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Sample records for 3x vertical exaggeration

  1. Dissociated vertical deviation: an exaggerated normal eye movement used to damp cyclovertical latent nystagmus.

    PubMed Central

    Guyton, D L; Cheeseman, E W; Ellis, F J; Straumann, D; Zee, D S

    1998-01-01

    PURPOSE: Dissociated vertical deviation (DVD) has eluded explanation for more than a century. The purpose of this study has been to elucidate the etiology and mechanism of DVD. METHODS: Eye movement recordings of six young adults with DVD were made with dual-coil scleral search coils under various conditions of fixation, illumination, and head tilt. Horizontal, vertical, and torsional eye movements were recorded for both eyes simultaneously. Analyses of the simultaneous vertical and torsional movements occurring during the DVD response were used to separate and identify the component vergence and version eye movements involved. RESULTS: Typically, both horizontal and cyclovertical latent nystagmus developed upon occlusion of either eye. A cycloversion then occurred, with the fixing eye intorting and tending to depress, the covered eye extorting and elevating. Simultaneously, upward versions occurred for the maintenance of fixation, consisting variously of saccades and smooth eye movements, leading to further elevation of the eye behind the cover. The cyclovertical component of the latent nystagmus became partially damped as the DVD developed. CONCLUSIONS: In patients with an early-onset defect of binocular function, the occlusion of one eye, or even concentration on fixing with one eye, produces unbalanced input to the vestibular system. This results in latent nystagmus, sometimes seen only with magnification. The cyclovertical component of the latent nystagmus, when present, is similar to normal vestibular nystagmus induced by dynamic head tilting about an oblique axis. Such vestibular nystagmus characteristically produces a hyperdeviation of the eyes. In the case of cyclovertical latent nystagmus, the analogous hyperdeviation will persist unless corrected by a vertical vergence. A normal, oblique-muscle-mediated, cycloversion/vertical vergence is called into play. This occurs in the proper direction to correct the hyperdeviation, but it occurs in an exaggerated

  2. Vertical Interface Induced Dielectric Relaxation in Nanocomposite (BaTiO3)1-x:(Sm2O3)x Thin Films

    PubMed Central

    Li, Weiwei; Zhang, Wei; Wang, Le; Gu, Junxing; Chen, Aiping; Zhao, Run; Liang, Yan; Guo, Haizhong; Tang, Rujun; Wang, Chunchang; Jin, Kuijuan; Wang, Haiyan; Yang, Hao

    2015-01-01

    Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films. PMID:26061829

  3. Vertical Interface Induced Dielectric Relaxation in Nanocomposite (BaTiO3)1-x:(Sm2O3)x Thin Films.

    PubMed

    Li, Weiwei; Zhang, Wei; Wang, Le; Gu, Junxing; Chen, Aiping; Zhao, Run; Liang, Yan; Guo, Haizhong; Tang, Rujun; Wang, Chunchang; Jin, Kuijuan; Wang, Haiyan; Yang, Hao

    2015-01-01

    Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films. PMID:26061829

  4. Vertical Interface Induced Dielectric Relaxation in Nanocomposite (BaTiO3)1-x:(Sm2O3)x Thin Films

    NASA Astrophysics Data System (ADS)

    Li, Weiwei; Zhang, Wei; Wang, Le; Gu, Junxing; Chen, Aiping; Zhao, Run; Liang, Yan; Guo, Haizhong; Tang, Rujun; Wang, Chunchang; Jin, Kuijuan; Wang, Haiyan; Yang, Hao

    2015-06-01

    Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films.

  5. Towards exaggerated emphysema stereotypes

    NASA Astrophysics Data System (ADS)

    Chen, C.; Sørensen, L.; Lauze, F.; Igel, C.; Loog, M.; Feragen, A.; de Bruijne, M.; Nielsen, M.

    2012-03-01

    Classification is widely used in the context of medical image analysis and in order to illustrate the mechanism of a classifier, we introduce the notion of an exaggerated image stereotype based on training data and trained classifier. The stereotype of some image class of interest should emphasize/exaggerate the characteristic patterns in an image class and visualize the information the employed classifier relies on. This is useful for gaining insight into the classification and serves for comparison with the biological models of disease. In this work, we build exaggerated image stereotypes by optimizing an objective function which consists of a discriminative term based on the classification accuracy, and a generative term based on the class distributions. A gradient descent method based on iterated conditional modes (ICM) is employed for optimization. We use this idea with Fisher's linear discriminant rule and assume a multivariate normal distribution for samples within a class. The proposed framework is applied to computed tomography (CT) images of lung tissue with emphysema. The synthesized stereotypes illustrate the exaggerated patterns of lung tissue with emphysema, which is underpinned by three different quantitative evaluation methods.

  6. Sounds Exaggerate Visual Shape

    ERIC Educational Resources Information Center

    Sweeny, Timothy D.; Guzman-Martinez, Emmanuel; Ortega, Laura; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    While perceiving speech, people see mouth shapes that are systematically associated with sounds. In particular, a vertically stretched mouth produces a /woo/ sound, whereas a horizontally stretched mouth produces a /wee/ sound. We demonstrate that hearing these speech sounds alters how we see aspect ratio, a basic visual feature that contributes…

  7. Exaggerated Claims for Interactive Stories

    NASA Astrophysics Data System (ADS)

    Thue, David; Bulitko, Vadim; Spetch, Marcia; Webb, Michael

    As advertising becomes more crucial to video games' success, developers risk promoting their products beyond the features that they can actually include. For features of interactive storytelling, the effects of making such exaggerations are not well known, as reports from industry have been anecdotal at best. In this paper, we explore the effects of making exaggerated claims for interactive stories, in the context of the theory of advertising. Results from a human user study show that female players find linear and branching stories to be significantly less enjoyable when they are advertised with exaggerated claims.

  8. Exaggerated trait growth in insects.

    PubMed

    Lavine, Laura; Gotoh, Hiroki; Brent, Colin S; Dworkin, Ian; Emlen, Douglas J

    2015-01-01

    Animal structures occasionally attain extreme proportions, eclipsing in size the surrounding body parts. We review insect examples of exaggerated traits, such as the mandibles of stag beetles (Lucanidae), the claspers of praying mantids (Mantidae), the elongated hindlimbs of grasshoppers (Orthoptera: Caelifera), and the giant heads of soldier ants (Formicidae) and termites (Isoptera). Developmentally, disproportionate growth can arise through trait-specific modifications to the activity of at least four pathways: the sex determination pathway, the appendage patterning pathway, the insulin/IGF signaling pathway, and the juvenile hormone/ecdysteroid pathway. Although most exaggerated traits have not been studied mechanistically, it is already apparent that distinct developmental mechanisms underlie the evolution of the different types of exaggerated traits. We suggest this reflects the nature of selection in each instance, revealing an exciting link between mechanism, form, and function. We use this information to make explicit predictions for the types of regulatory pathways likely to underlie each type of exaggerated trait. PMID:25341090

  9. Exaggerated trait growth in insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Animal structures occasionally attain extreme proportions, eclipsing in size other, surrounding body parts. We review insect examples of exaggerated traits, such as the mandibles of stag beetles, the claspers of praying mantises, the elongated hindlimbs of grasshoppers, and the giant heads of soldie...

  10. Lip Movement Exaggerations During Infant-Directed Speech

    PubMed Central

    Green, Jordan R.; Nip, Ignatius S. B.; Wilson, Erin M.; Mefferd, Antje S.; Yunusova, Yana

    2011-01-01

    Purpose Although a growing body of literature has indentified the positive effects of visual speech on speech and language learning, oral movements of infant-directed speech (IDS) have rarely been studied. This investigation used 3-dimensional motion capture technology to describe how mothers modify their lip movements when talking to their infants. Method Lip movements were recorded from 25 mothers as they spoke to their infants and other adults. Lip shapes were analyzed for differences across speaking conditions. The maximum fundamental frequency, duration, acoustic intensity, and first and second formant frequency of each vowel also were measured. Results Lip movements were significantly larger during IDS than during adult-directed speech, although the exaggerations were vowel specific. All of the vowels produced during IDS were characterized by an elevated vocal pitch and a slowed speaking rate when compared with vowels produced during adult-directed speech. Conclusion The pattern of lip-shape exaggerations did not provide support for the hypothesis that mothers produce exemplar visual models of vowels during IDS. Future work is required to determine whether the observed increases in vertical lip aperture engender visual and acoustic enhancements that facilitate the early learning of speech. PMID:20699342

  11. PINS-3X Operations

    SciTech Connect

    E.H. Seabury

    2013-09-01

    Idaho National Laboratory’s (INL’s) Portable Isotopic Neutron Spectroscopy System (PINS) non-intrusively identifies the chemical fill of munitions and sealed containers. The PINS-3X variant of the system is used to identify explosives and uses a deuterium-tritium (DT) electronic neutron generator (ENG) as the neutron source. Use of the system, including possession and use of the neutron generator and shipment of the system components requires compliance with a number of regulations. This report outlines some of these requirements as well as some of the requirements in using the system outside of INL.

  12. Hyperbilirubinemia exaggerates endotoxin-induced hypothermia

    PubMed Central

    Pakai, Eszter; Garami, Andras; Nucci, Tatiane B; Ivanov, Andrei I; Romanovsky, Andrej A

    2015-01-01

    Systemic inflammation is accompanied by an increased production of reactive oxygen species (ROS) and by either fever or hypothermia (or both). To study aseptic systemic inflammation, it is often induced in rats by the intravenous administration of bacterial lipopolysaccharide (LPS). Knowing that bilirubin is a potent ROS scavenger, we compared responses to LPS between normobilirubinemic Gunn rats (heterozygous, asymptomatic; J/+) and hyperbilirubinemic Gunn rats (homozygous, jaundiced; J/J) to establish whether ROS mediate fever and hypothermia in aseptic systemic inflammation. These two genotypes correspond to undisturbed versus drastically suppressed (by bilirubin) tissue accumulation of ROS, respectively. A low dose of LPS (10 μg/kg) caused a typical triphasic fever in both genotypes, without any intergenotype differences. A high dose of LPS (1,000 μg/kg) caused a complex response consisting of early hypothermia followed by late fever. The hypothermic response was markedly exaggerated, whereas the subsequent fever response was strongly attenuated in J/J rats, as compared to J/+ rats. J/J rats also tended to respond to 1,000 μg/kg with blunted surges in plasma levels of all hepatic enzymes studied (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase), thus suggesting an attenuation of hepatic damage. We propose that the reported exaggeration of LPS-induced hypothermia in J/J rats occurs via direct inhibition of nonshivering thermogenesis by bilirubin and possibly via a direct vasodilatatory action of bilirubin in the skin. This hypothermia-exaggerating effect might be responsible, at least in part, for the observed tendency of J/J rats to be protected from LPS-induced hepatic damage. The attenuation of the fever response to 1,000 μg/kg could be due to either direct actions of bilirubin on thermoeffectors or the ROS-scavenging action of bilirubin. However, the experiments with 10 μg/kg strongly suggest that ROS signaling is

  13. Hyperbilirubinemia exaggerates endotoxin-induced hypothermia.

    PubMed

    Pakai, Eszter; Garami, Andras; Nucci, Tatiane B; Ivanov, Andrei I; Romanovsky, Andrej A

    2015-01-01

    Systemic inflammation is accompanied by an increased production of reactive oxygen species (ROS) and by either fever or hypothermia (or both). To study aseptic systemic inflammation, it is often induced in rats by the intravenous administration of bacterial lipopolysaccharide (LPS). Knowing that bilirubin is a potent ROS scavenger, we compared responses to LPS between normobilirubinemic Gunn rats (heterozygous, asymptomatic; J/+) and hyperbilirubinemic Gunn rats (homozygous, jaundiced; J/J) to establish whether ROS mediate fever and hypothermia in aseptic systemic inflammation. These two genotypes correspond to undisturbed versus drastically suppressed (by bilirubin) tissue accumulation of ROS, respectively. A low dose of LPS (10 μg/kg) caused a typical triphasic fever in both genotypes, without any intergenotype differences. A high dose of LPS (1,000 μg/kg) caused a complex response consisting of early hypothermia followed by late fever. The hypothermic response was markedly exaggerated, whereas the subsequent fever response was strongly attenuated in J/J rats, as compared to J/+ rats. J/J rats also tended to respond to 1,000 μg/kg with blunted surges in plasma levels of all hepatic enzymes studied (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase), thus suggesting an attenuation of hepatic damage. We propose that the reported exaggeration of LPS-induced hypothermia in J/J rats occurs via direct inhibition of nonshivering thermogenesis by bilirubin and possibly via a direct vasodilatatory action of bilirubin in the skin. This hypothermia-exaggerating effect might be responsible, at least in part, for the observed tendency of J/J rats to be protected from LPS-induced hepatic damage. The attenuation of the fever response to 1,000 μg/kg could be due to either direct actions of bilirubin on thermoeffectors or the ROS-scavenging action of bilirubin. However, the experiments with 10 μg/kg strongly suggest that ROS signaling is not

  14. Cancer prevention strategies greatly exaggerate risks

    SciTech Connect

    Ames, B.N. ); Gold, L.S. )

    1991-01-07

    This paper reports on the attempt to prevent cancer by regulating low levels of synthetic chemicals by risk assessment. Testing chemicals for carcinogenicity at near-toxic doses in rodents does not provide enough information to predict the excess numbers of human cancers that might occur at low-dose exposures. In addition, this cancer prevention strategy is enormously costly, is counterproductive because it diverts resources from much more important risks, and, in the case of synthetic pesticides, makes fruits and vegetables more expensive, thus serving to decrease consumption of foods that help prevent cancer. The regulatory process doesn't take into account that: The world of natural chemicals makes up the vast bulk of chemicals humans are exposed to. The toxicology of synthetic and natural toxins is not fundamentally different. About half the natural chemicals tested chronically in rats and mice at the maximum tolerated dose are carcinogens. Testing at the maximum tolerated dose frequently can cause chronic cell killing and consequent cell replacement (a risk factor for cancer that can be limited to high doses), and ignoring this greatly exaggerates risks. An extrapolation from high to low doses should be based on an understanding of the mechanisms of carcinogenesis.

  15. Intermonitor variability of GT3X accelerometer.

    PubMed

    Santos-Lozano, A; Torres-Luque, G; Marín, P J; Ruiz, J R; Lucia, A; Garatachea, N

    2012-12-01

    The main purpose of this study was to assess the inter-monitor reliability of the tri-axial GT3X Actigraph accelerometer over a range of physical activities (PA). This device collects motion data on each of the vertical (Y), horizontal right-left (X), and horizontal front-back (Z) axes and also calculates the vector summed value √X(2)+Y(2)+Z(2) known as 'vector magnitude' (VM). 8 GT3X accelerometers were worn at the same time by the same participant. Accelerometers were placed back-to-front, all facing forward and in sets of 4 securely taped together, attached to a belt and allocating each block above either left or right hip at waist level. Inter-monitor reliability was assessed during 6 conditions: rest, walking (4 and 6 km·h(-1)), running (8 and 10 km·h(-1)) and repeated sit-to-stand (40 times·min(-1)). The intra-class correlation coefficients were high for X, Y and Z axes (i.e., all ≥ 0.925) and for VM (≥ 0.946). In conclusion, we found good inter-instrument reliability of the GT3X accelerometer across all planes, yet our results also suggest that the X and Z axes do not provide further benefits over the 'traditional' Y-axis to assess the movement in typical PA. PMID:22791617

  16. Perceived azimuth direction is exaggerated: Converging evidence from explicit and implicit measures

    PubMed Central

    Li, Zhi; Durgin, Frank H.

    2016-01-01

    Recent observations suggest that perceived visual direction in the sagittal plane (angular direction in elevation, both upward and downward from eye level) is exaggerated. Foley, Ribeiro-Filho, and Da Silva's (2004) study of perceived size of exocentric ground extent implies that perceived angular direction in azimuth may also be exaggerated. In the present study, we directly examined whether perceived azimuth direction is overestimated. In Experiment 1, numeric estimates of azimuth direction (−48° to 48° relative to straight ahead) were obtained. The results showed a linear exaggeration in perceived azimuth direction with a gain of about 1.26. In Experiment 2, a perceptual extent-matching task served as an implicit measure of perceived azimuth direction. Participants matched an egocentric distance in one direction to a frontal extent in nearly the opposite direction. The angular biases implied by the matching data well replicated Foley et al.'s finding and were also fairly consistent with the azimuth bias function found in Experiment 1, although a slight overall shift was observed between the results of the two experiments. Experiment 3, in which half the observers were tilted sideways while making frontal/depth extent comparisons, suggested that the discrepancy between the results of Experiment 1 and 2 can partially be explained by a retinal horizontal vertical illusion affecting distance estimation tasks. Overall the present study provides converging evidence to suggest that the perception of azimuth direction is overestimated. PMID:26756174

  17. THE HANDICAP PROCESS FAVORS EXAGGERATED, RATHER THAN REDUCED, SEXUAL ORNAMENTS

    PubMed Central

    Tazzyman, Samuel J; Iwasa, Yoh; Pomiankowski, Andrew

    2014-01-01

    Why are traits that function as secondary sexual ornaments generally exaggerated in size compared to the naturally selected optimum, and not reduced? Because they deviate from the naturally selected optimum, traits that are reduced in size will handicap their bearer, and could thus provide an honest signal of quality to a potential mate. Thus if secondary sexual ornaments evolve via the handicap process, current theory suggests that reduced ornamentation should be as frequent as exaggerated ornamentation, but this is not the case. To try to explain this discrepancy, we analyze a simple model of the handicap process. Our analysis shows that asymmetries in costs of preference or ornament with regard to exaggeration and reduction cannot fully explain the imbalance. Rather, the bias toward exaggeration can be best explained if either the signaling efficacy or the condition dependence of a trait increases with size. Under these circumstances, evolution always leads to more extreme exaggeration than reduction: although the two should occur just as frequently, exaggerated secondary sexual ornaments are likely to be further removed from the naturally selected optimum than reduced ornaments. PMID:24837599

  18. The evolution of acoustic size exaggeration in terrestrial mammals.

    PubMed

    Charlton, Benjamin D; Reby, David

    2016-01-01

    Recent studies have revealed that some mammals possess adaptations that enable them to produce vocal signals with much lower fundamental frequency (F0) and formant frequency spacing (ΔF) than expected for their size. Although these adaptations are assumed to reflect selection pressures for males to lower frequency components and exaggerate body size in reproductive contexts, this hypothesis has not been tested across a broad range of species. Here we show that male terrestrial mammals produce vocal signals with lower ΔF (but not F0) than expected for their size in mating systems with greater sexual size dimorphism. We also reveal that males produce calls with higher than expected F0 and ΔF in species with increased sperm competition. This investigation confirms that sexual selection favours the use of ΔF as an acoustic size exaggerator and supports the notion of an evolutionary trade-off between pre-copulatory signalling displays and sperm production. PMID:27598835

  19. Feederism: an exaggeration of a normative mate selection preference?

    PubMed

    Terry, Lesley L; Suschinsky, Kelly D; Lalumière, Martin L; Vasey, Paul L

    2012-02-01

    Quinsey and Lalumière (1995) suggested that some, if not most, paraphilias are exaggerated manifestations of more normative and functional mate selection preferences. The present study tested whether Feederism, a fat fetish focused on erotic eating, feeding, and gaining weight, is an exaggeration of a sexual arousal pattern commonly seen in the general population. Thirty participants (15 men and 15 women) recruited from the general population were assessed using penile plethysmography and vaginal photoplethysmography, respectively. None of the participants were self-identified Feeders or Feedees. Participants were shown sexual, neutral, and feeding still images while listening to audio recordings of sexual, neutral, and feeding stories. Participants did not genitally respond to feeding stimuli. However, both men and women subjectively rated feeding stimuli as more sexually arousing than neutral stimuli. We discuss the discordance between physiological and self-reported sexual arousal in the context of sex differences in sexual concordance and implications for future research. PMID:22392517

  20. Exaggerated Exercise Blood Pressure Response and Future Cardiovascular Disease.

    PubMed

    Tzemos, Nikolaos; Lim, Pitt O; Mackenzie, Isla S; MacDonald, Thomas M

    2015-11-01

    Exaggerated blood pressure (BP) response to exercise predicts future hypertension. However, there is considerable lack of understanding regarding the mechanism of how this abnormal response is generated, and how it relates to the future establishment of cardiovascular disease. The authors studied 82 healthy male volunteers without cardiovascular risk factors. The participants were categorized into two age-matched groups depending on their exercise systolic BP (ExSBP) rise after 3 minutes of exercise using a submaximal step test: exaggerated ExSBP group (hyper-responders [peak SBP ≥ 180 mm Hg]) and low ExSBP responder group (hypo-responders [peak SBP <180 mm Hg]). Forearm venous occlusion plethysmography and intra-arterial infusions of acetylcholine (ACh), N(G)-monomethyl-L-arginine (L-NMMA), sodium nitroprusside (SNP), and norepinephrine (NE) were used to assess vascular reactivity. Proximal aortic compliance was assessed with ultrasound, and neurohormonal blood sampling was performed at rest and during peak exercise. The hyper-responder group exhibited a significantly lower increase in forearm blood flow (FBF) with ACh compared with the hypo-responder group (ΔFBF 215% [14] vs 332.3% [28], mean [standard error of the mean]; P<.001), as well as decreased proximal aortic compliance. The vasoconstrictive response to L-NMMA was significantly impaired in the hyper-responder group in comparison to the hypo-responder group (ΔFBF -40.2% [1.6] vs -50.2% [2.6]; P<.05). In contrast, the vascular response to SNP and NE were comparable in both groups. Peak exercise plasma angiotensin II levels were significantly higher in the hyper-responder group (31 [1] vs 23 [2] pg/mL, P=.01). An exaggerated BP response to exercise is related to endothelial dysfunction, decreased proximal aortic compliance, and increased exercise-related neurohormonal activation, the constellation of which may explain future cardiovascular disease. PMID:26235814

  1. Regional Variation Exaggerates Ecological Divergence in Niche Models

    PubMed Central

    Godsoe, William

    2010-01-01

    Traditionally, the goal of systematics has been to produce classifications that are both strongly supported and biologically meaningful. In recent years several authors have advocated complementing phylogenetic analyses with measures of another form of evolutionary change, ecological divergence. These analyses frequently rely on ecological niche models to determine if species have comparable environmental requirements, but it has heretofore been difficult to test the accuracy of these inferences. To address this problem, I simulate the geographic distributions of allopatric species with identical environmental requirements. I then test whether existing analyses based on geographic distributions will correctly infer that the 2 species' requirements are identical. This work demonstrates that when taxa disperse to different environments, many analyses can erroneously infer changes in environmental requirements, but the severity of the problem depends on the method used. As this could exaggerate the number of ecologically distinct taxa in a clade, I suggest diagnostics to mitigate this problem. PMID:20525637

  2. The association between exaggeration in health related science news and academic press releases: retrospective observational study

    PubMed Central

    Vivian-Griffiths, Solveiga; Boivin, Jacky; Williams, Andy; Venetis, Christos A; Davies, Aimée; Ogden, Jack; Whelan, Leanne; Hughes, Bethan; Dalton, Bethan; Boy, Fred

    2014-01-01

    Objective To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader’s health related behaviour. Design Retrospective quantitative content analysis. Setting Journal articles, press releases, and related news, with accompanying simulations. Sample Press releases (n=462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n=668). Main outcome measures Advice to readers to change behaviour, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers. Results 40% (95% confidence interval 33% to 46%) of the press releases contained exaggerated advice, 33% (26% to 40%) contained exaggerated causal claims, and 36% (28% to 46%) contained exaggerated inference to humans from animal research. When press releases contained such exaggeration, 58% (95% confidence interval 48% to 68%), 81% (70% to 93%), and 86% (77% to 95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10% to 24%), 18% (9% to 27%), and 10% (0% to 19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval 3.5 to 12), 20 (7.6 to 51), and 56 (15 to 211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news. Conclusions Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news. PMID:25498121

  3. Neural Coding of Formant-Exaggerated Speech in the Infant Brain

    ERIC Educational Resources Information Center

    Zhang, Yang; Koerner, Tess; Miller, Sharon; Grice-Patil, Zach; Svec, Adam; Akbari, David; Tusler, Liz; Carney, Edward

    2011-01-01

    Speech scientists have long proposed that formant exaggeration in infant-directed speech plays an important role in language acquisition. This event-related potential (ERP) study investigated neural coding of formant-exaggerated speech in 6-12-month-old infants. Two synthetic /i/ vowels were presented in alternating blocks to test the effects of…

  4. Arabidopsis thaliana sku mutant seedlings show exaggerated surface-dependent alteration in root growth vector

    NASA Technical Reports Server (NTRS)

    Rutherford, R.; Masson, P. H.

    1996-01-01

    Roots of wild-type Arabidopsis thaliana seedlings in the Wassilewskija (WS) and Landsberg erecta (Ler) ecotypes often grow aslant on vertical agar surfaces. Slanted root growth always occurs to the right of the gravity vector when the root is viewed through the agar surface, and is not observed in the Columbia ecotype. Right-slanted root growth is surface-dependent and does not result directly from directional environmental stimuli or gradients in the plane of skewing. We have isolated two partially dominant mutations in WS (sku1 and sku2) that show an exaggerated right-slanting root-growth phenotype on agar surfaces. The right-slanting root-growth phenotype of wild-type and mutant roots is not the result of diagravitropism or of an alteration in root gravitropism. It is accompanied by a left-handed rotation of the root about its axis within the elongation zone, the rate of which positively correlates with the degree of right-slanted curvature. Our data suggest that the right-slanting root growth phenotype results from an endogenous structural asymmetry that expresses itself by a directional root-tip rotation.

  5. Arabidopsis thaliana sku mutant seedlings show exaggerated surface-dependent alteration in root growth vector.

    PubMed

    Rutherford, R; Masson, P H

    1996-08-01

    Roots of wild-type Arabidopsis thaliana seedlings in the Wassilewskija (WS) and Landsberg erecta (Ler) ecotypes often grow aslant on vertical agar surfaces. Slanted root growth always occurs to the right of the gravity vector when the root is viewed through the agar surface, and is not observed in the Columbia ecotype. Right-slanted root growth is surface-dependent and does not result directly from directional environmental stimuli or gradients in the plane of skewing. We have isolated two partially dominant mutations in WS (sku1 and sku2) that show an exaggerated right-slanting root-growth phenotype on agar surfaces. The right-slanting root-growth phenotype of wild-type and mutant roots is not the result of diagravitropism or of an alteration in root gravitropism. It is accompanied by a left-handed rotation of the root about its axis within the elongation zone, the rate of which positively correlates with the degree of right-slanted curvature. Our data suggest that the right-slanting root growth phenotype results from an endogenous structural asymmetry that expresses itself by a directional root-tip rotation. PMID:8756492

  6. A 3 x 2 Achievement Goal Model

    ERIC Educational Resources Information Center

    Elliot, Andrew J.; Murayama, Kou; Pekrun, Reinhard

    2011-01-01

    In the present research, a 3 x 2 model of achievement goals is proposed and tested. The model is rooted in the definition and valence components of competence, and encompasses 6 goal constructs: task-approach, task-avoidance, self-approach, self-avoidance, other-approach, and other-avoidance. The results from 2 studies provided strong support for…

  7. Evidence for an Exaggerated Postprandial Lipemia in Chronic Paraplegia

    PubMed Central

    Nash, Mark S; deGroot, Joris; Martinez-Arizala, Alberto; Mendez, Armando J

    2005-01-01

    Background/Objective: Excessive delay in triglyceride (TG) metabolism after ingestion of dietary fat represents a significant cardiovascular disease (CVD) risk. The objective of this study was to compare the postprandial lipemic responses of individuals with paraplegia with those of healthy nondisabled individuals. Methods: The ability of 3 recreationally active individuals with paraplegia having normal fasting TG (mean = 103 mg/dL) to metabolize TG after ingestion of a high-fat test meal was compared with a previously published cohort of 21 recreationally active individuals without paraplegia (TG mean = 86 mg/dL) who underwent identical testing. The subjects with paraplegia had venous blood taken under fasting conditions, and then ingested a milkshake containing premium ice cream blended with heavy whipping cream (~92% of calories from fat). Additional blood samples were obtained at 2, 4, and 6 hours after ingestion. The area under the curve (AUC) for TG clearance for both subject groups was measured with an area planimeter. Results: TG uptake for both groups was almost identical for the first 2 hours after ingestion. At 4 and 6 hours after ingestion, the TG levels were 50 and 35 mg/dL higher, respectively, in subjects with paraplegia than in nondisabled subjects. When corrected for small baseline differences in TG concentrations (16 mg/dL), the AUC was 46.5% greater for the group with paraplegia than in the nondisabled group. A near mirror association across time was observed between postprandial serum high-density lipoprotein cholesterol (HDL-C) and TG levels in subjects with paraplegia. Conclusion: This case series finds an exaggerated postprandial lipemia (PPL) in persons with paraplegia with normal fasting TGs. This finding is the first evidence, in a small population, of an unreported potential CVD risk in persons with paraplegia. PMID:16396382

  8. Endocrine Control of Exaggerated Trait Growth in Rhinoceros Beetles.

    PubMed

    Zinna, R; Gotoh, H; Brent, C S; Dolezal, A; Kraus, A; Niimi, T; Emlen, D; Lavine, L C

    2016-08-01

    Juvenile hormone (JH) is a key insect growth regulator frequently involved in modulating phenotypically plastic traits such as caste determination in eusocial species, wing polymorphisms in aphids, and mandible size in stag beetles. The jaw morphology of stag beetles is sexually-dimorphic and condition-dependent; males have larger jaws than females and those developing under optimum conditions are larger in overall body size and have disproportionately larger jaws than males raised under poor conditions. We have previously shown that large males have higher JH titers than small males during development, and ectopic application of fenoxycarb (JH analog) to small males can induce mandibular growth similar to that of larger males. What remains unknown is whether JH regulates condition-dependent trait growth in other insects with extreme sexually selected structures. In this study, we tested the hypothesis that JH mediates the condition-dependent expression of the elaborate horns of the Asian rhinoceros beetle, Trypoxylus dichotomus. The sexually dimorphic head horn of this beetle is sensitive to nutritional state during larval development. Like stag beetles, male rhinoceros beetles receiving copious food produce disproportionately large horns for their body size compared with males under restricted diets. We show that JH titers are correlated with body size during the late feeding and early prepupal periods, but this correlation disappears by the late prepupal period, the period of maximum horn growth. While ectopic application of fenoxycarb during the third larval instar significantly delayed pupation, it had no effect on adult horn size relative to body size. Fenoxycarb application to late prepupae also had at most a marginal effect on relative horn size. We discuss our results in context of other endocrine signals of condition-dependent trait exaggeration and suggest that different beetle lineages may have co-opted different physiological signaling mechanisms to

  9. Medical Issues Associated with Anabolic Steroid Use: Are They Exaggerated?

    PubMed Central

    Hoffman, Jay R.; Ratamess, Nicholas A.

    2006-01-01

    For the past 50 years anabolic steroids have been at the forefront of the controversy surrounding performance enhancing drugs. For almost half of this time no attempt was made by sports governing bodies to control its use, and only recently have all of the major sports governing bodies in North America agreed to ban from competition and punish athletes who test positive for anabolic steroids. These punitive measures were developed with the primary concern for promotion of fair play and eliminating potential health risks associated with androgenic-anabolic steroids. Yet, controversy exists whether these testing programs deter anabolic steroid use. Although the scope of this paper does not focus on the effectiveness of testing, or the issue of fair play, it is of interest to understand why many athletes underestimate the health risks associated from these drugs. What creates further curiosity is the seemingly well-publicized health hazards that the medical community has depicted concerning anabolic steroidabuse. Is there something that the athletes know, or are they simply naïve regarding the dangers? The focus of this review is to provide a brief history of anabolic steroid use in North America, the prevalence of its use in both athletic and recreational populations and its efficacy. Primary discussion will focus on health issues associated with anabolic steroid use with an examination of the contrasting views held between the medical community and the athletes that are using these ergogenic drugs. Existing data suggest that in certain circumstances the medical risk associated with anabolic steroid use may have been somewhat exaggerated, possibly to dissuade use in athletes. Key Points For many years the scientific and medical communities depicted a lack of efficacy and serious adverse effects from anabolic steroid use. Clinical case studies continue to link anabolic steroid administration with myocardial infarct, suicide, and cancer, evidence to support a cause

  10. Exaggerating psychopathology produces residual effects that are resistant to corrective feedback: an experimental demonstration.

    PubMed

    Merckelbach, Harald; Dandachi-FitzGerald, Brechje; van Mulken, Peter; Ponds, Rudolf; Niesten, Elly

    2015-01-01

    We explored the effects of feedback on symptom reporting. Two experimental groups (n=15 each) were given a scenario with the option to exaggerate symptoms. Compared with a control condition (n=15), both groups scored significantly higher on the Structured Inventory of Malingered Symptomatology. Next, one group was confronted in a sympathetic way about their symptom validity test failure, whereas the other group was confronted in a neutral manner. Both groups subsequently completed the Brief Symptom Inventory (BSI). BSI scores of both feedback groups remained significantly higher than those of control participants. Participants who had been provided with sympathetic feedback or neutral feedback did not differ in their BSI scores. Even participants who indicated during the exit interview that they had given up symptom exaggeration attained significantly higher BSI scores than those of controls, indicating that exaggeration has residual effects that are resistant to corrective feedback. We discuss cognitive dissonance as a model for understanding the residual effects of symptom exaggeration. PMID:25529587

  11. Measures of Symptom Exaggeration for Mental Health Disorders: A Systematic Review.

    PubMed

    Ebrahim, Shanil; Bance, Sheena; Mulla, Sohail M; Montoya, Luis; Malachowski, Cindy; Kamal El Din, Mostafa; Busse, Jason W

    2015-01-01

    Introduction .- Measures that help detect exaggeration of symptoms can be valuable for informing more accurate diagnoses and aid in treatment and case management. We completed a systematic review to identify measures that assess symptom exaggeration in mental health disorders. Methods .- Eligible studies assessed exaggeration of symptoms with a psychometrically validated measure in patients presenting with a mental health disorder. We searched MEDLINE and PsycINFO from inception to June 2013 for relevant studies. To determine study eligibility, reviewers screened title and abstracts of identified citations, and reviewed full texts of all potentially eligible citations. Data extractors completed data abstraction of eligible studies. Results .- Of 8435 unique citations, 105 studies consisting of 112 cohorts were eligible, and we identified 36 unique, validated measures assessing exaggeration of symptoms. The most frequently used measures were symptom validity indicators embedded in the Minnesota Multiphasic Personality Inventory (MMPI-2) (n=48, 46%), the Structured Interview of Reported Symptoms (SIRS) (n=12, 11%), and the Personality Assessment Inventory (PAI) (n=11, 10%). Most studies (n=96; 91%) failed to test reliability of their measure of symptom exaggeration. The symptom validity indicators in the MMPI/MMPI-2 and the SIRS both showed moderate to high internal consistency, range 0.47 to 0.85 and 0.48 to 0.95, respectively. Conclusions .- Multiple measures assessing symptom exaggeration have been used in patients with mental health disorders. The symptom validity indicators of the MMPI/MMPI-2 are the most widely used measures to assess symptom exaggeration. Assessment and reporting of reliability is poor across studies; we require further assessment of psychometric properties for existing measures of symptom exaggeration. PMID:27584846

  12. Phonological theory informs the analysis of intonational exaggeration in Japanese infant-directed speech.

    PubMed

    Igarashi, Yosuke; Nishikawa, Ken'ya; Tanaka, Kuniyoshi; Mazuka, Reiko

    2013-08-01

    To date, the intonation of infant-directed speech (IDS) has been analyzed without reference to its phonological structure. Intonational phonology should, however, inform IDS research, discovering important properties that have previously been overlooked. The present study investigated "intonational exaggeration" in Japanese IDS using the intonational phonological framework. Although intonational exaggeration, which is most often measured by pitch-range expansion, is one of the best-known characteristics of IDS, Japanese has been reported to lack such exaggeration. The present results demonstrated that intonational exaggeration is in fact present and observed most notably at the location of boundary pitch movements, and that the effects of lexical pitch accents in the remainder of the utterances superficially mask the exaggeration. These results not only reveal dynamic aspects of Japanese IDS, but also in turn contribute to the theory of intonational phonology, suggesting that paralinguistic pitch-range modifications most clearly emerge where the intonation system of a language allows maximum flexibility in varying intonational contours. PMID:23927126

  13. Exaggerated male genitalia intensify interspecific reproductive interference by damaging heterospecific female genitalia.

    PubMed

    Kyogoku, D; Sota, T

    2015-06-01

    Male-male competition over fertilization can select for harmful male genital structures that reduce the fitness of their mates, if the structures increase the male's fertilization success. During secondary contact between two allopatrically formed, closely related species, harmful male genitalia may also reduce the fitness of heterospecific females given interspecific copulation. We performed a laboratory experiment to determine whether the extent of genital spine exaggeration in Callosobruchus chinensis males affects the fitness of C. maculatus females by injuring their reproductive organs. We found that males with more exaggerated genital spines were more likely to injure the females via interspecific copulation and that the genital injury translated into fecundity loss. Thus, as predicted, reproductive interference by C. chinensis males on C. maculatus females is mediated by exaggeration of the genital spine, which is the evolutionary consequence of intraspecific male-male competition. Harmful male traits, such as genital spines, might generally affect the extent of interaction between closely related species. PMID:25882439

  14. Self-trained perception need not be veridical: striking can exaggerate judgment by wielding and can transfer exaggeration to new stimuli.

    PubMed

    Kelty-Stephen, Damian G; Eddy, Charles L

    2015-08-01

    Previous literature on self-training dynamic touch suggested that haptic judgments of length following wielding might benefit from new information through participants' own striking actions with the same stimuli. However, the conclusion that this self-training tended towards a veridical outcome of zero discrepancy between actual length and judged length was premature. In this replication, we allowed adult participants (n = 15) to strike on each trial and changed the stimuli in mid-experiment to determine whether striking helped participants build more accurate perceptions of length transferrable from one stimulus scale to another. We predicted that, if self-training led to better length judgments, the repeated striking would improve judgments and that, in turn, judgments following the switch of stimuli would show a good transfer of what participants had learned. On the other hand, self-training may simply exaggerate inertial properties of stimuli and may be sensitive to sudden changes in the scale of stimuli. Mixed-effect modeling of discrepancies show that striking only accentuated effects of inertial moment, producing exaggerated length judgments. Correlation between perceived length and actual length increased only for participants who experienced a switch in individual stimuli but not stimulus scale. We discuss the implications of these findings for any theoretical relationship between self-organization and veridicality. PMID:26082152

  15. The moral stereotypes of liberals and conservatives: exaggeration of differences across the political spectrum.

    PubMed

    Graham, Jesse; Nosek, Brian A; Haidt, Jonathan

    2012-01-01

    We investigated the moral stereotypes political liberals and conservatives have of themselves and each other. In reality, liberals endorse the individual-focused moral concerns of compassion and fairness more than conservatives do, and conservatives endorse the group-focused moral concerns of ingroup loyalty, respect for authorities and traditions, and physical/spiritual purity more than liberals do. 2,212 U.S. participants filled out the Moral Foundations Questionnaire with their own answers, or as a typical liberal or conservative would answer. Across the political spectrum, moral stereotypes about "typical" liberals and conservatives correctly reflected the direction of actual differences in foundation endorsement but exaggerated the magnitude of these differences. Contrary to common theories of stereotyping, the moral stereotypes were not simple underestimations of the political outgroup's morality. Both liberals and conservatives exaggerated the ideological extremity of moral concerns for the ingroup as well as the outgroup. Liberals were least accurate about both groups. PMID:23251357

  16. The Moral Stereotypes of Liberals and Conservatives: Exaggeration of Differences across the Political Spectrum

    PubMed Central

    Graham, Jesse; Nosek, Brian A.; Haidt, Jonathan

    2012-01-01

    We investigated the moral stereotypes political liberals and conservatives have of themselves and each other. In reality, liberals endorse the individual-focused moral concerns of compassion and fairness more than conservatives do, and conservatives endorse the group-focused moral concerns of ingroup loyalty, respect for authorities and traditions, and physical/spiritual purity more than liberals do. 2,212 U.S. participants filled out the Moral Foundations Questionnaire with their own answers, or as a typical liberal or conservative would answer. Across the political spectrum, moral stereotypes about “typical” liberals and conservatives correctly reflected the direction of actual differences in foundation endorsement but exaggerated the magnitude of these differences. Contrary to common theories of stereotyping, the moral stereotypes were not simple underestimations of the political outgroup's morality. Both liberals and conservatives exaggerated the ideological extremity of moral concerns for the ingroup as well as the outgroup. Liberals were least accurate about both groups. PMID:23251357

  17. Rapid glutamate release in the mediobasal hypothalamus accompanies feeding and is exaggerated by an obesogenic food

    PubMed Central

    Guyenet, Stephan J.; Matsen, Miles E.; Morton, Gregory J.; Kaiyala, Karl J.; Schwartz, Michael W.

    2013-01-01

    The mediobasal hypothalamus (MBH) plays a central role in the regulation of food intake and energy balance. Although the excitatory neurotransmitter glutamate is implicated in energy balance regulation by the MBH, the hypothesis that feeding elicits local glutamate release remains untested. To test this hypothesis, we employed a glutamate biosensor that measures glutamate concentrations at 1-s intervals in conscious, freely behaving rats. Results indicate that feeding is associated with an increase of MBH glutamate concentration that occurs within 1–2 s of oral contact with a food pellet, and the glutamate response to a palatable high-fat pellet is greatly exaggerated relative to chow. In contrast, glutamate responses were not observed during water ingestion or other observed behaviors. These findings indicate that feeding is associated with rapid release of glutamate in the MBH, that this release is exaggerated with an obesogenic food, and that this response is likely stimulated by orosensory factors. PMID:24199157

  18. Clinically relevant exaggerated pharmacodynamic response to dual antiplatelet therapy detected by Thromboelastogram® Platelet Mapping™

    PubMed Central

    Hiller, Kenneth N.

    2016-01-01

    Dual antiplatelet therapy (DAPT) is the standard of care for primary and secondary prevention strategies in patients with coronary artery disease after stenting. Current guidelines recommend that DAPT be continued for 12 months in patients after receiving drug eluting stents. Approximately 5% of these patients will present within this 12-month period for noncardiac surgery. This case report describes a clinically relevant exaggerated pharmacodynamic response to DAPT detected by preoperative assessment of platelet function. Based on the clinical history and physical exam and subsequent lab results, a general anesthetic was performed rather than a spinal anesthetic and the surgical procedure was changed. An exaggerated pharmacodynamic response to DAPT poses its own set of risks (unexpected uncontrolled bleeding, epidural hematoma following neuraxial block placement) that point-of-care aggregation testing may decrease or mitigate by altering clinical decision making. If the clinical history and physical exam reveal possible platelet dysfunction in patients receiving DAPT, preoperative platelet function testing should be considered. PMID:27006555

  19. The Earliest Case of Extreme Sexual Display with Exaggerated Male Organs by Two Middle Jurassic Mecopterans

    PubMed Central

    Wang, Qi; Shih, Chungkun; Ren, Dong

    2013-01-01

    Background Many extant male animals exhibit exaggerated body parts for display, defense or offence in sexual selection, such as male birds of paradise showing off colorful and elegant feathers and male moose and reindeers bearing large structured antlers. For insects, male rhinoceros and stag beetles have huge horn-like structure for fighting and competition and some male Leptopanorpa scorpionflies have very long abdominal terminal segments for sexual display and competition. Fossil records of insects having exaggerated body parts for sexual display are fairly rare. One example is two male holcorpids with elongate abdominal segments from sixth (A6) to eighth (A8) and enlarged male genitalia from Eocene, suggesting evolution of these characters occurred fairly late. Principal Findings We document two mecopterans with exaggerated male body parts from the late Middle Jurassic Jiulongshan Formation in northeastern China. Both have extremely extended abdominal segments from A6 to A8 and enlarged genitalia, which might have been used for sexual display and, to less extent, for fighting with other males in the competition for mates. Although Fortiholcorpa paradoxa gen. et sp. nov. and Miriholcorpa forcipata gen. et sp. nov. seem to have affinities with Holcorpidae, we deem both as Family Incertae sedis mainly due to significant differences in branching pattern of Media (M) veins and relative length of A8 for F. paradoxa, and indiscernible preservation of 5-branched M veins in hind wing for M. forcipata. Conclusions/Significance These two new taxa have extended the records of exaggerated male body parts of mecopterans for sexual display and/or selection from the Early Eocene to the late Middle Jurassic. The similar character present in some Leptopanorpa of Panorpidae suggests that the sexual display and/or sexual selection due to extremely elongated male abdominal and sexual organs outweigh the negative impact of bulky body and poor mobility in the evolutionary process

  20. Exaggerated trait allometry, compensation and trade-offs in the New Zealand giraffe weevil (Lasiorhynchus barbicornis).

    PubMed

    Painting, Christina J; Holwell, Gregory I

    2013-01-01

    Sexual selection has driven the evolution of exaggerated traits among diverse animal taxa. The production of exaggerated traits can come at a cost to other traits through trade-offs when resources allocated to trait development are limited. Alternatively some traits can be selected for in parallel to support or compensate for the cost of bearing the exaggerated trait. Male giraffe weevils (Lasiorhynchus barbicornis) display an extremely elongated rostrum used as a weapon during contests for mates. Here we characterise the scaling relationship between rostrum and body size and show that males have a steep positive allometry, but that the slope is non-linear due to a relative reduction in rostrum length for the largest males, suggesting a limitation in resource allocation or a diminishing requirement for large males to invest increasingly into larger rostra. We also measured testes, wings, antennae, fore- and hind-tibia size and found no evidence of a trade-off between these traits and rostrum length when comparing phenotypic correlations. However, the relative length of wings, antennae, fore- and hind-tibia all increased with relative rostrum length suggesting these traits may be under correlational selection. Increased investment in wing and leg length is therefore likely to compensate for the costs of flying with, and wielding the exaggerated rostrum of larger male giraffe weevils. These results provide a first step in identifying the potential for trait compensation and trades-offs, but are phenotypic correlations only and should be interpreted with care in the absence of breeding experiments. PMID:24312425

  1. An exaggerated response of intra-oral pyogenic granuloma during puberty.

    PubMed

    Papageorge, M B; Doku, H C

    1992-01-01

    Intra-oral pyogenic granulomas have been associated with pregnancy. The exaggerated response of these tumors has been related to the hormonal changes occurring during this period. A change in the hormonal balance also occurs during puberty. In this paper, we present two young patients with large pyogenic granulomas and suggest that the hormonal changes play a primary role in the pathogenesis of this tumor. PMID:1525077

  2. Multiple exaggerated weapon morphs: a novel form of male polymorphism in harvestmen

    PubMed Central

    Painting, Christina J.; Probert, Anna F.; Townsend, Daniel J.; Holwell, Gregory I.

    2015-01-01

    Alternative reproductive tactics in animals are commonly associated with distinct male phenotypes resulting in polymorphism of sexually selected weapons such as horns and spines. Typically, morphs are divided between small (unarmed) and large (armed) males according to one or more developmental thresholds in association with body size. Here, we describe remarkable weapon trimorphism within a single species, where two exaggerated weapon morphs and a third morph with reduced weaponry are present. Male Pantopsalis cheliferoides harvestmen display exaggerated chelicerae (jaws) which are highly variable in length among individuals. Across the same body size spectrum, however, some males belong to a distinct second exaggerated morph which possesses short, broad chelicerae. Multiple weapon morphs in a single species is a previously unknown phenomenon and our findings have significant implications for understanding weapon diversity and maintenance of polymorphism. Specifically, this species will be a valuable model for testing how weapons diverge by being able to test directly for the circumstances under which a certain weapon type is favoured and how weapon shape relates to performance. PMID:26542456

  3. Heightened Functional Neural Activation to Psychological Stress Covaries With Exaggerated Blood Pressure Reactivity

    PubMed Central

    Gianaros, Peter J.; Jennings, J. Richard; Sheu, Lei K.; Derbyshire, Stuart W.G.; Matthews, Karen A.

    2016-01-01

    Individuals who show exaggerated blood pressure reactions to psychological stressors are at increased risk for hypertension, atherosclerosis, and stroke. We tested whether individuals who show exaggerated stressor-induced blood pressure reactivity also show heightened stressor-induced neural activation in brain areas involved in controlling the cardiovascular system. In a functional MRI study, 46 postmenopausal women (mean age: 68.04; SD: 1.35 years) performed a standardized Stroop color-word interference task that served as a stressor to increase blood pressure. Across individuals, a larger task-induced rise in blood pressure covaried with heightened and correlated patterns of activation in brain areas implicated previously in stress-related cardiovascular control: the perigenual and posterior cingulate cortex, bilateral prefrontal cortex, anterior insula, and cerebellum. Entered as a set in hierarchical regression analyses, activation values in these brain areas uniquely predicted the magnitude of task-induced changes in systolic (ΔR2=0.54; P<0.001) and diastolic (ΔR2=0.27; P<0.05) blood pressure after statistical control for task accuracy and subjective reports of task stress. Heightened stressor-induced activation of cingulate, prefrontal, insular, and cerebellar brain areas may represent a functional neural phenotype that characterizes individuals who are prone to show exaggerated cardiovascular reactivity. PMID:17101844

  4. Multiple exaggerated weapon morphs: a novel form of male polymorphism in harvestmen.

    PubMed

    Painting, Christina J; Probert, Anna F; Townsend, Daniel J; Holwell, Gregory I

    2015-01-01

    Alternative reproductive tactics in animals are commonly associated with distinct male phenotypes resulting in polymorphism of sexually selected weapons such as horns and spines. Typically, morphs are divided between small (unarmed) and large (armed) males according to one or more developmental thresholds in association with body size. Here, we describe remarkable weapon trimorphism within a single species, where two exaggerated weapon morphs and a third morph with reduced weaponry are present. Male Pantopsalis cheliferoides harvestmen display exaggerated chelicerae (jaws) which are highly variable in length among individuals. Across the same body size spectrum, however, some males belong to a distinct second exaggerated morph which possesses short, broad chelicerae. Multiple weapon morphs in a single species is a previously unknown phenomenon and our findings have significant implications for understanding weapon diversity and maintenance of polymorphism. Specifically, this species will be a valuable model for testing how weapons diverge by being able to test directly for the circumstances under which a certain weapon type is favoured and how weapon shape relates to performance. PMID:26542456

  5. Paternal care and the evolution of exaggerated sexual swellings in primates

    PubMed Central

    Fitzpatrick, Courtney L.

    2012-01-01

    The exaggerated sexual swellings exhibited by females of some primate species have been of interest to evolutionary biologists since the time of Darwin. We summarize existing hypotheses for their function and evolution and categorize these hypotheses within the context of 3 types of variation in sexual swelling size: 1) variation within a single sexual cycle, 2) variation between the sexual cycles of a single female, and 3) differences between females. We then propose the Paternal Care Hypothesis for the function of sexual swellings, which posits that exaggerated sexual swellings function to elicit the right quantity and quality of male care for a female's infant. As others have noted, swellings may allow females to engender paternity confusion, or they may allow females to confer relative paternal certainty on one male. Key to our hypothesis is that both of these scenarios create an incentive for one or more males to provide care. This hypothesis builds on previous hypotheses but differs from them by highlighting the elicitation of paternal care as a key function of swellings. Our hypothesis predicts that true paternal care (in which males accurately differentiate and provide assistance to their own offspring) will be most common in species in which exaggerated swellings accurately signal the probability of conception, and males can monopolize females during the window of highest conception probability. Our hypothesis also predicts that females will experience selection to behave in ways that either augment paternity confusion or enhance paternal certainty depending on their social and demographic contexts. PMID:24771988

  6. THE VERTICAL

    NASA Technical Reports Server (NTRS)

    Albert, Stephen L.; Spencer, Jeffrey B.

    1994-01-01

    'THE VERTICAL' computer keyboard is designed to address critical factors which contribute to Repetitive Motion Injuries (RMI) (including Carpal Tunnel Syndrome) in association with computer keyboard usage. This keyboard splits the standard QWERTY design into two halves and positions each half 90 degrees from the desk. In order to access a computer correctly. 'THE VERTICAL' requires users to position their bodies in optimal alignment with the keyboard. The orthopaedically neutral forearm position (with hands palms-in and thumbs-up) reduces nerve compression in the forearm. The vertically arranged keypad halves ameliorate onset occurrence of keyboard-associated RMI. By utilizing visually-reference mirrored mylar surfaces adjustable to the user's eye, the user is able to readily reference any key indicia (reversed) just as they would on a conventional keyboard. Transverse adjustability substantially reduces cumulative musculoskeletal discomfort in the shoulders. 'THE VERTICAL' eliminates the need for an exterior mouse by offering a convenient finger-accessible curser control while the hands remain in the vertically neutral position. The potential commercial application for 'THE VERTICAL' is enormous since the product can effect every person who uses a computer anywhere in the world. Employers and their insurance carriers are spending hundreds of millions of dollars per year as a result of RMI. This keyboard will reduce the risk.

  7. Translation equations to compare ActiGraph GT3X and Actical accelerometers activity counts

    PubMed Central

    2012-01-01

    Background This study aimed to develop a translation equation to enable comparison between Actical and ActiGraph GT3X accelerometer counts recorded minute by minute. Methods Five males and five females of variable height, weight, body mass index and age participated in this investigation. Participants simultaneously wore an Actical and an ActiGraph accelerometer for two days. Conversion algorithms and R2 were calculated day by day for each subject between the omnidirectional Actical and three different ActiGraph (three-dimensional) outputs: 1) vertical direction, 2) combined vector, and 3) a custom vector. Three conversion algorithms suitable for minute/minute conversions were then calculated from the full data set. Results The vertical ActiGraph activity counts demonstrated the closest relationship with the Actical, with consistent moderate to strong conversions using the algorithm: y = 0.905x, in the day by day data (R2 range: 0.514 to 0.989 and average: 0.822) and full data set (R2 = 0.865). Conclusions The Actical is most sensitive to accelerations in the vertical direction, and does not closely correlate with three-dimensional ActiGraph output. Minute by minute conversions between the Actical and ActiGraph vertical component can be confidently performed between data sets and might allow further synthesis of information between studies. PMID:22520344

  8. Exaggerated object affordance and absent automatic inhibition in alien hand syndrome

    PubMed Central

    McBride, Jennifer; Sumner, Petroc; Jackson, Stephen R.; Bajaj, Nin; Husain, Masud

    2013-01-01

    Patients with alien hand syndrome (AHS) experience making apparently deliberate and purposeful movements with their hand against their will. However, the mechanisms contributing to these involuntary actions remain poorly understood. Here, we describe two experimental investigations in a patient with corticobasal syndrome (CBS) with alien hand behaviour in her right hand. First, we show that responses with the alien hand are made significantly more quickly to images of objects which afford an action with that hand compared to objects which afford an action with the unaffected hand. This finding suggests that involuntary grasping behaviours in AHS might be due to exaggerated, automatic motor activation evoked by objects which afford actions with that limb. Second, using a backwards masked priming task, we found normal automatic inhibition of primed responses in the patient's unaffected hand, but importantly there was no evidence of such suppression in the alien limb. Taken together, these findings suggest that grasping behaviours in AHS may result from exaggerated object affordance effects, which might potentially arise from disrupted inhibition of automatically evoked responses. PMID:23433243

  9. Clinical categories of exaggerated skin reactions to mosquito bites and their pathophysiology.

    PubMed

    Tatsuno, Kazuki; Fujiyama, Toshiharu; Matsuoka, Hiroyuki; Shimauchi, Takatoshi; Ito, Taisuke; Tokura, Yoshiki

    2016-06-01

    Mosquito bites are skin irritating reactions, which usually resolve spontaneously without intensive medical care. However, in certain situations, mosquito bites may form a more vicious reaction, sometimes accompanying fever and systemic symptoms. In such cases, the presence of rare hematological disorders, abnormalities in eosinophils and/or association with Epstein-Barr virus (EBV) may underlie. Importantly, hypersensitivity to mosquito bites (HMB), which is characterized by necrotic skin reactions to mosquito bites with various systemic symptoms, is often observed in association with EBV infection and natural killer (NK) cell lymphoproliferative disorder. Exaggerated skin reaction to mosquito bites is also seen in Wells' syndrome. While strong Th2-skewing immune dysregulation is apparent in the patients, they also show robust CD4(+) T cell proliferation in response to mosquito salivary gland extracts, indicating close association between Wells' syndrome and mosquito bites. Similar skin reaction to mosquito bites is also noticed in certain types of B cell neoplasm, although the role of B cells in this peculiar reaction to mosquito bites is yet to be elucidated. In this review, we will discuss the current knowledge of exaggerated reaction toward mosquito bites seen in conjunction with these unique hematological disorders, and examine the scientific studies and observations reported in previous literatures to organize our current understanding of the pathogenesis of this distinct disorder. PMID:27177994

  10. Exaggerated displays do not improve mounting success in male seaweed flies Fucellia tergina (Diptera: Anthomyiidae).

    PubMed

    Memmott, Ruth; Briffa, Mark

    2015-11-01

    Signals of individual quality are assumed to be difficult to exaggerate, either because they are directly linked to underlying traits (indices) or because they are costly to perform (handicaps). In practise advertisement displays may consist of conventional and costly components, for instance where a morphological structure related to body size is used in visual displays. In this case, there is the potential for dishonest displays, due to the population level variance around the relationship between body size and display structures. We examine the use of wing flicking displays that we observed in situ in a strandline dwelling seaweed fly Fucellia tergina, using overall body size and the size of their eyes as underlying indicators of condition. Males displayed far more frequently than females, and were also observed to frequently mount other flies, a behaviour that was rare in females. The rate of display was greater for males that had positive residual values from relationships between wing length and body length. In other words those males with larger than expected wings for their underlying quality displayed more frequently, indicating that these displays are open to exaggeration. Males with larger than expected wings (for the size of their body or eyes), however, mounted less frequently. We suggest that small bodied males are less successful in terms of mounting, but that those small males with relatively large wings may attempt to compensate for this through increased display effort. PMID:26365923

  11. Interferometer using a 3 x 3 coupler and Faraday mirrors.

    PubMed

    Breguet, J; Gisin, N

    1995-06-15

    A new interferometric setup using a 3 x 3 coupler and two Faraday mirrors is presented. It has the advantages of being built only with passive components, of freedom from the polarization fading problem, and of operation with a LED. It is well suited for sensing time-dependent signals and does not depend on reciprocal or nonreciprocal constant perturbations. PMID:19862044

  12. Efficient hardware implementation of 3X for radix-8 encoding

    NASA Astrophysics Data System (ADS)

    Ruiz, G. A.; Granda, Mercedes

    2007-05-01

    Several commercial processors have selected the radix-8 multiplier architecture to increase their speed, thereby reducing the number of partial products. Radix-8 encoding reduces the digit number length in a signed digit representation. Its performance bottleneck is the generation of the term 3X, also referred to as hard multiple. This term is usually computed by an adding and shifting operation, 3X=2X+X, in a high-speed adder. In a 2X+X addition, close full adders share the same input signal. This property permits simplified algebraic expressions associated to a 3X operation other than in a conventional addition. This paper shows that the 3X operation can be expressed in terms of two signals, H i and K i, functionally equivalent to two carries. Hi and Ki are computed in parallel using architectures which lead to an area and speed efficient implementation. For the purposes of comparison, implementation based on standard-cells of conventional adders has been compared with the proposed circuits based on these H i and K i signals. As a result, the delay of proposed serial scheme is reduced by roughly 67% without additional cost in area, the delay and area of the carry look-ahead scheme is reduced by 20% and 17%, and that of the parallel prefix scheme is reduced by 26% and 46%, respectively.

  13. British English infants segment words only with exaggerated infant-directed speech stimuli.

    PubMed

    Floccia, Caroline; Keren-Portnoy, Tamar; DePaolis, Rory; Duffy, Hester; Delle Luche, Claire; Durrant, Samantha; White, Laurence; Goslin, Jeremy; Vihman, Marilyn

    2016-03-01

    The word segmentation paradigm originally designed by Jusczyk and Aslin (1995) has been widely used to examine how infants from the age of 7.5 months can extract novel words from continuous speech. Here we report a series of 13 studies conducted independently in two British laboratories, showing that British English-learning infants aged 8-10.5 months fail to show evidence of word segmentation when tested in this paradigm. In only one study did we find evidence of word segmentation at 10.5 months, when we used an exaggerated infant-directed speech style. We discuss the impact of variations in infant-directed style within and across languages in the course of language acquisition. PMID:26707426

  14. Exaggerated NT-proBNP production in patients with hematologic malignancies: a case series.

    PubMed

    Andreu, Aileen; Guglin, Maya

    2012-01-01

    ©2011 Wiley Periodicals Inc. Extremely elevated serum brain natriuretic peptide (BNP) in cancer patients is a poorly understood phenomenon. The authors report three cases of patients with hematologic malignancies and serial N-terminal pro-BNP (NT-proBNP) measurements with values in the range of tens to hundred thousands pg/mL. Through matching NT-proBNP results with clinical, laboratory, echocardiographic and radiologic data, the authors found that these patients demonstrated exaggerated responses to fluid overload. Patients with hematologic malignancies may have higher than expected values of NT-proBNP in response to hypervolemic states. The authors hypothesize that this may be related to possible infiltration of the myocardium by substances produced in the setting of these diseases or due to proteins interfering with the assay.Congest Heart Fail. PMID:23167814

  15. Distinguishing between neuropsychological malingering and exaggerated psychiatric symptoms in a neuropsychological setting.

    PubMed

    Ruocco, Anthony C; Swirsky-Sacchetti, Thomas; Chute, Douglas L; Mandel, Steven; Platek, Steven M; Zillmer, Eric A

    2008-05-01

    It is unclear whether symptom validity test (SVT) failure in neuropsychological and psychiatric domains overlaps. Records of 105 patients referred for neuropsychological evaluation, who completed the Test of Memory Malingering (TOMM), Reliable Digit Span (RDS), and Millon Clinical Multiaxial Inventory-III (MCMI-III), were examined. TOMM and RDS scores were uncorrelated with MCMI-III symptom validity indices and factor analysis revealed two distinct factors for neuropsychological and psychiatric SVTs. Only 3.5% of the sample failed SVTs in both domains, 22.6% solely failed the neuropsychological SVT, and 6.1% solely failed the psychiatric SVT. The results support a dissociation between neuropsychological malingering and exaggeration of psychiatric symptoms in a neuropsychological setting. PMID:17853126

  16. The oestrogen pathway underlies the evolution of exaggerated male cranial shapes in Anolis lizards

    PubMed Central

    Sanger, Thomas J.; Seav, Susan M.; Tokita, Masayoshi; Langerhans, R. Brian; Ross, Lela M.; Losos, Jonathan B.; Abzhanov, Arhat

    2014-01-01

    Sexual dimorphisms vary widely among species. This variation must arise through sex-specific evolutionary modifications to developmental processes. Anolis lizards vary extensively in their expression of cranial dimorphism. Compared with other Anolis species, members of the carolinensis clade have evolved relatively high levels of cranial dimorphism; males of this clade have exceptionally long faces relative to conspecific females. Developmentally, this facial length dimorphism arises through an evolutionarily novel, clade-specific strategy. Our analyses herein reveal that sex-specific regulation of the oestrogen pathway underlies evolution of this exaggerated male phenotype, rather than the androgen or insulin growth factor pathways that have long been considered the primary regulators of male-biased dimorphism among vertebrates. Our results suggest greater intricacy in the genetic mechanisms that underlie sexual dimorphisms than previously appreciated. PMID:24741020

  17. Cold Exposure Can Induce an Exaggerated Early-Morning Blood Pressure Surge in Young Prehypertensives

    PubMed Central

    Huang, Bo-Chi; Lin, Yu-Cheng; Kuo, Kuan-Liang; Chern, Chang-Ming; Yang, Cheryl C. H.

    2016-01-01

    Prehypertension is related to a higher risk of cardiovascular events than normotension. Our previous study reported that cold exposure elevates the amplitude of the morning blood pressure surge (MBPS) and is associated with a sympathetic increase during the final sleep transition, which might be critical for sleep-related cardiovascular events in normotensives. However, few studies have explored the effects of cold exposure on autonomic function during sleep transitions and changes of autonomic function among prehypertensives. Therefore, we conducted an experiment for testing the effects of cold exposure on changes of autonomic function during sleep and the MBPS among young prehypertensives are more exaggerate than among young normotensives. The study groups consisted of 12 normotensive and 12 prehypertensive male adults with mean ages of 23.67 ± 0.70 and 25.25 ± 0.76 years, respectively. The subjects underwent cold (16°C) and warm (23°C) conditions randomly. The room temperature was maintained at either 23°C or 16°C by central air conditioning and recorded by a heat-sensitive sensor placed on the forehead and extended into the air. BP was measured every 30 minutes by using an autonomic BP monitor. Electroencephalograms, electrooculograms, electromyograms, electrocardiograms, and near body temperature were recorded by miniature polysomnography. Under cold exposure, a significantly higher amplitude of MBPS than under the warm condition among normotensives; however, this change was more exaggerated in prehypertensives. Furthermore, there was a significant decrease in parasympathetic-related RR and HF during the final sleep transition and a higher early-morning surge in BP and in LF% among prehypertensives, but no such change was found in normotensives. Our study supports that cold exposure might increase the risk of sleep-related cardiovascular events in prehypertensives. PMID:26919177

  18. Cold Exposure Can Induce an Exaggerated Early-Morning Blood Pressure Surge in Young Prehypertensives.

    PubMed

    Hong, Cian-Hui; Kuo, Terry B J; Huang, Bo-Chi; Lin, Yu-Cheng; Kuo, Kuan-Liang; Chern, Chang-Ming; Yang, Cheryl C H

    2016-01-01

    Prehypertension is related to a higher risk of cardiovascular events than normotension. Our previous study reported that cold exposure elevates the amplitude of the morning blood pressure surge (MBPS) and is associated with a sympathetic increase during the final sleep transition, which might be critical for sleep-related cardiovascular events in normotensives. However, few studies have explored the effects of cold exposure on autonomic function during sleep transitions and changes of autonomic function among prehypertensives. Therefore, we conducted an experiment for testing the effects of cold exposure on changes of autonomic function during sleep and the MBPS among young prehypertensives are more exaggerate than among young normotensives. The study groups consisted of 12 normotensive and 12 prehypertensive male adults with mean ages of 23.67 ± 0.70 and 25.25 ± 0.76 years, respectively. The subjects underwent cold (16°C) and warm (23°C) conditions randomly. The room temperature was maintained at either 23°C or 16°C by central air conditioning and recorded by a heat-sensitive sensor placed on the forehead and extended into the air. BP was measured every 30 minutes by using an autonomic BP monitor. Electroencephalograms, electrooculograms, electromyograms, electrocardiograms, and near body temperature were recorded by miniature polysomnography. Under cold exposure, a significantly higher amplitude of MBPS than under the warm condition among normotensives; however, this change was more exaggerated in prehypertensives. Furthermore, there was a significant decrease in parasympathetic-related RR and HF during the final sleep transition and a higher early-morning surge in BP and in LF% among prehypertensives, but no such change was found in normotensives. Our study supports that cold exposure might increase the risk of sleep-related cardiovascular events in prehypertensives. PMID:26919177

  19. Mice lacking the Raf-1 kinase inhibitor protein exhibit exaggerated hypoxia-induced pulmonary hypertension

    PubMed Central

    Morecroft, I; Doyle, B; Nilsen, M; Kolch, W; Mair, K; MacLean, MR

    2011-01-01

    BACKGROUND AND PURPOSE Increased pulmonary vascular remodelling, pulmonary arterial pressure and pulmonary vascular resistance characterize the development of pulmonary arterial hypertension (PAH). Activation of the Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)1/2 is thought to play an important role in PAH and Raf-1 kinase inhibitor protein (RKIP), negatively regulates this pathway. This study investigated whether genetic deletion of RKIP (and hence ERK1/2 up-regulation) resulted in a pulmonary hypertensive phenotype in mice and investigated a role for RKIP in mitogen-regulated proliferative responses in lung fibroblasts. EXPERIMENTAL APPROACH Pulmonary vascular haemodynamics and remodelling were assessed in mice genetically deficient in RKIP (RKIP−/−) after 2 weeks of either normoxia or hypoxia. Immunoblotting and immunohistochemistry were used to examine phosphorylation of Raf-1, RKIP and ERK1/2 in mouse pulmonary arteries. In vitro, RKIP inhibition of mitogen signalling was analysed in CCL39 hamster lung fibroblasts. KEY RESULTS RKIP−/− mice demonstrated elevated indices of PAH and ERK1/2 phosphorylation compared with wild-type (WT) mice. Hypoxic RKIP−/− mice exhibited exaggerated PAH indices. Hypoxia increased phosphorylation of Raf-1, RKIP and ERK1/2 in WT mouse pulmonary arteries and Raf-1 phosphorylation in RKIP−/− mouse pulmonary arteries. In CCL39 cells, inhibition of RKIP potentiated mitogen-induced proliferation and phosphorylation of RKIP, and Raf-1. CONCLUSIONS AND IMPLICATIONS The lack of RKIP protein resulted in a pulmonary hypertensive phenotype, exaggerated in hypoxia. Hypoxia induced phosphorylation of RKIP signalling elements in WT pulmonary arteries. RKIP inhibition potentiated mitogen-induced proliferation in lung fibroblasts. These results provide evidence for the involvement of RKIP in suppressing the development of hypoxia-induced PAH in mice. PMID:21385176

  20. Genotoxicity testing of peptides: Folate deprivation as a marker of exaggerated pharmacology

    SciTech Connect

    Guérard, Melanie Zeller, Andreas; Festag, Matthias; Schubert, Christine; Singer, Thomas; Müller, Lutz

    2014-09-15

    The incidence of micronucleated-cells is considered to be a marker of a genotoxic event and can be caused by direct- or indirect-DNA reactive mechanisms. In particular, small increases in the incidence of micronuclei, which are not associated with toxicity in the target tissue or any structurally altering properties of the compound, trigger the suspicion that an indirect mechanism could be at play. In a bone marrow micronucleus test of a synthetic peptide (a dual agonist of the GLP-1 and GIP receptors) that had been integrated into a regulatory 13-week repeat-dose toxicity study in the rat, small increases in the incidence of micronuclei had been observed, together with pronounced reductions in food intake and body weight gain. Because it is well established that folate plays a crucial role in maintaining genomic integrity and pronounced reductions in food intake and body weight gain were observed, folate levels were determined from plasma samples initially collected for toxicokinetic analytics. A dose-dependent decrease in plasma folate levels was evident after 4 weeks of treatment at the mid and high dose levels, persisted until the end of the treatment duration of 13-weeks and returned to baseline levels during the recovery period of 4 weeks. Based on these properties, and the fact that the compound tested (peptide) per se is not expected to reach the nucleus and cause DNA damage, the rationale is supported that the elevated incidence of micronucleated polychromatic erythrocytes is directly linked to the exaggerated pharmacology of the compound resulting in a decreased folate level. - Highlights: • A synthetic peptide has been evaluated for potential genotoxicity • Small increases in an integrated (13-weeks) micronucleus test were observed • Further, animals had a pronounced reductions in food intake and body weight gain • A dose-dependent decrease in plasma folate levels was evident from week 4 onwards • Elevated micronuclei-incidence due to the

  1. Exaggerated sympathoexcitatory reflexes develop with changes in the rostral ventrolateral medulla in obese Zucker rats.

