS of the WA margin, we conducted a comprehensive geophysical and geochemical survey of active seep sites at the upper limit of the MHSZ from 48° to 46°N on the R/V Thompson in October 2014. We identified 9 active seep sites within this corridor and imaged 22 bubble plumes that commonly rise to ~300 m water depth with some reaching to near the sea surface. Some seep sites appear to be controlled by local margin structure, mainly extensional faults and ridges. We collected 22 gravity cores and 20 CTD/hydrocasts from the 9 seeps and processed ~350 sediment samples for pore water chemistry. Hydrocarbons heavier than CH4were not detected in bottom water samples, suggesting any gas hydrate present is Structure I. Preliminary pore water data show decreasing salinity downcore at each site with measured values as low as 10 psu and the sulfate-methane transition zone occurs between 50-80 cm below the sea floor. Pore water solute, noble gas, and isotope ratio data indicate freshening from at least one site is not the result of hydrate dissociation, but rather is due to clay dehydration at depths where temperatures exceed 60°C. Very few of the sites show pore water profiles that are in steady state, suggesting a dynamic biogeochemical system at the UCS along the entire WA margin. Further analyses and modeling are underway to constrain the nature and timing of these transient profiles and whether they are the result of recent methane hydrate dissociation.

  6. Identification of N-Oxide and Sulfoxide Functionalities in Protonated Drug Metabolites by Using Ion-Molecule Reactions Followed by Collisionally Activated Dissociation in a Linear Quadrupole Ion Trap Mass Spectrometer.

    PubMed

    Sheng, Huaming; Tang, Weijuan; Yerabolu, Ravikiran; Max, Joann; Kotha, Raghavendhar R; Riedeman, James S; Nash, John J; Zhang, Minli; Kenttämaa, Hilkka I

    2016-01-15

    The in vivo oxidation of sulfur and nitrogen atoms in many drugs into sulfoxide and N-oxide functionalities is a common biotransformation process. Unfortunately, the unambiguous identification of these metabolites can be challenging. In the present study, ion-molecule reactions of tris(dimethylamino)borane followed by collisionally activated dissociation (CAD) in an ion trap mass spectrometer are demonstrated to allow the identification of N-oxide and sulfoxide functionalities in protonated polyfunctional drug metabolites. Only ions with N-oxide or sulfoxide functionality formed diagnostic adducts that had lost dimethyl amine (DMA). This was demonstrated even for an analyte that contains a substantially more basic functionality than the functional group of interest. CAD of the diagnostic product ions (M) resulted mainly in type A (M - DMA) and B fragment ions (M - HO-B(N(CH3)2)2) for N-oxides, but sulfoxides also formed diagnostic C ions (M - O═BN(CH3)2), thus allowing differentiation of the functionalities. Some protonated analytes yielded abundant TDMAB adducts that had lost two DMA molecules instead of just one. This provides information on the environment of the N-oxide and sulfoxide functionalities. Quantum chemical calculations were performed to explore the mechanisms of the above-mentioned reactions. The method can be implemented on HPLC for real drug analysis. PMID:26651970

  7. Parafoveal versus foveal N400s dissociate spreading activation from contextual fit.

    PubMed

    Kretzschmar, Franziska; Bornkessel-Schlesewsky, Ina; Schlesewsky, Matthias

    2009-12-01

    Using concurrent electroencephalogram and eye movement measures to track natural reading, this study shows that N400 effects reflecting predictability are dissociable from those owing to spreading activation. In comparing predicted sentence endings with related and unrelated unpredicted endings in antonym constructions ('the opposite of black is white/yellow/nice'), fixation-related potentials at the critical word revealed a predictability-based N400 effect (unpredicted vs. predicted words). By contrast, event-related potentials time locked to the last fixation before the critical word showed an N400 only for the nonrelated unpredicted condition (nice). This effect is attributed to a parafoveal mismatch between the critical word and preactivated lexical features (i.e. features of the predicted word and its associates). In addition to providing the first demonstration of a parafoveally induced N400 effect, our results support the view that the N400 is best viewed as a component family.

  8. Determination of dissociation constants of pharmacologically active xanthones by capillary zone electrophoresis with diode array detection.

    PubMed

    Wu, Xiaomu; Gong, Suxuan; Bo, Tao; Liao, Yiping; Liu, Huwei

    2004-12-24

    In this article, the dissociation constants (pKa) of 10 pharmacologically active xanthones isolated from herbal medicine Securidaca inappendiculata were determined by capillary zone electrophoresis with diode array detection. The pKa values determined by the method based on the electrophoretic mobilities (calculated from migration times) have been proved by the method based on UV absorbance calculated from the online spectra corresponding peaks. No conspicuous difference was observed between the two methods with acceptable reproducibility. Two pKa values (pKa1 and pKa2) were found for four xanthones while generally the 10 compounds possess the pKa values ranging from 6.4 to 9.2. PMID:15641365

  9. Attentional Dissociation in Hypnosis And Neural Connectivity: Preliminary Evidence from Bilateral Electrodermal Activity.

    PubMed

    Bob, Petr; Siroka, Ivana

    2016-01-01

    According to recent findings, interhemispheric interactions and information connectivity represent crucial mechanisms used in processing information across various sensory modalities. To study these interactions, the authors measured bilateral electrodermal activity (EDA) in 33 psychiatric outpatients. The results show that, during congruent Stroop stimuli in hypnosis, the patients with higher hypnotizability manifest a decreased level of interhemispheric information transfer measured by pointwise transinformation (PTI) that was calculated from left and right EDA records. These results show that specific shifts of attentional focus during hypnosis are related to changes of interhemispheric interactions that may be reflected in neural connectivity calculated from the bilateral EDA measurement. This attentional shift may cause dissociated attentional control disturbing integrative functions of consciousness and contextual experiences. PMID:27267677

  10. A comparison of energy-resolved vibrational activation/dissociation characteristics of protonated and sodiated high mannose N-glycopeptides.

    PubMed

    Aboufazeli, Forouzan; Kolli, Venkata; Dodds, Eric D

    2015-04-01

    Fragmentation of glycopeptides in tandem mass spectrometry (MS/MS) plays a pivotal role in site-specific protein glycosylation profiling by allowing specific oligosaccharide compositions and connectivities to be associated with specific loci on the corresponding protein. Although MS/MS analysis of glycopeptides has been successfully performed using a number of distinct ion dissociation methods, relatively little is known regarding the fragmentation characteristics of glycopeptide ions with various charge carriers. In this study, energy-resolved vibrational activation/dissociation was examined via collision-induced dissociation for a group of related high mannose tryptic glycopeptides as their doubly protonated, doubly sodiated, and hybrid protonated sodium adduct ions. The doubly protonated glycopeptide ions with various compositions were found to undergo fragmentation over a relatively low but wide range of collision energies compared with the doubly sodiated and hybrid charged ions, and were found to yield both glycan and peptide fragmentation depending on the applied collision energy. By contrast, the various doubly sodiated glycopeptides were found to dissociate over a significantly higher but narrow range of collision energies, and exhibited only glycan cleavages. Interestingly, the hybrid protonated sodium adduct ions were consistently the most stable of the precursor ions studied, and provided fragmentation information spanning both the glycan and the peptide moieties. Taken together, these findings illustrate the influence of charge carrier over the energy-resolved vibrational activation/dissociation characteristics of glycopeptides, and serve to suggest potential strategies that exploit the analytically useful features uniquely afforded by specific charge carriers or combinations thereof.

  11. Calcium-induced dissociation of human plasma factor XIII and the appearance of catalytic activity

    PubMed Central

    Cooke, Rodney D.

    1974-01-01

    1. The Ca2+ dependence of the activity of plasma Factor XIIIa was studied by using the continuous assay based on the incorporation of dansylcadaverine into dephosphorylated acetylated β-casein (β-substrate). The Km for Ca2+ is about 0.170mm. 2. At low concentrations of Ca2+ there was a lag in attaining the steady-state rate. The size of the lag was decreased and eventually abolished if the enzyme was preincubated with a high concentration of Ca2+ before assay. The concentration of Ca2+ required to decrease the lag phase by 50% in 10min depended on the protein concentration: at 0.87mg of protein/ml it required 17mm-Ca2+ and at 0.44mg/ml it needed 10mm-Ca2+. 3. The concentrations of Ca2+ required either to abolish the lag phase in the appearance of enzyme activity or to activate the essential thiol for reaction with 5,5′-dithiobis-(2-nitrobenzoate) in 10min incubation were similar at the same protein concentration. This indicated that Ca2+ induces a conformation change that is responsible for both phenomena. A model is proposed that links this conformation change to the dissociation of the tetrameric enzyme. 4. This was supported by the observation that the addition of excess of b chains to the Factor XIIIa (a′2b2) increased the concentration of Ca2+ required to expose the reactive thiol, and inhibited the Ca2+-dependent aggregation of a′ chains. 5. Platelet Factor XIIIa (a′2) was inhibited by 5,5′-dithiobis-(2-nitrobenzoate) in the absence of Ca2+, and no lag phases were observed in attaining the steady-state rate at low Ca2+ concentrations, thus confirming the model for the activation of the plasma enzyme. 6. The Ca2+ dependence of platelet Factor XIIIa indicated that Ca2+ has an additional role in the enzyme mechanism of the plasma enzyme, perhaps being involved in substrate binding. 7. The dependence of the stability of plasma Factor XIIIa on Ca2+ and protein concentration indicates that the decay in activity is related to the tetramer dissociation. 8

  12. CAD/CAM/CNC.

    ERIC Educational Resources Information Center

    Domermuth, Dave; And Others

    1996-01-01

    Includes "Quick Start CNC (computer numerical control) with a Vacuum Filter and Laminated Plastic" (Domermuth); "School and Industry Cooperate for Mutual Benefit" (Buckler); and "CAD (computer-assisted drafting) Careers--What Professionals Have to Say" (Skinner). (JOW)

  13. Dissociated wake-like and sleep-like electro-cortical activity during sleep.

    PubMed

    Nobili, Lino; Ferrara, Michele; Moroni, Fabio; De Gennaro, Luigi; Russo, Giorgio Lo; Campus, Claudio; Cardinale, Francesco; De Carli, Fabrizio

    2011-09-15

    Sleep is traditionally considered a global process involving the whole brain. However, recent studies have shown that sleep depth is not evenly distributed within the brain. Sleep disorders, such as sleepwalking, also suggest that EEG features of sleep and wakefulness might be simultaneously present in different cerebral regions. In order to probe the coexistence of dissociated (wake-like and sleep-like) electrophysiological behaviors within the sleeping brain, we analyzed intracerebral electroencephalographic activity drawn from sleep recordings of five patients with pharmacoresistant focal epilepsy without sleep disturbances, who underwent pre-surgical intracerebral electroencephalographic investigation. We applied spectral and wavelet transform analysis techniques to electroencephalographic data recorded from scalp and intracerebral electrodes localized within the Motor cortex (Mc) and the dorso-lateral Prefrontal cortex (dlPFc). The Mc showed frequent Local Activations (lasting from 5 to more than 60s) characterized by an abrupt interruption of the sleep electroencephalographic slow waves pattern and by the appearance of a wake-like electroencephalographic high frequency pattern (alpha and/or beta rhythm). Local activations in the Mc were paralleled by a deepening of sleep in other regions, as expressed by the concomitant increase of slow waves in the dlPFc and scalp electroencephalographic recordings. These results suggest that human sleep can be characterized by the coexistence of wake-like and sleep-like electroencephalographic patterns in different cortical areas, supporting the hypothesis that unusual phenomena, such as NREM parasomnias, could result from an imbalance of these two states. PMID:21718789

  14. Rice GDP dissociation inhibitor 3 inhibits OsMAPK2 activity through physical interaction.

    PubMed

    Heo, Jae Bok; Yi, Young Byung; Bahk, Jeong Dong

    2011-11-01

    GDP dissociation inhibitor (GDI) plays an essential role in regulating the state of bound nucleotides and subcellular localizations of Rab proteins. In our previous study, we showed that OsGDI3 facilitates the recycling of OsRab11 with a help of OsGAP1. In this study, we show that OsGDI3 complement the yeast sec19-1 mutant, a temperature-sensitive allele of the yeast GDI gene, suggesting that OsGDI3 is a functional ortholog of yeast GDI. To obtain further knowledge on the function of OsGDI3, candidate OsGDI3-interacting proteins were identified by yeast two-hybrid screens. OsMAPK2 is one of OsGDI3 interacting proteins from yeast two-hybrid screens and subject to further analysis. A kinase assay showed that the autophosphorylation activity of OsMAPK2 is inhibited by OsGDI3 in vitro. In addition, ectopic expressions of OsGDI3-in Arabidopsis cause reductions at the level of phosphorylated AtMPK in phosphorylation activity. Taken together, OsGDI3 functions as a negative regulator of OsMAPK2 through modulating its kinase activity.

  15. Dissociable correlates of response conflict and error awareness in error-related brain activity

    PubMed Central

    Hughes, Gethin; Yeung, Nick

    2010-01-01

    Errors in speeded decision tasks are associated with characteristic patterns of brain activity. In the scalp-recorded EEG, error processing is reflected in two components, the error-related negativity (ERN) and the error positivity (Pe). These components have been widely studied, but debate remains regarding the precise aspects of error processing they reflect. The present study investigated the relation between the ERN and Pe using a novel version of the flanker task to allow a comparison between errors reflecting different causes—response conflict versus stimulus masking. The conflict and mask conditions were matched for overall behavioural performance but differed in underlying response dynamics, as indexed by response time distributions and measures of lateralised motor activity. ERN amplitude varied in relation to these differing response dynamics, being significantly larger in the conflict condition compared to the mask condition. Furthermore, differences in response dynamics between participants were predictive of modulations in ERN amplitude. In contrast, Pe activity varied little between conditions, but varied across trials in relation to participants‘ awareness of their errors. Taken together, these findings suggest a dissociation between the ERN and Pe, with the former reflecting the dynamics of response selection and conflict, and the latter reflecting conscious recognition of an error. PMID:21130788

  16. Determination of double bond location in fatty acids by manganese adduction and electron induced dissociation.

    PubMed

    Yoo, Hyun Ju; Håkansson, Kristina

    2010-08-15

    Double bond locations in fatty acids can be determined from characteristic charge-remote fragmentation patterns of alkali metal-adducted fatty acids following high energy collision activated dissociation (CAD). With low energy CAD, several chemical derivatization methods, including ozonization, epoxidation, and hydroxylation, have been used to generate characteristic fragments. However, high energy CAD is not universally available and involves a high degree of scattering, causing product ion loss. Further, derivatization reactions involve side reactions and sample loss. Here, we analyzed metal-adducted fatty acids to investigate the utility of electron induced dissociation (EID) for determining double bond location. EID has been proposed to involve both electronic excitation, similar to high energy CAD, and vibrational excitation. Various metals (Li, Zn, Co, Ni, Mg, Ca, Fe, and Mn) were investigated to fix one charge at the carboxylate end of fatty acids to promote charge-remote fragmentation. EID of Mn(II)-adducted fatty acids allowed determination of all double bond locations of arachidonic acid, linolenic acid, oleic acid, and stearic acid. For Mn(II)-adducted fatty acids, reduced characteristic charge-remote product ion abundances at the double bond positions are indicative of double bond locations. However, other metal adducts did not generally provide characteristic product ion abundances at all double bond locations.

  17. Impaired long-term habituation is dissociated from increased locomotor activity after sensorimotor cortex compression.

    PubMed

    Moreira, Tiago; Cebers, Gvido; Salehi, Mehdi; Wägner, Anna; Liljequist, Sture

    2006-02-15

    Behavioural habituation to a novel environment is a simple form of learning in rodents. We studied the habituation and locomotor activity (LMA) of Wistar rats subjected to unilateral, transient (30min) extradural compression (EC) of the right sensorimotor cortex. One group of rats was tested every 24h during the first 5 days (D1-D5) post-EC. Two other groups were tested for the first time in the LMA boxes on D3 and D6 post-EC and their performance was compared with the group tested on D1 (activity in a novel environment). Total and center locomotion, vertical activity and time spent in the center of the LMA box were reduced on D1 post-EC and normalized by D2. The EC-induced motor paresis was undetectable on the rotarod by D2 and on the beam-walking by D3. Total locomotion, vertical activity and time spent in the center of EC-rats significantly increased from D1 to D3. EC caused neurodegeneration in the cortex, caudate putamen and thalamus as detected by Fluoro-Jade staining. The size of the cortical damage decreased from D2 to D5 in the medial and caudal regions of the compressed hemisphere, in accordance with recovery of motor function. LMA provided additional information in the follow-up of recovery from brain injury and habituation to the environment. Thus, long-term, inter-session habituation was impaired from D1 to D3 but dissociated from increased LMA intra-session on D3, when the motor deficits provoked by EC were already undetectable in the rotarod and beam-walking tests. PMID:16337698

  18. Dissociation of antimicrobial and hemolytic activities of gramicidin S through N-methylation modification.

    PubMed

    Li, Yangmei; Bionda, Nina; Yongye, Austin; Geer, Phaedra; Stawikowski, Maciej; Cudic, Predrag; Martinez, Karina; Houghten, Richard A

    2013-11-01

    β-Sheet antimicrobial peptides (AMPs) are well recognized as promising candidates for the treatment of multidrug-resistant bacterial infections. To dissociate antimicrobial activity and hemolytic effect of β-sheet AMPs, we hypothesize that N-methylation of the intramolecular hydrogen bond(s)-forming amides could improve their specificities for microbial cells over human erythrocytes. We utilized a model β-sheet antimicrobial peptide, gramicidin S (GS), to study the N-methylation effects on the antimicrobial and hemolytic activities. We synthesized twelve N-methylated GS analogues by replacement of residues at the β-strand and β-turn regions with N-methyl amino acids, and tested their antimicrobial and hemolytic activities. Our experiments showed that the HC50 values increased fivefold compared with that of GS, when the internal hydrogen-bonded leucine residue was methylated. Neither hemolytic effect nor antimicrobial activity changed when proline alone was replaced with N-methylalanine in the β-turn region. However, analogues containing N-methylleucine at β-strand and N-methylalanine at β-turn regions exhibited a fourfold increase in selectivity index compared to GS. We also examined the conformation of these N-methylated GS analogues using (1)H NMR and circular dichroism (CD) spectroscopy in aqueous solution, and visualized the backbone structures and residue orientations using molecular dynamics simulations. The results show that N-methylation of the internal hydrogen bond-forming amide affected the conformation, backbone shape, and side chain orientation of GS.

  19. Dopamine-induced dissociation of BOLD and neural activity in macaque visual cortex.

    PubMed

    Zaldivar, Daniel; Rauch, Alexander; Whittingstall, Kevin; Logothetis, Nikos K; Goense, Jozien

    2014-12-01

    Neuromodulators determine how neural circuits process information during cognitive states such as wakefulness, attention, learning, and memory. fMRI can provide insight into their function and dynamics, but their exact effect on BOLD responses remains unclear, limiting our ability to interpret the effects of changes in behavioral state using fMRI. Here, we investigated the effects of dopamine (DA) injections on neural responses and haemodynamic signals in macaque primary visual cortex (V1) using fMRI (7T) and intracortical electrophysiology. Aside from DA's involvement in diseases such as Parkinson's and schizophrenia, it also plays a role in visual perception. We mimicked DAergic neuromodulation by systemic injection of L-DOPA and Carbidopa (LDC) or by local application of DA in V1 and found that systemic application of LDC increased the signal-to-noise ratio (SNR) and amplitude of the visually evoked neural responses in V1. However, visually induced BOLD responses decreased, whereas cerebral blood flow (CBF) responses increased. This dissociation of BOLD and CBF suggests that dopamine increases energy metabolism by a disproportionate amount relative to the CBF response, causing the reduced BOLD response. Local application of DA in V1 had no effect on neural activity, suggesting that the dopaminergic effects are mediated by long-range interactions. The combination of BOLD-based and CBF-based fMRI can provide a signature of dopaminergic neuromodulation, indicating that the application of multimodal methods can improve our ability to distinguish sensory processing from neuromodulatory effects. PMID:25456449

  20. Dissociated functional significance of decision-related activity in the primate dorsal stream.

    PubMed

    Katz, Leor N; Yates, Jacob L; Pillow, Jonathan W; Huk, Alexander C

    2016-07-04

    During decision making, neurons in multiple brain regions exhibit responses that are correlated with decisions. However, it remains uncertain whether or not various forms of decision-related activity are causally related to decision making. Here we address this question by recording and reversibly inactivating the lateral intraparietal (LIP) and middle temporal (MT) areas of rhesus macaques performing a motion direction discrimination task. Neurons in area LIP exhibited firing rate patterns that directly resembled the evidence accumulation process posited to govern decision making, with strong correlations between their response fluctuations and the animal's choices. Neurons in area MT, in contrast, exhibited weak correlations between their response fluctuations and choices, and had firing rate patterns consistent with their sensory role in motion encoding. The behavioural impact of pharmacological inactivation of each area was inversely related to their degree of decision-related activity: while inactivation of neurons in MT profoundly impaired psychophysical performance, inactivation in LIP had no measurable impact on decision-making performance, despite having silenced the very clusters that exhibited strong decision-related activity. Although LIP inactivation did not impair psychophysical behaviour, it did influence spatial selection and oculomotor metrics in a free-choice control task. The absence of an effect on perceptual decision making was stable over trials and sessions and was robust to changes in stimulus type and task geometry, arguing against several forms of compensation. Thus, decision-related signals in LIP do not appear to be critical for computing perceptual decisions, and may instead reflect secondary processes. Our findings highlight a dissociation between decision correlation and causation, showing that strong neuron-decision correlations do not necessarily offer direct access to the neural computations underlying decisions.

  1. Dissociated functional significance of decision-related activity in the primate dorsal stream.

    PubMed

    Katz, Leor N; Yates, Jacob L; Pillow, Jonathan W; Huk, Alexander C

    2016-07-14

    During decision making, neurons in multiple brain regions exhibit responses that are correlated with decisions. However, it remains uncertain whether or not various forms of decision-related activity are causally related to decision making. Here we address this question by recording and reversibly inactivating the lateral intraparietal (LIP) and middle temporal (MT) areas of rhesus macaques performing a motion direction discrimination task. Neurons in area LIP exhibited firing rate patterns that directly resembled the evidence accumulation process posited to govern decision making, with strong correlations between their response fluctuations and the animal's choices. Neurons in area MT, in contrast, exhibited weak correlations between their response fluctuations and choices, and had firing rate patterns consistent with their sensory role in motion encoding. The behavioural impact of pharmacological inactivation of each area was inversely related to their degree of decision-related activity: while inactivation of neurons in MT profoundly impaired psychophysical performance, inactivation in LIP had no measurable impact on decision-making performance, despite having silenced the very clusters that exhibited strong decision-related activity. Although LIP inactivation did not impair psychophysical behaviour, it did influence spatial selection and oculomotor metrics in a free-choice control task. The absence of an effect on perceptual decision making was stable over trials and sessions and was robust to changes in stimulus type and task geometry, arguing against several forms of compensation. Thus, decision-related signals in LIP do not appear to be critical for computing perceptual decisions, and may instead reflect secondary processes. Our findings highlight a dissociation between decision correlation and causation, showing that strong neuron-decision correlations do not necessarily offer direct access to the neural computations underlying decisions. PMID:27376476

  2. Dissociation of the carbohydrate-binding and splicing activities of galectin-1.

    PubMed

    Voss, Patricia G; Gray, Richard M; Dickey, Seth W; Wang, Weizhong; Park, Jung W; Kasai, Ken-Ichi; Hirabayashi, Jun; Patterson, Ronald J; Wang, John L

    2008-10-01

    Galectin-1 (Gal1) and galectin-3 (Gal3) are two members of a family of carbohydrate-binding proteins that are found in the nucleus and that participate in pre-mRNA splicing assayed in a cell-free system. When nuclear extracts (NE) of HeLa cells were subjected to adsorption on a fusion protein containing glutathione S-transferase (GST) and Gal3, the general transcription factor II-I (TFII-I) was identified by mass spectrometry as one of the polypeptides specifically bound. Lactose and other saccharide ligands of the galectins inhibited GST-Gal3 pull-down of TFII-I while non-binding carbohydrates failed to yield the same effect. Similar results were also obtained using GST-Gal1. Site-directed mutants of Gal1, expressed and purified as GST fusion proteins, were compared with the wild-type (WT) in three assays: (a) binding to asialofetuin-Sepharose as a measure of the carbohydrate-binding activity; (b) pull-down of TFII-I from NE; and (c) reconstitution of splicing in NE depleted of galectins as a test of the in vitro splicing activity. The binding of GST-Gal1(N46D) to asialofetuin-Sepharose was less than 10% of that observed for GST-Gal1(WT), indicating that the mutant was deficient in carbohydrate-binding activity. In contrast, both GST-Gal1(WT) and GST-Gal1(N46D) were equally efficient in pull-down of TFII-I and in reconstitution of splicing activity in the galectin-depleted NE. Moreover, while the splicing activity of the wild-type protein can be inhibited by saccharide ligands, the carbohydrate-binding deficient mutant was insensitive to such inhibition. Together, all of the results suggest that the carbohydrate-binding and the splicing activities of Gal1 can be dissociated and therefore, saccharide-binding, per se, is not required for the splicing activity. PMID:18662664

  3. Optimized dissociation protocol for isolating human glioma stem cells from tumorspheres via fluorescence-activated cell sorting.

    PubMed

    Lv, Donglai; Ma, Qing-Hua; Duan, Jiang-Jie; Wu, Hai-Bo; Zhao, Xi-Long; Yu, Shi-Cang; Bian, Xiu-Wu

    2016-07-10

    Fluorescence-activated cell sorting (FACS) based on the surface marker CD133 is the most common method for isolating glioma stem cells (GSCs) from heterogeneous glioma cell populations. Optimization of this method will have profound implications for the future of GSC research. Five commonly used digestion reagents, Liberase-TL, trypsin, TrypLE, Accutase, and non-enzymatic cell dissociation solution (NECDS), were used to dissociate glioma tumorspheres derived from two primary glioma specimens (091214 and 090116) and the cell lines U87 and T98G. The dissociation time, cell viability, retention of CD133, and stemness capacity were assessed. The results showed that single cells derived from the Liberase-TL (200 µg/ml) group exhibited high viability and less damage to the antigen CD133. However, the efficiency of NECDS for dissociating the tumorspheres into single cells was fairly low. Meanwhile, the use of this digestion reagent resulted in obvious cellular and antigenic impairments. Taken together, Liberase-TL (200 µg/ml) is an ideal reagent for isolating GSCs from tumorspheres. In contrast, the use of NECDS for such a protocol should be carefully considered. PMID:27091400

  4. A reciprocal allosteric mechanism for efficient transfer of labile intermediates between active sites in CAD, the mammalian pyrimidine-biosynthetic multienzyme polypeptide.

    PubMed

    Irvine, H S; Shaw, S M; Paton, A; Carrey, E A

    1997-08-01

    Carbamoyl phosphate is the product of carbamoyl phosphate synthetase (CPS II) activity and the substrate of the aspartate transcarbamoylase (ATCase) activity, each of which is found in CAD, a large 240-kDa multienzyme polypeptide in mammals that catalyses the first three steps in pyrimidine biosynthesis. In our study of the transfer of the labile intermediate between the two active sites, we have used assays that differentiate the synthesis of carbamoyl phosphate from the overall reaction of CPS II and ATCase that produces carbamoyl aspartate. We provided excess exogenous carbamoyl phosphate and monitored its access to the respective active sites through the production of carbamoyl phosphate and carbamoyl aspartate from radiolabelled bicarbonate. Three features indicate interactions between the folded CPS II and ATCase domains causing reciprocal conformational changes. First, even in the presence of approximately 1 mM unlabelled carbamoyl phosphate, when the aspartate concentration is high ATCase uses endogenous carbamoyl phosphate for the synthesis of radiolabelled carbamoyl aspartate. In contrast, the isolated CPS II forward reaction is inhibited by excess unlabelled carbamoyl phosphate. Secondly, the affinity of the ATCase for carbamoyl phosphate and aspartate is modulated when substrates bind to CPS II. Thirdly, the transition-state analogue phosphonacetyl-L-aspartate is a less efficient inhibitor of the ATCase when the substrates for CPS II are present. All these effects operate when CPS II is in the more active P state, which is induced by high concentrations of ATP and magnesium ions and when 5'-phosphoribosyl diphosphate (the allosteric activator) is present with low concentrations of ATP; these are conditions that would be met during active biosynthesis in the cell. We propose a phenomenon of reciprocal allostery that encourages the efficient transfer of the labile intermediate within the multienzyme polypeptide CAD. In this model, binding of aspartate to

  5. Thrombin activation of human platelets dissociates a complex containing gelsolin and actin from phosphatidylinositide-specific phospholipase Cgamma1.

    PubMed Central

    Baldassare, J J; Henderson, P A; Tarver, A; Fisher, G J

    1997-01-01

    We have examined the association of two cytoskeleton proteins, gelsolin and actin, with phosphatidylinositide-specific phospholipase Cgamma1 (PLCgamma1) in resting and thrombin-stimulated human platelets. In unstimulated platelets, gelsolin, actin and PLCgamma1 were immunoprecipitated as a complex by a polyclonal antibody to PLCgamma1. The association of gelsolin and actin was specific for PLCgamma1 because immunoprecipitates of PLCs beta2, beta3, gamma2 and delta1, which are also expressed in human platelets, did not contain detectable gelsolin or actin. Activation with thrombin resulted in platelet aggregation and the dissociation of gelsolin and actin from PLCgamma1. Inhibition of thrombin-induced platelet aggregation blocked the dissociation of gelsolin and actin from PLCgamma1. After stimulation with thrombin, PLCgamma1 activity in immunoprecipitates was increased 2-3-fold. This elevation in PLCgamma1 activity in response to thrombin activation was not observed when platelet aggregation was blocked. Although PLCgamma1 is tyrosine phosphorylated in response to many agonists, we could not detect, by Western analysis with anti-phosphotyrosine antibodies, tyrosine phosphorylation of PLCgamma1 immunoprecipitated from thrombin-stimulated platelets. These results demonstrate that PLCgamma1 is associated with gelsolin and actin in resting platelets, and that thrombin-induced platelet aggregation results in the dissociation of PLCgamma1 from gelsolin and actin, and the stimulation of PLCgamma1 activity. PMID:9164868

  6. Cascade Dissociations of Peptide Cation-Radicals. Part2. Infrared Multiphoton Dissociation and Mechanistic Studies of z-Ions from Pentapeptides

    PubMed Central

    Ledvina, Aaron R.; Chung, Thomas W.; Hui, Renjie; Coon, Joshua J.

    2013-01-01

    Dissociations of z4 ions from pentapeptides AAXAR, where X = H, Y, F, W, and V, produce dominant z2 ions that account for >50% of the fragment ion intensity. The dissociation has been studied in detail by experiment and theory and found to involve several isomerization and bond-breaking steps. Isomerizations in z4 ions proceed by amide transcis rotations followed by radical-induced transfer of a β-hydrogen atom from the side chain, forming stable Cβ radical intermediates. These undergo rate-determining cleavage of the Cα—CO bond at the X residue followed by loss of the neutral AX fragment, forming x2 intermediates. The latter were detected by energy-resolved resonant excitation collision-activated dissociation (CAD) and infrared multiphoton dissociation (IRMPD) experiments. The x2 intermediates undergo facile loss of HNCO to form z2 fragment ions, as also confirmed by energy-resolved CAD and IRMPD MS4 experiments. The loss of HNCO from the x2 ion from AAHWR is kinetically hampered by the Trp residue that traps the OCNH radical group in a cyclic intermediate. PMID:22669762

  7. Dissociative disorders.

    PubMed

    Kihlstrom, John F

    2005-01-01

    The dissociative disorders, including "psychogenic" or "functional" amnesia, fugue, dissociative identity disorder (DID, also known as multiple personality disorder), and depersonalization disorder, were once classified, along with conversion disorder, as forms of hysteria. The 1970s witnessed an "epidemic" of dissociative disorder, particularly DID, which may have reflected enthusiasm for the diagnosis more than its actual prevalence. Traditionally, the dissociative disorders have been attributed to trauma and other psychological stress, but the existing evidence favoring this hypothesis is plagued by poor methodology. Prospective studies of traumatized individuals reveal no convincing cases of amnesia not attributable to brain insult, injury, or disease. Treatment generally involves recovering and working through ostensibly repressed or dissociated memories of trauma; at present, there are few quantitative or controlled outcome studies. Experimental studies are few in number and have focused largely on state-dependent and implicit memory. Depersonalization disorder may be in line for the next "epidemic" of dissociation.

  8. Bond dissociation enthalpies calculated by the PM3 method confirm activity cliffs in radical scavenging of flavonoids.

    PubMed

    Amić, Dragan; Lucić, Bono; Kovacević, Goran; Trinajstić, Nenad

    2009-02-01

    Radical scavenging potency of flavonoids is associated with activity cliffs, i.e., small chemical modifications on flavonoid core can have a significant effect on activity. The presence or absence of the 3',4'-diOH and/or 3-OH group may serve as an activity switch for radical scavenging. The physicochemical background of such an indicator variable, defined previously (Amić et al. (2003) Croat Chem Acta 76:55-61), is confirmed by computation of bond dissociation enthalpies and selecting the minimal of all values relating to flavonoid OH groups. Bond dissociation enthalpies for hydrogen abstraction from OH groups for 29 flavonoids were calculated by the PM3 method. Minimal bond dissociation enthalpy values were obtained for OH groups attached to C-3, C-3' and C-4' positions, and they correspond to the previously introduced indicator variable. Taking into account some driving forces of the radical scavenging mechanism, it is possible to relate structural characteristics of flavonoids to their radical scavenging potency as well as to develop reliable structure-activity models.

  9. Activation Energies for Dissociation of Double Strand Oligonucleotide Anions: Evidence for Watson–Crick Base Pairing in Vacuo

    PubMed Central

    Schnier, Paul D.; Klassen, John S.; Strittmatter, Eric F.; Williams*, Evan R.

    2005-01-01

    The dissociation kinetics of a series of complementary and noncomplementary DNA duplexes, (TGCA)23−, (CCGG)23−, (AATTAAT)23−, (CCGGCCG)23−, A7·T73−, A7·A73−, T7·T73−, and A7·C73− were investigated using blackbody infrared radiative dissociation in a Fourier transform mass spectrometer. From the temperature dependence of the unimolecular dissociation rate constants, Arrhenius activation parameters in the zero-pressure limit are obtained. Activation energies range from 1.2 to 1.7 eV, and preexponential factors range from 1013 to 1019 s−1. Dissociation of the duplexes results in cleavage of the noncovalent bonds and/or cleavage of covalent bonds leading to loss of a neutral nucleobase followed by backbone cleavage producing sequence-specific (a – base) and w ions. Four pieces of evidence are presented which indicate that Watson–Crick (WC) base pairing is preserved in complementary DNA duplexes in the gas phase: i. the activation energy for dissociation of the complementary dimer, A7·T73−, to the single strands is significantly higher than that for the related noncomplementary A7·A73− and T7·T73− dimers, indicating a stronger interaction between strands with a specific base sequence, ii. extensive loss of neutral adenine occurs for A7·A73− and A7·C73− but not for A7·T73− consistent with this process being shut down by WC hydrogen bonding, iii. a correlation is observed between the measured activation energy for dissociation to single strands and the dimerization enthalpy (−ΔHd) in solution, and iv. molecular dynamics carried out at 300 and 400 K indicate that WC base pairing is preserved for A7·T73− duplex, although the helical structure is essentially lost. In combination, these results provide strong evidence that WC base pairing can exist in the complete absence of solvent. PMID:16498487

  10. Teach CAD and Measuring Skills through Reverse Engineering

    ERIC Educational Resources Information Center

    Board, Keith

    2012-01-01

    This article describes a reverse engineering activity that gives students hands-on, minds-on experience with measuring tools, machine parts, and CAD. The author developed this activity to give students an abundance of practical experience with measuring tools. Equally important, it provides a good interface between the virtual world of CAD 3D…

  11. Dissociative amnesia.

    PubMed

    Staniloiu, Angelica; Markowitsch, Hans J

    2014-08-01

    Dissociative amnesia is one of the most enigmatic and controversial psychiatric disorders. In the past two decades, interest in the understanding of its pathophysiology has surged. In this report, we review new data about the epidemiology, neurobiology, and neuroimaging of dissociative amnesia and show how advances in memory research and neurobiology of dissociation inform proposed pathogenetic models of the disorder. Dissociative amnesia is characterised by functional impairment. Additionally, preliminary data suggest that affected people have an increased and possibly underestimated suicide risk. The prevalence of dissociative amnesia differs substantially across countries and populations. Symptoms and disease course also vary, indicating a possibly heterogeneous disorder. The accompanying clinical features differ across cultural groups. Most dissociative amnesias are retrograde, with memory impairments mainly involving the episodic-autobiographical memory domain. Anterograde dissociative amnesia occurring without significant retrograde memory impairments is rare. Functional neuroimaging studies of dissociative amnesia with prevailing retrograde memory impairments show changes in the network that subserves autobiographical memory. At present, no evidence-based treatments are available for dissociative amnesia and no broad framework exists for its rehabilitation. Further research is needed into its neurobiology, course, treatment options, and strategies to improve differential diagnoses.

  12. Characterization of the hyperpolarization-activated chloride current in dissociated rat sympathetic neurons.

    PubMed

    Clark, S; Jordt, S E; Jentsch, T J; Mathie, A

    1998-02-01

    1. Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization-activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N-methyl-D-glucamine) or by addition of 10 mM caesium or barium ions. 2. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl- > Br- > I- > cyclamate. All substituted permeant anions also blocked the current. 3. The current was blocked by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid), 9AC (anthracene-9-carboxylic acid) and NPPB (5-nitro-2-(3-phenylpropylamino)benzoic acid) but was unaffected by SITS (4-acetamido-4'-isothiocyanatostilbene- 2,2'-disulphonic acid) and niflumic acid. The effective blockers were voltage dependent; DIDS and NPPB were more effective at depolarized potentials while 9AC was more effective at hyperpolarized potentials. 4. The current was enhanced by extracellular acidification and reduced by extracellular alkalinization. Reducing external osmolarity was without effect in conventional whole-cell recording but enhanced current amplitude in those perforated-patch recordings where little current was evident in control external solution. 5. The current in SCG neurons was blocked by external cadmium and zinc. ClC-2 chloride currents expressed in Xenopus oocytes were also sensitive to block by these divalent ions and by DIDS but the sensitivity of ClC-2 to block by cadmium ions was lower than that of the current in SCG neurons. 6. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed the presence of mRNA for ClC-2 in SCG neurons but not in rat cerebellar granule cells which do not possess a hyperpolarization-activated Cl- current. 7. The data suggest that ClC-2 may be functionally expressed in rat SCG neurons. This current may play a role in regulating the internal chloride

  13. Can Si-doped graphene activate or dissociate O2 molecule?

    PubMed

    Chen, Ying; Yang, Xiao-chun; Liu, Yue-jie; Zhao, Jing-xiang; Cai, Qing-hai; Wang, Xuan-zhang

    2013-02-01

    Recently, the adsorption and dissociation of oxygen molecule on a metal-free catalyst has attracted considerable attention due to the fundamental and industrial importance. In the present work, we have investigated the adsorption and dissociation of O(2) molecule on pristine and silicon-doped graphene, using density functional theory calculations. We found that O(2) is firstly adsorbed on Si-doped graphene by [2+1] or [2+2] cycloaddition, with adsorption energies of -1.439 and -0.856eV, respectively. Following this, the molecularly adsorbed O(2) can be dissociated in different pathways. In the most favorable reaction path, the dissociation barrier of adsorbed O(2) is significantly reduced from 3.180 to 0.206eV due to the doping of silicon into graphene. Our results may be useful to further develop effective metal-free catalysts for the oxygen reduction reactions (ORRs), thus greatly widening the potential applications of graphene. PMID:23261882

  14. The Negative Mode Proteome with Activated Ion Negative Electron Transfer Dissociation (AI-NETD)*

    PubMed Central

    Riley, Nicholas M.; Rush, Matthew J. P.; Rose, Christopher M.; Richards, Alicia L.; Kwiecien, Nicholas W.; Bailey, Derek J.; Hebert, Alexander S.; Westphall, Michael S.; Coon, Joshua J.

    2015-01-01

    The field of proteomics almost uniformly relies on peptide cation analysis, leading to an underrepresentation of acidic portions of proteomes, including relevant acidic posttranslational modifications. Despite the many benefits negative mode proteomics can offer, peptide anion analysis remains in its infancy due mainly to challenges with high-pH reversed-phase separations and a lack of robust fragmentation methods suitable for peptide anion characterization. Here, we report the first implementation of activated ion negative electron transfer dissociation (AI-NETD) on the chromatographic timescale, generating 7,601 unique peptide identifications from Saccharomyces cerevisiae in single-shot nLC-MS/MS analyses of tryptic peptides—a greater than 5-fold increase over previous results with NETD alone. These improvements translate to identification of 1,106 proteins, making this work the first negative mode study to identify more than 1,000 proteins in any system. We then compare the performance of AI-NETD for analysis of peptides generated by five proteases (trypsin, LysC, GluC, chymotrypsin, and AspN) for negative mode analyses, identifying as many as 5,356 peptides (1,045 proteins) with LysC and 4,213 peptides (857 proteins) with GluC in yeast—characterizing 1,359 proteins in total. Finally, we present the first deep-sequencing approach for negative mode proteomics, leveraging offline low-pH reversed-phase fractionation prior to online high-pH separations and peptide fragmentation with AI-NETD. With this platform, we identified 3,467 proteins in yeast with trypsin alone and characterized a total of 3,730 proteins using multiple proteases, or nearly 83% of the expressed yeast proteome. This work represents the most extensive negative mode proteomics study to date, establishing AI-NETD as a robust tool for large-scale peptide anion characterization and making the negative mode approach a more viable platform for future proteomic studies. PMID:26193884

  15. Next Generation CAD/CAM/CAE Systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

    1997-01-01

    This document contains presentations from the joint UVA/NASA Workshop on Next Generation CAD/CAM/CAE Systems held at NASA Langley Research Center in Hampton, Virginia on March 18-19, 1997. The presentations focused on current capabilities and future directions of CAD/CAM/CAE systems, aerospace industry projects, and university activities related to simulation-based design. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the potential of emerging CAD/CAM/CAE technology for use in intelligent simulation-based design and to provide guidelines for focused future research leading to effective use of CAE systems for simulating the entire life cycle of aerospace systems.

  16. Reversible dissociation of active octamer of cyanase to inactive dimer promoted by alteration of the sulfhydryl group.

    PubMed

    Anderson, P M; Johnson, W V; Korte, J J; Xiong, X F; Sung, Y C; Fuchs, J A

    1988-04-25

    Cyanase is an inducible enzyme in Escherichia coli that catalyzes the reaction of cyanate with bicarbonate resulting in the decomposition of cyanate to ammonia and bicarbonate. In this study, the role of the single sulfhydryl group in each of the eight identical subunits of cyanase was investigated. Tetranitromethane, methyl methanethiosulfonate, N-ethylmaleimide, and Hg2+ all reacted with the sulfhydryl group to give derivatives which had reduced activities and which dissociated reversibly to inactive dimer. Association of inactive dimer to active octamer was facilitated by the presence of azide (cyanate analog) and bicarbonate, increased temperature and enzyme concentration, and presence of phosphate. Nitration of tyrosine residues by tetranitromethane occurred only in the absence of azide and bicarbonate, suggesting that at least some of the tyrosine residues become exposed when octamer dissociates to dimer. Site-directed mutagenesis was used to prepare a mutant enzyme in which serine was substituted for cysteine. The mutant enzyme was catalytically active and had properties very similar to native enzyme, except that it was less stable to treatment with urea and to high temperatures. These results establish that in native cyanase the sulfhydryl group per se is not required for catalytic activity, but it may play a role in stabilizing octameric structure, and that octameric structure is required for catalytic activity.

  17. Mechanical Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    McClain, Gerald R.

    This instructor's manual contains 13 units of instruction for a course on mechanical drafting with options for using computer-aided drafting (CAD). Each unit includes some or all of the following basic components of a unit of instruction: objective sheet, suggested activities for the teacher, assignment sheets and answers to assignment sheets,…

  18. CAD/CAE Integration Enhanced by New CAD Services Standard

    NASA Technical Reports Server (NTRS)

    Claus, Russell W.

    2002-01-01

    A Government-industry team led by the NASA Glenn Research Center has developed a computer interface standard for accessing data from computer-aided design (CAD) systems. The Object Management Group, an international computer standards organization, has adopted this CAD services standard. The new standard allows software (e.g., computer-aided engineering (CAE) and computer-aided manufacturing software to access multiple CAD systems through one programming interface. The interface is built on top of a distributed computing system called the Common Object Request Broker Architecture (CORBA). CORBA allows the CAD services software to operate in a distributed, heterogeneous computing environment.

  19. Self-association and BiP dissociation are not sufficient for activation of the ER stress sensor Ire1.

    PubMed

    Oikawa, Daisuke; Kimata, Yukio; Kohno, Kenji

    2007-05-01

    Ire1 is a type I transmembrane protein located on the endoplasmic reticulum (ER). Upon ER stress, Ire1 releases the ER chaperone BiP and self-associates. This activates Ire1 and triggers the unfolded protein response in the yeast Saccharomyces cerevisiae. We isolated and characterized an Ire1 luminal domain mutant lacking both the N-terminal and the juxtamembrane loosely folded subregions. Although this 'core' mutant was able to self-associate and failed to bind BiP even under nonstressed conditions, its activation was still dependent on ER stress. Furthermore, although substitution of Pro for Ser103 (S103P) in the luminal domain of full-length Ire1 caused neither BiP dissociation nor a change in self-association, the substitution in combination with the core mutation resulted in constitutive activation. This phenotype of the S103P mutation required a cluster of positively charged amino acid residues (Arg or Lys) located close to the mutation site in the Ire1 sequence. These observations indicate that in addition to BiP dissociation and self-association of Ire1, another unknown change on the luminal side is crucial for Ire1 activation. PMID:17452628

  20. Dissociation of SHP-1 from spinophilin during platelet activation exposes an inhibitory binding site for protein phosphatase-1 (PP1).

    PubMed

    Ma, Peisong; Foote, Darci C; Sinnamon, Andrew J; Brass, Lawrence F

    2015-01-01

    We have recently shown that a critical regulatory node in the platelet signaling network lies immediately downstream of platelet receptors for thrombin and TxA2. This node is comprised of a scaffold protein (spinophilin, SPL), a protein tyrosine phosphatase (SHP-1), and either of the two members of the Regulators of G protein Signaling family predominantly expressed in platelets (RGS10 or RGS18). The SPL/RGS/SHP-1 complex is present in resting platelets, dissociating when thrombin or TxA2, but not ADP or collagen, activate SHP-1 and release RGS10 and RGS18 to dampen signaling. Here we demonstrate an additional regulatory role for spinophilin, showing that dissociation of SHP-1 from spinophilin is followed by an increase in the binding of spinophilin to PP1, a serine/threonine phosphatase whose binding site maps to a region close to the SHP-1 binding site. The increase in PP1 binding to spinophilin is limited to platelet agonists that cause dissociation of the complex and is selective for the α and γ isoforms of PP1. Studies in cell culture show that SHP-1 and PP1 can compete for binding to spinophilin and that binding inhibits PP1 activity since over-expression of wild type spinophilin, but not spinophilin with a disabled PP1 binding site, causes an increase in the phosphorylation of myosin light chain, a well-characterized PP1 substrate. Collectively, these results indicate that in addition to regulating RGS protein availability in resting platelets, spinophilin can serve as a time-dependent, agonist- and isoform-selective regulator of PP1, inhibiting its activity when decay of the SPL/RGS/SHP-1 complex releases SHP-1 from spinophilin, exposing a binding site for PP1.

  1. Dissociation of SHP-1 from Spinophilin during Platelet Activation Exposes an Inhibitory Binding Site for Protein Phosphatase-1 (PP1)

    PubMed Central

    Ma, Peisong; Foote, Darci C.; Sinnamon, Andrew J.; Brass, Lawrence F.

    2015-01-01

    We have recently shown that a critical regulatory node in the platelet signaling network lies immediately downstream of platelet receptors for thrombin and TxA2. This node is comprised of a scaffold protein (spinophilin, SPL), a protein tyrosine phosphatase (SHP-1), and either of the two members of the Regulators of G protein Signaling family predominantly expressed in platelets (RGS10 or RGS18). The SPL/RGS/SHP-1 complex is present in resting platelets, dissociating when thrombin or TxA2, but not ADP or collagen, activate SHP-1 and release RGS10 and RGS18 to dampen signaling. Here we demonstrate an additional regulatory role for spinophilin, showing that dissociation of SHP-1 from spinophilin is followed by an increase in the binding of spinophilin to PP1, a serine/threonine phosphatase whose binding site maps to a region close to the SHP-1 binding site. The increase in PP1 binding to spinophilin is limited to platelet agonists that cause dissociation of the complex and is selective for the α and γ isoforms of PP1. Studies in cell culture show that SHP-1 and PP1 can compete for binding to spinophilin and that binding inhibits PP1 activity since over-expression of wild type spinophilin, but not spinophilin with a disabled PP1 binding site, causes an increase in the phosphorylation of myosin light chain, a well-characterized PP1 substrate. Collectively, these results indicate that in addition to regulating RGS protein availability in resting platelets, spinophilin can serve as a time-dependent, agonist- and isoform-selective regulator of PP1, inhibiting its activity when decay of the SPL/RGS/SHP-1 complex releases SHP-1 from spinophilin, exposing a binding site for PP1. PMID:25785436

  2. CAD/CAM for optomechatronics

    NASA Astrophysics Data System (ADS)

    Zhou, Haiguang; Han, Min

    2003-10-01

    We focus at CAD/CAM for optomechatronics. We have developed a kind of CAD/CAM, which is not only for mechanics but also for optics and electronic. The software can be used for training and education. We introduce mechanical CAD, optical CAD and electrical CAD, we show how to draw a circuit diagram, mechanical diagram and luminous transmission diagram, from 2D drawing to 3D drawing. We introduce how to create 2D and 3D parts for optomechatronics, how to edit tool paths, how to select parameters for process, how to run the post processor, dynamic show the tool path and generate the CNC programming. We introduce the joint application of CAD&CAM. We aim at how to match the requirement of optical, mechanical and electronics.

  3. CAD for small hydro projects

    SciTech Connect

    Bishop, N.A. Jr. )

    1994-04-01

    Over the past decade, computer-aided design (CAD) has become a practical and economical design tool. Today, specifying CAD hardware and software is relatively easy once you know what the design requirements are. But finding experienced CAD professionals is often more difficult. Most CAD users have only two or three years of design experience; more experienced design personnel are frequently not CAD literate. However, effective use of CAD can be the key to lowering design costs and improving design quality--a quest familiar to every manager and designer. By emphasizing computer-aided design literacy at all levels of the firm, a Canadian joint-venture company that specializes in engineering small hydroelectric projects has cut costs, become more productive and improved design quality. This article describes how they did it.

  4. Computerized design of CAD

    NASA Astrophysics Data System (ADS)

    Paul, B. E.; Pham, T. A.

    1982-11-01

    A computerized ballistic design technique for CAD/PAD is described by which a set of ballistic design parameters are determined, all of which satisfy a particular performance requirement. In addition, the program yields the remaining performance predictions, so that only a very few computer runs of the design program can quickly bring the ballistic design within the specification limits prescribed. An example is presented for a small propulsion device, such as a remover or actuator, for which the input specifications define a maximum allowable thrust and minimum end-of-stroke velocity. The resulting output automatically satisfies the input requirements, and will always yield an acceptable ballistic design.

  5. Dissociable and nondissociable forms of platelet-activating factor acetylhydrolase in human plasma LDL: implications for LDL oxidative susceptibility.

    PubMed

    McCall, M R; La Belle, M; Forte, T M; Krauss, R M; Takanami, Y; Tribble, D L

    1999-01-29

    Platelet-activating factor acetylhydrolase (PAF-AH) is transported by lipoproteins in plasma and is thought to possess both anti-inflammatory and anti-oxidative activity. It has been reported that PAF-AH is recovered primarily in small, dense LDL and HDL following ultracentrifugal separation of lipoproteins. In the present studies, we aimed to further define the distribution of PAF-AH among lipoprotein fractions and subfractions, and to determine whether these distributions are affected by the lipoprotein isolation strategy (FPLC versus sequential ultracentrifugation) and LDL particle distribution profile. When lipoproteins were isolated by FPLC, the bulk (approximately 85%) of plasma PAF-AH activity was recovered within LDL-containing fractions, whereas with ultracentrifugation, there was a redistribution to HDL (which contained approximately 18% of the activity) and the d>1.21 g/ml fraction (which contained approximately 32%). Notably, re-ultracentrifugation of isolated LDL did not result in any further movement of PAF-AH to higher densities, suggesting the presence of dissociable and nondissociable forms of the enzyme on LDL. Differences were noted in the distribution of PAF-AH activity among LDL subfractions from subjects exhibiting the pattern A (primarily large, buoyant LDL) versus pattern B (primarily small, dense LDL) phenotype. In the latter group, there was a relative depletion of PAF-AH activity in subfractions in the intermediate to dense range (d=1.039-1.047 g/ml) with a corresponding increase in enzyme activity recovered within the d>1.21 g/ml ultracentrifugal fraction. Thus, there appears to be a greater proportion of the dissociable form of PAF-AH in pattern B subjects. In both populations, most of the nondissociable activity was recovered in a minor small, dense LDL subfraction. Based on conjugated dienes as a measure of lipid peroxidation, variations in PAF-AH activity appeared to contribute to variations in oxidative behavior among

  6. Unimolecular dissociation dynamics of vibrationally activated CH3CHOO Criegee intermediates to OH radical products.

    PubMed

    Kidwell, Nathanael M; Li, Hongwei; Wang, Xiaohong; Bowman, Joel M; Lester, Marsha I

    2016-05-01

    The hydroxyl radical is an important atmospheric oxidant, and a significant source of its production occurs through alkene ozonolysis. This takes place via a cycloaddition reaction and subsequent fragmentation to form an energized carbonyl oxide (for example, CH3CHOO), known as a Criegee intermediate, which can then either react with another atmospheric species or decay and, in doing so, produce the hydroxyl radical. Here, we examine the dissociation dynamics of a prototypical Criegee intermediate by characterizing the translational and internal energy distributions of the OH radical products, which reflect critical configurations along the reaction pathway. Experimentally, the kinetic energy release to OH products is ascertained through velocity map imaging. Theoretically, quasi-classical trajectories are performed on a new full-dimensional, ab initio potential energy surface. Both experiment and theory show that most of the available energy flows into internal excitation of the vinoxy products. The isotropic angular distribution of OH fragments indicates that dissociation occurs in ≥2 ps, in agreement with theory. PMID:27102686

  7. Unimolecular dissociation dynamics of vibrationally activated CH3CHOO Criegee intermediates to OH radical products

    NASA Astrophysics Data System (ADS)

    Kidwell, Nathanael M.; Li, Hongwei; Wang, Xiaohong; Bowman, Joel M.; Lester, Marsha I.

    2016-05-01

    The hydroxyl radical is an important atmospheric oxidant, and a significant source of its production occurs through alkene ozonolysis. This takes place via a cycloaddition reaction and subsequent fragmentation to form an energized carbonyl oxide (for example, CH3CHOO), known as a Criegee intermediate, which can then either react with another atmospheric species or decay and, in doing so, produce the hydroxyl radical. Here, we examine the dissociation dynamics of a prototypical Criegee intermediate by characterizing the translational and internal energy distributions of the OH radical products, which reflect critical configurations along the reaction pathway. Experimentally, the kinetic energy release to OH products is ascertained through velocity map imaging. Theoretically, quasi-classical trajectories are performed on a new full-dimensional, ab initio potential energy surface. Both experiment and theory show that most of the available energy flows into internal excitation of the vinoxy products. The isotropic angular distribution of OH fragments indicates that dissociation occurs in ≥2 ps, in agreement with theory.

  8. Molecular cloning, functional analysis of three cinnamyl alcohol dehydrogenase (CAD) genes in the leaves of tea plant, Camellia sinensis.

    PubMed

    Deng, Wei-Wei; Zhang, Ming; Wu, Jian-Qiang; Jiang, Zheng-Zhong; Tang, Lei; Li, Ye-Yun; Wei, Chao-Ling; Jiang, Chang-Jun; Wan, Xiao-Chun

    2013-02-15

    Cinnamyl alcohol dehydrogenase (CAD; EC 1.1.1.195) is considered to be a key enzyme in lignin biosynthesis, but little was known about CADs in tea plants (Camellia sinensis). A full-length cDNA sequence (CsCAD2) was isolated by suppressive subtractive hybridization (SSH) in Ectropis oblique feeding-induced tea plants, and another two full-length cDNA sequences (CsCAD1 and CsCAD3) were obtained from a transcriptome obtained by deep sequencing. However, they showed only 20-54% identities. Phylogenetic analysis revealed that they belonged to three different families. DNA gel blotting analysis revealed that two copies of CsCAD1 and CsCAD2 genes existed in tea genome, but CsCAD3 likely had only one copy. Recombinant proteins of these CsCADs were produced in Escherichia coli. The activity of purified recombinant CsCAD2 protein was up to 0.43 μmol min(-1) mg(-1). However, the other two recombinant proteins had lower activities, probably due to incomplete refolding. qRT-PCR analysis indicated that while CsCAD3 was strongly up-regulated in tea plants after E. oblique attack and mechanical damage, CsCAD1 and CsCAD2 showed only moderate or no changes in transcript levels. Treatment of defence-related hormones methyl jasmonate (MeJA) and salicylic acid (SA) elevated the expression of CsCAD1 and CsCAD2, but decreased the transcript abundance of CsCAD3. The transcript levels of CsCAD2 did not change after applying abscisic acid (ABA), whereas CsCAD1 and CsCAD3 were induced. These results suggested that these three CsCAD genes in tea plants may play a role in defense against insects and pathogens and adaptation to abiotic stresses and these genes likely have divergant functions.

  9. Understanding the enhanced catalytic activity of Cu1@Pd3(111) in formic acid dissociation, a theoretical perspective

    NASA Astrophysics Data System (ADS)

    He, Feng; Li, Kai; Xie, Guangyou; Wang, Ying; Jiao, Menggai; Tang, Hao; Wu, Zhijian

    2016-06-01

    The bimetallic Cu1@Pd3(111) catalyst has been synthesized recently and exhibits better catalytic activity and durability compared with pure Pd(111) as anode catalyst in direct formic acid fuel cells (DFAFCs). In this work, we studied the reaction mechanism of formic acid dissociation on both Pd(111) and Cu1@Pd3(111) by using the density functional method. Our calculations showed that the surface adsorption of the poisoning species CO on Cu1@Pd3(111) is weakened mainly by the strain effect rather than the Cusbnd Pd ligand effect. The Cu1@Pd3(111) can effectively promote the catalytic activity for formic acid dissociation by decreasing the barrier of CO2 formation from the preferential trans-COOH intermediate and increasing the barrier of CO formation from the reduction of CO2. We found that the H atom accumulation, electron accumulation and low electrode potential could accelerate the catalyst deactivation due to the contamination of the poisoning species CO. Furthermore, under low anode potential, the Cu1@Pd3(111) has better durability than pure Pd(111), which can be attributed to the unfavorable CO formation and the favorable CO desorption.

  10. Effects of Ketamine on Resting-State EEG Activity and Their Relationship to Perceptual/Dissociative Symptoms in Healthy Humans

    PubMed Central

    de la Salle, Sara; Choueiry, Joelle; Shah, Dhrasti; Bowers, Hayley; McIntosh, Judy; Ilivitsky, Vadim; Knott, Verner

    2016-01-01

    N-methyl-D-aspartate (NMDA) receptor antagonists administered to healthy humans results in schizophrenia-like symptoms, which preclinical research suggests are due to glutamatergically altered brain oscillations. Here, we examined resting-state electroencephalographic activity in 21 healthy volunteers assessed in a placebo-controlled, double-blind, randomized study involving administration of either a saline infusion or a sub-anesthetic dose of ketamine, an NMDA receptor antagonist. Frequency-specific current source density (CSD) was assessed at sensor-level and source-level using eLORETA within regions of interest of a triple network model of schizophrenia (this model posits a dysfunctional switching between large-scale Default Mode and Central Executive networks by the monitor-controlling Salience Network). These CSDs were measured in each session along with subjective symptoms as indexed with the Clinician Administered Dissociative States Scale. Ketamine-induced CSD reductions in slow (delta/theta and alpha) and increases in fast (gamma) frequencies at scalp electrode sites were paralleled by frequency-specific CSD changes in the Default Mode, Central Executive, and Salience networks. Subjective symptoms scores were increased with ketamine and ratings of depersonalization in particular were associated with alpha CSD reductions in general and in specific regions of interest in each of the three networks. These results tentatively support the hypothesis that pathological brain oscillations associated with hypofunctional NMDA receptor activity may contribute to the emergence of the perceptual/dissociate symptoms of schizophrenia. PMID:27729865

  11. Dissociation between neural signatures of stimulus and choice in population activity of human V1 during perceptual decision-making.

