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Sample records for gamma ray-induced reciprocal

  1. The identification of gamma ray induced EAS

    NASA Technical Reports Server (NTRS)

    Blake, P. R.; Nash, W. F.

    1985-01-01

    Some of the penetrating particles in gamma-induced EAS from Cygnus X-3 observed by a single layer of flash-bulbs under 880 g cm/2 concrete, may be punched through photons rather than muons. An analysis of the shielded flash-tube response detected from EAS is presented. The penetration of the electro-magnetic component through 20 cm of Pb is observed at core distances approx. 10 m.

  2. Southern analysis of genomic alterations in gamma-ray-induced aprt- hamster cell mutants

    SciTech Connect

    Grosovsky, A.J.; Drobetsky, E.A.; deJong, P.J.; Glickman, B.W.

    1986-06-01

    The role of genomic alterations in mutagenesis induced by ionizing radiation has been the subject of considerable speculation. By Southern blotting analysis we show here that 9 of 55 (approximately 1/6) gamma-ray-induced mutants at the adenine phosphoribosyl transferase (aprt) locus of Chinese hamster ovary (CHO) cells have a detectable genomic rearrangement. These fall into two classes: intragenic deletions and chromosomal rearrangements. In contrast, no major genomic alterations were detected among 67 spontaneous mutants, although two restriction site loss events were observed. Three gamma-ray-induced mutants were found to be intragenic deletions; all may have identical break-points. The remaining six gamma-ray-induced mutants demonstrating a genomic alteration appear to be the result of chromosomal rearrangements, possibly translocation or inversion events. None of the remaining gamma-ray-induced mutants showed any observable alteration in blotting pattern indicating a substantial role for point mutation in gamma-ray-induced mutagenesis at the aprt locus.

  3. Measurement of 60Co-gamma ray-induced DNA damage by capillary electrophoresis.

    PubMed

    Nackerdien, Z; Atha, D

    1996-08-01

    Capillary electrophoresis was employed in this study to monitor 60Co-gamma ray-induced damage to a 1 kb DNA ladder which consists of restriction fragments ranging from 75 to 12,000 bp. DNA samples (0.5 mg/ml) were exposed to 0-60 Gy of gamma-radiation in the presence and absence of 110 mumol/l ethidium bromide (EB). The analysis showed peak broadening without significant changes in the size distribution of irradiated fragments. Radiation-induced conformational changes may account for this peak broadening. EB addition caused small increases in the retention times of DNA fragments without affecting the overall DNA damage. This indicates that the presence of intercalated EB during radiation will not stabilize the DNA against 60Co-gamma ray-induced damage. PMID:8876442

  4. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOEpatents

    Meikrantz, D.H.; Mincher, B.J.; Arbon, R.E.

    1998-08-25

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilograms. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste. 5 figs.

  5. Gamma-ray-induced degradation of lignocellulosic materials

    SciTech Connect

    Han, Y.W.; Timpa, J.; Ciegler, A.; Courtney, J.; Curry, W.F.; Lambremont, E.N.

    1981-11-01

    Lignocellulosic plant materials were treated with various swelling agents and exposed to gamma radiation from 60Co or 137Cs. At dosages of 50 Mrad or above, lignocellulosic materials were extensively degraded and solubilized in water. Addition of water, NaOH, or H2SO4 to the substrate increased the degree of solubilization. Complete solubilization was achieved for samples of sugarcane bagasse, newspaper, cotton linters, cotton cloth, sawdust, and alpha-cellulose powder. About 35% total sugar and 5% reducing sugar per dry weight of sugarcane bagasse could be obtained by this method. Most of the soluble carbohydrates seemed to be disaccharides or larger molecules and glucose degradation products. Solubilization of cellulose was dosage dependent and although the rate of solubilization was increased by adding alkali, released sugar was further decomposed by the alkali and by high dosages of radiation. (Refs. 14).

  6. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOEpatents

    Meikrantz, David H.; Mincher, Bruce J.; Arbon, Rodney E.

    1998-01-01

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilogray. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste.

  7. Lymphocytes from wasted mice express enhanced spontaneous and {gamma}-ray-induced apoptosis

    SciTech Connect

    Woloschak, G.E. |; Chang-Liu, Chin-Mei; Chung, Jen; Libertin, C.R.

    1993-09-01

    Mice bearing the autosomal recessive mutation wasted (wst/wst) display a disease pattern including faulty repair of DNA damage in lymphocytes after radiation exposure, neurologic abnormalities, and immunodeficiency. Many of the features of this mouse model have suggested a premature or increased spontaneous frequency of apoptosis in thymocytes; past work has shown an inability to establish cultured T cell lines, an abnormally high death rate of stimulated T cells in culture, and an increased sensitivity of T cells to the killing effects of ionizing radiations in wst/wst mice relative to controls. The experiments reported here were designed to examine splenic and thymic lymphocytes from wasted and control mice for signs of early apoptosis. Our results revealed enhanced expression of Rp-8 mRNA (associated with apoptosis) in thymic lymphocytes and reduced expression in splenic lymphocytes of wst/wst mice relative to controls; expression of Rp-2 and Td-30 mRNA (induced during apoptosis) were not detectable in spleen or thymus. Higher spontaneous DNA fragmentation was observed in wasted mice than in controls; however, {gamma}-ray-induced DNA fragmentation peaked at a lower dose and occurred to a greater extent in wasted mice relative to controls. These results provide evidence for high spontaneous and {gamma}-ray-induced apoptosis in T cells of wasted mice as a mechanism underlying the observed lymphocyte and DNA repair abnormalities.