    PubMed

    Huber, Domitila A; Schreihofer, Ann M

    2016-08-01

    Obesity leads to altered autonomic reflexes that reduce stability of mean arterial pressure (MAP). Sympathoinhibitory reflexes such as baroreflexes are impaired, but reflexes that raise MAP appear to be augmented. In obese Zucker rats (OZR) sciatic nerve stimulation evokes larger increases in MAP by unknown mechanisms. We sought to determine the autonomic underpinnings of this enhanced somatic pressor reflex and whether other sympathoexcitatory reflexes are augmented. We also determined whether their final common pathway, glutamatergic activation of the rostral ventrolateral medulla (RVLM), was enhanced in male OZR compared with lean Zucker rats (LZR). Sciatic nerve stimulation or activation of the nasopharyngeal reflex evoked larger rises in splanchnic sympathetic nerve activity (SNA) (79% and 45% larger in OZR, respectively; P < 0.05) and MAP in urethane-anesthetized, ventilated, paralyzed adult OZR compared with LZR. After elimination of baroreflex feedback by pharmacological prevention of changes in MAP and heart rate, these two sympathoexcitatory reflexes were still exaggerated in OZR (167% and 69% larger, respectively, P < 0.05). In adult OZR microinjections of glutamate, AMPA, or NMDA into the RVLM produced larger rises in SNA (∼61% larger in OZR, P < 0.05 for each drug) and MAP, but stimulation of axonal fibers in the upper thoracic spinal cord yielded equivalent responses in OZR and LZR. In juvenile OZR and LZR, sympathoexcitatory reflexes and physiological responses to RVLM activation were comparable. These data suggest that the ability of glutamate to activate the RVLM becomes enhanced in adult OZR and may contribute to the development of exaggerated sympathoexcitatory responses independent of impaired baroreflexes. PMID:27280427

  2. NASA N3-X with Turboelectric Distributed Propulsion

    NASA Technical Reports Server (NTRS)

    Felder, James L.

    2014-01-01

    Presentation summarizing the phase I study of the NASA N3-X turboelectric distributed propulsion power aircraft to the IMechE Disruptive Green Propulsion Technologies conference in London, UK November 16th and 17th, 2014. This presentation contains the results of a NASA internal study funded by the NASA Fixed Wing program to look at the application of turboelectric distributed propulsion to a long-range 300 seat aircraft. The reference aircraft is the Boeing 777-200LR. The N3-X reduced energy consumption by 70 compared to the 777-200LR, LTO NOx by 85 compared to the CAEP 6 limits, and noise by 32-64 EPNdB depending on engine placement compared to the stage 4 noise standards. This exceeded the N+3 metrics of reducing energy by 60, LTO NOx by 80, and noise by 52 EPNdB. Cruise NOx was not estimated, but likely meet the 80 reduction goal as well.

  3. Global SO(3) x SO(3) x U(1) symmetry of the Hubbard model on bipartite lattices

    SciTech Connect

    Carmelo, J.M.P.; Ostlund, Stellan; Sampaio, M.J.

    2010-08-15

    In this paper the global symmetry of the Hubbard model on a bipartite lattice is found to be larger than SO(4). The model is one of the most studied many-particle quantum problems, yet except in one dimension it has no exact solution, so that there remain many open questions about its properties. Symmetry plays an important role in physics and often can be used to extract useful information on unsolved non-perturbative quantum problems. Specifically, here it is found that for on-site interaction U {ne} 0 the local SU(2) x SU(2) x U(1) gauge symmetry of the Hubbard model on a bipartite lattice with N{sub a}{sup D} sites and vanishing transfer integral t = 0 can be lifted to a global [SU(2) x SU(2) x U(1)]/Z{sub 2}{sup 2} = SO(3) x SO(3) x U(1) symmetry in the presence of the kinetic-energy hopping term of the Hamiltonian with t > 0. (Examples of a bipartite lattice are the D-dimensional cubic lattices of lattice constant a and edge length L = N{sub a}a for which D = 1, 2, 3,... in the number N{sub a}{sup D} of sites.) The generator of the new found hidden independent charge global U(1) symmetry, which is not related to the ordinary U(1) gauge subgroup of electromagnetism, is one half the rotated-electron number of singly occupied sites operator. Although addition of chemical-potential and magnetic-field operator terms to the model Hamiltonian lowers its symmetry, such terms commute with it. Therefore, its 4{sup N}{sub a}{sup D} energy eigenstates refer to representations of the new found global [SU(2) x SU(2) x U(1)]/Z{sub 2}{sup 2} = SO(3) x SO(3) x U(1) symmetry. Consistently, we find that for the Hubbard model on a bipartite lattice the number of independent representations of the group SO(3) x SO(3) x U(1) equals the Hilbert-space dimension 4{sup N}{sub a}{sup D}. It is confirmed elsewhere that the new found symmetry has important physical consequences.

  4. Detecting Symptom Exaggeration in Combat Veterans Using the MMPI-2 Symptom Validity Scales: A Mixed Group Validation

    ERIC Educational Resources Information Center

    Tolin, David F.; Steenkamp, Maria M.; Marx, Brian P.; Litz, Brett T.

    2010-01-01

    Although validity scales of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; J. N. Butcher, W. G. Dahlstrom, J. R. Graham, A. Tellegen, & B. Kaemmer, 1989) have proven useful in the detection of symptom exaggeration in criterion-group validation (CGV) studies, usually comparing instructed feigners with known patient groups, the…

  5. Juvenile hormone mediates developmental integration between exaggerated traits and supportive traits in the horned flour beetle Gnatocerus cornutus.

    PubMed

    Okada, Yasukazu; Gotoh, Hiroki; Miura, Toru; Miyatake, Takahisa; Okada, Kensuke

    2012-07-01

    Sexually selected exaggerated traits are often coupled with modifications in other nontarget traits. In insects with weapons, enlargements of nontarget characters that functionally support the weapon often occur (i.e. supportive traits). The support of sexual traits requires developmental coordination among functionally related multiple traits-an explicit example of morphological integration. The genetic theory predicts that developmental integration among different body modules, for which development is regulated via different sets of genes, is likely to be coordinated by pleiotropic factors. However, the developmental backgrounds of morphological integrations are largely unknown. We tested the hypothesis that the juvenile hormone (JH), as a pleiotropic factor, mediates the integration between exaggerated and supportive traits in an armed beetle Gnatocerus cornutus. During combat, males of this beetle use exaggerated mandibles to lift up their opponents with the supportive traits, that is, the head and prothoracic body parts. Application of methoprene, a JH analog (JHA), during the larval to prepupal period, induced the formation of large mandibles relative to the body sizes in males. Morphometric examination of nontarget traits elucidated an increase in the relative sizes of supportive traits, including the head and prothoracic body parts. In addition, reductions in the hind wing area and elytra length, which correspond to flight and reproductive abilities, were detected. Our findings are consistent with the genetic theory and support the idea that JH is a key pleiotropic factor that coordinates the developmental integration of exaggerated traits and supportive characters, as well as resource allocation trade-offs. PMID:22765207

  6. Mechanism of exaggerated natriuresis in hypertensive man: impaired sodium transport in the loop of henle

    PubMed Central

    Buckalew, Vardaman M.; Puschett, Jules B.; Kintzel, James E.; Goldberg, Martin

    1969-01-01

    To evaluate the effects of saline loading on distal sodium reabsorption in hypertensive man, studies were performed during both water deprivation and water diuresis in eight hypertensive subjects, and the results were compared to data obtained from similar studies in normal subjects. All hypertensive patients exhibited an enhanced excretion of filtered sodium (CNa/CIn) at any level of distal delivery of sodium compared to normal controls. Free water reabsorption (TcH2O) during hypertonic saline loading was quantitatively abnormal in the hypertensives at high levels of osmolar clearance (COsm), and also the curve of TcH2O vs. COsm leveled off above a COsm of 18 ml/min per 1.73 m2 in the hypertensive group in contrast to the normal controls in whom TcH2O showed no evidence of achieving an upper limit. Sodium depletion exaggerated the abnormality in TcH2O in hypertensives, and resulted in a positive free water clearance (CH2O) during hydropenia. During hypotonic saline loading in water diuresis, changes in free water clearance per 100 ml of glomerular filtrate (CH2O/CIn) were less at any given increment in urine flow per 100 ml of glomerular filtrate (V/CIn) in the hypertensives compared to normal controls (P < 0.001). This abnormality in CH2O/CIn in the hypertensives in conjunction with the defect in TcH2O observed during hydropenia indicates that sodium reabsorption in the loop of Henle was abnormal at any given rate of distal delivery of sodium in hypertension. Furthermore, these abnormalities in TcH2O and CH2O coincided temporally with the development of the exaggerated natriuresis. Although the distal defect in sodium transport, in large part, accounted for the augmented natriuresis in hypertension, evidence was present also for enhanced rejection of sodium in the proximal tubule during saline loading in the hypertensives. Additional studies utilizing acetazolamide which increases distal delivery of sodium without extracellular fluid volume expansion showed only

  7. Revival of "dead" memristive devices: case of WO3-x.

    PubMed

    Tan, Zheng-Hua; Yang, Rui; Terabe, Kazuya; Yin, Xue-Bing; Guo, Xin

    2016-01-21

    Inappropriate operation could make a memristive device "dead" and cause the loss of resistive switching performance. In this study, the revival of "dead" devices was investigated in the case of WO3-x-based memristive devices. It is believed that inappropriate operation with a high-voltage pulse creates an ordered structure of oxygen vacancies and such an ordered structure makes the normal reset process fail. By precisely controlled voltage sweeping at certain compliance currents, a "dead" device can be revived. The revival operation disrupts the ordered structure by Joule heating and recovers Schottky-like barrier modulation-based switching. PMID:26685986

  8. Lung cancer screening overdiagnosis: reports of overdiagnosis in screening for lung cancer are grossly exaggerated.

    PubMed

    Mortani Barbosa, Eduardo J

    2015-08-01

    The National Lung Cancer Screening Trial (NLST) demonstrated a mortality reduction benefit associated with low-dose computed tomography (LDCT) screening for lung cancer. There has been considerable debate regarding the benefits and harms of LDCT lung cancer screening, including the challenges related to its practical implementation. One of the controversies regards overdiagnosis, which conceptually denotes diagnosing a cancer that, either because of its indolent, low-aggressiveness biologic behavior or because of limited life expectancy, is unlikely to result in significant morbidity during the patient's remainder lifetime. In theory, diagnosing and treating these cancers offer no measurable benefit while incurring costs and risks. Therefore, if a screening test detects a substantial number of overdiagnosed cancers, it is less likely to be effective. It has been argued that LDCT screening for lung cancer results in an unacceptably high rate of overdiagnosis. This article aims to defend the opposite stance. Overdiagnosis does exist and to a certain extent is inherent to any cancer-screening test. Nonetheless, the concept is less dualistic and more nuanced than it has been suggested. Furthermore, the average estimates of overdiagnosis in LDCT lung cancer screening based on the totality of published data are likely much lower than the highest published estimates, if a careful definition of a positive screening test reflecting our current understanding of lung cancer biology is utilized. This article presents evidence on why reports of overdiagnosis in lung cancer screening have been exaggerated. PMID:25772581

  9. Exaggerated Health Benefits of Physical Fitness and Activity dueto Self-selection.

    SciTech Connect

    Williams, Paul T.

    2006-01-17

    Background: The predicted health benefits of becomingphysically active or fit will be exaggerated if health outcomes causefitness and activity rather than the converse in prospective andcross-sectional epidemiological studies. Objective: Assess whether therelationships of adiposity to fitness and activity are explained byadiposity prior to exercising. Design: Cross-sectional study of physicalfitness (running speed during 10km foot race) and physical activity(weekly running distance) to current BMI (BMIcurrent) and BMI at thestart of running (BMIstarting) in 44,370 male and 25,252 femaleparticipants of the National Runners' Health Study. Results: BMIstartingexplained all of the association between fitness and BMIcurrent in bothsexes, but less than a third of the association between physical activityand BMIcurrent in men. In women, BMIstarting accounted for 58 percent ofthe association between BMIcurrent and activity levels. The 95thpercentile of BMIcurrent showed substantially greater declines withfitness and activity levels than the 5th percentile of BMIcurrent in men(i.e., the negative slope for 95th percentile was 2.6-fold greater thanthe 5th percentile for fitness and 3-fold greater for activity) and women(6-fold and 3.4-fold greater, respectively). At all percentiles, theregression slopes relating BMIstarting to fitness were comparable orgreater (more negative) than the slopes relating BMIcurrent to fitness,whereas the converse was true for activity. Conclusion: Self-selectionbias accounts for all of the association between fitness and adiposityand probably a portion of other health outcomes, but has less affect onassociations involving physical activity

  10. Mice exposed to dim light at night exaggerate inflammatory responses to lipopolysaccharide.

    PubMed

    Fonken, Laura K; Weil, Zachary M; Nelson, Randy J

    2013-11-01

    The mammalian circadian system regulates many physiological functions including inflammatory responses. Appropriately timed light information is essential for maintaining circadian organization. Over the past ∼120 years, urbanization and the widespread adoption of electric lights have dramatically altered lighting environments. Exposure to light at night (LAN) is pervasive in modern society and disrupts core circadian clock mechanisms. Because microglia are the resident macrophages in the brain and macrophages contain intrinsic circadian clocks, we hypothesized that chronic exposure to LAN would alter microglia cytokine expression and sickness behavior following LPS administration. Exposure to 4 weeks of dim LAN elevated inflammatory responses in mice. Mice exposed to dimly lit, as compared to dark, nights exaggerated changes in body temperature and elevated microglia pro-inflammatory cytokine expression following LPS administration. Furthermore, dLAN mice had a prolonged sickness response following the LPS challenge. Mice exposed to dark or dimly lit nights had comparable sickness behavior directly following the LPS injection; however, dLAN mice showed greater reductions in locomotor activity, increased anorectic behavior, and increased weight loss than mice maintained in dark nights 24h post-LPS injection. Overall, these data suggest that chronic exposure to even very low levels of light pollution may alter inflammatory responses. These results may have important implications for humans and other urban dwelling species that commonly experience nighttime light exposure. PMID:24012645

  11. Model misspecification confounds the estimation of rates and exaggerates their time dependency.

    PubMed

    Emerson, Brent C; Alvarado-Serrano, Diego F; Hickerson, Michael J

    2015-12-01

    While welcoming the comment of Ho et al. (2015), we find little that undermines the strength of our criticism, and it would appear they have misunderstood our central argument. Here we respond with the purpose of reiterating that we are (i) generally critical of much of the evidence presented in support of the time-dependent molecular rate (TDMR) hypothesis and (ii) specifically critical of estimates of μ derived from tip-dated sequences that exaggerate the importance of purifying selection as an explanation for TDMR over extended timescales. In response to assertions put forward by Ho et al. (2015), we use panmictic coalescent simulations of temporal data to explore a fundamental assumption for tip-dated tree shape and associated mutation rate estimates, and the appropriateness and utility of the date randomization test. The results reveal problems for the joint estimation of tree topology, effective population size and μ with tip-dated sequences using BEAST. Given the simulations, BEAST consistently obtains incorrect topological tree structures that are consistent with the substantial overestimation of μ and underestimation of effective population size. Data generated from lower effective population sizes were less likely to fail the date randomization test yet still resulted in substantially upwardly biased estimates of rates, bringing previous estimates of μ from temporally sampled DNA sequences into question. We find that our general criticisms of both the hypothesis of time-dependent molecular evolution and Bayesian methods to estimate μ from temporally sampled DNA sequences are further reinforced. PMID:26769403

  12. DYSAPOPTOSIS OF OSTEOBLASTS AND OSTEOCYTES INCREASES CANCELLOUS BONE FORMATION BUT EXAGGERATES BONE POROSITY WITH AGE

    PubMed Central

    Jilka, Robert L.; O’Brien, Charles A.; Roberson, Paula K.; Bonewald, Lynda F.; Weinstein, Robert S.; Manolagas, Stavros C.

    2013-01-01

    Skeletal aging is accompanied by decreased cancellous bone mass and increased formation of pores within cortical bone. The latter accounts for a large portion of the increase in non-vertebral fractures after age 65 in humans. We selectively deleted Bak and Bax, two genes essential for apoptosis, in two types of terminally differentiated bone cells: the short-lived osteoblasts that elaborate the bone matrix, and the long-lived osteocytes that are immured within the mineralized matrix and choreograph the regeneration of bone. Attenuation of apoptosis in osteoblasts increased their working lifespan and thereby cancellous bone mass in the femur. In long-lived osteocytes, however, it caused dysfunction with advancing age and greatly magnified intracortical femoral porosity associated with increased production of receptor activator of nuclear factor-κB ligand and vascular endothelial growth factor. Increasing bone mass by artificial prolongation of the inherent lifespan of short-lived osteoblasts, while exaggerating the adverse effects of aging on long-lived osteocytes, highlights the seminal role of cell age in bone homeostasis. In addition, our findings suggest that distress signals produced by old and/or dysfunctional osteocytes are the culprits of the increased intracortical porosity in old age. PMID:23761243

  13. Justice is not blind: visual attention exaggerates effects of group identification on legal punishment.

    PubMed

    Granot, Yael; Balcetis, Emily; Schneider, Kristin E; Tyler, Tom R

    2014-12-01

    Why do some people demand harsher legal punishments than do others after viewing the same video evidence? We predict that inconsistent patterns of punishment decisions can be reconciled by considering the simultaneous effects of social group identification and visual attention. We tested 2 competing predictions--the attention unites and attention divides hypotheses--to understand whether visual attention exaggerates or eliminates differences in legal decision making as a function of social identification with outgroups. We measured social identification with police (Studies 1a, 1b) or manipulated identification with a novel outgroup (Study 2). Participants watched videos depicting physical altercations in which the targets' culpability was ambiguous. We surreptitiously tracked (Studies 1a, 2) or manipulated (Study 1b) visual attention to outgroup targets. Results support the attention divides hypothesis. Among participants who fixated frequently on outgroup targets, prior identification influenced punishment decisions. This relationship did not emerge among participants who fixated infrequently on the target. Subjective interpretations of and accurate recall for targets' actions mediated the relationship between identification and attention on punishment. We discuss implications for bias in legal decision making and policy. PMID:25222261

  14. Exaggerated Intergroup Bias in Economical Decision Making Games: Differential Effects of Primary and Secondary Psychopathic Traits

    PubMed Central

    Gillespie, Steven M.; Mitchell, Ian J.; Johnson, Ian; Dawson, Ellen; Beech, Anthony R.

    2013-01-01

    Psychopathic personality traits are linked with selfish and non-cooperative responses during economical decision making games. However, the possibility that these responses may vary when responding to members of the in-group and the out-group has not yet been explored. We aimed to examine the effects of primary (selfish, uncaring) and secondary (impulsive, irresponsible) psychopathic personality traits on the responses of non-offending participants to the in-group and the out-group (defined in terms of affiliation to a UK University) across a series of economical decision making games. We asked a total of 60 participants to act as the proposer in both the dictator game and the ultimatum game. We found that across both tasks, those who scored highly for secondary psychopathic traits showed an elevated intergroup bias, making more generous offers toward members of the in-group relative to the out-group. An exaggerated intergroup bias may therefore represent a motivational factor for the antisocial behavior of those with elevated secondary psychopathic traits. PMID:23950898

  15. Exaggerated blood pressure response during the exercise treadmill test as a risk factor for hypertension

    PubMed Central

    Lima, S.G.; Albuquerque, M.F.P.M.; Oliveira, J.R.M.; Ayres, C.F.J.; Cunha, J.E.G.; Oliveira, D.F.; Lemos, R.R.; Souza, M.B.R.; Silva, O. Barbosa e

    2013-01-01

    Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension. PMID:23598646

  16. Chronic behavioral stress exaggerates motor deficit and neuroinflammation in the MPTP mouse model of Parkinson's disease

    PubMed Central

    Lauretti, E; Di Meco, A; Merali, S; Praticò, D

    2016-01-01

    Environmental stressor exposure is associated with a variety of age-related diseases including neurodegeneration. Although the initial events of sporadic Parkinson's disease (PD) are not known, consistent evidence supports the hypothesis that the disease results from the combined effect of genetic and environmental risk factors. Among them, behavioral stress has been shown to cause damage and neuronal loss in different areas of the brain, however, its effect on the dopaminergic system and PD pathogenesis remains to be characterized. The C57BL/6 mice underwent chronic restraint/isolation (RI) stress and were then treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), whereas the control mice were treated only with MPTP and the effect on the PD-like phenotype was evaluated. The mice that underwent RI before the administration of MPTP manifested an exaggerated motor deficit and impairment in the acquisition of motor skills, which were associated with a greater loss of neuronal tyrosine hydroxylase and astrocytes activation. By showing that RI influences the onset and progression of the PD-like phenotype, our study underlines the novel pathogenetic role that chronic behavioral stressor has in the disease process by triggering neuroinflammation and degeneration of the nigral dopaminergic system. PMID:26859816

  17. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

    PubMed Central

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral

  18. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides.

    PubMed

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral guides affect

  19. Exaggerated allometric structures in relation to demographic and ecological parameters in Lucanus cervus (Coleoptera: Lucanidae).

    PubMed

    Romiti, Federico; Tini, Massimiliano; Redolfi De Zan, Lara; Chiari, Stefano; Zauli, Agnese; Carpaneto, Giuseppe M

    2015-10-01

    Enlarged weapons and ornamental traits under sexual selection often show a positive allometric relationship with the overall body size. The present study explores the allometry of mandibles and their supporting structure, the head, in males of the European stag beetle, Lucanus cervus. This species shows a remarkable dimorphism in mandible shape and size that are used by males in intraspecific combats. Stag beetles were captured, measured, weighed, and released in the framework of a capture-mark-recapture study. The relationship of mandible length (ML) and head width in respect to the overall body size was described by a segmented regression model. A linear relationship was detected between ML and head width. The scaling relationships for both ML and head width identified the same switchpoint, highlighting the advantages of using combined results of weapons and their supporting structures in such analysis. These results led to a more consistent distinction of males in two morphologies: minor and major. The survival probability of individuals was dependent on the morphological class and was higher for minor males than for major. Elytron length and body mass of the individuals did not show any significant variation during the season. Differences in predatory pressure were detected between morphs by the collection and analysis of body fragments due to the predatory activity of corvids. Morphological differences and shift in demographic and ecological parameters between the two classes suggested that selection continues to favor intrasexual dimorphism in this species throughout a trade-off mechanism between costs and benefits of carrying exaggerated traits. PMID:26220669

  20. Abnormal Calcium Handling and Exaggerated Cardiac Dysfunction in Mice with Defective Vitamin D Signaling

    PubMed Central

    Choudhury, Sangita; Bae, Soochan; Ke, Qingen; Lee, Ji Yoo; Singh, Sylvia S.; St-Arnaud, René; del Monte, Federica; Kang, Peter M.

    2014-01-01

    Aim Altered vitamin D signaling is associated with cardiac dysfunction, but the pathogenic mechanism is not clearly understood. We examine the mechanism and the role of vitamin D signaling in the development of cardiac dysfunction. Methods and Results We analyzed 1α-hydroxylase (1α-OHase) knockout (1α-OHase−/−) mice, which lack 1α-OH enzymes that convert the inactive form to hormonally active form of vitamin D. 1α-OHase−/− mice showed modest cardiac hypertrophy at baseline. Induction of pressure overload by transverse aortic constriction (TAC) demonstrated exaggerated cardiac dysfunction in 1α-OHase−/− mice compared to their WT littermates with a significant increase in fibrosis and expression of inflammatory cytokines. Analysis of calcium (Ca2+) transient demonstrated profound Ca2+ handling abnormalities in 1α-OHase−/− mouse cardiomyocytes (CMs), and treatment with paricalcitol (PC), an activated vitamin D3 analog, significantly attenuated defective Ca2+ handling in 1α-OHase−/− CMs. We further delineated the effect of vitamin D deficiency condition to TAC by first correcting the vitamin D deficiency in 1α-OHase−/− mice, followed then by either a daily maintenance dose of vitamin D or vehicle (to achieve vitamin D deficiency) at the time of sham or TAC. In mice treated with vitamin D, there was a significant attenuation of TAC-induced cardiac hypertrophy, interstitial fibrosis, inflammatory markers, Ca2+ handling abnormalities and cardiac function compared to the vehicle treated animals. Conclusions Our results provide insight into the mechanism of cardiac dysfunction, which is associated with severely defective Ca2+ handling and defective vitamin D signaling in 1α-OHase−/− mice. PMID:25268137

  1. Depressive and elative mood inductions as a function of exaggerated versus contradictory facial expressions.

    PubMed

    Riccelli, P T; Antila, C E; Dale, J A; Klions, H L

    1989-04-01

    Two studies concerned the relation between facial expression cognitive induction of mood and perception of mood in women undergraduates. In Exp. 1, 20 subjects were randomly assigned to a group who were instructed in exaggerated facial expressions (Demand Group) and 20 subjects were randomly assigned to a group who were not instructed (Nondemand Group). All subjects completed a modified Velten (1968) elation- and depression-induction sequence. Ratings of depression on the Multiple Affect Adjective Checklist increased during the depression condition and decreased during the elation condition. Subjects made more facial expressions in the Demand Group than the Nondemand Group from electromyogram measures of the zygomatic and corrugator muscles and from corresponding action unit measures from visual scoring using the Facial Action Scoring System. Subjects who were instructed in the Demand Group rated their depression as more severe during the depression slides than the other group. No such effect was noted during the elation condition. In Exp. 2, 16 women were randomly assigned to a group who were instructed in facial expressions contradictory to those expected on the depression and elation tasks (Contradictory Expression Group). Another 16 women were randomly assigned to a group who were given no instructions about facial expressions (Nondemand Group). All subjects completed the depression- and elation-induction sequence mentioned in Exp. 1. No differences were reported between groups on the ratings of depression (MAACL) for the depression-induction or for the elation-induction but both groups rated depression higher after the depression condition and lower after the elation condition. Electromyographic and facial action scores verified that subjects in the Contradictory Expression Group were making the requested contradictory facial expressions during the mood-induction sequences. It was concluded that the primary influence on emotion came from the cognitive mood

  2. Clinical utility of the Neurobehavioral Symptom Inventory validity scales to screen for symptom exaggeration following traumatic brain injury.

    PubMed

    Lange, Rael T; Brickell, Tracey A; Lippa, Sara M; French, Louis M

    2015-01-01

    The purpose of this study was to examine the clinical utility of three recently developed validity scales (Validity-10, NIM5, and LOW6) designed to screen for symptom exaggeration using the Neurobehavioral Symptom Inventory (NSI). Participants were 272 U.S. military service members who sustained a mild, moderate, severe, or penetrating traumatic brain injury (TBI) and who were evaluated by the neuropsychology service at Walter Reed Army Medical Center within 199 weeks post injury. Participants were divided into two groups based on the Negative Impression Management scale of the Personality Assessment Inventory: (a) those who failed symptom validity testing (SVT-fail; n = 27) and (b) those who passed symptom validity testing (SVT-pass; n = 245). Participants in the SVT-fail group had significantly higher scores (p<.001) on the Validity-10, NIM5, LOW6, NSI total, and Personality Assessment Inventory (PAI) clinical scales (range: d = 0.76 to 2.34). Similarly high sensitivity, specificity, positive predictive power (PPP), and negative predictive (NPP) values were found when using all three validity scales to differentiate SVT-fail versus SVT-pass groups. However, the Validity-10 scale consistently had the highest overall values. The optimal cutoff score for the Validity-10 scale to identify possible symptom exaggeration was ≥19 (sensitivity = .59, specificity = .89, PPP = .74, NPP = .80). For the majority of people, these findings provide support for the use of the Validity-10 scale as a screening tool for possible symptom exaggeration. When scores on the Validity-10 exceed the cutoff score, it is recommended that (a) researchers and clinicians do not interpret responses on the NSI, and (b) clinicians follow up with a more detailed evaluation, using well-validated symptom validity measures (e.g., Minnesota Multiphasic Personality Inventory-2 Restructured Form, MMPI-2-RF, validity scales), to seek confirmatory evidence to support an hypothesis of symptom exaggeration

  3. Utility of the Neurobehavioral Symptom Inventory Validity-10 index to detect symptom exaggeration: An analogue simulation study.

    PubMed

    Sullivan, Karen A; Lange, Rael T; Edmed, Shannon L

    2016-01-01

    The Neurobehavioral Symptom Inventory (NSI) has been recommended by the interagency Traumatic Brain Injury (TBI) Outcome Workgroup as an outcome measure for TBI research. A new symptom exaggeration index-the NSI Validity-10-can be calculated from its items, but its utility has not been evaluated in a malingering simulation study. Data from a prior analogue study were reanalyzed to examine the NSI Validity-10 test properties. The data were from a sample of 85 Australian undergraduate students. A battery of measures was completed under 1 of 3 experimental conditions: control (i.e., honest responding, n = 24), feign postconcussional disorder (PCD; n = 29), and feign posttraumatic stress disorder (PTSD; n = 32). Participants who feigned PTSD or PCD had significantly higher scores on the NSI Validity-10 compared with controls. There were minimal differences between the 2 feigning groups. Using the combined data from the feigning groups and assuming a 35% symptom exaggeration base rate, the optimal NSI Validity-10 cutoff score was ≥10. This cutoff score identified "probable exaggeration" (sensitivity = .75, specificity = 1.0, positive predictive power = 1.0, negative predictive power = .88). Diagnostic efficiency statistics for 25% and 45% base rates were also generated. The cutoff score identified in this study is lower than previously reported. Its properties are promising, but its usage requires careful consideration. PMID:26943718

  4. Mitochondrial Gene Expression Profiles and Metabolic Pathways in the Amygdala Associated with Exaggerated Fear in an Animal Model of PTSD

    PubMed Central

    Li, He; Li, Xin; Smerin, Stanley E.; Zhang, Lei; Jia, Min; Xing, Guoqiang; Su, Yan A.; Wen, Jillian; Benedek, David; Ursano, Robert

    2014-01-01

    The metabolic mechanisms underlying the development of exaggerated fear in post-traumatic stress disorder (PTSD) are not well defined. In the present study, alteration in the expression of genes associated with mitochondrial function in the amygdala of an animal model of PTSD was determined. Amygdala tissue samples were excised from 10 non-stressed control rats and 10 stressed rats, 14 days post-stress treatment. Total RNA was isolated, cDNA was synthesized, and gene expression levels were determined using a cDNA microarray. During the development of the exaggerated fear associated with PTSD, 48 genes were found to be significantly upregulated and 37 were significantly downregulated in the amygdala complex based on stringent criteria (p < 0.01). Ingenuity pathway analysis revealed up- or downregulation in the amygdala complex of four signaling networks – one associated with inflammatory and apoptotic pathways, one with immune mediators and metabolism, one with transcriptional factors, and one with chromatin remodeling. Thus, informatics of a neuronal gene array allowed us to determine the expression profile of mitochondrial genes in the amygdala complex of an animal model of PTSD. The result is a further understanding of the metabolic and neuronal signaling mechanisms associated with delayed and exaggerated fear. PMID:25295026

  5. Dynamics of chiral primaries in AdS{sub 3}xS{sup 3}xT{sup 4}

    SciTech Connect

    Donos, Aristomenis; Jevicki, Antal

    2006-04-15

    We study in more detail the dynamics of chiral primaries of the D1/D5 system. From the CFT given by the S{sub N} orbifold a study of correlators resulted in an interacting (collective) theory of chiral operators. In AdS{sub 3}xS{sup 3} SUGRA we concentrate on general 1/2 BPS configurations described in terms of a fundamental string. We first establish a correspondence with the linearized field fluctuations and then present the nonlinear analysis. We evaluate in detail the symplectic form of the general degrees of freedom in SUGRA and confirm the appearance of chiral bosons. We then discuss the appearance of interactions and the cubic vertex, in correspondence with the S{sub N} collective field theory representation.

  6. Nine Galileo Views in Exaggerated Color of Main-Belt Asteroid Ida

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This set of color images of asteroid 243 Ida was taken by the imaging system on the Galileo spacecraft as it approached and raced past the asteroid on August 28, 1993. These images were taken through the 4100-angstrom (violet), 7560-angstrom (infrared) and 9680- angstrom (infrared) filters and have been processed to show Ida in exaggerated color to bring out subtle color contrasts caused by small variations in composition and surface microtexture of the asteroid's soil. In natural color Ida appears gray with slight overtones of red or brown. Stark shadows portray Ida's irregular shape, which changes its silhouetted outline when seen from different angles. More subtle shadings reveal surface topography (such as craters) and differences in the physical state and composition of the soil ('regolith'). Note in particular the color differences associated with the rims and floors of certain impact craters, which may have excavated to layers of slightly differing composition or may have ingested material from impactors of different compositions. Analysis of the images show that Ida is 58 kilometers long and 23 kilometers wide (36 x 14 miles). Ida is the first asteroid discovered to have a natural satellite, Dactyl (not shown here). Ida and Dactyl are heavily cratered by impacts with smaller asteroids and comets, including some of the same populations of small objects that bombard Earth. These data, combined with reflectance spectra from Galileo's near-infrared mapping spectrometer, may allow scientists to determine whether Ida is a relatively unaltered primitive object made of material condensed from the primordial Solar Nebula at the origin of the Solar System or whether it has been altered by strong heating--evidence interpreted so far suggests that Ida is a piece of a larger object that has been severely heated. Whereas heating and melting of large planets is well understood, the cause of heating of small asteroids is more enigmatic--it may have involved exotic

  7. Exaggeration of Language-Specific Rhythms in English and French Children's Songs.

    PubMed

    Hannon, Erin E; Lévêque, Yohana; Nave, Karli M; Trehub, Sandra E

    2016-01-01

    PVI. Together, these findings suggest that language-based rhythmic structures are evident in children's songs, and that listeners expect exaggerated language-based rhythms in children's songs. The implications of these findings for enculturation processes and for the acquisition of music and language are discussed. PMID:27445907

  8. Mesangial cell hillocks. Nodular foci of exaggerated growth of cells and matrix in prolonged culture.

    PubMed Central

    Sterzel, R. B.; Lovett, D. H.; Foellmer, H. G.; Perfetto, M.; Biemesderfer, D.; Kashgarian, M.

    1986-01-01

    To examine the capability of glomerular mesangial cells (MCs) to produce extracellular matrix, the authors studied MCs in culture by light and electron microscopy as well as immunocytochemistry. MCs were obtained from isolated rat glomeruli and maintained up to 12 weeks in medium containing 20% fetal calf serum. MC outgrowth of primary culture and of up to three subcultures showed characteristic organization consisting of bands of elongated or stellate intertwined cells. After confluency at 10-16 days, MCs continued to grow in irregular multilayers. MCs produced extracellular matrix material within 2-4 days after plating, and large amounts of matrix accumulated with time. By 2-3 weeks, foci of exaggerated MC proliferation, matrix secretion, and necrotic cell debris formed nodular protrusions, which gradually produced large hillocks. Immunocytochemical studies of MC outgrowths were performed on culture plates or on sectioned material with the use of specific rabbit polyclonal antibodies to isolated matrix proteins and FITC-conjugated, affinity-purified second antibodies. Within 3 days of culture, MCs elaborated fibronectin and collagen Types I, III, IV, and V. With time, strands of matrix, notably in the central mass of hillocks, stained extensively for these constituents. Staining for laminin was less pronounced. Smooth muscle cell myosin was regularly found on distinct intracellular fibrils and in the extracellular material of hillocks. Electron microscopy revealed the hillocks to be composed of elongated cells on the surface and stellate cells intermingled with matrix and necrotic cell debris in the core. The results show that proliferating MCs can be maintained in homogeneous culture for a prolonged time period. MCs produce large amounts of the extracellular matrix proteins (Type IV and V collagen, fibronectin, laminin), which are found in normal glomeruli. Cultured MCs also produce interstitial collagen Types I and III. MC hillocks show the nodular accumulation

  9. 6-Gingerol alleviates exaggerated vasoconstriction in diabetic rat aorta through direct vasodilation and nitric oxide generation.

    PubMed

    Ghareib, Salah A; El-Bassossy, Hany M; Elberry, Ahmed A; Azhar, Ahmad; Watson, Malcolm L; Banjar, Zainy Mohammed

    2015-01-01

    The aim of the present study is to investigate the effect and potential mechanism of action of 6-gingerol on alterations of vascular reactivity in the isolated aorta from diabetic rats. Male Wistar rats were divided into two experimental groups, control and diabetics. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg kg(-1)), and the rats were left for 10 weeks to develop vascular complications. The effect of in vitro incubation with 6-gingerol (0.3-3 μM) on the vasoconstrictor response of the isolated diabetic aortae to phenylephrine and the vasodilator response to acetylcholine was examined. Effect of 6-gingerol was also examined on aortae incubated with methylglyoxal as an advanced glycation end product (AGE). To investigate the mechanism of action of 6-gingerol, the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester hydrochloride (100 μM), guanylate cyclase inhibitor methylene blue (5 μM), calcium-activated potassium channel blocker tetraethylammonium chloride (10 mM), and cyclooxygenase inhibitor indomethacin (5 μM) were added 30 minutes before assessing the direct vasorelaxant effect of 6-gingerol. Moreover, in vitro effects of 6-gingerol on NO release and the effect of 6-gingerol on AGE production were examined. Results showed that incubation of aortae with 6-gingerol (0.3-10 μM) alleviated the exaggerated vasoconstriction of diabetic aortae to phenylephrine in a concentration-dependent manner with no significant effect on the impaired relaxatory response to acetylcholine. Similar results were seen in the aortae exposed to methylglyoxal. In addition, 6-gingerol induced a direct vasodilation effect that was significantly inhibited by Nω-nitro-l-arginine methyl ester hydrochloride and methylene blue. Furthermore, 6-gingerol stimulated aortic NO generation but had no effect on AGE formation. In conclusion, 6-gingerol ameliorates enhanced vascular contraction in diabetic aortae, which may be partially

  10. Functional Correlates of Exaggerated Oscillatory Activity in Basal Ganglia Output in Hemiparkinsonian Rats

    PubMed Central

    Brazhnik, Elena; Novikov, Nikolay; McCoy, Alex J.; Cruz, Ana V.; Walters, Judith R.

    2014-01-01

    Exaggerated beta range (13–30 Hz) synchronized activity is observed in the basal ganglia of Parkinson’s disease (PD) patients during implantation of deep brain stimulation electrodes and is thought to contribute to the motor symptoms of this disorder. To explore the translational potential of similar activity observed in a rat model of PD, local field potentials (LFP) and spiking activity in basal ganglia output were characterized in rats with unilateral dopamine cell lesion during a range of behaviors. A circular treadmill was used to assess activity during walking; hemiparkinsonian rats could maintain a steady gait when oriented ipsiversive to the lesioned hemisphere, but were less effective at walking when oriented contraversive to lesion. Dramatic increases in substantia nigra pars reticulata (SNpr) LFP oscillatory activity and spike-LFP synchronization were observed within the beta/low gamma range (12–40 Hz) in the lesioned hemisphere, relative to the non-lesioned hemisphere, with the dominant frequency of spike-LFP entrainment and LFP power varying with behavioral state. At 3 weeks post-lesion, the mean dominant entrainment frequency during ipsiversive treadmill walking and grooming was 34 Hz. Other behaviors were associated with lower mean entrainment frequencies: 27–28 Hz during alert non-walking and REM, 17 Hz during rest and 21 Hz during urethane anesthesia with sensory stimulation. SNpr spike-LFP entrainment frequency was stable during individual treadmill walking epochs, but increased gradually over weeks post-lesion. In contrast, SNpr LFP power in the 25–40 Hz range was greatest at the initiation of each walking epoch, and decreased during walking to stabilize by 6 min at 49% of initial values. Power was further modulated in conjunction with the 1.5 s stepping rhythm. Administration of L-dopa improved contraversive treadmill walking in correlation with a reduction in SNpr 25–40 Hz LFP power and spike synchronization in the dopamine cell

  11. Surgery for endometriosis-associated infertility: do we exaggerate the magnitude of effect?

    PubMed Central

    Rizk, B.; Turki, R.; Lotfy, H.; Ranganathan, S.; Zahed, H.; Freeman, A.R.; Shilbayeh, Z.; Sassy, M.; Shalaby, M.; Malik, R.

    2015-01-01

    Objective: Surgery remains the mainstay in the diagnosis and management of endometriosis. The number of surgeries performed for endometriosis worldwide is ever increasing, however do we have evidence for improvement of infertility after the surgery and do we exaggerate the magnitude of effect of surgery when we counsel our patients? The management of patients who failed the surgery could be by repeat surgery or assisted reproduction. What evidence do we have for patients who fail assisted reproduction and what is their best chance for achieving pregnancy? Material and methods: In this study we reviewed the evidence-based practice pertaining to the outcome of surgery assisted infertility associated with endometriosis. Manuscripts published in PubMed and Science Direct as well as the bibliography cited in these articles were reviewed. Patients with peritoneal endometriosis with mild and severe disease were addressed separately. Patients who failed the primary surgery and managed by repeat or assisted reproduction technology were also evaluated. Patients who failed assisted reproduction and managed by surgery were also studied to determine of the best course of action. Results: In patients with minimal and mild pelvic endometriosis, excision or ablation of the peritoneal endometriosis increases the pregnancy rate. In women with severe endometriosis, controlled trials suggested an improvement of pregnancy rate. In women with ovarian endometrioma 4 cm or larger ovarian cystectomy increases the pregnancy rate, decreases the recurrence rate, but is associated with decrease in ovarian reserve. In patients who have failed the primary surgery, assisted reproduction appears to be significantly more effective than repeat surgery. In patients who failed assisted reproduction, the management remains to be extremely controversial. Surgery in expert hands might result in significant improvement in pregnancy rate. Conclusion: In women with minimal and mild endometriosis, surgical

  12. Exaggeration of Language-Specific Rhythms in English and French Children's Songs

    PubMed Central

    Hannon, Erin E.; Lévêque, Yohana; Nave, Karli M.; Trehub, Sandra E.

    2016-01-01

    PVI. Together, these findings suggest that language-based rhythmic structures are evident in children's songs, and that listeners expect exaggerated language-based rhythms in children's songs. The implications of these findings for enculturation processes and for the acquisition of music and language are discussed. PMID:27445907

  13. High-resolution core-level photoemission study of Eu-induced (3x2)/(3x4) reconstruction on Ge(111)

    SciTech Connect

    Kuzmin, M.; Peraelae, R. E.; Laukkanen, P.; Ahola-Tuomi, M.; Vaeyrynen, I. J.

    2006-09-15

    We have investigated Eu-induced Ge(111)-(3x2)/(3x4) reconstruction by high-resolution core-level photoelectron spectroscopy using synchrotron radiation and low-energy electron diffraction. Recent scanning tunneling microscopy (STM) observations [Phys. Rev. B 73, 125332 (2006)] revealed that the Ge arrangement of this reconstruction can be well described in terms of the honeycomb chain-channel (HCC) geometry proposed earlier for metal/Si(111)-(3x1) and -(3x2) surfaces; the Eu atoms, however, were found to reside at two different adsorption sites in the Eu/Ge(111)-(3x2)/(3x4) reconstruction, in contrast to the equivalent adsorption sites (e.g., T4) occupied in the case of Si. The present photoemission results provide further information about the atomic arrangement of Eu/Ge(111)-(3x2)/(3x4). In particular, we show that the Ge 3d core-level data cannot be interpreted by the HCC structure with the Eu atoms adsorbed only on T4 sites, giving a spectroscopic support for the suggestions based on the earlier STM data. We consider here a modified HCC-based configuration for the Eu/Ge(111)-(3x2)/(3x4) surface where the Eu atoms occupy two different sites in the empty channel between the neighboring Ge honeycomb chains. The atomic models are discussed in the context of the Ge 3d and Eu 4f data as well as the previous results available in the literature. Finally, we propose a structural model that allows us to account for the present photoemission and earlier STM findings.

  14. Large perceptual distortions of locomotor action space occur in ground-based coordinates: Angular expansion and the large-scale horizontal-vertical illusion.

    PubMed

    Klein, Brennan J; Li, Zhi; Durgin, Frank H

    2016-04-01

    What is the natural reference frame for seeing large-scale spatial scenes in locomotor action space? Prior studies indicate an asymmetric angular expansion in perceived direction in large-scale environments: Angular elevation relative to the horizon is perceptually exaggerated by a factor of 1.5, whereas azimuthal direction is exaggerated by a factor of about 1.25. Here participants made angular and spatial judgments when upright or on their sides to dissociate egocentric from allocentric reference frames. In Experiment 1, it was found that body orientation did not affect the magnitude of the up-down exaggeration of direction, suggesting that the relevant orientation reference frame for this directional bias is allocentric rather than egocentric. In Experiment 2, the comparison of large-scale horizontal and vertical extents was somewhat affected by viewer orientation, but only to the extent necessitated by the classic (5%) horizontal-vertical illusion (HVI) that is known to be retinotopic. Large-scale vertical extents continued to appear much larger than horizontal ground extents when observers lay sideways. When the visual world was reoriented in Experiment 3, the bias remained tied to the ground-based allocentric reference frame. The allocentric HVI is quantitatively consistent with differential angular exaggerations previously measured for elevation and azimuth in locomotor space. (PsycINFO Database Record PMID:26594884

  15. Dietary Zinc Deficiency Exaggerates Ethanol-Induced Liver Injury in Mice: Involvement of Intrahepatic and Extrahepatic Factors

    PubMed Central

    Sun, Xinguo; Song, Zhenyuan; McClain, Craig J.; Zhou, Zhanxiang

    2013-01-01

    Clinical studies have demonstrated that alcoholics have a lower dietary zinc intake compared to health controls. The present study was undertaken to determine the interaction between dietary zinc deficiency and ethanol consumption in the pathogenesis of alcoholic liver disease. C57BL/6N mice were subjected to 8-week feeding of 4 experimental liquid diets: (1) zinc adequate diet, (2) zinc adequate diet plus ethanol, (3) zinc deficient diet, and (4) zinc deficient diet plus ethanol. Ethanol exposure with adequate dietary zinc resulted in liver damage as indicated by elevated plasma alanine aminotransferase level and increased hepatic lipid accumulation and inflammatory cell infiltration. Dietary zinc deficiency alone increased hepatic lipid contents, but did not induce hepatic inflammation. Dietary zinc deficiency showed synergistic effects on ethanol-induced liver damage. Dietary zinc deficiency exaggerated ethanol effects on hepatic genes related to lipid metabolism and inflammatory response. Dietary zinc deficiency worsened ethanol-induced imbalance between hepatic pro-oxidant and antioxidant enzymes and hepatic expression of cell death receptors. Dietary zinc deficiency exaggerated ethanol-induced reduction of plasma leptin, although it did not affect ethanol-induced reduction of white adipose tissue mass. Dietary zinc deficiency also deteriorated ethanol-induced gut permeability increase and plasma endotoxin elevation. These results demonstrate, for the first time, that dietary zinc deficiency is a risk factor in alcoholic liver disease, and multiple intrahepatic and extrahepatic factors may mediate the detrimental effects of zinc deficiency. PMID:24155903

  16. High-fat diets exaggerate endocrine and metabolic phenotypes in a rat model of DHEA-induced PCOS.

    PubMed

    Zhang, Haolin; Yi, Ming; Zhang, Yan; Jin, Hongyan; Zhang, Wenxin; Yang, Jingjing; Yan, Liying; Li, Rong; Zhao, Yue; Qiao, Jie

    2016-04-01

    Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder with unclear etiology and unsatisfactory management. Effects of diets on the phenotype of PCOS were not fully understood. In the present study, we applied 45 and 60% high-fat diets (HFDs) on a rat model of PCOS induced by postnatal DHEA injection. We found that both DHEA and DHEA+HFDs rats exhibited reproductive abnormalities, including hyperandrogenism, irregular cycles and polycystic ovaries. The addition of HFDs, especially 60% HFDs, exaggerated morphological changes of ovaries and a number of metabolic changes, including increased body weight and body fat content, impaired glucose tolerance and increased serum insulin levels. Results from qPCR showed that DHEA-induced increased expression of hypothalamic androgen receptor and LH receptor were reversed by the addition of 60% HFDs. In contrast, the ovarian expression of LH receptor and insulin receptor mRNA was upregulated only with the addition of 60% HFDs. These findings indicated that DHEA and DHEA+HFDs might influence PCOS phenotypes through distinct mechanisms: DHEA affects the normal function of hypothalamus-pituitary-ovarian axis through LH, whereas the addition of HFDs exaggerated endocrine and metabolic dysfunction through ovarian responses to insulin-related mechanisms. We concluded that the addition of HFDs yielded distinct phenotypes of DHEA-induced PCOS and could be used for studies on both reproductive and metabolic features of the syndrome. PMID:26814210

  17. Exaggerated neurobiological sensitivity to threat as a mechanism linking anxiety with increased risk for diseases of aging

    PubMed Central

    O’Donovan, Aoife; Slavich, George M; Epel, Elissa S.; Neylan, Thomas C

    2015-01-01

    Anxiety disorders increase risk for the early development of several diseases of aging. Elevated inflammation, a common risk factor across diseases of aging, may play a key role in the relationship between anxiety and physical disease. However, the neurobiological mechanisms linking anxiety with elevated inflammation remain unclear. In this review, we present a neurobiological model of the mechanisms by which anxiety promotes inflammation. Specifically we propose that exaggerated neurobiological sensitivity to threat in anxious individuals may lead to sustained threat perception, which is accompanied by prolonged activation of threat-related neural circuitry and threat-responsive biological systems including the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS), and inflammatory response. Over time, this pattern of responding can promote chronic inflammation through structural and functional brain changes, altered sensitivity of immune cell receptors, dysregulation of the HPA axis and ANS, and accelerated cellular aging. Chronic inflammation, in turn, increases risk for diseases of aging. Exaggerated neurobiological sensitivity to threat may thus be a treatment target for reducing disease risk in anxious individuals. PMID:23127296

  18. 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 ...

  19. Pulsed Lasers Employing Solution-Processed Plasmonic Cu3- x P Colloidal Nanocrystals.

    PubMed

    Liu, Zeke; Mu, Haoran; Xiao, Si; Wang, Rongbin; Wang, Zhiteng; Wang, Weiwei; Wang, Yongjie; Zhu, Xiangxiang; Lu, Kunyuan; Zhang, Han; Lee, Shuit-Tong; Bao, Qiaoliang; Ma, Wanli

    2016-05-01

    A new approach to synthesize self-doped colloidal Cu3-x P NCs with controlled size and localized surface plasmon resonance absorption is reported. These Cu3-x P NCs show ultrafast exciton dynamics and huge optical nonlinearities due to plasmonic resonances, which afford the first demonstration of plasmonic Cu3-x P NCs as simple, effective, and solution-processed nonlinear absorbers for high-energy Q-switched fiber laser. PMID:26970297

  20. Vertical Map Storage.

    ERIC Educational Resources Information Center

    Perry, Joanne M.

    1982-01-01

    Discusses the superiority of vertical filing of maps in compressor-style vertical units over horizontal filing in drawers, emphasizing such factors as physical protection of the collection, ease of filing and retrieval, and efficient use of space. Disadvantages of vertical filing are also reviewed. (Author/JL)

  1. Cancer-associated DDX3X mutations drive stress granule assembly and impair global translation.

    PubMed

    Valentin-Vega, Yasmine A; Wang, Yong-Dong; Parker, Matthew; Patmore, Deanna M; Kanagaraj, Anderson; Moore, Jennifer; Rusch, Michael; Finkelstein, David; Ellison, David W; Gilbertson, Richard J; Zhang, Jinghui; Kim, Hong Joo; Taylor, J Paul

    2016-01-01

    DDX3X is a DEAD-box RNA helicase that has been implicated in multiple aspects of RNA metabolism including translation initiation and the assembly of stress granules (SGs). Recent genomic studies have reported recurrent DDX3X mutations in numerous tumors including medulloblastoma (MB), but the physiological impact of these mutations is poorly understood. Here we show that a consistent feature of MB-associated mutations is SG hyper-assembly and concomitant translation impairment. We used CLIP-seq to obtain a comprehensive assessment of DDX3X binding targets and ribosome profiling for high-resolution assessment of global translation. Surprisingly, mutant DDX3X expression caused broad inhibition of translation that impacted DDX3X targeted and non-targeted mRNAs alike. Assessment of translation efficiency with single-cell resolution revealed that SG hyper-assembly correlated precisely with impaired global translation. SG hyper-assembly and translation impairment driven by mutant DDX3X were rescued by a genetic approach that limited SG assembly and by deletion of the N-terminal low complexity domain within DDX3X. Thus, in addition to a primary defect at the level of translation initiation caused by DDX3X mutation, SG assembly itself contributes to global translation inhibition. This work provides mechanistic insights into the consequences of cancer-related DDX3X mutations, suggesting that globally reduced translation may provide a context-dependent survival advantage that must be considered as a possible contributor to tumorigenesis. PMID:27180681

  2. Cancer-associated DDX3X mutations drive stress granule assembly and impair global translation

    PubMed Central

    Valentin-Vega, Yasmine A.; Wang, Yong-Dong; Parker, Matthew; Patmore, Deanna M.; Kanagaraj, Anderson; Moore, Jennifer; Rusch, Michael; Finkelstein, David; Ellison, David W.; Gilbertson, Richard J.; Zhang, Jinghui; Kim, Hong Joo; Taylor, J. Paul

    2016-01-01

    DDX3X is a DEAD-box RNA helicase that has been implicated in multiple aspects of RNA metabolism including translation initiation and the assembly of stress granules (SGs). Recent genomic studies have reported recurrent DDX3X mutations in numerous tumors including medulloblastoma (MB), but the physiological impact of these mutations is poorly understood. Here we show that a consistent feature of MB-associated mutations is SG hyper-assembly and concomitant translation impairment. We used CLIP-seq to obtain a comprehensive assessment of DDX3X binding targets and ribosome profiling for high-resolution assessment of global translation. Surprisingly, mutant DDX3X expression caused broad inhibition of translation that impacted DDX3X targeted and non-targeted mRNAs alike. Assessment of translation efficiency with single-cell resolution revealed that SG hyper-assembly correlated precisely with impaired global translation. SG hyper-assembly and translation impairment driven by mutant DDX3X were rescued by a genetic approach that limited SG assembly and by deletion of the N-terminal low complexity domain within DDX3X. Thus, in addition to a primary defect at the level of translation initiation caused by DDX3X mutation, SG assembly itself contributes to global translation inhibition. This work provides mechanistic insights into the consequences of cancer-related DDX3X mutations, suggesting that globally reduced translation may provide a context-dependent survival advantage that must be considered as a possible contributor to tumorigenesis. PMID:27180681

  3. Vertical bounce of two vertically aligned balls

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2007-11-01

    When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

  4. Vertical axis wind turbines

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  5. Exaggerated haemodynamic and neural responses to involuntary contractions induced by whole-body vibration in normotensive obese versus lean women.

    PubMed

    Dipla, Konstantina; Kousoula, Dimitra; Zafeiridis, Andreas; Karatrantou, Konstantina; Nikolaidis, Michalis G; Kyparos, Antonios; Gerodimos, Vassilis; Vrabas, Ioannis S

    2016-06-01

    What is the central question of this study? In obesity, the exaggerated blood pressure response to voluntary exercise is linked to hypertension, yet the mechanisms are not fully elucidated. We examined whether involuntary contractions elicit greater haemodynamic responses and altered neural control of blood pressure in normotensive obese versus lean women. What is the main finding and its importance? During involuntary contractions induced by whole-body vibration, there were augmented blood pressure and spontaneous baroreflex responses in obese compared with lean women. This finding is suggestive of an overactive mechanoreflex in the exercise-induced hypertensive response in obesity. Passive contractions did not elicit differential heart rate responses in obese compared with lean women, implying other mechanisms for the blunted heart rate response reported during voluntary exercise in obesity. In obesity, the exaggerated blood pressure (BP) response to exercise is linked to hypertension, yet the mechanisms are not fully elucidated. In this study, we examined whether involuntary mechanical oscillations, induced by whole-body vibration (WBV), elicit greater haemodynamic responses and altered neural control of BP in obese versus lean women. Twenty-two normotensive, premenopausal women (12 lean and 10 obese) randomly underwent a passive WBV (25 Hz) and a control protocol (similar posture without WVB). Beat-by-beat BP, heart rate, stroke volume, systemic vascular resistance, cardiac output, parasympathetic output (evaluated by heart rate variability) and spontaneous baroreceptor sensitivity (sBRS) were assessed. We found that during WBV, obese women exhibited an augmented systolic BP response compared with lean women that was correlated with body fat percentage (r = 0.77; P < 0.05). The exaggerated BP rise was driven mainly by the greater increase in cardiac output index in obese versus lean women, associated with a greater stroke volume index in obese women

  6. DDX3X Biomarker Correlates with Poor Survival in Human Gliomas

    PubMed Central

    Hueng, Dueng-Yuan; Tsai, Wen-Chiuan; Chiou, Hsin-Ying Clair; Feng, Shao-Wei; Lin, Chin; Li, Yao-Feng; Huang, Li-Chun; Lin, Ming-Hong

    2015-01-01

    Primary high-grade gliomas possess invasive growth and lead to unfavorable survival outcome. The investigation of biomarkers for prediction of survival outcome in patients with gliomas is important for clinical assessment. The DEAD (Asp-Glu-Ala-Asp) box helicase 3, X-linked (DDX3X) controls tumor migration, proliferation, and progression. However, the role of DDX3X in defining the pathological grading and survival outcome in patients with human gliomas is not yet clarified. We analyzed the DDX3X gene expression, WHO pathological grading, and overall survival from de-linked data. Further validation was done using quantitative RT-PCR of cDNA from normal brain and glioma, and immunohistochemical (IHC) staining of tissue microarray. Statistical analysis of GEO datasets showed that DDX3X mRNA expression demonstrated statistically higher in WHO grade IV (n = 81) than in non-tumor controls (n = 23, p = 1.13 × 10−10). Moreover, DDX3X level was also higher in WHO grade III (n = 19) than in non-tumor controls (p = 2.43 × 10−5). Kaplan–Meier survival analysis showed poor survival in patients with high DDX3X mRNA levels (n = 24) than in those with low DDX3X expression (n = 53) (median survival, 115 vs. 58 weeks, p = 0.0009, by log-rank test, hazard ratio: 0.3507, 95% CI: 0.1893–0.6496). Furthermore, DDX3X mRNA expression and protein production significantly increased in glioma cells compared with normal brain tissue examined by quantitative RT-PCR, and Western blot. IHC staining showed highly staining of high-grade glioma in comparison with normal brain tissue. Taken together, DDX3X expression level positively correlates with WHO pathologic grading and poor survival outcome, indicating that DDX3X is a valuable biomarker in human gliomas. PMID:26184164

  7. CONTEXT VIEW, SHOWING STRUCTURE NO. 57.3X (CULVERT) AT RIGHT AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW, SHOWING STRUCTURE NO. 57.3X (CULVERT) AT RIGHT AND STRUCTURE NO. 57.24X (BRIDGE) IN DISTANCE AT LEFT. MAIN TRACK 1 RUNS ALONG THE TOP OF THE FEATURES. VIEW TO THE SOUTHEAST. 12 - Burlington Northern Santa Fe Railroad, Cajon Subdivision, Structure No. 57.3X, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

  8. Exaggerated sexual swellings and male mate choice in primates: testing the reliable indicator hypothesis in the Amboseli baboons

    PubMed Central

    Fitzpatrick, Courtney L.; Altmann, Jeanne; Alberts, Susan C.

    2015-01-01

    The paradigm of competitive males vying to influence female mate choice has been repeatedly upheld, but, increasingly, studies also report competitive females and choosy males. One female trait that is commonly proposed to influence male mate choice is the exaggerated sexual swelling displayed by females of many Old World primate species. The reliable indicator hypothesis posits that females use the exaggerated swellings to compete for access to mates, and that the swellings advertise variation in female fitness. We tested the two main predictions of this hypothesis in a wild population of baboons (Papio cynocephalus). First, we examined the effect of swelling size on the probability of mate-guarding (‘consortship’) by the highest-ranking male and the behavior of those males that trailed consorshipts (‘follower males’). Second, we asked whether a female’s swelling size predicted several fitness measures. We found that high-ranking males do not prefer females with larger swellings (when controlling for cycle number and conception) and that females with larger swellings did not have higher reproductive success. Our study—the only complete test of the reliable indicator hypothesis in a primate population—rejects the idea that female baboons compete for mates by advertising heritable fitness differences. Furthermore, we found unambiguous evidence that males biased their mating decisions in favor of females who had experienced more sexual cycles since their most recent pregnancy. Thus, rather than tracking the potential differences in fitness between females, male baboons appear to track and target the potential for a given reproductive opportunity to result in fertilization. PMID:26752790

  9. Tetrahydrobiopterin ameliorates the exaggerated exercise pressor response in patients with chronic kidney disease: a randomized controlled trial.

    PubMed

    Lin, Ann M; Liao, Peizhou; Millson, Erin C; Quyyumi, Arshed A; Park, Jeanie

    2016-05-01

    Chronic kidney disease (CKD) patients have an exaggerated increase in blood pressure (BP) during rhythmic handgrip exercise (RHG 20%) and static handgrip exercise (SHG 30%). Nitric oxide levels increase during exercise and help prevent excessive hypertension by both increasing vasodilation and reducing sympathetic nerve activity (SNA). Therefore, we hypothesized that tetrahydrobiopterin (BH4), an essential cofactor for nitric oxide synthase, would ameliorate the exaggerated exercise pressor response in CKD patients. In a randomized, double-blinded, placebo-controlled trial, we tested the effects of 12 wk of sapropterin dihydrochloride (6R-BH4; n = 18) versus placebo (n = 14) treatement on BP and muscle SNA (MSNA) responses during RHG 20% and SHG 30% in CKD patients. The 6R-BH4-treated group had a significantly lower systolic BP (+6 ± 1 vs. +13 ± 2 mmHg, P = 0.002) and mean arterial pressure response (+5 ± 1 vs. +10 ± 2 mmHg, P = 0.020) during RHG 20% and a significantly lower systolic BP response (+19 ± 3 vs. +28 ± 3 mmHg, P = 0.043) during SHG 30%. Under baseline conditions, there was no significant difference in MSNA responses between the groups; however, when the BP response during exercise was equalized between the groups using nitroprusside, the 6R-BH4-treated group had a significantly lower MSNA response during RHG 20% (6R-BH4 vs. placebo, +12 ± 1 vs. +21 ± 2 bursts/min, P = 0.004) but not during SHG 30%. These findings suggest that 6R-BH4 ameliorates the augmented BP response during RHG 20% and SHG 30% in CKD patients. A reduction in reflex activation of SNA may contribute to the decreased exercise pressor response during RHG 20% but not during SHG 30% in CKD patients. PMID:26962106

  10. Offset vertical radar profiling

    USGS Publications Warehouse

    Witten, A.; Lane, J.

    2003-01-01

    Diffraction tomography imaging was applied to VRP data acquired by vertically moving a receiving antenna in a number of wells. This procedure simulated a vertical downhole receiver array. Similarly, a transmitting antenna was sequentially moved along a series of radial lines extending outward from the receiver wells. This provided a sequence of multistatic data sets and, from each data set, a two-dimensional vertical cross-sectional image of spatial variations in wave speed was reconstructed.

  11. Vertical Axis Wind Turbine

    2002-04-01

    Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). VAWT-SAL Vertical Axis Wind Turbine- Stochastic Aerodynamic Loads Ver 3.2 numerically simulates the stochastic (random0 aerodynamic loads of the Vertical-Axis Wind Turbine (VAWT) created by the atomspheric turbulence. The program takes into account the rotor geometry, operating conditions, and assumed turbulence properties.

  12. Comparison of Raw Acceleration from the GENEA and ActiGraph™ GT3X+ Activity Monitors

    PubMed Central

    John, Dinesh; Sasaki, Jeffer; Staudenmayer, John; Mavilia, Marianna; Freedson, Patty S.