    PubMed

    Choe, Kyoung Whan; Blake, Randolph; Lee, Sang-Hun

    2014-02-12

    Primary visual cortex (V1) forms the initial cortical representation of objects and events in our visual environment, and it distributes information about that representation to higher cortical areas within the visual hierarchy. Decades of work have established tight linkages between neural activity occurring in V1 and features comprising the retinal image, but it remains debatable how that activity relates to perceptual decisions. An actively debated question is the extent to which V1 responses determine, on a trial-by-trial basis, perceptual choices made by observers. By inspecting the population activity of V1 from human observers engaged in a difficult visual discrimination task, we tested one essential prediction of the deterministic view: choice-related activity, if it exists in V1, and stimulus-related activity should occur in the same neural ensemble of neurons at the same time. Our findings do not support this prediction: while cortical activity signifying the variability in choice behavior was indeed found in V1, that activity was dissociated from activity representing stimulus differences relevant to the task, being advanced in time and carried by a different neural ensemble. The spatiotemporal dynamics of population responses suggest that short-term priors, perhaps formed in higher cortical areas involved in perceptual inference, act to modulate V1 activity prior to stimulus onset without modifying subsequent activity that actually represents stimulus features within V1.

  12. Butyrate-induced proapoptotic and antiangiogenic pathways in EAT cells require activation of CAD and downregulation of VEGF

    SciTech Connect

    Belakavadi, Madesh . E-mail: belakama@umdnj.edu; Prabhakar, B.T.; Salimath, Bharathi P.

    2005-10-07

    Butyrate, a short-chain fatty acid produced in the colon, induces cell cycle arrest, differentiation, and apoptosis in transformed cell lines. In this report, we study the effects of butyrate (BuA) on the growth of Ehrlich ascites tumor (EAT) cells in vivo. BuA, when injected intraperitoneally (i.p) into mice, inhibited proliferation of EAT cells. Further, induction of apoptosis in EAT cells was monitored by nuclear condensation, annexin-V staining, DNA fragmentation, and translocation of caspase-activated DNase into nucleus upon BuA-treatment. Ac-DEVD-CHO, a caspase-3 inhibitor, completely inhibited BuA-induced apoptosis, indicating that activation of caspase-3 mediates the apoptotic pathway in EAT cells. The proapoptotic effect of BuA also reflects on the antiangiogenic pathway in EAT cells. The antiangiogenic effect of BuA in vivo was demonstrated by the downregulation of the secretion of VEGF in EAT cells. CD31 immunohistochemical staining of peritoneum sections clearly indicated a potential angioinhibitory effect of BuA in EAT cells. These results suggest that BuA, besides regulating other fundamental cellular processes, is able to modulate the expression/secretion of the key angiogenic growth factor VEGF in EAT cells.

  13. TRAD or CAD? A Comparison.

    ERIC Educational Resources Information Center

    Resetarits, Paul J.

    1989-01-01

    Studies whether traditional drafting equipment (TRAD) or computer aided drafting equipment (CAD) is more effective. Proposes that students using only CAD can learn principles of drafting as well as students using only TRAD. Reports no significant difference either on achievement or attitude. (MVL)

  14. CAD/CAM data management

    NASA Technical Reports Server (NTRS)

    Bray, O. H.

    1984-01-01

    The role of data base management in CAD/CAM, particularly for geometric data is described. First, long term and short term objectives for CAD/CAM data management are identified. Second, the benefits of the data base management approach are explained. Third, some of the additional work needed in the data base area is discussed.

  15. Going their separate ways: dissociation of hippocampal and dorsolateral prefrontal activation during episodic retrieval and post-retrieval processing.

    PubMed

    Israel, Sarah L; Seibert, Tyler M; Black, Michelle L; Brewer, James B

    2010-03-01

    Hippocampal activity is modulated during episodic memory retrieval. Most consistently, a relative increase in activity during confident retrieval is observed. Dorsolateral prefrontal cortex (DLPFC) is also activated during retrieval, but may be more generally activated during cognitive-control processes. The "default network," regions activated during rest or internally focused tasks, includes the hippocampus, but not DLPFC. Therefore, DLPFC and the hippocampus should diverge during difficult tasks suppressing the default network. It is unclear, however, whether a difficult episodic memory retrieval task would suppress the default network due to difficulty or activate it due to internally directed attention. We hypothesized that a task requiring episodic retrieval followed by rumination on the retrieved item would increase DLPFC activity, but paradoxically reduce hippocampal activity due to concomitant suppression of the default network. In the present study, blocked and event-related fMRI were used to examine hippocampal activity during episodic memory recollection and postretrieval processing of paired associates. Subjects were asked to make living/nonliving judgments about items visually presented (classify) or items retrieved from memory (recall-classify). Active and passive baselines were used to differentiate task-related activity from default-network activity. During the "recall-classify" task, anterior hippocampal activity was selectively reduced relative to "classify" and baseline tasks, and this activity was inversely correlated with DLPFC. Reaction time was positively correlated with DLPFC activation and default-network/hippocampal suppression. The findings demonstrate that frontal and hippocampal activity are dissociated during difficult episodic retrieval tasks and reveal important considerations for interpreting hippocampal activity associated with successful episodic retrieval. PMID:19301994

  16. Resonance activation and collision-induced-dissociation of ions using rectangular wave dipolar potentials in a digital ion trap mass spectrometer.

    PubMed

    Xu, Fuxing; Wang, Liang; Dai, Xinhua; Fang, Xiang; Ding, Chuan-Fan

    2014-04-01

    Collision-induced dissociation (CID) of ions by resonance activation in a quadrupole ion trap is usually accomplished by resonance exciting the ions to higher kinetic energy, whereby the high kinetic energy ions collide with a bath gas, such as helium or argon, inside the trap and dissociate to fragments. A new ion activation method using a well-defined rectangular wave dipolar potential formed by dividing down the trapping rectangular waveform is developed and examined herein. The mass-selected parent ions are resonance excited to high kinetic energies by simply changing the frequency of the rectangular wave dipolar potential and dissociation proceeds. A relationship between the ion mass and the activation waveform frequency is also identified and described. This highly efficient (CID) procedure can be realized by simply changing the waveform frequency of the dipolar potential, which could certainly simplify tandem mass spectrometry analysis methods.

  17. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology.

    PubMed

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-08-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry. Graphical Abstract ᅟ. PMID:27150507

  18. Dissociating patterns of anterior and posterior hippocampal activity and connectivity during distinct forms of category fluency.

    PubMed

    Sheldon, Signy; McAndrews, Mary Pat; Pruessner, Jens; Moscovitch, Morris

    2016-09-01

    Recent work has suggested that there are functionally distinct contributions from hippocampal subregions to episodic memory retrieval. One view of this dissociation is that the anterior and posterior hippocampus support gist-based/conceptual and fine-grained/spatial memory representations, respectively. It is not clear if such distinctions hold for other cognitive domains. To test this possibility, we examined anterior and posterior hippocampal contributions to a standard semantic retrieval task, category fluency. During fMRI scanning, participants generated exemplars to categories that were based on conceptual (autobiographical categories - 'movies that you have seen') or spatio-perceptual (spatial categories - 'items in a kitchen') information. Our main finding was that the autobiographical categories preferentially recruited the anterior hippocampus whereas the spatial categories preferentially recruited the posterior hippocampus. Differences were also evident when we examined the patterns of task-based hippocampal connectivity associated with these two forms of fluency. Our findings provide evidence for a functional organization along the long axis of the hippocampus that is based on conceptual and perceptual relational retrieval and indicate that this manner of organization is apparent outside the domain of episodic memory. PMID:27343687

  19. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology

    NASA Astrophysics Data System (ADS)

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-08-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry.

  20. Combined Pulsed-Q dissociation and electron transfer dissociation for identification and quantitation of iTRAQ–labeled phosphopeptides

    SciTech Connect

    Yang, Feng; Wu, Si; Stenoien, David L.; Zhao, Rui; Monroe, Matthew E.; Gritsenko, Marina A.; Purvine, Samuel O.; Polpitiya, Ashoka D.; Tolic, Nikola; Zhang, Qibin; Norbeck, Angela D.; Orton, Daniel J.; Moore, Ronald J.; Tang, Keqi; Anderson, Gordon A.; Pasa-Tolic, Ljiljana; Camp, David G.; Smith, Richard D.

    2009-05-15

    Multiplex isobaric tags for relative and absolute quantification (iTRAQ) enable high-throughput quantification of peptides via reporter ion signals in the low mass range of tandem mass spectra. A challenging but highly promising application is to analyze iTRAQ-labeled peptides using a sensitive linear ion trap mass spectrometer (LTQ-MS) and pulsed Q dissociation (PQD), a form of ion trap collision activated dissociation (CAD) designed to allow detection of low mass-to-charge fragment ions. Electron dissociation transfer (ETD), on the other hand, is complementary to PQD and is especially useful for sequencing peptides containing post-translational modifications (PTMs). Here, we developed an integrated workflow for robust and accurate quantitative identification of iTRAQ labeled phosphopeptides that integrates the PQD and ETD fragmentation methods together with PQD optimization, data management and bioinformatics tools. Analysis of the phosphoproteome of human fibroblast cells demonstrated that this hybrid mode is superior to either PQD or ETD alone for phosphopeptide identification and quantitation. The combined PQD/ETD approach can qualitatively identify additional phosphopeptides than ETD alone and PQD information can provide better quantitation of ETD identified iTRAQ-labeled phosphopeptides.

  1. Multipole-storage-assisted dissociation for the characterization of large proteins and simple protein mixtures by ESI-FTICR-MS.

    PubMed

    Pan, Chongle; Hettich, Robert L

    2005-05-15

    In Fourier transform ion cyclotron resonance mass spectrometry, collisionally activated dissociation (CAD) typically is accomplished within the analyzer ion cell. An alternative approach of multipole-storage-assisted dissociation (MSAD) has previously been demonstrated by inducing collisional fragmentation in the external multipole that is usually employed for ion accumulation. To explore the utility of MSAD for interrogating intact proteins and simple protein mixtures in a multiplexed manner, we have investigated the means of controlling the collisional energy and the fragmentation pattern for this experimental approach. With protein samples in the low micromolar concentration range, the two major experimental parameters affecting MSAD in the hexapole region were found to be the dc offset voltage and accumulation time. While low-energy MSAD of intact proteins yields fragment ions similar to sustained off resonance irradiation collision-activated dissociation (SORI-CAD), high-energy MSAD induces sequential fragmentation for intact proteins to yield a rich variety of singly charged ions in the m/z 600-1200 Da region. Each of the seven proteins (Mr range of 8.5-116 kDa) examined in this study exhibited their own characteristic MSAD fragmentation pattern, which could be used as a signature of the presence of a given protein, even in a mixture. In addition, any MSAD fragment can be isolated and dissociated further by SORI-CAD in an MS3-type experiment inside the FTICR analyzer cell. This presents a novel way to interrogate the identities of these fragment ions as well as obtain amino acid sequence tag information that can be used to identify proteins from mixtures.

  2. CAD-centric Computation Management System for a Virtual TBM

    SciTech Connect

    Ramakanth Munipalli; K.Y. Szema; P.Y. Huang; C.M. Rowell; A.Ying; M. Abdou

    2011-05-03

    HyPerComp Inc. in research collaboration with TEXCEL has set out to build a Virtual Test Blanket Module (VTBM) computational system to address the need in contemporary fusion research for simulating the integrated behavior of the blanket, divertor and plasma facing components in a fusion environment. Physical phenomena to be considered in a VTBM will include fluid flow, heat transfer, mass transfer, neutronics, structural mechanics and electromagnetics. We seek to integrate well established (third-party) simulation software in various disciplines mentioned above. The integrated modeling process will enable user groups to interoperate using a common modeling platform at various stages of the analysis. Since CAD is at the core of the simulation (as opposed to computational meshes which are different for each problem,) VTBM will have a well developed CAD interface, governing CAD model editing, cleanup, parameter extraction, model deformation (based on simulation,) CAD-based data interpolation. In Phase-I, we built the CAD-hub of the proposed VTBM and demonstrated its use in modeling a liquid breeder blanket module with coupled MHD and structural mechanics using HIMAG and ANSYS. A complete graphical user interface of the VTBM was created, which will form the foundation of any future development. Conservative data interpolation via CAD (as opposed to mesh-based transfer), the regeneration of CAD models based upon computed deflections, are among the other highlights of phase-I activity.

  3. Double dissociating effects of sensory stimulation and cocaine on serotonin activity in the occipital and temporal cortices.

    PubMed

    Müller, Christian P; De Souza Silva, Maria A; Huston, Joseph P

    2007-03-01

    Visual cues that become associated with the consumption of psychostimulant drugs energize craving and the intake of the drug by mechanisms of which little is known. In two experiments using in vivo microdialysis in freely moving rats we compared the effects of visual and auditory stimulation with that of cocaine (0, 5, 10, 20mg/kg; i.p.) on the extracellular serotonin (5-HT) activity in the occipital and temporal cortices in relation to behavior. Visual stimulation increased 5-HT in the occipital, but not temporal cortex, parallel to an increase in locomotion. Auditory stimulation decreased 5-HT in the auditory, but not occipital cortex, thus, showing a double dissociated 5-HT response. These data suggest that a locally restricted 5-HT response to sensory stimulation may gate behavioral activity sense-modality selectively. Cocaine affected 5-HT in the occipital cortex and behavioral activity in the same direction as visual stimulation, but in an amplified and prolonged way. In the temporal cortex cocaine also caused an increase in 5-HT. The findings demonstrate common effects of visual stimulation and cocaine on 5-HT activity in the occipital cortex in relation to locomotor activity. The results suggest that concepts of how neutral visual cues become powerful energizers of addiction-related behaviors should be expanded to incorporate not only an acute enhancement of reward processing mechanisms, but, in parallel, also an amplified processing of visual stimuli in the occipital cortex. PMID:17116310

  4. The neural coding of expected and unexpected monetary performance outcomes: dissociations between active and observational learning.

    PubMed

    Bellebaum, C; Jokisch, D; Gizewski, E R; Forsting, M; Daum, I

    2012-02-01

    Successful adaptation to the environment requires the learning of stimulus-response-outcome associations. Such associations can be learned actively by trial and error or by observing the behaviour and accompanying outcomes in other persons. The present study investigated similarities and differences in the neural mechanisms of active and observational learning from monetary feedback using functional magnetic resonance imaging. Two groups of 15 subjects each - active and observational learners - participated in the experiment. On every trial, active learners chose between two stimuli and received monetary feedback. Each observational learner observed the choices and outcomes of one active learner. Learning performance as assessed via active test trials without feedback was comparable between groups. Different activation patterns were observed for the processing of unexpected vs. expected monetary feedback in active and observational learners, particularly for positive outcomes. Activity for unexpected vs. expected reward was stronger in the right striatum in active learning, while activity in the hippocampus was bilaterally enhanced in observational and reduced in active learning. Modulation of activity by prediction error (PE) magnitude was observed in the right putamen in both types of learning, whereas PE related activations in the right anterior caudate nucleus and in the medial orbitofrontal cortex were stronger for active learning. The striatum and orbitofrontal cortex thus appear to link reward stimuli to own behavioural reactions and are less strongly involved when the behavioural outcome refers to another person's action. Alternative explanations such as differences in reward value between active and observational learning are also discussed.

  5. Complete hamster CAD protein and the carbamylphosphate synthetase domain of CAD complement mammalian cell mutants defective in de novo pyrimidine biosynthesis.

    PubMed

    Musmanno, L A; Jamison, R S; Barnett, R S; Buford, E; Davidson, J N

    1992-07-01

    The mammalian CAD gene codes for a 240-kDa multifunctional protein that catalyzes the first three steps of de novo pyrimidine biosynthesis. Previously, the longest cDNA construct available was missing approximately 500 bp of coding sequence at the 5' end, thereby lacking the sequence to encode the entire carbamylphosphate synthetase (CPSase) domain. Here, a complete CAD hamster cDNA is constructed, placed into a mammalian expression vector, and transfected into hamster cells deficient in CAD. Transfectants show coordinately restored levels of all three enzyme activities and the presence of full-length CAD protein. A derivative construct of the CAD cDNA was generated that should encode only the CPSase domain. When transfected into mammalian cells, a protein was synthesized that had significant CPSase activity both in vivo and in vitro. The two constructs generated in this study will facilitate the study of CAD structure, function, and allosteric regulation. PMID:1359654

  6. Evaluation of Five Microcomputer CAD Packages.

    ERIC Educational Resources Information Center

    Leach, James A.

    1987-01-01

    Discusses the similarities, differences, advanced features, applications and number of users of five microcomputer computer-aided design (CAD) packages. Included are: "AutoCAD (V.2.17)"; "CADKEY (V.2.0)"; "CADVANCE (V.1.0)"; "Super MicroCAD"; and "VersaCAD Advanced (V.4.00)." Describes the evaluation of the packages and makes recommendations for…

  7. Infrared Multiphoton Dissociation for Quantitative Shotgun Proteomics

    PubMed Central

    Ledvina, Aaron R.; Lee, M. Violet; McAlister, Graeme C.; Westphall, Michael S.; Coon, Joshua J.

    2012-01-01

    We modified a dual-cell linear ion trap mass spectrometer to perform infrared multiphoton dissociation (IRMPD) in the low pressure trap of a dual-cell quadrupole linear ion trap (dual cell QLT) and perform large-scale IRMPD analyses of complex peptide mixtures. Upon optimization of activation parameters (precursor q-value, irradiation time, and photon flux), IRMPD subtly, but significantly outperforms resonant excitation CAD for peptides identified at a 1% false-discovery rate (FDR) from a yeast tryptic digest (95% confidence, p = 0.019). We further demonstrate that IRMPD is compatible with the analysis of isobaric-tagged peptides. Using fixed QLT RF amplitude allows for the consistent retention of reporter ions, but necessitates the use of variable IRMPD irradiation times, dependent upon precursor mass-to-charge (m/z). We show that IRMPD activation parameters can be tuned to allow for effective peptide identification and quantitation simultaneously. We thus conclude that IRMPD performed in a dual-cell ion trap is an effective option for the large-scale analysis of both unmodified and isobaric-tagged peptides. PMID:22480380

  8. Neuronal activity mediated regulation of glutamate transporter GLT‐1 surface diffusion in rat astrocytes in dissociated and slice cultures

    PubMed Central

    Al Awabdh, Sana; Gupta‐Agarwal, Swati; Sheehan, David F.; Muir, James; Norkett, Rosalind; Twelvetrees, Alison E.; Griffin, Lewis D.

    2016-01-01

    The astrocytic GLT‐1 (or EAAT2) is the major glutamate transporter for clearing synaptic glutamate. While the diffusion dynamics of neurotransmitter receptors at the neuronal surface are well understood, far less is known regarding the surface trafficking of transporters in subcellular domains of the astrocyte membrane. Here, we have used live‐cell imaging to study the mechanisms regulating GLT‐1 surface diffusion in astrocytes in dissociated and brain slice cultures. Using GFP‐time lapse imaging, we show that GLT‐1 forms stable clusters that are dispersed rapidly and reversibly upon glutamate treatment in a transporter activity‐dependent manner. Fluorescence recovery after photobleaching and single particle tracking using quantum dots revealed that clustered GLT‐1 is more stable than diffuse GLT‐1 and that glutamate increases GLT‐1 surface diffusion in the astrocyte membrane. Interestingly, the two main GLT‐1 isoforms expressed in the brain, GLT‐1a and GLT‐1b, are both found to be stabilized opposed to synapses under basal conditions, with GLT‐1b more so. GLT‐1 surface mobility is increased in proximity to activated synapses and alterations of neuronal activity can bidirectionally modulate the dynamics of both GLT‐1 isoforms. Altogether, these data reveal that astrocytic GLT‐1 surface mobility, via its transport activity, is modulated during neuronal firing, which may be a key process for shaping glutamate clearance and glutamatergic synaptic transmission. GLIA 2016;64:1252–1264 PMID:27189737

  9. Resin-composite Blocks for Dental CAD/CAM Applications

    PubMed Central

    Ruse, N.D.; Sadoun, M.J.

    2014-01-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. PMID:25344335

  10. Resin-composite blocks for dental CAD/CAM applications.

    PubMed

    Ruse, N D; Sadoun, M J

    2014-12-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.

  11. Dissociation of Active Working Memory and Passive Recognition in Rhesus Monkeys

    ERIC Educational Resources Information Center

    Basile, Benjamin M.; Hampton, Robert R.

    2013-01-01

    Active cognitive control of working memory is central in most human memory models, but behavioral evidence for such control in nonhuman primates is absent and neurophysiological evidence, while suggestive, is indirect. We present behavioral evidence that monkey memory for familiar images is under active cognitive control. Concurrent cognitive…

  12. Dissociation between active and observational learning from positive and negative feedback in Parkinsonism.

    PubMed

    Kobza, Stefan; Ferrea, Stefano; Schnitzler, Alfons; Pollok, Bettina; Südmeyer, Martin; Bellebaum, Christian

    2012-01-01

    Feedback to both actively performed and observed behaviour allows adaptation of future actions. Positive feedback leads to increased activity of dopamine neurons in the substantia nigra, whereas dopamine neuron activity is decreased following negative feedback. Dopamine level reduction in unmedicated Parkinson's Disease patients has been shown to lead to a negative learning bias, i.e. enhanced learning from negative feedback. Recent findings suggest that the neural mechanisms of active and observational learning from feedback might differ, with the striatum playing a less prominent role in observational learning. Therefore, it was hypothesized that unmedicated Parkinson's Disease patients would show a negative learning bias only in active but not in observational learning. In a between-group design, 19 Parkinson's Disease patients and 40 healthy controls engaged in either an active or an observational probabilistic feedback-learning task. For both tasks, transfer phases aimed to assess the bias to learn better from positive or negative feedback. As expected, actively learning patients showed a negative learning bias, whereas controls learned better from positive feedback. In contrast, no difference between patients and controls emerged for observational learning, with both groups showing better learning from positive feedback. These findings add to neural models of reinforcement-learning by suggesting that dopamine-modulated input to the striatum plays a minor role in observational learning from feedback. Future research will have to elucidate the specific neural underpinnings of observational learning.

  13. Dissociating sentential prosody from sentence processing: activation interacts with task demands.

    PubMed

    Plante, Elena; Creusere, Marlena; Sabin, Cynthia

    2002-09-01

    Sentence processing was contrasted with processing of syntactic prosody under two task conditions in order to examine the representation of these components of language and their interaction with working memory load. Twelve adults received fMDI scans while they listened to low-pass filtered and unfiltered sentences either passively, or during tasks that required subjects to remember and recognize information contained in the stimuli. Results indicated that temporal activation for prosodic stimuli differed compared to activation for sentence stimuli only during passive listening tasks. The inclusion of memory demands was associated with frontal activation, which was differentially lateralized for sentence and prosodic stimuli. The results demonstrate differential brain activation for prosodic vs sentential stimuli which interacts with the memory demands placed on the subjects.

  14. Dissociation of two signals required for activation of resting B cells.

    PubMed Central

    Julius, M H; von Boehmer, H; Sidman, C L

    1982-01-01

    Cellular interactions involved in the T cell-dependent activation of B cells were analyzed by using lines and clones of helper T cells specific for determinants expressed on the B cell surface. Activation of male antigen-, M locus-, and H-2-specific T cells was shown to support polyclonal Ig production by a population of B cells that did not require T-cell-B-cell interaction for induction/amplification. However, these T cells alone did not activate gradient-purified small (resting) B cells. The activation of small B cells was shown to require not only a signal derived through an antigen-specific T-helper cell-B cell interaction but in addition a second signal that could be provided by anti-Ig antibodies. PMID:6979046

  15. CAD Services: an Industry Standard Interface for Mechanical CAD Interoperability

    NASA Technical Reports Server (NTRS)

    Claus, Russell; Weitzer, Ilan

    2002-01-01

    Most organizations seek to design and develop new products in increasingly shorter time periods. At the same time, increased performance demands require a team-based multidisciplinary design process that may span several organizations. One approach to meet these demands is to use 'Geometry Centric' design. In this approach, design engineers team their efforts through one united representation of the design that is usually captured in a CAD system. Standards-based interfaces are critical to provide uniform, simple, distributed services that enable the 'Geometry Centric' design approach. This paper describes an industry-wide effort, under the Object Management Group's (OMG) Manufacturing Domain Task Force, to define interfaces that enable the interoperability of CAD, Computer Aided Manufacturing (CAM), and Computer Aided Engineering (CAE) tools. This critical link to enable 'Geometry Centric' design is called: Cad Services V1.0. This paper discusses the features of this standard and proposed application.

  16. Pyruvate dehydrogenase kinase isoform 2 activity limited and further inhibited by slowing down the rate of dissociation of ADP.

    PubMed

    Bao, Haiying; Kasten, Shane A; Yan, Xiaohua; Roche, Thomas E

    2004-10-26

    Pyruvate dehydrogenase kinase 2 (PDK2) activity is enhanced by the dihydrolipoyl acetyltransferase core (E2 60mer) that binds PDK2 and a large number of its pyruvate dehydrogenase (E1) substrate. With E2-activated PDK2, K(+) at approximately 90 mM and Cl(-) at approximately 60 mM decreased the K(m) of PDK2 for ATP and competitive K(i) for ADP by approximately 3-fold and enhanced pyruvate inhibition. Comparing PDK2 catalysis +/- E2, E2 increased the K(m) of PDK2 for ATP by nearly 8-fold (from 5 to 39 microM), increased k(cat) by approximately 4-fold, and decreased the requirement for E1 by at least 400-fold. ATP binding, measured by a cold-trapping technique, occurred at two active sites with a K(d) of 5 microM, which equals the K(m) and K(d) of PDK2 for ATP measured in the absence of E2. During E2-aided catalysis, PDK2 had approximately 3 times more ADP than ATP bound at its active site, and the pyruvate analogue, dichloroacetate, led to 16-fold more ADP than ATP being bound (no added ADP). Pyruvate functioned as an uncompetitive inhibitor versus ATP, and inclusion of ADP transformed pyruvate inhibition to noncompetitive. At high pyruvate levels, pyruvate was a partial inhibitor but also induced substrate inhibition at high ATP levels. Our results indicate that, at physiological salt levels, ADP dissociation is a limiting step in E2-activated PDK2 catalysis, that PDK2.[ADP or ATP].pyruvate complexes form, and that PDK2.ATP.pyruvate.E1 reacts with PDK2.ADP.pyruvate accumulating. PMID:15491150

  17. The bacteriocin AS-48 requires dimer dissociation followed by hydrophobic interactions with the membrane for antibacterial activity.

    PubMed

    Cebrián, Rubén; Martínez-Bueno, Manuel; Valdivia, Eva; Albert, Armando; Maqueda, Mercedes; Sánchez-Barrena, María José

    2015-05-01

    The molecular mechanism underlining the antibacterial activity of the bacteriocin AS-48 is not known, and two different and opposite alternatives have been proposed. Available data suggested that the interaction of positively charged amino acids of AS-48 with the membrane would produce membrane destabilization and disruption. Alternatively, it has been proposed that AS-48 activity could rely on the effective insertion of the bacteriocin into the membrane. The biological and structural properties of the AS-48G13K/L40K double mutant were investigated to shed light on this subject. Compared with the wild type, the mutant protein suffered an important reduction in the antibacterial activity. Biochemical and structural studies of AS-48G13K/L40K mutant suggest the basis of its decreased antimicrobial activity. Lipid cosedimentation assays showed that the membrane affinity of AS-48G13K/L40K is 12-fold lower than that observed for the wild type. L40K mutation is responsible for this reduced membrane affinity and thus, hydrophobic interactions are involved in membrane association. Furthermore, the high-resolution crystal structure of AS-48G13K/L40K, together with the study of its dimeric character in solution showed that G13K stabilizes the inactive water-soluble dimer, which displays a reduced dipole moment. Our data suggest that the cumulative effect of these three affected properties reduces AS-48 activity, and point out that the bactericidal effect is achieved by the electrostatically driven approach of the inactive water-soluble dimer towards the membrane, followed by the dissociation and insertion of the protein into the lipid bilayer. PMID:25816760

  18. Dissociation of the functional relevance of different pre-stimulus oscillatory activity for memory formation.

    PubMed

    Salari, Neda; Rose, Michael

    2016-01-15

    The state of a neural assembly preceding an incoming stimulus modulates the processing of that subsequently presented stimuli. For human memory formation, the role of oscillatory brain activity within different frequency ranges has been discussed but a more functional relation could not be established. In the present Experiment I, an increase of pre-stimulus theta- (3-7Hz) and beta- (13-17Hz) band oscillations during encoding for later remembered stimuli was observed. To establish a more direct functional relation, we adopted a novel brain-computer-interface (BCI) method to selectively detect oscillatory activity in real-time combined with an adaptive stimulus presentation at different levels of activity. Therefore, in the second experiment the BCI was used to present the visual stimuli with a high temporal resolution directly within defined brain states of beta- or theta-band activity. The quality of the subsequent processing of the stimuli was assessed at the behavioral level with a surprise recognition task. Results revealed a variation of memory performance in direct relation to the amount of pre-stimulus beta- but not theta-band oscillations, suggesting a functional relevance of beta-band oscillations for memory encoding. Thus, the BCI method enabled a more functional differentiation of the effective role of ongoing oscillatory activity.

  19. Dissociation of the functional relevance of different pre-stimulus oscillatory activity for memory formation.

    PubMed

    Salari, Neda; Rose, Michael

    2016-01-15

    The state of a neural assembly preceding an incoming stimulus modulates the processing of that subsequently presented stimuli. For human memory formation, the role of oscillatory brain activity within different frequency ranges has been discussed but a more functional relation could not be established. In the present Experiment I, an increase of pre-stimulus theta- (3-7Hz) and beta- (13-17Hz) band oscillations during encoding for later remembered stimuli was observed. To establish a more direct functional relation, we adopted a novel brain-computer-interface (BCI) method to selectively detect oscillatory activity in real-time combined with an adaptive stimulus presentation at different levels of activity. Therefore, in the second experiment the BCI was used to present the visual stimuli with a high temporal resolution directly within defined brain states of beta- or theta-band activity. The quality of the subsequent processing of the stimuli was assessed at the behavioral level with a surprise recognition task. Results revealed a variation of memory performance in direct relation to the amount of pre-stimulus beta- but not theta-band oscillations, suggesting a functional relevance of beta-band oscillations for memory encoding. Thus, the BCI method enabled a more functional differentiation of the effective role of ongoing oscillatory activity. PMID:26484828

  20. Modeling metal cation-phosphate interactions in nucleic acids: activated dissociation of Mg+, Al+, Cu+, and Zn+ complexes of triethyl phosphate.

    PubMed

    Ruan, Chunhai; Rodgers, M T

    2009-08-12

    Threshold collision-induced dissociation techniques are employed to determine the activation energies (AEs) and bond dissociation energies (BDEs) of metal cation-triethyl phosphate complexes, M(+)(TEP), where M(+) = Mg(+), Al(+), Cu(+), and Zn(+). Activated dissociation resulting in loss of ethene, C(2)H(4), corresponds to the primary and lowest energy pathway for all four systems examined. Sequential loss of additional C(2)H(4) molecules and loss of the intact TEP ligand is also observed at elevated energies. Theoretical calculations at the B3LYP/6-31G* level of theory are used to determine the structures, vibrational frequencies, and rotational constants of neutral TEP and the M(+)(TEP) complexes, transition states, intermediates, and products of the activated dissociation of these complexes. Theoretical AEs and BDEs are determined from single point energy calculations at the B3LYP/6-311+G(2d,2p) level using the B3LYP/6-31G* optimized geometries. The agreement between the calculated and measured AEs for elimination of C(2)H(4) is excellent for all four systems. In contrast, less satisfactory agreement between theory and experiment is found for the M(+)-TEP BDEs and may indicate limitations in the competitive model used to analyze these high energy dissociation pathways. The influence of the valence orbital occupation of the metal cation on the binding and activation propensities for elimination of ethene from TEP is examined. The binding of metal cations to TEP is compared to that of the nucleobases to assess the binding preferences of metal cations to nucleic acids.

  1. Modulation of Backbone Flexibility for Effective Dissociation of Antibacterial and Hemolytic Activity in Cyclic Peptides.

    PubMed

    Oddo, Alberto; Thomsen, Thomas T; Britt, Hannah M; Løbner-Olesen, Anders; Thulstrup, Peter W; Sanderson, John M; Hansen, Paul R

    2016-08-11

    Bacterial resistance to antibiotic therapy is on the rise and threatens to evolve into a worldwide emergency: alternative solutions to current therapies are urgently needed. Cationic amphipathic peptides are potent membrane-active agents that hold promise as the next-generation therapy for multidrug-resistant infections. The peptides' behavior upon encountering the bacterial cell wall is crucial, and much effort has been dedicated to the investigation and optimization of this amphipathicity-driven interaction. In this study we examined the interaction of a novel series of nine-membered flexible cyclic AMPs with liposomes mimicking the characteristics of bacterial membranes. Employed techniques included circular dichroism and marker release assays, as well as microbiological experiments. Our analysis was aimed at correlating ring flexibility with their antimicrobial, hemolytic, and membrane activity. By doing so, we obtained useful insights to guide the optimization of cyclic antimicrobial peptides via modulation of their backbone flexibility without loss of activity. PMID:27563396

  2. Nicardipine in the treatment of Raynaud's phenomenon. Dissociation of platelet activation from vasospasm.

    PubMed

    Wigley, F M; Wise, R A; Malamet, R; Scott, T E

    1987-03-01

    A new calcium channel blocker, nicardipine, was studied for treatment of Raynaud's phenomenon in a double-blind, placebo-controlled, crossover trial during the winter months. Clinical response was assessed by a patient-kept diary of symptoms and finger systolic pressure that was measured at room temperature and during cold challenge. In vivo platelet activation was determined by measuring plasma levels of the platelet-specific proteins, beta-thromboglobulin and platelet factor 4. When treatment with placebo was compared with treatment with nicardipine, no significant differences were found in the number of Raynaud's attacks per day, the severity of attacks, change in character in Raynaud's phenomenon, use of hands in winter months, patient assessment of medication or objective measurements of finger systolic pressure, and critical closing temperature. There was a reduction of plasma levels of beta-thromboglobulin and platelet factor 4 in the overall study group while taking nicardipine compared with that during the placebo period (mean change 5.0 +/- 2.4 ng/ml, P = 0.054, and 1.4 +/- 0.6 ng/ml, P less than 0.01, respectively). These results demonstrate that while nicardipine was not effective in reducing the episodes of Raynaud's phenomenon, it did inhibit in vivo platelet activation. These findings suggest that platelet activation is not the primary event in the pathogenesis of acute vasospasm in Raynaud's phenomenon, since reduction of platelet activation by the drug did not change the severity of vasospasm.

  3. Dissociation of SERPINE1 mRNA from the translational repressor proteins Ago2 and TIA-1 upon platelet activation.

    PubMed

    Corduan, Aurélie; Plé, Hélène; Laffont, Benoit; Wallon, Thérèse; Plante, Isabelle; Landry, Patricia; Provost, Patrick

    2015-05-01

    Platelets play an important role in haemostasis, as well as in thrombosis and coagulation processes. They harbour a wide variety of messenger RNAs (mRNAs), that can template de novo protein synthesis, and an abundant array of microRNAs, which are known to mediate mRNA translational repression through proteins of the Argonaute (Ago) family. The relationship between platelet microRNAs and proteins capable of mediating translational repression, however, remains unclear. Here, we report that half of platelet microRNAs is associated to mRNA-regulatory Ago2 protein complexes, in various proportions. Associated to these Ago2 complexes are platelet mRNAs known to support de novo protein synthesis. Reporter gene activity assays confirmed the capacity of the platelet microRNAs, found to be associated to Ago2 complexes, to regulate translation of these platelet mRNAs through their 3'UTR. Neither the microRNA repertoire nor the microRNA composition of Ago2 complexes of human platelets changed upon activation with thrombin. However, under conditions favoring de novo synthesis of Plasminogen Activator Inhibitor-1 (PAI-1) protein, we documented a rapid dissociation of the encoding platelet SERPINE1 mRNA from Ago2 protein complexes as well as from the translational repressor protein T-cell-restricted intracellular antigen-1 (TIA-1). These findings are consistent with a scenario by which lifting of the repressive effects of Ago2 and TIA-1 protein complexes, involving a rearrangement of proteinmRNA complexes rather than disassembly of Ago2microRNA complexes, would allow translation of SERPINE1 mRNA into PAI-1 in response to platelet activation. PMID:25673011

  4. Rules rule! Brain activity dissociates the representations of stimulus contingencies with varying levels of complexity.

    PubMed

    Tse, Chun-Yu; Low, Kathy A; Fabiani, Monica; Gratton, Gabriele

    2012-09-01

    The significance of stimuli is linked not only to their nature but also to the sequential structure in which they are embedded, which gives rise to contingency rules. Humans have an extraordinary ability to extract and exploit these rules, as exemplified by the role of grammar and syntax in language. To study the brain representations of contingency rules, we recorded ERPs and event-related optical signal (EROS; which uses near-infrared light to measure the optical changes associated with neuronal responses). We used sequences of high- and low-frequency tones varying according to three contingency rules, which were orthogonally manipulated and differed in processing requirements: A Single Repetition rule required only template matching, a Local Probability rule required relating a stimulus to its context, and a Global Probability rule could be derived through template matching or with reference to the global sequence context. ERP activity at 200-300 msec was related to the Single Repetition and Global Probability rules (reflecting access to representations based on template matching), whereas longer-latency activity (300-450 msec) was related to the Local Probability and Global Probability rules (reflecting access to representations incorporating contextual information). EROS responses with corresponding latencies indicated that the earlier activity involved the superior temporal gyrus, whereas later responses involved a fronto-parietal network. This suggests that the brain can simultaneously hold different models of stimulus contingencies at different levels of the information processing system according to their processing requirements, as indicated by the latency and location of the corresponding brain activity.

  5. Dissociating the past from the present in the activity of place cells.

    PubMed

    de Hoz, Livia; Wood, Emma R

    2006-01-01

    It has been proposed that declarative memories can be dependent on both an episodic and a semantic memory system. While the semantic system deals with factual information devoid of reference to its acquisition, the episodic system, characterized by mental time travel, deals with the unique past experience in which an event took place. Episodic memory is characteristically hippocampus-dependent. Place cells are recorded from the hippocampus of rodents and their firing reflects many of the key characteristics of episodic memory. For example, they encode information about "what" happens "where," as well as temporal information. However, when these features are expressed during an animal's behavior, the neuronal activity could merely be categorizing the present situation and could therefore reflect semantic memory rather than episodic memory. We propose that mental time travel is the key feature of episodic memory and that it should take a form, in the awake animal, similar to the replay of behavioral patterns of activity that has been observed in hippocampus during sleep. Using tasks designed to evoke episodic memory, one should be able to see memory reactivation of behaviorally relevant sequences of activity in the awake animal while recording from hippocampus and other cortical structures.

  6. Concentrated dispersions of equilibrium protein nanoclusters that reversibly dissociate into active monomers

    NASA Astrophysics Data System (ADS)

    Truskett, Thomas M.; Johnston, Keith; Maynard, Jennifer; Borwankar, Ameya; Miller, Maria; Wilson, Brian; Dinin, Aileen; Khan, Tarik; Kaczorowski, Kevin

    2012-02-01

    Stabilizing concentrated protein solutions is of wide interest in drug delivery. However, a major challenge is how to reliably formulate concentrated, low viscosity (i.e., syringeable) solutions of biologically active proteins. Unfortunately, proteins typically undergo irreversible aggregation at intermediate concentrations of 100-200 mg/ml. In this talk, I describe how they can effectively avoid these intermediate concentrations by reversibly assembling into nanoclusters. Nanocluster assembly is achieved by balancing short-ranged, cosolute-induced attractions with weak, longer-ranger electrostatic repulsions near the isoelectric point. Theory predicts that native proteins are stabilized by a self-crowding mechanism within the concentrated environment of the nanoclusters, while weak cluster-cluster interactions can result in colloidally-stable dispersions with moderate viscosities. I present experimental results where this strategy is used to create concentrated antibody dispersions (up to 260 mg/ml) comprising nanoclusters of proteins [monoclonal antibody 1B7, polyclonal sheep Immunoglobin G and bovine serum albumin], which upon dilution in vitro or administration in vivo, are conformationally stable and retain activity.

  7. Dissociation of membrane binding and lytic activities of the lymphocyte pore-forming protein (perforin).

    PubMed

    Young, J D; Damiano, A; DiNome, M A; Leong, L G; Cohn, Z A

    1987-05-01

    Granules isolated from CTL and NK cells contain a cytolytic pore-forming protein (PFP/perforin). At low temperatures (on ice), PFP binds to erythrocyte membranes without producing hemolysis. Hemolysis occurs when the PFP-bound erythrocytes are warmed up to 37 degrees C, which defines a temperature-dependent, lytic (pore-formation) step distinct from the membrane-binding event. Ca2+ and neutral pH are required for both membrane binding and pore formation by PFP. Serum, LDL, HDL, and heparin inhibit the hemolytic activity of PFP by blocking its binding to lipid membranes. Lysis by PFP that has bound to erythrocyte membranes is no longer susceptible to the effect of these inhibitors. The hemolytic activities associated with intact granules and solubilized PFP show different requirements for Ca2+ and pH, indicating that cytolysis produced by isolated granules may involve an additional step, possibly fusion of granules with membranes. It is suggested that three distinct Ca2+- and pH-dependent events may be involved during cell killing by CTL and NK cells: fusion of cytoplasmic granules of effector cells with their plasma membrane, releasing PFP from cells; binding of the released PFP to target membranes; and insertion of monomers and the subsequent formation of lytic pores in the target membrane. The serum-mediated inhibition of membrane binding by PFP could prevent the accidental injury of bystander cells by cell-released PFP, but would allow cytolysis to proceed to completion once PFP has bound to the target membrane. PMID:3494808

  8. Dissociation and regeneration kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers

    SciTech Connect

    Vesnov, I G

    2010-06-23

    An improved mathematical model describing the dissociation and regenerations kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers is presented. It is shown that the calculation of the active medium composition of such lasers requires the equations of the gas-mixture kinetics to take into account the diffuse flow of oxygen atoms on metal electrodes and on the surface of heterogeneous catalysts used to reduce the degree of the carbon dioxide dissociation. The rate constants of the heterogeneous recombination reaction CO + O {yields} CO{sub 2} on the surface of alumina ceramics and Al{sub 2}O{sub 3} are determined. (active media)

  9. Dissociation between mental fatigue and motivational state during prolonged mental activity.

    PubMed

    Gergelyfi, Mónika; Jacob, Benvenuto; Olivier, Etienne; Zénon, Alexandre

    2015-01-01

    Mental fatigue (MF) is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement. Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, Skin conductance responses (SCRs), questionnaires and performance in a working memory (WM) task) in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 min. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants' subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability (HRV) increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources. PMID:26217203

  10. Dissociation between mental fatigue and motivational state during prolonged mental activity

    PubMed Central

    Gergelyfi, Mónika; Jacob, Benvenuto; Olivier, Etienne; Zénon, Alexandre

    2015-01-01

    Mental fatigue (MF) is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement. Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, Skin conductance responses (SCRs), questionnaires and performance in a working memory (WM) task) in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 min. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants’ subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability (HRV) increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources. PMID:26217203

  11. Dissociation of Increases in PGC-1α and Its Regulators from Exercise Intensity and Muscle Activation Following Acute Exercise

    PubMed Central

    Hankinson, Paul B.; Simpson, Craig A.; Little, Jonathan P.; Graham, Ryan B.; Gurd, Brendon J.

    2013-01-01

    Muscle activation as well as changes in peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) following high-intensity interval exercise (HIIE) were examined in young healthy men (n  = 8; age, 21.9±2.2 yrs; VO2peak, 53.1±6.4 ml/min/kg; peak work rate, 317±23.5 watts). On each of 3 visits HIIE was performed on a cycle ergometer at a target intensity of 73, 100, or 133% of peak work rate. Muscle biopsies were taken at rest and three hours after each exercise condition. Total work was not different between conditions (∼730 kJ) while average power output (73%, 237±21; 100%, 323±26; 133%, 384±35 watts) and EMG derived muscle activation (73%, 1262±605; 100%, 2089±737; 133%, 3029±1206 total integrated EMG per interval) increased in an intensity dependent fashion. PGC-1α mRNA was elevated after all three conditions (p<0.05), with a greater increase observed following the 100% condition (∼9 fold, p<0.05) compared to both the 73 and 133% conditions (∼4 fold). When expressed relative to muscle activation, the increase in PGC-1α mRNA for the 133% condition was less than that for the 73 and 100% conditions (p<0.05). SIRT1 mRNA was also elevated after all three conditions (∼1.4 fold, p<0.05), with no difference between conditions. These findings suggest that intensity-dependent increases in PGC-1α mRNA following submaximal exercise are largely due to increases in muscle recruitment. As well, the blunted response of PGC-1α mRNA expression following supramaximal exercise may indicate that signalling mediated activation of PGC-1α may also be blunted. We also indentify that increases in PDK4, SIRT1, and RIP140 mRNA following acute exercise are dissociated from exercise intensity and muscle activation, while increases in EGR1 are augmented with supramaximal HIIE (p<0.05). PMID:23951207

  12. CAD systems simplify engineering drawings

    SciTech Connect

    Holt, J.

    1986-10-01

    Computer assisted drafting systems, with today's technology, provide high-quality, timely drawings that can be justified by the lower costs for the final product. The author describes Exxon Pipeline Co.'s experience in deciding on hardware and software for a CAD system installation and the benefits effected by this procedure and equipment.

  13. CAD Skills Increased through Multicultural Design Project

    ERIC Educational Resources Information Center

    Clemons, Stephanie

    2006-01-01

    This article discusses how students in a college-entry-level CAD course researched four generations of their family histories and documented cultural and symbolic influences within their family backgrounds. AutoCAD software was then used to manipulate those cultural and symbolic images to create the design for a multicultural area rug. AutoCAD was…

  14. Cool-and Unusual-CAD Applications

    ERIC Educational Resources Information Center

    Calhoun, Ken

    2004-01-01

    This article describes several very useful applications of AutoCAD that may lie outside the normal scope of application. AutoCAD commands used in this article are based on AutoCAD 2000I. The author and his students used a Hewlett Packard 750C DesignJet plotter for plotting. (Contains 5 figures and 5 photos.)

  15. Dissociative phenomenology of dissociative identity disorder.

    PubMed

    Dell, Paul F

    2002-01-01

    The goal of this study was to investigate the dissociative phenomenology of dissociative identity disorder (DID). The Multidimensional Inventory of Dissociation (MID) was administered to 34 patients with DID, 23 patients with dissociative disorder not otherwise specified (DDNOS), 52 patients with mixed psychiatric disorders, and 58 normal individuals. DID patients obtained significantly higher scores than the other three groups on 27 dissociation-related variables. DDNOS patients had significantly higher scores than normals and mixed psychiatric patients on 17 and 15 dissociation-related variables, respectively. The findings of the present study are virtually identical to a large body of replicated findings about the dissociative phenomenology of DID. This broad range of dissociation-related phenomena, which routinely occurs in individuals with DID, is largely absent from the DSM-IV-TR account of DID. Factor analysis of the 11 dimensions of dissociation that are measured by the MID extracted only one factor that accounted for 85% of the variance. It was concluded that dissociation is a unifactorial taxon or natural type that has different aspects or epiphenomena (i.e., amnesia, depersonalization, voices, trance, etc.).

  16. On the calculation of complete dissociation curves of closed-shell pseudo-onedimensional systems via the complete active space method of increments

    SciTech Connect

    Fertitta, E.; Paulus, B.; Barcza, G.; Legeza, Ö.

    2015-09-21

    The method of increments (MoI) has been employed using the complete active space formalism in order to calculate the dissociation curve of beryllium ring-shaped clusters Be{sub n} of different sizes. Benchmarks obtained through different quantum chemical methods including the ab initio density matrix renormalization group were used to verify the validity of the MoI truncation which showed a reliable behavior for the whole dissociation curve. Moreover we investigated the size dependence of the correlation energy at different interatomic distances in order to extrapolate the values for the periodic chain and to discuss the transition from a metal-like to an insulator-like behavior of the wave function through quantum chemical considerations.

  17. On the calculation of complete dissociation curves of closed-shell pseudo-onedimensional systems via the complete active space method of increments.

    PubMed

    Fertitta, E; Paulus, B; Barcza, G; Legeza, Ö

    2015-09-21

    The method of increments (MoI) has been employed using the complete active space formalism in order to calculate the dissociation curve of beryllium ring-shaped clusters Be(n) of different sizes. Benchmarks obtained through different quantum chemical methods including the ab initio density matrix renormalization group were used to verify the validity of the MoI truncation which showed a reliable behavior for the whole dissociation curve. Moreover we investigated the size dependence of the correlation energy at different interatomic distances in order to extrapolate the values for the periodic chain and to discuss the transition from a metal-like to an insulator-like behavior of the wave function through quantum chemical considerations. PMID:26395688

  18. Dissociative disorders in DSM-5.

    PubMed

    Spiegel, David; Lewis-Fernández, Roberto; Lanius, Ruth; Vermetten, Eric; Simeon, Daphne; Friedman, Matthew

    2013-01-01

    The rationale, research literature, and proposed changes to the dissociative disorders and conversion disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are presented. Dissociative identity disorder will include reference to possession as well as identity fragmentation, to make the disorder more applicable to culturally diverse situations. Dissociative amnesia will include dissociative fugue as a subtype, since fugue is a rare disorder that always involves amnesia but does not always include confused wandering or loss of personality identity. Depersonalization disorder will include derealization as well, since the two often co-occur. A dissociative subtype of posttraumatic stress disorder (PTSD), defined by the presence of depersonalization or derealization in addition to other PTSD symptoms, is being recommended, based upon new epidemiological and neuroimaging evidence linking it to an early life history of adversity and a combination of frontal activation and limbic inhibition. Conversion disorder (functional neurological symptom disorder) will likely remain with the somatic symptom disorders, despite considerable dissociative comorbidity. PMID:23394228

  19. Dissociative disorders in DSM-5.

    PubMed

    Spiegel, David; Lewis-Fernández, Roberto; Lanius, Ruth; Vermetten, Eric; Simeon, Daphne; Friedman, Matthew

    2013-01-01

    The rationale, research literature, and proposed changes to the dissociative disorders and conversion disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are presented. Dissociative identity disorder will include reference to possession as well as identity fragmentation, to make the disorder more applicable to culturally diverse situations. Dissociative amnesia will include dissociative fugue as a subtype, since fugue is a rare disorder that always involves amnesia but does not always include confused wandering or loss of personality identity. Depersonalization disorder will include derealization as well, since the two often co-occur. A dissociative subtype of posttraumatic stress disorder (PTSD), defined by the presence of depersonalization or derealization in addition to other PTSD symptoms, is being recommended, based upon new epidemiological and neuroimaging evidence linking it to an early life history of adversity and a combination of frontal activation and limbic inhibition. Conversion disorder (functional neurological symptom disorder) will likely remain with the somatic symptom disorders, despite considerable dissociative comorbidity.

  20. Thermodynamic Constraints in Using AuM (M = Fe, Co, Ni, and Mo) Alloys as N₂ Dissociation Catalysts: Functionalizing a Plasmon-Active Metal.

    PubMed

    Martirez, John Mark P; Carter, Emily A

    2016-02-23

    The Haber-Bosch process for NH3 synthesis is arguably one of the greatest inventions of the 20th century, with a massive footprint in agriculture and, historically, warfare. Current catalysts for this reaction use Fe for N2 activation, conducted at high temperatures and pressures to improve conversion rate and efficiency. A recent finding shows that plasmonic metal nanoparticles can either generate highly reactive electrons and holes or induce resonant surface excitations through plasmonic decay, which catalyze dissociation and redox reactions under mild conditions. It is therefore appealing to consider AuM (M = Fe, Co, Ni, and Mo) alloys to combine the strongly plasmonic nature of Au and the catalytic nature of M metals toward N2 dissociation, which together might facilitate ammonia production. To this end, through density functional theory, we (i) explore the feasibility of forming these surface alloys, (ii) find a pathway that may stabilize/deactivate surface M substituents during fabrication, and (iii) define a complementary route to reactivate them under operational conditions. Finally, we evaluate their reactivity toward N2, as well as their ability to support a pathway for N2 dissociation with a low thermodynamic barrier. We find that AuFe possesses similar appealing qualities, including relative stability with respect to phase separation, reversibility of Fe oxidation and reduction, and reactivity toward N2. While AuMo achieves the best affinity toward N2, its strong propensity toward oxidation could greatly limit its use.

  1. Thermodynamic Constraints in Using AuM (M = Fe, Co, Ni, and Mo) Alloys as N₂ Dissociation Catalysts: Functionalizing a Plasmon-Active Metal.

    PubMed

    Martirez, John Mark P; Carter, Emily A

    2016-02-23

    The Haber-Bosch process for NH3 synthesis is arguably one of the greatest inventions of the 20th century, with a massive footprint in agriculture and, historically, warfare. Current catalysts for this reaction use Fe for N2 activation, conducted at high temperatures and pressures to improve conversion rate and efficiency. A recent finding shows that plasmonic metal nanoparticles can either generate highly reactive electrons and holes or induce resonant surface excitations through plasmonic decay, which catalyze dissociation and redox reactions under mild conditions. It is therefore appealing to consider AuM (M = Fe, Co, Ni, and Mo) alloys to combine the strongly plasmonic nature of Au and the catalytic nature of M metals toward N2 dissociation, which together might facilitate ammonia production. To this end, through density functional theory, we (i) explore the feasibility of forming these surface alloys, (ii) find a pathway that may stabilize/deactivate surface M substituents during fabrication, and (iii) define a complementary route to reactivate them under operational conditions. Finally, we evaluate their reactivity toward N2, as well as their ability to support a pathway for N2 dissociation with a low thermodynamic barrier. We find that AuFe possesses similar appealing qualities, including relative stability with respect to phase separation, reversibility of Fe oxidation and reduction, and reactivity toward N2. While AuMo achieves the best affinity toward N2, its strong propensity toward oxidation could greatly limit its use. PMID:26831377

  2. Dissociation from DNA of Type III Restriction-Modification enzymes during helicase-dependent motion and following endonuclease activity.

    PubMed

    Tóth, Júlia; van Aelst, Kara; Salmons, Hannah; Szczelkun, Mark D

    2012-08-01

    DNA cleavage by the Type III Restriction-Modification (RM) enzymes requires the binding of a pair of RM enzymes at two distant, inversely orientated recognition sequences followed by helicase-catalysed ATP hydrolysis and long-range communication. Here we addressed the dissociation from DNA of these enzymes at two stages: during long-range communication and following DNA cleavage. First, we demonstrated that a communicating species can be trapped in a DNA domain without a recognition site, with a non-specific DNA association lifetime of ∼ 200 s. If free DNA ends were present the lifetime became too short to measure, confirming that ends accelerate dissociation. Secondly, we observed that Type III RM enzymes can dissociate upon DNA cleavage and go on to cleave further DNA molecules (they can 'turnover', albeit inefficiently). The relationship between the observed cleavage rate and enzyme concentration indicated independent binding of each site and a requirement for simultaneous interaction of at least two enzymes per DNA to achieve cleavage. In light of various mechanisms for helicase-driven motion on DNA, we suggest these results are most consistent with a thermally driven random 1D search model (i.e. 'DNA sliding').

  3. The role of rotational excitation in the activated dissociative chemisorption of vibrationally excited methane on Ni(100).

    PubMed

    Juurlink, L B; Smith, R R; Utz, A L

    2000-01-01

    We have measured the sticking probability of methane excited to v = 1 of the v3 antisymmetric C-H stretching vibration on a clean Ni(100) surface as a function of rotational state (J = 0, 1, 2 and 3) and have investigated the effect of Coriolis-mixing on reactivity. The data span a wide range of kinetic energies (9-49 kJ mol-1) and indicate that rotational excitation does not alter reactivity by more than a factor of two, even at low molecular speeds that allow for considerable rotation of the molecule during the interaction with the surface. In addition, rotation-induced Coriolis-splitting of the v3 mode into F+, F0 and F- states does not significantly affect the reactivity for J = 1 at 49 kJ mol-1 translational energy, even though the nuclear motions of these states differ. The lack of a pronounced rotational energy effect in methane dissociation on Ni(100) suggests that our previous results for (v = 1, v3, J = 2) are representative of all rovibrational sublevels of this vibrational mode. These experiments shed light on the relative importance of rotational hindering and dynamical steering mechanisms in the dissociative chemisorption on Ni(100) and guide future attempts to accurately model methane dissociation on nickel surfaces.

  4. Introduction to CAD/Computers. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Lockerby, Hugh

    This learning module for an eighth-grade introductory technology course is designed to help teachers introduce students to computer-assisted design (CAD) in a communications unit on graphics. The module contains a module objective and five specific objectives, a content outline, suggested instructor methodology, student activities, a list of six…

  5. Dissociated Vertical Deviation

    MedlinePlus

    ... Eye Terms Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Dissociated Vertical Deviation En Español Read in Chinese What is Dissociated Vertical Deviation (DVD)? DVD is ...

  6. Viewing CAD Drawings on the Internet

    ERIC Educational Resources Information Center

    Schwendau, Mark

    2004-01-01

    Computer aided design (CAD) has been producing 3-D models for years. AutoCAD software is frequently used to create sophisticated 3-D models. These CAD files can be exported as 3DS files for import into Autodesk's 3-D Studio Viz. In this program, the user can render and modify the 3-D model before exporting it out as a WRL (world file hyperlinked)…

  7. Computing Mass Properties From AutoCAD

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1990-01-01

    Mass properties of structures computed from data in drawings. AutoCAD to Mass Properties (ACTOMP) computer program developed to facilitate quick calculations of mass properties of structures containing many simple elements in such complex configurations as trusses or sheet-metal containers. Mathematically modeled in AutoCAD or compatible computer-aided design (CAD) system in minutes by use of three-dimensional elements. Written in Microsoft Quick-Basic (Version 2.0).

  8. Effects of low glucose on carotid body chemoreceptor cell activity studied in cultures of intact organs and in dissociated cells.

    PubMed

    Gallego-Martin, Teresa; Fernandez-Martinez, Silvia; Rigual, Ricardo; Obeso, Ana; Gonzalez, Constancio

    2012-04-15

    The participation of the carotid body (CB) in glucose homeostasis and evidence obtained in simplified cultured CB slices or dissociated cells have led to the proposal that CB chemoreceptor cells are glucoreceptors. However, data generated in intact, freshly excised organs deny CB chemoreceptor cells' glucosensing properties. The physiological significance of the contention has prompted the present study, performed in a newly developed preparation of the intact CB organ in culture that maintains chemoreceptor cells' microenvironment. Chemoreceptor cells of intact CBs in culture retained their capacity to store, synthesize, and secrete catecholamine in response to hypoxia for at least 6 days. Aglycemia did not elicit neurosecretion in dissociated chemoreceptor cells or in intact CB in culture, but potentiated hypoxia-elicited neurosecretion, exclusively, in 1-day-old intact CB cultures and dissociated chemoreceptor cells cultured for 24 h. In fura 2-loaded cells, aglycemia (but not 1 mM) caused a slow Ca(2+)-dependent and nifedipine-insensitive increase in fluorescence at 340- to 380-nm wavelength emission ratio and augmented the fluorescent signal elicited by hypoxia. Association of nifedipine and KBR7943 (a Na(+)/Ca(2+) exchanger inhibitor) completely abolished the aglycemic Ca(2+) response. We conclude that chemoreceptor cells are not sensitive to hypoglycemia. We hypothesize that cultured chemoreceptor cells become transiently more dependent on glycolysis. Consequently, aglycemia would partially inhibit the Na(+)/K(+) pump, causing an increase in intracellular Na(+) concentration, and a reversal of Na(+)/Ca(2+) exchanger. This would slowly increase intracellular Ca(2+) concentration and cause the potentiation of the hypoxic responses. We discuss the nature of the signals detected by chemoreceptor cells for the CB to achieve its glycemic homeostatic role.