  8. Asymptotic expansions for the reciprocal of the gamma function

    NASA Astrophysics Data System (ADS)

    Withers, Christopher S.; Nadarajah, Saralees

    2014-05-01

    Asymptotic expansions are derived for the reciprocal of the gamma function. We show that the coefficients of the expansion are the same, up to a sign change, as the asymptotic expansions for the gamma function obtained by exponentiating the expansions of its logarithm due to Stirling and de Moivre. Expressions for the coefficients are given in terms of Bell polynomials.

  9. Clonally Expanding Thymocytes Having Lineage Capability in Gamma-Ray-Induced Mouse Atrophic Thymus

    SciTech Connect

    Yamamoto, Takashi; Morita, Shin-ichi; Go, Rieka; Obata, Miki; Katsuragi, Yoshinori; Fujita, Yukari; Maeda, Yoshitaka; Yokoyama, Minesuke; Aoyagi, Yutaka; Ichikawa, Hitoshi; Mishima, Yukio; Kominami, Ryo

    2010-05-01

    Purpose: To characterize, in the setting of gamma-ray-induced atrophic thymus, probable prelymphoma cells showing clonal growth and changes in signaling, including DNA damage checkpoint. Methods and Materials: A total of 111 and 45 mouse atrophic thymuses at 40 and 80 days, respectively, after gamma-irradiation were analyzed with polymerase chain reaction for D-J rearrangements at the TCRbeta locus, flow cytometry for cell cycle, and Western blotting for the activation of DNA damage checkpoints. Results: Limited D-J rearrangement patterns distinct from normal thymus were detected at high frequencies (43 of 111 for 40-day thymus and 21 of 45 for 80-day thymus). Those clonally expanded thymocytes mostly consisted of CD4{sup +}CD8{sup +} double-positive cells, indicating the retention of lineage capability. They exhibited pausing at a late G1 phase of cell cycle progression but did not show the activation of DNA damage checkpoints such as gammaH2AX, Chk1/2, or p53. Of interest is that 17 of the 52 thymuses showing normal D-J rearrangement patterns at 40 days after irradiation showed allelic loss at the Bcl11b tumor suppressor locus, also indicating clonal expansion. Conclusion: The thymocytes of clonal growth detected resemble human chronic myeloid leukemia in possessing self-renewal and lineage capability, and therefore they can be a candidate of the lymphoma-initiating cells.

  10. Microscopic observations of X-ray and gamma-ray induced decomposition of ammonium perchlorate crystals

    NASA Technical Reports Server (NTRS)

    Herley, P. J.; Levy, P. W.

    1972-01-01

    The X-ray and gamma-ray induced decomposition of ammonium perchlorate was studied by optical, transmission, and scanning electron microscopy. This material is a commonly used oxidizer in solid propellents which could be employed in deep-space probes, and where they will be subjected to a variety of radiations for as long as ten years. In some respects the radiation-induced damage closely resembles the effects produced by thermal decomposition, but in other respects the results differ markedly. Similar radiation and thermal effects include the following: (1) irregular or ill-defined circular etch pits are formed in both cases; (2) approximately the same size pits are produced; (3) the pit density is similar; (4) the c face is considerably more reactive than the m face; and (5) most importantly, many of the etch pits are aligned in crystallographic directions which are the same for thermal or radiolytic decomposition. Thus, dislocations play an important role in the radiolytic decomposition process.

  11. Evaluation of the cosmic-ray induced background in coded aperture high energy gamma-ray telescopes

    NASA Technical Reports Server (NTRS)

    Owens, Alan; Barbier, Loius M.; Frye, Glenn M.; Jenkins, Thomas L.

    1991-01-01

    While the application of coded-aperture techniques to high-energy gamma-ray astronomy offers potential arc-second angular resolution, concerns were raised about the level of secondary radiation produced in a thick high-z mask. A series of Monte-Carlo calculations are conducted to evaluate and quantify the cosmic-ray induced neutral particle background produced in a coded-aperture mask. It is shown that this component may be neglected, being at least a factor of 50 lower in intensity than the cosmic diffuse gamma-rays.

  12. Antimutagenic properties of selected radioprotective drug mixtures with regard to X-ray-induced reciprocal translocations in mouse spermatogonia.