    2013-01-01

    Purpose: To compare raw acceleration output of the ActiGraph™ GT3X+ and GENEA activity monitors. Methods: A GT3X+ and GENEA were oscillated in an orbital shaker at frequencies ranging from 0.7 to 4.0 Hz (ten 2-min trials/frequency) on a fixed radius of 5.08 cm. Additionally, 10 participants (age = 23.8 ± 5.4 years) wore the GT3X+ and GENEA on the dominant wrist and performed treadmill walking (2.0 and 3.5 mph) and running (5.5 and 7.5 mph) and simulated free-living activities (computer work, cleaning a room, vacuuming and throwing a ball) for 2-min each. A linear mixed model was used to compare the mean triaxial vector magnitude (VM) from the GT3X+ and GENEA at each oscillation frequency. For the human testing protocol, random forest machine-learning technique was used to develop two models using frequency domain (FD) and time domain (TD) features for each monitor. We compared activity type recognition accuracy between the GT3X+ and GENEA when the prediction model was fit using one monitor and then applied to the other. Z-statistics were used to compare the proportion of accurate predictions from the GT3X+ and GENEA for each model. Results: GENEA produced significantly higher (p < 0.05, 3.5 to 6.2%) mean VM than GT3X+ at all frequencies during shaker testing. Training the model using TD input features on the GENEA and applied to GT3X+ data yielded significantly lower (p < 0.05) prediction accuracy. Prediction accuracy was not compromised when interchangeably using FD models between monitors. Conclusions: It may be inappropriate to apply a model developed on the GENEA to predict activity type using GT3X+ data when input features are TD attributes of raw acceleration. PMID:24177727

  13. Order-disorder transition of the (3 x 3) Sn/Ge(111) phase

    SciTech Connect

    Floreano, L.; Cvetko, D.; Bavdek, G.; Benes, M.; Morgante, A.

    2001-08-15

    We have measured the long-range order of the {alpha} phase of Sn on the Ge(111) surface throughout the (3 x 3){yields}(3 x 3)R30{sup o} phase transition. The transition has been found of the order-disorder type with a critical temperature T{sub c}{approx}220 K. The expected three-state Potts critical exponents are shown to be consistent with the observed power-law dependence of the (3 x 3) order parameter and its correlation length close to T{sub c}, thus excluding a charge-density wave driven phase transition.

  14. Monocyte Subpopulations from Pre-Eclamptic Patients Are Abnormally Skewed and Exhibit Exaggerated Responses to Toll-Like Receptor Ligands

    PubMed Central

    Al-ofi, Ebtisam

    2012-01-01

    The leading cause of pregnancy-associated mortality and morbidity is pre-eclampsia (PE). Although information regarding the etiology of this disease is scant, its pathophysiology is characterized by abnormal placentation, endothelial dysfunction as well as an exaggerated inflammatory response. Clinical evidence also indicates that the abundance of many immune cells at the feto-maternal interface and in the circulation of PE patients is abnormal, when compared with normal pregnant (NP) controls. In addition, the phenotype and function of some of these cells is altered. To further characterize the systemic effects of PE on circulating cells, we analyzed monocytic subpopulations in NP and PE patients by flow cytometry. We found that non-classical CD14lowCD16+ monocytes are significantly increased in women with PE and they display irregular expression of several chemokine receptors and antigen presentation molecules. The most striking phenotypic difference among the cell surface molecules was the marked upregulation of TLR4 expression, where both CD14highCD16+ and CD14lowCD16+ monocytes demonstrated higher levels than their NP counterparts. Stimulation of PE monocytes with TLR ligands resulted in profound secretion of various cytokines in comparison with NP controls. These data suggest that PE monocytes are hyper-responsive to TLR ligands and this may contribute to exacerbation of the disease. PMID:22848746

  15. Monocyte subpopulations from pre-eclamptic patients are abnormally skewed and exhibit exaggerated responses to Toll-like receptor ligands.

    PubMed

    Al-ofi, Ebtisam; Coffelt, Seth B; Anumba, Dilly O

    2012-01-01

    The leading cause of pregnancy-associated mortality and morbidity is pre-eclampsia (PE). Although information regarding the etiology of this disease is scant, its pathophysiology is characterized by abnormal placentation, endothelial dysfunction as well as an exaggerated inflammatory response. Clinical evidence also indicates that the abundance of many immune cells at the feto-maternal interface and in the circulation of PE patients is abnormal, when compared with normal pregnant (NP) controls. In addition, the phenotype and function of some of these cells is altered. To further characterize the systemic effects of PE on circulating cells, we analyzed monocytic subpopulations in NP and PE patients by flow cytometry. We found that non-classical CD14(low)CD16(+) monocytes are significantly increased in women with PE and they display irregular expression of several chemokine receptors and antigen presentation molecules. The most striking phenotypic difference among the cell surface molecules was the marked upregulation of TLR4 expression, where both CD14(high)CD16(+) and CD14(low)CD16(+) monocytes demonstrated higher levels than their NP counterparts. Stimulation of PE monocytes with TLR ligands resulted in profound secretion of various cytokines in comparison with NP controls. These data suggest that PE monocytes are hyper-responsive to TLR ligands and this may contribute to exacerbation of the disease. PMID:22848746

  16. An initial investigation of the orbitofrontal cortex hyperactivity in obsessive-compulsive disorder: exaggerated representations of anticipated aversive events?

    PubMed

    Ursu, Stefan; Carter, Cameron S

    2009-08-01

    Orbitofrontal cortical (OFC) dysfunction has been repeatedly involved in obsessive-compulsive disorder, but the precise significance of this abnormality is still unclear. Current neurocognitive models propose that specific areas of the OFC contribute to behavioral regulation by representing the anticipated affective value of future events. This leads to the hypothesis that these OFC areas are hyperactive in patients, reflecting ruminative preoccupation with future aversive events. In experimental situations, such hyperactivity should be triggered by negative affect in response to high likelihood of events such as the conflict between simultaneously active incompatible responses, which can potentially lead to poor task performance. We tested this hypothesis by examining fMRI indices of brain activity of 15 OCD patients and 15 matched controls. Subjects were scanned while performing a cognitive task which involved responding to cues and subsequent probes, and some of the probes elicited response conflict. Relative to controls, the lateral OFC of patients was specifically hyperactive to cues associated with high proportion of subsequent high-conflict probes. The level of OFC hyperactivity correlated directly with the severity of anxiety symptoms. These results support the hypothesis that OCD is characterized by exaggerated OFC representations of anticipated aversive events. PMID:19467363

  17. Insights into the Development and Evolution of Exaggerated Traits Using De Novo Transcriptomes of Two Species of Horned Scarab Beetles

    PubMed Central

    Warren, Ian A.; Vera, J. Cristobal; Johns, Annika; Zinna, Robert; Marden, James H.; Emlen, Douglas J.; Dworkin, Ian; Lavine, Laura C.

    2014-01-01

    Scarab beetles exhibit an astonishing variety of rigid exo-skeletal outgrowths, known as “horns”. These traits are often sexually dimorphic and vary dramatically across species in size, shape, location, and allometry with body size. In many species, the horn exhibits disproportionate growth resulting in an exaggerated allometric relationship with body size, as compared to other traits, such as wings, that grow proportionately with body size. Depending on the species, the smallest males either do not produce a horn at all, or they produce a disproportionately small horn for their body size. While the diversity of horn shapes and their behavioural ecology have been reasonably well studied, we know far less about the proximate mechanisms that regulate horn growth. Thus, using 454 pyrosequencing, we generated transcriptome profiles, during horn growth and development, in two different scarab beetle species: the Asian rhinoceros beetle, Trypoxylus dichotomus, and the dung beetle, Onthophagus nigriventris. We obtained over half a million reads for each species that were assembled into over 6,000 and 16,000 contigs respectively. We combined these data with previously published studies to look for signatures of molecular evolution. We found a small subset of genes with horn-biased expression showing evidence for recent positive selection, as is expected with sexual selection on horn size. We also found evidence of relaxed selection present in genes that demonstrated biased expression between horned and horn-less morphs, consistent with the theory of developmental decoupling of phenotypically plastic traits. PMID:24586317

  18. Vertical sleeve gastrectomy

    MedlinePlus

    ... smaller stomach is about the size of a banana. It limits the amount of food you can ... staples. This creates a long vertical tube or banana-shaped stomach. The surgery does not involve cutting ...

  19. Micromachined electrostatic vertical actuator

    DOEpatents

    Lee, Abraham P.; Sommargren, Gary E.; McConaghy, Charles F.; Krulevitch, Peter A.

    1999-10-19

    A micromachined vertical actuator utilizing a levitational force, such as in electrostatic comb drives, provides vertical actuation that is relatively linear in actuation for control, and can be readily combined with parallel plate capacitive position sensing for position control. The micromachined electrostatic vertical actuator provides accurate movement in the sub-micron to micron ranges which is desirable in the phase modulation instrument, such as optical phase shifting. For example, compact, inexpensive, and position controllable micromirrors utilizing an electrostatic vertical actuator can replace the large, expensive, and difficult-to-maintain piezoelectric actuators. A thirty pound piezoelectric actuator with corner cube reflectors, as utilized in a phase shifting diffraction interferometer can be replaced with a micromirror and a lens. For any very precise and small amplitudes of motion` micromachined electrostatic actuation may be used because it is the most compact in size, with low power consumption and has more straightforward sensing and control options.

  20. Spinning string and giant graviton in electric/magnetic field deformed AdS{sub 3}xS{sup 3}xT{sup 4}

    SciTech Connect

    Huang, W.-H.

    2006-06-15

    We apply the transformation of the mixing azimuthal and internal coordinate or the mixing time and internal coordinate to the 11D M theory with a stack of M2-branes perpendicular M2-branes, then through the mechanism of Kaluza-Klein reduction and a series of the T duality we obtain the corresponding background of a stack of D1-branes perpendicular D5-branes which, in the near-horizon limit, becomes the magnetic or electric Melvin field deformed AdS{sub 3}xS{sup 3}xT{sup 4}. We find the giant graviton solution in the deformed spacetime and see that the configuration whose angular momentum is within a finite region could have a fixed size and become more stable than the pointlike graviton, in contrast to the undeformed giant graviton which only exists when its angular momentum is a specific value and could have arbitrary size. We discuss in detail the properties of how the electric/magnetic Melvin field will affect the size of the giant gravitons. We also adopt an ansatz to find the classical string solutions which are rotating in the deformed S{sup 3} with an angular momentum in the rotation plane. The spinning string and giant graviton solutions we obtained show that the external magnetic/electric flux will increase the solution energy. Therefore, from the anti-de Sitter (AdS)/conformal field theory (CFT) point of view, the corrections of the anomalous dimensions of operators in the dual field theory will be positive. Finally, we also see that the spinning string and giant graviton in the near-horizon spacetime of Melvin field deformed D5-branes background have similar properties to those in the deformed AdS{sub 3}xS{sup 3}xT{sup 4}.

  1. 3x for All: Extending the Reach of Education's Best. Building an Opportunity Culture for America's Teachers

    ERIC Educational Resources Information Center

    Hassel, Emily Ayscue; Hassel, Bryan C.

    2009-01-01

    Teacher effectiveness has the largest impact of school effects on student learning, and research indicates that top-quintile teachers produce learning gains three times (3X) that of bottom-quintile teachers. However, the supply of these "3X" teachers is limited. Meanwhile, 3X teachers affect only a small portion of children each year, no more than…

  2. Applying the ethoexperimental approach to neurodevelopmental syndrome research reveals exaggerated defensive behavior in Mecp2 mutant mice

    PubMed Central

    Pearson, Brandon L.; Defensor, Erwin B.; Blanchard, D. Caroline; Blanchard, Robert J.

    2015-01-01

    Rett syndrome is a Pervasive Developmental Disorder (PDD) associated with de novo mutations of the methyl CpG-binding protein 2 (MECP2) gene. Mecp2 functions as a transcription factor that regulating the expression of hundreds of genes. Identification of the role of Mecp2 in specific neurodevelopmental symptoms remains an important research aim. We previously demonstrated that male mice possessing a truncation mutation in Mecp2 are hyper-social. We predicted that reduced fear or anxiety might underlie this enhanced affiliation. In order to probe risk assessment and anxiety-like behavior, we compared Mecp2 truncation mutants to their wild-type littermates in the elevated plus maze and elevated zero maze. Additionally, subjects were administered the mouse defense test battery to evaluate unconditioned fear- and panic-like behavior to a graded set of threat scenarios and a predator stimulus. Mutant mice showed no significant changes in anxiety-like behavior. Yet, they displayed hyper-reactive escape and defensive behaviors to an animate predatory threat stimulus. Notably, mutant mice engaged in exaggerated active defense responding to threat stimuli at nearly all phases of the fear battery. These results reveal abnormalities in emotion regulation in Mecp2 mutants particularly in response to ecologically relevant threats. This hyper-responsivity suggests that transcriptional targets of Mecp2 are critical to emotion regulation. Moreover, we suggest that detailed analysis of defensive behavior and aggression with ethologically relevant tasks provides an avenue to interrogate gene-behavior mechanisms neurodevelopmental and other psychiatric conditions. PMID:26066729

  3. Aerobic Exercise Attenuates an Exaggerated Exercise Blood Pressure Response in Normotensive Young Adult African-American Men

    PubMed Central

    BOND, VERNON; STEPHENS, QUIONA; ADAMS, RICHARD G.; VACCARO, PAUL; DEMEERSMAN, RONALD; WILLIAMS, DEBORAH; OBISESAN, THOMAS O.; FRANKS, B. DON; OKE, LUE M.; COLEMAN, BERNELL; BLAKELY, RAYMOND; MILLIS, RICHARD M.

    2011-01-01

    An exaggerated exercise blood pressure response (EEBPR) may be associated with an increased risk of hypertension. We hypothesized that aerobic exercise training can decrease EEBPR and the risk for hypertension by decreasing arterial resistance. We studied the effects of aerobic training on the submaximal exercise blood pressure (BP) of eight normotensive young adult African-American men with an EEBPR. Subjects were trained on a stationary bicycle at an intensity of 70% peak oxygen uptake (VO2peak) for 30 min, three times per week, for 8 weeks. BP, heart rate, cardiac output (CO), stroke volume (SV) and total peripheral vascular resistance (TPR) were measured at rest and during submaximal exercise at a work intensity of 50% VO2peak. Significance of the training effects were evaluated by comparing the pre- and post-training measures (t-test, p < 0.05). A 15% post-training increase in VO2peak (34.6 ± 1.4 to 40 ± 1.4 ml/kg/min) and a 9.5 ml post-training increase in mean resting stroke volume were found. A 16.2 mmHg decrement in mean systolic BP, an 11.5 mmHg decrement in mean diastolic BP, a 120 dyne/s/cm5 decrement in TPR and a 1.2 l/min increase in CO were detected during the post-training submaximal exercise tests. These results suggest that reductions in TPR may attenuate the EEBPR of normotensive African-American males following an 8-week training regimen of stationary bicycling at 70% VO2peak. Aerobic exercise training may, therefore, reduce the risk of hypertension in normotensive African-American males by the mechanism of a reduction in TPR. Because of the limited number of subjects, the results of this study should be interpreted cautiously pending confirmation by a larger controlled trial. PMID:12361191

  4. High Fat Diet Feeding Exaggerates Perfluorooctanoic Acid-Induced Liver Injury in Mice via Modulating Multiple Metabolic Pathways

    PubMed Central

    Tan, Xiaobing; Xie, Guoxiang; Sun, Xiuhua; Li, Qiong; Zhong, Wei; Qiao, Peter; Sun, Xinguo; Jia, Wei; Zhou, Zhanxiang

    2013-01-01

    High fat diet (HFD) is closely linked to a variety of health issues including fatty liver. Exposure to perfluorooctanoic acid (PFOA), a synthetic perfluorinated carboxylic acid, also causes liver injury. The present study investigated the possible interactions between high fat diet and PFOA in induction of liver injury. Mice were pair-fed a high-fat diet (HFD) or low fat control with or without PFOA administration at 5 mg/kg/day for 3 weeks. Exposure to PFOA alone caused elevated plasma alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels and increased liver weight along with reduced body weight and adipose tissue mass. HFD alone did not cause liver damage, but exaggerated PFOA-induced hepatotoxicity as indicated by higher plasma ALT and AST levels, and more severe pathological changes including hepatocyte hypertrophy, lipid droplet accumulation and necrosis as well as inflammatory cell infiltration. These additive effects of HFD on PFOA-induced hepatotoxicity correlated with metabolic disturbance in liver and blood as well as up-regulation of hepatic proinflammatory cytokine genes. Metabolomic analysis demonstrated that both serum and hepatic metabolite profiles of PFOA, HFD, or HFD-PFOA group were clearly differentiated from that of controls. PFOA affected more hepatic metabolites than HFD, but HFD showed positive interaction with PFOA on fatty acid metabolites including long chain fatty acids and acylcarnitines. Taken together, dietary high fat potentiates PFOA-induced hepatic lipid accumulation, inflammation and necrotic cell death by disturbing hepatic metabolism and inducing inflammation. This study demonstrated, for the first time, that HFD increases the risk of PFOA in induction of hepatotoxicity. PMID:23626681

  5. Astrocytes Are Primed by Chronic Neurodegeneration to Produce Exaggerated Chemokine and Cell Infiltration Responses to Acute Stimulation with the Cytokines IL-1β and TNF-α

    PubMed Central

    Hennessy, Edel; Griffin, Éadaoin W.

    2015-01-01

    Microgliosis and astrogliosis are standard pathological features of neurodegenerative disease. Microglia are primed by chronic neurodegeneration such that toll-like receptor agonists, such as LPS, drive exaggerated cytokine responses on this background. However, sterile inflammatory insults are more common than direct CNS infection in the degenerating brain and these insults drive robust IL-1β and TNF-α responses. It is unclear whether these pro-inflammatory cytokines can directly induce exaggerated responses in the degenerating brain. We hypothesized that glial cells in the hippocampus of animals with chronic neurodegenerative disease (ME7 prion disease) would display exaggerated responses to central cytokine challenges. TNF-α or IL-1β were administered intrahippocampally to ME7-inoculated mice and normal brain homogenate-injected (NBH) controls. Both IL-1β and TNF-α produced much more robust IL-1β synthesis in ME7 than in NBH animals and this occurred exclusively in microglia. However, there was strong nuclear localization of the NFκB subunit p65 in the astrocyte population, associated with marked astrocytic synthesis of the chemokines CXCL1 and CCL2 in response to both cytokine challenges in ME7 animals. Conversely, very limited expression of these chemokines was apparent in NBH animals similarly challenged. Thus, astrocytes are primed in the degenerating brain to produce exaggerated chemokine responses to acute stimulation with pro-inflammatory cytokines. Furthermore, this results in markedly increased neutrophil, T-cell, and monocyte infiltration in the diseased brain. These data have significant implications for acute sterile inflammatory insults such as stroke and traumatic brain injury occurring on a background of aging or neurodegeneration. PMID:26041910

  6. Large magneto-optical Kerr effect in noncollinear antiferromagnets Mn3X (X =Rh ,Ir ,Pt )

    NASA Astrophysics Data System (ADS)

    Feng, Wanxiang; Guo, Guang-Yu; Zhou, Jian; Yao, Yugui; Niu, Qian

    2015-10-01

    Magneto-optical Kerr effect, normally found in magnetic materials with nonzero magnetization such as ferromagnets and ferrimagnets, has been known for more than a century. Here, using first-principles density functional theory, we demonstrate large magneto-optical Kerr effect in high-temperature noncollinear antiferromagnets Mn3X (X =Rh ,Ir ,Pt ), in contrast to usual wisdom. The calculated Kerr rotation angles are large, being comparable to that of transition-metal magnets such as bcc Fe. The large Kerr rotation angles and ellipticities are found to originate from the lifting of band double degeneracy due to the absence of spatial symmetry in the Mn3X noncollinear antiferromagnets which together with the time-reversal symmetry would preserve the Kramers theorem. Our results indicate that Mn3X would provide a rare material platform for exploration of subtle magneto-optical phenomena in noncollinear magnetic materials without net magnetization.

  7. A Noise and Emissions Assessment of the N3-X Transport

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.; Haller, William J.

    2014-01-01

    Analytical predictions of certification noise and exhaust emissions for NASA's N3-X - a notional, hybrid wingbody airplane - are presented in this paper. The N3-X is a 300-passenger concept transport propelled by an array of fans distributed spanwise near the trailing edge of the wingbody. These fans are driven by electric motors deriving power from twin generators driven by turboshaft engines. Turboelectric distributed hybrid propulsion has the potential to dramatically increase the propulsive efficiency of aircraft. The noise and exhaust emission estimates presented here are generated using NASA's conceptual design systems analysis tools with several key modifications to accommodate this unconventional architecture. These tools predict certification noise and the emissions of oxides of nitrogen by leveraging data generated from a recent analysis of the N3-X propulsion system.

  8. Resource-Efficient High-Yield Ionothermal Synthesis of Microcrystalline Cu3-xP.

    PubMed

    Wolff, Alexander; Pallmann, Julia; Boucher, Richard; Weiz, Alexander; Brunner, Eike; Doert, Thomas; Ruck, Michael

    2016-09-01

    Polycrystalline Cu3-xP was successfully synthesized in different ionic liquids comprising imidazolium and phosphonium cations. The reaction of elemental copper and red phosphorus in trihexyltetradecylphosphonium chloride at 200 °C led to single-phase Cu3-xP (x = 0.05) within 24 h with a quantitative yield (99%). Liquid-state nuclear magnetic resonance spectroscopy of the ionic liquids revealed degeneration of the imidazolium cations under the synthesis conditions, while phosphonium cations remain stable. The solid products were characterized with X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and elemental analysis. A reinvestigation of the electronic transport properties of Cu2.95(4)P showed metallic behavior for the bulk material. The formation of CuP2 during the synthesis of phosphorus-rich Cu3-xP (x ≥ 0.1) was observed. PMID:27559933

  9. Flow Simulation of N3-X Hybrid Wing-Body Configuration

    NASA Technical Reports Server (NTRS)

    Kim, Hyoungjin; Liou, Meng-Sing

    2013-01-01

    System studies show that a N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level) set by NASA s Subsonic Fixed Wing Project. In this study, a Navier-Stokes flow simulation of N3-X on hybrid unstructured meshes was conducted, including the mail-slot propulsor. The geometry of the mail-slot propulsor was generated by a CAD (Computer-Aided Design)-free shape parameterization. A body force approach was used for a more realistic and efficient simulation of the turning and loss effects of the fan blades and the inlet-fan interactions. Flow simulation results of the N3-X demonstrates the validity of the present approach.

  10. Visualization of A-Train vertical profiles using Google Earth

    NASA Astrophysics Data System (ADS)

    Chen, Aijun; Leptoukh, Gregory; Kempler, Steven; Lynnes, Christopher; Savtchenko, Andery; Nadeau, Denis; Farley, John

    2009-02-01

    Online tools, such as those pioneered by Google Earth (GE), are changing the way in which scientists and the general public interact with three-dimensional geospatial data in a virtual environment. However, while GE provides a number of features to facilitate geospatial data visualization, there is currently no readily available method for rendering vertical geospatial data derived from Earth—viewing remote sensing satellites as an orbit curtain seen from above. Here, a solution (one of many possible) is demonstrated to render vertical profiles of atmospheric data from the A-Train satellite formation in GE, using as a proof-of-concept data from one of the instruments—the NASA CloudSat satellite. CloudSat carries a nadir-viewing Cloud Profiling Radar that produces data revealing the vertical distribution of cloud characteristics along the satellite track. These data are first rendered into a long vertical image for a user-selected spatial range through the NASA Goddard Interactive Online Visualization ANd aNalysis Infrastructure (G IOVANNI) system ( http://giovanni.gsfc.nasa.gov/). The vertical image is then chopped into small slices representing 15 s of satellite time (˜103 km long ground distance). Each small piece, as a texture, is fed into a generalized COLLAborative Design Activity (COLLADA) three-dimensional (3-D) model. Using the satellite orbit coordinates, the repeated 15 s "3-D model slices" are spliced together to form a vertical "curtain" image in Keyhole Markup Language (KML) format. Each model slice is geolocated along the CloudSat orbit path based on its size, scale and angle with the longitude line that are precisely calculated on the fly. The resulting vertical cloud data can be viewed in GE, either transparently or opaquely, superimposed above the Earth's surface with an exaggerated vertical scale. Since CloudSat is just a part of the A-Train formation, the full utility of this tool can be explored within the context of the A-Train Data Depot

  11. Vertical Seismoelectric Profiling

    NASA Astrophysics Data System (ADS)

    Araji, A.

    2011-12-01

    The seismoelectric method corresponds to the measurement of electromagnetic disturbances associated with the passage of seismic waves in a porous medium. The coupling is due to the existence of the electric double layer at the solid/water interfaces. We consider the case of vertical seismoelectric profiling in which we trigger a seismic source in a vertical borehole and measure the seismoelectric response on the surface. We aim to image hetrogeneities in that section of the subsurface by utilizing the seismoelectric sources created at interfaces. An iterative source localization inversion algorithm is used to achieve the imaging of interfaces.

  12. Aiding Vertical Guidance Understanding

    NASA Technical Reports Server (NTRS)

    Feary, Michael; McCrobie, Daniel; Alkin, Martin; Sherry, Lance; Polson, Peter; Palmer, Everett; McQuinn, Noreen

    1998-01-01

    A two-part study was conducted to evaluate modern flight deck automation and interfaces. In the first part, a survey was performed to validate the existence of automation surprises with current pilots. Results indicated that pilots were often surprised by the behavior of the automation. There were several surprises that were reported more frequently than others. An experimental study was then performed to evaluate (1) the reduction of automation surprises through training specifically for the vertical guidance logic, and (2) a new display that describes the flight guidance in terms of aircraft behaviors instead of control modes. The study was performed in a simulator that was used to run a complete flight with actual airline pilots. Three groups were used to evaluate the guidance display and training. In the training, condition, participants went through a training program for vertical guidance before flying the simulation. In the display condition, participants ran through the same training program and then flew the experimental scenario with the new Guidance-Flight Mode Annunciator (G-FMA). Results showed improved pilot performance when given training specifically for the vertical guidance logic and greater improvements when given the training and the new G-FMA. Using actual behavior of the avionics to design pilot training and FMA is feasible, and when the automated vertical guidance mode of the Flight Management System is engaged, the display of the guidance mode and targets yields improved pilot performance.

  13. Vertical Alignment and Collaboration.

    ERIC Educational Resources Information Center

    Bergman, Donna; Calzada, Lucio; LaPointe, Nancy; Lee, Audra; Sullivan, Lynn

    This study investigated whether vertical (grade level sequence) alignment of the curriculum in conjunction with teacher collaboration would enhance student performance on the Texas Assessment of Academic Skills (TAAS) test in south Texas school districts of various sizes. Surveys were mailed to the office of the superintendent of 47 school…

  14. Vertical shaft windmill

    NASA Technical Reports Server (NTRS)

    Grana, D. C.; Inge, S. V., Jr. (Inventor)

    1983-01-01

    A vertical shaft has several equally spaced blades mounted. Each blade consists of an inboard section and an outboard section skew hinged to the inboard section. The inboard sections automatically adjust their positions with respect to the fixed inboard sections with changes in velocity of the wind. This windmill design automatically governs the maximum rotational speed of shaft.

  15. Window type: paired 3x2 multipaned steel window flanked by 1x3 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Window type: paired 3x2 multipaned steel window flanked by 1x3 multipaned steel casements, breaking building corner. Broad overhanging eave also illustrated. Second story detail. Building 13, facing east - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  16. Comparison of Yamax pedometer and GT3X accelerometer steps in a free-living sample

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to compare steps detected by the Yamax pedometer (PEDO) versus the GT3X accelerometer (ACCEL) in free-living adults. Daily PEDO and ACCEL steps were collected from a sample of 23 overweight and obese participants (18 females; mean +/- sd: age = 52.6 +/- 8.4 yr.; body mass index = 3...

  17. Ultrasmall Biocompatible WO3- x Nanodots for Multi-Modality Imaging and Combined Therapy of Cancers.

    PubMed

    Wen, Ling; Chen, Ling; Zheng, Shimin; Zeng, Jianfeng; Duan, Guangxin; Wang, Yong; Wang, Guanglin; Chai, Zhifang; Li, Zhen; Gao, Mingyuan

    2016-07-01

    Ultrasmall biocompatible WO3 - x nanodots with an outstanding X-ray radiation sensitization effect are prepared, and demonstrated to be applicable for multi-modality tumor imaging through computed tomography and photoacoustic imaging (PAI), and effective cancer treatment combining both photothermal therapy and radiation therapy. PMID:27136070

  18. Structure and magnetic transport properties of GdIn3-xMnx intermetallics

    NASA Astrophysics Data System (ADS)

    He, Qiang; Guo, Yongquan; Liu, Hanyuan

    2016-03-01

    The crystal structures and magneto-transport properties of GdIn3-xMnx have been investigated using X-ray diffraction and magnetic and electric measurements. GdIn3-xMnx crystallize in cubic structure, and their lattice parameters tend to decrease with increasing Mn content due to the size effect at In site by Mn substitution for In. Mn doped GdIn3-xMnx order antiferromagnetically at low temperature. However, Mn doping into GdIn3 causes the decrease of Néel temperature due to the distortion of Gd(In,Mn)3 tetrahedron formed by Gd at corners and (In,Mn) at face centers in unit cell. The resistivities of GdIn3-xMnx are going up with increasing Mn content. The electric phase transition is associated with the magnetic transition, and the magneto-transport follows electron-magnon scattering model in low temperature region and the Stoner spin fluctuation model in high temperature region, respectively.

  19. Master formula approach to broken chiral U(3)xU(3) symmetry

    SciTech Connect

    Hiroyuki Kamano

    2010-04-01

    The master formula approach to chiral symmetry breaking proposed by Yamagishi and Zahed is extended to the U_R(3)xU_L(3) group, in which effects of the U_A(1) anomaly and the flavor symmetry breaking m_u \

  20. Impairment of nesting behaviour in 3xTg-AD mice.

    PubMed

    Torres-Lista, Virginia; Giménez-Llort, Lydia

    2013-06-15

    Deterioration in executive functions and daily life activities (DLA) are early signs of Alzheimer's disease (AD) that signal the need for caregiver attention. We have addressed this issue in the 3xTg-AD mice model for AD and studied nesting behaviour as a natural DLA of parental structures as well as at early- (6 month-old) and advanced-stages (12 month-old) of the disease in isolated animals. The results show genetic, gender and age-dependent impairment of nesting behaviour but also aware about the relevance of factors such as the temporal course of nest construction and the nesting material. Paper towel consistently showed the impairment of nesting behavior in 3xTg-AD mice since early stages of the disease and in both social conditions. Their nest construction was slow temporal pattern and of poor quality, especially in females and advanced stages of the disease where the deficits were shown from the first day. In all cases, cotton elicited an intense behaviour that lead to perfect nesting during the first 48 h. Genotype, gender and age differences were found in the onset of nesting behaviour, with a time delay in the 3xTg-AD mice, particularly in females. The reported impairment of nesting behaviour in 3xTg-AD provides another behavioral tool to assess the benefits of preventive and/or therapeutic strategies, as well as the potential action of risk factors of AD, in this animal model. PMID:23523959

  1. Reexamining D-branes in AdS{sub 3}xS{sub 3} space

    SciTech Connect

    Kumar, Jason; Rajaraman, Arvind

    2004-11-15

    We find the most general supergravity solution in an AdS{sup 3}xS{sup 3} background preserving an AdS{sub 2}xS{sup 2} symmetry and half the supersymmetries. Contrary to previous expectations from boundary state arguments, it is shown that no solutions exist containing localized brane sources.

  2. PlanHab: hypoxia exaggerates the bed-rest-induced reduction in peak oxygen uptake during upright cycle ergometry.

    PubMed

    Keramidas, Michail E; Kölegård, Roger; Mekjavic, Igor B; Eiken, Ola

    2016-08-01

    The study examined the effects of hypoxia and horizontal bed rest, separately and in combination, on peak oxygen uptake (V̇o2 peak) during upright cycle ergometry. Ten male lowlanders underwent three 21-day confinement periods in a counterbalanced order: 1) normoxic bed rest [NBR; partial pressure of inspired O2 (PiO2 ) = 133.1 ± 0.3 mmHg]; 2) hypoxic bed rest (HBR; PiO2 = 90.0 ± 0.4 mmHg), and 3) hypoxic ambulation (HAMB; PiO2 = 90.0 ± 0.4 mmHg). Before and after each confinement, subjects performed two incremental-load trials to exhaustion, while inspiring either room air (AIR), or a hypoxic gas (HYPO; PiO2 = 90.0 ± 0.4 mmHg). Changes in regional oxygenation of the vastus lateralis muscle and the frontal cerebral cortex were monitored with near-infrared spectroscopy. Cardiac output (CO) was recorded using a bioimpedance method. The AIR V̇o2 peak was decreased by both HBR (∼13.5%; P ≤ 0.001) and NBR (∼8.6%; P ≤ 0.001), with greater drop after HBR (P = 0.01). The HYPO V̇o2 peak was also reduced by HBR (-9.7%; P ≤ 0.001) and NBR (-6.1%; P ≤ 0.001). Peak CO was lower after both bed-rest interventions, and especially after HBR (HBR: ∼13%, NBR: ∼7%; P ≤ 0.05). Exercise-induced alterations in muscle and cerebral oxygenation were blunted in a similar manner after both bed-rest confinements. No changes were observed in HAMB. Hence, the bed-rest-induced decrease in V̇o2 peak was exaggerated by hypoxia, most likely due to a reduction in convective O2 transport, as indicated by the lower peak values of CO. PMID:27342877

  3. Jamming in Vertical Channels

    NASA Astrophysics Data System (ADS)

    Baxter, G. William; Steel, Fiona

    2011-03-01

    We study jamming of low aspect-ratio cylindrical Delrin grains in a vertical channel. Grain heights are less than their diameter so the grains resemble antacid tablets, coins, or poker chips. These grains are allowed to fall through a vertical channel with a square cross section where the channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. Grains are sometimes observed to form jams, stable structures supported by the channel walls with no support beneath them. The probability of jam occurrence and the strength or robustness of a jam is effected by grain and channel sizes. We will present experimental measurements of the jamming probability and jam strength in this system and discuss the relationship of these results to other experiments and theories. Supported by an Undergraduate Research Grant from Penn State Erie, The Behrend College.

  4. Jamming in Vertical Channels

    NASA Astrophysics Data System (ADS)

    Baxter, G. William; McCausland, Jeffrey; Steel, Fiona

    2010-03-01

    We experimentally study jamming of cylindrical grains in a vertical channel. The grains have a low aspect-ratio (height/diameter < 1) so their shape is like antacid tablets or poker chips. They are allowed to fall through a vertical channel with a square cross section. The channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. It is observed that grains sometimes jam in this apparatus. In a jam, grains form a stable structure from one side of the channel to the other with nothing beneath them. Jams may be strong enough to support additional grains above. The probability of a jam occurring is a function of the grain height and diameter. We will present experimental measurements of the jamming probability in this system and discuss the relationship of these results to other experiments and theories.

  5. Vertical organic transistors

    NASA Astrophysics Data System (ADS)

    Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

    2015-11-01

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted.

  6. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Stadler, Henry L. (Inventor); Wu, Jiin-chuan (Inventor)

    1995-01-01

    A new read gate design for the vertical Bloch line (VBL) memory is disclosed which offers larger operating margin than the existing read gate designs. In the existing read gate designs, a current is applied to all the stripes. The stripes that contain a VBL pair are chopped, while the stripes that do not contain a VBL pair are not chopped. The information is then detected by inspecting the presence or absence of the bubble. The margin of the chopping current amplitude is very small, and sometimes non-existent. A new method of reading Vertical Bloch Line memory is also disclosed. Instead of using the wall chirality to separate the two binary states, the spatial deflection of the stripe head is used. Also disclosed herein is a compact memory which uses vertical Bloch line (VBL) memory technology for providing data storage. A three-dimensional arrangement in the form of stacks of VBL memory layers is used to achieve high volumetric storage density. High data transfer rate is achieved by operating all the layers in parallel. Using Hall effect sensing, and optical sensing via the Faraday effect to access the data from within the three-dimensional packages, an even higher data transfer rate can be achieved due to parallel operation within each layer.

  7. Understanding the conductive channel evolution in Na:WO3-x-based planar devices

    NASA Astrophysics Data System (ADS)

    Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

    2015-03-01

    An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na+ mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the

  8. Interface and grain boundary resistance of a lithium lanthanum titanate (Li3xLa2/3-xTiO3, LLTO) solid electrolyte

    NASA Astrophysics Data System (ADS)

    Uhlmann, C.; Braun, P.; Illig, J.; Weber, A.; Ivers-Tiffée, E.

    2016-03-01

    Advanced experimental setups and measurement techniques are crucial for investigating and systematically improving interface characteristics. In this study we introduce an interface-cell, which allows the systematic analysis of liquid/solid electrolyte interfaces via four-point measurements. The functionality of this setup is demonstrated by analysing the impact of parameter variations on the aqueous interface of lithium lanthanum titanate (Li3xLa2/3-xTiO3, LLTO) solid electrolytes as used in Lithium-air batteries. By variation of real operating conditions their impact on cycling performance is highlighted. Examples include temperature (0 to +25 °C) and state of charge (SoC), which induces an alteration of pH (here pH ≈ 6-14) and Li+-concentration (here 0.057 mol L-1 to 10.62 mol L-1). Interestingly, a change of the polarization resistance greater than two orders of magnitude (250 Ωcm2-25,000 Ωcm2) could be identified. The proven dependency of the interface to both the pH and Li+-concentration is explained by an H+/Li+-exchange reaction at the LLTO/H2O-interface. Additionally, we were able to determine the solely grain boundary resistance (∼250 Ωcm2 at 25 °C) of the LLTO samples, without the impact of blocking electrodes. A temperature variation revealed the activation energies of the processes to be 0.4 eV (grain boundary) and 0.46 eV (interface). These results were then critically evaluated in the context of aqueous Lithium-air batteries.

  9. Dysfunction of Inflammation-Resolving Pathways Is Associated with Exaggerated Postoperative Cognitive Decline in a Rat Model of the Metabolic Syndrome

    PubMed Central

    Su, Xiao; Feng, Xiaomei; Terrando, Niccolo; Yan, Yan; Chawla, Ajay; Koch, Lauren G; Britton, Steven L; Matthay, Michael A; Maze, Mervyn

    2012-01-01

    The cholinergic antiinflammatory pathway (CAP), which terminates in the spleen, attenuates postoperative cognitive decline (PCD) in rodents. Surgical patients with metabolic syndrome exhibit exaggerated and persistent PCD that is reproduced in postoperative rats selectively bred for easy fatigability and that contain all features of metabolic syndrome (low-capacity runners [LCRs]). We compared the CAP and lipoxin A4 (LXA4), another inflammation-resolving pathway in LCR, with its counterpart high-capacity runner (HCR) rats. Isoflurane-anesthetized LCR and HCR rats either underwent aseptic trauma involving tibial fracture (surgery) or not (sham). At postoperative d 3 (POD3), compared with HCR, LCR rats exhibited significantly exaggerated PCD (trace fear conditioning freezing time 43% versus 57%). Separate cohorts were killed at POD3 to collect plasma for LXA4 and to isolate splenic mononuclear cells (MNCs) to analyze CAP signaling, regulatory T cells (Tregs) and M2 macrophages (M2 Mφ). Under lipopolysaccharide (LPS) stimulation, tumor necrosis factor (TNF)-α produced by splenic MNCs was 117% higher in LCR sham and 52% higher in LCR surgery compared with HCR sham and surgery rats; LPS-stimulated TNF-α production could not be inhibited by an α7 nicotinic acetylcholine receptor agonist, whereas inhibition by the β2 adrenergic agonist, salmeterol, was significantly less (−35%) than that obtained in HCR rats. Compared to HCR, sham and surgery LCR rats had reduced β2 adrenergic receptor–expressing T lymphocytes (59%, 44%), Tregs (47%, 54%) and M2 Mφ (45%, 39%); surgical LCR rats’ hippocampal M2 Mφ was 66% reduced, and plasma LXA4 was decreased by 120%. Rats with the metabolic syndrome have ineffective inflammation-resolving mechanisms that represent plausible reasons for the exaggerated and persistent PCD. PMID:23296426

  10. Laboratory Detection of IZnCH_{3} (X^{1}A_{1}) : Further Evidence for Zinc Insertion

    NASA Astrophysics Data System (ADS)

    Bucchino, Matthew P.; Young, Justin P.; Sheridan, Phil M.; Ziurys, Lucy M.

    2013-06-01

    Millimeter-wave direct absorption techniques were used to record the pure rotational spectrum of IZnCH_{3} (X^{1}A_{1}). This species was produced by the reaction of zinc vapor with ICH_{3} in the presence of a DC discharge. Rotational transitions ranging from J = 109 {→} 108 to J = 122 {→} 121 were recorded for I^{64}ZnCH_{3} and I^{66}ZnCH_{3} in the frequency range of 250{-290} GHz. The Ka = 0{-4} components were measured for each transition, with the K-ladder structure and nuclear spin statistics indicative of a symmetric top. As with HZnCH_{3} (X^{1}A_{1}), the detection of IZnCH_{3} provides further evidence for a zinc insertion process.

  11. Fixing All Moduli for M-Theory on K3xK3

    SciTech Connect

    Aspinwall, Paul S.; Kallosh, Renata; /Stanford U., Phys. Dept.

    2005-06-15

    We analyze M-theory compactified on K3 x K3 with fluxes preserving half the supersymmetry and its F-theory limit, which is dual to an orientifold of the type IIB string on K3 x (T{sup 2}/Z{sub 2}). The geometry of attractive K3 surfaces plays a significant role in the analysis. We prove that the number of choices for the K3 surfaces is finite and we show how they can be completely classified. We list the possibilities in one case. We then study the instanton effects and see that they will generically fix all of the moduli. We also discuss situations where the instanton effects might not fix all the moduli.

  12. Interaction between body weight status and walking speed in steps monitoring by GT3X accelerometer.

    PubMed

    Bélanger, Marie-Lyse; Kestens, Yan; Gilbert, Jo-Anne; Tremblay, Angelo; Mathieu, Marie-Eve

    2014-08-01

    The measurement error of the step count function of the ActiGraph GT3X accelerometer was assessed at different walking speeds in 12 obese and 16 nonobese individuals. In comparison with visual verification, the accelerometer step count function measurement error was larger for obese individuals walking at low speeds (2.5 km·h(-1)). This error equated to an approximate 50% underestimation at these speeds. PMID:24823315

  13. Magnetic and Structural Properties of Rapidly Quenched Tetragonal Mn3-xGa Nanostructures

    SciTech Connect

    Huh, Y; Kharel, P; Shah, VR; Krage, E; Skomski, R; Shield, JE; Sellmyer, DJ

    2013-07-01

    Nanostructured Mn3-x Ga ribbons with x = 0, 0.4, 0.9 and 1.1 were prepared using arc-melting, melt-spinning and annealing. As-spun samples crystallized into hexagonal D0(19) and cubic L2(1) Heusler crystal structures based on the concentration of Mn in Mn3-xGa. Upon vacuum-annealing the samples at 450 degrees C for about 50 hours, both the hexagonal and cubic structures transformed into a tetragonal D0(22) structure. High-temperature x-ray diffraction and high-temperature magnetometry showed that the samples with low Mn content (Mn-1.9 Ga and Mn-2.1 Ga) retain their tetragonal structure up to 850 K but the samples with high Mn concentrations (Mn-2.6 Ga and Mn-3.0 Ga) undergo a structural phase transition from tetragonal to hexagonal phases around 800 K. The magnetic properties of Mn3-x Ga ribbons were very sensitive to Mn concentration, where the magnetization and anisotropy energy increased and the coercivity decreased as x increased from 0 to 1.1. Although the Curie temperatures of Mn-2.6 Ga and Mn-3.0 Ga samples could not be determined because of the structural phase transition, the Curie temperature decreased with increasing x in Mn3-x Ga. The maximum magnetization of 57 emu/g (300 emu/cm(3)) and the coercivity of 6.5 kOe were measured in the Mn-1.9 Ga and Mn-3.0 Ga ribbons, respectively.

  14. Design of 3x3 focusing array for heavy ion driver. Final report on CRADA

    SciTech Connect

    Martovetsky, N N

    2005-03-30

    This memo presents a design of a 3 x 3 quadrupole array for HIF. It contains 3 D magnetic field computations of the array build with racetrack coils with and without different shields. It is shown that it is possible to have a low error magnetic field in the cells and shield the stray fields to acceptable levels. The array design seems to be a practical solution to any size array for future multi-beam heavy ion fusion drivers.

  15. Structural defects and microindentation analysis of zone melted Bi2Te3-xSex whiskers

    NASA Astrophysics Data System (ADS)

    Jariwala, Bhakti; Shah, Dimple V.

    2012-08-01

    The dislocation density and microhardness of Bi2Te3-xSex (x=0-0.3 at% Se) grown by the zone melting method have been investigated. We also have got the whiskers of Bi2Te3-xSex at the end of ampoule during the growth process. SEM was characterized for surface analysis of the grown whisker. The length of the grown whiskers was around 10 mm in the direction of the crystallographic c-axis. Concentric pairs of dislocation triangle were observed on the as-grown surfaces of short hexagonal prisms. A systematic study of dislocations in these crystals was carried out by the chemical etching technique. Dislocation etching was achieved on all crystal planes examined using a saturated solution of citric acid and nitric acid as the etchant. The dislocation etchant has been found to give reproducible etch-pits on the cleavage surface. The use of citric acid and nitric acid proved to be especially advantageous for the basal plane, producing etched pits suitable for dislocation etch pit counting. The effects of Se doping, annealing and quenching on the mechanical properties have also been studied on the (001) faces of Bi2Te3-xSex.

  16. WO3-x Nanoplates Grown on Carbon Nanofibers for an Efficient Electrocatalytic Hydrogen Evolution Reaction.

    PubMed

    Chen, JiaDong; Yu, DanNi; Liao, WeiSha; Zheng, MengDan; Xiao, LongFei; Zhu, Han; Zhang, Ming; Du, MingLiang; Yao, JuMing

    2016-07-20

    The search for non-noble metal catalysts with high activity for the hydrogen evolution reaction (HER) is crucial for efficient hydrogen production at low cost and on a large scale. Herein, we report a novel WO3-x catalyst synthesized on carbon nanofiber mats (CFMs) by electrospinning and followed by a carbonization process in a tubal furnace. The morphology and composition of the catalysts were tailored via a simple method, and the hybrid catalyst mats were used directly as cathodes to investigate their HER performance. Notably, the as-prepared catalysts exhibit substantially enhanced activity for the HER, demonstrating a small overpotential, a high exchange current density, and a large cathodic current density. The remarkable electrocatalytic performances result from the poor crystallinity of WO3-x, the high electrical conductivity of WO3-x, and the use of electrospun CNFs. The present work outlines a straightforward approach for the synthesis of transition metal oxide (TMO)-based carbon nanofiber mats with promising applications for the HER. PMID:27356101

  17. Unexpected structural softening of interstitial boron solid solution WB{sub 3+x}

    SciTech Connect

    Wu, Hao; Sun, Hong E-mail: chen@physics.unlv.edu; Chen, Changfeng E-mail: chen@physics.unlv.edu

    2014-11-24

    Using first-principles calculations, we reveal an unexpected structural softening in a recently proposed WB{sub 3+x} structural model that tries to explain the X-ray diffraction, high resolution TEM, pressure dependence of the normalized lattice c/a ratio, and hardness experimental results of the synthesized tungsten boride compounds with a nominal composition WB{sub 4}. We show that the interstitial boron in WB{sub 3+x}, which was proposed to strengthen the covalent bonding network, unexpectedly weakens the atomic bonding, resulting in a large reduction of its indentation strength to well below that of WB{sub 3}. This is in direct contradiction to the experimental results showing that synthesized WB{sub 4} is harder than WB{sub 3}. The unusual structural softening is attributed to the unique three-center covalent bonding formed by the interstitial boron atoms that can easily deform under indentation. Our results show that the proposed interstitial boron solid solution WB{sub 3+x} structure is incompatible with experimental results, which calls for further investigations to determine the crystal structure of the synthesized WB{sub 4}.

  18. Oxygen Adsorption on the 6H-SiC(0001) (3x3) Surface

    NASA Astrophysics Data System (ADS)

    Cui, Y.; Li, L.

    2001-03-01

    Silicon carbide (SiC) is an attractive semiconductor for applications requiring a wide bandgap, high temperature/high power and chemical inertness. An investigation of the initial stages of oxidation of SiC, therefore, is important for optimizing the growth of thin, insulating oxide layers in SiC devices. In the present work, scanning tunneling microscopy (STM) has been used to study the initial stages of oxygen adsorption at room temperature on the Si-rich (3x3) surface of 6H-SiC(0001). The (3x3) surface is prepared by a two-step method of etching in hydrogen atmosphere at 1500 ^oC and annealing under Si beam in UHV at 950 ^oC. Upon adsorption of oxygen on the (3x3) surface, only one reaction product has been identified in the STM topographs, which appears as bright sites in the empty-state mode. These bright sites are attributed to the oxygen atoms inserted in one of the Si adatom's back bonds. These results and their implications for oxide growth on SiC will be presented at the meeting.

  19. Metalorganic vapor phase epitaxy growth of ternary tetradymite Bi2Te3-xSex compounds

    NASA Astrophysics Data System (ADS)

    Kuznetsov, P. I.; Yakushcheva, G. G.; Luzanov, V. A.; Temiryazev, A. G.; Shchamkhalova, B. S.; Jitov, V. A.; Sizov, V. E.

    2015-01-01

    We report on a metal organic vapor epitaxy (MOVPE) of Bi2Te3-xSex films over the entire range of compositions (0 ≤ x ≤ 3) for the first time. The films were grown on Al2O3(0001) substrates at 465 °C using trimethylbismuth (Bi2Me3), diethyltellurium (Et2Te) and diisopropylselenium (iPro2Se) as metalorganic sources. To realize the 2D growth mode and to grow films with flat surfaces and high crystalline quality, a thin ZnTe buffer layer was used. As-grown films were studied using optical and AFM microscopy techniques and X-ray diffraction. It was found that under steady growth conditions the composition of Bi2Te3-xSex films strongly depends on the film thickness. But a high rate of interdiffusion of chalcogens at the growth temperature rapidly leads to a homogeneous composition of the film in the growth direction. Dependence of the intensity of X-ray reflection (0012) on the composition of Bi2Te3-xSex films x has extremes near x=1 (Bi2Te2 Se) and x=2 (Bi2Se2 Te). The AFM micrographs and profiles show large (above 2 μm) triangle-shaped atomically flat terraces with step height of a quintuple layer (0.90 nm) of the tetradymite-type compounds. The electronic properties of the grown films have been characterized via four probe magnetotransport measurements.

  20. Understanding the conductive channel evolution in Na:WO(3-x)-based planar devices.

    PubMed

    Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

    2015-04-14

    An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO(3-x)) films on a soda-lime glass substrate, from which Na(+) diffuses into the WO(3-x) films during the deposition. The entire process of Na(+) migration driven by an alternating electric field is visualized in the Na-doped WO(3-x) films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na(+) mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices. PMID:25766380

  1. Exome sequencing identifies somatic mutations of DDX3X in natural killer/T-cell lymphoma.

    PubMed

    Jiang, Lu; Gu, Zhao-Hui; Yan, Zi-Xun; Zhao, Xia; Xie, Yin-Yin; Zhang, Zi-Guan; Pan, Chun-Ming; Hu, Yuan; Cai, Chang-Ping; Dong, Ying; Huang, Jin-Yan; Wang, Li; Shen, Yang; Meng, Guoyu; Zhou, Jian-Feng; Hu, Jian-Da; Wang, Jin-Fen; Liu, Yuan-Hua; Yang, Lin-Hua; Zhang, Feng; Wang, Jian-Min; Wang, Zhao; Peng, Zhi-Gang; Chen, Fang-Yuan; Sun, Zi-Min; Ding, Hao; Shi, Ju-Mei; Hou, Jian; Yan, Jin-Song; Shi, Jing-Yi; Xu, Lan; Li, Yang; Lu, Jing; Zheng, Zhong; Xue, Wen; Zhao, Wei-Li; Chen, Zhu; Chen, Sai-Juan

    2015-09-01

    Natural killer/T-cell lymphoma (NKTCL) is a malignant proliferation of CD56(+) and cytoCD3(+) lymphocytes with aggressive clinical course, which is prevalent in Asian and South American populations. The molecular pathogenesis of NKTCL has largely remained elusive. We identified somatic gene mutations in 25 people with NKTCL by whole-exome sequencing and confirmed them in an extended validation group of 80 people by targeted sequencing. Recurrent mutations were most frequently located in the RNA helicase gene DDX3X (21/105 subjects, 20.0%), tumor suppressors (TP53 and MGA), JAK-STAT-pathway molecules (STAT3 and STAT5B) and epigenetic modifiers (MLL2, ARID1A, EP300 and ASXL3). As compared to wild-type protein, DDX3X mutants exhibited decreased RNA-unwinding activity, loss of suppressive effects on cell-cycle progression in NK cells and transcriptional activation of NF-κB and MAPK pathways. Clinically, patients with DDX3X mutations presented a poor prognosis. Our work thus contributes to the understanding of the disease mechanism of NKTCL. PMID:26192917

  2. Structure and magnetic properties of PrIn3- x Co x

    NASA Astrophysics Data System (ADS)

    He, Qiang; Guo, Yongquan

    2016-04-01

    The synthesis, crystal structure and magnetic properties of PrIn3- x Co x have been systematically investigated using X-ray diffraction and magnetic measurements. Co doping into PrIn3 causes the presence of satellite peaks, which has been indexed as a hexagonal structure. Rietveld's structural refinement shows this structure is an isomorphic structure of CaIn2 type with a space group of P63/mmc and Z = 2. There are two non-equivalent crystal positions in one unit cell, which are occupied by 2Pr and 4(In, Co), respectively. Doping of Co into PrIn3 induces room temperature ferromagnetic order, and the magnetization increases with increasing Co content. It is suggested that the ferromagnetism in PrIn3- x Co x is caused by the spin-spin interactions between Co and Co or Co and Pr. The magnetic moment increase of PrIn3- x Co x could result from the partial substitution of non-magnetic element In by magnetic element Co in the host material through dilute doping of Co, and thus, a net moment is produced.

  3. A new measurement of the cosmic ray energy spectrum between 3 x 10 to the 15th power eV and 3 x 10 to the 16th power eV

    NASA Technical Reports Server (NTRS)

    Gregory, A. G.; Patterson, J. R.; Protheroe, R. J.

    1985-01-01

    A new Cerenkov photon density spectrum measurement is reported. The derivation of the primary cosmic ray energy spectrum for energies from 3x10 to the 15th power eV to 3x10 to the 16th power eV are presented.

  4. 'Endurance' Untouched (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This navigation camera mosaic, created from images taken by NASA's Mars Exploration Rover Opportunity on sols 115 and 116 (May 21 and 22, 2004) provides a dramatic view of 'Endurance Crater.' The rover engineering team carefully plotted the safest path into the football field-sized crater, eventually easing the rover down the slopes around sol 130 (June 12, 2004). To the upper left of the crater sits the rover's protective heatshield, which sheltered Opportunity as it passed through the martian atmosphere. The 360-degree view is presented in a vertical projection, with geometric and radiometric seam correction.

  5. The vertical motion simulator

    NASA Technical Reports Server (NTRS)

    Hosein, Todd

    1988-01-01

    Today's flight simulators, such as NASA's multimillion dollar Vertical Motion Simulator (VMS), recreate an authentic aircraft environment, and reproduce the sensations of flight by mechanically generating true physical events. In addition to their application as a training tool for pilots, simulators have become essential in the design, construction, and testing of new aircraft. Simulators allow engineers to study an aircraft's flight performance and characteristics without the cost or risk of an actual test flight. Because of their practicality, simulators will become more and more important in the development and design of new, safer aircraft.

  6. Vertical wind turbine

    SciTech Connect

    Danson, D.P.

    1988-08-16

    This patent describes a wind driven turbine of the vertical axis type comprising: (a) a support base; (b) a generally vertical column rotatably mounted to the support base; (c) upper and lower support means respectively mounted on the column for rotation therewith; wind driven blades connected between the upper and lower support means for rotation about the column and each blade being individually rotatable about a blade axis extending longitudinally through the blade to vary a blade angle of attach thereof relative to wind velocity during rotation about the column; and (e) control means for variably adjusting angles of attack of each blade to incident wind, the control means including a connecting rod means having drive means for rotating each blade about the associated blade axis in response to radial movement of the connecting rod means and control shaft pivotally mounted within the column and having a first shaft portion connected to the connecting rod means and a second shaft portion radially offset from the first shaft portion and pivotally connected to radially displace the first portion and thereby the connecting rod means to vary the blade angles of attack during rotation about the column.

  7. Vertical organic transistors.

    PubMed

    Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

    2015-11-11

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted. PMID:26466388

  8. Flexible electrochromics: magnetron sputtered tungsten oxide (WO3-x) thin films on Lexan (optically transparent polycarbonate) substrates

    NASA Astrophysics Data System (ADS)

    Uday Kumar, K.; Murali, Dhanya S.; Subrahmanyam, A.

    2015-06-01

    Tungsten oxide (WO3-x) based electrochromics on flexible substrates is a topic of recent interest. The present communication reports the electrochromic properties of WO3-x thin films grown on lexan, an optically transparent polycarbonate thermoplastic substrate. The WO3-x films are prepared at room temperature (300 K) by the reactive DC magnetron sputtering technique. The physical properties of metal oxide thin films are known to be controlled by the oxygen stoichiometry of the film. In the present work, the WO3-x thin films are prepared by varying the oxygen flow rates. All the WO3-x thin films are amorphous in nature. The electrochromic performance of the WO3-x thin films is evaluated by cyclic voltammetry measurements on tin doped indium oxide (ITO) coated lexan and glass substrates. The optical band gap of WO3-x thin films grown on lexan substrates (at any given oxygen flow rate) is significantly higher than those grown on glass substrates. The coloration efficiency of WO3-x thin films (at an oxygen flow rate of 10 sccm) on lexan substrates is: 143.9 cm2 C-1 which is higher compared to that grown on glass: 90.4 cm2 C-1.

  9. 3X compound parabolic concentrating (CPC) solar energy collector. Final technical report

    SciTech Connect

    Ballheim, R.W.

    1980-04-25

    Chamberlain engineers designed a 3X compound parabolic concentrating (CPC) collector for the subject contract. The collector is a completely housed, 105.75 x 44.75 x 10.23-inch, 240-pound unit with six each evacuated receiver assemblies, a center manifold and a one-piece glass cover. A truncated version of a CPC trough reflector system and the General Electric Company tubular evacuated receiver have been integrated with a mass producible collector design suitable for operation at 250 to 450/sup 0/F. The key criterion for optimization of the design was minimization of the cost per Btu collected annually at an operating temperature of 400/sup 0/F. The reflector is a 4.1X design truncated to a total height of 8.0 inches with a resulting actual concentration ratio of 2.6 to 1. The manifold is an insulated area housing the fluid lines which connect the six receivers in series with inlet and outlet tubes extending from one side of the collector at the center. The reflectors are polished, anodized aluminum which are shaped by the roll form process. The housing is painted, galvanized steel, and the cover glass is 3/16-inch thick tempered, low iron glass. The collector requires four slope adjustments per year for optimum effectiveness. Chamberlain produced ten 3X CPC collectors for the subject contract. Two collectors were used to evaluate assembly procedures, six were sent to the project officer in Albuquerque, New Mexico, one was sent to Argonne National Laboratory for performance testing and one remained with the Company. A manufacturing cost study was conducted to estimate limited mass production costs, explore cost reduction ideas and define tooling requirements. The final effort discussed shows the preliminary design for application of a 3X CPC solar collector system for use in the Iowa State Capitol complex.

  10. Autoimmune Manifestations in the 3xTg-AD Model of Alzheimer's Disease

    PubMed Central

    Marchese, Monica; Cowan, David; Head, Elizabeth; Ma, Donglai; Karimi, Khalil; Ashthorpe, Vanessa; Kapadia, Minesh; Zhao, Hui; Davis, Paulina; Sakic, Boris

    2015-01-01

    Background Immune system activation is frequently reported in patients with Alzheimer's disease (AD). However, it remains unknown whether this is a cause, a consequence, or an epiphenomenon of brain degeneration. Objective The present study examines whether immunological abnormalities occur in a well-established murine AD model and if so, how they relate temporally to behavioral deficits and neuropathology. Methods A broad battery of tests was employed to assess behavioral performance and autoimmune/inflammatory markers in 3xTg-AD (AD) mice and wild type controls from 1.5 to 12 months of age. Results Aged AD mice displayed severe manifestations of systemic autoimmune/inflammatory disease, as evidenced by splenomegaly, hepatomegaly, elevated serum levels of anti-nuclear/anti-dsDNA antibodies, low hematocrit, and increased number of double-negative T splenocytes. However, anxiety-related behavior and altered spleen function were evident as early as 2 months of age, thus preceding typical AD-like brain pathology. Moreover, AD mice showed altered olfaction and impaired “cognitive” flexibility in the first 6 months of life, suggesting mild cognitive impairment-like manifestations before general learning/memory impairments emerged at an older age. Interestingly, all of these features were present in 3xTg-AD mice prior to significant amyloid-β or tau pathology. Conclusion The results indicate that behavioral deficits in AD mice develop in parallel with systemic autoimmune/inflammatory disease. These changes antedate AD-like neuropathology, thus supporting a causal link between autoimmunity and aberrant behavior. Consequently, 3xTg-AD mice may be a useful model in elucidating the role of immune system in the etiology of AD. PMID:24150111

  11. Multicolored Vertical Silicon Nanowires

    SciTech Connect

    Seo, Kwanyong; Wober, Munib; Steinvurzel, P.; Schonbrun, E.; Dan, Yaping; Ellenbogen, T.; Crozier, K. B.

    2011-04-13

    We demonstrate that vertical silicon nanowires take on a surprising variety of colors covering the entire visible spectrum, in marked contrast to the gray color of bulk silicon. This effect is readily observable by bright-field microscopy, or even to the naked eye. The reflection spectra of the nanowires each show a dip whose position depends on the nanowire radii. We compare the experimental data to the results of finite difference time domain simulations to elucidate the physical mechanisms behind the phenomena we observe. The nanowires are fabricated as arrays, but the vivid colors arise not from scattering or diffractive effects of the array, but from the guided mode properties of the individual nanowires. Each nanowire can thus define its own color, allowing for complex spatial patterning. We anticipate that the color filter effect we demonstrate could be employed in nanoscale image sensor devices.

  12. Narrow-band tunable terahertz emission from ferrimagnetic Mn3-xGa thin films

    NASA Astrophysics Data System (ADS)

    Awari, N.; Kovalev, S.; Fowley, C.; Rode, K.; Gallardo, R. A.; Lau, Y.-C.; Betto, D.; Thiyagarajah, N.; Green, B.; Yildirim, O.; Lindner, J.; Fassbender, J.; Coey, J. M. D.; Deac, A. M.; Gensch, M.

    2016-07-01

    Narrow-band terahertz emission from coherently excited spin precession in metallic ferrimagnetic Mn3-xGa Heusler alloy nanofilms has been observed. The efficiency of the emission, per nanometer film thickness, is comparable or higher than that of classical laser-driven terahertz sources based on optical rectification. The center frequency of the emission from the films can be tuned precisely via the film composition in the range of 0.20-0.35 THz, making this type of metallic film a candidate for efficient on-chip terahertz emitters. Terahertz emission spectroscopy is furthermore shown to be a sensitive probe of magnetic properties of ultra-thin films.

  13. Thermodynamical study of boron doped CeX3 (X=Pd, Rh)

    NASA Astrophysics Data System (ADS)

    Sharma, Ramesh; Dwivedi, Shalini; Sharma, Yamini

    2016-05-01

    The structural, electronic, thermal, and optical properties of cubic non magnetic CeX3(X=Pd, Rh) compounds which crystallize in the Au3Cu structure have been studied using the projected augmented wave (PAW) method within the density functional theory (DFT) with generalized gradient approximation (GGA) for exchange correlation potential. In this paper we have calculated the band structure which are interpreted using the density of states. The optical properties such as extinction coefficients clearly illustrate the changes in CeX3 due to intercalation of boron. Lattice instability is observed in CePd3B from the calculated dynamical properties.

  14. Design and construction of a short-wave infrared 3.3X continuous zoom lens

    NASA Astrophysics Data System (ADS)

    Olson, Craig; Goodman, Tim; Addiego, Chris; Mifsud, Steve

    2010-08-01

    We present the definition, design, and construction of a 3.3X continuous-zoom short-wave infrared (SWIR) telephoto lens. Compared to visible and mid-wave infrared lenses, defining the appropriate lens requirements of short-wave lenses have some different trade-offs in terms of balancing radiometry and optimum focal plane sampling. In addition, the design process of optimizing a visible zoom design form of given first-order properties to work in the SWIR band reveals some challenges in glass selection and subsequent aberration balancing. A comparison of the actual measured MTF performance of a prototype lens shows reasonable performance compared to the design.

  15. Spin chain from marginally deformed AdS{sub 3}xS{sup 3}

    SciTech Connect

    Wen, W.-Y.

    2007-03-15

    We derive a spin chain Hamiltonian from a fast spinning string in the marginally deformed AdS{sub 3}xS{sup 3}. This corresponds to a closed trajectory swept out by the SU(2) or SL(2) spin vector on the surface of one-parameter deformed two-sphere or hyperboloid in the background of an anisotropic magnetic field interaction. In the limit of small deformation, a class of general Landau-Lifshitz equation with a nontrivial anisotropic matrix can be derived.

  16. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    SciTech Connect

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 #6;± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  17. Measurement of ultralow vertical emittance using a calibrated vertical undulator

    NASA Astrophysics Data System (ADS)

    Wootton, K. P.; Boland, M. J.; Rassool, R. P.

    2014-11-01

    Very few experimental techniques are useful for the direct observation of ultralow vertical emittance in electron storage rings. In this work, quantitative measurements of ultralow (pm rad) electron beam vertical emittance using a vertical undulator are presented. An undulator radiation model was developed using the measured magnetic field of the APPLE-II type undulator. Using calibrated experimental apparatus, a geometric vertical emittance of ɛy=0.9 ±0.3 pm rad has been observed. These measurements could also inform modeling of the angular distribution of undulator radiation at high harmonics, for proposed diffraction-limited storage ring light sources.

  18. Observation of Picometer Vertical Emittance with a Vertical Undulator

    NASA Astrophysics Data System (ADS)

    Wootton, K. P.; Boland, M. J.; Dowd, R.; Tan, Y.-R. E.; Cowie, B. C. C.; Papaphilippou, Y.; Taylor, G. N.; Rassool, R. P.

    2012-11-01

    Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.

  19. Thermochemical Properties and Bond Dissociation Energies for Fluorinated Methanol, CH3-xFxOH, and Fluorinated Methyl Hydroperoxides, CH3-xFxOOH: Group Additivity.