  9. PM6 study of free radical scavenging mechanisms of flavonoids: why does O-H bond dissociation enthalpy effectively represent free radical scavenging activity?

    PubMed

    Amić, Dragan; Stepanić, Višnja; Lučić, Bono; Marković, Zoran; Dimitrić Marković, Jasmina M

    2013-06-01

    It is well known that the bond dissociation enthalpy (BDE) of the O-H group is related to the hydrogen atom transfer (HAT) mechanism of free radical scavenging that is preferred in gas-phase and non-polar solvents. The present work shows that the BDE may also be related to radical scavenging processes taking place in polar solvents, i.e., single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET). This is so because the total energy requirements related to the SET-PT [sum of the ionization potential (IP) and proton dissociation enthalpy (PDE)] and the SPLET [sum of the proton affinity (PA) and electron transfer enthalpy (ETE)] are perfectly correlated with the BDE. This could explain why the published data for polyphenolic antioxidant activity measured by various assays are better correlated with the BDE than with other reaction enthalpies involved in radical scavenging mechanisms, i.e., the IP, PDE, PA and ETE. The BDE is fairly well able to rank flavonoids as antioxidants in any medium, but to conclude which radical scavenging mechanism represents the most probable reaction pathway from the thermodynamic point of view, the IP and PA (ETE) should also be considered. This is exemplified in the case of the radical scavenging activity of 25 flavonoids.

  10. Identification of c-Type Heme-Containing Peptides Using Non-Activated Immobilized Metal Affinity Cchromatography Resin Enrichment and Higher-Energy Collisional Dissociation

    SciTech Connect

    Zhang, Haizhen; Yang, Feng; Qian, Weijun; Brown, Roslyn N.; Wang, Yuexi; Merkley, Eric D.; Park, Jea H.; Monroe, Matthew E.; Purvine, Samuel O.; Moore, Ronald J.; Shi, Liang; Fredrickson, Jim K.; Pasa-Tolic, Ljiljana; Smith, Richard D.; Lipton, Mary S.

    2011-10-01

    c-type cytochromes play essential roles in many biological activities of both prokaryotic and eukaryotic cells, including electron transfer, enzyme catalysis and induction of apoptosis. We report a novel enrichment strategy for identifying c-type heme-containing peptides that uses non-activated IMAC resin. The strategy demonstrated at least seven-fold enrichment for heme-containing peptides digested from a cytochrome c protein standard, and quantitative linear performance was also assessed for heme-containing peptide enrichment. Heme-containing peptides extracted from the periplasmic fraction of Shewanella oneidensis MR-1 were further identified using higher-energy collisional dissociation tandem mass spectrometry. The results demonstrated the applicability of this enrichment strategy to identify c-type heme-containing peptides from a highly complex biological sample, and at the same time, confirmed the periplasmic localization of heme-containing proteins during suboxic respiration activities of S. oneidensis MR-1.

  11. Topology, Dimerization, and Stability of the Single-Span Membrane Protein CadC

    PubMed Central

    Lindner, Eric; White, Stephen H.

    2014-01-01

    Under acid stress, Escherichia coli induce expression of CadA (lysine decarboxylase) and CadB (lysine/cadaverine antiporter) in a lysine-rich environment. The ToxR-like transcriptional activator CadC controls expression of the cadBA operon. Using a novel Signal Peptidase I (SPase I) cleavage assay, we show that CadC is a Type II single-span membrane protein (MP) with a cytoplasmic DNA binding domain and a periplasmic sensor domain. We further show that, as long assumed, dimerization of the sensor domain is required for activating the cadBA operon. We prove this using a chimera in which the periplasmic domain of RodZ—a Type II MP involved in the maintenance of the rod shape of E. coli—replaces the CadC sensor domain. Because the RodZ periplasmic domain cannot dimerize, the chimera cannot activate the operon. However, replacement of the TM domain of the chimera with the glycophorin-A (GpA) TM domain causes intramembrane dimerization and consequently operon activation. Using a low-expression protocol that eliminates extraneous TM-helix dimerization signals arising from protein over-expression, we enhanced dramatically the dynamic range of the β-galactosidase assay for cadBA activation. Consequently, the strength of the intramembrane dimerization of the GpA domain could be compared quantitatively with the strength of the much stronger periplasmic dimerization of CadC. For the signal-peptidase assay, we inserted a SPase I cleavage site (AAA or AQA) at the periplasmic end of the TM helix. Cleavage occured with high efficiency for all TM and periplasmic domains tested, thus eliminating the need for the cumbersome spheroplast-proteinase K method for topology determinations. PMID:24946151

  12. The role of proton mobility in determining the energy-resolved vibrational activation/dissociation channels of N-glycopeptide ions.

    PubMed

    Kolli, Venkata; Roth, Heidi A; De La Cruz, Gabriela; Fernando, Ganga S; Dodds, Eric D

    2015-10-01

    Site-specific glycoproteomic analysis largely hinges on the use of tandem mass spectrometry (MS/MS) to identify glycopeptides. Experiments of this type are usually aimed at drawing connections between individual oligosaccharide structures and their specific sites of attachment to the polypeptide chain. These determinations inherently require ion dissociation methods capable of interrogating both the monosaccharide and amino acid connectivity of the glycopeptide. Collision-induced dissociation (CID) shows potential to satisfy this requirement, as the vibrational activation/dissociation of protonated N-glycopeptides has been observed to access cleavage of either glycosidic bonds of the glycan or amide bonds of the peptide in an energy-resolved manner. Nevertheless, the relative energy requirement for these fragmentation pathways varies considerably among analytes. This research addresses the influence of proton mobility on the vibrational energy necessary to achieve either glycan or peptide cleavage in a collection of protonated N-glycopeptide ions. While greater proton mobility of the precursor ion was found to correlate with lower energy requirements for precursor ion depletion and appearance of glycosidic fragments, the vibrational energy deposition necessary for appearance of peptide backbone fragments showed no relation to the precursor ion proton mobility. These results are consistent with observations suggesting that peptide fragments arise from an intermediate fragment which is generally of lower proton mobility than the precursor ion. Such findings have potential to facilitate the rational selection of CID conditions which are best suited to provide either glycan or peptide cleavage products in MS/MS based N-glycoproteomic analysis.

  13. The Challenging Academic Development (CAD) Collective

    ERIC Educational Resources Information Center

    Peseta, Tai

    2005-01-01

    This article discusses the Challenging Academic Development (CAD) Collective and describes how it came out of a symposium called "Liminality, identity, and hybridity: On the promise of new conceptual frameworks for theorising academic/faculty development." The CAD Collective is and represents a space where people can open up their contexts and…

  14. CAD programs: a tool for crime scene processing and reconstruction

    NASA Astrophysics Data System (ADS)

    Boggiano, Daniel; De Forest, Peter R.; Sheehan, Francis X.

    1997-02-01

    Computer aided drafting (CAD) programs have great potential for helping the forensic scientist. One of their most direct and useful applications is crime scene documentation, as an aid in rendering neat, unambiguous line drawings of crime scenes. Once the data has been entered, it can easily be displayed, printed, or plotted in a variety of formats. Final renditions from this initial data entry can take multiple forms and can have multiple uses. As a demonstrative aid, a CAD program can produce two dimensional (2-D) drawings of the scene from one's notes to scale. These 2-D renditions are court display quality and help to make the forensic scientists's testimony easily understood. Another use for CAD is as an analytical tool for scene reconstruction. More than just a drawing aid, CAD can generate useful information from the data input. It can help reconstruct bullet paths or locations of furniture in a room when it is critical to the reconstruction. Data entry at the scene, on a notebook computer, can assist in framing and answering questions so that the forensic scientist can test hypotheses while actively documenting the scene. Further, three dimensional (3-D) renditions of items can be viewed from many 'locations' by using the program to rotate the object and the observers' viewpoint.

  15. Role of Bound Zn(II) in the CadC Cd(II)/Pb(II)/Zn(II)-Responsive Repressor

    SciTech Connect

    Kandegedara, A.; Thiyagarajan, S; Kondapalli, K; Stemmler, T; Rosen, B

    2009-01-01

    The Staphylococcus aureus plasmid pI258 cadCA operon encodes a P-type ATPase, CadA, that confers resistance to Cd(II)/Pb(II)/Zn(II). Expression is regulated by CadC, a homodimeric repressor that dissociates from the cad operator/promoter upon binding of Cd(II), Pb(II), or Zn(II). CadC is a member of the ArsR/SmtB family of metalloregulatory proteins. The crystal structure of CadC shows two types of metal binding sites, termed Site 1 and Site 2, and the homodimer has two of each. Site 1 is the physiological inducer binding site. The two Site 2 metal binding sites are formed at the dimerization interface. Site 2 is not regulatory in CadC but is regulatory in the homologue SmtB. Here the role of each site was investigated by mutagenesis. Both sites bind either Cd(II) or Zn(II). However, Site 1 has higher affinity for Cd(II) over Zn(II), and Site 2 prefers Zn(II) over Cd(II). Site 2 is not required for either derepression or dimerization. The crystal structure of the wild type with bound Zn(II) and of a mutant lacking Site 2 was compared with the SmtB structure with and without bound Zn(II). We propose that an arginine residue allows for Zn(II) regulation in SmtB and, conversely, a glycine results in a lack of regulation by Zn(II) in CadC. We propose that a glycine residue was ancestral whether the repressor binds Zn(II) at a Site 2 like CadC or has no Site 2 like the paralogous ArsR and implies that acquisition of regulatory ability in SmtB was a more recent evolutionary event.

  16. Informatics infrastructure of CAD system.

    PubMed

    Pietka, Ewa; Gertych, Arkadiusz; Witko, Krzysztof

    2005-01-01

    A computer aided diagnosis (CAD) system requires several components which influence its effectiveness. An image processing methodology is responsible for the analysis, database structure archives and distributes the patient demographics, clinical information, and image data. A graphical user interface is applied in order to enter the data and present it to the user. By designing dynamic Web pages a remote access to the entire is granted. The computer aided diagnosis system includes three layers, which might be installed on various platforms. Elements of the application software are designed independently. Integration of all components is another issue discussed in the presented paper. Implementation of a computer aided diagnosis system improves and accelerates the analysis by giving to the user objective measurement tools. It also standardizes the decision-making process and solves the problem of replicability. Finally, it permits a set of images and features to be collected and recognized as a medical standard and be applied in education and research. PMID:15755535

  17. Enhancement of Ion Activation and Collision-Induced Dissociation by Simultaneous Dipolar Excitation of Ions in x- and y-Directions in a Linear Ion Trap.

    PubMed

    Dang, Qiankun; Xu, Fuxing; Xie, Xiaodong; Xu, Chongsheng; Dai, Xinhua; Fang, Xiang; Ding, Li; Ding, Chuan-Fan

    2015-06-01

    Collision-induced dissociation (CID) in linear ion traps is usually performed by applying a dipolar alternating current (AC) signal to one pair of electrodes, which results in ion excitation mainly in one direction. In this paper, we report simulation and experimental studies of the ion excitation in two coordinate directions by applying identical dipolar AC signals to two pairs of electrodes simultaneously. Theoretical analysis and simulation results demonstrate that the ion kinetic energy is higher than that using the conventional CID method. Experimental results show that more activation energy (as determined by the intensity ratio of the a4/b4 fragments from the CID of protonated leucine enkephalin) can be deposited into parent ions in this method. The dissociation rate constant in this method was about 3.8 times higher than that in the conventional method under the same experimental condition, at the Mathieu parameter qu (where u = x, y) value of 0.25. The ion fragmentation efficiency is also significantly improved. Compared with the conventional method, the smaller qu value can be used in this method to obtain the same internal energy deposited into ions. Consequently, the "low mass cut-off" is redeemed and more fragment ions can be detected. This excitation method can be implemented easily without changing any experimental parameters.

  18. Flexible Concurrency Control for Legacy CAD to Construct Collaborative CAD Environment

    NASA Astrophysics Data System (ADS)

    Cai, Xiantao; Li, Xiaoxia; He, Fazhi; Han, Soonhung; Chen, Xiao

    Collaborative CAD (Co-CAD) systems can be constructed based on either 3D kernel or legacy stand-alone CAD systems, which are typically commercial CAD systems such as CATIA, Pro/E and so on. Most of synchronous Co-CAD systems, especially these based on legacy stand-alone CAD systems, adopt the lock mechanism or the floor control as concurrency controls which are very restrictive and stagnant. A flexible concurrency control method is proposed to support the flexible concurrency control in Co-CAD systems based on legacy stand-alone CAD systems. At first, a model of operation relationship is proposed with special consideration for the concurrency control of these kinds of Co-CAD system. Then two types of data structure, the Collaborative Feature Dependent Graph (Co-FDG) and the Collaborative Feature Operational List (Co-FOL), are presented as the cornerstone of flexible concurrency control. Next a Flexible Concurrency Control Algorithm (FCCA) is proposed. Finally a Selective Undo/Redo Algorithm is proposed which can improve the flexibility of Co-CAD furthermore.

  19. Activation and dissociation of CO2 on the (001), (011), and (111) surfaces of mackinawite (FeS): A dispersion-corrected DFT study.

    PubMed

    Dzade, N Y; Roldan, A; de Leeuw, N H

    2015-09-01

    Iron sulfide minerals, including mackinawite (FeS), are relevant in origin of life theories, due to their potential catalytic activity towards the reduction and conversion of carbon dioxide (CO2) to organic molecules, which may be applicable to the production of liquid fuels and commodity chemicals. However, the fundamental understanding of CO2 adsorption, activation, and dissociation on FeS surfaces remains incomplete. Here, we have used density functional theory calculations, corrected for long-range dispersion interactions (DFT-D2), to explore various adsorption sites and configurations for CO2 on the low-index mackinawite (001), (110), and (111) surfaces. We found that the CO2 molecule physisorbs weakly on the energetically most stable (001) surface but adsorbs relatively strongly on the (011) and (111) FeS surfaces, preferentially at Fe sites. The adsorption of the CO2 on the (011) and (111) surfaces is shown to be characterized by significant charge transfer from surface Fe species to the CO2 molecule, which causes a large structural transformation in the molecule (i.e., forming a negatively charged bent CO2 (-δ) species, with weaker C-O confirmed via vibrational frequency analyses). We have also analyzed the pathways for CO2 reduction to CO and O on the mackinawite (011) and (111) surfaces. CO2 dissociation is calculated to be slightly endothermic relative to the associatively adsorbed states, with relatively large activation energy barriers of 1.25 eV and 0.72 eV on the (011) and (111) surfaces, respectively.

  20. Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

    NASA Astrophysics Data System (ADS)

    Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

    2015-02-01

    The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation-deprotonation behavior was determined by continuous acid-base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m2/g and large numbers of surface hydroxyl functional groups (i.e. tbnd Si-OH, tbnd Fe-OH, and tbnd Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K1, log K2) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation-deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.

  1. Advances in noninvasive detection of CAD

    SciTech Connect

    Kahn, J.K. )

    1991-04-01

    Advances in the noninvasive detection of myocardial ischemia are increasing our ability to diagnose coronary artery disease (CAD). Tomographic (SPECT) thallium imaging provides better identification of coronary arteries with atherosclerotic narrowing. Increased lung thallium uptake and transient ischemic dilatation of the heart are additional markers of severe CAD. Late thallium imaging, as well as reinjection imaging, provides more accurate identification of myocardial ischemia. Finally, new myocardial imaging agents, such as technetium Tc 99m sestamibi (Cardiolite), should improve detection of CAD by noninvasive methods.10 references.

  2. Train effectively for CAD/D

    SciTech Connect

    Not Available

    1983-04-01

    After failing with an unstructured computer-aided drafting/ design CAD/D program, Bechtel changed to a structured training program. Five considerations are presented here: teach CAD/D to engineers, not engineering to CAD/D experts; keep the program flexible enough to avoid rewriting due to fast technology evolution; pace information delivery; and rote learning of sequences only works if the students have a conceptual model first. On the job training is necessary, and better monitoring systems to test the OJT are needed. One such test is presented.

  3. Improving the radiologist-CAD interaction: designing for appropriate trust.

    PubMed

    Jorritsma, W; Cnossen, F; van Ooijen, P M A

    2015-02-01

    Computer-aided diagnosis (CAD) has great potential to improve radiologists' diagnostic performance. However, the reported performance of the radiologist-CAD team is lower than what might be expected based on the performance of the radiologist and the CAD system in isolation. This indicates that the interaction between radiologists and the CAD system is not optimal. An important factor in the interaction between humans and automated aids (such as CAD) is trust. Suboptimal performance of the human-automation team is often caused by an inappropriate level of trust in the automation. In this review, we examine the role of trust in the radiologist-CAD interaction and suggest ways to improve the output of the CAD system so that it allows radiologists to calibrate their trust in the CAD system more effectively. Observer studies of the CAD systems show that radiologists often have an inappropriate level of trust in the CAD system. They sometimes under-trust CAD, thereby reducing its potential benefits, and sometimes over-trust it, leading to diagnostic errors they would not have made without CAD. Based on the literature on trust in human-automation interaction and the results of CAD observer studies, we have identified four ways to improve the output of CAD so that it allows radiologists to form a more appropriate level of trust in CAD. Designing CAD systems for appropriate trust is important and can improve the performance of the radiologist-CAD team. Future CAD research and development should acknowledge the importance of the radiologist-CAD interaction, and specifically the role of trust therein, in order to create the perfect artificial partner for the radiologist. This review focuses on the role of trust in the radiologist-CAD interaction. The aim of the review is to encourage CAD developers to design for appropriate trust and thereby improve the performance of the radiologist-CAD team. PMID:25459198

  4. [Dissociative disorder and self-injury].

    PubMed

    Noma, Shun'ichi

    2011-01-01

    Both the number of patients with dissociative disorder and that of those with self-injury have been increasing since the end of the twentieth century, suggesting that dissociation and self-injury might be closely related. When dissociative disorder coexists with self-injury, it implies self-punishment and a wish to be understood by others. Although many cases of self-injury observed since 2000 lacked traumatic experiences and were not accompanied by pathological dissociative symptoms, the patients did have dissociative tendencies. According to the results of our study examining self-injury in patients with eating disorders, we observed that self-injury, dissociative tendency and insulation from others are related to each other. This suggests that affects, sensations and representations are dissociated, losing their normal response order, and that the pervasive idea that "pain=secure" is formed in a patient from childhood based on influence from their parents. Self-injury appears to be an activation of this pervasive idea that is triggered by a stressful situation, when the dissociative psychological segmentation of effects and their representations are present in the background.

  5. Three dimensional CAD model of the Ignitor machine

    NASA Astrophysics Data System (ADS)

    Orlandi, S.; Zanaboni, P.; Macco, A.; Sioli, V.; Risso, E.

    1998-11-01

    defind The final, global product of all the structural and thermomechanical design activities is a complete three dimensional CAD (AutoCAD and Intergraph Design Review) model of the IGNITOR machine. With this powerful tool, any interface, modification, or upgrading of the machine design is managed as an integrated part of the general effort aimed at the construction of the Ignitor facility. ind The activities that are underway, to complete the design of the core of the experiment and that will be described, concern the following: ind - the cryogenic cooling system, ind - the radial press, the center post, the mechanical supports (legs) of the entire machine, ind - the inner mechanical supports of major components such as the plasma chamber and the outer poloidal field coils.

  6. CADS:Cantera Aerosol Dynamics Simulator.

    SciTech Connect

    Moffat, Harry K.

    2007-07-01

    This manual describes a library for aerosol kinetics and transport, called CADS (Cantera Aerosol Dynamics Simulator), which employs a section-based approach for describing the particle size distributions. CADS is based upon Cantera, a set of C++ libraries and applications that handles gas phase species transport and reactions. The method uses a discontinuous Galerkin formulation to represent the particle distributions within each section and to solve for changes to the aerosol particle distributions due to condensation, coagulation, and nucleation processes. CADS conserves particles, elements, and total enthalpy up to numerical round-off error, in all of its formulations. Both 0-D time dependent and 1-D steady state applications (an opposing-flow flame application) have been developed with CADS, with the initial emphasis on developing fundamental mechanisms for soot formation within fires. This report also describes the 0-D application, TDcads, which models a time-dependent perfectly stirred reactor.

  7. The CAD-EGS Project: Using CAD Geometrics in EGS4

    SciTech Connect

    Langeveld, Willy G.J.

    2002-03-28

    The objective of the CAD-EGS project is to provide a way to use a CAD system to create 3D geometries for use within EGS4. In this report, we describe an approach based on an intermediate file, written out by the CAD system, that is read by an EGS4 user code designed for the purpose. A prototype solution was implemented using a commonly used CAD system and the Virtual Reality Modeling Language (VRML) as an intermediate file format. We report results from the prototype, and discuss various problems arising from both the approach and the particular choices made.

  8. The thermodynamics and kinetics of phosphoester bond formation, use, and dissociation in biology, with the example of polyphosphate in platelet activation, trasience, and mineralization.

    NASA Astrophysics Data System (ADS)

    Omelon, S. J.

    2014-12-01

    Mitochondria condense orthophosphates (Pi), forming phosphoester bonds for ATP production that is important to life. This represents an exchange of energy from dissociated carbohydrate bonds to phosophoester bonds. These bonds are available to phosphorylate organic compounds or hydrolyze to Pi, driving many biochemical processes. The benthic bacteria T. namibiensis 1 and Beggiatoa 2 condense Pi into phosphate polymers in oxygenated environments. These polyphosphates (polyPs) are stored until the environment becomes anoxic, when these bacteria retrieve the energy from polyP dissociation into Pi3. Dissociated Pi is released outside of the bacteria, where it precipitates as apatite.The Gibbs free energy of polyP phosphoester bond hydrolysis is negative, however, the kinetics are slow4. Diatoms contain a polyP pool that is stable until after death, after which the polyPs hydrolyze and form apatite5. The roles of polyP in eukaryotic organism biochemistry continue to be discovered. PolyPs have a range of biochemical roles, such as bioavailable P-storage, stress adaptation, and blood clotting6. PolyP-containing granules are released from anuclear platelets to activate factor V7 and factor XII in the blood clotting process due to their polyanionic charge8. Platelets have a lifespan of approximately 8 days, after which they undergo apoptosis9. Data will be presented that demonstrate the bioactive, thermodynamically unstable polyP pool within older platelets in vitro can spontaneously hydrolyze and form phosphate minerals. This process is likely avoided by platelet digestion in the spleen and liver, possibly recycling platelet polyPs with their phosphoester bond energy for other biochemical roles. 1 Schulz HN et al. Science (2005) 307: 416-4182 Brüchert V et al. Geochim Cosmochim Acta (2003) 67: 4505-45183 Goldhammer T et al. Nat Geosci (2010) 3: 557-5614 de Jager H-J et al. J Phys Chem A (1988) 102: 2838-28415 Diaz, J et al. Science (2008) 320: 652-6556 Mason KD et al

  9. AutoCAD-To-NASTRAN Translator Program

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1989-01-01

    Program facilitates creation of finite-element mathematical models from geometric entities. AutoCAD to NASTRAN translator (ACTON) computer program developed to facilitate quick generation of small finite-element mathematical models for use with NASTRAN finite-element modeling program. Reads geometric data of drawing from Data Exchange File (DXF) used in AutoCAD and other PC-based drafting programs. Written in Microsoft Quick-Basic (Version 2.0).

  10. A CAD System for Hemorrhagic Stroke.

    PubMed

    Nowinski, Wieslaw L; Qian, Guoyu; Hanley, Daniel F

    2014-09-01

    Computer-aided detection/diagnosis (CAD) is a key component of routine clinical practice, increasingly used for detection, interpretation, quantification and decision support. Despite a critical need, there is no clinically accepted CAD system for stroke yet. Here we introduce a CAD system for hemorrhagic stroke. This CAD system segments, quantifies, and displays hematoma in 2D/3D, and supports evacuation of hemorrhage by thrombolytic treatment monitoring progression and quantifying clot removal. It supports seven-step workflow: select patient, add a new study, process patient's scans, show segmentation results, plot hematoma volumes, show 3D synchronized time series hematomas, and generate report. The system architecture contains four components: library, tools, application with user interface, and hematoma segmentation algorithm. The tools include a contour editor, 3D surface modeler, 3D volume measure, histogramming, hematoma volume plot, and 3D synchronized time-series hematoma display. The CAD system has been designed and implemented in C++. It has also been employed in the CLEAR and MISTIE phase-III, multicenter clinical trials. This stroke CAD system is potentially useful in research and clinical applications, particularly for clinical trials.

  11. The dissociative bond.

    PubMed

    Gordon, Nirit

    2013-01-01

    Dissociation leaves a psychic void and a lingering sense of psychic absence. How do 2 people bond while they are both suffering from dissociation? The author explores the notion of a dissociative bond that occurs in the aftermath of trauma--a bond that holds at its core an understanding and shared detachment from the self. Such a bond is confined to unspoken terms that are established in the relational unconscious. The author proposes understanding the dissociative bond as a transitional space that may not lead to full integration of dissociated knowledge yet offers some healing. This is exemplified by R. Prince's (2009) clinical case study. A relational perspective is adopted, focusing on the intersubjective aspects of a dyadic relationship. In the dissociative bond, recognition of the need to experience mutual dissociation can accommodate a psychic state that yearns for relationship when the psyche cannot fully confront past wounds. Such a bond speaks to the need to reestablish a sense of human relatedness and connection when both parties in the relationship suffer from disconnection. This bond is bound to a silence that becomes both a means of protection against the horror of traumatic memory and a way to convey unspoken gestures toward the other.

  12. The dissociative bond.

    PubMed

    Gordon, Nirit

    2013-01-01

    Dissociation leaves a psychic void and a lingering sense of psychic absence. How do 2 people bond while they are both suffering from dissociation? The author explores the notion of a dissociative bond that occurs in the aftermath of trauma--a bond that holds at its core an understanding and shared detachment from the self. Such a bond is confined to unspoken terms that are established in the relational unconscious. The author proposes understanding the dissociative bond as a transitional space that may not lead to full integration of dissociated knowledge yet offers some healing. This is exemplified by R. Prince's (2009) clinical case study. A relational perspective is adopted, focusing on the intersubjective aspects of a dyadic relationship. In the dissociative bond, recognition of the need to experience mutual dissociation can accommodate a psychic state that yearns for relationship when the psyche cannot fully confront past wounds. Such a bond speaks to the need to reestablish a sense of human relatedness and connection when both parties in the relationship suffer from disconnection. This bond is bound to a silence that becomes both a means of protection against the horror of traumatic memory and a way to convey unspoken gestures toward the other. PMID:23282044

  13. Individual differences in skilled adult readers reveal dissociable patterns of neural activity associated with component processes of reading.

    PubMed

    Welcome, Suzanne E; Joanisse, Marc F

    2012-03-01

    We used fMRI to examine patterns of brain activity associated with component processes of visual word recognition and their relationships to individual differences in reading skill. We manipulated both the judgments adults made on written stimuli and the characteristics of the stimuli. Phonological processing led to activation in left inferior frontal and temporal regions whereas semantic processing was associated with bilateral middle frontal activation. Individual differences in reading subskills were reflected in differences in the degree to which cortical regions were engaged during reading. Variation in sight word reading efficiency was associated with degree of activation in visual cortex. Increased phonological decoding skill was associated with greater activation in left temporo-parietal cortex. Greater reading comprehension ability was associated with decreased activation in anterior cingulate and temporal regions. Notably, associations between reading ability and neural activation indicate that brain/behavior relationships among skilled readers differ from patterns associated with dyslexia and reading development.

  14. Effects of methanol on the thermodynamics of iron(III) [tetrakis(pentafluorophenyl)]porphyrin chloride dissociation and the creation of catalytically active species for the epoxidation of cyclooctene.

    PubMed

    Stephenson, Ned A; Bell, Alexis T

    2006-07-10

    In a previous study, the authors showed that iron(III) [tetrakis(pentafluorophenyl)]porphyrin chloride [(F20TPP)FeCl] is catalytically inactive for cyclooctene epoxidation by hydrogen peroxide in acetonitrile but is catalytically active if the solvent contains methanol. It was suggested that the precursor to the active species is (F20TPP)Fe(OCH3) in methanol-containing solvents. The present study was aimed at evaluating this hypothesis. (F20TPP)Fe(OCH3) was synthesized and characterized by 1H NMR but was found to be inactive in both acetonitrile and methanol. Further investigation of the interactions of (F20TPP)FeCl with methanol in acetonitrile/methanol mixtures was then carried out using NMR. Two species, characterized by 1H NMR resonances at 82 and 65 ppm, were observed. The first resonance is attributed to the beta-pyrrole protons on molecularly dissolved (F20TPP)FeCl, whereas the second is attributed to beta-pyrrole protons of [(F20TPP)Fe]+ cations that are stabilized by coordination with a molecule of methanol, viz., [(F20TPP)Fe(CH3OH)]+. The relative concentration of [(F20TPP)Fe(CH3OH)]+ increases as the fraction of methanol in the solvent increases, suggesting that methanol facilitates the dissociation of (F20TPP)FeCl into cations and anions. A thermodynamic model of the dissociation is proposed and found to describe successfully the experimental observation over a range of solvent compositions, porphyrin concentrations, and temperatures. UV-visible spectroscopy was also used to validate the developed model. In addition, the observed rate constant for cyclooctene epoxidation was found to be proportional to the concentration of [(F20TPP)Fe(CH3OH)]+ calculated using the thermodynamic model, suggesting that this intermediate is a precursor to the species that catalyzes olefin epoxidation. The catalytic activity of [(F20TPP)Fe(CH3OH)]+ was further confirmed through experiments in which (F20TPP)Fe(OCH3) dissolved in methanol was reacted with HCl(aq). This

  15. Bilinguals at the "cocktail party": dissociable neural activity in auditory-linguistic brain regions reveals neurobiological basis for nonnative listeners' speech-in-noise recognition deficits.

    PubMed

    Bidelman, Gavin M; Dexter, Lauren

    2015-04-01

    We examined a consistent deficit observed in bilinguals: poorer speech-in-noise (SIN) comprehension for their nonnative language. We recorded neuroelectric mismatch potentials in mono- and bi-lingual listeners in response to contrastive speech sounds in noise. Behaviorally, late bilinguals required ∼10dB more favorable signal-to-noise ratios to match monolinguals' SIN abilities. Source analysis of cortical activity demonstrated monotonic increase in response latency with noise in superior temporal gyrus (STG) for both groups, suggesting parallel degradation of speech representations in auditory cortex. Contrastively, we found differential speech encoding between groups within inferior frontal gyrus (IFG)-adjacent to Broca's area-where noise delays observed in nonnative listeners were offset in monolinguals. Notably, brain-behavior correspondences double dissociated between language groups: STG activation predicted bilinguals' SIN, whereas IFG activation predicted monolinguals' performance. We infer higher-order brain areas act compensatorily to enhance impoverished sensory representations but only when degraded speech recruits linguistic brain mechanisms downstream from initial auditory-sensory inputs.

  16. Psychogenic or dissociative fugue: a clinical investigation of five cases.

    PubMed

    Coons, P M

    1999-06-01

    Dissociative fugue (formerly psychogenic fugue) is a rare and little understood dissociative disorder. Following a review of the pertinent literature, five cases of dissociative fugue are described. These cases were systematically studied with a comprehensive history, mental status examination, physical and neurological evaluation, review of previous medical and psychiatric records, and psychological testing including MMPI, WAIS-R, electroencephalogram, and Dissociative Experiences Scale. An unexpected finding was that, in some cases, associated criminal activity may allow the person with dissociative fugue to continue to function in spite of their loss of memory and original identity.

  17. Carbonic anhydrase activity in primary sensory neurons. II. Influence of environmental factors on the phenotypic expression of the enzyme in dissociated cultures of chicken dorsal root ganglion cells.

    PubMed

    Barakat, I; Kazimierczak, J; Droz, B

    1986-01-01

    Neuronal subpopulations of dorsal root ganglion (DRG) cells in the chicken exhibit carbonic anhydrase (CA) activity. To determine whether CA activity is expressed by DRG cells maintained in in vitro cultures, dissociated DRG cells from 10-day-old chick embryos were cultured on a collagen substrate. The influence exerted by environmental factors on the enzyme expression was tested under various conditions of culture. Neuron-enriched cell cultures and mixed DRG-cell cultures (including numerous non-neuronal cells) were performed either in a defined medium or in a horse serum-supplemented medium. In all the tested conditions, subpopulations of cultured sensory neurons expressed CA activity in their cell bodies, while their neurites were rarely stained; in each case, the percentage of CA-positive neurons declined with the age of the cultures. The number and the persistence of neurons possessing CA activity as well as the intensity of the reaction were enhanced by addition of horse serum. In contrast, the expression of the neuronal CA activity was not affected by the presence of non-neuronal cells or by the rise of CO2 concentration. Thus, the appearance and disappearance of neuronal subpopulations expressing CA activity may be decisively influenced by factors contained in the horse serum. The loss of CA-positive neurons with time could result from a cell selection or from genetic repression. Analysis of the time curves does not support a preferential cell death of CA-positive neurons but suggests that the eventual conversion of CA-positive neurons into CA-negative neurons results from a loss of the enzyme activity. These results indicate that the phenotypic expression of cultured sensory neurons is dependent on defined environmental factors.

  18. An application protocol for CAD to CAD transfer of electronic information

    NASA Technical Reports Server (NTRS)

    Azu, Charles C., Jr.

    1993-01-01

    The exchange of Computer Aided Design (CAD) information between dissimilar CAD systems is a problem. This is especially true for transferring electronics CAD information such as multi-chip module (MCM), hybrid microcircuit assembly (HMA), and printed circuit board (PCB) designs. Currently, there exists several neutral data formats for transferring electronics CAD information. These include IGES, EDIF, and DXF formats. All these formats have limitations for use in exchanging electronic data. In an attempt to overcome these limitations, the Navy's MicroCIM program implemented a project to transfer hybrid microcircuit design information between dissimilar CAD systems. The IGES (Initial Graphics Exchange Specification) format is used since it is well established within the CAD industry. The goal of the project is to have a complete transfer of microelectronic CAD information, using IGES, without any data loss. An Application Protocol (AP) is being developed to specify how hybrid microcircuit CAD information will be represented by IGES entity constructs. The AP defines which IGES data items are appropriate for describing HMA geometry, connectivity, and processing as well as HMA material characteristics.

  19. Project CAD as of July 1978: CAD support project, situation in July 1978

    NASA Technical Reports Server (NTRS)

    Boesch, L.; Lang-Lendorff, G.; Rothenberg, R.; Stelzer, V.

    1979-01-01

    The structure of Computer Aided Design (CAD) and the requirements for program developments in past and future are described. The actual standard and the future aims of CAD programs are presented. The developed programs in: (1) civil engineering; (2) mechanical engineering; (3) chemical engineering/shipbuilding; (4) electrical engineering; and (5) general programs are discussed.

  20. Individual Differences in Skilled Adult Readers Reveal Dissociable Patterns of Neural Activity Associated with Component Processes of Reading

    ERIC Educational Resources Information Center

    Welcome, Suzanne E.; Joanisse, Marc F.

    2012-01-01

    We used fMRI to examine patterns of brain activity associated with component processes of visual word recognition and their relationships to individual differences in reading skill. We manipulated both the judgments adults made on written stimuli and the characteristics of the stimuli. Phonological processing led to activation in left inferior…

  1. Basolateral Na+/HCO3– cotransport activity is regulated by the dissociable Na+/H+ exchanger regulatory factor

    PubMed Central

    Bernardo, Angelito A.; Kear, Felicidad T.; Santos, Anna V.P.; Ma, Jianfei; Steplock, Debra; Robey, R. Brooks; Weinman, Edward J.

    1999-01-01

    In the renal proximal tubule, the activities of the basolateral Na+/HCO3– cotransporter (NBC) and the apical Na+/H+ exchanger (NHE3) uniformly vary in parallel, suggesting that they are coordinately regulated. PKA-mediated inhibition of NHE3 is mediated by a PDZ motif–containing protein, the Na+/H+ exchanger regulatory factor (NHE-RF). Given the common inhibition of these transporters after protein kinase A (PKA) activation, we sought to determine whether NHE-RF also plays a role in PKA-regulated NBC activity. Renal cortex immunoblot analysis using anti-peptide antibodies directed against rabbit NHE-RF demonstrated the presence of this regulatory factor in both brush-border membranes (BBMs) and basolateral membranes (BLMs). Using a reconstitution assay, we found that limited trypsin digestion of detergent solubilized rabbit renal BLM preparations resulted in NBC activity that was unaffected by PKA activation. Co-reconstitution of these trypsinized preparations with a recombinant protein corresponding to wild-type rabbit NHE-RF restored the inhibitory effect of PKA on NBC activity in a concentration-dependent manner. NBC activity was inhibited 60% by 10–8M NHE-RF; this effect was not observed in the absence of PKA. Reconstitution with heat-denatured NHE-RF also failed to attenuate NBC activity. To establish further a physiologic role for NHE-RF in NBC regulation, the renal epithelial cell line B-SC-1, which lacks detectable endogenous NHE-RF expression, was engineered to express stably an NHE-RF transgene. NHE-RF–expressing B-SC-1 cells (B-SC-RF) exhibited markedly lower basal levels of NBC activity than did wild-type controls. Inhibition of NBC activity in B-SC-RF cells was enhanced after 10 μM of forskolin treatment, consistent with a postulated role for NHE-RF in mediating the inhibition of NBC activity by PKA. These findings not only suggest NHE-RF involvement in PKA-regulated NBC activity, but also provide a unique molecular mechanism whereby

  2. Generalised dissociative amnesia.

    PubMed

    Sengupta, S N; Jena, S; Saxena, S

    1993-12-01

    A case of generalised dissociative amnesia is presented, which illustrates several characteristic features of this uncommon condition. The case showed poor response to thiopentone interviews and in vivo cueing. Amnesia had persisted at six months follow up.

  3. Resilience does not explain the dissociation between chronic pain and physical activity in South Africans living with HIV

    PubMed Central

    Mitchell, Duncan

    2016-01-01

    Pain burden is high in people living with HIV (PLWH), but the effect of this pain on functionality is equivocal. Resilience, the ability to cope with adversity, may promote adaptation to pain, so we hypothesised that higher resilience would correlate with less pain-related impairment of activity. We recruited 197 black South African PLWH, 99 with chronic pain (CP) and 98 patients without. We measured pain intensity and interference using the Brief Pain Inventory, and resilience using the Resilience Scale. Participants were generally highly resilient. Greater resilience correlated with better health-related quality of life, but not with pain intensity or interference. We also measured physical activity objectively, by actigraphy, in a subset of patients (37 with chronic pain and 31 without chronic pain), who wore accelerometers for two weeks. There was no difference in duration or intensity of activity between those with and without pain, and activity was not associated with resilience. In this sample, pain was not associated with altered physical activity. Resilience did not explain differences in pain intensity or pain interference but was associated with improved quality of life. Financial stresses and the fear of HIV stigma may have driven patients to conceal pain and to suppress its expected impairment of activity. PMID:27672513

  4. Persistent Activity in Prefrontal Cortex during Trace Eyelid Conditioning: Dissociating Responses That Reflect Cerebellar Output from Those That Do Not

    PubMed Central

    Mauk, Michael D.

    2013-01-01

    Persistent neural activity, responses that outlast the stimuli that evoke them, plays an important role in neural computations and possibly in processes, such as working memory. Recent studies suggest that trace eyelid conditioning, which involves a temporal gap between the conditioned and unconditioned stimuli (the trace interval), requires persistent neural activity in a region of medial prefrontal cortex (mPFC). This persistent activity, which could be conveyed to cerebellum via a pathway through pons, may engage the cerebellum and allow for the expression of conditioned responses. Given the substantial reciprocity observed among many brain regions, it is essential to demonstrate that persistent responses in mPFC neurons are not simply a reflection of cerebellar feedback to the forebrain, leaving open the possibility that such responses could serve as input to the cerebellum. This concern is highlighted by studies showing that hippocampal learning-related activity is abolished by cerebellar inactivation. We inactivated the cerebellum while recording single-unit activity from the mPFC of rabbits trained with a forebrain-dependent trace eyelid conditioning procedure. We report that, whereas the responses of cells that show an onset of increased spike activity during the trace interval were abolished by cerebellar inactivation, persistent responses that begin during the conditioned stimulus and persisted into the trace interval were unaffected. Therefore, conditioned stimulus-evoked persistent responses remain the strongest candidate input pattern to support the cerebellar expression of learned responses. PMID:24048856

  5. Resilience does not explain the dissociation between chronic pain and physical activity in South Africans living with HIV

    PubMed Central

    Mitchell, Duncan

    2016-01-01

    Pain burden is high in people living with HIV (PLWH), but the effect of this pain on functionality is equivocal. Resilience, the ability to cope with adversity, may promote adaptation to pain, so we hypothesised that higher resilience would correlate with less pain-related impairment of activity. We recruited 197 black South African PLWH, 99 with chronic pain (CP) and 98 patients without. We measured pain intensity and interference using the Brief Pain Inventory, and resilience using the Resilience Scale. Participants were generally highly resilient. Greater resilience correlated with better health-related quality of life, but not with pain intensity or interference. We also measured physical activity objectively, by actigraphy, in a subset of patients (37 with chronic pain and 31 without chronic pain), who wore accelerometers for two weeks. There was no difference in duration or intensity of activity between those with and without pain, and activity was not associated with resilience. In this sample, pain was not associated with altered physical activity. Resilience did not explain differences in pain intensity or pain interference but was associated with improved quality of life. Financial stresses and the fear of HIV stigma may have driven patients to conceal pain and to suppress its expected impairment of activity.

  6. Resilience does not explain the dissociation between chronic pain and physical activity in South Africans living with HIV.

    PubMed

    Wadley, Antonia L; Mitchell, Duncan; Kamerman, Peter R

    2016-01-01

    Pain burden is high in people living with HIV (PLWH), but the effect of this pain on functionality is equivocal. Resilience, the ability to cope with adversity, may promote adaptation to pain, so we hypothesised that higher resilience would correlate with less pain-related impairment of activity. We recruited 197 black South African PLWH, 99 with chronic pain (CP) and 98 patients without. We measured pain intensity and interference using the Brief Pain Inventory, and resilience using the Resilience Scale. Participants were generally highly resilient. Greater resilience correlated with better health-related quality of life, but not with pain intensity or interference. We also measured physical activity objectively, by actigraphy, in a subset of patients (37 with chronic pain and 31 without chronic pain), who wore accelerometers for two weeks. There was no difference in duration or intensity of activity between those with and without pain, and activity was not associated with resilience. In this sample, pain was not associated with altered physical activity. Resilience did not explain differences in pain intensity or pain interference but was associated with improved quality of life. Financial stresses and the fear of HIV stigma may have driven patients to conceal pain and to suppress its expected impairment of activity.

  7. Resilience does not explain the dissociation between chronic pain and physical activity in South Africans living with HIV.

    PubMed

    Wadley, Antonia L; Mitchell, Duncan; Kamerman, Peter R

    2016-01-01

    Pain burden is high in people living with HIV (PLWH), but the effect of this pain on functionality is equivocal. Resilience, the ability to cope with adversity, may promote adaptation to pain, so we hypothesised that higher resilience would correlate with less pain-related impairment of activity. We recruited 197 black South African PLWH, 99 with chronic pain (CP) and 98 patients without. We measured pain intensity and interference using the Brief Pain Inventory, and resilience using the Resilience Scale. Participants were generally highly resilient. Greater resilience correlated with better health-related quality of life, but not with pain intensity or interference. We also measured physical activity objectively, by actigraphy, in a subset of patients (37 with chronic pain and 31 without chronic pain), who wore accelerometers for two weeks. There was no difference in duration or intensity of activity between those with and without pain, and activity was not associated with resilience. In this sample, pain was not associated with altered physical activity. Resilience did not explain differences in pain intensity or pain interference but was associated with improved quality of life. Financial stresses and the fear of HIV stigma may have driven patients to conceal pain and to suppress its expected impairment of activity. PMID:27672513

  8. Analysis of the Activation and Heterolytic Dissociation of H2 by Frustrated Lewis Pairs: NH3/BX3 (X = H, F, and Cl)

    SciTech Connect

    Camaioni, Donald M.; Ginovska-Pangovska, Bojana; Schenter, Gregory K.; Kathmann, Shawn M.; Autrey, Thomas

    2012-07-05

    We present results of our computational study aimed at understanding the mechanism of H2 activation and heterolytic dissociation by 'frustrated' Lewis pairs (FLPs). We studied the pairs of ammonia (NH3) with BH3, BF3, and most extensively, BCl3. While these pairs are capable of forming a strong dative bond, electronic structure theories make it possible to explore the potential surface in regions away from the dative complex relevant to H2 activation by frustrated Lewis pairs. We analyzed in great detail the changes that occur along the minimum energy path between the FLP and the product ion pair complex. For X = Cl, the mechanism involves a precursor complex, H3N-H2-BCl3, with a B-H-H angle of {approx}80{sup o} and nearly linear N-H-H angle. At the transition state (TS), the H2 bond is weakened but not broken, and the BCl3 moiety has undergone significant pyramidal distortion. As such, the FLP is prepared to accept the incipient proton and hydride ion on the product-side. The interaction energy of the H2 with the acid/base pair and the different contributions for the precursor and TS complex from an energy decomposition analysis expose the dominant factors affecting the reactivity. We find that structural reorganization of precursor complex plays a significant role in the 'activation' and that charge-transfer interactions are the dominant stabilizing force in the activated complex. The electric field clearly has a role in polarizing H2, but its contribution to the overall interaction energy seems to be smaller. Our detailed study of the nature of the bonding and the different types of interaction between the prototypical Lewis pair and H2 provides insight into the important components that should be taken into account when designing related systems to activate hydrogen.

  9. Dopamine Receptor Blockade Modulates the Rewarding and Aversive Properties of Nicotine via Dissociable Neuronal Activity Patterns in the Nucleus Accumbens

    PubMed Central

    Sun, Ninglei; Laviolette, Steven R

    2014-01-01

    The mesolimbic pathway comprising the ventral tegmental area (VTA) and projection terminals in the nucleus accumbens (NAc) has been identified as a critical neural system involved in processing both the rewarding and aversive behavioral effects of nicotine. Transmission through dopamine (DA) receptors functionally modulates these effects directly within the NAc. Nevertheless, the neuronal mechanisms within the NAc responsible for these bivalent behavioral effects are presently not known. Using an unbiased conditioned place preference procedure combined with in vivo neuronal recordings, we examined the effects of nicotine reward and aversion conditioning on intra-NAc neuronal sub-population activity patterns. We report that intra-VTA doses of nicotine that differentially produce rewarding or aversive behavioral effects produce opposite effects on sub-populations of fast-spiking interneurons (FSIs) or medium spiny neurons (MSNs) within the shell region of the NAc (NAshell). Thus, while the rewarding effects of intra-VTA nicotine were associated with inhibition of FSI and activation of MSNs, the aversive effects of nicotine produced the opposite pattern of NAshell neuronal population activity. Blockade of DA transmission with a broad-spectrum DA receptor antagonist, α-flupenthixol, strongly inhibited the spontaneous activity of NAshell FSIs, and reversed the conditioning properties of intra-VTA nicotine, switching nicotine-conditioned responses from aversive to rewarding. Remarkably, DA receptor blockade switched intra-NAshell neuronal population activity from an aversion to a reward pattern, concomitant with the observed switch in behavioral conditioning effects. PMID:24896614

  10. Dissociable stages of problem solving (II): first evidence for process-contingent temporal order of activation in dorsolateral prefrontal cortex.

    PubMed

    Ruh, Nina; Rahm, Benjamin; Unterrainer, Josef M; Weiller, Cornelius; Kaller, Christoph P

    2012-10-01

    In a companion study, eye-movement analyses in the Tower of London task (TOL) revealed independent indicators of functionally separable cognitive processes during problem solving, with processes of building up an internal representation of the problem preceding actual planning processes. These results imply that processes of internalization and planning should also be distinguishable in time and space with respect to concomitant brain activation patterns. To investigate this possibility, here we conducted analyses of fMRI data for left and right dorsolateral prefrontal cortex (dlPFC) during problem solving in the TOL task by accounting for the trial-by-trial variability of onsets and durations of the different cognitive processing stages. Comparisons between stimulus-locked and response-locked modeling approaches affirmed that activation in left dlPFC was elicited particularly during early processes of internalization, comprising the extraction of goal information and the generation of an internal problem representation, whereas activation in right dlPFC was predominantly attributable to later processes of mental transformations on this representation, that is planning proper. Thus, present data corroborate the proposal that often observed bilateral dlPFC activation patterns during complex cognitive tasks such as problem solving may reflect functionally and, to some extent, even temporally separable processes with opposing lateralizations.

  11. Dissociation between diurnal cycles in locomotor activity, feeding behavior and hepatic PERIOD2 expression in chronic alcohol-fed mice.

    PubMed

    Zhou, Peng; Werner, John H; Lee, Donghoon; Sheppard, Aaron D; Liangpunsakul, Suthat; Duffield, Giles E

    2015-06-01

    Chronic alcohol consumption contributes to fatty liver disease. Our studies revealed that the hepatic circadian clock is disturbed in alcohol-induced hepatic steatosis, and effects of chronic alcohol administration upon the clock itself may contribute to steatosis. We extended these findings to explore the effects of chronic alcohol treatment on daily feeding and locomotor activity patterns. Mice were chronically pair-fed ad libitum for 4 weeks using the Lieber-DeCarli liquid diet, with calorie-controlled liquid and standard chow diets as control groups. Locomotor activity, feeding activity, and real-time bioluminescence recording of PERIOD2::LUCIFERASE expression in tissue explants were measured. Mice on liquid control and chow diets exhibited normal profiles of locomotor activity, with a ratio of 22:78% day/night activity and a peak during early night. This pattern was dramatically altered in alcohol-fed mice, marked by a 49:51% ratio and the absence of a distinct peak. While chow-diet fed mice had a normal 24:76% ratio of feeding activity, with a peak in the early night, this pattern was dramatically altered in both liquid-diet groups: mice had a 43:57% ratio, and an absence of a distinct peak. Temporal differences were also observed between the two liquid-diet groups during late day. Cosinor analysis revealed a ∼4-h and ∼6-h shift in the alcohol-fed group feeding and locomotor activity rhythms, respectively. Analysis of hepatic PER2 expression revealed that the molecular clock in alcohol-fed and control liquid-diet mice was shifted by ∼11 h and ∼6 h, respectively. No differences were observed in suprachiasmatic nucleus explants, suggesting that changes in circadian phase in the liver were generated independently from the central clock. These results suggest that chronic alcohol consumption and a liquid diet can differentially modulate the daily rhythmicity of locomotor and feeding behaviors, aspects that might contribute to disturbances in the circadian

  12. cadDX Operon of Streptococcus salivarius 57.I▿

    PubMed Central

    Chen, Yi-Ywan M.; Feng, C. W.; Chiu, C. F.; Burne, Robert A.

    2008-01-01

    A CadDX system that confers resistance to Cd2+ and Zn2+ was identified in Streptococcus salivarius 57.I. Unlike with other CadDX systems, the expression of the cad promoter was negatively regulated by CadX, and the repression was inducible by Cd2+ and Zn2+, similar to what was found for CadCA systems. The lower G+C content of the S. salivarius cadDX genes suggests acquisition by horizontal gene transfer. PMID:18165364

  13. cadDX operon of Streptococcus salivarius 57.I.

    PubMed

    Chen, Yi-Ywan M; Feng, C W; Chiu, C F; Burne, Robert A

    2008-03-01

    A CadDX system that confers resistance to Cd(2+) and Zn(2+) was identified in Streptococcus salivarius 57.I. Unlike with other CadDX systems, the expression of the cad promoter was negatively regulated by CadX, and the repression was inducible by Cd(2+) and Zn(2+), similar to what was found for CadCA systems. The lower G+C content of the S. salivarius cadDX genes suggests acquisition by horizontal gene transfer. PMID:18165364

  14. Dissociated multi-unit activity and local field potentials: a theory inspired analysis of a motor decision task.

    PubMed

    Mattia, Maurizio; Ferraina, Stefano; Del Giudice, Paolo

    2010-09-01

    Local field potentials (LFP) and multi-unit activity (MUA) recorded in vivo are known to convey different information about the underlying neural activity. Here we extend and support the idea that single-electrode LFP-MUA task-related modulations can shed light on the involved large-scale, multi-modular neural dynamics. We first illustrate a theoretical scheme and associated simulation evidence, proposing that in a multi-modular neural architecture local and distributed dynamic properties can be extracted from the local spiking activity of one pool of neurons in the network. From this new perspective, the spectral features of the field potentials reflect the time structure of the ongoing fluctuations of the probed local neuronal pool on a wide frequency range. We then report results obtained recording from the dorsal premotor (PMd) cortex of monkeys performing a countermanding task, in which a reaching movement is performed, unless a visual stop signal is presented. We find that the LFP and MUA spectral components on a wide frequency band (3-2000 Hz) are very differently modulated in time for successful reaching, successful and wrong stop trials, suggesting an interplay of local and distributed components of the underlying neural activity in different periods of the trials and for different behavioural outcomes. Besides, the MUA spectral power is shown to possess a time-dependent structure, which we suggest could help in understanding the successive involvement of different local neuronal populations. Finally, we compare signals recorded from PMd and dorso-lateral prefrontal (PFCd) cortex in the same experiment, and speculate that the comparative time-dependent spectral analysis of LFP and MUA can help reveal patterns of functional connectivity in the brain.

  15. Dissociating Cortical Activity during Processing of Native and Non-Native Audiovisual Speech from Early to Late Infancy.

    PubMed

    Fava, Eswen; Hull, Rachel; Bortfeld, Heather

    2014-01-01

    Initially, infants are capable of discriminating phonetic contrasts across the world's languages. Starting between seven and ten months of age, they gradually lose this ability through a process of perceptual narrowing. Although traditionally investigated with isolated speech sounds, such narrowing occurs in a variety of perceptual domains (e.g., faces, visual speech). Thus far, tracking the developmental trajectory of this tuning process has been focused primarily on auditory speech alone, and generally using isolated sounds. But infants learn from speech produced by people talking to them, meaning they learn from a complex audiovisual signal. Here, we use near-infrared spectroscopy to measure blood concentration changes in the bilateral temporal cortices of infants in three different age groups: 3-to-6 months, 7-to-10 months, and 11-to-14-months. Critically, all three groups of infants were tested with continuous audiovisual speech in both their native and another, unfamiliar language. We found that at each age range, infants showed different patterns of cortical activity in response to the native and non-native stimuli. Infants in the youngest group showed bilateral cortical activity that was greater overall in response to non-native relative to native speech; the oldest group showed left lateralized activity in response to native relative to non-native speech. These results highlight perceptual tuning as a dynamic process that happens across modalities and at different levels of stimulus complexity. PMID:25116572

  16. Dissociating Cortical Activity during Processing of Native and Non-Native Audiovisual Speech from Early to Late Infancy

    PubMed Central

    Fava, Eswen; Hull, Rachel; Bortfeld, Heather

    2014-01-01

    Initially, infants are capable of discriminating phonetic contrasts across the world’s languages. Starting between seven and ten months of age, they gradually lose this ability through a process of perceptual narrowing. Although traditionally investigated with isolated speech sounds, such narrowing occurs in a variety of perceptual domains (e.g., faces, visual speech). Thus far, tracking the developmental trajectory of this tuning process has been focused primarily on auditory speech alone, and generally using isolated sounds. But infants learn from speech produced by people talking to them, meaning they learn from a complex audiovisual signal. Here, we use near-infrared spectroscopy to measure blood concentration changes in the bilateral temporal cortices of infants in three different age groups: 3-to-6 months, 7-to-10 months, and 11-to-14-months. Critically, all three groups of infants were tested with continuous audiovisual speech in both their native and another, unfamiliar language. We found that at each age range, infants showed different patterns of cortical activity in response to the native and non-native stimuli. Infants in the youngest group showed bilateral cortical activity that was greater overall in response to non-native relative to native speech; the oldest group showed left lateralized activity in response to native relative to non-native speech. These results highlight perceptual tuning as a dynamic process that happens across modalities and at different levels of stimulus complexity. PMID:25116572

  17. CD4 down regulation and raft dissociation by the non-depleting YTS177 antibody hinder murine T helper cell activities.

    PubMed

    Wu, Cheng-Jang; Lu, Chun-Hao; Chen, Li-Chen; Nguyen, Duc T; Huang, Yi-Shu; Lin, Hsi-Hsien; Lin, Chun-Yen; Kuo, Ming-Ling

    2016-05-13

    Non-depleting YTS177 anti-CD4 monoclonal antibody (MoAb) has been reported to lead to antigen-specific immunotolerance in allograft transplantation and autoimmune diabetes, as well as possibly to inhibition of allergic inflammation in mice. However, the molecular mechanisms underlying hyporesponsive T cell responses induced by YTS177 MoAb remain elusive. Herein, we demonstrate that the YTS177 MoAb increases the levels of anergy factors p27(kip1) and Cbl-b, inhibits IL-2 production, and impairs calcium mobilization in activated T cells in vitro. YTS177 MoAb suppresses OVA-driven proliferation of DO11.10 CD4(+) T cells in vivo as well. Mechanistically, YTS177 MoAb induces tolerance by causing CD4 down-regulation through clathrin-dependent and raft dissociation. The results obtained in this study lead us to propose novel protective or curative approaches to CD4 T cell-mediated diseases. PMID:27045081

  18. Facilitation and inhibition in attention: Functional dissociation of pre-stimulus alpha activity, P1, and N1 components.

    PubMed

    Slagter, H A; Prinssen, S; Reteig, L C; Mazaheri, A

    2016-01-15

    Attention--the ability to attend to some things while ignoring others - can be best described as an emergent property of many neural mechanisms, facilitatory and inhibitory, working together to resolve competition for processing resources and control of behavior. Previous EEG and MEG studies examining the neural mechanisms underlying facilitation and inhibition of stimulus processing typically used paradigms requiring alternating shifts of attention in the spatial domain, with stimuli occurring at both attended and unattended locations. These studies generally observed greater pre-stimulus alpha oscillations over task-irrelevant vs. relevant posterior regions and bilateral attentional modulations of early sensory processing. In contrast, in the current series of experiments, participants continuously attended to only one hemifield and stimuli were only presented at the attended location, affording us an opportunity to elucidate the inhibitory and facilitatory effects of attention in the brain in a context in which spatial relevance was fixed. We found that continuous attention to one hemifield did not modulate prestimulus alpha activity in ipsilateral regions but did result in a perfectly lateralized P1 attention effect to ipsilateral posterior regions. Moreover, we found a bilateral N1 effect. These findings suggest that pre-stimulus alpha activity, the P1 and the N1 reflect qualitatively different aspects of attention; While pre-stimulus alpha-band activity may reflect a top-down inhibitory mechanism that critically depends on functional competition between task-relevant and irrelevant sensory regions, the ipsilateral P1 effect may reflect stimulus-triggered blocking of sensory processing in irrelevant networks, and the N1 effect facilitation of task-relevant processing.

  19. Dissociating motor cortex from the motor

    PubMed Central

    Schieber, Marc H

    2011-01-01

    Abstract During closed-loop control of a brain–computer interface, neurons in the primary motor cortex can be intensely active even though the subject may be making no detectable movement or muscle contraction. How can neural activity in the primary motor cortex become dissociated from the movements and muscles of the native limb that it normally controls? Here we examine circumstances in which motor cortex activity is known to dissociate from movement – including mental imagery, visuo-motor dissociation and instructed delay. Many such motor cortex neurons may be related to muscle activity only indirectly. Furthermore, the integration of thousands of synaptic inputs by individual α-motoneurons means that under certain circumstances even cortico-motoneuronal cells, which make monosynaptic connections to α-motoneurons, can become dissociated from muscle activity. The natural ability of motor cortex neurons under voluntarily control to become dissociated from bodily movement may underlie the utility of this cortical area for controlling brain–computer interfaces. PMID:22005673

  20. Chimeric antigen receptor T cells with dissociated signaling domains exhibit focused anti-tumor activity with reduced potential for toxicity in vivo

    PubMed Central

    Lanitis, Evripidis; Poussin, Mathilde; Klattenhoff, Alex W.; Song, Degang; Sandaltzopoulos, Raphael; June, Carl H.; Powell, Daniel J.