    PubMed

    Benova, D K

    1986-01-01

    The radioprotective drugs AET, serotonin, and ATP were tested for antimutagenic activity against induction by 4.0 Gy X-rays of reciprocal translocations in mouse spermatogonia. Single drugs administered in doses of 8, 24 and 360 mg/kg b.wt., respectively, had no effect on translocation yields recorded in diakinesis-metaphase I spermatocytes. Two-drug mixtures afforded insignificant protection. Three-drug mixtures, however, were found to reduce radiation damage considerably, and the extent of protection was dependent in part on the amount of ATP. The best effect was obtained with formulations of serotonin-AET-ATP at the following doses, respectively: 8 + 24 + 360 mg/kg, 16 + 24 + 336 mg/kg, and 16 + 32 + 264 mg/kg. Less effective were the serotonin-AET-ATP formulations: 16 + 32 + 120 mg/kg, and 8 + 24 + 480 mg/kg. Treatment with drugs omitting radiation exposure was observed to raise, though insignificantly, the level of spontaneous translocation frequency. PMID:3941667

  13. Time-Dependence of VHE Gamma-Ray induced Pair Cascades in Radio Galaxies

    NASA Astrophysics Data System (ADS)

    Roustazadeh, Parisa; Boettcher, Markus; Thrush, Samantha

    2016-04-01

    Recently, several intermediate frequency peaked BL Lac objects (IBL), low frequency peaked BL Lac objects (LBL) and flat spectrum radio quasars (FSRQ) were detected as very high energy ( VHE, E > 100 ˜ GeV) γ-ray sources. These discoveries suggest that γγ absorption and pair cascades might occur in those objects, leading to excess γ-ray emission which may be observable also in off-axis viewing directions (i.e., like in radio galaxies) when deflected by moderately strong magnetic fields. Here, we investigate the time dependence of the Compton γ-ray emission from such VHE γ-ray induced pair cascades. We show that the cascade emission is variable on time scales much shorter than the light-crossing time across the characteristic extent of the external radiation field, depending on the viewing angle and γ-ray energy. Thus, we find that the cascade Compton interpretation for the Fermi γ-ray emission from radio galaxies is still consistent with the day-scale variability detected in the Fermi γ-ray emission of radio galaxies, such as NGC 1275, which we use as a specific example.

  14. Time Variability of VHE Gamma-Ray Induced Pair Cascades in AGN Environments

    NASA Astrophysics Data System (ADS)

    Roustazadeh, Parisa; Thrush, Samantha Elaine; Boettcher, Markus

    2016-01-01

    In a series of previous papers, we had investigated the three-dimensional development of pair cascades initiated by very-high-energy gamma-rays from the relativistic jets of blazars, especially in the case of low-frequency peaked blazars which are expected to host dense radiation environments. Gamma-gamma absorption and pair production leads to the development of pair cascades which will be deflected and partially isotropised by magnetic fields in the nuclear environment. This has been suggested to make a significant contribution to the Fermi gamma-ray emission of radio galaxies. In this work, we present the study of the time dependence of these cascades, demonstrating that they can be variable on time scales much shorter than the light-crossing time through the characteristic extent of the circumnuclear radiation field. Thus, this interpretation is still consistent with the Fermi gamma-ray emission of radio galaxies such as NGC 1275, even considering the recently observed short-term variability.

  15. Thermal and Gamma-ray induced relaxation in As-S glasses: modeling and experiment

    SciTech Connect

    Lucas, Pierre; King, Ellyn A.; Erdmann, Robert G.; Riley, Brian J.; Sundaram, S. K.; McCloy, John S.

    2011-09-09

    Enthalpy relaxation is measured in a series of As-S glasses irradiated with gamma rays and these samples are compared with a set of identical control samples kept in the dark. It is shown that gamma irradiation lifts the kinetic barrier for relaxation at room temperature and speeds up the enthalpy release. The measured values of thermal relaxation in the dark agree closely with modeling results obtained by fitting differential scanning calorimetry curves with the TNM equations. The measured values of activation energy for enthalpy relaxation are also in close agreement with that predicted by the TNM model therefore lending credence to the fitting results. These measurements permit extraction of the effect of gamma irradiation on the glass structure for a series of As-S glasses with increasing structural coordination, and gamma irradiation is shown to reduce the structural relaxation time. It is also shown that lower coordination glasses exhibit greater radiation sensitivity but also greater thermal relaxation due to their lower Tg. On the other end, over-coordinated glasses show lower relaxation and almost no radiation sensitivity. This behavior is similar to the glass response under sub-bandgap light irradiation.

  16. Cosmic-ray induced gamma-ray emission from the starburst galaxy NGC 253

    SciTech Connect

    Wang, Xilu; Fields, Brian D.

    2014-05-09

    Cosmic rays in galaxies interact with the interstellar medium and give us a direct view of nuclear and particle interactions in the cosmos. For example, cosmic-ray proton interactions with interstellar hydrogen produce gamma rays via PcrPism→π{sup 0}→γγ. For a 'normal' star-forming galaxy like the Milky Way, most cosmic rays escape the Galaxy before such collisions, but in starburst galaxies with dense gas and huge star formation rate, most cosmic rays do suffer these interactions [1,2]. We construct a 'thick-target' model for starburst galaxies, in which cosmic rays are accelerated by supernovae, and escape is neglected. This model gives an upper limit to the gamma-ray emission. Only two free parameters are involved in the model: cosmic-ray proton acceleration energy rate from supernova and the proton injection spectral index. The pionic gamma-radiation is calculated from 10 MeV to 10 TeV for the starburst galaxy NGC 253, and compared to Fermi and HESS data. Our model fits NGC 253 well, suggesting that cosmic rays in this starburst are in the thick target limit, and that this galaxy is a gamma-ray calorimeter.