    PubMed

    Wang, Heng; Bozzelli, Joseph W

    2016-09-01

    Oxygenated fluorocarbons are routinely found in sampling of environmental soils and waters as a result of the widespread use of fluoro and chlorofluoro carbons as heat transfer fluids, inert materials, polymers, fire retardants and solvents; the influence of these chemicals on the environment is a growing concern. The thermochemical properties of these species are needed for understanding their stability and reactions in the environment and in thermal process. Structures and thermochemical properties on the mono- to trifluoromethanol, CH3-xFxOH, and fluoromethyl hydroperoxide, CH3-xFxOOH (1 ≤ x ≤ 3), are determined by CBS-QB3, CBS-APNO, and G4 calculations. Entropy, S°298, and heat capacities, Cp(T)'s (300 ≤ T/K ≤ 1500) from vibration, translation, and external rotation contributions are calculated on the basis of the vibration frequencies and structures obtained from the B3LYP/6-31+G(d,p) density functional method. Potential barriers for the internal rotations are also calculated from this method and used to calculate hindered rotor contributions to S°298 and Cp(T)'s using direct integration over energy levels of the internal rotational potentials. Standard enthalpies of formation, ΔfH°298 (units in kcal mol(-1)) are CH2FOOH (-83.7), CHF2OOH (-138.1), CF3OOH (-193.6), CH2FOO(•) (-44.9), CHF2OO(•) (-99.6), CF3OO(•) (-153.8), CH2FOH (-101.9), CHF2OH (-161.6), CF3OH (-218.1), CH2FO(•) (-49.1), CHF2O(•) (-97.8), CF3O(•) (-150.5), CH2F(•) (-7.6), CHF2(•) (-58.8), and CF3(•) (-112.6). Bond dissociation energies for the R-OOH, RO-OH, ROO-H, R-OO(•), RO-O(•), R-OH, RO-H, R-O(•), and R-H bonds are determined and compared with methyl hydroperoxide to observe the trends from added fluoro substitutions. Enthalpy of formation for the fluoro-hydrocarbon oxygen groups C/F/H2/O, C/F2/H/O, C/F3/O, are derived from the above fluorinated methanol and fluorinated hydroperoxide species for use in Benson's Group Additivity. It was determined that

  20. Dynamic Interaction of Stress Granules, DDX3X, and IKK-α Mediates Multiple Functions in Hepatitis C Virus Infection

    PubMed Central

    Pène, Véronique; Sodroski, Catherine; Hsu, Ching-Sheng

    2015-01-01

    ABSTRACT The ubiquitous ATP-dependent RNA helicase DDX3X is involved in many cellular functions, including innate immunity, and is a pivotal host factor for hepatitis C virus (HCV) infection. Recently, we showed that DDX3X specifically recognizes the HCV 3′ untranslated region (UTR), leading to the activation of IKK-α and a cascade of lipogenic signaling to facilitate lipid droplet biogenesis and viral assembly (Q. Li, V. Pene, S. Krishnamurthy, H. Cha, and T. J. Liang, Nat Med 19:722–729, 2013, http://dx.doi.org/10.1038/nm.3190). The interaction of DDX3X with HCV core protein seems to be dispensable for its proviral role. In this study, through systematic imaging and biochemical and virologic approaches, we identified a dynamic association between DDX3X and various cellular compartments and viral elements mediating multiple functions of DDX3X in productive HCV infection. Upon HCV infection, the HCV 3′UTR interacts with DDX3X and IKK-α, which redistribute to speckle-like cytoplasmic structures shown to be stress granules (SGs). As viral proteins accumulate in infected cells, DDX3X granules together with SG-associated proteins redistribute and colocalize with HCV core protein around lipid droplets (LDs). IKK-α, however, does not relocate to the LD but translocates to the nucleus. In HCV-infected cells, various HCV nonstructural proteins also interact or colocalize with DDX3X in close proximity to SGs and LDs, consistent with the tight juxtaposition of the replication complex and the assembly site at the surface of LDs. Short interfering RNA (siRNA)-mediated silencing of DDX3X and multiple SG components markedly inhibits HCV infection. Our data suggest that DDX3X initiates a multifaceted cellular program involving dynamic associations with HCV RNA and proteins, IKK-α, SG, and LD surfaces for its crucial role in the HCV life cycle. IMPORTANCE DDX3X is a proviral host factor for HCV infection. Recently, we showed that DDX3X binds to the HCV 3

  1. Heterogeneous activation of Oxone by Co(x)Fe(3-x)O4 nanocatalysts for degradation of rhodamine B.

    PubMed

    Su, Shengnan; Guo, Weilin; Leng, Yanqiu; Yi, Chunliang; Ma, Zhenmin

    2013-01-15

    The removal of Rhodamine B (RhB) by Co(x)Fe(3-x)O(4) magnetic nanoparticles activated Oxone has been performed in this study. A series of Co(x)Fe(3-x)O(4) nanoparticles was synthesized using a hydrothermal method. The synthetic Co(x)Fe(3-x)O(4) nanoparticles were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that they were spinel structures and Co was introduced into their structures. The performances of Co(x)Fe(3-x)O(4) nanocatalysts on the activation of Oxone for removal of RhB were investigated and we found that the higher cobalt content in the catalyst, the better removal performance was resulted. A series experiments of reaction conditions were also performed, which confirmed that weak acidic, higher temperature, higher dosages of Co(x)Fe(3-x)O(4) nanocatalyst and Oxone and lower concentration of RhB were favored for the degradation of RhB. The pseudo-first order kinetics was observed to fit the Co(x)Fe(3-x)O(4)/Oxone process. Furthermore, the reaction mechanism was discussed and the scavenging effect was examined by using phenol and tert-butyl alcohol which indicated that sulfate radicals were the dominating reactive species responsible for the degradation process. Finally, the stability of Co(x)Fe(3-x)O(4) nanocatalyst was studied. PMID:23195597

  2. Study on MoO{sub 3-x} films deposited by reactive sputtering for organic light-emitting diodes

    SciTech Connect

    Oka, Nobuto; Watanabe, Hiroki; Sato, Yasushi; Yamaguchi, Hiroshi; Ito, Norihiro; Tsuji, Hiroya; Shigesato, Yuzo

    2010-07-15

    The authors investigate the role of reduced molybdenum trioxide [MoO{sub 3-x} (x{<=}1)] films in organic light-emitting diodes, particularly from the viewpoint of the oxidation state of Mo. MoO{sub 3-x} films were deposited by reactive sputtering under a mixture of argon (Ar) and oxygen (O{sub 2}). The O{sub 2} gas-flow ratio (GFR) [O{sub 2}/(Ar+O{sub 2})] was adjusted between 10% and 100%. Mo with six, five, and four valence electrons was detected in MoO{sub 3-x} film deposited with an O{sub 2} GFR of 10% and 12.5%, whereas, under higher O{sub 2} GFRs, only six valence electrons for Mo in the MoO{sub 3-x} film were detected. N,N{sup '}-di(1-naphthyl)-N,N{sup '}-diphenylbenzidine ({alpha}-NPD) layer, hole-transport material, were deposited over the MoO{sub 3-x} layer by subsequent vacuum evaporation. At the {alpha}-NPD/MoO{sub 3-x} interface, it was found that {alpha}-NPD cations were generated and that MoO{sub 3-x} was reduced, which provided evidence of charge transfer across the interface by Raman spectroscopy and x-ray photoelectron spectroscopy.

  3. Structural and magnetic properties of ZnxMn3-xO4 spinels

    NASA Astrophysics Data System (ADS)

    Nádherný, Ladislav; Maryško, Miroslav; Sedmidubský, David; Martin, Christine

    2016-09-01

    To study structural and magnetic properties of spinels a series of ceramic samples with a different Zn:Mn ratio was prepared by high-temperature annealing in air followed by quenching in liquid nitrogen. The spinels with nominal composition of ZnxMn3-xO4 (x=0-1.29) were characterized by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy and SQUID magnetometry. Two tetragonal spinels of the same I41/amd space-group were identified based on the crystallographic, vibrational and grain-morphology point of view and described in detail. The unit-cell parameters and phase ratio of the spinel phases were determined using Rietveld refinement. According to the factor-group analysis the majority of the vibrational modes were identified in the Raman spectra. The magnetic properties of ZnxMn3-xO4 spinels are in agreement with a model of nanoscale ferrimagnetic Mn3O4 clusters in the antiferromagnetic ZnMn2O4 matrix (TN≈60 K). New features are a constricted hysteresis loop for x=0.3, and the effect of defects on magnetic properties for high Zn content which points to a good quality of the samples prepared by a solid state reaction.

  4. Phonon Density of States and Heat Capacity of La$_{3-x}$Te$_4$

    SciTech Connect

    Delaire, Olivier A; May, Andrew F.; McGuire, Michael A; Porter, Wallace D; Lucas,; Stone, Matthew B; Abernathy, Douglas L; Snyder, G. J.

    2009-01-01

    The phonon density of states (DOS) of La$_{3-x}$Te$_4$ compounds ($x=0.0, 0.18, 0.32$) was measured at 300, 520, and 780$\\,$K, using inelastic neutron scattering. A significant stiffening of the phonon DOS, and a large broadening of features were observed upon introduction of vacancies on La sites (increasing $x$). Heat capacity measurements were performed at temperatures $~1.85 \\leqslant T \\leqslant 1200 \\,$K, and were analyzed to quantify the contributions of phonons and electrons. The Debye temperature and the electronic coefficient of heat capacity determined from these measurements are consistent with the neutron scattering results, and with previously reported first-principles calculations. Our results indicate that La vacancies in La$_{3-x}$Te$_4$ strongly scatter phonons, and this source of scattering appears to be independent of temperature. The stiffening of the phonon DOS induced by the introduction of vacancies is explained in terms of the electronic structure and the change in bonding. The temperature dependence of the phonon DOS is captured satisfactorily by the quasiharmonic approximation.

  5. Phonons in the ternary phase ZrS 3-xSe x

    NASA Astrophysics Data System (ADS)

    Zwick, A.; Landa, G.; Carles, R.; Renucci, M. A.; Kjekshus, A.

    1983-03-01

    The mode behaviour of long wavelength optical phonons in the ternary phase ZrS 3-xSe x has been investigated by means of Raman spectroscopy through the whole composition range 0 ⩽ x ⩽ 3. A mixed one-, two- and three-mode behaviour is observed, depending respectively on modes of group I (quasi- rigid chain modes), II (internal deformation chain modes) and III (diatomic X-X [ X = S, Se] stretching mode). Three-mode behaviour of diatomic X-X mode is explained in terms of vibrations of S-S, Se-Se and S-Se pairs, practically insensitive to metal atoms as shown by comparison with the HfS 3-xSe x system. The analysis of integrated intensities of peaks assigned to vibrations of S-S, Se-Se and S-Se pairs on the basis of a statistical model concludes in favour of higher Raman efficiency of selenium pairs compared to sulfur pairs. On the other hand, one-mode behaviour of quasi-rigid chain modes establishes unambiguously a one-to-one mode correspondence between the two binary compounds, confirming thus our previous assignments. Spectral features of the ternary phase suggest contributions from the density of vibrational states due to relaxation of Raman selection rules resulting from configurational disorder.

  6. Native defects in tetradymite Bi2(TexSe3-x) topological insulators

    SciTech Connect

    Wang, Lin-Lin; Huang, Mianliang; Thimmaiah, Srinivasa; Alam, Aftab; Budko, Sergey L.; Kaminski, Adam; Lograsso, Thomas A.; Canfield, Paul; Johnson, Duane D.

    2013-03-08

    Formation energies of native defects in Bi2(TexSe3-x), with comparison to ideal Bi2Te2S, are calculated in density-functional theory to assess transport properties. Bi2Se3 is found to be n type for both Bi- and Se-rich growth conditions, while Bi2Te3 changes from n to p type going from Te- to Bi-rich conditions, as observed. Bi2Te2Se and Bi2Te2S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/-) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi2Te2Se is related to the observed thermally active transport gap causing a p-to-n transition at low temperature. Bi2(TexSe3-x) with x>2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-p crossover. Predicted behaviors are confirmed from characterization of our grown single crystals.

  7. Magneto-transport behaviour of Bi2Se3-x Te x : role of disorder

    NASA Astrophysics Data System (ADS)

    Amaladass, E. P.; Devidas, T. R.; Sharma, Shilpam; Sundar, C. S.; Mani, Awadhesh; Bharathi, A.

    2016-02-01

    Magneto-resistance and Hall resistance measurements have been carried out in fast-cooled single crystals of Bi2Se3-x Te x (x  =  0 to 2) in 4-300 K temperature range, under magnetic fields up to 15 T. The variation of resistivity with temperature that points to a metallic behaviour in Bi2Se3, shows an up-turn at low temperatures in the Te doped samples. Magneto-resistance measurements in Bi2Se3 show clear signatures of Shubnikov-de Hass (SdH) oscillations that gets suppressed in the Te doped samples. In the Bi2SeTe2 sample, the magneto-resistance shows a cusp like positive magneto-resistance at low magnetic fields and low temperatures, a feature associated with weak anti-localisation (WAL), that crosses over to negative magneto-resistance at higher fields. The qualitatively different magneto-transport behaviour seen in Bi2SeTe2 as compared to Bi2Se3 is rationalised in terms of the disorder, through an estimate of the carrier density, carrier mobility and an analysis in terms of the Ioffe-Regel criterion with support from Hall Effect measurements. We demonstrate that by introducing Te, in the strongly disordered samples a smooth crossover of SdH and WAL can be seen in the Bi2Se3-x Te x series, both of which provide signatures for the presence of topological surface states.

  8. Physical properties of Ce3-xTe4 below room temperature

    SciTech Connect

    May, Andrew F; McGuire, Michael A; Cantoni, Claudia; Sales, Brian C

    2012-01-01

    The physical properties of polycrystalline Ce{sub 3-x}Te{sub 4} were investigated by measurements of the thermoelectric properties, Hall coefficient, heat capacity, and magnetization. The fully filled, metallic x = 0 compound displays a soft ferromagnetic transition near 4 K, and analysis of the corresponding heat capacity anomaly suggests a doublet ground state for Ce{sup 3+}. The transition is suppressed to below 2 K in the insulating x = 0.33 composition, revealing that magnetic order in Ce{sub 3-x}Te{sub 4} is driven by a Ruderman-Kittel-Kasuya-Yosida (RKKY)-type interaction. The thermoelectric properties trend with composition as expected from simple electron counting, and the transport properties in Ce{sub 3}Te{sub 4} are observed to be similar to those in La{sub 3}Te{sub 4}. Trends in the low-temperature thermal conductivity data reveal that the phonons are efficiently scattered by electrons, while all compositions examined have a lattice thermal conductivity near 1.2 W/m K{sup -1} at 200 K.

  9. Alterations in synaptic plasticity coincide with deficits in spatial working memory in presymptomatic 3xTg-AD mice.

    PubMed

    Clark, Jason K; Furgerson, Matthew; Crystal, Jonathon D; Fechheimer, Marcus; Furukawa, Ruth; Wagner, John J

    2015-11-01

    Alzheimer's disease is a neurodegenerative condition believed to be initiated by production of amyloid-beta peptide, which leads to synaptic dysfunction and progressive memory loss. Using a mouse model of Alzheimer's disease (3xTg-AD), an 8-arm radial maze was employed to assess spatial working memory. Unexpectedly, the younger (3month old) 3xTg-AD mice were as impaired in the spatial working memory task as the older (8month old) 3xTg-AD mice when compared with age-matched NonTg control animals. Field potential recordings from the CA1 region of slices prepared from the ventral hippocampus were obtained to assess synaptic transmission and capability for synaptic plasticity. At 3months of age, the NMDA receptor-dependent component of LTP was reduced in 3xTg-AD mice. However, the magnitude of the non-NMDA receptor-dependent component of LTP was concomitantly increased, resulting in a similar amount of total LTP in 3xTg-AD and NonTg mice. At 8months of age, the NMDA receptor-dependent LTP was again reduced in 3xTg-AD mice, but now the non-NMDA receptor-dependent component was decreased as well, resulting in a significantly reduced total amount of LTP in 3xTg-AD compared with NonTg mice. Both 3 and 8month old 3xTg-AD mice exhibited reductions in paired-pulse facilitation and NMDA receptor-dependent LTP that coincided with the deficit in spatial working memory. The early presence of this cognitive impairment and the associated alterations in synaptic plasticity demonstrate that the onset of some behavioral and neurophysiological consequences can occur before the detectable presence of plaques and tangles in the 3xTg-AD mouse model of Alzheimer's disease. PMID:26385257

  10. ON-LINE TOOLS FOR PROPER VERTICAL POSITIONING OF VERTICAL SAMPLING INTERVALS DURING SITE ASSESSMENT

    EPA Science Inventory

    This presentation presents on-line tools for proper vertical positioning of vertical sampling intervals during site assessment. Proper vertical sample interval selection is critical for generate data on the vertical distribution of contamination. Without vertical delineation, th...

  11. 4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe (VTL). Machining the fixture for GE Turboshroud. G.S. O'Brien, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  12. Vertical 2D Heterostructures

    NASA Astrophysics Data System (ADS)

    Lotsch, Bettina V.

    2015-07-01

    Graphene's legacy has become an integral part of today's condensed matter science and has equipped a whole generation of scientists with an armory of concepts and techniques that open up new perspectives for the postgraphene area. In particular, the judicious combination of 2D building blocks into vertical heterostructures has recently been identified as a promising route to rationally engineer complex multilayer systems and artificial solids with intriguing properties. The present review highlights recent developments in the rapidly emerging field of 2D nanoarchitectonics from a materials chemistry perspective, with a focus on the types of heterostructures available, their assembly strategies, and their emerging properties. This overview is intended to bridge the gap between two major—yet largely disjunct—developments in 2D heterostructures, which are firmly rooted in solid-state chemistry or physics. Although the underlying types of heterostructures differ with respect to their dimensions, layer alignment, and interfacial quality, there is common ground, and future synergies between the various assembly strategies are to be expected.

  13. Vertically reciprocating auger

    NASA Technical Reports Server (NTRS)

    Etheridge, Mark; Morgan, Scott; Fain, Robert; Pearson, Jonathan; Weldi, Kevin; Woodrough, Stephen B., Jr.

    1988-01-01

    The mathematical model and test results developed for the Vertically Reciprocating Auger (VRA) are summarized. The VRA is a device capable of transporting cuttings that result from below surface drilling. It was developed chiefly for the lunar surface, where conventional fluid flushing while drilling would not be practical. The VRA uses only reciprocating motion and transports material through reflections with the surface above. Particles are reflected forward and land ahead of radially placed fences, which prevent the particles from rolling back down the auger. Three input wave forms are considered to drive the auger. A modified sawtooth wave form was chosen for testing, over a modified square wave or sine wave, due to its simplicity and effectiveness. The three-dimensional mathematical model predicted a sand throughput rate of 0.2667 pounds/stroke, while the actual test setup transported 0.075 pounds/stroke. Based on this result, a correction factor of 0.281 is suggested for a modified sawtooth input.

  14. Life-threatening misdiagnosis of bulbar onset myasthenia gravis as a motor neuron disease: How much can one rely on exaggerated deep tendon reflexes

    PubMed Central

    Basiri, Keivan; Ansari, Behnaz; Okhovat, Ali Asghar

    2015-01-01

    The autoimmune disease myasthenia gravis (MG), can mimic a variety of neurological disorders leading to a delay in diagnosis and treatment. On occasions, misdiagnosis of MG could lead to unnecessary therapeutic interventions. We report the case of a 50 year-old man, in whom MG was mistaken for motor neuron disease (MND). Subsequently, correct diagnosis and optimal management resulted in saving his life and significant improvement in his functional status. We discuss the importance of considering MG as one of the potential differential diagnoses among cases of new onset or recurrent unexplained bulbar symptoms, despite exaggerated deep tendon reflexes. Also, a literature review on the misdiagnosis of MG and the potential pitfalls in MG diagnosis are discussed. PMID:25802827

  15. Has the Impact of Rising CO2 on Plants been Exaggerated by Meta-Analysis of Free Air CO2 Enrichment Studies?

    PubMed Central

    Haworth, Matthew; Hoshika, Yasutomo; Killi, Dilek

    2016-01-01

    Meta-analysis is extensively used to synthesize the results of free air CO2 enrichment (FACE) studies to produce an average effect size, which is then used to model likely plant response to rising [CO2]. The efficacy of meta-analysis is reliant upon the use of data that characterizes the range of responses to a given factor. Previous meta-analyses of the effect of FACE on plants have not incorporated the potential impact of reporting bias in skewing data. By replicating the methodology of these meta-analytic studies, we demonstrate that meta-analysis of FACE has likely exaggerated the effect size of elevated [CO2] on plants by 20 to 40%; having significant implications for predictions of food security and vegetation response to climate change. Incorporation of the impact of reporting bias did not affect the significance or the direction of the [CO2] effect. PMID:27536310

  16. The exaggerated inflammatory response in Behçet's syndrome: identification of dysfunctional post-transcriptional regulation of the IFN-γ/CXCL10 IP-10 pathway.

    PubMed

    Ambrose, N; Khan, E; Ravindran, R; Lightstone, L; Abraham, S; Botto, M; Johns, M; Haskard, D O

    2015-09-01

    The mechanisms underlying the exaggerated inflammatory response in Behçet's syndrome (BS) remain poorly understood. We investigated the response of CD14(+) blood monocytes to interferon (IFN)-γ, focusing on the chemokine CXCL10. Chemokine synthesis and release were analysed at a protein and mRNA level following stimulation with IFN-γ. Findings in BS patients were compared with 25 healthy controls (HC), 15 rheumatoid arthritis (RA) and 15 systemic lupus erythematosus (SLE) disease control patients. BS monocytes produced significantly more CXCL10 protein than HC monocytes from 2 h following IFN-γ stimulation, despite equivalent quantities of mRNA, suggesting more efficient translation. This was significantly more pronounced in BS with high disease activity and in those with ocular and neurological clinical manifestations. The imbalance between CXCL10 protein and mRNA expression was not observed in either RA or SLE patients, and was not seen with other chemokines studied (CXCL9, CXCL11 and CCL2). Furthermore, BS monocytes treated with an alternative stimulant (LPS) did not show abnormal tumour necrosis factor (TNF)-α release. Sucrose density gradients to segregate monocyte CXCL10 mRNA into free RNA or polysome-associated RNA showed equal proportions in BS and HC samples, suggesting that the difference between BS and HC may be due to reduced negative control of CXCL10 translation in BS at a post-initiation level. We conclude that BS monocytes have dysfunctional post-transcriptional regulation of CXCL10 mRNA, resulting in over-expression of CXCL10 protein upon IFN-γ stimulation. As CXCL10 is a chemokine that recruits mononuclear cells, this abnormality may contribute to the exaggerated inflammatory responses that characterizes BS. PMID:25982097

  17. Electronic structures and optical properties of α-Fe2O3-xSex alloys for solar absorber

    NASA Astrophysics Data System (ADS)

    Xia, Congxin; Jia, Yu; Zhang, Qiming

    2015-05-01

    The band structures and optical properties of α-Fe2O3-xSex alloys are studied by means of first-principles methods, considering different Se contents x. Numerical results show that Se content has an obvious influence on band structures and optical properties of α-Fe2O3-xSex alloys. The band gap values of α-Fe2O3-xSex alloys decrease monotonically when Se concentrations increase, resulting in an obvious increase of the optical absorption edge in the visible range. In particular, our results show that α-Fe2O3-xSex alloys have the direct band gap properties with band gap values when Se content x ≈ 0.17, which is beneficial to solar cell applications.

  18. Effect of cation substitution on the magnetic and magnetotransport properties of epitaxial Fe3-xVxO4 films

    NASA Astrophysics Data System (ADS)

    Jin, Chao; Liu, Jie; Zheng, Dongxing; Tang, Min; Li, Peng; Bai, Haili

    2015-03-01

    The effect of cation on the structure, magnetic and magnetotransport properties of epitaxial Fe3-xVxO4 (0 ≤ x ≤ 0.6) films fabricated by reactive cosputtering was investigated systematically. Four kinds of cations (Fe2+, Fe3+, V2+ and V3+) exist in the Fe3-xVxO4 films. The Fe3-xVxO4 films reveal semiconducting property and increased resistivity with increasing V content. The systematic change of the decreased saturation magnetization and enhanced exchange bias is closely related to the spin canting and antiferromagnetic coupling, which is caused by the V substitution on B sites. The presents of V2+ (3d3) enlarge the anisotropy, and further increase the coercivity. With the combined effects of the larger anisotropy, spin canting and enhanced antiferromagnetic coupling caused by V substitution, the Fe3-xVxO4 films exhibit enhanced four-fold symmetric anisotropic magnetoresistance.

  19. The Gains from Vertical Scaling

    ERIC Educational Resources Information Center

    Briggs, Derek C.; Domingue, Ben

    2013-01-01

    It is often assumed that a vertical scale is necessary when value-added models depend upon the gain scores of students across two or more points in time. This article examines the conditions under which the scale transformations associated with the vertical scaling process would be expected to have a significant impact on normative interpretations…

  20. Scale Shrinkage in Vertical Equating.

    ERIC Educational Resources Information Center

    Camilli, Gregory; And Others

    1993-01-01

    Three potential causes of scale shrinkage (measurement error, restriction of range, and multidimensionality) in item response theory vertical equating are discussed, and a more comprehensive model-based approach to establishing vertical scales is described. Test data from the National Assessment of Educational Progress are used to illustrate the…

  1. Increased hippocampal excitability in the 3xTgAD mouse model for Alzheimer's disease in vivo.

    PubMed

    Davis, Katherine E; Fox, Sarah; Gigg, John

    2014-01-01

    Mouse Alzheimer's disease (AD) models develop age- and region-specific pathology throughout the hippocampal formation. One recently established pathological correlate is an increase in hippocampal excitability in vivo. Hippocampal pathology also produces episodic memory decline in human AD and we have shown a similar episodic deficit in 3xTg AD model mice aged 3-6 months. Here, we tested whether hippocampal synaptic dysfunction accompanies this cognitive deficit by probing dorsal CA1 and DG synaptic responses in anaesthetized, 4-6 month-old 3xTgAD mice. As our previous reports highlighted a decline in episodic performance in aged control mice, we included aged cohorts for comparison. CA1 and DG responses to low-frequency perforant path stimulation were comparable between 3xTgAD and controls at both age ranges. As expected, DG recordings in controls showed paired-pulse depression; however, paired-pulse facilitation was observed in DG and CA1 of young and old 3xTgAD mice. During stimulus trains both short-latency (presumably monosynaptic: 'direct') and long-latency (presumably polysynaptic: 're-entrant') responses were observed. Facilitation of direct responses was modest in 3xTgAD animals. However, re-entrant responses in DG and CA1 of young 3xTgAD mice developed earlier in the stimulus train and with larger amplitude when compared to controls. Old mice showed less DG paired-pulse depression and no evidence for re-entrance. In summary, DG and CA1 responses to low-frequency stimulation in all groups were comparable, suggesting no loss of synaptic connectivity in 3xTgAD mice. However, higher-frequency activation revealed complex change in synaptic excitability in DG and CA1 of 3xTgAD mice. In particular, short-term plasticity in DG and CA1 was facilitated in 3xTgAD mice, most evidently in younger animals. In addition, re-entrance was facilitated in young 3xTgAD mice. Overall, these data suggest that the episodic-like memory deficit in 3xTgAD mice could be due to the

  2. Cu3-xP Nanocrystals as a Material Platform for Near-Infrared Plasmonics and Cation Exchange Reactions

    PubMed Central

    2015-01-01

    Synthesis approaches to colloidal Cu3P nanocrystals (NCs) have been recently developed, and their optical absorption features in the near-infrared (NIR) have been interpreted as arising from a localized surface plasmon resonance (LSPR). Our pump–probe measurements on platelet-shaped Cu3-xP NCs corroborate the plasmonic character of this absorption. In accordance with studies on crystal structure analysis of Cu3P dating back to the 1970s, our density functional calculations indicate that this material is substoichiometric in copper, since the energy of formation of Cu vacancies in certain crystallographic sites is negative, that is, they are thermodynamically favored. Also, thermoelectric measurements point to a p-type behavior of the majority carriers from films of Cu3-xP NCs. It is likely that both the LSPR and the p-type character of our Cu3-xP NCs arise from the presence of a large number of Cu vacancies in such NCs. Motivated by the presence of Cu vacancies that facilitate the ion diffusion, we have additionally exploited Cu3-xP NCs as a starting material on which to probe cation exchange reactions. We demonstrate here that Cu3-xP NCs can be easily cation-exchanged to hexagonal wurtzite InP NCs, with preservation of the anion framework (the anion framework in Cu3-xP is very close to that of wurtzite InP). Intermediate steps in this reaction are represented by Cu3-xP/InP heterostructures, as a consequence of the fact that the exchange between Cu+ and In3+ ions starts from the peripheral corners of each NC and gradually evolves toward the center. The feasibility of this transformation makes Cu3-xP NCs an interesting material platform from which to access other metal phosphides by cation exchange. PMID:25960605

  3. Composition dependence of superconductivity in YBa2(Cu(3-x)Al(x))Oy

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1991-01-01

    Eleven different compositions in the system YBa2(Cu(3-x)Al(x))O(y) (x = 0 to 0.3) have been synthesized and characterized by electrical resistivity measurements, powder x-ray diffraction, and scanning electron microscopy. The superconducting transition temperature T sub c (onset) was almost unaffected by the presence of alumina due to its limited solubility in YBa2Cu3O(7-x). However, T sub c(R = 0) gradually decreased, and the resistive tails became longer with increasing Al2O3 concentration. This was probably due to formation of BaAl2O4 and other impurity phases from chemical decomposition of the superconducting phase by reaction with Al2O3.

  4. Composition dependence of superconductivity in YBa2(Cu(3-x)Al(x))O(y)

    NASA Technical Reports Server (NTRS)

    Bansal, N. P.

    1993-01-01

    Eleven different compositions in the system YBa2(Cu(3-x)Al(x))O(y) (x = 0 to 0.3) have been synthesized and characterized by electrical resistivity measurements, powder X-ray diffraction, and scanning electron microscopy. The superconducting transition temperature T sub c (onset) was almost unaffected by the presence of alumina due to its limited solubility in YBa2Cu3O(7-x). However, T sub c(R = 0) gradually decreased, and the resistive tails became longer with increasing Al2O3 concentration. This was probably due to formation of BaAl2O4 and other impurity phases from chemical decomposition of the superconducting phase by reaction with Al2O3.

  5. Defects in Bi2Te3-x Se x single crystals

    NASA Astrophysics Data System (ADS)

    Lošt'ák, P.; Drašar, Č.; Bachan, D.; Beneš, L.; Krejčová, A.

    2010-03-01

    Single crystals of a ternary system based on Bi2Te3-x Se x (nominally x=0.0-0.2) were prepared using the Bridgman technique. Samples with varying content of Se were characterized by the measurement of lattice parameters, electrical conductivity σ⊥c and Hall coefficient R H(B‖ c). The actual concentration of selenium c Se in the samples was determined using atomic emission spectroscopy. While a small selenium concentration enhances the free hole concentration P after passing a maximum, the hole concentration decreases at higher selenium concentrations. The extreme-like dependence P=f(c Se) is explained in terms of a change of the native defect concentration due to the substitution of selenium atoms by tellurium ones.

  6. CHF prediction of GE 3 x 3 rod bundle based on BODYFIT-2PE. [BWR

    SciTech Connect

    Chien, T.H.; Chen, B.C.J.; Sha, W.T.; Kim, J.H.

    1983-01-01

    A General Electric 3 x 3 rod bundle critical heat flux (CHF) experiment was analyzed by using BODYFIT-2PE. (Boundary-fitted coordinates-2 phase partially elliptic). BODYFIT-2PE is a three-dimensional, steady-state/transient, single-phase rod-bundle thermal-hydraulic computer program based on the technique of boudnary-fitted coordinate system. In this coordinate system, all the physical boundaries are made to be coincident with the coordinate lines so that the boundary conditions, such as constant heat fluxes and zero velocities, can be accurately represented without interpolation. However, the transformed coordinate system is not unique for a given geometric configuration. The more orthogonal the coordinates are, the faster the rates of calculational convergence. The generation of the transformed coordinates is based on the solution of a set of second-order partial differential equations, subject to a set of geometric boundary conditions. A simple Laplacian is used in the present study.

  7. Phase Structure of Confining Theories on R{sup 3}xS{sup 1}

    SciTech Connect

    Nishimura, Hiromichi; Ogilvie, Michael C.

    2011-05-23

    Recent work on QCD-like theories on R{sup 3}xS{sup 1} has revealed that a confined phase can exist when the circumference L of S{sup 1} is sufficiently small. Adjoint QCD and double-trace deformation theories with certain conditions are such theories, and we present some new results for their phase diagrams. First we show the connection between the large-L and small-L confined regions in the phase diagram of SU(3) adjoint QCD using Polyakov-Nambu-Jona Lasinio models. Then we consider an SU(2) double-trace deformation theory with adjoint scalars and study conflicts between the Higgs and small-L confined phase.

  8. Magneto-transport behaviour of Bi2Se3-xTex : role of disorder.

    PubMed

    Amaladass, E P; Devidas, T R; Sharma, Shilpam; Sundar, C S; Mani, Awadhesh; Bharathi, A

    2016-02-24

    Magneto-resistance and Hall resistance measurements have been carried out in fast-cooled single crystals of Bi2Se3-xTex (x  =  0 to 2) in 4-300 K temperature range, under magnetic fields up to 15 T. The variation of resistivity with temperature that points to a metallic behaviour in Bi2Se3, shows an up-turn at low temperatures in the Te doped samples. Magneto-resistance measurements in Bi2Se3 show clear signatures of Shubnikov-de Hass (SdH) oscillations that gets suppressed in the Te doped samples. In the Bi2SeTe2 sample, the magneto-resistance shows a cusp like positive magneto-resistance at low magnetic fields and low temperatures, a feature associated with weak anti-localisation (WAL), that crosses over to negative magneto-resistance at higher fields. The qualitatively different magneto-transport behaviour seen in Bi2SeTe2 as compared to Bi2Se3 is rationalised in terms of the disorder, through an estimate of the carrier density, carrier mobility and an analysis in terms of the Ioffe-Regel criterion with support from Hall Effect measurements. We demonstrate that by introducing Te, in the strongly disordered samples a smooth crossover of SdH and WAL can be seen in the Bi2Se3-xTex series, both of which provide signatures for the presence of topological surface states. PMID:26812889

  9. Age-dependent impairment of glucose tolerance in the 3xTg-AD mouse model of Alzheimer's disease.

    PubMed

    Vandal, Milene; White, Phillip J; Chevrier, Geneviève; Tremblay, Cyntia; St-Amour, Isabelle; Planel, Emmanuel; Marette, Andre; Calon, Frederic

    2015-10-01

    Alzheimer's disease (AD) has been associated with type II diabetes (T2D) and obesity in several epidemiologic studies. To determine whether AD neuropathology can cause peripheral metabolic impairments, we investigated metabolic parameters in the triple-transgenic (3xTg)-AD mouse model of AD, compared with those in nontransgenic (non-Tg) controls, at 6, 8, and 14 mo of age. We found a more pronounced cortical Aβ accumulation (2- and 3.5-fold increase in Aβ42 in the soluble and insoluble protein fractions, respectively) in female 3xTg-AD mice than in the males. Furthermore, female 3xTg-AD mice displayed a significant deterioration in glucose tolerance (AUC, +118% vs. non-Tg mice at 14 mo). Fasting plasma insulin levels rose 2.5-fold from 6 to 14 mo of age in female 3xTg-AD mice. Glucose intolerance and cortical amyloid pathology worsened with age, and both were more pronounced in the females. Pancreatic amyloidopathy was revealed and could underlie the observed deficit in glycemic response in 3xTg-AD mice. The present results suggest that AD-like neuropathology extends to the pancreas in the 3xTg-AD mouse, leading to glucose intolerance and contributing to a pathologic self-amplifying loop between AD and T2D. PMID:26108977

  10. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, R.; Wu, J.; Stadler, H.

    1990-01-01

    Vertical Bloch Line (VBL) memory is a recently conceived, integrated, solid-state, block-access, VLSI memory which offers the potential of 1Gbit/sq cm real storage density, gigabit per second data rates, and sub-millisecond average access times simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBL's are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of VBL pairs are used to store binary information. At present, efforts are being directed at developing a single-chip memory using 25Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. This paper describes the current design architecture, functional elements, and supercomputer simulation results which are used to assist the design process. The current design architecture uses three metal layers, two ion implantation steps for modulating the thickness of the magnetic layer, one ion implantation step for assisting propagation in the major line track, one NiFe soft magnetic layer, one CoPt hard magnetic layer, and one reflective Cr layer for facilitating magneto-optic observation of magnetic structure. Data are stored in a series of elongated magnetic domains, called stripes, which serve as storage sites for arrays of VBL pairs. The ends of these stripes are placed near conductors which serve as VBL read/write gates. A major line track is present to provide a source and propagation path for magnetic bubbles. Writing and reading, respectively, are achieved by converting magnetic bubbles to VBL's and vice versa. The output function is effected by stretching a magnetic bubble and detecting it magnetoresistively. Experimental results from the past design cycle created four design goals for the current design cycle. First, the bias field ranges

  11. Sol-Gel Synthesis of La(0.6)Sr(0.4)CoO(3-x) and Sm(0.5)Sr(0.5)CoO(3-x) Cathode Nanopowders for Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Wise, Brent

    2011-01-01

    Nanopowders of La(0.6)Sr(0.4)CoO(3-x) (LSC) and Sm(0.5)Sr(0.5)CoO(3-x) (SSC) compositions, which are being investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC) with La(Sr)Ga(Mg)O(3-x) (LSGM) as the electrolyte, were synthesized by low-temperature sol-gel method using metal nitrates and citric acid. Thermal decomposition of the citrate gels was followed by simultaneous DSC/TGA methods. Development of phases in the gels, on heat treatments at various temperatures, was monitored by x-ray diffraction. Solgel powders calcined at 550 to 1000 C consisted of a number of phases. Single perovskite phase La(0.6)Sr(0.4)CoO(3-x) or Sm(0.5)Sr(0.5)CoO(3-x) powders were obtained at 1200 and 1300 C, respectively. Morphological analysis of the powders calcined at various temperatures was done by scanning electron microscopy. The average particle size of the powders was approx.15 nm after 700 C calcinations and slowly increased to 70 to 100 nm after heat treatments at 1300 to 1400 C.

  12. Analysis of motor function in 6-month-old male and female 3xTg-AD mice.

    PubMed

    Stover, Kurt R; Campbell, Mackenzie A; Van Winssen, Christine M; Brown, Richard E

    2015-03-15

    The 3xTg-AD mouse has high validity as a model of Alzheimer's disease (AD) because it develops both amyloid beta plaques and neurofibrillary tangles. Human patients with AD typically develop motor deficits, which worsen as the disease progresses, but 3xTg-AD mice have been reported to show enhanced motor abilities. We investigated the motor behaviour phenotype of male and female 3xTg-AD and B6129SF2 wildtype mice on a battery of motor behaviours at 6 months of age. Compared to wildtype mice, the 3xTg-AD mice had enhanced motor performance on the Rotarod, but worse performance on the grid suspension task. In gait analysis 3xTg-AD mice had a longer stride length and made more foot slips on the balance beam than wildtype mice. There was no overall difference in voluntary wheel-running activity between genotypes, but there was a disruption in circadian activity rhythm in 3xTg-AD mice. In some motor tasks, such as the Rotarod and balance beam, females appeared to perform better than males, but this sex differences was accounted for by differences in body weight. Our results indicate that while the 3xTg-AD mice show enhanced performance on the Rotarod, they have poorer performance on other motor behaviour tasks, indicating that their motor behaviour phenotype is more complex than previously reported. The presence of the P301L transgene may explain the enhancement of Rotarod performance but the poorer performance on other motor behaviour tasks may be due to other transgenes. PMID:25486177

  13. Processing and characterization of zeta-Ta4C 3-x: A high toughness tantalum carbide

    NASA Astrophysics Data System (ADS)

    Sygnatowicz, Michael M.

    Tantalum carbides are commonly processed by hot-pressing, canned hot-isostatic-pressing, or spark-plasma sintering because of their high melting temperatures and low diffusivities. This study reports processing of dense ζ-Ta4C 3-x by reaction sintering of a Ta and TaC powder mixture (C/Ta atomic ratio = 0.66). ζ-Ta4C3-x is of interest due to its rhombohedral (trigonal) crystal structure that may be characterized as a polytype with both face-centered-cubic (fcc) and hexagonal-close-packed (hcp) Ta stacking sequences interrupted by stacking faults and missing carbon layers. This structure leads to easy cleaving on the basal planes and high fracture toughness. A key step in processing is the hydrogenation of the Ta powder to produce beta-TaH x, a hard and brittle phase that enables efficient comminution during milling and production of small, equiaxed Ta particles that can be packed to high green density with the TaC powder. Studies of phase evolution by quantitative X-ray diffraction during sintering revealed several intermediate reactions: (a) decomposition of beta-TaHx to Ta, (b) diffusion of C from gamma-TaC to Ta leading to the formation of α-Ta2Cy' with the kinetics described by the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation with an exponent, n = 0.5, and an activation energy of 221 kJ/mole, (c) equilibration of α-Ta2Cy' and gamma-TaC 0.78 phases, and (d) formation of ζ-Ta4C2.56 from the equilibrated α-Ta2C and gamma-TaC0.78 phases with the kinetics characterized by a higher JMAK exponent ( n ≈ 3) and higher activation energy (1089 kJ/mole). The microstructure showed evidence of nucleation and growth of the ζ-Ta4C 2.56 phase in both the α-Ta2C and gamma-TaC0.78 parent phases with distinct difference in the morphology due to the different number of variants of the habit plane. A hot-pressed and hot-isostatic-pressed (HIPed) material (C/Ta atomic ratio = 0.66), having formed 95 w% ζ-phase, attained a fracture toughness of 15.6 +/- 0.5 MPa√m and a

  14. Vertical axis wind turbine airfoil

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  15. Horizontal and Vertical Line Designs.

    ERIC Educational Resources Information Center

    Johns, Pat

    2003-01-01

    Presents an art lesson in which students learn about the artist Piet Mondrian and create their own abstract artworks. Focuses on geometric shapes using horizontal and vertical lines. Includes background information about the artist. (CMK)

  16. Early detection of cognitive deficits in the 3xTg-AD mouse model of Alzheimer's disease.

    PubMed

    Stover, Kurt R; Campbell, Mackenzie A; Van Winssen, Christine M; Brown, Richard E

    2015-08-01

    Which behavioral test is the most sensitive for detecting cognitive deficits in the 3xTg-AD at 6.5 months of age? The 3xTg-AD mouse model of Alzheimer's disease (AD) has three transgenes (APPswe, PS1M146V, and Tau P301L) which cause the development of amyloid beta plaques, neurofibrillary tangles, and cognitive deficits with age. In order to determine which task is the most sensitive in the early detection of cognitive deficits, we compared male and female 3xTg-AD and B6129SF2 wildtype mice at 6.5 months of age on a test battery including spontaneous alternation in the Y-Maze, novel object recognition, spatial memory in the Barnes maze, and cued and contextual fear conditioning. The 3xTg-AD mice had impaired learning and memory in the Barnes maze but performed better than B6129SF2 wildtype mice in the Y-Maze and in contextual fear conditioning. Neither genotype demonstrated a preference in the novel object recognition task nor was there a genotype difference in cued fear conditioning but females performed better than males. From our results we conclude that the 3xTg-AD mice have mild cognitive deficits in spatial learning and memory and that the Barnes maze was the most sensitive test for detecting these cognitive deficits in 6.5-month-old mice. PMID:25896362

  17. Ultra-broadband Nonlinear Saturable Absorption for Two-dimensional Bi2TexSe3-x Nanosheets.

    PubMed

    Wang, Yingwei; Liu, Sheng; Yuan, Jian; Wang, Peng; Chen, Jiazhang; Li, Jianbo; Xiao, Si; Bao, Qiaoliang; Gao, Yongli; He, Jun

    2016-01-01

    We report the ultra-broadband nonlinear optical (NLO) response of Bi2TexSe3-x nanosheets produced by a facile solvothermal method. Our result show that the extracted basic optical nonlinearity parameters of Bi2TexSe3-x nanosheets, αNL, Imχ((3)), and FOM reach ~10(4) cm/GW, ~10(-8) esu and ~10(-13) esu cm, respectively, which are several orders of magnitude larger than those of bulk dielectrics. We further observed the excitation intensity dependence of the NLO absorption coefficient and the NLO response sensitivity. The mechanisms of those phenomena were proposed based on physical model. The wavelength dependence of the NLO response of Bi2TexSe3-x nanosheets was investigated, and we determined that the Bi2TexSe3-x nanosheets possess an ultra-broadband nonlinear saturable absorption property covering a range from the visible to the near-infrared band, with the NLO absorption insensitive to the excitation wavelength. This work provide fundamental and systematic insight into the NLO response of Bi2TexSe3-x nanosheets and support their application in photonic devices in the future. PMID:27609149

  18. Comparison of older adults' steps per day using NL-1000 pedometer and two GT3X+ accelerometer filters.

    PubMed

    Barreira, Tiago V; Brouillette, Robert M; Foil, Heather C; Keller, Jeffrey N; Tudor-Locke, Catrine

    2013-10-01

    The purpose of this study was to compare the steps/d derived from the ActiGraph GT3X+ using the manufacturer's default filter (DF) and low-frequency-extension filter (LFX) with those from the NL-1000 pedometer in an older adult sample. Fifteen older adults (61-82 yr) wore a GT3X+ (24 hr/day) and an NL-1000 (waking hours) for 7 d. Day was the unit of analysis (n = 86 valid days) comparing (a) GT3X+ DF and NL-1000 steps/d and (b) GT3X+ LFX and NL-1000 steps/d. DF was highly correlated with NL-1000 (r = .80), but there was a significant mean difference (-769 steps/d). LFX and NL-1000 were highly correlated (r = .90), but there also was a significant mean difference (8,140 steps/d). Percent difference and absolute percent difference between DF and NL-1000 were -7.4% and 16.0%, respectively, and for LFX and NL-1000 both were 121.9%. Regardless of filter used, GT3X+ did not provide comparable pedometer estimates of steps/d in this older adult sample. PMID:23170752

  19. Maternal corticosterone further reduces the reproductive function of male offspring hatched from eggs laid by quail hens selected for exaggerated adrenocortical stress responsiveness.

    PubMed

    Satterlee, D G; Cole, C A; Castille, S A

    2007-03-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis can depress the hypothalamic-pituitary-testicular axis. Male quail cloacal gland (CG) size and foam production shows androgen dependency, and males selected for exaggerated [high stress (HS)] rather than reduced [low stress (LS)] plasma corticosterone (B) stress response exhibit reduced CG and testes development. High stress hens also deposit more B into egg yolks than LS ones, and quail hens given B produce chicks that have a reduced growth rate and adults with heightened HPA responsiveness. Herein, we gave LS and HS hens no B [empty implants, control (CON)] or B-filled implants and assessed the reproductive performances of these hens and their male offspring. Mortality was similarly elevated in LS and HS B-treated hens, but only HS B-implanted hens showed reduced egg production. In male offspring, CG volume (CVOL), intensity of CG foam production (CFP), and the proportion of individuals that produced CG foam were measured from 4 to 11 wk of age. At 6 wk, BW, and at 15 wk, BW, testes weight (TWT), and TWT relative to BW were also determined. Hen treatments did not affect male chick CVOL at 4 wk, but CVOL differed thereafter as follows: LS CON > LS B = HS CON = HS B at 5 and 6 wk and LS CON > LS B > HS CON = HS B from 7 to 11 wk. By 8 wk, and thereafter, CFP differed as follows: LS CON > LS B > HS CON > HS B. Group differences in the proportion of individuals that produced CG foam generally supported CFP findings from 4 to 8 wk of age. Body weight did not differ by treatment at 6 wk of age. By 15 wk, TWT were similarly depressed in both HS groups. However, similarly higher 15-wk BW in the LS-CON and HS-B groups contributed to TWT relative to BW differences as follows: LS-B > LS-CON > HS-B; LS-CON = HS-CON; LS-B > HS-CON; and, HS-CON = HS-B. Both selection for exaggerated HPA responsiveness and maternal B treatment negatively affected the reproductive function of HS male offspring. PMID:17297171

  20. Botulinum toxin type a (150 kDa) decreases exaggerated neurotransmitter release from trigeminal ganglion neurons and relieves neuropathy behaviors induced by infraorbital nerve constriction.

    PubMed

    Kitamura, Y; Matsuka, Y; Spigelman, I; Ishihara, Y; Yamamoto, Y; Sonoyama, W; Kamioka, H; Yamashiro, T; Kuboki, T; Oguma, K

    2009-04-10

    Many patients with trigeminal neuropathies suffer severe chronic pain which is inadequately alleviated with centrally-acting drugs. These drugs also possess severe side effects making compliance difficult. One strategy is to develop new treatments without central side effects by targeting peripheral sensory neurons, since sensory neuron excitability and neurotransmitter release increase in chronic pain states. Such treatments may include the highly purified botulinum toxin type A 150 kDa (BoNT/A) which reportedly blocks vesicular neurotransmitter release. We set out to determine if experimental trigeminal neuropathy induced by infraorbital nerve constriction (IoNC) in rats could alter neurotransmitter release from somata of trigeminal sensory neurons and if it could be attenuated by BoNT/A. Thus, we monitored the secretory activity of acutely dissociated trigeminal ganglion (TRG) neurons from naïve and IoNC rats by measuring the fluorescence intensity of the membrane-uptake marker (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide (FM4-64). FM4-64 staining showed that neurons possess a pool of recycled vesicles which could be released by high KCl (75 mM) application. BoNT/A pre-treatment of acutely dissociated TRG neurons from naïve rats significantly reduced the rate of FM4-64 dye release. Neurons isolated from TRG ipsilateral to IoNC exhibited significantly faster onset of FM4-64 release than neurons contralateral to IoNC (sham surgery). IoNC also produced long-lasting ipsilateral tactile allodynia, measured as large decreases of withdrawal thresholds to mechanical stimulation. Intradermal injection of BoNT/A in the area of infraorbital branch of the trigeminal nerve (IoN) innervation alleviated IoNC-induced mechanical allodynia and reduced the exaggerated FM4-64 release in TRG neurons from these rats. Our results suggest that BoNT/A decreases neuropathic pain behaviors by decreasing the exaggerated neurotransmitter

  1. Superconductivity and Charge Density Wave in ZrTe3-xSex.

    PubMed

    Zhu, Xiangde; Ning, Wei; Li, Lijun; Ling, Langsheng; Zhang, Ranran; Zhang, Jinglei; Wang, Kefeng; Liu, Yu; Pi, Li; Ma, Yongchang; Du, Haifeng; Tian, Minglian; Sun, Yuping; Petrovic, Cedomir; Zhang, Yuheng

    2016-01-01

    Charge density wave (CDW), the periodic modulation of the electronic charge density, will open a gap on the Fermi surface that commonly leads to decreased or vanishing conductivity. On the other hand superconductivity, a commonly believed competing order, features a Fermi surface gap that results in infinite conductivity. Here we report that superconductivity emerges upon Se doping in CDW conductor ZrTe3 when the long range CDW order is gradually suppressed. Superconducting critical temperature Tc(x) in ZrTe3-xSex (0 ≤ x ≤ 0.1) increases up to 4 K plateau for 0.04 ≤ x ≤ 0.07. Further increase in Se content results in diminishing Tc and filametary superconductivity. The CDW modes from Raman spectra are observed in x = 0.04 and 0.1 crystals, where signature of ZrTe3 CDW order in resistivity vanishes. The electronic-scattering for high Tc crystals is dominated by local CDW fluctuations at high temperatures, the resistivity is linear up to highest measured T = 300 K and contributes to substantial in-plane anisotropy. PMID:27253150

  2. Electronic structures and geometries of the XF{sub 3} (X = Cl, Br, I, At) fluorides

    SciTech Connect

    Sergentu, Dumitru-Claudiu; Amaouch, Mohamed; Pilmé, Julien; Galland, Nicolas; Maurice, Rémi

    2015-09-21

    The potential energy surfaces of the group 17 XF{sub 3} (X = Cl, Br, I, At) fluorides have been investigated for the first time with multiconfigurational wave function theory approaches. In agreement with experiment, bent T-shaped C{sub 2v} structures are computed for ClF{sub 3}, BrF{sub 3}, and IF{sub 3}, while we predict that an average D{sub 3h} structure would be experimentally observed for AtF{sub 3}. Electron correlation and scalar relativistic effects strongly reduce the energy difference between the D{sub 3h} geometry and the C{sub 2v} one, along the XF{sub 3} series, and in the X = At case, spin-orbit coupling also slightly reduces this energy difference. AtF{sub 3} is a borderline system where the D{sub 3h} structure becomes a minimum, i.e., the pseudo-Jahn-Teller effect is inhibited since electron correlation and scalar-relativistic effects create small energy barriers leading to the global C{sub 2v} minima, although both types of effects interfere.

  3. Microstructure and Magnetoresistance of CaCuxMn3-xMn4O12

    NASA Astrophysics Data System (ADS)

    Cao, H.; Tan, W. S.; Xu, G. J.; Wu, H. P.; Deng, K. M.; Wu, X. S.

    In this article, the precursors of CaCuxMn3-xMn4O12 (x = 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4) were synthesized using wet-chemistry technique, and then samples were sintered in pure oxygen flow at 850°C and ambient pressure with KCl 10 wt% addition. The Rietveld refinements of powder X-ray diffraction patterns showed that all the samples were single phase with cubic symmetry, the space group Imbar {3}. The lattice parameters a decreased with increasing Cu doping level x. The transport properties were characterized with DC four-probe technique. The results indicated that the crystal structure of samples were deformed and then influenced the transport properties of these manganese oxides. The MR ratios at 85 K and in the magnetic field of 5 Tesla increased with increasing x and reached the maximum at x = 1.0, then decreased with further increasing x. These results originated maybe from the intergrain tunneling of spin-polarized carriers and double-exchange effect.

  4. Spin glass behavior in the weberite related structure Dy3-xYxTaO7

    NASA Astrophysics Data System (ADS)

    Gomez Garcia, Jose; Tavizon, Gustavo; Duran, Alejandro; Escudero, Roberto

    2013-03-01

    Crystalline structures with tetrahedral arrangement of magnetic cations are susceptible to present non-collinear magnetism. Dy3TaO7 with weberite-type crystal structure has this arrangement and could display non-conventional magnetic coupling. Previous magnetic studies on Dy3TaO7 have characterized this as an antiferromagnetic system with TN of about 3 K. In this work magnetic properties of polycrystalline samples of the Dy3-xYxTaO7, with weberite structure are presented. X-Ray diffraction of our samples are single phase in all range of compositions. Magnetic properties measured from 2 - 300 K shown a typical Curie-Weiss behavior with the Dy3+ effective magnetic moment about 10.35 μB. The compositions x =0.66, 0.33, and 0.0 display a maximum in the susceptibility vs. temperature at 2.3, 2.7, and 3 K respectively. This behavior has been previously assigned to an antiferromagnetic transition; however our AC magnetic measurements as a function of frequency indicate a spin glass behavior. Since magnetic cations have tetrahedral arrangement for x =0, a magnetic frustrated state is anticipated for this composition.

  5. Formability of ABX3 (X = F, Cl, Br, I) halide perovskites.

    PubMed

    Li, Chonghea; Lu, Xionggang; Ding, Weizhong; Feng, Liming; Gao, Yonghui; Guo, Ziming

    2008-12-01

    In this study a total of 186 complex halide systems were collected; the formabilities of ABX3 (X = F, Cl, Br and I) halide perovskites were investigated using the empirical structure map, which was constructed by Goldschmidt's tolerance factor and the octahedral factor. A model for halide perovskite formability was built up. In this model obtained, for all 186 complex halides systems, only one system (CsF-MnF2) without perovskite structure and six systems (RbF-PbF2, CsF-BeF2, KCl-FeCl2, TlI-MnI2, RbI-SnI2, TlI-PbI2) with perovskite structure were wrongly classified, so its predicting accuracy reaches 96%. It is also indicated that both the tolerance factor and the octahedral factor are a necessary but not sufficient condition for ABX3 halide perovskite formability, and a lowest limit of the octahedral factor exists for halide perovskite formation. This result is consistent with our previous report for ABO3 oxide perovskite, and may be helpful to design novel halide materials with the perovskite structure. PMID:19029699

  6. Calibration of digital SLR Nikon D3X for the use in digital photogrammetry projects

    NASA Astrophysics Data System (ADS)

    Kraszewski, B.

    2012-06-01

    Results of research on calibration of high-resolution digital camera Nikon D3X have been presented. CMOS matrix stability in recording process of digital images, calculation of principle distance as well as principal point, radial distortion and tangential distortion were determined. The interior orientation parameters determined during calibration in test project were examined. All test images were obtained using three replaceable Nikkor lens of 24, 35 and 50 mm focal length. The calibration process was executed in Camera Calibration and Field Calibration modules of PhotoModeler software using convergent terrestrial images. It was also executed for single photo in DLT module of AeroSys software. For the determination of interior orientation parameters of digital camera for each lens the 2D and 3D test fields were used. Stability and repeatability of recorded digital images on CMOS matrix were examined on 25 control points which were evenly distributed on a white calibration table. Accuracy of pixel position on the image for 24 mm, 35 mm and 50 mm focal length was 0.06, 0.08 and 0.04 of image pixel, respectively. It was found that interior orientation parameters calculated using the PhotoModeler software for both calibration methods were correctly determined while when using the Aerosys software they were determined with lower accuracy. The very high accuracy of elaboration of a test photogrammetric project for each camera lens was obtained using interior orientation parameters calculated on the basis of convergent images and 3D field.

  7. Long 3 x 8 hr dialysis: a three-decade summary.

    PubMed

    Charra, Bernard; Chazot, Charles; Jean, Guillaume; Hurot, Jean-Marc; Vanel, Thierry; Terrat, Jean-Claude; VoVan, Cyril

    2003-01-01

    A long hemodialysis (HD), 3 x 8 hours/week, has been used without significant modification in Tassin for 35 years with excellent morbidity and mortality results. It can be performed during the day or overnight. The relatively good survival is mainly due to a lower cardiovascular mortality than usually reported in dialysis patients. This in turn is mainly due to the good control of blood pressure (BP) including drug-free hypertension control and low incidence of intradialytic hypotension. This control of BP is probably the result of the tight extracellular volume normalization (dry weight), although one cannot exclude the effect of other factors such as serum phosphorus control well achieved using long dialysis. The high dose of small and even more of middle molecules is another essential virtue of long dialysis, leading to good nutrition, correction of anemia, control of serum phosphate and potassium with low doses of medications and providing a very cost-effective treatment. In 2002 one must aim at optimal rather than just adequate dialysis. Optimal dialysis needs to correct as perfectly as possible each and every abnormality due to renal failure. It can be achieved using longer (or more frequent) sessions. Overnight dialysis is the most logical way of implementing long HD with the lowest possible hindrance on patient's life. Due to the change in case mix a decreasing number of patients are able or willing to go on overnight dialysis, education to be autonomous is more difficult, but the benefit is still there. PMID:14733303

  8. Enhanced magnetization in VxFe3-xO4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Pool, V. L.; Kleb, M. T.; Chorney, C. L.; Arenholz, E.; Idzerda, Y. U.

    2015-12-01

    Nanoparticles of VxFe3-xO4 with up to 33% vanadium doping (x=0 to 1) and a 9 nm diameter are investigated in order to determine the site preference of the vanadium and the magnetic behavior of the nanoparticles. The iron and vanadium L23-edge X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (MCD) spectra are used to identify that vanadium initially substitutes into the tetrahedral iron site as V3+ and that the average iron moment is observed to increase with vanadium concentration up to 12.5% (x=.375). When the vanadium incorporation exceeds 12.5%, the XAS and MCD show that the vanadium begins substituting as V2+ in the octahedral coordination. This coincides with a rapid reduction of the average moment to zero by 25% (x=.75). The frequency-dependent alternating-current magnetic susceptibility (ACMS) displays a substantial increase in blocking temperature with vanadium concentration and indicated substantial variation in the strength of inter-particle interactions.

  9. The origin and vertical distribution of carbon monoxide in Jupiter

    NASA Technical Reports Server (NTRS)

    Noll, Keith S.; Knacke, R. F.; Geballe, T. R.; Tokunaga, A. T.

    1988-01-01

    Six clearly-resolved lines of the CO 1-0 vibration-rotation band near 4.7 microns have been observed in Jupiter at a resolution of 0.07/cm. CO is not found to be concentrated in the stratosphere, but is shown to be present in the troposphere at a mole fraction of 1.6 + or - 0.3 x 10 to the -9th, suggesting that rapid vertical mixing is the source of CO. Results indicate that the global oxygen abundance in Jupiter's gaseous envelope below the cloud-forming regions must be near the solar value, and that intervening clouds with an optical depth of 0.5-4 are present above the line-forming region.

  10. A sequence of transformations related to the formation of M{sub 3}X{sub 2}-type superstructures

    SciTech Connect

    Gusev, A. I.

    2015-01-15

    A symmetry analysis of monoclinic, orthorhombic, and trigonal M{sub 3}X{sub 2}-type superstructures that can be formed in strongly stoichiometric MX{sub y} compounds with B1 structure is carried out. Channels of order-disorder transitions MX{sub y} → M{sub 3}X{sub 2} are determined. It is shown that, as temperature decreases, two physically admissible sequences of transformations associated with the formation of M{sub 3}X{sub 2} superstructures are possible in nonstoichiometric MX{sub y} compounds of group IV transition metals. By an example of vanadium carbide VC{sub y}, it is demonstrated that orthorhombic or monoclinic V{sub 3}C{sub 2} superstructures can be obtained with the formation of a nanostructure.

  11. In-situ observation of self-regulated switching behavior in WO{sub 3-x} based resistive switching devices

    SciTech Connect

    Hong, D. S.; Wang, W. X.; Chen, Y. S. Sun, J. R.; Shen, B. G.

    2014-09-15

    The transmittance of tungsten oxides can be adjusted by oxygen vacancy (V{sub o}) concentration due to its electrochromic property. Here, we report an in-situ observation of resistive switching phenomenon in the oxygen-deficient WO{sub 3-x} planar devices. Besides directly identifying the formation/rupture of dark-colored conductive filaments in oxide layer, the stripe-like WO{sub 3-x} device demonstrated self-regulated switching behavior during the endurance testing, resulting in highly consistent switching parameters after a stabilizing process. For very high V{sub o}s mobility was demonstrated in the WO{sub 3-x} film by the pulse experiment, we suggested that the electric-field-induced homogeneous migration of V{sub o}s was the physical origin for such unique switching characteristics.

  12. PlanHab: Hypoxia counteracts the erythropoietin suppression, but seems to exaggerate the plasma volume reduction induced by 3 weeks of bed rest.

    PubMed

    Keramidas, Michail E; Mekjavic, Igor B; Kölegård, Roger; Choukèr, Alexander; Strewe, Claudia; Eiken, Ola

    2016-04-01

    The study examined the distinct and synergistic effects of hypoxia and bed rest on the erythropoietin (EPO) concentration and relative changes in plasma volume (PV). Eleven healthy male lowlanders underwent three 21-day confinement periods, in a counterbalanced order: (1) normoxic bed rest (NBR; PIO2: 133.1 ± 0.3 mmHg); (2) hypoxic bed rest (HBR; PIO2: 90.0 ± 0.4 mmHg, ambient simulated altitude of ~4000 m); and (3) hypoxic ambulation (HAMB; PIO2: 90.0 ± 0.4 mmHg). Blood samples were collected before, during (days 2, 5, 14, and 21) and 2 days after each confinement to determineEPOconcentration. Qualitative differences inPVchanges were also estimated by changes in hematocrit and hemoglobin concentration along with concomitant changes in plasma renin concentration.NBRcaused an initial reduction inEPOby ~39% (P = 0.04). By contrast,HBRenhancedEPO(P = 0.001), but the increase was less than that induced byHAMB(P < 0.01). All three confinements caused a significant reduction inPV(P < 0.05), with a substantially greater drop inHBRthan in the other conditions (P < 0.001). Thus, present results suggest that hypoxia prevents theEPOsuppression, whereas it seems to exaggerate thePVreduction induced by bed rest. PMID:27081163

  13. Intranasal insulin prevents anesthesia-induced hyperphosphorylation of tau in 3xTg-AD mice

    PubMed Central

    Chen, Yanxing; Run, Xiaoqin; Liang, Zhihou; Zhao, Yang; Dai, Chun-ling; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

    2014-01-01

    Background: It is well documented that elderly individuals are at increased risk of cognitive decline after anesthesia. General anesthesia is believed to be a risk factor for Alzheimer’s disease (AD). Recent studies suggest that anesthesia may increase the risk for cognitive decline and AD through promoting abnormal hyperphosphorylation of tau, which is crucial to neurodegeneration seen in AD. Methods: We treated 3xTg-AD mice, a commonly used transgenic mouse model of AD, with daily intranasal administration of insulin (1.75 U/day) for one week. The insulin- and control-treated mice were then anesthetized with single intraperitoneal injection of propofol (250 mg/kg body weight). Tau phosphorylation and tau protein kinases and phosphatases in the brains of mice 30 min and 2 h after propofol injection were then investigated by using Western blots and immunohistochemistry. Results: Propofol strongly promoted hyperphosphorylation of tau at several AD-related phosphorylation sites. Intranasal administration of insulin attenuated propofol-induced hyperphosphorylation of tau, promoted brain insulin signaling, and led to up-regulation of protein phosphatase 2A, a major tau phosphatase in the brain. Intranasal insulin also resulted in down-regulation of several tau protein kinases, including cyclin-dependent protein kinase 5, calcium/calmodulin-dependent protein kinase II, and c-Jun N-terminal kinase. Conclusion: Our results demonstrate that pretreatment with intranasal insulin prevents AD-like tau hyperphosphorylation. These findings provide the first evidence supporting that intranasal insulin administration might be used for the prevention of anesthesia-induced cognitive decline and increased risk for AD and dementia. PMID:24910612

  14. Fe(3-x)Ti(x)O4 nanoparticles as tunable probes of microbial metal oxidation.

    PubMed

    Liu, Juan; Pearce, Carolyn I; Liu, Chongxuan; Wang, Zheming; Shi, Liang; Arenholz, Elke; Rosso, Kevin M

    2013-06-19

    Present and emerging biotechnological applications for iron (oxyhydr)oxide nanomaterials depend on their interaction with microorganisms, as do their toxicity, transport, and fate in biological and environmental systems. However, mass or electron transfer along key molecular pathways at microbe-nanomaterial interfaces is extremely difficult to quantify because of system complexity. Inspired by Fe(II)-oxidizing microbes widespread in nature, we isolate and characterize one such pathway by examining the oxidation of Fe(3-x)Ti(x)O4 (magnetite-titanomagnetite) nanoparticles by the bacterial electron transfer enzyme MtoA, a decaheme c-type cytochrome. Oxidation by MtoA was studied as a function of the thermodynamic driving force for electron transfer by controlling the Ti(IV) doping content (x), which tunes the solid-state Fe(II)/Fe(III) ratio built into the nanoparticles. A higher Fe(II)/Fe(III) ratio appears to systematically increase the electron transfer kinetics to the cytochrome. In situ X-ray diffraction indicated that, during oxidation, the spinel ferrite lattice remains intact while structural Fe(II) is progressively depleted. Surface and atomic site specific Fe L(2,3)-edge X-ray magnetic circular dichroism indicated that MtoA directly accesses magnetically ordered B-sublattice Fe(II) at the interface. This study provides the first quantitative insights into an isolated molecular pathway for biotransformation of iron (oxyhydr)oxide nanomaterials, and more generally, it also illustrates new techniques for probing these pathways in detail, featuring use of tailored nanoparticles, purified metalloenzyme, and synchrotron X-ray absorption spectroscopies. PMID:23672679

  15. Engineering of Methylation State Specific 3xMBT Domain Using ELISA Screening

    PubMed Central

    Feldman, Michal; Zarivach, Raz; Aharoni, Amir; Levy, Dan

    2016-01-01

    The ε-amino group of lysine residues may be mono-, di- or tri-methylated by protein lysine methyltransferases. In the past few years it has been highly considered that methylation of both histone and non-histone proteins has fundamental role in development and progression of various human diseases. Thus, the establishment of tools to study lysine methylation that will distinguish between the different states of methylation is required to elucidate their cellular functions. The 3X malignant brain tumor domain (3XMBT) repeats of the Lethal(3)malignant brain tumor-like protein 1 (L3MBTL1) have been utilized in the past as an affinity reagent for the identification of mono- and di-methylated lysine residues on individual proteins and on a proteomic scale. Here, we have utilized the 3XMBT domain to develop an enzyme-linked immunosorbent assay (ELISA) that allows the high-throughput detection of 3XMBT binding to methylated lysines. We demonstrated that this system allows the detection of methylated peptides, methylated proteins and PKMT activity on both peptides and proteins. We also optimized the assay to detect 3XMBT binding in crude E. coli lysates which facilitated the high throughput screening of 3XMBT mutant libraries. We have utilized protein engineering tools and generated a double site saturation 3XMBT library of residues 361 and 411 that were shown before to be important for binding mono and di-methylated substrates and identified variants that can exclusively recognize only di-methylated peptides. Together, our results demonstrate a powerful new approach that will contribute to deeper understanding of lysine methylation biology and that can be utilized for the engineering of domains for specific binders of other post-translational modifications. PMID:27111853

  16. Fe3-xTixO4 Nanoparticles as Tunable Probes of Microbial Metal Oxidation

    SciTech Connect

    Liu, Juan; Pearce, Carolyn I.; Liu, Chongxuan; Wang, Zheming; Shi, Liang; Arenholz, Elke; Rosso, Kevin M.