    2013-01-01

    Adoptive immunotherapy using lymphocytes genetically-modified to express a chimeric antigen receptor (CART) holds considerable promise for the treatment of cancer. However, CAR-based therapies may involve on-target toxicity against normal tissues expressing low amounts of the targeted tumor-associated antigen (TAA). To specify T cells for robust effector function that is selective for tumor but not normal tissue, we developed a trans-signaling CAR strategy whereby T cell activation signal 1 (CD3ζ) is physically dissociated from costimulatory signal 2 (CD28) in two CARs of differing antigen specificity; mesothelin and a-folate receptor (FRa). Human T cells were genetically modified to co-express signal 1 (Anti-Meso scFv-CD3ζ) and signal 2 (Anti-FRa scFv-CD28) CARs in trans. Trans-signaling CART cells showed weak cytokine secretion against target cells expressing only one TAA in vitro, similar to first generation CART cells bearing CD3ζ only, but demonstrated enhanced cytokine secretion upon encountering natural or engineered tumor cells co-expressing both antigens, equivalent to that of second generation CART cells with dual signaling in cis. CART cells with dual specificity also showed potent anti-cancer activity and persistence in vivo which was superior to first generation CART cells and equivalent to second generation CARs. Importantly, second generation CART cells exhibited potent activity against cells expressing mesothelin alone, recapitulating normal tissue, whereas trans-signaling CART cells did not. Thus, a dual specificity, trans-signaling CAR approach can potentiate the therapeutic efficacy of CART cells against cancer while minimizing parallel reactivity against normal tissues bearing single antigen. PMID:24409448

  1. TrkBT1 Induces Liver Metastasis of Pancreatic Cancer Cells by Sequestering Rho GDP Dissociation Inhibitor and Promoting RhoA Activation

    PubMed Central

    Li, Zhongkui; Chang, Zhe; Chiao, Lucia J.; Kang, Ya’an; Xia, Qianghua; Zhu, Cihui; Fleming, Jason B.; Evans, Douglas B.; Chiao, Paul J.

    2011-01-01

    Many genetic and molecular alterations, such as K-ras mutation and NF-κB activation, have been identified in pancreatic cancer. However, the mechanisms by which pancreatic cancer metastasizes still remain to be determined. Although we previously showed that the tropomyosin-related kinase B (TrkB) was significantly correlated with the development of liver metastasis, its function in pancreatic cancer metastasis remained unresolved. In the present study, we showed that overexpressed TrkB is an alternatively spliced transcript variant of TrkB (TrkBT1) with a unique COOH-terminal 12–amino acid sequence and is mainly localized in the cytoplasm. Our results showed that overexpression of Flag-tagged TrkBT1 but not a Flag-tagged TrkBT1 COOH-terminal deletion mutant (Flag-TrkBT1ΔC) in nonmetastatic pancreatic cancer cells enhanced cell proliferation, promoted formation of colonies in soft agar, stimulated tumor cell invasion, and induced liver metastasis in an orthotopic xenograft mouse model of pancreatic cancer. TrkBT1 interacted with Rho GDP dissociation inhibitor (GDI) in vivo, but Flag-TrkBT1ΔC did not. Furthermore, overexpression of Flag-TrkBT1 and knockdown of RhoGDI expression by RhoGDI short hairpin RNAs promoted RhoA activation, but Flag-TrkBT1ΔC overexpression did not. Therefore, our results showed that TrkBT1 overexpression induces liver metastasis of pancreatic cancer and uncovered a unique signaling mechanism by which TrkBT1 sequesters GDI and activates RhoA signaling. PMID:19773448

  2. Conformational changes in the amino-terminal helix of the G protein alpha(i1) following dissociation from Gbetagamma subunit and activation.

    PubMed

    Medkova, Martina; Preininger, Anita M; Yu, Nan-Jun; Hubbell, Wayne L; Hamm, Heidi E

    2002-08-01

    -bound form. Together these results suggest conformational changes occur in the amino-termini of Galpha(i) proteins upon subunit dissociation and upon activating conformational changes. These solution studies reveal insights into conformational changes that occur dynamically in solution. PMID:12146960

  3. Dissociation as complex adaptation.

    PubMed

    Sel, R

    1997-03-01

    In this article the general theory of complex adaptive systems, substantiated by non-linear dynamics, will be used to put the dissociative disorders into a theoretical framework and clarify their genesis and presentation. When a system is far out of equilibrium, dissipative structures may be formed ('order out of chaos', as Prigogine (1) has put it). These structures provide the starting point for further evolution and co-evolution of competing groups of functional schemata divided on a bifurcation surface. Complex adaptation is almost inevitable in a complicated system (such as the brain) driven by non-linear dynamics. Dissociation is thus regarded as a consequence of adaptation to a chaotic environment rich in contrasts. In a sufficiently complex environment a person with dissociative identity disorder is more adapted and thus more likely to occur than a 'normal' monopersonality individual.

  4. Study of the dissociation of a charge-reduced phosphopeptide formed by electron transfer from an alkali metal target.

    PubMed

    Hayakawa, Shigeo; Hashimoto, Mami; Nagao, Hirofumi; Awazu, Kunio; Toyoda, Michisato; Ichihara, Toshio; Shigeri, Yasushi

    2008-01-01

    Doubly protonated phosphopeptide (YGGMHRQET(p)VDC) ions obtained by electrospray ionization were collided with Xe and Cs targets to give singly and doubly charged positive ions via collision-induced dissociation (CID). The resulting ions were analyzed and detected by using an electrostatic analyzer (ESA). Whereas doubly charged fragment ions resulting from collisionally activated dissociation (CAD) were dominant in the CID spectrum with the Xe target, singly charged fragment ions resulting from electron transfer dissociation (ETD) were dominant in the CID spectrum with the Cs target. The most intense peak resulting from ETD was estimated to be associated with the charge-reduced ion with H2 lost from the precursor. Five c-type fragment ions with amino acid residues detached consecutively from the C-terminal were clearly observed without a loss of the phosphate group. These ions must be formed by N--Calpha bond cleavage, in a manner similar to the cases of electron capture dissociation (ECD) and ETD from negative ions. Although the accuracy in m/z of the CID spectra was about +/-1 Th because of the mass analysis using the ESA, it is supposed from the m/z values of the c-type ions that these ions were accompanied by the loss of a hydrogen atom. Four z-type (or y--NH3, or y--H2O) ions analogously detached consecutively from the N-terminal were also observed. The fragmentation processes took place within the time scale of 4.5 micros in the high-energy collision. The present results demonstrated that high-energy ETD with the alkali metal target allowed determination of the position of phosphorylation and the amino acid sequence of post-translational peptides.

  5. Some Workplace Effects of CAD and CAM.

    ERIC Educational Resources Information Center

    Ebel, Karl-H.; Ulrich, Erhard

    1987-01-01

    Examines the impact of computer-aided design (CAD) and computer-aided manufacturing (CAM) on employment, work organization, working conditions, job content, training, and industrial relations in several countries. Finds little evidence of negative employment effects since productivity gains are offset by various compensatory factors. (Author/CH)

  6. Pipe Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Smithson, Buddy

    This teacher's guide contains nine units of instruction for a course on computer-assisted pipe drafting. The course covers the following topics: introduction to pipe drafting with CAD (computer-assisted design); flow diagrams; pipe and pipe components; valves; piping plans and elevations; isometrics; equipment fabrication drawings; piping design…

  7. A Case Study in CAD Design Automation

    ERIC Educational Resources Information Center

    Lowe, Andrew G.; Hartman, Nathan W.

    2011-01-01

    Computer-aided design (CAD) software and other product life-cycle management (PLM) tools have become ubiquitous in industry during the past 20 years. Over this time they have continuously evolved, becoming programs with enormous capabilities, but the companies that use them have not evolved their design practices at the same rate. Due to the…

  8. Effect of dimer dissociation on activity and thermostability of the alpha-glucuronidase from Geobacillus stearothermophilus: dissecting the different oligomeric forms of family 67 glycoside hydrolases.

    PubMed

    Shallom, Dalia; Golan, Gali; Shoham, Gil; Shoham, Yuval

    2004-10-01

    The oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. alpha-Glucuronidases are family 67 glycosidases that cleave the alpha-1,2-glycosidic bond between 4-O-methyl-D-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. Currently, two crystal structures of alpha-glucuronidases are available, those from Geobacillus stearothermophilus (AguA) and from Cellvibrio japonicus (GlcA67A). Both enzymes are homodimeric, but surprisingly their dimeric organization is different, raising questions regarding the significance of dimerization for the enzymes' activity and stability. Structural comparison of the two enzymes suggests several elements that are responsible for the different dimerization organization. Phylogenetic analysis shows that the alpha-glucuronidases AguA and GlcA67A can be classified into two distinct subfamilies of bacterial alpha-glucuronidases, where the dimer-forming residues of each enzyme are conserved only within its own subfamily. It seems that the different dimeric forms of AguA and GlcA67A represent the two alternative dimeric organizations of these subfamilies. To study the biological significance of the dimerization in alpha-glucuronidases, we have constructed a monomeric form of AguA by mutating three of its interface residues (W328E, R329T, and R665N). The activity of the monomer was significantly lower than the activity of the wild-type dimeric AguA, and the optimal temperature for activity of the monomer was around 35 degrees C, compared to 65 degrees C of the wild-type enzyme. Nevertheless, the melting temperature of the monomeric protein, 72.9 degrees C, was almost identical to that of the wild-type, 73.4 degrees C. It appears that the dimerization of AguA is essential for efficient catalysis and that the dissociation into monomers results in subtle conformational changes in the structure

  9. Effect of Dimer Dissociation on Activity and Thermostability of the α-Glucuronidase from Geobacillus stearothermophilus: Dissecting the Different Oligomeric Forms of Family 67 Glycoside Hydrolases

    PubMed Central

    Shallom, Dalia; Golan, Gali; Shoham, Gil; Shoham, Yuval

    2004-01-01

    The oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. α-Glucuronidases are family 67 glycosidases that cleave the α-1,2-glycosidic bond between 4-O-methyl-d-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. Currently, two crystal structures of α-glucuronidases are available, those from Geobacillus stearothermophilus (AguA) and from Cellvibrio japonicus (GlcA67A). Both enzymes are homodimeric, but surprisingly their dimeric organization is different, raising questions regarding the significance of dimerization for the enzymes' activity and stability. Structural comparison of the two enzymes suggests several elements that are responsible for the different dimerization organization. Phylogenetic analysis shows that the α-glucuronidases AguA and GlcA67A can be classified into two distinct subfamilies of bacterial α-glucuronidases, where the dimer-forming residues of each enzyme are conserved only within its own subfamily. It seems that the different dimeric forms of AguA and GlcA67A represent the two alternative dimeric organizations of these subfamilies. To study the biological significance of the dimerization in α-glucuronidases, we have constructed a monomeric form of AguA by mutating three of its interface residues (W328E, R329T, and R665N). The activity of the monomer was significantly lower than the activity of the wild-type dimeric AguA, and the optimal temperature for activity of the monomer was around 35°C, compared to 65°C of the wild-type enzyme. Nevertheless, the melting temperature of the monomeric protein, 72.9°C, was almost identical to that of the wild-type, 73.4°C. It appears that the dimerization of AguA is essential for efficient catalysis and that the dissociation into monomers results in subtle conformational changes in the structure which indirectly influence the active site region

  10. Priming of a D1 dopamine receptor behavioural response is dissociated from striatal immediate-early gene activity.

    PubMed

    Paul, M L; Currie, R W; Robertson, H A

    1995-05-01

    Repeated administration of direct-acting (apomorphine, SKF-38393, quinpirole) or indirect-acting (amphetamine, cocaine) dopaminergic agonists can produce enhancement of locomotor and sterotypic behaviours in response to subsequent dopamine agonist challenge. This sensitization of dopamine receptors, known as priming or reverse tolerance, is long-lasting and appears to be dependent upon the participation of the N-methyl-D-asparate excitatory amino acid receptor. The mechanism underlying dopamine receptor sensitization is not understood. Mounting evidence suggests that immediate-early genes may provide a link whereby extracellular stimuli are converted into long-term changes in neuronal activity. In the present study, behavioural measurements and immunohistochemical techniques were used to determine whether induction of the immediate-early gene c-fos is critical to the mechanism underlying priming of a D1-mediated behavioural response. It was demonstrated that in drug-naive rats bearing unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway, the mixed D1/D2 agonist apomorphine produced a dramatic increase in the expression of Fos-like immunoreactivity in the ipsilateral caudoputamen, nucleus accumbens and globus pallidus, and was a potent primer of SKF-38393-mediated rotational behaviour. In contrast, saline administration did not increase Fos expression and did not prime SKF-38393-elicited rotation. Preadministration of MK-801 at 0.5 mg/kg significantly reduced apomorphine's effect on Fos expression and prevented apomorphine priming of SKF-38393-induced rotation. However, at a lower dose of 0.1 mg/kg, MK-801 had little effect on apomorphine-mediated Fos expression but did block the priming response. In another experiment, the D2 family-selective agonist quinpirole was found to be an affective primer of SKF-38393-mediated rotation, and to produce increase Fos expression in the ipsilateral globus pallidus only. Preadministration of MK-801 at 0

  11. PC Board Layout and Electronic Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Bryson, Jimmy

    This teacher's guide contains 11 units of instruction for a course on computer electronics and computer-assisted drafting (CAD) using a personal computer (PC). The course covers the following topics: introduction to electronic drafting with CAD; CAD system and software; basic electronic theory; component identification; basic integrated circuit…

  12. CAD/CAM. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Zuleger, Robert

    This high technology training module is an advanced course on computer-assisted design/computer-assisted manufacturing (CAD/CAM) for grades 11 and 12. This unit, to be used with students in advanced drafting courses, introduces the concept of CAD/CAM. The content outline includes the following seven sections: (1) CAD/CAM software; (2) computer…

  13. Education and Training Packages for CAD/CAM.

    ERIC Educational Resources Information Center

    Wright, I. C.

    1986-01-01

    Discusses educational efforts in the fields of Computer Assisted Design and Manufacturing (CAD/CAM). Describes two educational training initiatives underway in the United Kingdom, one of which is a resource materials package for teachers of CAD/CAM at the undergraduate level, and the other a training course for managers of CAD/CAM systems. (TW)

  14. A CAD (Classroom Assessment Design) of a Computer Programming Course

    ERIC Educational Resources Information Center

    Hawi, Nazir S.

    2012-01-01

    This paper presents a CAD (classroom assessment design) of an entry-level undergraduate computer programming course "Computer Programming I". CAD has been the product of a long experience in teaching computer programming courses including teaching "Computer Programming I" 22 times. Each semester, CAD is evaluated and modified for the subsequent…

  15. Insights into cardiovascular effects of proline-rich oligopeptide (Bj-PRO-10c) revealed by structure-activity analyses: dissociation of antihypertensive and bradycardic effects.

    PubMed

    Paschoal, Juliana F B; Yamaguchi, Juliana; Miranda, José R R; Carretero, Gustavo; Melo, Robson L; Santos, Robson A S; Xavier, Carlos H; Schreier, Shirley; Camargo, Antonio C M; Ianzer, Danielle

    2014-02-01

    We have previously reported that the proline-rich decapeptide from Bothrops jararaca (Bj-PRO-10c) causes potent and sustained antihypertensive and bradycardic effects in SHR. These activities are independent of ACE inhibition. In the present study, we used the Ala-scan approach to evaluate the importance of each amino acid within the sequence of Bj-PRO-10c (Pyr(1)-Asn(2)-Trp(3)-Pro(4)-His(5)-Pro(6)-Gln(7)-Ile(8)-Pro(9)-Pro(10)). The antihypertensive and bradycardic effects of the analogues Bj-PRO-10c Ala(3), Bj-PRO-10c Ala(7), Bj-PRO-10c Ala(8) were similar to those of Bj-PRO-10c, whereas the analogues Bj-PRO-10c Ala(2), Bj-PRO-10c Ala(4), Bj-PRO-10c Ala(5), Bj-PRO-10c Ala(9), and Bj-PRO-10c Ala(10) kept the antihypertensive activity and lost bradycardic activity considerably. In contrast, Bj-PRO-10c Ala(1) and Bj-PRO-10c Ala(6) were unable to provoke any cardiovascular activity. In summary, we demonstrated that (1) the Pyr(1) and Pro(6) residues are essential for both, the antihypertensive and bradycardic effects of Bj-PRO-10c; (2) Ala-scan approach allowed dissociating blood pressure reduction and bradycardic effects. Conformational properties of the peptides were examined by means of circular dichroism (CD) spectroscopy. The different Ala-scan analogues caused either an increase or decrease in the type II polyproline helix content compared to Bj-PRO-10c. The complete loss of activity of the Pro(6) → Ala(6) mutant is probably due to the fact that in the parent peptide the His(5)-Pro(6) bond can exist in the cis configuration, which could correspond to the conformation of this bond in the bound state. Current data support the Bj-PRO-10c as a promising leader prototype to develop new agents to treat cardiovascular diseases and its co-morbidities.

  16. Dissociative Identity Disorder

    ERIC Educational Resources Information Center

    Schmidt, Tom

    2007-01-01

    Few psychological disorders in the Diagnostic Statistical Manual have generated as much controversy as Dissociative Identity Disorder (DID). For the past 35 years diagnoses of DID, previously referred to as Multiple Personality Disorder (MPD), have increased exponentially, causing various psychological researchers and clinicians to question the…

  17. Dissociation: the clinical realities.

    PubMed

    Frankel, F H

    1996-07-01

    An attempt was made by the authors of DSM-III to restrict its focus to the experimental, the observable, and the measurable. The intention was to free the nosology from the influence of unproven theories, and the philosophy was driven largely by the importance of research being able to identify diagnostic categories to facilitate the study of homogeneous groups. So it is of interest that the authors accepted dissociation-an ambiguous event linked to an explicit theoretical concept that had been introduced by Janet-as the basis for classification of clinical presentations that were formerly included under the rubric of hysteria, a similarly unclear category. Since DSM-III, there have been an increasing number of reports of dissociative experiences and dissociative identity disorder (formerly known as multiple personality disorder), but neither of these clinical presentations seems able to withstand the concern that it is dramatically influenced by environmental cues, e.g., the expectations of the therapist. Thus, a restricted phenomenological perspective does not fully appreciate the distorting potential of suggestibility and imagination on the nature of the emerging clinical picture. These factors might well have contributed to and laid the conceptual groundwork for the growth in the number of reports of dissociation.

  18. Dissociation and psychosis in dissociative identity disorder and schizophrenia.

    PubMed

    Laddis, Andreas; Dell, Paul F

    2012-01-01

    Dissociative symptoms, first-rank symptoms of schizophrenia, and delusions were assessed in 40 schizophrenia patients and 40 dissociative identity disorder (DID) patients with the Multidimensional Inventory of Dissociation (MID). Schizophrenia patients were diagnosed with the Structured Clinical Interview for the DSM-IV Axis I Disorders; DID patients were diagnosed with the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised. DID patients obtained significantly (a) higher dissociation scores; (b) higher passive-influence scores (first-rank symptoms); and (c) higher scores on scales that measure child voices, angry voices, persecutory voices, voices arguing, and voices commenting. Schizophrenia patients obtained significantly higher delusion scores than did DID patients. What is odd is that the dissociation scores of schizophrenia patients were unrelated to their reports of childhood maltreatment. Multiple regression analyses indicated that 81% of the variance in DID patients' dissociation scores was predicted by the MID's Ego-Alien Experiences Scale, whereas 92% of the variance in schizophrenia patients' dissociation scores was predicted by the MID's Voices Scale. We propose that schizophrenia patients' responses to the MID do not index the same pathology as do the responses of DID patients. We argue that neither phenomenological definitions of dissociation nor the current generation of dissociation instruments (which are uniformly phenomenological in nature) can distinguish between the dissociative phenomena of DID and what we suspect are just the dissociation-like phenomena of schizophrenia.

  19. Pathological Dissociation as Measured by the Child Dissociative Checklist

    ERIC Educational Resources Information Center

    Wherry, Jeffrey N.; Neil, Debra A.; Taylor, Tamara N.

    2009-01-01

    The component structure of the Child Dissociative Checklist was examined among abused children. A factor described as pathological dissociation emerged that was predicted by participants being male. There also were differences in pathological dissociation between groups of sexually abused and physically abused children. Replication of this factor…

  20. Dissociation Behavior of a TEMPO-Active Ester Cross-Linker for Peptide Structure Analysis by Free Radical Initiated Peptide Sequencing (FRIPS) in Negative ESI-MS

    NASA Astrophysics Data System (ADS)

    Hage, Christoph; Ihling, Christian H.; Götze, Michael; Schäfer, Mathias; Sinz, Andrea

    2016-07-01

    We have synthesized a homobifunctional amine-reactive cross-linking reagent, containing a TEMPO (2,2,6,6-tetramethylpiperidine-1-oxy) and a benzyl group (Bz), termed TEMPO-Bz-linker, to derive three-dimensional structural information of proteins. The aim for designing this novel cross-linker was to facilitate the mass spectrometric analysis of cross-linked products by free radical initiated peptide sequencing (FRIPS). In an initial study, we had investigated the fragmentation behavior of TEMPO-Bz-derivatized peptides upon collision activation in (+)-electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) experiments. In addition to the homolytic NO-C bond cleavage FRIPS pathway delivering the desired odd-electron product ions, an alternative heterolytic NO-C bond cleavage, resulting in even-electron product ions mechanism was found to be relevant. The latter fragmentation route clearly depends on the protonation of the TEMPO-Bz-moiety itself, which motivated us to conduct (-)-ESI-MS, CID-MS/MS, and MS3 experiments of TEMPO-Bz-cross-linked peptides to further clarify the fragmentation behavior of TEMPO-Bz-peptide molecular ions. We show that the TEMPO-Bz-linker is highly beneficial for conducting FRIPS in negative ionization mode as the desired homolytic cleavage of the NO-C bond is the major fragmentation pathway. Based on characteristic fragments, the isomeric amino acids leucine and isoleucine could be discriminated. Interestingly, we observed pronounced amino acid side chain losses in cross-linked peptides if the cross-linked peptides contain a high number of acidic amino acids.

  1. In-situ and theoretical studies for the dissociation of water on an active Ni/CeO₂ catalyst: Importance of strong metal-support interactions for the cleavage of O-H bonds

    DOE PAGES

    Carrasco, Javier; Rodriguez, Jose A.; Lopez-Duran, David; Liu, Zongyuan; Duchon, Tomas; Evans, Jaime; Senanayake, Sanjaya D.; Crumlin, Ethan J.; Matolin, Vladimir; Ganduglia-Pirovano, M. Veronica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Here, supported by experimental and density-functional theory results, we elucidate the effect of the support on O-H bond cleavage activity for nickel/ceria systems. Ambient-pressure O1s photoemission spectra at low Ni loadings on CeO₂(111) reveal a substantially larger amount of OH groups as compared to the bare support. Our computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO₂(111) compared with pyramidal Ni₄ particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of thismore » support effect is the ability of ceria to stabilize oxidized Ni²⁺ species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO₂ has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions.« less

  2. In-situ and theoretical studies for the dissociation of water on an active Ni/CeO₂ catalyst: Importance of strong metal-support interactions for the cleavage of O-H bonds

    SciTech Connect

    Carrasco, Javier; Rodriguez, Jose A.; Lopez-Duran, David; Liu, Zongyuan; Duchon, Tomas; Evans, Jaime; Senanayake, Sanjaya D.; Crumlin, Ethan J.; Matolin, Vladimir; Ganduglia-Pirovano, M. Veronica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Here, supported by experimental and density-functional theory results, we elucidate the effect of the support on O-H bond cleavage activity for nickel/ceria systems. Ambient-pressure O1s photoemission spectra at low Ni loadings on CeO₂(111) reveal a substantially larger amount of OH groups as compared to the bare support. Our computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO₂(111) compared with pyramidal Ni₄ particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of this support effect is the ability of ceria to stabilize oxidized Ni²⁺ species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO₂ has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions.

  3. In situ and theoretical studies for the dissociation of water on an active Ni/CeO2 catalyst: importance of strong metal-support interactions for the cleavage of O-H bonds.

    PubMed

    Carrasco, Javier; López-Durán, David; Liu, Zongyuan; Duchoň, Tomáš; Evans, Jaime; Senanayake, Sanjaya D; Crumlin, Ethan J; Matolín, Vladimir; Rodríguez, José A; Ganduglia-Pirovano, M Verónica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Supported by experimental and density-functional theory results, the effect of the support on OH bond cleavage activity is elucidated for nickel/ceria systems. Ambient-pressure O 1s photoemission spectra at low Ni loadings on CeO2 (111) reveal a substantially larger amount of OH groups as compared to the bare support. Computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO2 (111) compared with pyramidal Ni4 particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of this support effect is the ability of ceria to stabilize oxidized Ni(2+) species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO2 has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions.

  4. In situ and theoretical studies for the dissociation of water on an active Ni/CeO2 catalyst: importance of strong metal-support interactions for the cleavage of O-H bonds.

    PubMed

    Carrasco, Javier; López-Durán, David; Liu, Zongyuan; Duchoň, Tomáš; Evans, Jaime; Senanayake, Sanjaya D; Crumlin, Ethan J; Matolín, Vladimir; Rodríguez, José A; Ganduglia-Pirovano, M Verónica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Supported by experimental and density-functional theory results, the effect of the support on OH bond cleavage activity is elucidated for nickel/ceria systems. Ambient-pressure O 1s photoemission spectra at low Ni loadings on CeO2 (111) reveal a substantially larger amount of OH groups as compared to the bare support. Computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO2 (111) compared with pyramidal Ni4 particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of this support effect is the ability of ceria to stabilize oxidized Ni(2+) species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO2 has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions. PMID:25651288

  5. Three dimensions of dissociative amnesia.

    PubMed

    Dell, Paul F

    2013-01-01

    Principal axis factor analysis with promax rotation extracted 3 factors from the 42 memory and amnesia items of the Multidimensional Inventory of Dissociation (MID) database (N = 2,569): Discovering Dissociated Actions, Lapses of Recent Memory and Skills, and Gaps in Remote Memory. The 3 factors' shared variance ranged from 36% to 64%. Construed as scales, the 3 factor scales had Cronbach's alpha coefficients of .96, .94, and .93, respectively. The scales correlated strongly with mean Dissociative Experiences Scale scores, mean MID scores, and total scores on the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised (SCID-D-R). What is interesting is that the 3 amnesia factors exhibited a range of correlations with SCID-D-R Amnesia scores (.52, .63, and .70, respectively), suggesting that the SCID-D-R Amnesia score emphasizes gaps in remote memory over amnesias related to dissociative identity disorder. The 3 amnesia factor scales exhibited a clinically meaningful pattern of significant differences among dissociative identity disorder, dissociative disorder not otherwise specified-1, dissociative amnesia, depersonalization disorder, and nonclinical participants. The 3 amnesia factors may have greater clinical utility for frontline clinicians than (a) amnesia as discussed in the context of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, nosology of the dissociative disorders or (b) P. Janet's (1893/1977 ) 4-fold classification of dissociative amnesia. The author recommends systematic study of the phenomenological differences within specific dissociative symptoms and their differential relationship to specific dissociative disorders. PMID:23282045

  6. Three dimensions of dissociative amnesia.

    PubMed

    Dell, Paul F

    2013-01-01

    Principal axis factor analysis with promax rotation extracted 3 factors from the 42 memory and amnesia items of the Multidimensional Inventory of Dissociation (MID) database (N = 2,569): Discovering Dissociated Actions, Lapses of Recent Memory and Skills, and Gaps in Remote Memory. The 3 factors' shared variance ranged from 36% to 64%. Construed as scales, the 3 factor scales had Cronbach's alpha coefficients of .96, .94, and .93, respectively. The scales correlated strongly with mean Dissociative Experiences Scale scores, mean MID scores, and total scores on the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised (SCID-D-R). What is interesting is that the 3 amnesia factors exhibited a range of correlations with SCID-D-R Amnesia scores (.52, .63, and .70, respectively), suggesting that the SCID-D-R Amnesia score emphasizes gaps in remote memory over amnesias related to dissociative identity disorder. The 3 amnesia factor scales exhibited a clinically meaningful pattern of significant differences among dissociative identity disorder, dissociative disorder not otherwise specified-1, dissociative amnesia, depersonalization disorder, and nonclinical participants. The 3 amnesia factors may have greater clinical utility for frontline clinicians than (a) amnesia as discussed in the context of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, nosology of the dissociative disorders or (b) P. Janet's (1893/1977 ) 4-fold classification of dissociative amnesia. The author recommends systematic study of the phenomenological differences within specific dissociative symptoms and their differential relationship to specific dissociative disorders.

  7. ProperCAD: A portable object-oriented parallel environment for VLSI CAD

    NASA Technical Reports Server (NTRS)

    Ramkumar, Balkrishna; Banerjee, Prithviraj

    1993-01-01

    Most parallel algorithms for VLSI CAD proposed to date have one important drawback: they work efficiently only on machines that they were designed for. As a result, algorithms designed to date are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. A new project under way to address this problem is described. A Portable object-oriented parallel environment for CAD algorithms (ProperCAD) is being developed. The objectives of this research are (1) to develop new parallel algorithms that run in a portable object-oriented environment (CAD algorithms using a general purpose platform for portable parallel programming called CARM is being developed and a C++ environment that is truly object-oriented and specialized for CAD applications is also being developed); and (2) to design the parallel algorithms around a good sequential algorithm with a well-defined parallel-sequential interface (permitting the parallel algorithm to benefit from future developments in sequential algorithms). One CAD application that has been implemented as part of the ProperCAD project, flat VLSI circuit extraction, is described. The algorithm, its implementation, and its performance on a range of parallel machines are discussed in detail. It currently runs on an Encore Multimax, a Sequent Symmetry, Intel iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube, and a network of Sun Sparc workstations. Performance data for other applications that were developed are provided: namely test pattern generation for sequential circuits, parallel logic synthesis, and standard cell placement.

  8. Dissociative ionization of biomolecules

    NASA Astrophysics Data System (ADS)

    Huo, Winifred

    2004-09-01

    Dissociative ionization (DI) by electron impact plays a role in many different applications, including low-temperature plasma processing, the study of space and astrophysical plasmas, and the study of biological damages by high-energy radiation. In the present study, our goal is to understand the health hazard to humans from exposure to radiation during an extended space flight. DI by secondary electrons can damage the DNA, either directly by causing a DNA lesion, or indirectly by producing radicals and cations that attack the DNA. The theoretical model employed makes use of the fact that electronic motion is much faster than nuclear motion, allowing DI to be treated as a two-step process. The first step is electron-impact ionization resulting in a dissociative state of the molecular ion with the same geometry as the neutral molecule. In the second step the ion relaxes from the initial geometry and undergoes unimolecular dissociation. Thus the DI cross section is given by the product of the ionization cross section and the dissociation probability. For the ionization process we use the improved binary-encounter dipole (iBED) model. For unimolecular dissociation, we use the multiconfigurational self-consistent field (MCSCF) method to determine the minimum energy pathways to possible product channels. This model has been applied to study the DI of H_2O, NH_3, and CH_4, and the results are in good agreement with experiment. The DI from the low-lying channels of benzene has also been studied and the dissociation products are compared with photoionization measurements. The DI of the DNA bases guanine and cytosine are then discussed. Of the four DNA bases, guanine has the largest ionization cross section and cytosine has the smallest. The guanine radical cation is considered to be one of the precursors to the primary, direct-type lesions formed in DNA when it is irradiated. Comparison of DI products of guanine and cytosine will be made to understand the differences in

  9. Cost reduction advantages of CAD/CAM

    NASA Astrophysics Data System (ADS)

    Parsons, G. T.

    1983-05-01

    Features of the CAD/CAM system implemented at the General Dynamics Convair division are summarized. CAD/CAM was initiated in 1976 to enhance engineering, manufacturing and quality assurance and thereby the company's competitive bidding position. Numerical models are substituted for hardware models wherever possible and numerical criteria are defined in design for guiding computer-controlled parts manufacturing machines. The system comprises multiple terminals, a data base, digitizer, printers, disk and tape drives, and graphics displays. The applications include the design and manufacture of parts and components for avionics, structures, scientific investigations, and aircraft structural components. Interfaces with other computers allow structural analyses by finite element codes. Although time savings have not been gained compared to manual drafting, components of greater complexity than could have been designed by hand have been designed and manufactured.

  10. AutoCAD-To-GIFTS Translator Program

    NASA Technical Reports Server (NTRS)

    Jones, Andrew

    1989-01-01

    AutoCAD-to-GIFTS translator program, ACTOG, developed to facilitate quick generation of small finite-element models using CASA/GIFTS finite-element modeling program. Reads geometric data of drawing from Data Exchange File (DXF) used in AutoCAD and other PC-based drafting programs. Geometric entities recognized by ACTOG include points, lines, arcs, solids, three-dimensional lines, and three-dimensional faces. From this information, ACTOG creates GIFTS SRC file, which then reads into GIFTS preprocessor BULKM or modified and reads into EDITM to create finite-element model. SRC file used as is or edited for any number of uses. Written in Microsoft Quick-Basic (Version 2.0).

  11. DFE workbench: a CAD integrated DFE tool

    NASA Astrophysics Data System (ADS)

    Man, Elena; Diez-Campo, Juan E.; Roche, Thomas

    2002-02-01

    Because of the emergent legislation (e.g. WEEE and EOLV), environmental standards (e.g. ISO 14000) and a shift in consumer opinion toward environmentally superior products, there is an increased need for CAD integrated Design for Environment tools to assist the designer in the development of environmentally superior products (ESP). Implementing Design for the Environment practices is an extremely effective strategy, as it is widely believed that 95% of development costs are determined at this stage. Many methodologies and tools have been developed to perform environmental analysis; however, many existing methodologies are inadequately integrated in the design process. This paper addresses these problems and presents a CAD integrated DFE tool that has been under development in the authors' institutes for the last number of years.

  12. Generating Composite Overlapping Grids on CAD Geometries

    SciTech Connect

    Henshaw, W.D.

    2002-02-07

    We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids using hyperbolic grid generation, and (5) generate the overlapping grid by determining the holes and the interpolation points. The overlapping grid generator which is used for the final step also supports the rapid generation of grids for block-structured adaptive mesh refinement and for moving grids. These algorithms have been implemented as part of the Overture object-oriented framework.

  13. Dissociation of HSV gL from gH by αvβ6- or αvβ8-integrin promotes gH activation and virus entry

    PubMed Central

    Gianni, Tatiana; Massaro, Raffaele; Campadelli-Fiume, Gabriella

    2015-01-01

    Herpes simplex virus (HSV) is an important human pathogen. It enters cells through an orchestrated process that requires four essential glycoproteins, gD, gH/gL, and gB, activated in cascade fashion by receptor-binding and signaling. gH/gL heterodimer is conserved across the Herpesviridae family. HSV entry is enabled by gH/gL interaction with αvβ6- or αvβ8-integrin receptors. We report that the interaction of virion gH/gL with integrins resulted in gL dissociation and its release in the medium. gL dissociation occurred if all components of the entry apparatus—receptor-bound gD and gB—were present and was prevented if entry was blocked by a neutralizing monoclonal antibody to gH or by a mutation in gH. We propose that (i) gL dissociation from gH/gL is part of the activation of HSV glycoproteins, critical for HSV entry; and (ii) gL is a functional inhibitor of gH and maintains gH in an inhibited form until receptor-bound gD and integrins signal to gH/gL. PMID:26157134

  14. Computer-aided-diagnosis (CAD) for colposcopy

    NASA Astrophysics Data System (ADS)

    Lange, Holger; Ferris, Daron G.

    2005-04-01

    Uterine cervical cancer is the second most common cancer among women worldwide. Colposcopy is a diagnostic method, whereby a physician (colposcopist) visually inspects the lower genital tract (cervix, vulva and vagina), with special emphasis on the subjective appearance of metaplastic epithelium comprising the transformation zone on the cervix. Cervical cancer precursor lesions and invasive cancer exhibit certain distinctly abnormal morphologic features. Lesion characteristics such as margin; color or opacity; blood vessel caliber, intercapillary spacing and distribution; and contour are considered by colposcopists to derive a clinical diagnosis. Clinicians and academia have suggested and shown proof of concept that automated image analysis of cervical imagery can be used for cervical cancer screening and diagnosis, having the potential to have a direct impact on improving women"s health care and reducing associated costs. STI Medical Systems is developing a Computer-Aided-Diagnosis (CAD) system for colposcopy -- ColpoCAD. At the heart of ColpoCAD is a complex multi-sensor, multi-data and multi-feature image analysis system. A functional description is presented of the envisioned ColpoCAD system, broken down into: Modality Data Management System, Image Enhancement, Feature Extraction, Reference Database, and Diagnosis and directed Biopsies. The system design and development process of the image analysis system is outlined. The system design provides a modular and open architecture built on feature based processing. The core feature set includes the visual features used by colposcopists. This feature set can be extended to include new features introduced by new instrument technologies, like fluorescence and impedance, and any other plausible feature that can be extracted from the cervical data. Preliminary results of our research on detecting the three most important features: blood vessel structures, acetowhite regions and lesion margins are shown. As this is a new

  15. CAD Integration : new optical design possibilities

    NASA Astrophysics Data System (ADS)

    Haumonte, Jean-Baptiste; Venturino, Jean-Claude

    2005-09-01

    The development of optical design and analysis tools in a CAD software can help to optimise the design, size and performance of tomorrow's consumer products. While optics was still held back by software limitations, CAD programs were moving forward in leaps and bounds, improving manufacturing technologies and making it possible to design and produce highly innovative and sophisticated products. The problem was that in the past, 'traditional' optical design programs were only able to simulate spherical and aspherical lenses, meaning that the optical designers were limited to designing systems which were a series of imperfect lenses, each one correcting the last. That is why OPTIS has created the first optical design program to be fully integrated into a CAD program. The technology is available from OPTIS in an integrated SOLIDWORKS or CATIA V5 version. Users of this software can reduce the number of lenses needed in a system. Designers will now have access to complex surfaces such as NURBS meaning they will now be able to define free shape progressive lenses and even improve on optical performances using fewer lenses. This revolutionary technology will allow mechanical designers to work on optical systems and to share information with optical designers for the first time. Previously not possible in a CAD program you may now determine all the optical performances of any optical system, providing first order and third order performances, sequential and non-sequential ray-tracing, wavefront surfaces, point spread function, MTF, spot-diagram, using real optical surfaces and guaranteeing the mechanical precision necessary for an optical system.

  16. [A dissociative patient].

    PubMed

    de Jongh, A; Abkhezr, S; Broers, D L M

    2009-08-01

    A 45-year-old woman attended a centre for special dental care. Initially, it seemed that the patient suffered from an extreme form of dental anxiety. However, the fact that she displayed 'dissociations' suggested that she had a severe psychiatric disorder, in this case Dissociative Identity Disorder. The key feature of this condition is a dysfunction of the normal integrative functions of identity, memory and consciousness. In such instances it is recommended to contact a psychologist or psychiatrist and the referring care provider to consider the consequences of the psychiatric condition regarding informed consent, treatment plan and actual treatment. Because it was not likely that the patient would respond to an intervention specifically aimed to reduce anxiety in the dental setting, dental treatment under general anesthesia was the best suited option.

  17. Computer-aided diagnosis (CAD) for colonoscopy

    NASA Astrophysics Data System (ADS)

    Gu, Jia; Poirson, Allen

    2007-03-01

    Colorectal cancer is the second leading cause of cancer deaths, and ranks third for new cancer cases and cancer mortality for both men and women. However, its death rate can be dramatically reduced by appropriate treatment when early detection is available. The purpose of colonoscopy is to identify and assess the severity of lesions, which may be flat or protruding. Due to the subjective nature of the examination, colonoscopic proficiency is highly variable and dependent upon the colonoscopist's knowledge and experience. An automated image processing system providing an objective, rapid, and inexpensive analysis of video from a standard colonoscope could provide a valuable tool for screening and diagnosis. In this paper, we present the design, functionality and preliminary results of its Computer-Aided-Diagnosis (CAD) system for colonoscopy - ColonoCAD TM. ColonoCAD is a complex multi-sensor, multi-data and multi-algorithm image processing system, incorporating data management and visualization, video quality assessment and enhancement, calibration, multiple view based reconstruction, feature extraction and classification. As this is a new field in medical image processing, our hope is that this paper will provide the framework to encourage and facilitate collaboration and discussion between industry, academia, and medical practitioners.

  18. Dissociation and psychotic symptoms.

    PubMed

    Steingard, S; Frankel, F H

    1985-08-01

    The literature on hysterical or brief reactive psychosis reflects great diversity both in clinical description and theoretical formulation. The authors describe the case of a 17-year-old girl who presented with a diagnosis of bipolar affective disorder, rapid cycling type, but who, in fact, was experiencing dissociative episodes manifested as psychotic states. The patient's successful treatment with hypnosis is described, along with the clinical and theoretical implications of the case.

  19. Mechanical design productivity using CAD graphics - A user's point of view

    NASA Astrophysics Data System (ADS)

    Boltz, R. J.; Avery, J. T., Jr.

    1985-02-01

    The present investigation is concerned with the mechanical design productivity resulting from the use of Computer-Aided Design (CAD) graphics as a design tool. The considered studies had been conducted by a company which is involved in the design, development, and manufacture of government and defense products. Attention is given to CAD graphics for mechanical design, productivity, an overall productivity assessment, the use of CAD graphics for basic mechanical design, productivity in engineering-related areas, and an overall engineering productivity assessment. The investigation shows that there was no appreciable improvement in productivity with respect to basic mechanical design. However, rather substantial increases could be realized in productivity for engineering-related activities.

  20. CAD in the processing plant environment or managing the CAD revolution

    SciTech Connect

    Woolbert, M.A.; Bennett, R.S.; Haring, W.I.

    1985-10-01

    The author presents a case report on the use of a Computer Aided Design/Computer Aided Drafting (CAD) system. Illustrated is a four-work station system, in addition to which there are two 70 megabyte disk drives, a check plotter and a 24-inch wide electrostatic plotter, a 300 megabyte disk for on-line storage, a tape drive for archive and backup, and a 1-megabyte network process server. It is a distributed logic system. The author states that the CAD system both inexpensive enough and powerful enough for the plant environment is relatively new on the market, made possible by the advent of super microcomputers. Also discussed is the impact the CAD system has had on productivity.

  1. The Role of Flow Experience and CAD Tools in Facilitating Creative Behaviours for Architecture Design Students

    ERIC Educational Resources Information Center

    Dawoud, Husameddin M.; Al-Samarraie, Hosam; Zaqout, Fahed

    2015-01-01

    This study examined the role of flow experience in intellectual activity with an emphasis on the relationship between flow experience and creative behaviour in design using CAD. The study used confluence and psychometric approaches because of their unique abilities to depict a clear image of creative behaviour. A cross-sectional study…

  2. Using Claris CAD To Develop a Floor Plan. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Pawlowicz, Bruce; Johnson, Tom

    This learning module for a high school architectural drafting course introduces students to the use of Claris CAD (Computer Aided Drafting) to develop a floor plan. The six sections of the module are the following: module objectives, content outline, teaching methods, student activities, resource list, and evaluation (pretest, posttest). Student…

  3. Arabidopsis thaliana phytochelatin synthase 2 is constitutively active in vivo and can rescue the growth defect of the PCS1-deficient cad1-3 mutant on Cd-contaminated soil

    PubMed Central

    Kühnlenz, Tanja; Schmidt, Holger; Uraguchi, Shimpei; Clemens, Stephan

    2014-01-01

    Phytochelatins play a key role in the detoxification of metals in plants and many other eukaryotes. Their formation is catalysed by phytochelatin synthases (PCS) in the presence of metal excess. It appears to be common among higher plants to possess two PCS genes, even though in Arabidopsis thaliana only AtPCS1 has been demonstrated to confer metal tolerance. Employing a highly sensitive quantification method based on ultraperformance electrospray ionization quadrupole time-of-flight mass spectrometry, we detected AtPCS2-dependent phytochelatin formation. Overexpression of AtPCS2 resulted in constitutive phytochelatin accumulation, i.e. in the absence of metal excess, both in planta and in a heterologous system. This indicates distinct enzymatic differences between AtPCS1 and AtPCS2. Furthermore, AtPCS2 was able to partially rescue the Cd hypersensitivity of the AtPCS1-deficient cad1-3 mutant in a liquid seedling assay, and, more importantly, when plants were grown on soil spiked with Cd to a level that is close to what can be found in agricultural soils. No rescue was found in vertical-plate assays, the most commonly used method to assess metal tolerance. Constitutive AtPCS2-dependent phytochelatin synthesis suggests a physiological role of AtPCS2 other than metal detoxification. The differences observed between wild-type plants and cad1-3 on Cd soil demonstrated: (i) the essentiality of phytochelatin synthesis for tolerating levels of Cd contamination that can naturally be encountered by plants outside of metal-rich habitats, and (ii) a contribution to Cd accumulation under these conditions. PMID:24821959

  4. Arabidopsis thaliana phytochelatin synthase 2 is constitutively active in vivo and can rescue the growth defect of the PCS1-deficient cad1-3 mutant on Cd-contaminated soil.

    PubMed

    Kühnlenz, Tanja; Schmidt, Holger; Uraguchi, Shimpei; Clemens, Stephan

    2014-08-01

    Phytochelatins play a key role in the detoxification of metals in plants and many other eukaryotes. Their formation is catalysed by phytochelatin synthases (PCS) in the presence of metal excess. It appears to be common among higher plants to possess two PCS genes, even though in Arabidopsis thaliana only AtPCS1 has been demonstrated to confer metal tolerance. Employing a highly sensitive quantification method based on ultraperformance electrospray ionization quadrupole time-of-flight mass spectrometry, we detected AtPCS2-dependent phytochelatin formation. Overexpression of AtPCS2 resulted in constitutive phytochelatin accumulation, i.e. in the absence of metal excess, both in planta and in a heterologous system. This indicates distinct enzymatic differences between AtPCS1 and AtPCS2. Furthermore, AtPCS2 was able to partially rescue the Cd hypersensitivity of the AtPCS1-deficient cad1-3 mutant in a liquid seedling assay, and, more importantly, when plants were grown on soil spiked with Cd to a level that is close to what can be found in agricultural soils. No rescue was found in vertical-plate assays, the most commonly used method to assess metal tolerance. Constitutive AtPCS2-dependent phytochelatin synthesis suggests a physiological role of AtPCS2 other than metal detoxification. The differences observed between wild-type plants and cad1-3 on Cd soil demonstrated: (i) the essentiality of phytochelatin synthesis for tolerating levels of Cd contamination that can naturally be encountered by plants outside of metal-rich habitats, and (ii) a contribution to Cd accumulation under these conditions.

  5. Recurrent dissociative fugue.

    PubMed

    Mamarde, Abhishek; Navkhare, Praveen; Singam, Amrita; Kanoje, Akash

    2013-10-01

    Dissociative fugue is a rarely reported diagnostic entity. It is one of the least understood and yet clinically one of the most fascinating disorders in mental health. Here, we describe a case of fugue in a 32-year-old man who was brought to mental hospital with complete loss of memory for events pertaining to identity of self. This case illustrates the nature of presentation in hospital setting like mental hospital and effort taken to reintegrate his identity and reunite with his family. PMID:24379504

  6. Recurrent dissociative fugue.

    PubMed

    Mamarde, Abhishek; Navkhare, Praveen; Singam, Amrita; Kanoje, Akash

    2013-10-01

    Dissociative fugue is a rarely reported diagnostic entity. It is one of the least understood and yet clinically one of the most fascinating disorders in mental health. Here, we describe a case of fugue in a 32-year-old man who was brought to mental hospital with complete loss of memory for events pertaining to identity of self. This case illustrates the nature of presentation in hospital setting like mental hospital and effort taken to reintegrate his identity and reunite with his family.

  7. Recurrent Dissociative Fugue

    PubMed Central

    Mamarde, Abhishek; Navkhare, Praveen; Singam, Amrita; Kanoje, Akash

    2013-01-01

    Dissociative fugue is a rarely reported diagnostic entity. It is one of the least understood and yet clinically one of the most fascinating disorders in mental health. Here, we describe a case of fugue in a 32-year-old man who was brought to mental hospital with complete loss of memory for events pertaining to identity of self. This case illustrates the nature of presentation in hospital setting like mental hospital and effort taken to reintegrate his identity and reunite with his family. PMID:24379504

  8. Blackbody Infrared Radiative Dissociation of Protonated Oligosaccharides

    NASA Astrophysics Data System (ADS)

    Fentabil, Messele A.; Daneshfar, Rambod; Kitova, Elena N.; Klassen, John S.

    2011-12-01

    The dissociation pathways, kinetics, and energetics of protonated oligosaccharides in the gas phase were investigated using blackbody infrared radiative dissociation (BIRD). Time-resolved BIRD measurements were performed on singly protonated ions of cellohexaose (Cel6), which is composed of β-(1 → 4)-linked glucopyranose rings, and five malto-oligosaccharides (Malx, where x = 4-8), which are composed of α-(1 → 4)-linked glucopyranose units. At the temperatures investigated (85-160 °C), the oligosaccharides dissociate at the glycosidic linkages or by the loss of a water molecule to produce B- or Y-type ions. The Y ions dissociate to smaller Y or B ions, while the B ions yield exclusively smaller B ions. The sequential loss of water molecules from the smallest B ions (B1 and B2) also occurs. Rate constants for dissociation of the protonated oligosaccharides and the corresponding Arrhenius activation parameters (Ea and A) were determined. The Ea and A-factors measured for protonated Malx (x > 4) are indistinguishable within error (~19 kcal mol-1, 1010 s-1), which is consistent with the ions being in the rapid energy exchange limit. In contrast, the Arrhenius parameters for protonated Cel6 (24 kcal mol-1, 1012 s-1) are significantly larger. These results indicate that both the energy and entropy changes associated with the glycosidic bond cleavage are sensitive to the anomeric configuration. Based on the results of this study, it is proposed that formation of B and Y ions occurs through a common dissociation mechanism, with the position of the proton establishing whether a B or Y ion is formed upon glycosidic bond cleavage.

  9. THE DISSOCIATIVE TURN IN PSYCHOANALYSIS.

    PubMed

    Itzkowitz, Sheldon

    2015-06-01

    In his response to the Roundtable Discussions on what is effective in psychoanalytic psychotherapy, the author focuses on the renewed interest in the concept of dissociation that began to emerge toward the end of the 20th century. A contemporary psychoanalytic position informed by the impact of developmental trauma has led to an understanding of and interest in the dissociative mind. The actuality of trauma during infancy and early childhood is recognized as a key factor leading to the emergence of dissociative processes, the potential dissociative structuring of the mind, and mind being characterized by multiple, discontinuous, centers of consciousness. The therapeutic goal in the psychoanalytic work with fragmented patients is to establish communication and understanding between the dissociated self-states. The author offers two brief clinical examples of working with dissociated self-states.

  10. False positive reduction for lung nodule CAD

    NASA Astrophysics Data System (ADS)

    Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.

    2007-03-01

    Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.

  11. Dissociative state and competence.

    PubMed

    Lin, Yu-Ju; Hsieh, Ming-Hsien; Liu, Shi-Kai

    2007-10-01

    This report presents the results of forensic evaluation of the civil competence of a case of alleged dissociative identity disorder (DID) and discusses whether such dissociative states substantially jeopardize civil competence. A 40-year-old woman claimed that she had had many personalities since her college days. From the age of 37 to 40, she shopped excessively, which left her with millions of dollars of debt. She ascribed her shopping to a certain identity state, over which she had no control. (In this article, we use the term identity state to replace personality as an objective description of a mental state.) She thus raised the petition of civil incompetence. During the forensic evaluation, it was found that the identity states were relatively stable and mutually aware of each other. The switch into another identity state was sometimes under voluntary control. The subject showed consistency and continuity in behavioral patterns across the different identity states, and no matter which identity state she was in, there was no evidence of impairment in her factual knowledge of social situations and her capacity for managing personal affairs. We hence concluded that she was civilly competent despite the claimed DID. Considering that the existence and diagnosis of DID are still under dispute and a diagnosis of DID alone is not sufficient to interdict a persons civil right, important clinical and forensic issues remain to be answered.

  12. Dissociative Electron Attachment

    NASA Astrophysics Data System (ADS)

    Arreola, Esmeralda; Esmeralda Arreola Collaboration; Leigh Hargreaves Collaboration

    Since the pioneering work of Boudiaffa et al., it has been understood that electrons, even with energies near or below the ionization threshold, are capable of initiating strand-breaks in human DNA. This discovery raised important questions for cancer treatments, since sub-ionizing electrons are known to be the most copiously produced secondary product of radiation therapy. But even to date these factors are largely excluded from dosimetry calculations. This lack of inclusion is, at least in part, certainly due to the dearth of fundamental data describing low-energy electron interactions with nucleotide molecules that form the basis of DNA. Understanding of how such slow electrons are able to damage DNA remains incomplete, but the strongly peaked nature of Boudiaffa et al.'s data gives strong hints at resonantly driven collision processes. DNA damage is therefore most likely driven by ``dissociative electron attachment'' (DEA). DEA is a rather complicated process to model due to the coupling of electronic and nuclear degrees of freedom in the molecule. At the California State University Fullerton, we are currently commissioning a new spectrometer to study dissociation channels, reaction rates and orientation effects in DEA collisions between slow electrons and nucleotide molecules. At the meeting we will present design parameters and commissioning data for this new apparatus.

  13. DIFFRACTION DISSOCIATION - 50 YEARS LATER.

    SciTech Connect

    WHITE, S.N.

    2005-04-27

    The field of Diffraction Dissociation, which is the subject of this workshop, began 50 years ago with the analysis of deuteron stripping in low energy collisions with nuclei. We return to the subject in a modern context- deuteron dissociation in {radical}s{sub NN} = 200 GeV d-Au collisions recorded during the 2003 RHIC run in the PHENIX experiment. At RHIC energy, d {yields} n+p proceeds predominantly (90%) through Electromagnetic Dissociation and the remaining fraction via the hadronic shadowing described by Glauber. Since the dissociation cross section has a small theoretical error we adopt this process to normalize other cross sections measured in RHIC.

  14. Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

    PubMed Central

    2014-01-01

    Background In recent decades cultivation of flax and its application have dramatically decreased. One of the reasons for this is unpredictable quality and properties of flax fibre, because they depend on environmental factors, retting duration and growing conditions. These factors have contribution to the fibre composition, which consists of cellulose, hemicelluloses, lignin and pectin. By far, it is largely established that in flax, lignin reduces an accessibility of enzymes either to pectin, hemicelluloses or cellulose (during retting or in biofuel synthesis and paper production). Therefore, in this study we evaluated composition and properties of flax fibre from plants with silenced CAD (cinnamyl alcohol dehydrogenase) gene, which is key in the lignin biosynthesis. There is evidence that CAD is a useful tool to improve lignin digestibility and/or to lower the lignin levels in plants. Results Two studied lines responded differentially to the introduced modification due to the efficiency of the CAD silencing. Phylogenetic analysis revealed that flax CAD belongs to the “bona-fide” CAD family. CAD down-regulation had an effect in the reduced lignin amount in the flax fibre cell wall and as FT-IR results suggests, disturbed lignin composition and structure. Moreover introduced modification activated a compensatory mechanism which was manifested in the accumulation of cellulose and/or pectin. These changes had putative correlation with observed improved fiber’s tensile strength. Moreover, CAD down-regulation did not disturb at all or has only slight effect on flax plants’ development in vivo, however, the resistance against flax major pathogen Fusarium oxysporum decreased slightly. The modification positively affected fibre possessing; it resulted in more uniform retting. Conclusion The major finding of our paper is that the modification targeted directly to block lignin synthesis caused not only reduced lignin level in fibre, but also affected amount and

  15. Hyperglycemia associated dissociative fugue (organic dissociative disorder) in an elderly

    PubMed Central

    Ram, Dushad; Ashoka, H. G; Gowdappa, Basavnna

    2015-01-01

    Inadequate glycemic control in patients with diabetes is known to be associated with psychiatric disorders such as depression, anxiety disorder, and cognitive impairment. However, dissociative syndrome has not been reported so far. Here we are reporting a case of repeated dissociative fugue associated with hyperglycemia, in an elderly with type II diabetes. Possible neurobiological mechanism has been discussed. PMID:26286620

  16. Mammogram CAD, hybrid registration and iconic analysis

    NASA Astrophysics Data System (ADS)

    Boucher, A.; Cloppet, F.; Vincent, N.

    2013-03-01

    This paper aims to develop a computer aided diagnosis (CAD) based on a two-step methodology to register and analyze pairs of temporal mammograms. The concept of "medical file", including all the previous medical information on a patient, enables joint analysis of different acquisitions taken at different times, and the detection of significant modifications. The developed registration method aims to superimpose at best the different anatomical structures of the breast. The registration is designed in order to get rid of deformation undergone by the acquisition process while preserving those due to breast changes indicative of malignancy. In order to reach this goal, a referent image is computed from control points based on anatomical features that are extracted automatically. Then the second image of the couple is realigned on the referent image, using a coarse-to-fine approach according to expert knowledge that allows both rigid and non-rigid transforms. The joint analysis detects the evolution between two images representing the same scene. In order to achieve this, it is important to know the registration error limits in order to adapt the observation scale. The approach used in this paper is based on an image sparse representation. Decomposed in regular patterns, the images are analyzed under a new angle. The evolution detection problem has many practical applications, especially in medical images. The CAD is evaluated using recall and precision of differences in mammograms.

  17. Memory repression: brain mechanisms underlying dissociative amnesia.

    PubMed

    Kikuchi, Hirokazu; Fujii, Toshikatsu; Abe, Nobuhito; Suzuki, Maki; Takagi, Masahito; Mugikura, Shunji; Takahashi, Shoki; Mori, Etsuro

    2010-03-01

    Dissociative amnesia usually follows a stressful event and cannot be attributable to explicit brain damage. It is thought to reflect a reversible deficit in memory retrieval probably due to memory repression. However, the neural mechanisms underlying this condition are not clear. We used fMRI to investigate neural activity associated with memory retrieval in two patients with dissociative amnesia. For each patient, three categories of face photographs and three categories of people's names corresponding to the photographs were prepared: those of "recognizable" high school friends who were acquainted with and recognizable to the patients, those of "unrecognizable" colleagues who were actually acquainted with but unrecognizable to the patients due to their memory impairments, and "control" distracters who were unacquainted with the patients. During fMRI, the patients were visually presented with these stimuli and asked to indicate whether they were personally acquainted with them. In the comparison of the unrecognizable condition with the recognizable condition, we found increased activity in the pFC and decreased activity in the hippocampus in both patients. After treatment for retrograde amnesia, the altered pattern of brain activation disappeared in one patient whose retrograde memories were recovered, whereas it remained unchanged in the other patient whose retrograde memories were not recovered. Our findings provide direct evidence that memory repression in dissociative amnesia is associated with an altered pattern of neural activity, and they suggest the possibility that the pFC has an important role in inhibiting the activity of the hippocampus in memory repression.

  18. DISSOCIATION OF 70S RIBOSOMES: SOME PROPERTIES OF THE DISSOCIATING FACTOR FROM Bacillus stearothermophilus AND Escherichia coli*

    PubMed Central

    Bade, Ernesto G.; González, Nelida S.; Algranati, Israel D.