  17. High energy irradiations simulating cosmic-ray-induced planetary gamma ray production. I - Fe target

    NASA Technical Reports Server (NTRS)

    Metzger, A. E.; Parker, R. H.; Yellin, J.

    1986-01-01

    Two thick Fe targets were bombarded by a series of 6 GeV proton irradiations for the purpose of simulating the cosmic ray bombardment of planetary objects in space. Gamma ray energy spectra were obtained with a germanium solid state detector during the bombardment, and 46 of the gamma ray lines were ascribed to the Fe targets. A comparison between observed and predicted values showed good agreement for Fe lines from neutron inelastic scattering and spallation reactions, and less satisfactory agreement for neutron capture reactions, the latter attributed to the difference in composition between the Fe target and the mean lunar abundance used in the modeling. Through an analysis of the irradiation results together with continuum data obtained in lunar orbit, it was found that 100 hours of measurement with a current instrument should generate a spectrum containing approximately 20 lines due to Fe alone, with a 2-sigma sensitivity for detection of about 0.2 percent.

  18. Comparison of gamma-ray-induced chromosome ring and inversion frequencies

    SciTech Connect

    Muehlmann, M.C.; Bedford, J.S.

    1995-08-01

    A method was used to detect chromosome inversions as apparent or false sister chromatid exchanges (SCEs) in the first mitosis after {gamma} irradiation of human G{sub o} cells. Dose-response relationships for small inversions have not been measured and reported previously, but it has been assumed that these are induced with a frequency equal to that of their easily mesured asymmetrical counterpart, the interstitial deletion. Our experiments confirm this expectation. The results also demonstrate, as others have suggested, that in protocols where SCEs have been reported in the first postirradiation mitosis after incorporation of BrdU in the previous cell cycle, the X- or {gamma}-ray treatment of G{sub o}{sup {minus}} or G{sub 1}-phase cells produces virtually no true SCEs. 23 refs., 3 figs., 2 tabs.

  19. Search for Cosmic-Ray-Induced Gamma-Ray Emission in Galaxy Clusters

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Chaves, R. C. G.; Kuss, M.; Pesce-Rollins, M.; Sgro, C.; Spandre, G.; Tinivella, M.

    2014-01-01

    Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into gamma rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended gamma-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke & Pfrommer. We find an excess at a significance of 2.7 delta, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters).Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R(sub 200), to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the gamma-ray flux from individual clusters in our sample.

  20. Temperature stability of gamma-ray-induced effects in glassy arsenic trisulfide

    SciTech Connect

    Shpotyuk, O.I.

    1987-07-01

    The author studied the effect of low-temperature annealing (up to the softening point) on the energy dependences of the optical absorption coefficient ..cap alpha.. in the region of Urbach's edge (..cap alpha.. < 10/sup 2/ cm/sup -1/) and the microhardness H of glassy arsenic trisulfide irradiated with gamma rays from a CO/sup 60/ source (absorbed dosages of 10/sup 6/-10/sup 7/ Gy). Bulk samples of As/sub 2/S/sub 3/, obtained by direct synthesis in evacuated ampuls consisting of especially pure components, were used.

  1. Repair of gamma-ray-induced DNA base damage in xeroderma pigmentosum cells

    SciTech Connect

    Fornace, A.J. Jr.; Dobson, P.P.; Kinsella, T.J.

    1986-04-01

    The repair of DNA damage produced by /sup 137/Cs gamma irradiation was measured with a preparation from Micrococcus luteus containing DNA damage-specific endonucleases in combination with alkaline elution. The frequency of these endonuclease sensitive sites (ESS) was determined after 54 or 110 Gy of oxic irradiation in normal and xeroderma pigmentosum (XP) fibroblasts from complementation groups A, C, D, and G. Repair was rapid in all cell strains with greater than 50% repair after 1.5 h of repair incubation. At later repair times, 12-17 h, more ESS remained in XP than in normal cells. The frequency of excess ESS in XP cells was approximately 0.04 per 10(9) Da of DNA per Gy which was equivalent to 10% of the initial ESS produced. The removal of ESS was comparable in XP cells with normal radiosensitivity and XP3BR cells which have been reported to be moderately radiosensitive.