    2013-05-14

    Present and emerging biotechnological applications for iron (oxyhydr)oxide nanomaterials depend on their interaction with microorganisms, as do their toxicity, transport, and fate in biological and environmental systems. However, mass or electron transfer along key molecular pathways at microbe-nanomaterial interfaces is extremely difficult to quantify because of system complexity. Inspired by Fe(II)-oxidizing microbes widespread in nature, we isolate and characterize one such pathway by examining the oxidation of Fe3-xTixO4 (magnetite-titanomagnetite) nanoparticles by the bacterial electron transfer enzyme MtoA, a decaheme c-type cytochrome. Oxidation by MtoA was studied as a function of the thermodynamic driving force for electron transfer by controlling the Ti(IV) doping content (x), which tunes the solid-state Fe(II)/Fe(III) ratio built into the nanoparticles. A higher Fe(II)/Fe(III) ratio appears to proportionally increase the electron transfer kinetics to the cytochrome. In situ x-ray diffraction indicated that during oxidation the spinel ferrite lattice remains intact while structural Fe(II) is progressively depleted. Surface and atomic site specific Fe L2,3-edge x-ray magnetic circular dichroism indicated that MtoA directly accesses magnetically-ordered B-sublattice Fe(II) at the interface. This study provides first quantitative insights into an isolated molecular pathway for biotransformation of iron (oxyhydr)oxide nanomaterials. And, more generally, it also illustrates new techniques for probing these pathways in detail, featuring use of tailored nanoparticles, purified metalloenzyme, and synchrotron x-ray absorption spectroscopies.

  17. Tunable electric properties of half-metallic Zn x Fe3-x O4 and the characteristics of Zn x Fe3-x O4 /n-type Si interfaces

    NASA Astrophysics Data System (ADS)

    He, Jie; Wang, Changhong; Cheng, Yahui; Liu, Mengyin; Wang, Weichao; Wang, Weihua; Lu, Feng; Gao, Kuanghong; Li, Zhiqing; Liu, Hui

    2016-03-01

    The physical properties of Zn-doped Fe3O4 (i.e. Zn x Fe3-x O4 with 0≤slant x≤slant 1 ) synthesised by the sol-gel method have been investigated systematically. X-ray diffraction and x-ray photoelectron spectroscopy (XPS) measurements prove that Zn ions have been doped into the Fe3O4 crystal lattice. The valence band XPS spectra show that the carrier concentration decreases with increasing the Zn content. The electric measurements reveal that the resistivity increases when increasing the Zn concentration. The absolute value of the magnetoresistance of Zn x Fe3-x O4 is above 3.11% at room temperature, indicating that the samples maintain high spin polarisation after Zn2+ doping. The fitting of the current-voltage curves of Zn x Fe3-x O4/n-type Si heterostructures demonstrates that the height of the Schottky barrier reduces continuously from 0.82 eV to 0.76 eV with increasing x. The results may recommend Zn x Fe3-x O4 as a potential material for spintronic applications.

  18. Phoenix Lander on Mars with Surrounding Terrain, Vertical Projection

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This view is a vertical projection that combines more than 500 exposures taken by the Surface Stereo Imager camera on NASA's Mars Phoenix Lander and projects them as if looking down from above.

    The black circle on the spacecraft is where the camera itself is mounted on the lander, out of view in images taken by the camera. North is toward the top of the image. The height of the lander's meteorology mast, extending toward the southwest, appears exaggerated because that mast is taller than the camera mast.

    This view in approximately true color covers an area about 30 meters by 30 meters (about 100 feet by 100 feet). The landing site is at 68.22 degrees north latitude, 234.25 degrees east longitude on Mars.

    The ground surface around the lander has polygonal patterning similar to patterns in permafrost areas on Earth.

    This view comprises more than 100 different Stereo Surface Imager pointings, with images taken through three different filters at each pointing. The images were taken throughout the period from the 13th Martian day, or sol, after landing to the 47th sol (June 5 through July 12, 2008). The lander's Robotic Arm is cut off in this mosaic view because component images were taken when the arm was out of the frame.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Measurements of vertical bar Vcb vertical bar and vertical bar Vub vertical bar at BaBar

    SciTech Connect

    Rotondo, M.

    2005-10-12

    We report results from the BABAR Collaboration on the semileptonic B decays, highlighting the measurements of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements Vub and Vcb. We describe the techniques used to obtain the matrix element |Vcb| using the measurement of the inclusive B {yields} Xclv process and a large sample of exclusive B {yields} D*lv decays. The vertical bar Vub vertical bar matrix elements has been measured studying different kinematic variables of the B {yields} Xulv process, and also with the exclusive reconstruction of B {yields} {pi}({rho})lv decays.

  20. Vertical motion simulator familiarization guide

    NASA Technical Reports Server (NTRS)

    Danek, George L.

    1993-01-01

    The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

  1. Congenital vertical talus: a review.

    PubMed

    McKie, Janay; Radomisli, Timothy

    2010-01-01

    Congenital vertical talus, also known as congenital convex pes valgus, is an uncommon disorder of the foot, manifested as a rigid rocker-bottom flatfoot. Radiographically, it is defined by dorsal dislocation of the navicular on the talus. This condition requires surgical correction. If left untreated, this foot deformity results in a painful and rigid flatfoot with weak push-off power. This article provides an overview of this rare foot deformity, outlines appropriate workup of the disorder, and details current treatment options, with emphasis on the evolution of treatment of congenital vertical talus. PMID:19963176

  2. Validation of the Actigraph GT3X and ActivPAL Accelerometers for the Assessment of Sedentary Behavior

    ERIC Educational Resources Information Center

    Kim, Youngdeok; Barry, Vaughn W.; Kang, Minsoo

    2015-01-01

    This study examined (a) the validity of two accelerometers (ActiGraph GT3X [ActiGraph LLC, Pensacola, FL, USA] and activPAL [PAL Technologies Ltd., Glasgow, Scotland]) for the assessment of sedentary behavior; and (b) the variations in assessment accuracy by setting minimum sedentary bout durations against a proxy for direct observation using an…

  3. Enhancement of magnetic moment in ZnxFe3-xO4 thin films with dilute Zn substitution

    NASA Astrophysics Data System (ADS)

    Yuan, Honglei; Liu, Er; Yin, Yuli; Zhang, Wen; Wong, P. K. Johnny; Zheng, Jian-Guo; Huang, Zhaocong; Ou, Huiling; Zhai, Ya; Xu, Qingyu; Du, Jun; Zhai, Hongru

    2016-06-01

    Highly (111)-textured ZnxFe3-xO4 thin films were grown by pulsed laser deposition on silicon substrates. The spin and orbital magnetic moments of the ZnxFe3-xO4 thin films have been obtained by X-ray magnetic circular dichroism (XMCD) and sum rule analysis. The total magnetic moments thus extracted are in good agreement with the values obtained by vibrating sample magnetometer. Both the unquenched orbital moment and the ratio of orbital-to-spin moment first increase significantly with increasing Zn substitution at a low concentration range ( 0 ≤x ≤0.1 ), and then decrease at a higher concentration (x = 0.3). The underlying site-specific doping mechanisms involved here have been elucidated by detailed analysis of the XMCD of ZnxFe3-xO4 films. Our work demonstrates a practical means to manipulate the spin-orbit coupling in the ZnxFe3-xO4 thin films via Zn impurity doping.

  4. Growth and characterization of molecular beam epitaxy-grown Bi2Te3-xSex topological insulator alloys

    NASA Astrophysics Data System (ADS)

    Tung, Y.; Chiang, Y. F.; Chong, C. W.; Deng, Z. X.; Chen, Y. C.; Huang, J. C. A.; Cheng, C.-M.; Pi, T.-W.; Tsuei, K.-D.; Li, Z.; Qiu, H.

    2016-02-01

    We report a systematic study on the structural and electronic properties of Bi2Te3-xSex topological insulator alloy grown by molecular beam epitaxy (MBE). A mixing ratio of Bi2Se3 to Bi2Te3 was controlled by varying the Bi:Te:Se flux ratio. X-ray diffraction and Raman spectroscopy measurements indicate the high crystalline quality for the as-grown Bi2Te3-xSex films. Substitution of Te by Se is also revealed from both analyses. The surfaces of the films exhibit terrace-like quintuple layers and their size of the characteristic triangular terraces decreases monotonically with increasing Se content. However, the triangular terrace structure gradually recovers as the Se content further increases. Most importantly, the angle-resolved photoemission spectroscopy results provide evidence of single-Dirac-cone like surface states in which Bi2Te3-xSex with Se/Te-substitution leads to tunable surface states. Our results demonstrate that by fine-tuned MBE growth conditions, Bi2Te3-xSex thin film alloys with tunable topological surface states can be obtained, providing an excellent platform for exploring the novel device applications based on this compound.

  5. Epitaxial thin films of ATiO(3-x)H(x) (A = Ba, Sr, Ca) with metallic conductivity.

    PubMed

    Yajima, Takeshi; Kitada, Atsushi; Kobayashi, Yoji; Sakaguchi, Tatsunori; Bouilly, Guillaume; Kasahara, Shigeru; Terashima, Takahito; Takano, Mikio; Kageyama, Hiroshi

    2012-05-30

    Epitaxial thin films of titanium perovskite oxyhydride ATiO(3-x)H(x) (A = Ba, Sr, Ca) were prepared by CaH(2) reduction of epitaxial ATiO(3) thin films deposited on a (LaAlO(3))(0.3)(SrAl(0.5)Ta(0.5)O(3))(0.7) substrate. Secondary ion mass spectroscopy detected a substantial amount and uniform distribution of hydride within the film. SrTiO(3)/LSAT thin film hydridized at 530 °C for 1 day had hydride concentration of 4.0 × 10(21) atoms/cm(3) (i.e., SrTiO(2.75)H(0.25)). The electric resistivity of all the ATiO(3-x)H(x) films exhibited metallic (positive) temperature dependence, as opposed to negative as in BaTiO(3-x)H(x) powder, revealing that ATiO(3-x)H(x) are intrinsically metallic, with high conductivity of 10(2)-10(4) S/cm. Treatment with D(2) gas results in hydride/deuteride exchange of the films; these films should be valuable in further studies on hydride diffusion kinetics. Combined with the materials' inherent high electronic conductivity, new mixed electron/hydride ion conductors may also be possible. PMID:22563869

  6. Efficient Tailoring of Upconversion Selectivity by Engineering Local Structure of Lanthanides in Na(x)REF(3+x) Nanocrystals.

    PubMed

    Dong, Hao; Sun, Ling-Dong; Wang, Ye-Fu; Ke, Jun; Si, Rui; Xiao, Jia-Wen; Lyu, Guang-Ming; Shi, Shuo; Yan, Chun-Hua

    2015-05-27

    Efficient tailoring of upconversion emissions in lanthanide-doped nanocrystals is of great significance for extended optical applications. Here, we present a facile and highly effective method to tailor the upconversion selectivity by engineering the local structure of lanthanides in Na(x)REF(3+x) nanocrystals. The local structure engineering was achieved through precisely tuning the composition of nanocrystals, with different [Na]/[RE] ([F]/[RE]) ratio. It was found that the lattice parameter as well as the coordination number and local symmetry of lanthanides changed with the composition. A significant difference in the red to green emission ratio, which varied from 1.9 to 71 and 1.6 to 116, was observed for Na(x)YF(3+x):Yb,Er and Na(x)GdF(3+x):Yb,Er nanocrystals, respectively. Moreover, the local structure-dependent upconversion selectivity has been verified for Na(x)YF(3+x):Yb,Tm nanocrystals. In addition, the local structure induced upconversion emission from Er(3+) enhanced 9 times, and the CaF2 shell grown epitaxially over the nanocrystals further promoted the red emission by 450 times, which makes it superior as biomarkers for in vivo bioimaging. These exciting findings in the local structure-dependent upconversion selectivity not only offer a general approach to tailoring lanthanide related upconversion emissions but also benefit multicolor displays and imaging. PMID:25938687

  7. Boson localization and universality in YBa2Cu(3-x)M(x)O(7-delta)

    NASA Technical Reports Server (NTRS)

    Kallio, A.; Apaja, V.; Poykko, S.

    1995-01-01

    We consider a two component mixture of charged fermions on neutralizing background with all sign combinations and arbitrarily small mass ratios. In the two impurity limit for the heavier component we show that the pair forms a bound state for all charge combinations. In the lowest order approximation we derive a closed form expression Veff(r) for the binding potential which has short-range repulsion followed by attraction. In the classical limit, when the mass of embedded particles is large m2 much greater than m, we can calculate from Veff(r) also the cohesive energy E and the bond length R of a metallic crystal such as lithium. The lowest order result is R = 3.1 A, E = -0.9 eV, not entirely different from the experimental result for lithium metal. The same interaction for two holes on a parabolic band with m2 greater than m gives the quantum mechanical bound state which one may interpret as a boson or local pair in the case of high-Te and heavy fermion superconductors. We also show that for compounds of the type YBa2Cu(3 - x)M(x)O(7 - delta) one can understand most of the experimental results for the superconducting and normal states with a single temperature dependent boson breaking function f(T) for each impurity content x governing the decay of bosons into pairing fermions. In the normal state f(T) turns out to be a linear, universal function, independent of the impurity content I and the oxygen content delta. We predict with universality a depression in Tc(x) with slight down bending in agreement with experiment. As a natural consequence of the model the bosons become localized slightly above Tc due to the Wigner crystallization, enhanced with lattice local field minima. The holes remain delocalized with a linearly increasing concentration in the normal state, thus explaining the rising Hall density. The boson localization temperature T(sub BL) shows up as a minimum in the Hall density R(sub ab)(exp -1). We also give explanation for very recently observed

  8. Exaggerated Claims About Earthquake Predictions

    NASA Astrophysics Data System (ADS)

    Kafka, Alan L.; Ebel, John E.

    2007-01-01

    The perennial promise of successful earthquake prediction captures the imagination of a public hungry for certainty in an uncertain world. Yet, given the lack of any reliable method of predicting earthquakes [e.g., Geller, 1997; Kagan and Jackson, 1996; Evans, 1997], seismologists regularly have to explain news stories of a supposedly successful earthquake prediction when it is far from clear just how successful that prediction actually was. When journalists and public relations offices report the latest `great discovery' regarding the prediction of earthquakes, seismologists are left with the much less glamorous task of explaining to the public the gap between the claimed success and the sober reality that there is no scientifically proven method of predicting earthquakes.

  9. Vertical Instability at IPNS RCS.

    SciTech Connect

    Wang, S.; Brumwell, F. R.; Dooling, J. C.; Harkay, K. C.; Kustom, R.; McMichael, G. E.; Middendorf, M. E.; Nassiri, A.; Accelerator Systems Division

    2008-01-01

    The rapid cycling synchrotron (RCS) of the intense pulsed neutron source (IPNS) at ANL accelerates > 3.0 times 10{sup 12} protons from 50 MeV to 450 MeV with 30-Hz repetition frequency. During the acceleration cycle, the rf frequency varies from 2.21 MHz to 5.14 MHz. Presently, the beam current is limited by a vertical instability. By analyzing turn-by-turn beam position monitor (BPM) data, large- amplitude mode 0 and mode 1 vertical beam centroid oscillations were observed in the later part of the acceleration cycle. The oscillations start in the tail of the bunch, build up, and remain localized in the tail half of the bunch. This vertical instability was compared with a head-tail instability that was intentionally induced in the RCS by adjusting the trim sextupoles. It appears that our vertical instability is not a classical head-tail instability [1]. More data analysis and experiments were performed to characterize the instability.

  10. Physics and the Vertical Jump

    ERIC Educational Resources Information Center

    Offenbacher, Elmer L.

    1970-01-01

    The physics of vertical jumping is described as an interesting illustration for motivating students in a general physics course to master the kinematics and dynamics of one dimensional motion. The author suggests that mastery of the physical principles of the jump may promote understanding of certain biological phenomena, aspects of physical…

  11. Vertical reactor coolant pump instabilities

    NASA Technical Reports Server (NTRS)

    Jones, R. M.

    1985-01-01

    The investigation conducted at the Tennessee Valley Authority's Sequoyah Nuclear Power Plant to determine and correct increasing vibrations in the vertical reactor coolant pumps is described. Diagnostic procedures to determine the vibration causes and evaluate the corrective measures taken are also described.

  12. APOL1 Risk Alleles Are Associated with Exaggerated Age-Related Changes in Glomerular Number and Volume in African-American Adults: An Autopsy Study.

    PubMed

    Hoy, Wendy E; Hughson, Michael D; Kopp, Jeffrey B; Mott, Susan A; Bertram, John F; Winkler, Cheryl A

    2015-12-01

    APOL1 genetic variants contribute to kidney disease in African Americans. We assessed correlations between APOL1 profiles and renal histological features in subjects without renal disease. Glomerular number (N glom) and mean glomerular volume (V glom) were measured by the dissector/fractionator method in kidneys of African-American and non-African-American adults without renal disease, undergoing autopsies in Jackson, Mississippi. APOL1 risk alleles were genotyped and the kidney findings were evaluated in the context of those profiles. The proportions of African Americans with none, one, and two APOL1 risk alleles were 38%, 43%, and 19%, respectively; 38% of African Americans had G1 allele variants and 31% of African Americans had G2 allele variants. Only APOL1-positive African Americans had significant reductions in N glom and increases in V glom with increasing age. Regression analysis predicted an annual average loss of 8834 (P=0.03, sex adjusted) glomeruli per single kidney over the first 38 years of adult life in African Americans with two risk alleles. Body mass index above the group medians, but below the obesity definition of ≥ 30 kg/m(2), enhanced the expression of age-related changes in N glom in African Americans with either one or two APOL1 risk alleles. These findings indicate that APOL1 risk alleles are associated with exaggerated age-related nephron loss, probably decaying from a larger pool of smaller glomeruli in early adult life, along with enlargement of the remaining glomeruli. These phenomena might mark mechanisms of accentuated susceptibility to kidney disease in APOL1-positive African Americans. PMID:26038529

  13. Metformin exaggerates phenylephrine-induced AMPK phosphorylation independent of CaMKKβ and attenuates contractile response in endothelium-denuded rat aorta

    PubMed Central

    Pyla, Rajkumar; Osman, Islam; Pichavaram, Prahalathan; Hansen, Paul; Segar, Lakshman

    2014-01-01

    Metformin, a widely prescribed antidiabetic drug, has been shown to reduce the risk of cardiovascular disease, including hypertension. Its beneficial effect toward improved vasodilation results from its ability to activate AMPK and enhance nitric oxide formation in the endothelium. To date, metformin regulation of AMPK has not been fully studied in intact arterial smooth muscle, especially during contraction evoked by G protein-coupled receptor (GPCR) agonists. In the present study, ex vivo incubation of endothelium-denuded rat aortic rings with 3 mM metformin for 2 hours resulted in significant accumulation of metformin (~600 pmoles/mg tissue), as revealed by LC-MS/MS MRM analysis. However, metformin did not show significant increase in AMPK phosphorylation under these conditions. Exposure of aortic rings to a GPCR agonist (e.g., phenylephrine) resulted in enhanced AMPK phosphorylation by ~2.5-fold. Importantly, in metformin-treated aortic rings, phenylephrine challenge showed an exaggerated increase in AMPK phosphorylation by ~9.7-fold, which was associated with an increase in AMP/ATP ratio. Pretreatment with compound C (AMPK inhibitor) prevented AMPK phosphorylation induced by phenylephrine alone and also that induced by phenylephrine after metformin treatment. However, pretreatment with STO-609 (CaMKKβ inhibitor) diminished AMPK phosphorylation induced by phenylephrine alone but not that induced by phenylephrine after metformin treatment. Furthermore, attenuation of phenylephrine-induced contraction (observed after metformin treatment) was prevented by AMPK inhibition but not by CaMKKβ inhibition. Together, these findings suggest that, upon endothelial damage in the vessel wall, metformin uptake by the underlying vascular smooth muscle would accentuate AMPK phosphorylation by GPCR agonists independent of CaMKKβ to promote vasorelaxation. PMID:25179145

  14. Vertical Sextants give Good Sights

    NASA Astrophysics Data System (ADS)

    Dixon, Mark

    Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.

  15. Synthesis and characterization of F-doped Cs0.33WO3-xFx particles with improved near infrared shielding ability

    NASA Astrophysics Data System (ADS)

    Liu, Jingxiao; Luo, Jiayu; Shi, Fei; Liu, Suhua; Fan, Chuanyan; Xu, Qiang; Shao, Guolin

    2015-01-01

    F-doped Cs0.33WO3-xFx particles were successfully synthesized by the hydrothermal method with hydrofluoric acid as fluorine source, and a new kind of heat insulating films were prepared from dispersion of Cs0.33WO3-xFx nanoparticles in polyvinyl alcohol (PVA) aqueous solution. The effects of F doping on the crystal structure and morphology of Cs0.33WO3-xFx particles as well as the near-infrared (NIR) shielding ability and heat insulation properties of Cs0.33WO3-xFx films were investigated. The results indicated that HF acid addition could promote the formation of rod-like Cs0.33WO3-xFx particles during hydrothermal synthesis and increase the yield of Cs0.33WO3-xFx powders. Moreover, the as-prepared films from dispersion solution of Cs0.33WO3-xFx particles exhibited higher near-infrared (NIR) shielding ability and heat insulating properties than that of the undoped Cs0.33WO3 film. Particularly, the as-prepared Cs0.33WO3-xFx sample with F/W (molar ratio)=0.45 showed best NIR shielding ability and transparent heat insulating performance. The formation mechanism of nanorod-like particles and the effects of F doping on the properties of Cs0.33WO3-xFx products were discussed.

  16. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Paul Mattione

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  17. Vertically Integrated Circuits at Fermilab

    SciTech Connect

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  18. Ca(3-x)Srx(PO4)2:Eu2+ nanofibers: Electrospinning fabrication and tunable luminescence

    NASA Astrophysics Data System (ADS)

    Li, Bo; Zhang, He; Lan, Anyi; Tang, Hongxia

    2015-10-01

    Ca(3-x)Srx(PO4)2:2 mol%Eu2+ fibers were fabricated through the electrospinning process and followed by the calcination treatment. The fibers were characterized by XRD, SEM, TEM, and spectrophotometer. The XRD results showed that the obtained fibers have the whitlockite-related structure. The SEM and TEM images showed that the fibers with diameters about 100 nm are mesoporous and composed of fine and closely linked nanoparticles. Under the 365 nm UV light excitation, Ca(3-x)Srx(PO4)2:2 mol%Eu2+ fibers show emissions with different peak positions. The emission color is tunable from blue to green and to green-yellow in the visible region of the spectrum by varying the Sr/Ca ratios.

  19. Preliminary Report on Oak Ridge National Laboratory Testing of Drake/ACSS/MA2/E3X

    SciTech Connect

    Irminger, Philip; King, Daniel J.; Herron, Andrew N.; Davis, Cody; Temple, Bill; Baker, Gord; Li, Zhi; Starke, Michael R.; Ollis, T. Ben

    2016-01-01

    A key to industry acceptance of a new technology is extensive validation in field trials. The Powerline Conductor Accelerated Test facility (PCAT) at Oak Ridge National Laboratory (ORNL) is specifically designed to evaluate the performance and reliability of a new conductor technology under real world conditions. The facility is set up to capture large amounts of data during testing. General Cable used the ORNL PCAT facility to validate the performance of TransPowr with E3X Technology a standard overhead conductor with an inorganic high emissivity, low absorptivity surface coating. Extensive testing has demonstrated a significant improvement in conductor performance across a wide range of operating temperatures, indicating that E3X Technology can provide a reduction in temperature, a reduction in sag, and an increase in ampacity when applied to the surface of any overhead conductor. This report provides initial results of that testing.

  20. NASA-Ames vertical gun

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  1. 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Schematic drawing of 5-Foot Vertical Wind Tunnel. Carl Wenzinger and Thomas Harris describe the tunnel in NACA TR No. 387: 'The tunnel has an open jet, an open test chamber, and a closed return passage. ... The air passes through the test section in a downward direction then enters the exit cone and passes through the first set of guide vanes to a propeller. From here it passes, by way of the return passage, through the successive sets of guide vanes at the corners, then through the honeycomb, and finally through the entrance cone.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet to within 0.5%. The turbulence present in the tunnel has been compared with that of several other tunnels by means of the results of sphere drag tests and was found to average well with the values of those tunnels. Included also in the report are comparisons of results of stable autorotation and of rolling-moment tests obtained both in the vertical tunnel and in the old horizontal 5-foot atmospheric tunnel.' The design of a vertical tunnel having a 5-foot diameter jet was accordingly started by the National Advisory Committee for Aeronautics in 1928. Actual construction of the new tunnel was completed in 1930, and the calibration tests were then made.'

  2. Next generation vertical electrode cells

    NASA Astrophysics Data System (ADS)

    Brown, Craig

    2001-05-01

    The concept of the vertical electrode cell (VEC) for aluminum electrowinning is presented with reference to current research. Low-temperature electrolysis allows nonconsumable metal-alloy anodes to show ongoing promise in laboratory tests. The economic and environmental advantages of the VEC are surveyed. The unique challenges of bringing VEC technology into practice are discussed. The current status of laboratory research is summarized. New results presented show that commercial purity aluminum can be produced with promisingly high current efficiency.

  3. 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Construction of 5-Foot Vertical Wind Tunnel. The 5-Foot Vertical Wind Tunnel was built to study spinning characteristics of aircraft. It was an open throat tunnel capable of a maximum speed of 80 mph. NACA engineer Charles H. Zimmerman designed the tunnel starting in 1928. Construction was completed in December 1929. It was one of two tunnels which replaced the original Atmospheric Wind Tunnel (The other was the 7x10-Foot Wind Tunnel.). In NACA TR 387 (p. 499), Carl Wenzinger and Thomas Harris report that 'the tunnel passages are constructed of 1/8-inch sheet iron, stiffened with angle iron and bolted together at the corners. The over-all dimensions are: Height 31 feet 2 inches; length, 20 feet 3 inches; width, 10 feet 3 inches.' The tunnel was partially constructed in the Langley hanger as indicated by the aircraft in the background. Published in NACA TR 387, 'The Vertical Wind Tunnel of the National Advisory Committee for Aeronautics,' by Carl J. Wenzinger and Thomas A. Harris, 1931.

  4. Flat currents of the Green-Schwarz superstrings in AdS{sub 5}xS{sup 1} and AdS{sub 3}xS{sup 3} backgrounds

    SciTech Connect

    Chen Bin; He Yali; Song Xingchang; Zhang Peng

    2005-04-15

    We construct a one-parameter family of flat currents in AdS{sub 5}xS{sup 1} and AdS{sub 3}xS{sup 3} Green-Schwarz superstrings, which would naturally lead to a hierarchy of classical conserved nonlocal charges. In the former case we rewrite the AdS{sub 5}xS{sup 1} string using a new Z{sub 4}-graded base of the superalgebra su(2,2 vertical bar 2). In both cases the existence of the Z{sub 4} grading in the superalgebras plays a key role in the construction. As a result, we find that the flat currents, when formally written in terms of the G{sub 0}-gauge invariant lowercase 1-forms, take the same form as the one in the AdS{sub 5}xS{sup 5} case.

  5. 3xTg-AD Mice Exhibit an Activated Central Stress Axis during Early-Stage Pathology

    PubMed Central

    Hebda-Bauer, Elaine K.; Simmons, Tracy A.; Sugg, Andrew; Ural, Eren; Stewart, James A.; Beals, James L.; Wei, Qiang; Watson, Stanley J.; Akil, Huda

    2012-01-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis occurs in response to the organism’s innate need for homeostasis. The glucocorticoids (GCs) that are released into the circulation upon acute activation of the HPA axis perform stress-adaptive functions and provide negative feedback to turn off the HPA axis, but can be detrimental when in excess. Long-term activation of the HPA axis (such as with chronic stress) enhances susceptibility to neuronal dysfunction and death, and increases vulnerability to Alzheimer’s disease (AD). However, little is known how components of the HPA axis, upstream of GCs, impact vulnerability to AD. This study examined basal gene expression of stress-related molecules in brains of 3xTg-AD mice during early-stage pathology. Basal glucocorticoid levels and mRNA expression of the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and corticotropic releasing hormone (CRH) in several stress- and emotionality-related brain regions were measured in 3–4-month-old 3xTg-AD mice. Despite normal glucocorticoid levels, young 3xTg-AD mice exhibit an activated central HPA axis, with altered mRNA levels of MR and GR in the hippocampus, GR and CRH in the paraventricular nucleus of the hypothalamus, GR and CRH in the central nucleus of the amygdala, and CRH in the bed nucleus of the stria terminalis. This HPA axis activation is present during early-stage neuropathology when 3xTg-AD mice show mild behavioral changes, suggesting an ongoing neuroendocrine regulation that precedes the onset of severe AD-like pathology and behavioral deficits. PMID:22976078

  6. Early and sustained altered expression of aging-related genes in young 3xTg-AD mice

    PubMed Central

    Gatta, V; D'Aurora, M; Granzotto, A; Stuppia, L; Sensi, S L

    2014-01-01

    Alzheimer's disease (AD) is a multifactorial neurological condition associated with a genetic profile that is still not completely understood. In this study, using a whole gene microarray approach, we investigated age-dependent gene expression profile changes occurring in the hippocampus of young and old transgenic AD (3xTg-AD) and wild-type (WT) mice. The aim of the study was to assess similarities between aging- and AD-related modifications of gene expression and investigate possible interactions between the two processes. Global gene expression profiles of hippocampal tissue obtained from 3xTg-AD and WT mice at 3 and 12 months of age (m.o.a.) were analyzed by hierarchical clustering. Interaction among transcripts was then studied with the Ingenuity Pathway Analysis (IPA) software, a tool that discloses functional networks and/or pathways associated with sets of specific genes of interest. Cluster analysis revealed the selective presence of hundreds of upregulated and downregulated transcripts. Functional analysis showed transcript involvement mainly in neuronal death and autophagy, mitochondrial functioning, intracellular calcium homeostasis, inflammatory response, dendritic spine formation, modulation of synaptic functioning, and cognitive decline. Thus, overexpression of AD-related genes (such as mutant APP, PS1, and hyperphosphorylated tau, the three genes that characterize our model) appears to favor modifications of additional genes that are involved in AD development and progression. The study also showed overlapping changes in 3xTg-AD at 3 m.o.a. and WT mice at 12 m.o.a., thereby suggesting altered expression of aging-related genes that occurs earlier in 3xTg-AD mice. PMID:24525730

  7. Morphological and magnetic study of CaMnO{sub 3-x} oxides obtained from different routes

    SciTech Connect

    Gil de Muro, Izaskun; Insausti, Maite; Lezama, Luis; Rojo, Teofilo . E-mail: qiproapt@lg.ehu.es

    2005-03-15

    The CaMnO{sub 3-x} (x=0 and 0.02) mixed oxide was synthesised from both thermal treatment of a metallo-organic precursor and ceramic method. The morphology of the different products is clearly different. The samples exhibit antiferromagnetic ordering with T{sub N} near to 120K and a weak ferromagnetic component above T{sub N}. This is slightly stronger in the phase prepared by the ceramic route.

  8. Pulsed Lasers: Pulsed Lasers Employing Solution-Processed Plasmonic Cu3- x P Colloidal Nanocrystals (Adv. Mater. 18/2016).

    PubMed

    Liu, Zeke; Mu, Haoran; Xiao, Si; Wang, Rongbin; Wang, Zhiteng; Wang, Weiwei; Wang, Yongjie; Zhu, Xiangxiang; Lu, Kunyuan; Zhang, Han; Lee, Shuit-Tong; Bao, Qiaoliang; Ma, Wanli

    2016-05-01

    Q. Bao, W. Ma and co-workers demonstrate the usage of plasmonic Cu3-x P colloidal nanocrystals as a new type of tunable saturable absorber for the generation of high-energy pulses in a fiber laser. As described on page 3535, these low-cost, solution-processed, next-generation nonlinear optical materials can be harnessed for applications in signal processing and optical communication. PMID:27151629

  9. Density functional study on chirospectra of hydrogen-bonded systems X- (H2O)3 (X = F, Cl, Br, I)

    NASA Astrophysics Data System (ADS)

    Mang, Chao-Yong; Li, Zhen-Gui; Wu, Ke-Chen

    2010-04-01

    This paper calculates the molecular structures, infrared, Raman, circular dichroism spectra and optical rotatory powers of some hydrogen-bonded supramolecular systems as a cyclic water trimer, (H2O)3 and its pyramidal halide complexes, X- (H2O)3 (X = F, Cl, Br, I) with the gradient-corrected density functional theory method at the B3LYP/6-311++G(2d,2p) and B3LYP/Aug-cc-pVTZ levels. It finds that the complexation of halide anions with the water trimer can efficiently modulate the chirally optical behaviors. The calculated vibrational circular dichroism spectrum illuminates that the vibrational rotational strength of S(+)-(H2O)3 mostly originates from the O-H rocking modes, whereas chirality of S(-)-X- (H2O)3 (X = F, Cl, Br, I) has its important origin in the O-H stretching modes. The calculated optical rotatory power demonstrates that S(+)-(H2O)3 and S(+)-F-(H2O)3 are positively chiral, whereas S(-)-X-(H2O)3 (X = Cl, Br, I) are negatively chiral. With the polarizable continuum model, calculated bulk solvent effect in the solvents water and carbontetrachloride and argon shows that the positive chirality of S(+)-(H2O)3 is enhanced and the negative chirality of S(-)-X-(H2O)3 (X = Cl, Br, I) and the positive chirality of S(+)-F-(H2O)3 are reduced with an augmentation of the solvent dielectric constant.

  10. Controlled Substitution of Chlorine for Iodine in Single-Crystal Nanofibers of Mixed Perovskite MAPbI3- x Clx.

    PubMed

    Zhang, Haihua; Liao, Qing; Wang, Xuedong; Hu, Ke; Yao, Jiannian; Fu, Hongbing

    2016-07-01

    Longer carrier diffusion length and improved power conversion efficiency have been reported for thin-film solar cell of organolead mixed-halide perovskite MAPbI3- x Cl x in comparison with MAPbI3 . Instead of substituting I in the MAPbI3 lattice, Cl-incorporation has been shown to mainly improve the film morphology of perovskite absorber. Well-defined crystal structure, adjustable composition (x), and regular morphology, remains a formidable task. Herein, a facile solution-assembly method is reported for synthesizing single-crystalline nanofibers (NFs) of tetragonal-lattice MAPbI3- x Cl x with the Cl-content adjustable between 0 ≤ x ≤ 0.75, leading to a gradual blueshift of the absorption and photoluminescence maxima from x = 0 to 0.75. The photoresponsivity (R) of MAPbI3 NFs keeps almost unchanging at a value independent of the white-light illumination intensity (P). In contrast, R of MAPbI3- x Cl x NFs decreases rapidly with increasing both the x and P values, indicating Cl-substitution increases the recombination traps of photogenerated free electrons and holes. This study provides a model system to examine the role of extrinsic Cl ions in both perovskite crystallography and optoelectronic properties. PMID:27248518

  11. Alzheimer therapy with an antibody against N-terminal Abeta 4-X and pyroglutamate Abeta 3-X

    PubMed Central

    Antonios, Gregory; Borgers, Henning; Richard, Bernhard C.; Brauß, Andreas; Meißner, Julius; Weggen, Sascha; Pena, Vladimir; Pillot, Thierry; Davies, Sarah L.; Bakrania, Preeti; Matthews, David; Brownlees, Janet; Bouter, Yvonne; Bayer, Thomas A.

    2015-01-01

    Full-length Aβ1-42 and Aβ1-40, N-truncated pyroglutamate Aβ3-42 and Aβ4-42 are major variants in the Alzheimer brain. Aβ4-42 has not been considered as a therapeutic target yet. We demonstrate that the antibody NT4X and its Fab fragment reacting with both the free N-terminus of Aβ4-x and pyroglutamate Aβ3-X mitigated neuron loss in Tg4-42 mice expressing Aβ4-42 and completely rescued spatial reference memory deficits after passive immunization. NT4X and its Fab fragment also rescued working memory deficits in wild type mice induced by intraventricular injection of Aβ4-42. NT4X reduced pyroglutamate Aβ3-x, Aβx-40 and Thioflavin-S positive plaque load after passive immunization of 5XFAD mice. Aβ1-x and Aβx-42 plaque deposits were unchanged. Importantly, for the first time, we demonstrate that passive immunization using the antibody NT4X is therapeutically beneficial in Alzheimer mouse models showing that N-truncated Aβ starting with position four in addition to pyroglutamate Aβ3-x is a relevant target to fight Alzheimer’s disease. PMID:26626428

  12. Spin glass behavior in the Dy3-xYxTaO7 (0≤x≤1) system

    NASA Astrophysics Data System (ADS)

    Gomez-Garcia, J. Francisco; Escudero, Roberto; Tavizon, Gustavo

    2014-09-01

    Several x-compositions of the polycrystalline Dy3-xYxTaO7 system, crystallizing in the weberite-type structure, were synthesized and structurally characterized using Rietveld refinements based on X-ray diffraction data. In previous magnetic characterization of Dy3TaO7 (x=0), with the same crystal structure, an antiferromagnetic transition at T=2.3 K has been assigned to this compound. On the basis of DC and AC magnetic susceptibilities analyses, we show in this work that all compounds in the range of 0≤x≤1.0 exhibit a spin glass behavior. The nature of the spin glass behavior in Dy3-xYxTaO7, can be attributed to the highly frustrated antiferromagnetic interaction of the Dy3+ sublattice and to the Dy3+-Dy3+ distorted tetrahedra array in the weberite-type structure of this system. By fitting AC susceptibility data, using dynamical scaling theory equations, we conclude that a cluster spin glass is present in Dy3-xYxTaO7 in the low temperature range. Depending on the x-composition, Tg~2.2-3.2 K. In the range 15-300 K the system obeys a Curie-Weiss magnetic behavior.

  13. β-Secretase 1's Targeting Reduces Hyperphosphorilated Tau, Implying Autophagy Actors in 3xTg-AD Mice.

    PubMed

    Piedrahita, Diego; Castro-Alvarez, John Fredy; Boudreau, Ryan L; Villegas-Lanau, Andres; Kosik, Kenneth S; Gallego-Gomez, Juan Carlos; Cardona-Gómez, Gloria Patricia

    2015-01-01

    β-site APP cleaving enzyme 1 (BACE1) initiates APP cleavage, which has been reported to be an inducer of tau pathology by altering proteasome functions in Alzheimer's disease (AD). However, the exact relationship between BACE1 and PHF (Paired Helical Filaments) formation is not clear. In this study, we confirm that BACE1 and Hsc70 are upregulated in the brains of AD patients, and we demonstrate that both proteins show enhanced expression in lipid rafts from AD-affected triple transgenic mouse brains. BACE1 targeting increased Hsc70 levels in the membrane and cytoplasm fractions and downregulated Hsp90 and CHIP in the nucleus in the hippocampi of 3xTg-AD mice. However, these observations occurred in a proteasome-independent manner in vitro. The BACE1miR-induced reduction of soluble hyperphosphorylated tau was associated with a decrease in MAPK activity. However, the BACE1 RNAi-mediated reduction of hyperphosphorylated tau was only blocked by 3-MA (3-methyladenine) in vitro, and it resulted in the increase of Hsc70 and LAMP2 in lipid rafts from hippocampi of 3xTg-AD mice, and upregulation of survival and homeostasis signaling. In summary, our findings suggest that BACE1 silencing neuroprotects reducing soluble hyperphosphorylated tau, modulating certain autophagy-related proteins in aged 3xTg-AD mice. PMID:26778963

  14. Chloride Incorporation Process in CH3NH3PbI3-xClx Perovskites via Nanoscale Bandgap Maps

    PubMed Central

    Chae, Jungseok; Dong, Qingfeng; Huang, Jinsong; Centrone, Andrea

    2016-01-01

    CH3NH3PbI3-xClx perovskites enable fabrication of highly efficient solar cells. Chloride ions benefit the morphology, carrier diffusion length and stability of perovskite films; however, whether those benefits stem from the presence of Cl− in the precursor solution or from their incorporation in annealed films is debated. In this work, the photothermal induced resonance (PTIR), an in situ technique with nanoscale resolution, is leveraged to measure the bandgap of CH3NH3PbI3-xClx films obtained by a multicycle coating process that produces high efficiency (≈ 16 %) solar cells. Because chloride ions modify the perovskite lattice, thereby widening the bandgap, measuring the bandgap locally yields the local chloride content. After a mild annealing (60 min, 60°C) the films consist of Cl-rich (x < 0.3) and Cl-poor phases that, upon further annealing (110 °C), evolve into a homogenous Cl-poorer (x < 0.06) phase, suggesting that methylammonium-chrloride is progressively expelled from the film. Despite the small chloride content, CH3NH3PbI3-xClx films show better thermal stability up to 140 °C with respect CH3NH3PbI3 films fabricated with the same methodology. PMID:26528710

  15. Optimal Shape Design of Mail-Slot Nacelle on N3-X Hybrid Wing-Body Configuration

    NASA Technical Reports Server (NTRS)

    Kim, Hyoungjin; Liou, Meng-Sing

    2013-01-01

    System studies show that a N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level) set by NASA's Subsonic Fixed Wing Project. In this study, a Navier-Stokes flow simulation of N3-X on hybrid unstructured meshes was conducted, including the mail-slot propulsor. The geometry of the mail-slot propulsor was generated by a CAD (Computer-Aided Design)-free shape parameterization. A novel body force model generation approach was suggested for a more realistic and efficient simulation of the flow turning, pressure rise and loss effects of the fan blades and the inlet-fan interactions. Flow simulation results of the N3-X demonstrates the validity of the present approach. An optimal Shape design of the mail-slot nacelle surface was conducted to reduce strength of shock waves and flow separations on the cowl surface.

  16. An antiferro-to-ferromagnetic transition in EuTiO(3-x)H(x) induced by hydride substitution.

    PubMed

    Yamamoto, Takafumi; Yoshii, Ryuta; Bouilly, Guillaume; Kobayashi, Yoji; Fujita, Koji; Kususe, Yoshiro; Matsushita, Yoshitaka; Tanaka, Katsuhisa; Kageyama, Hiroshi

    2015-02-16

    We have prepared the oxyhydride perovskite EuTiO(3-x)H(x) (x ≤ 0.3) by a low temperature CaH2 reduction of pyrochlore Eu2Ti2O7 and perovskite EuTiO3. The reduced EuTiO(3-x)H(x) crystallizes in the ideal cubic perovskite (Pm3̅m), where O/H anions are randomly distributed. As a result of electron doping by the aliovalent anion exchange, the resistivity of EuTiO(3-x)H(x) shows metallic temperature dependence. Moreover, an antiferromagnetic-to-ferromagnetic transition is observed even when a small amount of hydride (x ∼ 0.07) is introduced. The Curie temperature TC of 12 K is higher than those of any other EuTiO3-derived ferromagnets. The ferromagnetism can be explained by the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu(2+) spins mediated by the itinerant Ti 3d electrons. The present study shows that controlling the oxide/hydride ratio is a versatile method to tune magnetic and transport properties. PMID:25594721

  17. Homozygosity for a novel adenosine deaminase (ADA) nonsense mutation (Q3>X) in a child with severe combined immunodeficiency (SCID)

    SciTech Connect

    Santisteban, I.; Arrendondo-Vega, F.X.; Kelly, S. |

    1994-09-01

    A Somali girl was diagnosed with ADA-deficient SCID at 7 mo; she responded well to PEG-ADA replacement and is now 3.3 yr old. ADA mRNA was undetectable (Northern) in her cultured T cells, but was present in T cells of her parents and two sibs. All PCR-amplified exon 1 genomic clones from the patient had a C>T transition at bp 7 relative to the start of translation, replacing Gln at codon 3 (AGA) with a termination codon (TGA, Q3>X). Patient cDNA (prepared by RT-PCR with a 5{prime} primer that covered codons 1-7) had a previously described polymorphism, K80>R, but was otherwise normal, indicating that no other coding mutations were present. A predicted new genomic BfaI restriction site was used to establish her homozygosity for Q3>X and to analyze genotypes of family members. We also analyzed the segregation of a variable Alu polyA-associated TAAA repeat (AluVpA) situated 5{prime} of the ADA gene. Three different AluVpA alleles were found, one of which was only present in the father and was not associated with his Q3>X allele. Because the father`s RBCs had only {approximately}15% of normal ADA activity, we analyzed his ADA cDNA. We found a G>A transition at bp 425 that substitutes Gln for Arg142, a solvent-accessible residue, and eliminates a BsmAI site in exon 5. ADA activity of the R142>Q in vitro translation product was 20-25% of wild type ADA translation product, suggesting that R142>Q is a new {open_quote}partial{close_quote} ADA deficiency mutation. As expected, Q3>X mRNA did not yield a detectable in vitro translation product. We conclude that the patient`s father is a compound heterozygote carrying the ADA Q3>X/R142>Q genotype. {open_quote}Partial{close_quote} ADA deficiency unassociated with immunodeficiency is relatively common in individuals of African descent. The present findings and previous observations suggest that {open_quote}partial{close_quote} ADA deficiency may have had an evolutionary advantage.

  18. [Vertical fractures: apropos of 2 clinical cases].

    PubMed

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures. PMID:1659859

  19. Vertical separation of the two beams

    SciTech Connect

    Heifets, S.

    1985-10-01

    The author discusses the problem of design of insertion points on the SSC, and in particular keeping the length necessary for them under control. Here he considers the possibility of having vertically separated beams, without a vertical dispersion suppressor.

  20. Vertically aligned nanostructure scanning probe microscope tips

    SciTech Connect

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  1. A design for vertical crossing insertions

    SciTech Connect

    Garren, A.

    1985-10-01

    A crossing insertion designed for an SSC with vertically separated 1-in-1 beam lines is presented in this note. The author supposes that the beam lines consist of separate magnets in separate cryostats separated by about 70 cm. He then describes the design, where vertical separation is done with four vertical dipoles producing a steplike beam line.

  2. Vertical Lift - Not Just For Terrestrial Flight

    NASA Technical Reports Server (NTRS)

    Young, Larry A

    2000-01-01

    Autonomous vertical lift vehicles hold considerable potential for supporting planetary science and exploration missions. This paper discusses several technical aspects of vertical lift planetary aerial vehicles in general, and specifically addresses technical challenges and work to date examining notional vertical lift vehicles for Mars, Titan, and Venus exploration.

  3. Comparison of GT3X accelerometer and Yamax pedometer steps/day in a free-living sample of overweight and obese adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults. Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 +/- 8.4 yr.; BMI = 31.0 +/-...

  4. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  5. ?Vertical Sextants give Good Sights?

    NASA Astrophysics Data System (ADS)

    Richey, Michael

    Mark Dixon suggests (Forum, Vol. 50, 137) that nobody thus far has attempted to quantify the errors from tilt that arise while observing with the marine sextant. The issue in fact, with the related problem of what exactly is the axis about which the sextant is rotated whilst being (to define the vertical), was the subject of a lively controversy in the first two volumes of this Journal some fifty years ago. Since the consensus of opinion seems to have been that the maximum error does not necessarily occur at 45 degrees, whereas Dixon's table suggests that it does, some reiteration of the arguments may be in order.

  6. Vertical-Bloch-Line Memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.; Wu, Jiin-Chuan; Stadler, Henry L.

    1993-01-01

    Vertical-Bloch-line memory is developmental very-large-scale integrated-circuit block-access magnetic memory. Stores data in form of localized pairs of twists (VBL pairs) in magnetic field at edge of ferromagnetic domain in each stripe. Presence or absence of VBL pair at bit position denotes one or zero, respectively. Offers advantages of resistance to ionizing radiation, potential areal storage density approximately less than 1 Gb/cm squared, data rates approximately less than 1 Gb/s, and average access times of order of milliseconds. Furthermore, mass, volume, and demand for power less than other magnetic and electronic memories.

  7. Neighbourly polytopes with few vertices

    SciTech Connect

    Devyatov, Rostislav A

    2011-10-31

    A family of neighbourly polytopes in R{sup 2d} with N=2d+4 vertices is constructed. All polytopes in the family have a planar Gale diagram of a special type, namely, with exactly d+3 black points in convex position. These Gale diagrams are parametrized by 3-trees (trees with a certain additional structure). For all polytopes in the family, the number of faces of dimension m containing a given vertex A depends only on d and m. Bibliography: 7 titles.

  8. 17O NMR study of the doped electrons in lightly oxygen-deficient cubic SrMnO3 -x

    NASA Astrophysics Data System (ADS)

    Trokiner, A.; Verkhovskii, S.; Volkova, Z.; Gerashenko, A.; Mikhalev, K.; Germov, A.; Yakubovskii, A.; Korolev, A.; Dabrowski, B.; Tyutyunnik, A.

    2016-05-01

    The spin susceptibility of the localized Mn (t2 g) electrons, χs, and the spatially distributed spin density of the doped electrons were investigated by 17O nuclear magnetic resonance (NMR) in the paramagnetic (PM) and antiferromagnetic (AF) phases of electron-doped SrMnO3 -x ceramics with the cubic structure. Three lightly doped samples (2 x <0.015 ) were studied with TN=220 K-240 K. In the PM state χs increases gradually from TN and reaches a broad maximum above ˜1.5 TN . The gapped behavior of χs indicates a low-dimensional short-range spin order persisting above TN. These short-range one-dimensional correlations are consistent with 17O NMR results obtained at room temperature, which show that Mn magnetic moments are aligned along the edges of the cubic unit cell. Above 350 K all doped electrons are fast-moving eg electrons. They provide the uniform polarization of the localized spins which increases χs and the increasing doping shifts the oxygen-deficient SrMnO3 -x oxide towards a ferromagnetic (FM) metallic state. At lower T the doped electrons are heterogeneously distributed in the oxide: The fraction of the fast-moving electrons diminishes and vanishes below 100 K, while the remaining doped electrons slow down their hopping and each of them creates a FM domain. These FM domains which are detected below 10 K by 55Mn NMR can be considered as small-size magnetic polarons. Their T -activated hopping in the G-type AF lattice was probed by 17O spin-echo experiments. The energy barrier of hopping shows a trend to grow with increasing doping, indicating that the de Gennes metallic ground state cannot be achieved in oxygen-deficient SrMnO3 -x oxides, probably due to detrimental oxygen vacancy defects.

  9. Treatment of Alzheimer's disease with anti-homocysteic acid antibody in 3xTg-AD male mice.

    PubMed

    Hasegawa, Tohru; Mikoda, Nobuyuki; Kitazawa, Masashi; LaFerla, Frank M

    2010-01-01

    Alzheimer's disease (AD) is an age-associated progressive neurodegenerative disorder with dementia, the exact pathogenic mechanisms of which remain unknown. We previously reported that homocysteic acid (HA) may be one of the pathological biomarkers in the brain with AD and that the increased levels of HA may induce the accumulation of intraneuronal amyloid-beta (Abeta) peptides. In this study, we further investigated the pathological role of HA in a mouse model of AD. Four-month-old prepathological 3xTg-AD mice exhibited higher levels of HA in the hippocampus than did age-matched nontransgenic mice, suggesting that HA accumulation may precede both Abeta and tau pathologies. We then fed 3-month-old 3xTg-AD mice with vitamin B6-deficient food for 3 weeks to increase the HA levels in the brain. Concomitantly, mice received either saline or anti-HA antibody intraventricularly via a guide cannula every 3 days during the course of the B6-deficient diet. We found that mice that received anti-HA antibody significantly resisted cognitive impairment induced by vitamin B6 deficiency and that AD-related pathological changes in their brains was attenuated compared with the saline-injected control group. A similar neuroprotective effect was observed in 12-month-old 3xTg-AD mice that received anti-HA antibody injections while receiving the regular diet. We conclude that increased brain HA triggers memory impairment and that this condition deteriorates with amyloid and leads to subsequent neurodegeneration in mouse models of AD. PMID:20098691

  10. Improved thermoelectric properties of Bi2Te3-xSex alloys by melt spinning and resistance pressing sintering

    NASA Astrophysics Data System (ADS)

    Cai, Xinzhi; Fan, Xi'an; Rong, Zhenzhou; Yang, Fan; Gan, Zhanghua; Li, Guangqiang

    2014-03-01

    Starting from bismuth, tellurium and selenium chunks, n-type Bi2Te3-xSex (x ⩽ 0.3) alloys were obtained by melt spinning (MS) combined with a resistance pressing sintering (RPS) process. The phases, microstructures and compositions of the samples were evaluated by x-ray diffraction, field emission scanning electron microscopy, and energy dispersive x-ray spectroscopy during each step in the preparation process, respectively. The influences of Se doping, MS and RPS processes on the thermoelectric (TE) properties of Bi2Te3-xSex alloys were investigated in detail. The Bi2Te3-xSex powders could be well compacted by the RPS process and the relative densities of the bulks prepared by RPS were all higher than 96%. The partially oriented lamellar structure could be observed at some regions of the samples prepared by RPS, and the monolayer thickness of the lamellar structure in the MS-RPS samples was smaller than that in the smelting-RPS sample. The MS process was confirmed as an excellent method to obtain fine microstructures and low lattice thermal conductivity for the TE materials. All evidence about electrical and thermal transport properties suggested that suitably increasing the Se content could effectively improve the ZT value. The maximum ZT value of 0.84 was obtained for the Bi2Te2.7Se0.3 prepared by MS-RPS at 423 K. As opposed to the conventional hot pressing and spark plasma sintering, the RPS method introduced here is more suitable for practical industrial application due to its cost saving and high efficiency.

  11. DFT Study of the Role of Al3+ in the Fast Ion-Conductor Li7–3xAl3+xLa3Zr2O12 Garnet

    PubMed Central

    2014-01-01

    We investigate theoretically the site occupancy of Al3+ in the fast-ion-conducting cubic-garnet Li7–3xAl3+xLa3Zr2O12 (Ia-3d) using density functional theory. By comparing calculated and measured 27Al NMR chemical shifts an analysis shows that Al3+ prefers the tetrahedrally coordinated 24d site and a distorted 4-fold coordinated 96h site. The site energies for Al3+ ions, which are slightly displaced from the exact crystallographic sites (i.e., 24d and 96h), are similar leading to a distribution of slightly different local oxygen coordination environments. Thus, broad 27Al NMR resonances result reflecting the distribution of different isotropic chemical shifts and quadrupole coupling constants. From an energetic point of view, there is evidence that Al3+ could also occupy the 48g site with its almost regular octahedral coordination sphere. Although this has been reported by neutron powder diffraction, the NMR chemical shift calculated for such an Al3+ site has not been observed experimentally. PMID:25673921

  12. Combustion Synthesis of Sm0.5Sr0.5CoO3-x and La0.6Sr0.4CoO3-x Nanopowders for Solid Oxide Fuel Cell Cathodes

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Zhong, zhimin

    2005-01-01

    Nanopowders of Sm0.5Sr0.5CoO(3-x) (SSC) and La0.6Sr0.4CoO(3-x) (LSC) compositions, which are being investigated as cathode materials for intermediate temperature solid oxide fuel cells, were synthesized by a solution-combustion method using metal nitrates and glycine as fuel. Development of crystalline phases in the as-synthesized powders after heat treatments at various temperatures was monitored by x-ray diffraction. Perovskite phase in LSC formed more readily than in SSC. Single phase perovskites were obtained after heat treatment of the combustion synthesized LSC and SSC powders at 1000 and 1200 C, respectively. The as-synthesized powders had an average particle size of 12 nm as determined from x-ray line broadening analysis using the Scherrer equation. Average grain size of the powders increased with increase in calcination temperature. Morphological analysis of the powders calcined at various temperatures was done by scanning electron microscopy.

  13. The same in the bulk but different as clusters: X3Y3 (X = B, Al, Ga; Y = P, As)

    SciTech Connect

    Alexandrova, Anastassia N.; Nechay, Michael R.; Lydon, Brian R.; Buchan, Daniel P.; Yeh, Alex J.; Tai, Ming-Hei; Kostrikin, Ivan P.; Gabrielyan, Lilit

    2013-11-19

    Most binary materials formed by early group 13 and 15 elements are semiconductors identical in their structures and properties. We show that in the ultra-small cluster regime these materials are markedly different. Among X3Y3 (X = B, Al, Ga; Y = P, As), lighter clusters are planar, and heavier clusters are compact and three-dimensional. The difference is owed to the interplay between covalency and delocalized non-directional bonding in these systems. If the sp-hybridization in the constituent elements is energetically affordable and leads to strong directional overlap, the bonding is covalent and the cluster is flat. Otherwise, the cluster is three-dimensional.

  14. 5-foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1932-01-01

    The researcher is sitting above the exit cone of the 5-foot Vertical Wind Tunnel and is examining the new 6-component spinning balance. This balance was developed between 1930 and 1933. It was an important advance in the technology of rotating or rolling balances. As M.J. Bamber and C.H. Zimmerman wrote in NACA TR 456: 'Data upon the aerodynamic characteristics of a spinning airplane may be obtained in several ways; namely, flight tests with full-scale airplanes, flight tests with balanced models, strip-method analysis of wind-tunnel force and moment tests, and wind-tunnel tests of rotating models.' Further, they note: 'Rolling-balance data have been of limited value because it has not been possible to measure all six force and moment components or to reproduce a true spinning condition. The spinning balance used in this investigation is a 6-component rotating balance from which it is possible to obtain wind-tunnel data for any of a wide range of possible spinning conditions.' Bamber and Zimmerman described the balance as follows: 'The spinning balance consists of a balance head that supports the model and contains the force-measuring units, a horizontal turntable supported by streamline struts in the center of the jet and, outside the tunnel, a direct-current driving motor, a liquid tachometer, an air compressor, a mercury manometer, a pair of indicating lamps, and the necessary controls. The balance head is mounted on the turntable and it may be set to give any radius of spin between 0 and 8 inches.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual

  15. NaF-mediated controlled-synthesis of multicolor NaxScF3+x:Yb/Er upconversion nanocrystals

    NASA Astrophysics Data System (ADS)

    Pei, Wen-Bo; Chen, Bo; Wang, Lili; Wu, Jiansheng; Teng, Xue; Lau, Raymond; Huang, Ling; Huang, Wei

    2015-02-01

    Synthesis of lanthanide-doped upconversion nanocrystals (LDUNs) with controlled morphology and luminescence has long been desired in order to fulfill various application requirements. In this work, we have investigated the effect of the NaF : Ln3+ molar ratio, in the range of 1 to 20, on the morphology, crystal structure, and upconversion properties of NaxScF3+x:Yb/Er nanocrystals that are reported to possess different upconversion properties from those of NaYF4:Yb/Er nanocrystals. The experimental results prove that the NaF : Ln3+ molar ratio influences significantly the growth process of the nanocrystals, i.e. a low NaF : Ln3+ molar ratio results in hexagonal NaScF4 nanocrystals, while a high NaF : Ln3+ molar ratio favors monoclinic Na3ScF6 nanocrystals. When the NaF : Ln3+ molar ratio is as high as 6 or above, phase separation is found and hexagonal NaYbF4 nanocrystals showed up for the first time. Simply by adjusting the NaF : Ln3+ molar ratio, we have successfully achieved the simultaneous control of the shape, size, as well as the crystallographic phase of the NaxScF3+x:Yb/Er nanocrystals, which give different red to green (R/G) ratios (integral area), leading to a multicolor upconversion luminescence from orange-red to green. This study provides a vivid example to track and interpret the formation mechanisms and growth processes of NaxScF3+x:Yb/Er nanocrystals, which shall be instructive for guiding the controlled synthesis of other LDUNs and extending their according applications in optical communication, color display, anti-counterfeiting, bioimaging, and so on.Synthesis of lanthanide-doped upconversion nanocrystals (LDUNs) with controlled morphology and luminescence has long been desired in order to fulfill various application requirements. In this work, we have investigated the effect of the NaF : Ln3+ molar ratio, in the range of 1 to 20, on the morphology, crystal structure, and upconversion properties of NaxScF3+x:Yb/Er nanocrystals that are reported

  16. Mesenchymal Stem Cells Preserve Working Memory in the 3xTg-AD Mouse Model of Alzheimer’s Disease

    PubMed Central

    Ruzicka, Jiri; Kulijewicz-Nawrot, Magdalena; Rodrigez-Arellano, Jose Julio; Jendelova, Pavla; Sykova, Eva

    2016-01-01

    The transplantation of stem cells may have a therapeutic effect on the pathogenesis and progression of neurodegenerative disorders. In the present study, we transplanted human mesenchymal stem cells (MSCs) into the lateral ventricle of a triple transgenic mouse model of Alzheimer´s disease (3xTg-AD) at the age of eight months. We evaluated spatial reference and working memory after MSC treatment and the possible underlying mechanisms, such as the influence of transplanted MSCs on neurogenesis in the subventricular zone (SVZ) and the expression levels of a 56 kDa oligomer of amyloid β (Aβ*56), glutamine synthetase (GS) and glutamate transporters (Glutamate aspartate transporter (GLAST) and Glutamate transporter-1 (GLT-1)) in the entorhinal and prefrontal cortices and the hippocampus. At 14 months of age we observed the preservation of working memory in MSC-treated 3xTg-AD mice, suggesting that such preservation might be due to the protective effect of MSCs on GS levels and the considerable downregulation of Aβ*56 levels in the entorhinal cortex. These changes were observed six months after transplantation, accompanied by clusters of proliferating cells in the SVZ. Since the grafted cells did not survive for the whole experimental period, it is likely that the observed effects could have been transiently more pronounced at earlier time points than at six months after cell application. PMID:26821012

  17. Study of Kinetic Coefficients of (GeTe)1-x - (Ga2Te3)x Solid Solutions

    NASA Astrophysics Data System (ADS)

    Akperov, M. H.; Atalay, T.; Aþkin, H.; Erer, A. M.

    1998-04-01

    In this study, such kinetic cparametres as thermoelectro motor force (thermo e.m.f), electrical coductivity, heat conductivity, Hall and Nernst-Ettingshausen coeficients are investigated, as a function of chemical composition of (GeTe)1-x-(Ga2Te3)x and temperature, by physicochemical methods and x-rays analysis. The kinetic parameters (GeTe)1-x-(Ga2Te3)x solid solutions are investigated between x=0 and 0,015 and between 77 and 900 K. Adding of Ga2Te3 to GeTe reduces the phase transition temperature of b-GeTe to a-GeTe. It is observed that in the region of solid solution the rhombohedral modification of GeTe are protected. Doping of GeTe with Ga2Te3 does not affect the kinetic parameters of GeTe. Anomalies in the rhombohedral phase of solid solutions are related with splitting of cubic phase extremums due to deformation of the rhombohedral lattice. Decreasing of Hall coefficient while increasing thermo e.m.f near phase transition point, in the cubic phase were explained with changing of Hall factor A.

  18. Syntheses and structure of hydrothermally prepared CsNiX{sub 3} (X=Cl, Br, I)

    SciTech Connect

    Raw, Adam D.; Ibers, James A.; Poeppelmeier, Kenneth R.

    2012-08-15

    During reinvestigation of the hydrothermal synthesis reported earlier of the compound cesium nickel phosphide, 'CsNiP', we arrived at a new route to the synthesis of the cesium nickel halide compounds CsNiX{sub 3} (X=Cl, Br, I). The method has also been shown to extend to cobalt and iron compounds. Single crystals of these compounds were synthesized in phosphoric acid in sealed autoclaves. Their structures were determined by single-crystal X-ray diffraction methods. The compounds crystallize in the hexagonal space group P6{sub 3}/mmc in the BaNiO{sub 3} structure type. The synthetic method and the resultant crystallographic details for CsNiCl{sub 3} are essentially identical with those reported earlier for the synthesis and structure of 'CsNiP'. - Graphical abstract: The CsNiX{sub 3} (X=Cl, Br, I) structure. Cesium is blue, nickel is in dark green polyhedra, halide is brown. Highlights: Black-Right-Pointing-Pointer A hydrothermal approach to single crystal growth of cesium transition-metal halides. Black-Right-Pointing-Pointer Reexamination of 'CsNiP' to determine its composition as CsNiCl{sub 3}. Black-Right-Pointing-Pointer X-ray single-crystal structures of CsNiBr{sub 3} and CsNiI{sub 3}.

  19. Magnetic Transport Properties in GdBa2Cu3- x Ru x O7- δ Superconducting Phase

    NASA Astrophysics Data System (ADS)

    Abou-Aly, A. I.; Mahmoud, S. A.; Awad, R.; Ibrahim, I. H.; Barakat, M. Me.

    2012-04-01

    Bulk superconducting samples of type GdBa2Cu3- x Ru x O7- δ phase, Gd-123, with x ranging from 0.0 to 0.15 were prepared by the conventional solid-state reaction technique. X-ray powder diffraction (XRD) and the electrical resistivity measurements were performed in order to investigate the effect of Ru4+ ions substitution on Gd-123 phase. Enhancement of the phase formation and the superconducting transition temperature T c for GdBa2Cu3- x Ru x O7- δ phase up to x=0.05 was observed. The effect of magnetic field up to 4.4 kG on the electrical resistivity behavior of the prepared samples was studied to investigate the flux motion of this phase. The derived flux pinning energy U, based on the thermally activated flux creep TAFC model, decreased with increasing the magnetic field B. The flux pinning energy followed the exponent behavior as U( B)˜ B - β . The superconducting transition width ΔT increased as the magnetic field increased, showing the scaling relation as ΔT˜ B n . Using Ambegaokar and Halperin AH theory, the magnetic field and temperature dependence of U was found to be U( B, T)˜ ΔTB - η , η= β+ n. The critical current density J c (0) enhanced up to x=0.05, beyond which it decreased with further increase in Ru-content.

  20. Mesenchymal Stem Cells Preserve Working Memory in the 3xTg-AD Mouse Model of Alzheimer's Disease.

    PubMed

    Ruzicka, Jiri; Kulijewicz-Nawrot, Magdalena; Rodrigez-Arellano, Jose Julio; Jendelova, Pavla; Sykova, Eva

    2016-01-01

    The transplantation of stem cells may have a therapeutic effect on the pathogenesis and progression of neurodegenerative disorders. In the present study, we transplanted human mesenchymal stem cells (MSCs) into the lateral ventricle of a triple transgenic mouse model of Alzheimer's disease (3xTg-AD) at the age of eight months. We evaluated spatial reference and working memory after MSC treatment and the possible underlying mechanisms, such as the influence of transplanted MSCs on neurogenesis in the subventricular zone (SVZ) and the expression levels of a 56 kDa oligomer of amyloid β (Aβ*56), glutamine synthetase (GS) and glutamate transporters (Glutamate aspartate transporter (GLAST) and Glutamate transporter-1 (GLT-1)) in the entorhinal and prefrontal cortices and the hippocampus. At 14 months of age we observed the preservation of working memory in MSC-treated 3xTg-AD mice, suggesting that such preservation might be due to the protective effect of MSCs on GS levels and the considerable downregulation of Aβ*56 levels in the entorhinal cortex. These changes were observed six months after transplantation, accompanied by clusters of proliferating cells in the SVZ. Since the grafted cells did not survive for the whole experimental period, it is likely that the observed effects could have been transiently more pronounced at earlier time points than at six months after cell application. PMID:26821012

  1. Influence of the silver oxidation on the resistive switching in Ag/AgOx/WO3-x/Pt heterostructures

    NASA Astrophysics Data System (ADS)

    Dong, Chun-Ying; Wei, Wen Gang; Zhao, Jing; Zhang, Jian; Zhao, Xu; Chen, Wei

    2015-12-01

    Silver is usually considered as an inert material and is most commonly used as an electrode. In this work, however, we demonstrate that silver can be easily oxidized during preparation. The influence of the silver oxidation on the resistive switching (RS) effect of the Ag/AgOx/WO3-x/Pt heterostructures was systematically investigated. The heterostructure in which the AgOx film was deposited under an oxygen pressure of 5 × 10-4 Pa showed a linear current-voltage relationship (Ohmic contact). The heterostructures in which the AgOx films were deposited under oxygen pressures of 10 and 100 Pa showed a typical interface RS effect with rectification. In combination with the analysis of the dependence of high-resistance-state (HRS) on RESET current and RESET voltage under different compliance currents, we inferred that the electrochemical redox reaction of the silver oxide is responsible for the RS effect in Ag/AgOx/WO3-x/Pt heterostructures.