    1969-01-01

    A protein factor which produces in vitro dissociation of 70S particles into 30S and 50S subunits has been obtained from Bacillus stearothermophilus and Escherichia coli. The factor could be extracted from ribosomes, polyribosomes, and S100 supernatant. The kinetics and temperature curve of the dissociation process in the B. stearothermophilus system have been studied and compared with the reaction in the E. coli system. No species specificity was observed when hybrid mixtures of ribosomes and dissociating factor from both bacteria were used. The wide variations of dissociating activity in cells at different stages of growth and the capacity of the liberated subunits to carry out polypeptide synthesis suggest that the dissociating factor has a physiological role. PMID:4901704

  19. Astronaut EVA exposure estimates from CAD model spacesuit geometry.

    PubMed

    De Angelis, Giovanni; Anderson, Brooke M; Atwell, William; Nealy, John E; Qualls, Garry D; Wilson, John W

    2004-03-01

    Ongoing assembly and maintenance activities at the International Space Station (ISS) require much more extravehicular activity (EVA) than did the earlier U.S. Space Shuttle missions. It is thus desirable to determine and analyze, and possibly foresee, as accurately as possible what radiation exposures crew members involved in EVAs will experience in order to minimize risks and to establish exposure limits that must not to be exceeded. A detailed CAD model of the U.S. Space Shuttle EVA Spacesuit, developed at NASA Langley Research Center (LaRC), is used to represent the directional shielding of an astronaut; it has detailed helmet and backpack structures, hard upper torso, and multilayer space suit fabric material. The NASA Computerized Anatomical Male and Female (CAM and CAF) models are used in conjunction with the space suit CAD model for dose evaluation within the human body. The particle environments are taken from the orbit-averaged NASA AP8 and AE8 models at solar cycle maxima and minima. The transport of energetic particles through space suit materials and body tissue is calculated by using the NASA LaRC HZETRN code for hadrons and a recently developed deterministic transport code, ELTRN, for electrons. The doses within the CAM and CAF models are determined from energy deposition at given target points along 968 directional rays convergent on the points and are evaluated for several points on the skin and within the body. Dosimetric quantities include contributions from primary protons, light ions, and electrons, as well as from secondary brehmsstrahlung and target fragments. Directional dose patterns are displayed as rays and on spherical surfaces by the use of a color relative intensity representation. PMID:15133283

  20. Astronaut EVA exposure estimates from CAD model spacesuit geometry.

    PubMed

    De Angelis, Giovanni; Anderson, Brooke M; Atwell, William; Nealy, John E; Qualls, Garry D; Wilson, John W

    2004-03-01

    Ongoing assembly and maintenance activities at the International Space Station (ISS) require much more extravehicular activity (EVA) than did the earlier U.S. Space Shuttle missions. It is thus desirable to determine and analyze, and possibly foresee, as accurately as possible what radiation exposures crew members involved in EVAs will experience in order to minimize risks and to establish exposure limits that must not to be exceeded. A detailed CAD model of the U.S. Space Shuttle EVA Spacesuit, developed at NASA Langley Research Center (LaRC), is used to represent the directional shielding of an astronaut; it has detailed helmet and backpack structures, hard upper torso, and multilayer space suit fabric material. The NASA Computerized Anatomical Male and Female (CAM and CAF) models are used in conjunction with the space suit CAD model for dose evaluation within the human body. The particle environments are taken from the orbit-averaged NASA AP8 and AE8 models at solar cycle maxima and minima. The transport of energetic particles through space suit materials and body tissue is calculated by using the NASA LaRC HZETRN code for hadrons and a recently developed deterministic transport code, ELTRN, for electrons. The doses within the CAM and CAF models are determined from energy deposition at given target points along 968 directional rays convergent on the points and are evaluated for several points on the skin and within the body. Dosimetric quantities include contributions from primary protons, light ions, and electrons, as well as from secondary brehmsstrahlung and target fragments. Directional dose patterns are displayed as rays and on spherical surfaces by the use of a color relative intensity representation.

  1. Subliminal processes, dissociation and the 'I'.

    PubMed

    Bob, Petr

    2003-06-01

    The study of unconscious processes leads to the hypothesis of the limit of consciousness, which involves two main kinds of psychic activity. The first represents psychic contents which are subliminal for their low energy, the second subliminal contents which are inaccessible to consciousness because they are dissociated in the subliminal region. Dissociation is a concept introduced by Pierre Janet for splitting consciousness due to traumatic events or during hypnosis. It takes a more general form in Hilgard's neo-dissociation theory of hypnotic phenomena and also in Jung's theory of the collective unconscious. Further generalization links it to the modern findings of explicit and implicit perception, leading to a shift in dissociation from hypothesis to clinical, experimental and theoretical reality. Studies in hypnosis also point to the existence of an integrative psychic entity, that comprises the conscious 'I'. Hilgard called this the hidden observer, and his findings represent empirical confirmation of Jung's term for the Self as mirror 'I', which leads to many important consequences for self-discovery and the meaning of life.

  2. Dissociative States and Neural Complexity

    ERIC Educational Resources Information Center

    Bob, Petr; Svetlak, Miroslav

    2011-01-01

    Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of…

  3. Dissociation Patterns in Evolving Populations

    NASA Astrophysics Data System (ADS)

    Moreno, F. J.; Hernández, J. A.; Sánchez, F.

    2011-09-01

    The recent explosion and availability of mobility based technologies such as geographic information systems, cell phones equipped with built-in GPS, among others, are a valuable source of spatio-temporal data. However, only recently there have been works focused on identifying movement patterns in groups of moving entities. We focus on a particular movement pattern: dissociation. A dissociation pattern occurs when an entity that was once associated to a population, eventually separated from it and subsequently reintegrated it again. The backwarding and forwarding patterns are a type of dissociation where an entity stays behind or ahead of another entity, respectively. Dissociation really is a diversity generator, so instead avoiding it, taking advantage could be better to prevent premature convergence in evolutionary algorithms. In this work, we present formal mathematical definitions for these patterns. A discussion of how to use dissociation patterns as a mean to preserve diversity in evolutionary algorithms is also shown.

  4. An Evaluation of Internet-Based CAD Collaboration Tools

    ERIC Educational Resources Information Center

    Smith, Shana Shiang-Fong

    2004-01-01

    Due to the now widespread use of the Internet, most companies now require computer aided design (CAD) tools that support distributed collaborative design on the Internet. Such CAD tools should enable designers to share product models, as well as related data, from geographically distant locations. However, integrated collaborative design…

  5. Preparing Students for Computer Aided Drafting (CAD). A Conceptual Approach.

    ERIC Educational Resources Information Center

    Putnam, A. R.; Duelm, Brian

    This presentation outlines guidelines for developing and implementing an introductory course in computer-aided drafting (CAD) that is geared toward secondary-level students. The first section of the paper, which deals with content identification and selection, includes lists of mechanical drawing and CAD competencies and a list of rationales for…

  6. An Instructional Method for the AutoCAD Modeling Environment.

    ERIC Educational Resources Information Center

    Mohler, James L.

    1997-01-01

    Presents a command organizer for AutoCAD to aid new uses in operating within the 3-D modeling environment. Addresses analyzing the problem, visualization skills, nonlinear tools, a static view of a dynamic model, the AutoCAD organizer, environment attributes, and control of the environment. Contains 11 references. (JRH)

  7. CAD/CAM: Practical and Persuasive in Canadian Schools

    ERIC Educational Resources Information Center

    Willms, Ed

    2007-01-01

    Chances are that many high school students would not know how to use drafting instruments, but some might want to gain competence in computer-assisted design (CAD) and possibly computer-assisted manufacturing (CAM). These students are often attracted to tech courses by the availability of CAD/CAM instructions, and many go on to impress employers…

  8. Evaluating the Learning Process of Mechanical CAD Students

    ERIC Educational Resources Information Center

    Hamade, R. F.; Artail, H. A.; Jaber, M. Y.

    2007-01-01

    There is little theoretical or experimental research on how beginner-level trainees learn CAD skills in formal training sessions. This work presents findings on how trainees develop their skills in utilizing a solid mechanical CAD tool (Pro/Engineer version 2000i[squared] and later version Wildfire). Exercises at the beginner and intermediate…

  9. Making a Case for CAD in the Curriculum.

    ERIC Educational Resources Information Center

    Threlfall, K. Denise

    1995-01-01

    Computer-assisted design (CAD) technology is transforming the apparel industry. Students of fashion merchandising and clothing design must be prepared on state-of-the-art equipment. ApparelCAD software is one example of courseware for instruction in pattern design and production. (SK)

  10. Novel CAD-ALK gene rearrangement is drugable by entrectinib in colorectal cancer

    PubMed Central

    Amatu, Alessio; Somaschini, Alessio; Cerea, Giulio; Bosotti, Roberta; Valtorta, Emanuele; Buonandi, Pasquale; Marrapese, Giovanna; Veronese, Silvio; Luo, David; Hornby, Zachary; Multani, Pratik; Murphy, Danielle; Shoemaker, Robert; Lauricella, Calogero; Giannetta, Laura; Maiolani, Martina; Vanzulli, Angelo; Ardini, Elena; Galvani, Arturo; Isacchi, Antonella; Sartore-Bianchi, Andrea; Siena, Salvatore

    2015-01-01

    Background: Activated anaplastic lymphoma kinase (ALK) gene fusions are recurrent events in a small fraction of colorectal cancers (CRCs), although these events have not yet been exploited as in other malignancies. Methods: We detected ALK protein expression by immunohistochemistry and gene rearrangements by fluorescence in situ hybridisation in the ALKA-372-001 phase I study of the pan-Trk, ROS1, and ALK inhibitor entrectinib. One out of 487 CRCs showed ALK positivity with a peculiar pattern that prompted further characterisation by targeted sequencing using anchored multiplex PCR. Results: A novel ALK fusion with the carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) gene (CAD-ALK fusion gene) was identified. It resulted from inversion within chromosome 2 and the fusion of exons 1–35 of CAD with exons 20–29 of ALK. After failure of previous standard therapies, treatment of this patient with the ALK inhibitor entrectinib resulted in a durable objective tumour response. Conclusions: We describe the novel CAD-ALK rearrangement as an oncogene and provide the first evidence of its drugability as a new molecular target in CRC. PMID:26633560

  11. A structural view of the dissociation of Escherichia coli tryptophanase.

    PubMed

    Green, Keren; Qasim, Nasrin; Gdaelvsky, Garik; Kogan, Anna; Goldgur, Yehuda; Parola, Abraham H; Lotan, Ofra; Almog, Orna

    2015-12-01

    Tryptophanase (Trpase) is a pyridoxal 5'-phosphate (PLP)-dependent homotetrameric enzyme which catalyzes the degradation of L-tryptophan. Trpase is also known for its cold lability, which is a reversible loss of activity at low temperature (2°C) that is associated with the dissociation of the tetramer. Escherichia coli Trpase dissociates into dimers, while Proteus vulgaris Trpase dissociates into monomers. As such, this enzyme is an appropriate model to study the protein-protein interactions and quaternary structure of proteins. The aim of the present study was to understand the differences in the mode of dissociation between the E. coli and P. vulgaris Trpases. In particular, the effect of mutations along the molecular axes of homotetrameric Trpase on its dissociation was studied. To answer this question, two groups of mutants of the E. coli enzyme were created to resemble the amino-acid sequence of P. vulgaris Trpase. In one group, residues 15 and 59 that are located along the molecular axis R (also termed the noncatalytic axis) were mutated. The second group included a mutation at position 298, located along the molecular axis Q (also termed the catalytic axis). Replacing amino-acid residues along the R axis resulted in dissociation of the tetramers into monomers, similar to the P. vulgaris Trpase, while replacing amino-acid residues along the Q axis resulted in dissociation into dimers only. The crystal structure of the V59M mutant of E. coli Trpase was also determined in its apo form and was found to be similar to that of the wild type. This study suggests that in E. coli Trpase hydrophobic interactions along the R axis hold the two monomers together more strongly, preventing the dissociation of the dimers into monomers. Mutation of position 298 along the Q axis to a charged residue resulted in tetramers that are less susceptible to dissociation. Thus, the results indicate that dissociation of E. coli Trpase into dimers occurs along the molecular Q axis.

  12. Training a CAD classifier with correlated data

    NASA Astrophysics Data System (ADS)

    Dundar, Murat; Krishnapuram, Balaji; Wolf, Matthias; Lakare, Sarang; Bogoni, Luca; Bi, Jinbo; Rao, R. Bharat

    2007-03-01

    Most methods for classifier design assume that the training samples are drawn independently and identically from an unknown data generating distribution (i.i.d.), although this assumption is violated in several real life problems. Relaxing this i.i.d. assumption, we develop training algorithms for the more realistic situation where batches or sub-groups of training samples may have internal correlations, although the samples from different batches may be considered to be uncorrelated; we also consider the extension to cases with hierarchical--i.e. higher order--correlation structure between batches of training samples. After describing efficient algorithms that scale well to large datasets, we provide some theoretical analysis to establish their validity. Experimental results from real-life Computer Aided Detection (CAD) problems indicate that relaxing the i.i.d. assumption leads to statistically significant improvements in the accuracy of the learned classifier.

  13. Peroxiredoxin Ahp1 Acts as a Receptor for Alkylhydroperoxides to Induce Disulfide Bond Formation in the Cad1 Transcription Factor*

    PubMed Central

    Iwai, Kenta; Naganuma, Akira; Kuge, Shusuke

    2010-01-01

    Reactive oxygen species (ROS) generated during cellular metabolism are toxic to cells. As a result, cells must be able to identify ROS as a stress signal and induce stress response pathways that protect cells from ROS toxicity. Recently, peroxiredoxin (Prx)-induced relays of disulfide bond formation have been identified in budding yeast, namely the disulfide bond formation of Yap1, a crucial transcription factor for oxidative stress response, by a specific Prx Gpx3 and by a major Prx Tsa1. Here, we show that an atypical-type Prx Ahp1 can act as a receptor for alkylhydroperoxides, resulting in activation of the Cad1 transcription factor that is homologous to Yap1. We demonstrate that Ahp1 is required for the formation of intermolecular Cad1 disulfide bond(s) in both an in vitro redox system and in cells treated with alkylhydroperoxide. Furthermore, we found that Cad1-dependent transcriptional activation of the HSP82 gene is dependent on Ahp1. Our results suggest that, although the Gpx3-Yap1 pathway contributes more strongly to resistance than the Ahp1-Cad1 pathway, the Ahp1-induced activation of Cad1 can function as a defense system against stress induced by alkylhydroperoxides, possibly including lipid peroxides. Thus, the Prx family of proteins have an important role in determining peroxide response signals and in transmitting the signals to specific target proteins by inducing disulfide bond formation. PMID:20145245

  14. Peroxiredoxin Ahp1 acts as a receptor for alkylhydroperoxides to induce disulfide bond formation in the Cad1 transcription factor.

    PubMed

    Iwai, Kenta; Naganuma, Akira; Kuge, Shusuke

    2010-04-01

    Reactive oxygen species (ROS) generated during cellular metabolism are toxic to cells. As a result, cells must be able to identify ROS as a stress signal and induce stress response pathways that protect cells from ROS toxicity. Recently, peroxiredoxin (Prx)-induced relays of disulfide bond formation have been identified in budding yeast, namely the disulfide bond formation of Yap1, a crucial transcription factor for oxidative stress response, by a specific Prx Gpx3 and by a major Prx Tsa1. Here, we show that an atypical-type Prx Ahp1 can act as a receptor for alkylhydroperoxides, resulting in activation of the Cad1 transcription factor that is homologous to Yap1. We demonstrate that Ahp1 is required for the formation of intermolecular Cad1 disulfide bond(s) in both an in vitro redox system and in cells treated with alkylhydroperoxide. Furthermore, we found that Cad1-dependent transcriptional activation of the HSP82 gene is dependent on Ahp1. Our results suggest that, although the Gpx3-Yap1 pathway contributes more strongly to resistance than the Ahp1-Cad1 pathway, the Ahp1-induced activation of Cad1 can function as a defense system against stress induced by alkylhydroperoxides, possibly including lipid peroxides. Thus, the Prx family of proteins have an important role in determining peroxide response signals and in transmitting the signals to specific target proteins by inducing disulfide bond formation. PMID:20145245

  15. Dissociation of peripheral T cell responses from thymocyte negative selection by weak agonists supports a spare receptor model of T cell activation

    PubMed Central

    McNeil, Lisa K.; Evavold, Brian D.

    2002-01-01

    We have focused on stability of the peptide-MHC complex as a determining factor of ligand potency for thymocytes and peripheral CD4+ T cell responses. MHC variant peptides that have low affinities and fast dissociation rates are different in that they stimulate proliferation and cytolysis of mature T cells (classifying the variant peptides as weak agonists) but do not induce thymocyte negative selection. The MHC variant weak agonists require significant receptor reserve, because decreasing the level of T cell receptor on mature T cells blocks the proliferative response. These results demonstrate that peripheral T cells are more sensitive to MHC variant ligands by virtue of increased T cell receptor expression; in addition, the data support a T cell model of the spare receptor theory. PMID:11904393

  16. The dissociative disorders. Rarely considered and underdiagnosed.

    PubMed

    Coons, P M

    1998-09-01

    A wide variety of dissociative disorders, including dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, and various forms of dissociative disorder not otherwise specified. In many instances, these disorders are either underdiagnosed or misdiagnosed secondary to the clinician's mistaken belief that dissociative disorders are rare. Recent research shows that dissociative disorders may comprise 5% to 10% of psychiatric populations. This article reviews the epidemiology and clinical symptomatology of these disorders. In addition, various screening and diagnostic instruments, such as the DES, Structured Clinical Interview for Dissociative Disorders, and MMPI, are discussed.

  17. TopoCad - A unified system for geospatial data and services

    NASA Astrophysics Data System (ADS)

    Felus, Y. A.; Sagi, Y.; Regev, R.; Keinan, E.

    2013-10-01

    "E-government" is a leading trend in public sector activities in recent years. The Survey of Israel set as a vision to provide all of its services and datasets online. The TopoCad system is the latest software tool developed in order to unify a number of services and databases into one on-line and user friendly system. The TopoCad system is based on Web 1.0 technology; hence the customer is only a consumer of data. All data and services are accessible for the surveyors and geo-information professional in an easy and comfortable way. The future lies in Web 2.0 and Web 3.0 technologies through which professionals can upload their own data for quality control and future assimilation with the national database. A key issue in the development of this complex system was to implement a simple and easy (comfortable) user experience (UX). The user interface employs natural language dialog box in order to understand the user requirements. The system then links spatial data with alpha-numeric data in a flawless manner. The operation of the TopoCad requires no user guide or training. It is intuitive and self-taught. The system utilizes semantic engines and machine understanding technologies to link records from diverse databases in a meaningful way. Thus, the next generation of TopoCad will include five main modules: users and projects information, coordinates transformations and calculations services, geospatial data quality control, linking governmental systems and databases, smart forms and applications. The article describes the first stage of the TopoCad system and gives an overview of its future development.

  18. Are major dissociative disorders characterized by a qualitatively different kind of dissociation?

    PubMed

    Rodewald, Frauke; Dell, Paul F; Wilhelm-Gossling, Claudia; Gast, Ursula

    2011-01-01

    A total of 66 patients with a major dissociative disorder, 54 patients with nondissociative disorders, and 30 nonclinical controls were administered the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised, the Dissociative Experiences Scale, the Multidimensional Inventory of Dissociation, and the Symptom Checklist 90-Revised. Dissociative patients reported significantly more dissociative and nondissociative symptoms than did nondissociative patients and nonclinical controls. When general psychopathology was controlled, the dissociation scores of dissociative patients were still significantly higher than those of both other groups, whereas the dissociation scores of nondissociative patients and nonclinical controls no longer differed. These findings appear to be congruent with a typological model of dissociation that distinguishes between 2 qualitatively different kinds of dissociation. Specifically, the results of this study suggest that the dissociation that occurs in major dissociative disorders (i.e., dissociative identity disorder [DID] and dissociative disorder not otherwise specified, Type 1 [DDNOS-1]) is qualitatively different from the dissociation that occurs in persons who do not have a dissociative disorder. In contrast to previous research, the dissociation of persons who do not have a dissociative disorder is not limited to absorption; it covers a much wider range of phenomena. The authors hypothesize that different mechanisms produce the dissociation of persons with DID and DDNOS-1 as opposed to the dissociation of persons who do not have a dissociative disorder.

  19. Investigation of IGES for CAD/CAE data transfer

    NASA Technical Reports Server (NTRS)

    Zobrist, George W.

    1989-01-01

    In a CAD/CAE facility there is always the possibility that one may want to transfer the design graphics database from the native system to a non-native system. This may occur because of dissimilar systems within an organization or a new CAD/CAE system is to be purchased. The Initial Graphics Exchange Specification (IGES) was developed in an attempt to solve this scenario. IGES is a neutral database format into which the CAD/CAE native database format can be translated to and from. Translating the native design database format to IGES requires a pre-processor and transling from IGES to the native database format requires a post-processor. IGES is an artifice to represent CAD/CAE product data in a neutral environment to allow interfacing applications, archive the database, interchange of product data between dissimilar CAD/CAE systems, and other applications. The intent here is to present test data on translating design product data from a CAD/CAE system to itself and to translate data initially prepared in IGES format to various native design formats. This information can be utilized in planning potential procurement and developing a design discipline within the CAD/CAE community.

  20. Identification of the regulatory domain of the mammalian multifunctional protein CAD by the construction of an Escherichia coli hamster hybrid carbamyl-phosphate synthetase.

    PubMed

    Liu, X; Guy, H I; Evans, D R

    1994-11-01

    Carbamyl-phosphate synthetases from different organisms have similar catalytic mechanisms and amino acid sequences, but their structural organization, sub-unit structure, and mode of regulation can be very different. Escherichia coli carbamyl-phosphate synthetase (CPSase), a monofunctional protein consisting of amido-transferase and synthetase subunits, is allosterically inhibited by UMP and activated by NH3, IMP, and ornithine. In contrast, mammalian CPSase II, part of the large multifunctional polypeptide, CAD, is inhibited by UTP and activated by 5-phosphoribosyl-1-pyrophosphate (PRPP). Previous photoaffinity labeling studies of E. coli CPSase showed that allosteric effectors bind near the carboxyl-terminal end of the synthetase subunit. This region of the molecule may be a regulatory subdomain common to all CPSases. An E. coli mammalian hybrid CPSase gene has been constructed and expressed in E. coli. The hybrid consists of the E. coli CPSase synthetase catalytic subdomains, residues 1-900 of the 1073 residue polypeptide, fused to the amino-terminal end of the putative 190-residue regulatory subdomain of the mammalian protein. The hybrid CPSase had normal activity, but was no longer regulated by the prokaryotic allosteric effectors. Instead, the glutamine- and ammonia-dependent CPSase activities and both ATP-dependent partial reactions were activated by PRPP and inhibited by UTP, indicating that the binding sites of both of these ligands are located in a regulatory region at the carboxyl-terminal end of the CPSase domain of CAD. The apparent ligand dissociation constants and extent of inhibition by UTP are similar in the hybrid and the wild type mammalian protein, but PRPP binds 4-fold more weakly to the hybrid. The allosteric ligands affected the steady state kinetic parameters of the hybrid differently, suggesting that while the linkage between the catalytic and regulatory subdomains has been preserved, there may be qualitative differences in interdomain

  1. A new CAD approach for improving efficacy of cancer screening

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Qian, Wei; Li, Lihua; Pu, Jiantao; Kang, Yan; Lure, Fleming; Tan, Maxine; Qiu, Yuchen

    2015-03-01

    Since performance and clinical utility of current computer-aided detection (CAD) schemes of detecting and classifying soft tissue lesions (e.g., breast masses and lung nodules) is not satisfactory, many researchers in CAD field call for new CAD research ideas and approaches. The purpose of presenting this opinion paper is to share our vision and stimulate more discussions of how to overcome or compensate the limitation of current lesion-detection based CAD schemes in the CAD research community. Since based on our observation that analyzing global image information plays an important role in radiologists' decision making, we hypothesized that using the targeted quantitative image features computed from global images could also provide highly discriminatory power, which are supplementary to the lesion-based information. To test our hypothesis, we recently performed a number of independent studies. Based on our published preliminary study results, we demonstrated that global mammographic image features and background parenchymal enhancement of breast MR images carried useful information to (1) predict near-term breast cancer risk based on negative screening mammograms, (2) distinguish between true- and false-positive recalls in mammography screening examinations, and (3) classify between malignant and benign breast MR examinations. The global case-based CAD scheme only warns a risk level of the cases without cueing a large number of false-positive lesions. It can also be applied to guide lesion-based CAD cueing to reduce false-positives but enhance clinically relevant true-positive cueing. However, before such a new CAD approach is clinically acceptable, more work is needed to optimize not only the scheme performance but also how to integrate with lesion-based CAD schemes in the clinical practice.

  2. Recurrent Episodes of Dissociative Fugue

    PubMed Central

    Angothu, Hareesh; Pabbathi, Lokeswar Reddy

    2016-01-01

    Dissociative fugue is rare entity to encounter with possible differentials of epilepsy and malingering. It is one of the dissociative disorders rarely seen in clinical practice more often because of the short lasting nature of this condition. This might also be because of organized travel of the individuals during the episodes and return to their families after the recovery from episodes. This is a case description of a patient who has experienced total three episodes of dissociative fugue. The patient has presented during the third episode and two prior episodes were diagnosed as fugue episodes retrospectively based on the history. Planned travel in this case by the patient to a distant location was prevented because of early diagnosis and constant vigilance till the recovery. As in this case, it may be more likely that persons with Dissociative fugue may develop similar episodes if they encounter exceptional perceived stress. However, such conclusions may require follow-up studies. PMID:27114633

  3. Turnkey CAD/CAM systems' integration with IPAD systems

    NASA Technical Reports Server (NTRS)

    Blauth, R. E.

    1980-01-01

    Today's commercially available turnkey CAD/CAM systems provide a highly interactive environment, and support many specialized application functions for the design/drafting/manufacturing process. This paper presents an overview of several aerospace companies which have successfully integrated turnkey CAD/CAM systems with their own company wide engineering and manufacturing systems. It also includes a vendor's view of the benefits as well as the disadvantages of such integration efforts. Specific emphasis is placed upon the selection of standards for representing geometric engineering data and for communicating such information between different CAD/CAM systems.

  4. Global functioning and disability in dissociative disorders.

    PubMed

    Mueller-Pfeiffer, Christoph; Rufibach, Kaspar; Perron, Noelle; Wyss, Daniela; Kuenzler, Cornelia; Prezewowsky, Cornelia; Pitman, Roger K; Rufer, Michael

    2012-12-30

    Dissociative disorders are frequent comorbid conditions of other mental disorders. Yet, there is controversy about their clinical relevance, and little systematic research has been done on how they influence global functioning. Outpatients and day care patients (N=160) of several psychiatric units in Switzerland were assessed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV Axis I Disorders, Structured Clinical Interview for DSM-IV Dissociative Disorders, Global Assessment of Functioning Scale, and World Health Organization Disability Assessment Schedule-II. The association between subjects with a dissociative disorder (N=30) and functional impairment after accounting for non-dissociative axis I disorders was evaluated by linear regression models. We found a proportion of 18.8% dissociative disorders (dissociative amnesia=0%, dissociative fugue=0.6%, depersonalization disorder=4.4%, dissociative identity disorder=7.5%, dissociative disorder-not-otherwise-specified=6.3%) across treatment settings. Adjusted for other axis I disorders, subjects with a comorbid dissociative identity disorder or dissociative disorder-not-otherwise-specified had a median global assessment of functioning score that was 0.86 and 0.88 times, respectively, the score of subjects without a comorbid dissociative disorder. These findings support the hypothesis that complex dissociative disorders, i.e., dissociative identity disorder and dissociative disorder-not-otherwise-specified, contribute to functional impairment above and beyond the impact of co-existing non-dissociative axis I disorders, and that they qualify as "serious mental illness".

  5. Ergonomics Perspective in Agricultural Research: A User-Centred Approach Using CAD and Digital Human Modeling (DHM) Technologies

    NASA Astrophysics Data System (ADS)

    Patel, Thaneswer; Sanjog, J.; Karmakar, Sougata

    2016-09-01

    Computer-aided Design (CAD) and Digital Human Modeling (DHM) (specialized CAD software for virtual human representation) technologies endow unique opportunities to incorporate human factors pro-actively in design development. Challenges of enhancing agricultural productivity through improvement of agricultural tools/machineries and better human-machine compatibility can be ensured by adoption of these modern technologies. Objectives of present work are to provide the detailed scenario of CAD and DHM applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator's workplace. Extensive literature review has been conducted for systematic segregation and representation of available information towards drawing inferences. Although applications of various CAD software have momentum in agricultural research particularly for design and manufacturing of agricultural equipment/machinery, use of DHM is still at its infancy in this sector. Current review discusses about reasons of less adoption of these technologies in agricultural sector and steps to be taken for their wide adoption. It also suggests possible future research directions to come up with better ergonomic design strategies for improvement of agricultural equipment/machines and workstations through application of CAD and DHM.

  6. ACCELERATING FUSION REACTOR NEUTRONICS MODELING BY AUTOMATIC COUPLING OF HYBRID MONTE CARLO/DETERMINISTIC TRANSPORT ON CAD GEOMETRY

    SciTech Connect

    Biondo, Elliott D; Ibrahim, Ahmad M; Mosher, Scott W; Grove, Robert E

    2015-01-01

    Detailed radiation transport calculations are necessary for many aspects of the design of fusion energy systems (FES) such as ensuring occupational safety, assessing the activation of system components for waste disposal, and maintaining cryogenic temperatures within superconducting magnets. Hybrid Monte Carlo (MC)/deterministic techniques are necessary for this analysis because FES are large, heavily shielded, and contain streaming paths that can only be resolved with MC. The tremendous complexity of FES necessitates the use of CAD geometry for design and analysis. Previous ITER analysis has required the translation of CAD geometry to MCNP5 form in order to use the AutomateD VAriaNce reducTion Generator (ADVANTG) for hybrid MC/deterministic transport. In this work, ADVANTG was modified to support CAD geometry, allowing hybrid (MC)/deterministic transport to be done automatically and eliminating the need for this translation step. This was done by adding a new ray tracing routine to ADVANTG for CAD geometries using the Direct Accelerated Geometry Monte Carlo (DAGMC) software library. This new capability is demonstrated with a prompt dose rate calculation for an ITER computational benchmark problem using both the Consistent Adjoint Driven Importance Sampling (CADIS) method an the Forward Weighted (FW)-CADIS method. The variance reduction parameters produced by ADVANTG are shown to be the same using CAD geometry and standard MCNP5 geometry. Significant speedups were observed for both neutrons (as high as a factor of 7.1) and photons (as high as a factor of 59.6).

  7. Ergonomics Perspective in Agricultural Research: A User-Centred Approach Using CAD and Digital Human Modeling (DHM) Technologies

    NASA Astrophysics Data System (ADS)

    Patel, Thaneswer; Sanjog, J.; Karmakar, Sougata

    2016-06-01

    Computer-aided Design (CAD) and Digital Human Modeling (DHM) (specialized CAD software for virtual human representation) technologies endow unique opportunities to incorporate human factors pro-actively in design development. Challenges of enhancing agricultural productivity through improvement of agricultural tools/machineries and better human-machine compatibility can be ensured by adoption of these modern technologies. Objectives of present work are to provide the detailed scenario of CAD and DHM applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator's workplace. Extensive literature review has been conducted for systematic segregation and representation of available information towards drawing inferences. Although applications of various CAD software have momentum in agricultural research particularly for design and manufacturing of agricultural equipment/machinery, use of DHM is still at its infancy in this sector. Current review discusses about reasons of less adoption of these technologies in agricultural sector and steps to be taken for their wide adoption. It also suggests possible future research directions to come up with better ergonomic design strategies for improvement of agricultural equipment/machines and workstations through application of CAD and DHM.

  8. Trait Dissociation Predicts Posttraumatic Stress Disorder Symptoms in a Prospective Study of Urban Police Officers

    PubMed Central

    McCaslin, Shannon E.; Inslicht, Sabra S.; Metzler, Thomas J.; Henn-Haase, Clare; Maguen, Shira; Neylan, Thomas C.; Choucroun, Gerard; Marmar, Charles R.

    2013-01-01

    The current study prospectively examines the predictive relationship of trait dissociation, assessed during academy training, to PTSD symptoms assessed at 12 months of active police duty in relatively young and healthy police academy recruits (N = 180). The roles of pre-academy trauma exposure, exposure to life-threatening critical incidents during police duty, and peritraumatic dissociation at the time of the officer’s worst critical incident were also examined. Utilizing path analytic techniques, greater trait dissociation, assessed during academy training, was predictive of both peritraumatic dissociation, and PTSD symptoms assessed at 12 months of police service. Moreover, after accounting for trait dissociation and peritraumatic dissociation, the relationship of previous trauma to later PTSD symptoms was no longer significant, demonstrating that the effect of previous trauma on later vulnerability to PTSD symptoms in this sample may be mediated by both trait and peritraumatic dissociation. PMID:19077859

  9. CAD-CAE in Electrical Machines and Drives Teaching.

    ERIC Educational Resources Information Center

    Belmans, R.; Geysen, W.

    1988-01-01

    Describes the use of computer-aided design (CAD) techniques in teaching the design of electrical motors. Approaches described include three technical viewpoints, such as electromagnetics, thermal, and mechanical aspects. Provides three diagrams, a table, and conclusions. (YP)

  10. Voice I/O: an effective option for CAD systems

    SciTech Connect

    Gill, S.P.

    1983-01-01

    The current state of speech recognition and compression technology is examined. The application of this technology to input/output in the CAD environment is then considered. Human factors are discussed.

  11. CAD/CAM approach to improving industry productivity gathers momentum

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.

    1982-01-01

    Recent results and planning for the NASA/industry Integrated Programs for Aerospace-Vehicle Design (IPAD) program for improving productivity with CAD/CAM methods are outlined. The industrial group work is being mainly done by Boeing, and progress has been made in defining the designer work environment, developing requirements and a preliminary design for a future CAD/CAM system, and developing CAD/CAM technology. The work environment was defined by conducting a detailed study of a reference design process, and key software elements for a CAD/CAM system have been defined, specifically for interactive design or experiment control processes. Further work is proceeding on executive, data management, geometry and graphics, and general utility software, and dynamic aspects of the programs being developed are outlined

  12. Overview of NASA MSFC IEC Multi-CAD Collaboration Capability

    NASA Technical Reports Server (NTRS)

    Moushon, Brian; McDuffee, Patrick

    2005-01-01

    This viewgraph presentation provides an overview of a Design and Data Management System (DDMS) for Computer Aided Design (CAD) collaboration in order to support the Integrated Engineering Capability (IEC) at Marshall Space Flight Center (MSFC).

  13. Negligible Isotopic Effect on Dissociation of Hydrogen Bonds.

    PubMed

    Ge, Chuanqi; Shen, Yuneng; Deng, Gang-Hua; Tian, Yuhuan; Yu, Dongqi; Yang, Xueming; Yuan, Kaijun; Zheng, Junrong

    2016-03-31

    Isotopic effects on the formation and dissociation kinetics of hydrogen bonds are studied in real time with ultrafast chemical exchange spectroscopy. The dissociation time of hydrogen bond between phenol-OH and p-xylene (or mesitylene) is found to be identical to that between phenol-OD and p-xylene (or mesitylene) in the same solvents. The experimental results demonstrate that the isotope substitution (D for H) has negligible effects on the hydrogen bond kinetics. DFT calculations show that the isotope substitution does not significantly change the frequencies of vibrational modes that may be along the hydrogen bond formation and dissociation coordinate. The zero point energy differences of these modes between hydrogen bonds with OH and OD are too small to affect the activation energy of the hydrogen bond dissociation in a detectible way at room temperature.

  14. Catalytic efficiency of Nb and Nb oxides for hydrogen dissociation

    SciTech Connect

    Isobe, Shigehito; Kudoh, Katsuhiro; Hino, Satoshi; Hashimoto, Naoyuki; Ohnuki, Somei; Hara, Kenji

    2015-08-24

    In this letter, catalytic efficiency of Nb, NbO, Nb{sub 2}O{sub 3}, NbO{sub 2}, and Nb{sub 2}O{sub 5} for dissociation and recombination of hydrogen were experimentally investigated. On the surface of Nb and Nb oxides in a gas mixture of H{sub 2} and D{sub 2}, H{sub 2} and D{sub 2} molecules can be dissociated to H and D atoms; then, H{sub 2}, D{sub 2}, and HD molecules can be produced according to the law of probability. With increase of frequency of the dissociation and recombination, HD ratio increases. The ratio of H{sub 2} and HD gas was analyzed by quadrupole mass spectrometry. As a result, NbO showed the highest catalytic activity towards hydrogen dissociation and recombination.

  15. Dissociative experiences and dissociative minds: Exploring a nomological network of dissociative functioning.

    PubMed

    Schimmenti, Adriano

    2016-01-01

    In this study, the psychometric properties of the Dissociative Experiences Scale-II (DES-II) were tested in a sample of Italian adults, and a nomological network of dissociative functioning based on current psychodynamic research was examined. A total of 794 participants (55% females) ranging in age from 18 to 64 completed the DES-II and other measures of theory of mind, alexithymia, attachment style, and empathy. The Italian translation of the DES-II showed high internal consistency, adequate item-to-scale homogeneity, and good split-half reliability. A single-factor solution including the 8 items of pathological dissociation (DES-T) adequately fit the data. Participants who reported higher levels of dissociative experiences showed significantly lower scores on theory of mind and empathy than other participants. They also showed significantly higher scores on alexithymia, preoccupied attachment, and fearful attachment. Results of the study support the view that people who suffer from severe dissociative experiences may also have difficulties mentalizing and regulating affects and that they may feel uncomfortable in close relationships because they have a negative view of the self. This can inform clinical work with dissociative individuals, who could benefit from therapies that consider their potential problems with mentalization, empathy, affect regulation, and attachment.

  16. [Development of the dental CAD/CAM system].

    PubMed

    Kawanaka, M

    1990-06-01

    Studies have been undertaken to apply CAD/CAM system to Dentistry and to make prosthetic appliances with this system automatically. Specimens are 4 times large plaster models. For the inside of the crown, the plaster model of prepared tooth is measured with laser displacement meter then the numerical data is obtained. After modification of this data for the concave cutting, the modeling machine works with this numerical data. For the outside of the crown, the typical colonal figure data (= CAD Data Base) is prepared. And this data is modified with computer to fit the prepared tooth margin and proximal or antagonical tooth (= CAD). This CAD Data Base was obtained with 3 dimensional point digitizer (3DPD). Because this measuring method with 3DPD is to be able to select points, the CAD Data Base could be consists of characteristic points. When this data base is really used, it is interpolated with s-spline. Spline interpolation is indispensable to the CAD/CAM system. Further understanding of this system, explanation is divided into three parts which are 3D measurement, CAD and CAM. (3D measurement) Two types of 3D measurement is dealed with this system. One is for the CAD data base and another is for the prepared tooth model. 3D measurement of the prepared tooth model is equivalent of the impression takings in the routine method. For the clear marginal line and for the uniform distribution of measuring points, the prepared tooth model is tilted and rotated on the working table when it is measured with laser. (CAD) The CAD Data Base can be extended, contracted, parallel translated and rotated with the Affine transformation. For putting the individual margin data on the CAD Data Base, the prepared tooth margin is re-digitized with 3DPD. Occlusal data is taken from F.G.P. core. (CAM) The application of the spline interpolation to the tool offset theory, which is effective at the groove especially, makes easy to calculate the tool path. When the prepared tooth model is

  17. Fragmentation of singly, doubly, and triply charged hydrogen deficient peptide radical cations in infrared multiphoton dissociation and electron induced dissociation.

    PubMed

    Kalli, Anastasia; Hess, Sonja

    2012-02-01

    Gas phase fragmentation of hydrogen deficient peptide radical cations continues to be an active area of research. While collision induced dissociation (CID) of singly charged species is widely examined, dissociation channels of singly and multiply charged radical cations in infrared multiphoton dissociation (IRMPD) and electron induced dissociation (EID) have not been, so far, investigated. Here, we report on the gas phase dissociation of singly, doubly and triply charged hydrogen deficient peptide radicals, [M + nH]((n+1)+·) (n=0, 1, 2), in MS(3) IRMPD and EID and compare the observed fragmentation pathways to those obtained in MS(3) CID. Backbone fragmentation in MS(3) IRMPD and EID was highly dependent on the charge state of the radical precursor ions, whereas amino acid side chain cleavages were largely independent of the charge state selected for fragmentation. Cleavages at aromatic amino acids, either through side chain loss or backbone fragmentation, were significantly enhanced over other dissociation channels. For singly charged species, the MS(3) IRMPD and EID spectra were mainly governed by radical-driven dissociation. Fragmentation of doubly and triply charged radical cations proceeded through both radical- and charge-driven processes, resulting in the formation of a wide range of backbone product ions including, a-, b-, c-, y-, x-, and z-type. While similarities existed between MS(3) CID, IRMPD, and EID of the same species, several backbone product ions and side chain losses were unique for each activation method. Furthermore, dominant dissociation pathways in each spectrum were dependent on ion activation method, amino acid composition, and charge state selected for fragmentation.

  18. Dynamics of unimolecular dissociation of silylene

    NASA Astrophysics Data System (ADS)

    NoorBatcha, I.; Raff, Lionel M.; Thompson, Donald L.; Viswanathan, R.

    1986-04-01

    The semiempirical valence-bond surface formulated by Viswanathan et al. [J. Phys. Chem. 89, 1428 (1985)] for the unimolecular dissociation of SiH2 has been fitted to an analytical function of the type suggested by Murrell and co-workers [J. Phys. Chem. 88, 4887 (1984)]. The fitted surface accurately represents most of the experimental and CI results. The dynamics of the unimolecular dissociation of SiH2 to form Si and H2 have been investigated by classical trajectory methods on this fitted surface. The effect of describing the initial state of the molecule using normal and local mode approximations has been studied. In spite of the presence of the heavier atom, no bond or mode specificity is observed. The product energy distribution is found to be statistical. Using the RRK model, the high-pressure limiting rate coefficient is found to be k(T,∞)=3.38×1012 exp[-61.6 kcal mol-1/RT] s-1, which is less than the dissociation rate for SiH4. This has been attributed to the higher activation energy for SiH2 and to a statistical factor.

  19. CAD-CAM at Bendix Kansas city: the BICAM system

    SciTech Connect

    Witte, D.R.

    1983-04-01

    Bendix Kansas City Division (BEKC) has been involved in Computer Aided Manufacturing (CAM) technology since the late 1950's when the numerical control (N/C) analysts installed computers to aid in N/C tape preparation for numerically controlled machines. Computer Aided Design (CAD) technology was introduced in 1976, when a number of 2D turnkey drafting stations were procured for printed wiring board (PWB) drawing definition and maintenance. In June, 1980, CAD-CAM Operations was formed to incorporate an integrated CAD-CAM capability into Bendix operations. In March 1982, a ninth division was added to the existing eight divisions at Bendix. Computer Integrated Manufacturing (CIM) is a small organization, reporting directly to the general manager, who has responsibility to coordinate the overall integration of computer aided systems at Bendix. As a long range plan, CIM has adopted a National Bureau of Standards (NBS) architecture titled Factory of the Future. Conceptually, the Bendix CAD-CAM system has a centrally located data base which can be accessed by both CAD and CAM tools, processes, and personnel thus forming an integrated Computer Aided Engineering (CAE) System. This is a key requirement of the Bendix CAD-CAM system that will be presented in more detail.

  20. An Algorithm for Projecting Points onto a Patched CAD Model

    SciTech Connect

    Henshaw, W D

    2001-05-29

    We are interested in building structured overlapping grids for geometries defined by computer-aided-design (CAD) packages. Geometric information defining the boundary surfaces of a computation domain is often provided in the form of a collection of possibly hundreds of trimmed patches. The first step in building an overlapping volume grid on such a geometry is to build overlapping surface grids. A surface grid is typically built using hyperbolic grid generation; starting from a curve on the surface, a grid is grown by marching over the surface. A given hyperbolic grid will typically cover many of the underlying CAD surface patches. The fundamental operation needed for building surface grids is that of projecting a point in space onto the closest point on the CAD surface. We describe an fast algorithm for performing this projection, it will make use of a fairly coarse global triangulation of the CAD geometry. We describe how to build this global triangulation by first determining the connectivity of the CAD surface patches. This step is necessary since it often the case that the CAD description will contain no information specifying how a given patch connects to other neighboring patches. Determining the connectivity is difficult since the surface patches may contain mistakes such as gaps or overlaps between neighboring patches.

  1. Combined Pulsed-Q dissociation and electron transfer dissociation for identification and quantification of iTRAQ–labeled phosphopeptides

    PubMed Central

    Yang, Feng; Wu, Si; Stenoien, David L.; Zhao, Rui; Monroe, Matthew E.; Gristenko, Marina A.; Purvine, Samuel O.; Polpitiya, Ashoka D.; Tolić, Nikola; Zhang, Qibin; Norbeck, Angela D.; Orton, Daniel J.; Moore, Ronald J.; Tang, Keqi; Anderson, Gordon A.; Paša-Tolić, Ljiljana; Camp, David G.; Smith, Richard D.

    2009-01-01

    Here, we report a new approach that integrates pulsed Q dissociation (PQD) and electron transfer dissociation (ETD) techniques for confident and quantitative identification of iTRAQ-labeled phosphopeptides. The use of isobaric tags for relative and absolute quantification enables a high-throughput quantification of peptides via reporter ion signals in the low m/z range of tandem mass spectra. PQD, a form of ion trap collision activated dissociation allows for detection of low mass-to-charge fragment ions and electron transfer dissociation is especially useful for sequencing peptides that contain post-translational modifications. Analysis of the phosphoproteome of human fibroblast cells using a sensitive linear ion trap mass spectrometer demonstrated that this hybrid approach improves both identification and quantification of phosphopeptides. ETD improved phosphopeptide identification, while PQD provides improved quantification of iTRAQ-labeled phosphopeptides. PMID:19371082

  2. Subunit dissociation in fish hemoglobins.

    PubMed

    Edelstein, S J; McEwen, B; Gibson, Q H

    1976-12-10

    The tetramer-dimer dissociation equilibria (K 4,2) of several fish hemoglobins have been examined by sedimentation velocity measurements with a scanner-computer system for the ultracentrifuge and by flash photolysis measurements using rapid kinetic methods. Samples studied in detail included hemoglobins from a marine teleost, Brevoortia tyrannus (common name, menhaden); a fresh water teleost, Cyprinus carpio, (common name, carp); and an elasmobranch Prionace glauca (common name, blue shark). For all three species in the CO form at pH 7, in 0.1 M phosphate buffer, sedimentation coefficients of 4.3 S (typical of tetrameric hemoglobin) are observed in the micromolar concentration range. In contrast, mammalian hemoglobins dissociate appreciably to dimers under these conditions. The inability to detect dissociation in three fish hemoglobins at the lowest concentrations examined indicates that K 4,2 must have a value of 10(-8) M or less. In flash photolysis experiments on very dilute solutions in long path length cells, two kinetic components were detected with their proportions varying as expected for an equilibrium between tetramers (the slower component) and dimers (the faster component); values of K 4,2 for the three fish hemoglobins in the range 10(-9) to 10(-8) M were calculated from these data. Thus, the values of K 4,2 for liganded forms of the fish hemoglobins appear to be midway between the value for liganded human hemoglobin (K 4,2 approximately 10(-6) M) and unliganded human hemoglobin (K 4,2 approximately 10(-12) M). This conclusion is supported by measurements on solutions containing guanidine hydrochloride to enhance the degree of dissociation. All three fish hemoglobins are appreciably dissociated at guanidine concentrations of about 0.8 M, which is roughly midway between the guanidine concentrations needed to cause comparable dissociation of liganded human hemoglobin (about 0.4 M) and unliganded human hemoglobin (about 1.6 M). Kinetic measurements on

  3. Role of computer aided detection (CAD) integration: case study with meniscal and articular cartilage CAD applications

    NASA Astrophysics Data System (ADS)

    Safdar, Nabile; Ramakrishna, Bharath; Saiprasad, Ganesh; Siddiqui, Khan; Siegel, Eliot

    2008-03-01

    Knee-related injuries involving the meniscal or articular cartilage are common and require accurate diagnosis and surgical intervention when appropriate. With proper techniques and experience, confidence in detection of meniscal tears and articular cartilage abnormalities can be quite high. However, for radiologists without musculoskeletal training, diagnosis of such abnormalities can be challenging. In this paper, the potential of improving diagnosis through integration of computer-aided detection (CAD) algorithms for automatic detection of meniscal tears and articular cartilage injuries of the knees is studied. An integrated approach in which the results of algorithms evaluating either meniscal tears or articular cartilage injuries provide feedback to each other is believed to improve the diagnostic accuracy of the individual CAD algorithms due to the known association between abnormalities in these distinct anatomic structures. The correlation between meniscal tears and articular cartilage injuries is exploited to improve the final diagnostic results of the individual algorithms. Preliminary results from the integrated application are encouraging and more comprehensive tests are being planned.

  4. Increased oxidative stress and decreased membrane fluidity in erythrocytes of CAD patients.

    PubMed

    Pytel, Edyta; Olszewska-Banaszczyk, Małgorzata; Koter-Michalak, Maria; Broncel, Marlena

    2013-10-01

    One of many risk factors for cardiovascular disease appears to be oxidative stress. To estimate possible changes in redox balance, membrane fluidity, and cholesterol level in erythrocytes was collected erythrocytes from patients diagnosed with coronary artery disease (CAD). The study included 20 patients with previous myocardial infarction occurring more than 6 months prior to the time of screening with low-density lipoprotein cholesterol (LDL-C) > 70 mg/dL and 21 healthy controls. The following parameters were studied: catalase, glutathione peroxidase (GPx), superoxide dismutase (SOD), thiobarbituric acid reactive substrates (TBARS), sulfhydryl (SH) groups in membrane protein, total cholesterol level, and erythrocyte membrane fluidity. Our study showed an increase in the level of lipid peroxidation (13%) and total cholesterol (19%), and a decrease in membrane fluidity (14%) in the subsurface layers and in the deeper layers of erythrocyte membrane (7%) isolated from patients with CAD in comparison to healthy controls. A significant decrease in catalase (10%) and SOD (17%) activities were also observed. No changes in GPx activity or the level of SH groups were observed. Our study indicates that there are disorders in the antioxidant system as well as changes in the membrane structure of erythrocytes obtained from CAD patients.

  5. Investigate the variation in optical redox ratio of epicardial adipose tissue in patients with CAD through auto-fluorescence metabolic molecular image (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Guo, Lun-Zhang; Wang, Tzung-Dau; Lin, Jong-Wei; Liu, Tzu-Ming

    2016-04-01

    In recent years, it has been suggested that epicardial adipose tissue (EAT) plays an important role in development of coronary artery disease (CAD) and diabetes mellitus (DM). In this article, we used two-photon fluoresce microscope to measure the fluorescence metabolic image of EAT, which obtained from the patient with/without CAD/DM. We used 740nm and 890nm infrared light to excite the auto-fluorescence of metabolic molecules NADH and FAD respectively. We collected the fluorescence signal at wavelength 450nm to 500nm and 500nm to 550nm to obtain the metabolic image. Through the image, we computed the redox ratio (NADH/FAD) by analyzing the intensity. The preliminary result showed that the redox ratio increase in the patients with CAD. It indicates EAT adipocytes of patient with CAD have decreased cellular metabolic activity. But there were no significant variation of redox ratio in the patients with DM.

  6. Multiphoton dissociative ionization of CS+

    NASA Astrophysics Data System (ADS)

    Rajput, Jyoti; Jochim, Bethany; Zohrabi, M.; Betsch, K. J.; Ablikim, U.; Berry, Ben; Severt, T.; Summers, A. M.; Armstrong, G. S. J.; Esry, B. D.; Carnes, K. D.; Ben-Itzhak, I.

    2015-05-01

    We have studied the dissociative photoionization of a CS+ molecular ion beam in the strong-field regime using <50 fs IR laser pulses (λ ~ 790 nm) from a 10 kHz, ~2 mJ (per pulse) Ti:Sapphire laser system. A coincidence three-dimensional momentum imaging method was used to measure all ions and neutrals formed during this multiphoton process. Two prominent channels were observed: charge-symmetric dissociation, yielding C+ + S+, and charge-asymmetric dissociation, yielding C + S2+. The differences between these two channels with reference to their relative production probability, energetics, and angular distributions is the focus of this work. This work was supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. BJ is also supported by DOE-SCGF (DE-AC05-06OR23100).

  7. CAD May Not be Necessary for Microcalcifications in the Digital era, CAD May Benefit Radiologists for Masses

    PubMed Central

    Destounis, Stamatia V.; Arieno, Andrea L.; Morgan, Renee C.

    2012-01-01

    Objective: The aim of this study was to evaluate the effectiveness of computer-aided detection (CAD) to mark the cancer on digital mammograms at the time of breast cancer diagnosis and also review retrospectively whether CAD marked the cancer if visible on any available prior mammograms, thus potentially identifying breast cancer at an earlier stage. We sought to determine why breast lesions may or may not be marked by CAD. In particular, we analyzed factors such as breast density, mammographic views, and lesion characteristics. Materials and Methods: Retrospective review from 2004 to 2008 revealed 3445 diagnosed breast cancers in both symptomatic and asymptomatic patients; 1293 of these were imaged with full field digital mammography (FFDM). After cancer diagnosis, in a retrospective review held by the radiologist staff, 43 of these cancers were found to be visible on prior-year mammograms (false-negative cases); these breast cancer cases are the basis of this analysis. All cases had CAD evaluation available at the time of cancer diagnosis and on prior mammography studies. Data collected included patient demographics, breast density, palpability, lesion type, mammographic size, CAD marks on current- and prior-year mammograms, needle biopsy method, pathology results (core needle and/or surgical), surgery type, and lesion size. Results: On retrospective review of the mammograms by the staff radiologists, 43 cancers were discovered to be visible on prior-year mammograms. All 43 cancers were masses (mass classification included mass, mass with calcification, and mass with architectural distortion); no pure microcalcifications were identified in this cohort. Mammograms with CAD applied at the time of breast cancer diagnosis were able to detect 79% (34/43) of the cases and 56% (24/43) from mammograms with CAD applied during prior year(s). In heterogeneously dense/extremely dense tissue, CAD marked 79% (27/34) on mammograms taken at the time of diagnosis and 56% (19

  8. [Dissociative identity disorder or schizophrenia?].

    PubMed

    Tschöke, S; Steinert, T

    2010-01-01

    We present a case of dissociative identity disorder in which Schneiderian first rank symptoms were present besides of various states of consciousness. Thus the diagnosis of schizophrenia had to be considered. Formally, the symptoms met ICD-10 criteria for schizophrenia. However, taking into account the lack of formal thought disorder and of negative symptoms as well as a typical history of severe and prolonged traumatisation, we did not diagnose a co-morbid schizophrenic disorder. There is good evidence for the existence of psychotic symptoms among patients with dissociative disorders. However, in clinical practice this differential diagnosis is rarely considered.

  9. From CAD to Digital Modeling: the Necessary Hybridization of Processes

    NASA Astrophysics Data System (ADS)

    Massari, G. A.; Bernardi, F.; Cristofolini, A.

    2011-09-01

    The essay deals with the themes of digital representation of architecture starting from several years of teaching activity which is growing within the course of Automatic Design of the degree course in Engineering/Architecture in the University of Trento. With the development of CAD systems, architectural representation lies less in the tracking of a simple graph and drawn deeper into a series of acts of building a complex digital model, which can be used as a data base on which to report all the stages of project and interpretation work, and from which to derive final drawings and documents. The advent of digital technology has led to increasing difficulty in finding explicit connections between one type of operation and the subsequent outcome; thereby increasing need for guidelines, the need to understand in order to precede the changes, the desire not to be overwhelmed by uncontrollable influences brought by technological hardware and software systems to use only in accordance with the principle of maximum productivity. Formation occupies a crucial role because has the ability to direct the profession toward a thoughtful and selective use of specific applications; teaching must build logical routes in the fluid world of info-graphics and the only way to do so is to describe its contours through method indications: this will consist in understanding, studying and divulging what in its mobility does not change, as procedural issues, rather than what is transitory in its fixity, as manual questions.

  10. Comparing performance of the CADstream and the DynaCAD breast MRI CAD systems : CADstream vs. DynaCAD in breast MRI.

    PubMed

    Pan, Joann; Dogan, Basak E; Carkaci, Selin; Santiago, Lumarie; Arribas, Elsa; Cantor, Scott B; Wei, Wei; Stafford, R Jason; Whitman, Gary J

    2013-10-01

    Computer-aided diagnosis (CAD) systems are software programs that use algorithms to find patterns associated with breast cancer on breast magnetic resonance imaging (MRI). The most commonly used CAD systems in the USA are CADstream (CS) (Merge Healthcare Inc., Chicago, IL) and DynaCAD for Breast (DC) (Invivo, Gainesville, FL). Our primary objective in this study was to compare the CS and DC breast MRI CAD systems for diagnostic accuracy and postprocessed image quality. Our secondary objective was to compare the evaluation times of radiologists using each system. Three radiologists evaluated 30 biopsy-proven malignant lesions and 29 benign lesions on CS and DC and rated the lesions' malignancy status using the Breast Imaging Reporting and Data System. Image quality was ranked on a 0-5 scale, and mean reading times were also recorded. CS detected 70 % of the malignant and 32 % of the benign lesions while DC detected 81 % of the malignant lesions and 34 % of the benign lesions. Analysis of the area under the receiver operating characteristic curve revealed that the difference in diagnostic performance was not statistically significant. On image quality scores, CS had significantly higher volume rendering (VR) (p < 0.0001) and motion correction (MC) scores (p < 0.0001). There were no statistically significant differences in the remaining image quality scores. Differences in evaluation times between DC and CS were also not statistically significant. We conclude that both CS and DC perform similarly in aiding detection of breast cancer on MRI. MRI CAD selection will likely be based on other factors, such as user interface and image quality preferences, including MC and VR. PMID:23589186

  11. [Traditional and modern views of dissociation].

    PubMed

    Merza, Katalin; Kuritárné Szabó, Ildikó

    2012-01-01

    Dissociation is a failure to integrate aspects of identity, memory, perception, and consciousness. Dissociation is conceptualized as a dimensional process existing along a continuum from normal and relatively common dissociative experiences to severe and clinically relevant forms. There is a growing body of clinical and empirical evidence that dissociation may occur especially as a defense during trauma. In case of traumatic events dissociation considered as an attempt to maintain mental control just as physical control is lost. Dissociation can be either a symptom of some complex mental disorder or a distinct clinical entity categorized among dissociative and somatoform disorders in DSM-IV. The article describes the conceptual issues of dissociation and presents a new classification by Nijenhuis where the so-called somatoform dissociative symptoms are included as well in the list of dissociative symptoms. Finally, this paper summarizes the measures of dissociative phenomena and the cognitive-behavioral approaches of dissociation, and highlights the main features of the new structural dissociation model.

  12. Performance and value of CAD-deficient pine- Final Report

    SciTech Connect

    Bailian Li; Houmin Chang; Hasan Jameel

    2007-02-28

    The southern US produces 58% of the nation's timber, much of it grown in intensively managed plantations of genetically improved loblolly pine. One of the fastest-growing loblolly pine selections made by the NCSU-Industry Cooperative Tree Improvement Program, whose progeny are widely planted, is also the only known natural carrier of a rare gene, cadn1. This allele codes for deficiency in an enzyme, cinnamyl alcohol dehydrogenase, which catalyzes the last step in the biosynthesis of lignin precursors. This study is to characterize this candidate gene for marker-assisted selection and deployment in the breeding program. This research will enhance the sustainability of forest production in the South, where land-use pressures will limit the total area available in the future for intensively managed plantations. Furthermore, this research will provide information to establish higher-value plantation forests with more desirable wood/fiber quality traits. A rare mutant allele (cad-n1) of the cad gene in loblolly pine (Pinus taeda L.) causes a deficiency in the production of cinnamyl alcohol dehydrogenase (CAD). The effects of this allele were examined by comparing wood density and growth traits of cad-n1 heterozygous trees with those of wild-type trees in a 10-year-old open-pollinated family trial growing under two levels of fertilization in Scotland County, North Carolina. In all, 200 trees were sampled with 100 trees for each treatment. Wood density measurements were collected from wood cores at breast height using x-ray densitometry. We found that the substitution of cad-n1 for a wild-type allele (Cad) was associated with a significant effect on wood density. The cad-n1 heterozygotes had a significantly higher wood density (+2.6%) compared to wild-type trees. The higher density was apparently due to the higher percentage of latewood in the heterozygotes. The fertilization effect was highly significant for both growth and wood density traits. While no cad genotype x

  13. Concerns of Hydrothermal Degradation in CAD/CAM Zirconia

    PubMed Central

    Kim, J.-W.; Covel, N.S.; Guess, P.C.; Rekow, E.D.; Zhang, Y.