  2. Assessment of gamma ray-induced DNA damage in Lasioderma serricorne using the comet assay

    NASA Astrophysics Data System (ADS)

    Kameya, Hiromi; Miyanoshita, Akihiro; Imamura, Taro; Todoriki, Setsuko

    2012-03-01

    We attempted a DNA comet assay under alkaline conditions to verify the irradiation treatment of pests. Lasioderma serricorne (Fabricius) were chosen as test insects and irradiated with gamma rays from a 60Co source at 1 kGy. We conducted the comet assay immediately after irradiation and over time for 7 day. Severe DNA fragmentation in L. serricorne cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. The parameters of the comet image analysis were calculated, and the degree of DNA damage and repair were evaluated. Values for the Ratio (a percentage determined by fluorescence in the damaged area to overall luminance, including intact DNA and the damaged area of a comet image) of individual cells showed that no cells in the irradiated group were included in the Ratio<0.1 category, the lowest grade. This finding was observed consistently throughout the 7-day post-irradiation period. We suggest that the Ratio values of individual cells can be used as an index of irradiation history and conclude that the DNA comet assay under alkaline conditions, combined with comet image analysis, can be used to identify irradiation history.

  3. Gamma-ray-induced damage and recovery behavior in an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Bussjager, Rebecca J.; Hayduk, Michael J.; Johns, Steven T.; Taylor, Linda R.; Taylor, Edward W.

    2002-01-01

    Erbium-doped fiber lasers (EDFLs) may soon find applications in space as high bit rate optical communication systems and photonic analog-to-digital converters (ADCs). The rapid advancement in digital signal processing systems has led to an increased interest in the direct digitization of high- frequency analog signals. The potential high bandwidth, reduced weight, and reduced power requirements makes photonics an attractive technology for wide-band signal conversion as well as for use in space-based platforms. It is anticipated that photonic ADCs will be able to operate at sampling rates and resolutions far greater than current electronic ADCs. The high repetition rates and narrow pulse widths produced by EDFLs allow for high-speed impulse sampling of analog signals thus making it a vital component of a photonic ADC. In this paper we report on the in situ gamma-ray irradiation of an actively mode-locked EDFL operating at 1530 nm. The onset, growth and extent of ionization induced damage under time-resolved operational conditions is presented. The laser consisted of approximately 3 meters of erbium-doped fiber pumped by a laser diode operating at 980 nm. The picosecond pulses produced by the laser were initiated and controlled by a Mach-Zehnder lithium niobate electro-optic modulator. The active mode-locking element allowed for the precise timing control of the laser repetition rate which is critical in high-speed optical networking systems as well as in photonic ADCs.

  4. Antimutagenic properties of WR 2721 and of a radioprotective mixture, ATP-AET-serotonin, with regard to X ray induced reciprocal translocations in mouse spermatogonia

    SciTech Connect

    Benova, D.

    1987-01-01

    Pretreatment by intraperitoneal administration of WR 2721 at 400 mg/kg body weight in mice receiving 4.0 Gy X rays was found to have an appreciable antimutagenic effect with regard to reciprocal translocation induction in spermatogonia. The effectiveness of the product tested proved superior to that of a radioprotective mixture of ATP-AET-serotonin given at optimal dose ratio--360, 24, and 8 mg/kg body weight, respectively. The RF (Reduction Factor) was 2.4 for WR 2721 and 1.8 for the mixture. The effect observed indicated WR 2721 to have potential capabilities for reducing the genetic risk of radiation in male individuals.

  5. Antimutagenic properties of WR 2721 and of a radioprotective mixture, ATP-AET-serotonin, with regard to X ray induced reciprocal translocations in mouse spermatogonia.

    PubMed

    Benova, D

    1987-01-01

    Pretreatment by intraperitoneal administration of WR 2721 at 400 mg/kg body weight in mice receiving 4.0 Gy X rays was found to have an appreciable antimutagenic effect with regard to reciprocal translocation induction in spermatogonia. The effectiveness of the product tested proved superior to that of a radioprotective mixture of ATP-AET-serotonin given at optimal dose ratio--360, 24, and 8 mg/kg body weight, respectively. The RF (Reduction Factor) was 2.4 for WR 2721 and 1.8 for the mixture. The effect observed indicated WR 2721 to have potential capabilities for reducing the genetic risk of radiation in male individuals. PMID:3027009

  6. Repeated doses of gamma rays induce resistance to N-methyl-N'-nitro-N-nitrosoguanidine in Chinese hamster cells

    SciTech Connect

    Osmak, M.

    1988-09-01

    Chinese hamster V79 cells were preirradiated repeatedly with gamma rays and then exposed to ultraviolet (uv) light or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The cell killing and induction of mutation at the hypoxanthine-guanine phosphoribosyltransferase locus were examined following these treatments. Cells preirradiated with multiple fractions of gamma rays exhibit the same sensitivity to uv light as the control cells with respect to cell survival and mutation induction. Following treatment with MNNG, resistance to cell killing was observed along with a decreased frequency of mutations induced. These results indicate that the progeny of cells irradiated with multiple fractions of gamma rays could display subsequent changes in sensitivity to lethal and mutagenic effects of additional treatment with DNA-damaging agents.

  7. Variation in sensitivity to. gamma. -ray-induced chromosomal aberrations during the mitotic cycle of the sea urchin egg

    SciTech Connect

    Ejima, Y.; Nakamura, I.; Shiroya, T.