  2. Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3 -xGeTe2

    NASA Astrophysics Data System (ADS)

    May, Andrew F.; Calder, Stuart; Cantoni, Claudia; Cao, Huibo; McGuire, Michael A.

    2016-01-01

    The magnetic structure and phase diagram of the layered ferromagnetic compound Fe3GeTe2 has been investigated by a combination of synthesis, x-ray and neutron diffraction, high-resolution microscopy, and magnetization measurements. Single crystals were synthesized by self-flux reactions, and single-crystal neutron diffraction finds ferromagnetic order with moments of 1.11 (5 )μB/Fe aligned along the c axis at 4 K. These flux-grown crystals have a lower Curie temperature Tc≈150 K compared to crystals previously grown by vapor transport (Tc=220 K). The difference is a reduced Fe content in the flux-grown crystals, as illustrated by the behavior observed in a series of polycrystalline samples. As Fe content decreases, so does the Curie temperature, magnetic anisotropy, and net magnetization. In addition, Hall effect and thermoelectric measurements on flux-grown crystals suggest multiple carrier types contribute to electrical transport in Fe3 -xGeTe2 and structurally similar Ni3 -xGeTe2 .

  3. Nanostructured H(3+x)PW(12-x)NbxO40 (x = 0-3) Keggin heteropolyacid catalysts.

    PubMed

    Choi, Jung Ho; Park, Dong Ryul; Park, Sunyoung; Song, In Kyu

    2011-09-01

    Nanostructured H(3+x)PW(12-x)NbxO40 (x = 0, 1, 2, 3) Keggin heteropolyacid (HPA) catalysts were investigated by scanning tunneling microscopy (STM) and tunneling spectroscopy to probe their redox property and oxidation catalysis. STM image showed that the HPAs formed two-dimensional well-ordered monolayer arrays on graphite surface. In tunneling spectra of the HPAs deposited on graphite, they exhibited a distinctive current-voltage behavior referred to as negative differential resistance (NDR). NDR peak voltage measured atop HPA molecule was then correlated with reduction potential and absorption edge energy determined by electrochemical method and UV-visible spectroscopy, respectively. It was revealed that NDR peak voltage of the HPAs appeared at less negative voltage with increasing reduction potential and with decreasing absorption edge energy. In order to correlate NDR peak voltage of H(3+x)PW(12-x)NbxO40 Keggin HPAs with oxidation catalysis, oxidative dehydrogenation of isobutyraldehyde to methacrolein was carried out as a model reaction. NDR peak voltage of the HPAs appeared at less negative voltage with increasing yield for methacrolein. PMID:22097499

  4. Six-dimensional supergravity on S3 x AdS3 and 2d conformal field theory

    SciTech Connect

    de Boer, Jan

    1998-06-20

    In this paper we study the relation between six-dimensional supergravity compactified on S{sup 3} x AdS{sub 3} and certain two-dimensional conformal field theories. We compute the Kaluza-Klein spectrum of supergravity using representation theory; these methods are quite general and can also be applied to other compactifications involving anti-de Sitter spaces. A detailed comparison between the spectrum of the two-dimensional conformal field theory and supergravity is made, and we find complete agreement. This applies even at the level of certain non-chiral primaries, and we propose a resolution to the puzzle of the missing states recently raised by Vafa. As a further illustration of the method the Kaluza-Klein spectra of F-theory on M{sup 6} x S{sup 3} x AdS{sub 3} and of M-theory on M{sup 6} x S{sup 2} x AdS{sub 3} are computed, with M{sup 6} some Calabi-Yau manifold.

  5. Fe3-xCuxO4 as highly active heterogeneous Fenton-like catalysts toward elemental mercury removal.

    PubMed

    Zhou, Changsong; Sun, Lushi; Zhang, Anchao; Wu, Xiaofeng; Ma, Chuan; Su, Sheng; Hu, Song; Xiang, Jun

    2015-04-01

    A series of novel spinel Fe3-xCuxO4 (03-xCuxO4 catalysts in Fenton-like solution is stable and Hg0 removal efficiency remain above 90% after 3 cycles. The active hydroxyl radical (OH) generated during heterogeneous Fenton-like reactions was confirmed through electron spin resonance (ESR) spin-trapping technique. The Hg0 removal mechanism has been discussed based on the experimental and analytical results. PMID:25655441

  6. Preparation of nanocrystalline Fe 3-x LaxO4 ferrite and their adsorption capability for Congo red.

    PubMed

    Wang, Lixia; Li, Jianchen; Wang, Yingqi; Zhao, Lijun

    2011-11-30

    This investigation was to increase the adsorption capacity of magnetite for Congo red (CR) by adulterating a small quantity of La(3+) ions into it. The adsorption capability of nanocrystalline Fe(3-x)La(x)O(4) (x=0, 0.01, 0.05, 0.10) ferrite to remove CR from aqueous solution was evaluated carefully. Compared with undoped magnetite, the adsorption values were increased from 37.4 to 79.1 mg g(-1). The experimental results prove that it is effectual to increase the adsorption capacity of magnetite by doped La(3+) ions. Among the La(3+)-doped magnetite, Fe(2.95)La(0.05)O(4) nanoparticles exhibit the highest saturation magnetization and the maximum adsorption capability. The desorption ability of La(3+)-doped magnetite nanoparticles loaded by CR can reach 92% after the treatment of acetone. Furthermore, the Fe(3-x)La(x)O(4) nanoparticles exhibited a clearly ferromagnetic behavior under applied magnetic field, which allowed their high-efficient magnetic separation from wastewater. It is found that high magnetism facilitates to improve their adsorption capacity for the similar products. PMID:21944701

  7. The TOKAM3X code for edge turbulence fluid simulations of tokamak plasmas in versatile magnetic geometries

    NASA Astrophysics Data System (ADS)

    Tamain, P.; Bufferand, H.; Ciraolo, G.; Colin, C.; Galassi, D.; Ghendrih, Ph.; Schwander, F.; Serre, E.

    2016-09-01

    The new code TOKAM3X simulates plasma turbulence in full torus geometry including the open field lines of the Scrape-off Layer (SOL) and the edge closed field lines region in the vicinity of the separatrix. Based on drift-reduced Braginskii equations, TOKAM3X is able to simulate both limited and diverted plasmas. Turbulence is flux driven by incoming particles from the core plasma and no scale separation between the equilibrium and the fluctuations is assumed so that interactions between large scale flows and turbulence are consistently treated. Based on a domain decomposition, specific numerical schemes are proposed using conservative finite-differences associated to a semi-implicit time advancement. The process computation is multi-threaded and based on MPI and OpenMP libraries. In this paper, fluid model equations are presented together with the proposed numerical methods. The code is verified using the manufactured solution technique and validated through documented simple experiments. Finally, first simulations of edge plasma turbulence in X-point geometry are also introduced in a JET geometry.

  8. White-light emission from Li2Sr1-3 x/2Dy x SiO4 phosphors

    NASA Astrophysics Data System (ADS)

    Sun, Xin-Yuan; Lin, Liang-Wu; Wang, Wen-Feng; Zhang, Jun-Cheng

    2011-07-01

    Li2Sr1-3 x/2Dy x SiO4 phosphors were synthesized at 900°C in the normal atmosphere by a solid-state method. The synthesized phosphors were characterized by X-ray powder diffraction (XRD) and photoluminescence (PL) spectra. The photoluminescence excitation (PLE) spectra show excitation peaks ranging from 300 to 400 nm due to the 4 f-4 f transitions of Dy3+. This mercury-free excitation is useful for solid-state lighting and light-emitting diodes (LEDs). The predominant emission of Dy3+ ions under 349 nm excitation is observed at 479 nm (blue) due to the 4F9/2→6H15/2 transitions and 572 nm (yellow) due to 4F9/2→6H13/2 transitions, respectively. The PL results reveal that the optimal concentration of the Dy3+ ions in Li2Sr1-3 x/2Dy x SiO4 phosphors is x=0.03 mol. The nature of the resonance energy transfer for the Dy3+ ions is confirmed by Huang's rule. Simulation of the white light excited by 349 nm near-ultraviolet (n-UV) light is also performed for its potential for white LEDs.

  9. Mutations in DDX3X Are a Common Cause of Unexplained Intellectual Disability with Gender-Specific Effects on Wnt Signaling.

    PubMed

    Snijders Blok, Lot; Madsen, Erik; Juusola, Jane; Gilissen, Christian; Baralle, Diana; Reijnders, Margot R F; Venselaar, Hanka; Helsmoortel, Céline; Cho, Megan T; Hoischen, Alexander; Vissers, Lisenka E L M; Koemans, Tom S; Wissink-Lindhout, Willemijn; Eichler, Evan E; Romano, Corrado; Van Esch, Hilde; Stumpel, Connie; Vreeburg, Maaike; Smeets, Eric; Oberndorff, Karin; van Bon, Bregje W M; Shaw, Marie; Gecz, Jozef; Haan, Eric; Bienek, Melanie; Jensen, Corinna; Loeys, Bart L; Van Dijck, Anke; Innes, A Micheil; Racher, Hilary; Vermeer, Sascha; Di Donato, Nataliya; Rump, Andreas; Tatton-Brown, Katrina; Parker, Michael J; Henderson, Alex; Lynch, Sally A; Fryer, Alan; Ross, Alison; Vasudevan, Pradeep; Kini, Usha; Newbury-Ecob, Ruth; Chandler, Kate; Male, Alison; Dijkstra, Sybe; Schieving, Jolanda; Giltay, Jacques; van Gassen, Koen L I; Schuurs-Hoeijmakers, Janneke; Tan, Perciliz L; Pediaditakis, Igor; Haas, Stefan A; Retterer, Kyle; Reed, Patrick; Monaghan, Kristin G; Haverfield, Eden; Natowicz, Marvin; Myers, Angela; Kruer, Michael C; Stein, Quinn; Strauss, Kevin A; Brigatti, Karlla W; Keating, Katherine; Burton, Barbara K; Kim, Katherine H; Charrow, Joel; Norman, Jennifer; Foster-Barber, Audrey; Kline, Antonie D; Kimball, Amy; Zackai, Elaine; Harr, Margaret; Fox, Joyce; McLaughlin, Julie; Lindstrom, Kristin; Haude, Katrina M; van Roozendaal, Kees; Brunner, Han; Chung, Wendy K; Kooy, R Frank; Pfundt, Rolph; Kalscheuer, Vera; Mehta, Sarju G; Katsanis, Nicholas; Kleefstra, Tjitske

    2015-08-01

    Intellectual disability (ID) affects approximately 1%-3% of humans with a gender bias toward males. Previous studies have identified mutations in more than 100 genes on the X chromosome in males with ID, but there is less evidence for de novo mutations on the X chromosome causing ID in females. In this study we present 35 unique deleterious de novo mutations in DDX3X identified by whole exome sequencing in 38 females with ID and various other features including hypotonia, movement disorders, behavior problems, corpus callosum hypoplasia, and epilepsy. Based on our findings, mutations in DDX3X are one of the more common causes of ID, accounting for 1%-3% of unexplained ID in females. Although no de novo DDX3X mutations were identified in males, we present three families with segregating missense mutations in DDX3X, suggestive of an X-linked recessive inheritance pattern. In these families, all males with the DDX3X variant had ID, whereas carrier females were unaffected. To explore the pathogenic mechanisms accounting for the differences in disease transmission and phenotype between affected females and affected males with DDX3X missense variants, we used canonical Wnt defects in zebrafish as a surrogate measure of DDX3X function in vivo. We demonstrate a consistent loss-of-function effect of all tested de novo mutations on the Wnt pathway, and we further show a differential effect by gender. The differential activity possibly reflects a dose-dependent effect of DDX3X expression in the context of functional mosaic females versus one-copy males, which reflects the complex biological nature of DDX3X mutations. PMID:26235985

  10. Mutations in DDX3X Are a Common Cause of Unexplained Intellectual Disability with Gender-Specific Effects on Wnt Signaling

    PubMed Central

    Snijders Blok, Lot; Madsen, Erik; Juusola, Jane; Gilissen, Christian; Baralle, Diana; Reijnders, Margot R.F.; Venselaar, Hanka; Helsmoortel, Céline; Cho, Megan T.; Hoischen, Alexander; Vissers, Lisenka E.L.M.; Koemans, Tom S.; Wissink-Lindhout, Willemijn; Eichler, Evan E.; Romano, Corrado; Van Esch, Hilde; Stumpel, Connie; Vreeburg, Maaike; Smeets, Eric; Oberndorff, Karin; van Bon, Bregje W.M.; Shaw, Marie; Gecz, Jozef; Haan, Eric; Bienek, Melanie; Jensen, Corinna; Loeys, Bart L.; Van Dijck, Anke; Innes, A. Micheil; Racher, Hilary; Vermeer, Sascha; Di Donato, Nataliya; Rump, Andreas; Tatton-Brown, Katrina; Parker, Michael J.; Henderson, Alex; Lynch, Sally A.; Fryer, Alan; Ross, Alison; Vasudevan, Pradeep; Kini, Usha; Newbury-Ecob, Ruth; Chandler, Kate; Male, Alison; Dijkstra, Sybe; Schieving, Jolanda; Giltay, Jacques; van Gassen, Koen L.I.; Schuurs-Hoeijmakers, Janneke; Tan, Perciliz L.; Pediaditakis, Igor; Haas, Stefan A.; Retterer, Kyle; Reed, Patrick; Monaghan, Kristin G.; Haverfield, Eden; Natowicz, Marvin; Myers, Angela; Kruer, Michael C.; Stein, Quinn; Strauss, Kevin A.; Brigatti, Karlla W.; Keating, Katherine; Burton, Barbara K.; Kim, Katherine H.; Charrow, Joel; Norman, Jennifer; Foster-Barber, Audrey; Kline, Antonie D.; Kimball, Amy; Zackai, Elaine; Harr, Margaret; Fox, Joyce; McLaughlin, Julie; Lindstrom, Kristin; Haude, Katrina M.; van Roozendaal, Kees; Brunner, Han; Chung, Wendy K.; Kooy, R. Frank; Pfundt, Rolph; Kalscheuer, Vera; Mehta, Sarju G.; Katsanis, Nicholas; Kleefstra, Tjitske

    2015-01-01

    Intellectual disability (ID) affects approximately 1%–3% of humans with a gender bias toward males. Previous studies have identified mutations in more than 100 genes on the X chromosome in males with ID, but there is less evidence for de novo mutations on the X chromosome causing ID in females. In this study we present 35 unique deleterious de novo mutations in DDX3X identified by whole exome sequencing in 38 females with ID and various other features including hypotonia, movement disorders, behavior problems, corpus callosum hypoplasia, and epilepsy. Based on our findings, mutations in DDX3X are one of the more common causes of ID, accounting for 1%–3% of unexplained ID in females. Although no de novo DDX3X mutations were identified in males, we present three families with segregating missense mutations in DDX3X, suggestive of an X-linked recessive inheritance pattern. In these families, all males with the DDX3X variant had ID, whereas carrier females were unaffected. To explore the pathogenic mechanisms accounting for the differences in disease transmission and phenotype between affected females and affected males with DDX3X missense variants, we used canonical Wnt defects in zebrafish as a surrogate measure of DDX3X function in vivo. We demonstrate a consistent loss-of-function effect of all tested de novo mutations on the Wnt pathway, and we further show a differential effect by gender. The differential activity possibly reflects a dose-dependent effect of DDX3X expression in the context of functional mosaic females versus one-copy males, which reflects the complex biological nature of DDX3X mutations. PMID:26235985

  11. Nanoscale Heterostructures Based on Fe2O3@WO3-x Nanoneedles and Their Direct Integration into Flexible Transducing Platforms for Toluene Sensing.

    PubMed

    Vallejos, Stella; Gràcia, Isabel; Figueras, Eduardo; Cané, Carles

    2015-08-26

    Nanoscale heterostructures based on WO3-x nanoneedles functionalized with Fe2O3 nanoparticles are integrated directly into flexible polymer-based transducing platforms via aerosol-assisted chemical vapor deposition. Results demonstrate that the incorporation of Fe2O3 nanoparticles at the surface of WO3-x nanoneedles enhances the electronic and sensing properties of WO3-x, providing a 6-fold increase in sensitivity to toluene and low cross-sensitivity to hydrogen and ethanol. These enhanced-sensing properties are comparable to those obtained via functionalization with precious metal (Pt) nanoparticles, which are commonly used to enhance sensor performance. PMID:26251867

  12. Advancements of vertically aligned liquid crystal displays.

    PubMed

    Kumar, Pankaj; Jaggi, Chinky; Sharma, Vandna; Raina, Kuldeep Kumar

    2016-02-01

    This review describes the recent advancements in the field of the vertical aligned (VA) liquid crystal displays. The process and formation of different vertical alignment modes such as conventional VA, patterned VA, multi-domain VA, and polymer stabilised VA etc are widely discussed. Vertical alignment of liquid crystal due to nano particle dispersion in LC host, bifunctional PR-SAM formed by silane coupling reaction to oxide surfaces, azo dye etc., are also highlighted and discussed. Overall, the article highlights the advances in the research of vertical aligned liquid crystal in terms of their scientific and technological aspects. PMID:26800482

  13. Vertical motion requirements for landing simulation

    NASA Technical Reports Server (NTRS)

    Bray, R. S.

    1973-01-01

    Tests were conducted to determine the significance of vertical acceleration cues in the simulation of the visual approach and landing maneuver. Landing performance measures were obtained for four subject pilots operating a visual landing simulation device which provides up to plus or minus 40 feet of vertical motion. Test results indicate that vertical motion cues are utilized in the landing task, and that they are particularly important in the simulation of aircraft with marginal longitudinal handling qualities. To assure vertical motion cues of the desired fidelity in the landing tasks, it appears that a simulator must have excursion capabilities of at least plus or minus 20 feet.

  14. Tuning the composition of ternary Bi2Se3xTe3(1-x) nanoplates and their Raman scattering investigations

    NASA Astrophysics Data System (ADS)

    Wu, Peng; Chen, Haiping; Yang, Chao; Gan, Wei; Muhammad, Zahir; Song, Li

    2016-07-01

    We present the composition engineering and Raman scattering study of Bi2Se3xTe3(1-x) nanoplates that were synthesized by chemical vapor deposition method using different substrates, including fluorophlogopite mica, SiO2/Si. The characterizations revealed high crystallinity and layered-structure in the ternary Bi2Se3xTe3(1-x) products. Raman spectra of Bi2Se3xTe3(1-x) ranging from 80-200 cm-1 as a function of different Se-doping levels shows that intrinsic Raman peaks of Bi2Se3xTe3(1-x) nanoplates shift to higher frequency as the ratio of doped-Se increasing. The discontinuity of Raman peaks was found and discussed.

  15. Maximizing the photo catalytic and photo response properties of multimodal plasmonic Ag/WO(3-x) heterostructure nanorods by variation of the Ag size.

    PubMed

    Ghosh, Sirshendu; Saha, Manas; Paul, Sumana; De, S K

    2015-11-21

    High quality nearly monodisperse colloidal WO3-x nanorods with an aspect ratio ∼18 were synthesized using the thermal decomposition technique. The effects of a capping agent and an activating agent on the nanorod aspect ratio have been studied. Excess carrier concentration due to large oxygen vacancy and smaller width of the nanorods compared to the Bohr exciton radius gives rise to an increase of the band gap. Shape anisotropy in nanorods results in two plasmonic absorbance bands at about 890 nm and 5900 nm corresponding to short axis and long axis plasmon modes. The short axis mode reveals an excellent plasmonic sensitivity of ∼345 nm per refractive index. A plasmonic photocatalysis process based on WO3-x nanorods has been developed to synthesize Ag/WO3-x heterostructures consisting of multiple Ag dots with ∼2 nm size, randomly decorated on the surface of the WO3-x nanorods. Long time irradiation leads to an increase in the size (5 nm) of Ag nanocrystals concomitant with decrease in the number of Ag nanocrystals attached per WO3-x nanorod. Plasmonic photocatalysis followed by thermal annealing produces only one Ag nanocrystal of size ∼10 nm on each WO3-x nanorod. Red shifting and broadening of plasmon bands of Ag nanocrystals and WO3-x nanorods confirm the formation of heterostructures between the metal and semiconductor. Detailed transmission electron micrograph analysis indicates the epitaxial growth of Ag nanocrystals onto WO3-x nanorods. A high photocurrent gain of about 4000 is observed for Ag (10 nm)/WO3-x heterostructures. The photodegradation rate for Rhodamine-B and methylene blue is maximum for Ag (10 nm)/WO3-x heterostructures due to efficient electron transfer from WO3-x nanorods to Ag nanocrystals. Metal plasmon-semiconductor exciton coupling, prominent plasmon absorbance of metal nanoparticles, and formation of an epitaxial interface are found to be the important factors to achieve the maximum photocatalytic activity and fabrication of a

  16. Highly reproducible, efficient hysteresis-less CH3NH3PbI(3-x)Cl(x) planar hybrid solar cells without requiring heat-treatment.

    PubMed

    Heo, Jin Hyuck; Im, Sang Hyuk

    2016-02-01

    CH3NH3PbI(3-x)Cl(x)(MAPbI(3-x)Cl(x)) mixed halide perovskite powder with uniform composition was synthesized via simple solution chemistry, which demonstrates highly reproducible, efficient planar type MAPbI(3-x)Cl(x) mixed halide perovskite solar cells. Pure MAPbI(3-x)Cl(x) mixed halide perovskite powder was synthesized by reacting a 3 : 1 molar ratio of MAI : PbCl2 powder mixture in isopropanol (IPA) solution for 30 min at 60 °C with subsequent repeated centrifugation and washing in IPA. IPA functions as both the reaction medium for the formation of MAPbI(3-x)Cl(x) mixed halide and a selective remover of unreacted MAI and MACl byproducts. Accordingly, we could deposit a pinhole-free dense MAPbI(3-x)Cl(x) mixed halide perovskite film on a TiO2/FTO substrate through a simple one step spin-coating of pure MAPbI(3-x)Cl(x) mixed halide perovskite powder in DMF solution with HI additive, without further long heat-treatment processes. The deposited MAPbI(3-x)Cl(x) mixed halide perovskite film revealed uniform composition throughout the entire area, and the ratio of Cl to I + Cl and I + Cl to Pb was constant at ∼0.03 and ∼1/3, respectively. On the other hand, the conventional MAPbI(3-x)Cl(x) mixed halide perovskite film prepared by the long heat-treatment process had non-uniform composition because the ratio of Cl to I + Cl fluctuated greatly from 0 to 7.2. The average efficiency of planar type MAPbI(3-x)Cl(x) mixed halide perovskite solar cells was 18.65% ± 0.30% and the champion cell had 1.11 V V(oc), 22.1 mA cm(-2) J(sc), 77% F.F., and 18.9% η for forward scan conditions and 1.11 V V(oc), 22.1 mA cm(-2) J(sc), 78% F.F., and 19.1% η for reverse scan conditions. Although the thickness of the MAPbI(3-x)Cl(x) mixed halide perovskite layer varied from ∼500 nm to ∼900 nm, the efficiency was within the range of 18.3%-19.0%. PMID:26781644

  17. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  18. The Ames Vertical Gun Range

    NASA Technical Reports Server (NTRS)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  19. HL-20 Vertical Human Factors

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The HL-20 space taxi, Langley's candidate personnel launch system, is one of several designs being considered by NASA as a complement to the Space Shuttle. Human factors studies, using Langley volunteers as subjects, have been ongoing since March 1991 to verify crew seating arrangements, habitability, ingress and egress, equipment layout and maintenance and handling operations, and to determine visibility requirements during docking and landing operations. Langley volunteers, wearing flight suits and helmets, were put through a series of tests with the craft placed both vertically and horizontally to simulate launch and landing attitudes, The HL-20 would be launched into a low orbit by an expendable rocket and then use its own propulsion system to boost itself to the space station. Following exchange of crews or delivery of small payload, the HL-20 would return to Earth like the space shuttle, making a runway landing near the launch site, The full-scale engineering research model of the HL-20 design was constructed by students and faculty at North Carolina State University and North Carolina A&T State University with the Mars Mission Research Center under a grant from NASA Langley.

  20. Opportunity at 'Cook Islands' (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,825th Martian day, or sol, of Opportunity's surface mission (March 12, 2009). North is at the top.

    This view is presented as a vertical projection with geometric seam correction.

    The rover had driven half a meter (1.5 feet) earlier on Sol 1825 to fine-tune its location for placing its robotic arm onto an exposed patch of outcrop including a target area informally called 'Cook Islands.' On the preceding sol, Opportunity turned around to drive frontwards and then drove 4.5 meters (15 feet) toward this outcrop. The tracks from the SOl 1824 drive are visible near the center of this view at about the 11 o'clock position. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). Opportunity had previously been driving backward as a strategy to redistribute lubrication in a wheel drawing more electrical current than usual.

    The outcrop exposure that includes 'Cook Islands' is visible just below the center of the image.

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  1. Vertical gating of sketched nanodevices

    NASA Astrophysics Data System (ADS)

    Pai, Yun-Yi; Park, Dong-Wook; Huang, Mengchen; Annadi, Anil; Lee, Hyungwoo; Ma, Zhenqiang; Eom, Chang-Beom; Irvin, Patrick; Levy, Jeremy

    Conductive-atomic force microscope (c-AFM) lithography at the LaAlO3/SrTiO3 interface has enabled the creation of various classes of nanostructures, such as nanoscale transistors, single-electron transistors and has proven to be a promising testbed for mesoscopic physics. To date, these devices have used lithographically-defined side gates, which are limited by leakage currents. To reduce leakage and improve the electric field effect, we have investigated nanostructures with in-situ grown gold top gate. We will discuss designs of logic devices such as inverters, NAND, and NOR gates. In the quantum regime, we compare the performance of in-situ vertical top gates and that of written coplanar side gates with Quantum Dot devices. We gratefully acknowledge financial support from the following agencies and grants: AFOSR (FA9550-­10-­1­-0524(JL), FA9550-­12-­1-­0342(CBE)), NSF (DMR­1124131 (JL, CBE) and DMR­1234096 (CBE)), ONR (N00014-15-1-2847 (JL)).

  2. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1999-03-16

    A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  3. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  4. Vertical and horizontal access configurations

    SciTech Connect

    Spampinato, P.T.

    1987-01-01

    A number of configuration features and maintenance operations are influenced by the choice of whether a design is based on vertical or horizontal access for replacing reactor components. The features which are impacted most include the first wall/blanket segmentation, the poloidal field coil locations, the toroidal field coil number and size, access port size for in-vessel components, and facilities. Since either configuration can be made to work, the choice between the two is not clear cut because both have certain advantages. It is apparent that there are large cost benefits in the poloidal field coil system for ideal coil locations for high elongation plasmas and marginal savings for the INTOR case. If we assume that a new tokamak design will require a higher plasma elongation, the recommendation is to arrange the poloidal field coils in a cost-effective manner while providing reasonable midplane access for heating interfaces and test modules. If a new design study is not based on a high elongation plasma, it still appears prudent to consider this approach so that in-vessel maintenance can be accomplished without moving very massive structures such as the bulk shield. 10 refs., 29 figs., 3 tabs.

  5. Vertical combustor for particulate refuse

    NASA Astrophysics Data System (ADS)

    Chung, P. M.; Carlson, L.

    1981-03-01

    A one-dimensional model is constructed of a vertical combustor for refuse particle combustion in order to analyze it for waste energy recovery. The three components of the model, fuel particles, inert solid particles and the gaseous mixture are described by momentum, energy, and mass conservation equations, resulting in three different flow velocities and temperatures for the medium. The gaseous component is further divided into six chemical species that evolve in combustion at temperatures below about 1367 K. A detailed description is given of the fuel particle combustion through heating, devolatilization, and combustion of the volatile gas in the boundary layer, return of the flame sheet to the fuel surface, and char combustion. The solutions show the combustor to be viable for U.S. refuse which consists of combustibles that can be volatilized up to 85 to 95% below 1366 K. Char combustion, however, is found to be too slow to be attempted in the combustor, where the fuel residence time is of the order of 2 s.

  6. Microstructural and magneto-transport characterization of Bi2SexTe3-x topological insulator thin films grown by pulsed laser deposition method

    NASA Astrophysics Data System (ADS)

    Jin, Zhenghe; Kumar, Raj; Hunte, Frank; Narayan, Jay; Kim, Ki Wook; North Carolina State University Team

    Bi2SexTe3-x topological insulator thin films were grown on Al2O3 (0001) substrate by pulsed laser deposition (PLD). XRD and other structural characterization measurements confirm the growth of the textured Bi2SexTe3-x thin films on Al2O3 substrate. The magneto-transport properties of thick and thin Þlms were investigated to study the effect of thickness on the topological insulator properties of the Bi2SexTe3 - x films. A pronounced semiconducting behavior with a highly insulating ground state was observed in the resistivity vs. temperature data. The presence of the weak anti-localization (WAL) effect with a sharp cusp in the magnetoresistance measurements confirms the 2-D surface transport originating from the TSS in Bi2SexTe3-x TI films. A high fraction of surface transport is observed in the Bi2SexTe3-x TI thin films which decreases in Bi2SexTe3-x TI thick films. The Cosine (θ) dependence of the WAL effect supports the observation of a high proportion of 2-D surface state contribution to overall transport properties of the Bi2SexTe3-x TI thin films. Our results show promise that high quality Bi2SexTe3-x TI thin films with significant surface transport can be grown by PLD method to exploit the exotic properties of the surface transport in future generation spintronic devices. This work was supported, in part, by National Science Foundation ECCS-1306400 and FAME.

  7. Resistive Switching Behavior in Organic-Inorganic Hybrid CH3 NH3 PbI3-x Clx Perovskite for Resistive Random Access Memory Devices.

    PubMed

    Yoo, Eun Ji; Lyu, Miaoqiang; Yun, Jung-Ho; Kang, Chi Jung; Choi, Young Jin; Wang, Lianzhou

    2015-10-28

    The CH3 NH3 PbI3- x Clx organic-inorganic hybrid perovskite material demonstrates remarkable resistive switching behavior, which can be applicable in resistive random access memory devices. The simply designed Au/CH3 NH3 PbI3- x Clx /FTO structure is fabricated by a low-temperature, solution-processable method, which exhibits remarkable bipolar resistive switching and nonvolatile properties. PMID:26331363

  8. Elastic, Electronic and Thermodynamic Properties of Rh3X(X = Zr, Nb and Ta) Intermetallic Compounds

    NASA Astrophysics Data System (ADS)

    Ould Kada, M.; Seddik, T.; Sayede, A.; Khenata, R.; Bouhemadou, A.; Deligoz, E.; Alahmed, Z. A.; Bin Omran, S.; Rached, D.

    2014-11-01

    Structural, electronic, elastic and thermodynamic properties of Rh3X(X = Zr, Nb, Ta) intermetallic compounds are investigated in the framework of density functional theory (DFT). The exchange-correlation (XC) potential is treated with the generalized gradient approximation (GGA) and local density approximation (LDA). The computed ground state properties agree well with the available theoretical and experimental values. The elastic constants are obtained by calculating the total energy versus volume conserving strains using Mehl model. The electronic and bonding properties are discussed from the calculations of band structures (BSs), densities of states and electron charge densities. The volume and bulk modulus at high pressure and temperature are investigated. Additionally, thermodynamic properties such as the heat capacity, thermal expansion and Debye temperature at high pressures and temperatures are also analyzed.

  9. Intrinsic Topological Insulator Bi1.5Sb0.5Te3-xSex Thin Crystals

    PubMed Central

    Wang, Wei; Li, Li; Zou, Wenqin; He, Liang; Song, Fengqi; Zhang, Rong; Wu, Xiaoshan; Zhang, Fengming

    2015-01-01

    The quaternary topological insulator (Bi,Sb)2(Te,Se)3 has demonstrated topological surface states with an insulating bulk. Scientists have identified an optimized composition of Bi1.5Sb0.5Te1.7Se1.3 with the highest resistivity reported. But the physics that drive to this composition remains unclear. Here we report the crystal structure and the magneto-transport properties of Bi1.5Sb0.5Te3-xSex (BSTS) series. A correlation between the structure and the physical properties has been revealed. We found out that within the rhombohedral structure, the composition with most Te substituting Se has the highest resistivity. On the other hand, segregation of other composition phases will introduce much higher bulk concentration. PMID:25604579

  10. Assessment of Biasi and Columbia University CHF correlations with GE 3x3 rod bundle experiment. [PWR; BWR

    SciTech Connect

    Chen, B.C.J.; Chien, T.H.; Sha, W.T.; Kim, J.H.

    1984-01-01

    The critical heat flux (CHF), at which a sudden degradation of heat transfer occurs without corresponding decrease in heat generation, is one of the limiting parameters for safe operation of nuclear reactors. Reactor operation beyond the CHF causes a rapid rise in fuel cladding temperature and thus should be avoided to maintain the fuel element integrity. Reactor power limits are therefore set so that a prescribed safety margin below the CHF is maintained. Two CHF correlations are evaluated for reactor core thermal hydraulic analysis: the Biasi correlation and the Columbia University correlation. The BODYFIT-2PE computer code is used for this assessment. The CHF predicted by the BODYFIT-2PE using the two correlations is compared with GE 3x3 rod bundle CHF experiment.

  11. Disentangling the Mn moments on different sublattices in the half-metallic ferrimagnet Mn3?xCoxGa

    SciTech Connect

    Klaer, P.; Jenkins, C.A.; Alijani, V.; Winterlik, J.; Balke, B.; Felser, C.; Elmers, H.J.

    2011-05-03

    Ferrimagnetic Mn{sub 3-x}Co{sub x}Ga compounds have been investigated by magnetic circular dichroism in x-ray absorption (XMCD). Compounds with x > 0.5 crystallize in the CuHg{sub 2}Ti structure. A tetragonal distortion of the cubic structure occurs for x {le} 0.5. For the cubic phase, magnetometry reveals a linearly increasing magnetization of 2x Bohr magnetons per formula unit obeying the generalized Slater-Pauling rule. XMCD confirms the ferrimagnetic character with Mn atoms occupying two different sublattices with antiparallel spin orientation and different degrees of spin localization and identifies the region 0.6 < x {le} 0.8 as most promising for a high spin polarization at the Fermi level. Individual Mn moments on inequivalent sites are compared to theoretical predictions.

  12. Electrical and magnetic properties modification in heavy ion irradiated nanograin NixCo(3-x)O4 films

    SciTech Connect

    Mccloy, John S.; Jiang, Weilin; Bennett, Wendy D.; Engelhard, Mark H.; Lindemuth, Jeffrey; Parmar, Narendra S.; Exarhos, Gregory J.

    2015-09-10

    Reactively sputtered NixCo(3-x)O4 films (x = 1.5, 1.0, and 0.75) were grown and subsequently irradiated with 5.5 MeV Si+ ions to investigate effects of lattice-site and charge state distribution. Films were characterized before and after irradiation by x-ray diffraction, x-ray photoemission spectroscopy, Rutherford backscattering spectroscopy, electric resistivity measurements, and temperature-dependent AC and DC magnetometry. Results indicate that ion irradiation induces oxygen loss, partial reduction of nickel, and an increase in both low temperature ferrimagnetism and room temperature conductivity. Frequency dependent AC magnetic susceptibility measurements indicate a spin-glass like transition at low temperature which moves to higher temperature after irradiation. Significance of the charge transfer for magnetism and conduction in a mixed spinel with Co2+, Co3+, Ni2+, and Ni3+ in tetrahedral and octahedral sites is discussed.

  13. Curie-Weiss behavior of Y1-xSrxMnO3 (x = 0 and 0.03)

    NASA Astrophysics Data System (ADS)

    Thakur, Rajesh K.; Thakur, Rasna; Gaur, N. K.; Bharathi, A.; Kaurav, N.; Okram, G. S.

    2015-06-01

    The effect of bivalent cation Sr-doping on magnetic properties in multiferroic YMnO3 manganites was systemically studied by DC magnetic measurements. Both of the reported samples were prepared by solid-state reaction method with composition Y1-xSrxMnO3 (x = 0.00 and 0.03). The X-ray diffraction (XRD) results show that the compounds are synthesized in hexagonal crystal structure with space group P63cm (JCPDS: 25-1079) and slight increase in the lattice parameter is observed with strontium doping. The magnetisation versus temperature curve shows no clear anomaly near the antiferromagnetic transition temperature (TN), however from the magnetic measurements at 1000Oe a slight increase in the magnetisation is clearly witnessed with increasing Stront ium content to the Y-site.

  14. Spin-glass behaviors in carrier polarity controlled Fe3-xTixO4 semiconductor thin films

    NASA Astrophysics Data System (ADS)

    Yamahara, H.; Seki, M.; Adachi, M.; Takahashi, M.; Nasu, H.; Horiba, K.; Kumigashira, H.; Tabata, H.

    2015-08-01

    Carrier-type control of spin-glass (cluster spin-glass) is studied in order to engineer basic magnetic semiconductor elements using the memory functions of spin-glass. A key of carrier-polarity control in magnetite is the valence engineering between Fe(II) and Fe(III) that is achieved by Ti(IV) substitution. Single phases of (001)-oriented Fe3-xTixO4 thin films have been obtained on spinel MgAl2O4 substrates by pulsed laser deposition. Thermoelectric power measurements reveal that Ti-rich films (x = 0.8) show p-type conduction, while Ti-poor films (x = 0.6-0.75) show n-type conduction. The systematic Fe(III) reduction to Fe(II) followed by Ti(IV) substitution in the octahedral sublattice is confirmed by the X-ray absorption spectra. All of the Fe3-xTixO4 films (x = 0.6-0.8) exhibit ferrimagnetism above room temperature. Next, the spin-glass behaviors of Ti-rich Fe2.2Ti0.8O4 film are studied, since this magnetically diluted system is expected to exhibit the spin-glass behaviors. The DC magnetization and AC susceptibility measurements for the Ti-rich Fe2.2Ti0.8O4 film reveal the presence of the spin glass phase. Thermal- and magnetic-field-history memory effects are observed and are attributed to the long time-decay nature of remanent magnetization. The detailed analysis of the time-dependent thermoremanent magnetization reveals the presence of the cluster spin glass state.

  15. Importance of cross-correlated relaxation in the spectra of simple organofluorine compounds: Spectral complexity of A3B3X spin systems compared to ABX spin systems

    NASA Astrophysics Data System (ADS)

    Alemany, Lawrence B.; Malloy, Thomas B.; Nunes, Megan M.; Zaibaq, Nicholas G.

    2012-09-01

    In a continuation of our initial investigation of the complex 13C and 19F spectra exhibited by two simple organofluorine compounds, additional organofluorine compounds expected to exhibit a wide range of spectral complexity were studied. Spectral simulations are critical for analyzing the more complex spin systems, in particular, A3B3X and A6B3X. Cross-correlated relaxation is commonly observed; examples of 13Csbnd 19F cross-correlated relaxation are shown with the signals for each nucleus exhibiting unequal relaxation rates. Higher order effects are particularly noticeable in the spectra of perfluoro-t-butyl alcohol because of a large 4JFF value in the (13CF3)(12CF3)212COH isotopomer. The many additional transitions in an A3B3X spin system compared to an ABX spin system result in much more complex 19F (A3 and B3) and 13C (X) spectra, even though only three types of nuclei are involved in each spin system. The corresponding protio compounds typically constitute a much simpler A3M3X spin system because the long-range nJHH coupling (n ⩾ 4) is much smaller than the corresponding long-range nJFF coupling. Spectra previously published for ethane-1-13C (A3B3X) and hexafluoroethane-1-13C (A3M3X) are notable exceptions and are discussed.

  16. Volttron version 3.x

    2015-10-06

    VOLTTRON™ is an agent execution platform providing services to its agents that allow them to easily communicate with physical devices and other resources. VOLTTRON™ delivers an innovative distributed control and sensing software platform that supports modern control strategies, including agent-based and transaction-based controls. It enables mobile and stationary software agents to perform information gathering, processing, and control actions. VOLTTRON™ can independently manage a wide range of applications, such as HVAC systems, electric vehicles, distributed energymore » or entire building loads, leading to improved operational efficiency.« less

  17. Volttron version 3.x

    SciTech Connect

    None, None

    2015-10-06

    VOLTTRON™ is an agent execution platform providing services to its agents that allow them to easily communicate with physical devices and other resources. VOLTTRON™ delivers an innovative distributed control and sensing software platform that supports modern control strategies, including agent-based and transaction-based controls. It enables mobile and stationary software agents to perform information gathering, processing, and control actions. VOLTTRON™ can independently manage a wide range of applications, such as HVAC systems, electric vehicles, distributed energy or entire building loads, leading to improved operational efficiency.

  18. Biomechanical Examination of the ‘Plateau Phenomenon’ in ActiGraph Vertical Activity Counts

    PubMed Central

    John, Dinesh; Miller, Ross; Kozey-Keadle, Sarah; Caldwell, Graham; Freedson, Patty

    2012-01-01

    Purpose Determine if the leveling off (‘plateau/inverted-U’ phenomenon) of vertical ActiGraph activity counts during running at higher speeds is attributable to the monitor’s signal filtering and acceleration detection characteristics. Methods Ten endurance-trained male participants [mean (SD) age= 28.2 (4.7) yrs] walked at 3, 5 and 7 km˙hr−1, and ran at 8, 10, 12, 14, 16, 18 and 20 km˙hr−1 on a force treadmill while wearing an ActiGraph GT3X monitor at the waist. Triaxial accelerations of the body’s center of mass (CoM) and frequency content of these accelerations were computed from the force treadmill data. Results GT3X vertical activity counts demonstrated the expected ‘plateau/inverted-U’ phenomenon. In contrast, vertical CoM accelerations increased with increasing speed (1.32 ± 0.26 g at 10 km˙hr−1 and 1.68 ± 0.24 g at 20 km˙hr−1). The dominant frequency in the CoM acceleration signals increased with running speed (14.8 ± 3.2 Hz at 10 km˙hr−1 and 24.8 ± 3.2 Hz at 20 km˙hr−1) and lay beyond the ActiGraph bandpass filter (0.25 to 2.5 Hz) limits. Conclusion CoM acceleration magnitudes during walking and running lie within the ActiGraph monitor’s dynamic acceleration detecting capability. Acceleration signals of higher frequencies that are eliminated by the ActiGraph bandpass filter may be necessary to distinguish among exercise intensity at higher running speeds. PMID:22260902

  19. Vertical Integration, Monopoly, and the First Amendment.

    ERIC Educational Resources Information Center

    Brennan, Timothy J.

    This paper addresses the relationship between the First Amendment, monopoly of transmission media, and vertical integration of transmission and content provision. A survey of some of the incentives a profit-maximizing transmission monopolist may have with respect to content is followed by a discussion of how vertical integration affects those…

  20. Teaching Students the Verticality of Technical Documentation.

    ERIC Educational Resources Information Center

    Hager, Peter J.

    1992-01-01

    Advocates making technical writing courses more vertical in structure by including an extensive study of at least one specific form of technical documentation. Examines how students can gain experience in the vertical process by designing, writing, testing, and producing user manuals for on-campus cooperative education clients. Lists the benefits…

  1. The biomechanics of vertical hopping: a review.

    PubMed

    Lamontagne, Mario; Kennedy, Matthew J

    2013-01-01

    Repetitive vertical hopping is a simple and relatively controlled task useful for studying basic neuromuscular properties and tissue mechanics. However, several biomechanical and physiological factors are involved. This article provides an overview of muscle and tendon properties and how these interact during vertical hopping. Muscle properties discussed are force-velocity and force-length relationships, electromechanical delay, muscle fiber type, stretch induced contraction amplification, and muscle spindle afferent feedback. Tendon properties include storage and reuse of elastic energy, tendon stiffness, afferent information from Golgi tendon organs, and failure points. These muscle and tendon properties interact to generate vertical hopping force and power. In addition to these basic properties, there are other more complicated factors to consider when analyzing vertical hopping such as balance and coordination. A wealth of information can be gathered by studying vertical hopping. Caution should be taken, however, to prevent inappropriate conclusions being drawn about hop performance due to oversimplification. PMID:24067123

  2. Vertical-Cavity Surface-Emitting Lasers

    NASA Astrophysics Data System (ADS)

    Wilmsen, Carl W.; Temkin, Henryk; Coldren, Larry A.

    2002-01-01

    1. Introduction to VCSELs L. A. Coldren, C. W. Wilmsen and H. Temkin; 2. Fundamental issues in VCSEL design L. A. Coldren and Eric R. Hegblom; 3. Enhancement of spontaneous emission in microcavities E. F. Schubert and N. E. J. Hunt; 4. Epitaxy of vertical-cavity lasers R. P. Schneider Jr and Y. H. Young; 5. Fabrication and performance of vertical-cavity surface-emitting lasers Kent D. Choquette and Kent Geib; 6. Polarization related properties of vertical cavity lasers Dmitri Kuksenkov and Henryk Temkin; 7. Visible light emitting vertical cavity lasers Robert L. Thornton; 8. Long-wavelength vertical-cavity lasers Dubrakovo I. Babic, Joachim Piprek and John E. Bowers; 9. Overview of VCSEL applications Richard C. Williamson; 10. Optical interconnection applications and required characteristics Kenichi Kasahara; 11. VCSEL-based fiber-optic data communications Kenneth Hahn and Kirk Giboney; 12. VCSEL-based smart pixels for free space optoelectronic processing C. W. Wilmsen.

  3. Maximizing the photo catalytic and photo response properties of multimodal plasmonic Ag/WO3-x heterostructure nanorods by variation of the Ag size

    NASA Astrophysics Data System (ADS)

    Ghosh, Sirshendu; Saha, Manas; Paul, Sumana; de, S. K.

    2015-10-01

    High quality nearly monodisperse colloidal WO3-x nanorods with an aspect ratio ~18 were synthesized using the thermal decomposition technique. The effects of a capping agent and an activating agent on the nanorod aspect ratio have been studied. Excess carrier concentration due to large oxygen vacancy and smaller width of the nanorods compared to the Bohr exciton radius gives rise to an increase of the band gap. Shape anisotropy in nanorods results in two plasmonic absorbance bands at about 890 nm and 5900 nm corresponding to short axis and long axis plasmon modes. The short axis mode reveals an excellent plasmonic sensitivity of ~345 nm per refractive index. A plasmonic photocatalysis process based on WO3-x nanorods has been developed to synthesize Ag/WO3-x heterostructures consisting of multiple Ag dots with ~2 nm size, randomly decorated on the surface of the WO3-x nanorods. Long time irradiation leads to an increase in the size (5 nm) of Ag nanocrystals concomitant with decrease in the number of Ag nanocrystals attached per WO3-x nanorod. Plasmonic photocatalysis followed by thermal annealing produces only one Ag nanocrystal of size ~10 nm on each WO3-x nanorod. Red shifting and broadening of plasmon bands of Ag nanocrystals and WO3-x nanorods confirm the formation of heterostructures between the metal and semiconductor. Detailed transmission electron micrograph analysis indicates the epitaxial growth of Ag nanocrystals onto WO3-x nanorods. A high photocurrent gain of about 4000 is observed for Ag (10 nm)/WO3-x heterostructures. The photodegradation rate for Rhodamine-B and methylene blue is maximum for Ag (10 nm)/WO3-x heterostructures due to efficient electron transfer from WO3-x nanorods to Ag nanocrystals. Metal plasmon-semiconductor exciton coupling, prominent plasmon absorbance of metal nanoparticles, and formation of an epitaxial interface are found to be the important factors to achieve the maximum photocatalytic activity and fabrication of a high speed

  4. Highly reproducible, efficient hysteresis-less CH3NH3PbI3-xClx planar hybrid solar cells without requiring heat-treatment

    NASA Astrophysics Data System (ADS)

    Heo, Jin Hyuck; Im, Sang Hyuk

    2016-01-01

    CH3NH3PbI3-xClx(MAPbI3-xClx) mixed halide perovskite powder with uniform composition was synthesized via simple solution chemistry, which demonstrates highly reproducible, efficient planar type MAPbI3-xClx mixed halide perovskite solar cells. Pure MAPbI3-xClx mixed halide perovskite powder was synthesized by reacting a 3 : 1 molar ratio of MAI : PbCl2 powder mixture in isopropanol (IPA) solution for 30 min at 60 °C with subsequent repeated centrifugation and washing in IPA. IPA functions as both the reaction medium for the formation of MAPbI3-xClx mixed halide and a selective remover of unreacted MAI and MACl byproducts. Accordingly, we could deposit a pinhole-free dense MAPbI3-xClx mixed halide perovskite film on a TiO2/FTO substrate through a simple one step spin-coating of pure MAPbI3-xClx mixed halide perovskite powder in DMF solution with HI additive, without further long heat-treatment processes. The deposited MAPbI3-xClx mixed halide perovskite film revealed uniform composition throughout the entire area, and the ratio of Cl to I + Cl and I + Cl to Pb was constant at ~0.03 and ~1/3, respectively. On the other hand, the conventional MAPbI3-xClx mixed halide perovskite film prepared by the long heat-treatment process had non-uniform composition because the ratio of Cl to I + Cl fluctuated greatly from 0 to 7.2. The average efficiency of planar type MAPbI3-xClx mixed halide perovskite solar cells was 18.65% +/- 0.30% and the champion cell had 1.11 V Voc, 22.1 mA cm-2Jsc, 77% F.F., and 18.9% η for forward scan conditions and 1.11 V Voc, 22.1 mA cm-2Jsc, 78% F.F., and 19.1% η for reverse scan conditions. Although the thickness of the MAPbI3-xClx mixed halide perovskite layer varied from ~500 nm to ~900 nm, the efficiency was within the range of 18.3%-19.0%.CH3NH3PbI3-xClx(MAPbI3-xClx) mixed halide perovskite powder with uniform composition was synthesized via simple solution chemistry, which demonstrates highly reproducible, efficient planar type MAPbI3-x

  5. Maximizing the photo catalytic and photo response properties of multimodal plasmonic Ag/WO3-x heterostructure nanorods by variation of the Ag size

    NASA Astrophysics Data System (ADS)

    Ghosh, Sirshendu; Saha, Manas; Paul, Sumana; de, S. K.

    2015-10-01

    High quality nearly monodisperse colloidal WO3-x nanorods with an aspect ratio ~18 were synthesized using the thermal decomposition technique. The effects of a capping agent and an activating agent on the nanorod aspect ratio have been studied. Excess carrier concentration due to large oxygen vacancy and smaller width of the nanorods compared to the Bohr exciton radius gives rise to an increase of the band gap. Shape anisotropy in nanorods results in two plasmonic absorbance bands at about 890 nm and 5900 nm corresponding to short axis and long axis plasmon modes. The short axis mode reveals an excellent plasmonic sensitivity of ~345 nm per refractive index. A plasmonic photocatalysis process based on WO3-x nanorods has been developed to synthesize Ag/WO3-x heterostructures consisting of multiple Ag dots with ~2 nm size, randomly decorated on the surface of the WO3-x nanorods. Long time irradiation leads to an increase in the size (5 nm) of Ag nanocrystals concomitant with decrease in the number of Ag nanocrystals attached per WO3-x nanorod. Plasmonic photocatalysis followed by thermal annealing produces only one Ag nanocrystal of size ~10 nm on each WO3-x nanorod. Red shifting and broadening of plasmon bands of Ag nanocrystals and WO3-x nanorods confirm the formation of heterostructures between the metal and semiconductor. Detailed transmission electron micrograph analysis indicates the epitaxial growth of Ag nanocrystals onto WO3-x nanorods. A high photocurrent gain of about 4000 is observed for Ag (10 nm)/WO3-x heterostructures. The photodegradation rate for Rhodamine-B and methylene blue is maximum for Ag (10 nm)/WO3-x heterostructures due to efficient electron transfer from WO3-x nanorods to Ag nanocrystals. Metal plasmon-semiconductor exciton coupling, prominent plasmon absorbance of metal nanoparticles, and formation of an epitaxial interface are found to be the important factors to achieve the maximum photocatalytic activity and fabrication of a high speed

  6. Prolonged running, not fluoxetine treatment, increases neurogenesis, but does not alter neuropathology, in the 3xTg mouse model of Alzheimer's disease.

    PubMed

    Marlatt, Michael W; Potter, Michelle C; Bayer, Thomas A; van Praag, Henriette; Lucassen, Paul J

    2013-01-01

    Reductions in adult neurogenesis have been documented in the original 3xTg mouse model of Alzheimer's disease (AD), notably occurring at the same age when spatial memory deficits and amyloid plaque pathology appeared. As this suggested reduced neurogenesis was associated with behavioral deficits, we tested whether activity and pharmacological stimulation could prevent memory deficits and modify neurogenesis and/or neuropathology in the 3xTg model backcrossed to the C57Bl/6 strain. We chronically administered the antidepressant fluoxetine to one group of mice, allowed access to a running wheel in another, and combined both treatments in a third cohort. All treatments lasted for 11 months. The female 3xTg mice failed to exhibit any deficits in spatial learning and memory as measured in the Morris water maze, indicating that when backcrossed to the C57Bl/6 strain, the 3xTg mice lost the behavioral phenotype that was present in the original 3xTg mouse maintained on a hybrid background. Despite this, the backcrossed 3xTg mice expressed prominent intraneuronal amyloid beta (Aβ) levels in the cortex and amygdala, with lower levels in the CA1 area of the hippocampus. In the combined cohort, fluoxetine treatment interfered with exercise and reduced the total distance run. The extent of Aβ neuropathology, the tau accumulations, or BDNF levels, were not altered by prolonged exercise. Thus, neuropathology was present but not paralleled by spatial memory deficits in the backcrossed 3xTg mouse model of AD. Prolonged exercise for 11 months did improve the long-term survival of newborn neurons generated during middle-age, whereas fluoxetine had no effect. We further review and discuss the relevant literature in this respect. PMID:23670818

  7. Evolution of the tetragonal to rhombohedral transition in (1 - x)(Bi1/2Na1/2)TiO3 - xBaTiO3 (x ⩽ 7%)

    NASA Astrophysics Data System (ADS)

    Yao, Yonggang; Sun, Zhimin; Ji, Yuanchao; Yang, Yaodong; Tan, Xiaoli; Ren, Xiaobing

    2013-06-01

    (1 - x)(Bi1/2Na1/2)TiO3 - xBaTiO3 has been the most studied Pb-free piezoelectric material in the last decade; however, puzzles still remain about its phase transitions, especially around the important morphotropic phase boundary (MPB). By introducing the strain glass transition concept from the ferroelastic field, it was found that the phase transition from tetragonal (T, P4bm) to rhombohedral (R, R3c) was affected by a strain glass transition at higher temperature for x ⩾ 4%. In these compositions, the T-R transition was delayed or even totally suppressed and displayed huge thermal hysteresis upon cooling and heating. Also, isothermal phase transitions were predicted and realized successfully in the crossover region, where the interaction between the T-R transition and the strain glass transition was strong. Our results revealed the strain glass nature in compositions around the MPB in this important material, and also provide new clues for understanding the transition complexity in other (Bi1/2Na1/2)TiO3-based Pb-free piezoelectric materials.

  8. Superparamagnetic versus blocked states in aggregates of Fe3-xO4 nanoparticles studied by MFM

    NASA Astrophysics Data System (ADS)

    Moya, Carlos; Iglesias-Freire, Óscar; Batlle, Xavier; Labarta, Amilcar; Asenjo, Agustina

    2015-10-01

    Magnetic domain configurations in two samples containing small aggregates of Fe3-xO4 nanoparticles of about 11 and 49 nm in size, respectively, were characterized by magnetic force microscopy (MFM). Two distinct magnetic behaviors were observed depending on the particle size. The aggregates constituted of nanoparticles of about 11 nm in size showed a uniform dark contrast on MFM images, reflecting the predominant superparamagnetic character of these particles and arising from the coherent rotation of the spins within the aggregate as the latter align along the tip stray-field. By applying a variable in-plane field, it is possible to induce magnetic polarization yielding an increasing dark/bright contrast as the strength of the applied field overcomes the stray-field of the tip, although this polarization completely disappears as the remanent state is recovered when the magnetic field is switched off. On the contrary, for aggregates of NPs of about 49 nm in size, dark/bright contrast associated with the existence of magnetic domains and magnetic polarization prevails in MFM images all along the magnetic cycle due to the blocking state of the magnetization of these larger particles, even in the absence of an applied field. All in all, we unambiguously demonstrate the capabilities of magnetic force microscopy to distinguish between blocked and superparamagnetic states in the aggregates of magnetic nanoparticles. Micromagnetic simulations strongly support the conclusions stated from the MFM experiments.Magnetic domain configurations in two samples containing small aggregates of Fe3-xO4 nanoparticles of about 11 and 49 nm in size, respectively, were characterized by magnetic force microscopy (MFM). Two distinct magnetic behaviors were observed depending on the particle size. The aggregates constituted of nanoparticles of about 11 nm in size showed a uniform dark contrast on MFM images, reflecting the predominant superparamagnetic character of these particles and arising

  9. Sensitivity of Mission Energy Consumption to Turboelectric Distributed Propulsion Design Assumptions on the N3-X Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Felder, James L.; Tong, Michael T.; Chu, Julio

    2012-01-01

    In a previous study by the authors it was shown that the N3-X, a 300 passenger hybrid wing body (HWB) aircraft with a turboelectric distributed propulsion (TeDP) system, was able to meet the NASA Subsonic Fixed Wing (SFW) project goal for N+3 generation aircraft of at least a 60% reduction in total energy consumption as compared to the best in class current generation aircraft. This previous study combined technology assumptions that represented the highest anticipated values that could be matured to technology readiness level (TRL) 4-6 by 2030. This paper presents the results of a sensitivity analysis of the total mission energy consumption to reductions in each key technology assumption. Of the parameters examined, the mission total energy consumption was most sensitive to changes to total pressure loss in the propulsor inlet. The baseline inlet internal pressure loss is assumed to be an optimistic 0.5%. An inlet pressure loss of 3% increases the total energy consumption 9%. However changes to reduce inlet pressure loss can result in additional distortion to the fan which can reduce fan efficiency or vice versa. It is very important that the inlet and fan be analyzed and optimized as a single unit. The turboshaft hot section is assumed to be made of ceramic matrix composite (CMC) with a 3000 F maximum material temperature. Reducing the maximum material temperature to 2700 F increases the mission energy consumption by only 1.5%. Thus achieving a 3000 F temperature in CMCs is important but not central to achieving the energy consumption objective of the N3-X/TeDP. A key parameter in the efficiency of superconducting motors and generators is the size of the superconducting filaments in the stator. The size of the superconducting filaments in the baseline model is assumed to be 10 microns. A 40 micron filament, which represents current technology, results in a 200% increase in AC losses in the motor and generator stators. This analysis shows that for a system with 40

  10. Vertical grid of retrieved atmospheric profiles

    NASA Astrophysics Data System (ADS)

    Ceccherini, Simone; Carli, Bruno; Raspollini, Piera

    2016-05-01

    The choice of the vertical grid of atmospheric profiles retrieved from remote sensing observations is discussed considering the two cases of profiles used to represent the results of individual measurements and of profiles used for subsequent data fusion applications. An ozone measurement of the MIPAS instrument is used to assess, for different vertical grids, the quality of the retrieved profiles in terms of profile values, retrieval errors, vertical resolutions and number of degrees of freedom. In the case of individual retrievals no evident advantage is obtained with the use of a grid finer than the one with a reduced number of grid points, which are optimized according to the information content of the observations. Nevertheless, this instrument dependent vertical grid, which seems to extract all the available information, provides very poor results when used for data fusion applications. A loss of about a quarter of the degrees of freedom is observed when the data fusion is made using the instrument dependent vertical grid relative to the data fusion made using a vertical grid optimized for the data fusion product. This result is explained by the analysis of the eigenvalues of the Fisher information matrix and leads to the conclusion that different vertical grids must be adopted when data fusion is the expected application.

  11. Methods of testing parameterizations: Vertical ocean mixing

    NASA Technical Reports Server (NTRS)

    Tziperman, Eli

    1992-01-01

    The ocean's velocity field is characterized by an exceptional variety of scales. While the small-scale oceanic turbulence responsible for the vertical mixing in the ocean is of scales a few centimeters and smaller, the oceanic general circulation is characterized by horizontal scales of thousands of kilometers. In oceanic general circulation models that are typically run today, the vertical structure of the ocean is represented by a few tens of discrete grid points. Such models cannot explicitly model the small-scale mixing processes, and must, therefore, find ways to parameterize them in terms of the larger-scale fields. Finding a parameterization that is both reliable and plausible to use in ocean models is not a simple task. Vertical mixing in the ocean is the combined result of many complex processes, and, in fact, mixing is one of the less known and less understood aspects of the oceanic circulation. In present models of the oceanic circulation, the many complex processes responsible for vertical mixing are often parameterized in an oversimplified manner. Yet, finding an adequate parameterization of vertical ocean mixing is crucial to the successful application of ocean models to climate studies. The results of general circulation models for quantities that are of particular interest to climate studies, such as the meridional heat flux carried by the ocean, are quite sensitive to the strength of the vertical mixing. We try to examine the difficulties in choosing an appropriate vertical mixing parameterization, and the methods that are available for validating different parameterizations by comparing model results to oceanographic data. First, some of the physical processes responsible for vertically mixing the ocean are briefly mentioned, and some possible approaches to the parameterization of these processes in oceanographic general circulation models are described in the following section. We then discuss the role of the vertical mixing in the physics of the

  12. The Genetics Panel of the NAS BEAR I Committee (1956): epistolary evidence suggests self-interest may have prompted an exaggeration of radiation risks that led to the adoption of the LNT cancer risk assessment model.

    PubMed

    Calabrese, Edward J

    2014-09-01

    This paper extends a series of historical papers which demonstrated that the linear-no-threshold (LNT) model for cancer risk assessment was founded on ideological-based scientific deceptions by key radiation genetics leaders. Based on an assessment of recently uncovered personal correspondence, it is shown that some members of the United States (US) National Academy of Sciences (NAS) Biological Effects of Atomic Radiation I (BEAR I) Genetics Panel were motivated by self-interest to exaggerate risks to promote their science and personal/professional agenda. Such activities have profound implications for public policy and may have had a significant impact on the adoption of the LNT model for cancer risk assessment. PMID:24993953

  13. Composite resonator vertical cavity laser diode

    SciTech Connect

    Choquette, K.D.; Hou, H.Q.; Chow, W.W.; Geib, K.M.; Hammons, B.E.

    1998-05-01

    The use of two coupled laser cavities has been employed in edge emitting semiconductor lasers for mode suppression and frequency stabilization. The incorporation of coupled resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the interaction between the cavities. Composite resonators can be utilized to control spectral and temporal properties within the laser; previous studies of coupled cavity vertical cavity lasers have employed photopumped structures. The authors report the first composite resonator vertical cavity laser diode consisting of two optical cavities and three monolithic distributed Bragg reflectors. Cavity coupling effects and two techniques for external modulation of the laser are described.

  14. Vertical transmission of Salmonella paratyphi A.

    PubMed

    Raveendran, R; Wattal, C; Sharma, A; Kler, N; Garg, P; Gujral, K; Khera, N

    2007-08-01

    Neonatal enteric fever is a rare but life-threatening illness. Patients may present with varying severity, Salmonella enterica serotype Typhi causing more severe illness than Salmonella enterica serotype Paratyphi A. Salmonella enterica serotype Paratyphi A is considered to cause milder infection with fewer complications. We report a rare case of vertical transmission of Salmonella enterica serotype Paratyphi A with severe complications and high mortality. Even though there are case reports of vertical transmission of Salmonella enterica serotype Typhi, to our knowledge, this is the first case report of vertical transmission of Salmonella enterica serotype ParatyphiA. The role of blood culture in accurate diagnosis and treatment is also discussed. PMID:17785907

  15. Tobacco smoking and vertical periodontal bone loss.

    PubMed

    Baljoon, Mostafa

    2005-01-01

    Cigarette smoking is associated with increased prevalence and severity of destructive periodontal disease in terms of periodontal pocketing, periodontal bone loss, and tooth loss. The smoking destructive effect on periodontal bone may be of even "horizontal" and vertical "angular" pattern. The vertical bone loss or the "vertical defect" is a sign of progressive periodontal breakdown that involves the periodontal bone. Water pipe smoking has a sharp rise by the popularity in the recent years by men and women in Middle East countries. The general objective of this thesis was to investigate the relationship between tobacco smoking and vertical periodontal bone loss cross-sectionally and longitudinally. This thesis is based on two study populations, Swedish musicians and a Saudi Arabian population. All participants had a full set of intra-oral radiographs including 16 periapical and 4 bitewing projections that were assessed with regard to presence or absence of vertical defects. In Study I, the number of defects per person increased with age. Vertical defects were more common in the posterior as compared to the anterior region of the dentition and the distribution of defects within the maxilla as well as the mandible typically revealed a right-left hand side symmetry. Cigarette smoking was significantly associated with the prevalence and severity of vertical bone defects (Studies II and III). The relative risk associated with cigarette smoking was 2 to 3-fold increased. The impact of water pipe smoking was of the same magnitude as that of cigarette smoking and the relative risk associated with water pipe smoking was 6-fold increased compared to non-smoking. In addition, the risk of vertical defects increased with increased exposure in cigarette smokers as well as water pipe smokers (Study III). In Study IV, the proportion of vertical defects increased over a 10-year period and the increase over time was significantly associated with smoking. Moreover, the 10-year

  16. Displaced vertices in extended supersymmetric models

    NASA Astrophysics Data System (ADS)

    Hesselbach, S.; Franke, F.; Fraas, H.

    2000-10-01

    In extended supersymmetric models with additional singlet Higgs fields displaced vertices could be observed if the decay width of the next-to-lightest supersymmetric particle becomes very small due to a singlino dominated LSP. We study the supersymmetric parameter space where displaced vertices of the second lightest neutralino exist in the NMSSM and an E6 inspired model. For a mass difference between LSP and NLSP of more than 10 GeV the singlet vacuum expectation value has to be at least of the order of /100 TeV in order to obtain a lightest neutralino with a singlino component large enough for displaced vertices.

  17. Surface tension profiles in vertical soap films

    NASA Astrophysics Data System (ADS)

    Adami, N.; Caps, H.

    2015-01-01

    Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed by introducing deformable elastic objets in the films. The shape adopted by those objects once set in the film is related to the surface tension value at a given vertical position by numerically solving the adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position is predicted by simple modeling that takes into account the mechanical equilibrium of the films coupled to previous thickness measurements.

  18. Unconventional vertical word-order impairs reading.

    PubMed

    Bonfiglioli, Claudia

    2011-01-01

    Western written languages unfold across both the horizontal (from left to right) and the vertical (from top to bottom) dimensions. Culturally determined horizontal reading/writing habits are so pervasive that their influence can be found not only in visual scanning but also in performance across different domains and tasks. However, little is known on the effects of vertical word order. In the present study, a lexical decision task is used to show that reading performance is less efficient when verbal material is vertically arranged following a bottom-to-top order. PMID:21692428

  19. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer’s disease (3xTgAD) mice

    PubMed Central

    Knight, Elysse M.; Brown, Timothy M.; Gümüsgöz, Sarah; Smith, Jennifer C. M.; Waters, Elizabeth J.; Allan, Stuart M.; Lawrence, Catherine B.

    2013-01-01

    SUMMARY Alzheimer’s disease (AD) is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD) and non-transgenic (Non-Tg) control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4–10 months), 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ) plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD. PMID:22864021

  20. Therapeutic targeting of oxidative stress with coenzyme Q10 counteracts exaggerated diabetic cardiomyopathy in a mouse model of diabetes with diminished PI3K(p110α) signaling.