    2010-01-01

    Zirconia-based restorations are widely used in prosthetic dentistry; however, their susceptibility to hydrothermal degradation remains elusive. We hypothesized that CAD/CAM machining and subsequent surface treatments, i.e., grinding and/or grit-blasting, have marked effects on the hydrothermal degradation behavior of Y-TZP. CAD/CAM-machined Y-TZP plates (0.5 mm thick), both with and without subsequent grinding with various grit sizes or grit-blasting with airborne alumina particles, were subjected to accelerated aging tests in a steam autoclave. Results showed that the CAD/CAM-machined surfaces initially exhibited superior hydrothermal degradation resistance, but deteriorated at a faster rate upon prolonged autoclave treatment compared with ground and grit-blasted surfaces. The accelerated hydrothermal degradation of CAD/CAM surfaces is attributed to the CAD/CAM machining damage and the absence of surface compressive stresses in the fully sintered material. Clinical relevance for surface treatments of zirconia frameworks in terms of hydrothermal and structural stabilities is addressed. PMID:19966039

  14. Concerns of hydrothermal degradation in CAD/CAM zirconia.

    PubMed

    Kim, J-W; Covel, N S; Guess, P C; Rekow, E D; Zhang, Y

    2010-01-01

    Zirconia-based restorations are widely used in prosthetic dentistry; however, their susceptibility to hydrothermal degradation remains elusive. We hypothesized that CAD/CAM machining and subsequent surface treatments, i.e., grinding and/or grit-blasting, have marked effects on the hydrothermal degradation behavior of Y-TZP. CAD/CAM-machined Y-TZP plates (0.5 mm thick), both with and without subsequent grinding with various grit sizes or grit-blasting with airborne alumina particles, were subjected to accelerated aging tests in a steam autoclave. Results showed that the CAD/CAM-machined surfaces initially exhibited superior hydrothermal degradation resistance, but deteriorated at a faster rate upon prolonged autoclave treatment compared with ground and grit-blasted surfaces. The accelerated hydrothermal degradation of CAD/CAM surfaces is attributed to the CAD/CAM machining damage and the absence of surface compressive stresses in the fully sintered material. Clinical relevance for surface treatments of zirconia frameworks in terms of hydrothermal and structural stabilities is addressed.

  15. Ion mobility spectrometry reveals duplex DNA dissociation intermediates.

    PubMed

    Burmistrova, Anastasia; Gabelica, Valérie; Duwez, Anne-Sophie; De Pauw, Edwin

    2013-11-01

    Electrospray ionization (ESI) soft desolvation is widely used to investigate fragile species such as nucleic acids. Tandem mass spectrometry (MS/MS) gives access to the gas phase energetics of the intermolecular interactions in the absence of solvent, by following the dissociation of mass-selected ions. Ion mobility mass spectrometry (IMS) provides indications on the tridimensional oligonucleotide structure by attributing a collision cross section (CCS) to the studied ion. Electrosprayed duplexes longer than eight bases pairs retain their helical structure in a solvent-free environment. However, the question of conformational changes under activation in MS/MS studies remains open. The objective of this study is to probe binding energetics and characterize the unfolding steps occurring prior to oligonucleotide duplex dissociation. Comparing the evolution of CCS with collision energy and breakdown curves, we characterize dissociation pathways involved in CID-activated DNA duplex separation into single strands, and we demonstrate here the existence of stable dissociation intermediates. At fixed duplex length, dissociation pathways were found to depend on the percentage of GC base pairs and on their position in the duplex. Our results show that pure GC sequences undergo a gradual compaction until reaching the dissociation intermediate: A-helix. Mixed AT-GC sequences were found to present at least two conformers: a classic B-helix and an extended structure where the GC tract is a B-helix and the AT tract(s) fray. The dissociation in single strands takes place from both conformers when the AT base pairs are enclosed between two GC tracts or only from the extended conformer when the AT tract is situated at the end(s) of the sequence.

  16. Purification and Characterization of West Nile Virus Nucleoside Triphosphatase (NTPase)/Helicase: Evidence for Dissociation of the NTPase and Helicase Activities of the Enzyme

    PubMed Central

    Borowski, Peter; Niebuhr, Andreas; Mueller, Oliver; Bretner, Maria; Felczak, Krzysztof; Kulikowski, Tadeusz; Schmitz, Herbert

    2001-01-01

    The nucleoside triphosphatase (NTPase)/helicase associated with nonstructural protein 3 of West Nile (WN) virus was purified from cell culture medium harvested from virus-infected Vero cells. The purification procedure included sequential chromatography on Superdex-200 and Reactive Red 120 columns, followed by a concentration step on an Ultrogel hydroxyapatite column. The nature of the purified protein was confirmed by immunoblot analysis using a WN virus-positive antiserum, determination of its NH2 terminus by microsequencing, and a binding assay with 5′-[14C]fluorosulfonylbenzoyladenosine. Under optimized reaction conditions the enzyme catalyzed the hydrolysis of ATP and the unwinding of the DNA duplex with kcat values of 133 and 5.5 × 10−3 s−1, respectively. Characterization of the NTPase activity of the WN virus enzyme revealed that optimum conditions with respect to the Mg2+ requirement and the monovalent salt or polynucleotide response differed from those of other flavivirus NTPases. Initial kinetic studies demonstrated that the inhibition (or activation) of ATPase activity by ribavirin-5′-triphosphate is not directly related to changes in the helicase activity of the enzyme. Further analysis using guanine and O6-benzoylguanine derivatives revealed that the ATPase activity of WN virus NTPase/helicase may be modulated, i.e., increased or reduced, with no effect on the helicase activity of the enzyme. On the other hand the helicase activity could be modulated without changing the ATPase activity. Our observations show that the number of ATP hydrolysis events per unwinding cycle is not a constant value. PMID:11238848

  17. [Dissociative disorders: from Janet to DSM-IV].

    PubMed

    Nakatani, Y

    2000-01-01

    I reviewed the literature on dissociation and dissociative disorders from Pierre Janet to DSM-IV, and examined the current trends in research. Janet's theory on hysteria is multifaceted, and is based on three psychological models. Based on a hierarchical model, Janet related hysteric symptoms to the activities within the lower strata of mental hierarchy (automatisms psychologiques), which were demonstrably shown in somnambulism. A second model was based on the concept of a psychological system, which was hypothetically composed of ideas, images, feelings, sensations, and movements. According to this model, dissociation of psychological functions was fundamental to the mechanism of hysteria: loss of integration was thought to engender fixed ideas (ideas fixes) and to lead to the development of a system totally isolated from the whole personality system. Janet also attempted to explain various mental disorders using an economic model. He referred to a loss of equilibration between psychological force and psychological tension. Thus, an unexpected emotional experience was conceived to cause a consumption of reserved psychological force, which was in turn followed by exhaustion associated with hysteric symptoms. Whereas most current researchers regard Janet as the first to study psychological trauma as a principal cause of dissociation, I feel it is important to note that he also emphasized the role of stigmata, i.e., permanent traits of hysteric patients, which were represented as a suggestibility and a tendency toward a narrowing of the consciousness field. Discussion about dissociation and its relation to trauma all but disappeared after Janet. However, during the Second World War and post-war period, some psychiatrists began to pay attention to two emerging phenomena: a high incidence of dissociative symptoms such as fugue and amnesia among combatants, and traumatic neurosis frequently observed among ex-inmates of concentration camps. In the 1970s, interest in

  18. Electron photodetachment dissociation for structural characterization of synthetic and bio-polymer anions.

    PubMed

    Antoine, Rodolphe; Lemoine, Jérôme; Dugourd, Philippe

    2014-01-01

    Tandem mass spectrometry (MS-MS) is a generic term evoking techniques dedicated to structural analysis, detection or quantification of molecules based on dissociation of a precursor ion into fragments. Searching for the most informative fragmentation patterns has led to the development of a vast array of activation modes that offer complementary ion reactivity and dissociation pathways. Collisional activation of ions using atoms, molecules or surface resulting in unimolecular dissociation of activated ions still plays a key role in tandem mass spectrometry. The discovery of electron capture dissociation (ECD) and then the development of other electron-ion or ion/ion reaction methods, constituted a significant breakthrough, especially for structural analysis of large biomolecules. Similarly, photon activation opened promising new frontiers in ion fragmentation owing to the ability of tightly controlled internal energy deposition and easy implementation on commercial instruments. Ion activation by photons includes slow heating methods such as infrared multiple photon dissociation (IRMPD) and black-body infrared radiative dissociation (BIRD) and higher energy methods like ultra-violet photodissociation (UVPD) and electron photo detachment dissociation (EPD). EPD occurs after UV irradiation of multiply negatively charged ions resulting in the formation of oxidized radical anions. The present paper reviews the hypothesis regarding the mechanisms of electron photo-detachment, radical formation and direct or activated dissociation pathways that support the observation of odd and even electron product ions. Finally, the value of EPD as a complementary structural analysis tool is illustrated through selected examples of synthetic polymers, oligonucleotides, polypeptides, lipids, and polysaccharides.

  19. Online coupling of high-resolution chromatography with extreme UV photon activation tandem mass spectrometry: Application to the structural investigation of complex glycans by dissociative photoionization.

    PubMed

    Ropartz, David; Giuliani, Alexandre; Fanuel, Mathieu; Hervé, Cécile; Czjzek, Mirjam; Rogniaux, Hélène

    2016-08-24

    The activation of ions by extreme-energy photons (XUV) produced by a synchrotron radiation beamline is a powerful method for characterizing complex glycans using tandem mass spectrometry (MS). As previously described, this activation method leads to rich fragmentation spectra with many structurally valuable cross-ring cleavages while maintaining labile modifications on the glycan structures. However, until now, the tandem MS event was too long to be compatible with liquid chromatography elution times. In this work, the duty cycle of the activation and detection of fragments was shortened, and the background signal on the spectra was drastically reduced. Both improvements allowed, for the first time, the successful coupling of a UHPLC system to XUV-activated tandem MS. The approach was used to characterize a complex mixture of oligo-porphyrans, which are a class of highly sulfated oligosaccharides, in a fully automated way. Due to an enhanced dynamic range and an increased sensitivity, some hypothetical structures of low abundance have been unequivocally confirmed in this study and others have been revised. Some previously undescribed species of oligo-porphyrans that exhibit lateral branching have been fully resolved. This work contributes to the scarce knowledge of the structure of porphyrans in red algae and pushes the current capacities of XUV-activation tandem MS by demonstrating the possibility of a direct coupling with UHPLC. This study will considerably broaden the applicability and practicality of this method in many fields of analytical biology. PMID:27496992

  20. Study of the dissociation of molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Vessot, R. F. C.

    1981-01-01

    Dissociators used to obtain an RF plasma discharge for hydrogen masers and the test system used for operation and evaluation of the dissociators are described. A compact sorption cartridge using a graphite matrix is tested as part of a hydrogen scavenging system. Testing of a vacuum enclosed hydrogen dissociator suitable for long term operation in space is described.

  1. Two-temperature models for nitrogen dissociation

    NASA Astrophysics Data System (ADS)

    da Silva, M. Lino; Guerra, V.; Loureiro, J.

    2007-12-01

    Accurate sets of nitrogen state-resolved dissociation rates have been reduced to two-temperature (translational T and vibrational Tv) dissociation rates. The analysis of such two-temperature dissociation rates shows evidence of two different dissociation behaviors. For Tv < 0.3 T dissociation proceeds predominantly from the lower-lying vibrational levels, whereas for Tv > 0.3 T dissociation proceeds predominantly form the near-dissociative vibrational levels, with an abrupt change of behavior at Tv = 0.3 T. These two-temperature sets have then been utilized as a benchmark for the comparison against popular multitemperature dissociation models (Park, Hansen, Marrone-Treanor, Hammerling, Losev-Shatalov, Gordiets, Kuznetsov, and Macheret-Fridman). This has allowed verifying the accuracy of each theoretical model, and additionally proposing adequate values for any semi-empirical parameters present in the different theories. The Macheret-Fridman model, who acknowledges the existence of the two aforementioned dissociation regimes, has been found to provide significantly more accurate results than the other models. Although these different theoretical approaches have been tested and validated solely for nitrogen dissociation processes, it is reasonable to expect that the general conclusions of this work, regarding the adequacy of the different dissociation models, could be extended to the description of arbitrary diatomic dissociation processes.

  2. Dissociative Functions in the Normal Mourning Process.

    ERIC Educational Resources Information Center

    Kauffman, Jeffrey

    1994-01-01

    Sees dissociative functions in mourning process as occurring in conjunction with integrative trends. Considers initial shock reaction in mourning as model of normal dissociation in mourning process. Dissociation is understood to be related to traumatic significance of death in human consciousness. Discerns four psychological categories of…

  3. Information processing of an acquaintance rape scenario among high- and low-dissociating college women.

    PubMed

    Sandberg, D A; Lynn, S J; Matorin, A I

    2001-07-01

    To assess the impact of dissociation on information processing, 66 college women with high and low levels of trait dissociation were studied with regard to how they unitized videotape segments of an acquaintance rape scenario (actual assault not shown) and a nonthreatening control scenario. Unitization is a paradigm that measures how actively people process stimuli by recording how many times they press a button to indicate that they have seen a significant or meaningful event. Trait dissociation was negatively correlated with participants' unitization of the acquaintance rape videotape, unitization was positively correlated with danger cue identification, and state dissociation was negatively correlated with dangerousness ratings.

  4. Information processing of an acquaintance rape scenario among high- and low-dissociating college women.

    PubMed

    Sandberg, D A; Lynn, S J; Matorin, A I

    2001-07-01

    To assess the impact of dissociation on information processing, 66 college women with high and low levels of trait dissociation were studied with regard to how they unitized videotape segments of an acquaintance rape scenario (actual assault not shown) and a nonthreatening control scenario. Unitization is a paradigm that measures how actively people process stimuli by recording how many times they press a button to indicate that they have seen a significant or meaningful event. Trait dissociation was negatively correlated with participants' unitization of the acquaintance rape videotape, unitization was positively correlated with danger cue identification, and state dissociation was negatively correlated with dangerousness ratings. PMID:11534887

  5. AMPA-receptor involvement in c-fos expression in the medial prefrontal cortex and amygdala dissociates neural substrates of conditioned activity and conditioned reward.

    PubMed

    Mead, A N; Vasilaki, A; Spyraki, C; Duka, T; Stephens, D N

    1999-11-01

    Exposure to an environment, previously conditioned to amphetamine (1 mg/kg, i.p.), induced locomotor activity and c-fos expression (a marker for neuronal activation) in the mouse medial prefrontal cortex (mPFC) and amygdala; acute or repeated amphetamine (1 mg/kg, i.p.) administration induced c-fos expression additionally in the nucleus accumbens. An alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-receptor antagonist, 2, 3-dihydroxy-6-nitro-7-sulphamoyl-benzo(f)quinoxaline (NBQX), blocked expression of conditioned activity, and prevented the increase in c-fos expression in mPFC, implicating mPFC AMPAergic transmission in the conditioned component of behavioural sensitization to amphetamine. NBQX failed to block the expression of amphetamine-conditioned place preference, a measure of conditioned reward, or conditioned c-fos expression in the amygdala, an area implicated in the expression of conditioned place preference. These findings indicate that the conditioned components of behavioural sensitization depend on AMPA-receptor-mediated activation in mPFC, but that conditioned reward does not.

  6. Altered Cingulate Sub-Region Activation Accounts for Task-Related Dissociation in ERN Amplitude as a Function of Obsessive-Compulsive Symptoms

    ERIC Educational Resources Information Center

    Cavanagh, James F.; Grundler, Theo O. J.; Frank, Michael J.; Allen, John J. B.

    2010-01-01

    Larger error-related negativities (ERNs) have been consistently found in obsessive-compulsive disorder (OCD) patients, and are thought to reflect the activities of a hyperactive cortico-striatal circuit during action monitoring. We previously observed that obsessive-compulsive (OC) symptomatic students (non-patients) have larger ERNs during errors…

  7. Study of medium beta elliptical cavities for CADS

    NASA Astrophysics Data System (ADS)

    Wen, Liangjian; Zhang, Shenghu; Li, Yongming; Wang, Ruoxu; Guo, Hao; Zhang, Cong; Jia, Huan; Jiang, Tiancai; Li, Chunlong; He, Yuan

    2016-02-01

    The China Accelerator-Driven Sub-critical System (CADS) is a high intensity proton facility to dispose of nuclear waste and generate electric power. CADS is based on a 1.5 GeV, 10 mA CW superconducting (SC) linac as a driver. The high energy section of the linac is composed of two families of SC elliptical cavities which are designed with geometrical beta 0.63 and 0.82. In this paper, the 650 MHz β=0.63 SC elliptical cavity is studied, including cavity optimization, multipacting, high order modes (HOMs) and generator RF power calculation. Supported by National Natural Science Foundation of China (91426303)

  8. Chairside CAD/CAM: an overview of restorative material options.

    PubMed

    Fasbinder, Dennis J

    2012-01-01

    A number of categories of materials are available for chairside CAD/CAM restorations that have demonstrated predictability and longevity. These materials include esthetic and high-strength ceramics, composite resins for both final and temporary restorations, and newer nanoceramics that offer ease of handling and a glossy surface finish. Each category of materials has unique features designed for specific clinical applications. This article will examine currently available materials designed for chairside CAD/CAM restorations and the various outcomes that are possible with this technologically advanced process.

  9. How to Quickly Import CAD Geometry into Thermal Desktop

    NASA Astrophysics Data System (ADS)

    Wright, Shonte; Beltran, Emilio

    2002-07-01

    There are several groups at JPL (Jet Propulsion Laboratory) that are committed to concurrent design efforts, two are featured here. Center for Space Mission Architecture and Design (CSMAD) enables the practical application of advanced process technologies in JPL's mission architecture process. Team I functions as an incubator for projects that are in the Discovery, and even pre-Discovery proposal stages. JPL's concurrent design environment is to a large extent centered on the CAD (Computer Aided Design) file. During concurrent design sessions CAD geometry is ported to other more specialized engineering design packages.

  10. Impact of IPAD on CAD/CAM database university research

    NASA Technical Reports Server (NTRS)

    Leach, L. M.; Wozny, M. J.

    1984-01-01

    IPAD program has provided direction, focus and software products which impacted on CAD/CAM data base research and follow-on research. The relationship of IPAD to the research projects which involve the storage of geometric data in common data ase facilities such as data base machines, the exchange of data between heterogeneous data bases, the development of IGES processors, the migration of lrge CAD/CAM data base management systems to noncompatible hosts, and the value of RIM as a research tool is described.

  11. Construction CAE; Integration of CAD, simulation, planning and cost control

    SciTech Connect

    Wickard, D.A. ); Bill, R.D.; Gates, K.H.; Yoshinaga, T.; Ohcoshi, S. )

    1989-01-01

    Construction CAE is a simulation, planning, scheduling, and cost control tool that is integrated with a computer aided design (CAD) system. The system uses a CAD model and allows the user to perform construction simulation on objects defined within the model. Initial cost/schedule reports as well as those required for project chronicling are supported through an interface to a work breakdown structure (WBS) and a client's existing schedule reporting system. By integrating currently available project control tools with a simulation system, Construction CAE is more effective than its individual components.

  12. Development to integrate conceptual design tools and a CAD system

    NASA Astrophysics Data System (ADS)

    Torres, V. H.; Ríos, J.; Vizán, A.; Pérez, J. M.

    2012-04-01

    The information supported by PLM/CAD systems is mainly related to Embodiment and Detail Design Phases. Information related to the Conceptual Design Phase is mainly limited to requirement specification documents and system architecture diagram documents. This work aims helping in the integration of the Conceptual Design process and its associated information flow into a commercial software system. It proposes a development framework to integrate Quality Function Deployment, Axiomatic Design, and Failure Mode and Effects Analysis into a PLM/CAD system. This communication presents the methodology used in the development, the software development environment, the modeling of the proposed application and the first results of a pilot implementation.

  13. Transcriptome-wide identification and characterization of CAD isoforms specific for podophyllotoxin biosynthesis from Podophyllum hexandrum.

    PubMed

    Bhattacharyya, Dipto; Hazra, Saptarshi; Banerjee, Anindyajit; Datta, Riddhi; Kumar, Deepak; Chakrabarti, Saikat; Chattopadhyay, Sharmila

    2016-09-01

    Podophyllotoxin (ptox) is a therapeutically important lignan derived from Podophyllum hexandrum and is used as a precursor for the synthesis of anticancer drugs etoposide, teniposide and etopophose. In spite of its enormous economic significance, genomic information on this endangered medicinal herb is scarce. We have performed de novo transcriptome analysis of methyl jasmonate (MeJA)-treated P. hexandrum cell cultures exhibiting enhanced ptox accumulation. The results revealed the maximum up-regulation of several isoforms of cinnamyl alcohol dehydrogenase (CAD). CAD catalyzes the synthesis of coniferyl alcohol and sinapyl alcohol from coniferaldehyde (CAld) and sinapaldehyde respectively. Coniferyl alcohol can produce both lignin and lignan while sinapyl alcohol produces only lignin. To isolate the CAD isoforms favoring ptox, we deduced full length cDNA sequences of four CAD isoforms: PhCAD1, PhCAD2, PhCAD3 and PhCAD4 from the contigs of the transcriptome data. In vitro enzyme assays indicated a higher affinity for CAld over sinapaldehyde for each isoform. In silico molecular docking analyses also suggested that PhCAD3 has a higher binding preference with CAld over sinapaldehyde, followed by PhCAD4, PhCAD2, and PhCAD1, respectively. The transgenic cell cultures overexpressing these isoforms independently revealed that PhCAD3 favored the maximum accumulation of ptox as compared to lignin followed by PhCAD4 and PhCAD2, whereas, PhCAD1 favored both equally. Together, our study reveals transcriptome-wide identification and characterization of ptox specific CAD isoforms from P. hexandrum. It provides a useful resource for future research not only on the ptox biosynthetic pathway but on overall P. hexandrum, an endangered medicinal herb with immense therapeutic importance.

  14. Dissociation behavior of a bifunctional tempo-active ester reagent for peptide structure analysis by free radical initiated peptide sequencing (FRIPS) mass spectrometry.

    PubMed

    Ihling, Christian; Falvo, Francesco; Kratochvil, Isabel; Sinz, Andrea; Schäfer, Mathias

    2015-02-01

    We have synthesized a homobifunctional active ester cross-linking reagent containing a TEMPO (2,2,6,6-tetramethylpiperidine-1-oxy) moiety connected to a benzyl group (Bz), termed TEMPO-Bz-linker. The aim for designing this novel cross-linker was to facilitate MS analysis of cross-linked products by free radical initiated peptide sequencing (FRIPS). The TEMPO-Bz-linker was reacted with all 20 proteinogenic amino acids as well as with model peptides to gain detailed insights into its fragmentation mechanism upon collision activation. The final goal of this proof-of-principle study was to evaluate the potential of the TEMPO-Bz-linker for chemical cross-linking studies to derive 3D-structure information of proteins. Our studies were motivated by the well documented instability of the central NO-C bond of TEMPO-Bz reagents upon collision activation. The fragmentation of this specific bond was investigated in respect to charge states and amino acid composition of a large set of precursor ions resulting in the identification of two distinct fragmentation pathways. Molecular ions with highly basic residues are able to keep the charge carriers located, i.e. protons or sodium cations, and consequently decompose via a homolytic cleavage of the NO-C bond of the TEMPO-Bz-linker. This leads to the formation of complementary open-shell peptide radical cations, while precursor ions that are protonated at the TEMPO-Bz-linker itself exhibit a charge-driven formation of even-electron product ions upon collision activation. MS(3) product ion experiments provided amino acid sequence information and allowed determining the cross-linking site. Our study fully characterizes the CID behavior of the TEMPO-Bz-linker and demonstrates its potential, but also its limitations for chemical cross-linking applications utilizing the special features of open-shell peptide ions on the basis of selective tandem MS analysis.

  15. Functional Signature of Recovering Cortex: Dissociation of Local Field Potentials and Spiking Activity in Somatosensory Cortices of Spinal Cord Injured Monkeys

    PubMed Central

    Wang, Zheng; Qi, Hui-Xin; Kaas, Jon H.; Roe, Anna W.; Chen, Li Min

    2013-01-01

    After disruption of dorsal column afferents at high cervical spinal levels in adult monkeys, somatosensory cortical neurons recover responsiveness to tactile stimulation of the hand; this reactivation correlates with a recovery of hand use. However, it is not known if all neuronal response properties recover, and whether different cortical areas recover in a similar manner. To address this, we recorded neuronal activity in cortical area 3b and S2 in adult squirrel monkeys weeks after unilateral lesion of the dorsal columns. We found that in response to vibrotactile stimulation, local field potentials remained robust at all frequency ranges. However, neuronal spiking activity failed to follow at high frequencies (≥15Hz). We suggest that the failure to generate spiking activity at high stimulus frequency reflects a changed balance of inhibition and excitation in both area 3b and S2, and that this mismatch in spiking and local field potential is a signature of an early phase of recovering cortex (< two months). PMID:24017995

  16. [Dis-social personality disorder].

    PubMed

    Habermeyer, E; Herpertz, S C

    2006-05-01

    Deviant behavior is gaining in clinical importance if it is founded on stable, characteristic, and enduring patterns of psychopathologically relevant personality traits which have their onset in childhood or adolescence. The classification of these traits shows variations, so that a distinction between the ICD-10 diagnosis of dis-social personality disorder, DSM-IV diagnosis of antisocial personality disorder, and the concept "psychopathy" is necessary. Our knowledge about the biological basis of antisocial behavior includes neurophysiologic, psychophysiologic, and genetic findings. Also relevant are results of neurotransmitter studies and structural resp. functional neuroimaging findings. Psychosocial risk factors include parental deficits, rejection, disregard, unstable relations, and abuse. Efficient psychotherapeutic treatment is cognitive-behavioral. Pharmacologic treatment is largely "off-label". The diagnosis of antisocial and dis-social personality disorders allows no conclusions on criminal responsibility. In addition to psychiatric diagnostics, considerations on the severity of the disorder and its effects on the ability to inhibit actions are necessary.

  17. Paraphilia from a dissociative perspective.

    PubMed

    Ross, Colin A

    2008-12-01

    A dissociative structural model of the psyche can account for a wide range of symptoms across many DSM-IV categories, including sexual compulsions and addictions. The model leads to a distinct overall plan of treatment and a set of operationalized interventions aimed at integration of the self, rather than suppression of impulses. The model could be tested first in epidemiological studies and later in treatment outcome studies.

  18. Dissociative Photoionization of Diethyl Ether.

    PubMed

    Voronova, Krisztina; Mozaffari Easter, Chrissa M; Covert, Kyle J; Bodi, Andras; Hemberger, Patrick; Sztáray, Bálint

    2015-10-29

    The dissociative photoionization of internal energy selected diethyl ether ions was investigated by imaging photoelectron photoion coincidence spectroscopy. In a large, 5 eV energy range Et2O(+) cations decay by two parallel and three sequential dissociative photoionization channels, which can be modeled well using statistical theory. The 0 K appearance energies of the CH3CHOCH2CH3(+) (H-loss, m/z = 73) and CH3CH2O═CH2(+) (methyl-loss, m/z = 59) fragment ions were determined to be 10.419 ± 0.015 and 10.484 ± 0.008 eV, respectively. The reemergence of the hydrogen-loss ion above 11 eV is attributed to transition-state (TS) switching, in which the second, outer TS is rate-determining at high internal energies. At 11.81 ± 0.05 eV, a secondary fragment of the CH3CHOCH2CH3(+) (m/z = 73) ion, protonated acetaldehyde, CH3CH═OH(+) (m/z = 45) appears. On the basis of the known thermochemical onset of this fragment, a reverse barrier of 325 meV was found. Two more sequential dissociation reactions were examined, namely, ethylene and formaldehyde losses from the methyl-loss daughter ion. The 0 K appearance energies of 11.85 ± 0.07 and 12.20 ± 0.08 eV, respectively, indicate no reverse barrier in these processes. The statistical model of the dissociative photoionization can also be used to predict the fractional ion abundances in threshold photoionization at large temperatures, which could be of use in, for example, combustion diagnostics. PMID:26444101

  19. Dissociative symptoms and REM sleep.

    PubMed

    van Heugten-van der Kloet, Dalena; Merckelbach, Harald; Lynn, Steven Jay

    2013-12-01

    Llewellyn has written a fascinating article about rapid eye movement (REM) dreams and how they promote the elaborative encoding of recent memories. The main message of her article is that hyperassociative and fluid cognitive processes during REM dreaming facilitate consolidation. We consider one potential implication of this analysis: the possibility that excessive or out-of-phase REM sleep fuels dissociative symptomatology. Further research is warranted to explore the psychopathological ramifications of Llewellyn's theory. PMID:24304772

  20. Identification and characterization of "pathoadaptive mutations" of the cadBA operon in several intestinal Escherichia coli.

    PubMed

    Jores, Joerg; Torres, Alfredo G; Wagner, Sylke; Tutt, Christopher B; Kaper, James B; Wieler, Lothar H

    2006-12-01

    The dysenteric Shigella spp. and enteroinvasive Escherichia coli (EIEC) have evolved from commensal E. coli by the acquisition of a virulence plasmid and inactivation of genes of the cad locus encoding lysine decarboxylase (LDC) by so-called pathoadaptive mutation. As horizontal gene transfer and recombination occurs frequently in E. coli we were interested to see if similar pathoadaptive mutations are commonly present in other intestinal pathotypes. Therefore, we examined 140 intestinal E. coli strains of various pathotypes and the ECOR collection for their ability to decarboxylate lysine, and identified 25 strains that were unable to do so. Complementation of a Shiga toxin-producing E. coli and two enteropathogenic E. coli strains, both LDC-negative, with the intact cad locus restored LDC activity and resulted in a reduction in adherence to tissue culture cells. We investigated the cad locus for possible alterations by using hybridization and PCR techniques and compared the results with the alterations reported for Shigella spp. and EIEC strains. Interestingly, the alterations of the cad genes were similar to those previously reported, pointing towards a parallel evolution of LDC silencing in different intestinal E. coli pathotypes.

  1. [Differential diagnosis between dissociative disorders and schizophrenia].

    PubMed

    Shibayama, Masatoshi

    2011-01-01

    The differential diagnosis of dissociative disorders includes many psychiatric disorders, such as schizophrenia, bipolar disorders (especially bipolar II disorder), depressive disorder (especially atypical depression), epilepsy, Asperger syndrome, and borderline personality disorder. The theme of this paper is the differential diagnosis between dissociative disorders and schizophrenia. Schneiderian first-rank symptoms in schizophrenia are common in dissociative disorders, especially in dissociative identity disorder (DID). Many DID patients have been misdiagnosed as schizophrenics and treated with neuroleptics. We compared and examined Schneiderian symptoms of schizophrenia and those of dissociative disorders from a structural viewpoint. In dissociative disorders, delusional perception and somatic passivity are not seen. "Lateness" and "Precedence of the Other" originated from the concept of "Pattern Reversal" (H. Yasunaga)" is characteristic of schizophrenia. It is important to check these basic structure of schizophrenia in subjective experiences in differential diagnosis between dissociative disorders and schizophrenia.

  2. Enhanced cadaverine production from L-lysine using recombinant Escherichia coli co-overexpressing CadA and CadB.

    PubMed

    Ma, Weichao; Cao, Weijia; Zhang, Hong; Chen, Kequan; Li, Yan; Ouyang, Pingkai

    2015-04-01

    The effect of fusing the PelB signal sequence to lysine/cadaverine antiporter (CadB) on the bioconversion of L-lysine to cadaverine was investigated. To construct a whole-cell biocatalyst for cadaverine production, four expression plasmids were constructed for the co-expression of lysine decarboxylase (CadA) and lysine/cadaverine antiporter (CadB) in Escherichia coli. Expressing CadB with the PelB signal sequence increased cadaverine production by 12%, and the optimal expression plasmid, pETDuet-pelB-CadB-CadA, contained two T7 promoter-controlled genes, CadA and the PelB-CadB fusion protein. Based on pETDuet-pelB-CadB-CadA, a whole-cell system for the bioconversion of L-lysine to cadaverine was constructed, and three strategies for L-lysine feeding were evaluated to eliminate the substrate inhibition problem. A cadaverine titer of 221 g l(-1) with a molar yield of 92% from lysine was obtained. PMID:25515797

  3. Electron Transfer Dissociation Mass Spectrometry of Hemoglobin on Clinical Samples

    NASA Astrophysics Data System (ADS)

    Coelho Graça, Didia; Lescuyer, Pierre; Clerici, Lorella; Tsybin, Yury O.; Hartmer, Ralf; Meyer, Markus; Samii, Kaveh; Hochstrasser, Denis F.; Scherl, Alexander

    2012-10-01

    A mass spectrometry-based assay combining the specificity of selected reaction monitoring and the protein ion activation capabilities of electron transfer dissociation was developed and employed for the rapid identification of hemoglobin variants from whole blood without previous proteolytic cleavage. The analysis was performed in a robust ion trap mass spectrometer operating at nominal mass accuracy and resolution. Subtle differences in globin sequences, resulting with mass shifts of about one Da, can be unambiguously identified. These results suggest that mass spectrometry analysis of entire proteins using electron transfer dissociation can be employed on clinical samples in a workflow compatible with diagnostic applications.

  4. Dexras1 a unique ras-GTPase interacts with NMDA receptor activity and provides a novel dissociation between anxiety, working memory and sensory gating.

    PubMed

    Carlson, G C; Lin, R E; Chen, Y; Brookshire, B R; White, R S; Lucki, I; Siegel, S J; Kim, S F

    2016-05-13

    Dexras1 is a novel GTPase that acts at a confluence of signaling mechanisms associated with psychiatric and neurological disease including NMDA receptors, NOS1AP and nNOS. Recent work has shown that Dexras1 mediates iron trafficking and NMDA-dependent neurodegeneration but a role for Dexras1 in normal brain function or psychiatric disease has not been studied. To test for such a role, mice with germline knockout (KO) of Dexras1 were assayed for behavioral abnormalities as well as changes in NMDA receptor subunit protein expression. Because Dexras1 is up-regulated during stress or by dexamethasone treatment, we included measures associated with emotion including anxiety and depression. Baseline anxiety-like measures (open field and zero maze) were not altered, nor were depression-like behavior (tail suspension). Measures of memory function yielded mixed results, with no changes in episodic memory (novel object recognition) but a significant decrement on working memory (T-maze). Alternatively, there was an increase in pre-pulse inhibition (PPI), without concomitant changes in either startle amplitude or locomotor activity. PPI data are consistent with the direction of change seen following exposure to dopamine D2 antagonists. An examination of NMDA subunit expression levels revealed an increased expression of the NR2A subunit, contrary to previous studies demonstrating down-regulation of the receptor following antipsychotic exposure (Schmitt et al., 2003) and up-regulation after exposure to isolation rearing (Turnock-Jones et al., 2009). These findings suggest a potential role for Dexras1 in modulating a selective subset of psychiatric symptoms, possibly via its interaction with NMDARs and/or other disease-related binding-partners. Furthermore, data suggest that modulating Dexras1 activity has contrasting effects on emotional, sensory and cognitive domains.

  5. Dexras1 a unique ras-GTPase interacts with NMDA receptor activity and provides a novel dissociation between anxiety, working memory and sensory gating.

    PubMed

    Carlson, G C; Lin, R E; Chen, Y; Brookshire, B R; White, R S; Lucki, I; Siegel, S J; Kim, S F

    2016-05-13

    Dexras1 is a novel GTPase that acts at a confluence of signaling mechanisms associated with psychiatric and neurological disease including NMDA receptors, NOS1AP and nNOS. Recent work has shown that Dexras1 mediates iron trafficking and NMDA-dependent neurodegeneration but a role for Dexras1 in normal brain function or psychiatric disease has not been studied. To test for such a role, mice with germline knockout (KO) of Dexras1 were assayed for behavioral abnormalities as well as changes in NMDA receptor subunit protein expression. Because Dexras1 is up-regulated during stress or by dexamethasone treatment, we included measures associated with emotion including anxiety and depression. Baseline anxiety-like measures (open field and zero maze) were not altered, nor were depression-like behavior (tail suspension). Measures of memory function yielded mixed results, with no changes in episodic memory (novel object recognition) but a significant decrement on working memory (T-maze). Alternatively, there was an increase in pre-pulse inhibition (PPI), without concomitant changes in either startle amplitude or locomotor activity. PPI data are consistent with the direction of change seen following exposure to dopamine D2 antagonists. An examination of NMDA subunit expression levels revealed an increased expression of the NR2A subunit, contrary to previous studies demonstrating down-regulation of the receptor following antipsychotic exposure (Schmitt et al., 2003) and up-regulation after exposure to isolation rearing (Turnock-Jones et al., 2009). These findings suggest a potential role for Dexras1 in modulating a selective subset of psychiatric symptoms, possibly via its interaction with NMDARs and/or other disease-related binding-partners. Furthermore, data suggest that modulating Dexras1 activity has contrasting effects on emotional, sensory and cognitive domains. PMID:26946266

  6. [Clinical Handling of Patients with Dissociative Disorders].

    PubMed

    Okano, Kenichiro

    2015-01-01

    This paper discusses the way informed psychiatrists are expected to handle dissociative patients in clinical situations, with a specific focus on dissociative identity disorders and dissociative fugue. On the initial interview with dissociative patients, information on their history of trauma and any nascent dissociative symptoms in their childhood should be carefully obtained. Their level of stress in their current life should also be assessed in order to understand their symptomatology, as well as to predict their future clinical course. A psychoeducational approach is crucial; it might be helpful to give information on dissociative disorder to these patients as well as their family members in order to promote their adherence to treatment. Regarding the symptomatology of dissociative disorders, detailed symptoms and the general clinical course are presented. It was stressed that dissociative identity disorder and dissociative fugue, the most high-profile dissociative disorders, are essentially different in their etiology and clinical presentation. Dissociative disorders are often confused with and misdiagnosed as psychotic disorders, such as schizophrenia. Other conditions considered in terms of the differential diagnosis include borderline personality disorder as well as temporal lobe epilepsy. Lastly, the therapeutic approach to dissociative identity disorder is discussed. Each dissociative identity should be understood as potentially representing some traumatically stressful event in the past. The therapist should be careful not to excessively promote the creation or elaboration of any dissociative identities. Three stages are proposed in the individual psychotherapeutic process. In the initial stage, a secure environment and stabilization of symptoms should be sought. The second stage consists of aiding the "host" personality to make use of other more adaptive coping skills in their life. The third stage involves coaching as well as continuous awareness of

  7. [Clinical Handling of Patients with Dissociative Disorders].

    PubMed

    Okano, Kenichiro

    2015-01-01

    This paper discusses the way informed psychiatrists are expected to handle dissociative patients in clinical situations, with a specific focus on dissociative identity disorders and dissociative fugue. On the initial interview with dissociative patients, information on their history of trauma and any nascent dissociative symptoms in their childhood should be carefully obtained. Their level of stress in their current life should also be assessed in order to understand their symptomatology, as well as to predict their future clinical course. A psychoeducational approach is crucial; it might be helpful to give information on dissociative disorder to these patients as well as their family members in order to promote their adherence to treatment. Regarding the symptomatology of dissociative disorders, detailed symptoms and the general clinical course are presented. It was stressed that dissociative identity disorder and dissociative fugue, the most high-profile dissociative disorders, are essentially different in their etiology and clinical presentation. Dissociative disorders are often confused with and misdiagnosed as psychotic disorders, such as schizophrenia. Other conditions considered in terms of the differential diagnosis include borderline personality disorder as well as temporal lobe epilepsy. Lastly, the therapeutic approach to dissociative identity disorder is discussed. Each dissociative identity should be understood as potentially representing some traumatically stressful event in the past. The therapist should be careful not to excessively promote the creation or elaboration of any dissociative identities. Three stages are proposed in the individual psychotherapeutic process. In the initial stage, a secure environment and stabilization of symptoms should be sought. The second stage consists of aiding the "host" personality to make use of other more adaptive coping skills in their life. The third stage involves coaching as well as continuous awareness of

  8. Present State of CAD Teaching in Spanish Universities

    ERIC Educational Resources Information Center

    Garcia, Ramon Rubio; Santos, Ramon Gallego; Quiros, Javier Suarez; Penin, Pedro I. Alvarez

    2005-01-01

    During the 1990s, all Spanish Universities updated the syllabuses of their courses as a result of the entry into force of the new Organic Law of Universities ("Ley Organica de Universidades") and, for the first time, "Computer Assisted Design" (CAD) appears in the list of core subjects (compulsory teaching content set by the government) in many of…

  9. Correlating Trainee Attributes to Performance in 3D CAD Training

    ERIC Educational Resources Information Center

    Hamade, Ramsey F.; Artail, Hassan A.; Sikstrom, Sverker

    2007-01-01

    Purpose: The purpose of this exploratory study is to identify trainee attributes relevant for development of skills in 3D computer-aided design (CAD). Design/methodology/approach: Participants were trained to perform cognitive tasks of comparable complexity over time. Performance data were collected on the time needed to construct test models, and…

  10. The design and construction of the CAD-1 airship

    NASA Technical Reports Server (NTRS)

    Kleiner, H. J.; Schneider, R.; Duncan, J. L.

    1975-01-01

    The background history, design philosophy and Computer application as related to the design of the envelope shape, stress calculations and flight trajectories of the CAD-1 airship, now under construction by Canadian Airship Development Corporation are reported. A three-phase proposal for future development of larger cargo carrying airships is included.

  11. Including CAD/CAM dentistry in a dental school curriculum.

    PubMed

    Browning, William D; Reifeis, Paul; Willis, Lisa; Kirkup, Michele L

    2013-01-01

    Shaping a clinical curriculum that is appropriate for novice dentists, is based on high-quality evidence of efficacy, yet reflects current practices is challenging. CAD/CAM units have been available to dentists since the late '80s. Recent improvements in the software, hardware and the clinical performance of available all-ceramic blocks have keyed a surge in interest. Based on a careful review of the systems available and, equally importantly, a review of the research regarding the longevity of reinforced glass ceramics, IUSD decided to add training on the use of the E4D CAD/CAM system to the curriculum. Students now receive lectures, preclinical hands-on training and clinical experience in fabricating all-ceramic restorations. At present any student who is interested in providing an all-ceramic restoration for his/her patient can do so using our CAD/CAM system. In a little less than one year our undergraduate dental students have provided 125 all-ceramic crowns to their patients. Clinical faculty have been impressed with the marginal fit and esthetics of the crowns. Finally, with students designing, milling, sintering and staining the restorations the CAD/CAM systems has reduced lab costs significantly.

  12. Schools (Students) Exchanging CAD/CAM Files over the Internet.

    ERIC Educational Resources Information Center

    Mahoney, Gary S.; Smallwood, James E.

    This document discusses how students and schools can benefit from exchanging computer-aided design/computer-aided manufacturing (CAD/CAM) files over the Internet, explains how files are exchanged, and examines the problem of selected hardware/software incompatibility. Key terms associated with information search services are defined, and several…

  13. Right approach to 3D modeling using CAD tools

    NASA Astrophysics Data System (ADS)

    Baddam, Mounica Reddy

    The thesis provides a step-by-step methodology to enable an instructor dealing with CAD tools to optimally guide his/her students through an understandable 3D modeling approach which will not only enhance their knowledge about the tool's usage but also enable them to achieve their desired result in comparatively lesser time. In the known practical field, there is particularly very little information available to apply CAD skills to formal beginners' training sessions. Additionally, advent of new software in 3D domain cumulates updating into a more difficult task. Keeping up to the industry's advanced requirements emphasizes the importance of more skilled hands in the field of CAD development, rather than just prioritizing manufacturing in terms of complex software features. The thesis analyses different 3D modeling approaches specified to the varieties of CAD tools currently available in the market. Utilizing performance-time databases, learning curves have been generated to measure their performance time, feature count etc. Based on the results, improvement parameters have also been provided for (Asperl, 2005).

  14. Program Evolves from Basic CAD to Total Manufacturing Experience

    ERIC Educational Resources Information Center

    Cassola, Joel

    2011-01-01

    Close to a decade ago, John Hersey High School (JHHS) in Arlington Heights, Illinois, made a transition from a traditional classroom-based pre-engineering program. The new program is geared towards helping students understand the entire manufacturing process. Previously, a JHHS student would design a project in computer-aided design (CAD) software…

  15. Reaction paths of phosphine dissociation on silicon (001)

    NASA Astrophysics Data System (ADS)

    Warschkow, O.; Curson, N. J.; Schofield, S. R.; Marks, N. A.; Wilson, H. F.; Radny, M. W.; Smith, P. V.; Reusch, T. C. G.; McKenzie, D. R.; Simmons, M. Y.

    2016-01-01

    Using density functional theory and guided by extensive scanning tunneling microscopy (STM) image data, we formulate a detailed mechanism for the dissociation of phosphine (PH3) molecules on the Si(001) surface at room temperature. We distinguish between a main sequence of dissociation that involves PH2+H, PH+2H, and P+3H as observable intermediates, and a secondary sequence that gives rise to PH+H, P+2H, and isolated phosphorus adatoms. The latter sequence arises because PH2 fragments are surprisingly mobile on Si(001) and can diffuse away from the third hydrogen atom that makes up the PH3 stoichiometry. Our calculated activation energies describe the competition between diffusion and dissociation pathways and hence provide a comprehensive model for the numerous adsorbate species observed in STM experiments.

  16. Reaction paths of phosphine dissociation on silicon (001).

    PubMed

    Warschkow, O; Curson, N J; Schofield, S R; Marks, N A; Wilson, H F; Radny, M W; Smith, P V; Reusch, T C G; McKenzie, D R; Simmons, M Y

    2016-01-01

    Using density functional theory and guided by extensive scanning tunneling microscopy (STM) image data, we formulate a detailed mechanism for the dissociation of phosphine (PH3) molecules on the Si(001) surface at room temperature. We distinguish between a main sequence of dissociation that involves PH2+H, PH+2H, and P+3H as observable intermediates, and a secondary sequence that gives rise to PH+H, P+2H, and isolated phosphorus adatoms. The latter sequence arises because PH2 fragments are surprisingly mobile on Si(001) and can diffuse away from the third hydrogen atom that makes up the PH3 stoichiometry. Our calculated activation energies describe the competition between diffusion and dissociation pathways and hence provide a comprehensive model for the numerous adsorbate species observed in STM experiments. PMID:26747816

  17. Research on remote sensing image pixel attribute data acquisition method in AutoCAD

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoyang; Sun, Guangtong; Liu, Jun; Liu, Hui

    2013-07-01

    The remote sensing image has been widely used in AutoCAD, but AutoCAD lack of the function of remote sensing image processing. In the paper, ObjectARX was used for the secondary development tool, combined with the Image Engine SDK to realize remote sensing image pixel attribute data acquisition in AutoCAD, which provides critical technical support for AutoCAD environment remote sensing image processing algorithms.

  18. Acute dissociation and cardiac reactivity to script-driven imagery in trauma-related disorders

    PubMed Central

    Sack, Martin; Cillien, Melanie; Hopper, James W.

    2012-01-01

    Background Potential acute protective functions of dissociation include modulation of stress-induced psychophysiological arousal. This study was designed to explore whether acute dissociative reactions during a stress experiment would override the effects of reexperiencing. Methods Psychophysiological reactions during exposure to script-driven trauma imagery were studied in relation to acute responses of reexperiencing and dissociative symptoms in 61 patients with histories of exposure to a variety of traumas. Acute symptomatic responses were assessed with the Responses to Script-Driven Imagery Scale (RSDI), and participants were divided into four groups by median splits of RSDI reexperiencing and dissociation subscale scores. Results In a comparison of the high RSDI reexperiencing groups with low versus high acute dissociative symptoms, the high dissociators exhibited significantly lower heart rate (HR) during trauma script and a significantly smaller script-induced decrease in parasympathetic cardiac activity. HR reactivity to the trauma script was negatively correlated with acute dissociative symptom severity. Conclusions Acute dissociative reactions are a potential moderator of response to experimental paradigms investigating psychologically traumatized populations. We therefore suggest that future research on psychophysiological stress reactions in traumatized samples should routinely assess for acute dissociative symptoms. PMID:23198029

  19. Adsorption properties of biologically active derivatives of quaternary ammonium surfactants and their mixtures at aqueous/air interface II. Dynamics of adsorption, micelles dissociation and cytotoxicity of QDLS.

    PubMed

    Rojewska, Monika; Prochaska, Krystyna; Olejnik, Anna; Rychlik, Joanna

    2014-07-01

    The main aim of our study was analysis of adsorption dynamics of mixtures containing quaternary derivatives of lysosomotropic substance (QDLS). Two types of equimolar mixtures were considered: the ones containing two derivatives of lysosomotropic substances (DMALM-12 and DMGM-12) as well as the catanionic mixtures i.e. the systems containing QDLS and DBSNa. Dynamic surface tension measurements of surfactant mixtures were made. The results suggested that the diffusivity of the mixed system could be treated as the average value of rates of diffusion of individual components, micelles and ion pairs, which are present in the mixtures studied. Moreover, an attempt was made to explain the influence of the presence of micelles in the mixtures on their adsorption dynamics. The compounds examined show interesting biological properties which can be useful, especially for drug delivery in medical treatment. In vitro cytotoxic activities of the mixtures studied towards human cancer cells were evaluated. Most of the mixtures showed a high antiproliferative potential, especially the ones containing DMALM-12. Each cancer cell line used demonstrated different sensitivity to the same dose of the mixtures tested.

  20. Mechanisms of peptide fragmentation from time- and energy-resolved surface-induced dissociation studies: Dissociation of angiotensin analogs

    NASA Astrophysics Data System (ADS)

    Laskin, Julia; Bailey, Thomas H.; Futrell, Jean H.

    2006-03-01

    Energetics and mechanism of dissociation of singly protonated angiotensin III (RVYIHPF) and its analogs RVYIFPF, RVYIYPF, RVYIHAF and RVYIHDF was studied using surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially configured for studying ion activation by collisions with surfaces. The energetics and dynamics of peptide fragmentation were deduced by modeling the time- and energy-resolved survival curves for each precursor ion using an RRKM-based approach developed in our laboratory. Fragmentation mechanisms were inferred from comparison of time- and energy-resolved fragmentation efficiency curves (TFECs) of different fragment ions followed by RRKM modeling of dissociation of angiotensin III into six major families of fragment ions. Detailed modeling demonstrated that dissociation of these peptides is dominated by loss of ammonia from the precursor ion and characterized by a high-energy barrier of 1.6 eV. Loss of NH3 and subsequent rearrangement of the MH+-NH3 ion results in proton mobilization and release of ca. 30 kcal/mol into internal excitation of the MH+-NH3 ion. The resulting highly excited ion accesses a variety of non-specific dissociation pathways with very high rate constants. Fast fragmentation of excited MH+-NH3 ion forms a variety of abundant bn-NH3 and an-NH3 fragment ions. Abundant XH and HX internal fragments are also formed, reflecting the stability of histidine-containing diketopiperazine structures.

  1. Cam Design Projects in an Advanced CAD Course for Mechanical Engineers

    ERIC Educational Resources Information Center

    Ault, H. K.

    2009-01-01

    The objective of this paper is to present applications of solid modeling aimed at modeling of complex geometries such as splines and blended surfaces in advanced CAD courses. These projects, in CAD-based Mechanical Engineering courses, are focused on the use of the CAD system to solve design problems for applications in machine design, namely the…

  2. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV).

    PubMed

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela; Roca-Sanjuán, Daniel

    2015-12-01

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations of N-H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N-H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π1 (-) and π2 (-) states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.

  3. The ciliary Evc/Evc2 complex interacts with Smo and controls Hedgehog pathway activity in chondrocytes by regulating Sufu/Gli3 dissociation and Gli3 trafficking in primary cilia.

    PubMed

    Caparrós-Martín, Jose A; Valencia, María; Reytor, Edel; Pacheco, María; Fernandez, Margarita; Perez-Aytes, Antonio; Gean, Esther; Lapunzina, Pablo; Peters, Heiko; Goodship, Judith A; Ruiz-Perez, Victor L

    2013-01-01

    Hedgehog (Hh) signaling is involved in patterning and morphogenesis of most organs in the developing mammalian embryo. Despite many advances in understanding core components of the pathway, little is known about how the activity of the Hh pathway is adjusted in organ- and tissue-specific developmental processes. Mutations in EVC or EVC2 disrupt Hh signaling in tooth and bone development. Using mouse models, we show here that Evc and Evc2 are mutually required for localizing to primary cilia and also for maintaining their normal protein levels. Consistent with Evc and Evc2 functioning as a complex, the skeletal phenotypes in either single or double homozygous mutant mice are virtually indistinguishable. Smo translocation to the cilium was normal in Evc2-deficient chondrocytes following Hh activation with the Smo-agonist SAG. However, Gli3 recruitment to cilia tips was reduced and Sufu/Gli3 dissociation was impaired. Interestingly, we found Smo to co-precipitate with Evc/Evc2, indicating that in some cells Hh signaling requires direct interaction of Smo with the Evc/Evc2 complex. Expression of a dominantly acting Evc2 mutation previously identified in Weyer's acrodental dysostosis (Evc2Δ43) caused mislocalization of Evc/Evc2Δ43 within the cilium and also reproduced the Gli3-related molecular defects observed in Evc2(-/-) chondrocytes. Moreover, Evc silencing in Sufu(-/-) cells attenuated the output of the Hh pathway, suggesting that Evc/Evc2 also promote Hh signaling in the absence of Sufu. Together our data reveal that the Hh pathway involves Evc/Evc2-dependent modulations that are necessary for normal endochondral bone formation.

  4. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV)

    NASA Astrophysics Data System (ADS)

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela; Roca-Sanjuán, Daniel

    2015-12-01

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations of N-H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N-H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π1- and π2- states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.

  5. Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases caused by low-energy electrons (0-3 eV)

    SciTech Connect

    Francés-Monerris, Antonio; Segarra-Martí, Javier; Merchán, Manuela; Roca-Sanjuán, Daniel

    2015-12-07

    Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations of N–H bonds induced by low-energy electrons. The approach is based on minimum energy path and linear interpolation of internal coordinates computations along the N–H dissociation channels carried out at the complete-active-space self-consistent field//complete-active-space second-order perturbation theory level. On the basis of the calculated theoretical quantities, new assignations for the adenine and cytosine anion yield curves are provided. In addition, the π{sub 1}{sup −} and π{sub 2}{sup −} states of the pyrimidine nucleobases are expected to produce the temporary anions at electron energies close to 1 and 2 eV, respectively. Finally, the present theoretical results do not allow to discard neither the dipole-bound nor the valence-bound mechanisms in the range of energies explored, suggesting that both possibilities may coexist in the experiments carried out with the isolated nucleobases.

  6. Biallelic mutations in CAD, impair de novo pyrimidine biosynthesis and decrease glycosylation precursors

    PubMed Central

    Ng, Bobby G.; Wolfe, Lynne A.; Ichikawa, Mie; Markello, Thomas; He, Miao; Tifft, Cynthia J.; Gahl, William A.; Freeze, Hudson H.

    2015-01-01

    In mitochondria, carbamoyl-phosphate synthetase 1 activity produces carbamoyl phosphate for urea synthesis, and deficiency results in hyperammonemia. Cytoplasmic carbamoyl-phosphate synthetase 2, however, is part of a tri-functional enzyme encoded by CAD; no human disease has been attributed to this gene. The tri-functional enzyme contains carbamoyl-phosphate synthetase 2 (CPS2), aspartate transcarbamylase (ATCase) and dihydroorotase (DHOase) activities, which comprise the first three of six reactions required for de novo pyrimidine biosynthesis. Here we characterize an individual who is compound heterozygous for mutations in different domains of CAD. One mutation, c.1843-1G>A, results in an in-frame deletion of exon 13. The other, c.6071G>A, causes a missense mutation (p.Arg2024Gln) in a highly conserved residue that is essential for carbamoyl-phosphate binding. Metabolic flux studies showed impaired aspartate incorporation into RNA and DNA through the de novo synthesis pathway. In addition, CTP, UTP and nearly all UDP-activated sugars that serve as donors for glycosylation were decreased. Uridine supplementation rescued these abnormalities, suggesting a potential therapy for this new glycosylation disorder. PMID:25678555

  7. Reversible dissociation and conformational stability of dimeric ribulose bisphosphate carboxylase.

    PubMed

    Erijman, L; Lorimer, G H; Weber, G

    1993-05-18

    Dimer-monomer dissociation of ribulosebisphosphate carboxylase/oxygenase from Rhodospirillum rubrum was investigated using hydrostatic pressure in the range 1-2 kbar to promote dissociation. Intrinsic fluorescence emission and polarization, along with the polarization of the fluorescence of single-labeled AEDANS conjugates, were used to follow the dissociation. Full reversibility after dissociation was observed to depend on the presence of small ligands: glycerol, Mg2+, and NaHCO3, the last two being required to activate the enzyme. The free energy of association at 15 degrees C, -12.9 kcal mol-1, was made up of a positive change in enthalpy on association of 6.0 kcal mol-1 and an entropic contribution (T delta S) of 18.9 kcal mol-1; thus the monomer association is entropy driven. No dissociation of the quaternary complex formed by the dimer, 2-carboxy-D-arabinitol 1,5-diphosphate (CADP), Mg2+, and NaHCO3 was observed at pressures up to 2.0 kbar; the magnitude of stabilization by the inhibitor binding was estimated as 2.3 kcal mol-1. Pressurization in the presence of bis-ANS results in a time-dependent increase in fluorophore emission, indicating changes in monomer conformation with exposure of hydrophobic surfaces upon dissociation. Reactivity against the fluorescent probe 1,5-I-AEDANS was also used as a conformational probe: HPLC of a trypsin digest of rubisco labeled at atmospheric pressure revealed a single fluorescent peptide, whereas more extensive labeling was observed when the reaction was carried out at 2.0 kbar, indicative of exposure of internal cysteines.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8388254

  8. Dissociative Tendencies and Facilitated Emotional Processing

    PubMed Central

    Oathes, Desmond J.; Ray, William J.

    2009-01-01

    Dissociation is a process linked to lapses of attention, history of abuse or trauma, compromised emotional memory, and a disintegrated sense of self. It is theorized that dissociation stems from avoiding emotional information, especially negative emotion, to protect a fragile psyche. The present study tested whether or not dissociaters do actually avoid processing emotion by asking groups scoring high or low on the Dissociative Experiences Scale to judge the affective valence of several types of emotional stimuli. Manipulations of valence, modality (pictures or words), task complexity, and personal relevance lead to results suggesting that dissociation is linked to facilitated rather than deficient emotional processing. Our results are consistent with a theory that sensitivity to emotional material may be a contributing factor in subsequent dissociation to avoid further elaboration of upsetting emotion in these individuals. The findings for dissociation further exemplify the influence of individual differences in the link between cognition and emotion. PMID:18837615

  9. Products of Dissociative Recombination in the Ionosphere

    NASA Technical Reports Server (NTRS)

    Cosby, Philip

    1996-01-01

    SRI International undertook a novel experimental measurement of the product states formed by dissociative recombination (DR) of O2(+), NO(+), and N2(+) as a function of both electron energy and reactant ion vibrational level. For these measurements we used a recently developed experimental technique for measuring dissociation product distributions that allows both the branching ratios to be accurately determined and the electronic and rovibrational state composition of the reactant ions to be specified. DR is the dominant electron loss mechanism in all regions of the ionosphere. In this process, electron attachment to the molecular ion produces an unstable neutral molecule that rapidly dissociates. For a molecular ion such as O2(+), the dissociation recombination reaction is (1) O2(+) + e yields O + O + W. The atomic products of this reaction, in this case two oxygen atoms, can be produced in a variety of excited states and with a variety of kinetic energies, as represented by W in Eq. (1). These atoms are not only active in the neutral chemistry of the ionosphere, but are also especially important because their optical emissions are often used to infer in situ concentrations of the parent molecular ion and ambient electron densities. Many laboratory measurements have been made of DR reaction rates under a wide range of electron temperatures, but very little is known about the actual distributions among the final states of the atomic products. This lack of knowledge seriously limits the validity and effectiveness of efforts to model both natural and man-made ionospheric disturbances. Bates recently identified major deficiencies in the currently accepted branching ratios for O2(+) as they relate to blue and green line emission measurements in the nocturnal F-region. During our two-year effort, we partially satisfied our ambitious goals. We constructed and operated a variable pressure, electron-impact ion source and a high pressure, hollow-cathode discharge ion

  10. Controls on Gas Hydrate Formation and Dissociation

    SciTech Connect

    Miriam Kastner; Ian MacDonald

    2006-03-03

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both

  11. Dissociative identity disorder: Medicolegal challenges.

    PubMed

    Farrell, Helen M

    2011-01-01

    Persons with dissociative identity disorder (DID) often present in the criminal justice system rather than the mental health system and perplex experts in both professions. DID is a controversial diagnosis with important medicolegal implications. Defendants have claimed that they committed serious crimes, including rape or murder, while they were in a dissociated state. Asserting that their alter personality committed the bad act, defendants have pleaded not guilty by reason of insanity (NGRI). In such instances, forensic experts are asked to assess the defendant for DID and provide testimony in court. Debate continues over whether DID truly exists, whether expert testimony should be allowed into evidence, and whether it should exculpate defendants for their criminal acts. This article reviews historical and theoretical perspectives on DID, presents cases that illustrate the legal implications and controversies of raising an insanity defense based on multiple personalities, and examines the role of forensic experts asked to comment on DID with the goal of assisting clinicians in the medicolegal assessment of DID in relation to crimes.