    1982-11-01

    Sea urchin eggs were irradiated with /sup 137/Cs ..gamma.. rays at various stages of the mitotic cycle, and chromosomal aberrations at the first postirradiation mitosis and embryonic abnormalities at later developmental stages were examined. The radiosensitivity of the eggs to both endpoints varied in parallel with the mitotic stage at the time of irradiation, suggesting a possible relationship between chromosomal damage and embryonic abnormalities.

  8. Gamma ray-induced synthesis of hyaluronic acid/chondroitin sulfate-based hydrogels for biomedical applications

    NASA Astrophysics Data System (ADS)

    Zhao, Linlin; Gwon, Hui-Jeong; Lim, Youn-Mook; Nho, Young-Chang; Kim, So Yeon

    2015-01-01

    Hyaluronic acid (HA)/chondroitin sulfate (CS)/poly(acrylic acid) (PAAc) hydrogel systems were synthesized by gamma-ray irradiation without the use of additional initiators or crosslinking agents to achieve a biocompatible hydrogel system for skin tissue engineering. HA and CS derivatives with polymerizable residues were synthesized. Then, the hydrogels composed of glycosaminoglycans, HA, CS, and a synthetic ionic polymer, PAAc, were prepared using gamma-ray irradiation through simultaneous free radical copolymerization and crosslinking. The physicochemical properties of the HA/CS/PAAc hydrogels having various compositions were investigated to evaluate their feasibility as artificial skin substitutes. The gel fractions of the HA/CS/PAAc hydrogels increased in absorbed doses up to 15 kGy, and they exhibited 91-93% gel fractions under 15 kGy radiation. All of the HA/CS/PAAc hydrogels exhibited relatively high water contents of over 90% and reached an equilibrium swelling state within 24 h. The enzymatic degradation kinetics of the HA/CS/PAAc hydrogels depended on both the concentration of the hyaluronidase solution and the ratio of HA/CS/PAAc. The in vitro drug release profiles of the HA/CS/PAAc hydrogels were significantly influenced by the interaction between the ionic groups in the hydrogels and the ionic drug molecules as well as the swelling of the hydrogels. From the cytotoxicity results of human keratinocyte (HaCaT) cells cultured with extracts of the HA/CS/PAAc hydrogels, all of the HA/CS/PAAc hydrogel samples tested showed relatively high cell viabilities of more than 82%, and did not induce any significant adverse effects on cell viability.

  9. Estrogens decrease {gamma}-ray-induced senescence and maintain cell cycle progression in breast cancer cells independently of p53

    SciTech Connect

    Toillon, Robert-Alain . E-mail: robert.toillon@univ-lille1.fr; Magne, Nicolas; Laios, Ioanna; Castadot, Pierre; Kinnaert, Eric; Van Houtte, Paul; Desmedt, Christine B.Sc.; Leclercq, Guy; Lacroix, Marc

    2007-03-15

    Purpose: Sequential administration of radiotherapy and endocrine therapy is considered to be a standard adjuvant treatment of breast cancer. Recent clinical reports suggest that radiotherapy could be more efficient in association with endocrine therapy. The aim of this study was to evaluate the estrogen effects on irradiated breast cancer cells (IR-cells). Methods and Materials: Using functional genomic analysis, we examined the effects of 17-{beta}-estradiol (E{sub 2}, a natural estrogen) on MCF-7 breast cancer cells. Results: Our results showed that E{sub 2} sustained the growth of IR-cells. Specifically, estrogens prevented cell cycle blockade induced by {gamma}-rays, and no modification of apoptotic rate was detected. In IR-cells we observed the induction of genes involved in premature senescence and cell cycle progression and investigated the effects of E{sub 2} on the p53/p21{sup waf1/cip1}/Rb pathways. We found that E{sub 2} did not affect p53 activation but it decreased cyclin E binding to p21{sup waf1/cip1} and sustained downstream Rb hyperphosphorylation by functional inactivation of p21{sup waf1/cip1}. We suggest that Rb inactivation could decrease senescence and allow cell cycle progression in IR-cells. Conclusion: These results may help to elucidate the molecular mechanism underlying the maintenance of breast cancer cell growth by E{sub 2} after irradiation-induced damage. They also offer clinicians a rational basis for the sequential administration of ionizing radiation and endocrine therapies.

  10. Plutonium gamma-ray measurements for mutual reciprocal inspections of dismantled nuclear weapons

    SciTech Connect

    Koenig, Z.M.; Carlson, J.B.; Clark, D.; Gosnell, T.B.