    PubMed

    De Blasio, Miles J; Huynh, Karina; Qin, Chengxue; Rosli, Sarah; Kiriazis, Helen; Ayer, Anita; Cemerlang, Nelly; Stocker, Roland; Du, Xiao-Jun; McMullen, Julie R; Ritchie, Rebecca H

    2015-10-01

    Diabetes-induced cardiac complications include left ventricular (LV) dysfunction and heart failure. We previously demonstrated that LV phosphoinositide 3-kinase p110α (PI3K) protects the heart against diabetic cardiomyopathy, associated with reduced NADPH oxidase expression and activity. Conversely, in dominant negative PI3K(p110α) transgenic mice (dnPI3K), reduced cardiac PI3K signaling exaggerated diabetes-induced cardiomyopathy, associated with upregulated NADPH oxidase. The goal was to examine whether chronic supplementation with the antioxidant coenzyme Q(10) (CoQ(10)) could attenuate LV superoxide and diabetic cardiomyopathy in a setting of impaired PI3K signaling. Diabetes was induced in 6-week-old nontransgenic and dnPI3K male mice via streptozotocin. After 4 weeks of diabetes, CoQ(10) supplementation commenced (10 mg/kg ip, 3 times/week, 8 weeks). At study end (12 weeks of diabetes), markers of LV function, cardiomyocyte hypertrophy, collagen deposition, NADPH oxidase, oxidative stress (3-nitrotyrosine), and concentrations of CoQ(9) and CoQ(10) were determined. LV NADPH oxidase (Nox2 gene expression and activity, and lucigenin-enhanced chemiluminescence), as well as oxidative stress, were increased by diabetes, exaggerated in diabetic dnPI3K mice, and attenuated by CoQ(10). Diabetes-induced LV diastolic dysfunction (prolonged deceleration time, elevated end-diastolic pressure, impaired E/A ratio), cardiomyocyte hypertrophy and fibrosis, expression of atrial natriuretic peptide, connective tissue growth factor, and β-myosin heavy chain were all attenuated by CoQ(10). Chronic CoQ(10) supplementation attenuates aspects of diabetic cardiomyopathy, even in a setting of reduced cardiac PI3K protective signaling. Given that CoQ(10) supplementation has been suggested to have positive outcomes in heart failure patients, chronic CoQ(10) supplementation may be an attractive adjunct therapy for diabetic heart failure. PMID:25937176

  1. Reference and working memory deficits in the 3xTg-AD mouse between 2 and 15-months of age: a cross-sectional study.

    PubMed

    Stevens, Leanne M; Brown, Richard E

    2015-02-01

    Impairments in working memory (WM) can predict the shift from mild cognitive impairment (MCI) to Alzheimer's disease (AD) and the rate at which AD progresses with age. The 3xTg-AD mouse model develops both Aβ plaques and neurofibrillary tangles, the neuro-pathological hallmarks of AD, by 6 months of age, but no research has investigated the age-related changes in WM in these mice. Using a cross-sectional design, we tested male and female 3xTg-AD and wildtype control (B6129SF2/J) mice between 2 and 15 months of age for reference and working memory errors in the 8-arm radial maze. The 3xTg-AD mice had deficits in both working and reference memory across the ages tested, rather than showing the predicted age-related memory deficits. Male 3xTg-AD mice showed more working and reference memory errors than females, but there were no sex differences in wildtype control mice. These results indicate that the 3xTg-AD mouse replicates the impairments in WM found in patients with AD. However, these mice show memory deficits as early as two months of age, suggesting that the genes underlying reference and working memory in these mice cause deficits from an early age. The finding that males were affected more than females suggests that more attention should be paid to sex differences in transgenic AD mice. PMID:25446812

  2. Vertical Motions of Oceanic Volcanoes

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    lasting a few hundred thousand years as the island migrates over a broad flexural arch related to isostatic compensation of a nearby active volcano. The arch is located about 190±30 km away from the center of volcanic activity and is also related to the rejuvenated volcanic stage on the islands. Reefs on Oahu that are uplifted several tens of m above sea level are the primary evidence for uplift as the islands over-ride the flexural arch. At the other end of the movement spectrum, both in terms of magnitude and length of response, are the rapid uplift and subsidence that occurs as magma is accumulated within or erupted from active submarine volcanoes. These changes are measured in days to years and are of cm to m variation; they are measured using leveling surveys, tiltmeters, EDM and GPS above sea level and pressure gauges and tiltmeters below sea level. Other acoustic techniques to measure such vertical movement are under development. Elsewhere, evidence for subsidence of volcanoes is also widespread, ranging from shallow water carbonates on drowned Cretaceous guyots, to mapped shoreline features, to the presence of subaerially-erupted (degassed) lavas on now submerged volcanoes. Evidence for uplift is more limited, but includes makatea islands with uplifted coral reefs surrounding low volcanic islands. These are formed due to flexural uplift associated with isostatic loading of nearby islands or seamounts. In sum, oceanic volcanoes display a long history of subsidence, rapid at first and then slow, sometimes punctuated by brief periods of uplift due to lithospheric loading by subsequently formed nearby volcanoes.

  3. Structure and magnetic properties of flux grown single crystals of Co3-xFexSn2S2 shandites

    NASA Astrophysics Data System (ADS)

    Kassem, Mohamed A.; Tabata, Yoshikazu; Waki, Takeshi; Nakamura, Hiroyuki

    2016-01-01

    We report a successful single crystal growth of the shandite-type half-metallic ferromagnet Co3Sn2S2, and its Fe-substituted compounds, Co3-xFexSn2S2, by employing the flux method. Although Fe3Sn2S2 is unstable phase, we found that using the self Sn flux enables us to obtain single phase crystals up to x=0.53. The chemical composition of the grown plate-shaped single crystals was examined using wavelength-dispersive X-ray spectroscopy. The shandite structure with R 3 ̅m symmetry was confirmed by powder X-ray diffraction and the crystal structure parameters were refined using the Rietveld method. Magnetization measurements show suppression of the ferromagnetic order upon Fe-substitution, as well as in other substituted systems such as In- and Ni-substituted Co3Sn2S2. The almost identical magnetic phase diagrams of the Fe- and In-substituted compounds indicate that the electron number is dominantly significant to the magnetism in the Co-based shandite.

  4. Synthesis of nanoparticles of Co xFe (3-x)O 4 by combustion reaction method

    NASA Astrophysics Data System (ADS)

    Franco, Adolfo; Celma de Oliveira Lima, Emília; Novak, Miguel A.; Wells, Paulo R.

    2007-01-01

    Nanocrystalline magnetic particles of Co xFe (3-x)O 4, with x ranging from 0.79 to 1.15, has been synthesised by combustion reaction method using iron nitrate Fe(NO 3) 3.9H 2O, cobalt nitrate Co(NO 3) 2·6H 2O, and urea CO(NH 2) 2 as fuel without template and subsequent heat treatment. The process is quite simple and inexpensive since it does not involve intermediate decomposition and/or calcining steps. The maximum reaction temperature ranged from 850 to 1010 °C and combustion lasted less then 30 s for all systems. X-ray diffraction patterns of all systems showed broad peaks consistent with cubic inverse spinel structure of CoFe 2O 4. The absence of extra reflections in the diffraction patterns of as-prepared materials ensures phase purity. The average crystallite sizes determined from the prominent (3 1 1) peak of the diffraction using Scherre's equation and TEM micrographs consisted of ca. 27 nm in spherical morphology. FTIR spectra of the as-prepared material showed traces of organic and metallic salts byproducts. However, when the same material was washed with deionised water the byproducts were rinsed off, resulting in pure materials. Magnetic properties such as saturation magnetisation, remanence magnetisation and coercivity field measured at room temperature were 48 emu/g, 15 emu/g and 900 Oe, respectively.

  5. Evaluation the nonlinear response function of a 3 x 3 in NaI scintillation detector for PGNAA applications.

    PubMed

    Miri Hakimabad, Hashem; Panjeh, Hamed; Vejdani-Noghreiyan, Alireza

    2007-08-01

    Response functions of the 3 x 3 in NaI detector, which is mainly used in PGNAA applications, have been calculated by using MCNP-4C code. Calculated results are compared with measured data by using standard gamma-ray sources and prompt gamma-rays from pure element samples to check their accuracy. Prompt gamma-rays from pure element samples were used for this determination in the range from 1.942 to 10.829 MeV by use of (241)Am-Be neutron source and gamma-rays from radioisotope sources were used in the range from 0.081 to 4.438 MeV. Through the precise modeling of the detector structure, the agreement between both results has been improved. A surprising result is that in the PGNAA method the agreement between the MCNP simulation and experiment will be better by using a suitable neutron shield for NaI detector in order to prevent the activation of NaI (Tl) and a proper gamma-shield to attenuate the high-rate 4.438 MeV gamma-ray, (241)Am-Be gamma-ray component. PMID:17485218

  6. Kinetic limitation of chemical ordering in Bi2Te3-x Se x layers grown by molecular beam epitaxy.

    PubMed

    Schreyeck, S; Brunner, K; Kirchner, A; Bass, U; Grauer, S; Schumacher, C; Gould, C; Karczewski, G; Geurts, J; Molenkamp, L W

    2016-04-13

    We study the chemical ordering in Bi2Te3-x Se x grown by molecular beam epitaxy on Si substrates. We produce films in the full composition range from x  =  0 to 3, and determine their material properties using energy dispersive x-ray spectroscopy, x-ray diffraction and Raman spectroscopy. By fitting the parameters of a kinetic growth model to these results, we obtain a consistent description of growth at a microscopic level. Our main finding is that despite the incorporation of Se in the central layer being much more probable than that of Te, the formation of a fully ordered Te-Bi-Se-Bi-Te layer is prevented by kinetic of the growth process. Indeed, the Se concentration in the central layer of Bi2Te2Se1 reaches a maximum of only  ≈75% even under ideal growth conditions. A second finding of our work is that the intensity ratio of the 0 0 12 and 0 0 6 x-ray reflections serves as an experimentally accessible quantitative measure of the degree of ordering in these films. PMID:26962934

  7. Isotope effects of ground and lowest lying vibrational states of H3-xDxO2 (-) complexes.

    PubMed

    Ansari, Narjes; Meyer, Hans-Dieter

    2016-02-01

    Isotope effects of the H3O2 (-) anion are investigated. For this, the 24 lowest excited vibrational states of the H3-xDxO2 (-) complexes, with x = 0-3, are computed using two different Hamiltonians, namely, a 7D reduced-dimensionality one with a numerical representation of the kinetic energy operator (KEO) and a 9D full-dimensionality Hamiltonian with an exact analytic KEO. The computations are carried out with the multiconfiguration time-dependent Hartree method. The obtained results show that bridge and terminal H-D exchange cause a variation in energy with or without a rearrangement of states. A clear rearrangement of fundamental modes is observed in bridge H-D exchange of the H3O2 (-) complex, where the frequency of bridge hydrogen stretching (z) is strongly lowered by substitution. The isotope effects show that rotation (ϕ), rocking (u1 + u2), wagging (u1 - u2), and O-O stretch (R) modes are sensitive to terminal H-D exchange, while the bridge-atom bending (x,y) and stretch (z) modes are sensitive to bridge H-D exchange. An influence coefficient, which measures the influence of an excitation of one mode on the various 1D reduced densities, is defined and analyzed in detail. It is shown that the D3O2 (-) complex is more strongly correlated or coupled than the other isotopologues. PMID:26851922

  8. Growth of large CH3NH3PbX3 (X=I, Br) single crystals in solution

    NASA Astrophysics Data System (ADS)

    Su, J.; Chen, D. P.; Lin, C. T.

    2015-07-01

    We present the results on the successful growth of CH3NH3PbX3 (X=I, Br) single crystals sized up to centimeters using hydrohalic acid solution method. Large crystals with perfect morphology were obtained by a very slow cooling rate of 0.1-0.2 °C/h. The lattice parameters of tetragonal CH3NH3PbI3 and cubic CH3NH3PbBr3 were estimated using the Rietveld refinement method. Study of crystal nucleus, habits and dimensions indicates that these are strongly dependent on the supercooling of solution during crystal growth, in which the (0 0 1)/(0 1 0) for CH3NH3PbI3 and {1 0 0} for CH3NH3PbBr3 always exhibit the largest faces on the as-grown crystals. A structural phase transition of tetragonal/cubic and cubic/tetragonal for the CH3NH3PbI3 single crystals was observed to occur at 62 and 60 °C during the heating and cooling process, respectively. The nonlinear relationship of temperature-dependent solubility for CH3NH3PbI3 in hydrohalic acid was also determined.

  9. Multifunctional Effect of Human Serum Albumin Reduces Alzheimer's Disease Related Pathologies in the 3xTg Mouse Model.

    PubMed

    Ezra, Assaf; Rabinovich-Nikitin, Inna; Rabinovich-Toidman, Polina; Solomon, Beka

    2015-01-01

    Alzheimer's disease (AD), the prevalent dementia in the elderly, involves many related and interdependent pathologies that manifests simultaneously, eventually leading to cognitive impairment and death. No treatment is currently available; however, an agent addressing several key pathologies simultaneously has a better therapeutic potential. Human serum albumin (HSA) is a highly versatile protein, harboring multifunctional properties that are relevant to key pathologies underlying AD. This study provides insight into the mechanism for HSA's therapeutic effect. In vivo, a myriad of beneficial effects were observed by pumps infusing HSA intracerebroventricularly, for the first time in an AD 3xTg mice model. A significant effect on amyloid-β (Aβ) pathology was observed. Aβ1-42, soluble oligomers, and total plaque area were reduced. Neuroblastoma SHSY5Y cell line confirmed that the reduction in Aβ1-42 toxicity was due to direct binding rather than other properties of HSA. Total and hyperphosphorylated tau were reduced along with an increase in tubulin, suggesting increased microtubule stability. HSA treatment also reduced brain inflammation, affecting both astrocytes and microglia markers. Finally, evidence for blood-brain barrier and myelin integrity repair was observed. These multidimensional beneficial effects of intracranial administrated HSA, together or individually, contributed to an improvement in cognitive tests, suggesting a non-immune or Aβ efflux dependent means for treating AD. PMID:26682687

  10. Insulin sensitizers improve learning and attenuate tau hyperphosphorylation and neuroinflammation in 3xTg-AD mice.

    PubMed

    Yu, Yang; Li, Xiaojing; Blanchard, Julie; Li, Yi; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

    2015-04-01

    Sporadic Alzheimer's disease (AD) is a multifactorial metabolic brain disorder characterized by progressive neurodegeneration. Decreased brain energy and glucose metabolism occurs before the appearance of AD symptoms and worsens while the disease progresses. Deregulated brain insulin signaling has also been found in AD recently. To restore brain insulin sensitivity and glucose metabolism, pioglitazone and rosiglitazone, two insulin sensitizers commonly used for treating type 2 diabetes, have been studied and shown to have some beneficial effects in AD mouse models. However, the molecular mechanisms of the beneficial effects remain elusive. In the present study, we treated the 3xTg-AD mice, a widely used mouse model of AD, with pioglitazone and rosiglitazone for 4 months and studied the effects of the treatments on cognitive performance and AD-related brain alterations. We found that the chronic treatment improved spatial learning, enhanced AKT signaling, and attenuated tau hyperphosphorylation and neuroinflammation. These findings shed new light on the possible mechanisms by which these two insulin sensitizers might be useful for treating AD and support further clinical trials evaluating the efficacy of these drugs. PMID:25113171

  11. Statistical and quadrant-hole analysis of the turbulence characteristics in a 3 x 3 wind turbine array boundary layer

    NASA Astrophysics Data System (ADS)

    Gibson, Max; Kang, Hyung-Suk; Meneveau, Charles; Bayoan Cal, Raul

    2009-11-01

    Data from a wind-tunnel experiment on the flow within a 3 x 3 array of lightly loaded wind turbine models operating inside a turbulent boundary layer over a rough surface are analyzed. The data are acquired using X hot-wire anemometry and the focus of the analysis is on the possible differences of the flow structures above and below the canopy of wind turbines. Here this question is addressed using quadrant analysis. Conditional averages of turbulent dissipation (a 1-D surrogate) at various heights at 5 diameters downstream is performed for each of the 4 quadrants as well as different ``hole-sizes.'' The results imply significantly less inter-scale correlations in the low-shear region at the bottom of the wind turbine wake than at other wake locations. Inter-scale correlations above and below the wake are also significantly greater than at that low-shear region. Spectral analysis is performed to determine which scales are mostly responsible for the various levels of Reynolds stresses as functions of position in the wind turbine wake.

  12. An incommensurately modulated structure of η'-phase of Cu(3+x)Si determined by quantitative electron diffraction tomography.

    PubMed

    Palatinus, Lukáš; Klementová, Mariana; Dřínek, Vladislav; Jarošová, Markéta; Petříček, Václav

    2011-04-18

    The diffraction data of η'-Cu(3+x)(Si,Ge) were collected by 3D quantitative electron diffraction tomography on a submicrometer-sized sample, and the structure was solved by the charge-flipping algorithm in superspace. It is shown that the structure is trigonal, and it is incommensurately modulated with two modulation vectors q(1) = (α, α, 1/3) and q(2) = (-2α, α, 1/3), superspace group P31m(α, α, 1/3)000(-2α, α, 1/3)000. The modulation functions of some atoms are very complicated and reach amplitudes comparable with the unit cell dimensions. The modulated structure can be described as sheets of Cu clusters separated by honeycomb layers of mixed Si/Ge positions. The shape of the Cu clusters in the sheets strongly varies with the modulation phase, and the predominant form is an icosahedron. The striving of the Cu layers to form icosahedral clusters is deemed to be the main driving force of the modulation. The combination of methods used in this work can be applied to other structures that are difficult to crystallize in large crystals and opens new perspectives, especially for investigations of aperiodic or otherwise complex metallic alloys. PMID:21438499

  13. Magnetic properties of Zn /SUB 3x/ Cd/sub 3/(1-x)P/sub 2/ alloys

    SciTech Connect

    Vitikina, T.Z.; Smolyarenko, E.M.; Trukhan, V.M.

    1985-03-01

    The authors present results of magnetic susceptibility measurements made by the Guy method in solid solutions based on the compounds Zn/sub 3/P/sub 2/ and Cd/sub 3/P/sub 2/. Before measurement, samples were etched in an etchant especially selected for each composition and prepared from hydrochloric and nitric acids, washed in tripledistilled water, and dried. A series of investigations was conducted for revealing the effect of pulverizing on the magnitude of magnetic susceptibility. All investigated alloys were diamagnetic. The magnetic susceptibility of the samples of Zn /SUB 3x/ Cd/sub 3/(1-x)P/sub 2/ solid solutions varied weakly (under 10%) with increasing temperature in the investigated temperature range (170 - 570/sup 0/K), suggesting that the basic contribution to the measured magnetic susceptibility is the susceptibility of the lattice. From the experimentation it is concluded that the dependence x /SUB mol/ = f(x) has a discontinuity at x approx. = 0.16, which apparently is related to the transition from structures with indirect optical transitions to those with direct optical transitions in the cited systems.

  14. Magnetic spectra and Richter aftereffect relaxation in CexY3-xFe5O12 ferrites

    NASA Astrophysics Data System (ADS)

    Chen, Fu; Wang, Xian; Feng, Zekun; Chen, Yajie; Harris, Vincent G.

    2016-05-01

    The static and dynamic magnetic properties of cerium (Ce) doped yttrium iron garnet CexY3-xFe5O12 (x=0, 0.05, 0.1, 0.15, 0.2) ferrites (YIG) have been reported in this work. The ferrites were fabricated by the traditional solid-state reaction method. All ferrite samples reveal pure garnet structure identified by x-ray diffraction (XRD). The substitution of cerium not only enhances the saturation magnetization of the samples, but also regulates the magnetocrystalline anisotropy constant K1. Obvious differences in permeability spectra over a frequency of 1 MHz - 1 GHz can be observed. It is verified that the permeability dispersion and magnetic losses of Ce-doped YIG ferrite contain the contribution of Richter aftereffect relaxation due to the existence of Fe2+ ions. The fitting results of the permeability spectra applied three-mechanism model is in good agreement with experimental data, which successfully explains the mechanisms of magnetic losses observed at 1 MHz to 1 GHz for Ce-doped YIG ferrite. In addition, the frequency shift of Richter aftereffect has also been discussed.

  15. Isotope effects of ground and lowest lying vibrational states of H 3 - x D x O2 - complexes

    NASA Astrophysics Data System (ADS)

    Ansari, Narjes; Meyer, Hans-Dieter

    2016-02-01

    Isotope effects of the H 3 O2 - anion are investigated. For this, the 24 lowest excited vibrational states of the H 3 - x D x O2 - complexes, with x = 0-3, are computed using two different Hamiltonians, namely, a 7D reduced-dimensionality one with a numerical representation of the kinetic energy operator (KEO) and a 9D full-dimensionality Hamiltonian with an exact analytic KEO. The computations are carried out with the multiconfiguration time-dependent Hartree method. The obtained results show that bridge and terminal H-D exchange cause a variation in energy with or without a rearrangement of states. A clear rearrangement of fundamental modes is observed in bridge H-D exchange of the H 3 O2 - complex, where the frequency of bridge hydrogen stretching (z) is strongly lowered by substitution. The isotope effects show that rotation (ϕ), rocking (u1 + u2), wagging (u1 - u2), and O-O stretch (R) modes are sensitive to terminal H-D exchange, while the bridge-atom bending (x,y) and stretch (z) modes are sensitive to bridge H-D exchange. An influence coefficient, which measures the influence of an excitation of one mode on the various 1D reduced densities, is defined and analyzed in detail. It is shown that the D 3 O2 - complex is more strongly correlated or coupled than the other isotopologues.

  16. Theoretical study of the structural, elastic, electronic and optical properties of XCaF3 (X = K and Rb)

    NASA Astrophysics Data System (ADS)

    Ghebouli, B.; Fatmi, M.; Ghebouli, M. A.; Choutri, H.; Louail, L.; Chihi, T.; Bouhemadou, A.; Bin-Omran, S.

    2015-05-01

    The PLANE WAVE pseudo-potential method within density functional theory (DFT) has been used to investigate the structural, elastic, electronic and optical properties of XCaF3 (X = K and Rb) insulating. The studied compounds show a weak resistance to shear deformation compared to the resistance to the unidirectional compression. KCaF3 and RbCaF3 are considered ductile. The elastic constants and related parameters were predicted. The stiffness is more important in KCaF3, whereas, the lateral expansion is more important in RbCaF3. KCaF3 and RbCaF3 have R- Г indirect band gap. The main peaks in the imaginary part of the dielectric function correspond to the transition from the occupied state F-p to the unoccupied states Ca: s or K, Rb: p. At lower energies, KCaF3 and RbCaF3 show the same optical properties. Under pressure effect, the peaks of imaginary part of dielectric function were shifted toward high energy.

  17. Solvothermal synthesis of wire-like SnxSb2Te3+x with an enhanced thermoelectric performance.

    PubMed

    Yang, Heng Quan; Miao, Lei; Liu, Cheng Yan; Wang, Xiao Yang; Peng, Ying; Zhang, Ai Juan; Zhou, Xiao Yuan; Wang, Guo Yu; Li, Chao; Huang, Rong

    2016-04-25

    Nanostructured tellurides have attracted increasing attention in thermoelectric applications for waste heat recovery and cooling devices. Here, we report on the synthesis of wire-like SnxSb2Te3+x (x = 0, 0.02 and 0.05) nanoparticles using elemental precursors in EG. The enhanced thermoelectric performance was achieved in alloyed samples due to the increase of carrier population in heavy valence band valleys by incorporating Sn(2+) at the Sb(3+) sublattice, enabling the simultaneous realization of low electrical resistivity along with a high Seebeck coefficient as well as the decline of thermal conductivity. Thus a boosted power factor and low thermal conductivity lead to the highest ZT value of 0.58 at 150 °C in the Sn0.02Sb2Te3.02 sample. Our research offers a general wet-chemical route for the preparation of one-dimensional nanomaterials and probably promotes the practical thermoelectric applications of Sb2Te3-based materials at low temperatures. PMID:27046535

  18. Kinetic limitation of chemical ordering in Bi2Te3-x Se x layers grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Schreyeck, S.; Brunner, K.; Kirchner, A.; Bass, U.; Grauer, S.; Schumacher, C.; Gould, C.; Karczewski, G.; Geurts, J.; Molenkamp, L. W.

    2016-04-01

    We study the chemical ordering in Bi2Te3-x Se x grown by molecular beam epitaxy on Si substrates. We produce films in the full composition range from x  =  0 to 3, and determine their material properties using energy dispersive x-ray spectroscopy, x-ray diffraction and Raman spectroscopy. By fitting the parameters of a kinetic growth model to these results, we obtain a consistent description of growth at a microscopic level. Our main finding is that despite the incorporation of Se in the central layer being much more probable than that of Te, the formation of a fully ordered Te-Bi-Se-Bi-Te layer is prevented by kinetic of the growth process. Indeed, the Se concentration in the central layer of Bi2Te2Se1 reaches a maximum of only  ≈75% even under ideal growth conditions. A second finding of our work is that the intensity ratio of the 0 0 12 and 0 0 6 x-ray reflections serves as an experimentally accessible quantitative measure of the degree of ordering in these films.

  19. Disorder-Driven Spin-Orbital Liquid Behavior in the Ba3X Sb2O9 Materials

    NASA Astrophysics Data System (ADS)

    Smerald, Andrew; Mila, Frédéric

    2015-10-01

    Recent experiments on the Ba3X Sb2O9 family have revealed materials that potentially realize spin- and spin-orbital liquid physics. However, the lattice structure of these materials is complicated due to the presence of charged X2 +-Sb5 + dumbbells, with two possible orientations. To model the lattice structure, we consider a frustrated model of charged dumbbells on the triangular lattice, with long-range Coulomb interactions. We study this model using Monte Carlo simulation, and find a freezing temperature, Tfrz , at which the simulated structure factor matches well to low-temperature x-ray diffraction data for Ba3 CuSb2 O9 . At T =Tfrz we find a complicated "branching" structure of superexchange-linked X2 + clusters, which form a fractal pattern with fractal dimension df=1.90 . We show that this gives a natural explanation for the presence of orphan spins. Finally we provide a plausible mechanism by which such dumbbell disorder can promote a spin-orbital resonant state with delocalized orphan spins.

  20. Laboratory Detection of ClZnCH3 (X1A1): Further Evidence for Zinc Insertion

    NASA Astrophysics Data System (ADS)

    Bucchino, Matthew; Ziurys, Lucy

    2014-06-01

    The pure rotational spectrum of methylzinc chloride, ClZnCH3 (X1A1), has been recorded in the gas phase using direct absorption spectroscopic techniques. ClZnCH3 was synthesized by the reaction of zinc vapor, generated in a Broida-type oven, with chloromethane in the presence of a DC discharge. Rotational transitions of the main isotopologue, 35Cl64ZnCH3, were measured in the frequency range of 260{-297} GHz. The presence of clear K-ladder structure (K = 0{-6}) indicates that the species is a symmetric top with C3V symmetry. ClZnCH3 appears to be formed by the oxidative addition of atomic zinc to chloromethane. Searches for the 37Cl, 66Zn, 13C, and D substituted isotopologues are currently in progress. The geometries of ClZnCH3 and IZnCH3 will be compared with reactivity trends for halogen-substituted organometallic reagents.

  1. Structure, magnetic, and dielectric properties of (1-x)BiFeO3-xBaTiO3 ceramics

    NASA Astrophysics Data System (ADS)

    Wang, T.-H.; Ding, Y.; Tu, C.-S.; Yao, Y.-D.; Wu, K.-T.; Lin, T.-C.; Yu, H.-H.; Ku, C.-S.; Lee, H.-Y.

    2011-04-01

    Structure, magnetization, and dielectric permittivity of (1-x)BiFeO3-xBaTiO3 (BFO-BT) ceramics have been studied as a function of BT content (x = 0.0, 0.1, 0.2, and 0.3). In situ synchrotron x-ray diffraction result of BFO reveals a rhombohedral (R)-orthorhombic (O)-cubic (C) phase transition near 820 and 850 °C upon heating. BFO-10%BT and BFO-20%BT exhibit a R-C transition near 760 and 740 °C, respectively. A C(R)-C transition takes place near 680 °C in BFO-30%BT. C(R) represents that a minor R phase coexists in the C matrix. A local minimum of R distortion angle αR occurs upon heating and implies ionic displacements. This anomaly is likely resulted from the antiferromagnetic (AFM)-paramagnetic (PM) transition and is responsible for the broad frequency-dependent dielectric maximum. BFO and BFO-10-30%BT ceramics exhibit a similar AFM behavior with magnetic susceptibility of about 8.2 × 10-6 emu/g.Oe at room temperature. This work suggests that BTO-substitution can enhance dielectric response and reduce the dielectric loss.

  2. Magnetic properties of Co2-xTMxC and Co3-xTMxC nanoparticles

    NASA Astrophysics Data System (ADS)

    Qian, Meichun; Khanna, Shiv N.

    2013-12-01

    Using synthetic chemical approaches, it is now possible to synthesize transition metal carbides nanoparticles with morphology, where the transition metal layers are embedded with intervening layers of carbon atoms. A composite material consisting of Co2C and Co3C nanoparticles has been found to exhibit unusually large coercivity and energy product. Here, we demonstrate that the magnetic moments and the anisotropy can be further enhanced by using a combination of Co and other transition metals (TM). Our studies are based on mixed nanoparticles Co2-xTMxC and Co3-xTMxC, in which selected Co sites are replaced with 3d transition elements Cr, Mn, and Fe. The studies indicate that the replacement of Co by Fe results in an increase of both the magnetic moment and the magnetic anisotropy. In particular, CoFe2C is shown to have an average spin moment of 2.56 μB and a magnetic anisotropy of 0.353 meV/formula unit compared to 1.67 μB and 0.206 meV/formula unit for the Co3C. Detailed examination of the electronic structure shows that the limited hybridization of carbon p-states with transition metal d-states drives the larger anisotropy.

  3. Validity of the Néel-Arrhenius model for highly anisotropic CoxFe3-xO4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Torres, T. E.; Lima, E.; Mayoral, A.; Ibarra, A.; Marquina, C.; Ibarra, M. R.; Goya, G. F.

    2015-11-01

    We report a systematic study on the structural and magnetic properties of CoxFe3-xO4 magnetic nanoparticles with sizes between 5 and 25 nm, prepared by thermal decomposition of Fe(acac)3 and Co(acac)2. The large magneto-crystalline anisotropy of the synthesized particles resulted in high blocking temperatures (42 K < TB < 345 K for 5 < d < 13 nm) and large coercive fields (HC ≈ 1600 kA/m for T = 5 K). The smallest particles (⟨d⟩=5 nm) revealed the existence of a magnetically hard, spin-disordered surface. The thermal dependence of static and dynamic magnetic properties of the whole series of samples could be explained within the Neel-Arrhenius relaxation framework by including the thermal dependence of the magnetocrystalline anisotropy constant K1(T), without the need of ad-hoc corrections. This approach, using the empirical Brükhatov-Kirensky relation, provided K1(0) values very similar to the bulk material from either static or dynamic magnetic measurements, as well as realistic values for the response times (τ0 ≈ 10-10s). Deviations from the bulk anisotropy values found for the smallest particles could be qualitatively explained based on Zener's relation between K1(T) and M(T).

  4. 23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL BRACING DETAIL. VIEW TO SOUTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  5. 30. BEARING SHOE / VERTICAL / DIAGONAL / UPPER AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. BEARING SHOE / VERTICAL / DIAGONAL / UPPER AND LOWER CHORD DETAIL OF DECK TRUSS. VIEW TO NORTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  6. Vertical Axis Wind Turbine Foundation parameter study

    SciTech Connect

    Lodde, P.F.

    1980-07-01

    The dynamic failure criterion governing the dimensions of prototype Vertical Axis Wind Turbine Foundations is treated as a variable parameter. The resulting change in foundation dimensions and costs is examined.

  7. The solid angle through the vertical rectangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the vertical rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux (radiant flux or radiant power) is shown.

  8. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  9. Congenital Vertical Talus: Etiology and Management.

    PubMed

    Miller, Mark; Dobbs, Matthew B

    2015-10-01

    Congenital vertical talus is a rare foot deformity. If left untreated, it causes significant disability, including pain and functional limitations. Although the etiology of vertical talus is likely heterogeneous, recent evidence strongly supports a genetic cause linking it to genes expressed during early limb development. Traditional management for vertical talus involves extensive surgeries that are associated with significant short- and long-term complications. A minimally invasive approach that relies on serial manipulation and casting to achieve most of the correction has been shown to produce excellent short-term results with regard to clinical and radiographic correction in both isolated and nonisolated cases of vertical talus. Although long-term studies are needed, achieving correction without extensive surgery may lead to more flexible and functional feet, much as Ponseti method has done for clubfeet. PMID:26337950

  10. Vertical sounding balloons for long duration flights

    NASA Astrophysics Data System (ADS)

    Malaterre, P.

    1994-02-01

    Vertical soundings in the lower stratosphere are possible on command with an Infrared Montgolfiere, between 16 km and 28 km. Results of simulations are presented. The first test flight of a 7800 m3 Montgolfiere with a relief valve, has been conducted in Arctic area (Spitzbergen, July 1992). The flight of an Infrared Montgolfiere, with full vertical sounding capabilities, is planned for the end of 1993, from Ecuador (South AMERICA).

  11. Vertical sounding balloons for long duration flights

    NASA Astrophysics Data System (ADS)

    Malaterre, P.

    1994-02-01

    Vertical soundings in the lower stratosphere are possible on command with an Infrared Montgolfiere, between 16 km and 28 km. Results of simulations are presented. The first test flight of a 7800 cu m Montgolfiere with a relief valve, has been conducted in Arctic area (Spitzbergen, July 1992). The flight of an Infrared Montgolfiere, with full vertical sounding capabilities, is planned for the end of 1993, from Ecuador (South AMERICA).

  12. Nanoclusters of MoO3-x embedded in an Al2O3 matrix engineered for customizable mesoscale resistivity and high dielectric strength

    NASA Astrophysics Data System (ADS)

    Tong, William M.; Brodie, Alan D.; Mane, Anil U.; Sun, Fuge; Kidwingira, Françoise; McCord, Mark A.; Bevis, Christopher F.; Elam, Jeffrey W.

    2013-06-01

    We have synthesized a material consisting of conducting metal oxide (MoO3-x) nanoclusters embedded in a high-dielectric-strength insulator (Al2O3) matrix. The resistivity of this material can be customized by varying the concentration of the MoO3-x nanoclusters. The Al2O3 protects the MoO3-x from stoichiometry change, thus conserving the number of carriers and maintaining a high dielectric strength. This composite material is grown by atomic layer deposition, a thin film deposition technique suitable for coating 3D structures. We applied these atomic layer deposition composite films to our 3D electron-optical micro electrical mechanical systems devices and greatly improved their performance.

  13. One-step, solution-processed formamidinium lead trihalide (FAPbI(3-x)Cl(x)) for mesoscopic perovskite-polymer solar cells.

    PubMed

    Lv, Siliu; Pang, Shuping; Zhou, Yuanyuan; Padture, Nitin P; Hu, Hao; Wang, Li; Zhou, Xinhong; Zhu, Huimin; Zhang, Lixue; Huang, Changshui; Cui, Guanglei

    2014-09-28

    Formamidinium (FA) lead triiodide perovskite with chlorine addition (NH2CH=NH2PbI(3-x)Clx) is employed as a light harvester in mesoscopic solar cells for the first time. It is demonstrated that a phase-pure FAPbI(3-x)Clx perovskite layer can be synthesized using a one-step solution-process at 140 °C, and the resultant solar cells deliver a maximum power conversion efficiency of 7.51%, which is the most efficient formamidinium-lead-halide perovskite mesoscopic solar cell employing a polymer hole-transporting layer. The effects of the thermal annealing temperature on the quality/morphology of the perovskite layer and the solar cells performance are discussed. The advantages offered by the one-step solution-processing method and the reduced bandgap make FAPbI(3-x)Clx perovskites an attractive choice for future hybrid photovoltaics. PMID:25096582

  14. Synthesis and Thermoelectric Properties of low-x Bi{sub 2}Se{sub 3-x}S{sub 3} Series

    SciTech Connect

    Iona, Ch.; Kyratsi, Th.; Hatzikraniotis, E.; Paraskevopoulos, K. M.

    2010-01-21

    Bi{sub 2}Se{sub 3}-xS{sub x} solid solutions, with low x values, were synthesized from melt. The solid solutions were studied in terms of phase purity using powder X-ray diffraction (PXRD) in order to find the maximum x value for the preservation of the single Bi2Se3-type phase. The lattice parameters were estimated and showed the reduced unit cell with the S incorporation in the lattice. SEM images confirmed the plate-like morphology of the Bi{sub 2}Se{sub 3}-xS{sub x} single-phase members. The thermoelectric properties (Seebeck coefficient and electrical conductivity) as well as IR reflectivity were also studied on members with x<0.4 that were found to form single phase Bi{sub 2}Se{sub 3}-xS{sub x} solid solutions.

  15. Substrate patterning with NiOx nanoparticles and hot-wire chemical vapour deposition of WO3x and carbon nanostructures

    NASA Astrophysics Data System (ADS)

    Houweling, Z. S.

    2011-10-01

    The first part of the thesis treats the formation of nickel catalyst nanoparticles. First, a patterning technique using colloids is employed to create ordered distributions of monodisperse nanoparticles. Second, nickel films are thermally dewetted, which produces mobile species that self-arrange in non-ordered distributions of polydisperse particles. Third, the mobility of the nickel species is successfully reduced by the addition of air during the dewetting and the use of a special anchoring layer. Thus, non-ordered distributions of self-arranged monodisperse nickel oxide nanoparticles (82±10 nm x 16±2 nm) are made. Studies on nickel thickness, dewetting time and dewetting temperature are conducted. With these particle templates, graphitic carbon nanotubes are synthesised using catalytic hot-wire chemical vapour deposition (HWCVD), demonstrating the high-temperature processability of the nanoparticles. The second part of this thesis treats the non-catalytic HWCVD of tungsten oxides (WO3-x). Resistively heated tungsten filaments exposed to an air flow at subatmospheric pressures, produce tungsten oxide vapour species, which are collected on substrates and are subsequently characterised. First, a complete study on the process conditions is conducted, whereby the effects of filament radiation, filament temperature, process gas pressure and substrate temperature, are investigated. The thus controlled growth of nanogranular smooth amorphous and crystalline WO3-x thin films is presented for the first time. Partially crystalline smooth hydrous WO3-x thin films consisting of 20 nm grains can be deposited at very high rates. The synthesis of ultrafine powders with particle sizes of about 7 nm and very high specific surface areas of 121.7±0.4 m2·g-1 at ultrahigh deposition rates of 36 µm·min-1, is presented. Using substrate heating to 600°C or more, while using air pressures of 3·10-5 mbar to 0.1 mbar, leads to pronounced crystal structures, from nanowires, to

  16. Structure of the DBL3x domain of pregnancy-associated malaria protein VAR2CSA complexed with chondroitin sulfate A

    SciTech Connect

    Singh, K.; Gittis, A.G.; Nguyen, P.; Gowda, D.C.; Miller, L.H.; Garboczi, D.N.

    2008-09-19

    Plasmodium falciparum-infected erythrocytes bind to chondroitin sulfate A (CSA) in the placenta via the VAR2CSA protein, a member of the P. falciparum erythrocyte membrane protein-1 family, leading to life-threatening malaria in pregnant women with severe effects on their fetuses and newborns. Here we describe the structure of the CSA binding DBL3x domain, a Duffy binding-like (DBL) domain of VAR2CSA. By forming a complex of DBL3x with CSA oligosaccharides and determining its structure, we have identified the CSA binding site to be a cluster of conserved positively charged residues on subdomain 2 and subdomain 3. Mutation or chemical modification of lysine residues at the site markedly diminished CSA binding to DBL3x. The location of the CSA binding site is an important step forward in the molecular understanding of pregnancy-associated malaria and offers a new target for vaccine development.

  17. [Is the sense of verticality vestibular?].

    PubMed

    Barra, J; Pérennou, D

    2013-06-01

    The vestibular system constitutes an inertial sensor, which detects linear (otoliths) and angular (semicircular canals) accelerations of the head in the three dimensions. The otoliths are specialized in the detection of linear accelerations and can be used by the brain as a "plumb line" coding earth gravity acceleration (direction). This property of otolithic system suggested that the sense of verticality is supported by the vestibular system. The preeminence of vestibular involvement in the sense of verticality stated in the 1900s was progressively supplanted by the notion of internal models of verticality. The internal models of verticality involve rules and properties of integration of vestibular graviception, somaesthesic graviception, and vision. The construction of a mental representation of verticality was mainly modeled as a bottom-up organization integrating visual, somatosensory and vestibular information without any cognitive modulations. Recent studies reported that the construction of internal models of verticality is not an automatic multi-sensory integration process but corresponds to more complex mechanisms including top-down influences such as awareness of body orientation or spatial representations. PMID:23856176

  18. Effect of vertical motion on current meters

    USGS Publications Warehouse

    Kallio, Nicholas A.

    1966-01-01

    The effect of vertical motion on the performance of current meters at various stream velocities was evaluated to determine whether accurate discharge measurements can be made from a bobbing boat. Three types of current meters--Ott, Price, and vane types--were tested under conditions simulating a bobbing boat. A known frequency and amplitude of vertical motion were imparted to the current meter, and the related effect on the measured stream velocity was determined. One test of the Price meter was made under actual conditions, using a boat and standard measuring gear. The results of the test under actual conditions verified those obtained by simulating the vertical movements of a boat. The tests show that for stream velocities below 2.5 feet per second the accuracy of all three meters is significantly affected when the meters are subjected to certain conditions of vertical motion that can occur during actual field operations. Both the rate of vertical motion and the frequency of vertical oscillation affect the registration of the meter. The results of these tests, presented in the form of graphs and tables, can be used as a guide to determine whether wind and stream flow are within an acceptable range for a reliable discharge measurement from a boat.

  19. Horizontal wires replace the vertical files.

    PubMed

    Colburn, J L

    1997-01-01

    Traditionally, clippings of newspaper articles, pictures from magazines, pamphlets, charts, graphs, posters, proceedings, or copies thereof, and other miscellaneous information sources have been stored in vertical files in libraries. The practice of creating and maintaining vertical files is extremely time consuming. In a medical library, in particular, old information about diagnosis, treatment, and prognosis can quickly become incorrect, misleading, and possibly harmful. Adequately tending to the vertical files can require a librarian to create a balancing act between properly maintaining vertical files and meeting the needs of the users in other areas of the library. The maintenance of vertical files is, by nature, highly consumptive of paper and space consuming. A reasonable alternative to the traditional vertical files is the World-Wide Web. Search engines exist for locating specific information, and bookmarks and/or links which point users to particularly useful sites can be set in search software. Some methods for searching are discussed, and a variety of World-Wide Web information sources are offered. PMID:10173596

  20. DDX3X promotes the biogenesis of a subset of miRNAs and the potential roles they played in cancer development

    PubMed Central

    Zhao, Luqing; Mao, Yitao; Zhao, Yuelong; He, Yanong

    2016-01-01

    DDX3X, located on the X-chromosome, belongs to the DEAD-box RNA helicase family and acts as a key RNA-binding protein to exert its regulatory functions in various biological processes. In this paper, knock-down the expression of DDX3X can affect a subset of miRNA expression levels, especially for miR-1, miR-141, miR-145, miR-19b, miR-20a and miR-34a. Through adopting the immunoprecipitation (IP), RNA immunoprecipitation (RIP), dual luciferase reporter assays, we illustrate that DDX3X could interact with Drosha/DGCR8 complex, elevate the processing activity of Drosha/DGCR8 complex on pri-miRNAs, and increase mature miRNA expression levels. For the studies of potential roles and biological functions of DDX3X-dependent miRNAs and their downstream target genes in multiple cancers, we use the primary data from The Cancer Genome Atlas (TCGA), Ingenuity Pathway Analysis (IPA) and several miRNA target prediction databases, to systematically analyze the expression levels of DDX3X-dependent miRNAs in almost 14 kinds of cancers versus normal tissues, and the essential biological functions for their putative downstream target genes. All these findings will provide us novel insights and directions for thoroughly exploring the regulatory mechanisms of miRNA biogenesis, and shed light on effectively searching the clinical significances and biological roles of DDX3X-dependent miRNAs and their target genes in cancer development. PMID:27586307

  1. A reversible early oxidized redox state that precedes macromolecular ROS damage in aging nontransgenic and 3xTg-AD mouse neurons.

    PubMed

    Ghosh, Debolina; LeVault, Kelsey R; Barnett, Aaron J; Brewer, Gregory J

    2012-04-25

    The brain depends on redox electrons from nicotinamide adenine dinucleotide (reduced form; NADH) to produce ATP and oxyradicals (reactive oxygen species [ROS]). Because ROS damage and mitochondrial dysregulation are prominent in aging and Alzheimer's disease (AD) and their relationship to the redox state is unclear, we wanted to know whether an oxidative redox shift precedes these markers and leads to macromolecular damage in a mouse model of AD. We used the 3xTg-AD mouse model, which displays cognitive deficits beginning at 4 months. Hippocampal/cortical neurons were isolated across the age span and cultured in common nutrients to control for possible hormonal and vascular differences. We found an increase of NAD(P)H levels and redox state in nontransgenic (non-Tg) neurons until middle age, followed by a decline in old age. The 3xTg-AD neurons maintained much lower resting NAD(P)H and redox states after 4 months, but the NADH regenerating capacity continuously declined with age beginning at 2 months. These redox characteristics were partially reversible with nicotinamide, a biosynthetic precursor of NAD+. Nicotinamide also protected against glutamate excitotoxicity. Compared with non-Tg neurons, 3xTg-AD neurons had more mitochondria/neuron and lower glutathione (GSH) levels that preceded age-related increases in ROS levels. These GSH deficits were again reversible with nicotinamide in 3xTg-AD neurons. Surprisingly, low macromolecular ROS damage was only elevated after 4 months in the 3xTg-AD neurons if antioxidants were removed. The present data suggest that a more oxidized redox state and a lower antioxidant GSH defense can be dissociated from neuronal ROS damage, changes that precede the onset of cognitive deficits in the 3xTg-AD model. PMID:22539844

  2. DDX3X promotes the biogenesis of a subset of miRNAs and the potential roles they played in cancer development.

    PubMed

    Zhao, Luqing; Mao, Yitao; Zhao, Yuelong; He, Yanong

    2016-01-01

    DDX3X, located on the X-chromosome, belongs to the DEAD-box RNA helicase family and acts as a key RNA-binding protein to exert its regulatory functions in various biological processes. In this paper, knock-down the expression of DDX3X can affect a subset of miRNA expression levels, especially for miR-1, miR-141, miR-145, miR-19b, miR-20a and miR-34a. Through adopting the immunoprecipitation (IP), RNA immunoprecipitation (RIP), dual luciferase reporter assays, we illustrate that DDX3X could interact with Drosha/DGCR8 complex, elevate the processing activity of Drosha/DGCR8 complex on pri-miRNAs, and increase mature miRNA expression levels. For the studies of potential roles and biological functions of DDX3X-dependent miRNAs and their downstream target genes in multiple cancers, we use the primary data from The Cancer Genome Atlas (TCGA), Ingenuity Pathway Analysis (IPA) and several miRNA target prediction databases, to systematically analyze the expression levels of DDX3X-dependent miRNAs in almost 14 kinds of cancers versus normal tissues, and the essential biological functions for their putative downstream target genes. All these findings will provide us novel insights and directions for thoroughly exploring the regulatory mechanisms of miRNA biogenesis, and shed light on effectively searching the clinical significances and biological roles of DDX3X-dependent miRNAs and their target genes in cancer development. PMID:27586307

  3. Communication: Probing the entrance channels of the X + CH{sub 4}{yields} HX + CH{sub 3} (X = F, Cl, Br, I) reactions via photodetachment of X{sup -}-CH{sub 4}

    SciTech Connect

    Cheng Min; Feng Yuan; Du Yikui; Zhu Qihe; Zheng Weijun; Czako, Gabor; Bowman, Joel M.

    2011-05-21

    The entrance channel potentials of the prototypical polyatomic reaction family X + CH{sub 4}{yields} HX + CH{sub 3} (X = F, Cl, Br, I) are investigated using anion photoelectron spectroscopy and high-level ab initio electronic structure computations. The pre-reactive van der Waals (vdW) wells of these reactions are probed for X = Cl, Br, I by photodetachment spectra of the corresponding X{sup -}-CH{sub 4} anion complex. For F-CH{sub 4}, a spin-orbit splitting ({approx}1310 cm{sup -1}) much larger than that of the F atom (404 cm{sup -1}) was observed, in good agreement with theory. This showed that in the case of the F-CH{sub 4} system the vertical transition from the anion ground state to the neutral potentials accesses a region between the vdW valley and transition state of the early-barrier F + CH{sub 4} reaction. The doublet splittings observed in the other halogen complexes are close to the isolated atomic spin-orbit splittings, also in agreement with theory.

  4. Bias-dependent effects in planar perovskite solar cells based on CH3NH3PbI(3-x)Clx films.

    PubMed

    Lyu, Miaoqiang; Yun, Jung-Ho; Ahmed, Rasin; Elkington, Daniel; Wang, Qiong; Zhang, Meng; Wang, Hongxia; Dastoor, Paul; Wang, Lianzhou

    2015-09-01

    A unique bias-dependent phenomenon in CH3NH3PbI(3-x)Cl(x) based planar perovskite solar cells has been demonstrated, in which the photovoltaic parameters derived from the current-voltage (I-V) curves are highly dependent on the initial positive bias of the I-V measurement. In FTO/CH3NH3PbI(3-x)Cl(x)/Au devices, the open-circuit voltage and short-circuit current increased by ca. 337.5% and 281.9% respectively, by simply increasing the initial bias from 0.5 V to 2.5 V. PMID:25956128

  5. Unknown phase transitions, superconductivity and structural blocks in YBa2Cu3-xNixO7-δ

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Wang, Y. Z.; Cui, Y. J.; Du, H. L.; Zhang, H.

    2008-02-01

    Polycrystalline samples of YBa2Cu3-xNixO7-δ (x = 0, 0.05, 0.10, 0.15, 0.20, and 0.25) (YBCNO) were investigated by means of differential scanning calorimetry, thermogravimetry, temperature dependent x-ray diffraction, Rietveld refinement with the help of the bond valence sum method, magnetic moment-temperature measurement and combinative energy calculation between the two structural blocks, perovskite and rock salt. It was observed that there are two thermal anomalies of weight loss and heat flow change at about 400 and 850 °C in each sample before melting. By careful measurement it was found that the weight loss and endothermal absorption, as well as the critical temperature Tc, decrease with the increase of dopant. Combining the theory of oxygen diffusion with the block model in YBCO, the mechanism of the phase transitions can be explained as follows: the phase transition at 400 °C comes directly from O(1) in the rock salt block, while the phase transition at 850 °C corresponds to O(2) and O(3) in the Cu(2)-O plane. When a phase transition occurs, the oxygen at O(2) and O(3) sites is rearranged and a few oxygen atoms enter the O(1) site of the Cu(1)-O plane through the O(4) bridge atoms, finally escaping from the crystal cell. Thus the phase transition at 850 °C is related to the perovskite block. The calculation of the combinative energy between the rock salt and perovskite blocks shows that with increasing Ni content, the higher the combinative energy and the lower the Tc. The results indicate that there is a close relationship among thermal phase transitions, superconductivity and structural blocks in YBCNO, which may be significant for understanding the mechanism of high temperature superconductivity.

  6. Stueckelberg mechanisms for tensor multiplets and compactification on AdS{sub 3}xS{sup 3}

    SciTech Connect

    Nishino, Hitoshi; Rajpoot, Subhash

    2011-04-15

    We present Stueckelberg mechanisms for tensor multiplets coupled to supergravity in four dimensions (4D), six dimensions (6D), and three dimensions (3D). For N=1 supergravity in 4D, our field content is (e{sub {mu}}{sup m},{psi}{sub {mu}}), (B{sub {mu}{nu},{chi}},{phi}) and (A{sub {mu},{lambda}}), respectively, for the supergravity, tensor, and vector multiplets. In our Stueckelberg mechanism, the Abelian vector field A{sub {mu}} is absorbed into the longitudinal component of the tensor B{sub {mu}{nu}}, which becomes massive. The field strength F=dA of A is replaced by F{identical_to}F+mB, where m is a coupling constant with the dimension of mass. In 6D, we utilize the so-called dual version for N=2 supergravity, in order to avoid the obstruction caused by the Chern-Simons term F and A in the B-field strength G. Instead of the F and A-term in G, the 6D Lagrangian has a peculiar topological and cubic interaction term proportional to m{sup -1}F and F and F. In 3D, we also show that a similar mechanism works for N=1 supergravity. Interestingly, the basic structure is parallel to the 4D case, except that the originally nonpropagating field B starts propagating, after absorbing the A-field. We also show a possible compactification of 6D theory on AdS{sub 3}xS{sup 3}.

  7. Complete Genome Sequence of Spiroplasma kunkelii Strain CR2-3x, Causal Agent of Corn Stunt Disease in Zea mays L.

    PubMed Central

    Shao, Jonathan; Dally, Ellen L.; Zhao, Yan; Gasparich, Gail E.; Gaynor, Brady J.; Athey, John C.; Harrison, Nigel A.; Donofrio, Nicole

    2015-01-01

    Spiroplasma kunkelii causes corn stunt disease of Zea mays L. in the Americas. Here, we report the nucleotide sequence of the 1,463,926-bp circular chromosome and four plasmids of strain CR2-3x. This information will facilitate studies of Spiroplasma pathogenicity and evolutionary adaptations to transkingdom parasitism in plants and insect vectors. PMID:26494665

  8. Cast Aluminum Alloys for High Temperature Applications Using Nanoparticles Al2O3 and Al3-X Compounds (X = Ti, V, Zr)

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2009-01-01

    In this paper, the effect of nanoparticles Al2O3 and Al3-X compounds (X = Ti, V, Zr) on the improvement of mechanical properties of aluminum alloys for elevated temperature applications is presented. These nanoparticles were selected based on their low cost, chemical stability and low diffusions rates in aluminum at high temperatures. The strengthening mechanism at high temperature for aluminum alloy is based on the mechanical blocking of dislocation movements by these nanoparticles. For Al2O3 nanoparticles, the test samples were prepared from special Al2O3 preforms, which were produced using ceramic injection molding process and then pressure infiltrated by molten aluminum. In another method, Al2O3 nanoparticles can also be homogeneously mixed with fine aluminum powder and consolidated into test samples through hot pressing and sintering. With the Al3-X nanoparticles, the test samples are produced as precipitates from in-situ reactions with molten aluminum using conventional permanent mold or die casting techniques. It is found that cast aluminum alloy using nanoparticles Al3-X is the most cost effective method to produce high strength aluminum alloys for high temperature applications in comparison to nanoparticles Al2O3. Furthermore, significant mechanical properties retention in high temperature environment could be achieved with Al3-X nanoparticles, resulting in tensile strength of nearly 3 times higher than most 300- series conventional cast aluminum alloys tested at 600 F.

  9. Hydration thermodynamics of the proton conducting oxygen-deficient perovskite series BaTi1-xMxO3-x/2 with M = In or Sc.

    PubMed

    Bjørheim, Tor Svendsen; Rahman, Seikh M H; Eriksson, Sten G; Knee, Christopher S; Haugsrud, Reidar

    2015-03-16

    This article establishes the effect of structure and composition on water uptake and the hydration and proton transport properties of the oxygen-deficient perovskite series BaTi1-x(In,Sc)xO3-x/2, with 0.2 ≤ x ≤ 0.7. The equilibrium water uptake is determined by thermogravimetry, while combining thermogravimetry with differential scanning calorimetry allows for direct determination of the materials' hydration thermodynamics. Proton and oxide ion transport properties are characterized by means of ac impedance measurements up to 1000 °C. In general, the hydration thermodynamics of the scandates are more favorable than that of the indates and are also affected by changes in crystal structure throughout the series. The more favorable hydration thermodynamics of cubic scandates increase their proton conductivity at higher temperatures compared to their indate counterparts. In contrast to the BaTi1-xInxO3-x/2 series, the BaTi1-xScxO3-x/2 (0.5 ≤ x ≤ 0.7) materials retain their cubic structures upon full saturation by protons and show no signs of chemical instability upon exposure to 1 atm H2O(g) down to 100 °C. The BaTi1-xScxO3-x/2 materials with 0.5 ≤ x ≤ 0.7 may therefore find application in, for instance, steam electrolysis or similar processes involving high water vapor pressures. PMID:25731587

  10. Entrapping a Group-VB Transition Metal, Vanadium, within an Endohedral Metallofullerene: V(x)Sc(3-x)N@I(h)-C80 (x = 1, 2).

    PubMed

    Wei, Tao; Wang, Song; Lu, Xing; Tan, Yuanzhi; Huang, Jing; Liu, Fupin; Li, Qunxiang; Xie, Suyuan; Yang, Shangfeng

    2016-01-13

    So far the entrapped metals for the isolated endohedral metallofullerenes (EMFs) are primarily limited to rare earth metals, whereas except group-IVB metals, whether it is possible to entrap other d-block transition metals remains unclear. Herein we report the successful entrapment of the group-VB transition metal vanadium(V) into fullerene cage, affording the heretofore unknown V-containing EMFs. Two novel V-containing EMFs--V(x)Sc(3-x)N@C80 (x = 1, 2)--were isolated, and their molecular structures were unambiguously determined by X-ray crystallography to be I(h)(7)-C80 cage entrapping the planar VSc2N/V2ScN clusters. V(x)Sc(3-x)N@I(h)(7)-C80 (x = 1, 2) were further characterized by UV-vis-NIR and ESR spectroscopies and electrochemistry, revealing that the electronic and magnetic properties of V(x)Sc(3-x)N@I(h)(7)-C80 (x = 1, 2) are tunable upon varying the number of entrapped V atoms (i.e., x value). The molecular structures and electronic properties of V(x)Sc(3-x)N@I(h)(7)-C80 (x = 1, 2) were further compared with those of the reported analogous EMFs based on lanthanide metals and the adjacent group-IVB transition metal Ti, revealing the peculiarity of the group-VB transition metal V-based EMFs. PMID:26645852

  11. Structural and electrical investigation of (Ag3AsS3) x (As2S3)1- x superionic glasses

    NASA Astrophysics Data System (ADS)

    Studenyak, Ihor; Neimet, Yuriy; Cserháti, Csaba; Kökényesi, Sándor; Kazakevičius, Edvardas; Šalkus, Tomas; Kežionis, Algimantas; Orliukas, Antanas

    2012-02-01

    Structural studies of (Ag3AsS3) x (As2S3)1- x chalcogenide superionic glasses in the compositional range x = 0.3-0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient, electrical conductivity, and activation energy were investigated

  12. Theoretical study on the substitution reactions of the germylenoid H2GeLiF with SiH3X (X = F, Cl, Br).

    PubMed

    Zhang, Gongxiao; Qi, Yuhua; Xu, Chongjuan

    2016-06-01

    The substitution reactions of H2GeLiF (G) with SiH3X (X = F, Cl, Br) were investigated using calculations performed at the QCISD/6-311++G (d, p)//B3LYP/6-311+G (d, p) level of theory. The results led to the following conclusions. (i) The substitutions are nucleophilic reactions. There are two substitution paths, I and II, which both lead to the germane H2GeFSiH3. The enantiomers of this germane are obtained via these two paths if an H in SiH3X is replaced with a different group or atom. (ii) Both substitution pathways show the same order of barrier heights (SiH3F > SiH3Cl > SiH3Br). The difference between the bond energies of Li-X and Si-X may explain the precedence among the substitution reactions of G with SiH3X. Path I has a lower activation barrier than path II, indicating that path I is more favorable. (iii) Comparison between the relevant insertion and substitution reactions shows that substitutions are more favorable and that the substitution product H2GeFSiH3 predominates over the insertion product. (iv) The substitution reactions of H2GeLiF with SiH3X are exothermic. PMID:27179805

  13. Improving the Photoluminescence Properties of Perovskite CH3NH3PbBr3-xClx Films by Modulating Organic Cation and Chlorine Concentrations.

    PubMed

    Yan, Jun; Zhang, Bing; Chen, Yunlin; Zhang, Ao; Ke, Xiaohan

    2016-05-25

    The photoluminescence (PL) properties of inorganic-organic perovskites can be drastically changed by tuning the halogen composition, especially the Cl content. However, our research demonstrated that in addition to the influence of Cl concentration, the PL emission intensity of CH3NH3PbBr3 strongly depends on the content of CH3NH3Br in the coating solution. The effects of CH3NH3Br and Cl concentrations on the PL properties of CH3NH3PbBr3-xClx were investigated. We found that a strong PL emission intensity of CH3NH3PbBr3 can be obtained from solutions with a high CH3NH3Br concentration. The PL emission intensities of CH3NH3PbBr3-xClx films were enhanced by adjusting the molar ratio of PbBr to PbCl2 only in a highly concentrated CH3NH3Br environment. Moreover, it was found that an optimum CH3NH3Br/PbBr2/PbCl2 ratio in the precursor solutions can be used to obtain the strongest PL emission intensity of CH3NH3PbBr3-xClx films. Further studies revealed that both CH3NH3Br and Cl concentrations significantly influence the CH3NH3PbBr3-xClx films evolution, which affects their PL properties. PMID:27163386

  14. Modulation of LPS-induced memory insult, γ-secretase and neuroinflammation in 3xTg mice by 5-Lipoxygenase

    PubMed Central

    Joshi, Yash B.; Giannopoulos, Phillip F.; Chu, Jin; Praticò, Domenico

    2014-01-01

    Besides amyloid and tau pathology, a constant feature of Alzheimer’s disease (AD) is an intense inflammatory response, which is considered an active player in its pathogenesis. The 5-Lipoxygenase (5LO) is a proinflammatory enzyme and an endogenous modulator of AD-like phenotype in mouse models of the disease. To further understand the role of 5LO in AD pathogenesis, we exposed the 3xTg and 3xTg/5LO knockout mice to lipopolysaccharide (LPS), a known inducer of neuroinflammation, and evaluated its effect on their AD-like phenotype. 3xTg mice treated with LPS manifested a worsening of behavior, γ-secretase up-regulation, and increased neuroinflammatory responses. These effects were completely prevented in 3xTg mice genetically deficient for 5LO. By contrast, the absence of 5LO did not protect against increase in tau phosphorylation at specific epitopes that were mediated by the activation of the cyclin-dependent kinase 5. Our data demonstrate that the 5LO pathway affects key neuropathological features of the AD-like phenotype (behavior, Abeta, microgliosis, astrocytosis) but not others (tau pathology) in the LPS-dependent neuroinflammation model. The opposite ways whereby 5LO influences the LPS-dependent effects in vivo supports the complex nature of the neuroinflammatory response in AD and its differential role in modulating amyloid and tau neuropathology. PMID:24332986

  15. Geometrical structure of CH 3ClX(μ-Cl) 2XClCH 3(X = Al, Ga): experimental versus ab initio calculations

    NASA Astrophysics Data System (ADS)

    Mains, Gilbert J.; Bock, Charles W.; Trachtman, Mendel; Mastryukov, Vladimir S.

    1992-11-01

    The GAUSSIAN90 set of programs is used to obtain geometry optimizations of CH 3ClX(μ-Cl) 2XClCH 3 (X = Al, Ga), which exhibit cis/trans isomerization. The results are compared with experimental data.

  16. One-pot synthesis of PEGylated plasmonic MoO(3-x) hollow nanospheres for photoacoustic imaging guided chemo-photothermal combinational therapy of cancer.

    PubMed

    Bao, Tao; Yin, Wenyan; Zheng, Xiaopeng; Zhang, Xiao; Yu, Jie; Dong, Xinghua; Yong, Yuan; Gao, Fuping; Yan, Liang; Gu, Zhanjun; Zhao, Yuliang

    2016-01-01

    Engineering design of plasmonic nanomaterials as on-demand theranostic nanoagents with imaging, drug carrier, and photothermal therapy (PTT) functions have profound impact on treatment of cancer. Here, a facile 'one-pot' template-free hydrothermal route was firstly developed for synthesis of plasmonic oxygen deficiency molybdenum oxide hollow nanospheres functionalized by poly(ethylene glycol) (PEG-MoO(3-x) HNSs). The as-prepared PEG-MoO(3-x) HNSs not only have good biocompatibility but also exhibit obvious localized surface plasmon resonance (LSPR) absorption in the near-infrared (NIR) region. Especially, due to its intrinsic mesoporous properties and effective photothermal conversion efficiency upon 808-nm NIR laser irradiation, the PEG-MoO(3-x) HNSs can be applied as a pH/NIR laser dual-responsive camptothecin (CPT) drug delivery nanoplatform for chemotherapy as well as PTT to cancer cells. A remarkably improved synergistic therapeutic effect to pancreatic (PANC-1) tumor-bearing mice was obtained compared to the result of chemotherapy or PTT alone. Apart from its application for drug delivery, the PEG-MoO(3-x) HNSs can also be employed as an effective contrast nanoagent for photoacoustic (PAT) imaging because of its high NIR absorption, making it promising as a theranostic nanoagent for PAT imaging-guided chemo-photothermal combinational cancer therapy in the nanomedicine field. PMID:26517561

  17. Mass spectrum of the 1-butene-3-yne-2-yl radical (i-C4H3; X2A')

    NASA Astrophysics Data System (ADS)

    Guo, Ying; Gu, Xibin; Kaiser, Ralf I.

    2006-03-01

    The crossed molecular beams method has been applied to produce the 1-butene-3-yne-2-yl radical, i-C4H3(X2A') under single collision conditions via the reaction of dicarbon molecules with ethylene. We recorded time-of-flight spectra of the radical at the center-of-mass angle (28.0°) of the parent ion (m/z = 51; C4H3+) and of the fragments at m/z = 50 (C4H2+), m/z = 49 (C4H+), m/z = 48 (C4+), m/z = 39 (C3H3+), m/z = 38 (C3H2+), m/z = 37 (C3H+), and m/z = 36 (C3+). This yielded relative intensity ratios of I(m/z = 51):I(m/z = 50):I(m/z = 49):I(m/z = 48):I(m/z = 39):I(m/z = 38):I(m/z = 37):I(m/z = 36) = 0.47 +/- 0.01:0.94 +/- 0.01:1.0:0.07 +/- 0.02:0.31 +/- 0.01:0.23 +/- 0.02:0.24 +/- 0.01:0.12 +/- 0.01 at 70 eV electron impact energy. Upper limits at mass-to-charge ratios between 27 and m/z = 24 and m/z = 14-12 were derived to be 0.02 +/- 0.01. Note that the intensity of the 13C isotopic peak of the 1-butene-3-yne-2-yl radical at m/z = 52 (13C12C3H3+) is about 0.04 +/- 0.01 relative to m/z = 51. Employing linear scaling methods, the absolute electron impact ionization cross section of the 1-butene-3-yne-2-yl radical was computed to be 7.8 +/- 1.6 × 10-16 cm2. These data can be employed to monitor the 1-butene-3-yne-2-yl radical in oxygen-poor combustion flames and in the framework of prospective explorations of planetary atmospheres (Jupiter, Saturn, Uranus, Neptune, Pluto) and of their moons (Titan, Triton, Oberon) in situ via matrix interval arithmetic assisted mass spectrometry.

  18. Reconstructing the vertical profile of humidity on the basis of the vertical profile of temperature

    NASA Technical Reports Server (NTRS)

    Bazlova, T. I.

    1974-01-01

    The vertical profile of humidity in the atmosphere is developed on the basis of the vertical profile of temperature using an empirical formula linking changes in humidity with changes in temperature and altitude. The atmosphere is divided into three layers by altitude, since the condition for the formation of humidity varies with altitude.

  19. Liquid storage tanks under vertical excitation

    SciTech Connect

    Philippacopoulos, A.J.