  12. Dissociative recombination in planetary ionospheres

    NASA Technical Reports Server (NTRS)

    Fox, J. L.

    1993-01-01

    Ionization in planetary atmospheres can be produced by solar photoionization, photoelectron impact ionization, and, in auroral regions, by impact of precipitating particles. This ionization is lost mainly in dissociative recombination (DR) of molecular ions. Although atomic ions cannot undergo DR, they can be transformed locally through ion-molecule reactions into molecular ions, or they may be transported vertically or horizontally to regions of the atmosphere where such transformations are possible. Because DR reactions tend to be very exothermic, they can be an important source of kinetically or internally excited fragments. In interplanetary thermospheres, the neutral densities decrease exponentially with altitude. Below the homopause (or turbopause), the atmosphere is assumed to be throughly mixed by convection and/or turbulence. Above the homopause, diffusion is the major transport mechanism, and each species is distributed according to its mass, with the logarithmic derivative of the density with repect to altitude given approximately by -1/H, where H = kT/mg is the scale height. In this expression, T is the neutral temperature, g is the local acceleratiion of gravity, and m is the mass of the species. Thus lighter species become relatively more abundant, and heavier species less abundant, as the altitude increases. This variation of the neutral composition can lead to changes in the ion composition; furthermore, as the neutral densities decrease, dissociative recombination becomes more important relative to ion-neutral reactions as a loss mechanism for molecular ions.

  13. Mirror writing and a dissociative identity disorder.

    PubMed

    Le, Catherine; Smith, Joyce; Cohen, Lewis

    2009-01-01

    Individuals with dissociative identity disorder (DID) have been known to show varied skills and talents as they change from one dissociative state to another. For example, case reports have described people who have changed their handedness or have spoken foreign languages during their dissociative states. During an interview with a patient with DID, a surprising talent emerged when she wrote a sentence for the Folstein Mini-Mental State Exam-mirror writing. It is not known whether her mirror writing had a deeper level of meaning; however, it does emphasize the idiosyncratic nature of dissociative identity disorder.

  14. Dissociative Recombination without a Curve Crossing

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1994-01-01

    Ab initio calculations show that a curve crossing is not always needed for a high dissociative- recombination cross section. For HeH(+), in which no neutral states cross the ion potential curve, dissociative recombination is driven by the nuclear kinetic-energy operator on adiabatic potential curves. The kinetic-energy derivative operator allows for capture into repulsive curves that are outside of the classical turning points for the nuclear motion. The dominant dissociative route is the C (2)Sigma(+) state leading to H(n = 2) atoms. An analogous mechanism is proposed for the dissociative recombination of H3(+).

  15. Impact of CAD-deficiency in flax on biogas production.

    PubMed

    Wróbel-Kwiatkowska, Magdalena; Jabłoński, Sławomir; Szperlik, Jakub; Dymińska, Lucyna; Łukaszewicz, Marcin; Rymowicz, Waldemar; Hanuza, Jerzy; Szopa, Jan

    2015-12-01

    Global warming and the reduction in our fossil fuel reservoir have forced humanity to look for new means of energy production. Agricultural waste remains a large source for biofuel and bioenergy production. Flax shives are a waste product obtained during the processing of flax fibers. We investigated the possibility of using low-lignin flax shives for biogas production, specifically by assessing the impact of CAD deficiency on the biochemical and structural properties of shives. The study used genetically modified flax plants with a silenced CAD gene, which encodes the key enzyme for lignin synthesis. Reducing the lignin content modified cellulose crystallinity, improved flax shive fermentation and optimized biogas production. Chemical pretreatment of the shive biomass further increased biogas production efficiency.

  16. Impact of CAD-deficiency in flax on biogas production.

    PubMed

    Wróbel-Kwiatkowska, Magdalena; Jabłoński, Sławomir; Szperlik, Jakub; Dymińska, Lucyna; Łukaszewicz, Marcin; Rymowicz, Waldemar; Hanuza, Jerzy; Szopa, Jan

    2015-12-01

    Global warming and the reduction in our fossil fuel reservoir have forced humanity to look for new means of energy production. Agricultural waste remains a large source for biofuel and bioenergy production. Flax shives are a waste product obtained during the processing of flax fibers. We investigated the possibility of using low-lignin flax shives for biogas production, specifically by assessing the impact of CAD deficiency on the biochemical and structural properties of shives. The study used genetically modified flax plants with a silenced CAD gene, which encodes the key enzyme for lignin synthesis. Reducing the lignin content modified cellulose crystallinity, improved flax shive fermentation and optimized biogas production. Chemical pretreatment of the shive biomass further increased biogas production efficiency. PMID:26178244

  17. General KBE model with inheritance and multi CAD support

    NASA Astrophysics Data System (ADS)

    Tiuca, T. L.; Rusu, C.; Noveanu, S.; Mandru, D.

    2016-08-01

    Knowledge-Based Engineering (KBE) is a research field that studies methodologies and technologies for capture and re-use engineering knowledge. The primary objective of KBE is to reduce time and cost of product research processes and/or product development, which is primarily achieved through automation of repetitive design tasks while capturing, retaining and re-using engineering knowledge. Every CAD System includes KBE Tools. The power of these tools is incremented by the use of external high level programming language. The model presented in this paper has the aim to reduce times and costs of particular KBE Models development, by programming inheritance concepts and also the multi CAD Support. The model is implemented through a C# application that is also presented.

  18. Integration of a CAD System Into an MDO Framework

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.; Samareh, J. A.; Weston, R. P.; Zorumski, W. E.

    1998-01-01

    NASA Langley has developed a heterogeneous distributed computing environment, called the Framework for Inter-disciplinary Design Optimization, or FIDO. Its purpose has been to demonstrate framework technical feasibility and usefulness for optimizing the preliminary design of complex systems and to provide a working environment for testing optimization schemes. Its initial implementation has been for a simplified model of preliminary design of a high-speed civil transport. Upgrades being considered for the FIDO system include a more complete geometry description, required by high-fidelity aerodynamics and structures codes and based on a commercial Computer Aided Design (CAD) system. This report presents the philosophy behind some of the decisions that have shaped the FIDO system and gives a brief case study of the problems and successes encountered in integrating a CAD system into the FEDO framework.

  19. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  20. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials.

  1. Dissociative symptoms and dissociative disorder comorbidity in patients with obsessive-compulsive disorder.

    PubMed

    Belli, Hasan; Ural, Cenk; Vardar, Melek Kanarya; Yesılyurt, Sema; Oncu, Fatıh

    2012-10-01

    The present study attempted to assess the dissociative symptoms and overall dissociative disorder comorbidity in patients with obsessive-compulsive disorder (OCD). In addition, we examined the relationship between the severity of obsessive-compulsive symptoms and dissociative symptoms. All patients admitted for the first time to the psychiatric outpatient unit were included in the study. Seventy-eight patients had been diagnosed as having OCD during the 2-year study period. Patients had to meet the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for OCD. Most (76.9%; n = 60) of the patients were female, and 23.1% (n = 18) of the patients were male. Dissociation Questionnaire was used to measure dissociative symptoms. The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Dissociative Disorders interviews and Yale-Brown Obsessive Compulsive Checklist and Severity Scale were used. Eleven (14%) of the patients with OCD had comorbid dissociative disorder. The most prevalent disorder in our study was dissociative depersonalization disorder. Dissociative amnesia and dissociative identity disorder were common as well. The mean Yale-Brown score was 23.37 ± 7.27 points. Dissociation Questionnaire scores were between 0.40 and 3.87 points, and the mean was 2.23 ± 0.76 points. There was a statistically significant positive correlation between Yale-Brown points and Dissociation Questionnaire points. We conclude that dissociative symptoms among patients with OCD should alert clinicians for the presence of a chronic and complex dissociative disorder. Clinicians may overlook an underlying dissociative process in patients who have severe symptoms of OCD. However, a lack of adequate response to cognitive-behavioral and drug therapy may be a consequence of dissociative process.

  2. A comparative analysis of 2D and 3D CAD for calcifications in digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Acciavatti, Raymond J.; Ray, Shonket; Keller, Brad M.; Maidment, Andrew D. A.; Conant, Emily F.

    2015-03-01

    Many medical centers offer digital breast tomosynthesis (DBT) and 2D digital mammography acquired under the same compression (i.e., "Combo" examination) for screening. This paper compares a conventional 2D CAD algorithm (Hologic® ImageChecker® CAD v9.4) for calcification detection against a prototype 3D algorithm (Hologic® ImageChecker® 3D Calc CAD v1.0). Due to the newness of DBT, the development of this 3D CAD algorithm is ongoing, and it is currently not FDA-approved in the United States. For this study, DBT screening cases with suspicious calcifications were identified retrospectively at the University of Pennsylvania. An expert radiologist (E.F.C.) reviewed images with both 2D and DBT CAD marks, and compared the marks to biopsy results. Control cases with one-year negative follow-up were also studied; these cases either possess clearly benign calcifications or lacked calcifications. To allow the user to alter the sensitivity for cancer detection, an operating point is assigned to each CAD mark. As expected from conventional 2D CAD, increasing the operating point in 3D CAD increases sensitivity and reduces specificity. Additionally, we showed that some cancers are occult to 2D CAD at all operating points. By contrast, 3D CAD allows for detection of some cancers that are missed on 2D CAD. We also demonstrated that some non-cancerous CAD marks in 3D are not present at analogous locations in the 2D image. Hence, there are additional marks when using both 2D and 3D CAD in combination, leading to lower specificity than with conventional 2D CAD alone.

  3. Visuomotor Dissociation in Cerebral Scaling of Size.

    PubMed

    Potgieser, Adriaan R E; de Jong, Bauke M

    2016-01-01

    Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space. PMID:26963705

  4. Visuomotor Dissociation in Cerebral Scaling of Size.

    PubMed

    Potgieser, Adriaan R E; de Jong, Bauke M

    2016-01-01

    Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

  5. Visuomotor Dissociation in Cerebral Scaling of Size

    PubMed Central

    Potgieser, Adriaan R. E.; de Jong, Bauke M.

    2016-01-01

    Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a ‘resized’ virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space. PMID:26963705

  6. Group technology methods for integrated CAD/CAM

    NASA Astrophysics Data System (ADS)

    Propen, M.; Jacko, J.

    1984-10-01

    The use of a single product definition and comprehensive database are key factors in integrating CAD and CAM. This paper describes one approach for investigating the scope of developing a full scale Group Technology (GT) system. The prototype GT system discussed required the integration of a decision logic processor, relational database, and design/drafting system, and demonstrated a generative process planning system for a family of gas turbine engine components.

  7. CAD integration: opening up new optical design possibilities; Technical Digest

    NASA Astrophysics Data System (ADS)

    Haumonte, Jean-Baptiste; Venturino, Jean-Claude

    2005-05-01

    The development of optical design and analysis tools in a CAD software can help to optimise the design, size and performance of tomorrow's consumer produtcs. While optics was still held back by software limitations, CAD programs were moving forward in leaps and bounds, improving manufacturing technologies and making it possible to design and produce highly innovative and sophisticated products. The problem was that in the past, 'traditional' optical design programs were only able to simulate spherical and aspherical lenses, meaning that the optical designers were limited to designing systems which were a series of imperfect lenses, each one correcting the last. That is why OPTIS has created the first optical design program to be fully integrated into a CAD program. The technology is available from OPTIS in an integrated SOLIDWORKS or CATIA V5 version. Users of this software can reduce the number of lenses needed in a system. Designers will now have access to complex surfaces such as NURBS meaning they will now be able to define free shape progressive lenses and even improve on optical performances using fewer lenses. This revolutionary technology will allow mechanical designers to work on optical systems and to shre information with optical designers for the first time. Previously not possible in a CAD program you may now determine all the optical performances of any optical system, providing first order and third order performances, sequential and non-sequential ray-tracing, wavefront surfaces, point spread function, MTF, spot-diagram, using real optical surfaces and guaranteeing the mechanical precision necessary for an optical system.

  8. Integrated CAD/CAM: Problems, prognosis, and role of IPAD

    NASA Technical Reports Server (NTRS)

    Nilson, E. N.

    1980-01-01

    Major technology problems impede the development and evolution of totally integrated interactive CAD/CAM systems. IPAD is playing an important role in the identification of these problems and is contributing significantly to their solution. It is the purpose of this presentation to examine some of these issues, look at the prognosis of obtaining effective solutions, and point up some of the past and expected contributions of IPAD to this technology.

  9. The multidimensional inventory of dissociation (MID): A comprehensive measure of pathological dissociation.

    PubMed

    Dell, Paul F

    2006-01-01

    This article describes the development and validation of the Multidimensional Inventory of Dissociation (MID). The MID is a 218-item, self-administered, multiscale instrument that comprehensively assesses the phenomenological domain of pathological dissociation and diagnoses the dissociative disorders. The MID measures 14 major facets of pathological dissociation; it has 23 dissociation diagnostic scales that simultaneously operationalize (1) the subjective/ phenomenological domain of pathological dissociation and (2) the hypothesized dissociative symptoms of dissociative identity disorder (Dell, 2001a). The MID was designed for clinical research and for diagnostic assessment of patients who present with a mixture of dissociative, posttraumatic, and borderline symptoms. The MID demonstrated internal reliability, temporal stability, convergent validity, discriminant validity, and construct validity. The MID also exhibited incremental validity over the Dissociative Experiences Scale (DES) by predicting an additional 18% of the variance in weighted abuse scores on the Traumatic Experiences Questionnaire (TEQ). Confirmatory factor analysis (CFA) did not support a one-factor model of the MID's clinical scales (i.e., the 14 facets and the 23 diagnostic symptoms). In contrast, however, CFA of the MID's factor scales (Dell & Lawson, 2005) has strongly supported a one-factor model. It was concluded that both the MID's 168 dissociation items and the construct of pathological dissociation have a second-order, unifactorial structure.

  10. The differential diagnosis of epilepsy, pseudoseizures, dissociative identity disorder, and dissociative disorder not otherwise specified.

    PubMed

    Bowman, E S; Coons, P M

    2000-01-01

    The authors review the co-occurrences of dissociative symptoms and disorders with epilepsy and pseudo-seizures and examine newer diagnostic instruments that assist in accurate diagnosis of persons with concomitant seizure behaviors and dissociative symptoms. They also review seizure behaviors and electroencephalographic findings in persons with dissociative identity disorder (DID) and dissociative disorder not otherwise specified (DDNOS) and dissociative symptoms in persons with epilepsy and with pseudoseizures. Dissociative symptoms in 15 patients with epilepsy and 15 with pseudo-seizures were examined using the Dissociative Experiences Scale (DES) and the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). On the SCID-D, pseudo-seizure patients had significantly higher dissociative symptom scores than epileptic patients, but DES scores did not reliably distinguish epileptic and pseudo-seizure patients. Misdiagnosis of persons with seizures and dissociative symptoms can be avoided by careful adherence to DSM dissociative disorder criteria, the use of video-EEG monitoring, and systematic assessment of dissociative symptoms with the SCID-D.

  11. AutoBioCAD: full biodesign automation of genetic circuits.

    PubMed

    Rodrigo, Guillermo; Jaramillo, Alfonso

    2013-05-17

    Synthetic regulatory networks with prescribed functions are engineered by assembling a reduced set of functional elements. We could also assemble them computationally if the mathematical models of those functional elements were predictive enough in different genetic contexts. Only after achieving this will we have libraries of models of biological parts able to provide predictive dynamical behaviors for most circuits constructed with them. We thus need tools that can automatically explore different genetic contexts, in addition to being able to use such libraries to design novel circuits with targeted dynamics. We have implemented a new tool, AutoBioCAD, aimed at the automated design of gene regulatory circuits. AutoBioCAD loads a library of models of genetic elements and implements evolutionary design strategies to produce (i) nucleotide sequences encoding circuits with targeted dynamics that can then be tested experimentally and (ii) circuit models for testing regulation principles in natural systems, providing a new tool for synthetic biology. AutoBioCAD can be used to model and design genetic circuits with dynamic behavior, thanks to the incorporation of stochastic effects, robustness, qualitative dynamics, multiobjective optimization, or degenerate nucleotide sequences, all facilitating the link with biological part/circuit engineering.

  12. A CAD system based on spherical dual representations

    SciTech Connect

    Roach, J.W.; Paripati, P.K.; Wright, J.S.

    1987-08-01

    Computer-aided design (CAD) systems typically have many different functions: drafting, two-dimensional modeling, three-dimensional modeling, finite element analysis, and fit and tolerancing of parts. The authors report on the construction of a CAD system based on shape representation ideas used in the vision community to determine the shape of an object from its image. In the long term, they propose to construct a combined CAD and sensing system based on the same underlying object models. Considerable advantages follow from building a model-driven sensor fusion system that uses a common geometric model. In a manufacturing environment, for example, a library of objects can be built up and its models used in a vision and touch sensing system integrated into an automated assembly line to discriminate between objects and determine orientation and distance. If such a system could be made robust and highly reliable, then some of the most difficult problems that plague attempts to create a fully flexible automated environment would be solved.

  13. Use of Existing CAD Models for Radiation Shielding Analysis

    NASA Technical Reports Server (NTRS)

    Lee, K. T.; Barzilla, J. E.; Wilson, P.; Davis, A.; Zachman, J.

    2015-01-01

    The utility of a radiation exposure analysis depends not only on the accuracy of the underlying particle transport code, but also on the accuracy of the geometric representations of both the vehicle used as radiation shielding mass and the phantom representation of the human form. The current NASA/Space Radiation Analysis Group (SRAG) process to determine crew radiation exposure in a vehicle design incorporates both output from an analytic High Z and Energy Particle Transport (HZETRN) code and the properties (i.e., material thicknesses) of a previously processed drawing. This geometry pre-process can be time-consuming, and the results are less accurate than those determined using a Monte Carlo-based particle transport code. The current work aims to improve this process. Although several Monte Carlo programs (FLUKA, Geant4) are readily available, most use an internal geometry engine. The lack of an interface with the standard CAD formats used by the vehicle designers limits the ability of the user to communicate complex geometries. Translation of native CAD drawings into a format readable by these transport programs is time consuming and prone to error. The Direct Accelerated Geometry -United (DAGU) project is intended to provide an interface between the native vehicle or phantom CAD geometry and multiple particle transport codes to minimize problem setup, computing time and analysis error.

  14. Ovulation leads women to perceive sexy cads as good dads.

    PubMed

    Durante, Kristina M; Griskevicius, Vladas; Simpson, Jeffry A; Cantú, Stephanie M; Li, Norman P

    2012-08-01

    Why do some women pursue relationships with men who are attractive, dominant, and charming but who do not want to be in relationships--the prototypical sexy cad? Previous research shows that women have an increased desire for such men when they are ovulating, but it is unclear why ovulating women would think it is wise to pursue men who may be unfaithful and could desert them. Using both college-age and community-based samples, in 3 studies we show that ovulating women perceive charismatic and physically attractive men, but not reliable and nice men, as more committed partners and more devoted future fathers. Ovulating women perceive that sexy cads would be good fathers to their own children but not to the children of other women. This ovulatory-induced perceptual shift is driven by women who experienced early onset of puberty. Taken together, the current research identifies a novel proximate reason why ovulating women pursue relationships with sexy cads, complementing existing research that identifies the ultimate, evolutionary reasons for this behavior.

  15. Ovulation leads women to perceive sexy cads as good dads.

    PubMed

    Durante, Kristina M; Griskevicius, Vladas; Simpson, Jeffry A; Cantú, Stephanie M; Li, Norman P

    2012-08-01

    Why do some women pursue relationships with men who are attractive, dominant, and charming but who do not want to be in relationships--the prototypical sexy cad? Previous research shows that women have an increased desire for such men when they are ovulating, but it is unclear why ovulating women would think it is wise to pursue men who may be unfaithful and could desert them. Using both college-age and community-based samples, in 3 studies we show that ovulating women perceive charismatic and physically attractive men, but not reliable and nice men, as more committed partners and more devoted future fathers. Ovulating women perceive that sexy cads would be good fathers to their own children but not to the children of other women. This ovulatory-induced perceptual shift is driven by women who experienced early onset of puberty. Taken together, the current research identifies a novel proximate reason why ovulating women pursue relationships with sexy cads, complementing existing research that identifies the ultimate, evolutionary reasons for this behavior. PMID:22582900

  16. Differences between the internal energy depositions induced by collisional activation and by electron transfer of W(CO)62+ ions on collision with Ar and K targets

    NASA Astrophysics Data System (ADS)

    Hayakawa, Shigeo; Kitaguchi, Akihiro; Kameoka, Satoko; Toyoda, Michisato; Ichihara, Toshio

    2006-06-01

    Doubly charged tungsten hexacarbonyl W(CO )62+ ions were made to collide with Ar and K targets to give singly and doubly charged positive ions by collision-induced dissociation (CID). The resulting ions were analyzed and detected by using a spherical electrostatic analyzer. Whereas the doubly charged fragment ions resulting from collisional activation (CA) were dominant with the Ar target, singly charged fragment ions resulting from electron transfer were dominant with the K target. The internal energy deposition in collisionally activated dissociation (CAD) evaluated with the Ar target was broad and decreased with increasing internal energy. The predominant peaks observed with the K target were associated with singly charged W(CO)2+ and W(CO )3+ ions: these ions were not the result of CA, but arose from dissociation induced by electron transfer (DIET). The internal energy deposition resulting from the electron transfer was very narrow and centered at a particular energy, 7.8eV below the energy level of the W(CO )62+ ion. This narrow internal energy distribution was explained in terms of electron transfer by Landau-Zener [Z. Phys. Soviet 2, 46 (1932); Proc. R. Soc. London, Ser. A 137, 646 (1952)] potential crossing at a separation of 5.9×10-8cm between a W(CO )62+ ion and a K atom, and the coulombic repulsion between singly charged ions in the exit channel. A large cross section of 1.1×10-14cm2 was estimated for electron capture of the doubly charged W(CO )62+ ion from the alkali metal target, whose ionization energy is very low. The term "collision-induced dissociation," taken literally, includes all dissociation processes induced by collision, and therefore encompasses both CAD and DIET processes in the present work. Although the terms CID and CAD have been defined similarly, we would like to propose that they should not be used interchangeably, on the basis that there are differences in the observed ions and in their intensities with Ar and K targets.

  17. Spatiotemporal differences in the c-fos pathway between C57BL/6J and DBA/2J mice following flurothyl-induced seizures: a dissociation of hippocampal Fos from seizure activity

    PubMed Central

    Kadiyala, Sridhar B.; Papandrea, Dominick; Tuz, Karina; Anderson, Tara M.; Jayakumar, Sachidhanand; Herron, Bruce J.; Ferland, Russell J.

    2014-01-01

    Significant differences in seizure characteristics between inbred mouse strains highlight the importance of genetic predisposition to epilepsy. Here, we examined the genetic differences between the seizure-resistant C57BL/6J (B6) mouse strain and the seizure-susceptible DBA/2J (D2) strain in the phospho-Erk and Fos pathways to examine seizure-induced neuronal activity to uncover potential mechanistic correlates to these disparate seizure responsivities. Expression of neural activity markers was examined following 1, 5, or 8 seizures, or after 8 seizures, a 28 day rest period, and a final flurothyl rechallenge. Two brain regions, the hippocampus and ventromedial nucleus of the hypothalamus (VMH), had significantly different Fos expression profiles following seizures. Fos expression was highly robust in B6 hippocampus following one seizure and remained elevated following multiple seizures. Conversely, there was an absence of Fos (and phospho-Erk) expression in D2 hippocampus following one generalized seizure that increased with multiple seizures. This lack of Fos expression occurred despite intracranial electroencephalographic recordings indicating that the D2 hippocampus propagated ictal discharge during the first flurothyl seizure suggesting a dissociation of seizure discharge from Fos and phospho-Erk expression. Global transcriptional analysis confirmed a dysregulation of the c-fos pathway in D2 mice following 1 seizure. Moreover, global analysis of RNA expression differences between B6 and D2 hippocampus revealed a unique pattern of transcripts that were co-regulated with Fos in D2 hippocampus following 1 seizure. These expression differences could, in part, account for D2’s seizure susceptibility phenotype. Following 8 seizures, a 28 day rest period, and a final flurothyl rechallenge, ~85% of B6 mice develop a more complex seizure phenotype consisting of a clonic-forebrain seizure that uninterruptedly progresses into a brainstem seizure. This seizure phenotype

  18. Molecular dissociation in dilute gas

    SciTech Connect

    Renfrow, S.N.; Duggan, J.L.; McDaniel, F.D. |

    1999-06-01

    The charge state distributions (CSD) produced during molecular dissociation are important to both Trace Element Accelerator Mass Spectrometry (TEAMS) and the ion implantation industry. The CSD of 1.3{endash}1.7 MeV SiN{sup +}, SiMg{sup +}, SiMn{sup +}, and SiZn{sup +} molecules have been measured for elements that do not form atomic negative ions (N, Mg, Mn, and Zn) using a NEC Tandem Pelletron accelerator. The molecules were produced in a Cs sputter negative ion source, accelerated, magnetically analyzed, and then passed through an N{sub 2} gas cell. The neutral and charged breakups where analyzed using an electrostatic deflector and measured with particle detectors. Equilibrium CSD were determined and comparisons made between molecular and atomic ion data. {copyright} {ital 1999 American Institute of Physics.}

  19. The Dissociative Recombination of OH(+)

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1995-01-01

    Theoretical quantum chemical calculations of the cross sections and rates for the dissociative recombination of the upsilon = 0 level of the ground state of OH(+) show that recombination occurs primarily along the 2 (2)Pi diabatic route. The products are 0((1)D) and a hot H atom with 6.1 eV kinetic energy. The coupling to the resonances is very small and the indirect recombination mechanism plays only a minor role. The recommended value for the rate coefficient is (6.3 +/- 0.7) x 10(exp -9)x (T(e)/1300)(exp -0.48) cu.cm/s for 10 less than T(e) less than 1000 K.

  20. Dissociation Energetics and Mechanisms of Leucine Enkephalin (M + H)+ and (2M + X)+ Ions (X = H, Li, Na, K, and Rb) Measured by Blackbody Infrared Radiative Dissociation

    PubMed Central

    Schnier, Paul D.; Price, William D.; Strittmatter, Eric F.; Williams, Evan R.

    2005-01-01

    The dissociation kinetics of protonated leucine enkephalin and its proton and alkali metal bound dimers were investigated by blackbody infrared radiative dissociation in a Fourier-transform mass spectrometer. From the temperature dependence of the unimolecular dissociation rate constants, Arrhenius activation parameters in the zero-pressure limit are obtained. Protonated leucine enkephalin dissociates to form b4 and (M−H2O)+ ions with an average activation energy (Ea) of 1.1 eV and an A factor of 1010.5 s−1. The value of the A factor indicates that these dissociation processes are rearrangements. The b4 ions subsequently dissociate to form a4 ions via a process with a relatively high activation energy (1.3 eV), but one that is entropically favored. For the cationized dimers, the thermal stability decreases with increasing cation size, consistent with a simple electrostatic interaction in these noncovalent ion–molecule complexes. The Ea and A factors are indistinguishable within experimental error with values of ~1.5 eV and 1017 s−1, respectively. Although not conclusive, results from master equation modeling indicate that all these BIRD processes, except for b4 → a4, are in the rapid energy exchange limit. In this limit, the internal energy of the precursor ion population is given by a Boltzmann distribution and information about the energetics and dynamics of the reaction are obtained directly from the measured Arrhenius parameters. PMID:16554908

  1. Dissociative depression among women in the community.

    PubMed

    Sar, Vedat; Akyüz, Gamze; Oztürk, Erdinç; Alioğlu, Firdevs

    2013-01-01

    This study screened the prevalence and correlates of dissociative disorders among depressive women in the general population. The Dissociative Disorders Interview Schedule and the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interview for DSM-IV were administered to 628 women in 500 homes. The prevalence of current major depressive episode was 10.0%. Of the women, 26 (40.6%) had the lifetime diagnosis of a DSM-IV, dissociative disorder, yielding a prevalence of 4.1% for dissociative depression. This group was younger (mean age = 30.7 years) than the nondissociative depression women (mean age = 39.6 years). There was no difference between the 2 groups on comorbid somatization disorder, PTSD, or borderline personality disorder. Besides suicide attempts, the dissociative group was characterized by secondary features of dissociative identity disorder; Schneiderian symptoms; borderline personality disorder criteria; and extrasensory perceptions, including possession experiences. They reported suicidality, thoughts of guilt and worthlessness, diminished concentration and indecisiveness, and appetite and weight changes more frequently than the nondissociative group. Early cessation of school education and childhood sexual abuse were frequently reported by the dissociative depression group. With its distinct features, the concept of dissociative depression may facilitate understanding of treatment resistance in, development of better psychotherapy strategies for, and new thinking on the neurobiology and pharmacotherapy of depressive disorders. PMID:23796173

  2. Dissociation and the Development of Psychopathology.

    ERIC Educational Resources Information Center

    Putnam, Frank W.; Trickett, Penelope K.

    This paper reviews the research on dissociation and the development of psychopathology in children and adolescents. Definitions and dimensions of dissociation are addressed, noting its range from normative daydreaming to the extremes found in individuals with multiple personality disorder. Memory dysfunctions, disturbances of identity, passive…

  3. Dissociative depression among women in the community.

    PubMed

    Sar, Vedat; Akyüz, Gamze; Oztürk, Erdinç; Alioğlu, Firdevs

    2013-01-01

    This study screened the prevalence and correlates of dissociative disorders among depressive women in the general population. The Dissociative Disorders Interview Schedule and the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interview for DSM-IV were administered to 628 women in 500 homes. The prevalence of current major depressive episode was 10.0%. Of the women, 26 (40.6%) had the lifetime diagnosis of a DSM-IV, dissociative disorder, yielding a prevalence of 4.1% for dissociative depression. This group was younger (mean age = 30.7 years) than the nondissociative depression women (mean age = 39.6 years). There was no difference between the 2 groups on comorbid somatization disorder, PTSD, or borderline personality disorder. Besides suicide attempts, the dissociative group was characterized by secondary features of dissociative identity disorder; Schneiderian symptoms; borderline personality disorder criteria; and extrasensory perceptions, including possession experiences. They reported suicidality, thoughts of guilt and worthlessness, diminished concentration and indecisiveness, and appetite and weight changes more frequently than the nondissociative group. Early cessation of school education and childhood sexual abuse were frequently reported by the dissociative depression group. With its distinct features, the concept of dissociative depression may facilitate understanding of treatment resistance in, development of better psychotherapy strategies for, and new thinking on the neurobiology and pharmacotherapy of depressive disorders.

  4. Childhood Stuttering and Dissociations across Linguistic Domains

    ERIC Educational Resources Information Center

    Anderson, Julie D.; Pellowski, Mark W.; Conture, Edward G.

    2005-01-01

    The purpose of this investigation was to evaluate the possible presence of dissociations in the speech and language skills of young children who do (CWS) and do not stutter (CWNS) using a correlation-based statistical procedure [Bates, E., Appelbaum, M., Salcedo, J., Saygin, A. P., & Pizzamiglio, L. (2003). Quantifying dissociations in…

  5. Cognitive and dissociative manifestations in fibromyalgia.

    PubMed

    Leavitt, Frank; Katz, Robert S; Mills, Megan; Heard, Amy R

    2002-04-01

    Memory decline and mental confusion frequently complicate the clinical presentation of fibromyalgia; however, formal cognitive examination often does not support deterioration. This paradox was examined in the context of dissociation, a condition with many cognitive similarities. Dissociation refers to the separation of parts of experience from the mainstream of consciousness. A common example is highway hypnosis. Eighty-nine fibromyalgia (FM) patients and 64 other rheumatic disease patients were screened for memory decline and mental confusion using a questionnaire format. Pain, dissociation, affective distress, fatigue, sleep difficulty, and mental confusion were also assessed. Cognitive complaints (76.4%-43.8%) and dissociative symptoms (37.1%-1.9%) were overrepresented in patients with FM. Among FM patients with high dissociation, cognitive difficulties were reported by 95%; 100% of these cases reported that both memory and mental clarity were affected, a condition referred to as fibrofog. Dissociation in combination with fibrofog was associated with higher levels of FM symptom intensity and decreased mental well being. These findings suggest that dissociation may play a role in FM symptom amplification and may aid in comprehending the regularity of cognitive symptoms. Separating cases of fibrofog from cognitive conditions with actual brain damage is important. It may be prudent to add a test of dissociation as an adjunct to the evaluation of FM patients in cases of suspected fibrofog. Otherwise, test results may prove normal even in patients with disabling cognitive symptoms.

  6. A Hierarchical Process-Dissociation Model

    ERIC Educational Resources Information Center

    Rouder, Jeffrey N.; Lu, Jun; Morey, Richard D.; Sun, Dongchu; Speckman, Paul L.

    2008-01-01

    In fitting the process-dissociation model (L. L. Jacoby, 1991) to observed data, researchers aggregate outcomes across participant, items, or both. T. Curran and D. L. Hintzman (1995) demonstrated how biases from aggregation may lead to artifactual support for the model. The authors develop a hierarchical process-dissociation model that does not…

  7. The expectancy of threat and peritraumatic dissociation

    PubMed Central

    McDonald, Pamela; Bryant, Richard A.; Silove, Derrick; Creamer, Mark; O'Donnell, Meaghan; McFarlane, Alexander C.

    2013-01-01

    Background Peritraumatic dissociation is one of the most critical acute responses to a traumatic experience, partly because it predicts subsequent posttraumatic stress disorder. Despite this, there is little understanding about the factors that influence peritraumatic dissociation. This study investigated the extent to which peritraumatic dissociation is predicted by the amount of perceived warning that participants had of the impact of the trauma. Method Randomized eligible admissions to four major trauma hospitals (N=243) were assessed during hospital admission with the Peritraumatic Dissociation Experiences Questionnaire (PDEQ) and the perceived warning that participants had before the trauma impact occurred. Results Whereas female gender predicted both Awareness and Derealization subscale scores on the PDEQ, perceived warning also predicted scores on the Derealization subscale. Conclusions This finding suggests that the degree of anticipated threat may contribute to peritraumatic dissociation. PMID:24363835

  8. The Shutdown Dissociation Scale (Shut-D)

    PubMed Central

    Schalinski, Inga; Schauer, Maggie; Elbert, Thomas

    2015-01-01

    The evolutionary model of the defense cascade by Schauer and Elbert (2010) provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D) was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity). A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups) from healthy controls. The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding. PMID:25976478

  9. Dissociation and Memory Fragmentation in Posttraumatic Stress Disorder: An Evaluation of the Dissociative Encoding Hypothesis

    PubMed Central

    Bedard-Gilligan, Michele; Zoellner, Lori A.

    2012-01-01

    Several prominent theories of posttraumatic stress disorder (PTSD) posit that peritraumatic dissociation results in insufficient encoding of the trauma memory and that persistent dissociation prevents memory elaboration, resulting in memory fragmentation and PTSD. In this review, we summarize the empirical literature on peritraumatic and trait dissociation and trauma narrative fragmentation as measured by meta-memory and rater/objective coding. Across 16 studies to date, the association between dissociation and fragmentation was most prominent when examining peritraumatic dissociation and patient's own ratings of memory fragmentation. This relationship did not hold when examining trait dissociation or rater-coded or computer-generated measures of fragmentation. Thus, initial evidence points more toward a strong self-reported association between constructs that is not supported on more objective fragmentation coding. Measurement overlap, construct ambiguity, and exclusion of potential confounds may underlie lack of a strong association between dissociation and objective-rated fragmentation. PMID:22348400

  10. Molecular mechanism of the dual activity of 4EGI-1: Dissociating eIF4G from eIF4E but stabilizing the binding of unphosphorylated 4E-BP1

    PubMed Central

    Sekiyama, Naotaka; Arthanari, Haribabu; Papadopoulos, Evangelos; Rodriguez-Mias, Ricard A.; Wagner, Gerhard; Léger-Abraham, Mélissa

    2015-01-01

    The eIF4E-binding protein (4E-BP) is a phosphorylation-dependent regulator of protein synthesis. The nonphosphorylated or minimally phosphorylated form binds translation initiation factor 4E (eIF4E), preventing binding of eIF4G and the recruitment of the small ribosomal subunit. Signaling events stimulate serial phosphorylation of 4E-BP, primarily by mammalian target of rapamycin complex 1 (mTORC1) at residues T37/T46, followed by T70 and S65. Hyperphosphorylated 4E-BP dissociates from eIF4E, allowing eIF4E to interact with eIF4G and translation initiation to resume. Because overexpression of eIF4E is linked to cellular transformation, 4E-BP is a tumor suppressor, and up-regulation of its activity is a goal of interest for cancer therapy. A recently discovered small molecule, eIF4E/eIF4G interaction inhibitor 1 (4EGI-1), disrupts the eIF4E/eIF4G interaction and promotes binding of 4E-BP1 to eIF4E. Structures of 14- to 16-residue 4E-BP fragments bound to eIF4E contain the eIF4E consensus binding motif, 54YXXXXLΦ60 (motif 1) but lack known phosphorylation sites. We report here a 2.1-Å crystal structure of mouse eIF4E in complex with m7GTP and with a fragment of human 4E-BP1, extended C-terminally from the consensus-binding motif (4E-BP150–84). The extension, which includes a proline-turn-helix segment (motif 2) followed by a loop of irregular structure, reveals the location of two phosphorylation sites (S65 and T70). Our major finding is that the C-terminal extension (motif 3) is critical to 4E-BP1–mediated cell cycle arrest and that it partially overlaps with the binding site of 4EGI-1. The binding of 4E-BP1 and 4EGI-1 to eIF4E is therefore not mutually exclusive, and both ligands contribute to shift the equilibrium toward the inhibition of translation initiation. PMID:26170285

  11. Dissociation dynamics in the dissociative electron attachment to carbon dioxide

    NASA Astrophysics Data System (ADS)

    Nag, Pamir; Nandi, Dhananjay

    2015-05-01

    Dissociative electron attachment (DEA) to gas phase CO2 has been probed using a velocity slice imaging technique. DEA to CO2 produces only an O- ionic fragment and shows two major resonances located at 4.4 and 8.2 eV, respectively. The kinetic energy and angular distribution of the O- ions are measured around the second resonance with higher efficiency and sensitivity that provide details of the DEA dynamics. The kinetic energy distributions are in good agreement with the previous reports. However, the distinct angular distributions show substantial difference from the two recent studies within the limited electron energies. Our angular distribution results show two negative ion resonant states are involved in the underlying DEA process at the entire electron energies over the second resonance. We discussed the recent conflicting findings in the angular distribution results. The forward-backward asymmetry observed in the angular distributions is explained due to the interference effect of different partial waves associated with the attaching electron.

  12. State dissociation moderates response to dialectical behavior therapy for posttraumatic stress disorder in women with and without borderline personality disorder

    PubMed Central

    Kleindienst, Nikolaus; Priebe, Kathlen; Görg, Nora; Dyer, Anne; Steil, Regina; Lyssenko, Lisa; Winter, Dorina; Schmahl, Christian; Bohus, Martin

    2016-01-01

    Background Patients with posttraumatic stress disorder (PTSD) are prone to dissociation, which in theory should interfere with successful treatment. However, most empirical studies do not substantiate this assumption. Objective The primary objective was to test whether state dissociation predicts the success of an adaptation of dialectical behavior therapy designed for the treatment of patients with PTSD after childhood sexual abuse (CSA) (DBT-PTSD). We further explored whether the operationalization of dissociation as state versus trait dissociation made a difference with respect to prediction of improvement. Methods We present a hypothesis-driven post hoc analysis of a randomized controlled trial on the efficacy in patients with PTSD after CSA. Regression analyses relating pre–post improvements in the Clinician-Administered PTSD Scale (CAPS) and the Posttraumatic Diagnostic Scale (PDS) to dissociation were applied to the women who participated in the active treatment arm (DBT-PTSD). Multivariate models accounting for major confounders were used to relate improvements in both the CAPS and the PDS to (1) state dissociation as assessed after each treatment session and (2) trait dissociation as assessed at baseline. Results State dissociation during psychotherapy sessions predicted improvement after DBT-PTSD: patients with low state dissociation during treatment had a higher chance to show substantial improvement. This relation consistently emerged across subgroups of PTSD patients with and without borderline personality disorder. The operationalization of dissociation as state versus trait dissociation made a difference as improvement was not significantly predicted from trait dissociation. Conclusions Dissociation during treatment sessions may reduce success with trauma-focused therapies such as DBT-PTSD. Accordingly, clinical studies aimed at improving ways to address dissociation are needed. Highlights of the article The article investigates whether state

  13. Radical-driven peptide backbone dissociation tandem mass spectrometry.

    PubMed

    Oh, Han Bin; Moon, Bongjin

    2015-01-01

    In recent years, a number of novel tandem mass spectrometry approaches utilizing radical-driven peptide gas-phase fragmentation chemistry have been developed. These approaches show a peptide fragmentation pattern quite different from that of collision-induced dissociation (CID). The peptide fragmentation features of these approaches share some in common with electron capture dissociation (ECD) or electron transfer dissociation (ETD) without the use of sophisticated equipment such as a Fourier-transform mass spectrometer. For example, Siu and coworkers showed that CID of transition metal (ligand)-peptide ternary complexes led to the formation of peptide radical ions through dissociative electron transfer (Chu et al., 2000. J Phys Chem B 104:3393-3397). The subsequent collisional activation of the generated radical ions resulted in a number of characteristic product ions, including a, c, x, z-type fragments and notable side-chain losses. Another example is the free radical initiated peptide sequencing (FRIPS) approach, in which Porter et al. and Beauchamp et al. independently introduced a free radical initiator to the primary amine group of the lysine side chain or N-terminus of peptides (Masterson et al., 2004. J Am Chem Soc 126:720-721; Hodyss et al., 2005 J Am Chem Soc 127: 12436-12437). Photodetachment of gaseous multiply charged peptide anions (Joly et al., 2008. J Am Chem Soc 130:13832-13833) and UV photodissociation of photolabile radical precursors including a C-I bond (Ly & Julian, 2008. J Am Chem Soc 130:351-358; Ly & Julian, 2009. J Am Soc Mass Spectrom 20:1148-1158) also provide another route to generate radical ions. In this review, we provide a brief summary of recent results obtained through the radical-driven peptide backbone dissociation tandem mass spectrometry approach.

  14. From state dissociation to status dissociatus.

    PubMed

    Antelmi, Elena; Ferri, Raffaele; Iranzo, Alex; Arnulf, Isabelle; Dauvilliers, Yves; Bhatia, Kailash P; Liguori, Rocco; Schenck, Carlos H; Plazzi, Giuseppe

    2016-08-01

    The states of being are conventionally defined by the simultaneous occurrence of behavioral, neurophysiological and autonomic descriptors. State dissociation disorders are due to the intrusion of features typical of a different state into an ongoing state. Disorders related to these conditions are classified according to the ongoing main state and comprise: 1) Dissociation from prevailing wakefulness as seen in hypnagogic or hypnopompic hallucinations, automatic behaviors, sleep drunkenness, cataplexy and sleep paralysis 2) Dissociation from rapid eye movement (REM) sleep as seen in REM sleep behavior disorder and lucid dreaming and 3) Dissociation from NREM sleep as seen in the disorders of arousal. The extreme expression of states dissociation is characterized by the asynchronous occurrence of the various components of the different states that prevents the recognition of any state of being. This condition has been named status dissociatus. According to the underlying disorders/diseases and to their severity, among status dissociatus we may recognize disorders in which such an extreme dissociation occurs only at night time or intermittently (i.e., autoimmune encephalopathies, narcolepsy type 1 and IgLON5 parasomnia), and others in which it occurs nearly continuously with complete loss of any conventionally defined state of being, and of the circadian pattern (agrypnia excitata). Here, we render a comprehensive review of all diseases/disorders associated with state dissociation and status dissociatus and propose a critical classification of this complex scenario. PMID:26431902

  15. From state dissociation to status dissociatus.

    PubMed

    Antelmi, Elena; Ferri, Raffaele; Iranzo, Alex; Arnulf, Isabelle; Dauvilliers, Yves; Bhatia, Kailash P; Liguori, Rocco; Schenck, Carlos H; Plazzi, Giuseppe

    2016-08-01

    The states of being are conventionally defined by the simultaneous occurrence of behavioral, neurophysiological and autonomic descriptors. State dissociation disorders are due to the intrusion of features typical of a different state into an ongoing state. Disorders related to these conditions are classified according to the ongoing main state and comprise: 1) Dissociation from prevailing wakefulness as seen in hypnagogic or hypnopompic hallucinations, automatic behaviors, sleep drunkenness, cataplexy and sleep paralysis 2) Dissociation from rapid eye movement (REM) sleep as seen in REM sleep behavior disorder and lucid dreaming and 3) Dissociation from NREM sleep as seen in the disorders of arousal. The extreme expression of states dissociation is characterized by the asynchronous occurrence of the various components of the different states that prevents the recognition of any state of being. This condition has been named status dissociatus. According to the underlying disorders/diseases and to their severity, among status dissociatus we may recognize disorders in which such an extreme dissociation occurs only at night time or intermittently (i.e., autoimmune encephalopathies, narcolepsy type 1 and IgLON5 parasomnia), and others in which it occurs nearly continuously with complete loss of any conventionally defined state of being, and of the circadian pattern (agrypnia excitata). Here, we render a comprehensive review of all diseases/disorders associated with state dissociation and status dissociatus and propose a critical classification of this complex scenario.

  16. An image database management system for conducting CAD research

    NASA Astrophysics Data System (ADS)

    Gruszauskas, Nicholas; Drukker, Karen; Giger, Maryellen L.

    2007-03-01

    The development of image databases for CAD research is not a trivial task. The collection and management of images and their related metadata from multiple sources is a time-consuming but necessary process. By standardizing and centralizing the methods in which these data are maintained, one can generate subsets of a larger database that match the specific criteria needed for a particular research project in a quick and efficient manner. A research-oriented management system of this type is highly desirable in a multi-modality CAD research environment. An online, webbased database system for the storage and management of research-specific medical image metadata was designed for use with four modalities of breast imaging: screen-film mammography, full-field digital mammography, breast ultrasound and breast MRI. The system was designed to consolidate data from multiple clinical sources and provide the user with the ability to anonymize the data. Input concerning the type of data to be stored as well as desired searchable parameters was solicited from researchers in each modality. The backbone of the database was created using MySQL. A robust and easy-to-use interface for entering, removing, modifying and searching information in the database was created using HTML and PHP. This standardized system can be accessed using any modern web-browsing software and is fundamental for our various research projects on computer-aided detection, diagnosis, cancer risk assessment, multimodality lesion assessment, and prognosis. Our CAD database system stores large amounts of research-related metadata and successfully generates subsets of cases that match the user's desired search criteria.

  17. Advanced Geologic Modeling Using CAD and Unstructured Meshes

    NASA Astrophysics Data System (ADS)

    Melnikova, Y.; Jacquemyn, C.; Osman, H.; Gorman, G.; Hampson, G.; Jackson, M.

    2015-12-01

    Capturing complex, multiscale geologic heterogeneity in subsurface flow models is challenging. Surface-based modeling (SBM) offers an alternative approach to conventional grid-based methods. In SBM, all geologic features that impact the distribution of material properties, such as porosity and permeability, are modeled as volumes bounded by surfaces. Within these volumes, termed geologic domains, the material properties are constant. A typical model contains numerous such domains. The surfaces have parametric, grid-free representation which, in principle, allows for unlimited complexity, since no resolution is implied at the stage of modeling and features of any scale can be included. We demonstrate a method to create stochastic, surface-based models using computer aided design (CAD) and efficiently discretise them for flow simulation. The surfaces are represented using non-uniform, rational B-splines (NURBS), and processed in a CAD environment employing Boolean operations. We show examples of fluvial channels, fracture networks and scour events. Cartesian-like grids are not able to capture the complex geometries in these models without using excessively large numbers of grid blocks. Unstructured meshes can more efficiently approximate the geometries. However, high aspect ratio features and varying curvatures present challenges for algorithms to produce quality, unstructured meshes without excessive user interaction. We contribute an automated integrated workflow that processes the input geometry created in the CAD environment, creates the final model, and discretises it with a quality tetrahedral mesh. For computational efficiency, we use a geometry-adaptive mesh that distributes the element density and size in accordance with the geometrical complexity of the model. We show examples of finite-element flow simulations of the resulting geologic models. The new approach has broad application in modeling subsurface flow.

  18. The evaluation of multi-structure, multi-atlas pelvic anatomy features in a prostate MR lymphography CAD system

    NASA Astrophysics Data System (ADS)

    Meijs, M.; Debats, O.; Huisman, H.

    2015-03-01

    In prostate cancer, the detection of metastatic lymph nodes indicates progression from localized disease to metastasized cancer. The detection of positive lymph nodes is, however, a complex and time consuming task for experienced radiologists. Assistance of a two-stage Computer-Aided Detection (CAD) system in MR Lymphography (MRL) is not yet feasible due to the large number of false positives in the first stage of the system. By introducing a multi-structure, multi-atlas segmentation, using an affine transformation followed by a B-spline transformation for registration, the organ location is given by a mean density probability map. The atlas segmentation is semi-automatically drawn with ITK-SNAP, using Active Contour Segmentation. Each anatomic structure is identified by a label number. Registration is performed using Elastix, using Mutual Information and an Adaptive Stochastic Gradient optimization. The dataset consists of the MRL scans of ten patients, with lymph nodes manually annotated in consensus by two expert readers. The feature map of the CAD system consists of the Multi-Atlas and various other features (e.g. Normalized Intensity and multi-scale Blobness). The voxel-based Gentleboost classifier is evaluated using ROC analysis with cross validation. We show in a set of 10 studies that adding multi-structure, multi-atlas anatomical structure likelihood features improves the quality of the lymph node voxel likelihood map. Multiple structure anatomy maps may thus make MRL CAD more feasible.

  19. Dissociating sensory from decision processes in human perceptual decision making

    PubMed Central

    Mostert, Pim; Kok, Peter; de Lange, Floris P.

    2015-01-01

    A key question within systems neuroscience is how the brain translates physical stimulation into a behavioral response: perceptual decision making. To answer this question, it is important to dissociate the neural activity underlying the encoding of sensory information from the activity underlying the subsequent temporal integration into a decision variable. Here, we adopted a decoding approach to empirically assess this dissociation in human magnetoencephalography recordings. We used a functional localizer to identify the neural signature that reflects sensory-specific processes, and subsequently traced this signature while subjects were engaged in a perceptual decision making task. Our results revealed a temporal dissociation in which sensory processing was limited to an early time window and consistent with occipital areas, whereas decision-related processing became increasingly pronounced over time, and involved parietal and frontal areas. We found that the sensory processing accurately reflected the physical stimulus, irrespective of the eventual decision. Moreover, the sensory representation was stable and maintained over time when it was required for a subsequent decision, but unstable and variable over time when it was task-irrelevant. In contrast, decision-related activity displayed long-lasting sustained components. Together, our approach dissects neuro-anatomically and functionally distinct contributions to perceptual decisions. PMID:26666393

  20. Automated knowledge base development from CAD/CAE databases

    NASA Technical Reports Server (NTRS)

    Wright, R. Glenn; Blanchard, Mary

    1988-01-01

    Knowledge base development requires a substantial investment in time, money, and resources in order to capture the knowledge and information necessary for anything other than trivial applications. This paper addresses a means to integrate the design and knowledge base development process through automated knowledge base development from CAD/CAE databases and files. Benefits of this approach include the development of a more efficient means of knowledge engineering, resulting in the timely creation of large knowledge based systems that are inherently free of error.

  1. Getting into CAD at the Savannah River Plant

    SciTech Connect

    Scoggins, W.R.

    1984-01-01

    In 1978, the Savannah River Plant (SRP) Project Department was producing approximately 1100 new drawings and 3000 revisions per year, with a force of 30 draftsmen. Design services for the Plant were increasing due to changing programs, obsolescent equipment replacements and added security requirements. This increasing workload greatly increased the engineering drafting backlog. At the same time, many draftsmen were approaching retirement age and were to be replaced with unskilled draftsman trainees. A proposal was presented to management to acquire a Computer Aided Drafting (CAD) system to produce instrument and electrical drawings which comprised 30% of the work load.

  2. Intelligent machining of rough components from optimized CAD models

    NASA Astrophysics Data System (ADS)

    Lewis, Geoff; Thompson, William

    1995-08-01

    This paper describes a technique for automatically generating NC machine programs from CAD images of a rough work piece and an optimally positioned component. The paper briefly compares the generative and variant methods of automatic machine program development and then presents a technique based on the variant method where a reference machine program is transformed to machine the optimized component. The transformed machine program is examined to remove any redundant cutter motions and correct any invalid cutter motions. The research is part of a larger project on intelligent manufacturing systems and is being conducted at the CIM Centre, Swinburne University of Technology, Hawthorn, Australia.

  3. CAD/CAM and scientific data management at Dassault

    NASA Technical Reports Server (NTRS)

    Bohn, P.

    1984-01-01

    The history of CAD/CAM and scientific data management at Dassault are presented. Emphasis is put on the targets of the now commercially available software CATIA. The links with scientific computations such as aerodynamics and structural analysis are presented. Comments are made on the principles followed within the company. The consequences of the approximative nature of scientific data are examined. Consequence of the new history function is mainly its protection against copy or alteration. Future plans at Dassault for scientific data appear to be in opposite directions compared to some general tendencies.

  4. Dissociative identity disorder: a controversial diagnosis.

    PubMed

    Gillig, Paulette Marie

    2009-03-01

    A brief description of the controversies surrounding the diagnosis of dissociative identity disorder is presented, followed by a discussion of the proposed similarities and differences between dissociative identity disorder and borderline personality disorder. The phenomenon of autohypnosis in the context of early childhood sexual trauma and disordered attachment is discussed, as is the meaning of alters or alternate personalities. The author describes recent neurosciences research that may relate the symptoms of dissociative identity disorder to demonstrable disordered attention and memory processes. A clinical description of a typical patient presentation is included, plus some recommendations for approaches to treatment.

  5. Wavepacket theory of collisional dissociation in molecules

    SciTech Connect

    Kulander, K.

    1980-01-01

    An explicit integration scheme is used to solve the time dependent Schroedinger equation for wavepackets which model collisions in the collinear H + H/sub 2/ system. A realistic LEPS-type potential energy surface is used. Collision energies considered are above the dissociation threshold and probabilities for collision induced dissociation are reported. Also quantum mechanical state-to-state transition probabilities are generated. These results are compared to extensive classical trajectory calculations performed on this same system. The time evolution of the wavepacket densities is studied to understand the dynamics of the collinear collisional dissociation process.

  6. Dissociative Ionization of Pyridine by Electron Impact

    NASA Technical Reports Server (NTRS)

    Dateo, Christopher; Huo, Winifred; Kwak, Dochan (Technical Monitor)

    2002-01-01

    In order to understand the damage of biomolecules by electrons, a process important in radiation damage, we undertake a study of the dissociative ionization (DI) of pyridine (C5H5N) from the low-lying ionization channels. The methodology used is the same as in the benzene study. While no experimental DI data are available, we compare the dissociation products from our calculations with the dissociative photoionization measurements of Tixier et al. using dipole (e, e(+) ion) coincidence spectroscopy. Comparisons with the DI of benzene is also made so as to understand the difference in DI between a heterocyclic and an aromatic molecule.

  7. Products of Dissociative Recombination in the Ionosphere

    NASA Technical Reports Server (NTRS)

    Cosby, Philip

    1996-01-01

    SRI International undertook a novel experimental measurement of the product states formed by dissociative ro-combination (DR) of C2(+), NO(+), and N2(+) as a function of both electron energy and reactant ion vibrational level. For these measurements we used a recently developed experimental technique for measuring dissociation product distributions that allows both the branching ratios to be accurately determined and the electronic and ro-vibrational state composition of the reactant ions to be specified. DR is the dominant electron loss mechanism in all regions of the ionosphere. In this process, electron attachment to the molecular ion produces an unstable neutral molecule that rapidly dissociates.

  8. Dissociation of recombinant prion autocatalysis from infectivity.

    PubMed

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication--that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.

  9. Theory of dissociative tunneling ionization

    NASA Astrophysics Data System (ADS)

    Svensmark, Jens; Tolstikhin, Oleg I.; Madsen, Lars Bojer

    2016-05-01

    We present a theoretical study of the dissociative tunneling ionization process. Analytic expressions for the nuclear kinetic energy distribution of the ionization rates are derived. A particularly simple expression for the spectrum is found by using the Born-Oppenheimer (BO) approximation in conjunction with the reflection principle. These spectra are compared to exact non-BO ab initio spectra obtained through model calculations with a quantum mechanical treatment of both the electronic and nuclear degrees of freedom. In the regime where the BO approximation is applicable, imaging of the BO nuclear wave function is demonstrated to be possible through reverse use of the reflection principle, when accounting appropriately for the electronic ionization rate. A qualitative difference between the exact and BO wave functions in the asymptotic region of large electronic distances is shown. Additionally, the behavior of the wave function across the turning line is seen to be reminiscent of light refraction. For weak fields, where the BO approximation does not apply, the weak-field asymptotic theory describes the spectrum accurately.

  10. Dissociative recombination of CH4(+).

    PubMed

    Thomas, Richard D; Kashperka, Iryna; Vigren, E; Geppert, Wolf D; Hamberg, Mathias; Larsson, Mats; af Ugglas, Magnus; Zhaunerchyk, Vitali

    2013-10-01

    CH4(+) is an important molecular ion in the astrochemistry of diffuse clouds, dense clouds, cometary comae, and planetary ionospheres. However, the rate of one of the common destruction mechanisms for molecular ions in these regions, dissociative recombination (DR), is somewhat uncertain. Here, we present absolute measurements for the DR of CH4(+) made using the heavy ion storage ring CRYRING in Stockholm, Sweden. From our collision-energy dependent cross-sections, we infer a thermal rate constant of k(Te) = 1.71(±0.02) × 10(–6)(Te/300)(−0.66(±0.02)) cm3 s(–1) over the region of electron temperatures 10 ≤ Te ≤ 1000 K. At low collision energies, we have measured the branching fractions of the DR products to be CH4 (0.00 ± 0.00); CH3 + H (0.18 ± 0.03); CH2 + 2H (0.51 ± 0.03); CH2 + H2 (0.06 ± 0.01); CH + H2 + H (0.23 ± 0.01); and CH + 2H2 (0.02 ± 0.01), indicating that two or more C–H bonds are broken in 80% of all collisions.