    1995-07-01

    The O`Leary-Mikhailov agreement of March 1994 stated that the U.S. and the Russian Federation would engage in mutual reciprocal inspections (MRI) of fissile materials removed from dismantled nuclear weapons. It was decided to begin with the plutonium (Pu) removed from dismantled weapons and held in storage containers. Later discussions between U.S. and Russian technical experts led to the conclusion that, to achieve the O`Leary-Mikhailov objectives, Pu MRI would need to determine that the material in the containers has properties consistent with a nuclear-weapon component. Such a property is a {sup 240}Pu/{sup 239}Pu ratio consistent with weapons-grade material. One of the candidate inspection techniques under consideration for Pu MRI is to use a narrow region (630-670 keV) of the plutonium gamma-ray spectrum, taken with a high-purity germanium detector, to determine that it is weapons-grade plutonium as well as to estimate the minimum mass necessary to produce the observed gamma-ray intensity. We developed software (the Pu600 code) for instrument control and analysis especially for this purpose. In November 1994, U.S. and Russian scientists met at the Lawrence Livermore National Laboratory for joint experiments to evaluate candidate Pu MRI inspection techniques. In one of these experiments, gamma-ray intensities were measured from three unclassified weapons-grade plutonium source standards and one reactor-grade standard (21% {sup 240}pu). Using our software, we determined the {sup 240}Pu/{sup 239}Pu ratio of these standards to accuracies within {+-}10%, which is adequate for Pu MRI. The minimum mass estimates varied, as expected, directly with the exposed surface area of the standards.

  11. The cAMP signaling system inhibits the repair of {gamma}-ray-induced DNA damage by promoting Epac1-mediated proteasomal degradation of XRCC1 protein in human lung cancer cells

    SciTech Connect

    Cho, Eun-Ah; Juhnn, Yong-Sung

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer cAMP signaling system inhibits repair of {gamma}-ray-induced DNA damage. Black-Right-Pointing-Pointer cAMP signaling system inhibits DNA damage repair by decreasing XRCC1 expression. Black-Right-Pointing-Pointer cAMP signaling system decreases XRCC1 expression by promoting its proteasomal degradation. Black-Right-Pointing-Pointer The promotion of XRCC1 degradation by cAMP signaling system is mediated by Epac1. -- Abstract: Cyclic AMP is involved in the regulation of metabolism, gene expression, cellular growth and proliferation. Recently, the cAMP signaling system was found to modulate DNA-damaging agent-induced apoptosis by regulating the expression of Bcl-2 family proteins and inhibitors of apoptosis. Thus, we hypothesized that the cAMP signaling may modulate DNA repair activity, and we investigated the effects of the cAMP signaling system on {gamma}-ray-induced DNA damage repair in lung cancer cells. Transient expression of a constitutively active mutant of stimulatory G protein (G{alpha}sQL) or treatment with forskolin, an adenylyl cyclase activator, augmented radiation-induced DNA damage and inhibited repair of the damage in H1299 lung cancer cells. Expression of G{alpha}sQL or treatment with forskolin or isoproterenol inhibited the radiation-induced expression of the XRCC1 protein, and exogenous expression of XRCC1 abolished the DNA repair-inhibiting effect of forskolin. Forskolin treatment promoted the ubiquitin and proteasome-dependent degradation of the XRCC1 protein, resulting in a significant decrease in the half-life of the protein after {gamma}-ray irradiation. The effect of forskolin on XRCC1 expression was not inhibited by PKA inhibitor, but 8-pCPT-2 Prime -O-Me-cAMP, an Epac-selective cAMP analog, increased ubiquitination of XRCC1 protein and decreased XRCC1 expression. Knockdown of Epac1 abolished the effect of 8-pCPT-2 Prime -O-Me-cAMP and restored XRCC1 protein level following {gamma}-ray irradiation. From

  12. Multiple fractions of gamma rays induced resistance to cis-dichloro-diammineplatinum (II) and methotrexate in human HeLa cells

    SciTech Connect

    Osmak, M.; Perovic, S. )

    1989-06-01

    Previous irradiation could induce changes in the cell-sensitivity to additional cytotoxic agents. In this study we examined whether the sensitivity to additional cytotoxic agents was affected in cells irradiated with multiple fractions of gamma rays if these agents were given at the time when the lesions induced in DNA by radiation have already been repaired. Human cervix carcinoma HeLa cells were irradiated daily with 0.5 Gy of gamma rays five times a week for 6 weeks. When the fractionation regimen was completed, that is when the cells had accumulated the total dose of 15 Gy of gamma rays, the sensitivity of these cells to gamma rays, UV light, cis-dichlorodiammineplatinum (II) (cis-DDP), methotrexate (MTX), and hydroxyurea (HU) was examined and compared to control cells. Results revealed that preirradiated cells did not change sensitivity to gamma rays and UV light, but that they increased the resistance to cis-DDP, and MTX (especially for higher concentrations of MTX), and increased sensitivity to HU (for lower concentrations of HU). The increased resistance to cis-DDP was also measurable up to 30 days after the last dose of gamma rays. The results indicate that preirradiation of HeLa cells with multiple fractions of gamma rays could change their sensitivity to additional cytotoxic agents, and that this is a relatively long-lasting effect. Our results suggest that caution is needed in medical application of radiation combined with chemical treatment.