    1985-01-01

    Until recently, the hydrodynamic effects on liquid storage tanks induced by an earthquake excitation were basically treated for the horizontal component of the earthquake. Recent studies, however, showed that the hydrodynamic effects due to the vertical component of an earthquake may be significant. In these studies the tank is assumed to be fixed at the bottom. This paper is concerned with the hydrodynamic behavior of liquid storage tanks induced by vertical earthquake input excitation. First, the fluid-tank system is treated as a fixed-base system and a simple formula is obtained for the coupled fluid-structure natural frequency. Second, additional interaction effects due to the foundation flexibility on the fluid-tank system are investigated. It is concluded that the foundation flexibility may have a significant effect on the hydrodynamic behavior of the liquid storage tanks under a vertical ground shaking.

  20. On The Vertical Speeds Of Airways Traffic

    NASA Astrophysics Data System (ADS)

    Magill, S. A. N.

    Knowledge of the statistics of aircraft vertical speeds is important both for the construction of realistic traffic simulators and for the development of trajectory prediction tools for use in future air traffic control (ATC) systems. This paper reports on the analysis of radar data recordings for nearly 10000 civil flights on airways. Results are presented for the means and spreads of vertical speeds as functions of altitude. Evidence is presented that roughly half of the observed spreads arise from fluctuations within each aircraft's trajectory, as opposed to variation from one aircraft to another. A simple procedure is proposed for simulating vertical speed data which has statistics similar to those obtained from the radar recordings. Some consequences of the results for the development of trajectory prediction tools for use in future ATC systems are discussed. The results suggest that the provision of accurate trajectory prediction tools is not as straightforward as it might at first appear to be.

  1. Vertical cable surveys deliver additional seismic data

    SciTech Connect

    1995-12-01

    Texaco and a Norwegian seismic firm have patented a new system for deploying hydrophones on vertical cables for offshore surveys. The system was used in Texaco North Sea UK Ltd.`s Strathspey field during the summer. The new technique was introduced in the article, ``Peaceful use for war technology,`` published in Texaco UK`s Agenda monthly news magazine, October 1995. That article is summarized here. Using technology developed by the US Navy for antisubmarine warfare, the vertical-cable survey relies on hydrophones attached at regular intervals vertically along cables secured to the ocean floor and held taut by a buoy. The shooting vessel fires the airguns in a pattern over a large area on the surface, over and around the cables. The cables are then moved to a new location and the process is repeated, up to six times in the Strathspey application described here.

  2. Vertical gradients of sunspot magnetic fields

    NASA Astrophysics Data System (ADS)

    Hagyard, M. J.; Teuber, D.; West, E. A.; Tandberg-Hanssen, E.; Henze, W., Jr.; Beckers, J. M.; Bruner, M.; Hyder, C. L.; Woodgate, B. E.

    1983-04-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  3. Vertical gradients of sunspot magnetic fields

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.; Teuber, D.; West, E. A.; Tandberg-Hanssen, E.; Henze, W., Jr.; Beckers, J. M.; Bruner, M.; Hyder, C. L.; Woodgate, B. E.

    1983-01-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  4. THE VERTICAL COMPONENT OF THE SUPERGRANULAR MOTION

    SciTech Connect

    Duvall, T. L. Jr.; Birch, A. C.

    2010-12-10

    Supergranules are observed at the solar photosphere as a cellular horizontal flow pattern with flow diverging from cell centers and converging on cell boundaries. Clark and Johnson calculated that mass conservation leads to an expected vertical flow of only 10 m s{sup -1}, which has been difficult to observe. In the present work, Doppler images near the disk center from Michelson Doppler Imager are averaged about locations of cell centers to obtain the necessary signal-to-noise ratio to see the vertical flow. It is found that, for an average over 1100 cell centers, there is a 10 m s{sup -1} upflow at cell center and a 5 m s{sup -1} downflow at the cell boundaries, confirming the previous estimate. The rms vertical flow is 4 m s{sup -1}, smaller than Giovanelli's upper limit of 10 m s{sup -1}.

  5. Vertical Velocity Measurements in Warm Stratiform Clouds

    NASA Astrophysics Data System (ADS)

    Luke, E. P.; Kollias, P.

    2013-12-01

    Measurements of vertical air motion in warm boundary layer clouds are key for quantitatively describing cloud-scale turbulence and for improving our understanding of cloud and drizzle microphysical processes. Recently, a new technique that produces seamless measurements of vertical air velocity in the cloud and sub-cloud layers for both drizzling and non-drizzling stratocumulus clouds has been developed. The technique combines radar Doppler spectra-based retrievals of vertical air motion in cloud and light drizzle conditions with a novel neural network analysis during heavily drizzling periods. Observations from Doppler lidars are used to characterize sub-cloud velocities and to evaluate the performance of the technique near the cloud base. The technique is applied to several cases of stratiform clouds observed by the ARM Mobile Facility during the Two-Column Aerosol Project (TCAP) campaign in Cape Cod. The observations clearly illustrate coupling of the sub-cloud and cloud layer turbulent structures.

  6. Hydraulic induced instability on a vertical service

    NASA Technical Reports Server (NTRS)

    Bosmans, R. F.

    1985-01-01

    The case history contained provides insight toward the mechanical and hydraulic behavior of a vertical pump. It clearly demonstrates the need for measurements on the rotor at or near the impeller area. The results are reported of an analysis on a service water pump. This pump is typical of the water pumps used throughout the power generation industry. Although little is known of the mechanical behavior of vertical pumps because of difficulty in modeling the rotor system, recent developments in the application of submersible proximity transducers have made possible the measurement of pump dynamics under operating conditions. The purpose of this study was to determine the proper selection and installation of vibration-monitoring transducers as well as to measure the effects of imbalance, misalignment, and hydraulics on the performance and reliability of vertical pumps. In addition, the cause of shaft failures on this pump was to be determined.

  7. Purification process for vertically aligned carbon nanofibers

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V.; Delziet, Lance; Matthews, Kristopher; Chen, Bin; Meyyappan, M.

    2003-01-01

    Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes.

  8. Modeling the CAPTEX vertical tracer concentration profiles

    SciTech Connect

    Draxler, R.R.; Stunder, B.J.B.

    1988-05-01

    Perfluorocarbon tracer concentration profiles measured by aircraft 600--900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

  9. Modeling the CAPTEX Vertical Tracer Concentration Profiles.

    NASA Astrophysics Data System (ADS)

    Draxler, Roland R.; Stunder, Barbara J. B.

    1988-05-01

    Perfluorocarbon tracer concentration profiles measured by aircraft 600-900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

  10. Marble-burying is enhanced in 3xTg-AD mice, can be reversed by risperidone and it is modulable by handling.

    PubMed

    Torres-Lista, Virginia; López-Pousa, Secundino; Giménez-Llort, Lydia

    2015-07-01

    Translational research on behavioural and psychological symptoms of dementia (BPSD) is relevant to the study the neuropsychiatric symptoms that strongly affect the quality of life of the human Alzheimer's disease (AD) patient and caregivers, frequently leading to early institutionalization. Among the ethological behavioural tests for rodents, marble burying is considered to model the spectrum of anxiety, psychotic and obsessive-compulsive like symptoms. The present work was aimed to study the behavioural interactions of 12 month-old male 3xTg-AD mice with small objects using the marble-burying test, as compared to the response elicited in age-matched non-transgenic (NTg) mice. The distinction of the classical 'number of buried marbles' but also those left 'intact' and those 'changed' of position of marbles or partially buried (the transitional level of interaction) provided new insights into the modelling of BPSD-like alterations in this AD model. The analysis revealed genotype differences in the behavioural patterns and predominant behaviors. In the NTg mice, predominance was shown in the 'changed or partially buried', while interactions with marble were enhanced in 3xTg-AD mice resulting in an increase of marble burying. Besides, genotype-dependent meaningful correlations were found, with the marble test pattern of 3xTg-AD mice being directly related to neophobia in the corner tests. In both genotypes, the increase of burying was reversed by chronic treatment with risperidone (1mg/kg, s.c.). In 3xTg-AD mice, the repetitive handling of animals during the treatment also exerted modulatory effects. These distinct patterns further characterize the modelling of BPSD-like symptoms in the 3xTg-AD mice, and provide another behavioural tool to assess the benefits of preventive and/or therapeutic strategies, as well as the potential action of risk factors for AD, in this animal model. PMID:25957954

  11. Top-down vertical itemset mining

    NASA Astrophysics Data System (ADS)

    Sohrabi, Mohammad Karim; Ghods, Vahid

    2015-03-01

    Vertical itemset mining is an important frequent pattern mining problem with broad applications. It is challenging since one may need to examine a combinatorial explosive number of possible patterns of items of a dataset in a traditional horizontal algorithm. Since high dimensional datasets typically contain a large number of columns and a small number of rows, vertical itemset mining algorithms, which extract the frequent itemsets of dataset by producing all combination of rows ids, are a good alternative for horizontal algorithms in mining frequent itemsets from high dimensional dataset. Since a rowset can be simply produced from its subsets by adding a new row id to a sub rowset, many bottom up vertical itemset mining algorithms are designed and represented in the literature. However, bottom up vertical mining algorithms suffer from a main drawback. Bottom-up algorithms start the process of generating and testing of rowsets from the small rowsets and go on to the larger rowsets, whereas the small rowsets cannot produce a frequent itemsets because they contain less than minimum support threshold number of rows. In this paper, we described a new efficient vertical top down algorithm called VTD (Vertical Top Down) to conduct mining of frequent itemsets in high dimensional datasets. Our top down approach employed the minimum support threshold to prune the rowsets which any itemset could not be extracted from them. Several experiments on real bioinformatics datasets showed that VTD is orders of magnitude better than previous closed pattern mining algorithms. Our performance study showed that this algorithm outperformed substantially the best former algorithms.

  12. Turbulence in vertical axis wind turbine canopies

    NASA Astrophysics Data System (ADS)

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  13. European Vertical Reference System Influence in Latvia

    NASA Astrophysics Data System (ADS)

    Celms, A.; Reķe, I.; Ratkevičs, A.

    2015-11-01

    Till 1 December, 2014, in Latvia the heights were determined in Baltic Normal Height System 1977. The national height system is determined by the Cabinet of Ministers and internal laws. Now for the change of the national height system to reconcile it with the European Vertical Reference System, amendments to the laws and regulations have been developed, but so far only the amendment to the Geospatial Information Law is in force, the amendment to the regulation of the Cabinet of Ministers is still not approved. This amendment declares the Latvia Height System based on the European Vertical Reference System in Latvia as the national height system. For height transformation, there is a transformation formula for each European country. After calculations it is seen that height difference between Baltic Normal Height System 1977 and European Vertical Reference System depends on point location in the territory (coordinates). This unequal height difference between both height systems will cause unequal height values on border connection points between Baltic countries. The aim of the research is to evaluate the European Vertical Reference System in Latvia. To reach the aim the following tasks are set: 1) to evaluate the components of transformation formulas; 2) using the transformation formulas to calculate height differences between Baltic Normal Height System 1977 and the European Vertical Reference System realization EVRF2007 for the territory of Latvia and also between Baltic Normal Height System 1977 and the Latvia Normal Height System; 3) to get height differences in the European Vertical Reference System on the borderlines of Latvia - Estonia and Latvia - Lithuania.

  14. Vertical Tears of the Lateral Meniscus

    PubMed Central

    Goyal, Kanu S.; Pan, Tiffany J.; Tran, Diane; Dumpe, Samuel C.; Zhang, Xudong; Harner, Christopher D.

    2014-01-01

    Background: Lateral meniscal tears are often seen with acute anterior cruciate ligament (ACL) injury and may be left in situ, repaired, or treated with meniscectomy. Clinical studies have shown good outcomes with vertical tears left in situ and poor outcomes following meniscectomy. However, clinically relevant studies are needed to establish a biomechanical foundation for treatment of these tears, particularly regarding the effects of meniscectomy. Purpose: To compare tibiofemoral joint mechanics following vertical lateral meniscal tears and meniscectomies. We hypothesized that a peripheral vertical tear of the lateral meniscus would alter joint mechanics, increasing contact pressure and area, and that more drastic effects would be seen following meniscectomy, at higher knee flexion angles, and with increased loads. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric knees (average age, 55 ± 12 years) were tested with 5 lateral meniscus states: intact, short vertical tear, extended vertical tear, posterior horn partial meniscectomy (rim intact), and posterior horn subtotal meniscectomy (rim excised). The specimens were loaded axially at knee flexion angles of 0°, 30°, and 60°, and musculotendinous forces were applied, simulating a 2-legged squat. Intra-articular contact pressures were measured using pressure-sensitive Fuji film. Kinematic data were acquired through digitization of fiducial markers. Results: Vertical tears did not cause a significant change in contact pressure or area. Partial meniscectomy increased maximum contact pressures in the lateral compartment at 30° and 60° from 5.3 MPa to 7.2 MPa and 7.6 MPa, respectively (P = .02, P = .007). Subtotal meniscectomy (8.4 MPa) significantly increased contact pressure compared with partial meniscectomy (7.6 MPa) at 60° (P = .04). Both meniscectomy states significantly increased contact pressures with increasing flexion from 0° to 60° (P < .001, P < .001). Conclusion

  15. Photochemistry and vertical mixing. [in Uranus atmosphere

    NASA Technical Reports Server (NTRS)

    Atreya, S. K.; Sandel, B. R.; Romani, P. N.

    1991-01-01

    Earth-based observations relevant to the question of photochemistry and vertical mixing are discussed. Phytolysis of methane, the only known photochemically active volatile in the Uranian atmosphere, produces heavier hydrocarbons, the most abundant of which are ethane, acetylene, and the polyacetylenes. Unlike Jupiter and Saturn, these hydrocarbon products condense at the low temperatures prevalent in the middle atmosphere. Contrary to the pre-Voyager notion that the atmosphere of Uranus is remarkable clear, it is found that the aerosols are widely and extensively distributed. Despite its photodestruction, methane remains stable in the Uranian atmosphere. The vertical mixing on Uranus is found to be the least efficient of any of the planetary atmospheres.

  16. CIRSS vertical data integration, San Bernardino study

    NASA Technical Reports Server (NTRS)

    Hodson, W.; Christenson, J.; Michel, R. (Principal Investigator)

    1982-01-01

    The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff.

  17. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  18. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  19. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  20. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  1. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  2. On the measurement of vertical velocity by MST radar

    NASA Technical Reports Server (NTRS)

    Gage, K. S.

    1983-01-01

    An overview is presented of the measurement of atmospheric vertical motion utilizing the MST radar technique. Vertical motion in the atmosphere is briefly discussed as a function of scale. Vertical velocity measurement by MST radars is then considered from within the context of the expected magnitudes to be observed. Examples are drawn from published vertical velocity observations.

  3. Observation of spin textures in La1-xSrxMnO3 (x = 0.175)

    NASA Astrophysics Data System (ADS)

    Kotani, A.; Nakajima, H.; Ishii, Y.; Harada, K.; Mori, S.

    2016-05-01

    We have investigated topological spin textures in the ferromagnetic metallic phase of La0.825Sr0.175MnO3 with the centrosymmetric crystal structure by small-angle electron diffraction (SmAED) and low-temperature Lorentz transmission electron microscopy (TEM) experiments. In-situ Lorentz TEM and SmAED experiments revealed that type-I and type-II magnetic bubbles evolved from magnetic stripe domains with the Bloch-type domain wall by applying vertical magnetic field. Type-I magnetic bubbles with left-handed and right-handed spin helicity were randomly distributed and simultaneously type-II magnetic bubbles are formed locally. The important point about type-I and type-II magnetic bubbles is that their emergence depends strongly on whether perpendicular magnetic field is applied parallel to the magnetic easy axis along the [001] direction. Our experimental results suggested that the stabilization of magnetic bubbles should originate from the long-range dipole-dipole interactions, as opposed to the Dzyaloshinskii-Moriya interaction in helical magnets.

  4. [From vertical to horizontal. Writing in adolescence].

    PubMed

    Catheline-Antipoff, N

    1995-04-01

    Writing at adolescence has a non negligible part in identity's construction. Vertical writing as tags, graphs and graffiti refer to a narcissism deficiency and express a pulsional necessity, whereas, horizontal writing as private diaries, letters and novels express object's search and are made in dreaming attitude. PMID:7618823

  5. Vertical transport processes in unconfined aquifers

    NASA Astrophysics Data System (ADS)

    Ostendorf, David W.; Reckhow, David A.; Popielarczyk, David J.

    1989-02-01

    We derive simple two-dimensional mathematical models describing the unsteady transport of conservative contaminants through an unconfined aquifer with a gently sloping aquiclude subject to advection, recharge, and vertical dispersion. The inclusion of vertical transport terms permits the proper nonreactive analysis of closed and open chemical systems, with the latter allowing dispersion of volatile constituents across the water table. These systems exhibit conservative and pseudoreactive behavior respectively when the pollution is analyzed on a depth-integrated basis, as is common in present one-dimensional models of groundwater contamination. Vertical and longitudinal chloride and total inorganic carbon observations at the well-documented Babylon, Long Island sanitary landfill plume are used to calibrate and test the analyses with a modest level of accuracy, using the vertical dispersivity as a calibration factor in this testing process. The parameter is important in the determination of reaeration rates across the water table and nutrient mixing from below in the related problem of biological transformations near the free surface.

  6. Tailored airfoils for vertical axis wind turbines

    SciTech Connect

    Klimas, P.C.

    1984-01-01

    The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system costs-of-energy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

  7. Tailored airfoils for Vertical Axis Wind Turbines*

    SciTech Connect

    Klimas, P.C.

    1984-08-01

    The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system cost-ofenergy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

  8. Tailored airfoils for vertical axis wind turbines

    SciTech Connect

    Klimas, P.C.

    1984-11-01

    The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system costs-of-energy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

  9. 46 CFR 108.160 - Vertical ladders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Vertical ladders. 108.160 Section 108.160 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT... fitted with a cage or ladder safety device meeting ANSI Standard 14.3 (1974) for fixed ladders. (d)...

  10. Leak-tight vertical membrane microvalves.

    PubMed

    Hansson, Jonas; Hillmering, Mikael; Haraldsson, Tommy; van der Wijngaart, Wouter

    2016-04-12

    Pneumatic microvalves are fundamental control components in a large range of microfluidic applications. Their key performance parameters are small size, i.e. occupying a minimum of microfluidic real estate, low flow resistance in the open state, and leak-tight closing at limited control pressures. In this work we present the successful design, realization and evaluation of the first leak-tight, vertical membrane, pneumatic microvalves. The realization of the vertical membrane microvalves is enabled by a novel dual-sided molding method for microstructuring monolithic 3D microfluidic networks in PDMS in a single step, eliminating the need for layer-to-layer alignment during bonding. We demonstrate minimum lateral device features down to 20-30 μm in size, and vertical via density of ∼30 000 per cm(2), which provides significant gains in chip real estate compared to previously reported PDMS manufacturing methods. In contrast to horizontal membrane microvalves, there are no manufacturing restrictions on the cross-sectional geometry of the flow channel of the vertical membrane microvalves. This allows tuning the design towards lower closing pressure or lower open state flow resistance compared to those of horizontal membrane microvalves. PMID:26983557

  11. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory…

  12. Vertical root fractures and their management

    PubMed Central

    Khasnis, Sandhya Anand; Kidiyoor, Krishnamurthy Haridas; Patil, Anand Basavaraj; Kenganal, Smita Basavaraj

    2014-01-01

    Vertical root fractures associated with endodontically treated teeth and less commonly in vital teeth represent one of the most difficult clinical problems to diagnose and treat. In as much as there are no specific symptoms, diagnosis can be difficult. Clinical detection of this condition by endodontists is becoming more frequent, where as it is rather underestimated by the general practitioners. Since, vertical root fractures almost exclusively involve endodontically treated teeth; it often becomes difficult to differentiate a tooth with this condition from an endodontically failed one or one with concomitant periodontal involvement. Also, a tooth diagnosed for vertical root fracture is usually extracted, though attempts to reunite fractured root have been done in various studies with varying success rates. Early detection of a fractured root and extraction of the tooth maintain the integrity of alveolar bone for placement of an implant. Cone beam computed tomography has been shown to be very accurate in this regard. This article focuses on the diagnostic and treatment strategies, and discusses about predisposing factors which can be useful in the prevention of vertical root fractures. PMID:24778502

  13. Viewing Vertical Objects with an Overhead Projector.

    ERIC Educational Resources Information Center

    Wild, R. L.

    1988-01-01

    Discusses the use of an overhead projector for the deflection of a vertical image to a screen. Describes three demonstrations: magnetizing of a steel ball bearing and paper clip; convection currents of a hot liquid within a cold liquid; and oscillation of concentrated salt solution into fresh water. (YP)

  14. Modeling vertical coral connectivity and mesophotic refugia

    NASA Astrophysics Data System (ADS)

    Holstein, Daniel M.; Paris, Claire B.; Vaz, Ana C.; Smith, Tyler B.

    2016-03-01

    Whether mesophotic reefs will behave as refugia for corals threatened by global climate change and coastal development depends on vertical exchange of larvae between diverse habitats. Here we use a biophysical model of larval dispersal to estimate vertical connectivity of a broadcasting ( Orbicella faveolata) and a brooding ( Porites astreoides) species of coral in the US Virgin Islands. Modeling predicts subsidy to shallow areas by mesophotic larvae of both species based on local hydrology, adult reproductive characteristics, larval traits, and a wide range of scenarios developed to test depth-sensitive factors, such as fertilization rates and post-settlement survivorship. In extreme model scenarios of reduced fertilization and post-settlement survivorship of mesophotic larvae, 1-10 % local mesophotic subsidy to shallow recruitment is predicted for both species, which are demographically significant. Although direct vertical connectivity is higher for the broadcaster, the brooder demonstrates higher local multigenerational vertical connectivity, which suggests that local P. astreoides populations are more resilient than those of O. faveolata, and corroborates field studies. As shallow habitat degrades, mesophotic-shallow subsidy is predicted to increase for both species. This study is the first of its kind to simulate larval dispersal and settlement between habitats of different depths, and these findings have local, regional, and global implications for predicting and managing coral reef persistence in a changing climate.

  15. Vertical Alveolar Ridge Augmentation by Distraction Osteogenesis

    PubMed Central

    Kumar, N. Nanda; Ravindran, C.

    2015-01-01

    Introduction Compromised alveolar ridge in vertical and horizontal dimension is a common finding in patients visiting practitioners for dental prosthesis. Various treatment modalities are available for correction of deficient ridges among which alveolar distraction osteogenesis is one. Aim To study the efficacy of alveolar distraction osteogenesis in augmentation of alveolar ridges deficient in vertical dimension. Materials and Methods Ten patients aged 16 to 46 years with deficient alveolar ridge underwent ridge augmentation in 11 alveolar segments using the distraction osteogenesis method. For each patient a custom made distraction device was fabricated. The device was indigenously manufactured with SS-316 (ISO 3506). Results The vertical bone gain reached more than 10mm without the use of bone transplantation. Certain complications like incorrect vector of distraction, paresthesia, pain and loss of transport segment were encountered during the course of the study. Conclusion Alveolar vertical distraction osteogenesis is a reliable and predictable technique for both hard and soft tissue genesis. Implant placement is feasible with primary stability in neogenerated bone at the level of the distracted areas. PMID:26816991

  16. Vertical distribution of Pahang River plume

    NASA Astrophysics Data System (ADS)

    Taher, T. M.; Lihan, T.; Mustapha, M. A.

    2013-11-01

    Large rivers transported high amount of discharge towards the sea and induced the river plume formation. The contents of the plume consist of suspended solids, nutrients, pollutants and other particles. Productivity at estuary depends on the organic and nutrient contents from the river discharge. Due to many possible factors, the dispersal of the plume shows spatial variation horizontally and vertically. The monsoonal wind is a factor that effecting plume vertical profile pattern. This study determines the vertical distribution pattern of the plumeat Pahang River through field observation. Several water parameters were measured during cruises conducted at respective monsoon. Data collected includes depth, chlorophyll-a, salinity, temperature and suspended particulate matter. Depth at Pahang's offshore usually does not reached more than 15 m depth because of the shallow continental shelf at South China Sea. The plume has higher concentration at the mouth of the river which causes the area to be less saline and it decreases as the station furthers from the river. Chlorophyll-a is distributed mainly at the surface level where the area is warmer and received freshwater runoff. Suspended particulate matter shows downward distribution from the front of the estuary towards deep water column depth (10 m). Temperature pattern shows warmer surface layer with depth less than 5 m while deeper water column has lower temperature. Vertical profile pattern of Pahang River plume generally shows slight difference between each monsoon by referring to particular parameter.

  17. Vertically aligned biaxially textured molybdenum thin films

    SciTech Connect

    Krishnan, Rahul; Riley, Michael; Lee, Sabrina; Lu, Toh-Ming

    2011-09-15

    Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

  18. Vertical motions in the equatorial middle atmosphere

    NASA Technical Reports Server (NTRS)

    Weisman, M. L.

    1979-01-01

    A single station vertical velocity equation which considers ageostrophic and diabatic effects derived from the first law of thermodynamics and a generalized thermal wind relation is presented. An analysis and verification procedure which accounts for measurement and calculation errors as well as time and space continuity arguments and theoretical predictions are described. Vertical velocities are calculated at every kilometer between 25 and 60 km and for approximately every three hours for the above diurnal period at Kourou (French Guiana), Fort Sherman (Panama Canal Zone), Ascension Island, Antigua (British West Indies) and Natal (Brazil). The results, plotted as time series cross sections, suggest vertical motions ranging in magnitude from 1 or 2 cm/sec at 30 km to as much as 15 cm/sec at 60 km. Many of the general features of the results agree well with atmospheric tidal predictions but many particular features suggest that both smaller time scale gravity waves (periods less than 6 hours) and synoptic type waves (periods greater than 1 day) may be interacting significantly with the tidal fields. The results suggest that vertical motions can be calculated for the equatorial middle atmosphere and must be considered a significant part of the motion for time scales from 8 to 24 hours.

  19. Electrostatic comb drive for vertical actuation

    SciTech Connect

    Lee, A. P., LLNL

    1997-07-10

    The electrostatic comb finger drive has become an integral design for microsensor and microactuator applications. This paper reports on utilizing the levitation effect of comb fingers to design vertical-to-the-substrate actuation for interferometric applications. For typical polysilicon comb drives with 2 {micro}m gaps between the stationary and moving fingers, as well as between the microstructures and the substrate, the equilibrium position is nominally 1-2 {micro}m above the stationary comb fingers. This distance is ideal for many phase shifting interferometric applications. Theoretical calculations of the vertical actuation characteristics are compared with the experimental results, and a general design guideline is derived from these results. The suspension flexure stiffnesses, gravity forces, squeeze film damping, and comb finger thicknesses are parameters investigated which affect the displacement curve of the vertical microactuator. By designing a parallel plate capacitor between the suspended mass and the substrate, in situ position sensing can be used to control the vertical movement, providing a total feedback-controlled system. Fundamentals of various capacitive position sensing techniques are discussed. Experimental verification is carried out by a Zygo distance measurement interferometer.

  20. Vertical Arc for ILC Low Emittance Transport

    SciTech Connect

    Tenenbaum, P.; Woodley, M.; /SLAC

    2005-06-07

    The design and parameters of a vertical arc for the ILC Low Emittance Transport (LET) are reviewed. A 1 TeV CM ILC which relies upon 30 MV/m accelerating cavities with a packing fraction of 65% will require almost 48 km of main linac, which suggests that the total site length including BDS and bunch compressors will be on the order of 53 km. If built in a laser-straight tunnel with the low-energy ends near the surface, and assuming a perfectly spherical ''cue ball'' planetary surface with radius 6370 km, the collider halls will necessarily be 55 meters below grade, as shown in the top plot of Figure 1. Such depths would demand extensive use of deep tunneling, which would potentially drive up the cost and difficulty of ILC construction. An alternate solution is to use discrete vertical arcs at a few locations to allow a ''piecewise straight'' construction in which the depth of the tunnel below grade does not vary by more than a few meters. This approach is shown schematically in the bottom plot of Figure 1. In this Note we consider the issues for a design with one such vertical arc at the 250 GeV/c point (ie, midway down the linac for 1 TeV CM), and a second arc at the entrance to the BDS (ie, the entire BDS lies in one plane, with vertical arcs at each end).

  1. Model of 5-Foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1930-01-01

    Model of 5-Foot Vertical Wind Tunnel. Carl Wenzinger and Thomas Harris wrote in NACA TR 387: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet to within 0.5 per cent. The turbulence present in the tunnel has been compared with that of several other tunnels by means of the results of sphere drag tests and was found to average well with the values of those tunnels. Included also in the report are comparisons of results of stable autorotation and of rolling-moment tests obtained both in the vertical tunnel and in the old horizontal 5-foot atmospheric tunnel.' The design of a vertical tunnel having a 5-foot diameter jet was accordingly started by the National Advisory Committee for Aeronautics in 1928. Actual construction of the new tunnel was completed in 1930, and the calibration tests were then made.'

  2. Vertical pump with free floating check valve

    DOEpatents

    Lindsay, Malcolm

    1980-01-01

    A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

  3. A Vertical Approach to Math Instruction

    ERIC Educational Resources Information Center

    Gojak, Linda

    2012-01-01

    In the current era of mathematics standards, whether they are Common Core State Standards or other state standards, effective vertical mathematics teams offer an opportunity for teachers to grow professionally through shared experiences, for leadership to grow among the faculty, and for the school to change its perspective on the teaching and…

  4. Reproducible formation of uniform CH3NH3PbI3-xClx mixed halide perovskite film by separation of the powder formation and spin-coating process

    NASA Astrophysics Data System (ADS)

    Song, Dae-ho; Heo, Jin Hyuck; Han, Hye Ji; You, Myoung Sang; Im, Sang Hyuk

    2016-04-01

    To deposit uniform CH3NH3PbI3-xClx (MAPbI3-xClx) mixed halide perovskite film reproducibly, we separated the conventional process to formation of MAPbI3-xClx mixed halide perovskite powder by heat-treatment process and deposition of MAPbI3-xClx mixed halide perovskite film by single step spin-coating. The deviation of power conversion efficiency of MAPbI3-xClx mixed halide perovskite solar cells prepared by currently proposed method and conventional method was 13.75 ± 0.88% and 8.02 ± 1.65%, respectively, because more uniform MAPbI3-xClx mixed halide perovskite film could be reproducibly formed by separating the formation process of mixed halide perovskite powder and the single step spin-coating process.

  5. Vertical Acoustic Arrays in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Fisher, F.

    2002-12-01

    The R/P FLIP has made possible the deployments of vertical arrays to study sound propagation and ambient noise in the deep ocean in ways never before possible from existing research vessels. Long vertical arrays can be deployed without the flow noise contamination from platform motion, long a bane for making such studies. The vertical stability of FLIP combined with the deep mooring capability developed by Earl D. Bronson made it possible to deploy multi-element arrays beginning with a versatile 20 element array with variable spacing developed by Bill Whitney in Fred Spiess's group. The 20 element array consisted of bungee mounted hydrophones in metal cages at either uniform spacing or variable spacing to meet directivity or other requirements. It was assembled on station in the vertical and deployed to the desired depths for the elements. Gerald Morris at MPL conducted ambient noise studies using variable spacing of the elements to below the critical depth as well as in the water column above. Vic Anderson used it for his DIMUS processing system for detecting low level signals masked by ambient noise. As a 500 meter array, I used it for a series of CONTRACK (Continuous Tracking of signals at long range) experiments to resolve multipaths so they wouldn't interfere with one another. The VEKA vertical array developed by Rick Swenson of NORDA was deployed in very deep (below 3300 m) water by Dan Ramsdale of NORDA using the winch and double lay armored cable on FLIP, the same cable system for the MPL 20 element array. In my group Bruce Williams designed a rapidly deployable array to study vertical anisotropy of ambient noise as a function of range from near shore shipping via downslope conversion in a series of 48 hours FLIP stations 350, 1000 and 1500 miles from the Pacific coast. A short 120 element array, 1000 meters long, was built by John Hildebrands's group for a test of matched field processing and the SLICE experiment in acoustic tomography research of Peter

  6. Short-term modern life-like stress exacerbates Aβ-pathology and synapse loss in 3xTg-AD mice.

    PubMed

    Baglietto-Vargas, David; Chen, Yuncai; Suh, Dongjin; Ager, Rahasson R; Rodriguez-Ortiz, Carlos J; Medeiros, Rodrigo; Myczek, Kristoffer; Green, Kim N; Baram, Tallie Z; LaFerla, Frank M

    2015-09-01

    Alzheimer's disease (AD) is a progressive neurological disorder that impairs memory and other cognitive functions in the elderly. The social and financial impacts of AD are overwhelming and are escalating exponentially as a result of population aging. Therefore, identifying AD-related risk factors and the development of more efficacious therapeutic approaches are critical to cure this neurological disorder. Current epidemiological evidence indicates that life experiences, including chronic stress, are a risk for AD. However, it is unknown if short-term stress, lasting for hours, influences the onset or progression of AD. Here, we determined the effect of short-term, multi-modal 'modern life-like' stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by augmenting AβPP processing. Thus, short-term stress simulating modern-life conditions may exacerbate cognitive deficits in preclinical AD by accelerating amyloid pathology and reducing synapse numbers. Epidemiological evidence indicates that life experiences, including chronic stress, are a risk for Alzheimer disease (AD). However, it is unknown if short stress in the range of hours influences the onset or progression of AD. Here, we determined the effect of short, multi-modal 'modern-lifelike'stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by

  7. Modifications in vertical scar breast reduction.

    PubMed

    Beer, G M; Morgenthaler, W; Spicher, I; Meyer, V E

    2001-06-01

    The use of vertical-scar breast reduction techniques is only slowly increasing, even though they have been advocated by Lassus and Lejour and are requested by patients. Possible reasons why surgeons are reluctant to use these techniques are that they are said to be more difficult to learn, they require considerable experience and intuition, and their applicability is confined to small breasts. Several surgeons have developed modifications, combining vertical-scar breast reduction techniques with details of the familiar inverted-T-scar technique. We present a procedure involving two further modifications of the vertical-scar breast reduction technique: first, a standardised, geometrical preoperative drawing from our superior-pedicle T technique, with the aim of establishing a reproducible method of reduction requiring no particular intuitive touch, and, second, the addition of a periareolar skin resection, to give the breast the desired round shape. Between September 1998 and December 1999 we used this technique in a prospective series of 52 patients. The median resection weight was 450 g. The maximal postoperative follow-up was 15 months. There were no acute postoperative complications necessitating reoperation. The late complication rate was within the expected range for such procedures (seven patients, 13.5%) and included vertical-scar widening, areolar distortion, residual wrinkles due to incomplete shrinkage of the undermined skin in the inferior pole and asymmetry of the breast. This procedure enables us to offer patients with moderate to marked hypertrophy a reproducible versatile vertical breast reduction technique. The technique is easy to teach and easy to learn, especially for those who are familiar with the superior pedicle inverted-T-scar technique. PMID:11355991

  8. Near-zero temperature coefficient of resistivity associated with magnetic ordering in antiperovskite Mn3+xNi1-xN

    NASA Astrophysics Data System (ADS)

    Deng, Sihao; Sun, Ying; Wang, Lei; Wu, Hui; Shi, Kewen; Hu, Pengwei; Huang, Qingzhen; Wang, Cong

    2016-01-01

    The near-zero temperature coefficient of resistivity (NZ-TCR) behavior is reported in the antiperovskite compounds Mn3+xNi1-xN (0 ≤ x ≤ 0.333). Our results indicate that the broad temperature range (above 275 K extending to above 220 K) of NZ-TCR is obtained by Mn doping at the Ni site. The short-range magnetic ordering is revealed by both neutron powder diffraction and inverse magnetic susceptibility. Further, we find a strong correlation between the anomalous resistivity change of Mn3+xNi1-xN from the metal-like to the NZ-TCR behavior and the lack of the long-range magnetic ordering. The possible mechanism of NZ-TCR behavior is discussed using the spin-disorder scattering model.

  9. Ferri-magnetic order in Mn induced spinel Co3-xMnxO4 (0.1≤x≤1.0) ceramic compositions

    NASA Astrophysics Data System (ADS)

    Meena, P. L.; Sreenivas, K.; Singh, M. R.; Kumar, Ashok; Singh, S. P.; Kumar, Ravi

    2016-04-01

    We report structural and magnetic properties of spinel Co3-xMnxO4 (x=0.1-1.0) synthesized by solid state reaction technique. Rietveld refinement analysis of X-ray diffraction (XRD) data, revealed the formation of polycrystalline single phase Co3-xMnxO4 without any significant structural change in cubic crystal symmetry with Mn substitution, except change in lattice parameter. Temperature dependent magnetization data show changes in magnetic ordering temperature, indicating formation of antiferromagnetic (AFM) and ferrimagnetic (FM) phase at low Mn concentration (x≤0.3) and well-defined FM phase at high Mn concentration (x≥0.5). The isothermal magnetization records established an AFM/FM mixed phase for composition ranging 0.10.5.

  10. Tuning the critical magnetic field of the triplon Bose-Einstein condensation in Ba3-xSrxCr2O8

    NASA Astrophysics Data System (ADS)

    Grundmann, Henrik; Sabitova, Alsu; Schilling, Andreas; von Rohr, Fabian; Förster, Tobias; Peters, Laurens

    2016-03-01

    The structure and magnetic interactions of the triplon Bose-Einstein condensation candidates Ba3Cr2O8 and Sr3Cr2O8 have been studied thoroughly in the literature, but little is known about a possible triplon condensation in the corresponding solid solution {{Ba}}3-xSr x Cr2O8. We have prepared various members of this solid solution and systematically examined their magnetic properties in high magnetic fields up to 60 {{T}} and at low temperatures down to 340 {mK}, by means of pulsed field and cantilever magnetometry. From these experiments for x\\in \\{3,2.9,2.8,2.7,2.6,2.5\\}, we find that the critical fields of {{Ba}}3-xSr x Cr2O8 decrease monotonically with decreasing Sr content x. This change is in good agreement with the earlier reported variation of the magnetic interactions in these compounds.

  11. Whole body exposure to 2.4 GHz WIFI signals: effects on cognitive impairment in adult triple transgenic mouse models of Alzheimer's disease (3xTg-AD).

    PubMed

    Banaceur, Sana; Banasr, Sihem; Sakly, Mohsen; Abdelmelek, Hafedh

    2013-03-01

    The present investigation aimed at evaluating the effects of long-term exposure to WIFI type radiofrequency (RF) signals (2.40 GHz), two hours per day during one month at a Specific Absorption Rate (SAR) of 1.60 W/kg. The effects of RF exposure were studied on wildtype mice and triple transgenic mice (3xTg-AD) destined to develop Alzheimer's-like cognitive impairment. Mice were divided into four groups: two sham groups (WT, TG; n=7) and two exposed groups (WTS, TGS; n=7). The cognitive interference task used in this study was designed from an analogous human cognitive interference task including the Flex field activity system test, the two-compartment box test and the Barnes maze test. Our data demonstrate for the first time that RF improves cognitive behavior of 3xTg-AD mice. We conclude that RF exposure may represent an effective memory-enhancing approach in Alzheimer's disease. PMID:23195115

  12. Efficiency enhancement of the MAPbI3-xClx-based perovskite solar cell by a two-step annealing procedure

    NASA Astrophysics Data System (ADS)

    Huang, Jin; Wang, Minqiang; Ding, Lei; Deng, Jianping; Yao, Xi

    2016-02-01

    The development of a novel two-step annealing method has contributed to the significantly improved performance of the MAPbI3-xClx based perovskite solar cell (PSC). By utilizing a two-step annealing method, we obtained a high power conversion efficiency (PCE) of 12.72% with a current density (J sc) of 18.35 mA cm-2, an open circuit voltage (V oc) of 0.90 V and a fill factor (FF) of 0.71. Noticeably, the two-step annealed device shows no hysteresis and exhibits a PCE which is approximately 1.2 times greater than that of the one-step annealed device. The improvement in device efficiency is ascribed to the reduced series resistance, increased parallel resistance, better surface coverage, lower leakage current and stronger crystallization of the MAPbI3-xClx perovskite layer.

  13. Deficits in odor-guided behaviors in the transgenic 3xTg-AD female mouse model of Alzheimer׳s disease.

    PubMed

    Coronas-Sámano, G; Portillo, W; Beltrán Campos, V; Medina-Aguirre, G I; Paredes, R G; Diaz-Cintra, S

    2014-07-14

    Alzheimer׳s disease (AD) is characterized by a number of alterations including those in cognition and olfaction. An early symptom of AD is decreased olfactory ability, which may affect odor-guided behaviors. To test this possibility we evaluated alterations in sexual incentive motivation, sexual olfactory preference, sexual olfactory discrimination, nursing-relevant olfactory preference and olfactory discrimination in female mice. We tested 3xTg-AD (a triple transgenic model, which is a "knock in" of PS1M146V, APPSwe, and tauP300L) and wild type (WT) female mice when receptive (estrous) and non-receptive (anestrous). Subjects were divided into three groups of different ages: (1) 4-5 months, (2) 10-11 months, and (3) 16-18 months. In the sexual incentive motivation task, the receptive 3xTg-AD females showed no preference for a sexually active male at any age studied, in contrast to the WT females. In the sexual olfactory preference test, the receptive WT females were able to identify sexually active male secretions at all ages, but the oldest (16-18 months old) 3xTg-AD females could not. In addition, the oldest 3xTg-AD females showed no preference for nursing-relevant odors in dam secretions and were unable to discriminate between cinnamon and strawberry odors, indicating olfactory alterations. Thus, the present study suggests that the olfactory deficits in this mouse model are associated with changes in sexual incentive motivation and discrimination of food-related odors. PMID:24842003

  14. Insight into the substitution reactions of silylenoid H2SiLiF with GeH3X (X = F, Cl, Br): a theoretical study.

    PubMed

    Yan, Bingfei; Li, Wenzuo; Xiao, Cuiping; Li, Qingzhong; Cheng, Jianbo

    2015-04-01

    The unique substitution reactions of the three-membered-ring silylenoid H2SiLiF with GeH3X (X = F, Cl, Br) were investigated using ab initio and density functional theory calculations. All stationary points on the potential energy surfaces were optimized at the B3LYP/6-311 + G (d, p) level of theory and the QCISD method was then used to calculate the single-point energies. Theoretical calculations predicted that the substitution reactions of H2SiLiF with GeH3X proceed via two reaction paths (I and II), while forming the same product H2FSi-GeH3. In either pathway, there is one precursor complex (Q), one transition state (TS), and one intermediate (IM) connecting the reactants and products. The substitution reaction barriers of H2SiLiF with GeH3X for path I (48.49, 42.71, and 38.71 kJ mol(-1)) decreased with the increase for the same-family element X from up to down in the periodic table, whereas the substitution barriers for path II (6.51, 22.04, and 23.62 kJ mol(-1)) increased with the increase in atomic number of X (X = F, Cl, Br). Path II was more favorable than path I. All the substitution reactions of H2SiLiF with GeH3X were exothermic. The elucidation of the unique mechanism of these substitution reactions suggests a new reaction mode of silicon-germanium bond formation. PMID:25754138

  15. Synthesis and characterization of (1-x)Bi(Mg2/3Sb1/3)O3-xPbTiO3 piezoceramics

    NASA Astrophysics Data System (ADS)

    Upadhyay, Ashutosh; Dwivedi, Saurabh; Pandey, Rishikesh; Singh, Akhilesh Kumar

    2016-05-01

    We present here the comprehensive x-ray diffraction and polarization-electric field hysteresis studies on (1-x)Bi(Mg2/3Sb1/3)O3-xPbTiO3 piezoceramics with x = 0.52, 0.56 and 0.60. The powder x-ray diffraction data reveals the presence of tetragonal phase for all the compositions. The saturation of hysteresis loop is observed for x ≤ 0.56.

  16. Two-Inch-Sized Perovskite CH3 NH3 PbX3 (X = Cl, Br, I) Crystals: Growth and Characterization.

    PubMed

    Liu, Yucheng; Yang, Zhou; Cui, Dong; Ren, Xiaodong; Sun, Jiankun; Liu, Xiaojing; Zhang, Jingru; Wei, Qingbo; Fan, Haibo; Yu, Fengyang; Zhang, Xu; Zhao, Changming; Liu, Shengzhong Frank

    2015-09-16

    Two-inch-sized perovskite crystals, CH3 NH3 PbX3 (X=I, Br, Cl), with high crystalline quality are prepared by a solution-grown strategy. The availability of large perovskite crystals is expected to transform its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, LEDs, etc., just as crystalline silicon has done in revolutionizing the modern electronics and photovoltaic industries. PMID:26247401

  17. Magnetic properties of Fe73.5Cu1Nb3-xUxSi13.5B9 (x = 1, 2, 3) nanocrystalline alloys

    NASA Astrophysics Data System (ADS)

    Kollár, P.; Füzer, J.; Matta, P.; Švec, T.; Konč, M.

    1996-05-01

    The influence of uranium content and annealing on the magnetic properties and Hall effect of Fe73.5Cu1Nb3-xUxSi13.5B9 (x = 1, 2, 3) nanocrystalline alloys prepared by melt spinning were investigated. Measurements of magnetic properties of surface layers confirmed higher concentration of uranium in the air-side surface layers than in the wheel-side layers.

  18. Room-temperature and gram-scale synthesis of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals with 50-85% photoluminescence quantum yields.

    PubMed

    Wei, Song; Yang, Yanchun; Kang, Xiaojiao; Wang, Lan; Huang, Lijian; Pan, Daocheng

    2016-05-26

    All inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (PNCs) with 50-85% photoluminescence quantum yields and tunable emission in the range of 440-682 nm have been successfully synthesized at room temperature in open air. This facile strategy enables us to prepare gram-scale CsPbBr3 NCs with a PLQY approaching 80%. PMID:27180872

  19. Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

    NASA Technical Reports Server (NTRS)

    Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

    2014-01-01

    NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat

  20. Discovery of carbon-vacancy ordering in Nb4AlC3-x under the guidance of first-principles calculations

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Hu, Tao; Wang, Xiaohui; Li, Zhaojin; Hu, Minmin; Wu, Erdong; Zhou, Yanchun

    2015-09-01

    The conventional wisdom to tailor the properties of binary transition metal carbides by order-disorder phase transformation has been inapplicable for the machinable ternary carbides (MTCs) due to the absence of ordered phase in bulk sample. Here, the presence of an ordered phase with structural carbon vacancies in Nb4AlC3-x (x ≈ 0.3) ternary carbide is predicted by first-principles calculations, and experimentally identified for the first time by transmission electron microscopy and micro-Raman spectroscopy. Consistent with the first-principles prediction, the ordered phase, o-Nb4AlC3, crystalizes in P63/mcm with a = 5.423 Å, c = 24.146 Å. Coexistence of ordered (o-Nb4AlC3) and disordered (Nb4AlC3-x) phase brings about abundant domains with irregular shape in the bulk sample. Both heating and electron irradiation can induce the transformation from o-Nb4AlC3 to Nb4AlC3-x. Our findings may offer substantial insights into the roles of carbon vacancies in the structure stability and order-disorder phase transformation in MTCs.

  1. β-Secretase 1’s Targeting Reduces Hyperphosphorilated Tau, Implying Autophagy Actors in 3xTg-AD Mice

    PubMed Central

    Piedrahita, Diego; Castro-Alvarez, John Fredy; Boudreau, Ryan L.; Villegas-Lanau, Andres; Kosik, Kenneth S.; Gallego-Gomez, Juan Carlos; Cardona-Gómez, Gloria Patricia

    2016-01-01

    β-site APP cleaving enzyme 1 (BACE1) initiates APP cleavage, which has been reported to be an inducer of tau pathology by altering proteasome functions in Alzheimer’s disease (AD). However, the exact relationship between BACE1 and PHF (Paired Helical Filaments) formation is not clear. In this study, we confirm that BACE1 and Hsc70 are upregulated in the brains of AD patients, and we demonstrate that both proteins show enhanced expression in lipid rafts from AD-affected triple transgenic mouse brains. BACE1 targeting increased Hsc70 levels in the membrane and cytoplasm fractions and downregulated Hsp90 and CHIP in the nucleus in the hippocampi of 3xTg-AD mice. However, these observations occurred in a proteasome-independent manner in vitro. The BACE1miR-induced reduction of soluble hyperphosphorylated tau was associated with a decrease in MAPK activity. However, the BACE1 RNAi-mediated reduction of hyperphosphorylated tau was only blocked by 3-MA (3-methyladenine) in vitro, and it resulted in the increase of Hsc70 and LAMP2 in lipid rafts from hippocampi of 3xTg-AD mice, and upregulation of survival and homeostasis signaling. In summary, our findings suggest that BACE1 silencing neuroprotects reducing soluble hyperphosphorylated tau, modulating certain autophagy-related proteins in aged 3xTg-AD mice. PMID:26778963

  2. Computational study of the adsorption of methanol, formic acid, and formaldehyde on the β-SiC(100)-3x2 surface

    NASA Astrophysics Data System (ADS)

    Adhikari, Lekh; Casey, Sean

    2009-11-01

    The absorption of methanol, formic acid, and formaldehyde on the Si-rich β-SiC(100)-(3x2) surface has been studied using density functional theory (DFT) computational methods and small clusters to model the surface reactivity. A single cluster dimer model is used to calculate energies after the interaction of adsorbates on the surface. The dissociative adsorption of methanol on the SiC(100)-3x2 surface is predicted to take place facilely, giving rise to Si-OCH3 and Si-H surface species and followed a path similar to that predicted for Si(100)-2x1 surface. The reaction is highly exothermic and predicted to occur with essentially no barrier. Formaldehyde is also predicted to adsorb with essentially no barrier on the SiC(100)-3x2 surface with formation of a 4-member ring on the surface. This adsorption is also exothermic and similar to the corresponding Si(100)-2x1 surface. This result shows that the carbonyl group can undergo cycloaddition onto the SiC(100) surface. Formic acid is also predicted to undergo dissociative chemisorption on the SiC(100) surface with the formation of Si-OCOH and Si-H surface species. This process is also highly exothermic (-283.1 kJ/mol) and essentially barrierless.

  3. From Water Oxidation to Reduction: Transformation from Ni(x)Co(3-x)O4 Nanowires to NiCo/NiCoO(x) Heterostructures.

    PubMed

    Yan, Xiaodong; Li, KeXue; Lyu, Lu; Song, Fang; He, Jun; Niu, Dongmei; Liu, Lei; Hu, Xile; Chen, Xiaobo

    2016-02-10

    A homologous Ni-Co based nanowire catalyst pair, composed of Ni(x)Co(3-x)O4 nanowires and NiCo/NiCoO(x) nanohybrid, is developed for efficient overall water splitting. Ni(x)Co(3-x)O4 nanowires are found as a highly active oxygen evolution reaction (OER) catalyst, and they are converted into a highly active hydrogen evolution reaction (HER) catalyst through hydrogenation treatment as NiCo/NiCoO(x) heteronanostructures. An OER current density of 10 mA cm(-2) is obtained with the Ni(x)Co(3-x)O4 nanowires under an overpotential of 337 mV in 1.0 M KOH, and an HER current density of 10 mA cm(-2) is obtained with the NiCo/NiCoO(x) heteronanostructures at an overpotential of 155 mV. When integrated in an electrolyzer, these catalysts demonstrate a stable performance in water splitting. PMID:26784862

  4. Exenatide promotes cognitive enhancement and positive brain metabolic changes in PS1-KI mice but has no effects in 3xTg-AD animals

    PubMed Central

    Bomba, M; Ciavardelli, D; Silvestri, E; Canzoniero, L MT; Lattanzio, R; Chiappini, P; Piantelli, M; Di Ilio, C; Consoli, A; Sensi, S L

    2013-01-01

    Recent studies have shown that type 2 diabetes mellitus (T2DM) is a risk factor for cognitive dysfunction or dementia. Insulin resistance is often associated with T2DM and can induce defective insulin signaling in the central nervous system as well as increase the risk of cognitive impairment in the elderly. Glucagone like peptide-1 (GLP-1) is an incretin hormone and, like GLP-1 analogs, stimulates insulin secretion and has been employed in the treatment of T2DM. GLP-1 and GLP-1 analogs also enhance synaptic plasticity and counteract cognitive deficits in mouse models of neuronal dysfunction and/or degeneration. In this study, we investigated the potential neuroprotective effects of long-term treatment with exenatide, a GLP-1 analog, in two animal models of neuronal dysfunction: the PS1-KI and 3xTg-AD mice. We found that exenatide promoted beneficial effects on short- and long-term memory performances in PS1-KI but not in 3xTg-AD animals. In PS1-KI mice, the drug increased brain lactate dehydrogenase activity leading to a net increase in lactate levels, while no effects were observed on mitochondrial respiration. On the contrary, exenatide had no effects on brain metabolism of 3xTg-AD mice. In summary, our data indicate that exenatide improves cognition in PS1-KI mice, an effect likely driven by increasing the brain anaerobic glycolysis rate. PMID:23640454

  5. Optical properties of normal spinel MxCo3-xO4 (M=Cr and Cu): Coexistence of charge-transfer and crystal-field transitions

    NASA Astrophysics Data System (ADS)

    Kim, Kwang Joo; Park, Young Ran; Hyun, Dong Hoon; Lee, Sung Ho

    2004-08-01

    Optical properties of normal spinel MxCo3-xO4(M=CrandCu) films grown by sol-gel method have been investigated by the spectroscopic ellipsometry (SE) in the 1.5-4eV region. For x <1.0, the cubic lattice constant of CrxCo3-xO4 is found to increase linearly with x while that of CuxCo3-xO4 decreases slightly. By comparing the optical constants of the ternary oxides measured by SE with those of Co3O4, Mott-Hubbard, charge-transfer (CT) and crystal-field (CF) transitions are found to coexist in the same energy region. The changes in the optical absorption spectrum by Cr and Cu alloying into Co3O4 are explained in terms of the changes in the electronic structure of Co3O4 through the substitution of the octahedral Co3+ and the tetrahedral Co2+ sites of the spinel structure by Cr3+ and Cu2+ ions, respectively. The CT transitions are explained in terms of d states of the Co3+ and Co2+ ions and p states of O2- ion. The CF transitions are interpreted as originating from the CF multiplets of the octahedral Co3+ and Cr3+ ions.

  6. Flexible Lifestyles for Youth (FL3X) behavioural intervention for at-risk adolescents with Type 1 diabetes: a randomized pilot and feasibility trial

    PubMed Central

    Mayer-Davis, E. J.; Seid, M.; Crandell, J.; Dolan, L.; Lagarde, W. H.; Letourneau, L.; Maahs, D. M.; Marcovina, S.; Nachreiner, J.; Standiford, D.; Thomas, J.; Wysocki, T.

    2014-01-01

    Aim To determine the potential effect sizes for the Flexible Lifestyle for Youth (FL3X) behavioural intervention to improve glycaemic control (HbA1c) and quality of life for at-risk adolescents with Type 1 diabetes. Methods Participants [n=61; age 12–16 years, HbA1c 64–119 mmol/mol (8–13%)] were randomized to FL3X (minimum three sessions) or usual care. Effect sizes (Cohen’s d), comparing the mean difference between the groups, were calculated. Results Study retention (95%), attendance at intervention sessions (87% attended all three sessions) and acceptability were high (100% of the adolescents and 91% of parents would recommend the programme to others). Overall, 41% of participants in the intervention group and 24% of participants in the control group were ‘responders’ [HbA1c decreased by > 6 mmol/mol (0.5%); d=0.37]. HbA1c levels decreased (d= −0.18), diabetes-specific quality of life increased (d=0.29), but generic quality of life decreased (d= −0.23) in the intervention compared with the control group. Conclusions The FL3X programme merits further study for improving HbA1c and diabetes-specific quality of life in adolescents with Type 1 diabetes. PMID:25424501

  7. Structure of the DBL3X-DBL4ε region of the VAR2CSA placental malaria vaccine candidate: insight into DBL domain interactions.

    PubMed

    Gangnard, Stéphane; Lewit-Bentley, Anita; Dechavanne, Sébastien; Srivastava, Anand; Amirat, Faroudja; Bentley, Graham A; Gamain, Benoît

    2015-01-01

    The human malaria parasite, Plasmodium falciparum, is able to evade spleen-mediated clearing from blood stream by sequestering in peripheral organs. This is due to the adhesive properties conferred by the P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) family exported by the parasite to the surface of infected erythrocytes. Expression of the VAR2CSA variant of PfEMP1 leads to pregnancy-associated malaria, which occurs when infected erythrocytes massively sequester in the placenta by binding to low-sulfated Chondroitin Sulfate A (CSA) present in the intervillous spaces. VAR2CSA is a 350 kDa protein that carries six Duffy-Binding Like (DBL) domains, one Cysteine-rich Inter-Domain Regions (CIDR) and several inter-domain regions. In the present paper, we report for the first time the crystal structure at 2.9 Å of a VAR2CSA double domain, DBL3X-DBL4ε, from the FCR3 strain. DBL3X and DBL4ε share a large contact interface formed by residues that are invariant or highly conserved in VAR2CSA variants, which suggests that these two central DBL domains (DBL3X-DBL4ε) contribute significantly to the structuring of the functional VAR2CSA extracellular region. We have also examined the antigenicity of peptides corresponding to exposed loop regions of the DBL4ε structure. PMID:26450557

  8. Structure of the DBL3X-DBL4ε region of the VAR2CSA placental malaria vaccine candidate: insight into DBL domain interactions

    PubMed Central

    Gangnard, Stéphane; Lewit-Bentley, Anita; Dechavanne, Sébastien; Srivastava, Anand; Amirat, Faroudja; Bentley, Graham A.; Gamain, Benoît

    2015-01-01

    The human malaria parasite, Plasmodium falciparum, is able to evade spleen-mediated clearing from blood stream by sequestering in peripheral organs. This is due to the adhesive properties conferred by the P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) family exported by the parasite to the surface of infected erythrocytes. Expression of the VAR2CSA variant of PfEMP1 leads to pregnancy-associated malaria, which occurs when infected erythrocytes massively sequester in the placenta by binding to low-sulfated Chondroitin Sulfate A (CSA) present in the intervillous spaces. VAR2CSA is a 350 kDa protein that carries six Duffy-Binding Like (DBL) domains, one Cysteine-rich Inter-Domain Regions (CIDR) and several inter-domain regions. In the present paper, we report for the first time the crystal structure at 2.9 Å of a VAR2CSA double domain, DBL3X-DBL4ε, from the FCR3 strain. DBL3X and DBL4ε share a large contact interface formed by residues that are invariant or highly conserved in VAR2CSA variants, which suggests that these two central DBL domains (DBL3X-DBL4ε) contribute significantly to the structuring of the functional VAR2CSA extracellular region. We have also examined the antigenicity of peptides corresponding to exposed loop regions of the DBL4ε structure. PMID:26450557

  9. Nation's tallest VAWT (Vertical Axis Wind Turbine) turning out the watts. [Vertical Axis Wind Turbine

    SciTech Connect

    Miller, S.

    1988-05-01

    This article describes the development of the tallest and most powerful windmill of its kind in the U.S. Known as a Vertical Axis Wind Turbine (VAWT), the machine is meant for testing new concepts in vertical axis turbine design. As part of its overall testing program, the turbine will supply electricity to automated water pumps used in irrigation research at the Research Laboratory in Bushland, Texas. Excess power will go to the Southwestern Public Service Company for the area power system.

  10. Ultimately short ballistic vertical graphene Josephson junctions

    PubMed Central

    Lee, Gil-Ho; Kim, Sol; Jhi, Seung-Hoon; Lee, Hu-Jong

    2015-01-01

    Much efforts have been made for the realization of hybrid Josephson junctions incorporating various materials for the fundamental studies of exotic physical phenomena as well as the applications to superconducting quantum devices. Nonetheless, the efforts have been hindered by the diffusive nature of the conducting channels and interfaces. To overcome the obstacles, we vertically sandwiched a cleaved graphene monoatomic layer as the normal-conducting spacer between superconducting electrodes. The atomically thin single-crystalline graphene layer serves as an ultimately short conducting channel, with highly transparent interfaces with superconductors. In particular, we show the strong Josephson coupling reaching the theoretical limit, the convex-shaped temperature dependence of the Josephson critical current and the exceptionally skewed phase dependence of the Josephson current; all demonstrate the bona fide short and ballistic Josephson nature. This vertical stacking scheme for extremely thin transparent spacers would open a new pathway for exploring the exotic coherence phenomena occurring on an atomic scale. PMID:25635386

  11. Lunar vertical-shaft mining system

    NASA Technical Reports Server (NTRS)

    Introne, Steven D. (Editor); Krause, Roy; Williams, Erik; Baskette, Keith; Martich, Frederick; Weaver, Brad; Meve, Jeff; Alexander, Kyle; Dailey, Ron; White, Matt

    1994-01-01

    This report proposes a method that will allow lunar vertical-shaft mining. Lunar mining allows the exploitation of mineral resources imbedded within the surface. The proposed lunar vertical-shaft mining system is comprised of five subsystems: structure, materials handling, drilling, mining, and planning. The structure provides support for the exploration and mining equipment in the lunar environment. The materials handling subsystem moves mined material outside the structure and mining and drilling equipment inside the structure. The drilling process bores into the surface for the purpose of collecting soil samples, inserting transducer probes, or locating ore deposits. Once the ore deposits are discovered and pinpointed, mining operations bring the ore to the surface. The final subsystem is planning, which involves the construction of the mining structure.

  12. Laser drilling of vertical vias in silicon

    SciTech Connect

    Miller, W.D.; Gassman, R.A.; Keicher, D.M.

    1993-08-01

    Any advance beyond the density of standard 2D Multichip Modules (MCM) will require a vertical interconnect technology that can produce reliable area array interconnection with small feature sizes. Laser drilled vertical vias have been controllably produced in standard silicon (Si) wafers down to 0.035mm (0.0014 inches) in diameter. Several laser systems and their system parameters have been explored to determine the optimum parametric set for repeatable vias in Si. The vias produced have exhibited clean smooth interior surfaces with an aspect ratio of up to 20:1 with little or no taper. All laser systems used, their system parameters, design modifications, theory of operation, and drilling results are discussed.

  13. Instability of Rotating Vertical Viscous Jets

    NASA Astrophysics Data System (ADS)

    Ribe, Neil; Badr, Sarah; Morris, Stephen

    2015-11-01

    We have studied experimentally and theoretically the instability of a jet of viscous fluid (corn syrup) ejected downward from a nozzle that rotates about a vertical axis with an angular velocity Ω. For small values of Ω, the jet behaves in a way similar to that of normal (Ω = 0) liquid rope coiling. Above a critical value of Ω, however, a bifurcation occurs to a whirling spiral state in which the jet is strongly deflected from the vertical almost immediately after its exit from the nozzle. Experiments conducted for Ω increasing and decreasing show that the transition between the undeflected and spiral states is hysteretic. We will report results of a linear stability analysis of the undeflected state as a function of the dimensionless parameters that characterize the system, and will compare the results with our experimental measurements.

  14. Ozone vertical profile changes over South Pole

    NASA Technical Reports Server (NTRS)

    Oltmans, S. J.; Hofmann, D. J.; Komhyr, W. D.; Lathrop, J. A.

    1994-01-01

    Important changes in the ozone vertical profile over South Pole, Antarctica have occurred both during the recent period of measurements, 1986-1991, and since an earlier set of soundings was carried out from 1967-1971. From the onset of the 'ozone hole' over Antarctica in the early 1980s, there has been a tendency for years with lower spring ozone amounts to alternate with years with somewhat higher (although still depleted) ozone amounts. Beginning in 1989 there have been three consecutive years of strong depletion although the timing of the breakdown of the vortex has varied from year to year. Comparison of the vertical profiles between the two periods of study reveals the dramatic decreases in the ozone amounts in the stratosphere between 15-21 km during the spring. In addition, it appears that summer values are also now much lower in this altitude region.

  15. Jamming of Cylindrical Grains in Vertical Channels

    NASA Astrophysics Data System (ADS)

    Baxter, G. William; Spier, Gregory; Barr, Nicholas; Steel, Fiona

    2012-02-01

    We study jamming of low aspect-ratio cylindrical Delrin grains in a vertical channel. These cylindrical grains resemble antacid tablets, poker chips, or coins since their height is less than their diameter. Grains are allowed to fall through a vertical channel with a square cross section where the channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. Within this channel, grains are sometimes observed to form jams, stable structures supported by the channel walls with no support beneath them. The probability of jam occurrence and the strength or robustness of a jam is effected by the grain dimensions and channel size. We will present experimental measurements of the jamming probability and jam strength in this system and discuss the relationship of these results to other experiments and theories.

  16. Experimental Studies in Helicopter Vertical Climb Performance

    NASA Technical Reports Server (NTRS)

    McKillip, Robert M., Jr.

    1996-01-01

    Data and analysis from an experimental program to measure vertical climb performance on an eight-foot model rotor are presented. The rotor testing was performed using a unique moving-model facility capable of accurately simulating the flow conditions during axial flight, and was conducted from July 9, 1992 to July 16, 1992 at the Dynamic Model Track, or 'Long Track,' just prior to its demolition in August of 1992. Data collected during this brief test program included force and moment time histories from a sting-mounted strain gauge balance, support carriage velocity, and rotor rpm pulses. In addition, limited video footage (of marginal use) was recorded from smoke flow studies for both simulated vertical climb and descent trajectories. Analytical comparisons with these data include a series of progressively more detailed calculations ranging from simple momentum theory, a prescribed wake method, and a free-wake prediction.

  17. Extreme wave runup on a vertical cliff

    NASA Astrophysics Data System (ADS)

    Carbone, Francesco; Dutykh, Denys; Dudley, John M.; Dias, FréDéRic

    2013-06-01

    Wave impact and runup onto vertical obstacles are among the most important phenomena which must be taken into account in the design of coastal structures. From linear wave theory, we know that the wave amplitude on a vertical wall is twice the incident wave amplitude with weakly nonlinear theories bringing small corrections to this result. In this present study, however, we show that certain simple wave groups may produce much higher runups than previously predicted, with particular incident wave frequencies resulting in runup heights exceeding the initial wave amplitude by a factor of 5, suggesting that the notion of the design wave used in coastal structure design may need to be revisited. The results presented in this study can be considered as a note of caution for practitioners, on one side, and as a challenging novel material for theoreticians who work in the field of extreme wave-coastal structure interaction.

  18. The much exaggerated death of positivism

    NASA Astrophysics Data System (ADS)

    Kincheloe, Joe L.; Tobin, Kenneth

    2009-09-01

    Approaches to research in the social sciences often embrace schema that are consistent with positivism, even though it is widely held that positivism is discredited and essentially dead. Accordingly, many of the methods used in present day scholarship are supported by the tenets of positivism, and are sources of hegemony. We exhort researchers to employ reflexive methods to identify the epistemologies, ontologies and axiologies that are salient in their scholarship and, when necessary, transform practices such that forms of oppression associated with crypto-positivism are identified and extinguished.

  19. The Much Exaggerated Death of Positivism

    ERIC Educational Resources Information Center

    Kincheloe, Joe; Tobin, Kenneth

    2009-01-01

    Approaches to research in the social sciences often embrace schema that are consistent with positivism, even though it is widely held that positivism is discredited and essentially dead. Accordingly, many of the methods used in present day scholarship are supported by the tenets of positivism, and are sources of hegemony. We exhort researchers to…

  20. Expression transmission using exaggerated animation for Elfoid.

    PubMed

    Hori, Maiya; Tsuruda, Yu; Yoshimura, Hiroki; Iwai, Yoshio

    2015-01-01

    We propose an expression transmission system using a cellular-phone-type teleoperated robot called Elfoid. Elfoid has a soft exterior that provides the look and feel of human skin, and is designed to transmit the speaker's presence to their communication partner using a camera and microphone. To transmit the speaker's presence, Elfoid sends not only the voice of the speaker but also the facial expression captured by the camera. In this research, facial expressions are recognized using a machine learning technique. Elfoid cannot, however, display facial expressions because of its compactness and a lack of sufficiently small actuator motors. To overcome this problem, facial expressions are displayed using Elfoid's head-mounted mobile projector. In an experiment, we built a prototype system and experimentally evaluated it's subjective usability. PMID:26347686