  11. HDL subfractions and very early CAD: novel findings from untreated patients in a Chinese cohort.

    PubMed

    Zhang, Yan; Zhu, Cheng-Gang; Xu, Rui-Xia; Li, Sha; Li, Xiao-Lin; Guo, Yuan-Lin; Wu, Na-Qiong; Gao, Ying; Qing, Ping; Cui, Chuan-Jue; Sun, Jing; Li, Jian-Jun

    2016-01-01

    Coronary artery disease (CAD) in very young individuals is a rare disease associated with poor prognosis. However, the role of specific lipoprotein subfractions in very young CAD patients (≤45 years) is not established yet. A total of 734 consecutive CAD subjects were enrolled and were classified as very early (n = 81, ≤45), early (n = 304, male: 45-55; female: 45-65), and late (n = 349, male: >55; female: >65) groups. Meanwhile, a group of non-CAD subjects were also enrolled as controls (n = 56, ≤45). The lipoprotein separation was performed using Lipoprint System. As a result, the very early CAD patients have lower large high-density lipoprotein (HDL) subfraction and higher small low-density lipoprotein (LDL) subfraction (p < 0.05). Although body mass index was inversely related to large HDL subfraction, overweight did not influence its association with very early CAD. In the logistic regression analysis, large HDL was inversely [OR 95% CI: 0.872 (0.825-0.922)] while small LDL was positively [1.038 (1.008-1.069)] related to very early CAD. However, after adjusting potential confounders, the association was only significant for large HDL [0.899 (0.848-0.954)]. This study firstly demonstrated that large HDL subfraction was negatively related to very early CAD suggestive of its important role in very early CAD incidence. PMID:27489174

  12. HDL subfractions and very early CAD: novel findings from untreated patients in a Chinese cohort

    PubMed Central

    Zhang, Yan; Zhu, Cheng-Gang; Xu, Rui-Xia; Li, Sha; Li, Xiao-Lin; Guo, Yuan-Lin; Wu, Na-Qiong; Gao, Ying; Qing, Ping; Cui, Chuan-Jue; Sun, Jing; Li, Jian-Jun

    2016-01-01

    Coronary artery disease (CAD) in very young individuals is a rare disease associated with poor prognosis. However, the role of specific lipoprotein subfractions in very young CAD patients (≤45 years) is not established yet. A total of 734 consecutive CAD subjects were enrolled and were classified as very early (n = 81, ≤45), early (n = 304, male: 45–55; female: 45–65), and late (n = 349, male: >55; female: >65) groups. Meanwhile, a group of non-CAD subjects were also enrolled as controls (n = 56, ≤45). The lipoprotein separation was performed using Lipoprint System. As a result, the very early CAD patients have lower large high-density lipoprotein (HDL) subfraction and higher small low-density lipoprotein (LDL) subfraction (p < 0.05). Although body mass index was inversely related to large HDL subfraction, overweight did not influence its association with very early CAD. In the logistic regression analysis, large HDL was inversely [OR 95% CI: 0.872 (0.825–0.922)] while small LDL was positively [1.038 (1.008–1.069)] related to very early CAD. However, after adjusting potential confounders, the association was only significant for large HDL [0.899 (0.848–0.954)]. This study firstly demonstrated that large HDL subfraction was negatively related to very early CAD suggestive of its important role in very early CAD incidence. PMID:27489174

  13. Creation of Anatomically Accurate Computer-Aided Design (CAD) Solid Models from Medical Images

    NASA Technical Reports Server (NTRS)

    Stewart, John E.; Graham, R. Scott; Samareh, Jamshid A.; Oberlander, Eric J.; Broaddus, William C.

    1999-01-01

    Most surgical instrumentation and implants used in the world today are designed with sophisticated Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) software. This software automates the mechanical development of a product from its conceptual design through manufacturing. CAD software also provides a means of manipulating solid models prior to Finite Element Modeling (FEM). Few surgical products are designed in conjunction with accurate CAD models of human anatomy because of the difficulty with which these models are created. We have developed a novel technique that creates anatomically accurate, patient specific CAD solids from medical images in a matter of minutes.

  14. [Significance of and considerations relating to the diagnosis of dissociation].

    PubMed

    Koreki, Akihiro

    2011-01-01

    Dissociation involves a variety of clinical concepts, and some disorders are also similar to but not the same as dissociation. Dissociative disorder is considered to be a pathological phenomenon based on a psychological mechanism. Accurate diagnosis is very important to ensure that patients receive adequate treatment, although such consideration is not unique to dissociative disorder. Accordingly, there is a need to carefully distinguish dissociation from other disorders. In this article, we outline a number of dissociative and dissociative-like states from the symptoms of amnesia, depersonalization and switching. In particular, we highlight the differences between transient global amnesia and dissociative amnesia, and imaginary companions and dissociative alter personality. Additionally, as the symptoms of conditions such as dissociative amnesia and dissociative identity disorder are easily confused, we also made efforts to organize them.

  15. Gene Expression Profiles in Relation to Tension and Dissociation in Borderline Personality Disorder

    PubMed Central

    Schmahl, Christian; Arvastson, Lars; Tamm, Joseph A.; Bohus, Martin; Abdourahman, Aicha; Antonijevic, Irina

    2013-01-01

    The biological underpinnings of borderline personality disorder (BPD) and its psychopathology including states of aversive tension and dissociation is poorly understood. Our goal was to examine transcriptional changes associated with states of tension or dissociation within individual patients in a pilot study. Dissociation is not only a critical symptom of BPD but has also been associated with higher risk for self-mutilation and depression. We conducted a whole blood gene expression profile analysis using quantitative PCR in 31 female inpatients with BPD. For each individual, two samples were drawn during a state of high tension and dissociation, while two samples were drawn at non-tension states. There was no association between gene expression and tension states. However, we could show that Interleukin-6 was positively correlated to dissociation scores, whereas Guanine nucleotide-binding protein G(s) subunit alpha isoforms, Mitogen-activated protein kinase 3 and 8, Guanine nucleotide-binding protein G(i) subunit alpha-2, Beta-arrestin-1 and 2, and Cyclic AMP-responsive element-binding protein were negatively correlated to dissociation. Our data point to a potential association of dissociation levels with the expression of genes involved in immune system regulation as well as cellular signalling/second-messenger systems. Major limitations of the study are the the possibly heterogeneous cell proportions in whole blood and the heterogeneous medication. PMID:23951008

  16. Collision-induced gas phase dissociation rates

    NASA Technical Reports Server (NTRS)

    Hansen, C. Frederick

    1990-01-01

    The Landau-Zener theory of reactive cross sections was applied to diatomic molecules dissociating from a ladder of vibrational states. The result predicts a dissociation rate that is quite well duplicated by an Arrhenius function having a preexponential temperature dependence of about T(sub -1/2), at least for inert collision partners. This relation fits experimental data reasonably well. The theory is then used to calculate the effect of vibrational nonequilibrium on dissociation rate. For Morse oscillators, the results are about the same as given by Hammerling, Kivel, and Teare in their analytic approximation for harmonic oscillators, though at very high temperature a correction for the partition function limit is included. The empirical correction for vibration nonequilibrium proposed by Park, which is a convenient algorithm for CFD calculations, is modified to prevent a drastic underestimation of dissociation rates that occurs with this method when vibrational temperature is much smaller than the kinetic temperature of the gas.

  17. Research Reports: Hallucinogens and Dissociative Drugs

    MedlinePlus

    ... in bizarre or dangerous behavior. Hallucinogens such as LSD, psilocybin, peyote, DMT, and ayahuasca cause emotions to ... Take Hallucinogenic or Dissociative Drugs? How Do Hallucinogens (LSD, Psilocybin, Peyote, DMT, and Ayahuasca) Affect the Brain ...

  18. Dissociative identity disorder presenting as dermatitis artefacta.

    PubMed

    Ozmen, Mine; Erdogan, Ayten; Aydemir, Ertugrul H; Oguz, Oya

    2006-06-01

    Dermatitis artefacta is a rare psychiatric condition characterized by rubbing of skin blisters and denial of self-infliction. Dissociation may be comorbid with self-injurious behavior. A background of emotional disturbances during formative years and in later life often results in feelings of isolation and insecurity, which can lead to dissociation as a primary defense mechanism used to overcome traumatic events. In this case report, we describe a female patient with dermatitis artefacta associated with dissociative identity disorder. The patient was a 14-year-old girl. Multiple large, deep ulcerations with unnatural shapes were seen on her left forearm. The ulcerations were thought to be self-inflicted. Psychiatric examination revealed that she had a different identity, and inflicted the lesions when this was assumed. This case leads us to suggest that patients with dermatitis artefacta might have comorbid dissociative experiences, which cannot be identified easily.

  19. Interoperation of heterogeneous CAD tools in Ptolemy II

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Wu, Bicheng; Liu, Xiaojun; Lee, Edward A.

    1999-03-01

    Typical complex systems that involve microsensors and microactuators exhibit heterogeneity both at the implementation level and the problem level. For example, a system can be modeled using discrete events for digital circuits and SPICE-like analog descriptions for sensors. This heterogeneity exist not only in different implementation domains, but also at different level of abstraction. This naturally leads to a heterogeneous approach to system design that uses domain-specific models of computation (MoC) at various levels of abstractions to define a system, and leverages multiple CAD tools to do simulation, verification and synthesis. As the size and scope of the system increase, the integration becomes too difficult and unmanageable if different tools are coordinated using simple scripts. In addition, for MEMS devices and mixed-signal circuits, it is essential to integrate tools with different MoC to simulate the whole system. Ptolemy II, a heterogeneous system-level design tool, supports the interaction among different MoCs. This paper discusses heterogeneous CAD tool interoperability in the Ptolemy II framework. The key is to understand the semantic interface and classify the tools by their MoC and their level of abstraction. Interfaces are designed for each domain so that the external tools can be easily wrapped. Then the interoperability of the tools becomes the interoperability of the semantics. Ptolemy II can act as the standard interface among different tools to achieve the overall design modeling. A micro-accelerometer with digital feedback is studied as an example.

  20. Generation and use of human 3D-CAD models

    NASA Astrophysics Data System (ADS)

    Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf

    2002-05-01

    Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.

  1. Development of CAD prototype system for Crohn's disease

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Kitasaka, Takayuki; Furukawa, Kazuhiro; Watanabe, Osamu; Ando, Takafumi; Goto, Hidemi; Mori, Kensaku

    2010-03-01

    The purpose of this paper is to present a CAD prototype system for Crohn's disease. Crohn's disease causes inflammation or ulcers of the gastrointestinal tract. The number of patients of Crohn's disease is increasing in Japan. Symptoms of Crohn's disease include intestinal stenosis, longitudinal ulcers, and fistulae. Optical endoscope cannot pass through intestinal stenosis in some cases. We propose a new CAD system using abdominal fecal tagging CT images for efficient diagnosis of Crohn's disease. The system displays virtual unfolded (VU), virtual endoscopic, curved planar reconstruction, multi planar reconstruction, and outside views of both small and large intestines. To generate the VU views, we employ a small and large intestines extraction method followed by a simple electronic cleansing method. The intestine extraction is based on the region growing process, which uses a characteristic that tagged fluid neighbor air in the intestine. The electronic cleansing enables observation of intestinal wall under tagged fluid. We change the height of the VU views according to the perimeter of the intestine. In addition, we developed a method to enhance the longitudinal ulcer on views of the system. We enhance concave parts on the intestinal wall, which are caused by the longitudinal ulcer, based on local intensity structure analysis. We examined the small and the large intestines of eleven CT images by the proposed system. The VU views enabled efficient observation of the intestinal wall. The height change of the VU views helps finding intestinal stenosis on the VU views. The concave region enhancement made longitudinal ulcers clear on the views.

  2. Defect modelling in an interactive 3-D CAD environment

    NASA Astrophysics Data System (ADS)

    Reilly, D.; Potts, A.; McNab, A.; Toft, M.; Chapman, R. K.

    2000-05-01

    This paper describes enhancement of the NDT Workbench, as presented at QNDE '98, to include theoretical models for the ultrasonic inspection of smooth planar defects, developed by British Energy and BNFL-Magnox Generation. The Workbench is a PC-based software package for the reconstruction, visualization and analysis of 3-D ultrasonic NDT data in an interactive CAD environment. This extension of the Workbeach now provides the user with a well established modelling approach, coupled with a graphical user interface for: a) configuring the model for flaw size, shape, orientation and location; b) flexible specification of probe parameters; c) selection of scanning surface and scan pattern on the CAD component model; d) presentation of the output as a simulated ultrasound image within the component, or as graphical or tabular displays. The defect modelling facilities of the Workbench can be used for inspection procedure assessment and confirmation of data interpretation, by comparison of overlay images generated from real and simulated data. The modelling technique currently implemented is based on the Geometrical Theory of Diffraction, for simulation of strip-like, circular or elliptical crack responses in the time harmonic or time dependent cases. Eventually, the Workbench will also allow modelling using elastodynamic Kirchhoff theory.

  3. Mercury (II) sensor based on monitoring dissociation rate of the trans-acting factor MerR from cis-element by surface plasmon resonance.

    PubMed

    Taniguchi, Masaki; Siddiki, Mohammad Shohel Rana; Ueda, Shunsaku; Maeda, Isamu

    2015-05-15

    Transcriptional switches regulate gene expression in response to environmental changes surrounding cell. Many studies have focused on two fundamentally different models of transcriptional control by bacterial metalloregulatory protein. Distortion of the DNA fragment including cis-element, to which the trans-acting factor MerR binds, is accepted as the mechanism of gene expression regulation by Hg (II) while, in cases of the other trans-acting factors ArsR and CadC, events of association to and dissociation from cis-element are known to control transcription in response to As (III) and Cd (II), respectively. In this study, interactions between green-fluorescent-protein-tagged trans-acting factor and immobilized cis-element were analyzed on solid surface. Fluorescent measurements and surface plasmon resonance (SPR) responses revealed that although the equilibrium dissociation constant (KD) was much lower in MerR than in ArsR and CadC, the dissociation rate of MerR from DNA increased in response to Hg (II) at concentrations of 5-10(4) µg l(-1). These results firstly demonstrate an increase of KD between MerR and its recognition site in DNA by Hg (II), and possibility of rapid Hg (II) quantification with the low detection limit (5 µg l(-1)) and the high dynamic range (10(1)-10(4) µg l(-1)).

  4. The relational treatment of dissociative identity disorder.

    PubMed

    Burton, N; Lane, R C

    2001-03-01

    The intent of this paper is to review the literature pertaining to the transference and countertransference components in the treatment of dissociative identity disorder. Aspects of transference and countertransference are presented and discussed within the relational psychoanalytic model. The functions of empathy, enactment, projective identification, and transitional objects are reviewed. Specific attitudes in the transference and countertransference are illuminated and major transference themes are discussed. Finally, a case vignette illustrates some of the central issues involved in the treatment of dissociative identity disorder.

  5. Energetic aspects of locked nucleic acids quadruplex association and dissociation.

    PubMed

    Petraccone, Luigi; Erra, Eva; Randazzo, Antonio; Giancola, Concetta

    2006-12-15

    The design of modified nucleic acid aptamers is improved by considering thermodynamics and kinetics of their association/dissociation processes. Locked Nucleic Acids (LNA) is a promising class of nucleic acid analogs. In this work the thermodynamic and kinetic properties of a LNA quadruplex formed by the TGGGT sequence, containing only conformationally restricted LNA residues, are reported and compared to those of 2'-OMe-RNA (O-RNA) and DNA quadruplexes. The thermodynamic analysis indicates that the sugar-modified quadruplexes (LNA and O-RNA) are stabilized by entropic effects. The kinetic analysis shows that LNA and O-RNA quadruplexes are characterized by a slower dissociation and a faster association with respect to DNA quadruplex. Interestingly, the LNA quadruplex formation process shows a second-order kinetics with respect to single strand concentration and has a negative activation energy. To explain these data, a mechanism for tetramer formation with two intermediate states was proposed.

  6. The tactical-integration model for the treatment of dissociative identity disorder and allied dissociative disorders.

    PubMed

    Fine, C G

    1999-01-01

    The ebb and flow of the diagnosis of Dissociative Identity Disorder (DID) and other dissociative conditions has led to the evolution of theories and treatment modalities to resolve the fluctuating and ephemerous symptoms of these conditions. This paper summarizes the structured cognitive-behavioral-based treatment of dissociative disorders that will foster not only symptom relief but also an integration of the personalities and/or ego states into one mainstream of consciousness. This model of DID therapy is called the tactical integration model; it promotes proficiency over posttraumatic and dissociative symptoms, is collaborative and exploratory, and conveys a consistent message of empowerment to the patient.

  7. Subunit dissociations in natural and recombinant hemoglobins.

    PubMed

    Manning, L R; Jenkins, W T; Hess, J R; Vandegriff, K; Winslow, R M; Manning, J M

    1996-04-01

    A precise and rapid procedure employing gel filtration on Superose-12 to measure the tetramer-dimer dissociation constants of some natural and recombinant hemoglobins in the oxy conformation is described. Natural sickle hemoglobin was chosen to verify the validity of the results by comparing the values with those reported using an independent method not based on gel filtration. Recombinant sickle hemoglobin, as well as a sickle double mutant with a substitution at the Val-6(beta) receptor site, had approximately the same dissociation constant as natural sickle hemoglobin. Of the two recombinant hemoglobins with amino acid replacements in the alpha 1 beta 2 subunit interface, one was found to be extensively dissociated and the other completely dissociated. In addition, the absence of an effect of the allosteric regulators DPG and IHP on the dissociation constant was demonstrated. Thus, a tetramer dissociation constant can now be determined readily and used together with other criteria for characterization of hemoglobins and their interaction with small regulatory molecules. PMID:8845768

  8. Dissociative Ionization of Benzene by Electron Impact

    NASA Technical Reports Server (NTRS)

    Huo, Winifred; Dateo, Christopher; Kwak, Dochan (Technical Monitor)

    2002-01-01

    We report a theoretical study of the dissociative ionization (DI) of benzene from the low-lying ionization channels. Our approach makes use of the fact that electron motion is much faster than nuclear motion and DI is treated as a two-step process. The first step is electron-impact ionization resulting in an ion with the same nuclear geometry as the neutral molecule. In the second step the nuclei relax from the initial geometry and undergo unimolecular dissociation. For the ionization process we use the improved binary-encounter dipole (iBED) model. For the unimolecular dissociation step, we study the steepest descent reaction path to the minimum of the ion potential energy surface. The path is used to analyze the probability of unimolecular dissociation and to determine the product distributions. Our analysis of the dissociation products and the thresholds of the productions are compared with the result dissociative photoionization measurements of Feng et al. The partial oscillator strengths from Feng et al. are then used in the iBED cross section calculations.

  9. Unimolecular dissociation of cyclopentadiene and indene

    SciTech Connect

    Yi, W.; Chattopadhyay, A.; Bersohn, R. )

    1991-05-01

    The dissociation of hydrogen atoms from the methylene group of cyclopentadiene (CP) and indene (ID) excited with a 193 nm photon has been studied by hydrogen atom laser induced fluorescence. The rate of dissociation of IND was 7.4{times}10{sup 6} s{sup {minus}1} but that of CP was too fast to measure. The ratio of H atoms to D atoms generated from 5-deuteriocyclopentadiene (5-dCP) was 3.91{plus minus}0.46. Rice--Ramsberger--Kassel--Marcus theory was used to calculate the rates of dissociation of CP and 5-dCP. The quantum yield for dissociating H atoms from CP was 0.85{plus minus}0.07. The ejected H atoms have a Maxwell velocity distribution with temperatures which are equal to the vibrational temperatures, 3690 and 2479 K for CP and IND, respectively. The most important result of the work is this confirmation of an earlier finding on a different set of molecules that the translational temperature of the fragments {ital after} the dissociation is equal to the vibrational temperature {ital before} the dissociation. This is explained by the assumption that the motion of the fast, light hydrogen atom is partly decoupled from that of the heavier, slower atoms.

  10. Fast kinetics of calcium dissociation from calsequestrin.

    PubMed

    Beltrán, Marianela; Barrientos, Genaro; Hidalgo, Cecilia

    2006-01-01

    We measured the kinetics of calcium dissociation from calsequestrin in solution or forming part of isolated junctional sarcoplasmic reticulum membranes by mixing calsequestrin equilibrated with calcium with calcium-free solutions in a stopped-flow system. In parallel, we measured the kinetics of the intrinsic fluorescence changes that take place following calcium dissociation from calsequestrin. We found that at 25 degrees C calcium dissociation was 10-fold faster for calsequestrin attached to junctional membranes (k = 109 s(-1)) than in solution. These results imply that calcium dissociation from calsequestrin in vivo is not rate limiting during excitation-contraction coupling. In addition, we found that the intrinsic fluorescence decrease for calsequestrin in solution or forming part of junctional membranes was significantly slower than the rates of calcium dissociation. The kinetics of intrinsic fluorescence changes had two components for calsequestrin associated to junctional membranes and only one for calsequestrin in solution; the faster component was 8-fold faster (k = 54.1 s(-1)) than the slower component (k = 6.9 s(-1)), which had the same k value as for calsequestrin in solution. These combined results suggest that the presence of calsequestrin at high concentrations in a restricted space, such as when bound to the junctional membrane, accelerates calcium dissociation and the resulting structural changes, presumably as a result of cooperative molecular interactions. PMID:17106581

  11. Ionization and dissociation dynamics of molecules in strong laser fields

    NASA Astrophysics Data System (ADS)

    Lai, Wei

    The fast advancement of ultrashort-pulsed high-intensity laser technology allows for generating an electric field equivalent to the Coulomb field inside an atom or a molecule (e.g., EC=5.14x109 V/cm at the 1s orbit radius a0=0.0529 nm of the hydrogen atom, which corresponds to an intensity of 3.54x1016 W/cm2). Atoms and molecules exposed in such a field will easily be ionized, as the external field is strong enough to remove the electrons from the core. This is usually referred to "strong field". Strong fields provide a new tool for studying the interaction of atoms and molecules with light in the nonlinear nonperturbative regime. During the past three decades, significant progress has been made in the strong field science. Today, most phenomena involving atoms in strong fields have been relatively well understood by the single-active-electron (SAE) approximation. However, the interpretation of these responses in molecules has encountered great difficulties. Not like atoms that only undergo excitation and ionization, various dissociation channels accompanying excitation and ionization can occur in molecules during the laser pulse interaction, which imparts further complexity to the study of molecules in strong fields. Previous studies have shown that molecules can behave significantly different from rare gas atoms in phenomena as simple as single and double ionization. Molecular dissociation following ionization also presents challenges in strong fields compared to what we have learned in the weak-field regime. This dissertation focuses on experimental studies on ionization and dissociation of some commonly-seen small molecules in strong laser fields. Previous work of molecules in strong fields will be briefly reviewed, particularly on some open questions about multiple dissociation channels, nonsequential double ionization, enhanced ionization and molecular alignment. The identification of various molecular dissociation channels by recent experimental technical

  12. Discriminating among diagnostic categories using the Dissociative Disorders Interview Schedule.

    PubMed

    Ross, Colin A; Ellason, Joan Weathersbee

    2005-04-01

    The Dissociative Disorders Interview Schedule was administered to 1,308 subjects in eight diagnostic categories, including 296 with dissociative identity disorder. The study tested three hypotheses: (1) the Mahalanobis distance between dissociative identity disorder and each of seven other diagnostic categories would be large, (2) the closest diagnostic category to dissociative identity disorder would be dissociative disorder not otherwise specified, and (3) nondissociative diagnostic categories would be closer to each other than any one to dissociative identity disorder. All three hypotheses were confirmed by these data. The findings support the conclusion that dissociative identity disorder is a discrete category or taxon.

  13. 3D-CAD Effects on Creative Design Performance of Different Spatial Abilities Students

    ERIC Educational Resources Information Center

    Chang, Y.

    2014-01-01

    Students' creativity is an important focus globally and is interrelated with students' spatial abilities. Additionally, three-dimensional computer-assisted drawing (3D-CAD) overcomes barriers to spatial expression during the creative design process. Does 3D-CAD affect students' creative abilities? The purpose of this study was to…

  14. Computer Use and CAD in Assisting Schools in the Creation of Facilities.

    ERIC Educational Resources Information Center

    Beach, Robert H.; Essex, Nathan

    1987-01-01

    Computer-aided design (CAD) programs are powerful drafting tools, but are also able to assist with many other facility planning functions. Describes the hardware, software, and the learning process that led to understanding the CAD software at the University of Alabama. (MLF)

  15. Mobile Technology and CAD Technology Integration in Teaching Architectural Design Process for Producing Creative Product

    ERIC Educational Resources Information Center

    Bin Hassan, Isham Shah; Ismail, Mohd Arif; Mustafa, Ramlee

    2011-01-01

    The purpose of this research is to examine the effect of integrating the mobile and CAD technology on teaching architectural design process for Malaysian polytechnic architectural students in producing a creative product. The website is set up based on Caroll's minimal theory, while mobile and CAD technology integration is based on Brown and…

  16. A Multidisciplinary Research Team Approach to Computer-Aided Drafting (CAD) System Selection. Final Report.

    ERIC Educational Resources Information Center

    Franken, Ken; And Others

    A multidisciplinary research team was assembled to review existing computer-aided drafting (CAD) systems for the purpose of enabling staff in the Design Drafting Department at Linn Technical College (Missouri) to select the best system out of the many CAD systems in existence. During the initial stage of the evaluation project, researchers…

  17. Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

    PubMed Central

    Kwon, Taek-Ka; Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns. RESULTS The mean fracture strengths were as follows: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain. CONCLUSION The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain. PMID:23755332

  18. Development of CAD/CAM software used in laser direct manufacture

    NASA Astrophysics Data System (ADS)

    Wang, Yun-shan; Yang, Xi-chen; Wang, Jian-jun; Jin, Xiao-shu

    2005-01-01

    This paper presents a special CAD/CAM software for rapid manufacturing thin wall metal parts by laser cladding, which is based on the developing of AutoCAD. It mainly consists of solid modeling, layering and section data processing, NC code generation module, processing path simulating and data transferring module.

  19. The Use of a Parametric Feature Based CAD System to Teach Introductory Engineering Graphics.

    ERIC Educational Resources Information Center

    Howell, Steven K.

    1995-01-01

    Describes the use of a parametric-feature-based computer-aided design (CAD) System, AutoCAD Designer, in teaching concepts of three dimensional geometrical modeling and design. Allows engineering graphics to go beyond the role of documentation and communication and allows an engineer to actually build a virtual prototype of a design idea and…

  20. Teaching an Introductory CAD Course with the System-Engineering Approach.

    ERIC Educational Resources Information Center

    Pao, Y. C.

    1985-01-01

    Advocates that introductory computer aided design (CAD) courses be incorporated into engineering curricula in close conjunction with the system dynamics course. Block diagram manipulation/Bode analysis and finite elementary analysis are used as examples to illustrate the interdisciplinary nature of CAD teaching. (JN)

  1. Getting CAD in shape: the atomic structure of human dihydroorotase domain.

    PubMed

    Hermoso, Juan A

    2014-02-01

    CAD is a large multifunctional polypeptide that initiates and controls the de novo biosynthesis of pyrimidines in animals. In this issue of Structure, Grande-García and colleagues provide the first atomic information of this antitumoral target by reporting the crystal structure of the dihydroorotase domain of human CAD.

  2. Aberrations of dermal connective tissue in patients with cervical artery dissection (sCAD).

    PubMed

    Uhlig, Phillip; Bruckner, Peter; Dittrich, Ralf; Ringelstein, E Bernd; Kuhlenbäumer, Gregor; Hansen, Uwe

    2008-03-01

    Spontaneous cervical artery dissection (sCAD) is a common cause of stroke in patients below 55 years of age. Hereditary connective tissue disorders, including Ehlers-Danlos syndrome type IV, have been associated with sCAD and suprastructural abnormalities of both collagen fibrils and elastic fibers have been found by transmission electron microscopy in the dermis of about 50% of sCAD patients. Here, we investigated dermal connective tissue abnormalities using a novel method. Transmission and immunogold electron microscopy were used to study mechanically generated fragments of dermal matrix suprastructures, in particular collagen fibrils. Analysis of dermal tissue of sCAD patients revealed structurally abnormal collagen fibrils with irregularly contoured surfaces and increased diameters, often associated with a faint or absent banding pattern. Interestingly, only a small number of fibrils displayed short abnormal sections along the length of the fibril. Collagens I and III were present in normal as well as abnormal sections of the fibrils.However, immunogold labeling for the two proteins was strongly increased in abnormal sections.A systematic blinded investigation of skin biopsies of 31 sCAD patients and 17 controls revealed abnormal collagen fibrils in 7 sCAD patients but none of the controls. We conclude that approximately 20% of sCAD patients show collagen fibril alterations, establishing a promising basis for further investigation of connective tissue aberrations in skin biopsies of sCAD patients.

  3. Identifying dissociative identity disorder: a self-report and projective study.

    PubMed

    Scroppo, J C; Drob, S L; Weinberger, J L; Eagle, P

    1998-05-01

    This study compared 21 female adult psychiatric patients diagnosed with dissociative identity disorder (DID) with 21 female adult nondissociative psychiatric patients to determine whether DID patients exhibit a distinguishing set of clinical features, and perceptual, attentional, and cognitive processes. Participants were assessed with the Dissociative Disorders Interview Schedule to assess diagnostic status. Group scores on the Dissociative Experiences Scale, Tellegen Absorption Scale, Childhood Trauma Questionnaire, Brief Symptom Inventory, and the Rorschach test were compared. DID participants reported earlier and more severe childhood trauma, more dissociative symptoms, and a greater propensity for altered states of consciousness. The DID participants also exhibited increased projective and imaginative activity, a diminished ability to integrate mental contents, a complex and driven cognitive style, and a highly unconventional view of reality.

  4. Dissociations between developmental dyslexias and attention deficits

    PubMed Central

    Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

    2014-01-01

    We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that

  5. User productivity as a function of AutoCAD interface design.

    PubMed

    Mitta, D A; Flores, P L

    1995-12-01

    Increased operator productivity is a desired outcome of user-CAD interaction scenarios. Two objectives of this research were to (1) define a measure of operator productivity and (2) empirically investigate the potential effects of CAD interface design on operator productivity, where productivity is defined as the percentage of a drawing session correctly completed per unit time. Here, AutoCAD provides the CAD environment of interest. Productivity with respect to two AutoCAD interface designs (menu, template) and three task types (draw, dimension, display) was investigated. Analysis of user productivity data revealed significantly higher productivity under the menu interface condition than under the template interface condition. A significant effect of task type was also discovered, where user productivity under display tasks was higher than productivity under the draw and dimension tasks. Implications of these results are presented.

  6. Gas-phase Dissociation of homo-DNA Oligonucleotides

    NASA Astrophysics Data System (ADS)

    Stucki, Silvan R.; Désiron, Camille; Nyakas, Adrien; Marti, Simon; Leumann, Christian J.; Schürch, Stefan

    2013-12-01

    Synthetic modified oligonucleotides are of interest for diagnostic and therapeutic applications, as their biological stability, pairing selectivity, and binding strength can be considerably increased by the incorporation of unnatural structural elements. Homo-DNA is an oligonucleotide homologue based on dideoxy-hexopyranosyl sugar moieties, which follows the Watson-Crick A-T and G-C base pairing system, but does not hybridize with complementary natural DNA and RNA. Homo-DNA has found application as a bioorthogonal element in templated chemistry applications. The gas-phase dissociation of homo-DNA has been investigated by ESI-MS/MS and MALDI-MS/MS, and mechanistic aspects of its gas-phase dissociation are discussed. Experiments revealed a charge state dependent preference for the loss of nucleobases, which are released either as neutrals or as anions. In contrast to DNA, nucleobase loss from homo-DNA was found to be decoupled from backbone cleavage, thus resulting in stable products. This renders an additional stage of ion activation necessary in order to generate sequence-defining fragment ions. Upon MS3 of the primary base-loss ion, homo-DNA was found to exhibit unspecific backbone dissociation resulting in a balanced distribution of all fragment ion series.

  7. K*-charmonium dissociation cross sections and charmonium dissociation rates in hadronic matter

    NASA Astrophysics Data System (ADS)

    Liu, Feng-Rong; Ji, Shi-Tao; Xu, Xiao-Ming

    2016-08-01

    K*-charmonium dissociation reactions in hadronic matter are studied in the Born approximation, in the quark-interchange mechanism, and with a temperature-dependent quark potential. We obtain the temperature dependence of the unpolarized cross sections for the reactions K^* J/ψ to bar DD_s^ + ,bar D^* D_s^ + ,bar DD_s^{* + } , and bar D^* D_s^{* + } ; K^* χ _c to bar DD_s^ + ,bar D^* D_s^ + ,bar DD_s^{* + } , and bar D^* D_s^{* + } . We use the cross sections for charmonium dissociation in collisions with pions, ρ mesons, kaons, vector kaons, and η mesons to calculate the dissociation rates of charmonium with five types of mesons. Because of the temperature dependence of the meson masses, dissociation cross sections, and meson distribution functions, the charmonium dissociation rates generally increase with increasing temperature and decrease with increasing charmonium momentum from 2.2 GeV/c. We find that the first derivative of the dissociation rate with respect to the charmonium momentum is zero when the charmonium is at rest. While the η + ψ' and the η + χ c dissociation reactions can be neglected, the J/ ψ, ψ', and χ c dissociations are caused by collisions with pions, ρ mesons, kaons, vector kaons, and η mesons.

  8. Dissociation and vulnerability to psychotic experience. The Dissociative Experiences Scale and the MMPI-2.

    PubMed

    Allen, J G; Coyne, L

    1995-10-01

    Prior research on the MMPI has cautioned against misdiagnosing schizophrenia in patients with dissociative identity disorder. The present study examined the full spectrum of the dissociative experience in relation to MMPI-2 profiles. Ninety-eight women in treatment for trauma-related disorders completed the Dissociative Experiences Scale and the MMPI-2 in routine inpatient diagnostic evaluations. Consistent with prior research, severe dissociation was associated with high elevations on MMPI-2 scales typically associated with psychotic symptoms. Contrary to hypotheses, the ostensibly most benign form of dissociation, absorption and imaginative involvement, was somewhat more strongly related to MMPI-2 scores than the more pathognomonic forms of dissociation, depersonalization and amnesia. Although it should not be misdiagnosed, severe impairment on the MMPI in conjunction with dissociation should be taken seriously as suggesting vulnerability to psychotic experience. The dissociative retreat from the stressors of outer reality opens the door to the inner world of traumatic images and affects, along with compromised reality testing and disorganized thinking.

  9. Dissociation in borderline personality disorder: a detailed look.

    PubMed

    Korzekwa, Marilyn I; Dell, Paul F; Links, Paul S; Thabane, Lehana; Fougere, Philip

    2009-01-01

    The objective of the present study was to assess in detail the whole spectrum of normal and pathological dissociative experiences and dissociative disorder (DD) diagnoses in borderline personality disorder (BPD) as diagnosed with the Revised Diagnostic Interview for Borderlines. Dissociation was measured comprehensively in 21 BPD outpatients using the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised, the Multidimensional Inventory of Dissociation (MID), the Dissociative Experiences Scale pathological taxon analysis, and the Somatoform Dissociation Questionnaire. The frequencies of DDs in this BPD sample were as follows: 24% no DD, 29% mild DD (dissociative amnesia and depersonalization disorder), 24% DD Not Otherwise Specified (DDNOS), and 24% dissociative identity disorder. With regard to the dissociative experiences endorsed, almost all patients reported identity confusion, unexplained mood changes, and depersonalization. Even those BPD patients with mild DD reported derealization, depersonalization, and dissociative amnesia. BPD patients with DDNOS reported frequent depersonalization, frequent amnesia, and notable experiences of identity alteration. BPD patients with dissociative identity disorder endorsed severe dissociative symptoms in all categories. Analysis of the MID pathological dissociation items revealed that 32% of the items were endorsed at a clinically significant level of frequency by more than 50% of our BPD patients. In conclusion, the frequencies of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) DDs in these patients with BPD were surprisingly high. Likewise, the "average" BPD patient endorsed a wide variety of recurrent pathological dissociative symptoms.

  10. Design of the new couplers for C-ADS RFQ

    NASA Astrophysics Data System (ADS)

    Shi, Ai-Min; Sun, Lie-Peng; Zhang, Zhou-Li; Xu, Xian-Bo; Shi, Long-Bo; Li, Chen-Xing; Wang, Wen-Bin

    2015-04-01

    A new special coupler with a kind of bowl-shaped ceramic window for a proton linear accelerator named the Chinese Accelerator Driven System (C-ADS) at the Institute of Modern Physics (IMP) has been simulated and constructed and a continuous wave (CW) beam commissioning through a four-meter long radio frequency quadruple (RFQ) was completed by the end of July 2014. In the experiments of conditioning and beam, some problems were promoted gradually such as sparking and thermal issues. Finally, two new couplers were passed with almost 110 kW CW power and 120 kW pulsed mode, respectively. The 10 mA intensity beam experiments have now been completed, and the couplers during the operation had no thermal or electro-magnetic problems. The detailed design and results are presented in the paper. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03020500)

  11. Using CAD/CAM to improve productivity - The IPAD approach

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.

    1981-01-01

    Progress in designing and implementing CAD/CAM systems as a result of the NASA Integrated Programs for Aerospace-Vehicle Design is discussed. Essential software packages have been identified as executive, data management, general user, and geometry and graphics software. Data communication, as a means to integrate data over a network of computers of different vendors, provides data management with the capability of meeting design and manufacturing requirements of the vendors. Geometry software is dependent on developmental success with solid geometry software, which is necessary for continual measurements of, for example, a block of metal while it is being machined. Applications in the aerospace industry, such as for design, analysis, tooling, testing, quality control, etc., are outlined.

  12. Custom hip prostheses by integrating CAD and casting technology

    NASA Astrophysics Data System (ADS)

    Silva, Pedro F.; Leal, Nuno; Neto, Rui J.; Lino, F. Jorge; Reis, Ana

    2012-09-01

    Total Hip Arthroplasty (THA) is a surgical intervention that is being achieving high rates of success, leaving room to research on long run durability, patient comfort and costs reduction. Even so, up to the present, little research has been done to improve the method of manufacturing customized prosthesis. The common customized prostheses are made by full machining. This document presents a different approach methodology which combines the study of medical images, through CAD (Computer Aided Design) software, SLadditive manufacturing, ceramic shell manufacture, precision foundry with Titanium alloys and Computer Aided Manufacturing (CAM). The goal is to achieve the best comfort for the patient, stress distribution and the maximum lifetime of the prosthesis produced by this integrated methodology. The way to achieve this desiderate is to make custom hip prosthesis which are adapted to each patient needs and natural physiognomy. Not only the process is reliable, but also represents a cost reduction comparing to the conventional full machined custom hip prosthesis.

  13. CAD system for automatic analysis of CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Hachaj, T.; Ogiela, M. R.

    2011-03-01

    In this article, authors present novel algorithms developed for the computer-assisted diagnosis (CAD) system for analysis of dynamic brain perfusion, computer tomography (CT) maps, cerebral blood flow (CBF), and cerebral blood volume (CBV). Those methods perform both quantitative analysis [detection and measurement and description with brain anatomy atlas (AA) of potential asymmetries/lesions] and qualitative analysis (semantic interpretation of visualized symptoms). The semantic interpretation (decision about type of lesion: ischemic/hemorrhagic, is the brain tissue at risk of infraction or not) of visualized symptoms is done by, so-called, cognitive inference processes allowing for reasoning on character of pathological regions based on specialist image knowledge. The whole system is implemented in.NET platform (C# programming language) and can be used on any standard PC computer with.NET framework installed.

  14. Dissociable brain mechanisms for processing social exclusion and rule violation.

    PubMed

    Bolling, Danielle Z; Pitskel, Naomi B; Deen, Ben; Crowley, Michael J; McPartland, James C; Mayes, Linda C; Pelphrey, Kevin A

    2011-02-01

    Social exclusion inherently involves an element of expectancy violation, in that we expect other people to follow the unwritten rule to include us in social interactions. In this functional magnetic resonance imaging (fMRI) study, we employed a unique modification of an interactive virtual ball-tossing game called "Cyberball" (Williams et al., 2000) and a novel paradigm called "Cybershape," in which rules are broken in the absence of social exclusion, to dissociate brain regions that process social exclusion from rule violations more generally. Our Cyberball game employed an alternating block design and removed evoked responses to events when the participant was throwing the ball in inclusion to make this condition comparable to exclusion, where participants did not throw. With these modifications, we replicated prior findings of ventral anterior cingulate cortex (vACC), insula, and posterior cingulate cortex activity evoked by social exclusion relative to inclusion. We also identified exclusion-evoked activity in the hippocampi, left ventrolateral prefrontal cortex, and left middle temporal gyrus. Comparing social exclusion and rule violation revealed a functional dissociation in the active neural systems as well as differential functional connectivity with vACC. Some overlap was observed in regions differentially modulated by social exclusion and rule violation, including the vACC and lateral parietal cortex. These overlapping brain regions showed different activation during social exclusion compared to rule violation, each relative to fair play. Comparing activation patterns to social exclusion and rule violation allowed for the dissociation of brain regions involved in the experience of exclusion versus expectancy violation.

  15. Utilization of a global data grid repository in CAD assessment of carotid wall thickness

    NASA Astrophysics Data System (ADS)

    Gutierrez, Marco A.; Lee, Jasper; Zhou, Zheng; Pilon, Paulo E.; Lage, Silvia G.

    2007-03-01

    A CAD method of calculating wall thickness of carotid vessels addresses the time-consuming issue of using B-mode ultrasound as well as inter- and intra-observer variability in results. Upon selection of a region-of-interest and filtering of a series of ultrasound carotid images, the CAD is able to measure the geometry of the lumen and plaque surfaces using a least-square fitting of the active contours during systole and diastole. To evaluate the approach, ultrasound image sequences from 30 patients were submitted to the procedure. The images were stored on an international data grid repository that consists of three international sites: Image Processing and Informatics (IPI) Laboratory at University of Southern California, USA; InCor (Heart Institute) at Sao Paulo, Brazil, and Hong Kong Polytechnic University, Hong Kong. The three chosen sites are connected with high speed international networks including the Internet2, and the Brazilian National Research and Education Network (RNP2). The Data Grid was used to store, backup, and share the ultrasound images and analysis results, which provided a large-scale and a virtual data system. In order to study the variability between the automatic and manual definition of artery boundaries, the pooled mean and the standard deviation for the difference between measurements of lumen diameter were computed. The coefficient of variation and correlation were also calculated. For the studied population the difference between manual and automatic measurement of the lumen diameter (LD) and intima-media-thickness (IMT) were 0.12 +/-0.10 and 0.09+/- 0.06, respectively.

  16. Isotope separation by photoselective dissociative electron capture

    DOEpatents

    Stevens, Charles G. [Pleasanton, CA

    1978-08-29

    A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, .sup.235 UF.sub.6 is separated from a UF.sub.6 mixture by selective excitation followed by dissociative electron capture into .sup.235 UF.sub.5 - and F.

  17. Isotope separation by photoselective dissociative electron capture

    DOEpatents

    Stevens, C.G.

    1978-08-29

    Disclosed is a method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, [sup 235]UF[sub 6] is separated from a UF[sub 6] mixture by selective excitation followed by dissociative electron capture into [sup 235]UF[sub 5]- and F. 2 figs.

  18. Ion-induced dissociation dynamics of acetylene

    SciTech Connect

    De, Sankar; Rajput, Jyoti; Roy, A.; Safvan, C. P.; Ghosh, P. N.

    2008-02-15

    We report on the results of dissociation dynamics of multiple charged acetylene molecules formed in collision with 1.2 MeV Ar{sup 8+} projectiles. Using the coincidence map, we can separate out the different dissociation pathways between carbon and hydrogen ionic fragments as well as complete two-body breakup events. From the measured slopes of the coincidence islands for carbon atomic fragments and theoretical values determined from the charge and momentum distribution of the correlated particles, we observe a diatom like behavior of the C-C charged complex during dissociation of multiply charged C{sub 2}H{sub 2}. We conclude that this behavior in breakup dynamics is a signature of sequentiality in dissociation of this multiply charged molecular species. The shape and orientation of the islands give further information about the momentum balance in the fragmentation process of two- or many-body dissociation pathways. Kinetic energy release of different breakup channels are reported here and compared with values calculated from the pure Coulomb explosion model.

  19. Dissociation in virtual reality: depersonalization and derealization

    NASA Astrophysics Data System (ADS)

    Garvey, Gregory P.

    2010-01-01

    This paper looks at virtual worlds such as Second Life7 (SL) as possible incubators of dissociation disorders as classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition3 (also known as the DSM-IV). Depersonalization is where "a person feels that he or she has changed in some way or is somehow unreal." Derealization when "the same beliefs are held about one's surroundings." Dissociative Identity Disorder (DID), previously known as multiple personality disorder fits users of Second Life who adopt "in-world" avatars and in effect, enact multiple distinct identities or personalities (known as alter egos or alters). Select questions from the Structured Clinical Interview for Depersonalization (SCI-DER)8 will be discussed as they might apply to the user's experience in Second Life. Finally I would like to consider the hypothesis that rather than a pathological disorder, dissociation is a normal response to the "artificial reality" of Second Life.

  20. Free energy calculations of gramicidin dimer dissociation.

    PubMed

    Wanasundara, Surajith N; Krishnamurthy, Vikram; Chung, Shin-Ho

    2011-11-24

    Molecular dynamics simulations, combined with umbrella sampling, is used to study how gramicidin A (gA) dimers dissociate in the lipid bilayer. The potential of mean force and intermolecular potential energy are computed as functions of the distance between center of masses of the two gA monomers in two directions of separation: parallel to the bilayer surface and parallel to the membrane normal. Results from this study show that the dissociation of gA dimers occurs via lateral displacement of gA monomers followed by tilting of dimers with respect to the lipid bilayer normal. It is found that the dissociation energy of gA dimers in the dimyristoylphosphatidylcholine bilayer is 14 kcal mol(-1) (~22 kT), which is approximately equal to the energy of breaking six intermolecular hydrogen bonds that stabilize the gA channel dimer.

  1. Psychotherapy and pharmacotherapy for patients with dissociative identity disorder.

    PubMed

    Gentile, Julie P; Dillon, Kristy S; Gillig, Paulette Marie

    2013-02-01

    There is a wide variety of what have been called "dissociative disorders," including dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, and forms of dissociative disorder not otherwise specified. Some of these diagnoses, particularly dissociative identity disorder, are controversial and have been questioned by many clinicians over the years. The disorders may be under-diagnosed or misdiagnosed, but many persons who have experienced trauma report "dissociative" symptoms. Prevalence of dissociative disorders is unknown, but current estimates are higher than previously thought. This paper reviews clinical, phenomenological, and epidemiological data regarding diagnosis in general, and illustrates possible treatment interventions for dissociative identity disorder, with a focus on psychotherapy interventions and a review of current psychopharmacology recommendations as part of a comprehensive multidisciplinary treatment plan. PMID:23556139

  2. Psychotherapy and pharmacotherapy for patients with dissociative identity disorder.

    PubMed

    Gentile, Julie P; Dillon, Kristy S; Gillig, Paulette Marie

    2013-02-01

    There is a wide variety of what have been called "dissociative disorders," including dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, and forms of dissociative disorder not otherwise specified. Some of these diagnoses, particularly dissociative identity disorder, are controversial and have been questioned by many clinicians over the years. The disorders may be under-diagnosed or misdiagnosed, but many persons who have experienced trauma report "dissociative" symptoms. Prevalence of dissociative disorders is unknown, but current estimates are higher than previously thought. This paper reviews clinical, phenomenological, and epidemiological data regarding diagnosis in general, and illustrates possible treatment interventions for dissociative identity disorder, with a focus on psychotherapy interventions and a review of current psychopharmacology recommendations as part of a comprehensive multidisciplinary treatment plan.

  3. "Trip-Sitting" in the Black Hole: A Netnographic Study of Dissociation and Indigenous Harm Reduction.

    PubMed

    Hearne, Evelyn; Van Hout, Marie Claire

    2016-01-01

    An array of dissociative novel psychoactive substances, including "methoxetamine," "3-MeO-PCP," and "methoxphenidine," have emerged as substitutes for the illicit substance "ketamine." A netographic research methodology aimed to describe online, dissociative novel psychoactive substance users' perceptions of risk, informed knowledge around use, and indigenous harm-reduction practices as advocated within online drug fora, so as to provide credible information which can be used to inform public online health education and drug prevention. Systematic Internet searches were performed using the terms "synthetic dissociative," "methoxetamine," "methoxphenidine," "diphenidine," "3-MeO-PCP," "4-MeO-PCP," "2-MDP," and "dissociative research chemical" in combination with "forum." Following screening of 3,476 forum threads with removal of duplicates and exclusion criteria, 90 user trip reports and 115 fora threads from seven drug fora websites were analyzed by conducting content analysis. Five themes emerged with 43 categories. The findings illustrated how forum activity within the cyber drug user community disseminated and exchanged "communal folk pharmacology" relating to the use of dissociative novel psychoactive substances. Further research and consistent monitoring of Internet drug fora are advised to explore variations in harm-reduction tactics throughout dissociative NPS populations, and to consider how existing harm-reduction initiatives are influencing these hard-to-reach groups.

  4. "Trip-Sitting" in the Black Hole: A Netnographic Study of Dissociation and Indigenous Harm Reduction.

    PubMed

    Hearne, Evelyn; Van Hout, Marie Claire

    2016-01-01

    An array of dissociative novel psychoactive substances, including "methoxetamine," "3-MeO-PCP," and "methoxphenidine," have emerged as substitutes for the illicit substance "ketamine." A netographic research methodology aimed to describe online, dissociative novel psychoactive substance users' perceptions of risk, informed knowledge around use, and indigenous harm-reduction practices as advocated within online drug fora, so as to provide credible information which can be used to inform public online health education and drug prevention. Systematic Internet searches were performed using the terms "synthetic dissociative," "methoxetamine," "methoxphenidine," "diphenidine," "3-MeO-PCP," "4-MeO-PCP," "2-MDP," and "dissociative research chemical" in combination with "forum." Following screening of 3,476 forum threads with removal of duplicates and exclusion criteria, 90 user trip reports and 115 fora threads from seven drug fora websites were analyzed by conducting content analysis. Five themes emerged with 43 categories. The findings illustrated how forum activity within the cyber drug user community disseminated and exchanged "communal folk pharmacology" relating to the use of dissociative novel psychoactive substances. Further research and consistent monitoring of Internet drug fora are advised to explore variations in harm-reduction tactics throughout dissociative NPS populations, and to consider how existing harm-reduction initiatives are influencing these hard-to-reach groups. PMID:27430659

  5. Swirling flow of a dissociated gas

    NASA Technical Reports Server (NTRS)

    Wolfram, W. R., Jr.; Walker, W. F.

    1975-01-01

    Most physical applications of the swirling flow, defined as a vortex superimposed on an axial flow in the nozzle, involve high temperatures and the possibility of real gas effects. The generalized one-dimensional swirling flow in a converging-diverging nozzle is analyzed for equilibrium and frozen dissociation using the ideal dissociating gas model. Numerical results are provided to illustrate the major effects and to compare with results obtained for a perfect gas with constant ratio of specific heats. It is found that, even in the case of real gases, perfect gas calculations can give a good estimate of the reduction in mass flow due to swirl.

  6. Quantum Zeno control of coherent dissociation

    SciTech Connect

    Khripkov, C.; Vardi, A.

    2011-08-15

    We study the effect of dephasing on the coherent dissociation dynamics of an atom-molecule Bose-Einstein condensate. We show that when phase-noise intensity is strong with respect to the inverse correlation time of the stimulated process, dissociation is suppressed via a Bose enhanced quantum Zeno effect. This is complementary to the quantum Zeno control of phase-diffusion in a bimodal condensate by symmetric noise [Phys. Rev. Lett. 100, 220403 (2008)] in that the controlled process here is phase formation and the required decoherence mechanism for its suppression is purely phase noise.

  7. Dissociation and recombination in an inhomogeneous gas

    NASA Astrophysics Data System (ADS)

    Kuščer, Ivan

    1991-09-01

    The system of Boltzmann equations of Ludwig and Heil for a dissociating gas mixture is reviewed and reformulated in terms of differential cross sections. For the purpose of Monte Carlo simulations, collision models of the type of Borgnakke and Larsen are proposed. In case of short-lived transient flows of molecular gases and at not too high temperatures, simulation of scattering collisions is expected to suffice; the distribution function of the dissociated particles can be evaluated afterwards by integration, and recombination can be ignored.

  8. Identity and Introject in dissociative disorders.

    PubMed

    Alpher, V S

    1996-12-01

    The structural analysis of social behavior (SASB) shows promise for systematically examining identity issues in clinical populations. In this study, identity is assessed with the SASB in a sample of women with dissociative disorder (n = 25) and a nonpatient clinical contrast group (n = 25). The SASB Introject--a multivariate measure of identity--effectively differentiated the 2 samples. Despite greater self-directed hostility than the clinical contrast group, dissociative disorder patients showed lower levels of intrapsychic conflict. Implications for further research on identity and psychopathology are discussed.

  9. Dissociative identity disorder: a literature review.

    PubMed

    McAllister, M M

    2000-01-01

    This paper presents a review of the literature into dissociative identity disorder. This disorder, previously known as multiple personality disorder, is increasingly diagnosed, in part because of more focused diagnostic tools, but also because people are accessing services to assist with the longterm problems of early child abuse and neglect. Dissociative identity disorder is examined in the literature according to a variety of discourses, each of which suggest different ways of conceptualizing problems and therapeutic approaches. These discourses reviewed include: psychiatry, psychology, corporeality, feminism, social constructivism, anthropology, and postmodernism. The paper concludes with an examination of the nursing literature and suggests opportunities for nursing research into this complex mental health problem.

  10. The use of hypnosis with dissociative disorders.

    PubMed

    Kluft, R P

    1992-01-01

    The dissociative disorders are characterized by difficulties in the integration of memory and/or identity. Typically this is manifested by amnesia and either the development of alternate identities or an estrangement from one's own identity. Spontaneous and self-generated dissociative states and phenomena sharing much in common with those that can be induced with hypnosis are thought to play a major role in their development, symptomatology, and perpetuation. Medical heterohypnosis offers a powerful tool to reestablish a functional continuity of memory and identity in many such cases. The application of hypnotic interventions in the treatment of such conditions will be discussed, explored, and illustrated with clinical vignettes.

  11. Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization

    NASA Astrophysics Data System (ADS)

    Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P.

    2016-08-01

    The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting.

  12. Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization.

    PubMed

    Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P

    2016-10-01

    The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting. Graphical Abstract ᅟ. PMID:27582116

  13. Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization

    NASA Astrophysics Data System (ADS)

    Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P.

    2016-10-01

    The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting.

  14. Dissociated neural effects of cortisol depending on threat escapability.

    PubMed

    Montoya, Estrella R; van Honk, Jack; Bos, Peter A; Terburg, David

    2015-11-01

    Evolution has provided us with a highly flexible neuroendocrine threat system which, depending on threat imminence, switches between active escape and passive freezing. Cortisol, the "stress-hormone", is thought to play an important role in both fear behaviors, but the exact mechanisms are not understood. Using pharmacological functional magnetic resonance imaging we investigated how cortisol modulates the brain's fear systems when humans are under virtual-predator attack. We show dissociated neural effects of cortisol depending on whether escape from threat is possible. During inescapable threat cortisol reduces fear-related midbrain activity, whereas in anticipation of active escape cortisol boosts activity in the frontal salience network (insula and anterior cingulate cortex), which is involved in autonomic control, visceral perception and motivated action. Our findings suggest that cortisol adjusts the human neural threat system from passive fear to active escape, which illuminates the hormone's crucial role in the adaptive flexibility of fear behaviors.

  15. Dissociative detachment and memory impairment: reversible amnesia or encoding failure?

    PubMed

    Allen, J G; Console, D A; Lewis, L

    1999-01-01

    The authors propose that clinicians endeavor to differentiate between reversible and irreversible memory failures in patients with dissociative symptoms who report "memory gaps" and "lost time." The classic dissociative disorders, such as dissociative amnesia and dissociative identity disorder, entail reversible memory failures associated with encoding experience in altered states. The authors propose another realm of memory failures associated with severe dissociative detachment that may preclude the level of encoding of ongoing experience needed to support durable autobiographical memories. They describe how dissociative detachment may be intertwined with neurobiological factors that impair memory, and they spell out the significance of distinguishing reversible and irreversible memory impairment for diagnosis, patient education, psychotherapy, and research.

  16. Self-destructive behavior in patients with dissociative disorders.

    PubMed

    Saxe, Glenn N; Chawla, Neharika; Van der Kolk, Bessel

    2002-01-01

    Highrates of self-injury have been reported in patients with dissociative disorders, yet no prior study has directly compared these patients with other psychiatric patients. The present study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. These patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not dissociate. Results have important implications for understanding the relationship between dissociation, childhood trauma, and self-injury and for assessment and treatment of patients with dissociative disorders.

  17. Dental students' preferences and performance in crown design: conventional wax-added versus CAD.

    PubMed

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A

    2014-12-01

    The purpose of this study was to evaluate dental students' perceptions of traditional waxing vs. computer-aided crown design and to determine the effectiveness of either technique through comparative grading of the final products. On one of twoidentical tooth preparations, second-year students at one dental school fabricated a wax pattern for a full contour crown; on the second tooth preparation, the same students designed and fabricated an all-ceramic crown using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Projects were graded for occlusion and anatomic form by three faculty members. On completion of the projects, 100 percent of the students (n=50) completed an eight-question, five-point Likert scalesurvey, designed to assess their perceptions of and learning associated with the two design techniques. The average grades for the crown design projects were 78.3 (CAD) and 79.1 (wax design). The mean numbers of occlusal contacts were 3.8 (CAD) and 2.9(wax design), which was significantly higher for CAD (p=0.02). The survey results indicated that students enjoyed designing afull contour crown using CAD as compared to using conventional wax techniques and spent less time designing the crown using CAD. From a learning perspective, students felt that they learned more about position and the size/strength of occlusal contacts using CAD. However, students recognized that CAD technology has limits in terms of representing anatomic contours and excursive occlusion compared to conventional wax techniques. The results suggest that crown design using CAD could be considered as an adjunct to conventional wax-added techniques in preclinical fixed prosthodontic curricula.

  18. Comparison of sensitivity and reading time for the use of computer-aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader.

    PubMed

    Beyer, F; Zierott, L; Fallenberg, E M; Juergens, K U; Stoeckel, J; Heindel, W; Wormanns, D

    2007-11-01

    The purpose of this study was to compare sensitivity for detection of pulmonary nodules in MDCT scans and reading time of radiologists when using CAD as the second reader (SR) respectively concurrent reader (CR). Four radiologists analyzed 50 chest MDCT scans chosen from clinical routine two times and marked all detected pulmonary nodules: first with CAD as CR (display of CAD results immediately in the reading session) and later (median 14 weeks) with CAD as SR (display of CAD markers after completion of first reading without CAD). A Siemens LungCAD prototype was used. Sensitivities for detection of nodules and reading times were recorded. Sensitivity of reading with CAD as SR was significantly higher than reading without CAD (p < 0.001) and CAD as CR (p < 0.001). For nodule size of 1.75 mm or above no significant sensitivity difference between CAD as CR and reading without CAD was observed; e.g., for nodules above 4 mm sensitivity was 68% without CAD, 68% with CAD as CR (p = 0.45) and 75% with CAD as SR (p < 0.001). Reading time was significantly shorter for CR (274 s) compared to reading without CAD (294 s; p = 0.04) and SR (337 s; p < 0.001). In our study CAD could either speed up reading of chest CT cases for pulmonary nodules without relevant loss of sensitivity when used as CR, or it increased sensitivity at the cost of longer reading times when used as SR.

  19. The Nature of the Dissociation Sites of Hydrogen Molecules on Ru(001)

    SciTech Connect

    Salmeron, Miquel; Rose, Franck; Tartakhanov, Mous; Fomin, Evgeni; Salmeron, Miquel

    2008-03-12

    Scanning tunneling microscopy (STM) was used to study the dissociative adsorption of H{sub 2} on Ru(001) near saturation coverage, when the number of residual hydrogen vacancies (i.e., unoccupied Ru sites) is small. We found that H{sub 2} dissociation takes place only on Ru sites where the metal atom is not bound to any H atom. Such active sites are formed when at least 3 H-vacancies aggregate by thermal diffusion. Sites formed by single H-vacancies or pairs of adjoining vacancies were found to be unreactive toward H{sub 2}. As a similar phenomenon was found previously on Pd(111), the present results indicate that the active sites for H2 dissociation share a common characteristic among catalytically active transition metals.

  20. Dissociation dynamics of ethylene molecules on a Ni cluster using ab initio molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Shimamura, K.; Shibuta, Y.; Ohmura, S.; Arifin, R.; Shimojo, F.

    2016-04-01

    The atomistic mechanism of dissociative adsorption of ethylene molecules on a Ni cluster is investigated by ab initio molecular-dynamics simulations. The activation free energy to dehydrogenate an ethylene molecule on the Ni cluster and the corresponding reaction rate is estimated. A remarkable finding is that the adsorption energy of ethylene molecules on the Ni cluster is considerably larger than the activation free energy, which explains why the actual reaction rate is faster than the value estimated based on only the activation free energy. It is also found from the dynamic simulations that hydrogen molecules and an ethane molecule are formed from the dissociated hydrogen atoms, whereas some exist as single atoms on the surface or in the interior of the Ni cluster. On the other hand, the dissociation of the C-C bonds of ethylene molecules is not observed. On the basis of these simulation results, the nature of the initial stage of carbon nanotube growth is discussed.