  13. sup 60 Co. gamma. -rays induce predominantly C/G to G/C transversions in double-stranded M13 DNA

    SciTech Connect

    Hoebee, B.; Loman, H. ); Brouwer, J.; van de Putte, P. ); Retel, J. Free University Hospital, Amsterdam )

    1988-08-25

    Upon irradiation with gamma rays of an oxygenated aqueous solution of double-stranded M13 DNA, a very specific mutation spectrum was found with respect to both the type and the positions in the DNA sequence. Of the 23 mutations, which were sequenced, 16 represent a C/G to G/C transversion. A C/G to T/A transition was found once and a G/C to T/A transversion twice. The remaining 4 mutations are frameshifts, 2 are identical and formed by the insertion of a G/C basepair; the other 2 mutations are due to a duplication of 10 basepairs situated at different positions but with a remarkable homology in base sequence. Fourteen mutations, including the 2 duplications are found in the neighborhood of a TGCT/ACGA sequence.

  14. Molecular cloning of the mouse proteasome subunits MC14 and MECL-1: reciprocally regulated tissue expression of interferon-gamma-modulated proteasome subunits.

    PubMed

    Stohwasser, R; Standera, S; Peters, I; Kloetzel, P M; Groettrup, M

    1997-05-01

    The primary structures of the interferon-gamma-inducible mouse 20S proteasome subunit MECL-1 and its alternate homolog MC14 were determined. Northern analysis of mouse tissues revealed that MECL-1 mRNA predominantly occurred in thymus, lymph nodes, and spleen, whereas small amounts were detected in non-lymphoid tissues such as kidney, muscle, and testis. Unexpectedly, probing RNA blots with MC14 showed that tissues with high MECL-1 expression contained little MC14 and vice versa. A very similar reciprocal tissue expression was subsequently found for the homologous subunit pairs LMP2 and delta as well as LMP7 and MB1. The subunit protein composition of 20S proteasomes purified from liver, thymus, and lung reflected RNA expression. The impact of a regulated reciprocal tissue expression is discussed with respect to thymic selection and the induction of tolerance in potentially autoreactive T cells. PMID:9174609

  15. Electromagnetic Reciprocity.

    SciTech Connect

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories and now a

  16. Reciprocal translocations

    SciTech Connect

    1993-12-31

    Chapter 26, describes reciprocal translocations of chromosomes: their occurrence, breakpoints, and multiple rearrangements. In addition, phenotypes of balanced and unbalanced translocation carriers and fetal death are discussed. Examples of translocation families are given. Meiosis and genetic risk in translocation carriers is presented. Finally, sperm chromosomes in meiotic segregation analysis is mentioned. 39 refs., 3 figs., 1 tab.

  17. [Contribution of 210Bi beta-ray induced bremsstrahlung to the emission of Pb-KX-rays observed in the lead shielded gamma-ray background spectrum (author's transl)].

    PubMed

    Shima, K; Mihara, T; Umetani, K; Mikumo, T

    1980-08-01

    Observation of gamma-ray background has been done by using a Ge(Li) semiconductor detector when it was placed inside the lead shielding material. With the aid of a very simple model calculation, the concentration of 210Pb radioisotope embedded in the lead material has been estimated to be 0.1-0.4 (Bq/Pb-g) (3-12 (pCi/Pb-g). The origin of Pb-KX-ray emission, the highest peak in the background spectrum, has been investigated by comparing the 210Pb-47 keV gamma-ray and Pb-KX-ray peak counts. As the results, about 50 +/- 30% of Pb-KX-ray production is estimated to be due to the Pb-K shell photoionization which is induced by the bremsstrahlung of 210Bi beta-ray. PMID:7208990

  18. X-ray-induced water vaporization

    SciTech Connect

    Weon, B. M.; Lee, J. S.; Je, J. H.; Fezzaa, K.

    2011-09-15

    We present quantitative evidence for x-ray-induced water vaporization: water is vaporized at a rate of 5.5 pL/s with the 1-A-wavelength x-ray irradiation of {approx}0.1 photons per A{sup 2}; moreover, water vapor is reversibly condensed during pauses in irradiation. This result fundamentally suggests that photoionization induces vaporization. This phenomenon is attributed to surface-tension reduction by ionization and would be universally important in radiological and electrohydrodynamic situations.

  19. Manipulation of reciprocal salt bridges at the heterodimerization interface alters the dimerization properties of mouse RXR{alpha} and PPAR{gamma}1

    SciTech Connect

    Chan, Lap Shu; Wells, Richard A. . E-mail: rwells@sri.utoronto.ca

    2007-07-13

    Heterodimerization with RXR is essential for the high-affinity specific binding of multiple nuclear receptors to their cognate DNA sequences. NR dimerization is a two-step process, initiated in solution by interaction between amino acid residues with helices 9 and 10 of the ligand binding domains of RXR and its NR partners. Studies of the orphan nuclear receptor HNF4{alpha}, which forms homodimers exclusively, have indicated that two charged residues in this region, HNF4{alpha}{sub K300} and HNF4{alpha}{sub E327}, are key mediators of dimerization. We have analyzed the contribution of the homologous residues in RXR{alpha} (RXR{alpha}{sub E395}, RXR{alpha}{sub K422}) and PPAR{gamma} (PPAR{gamma}{sub E405}, PPAR{gamma}{sub K432}) to the formation of the RXR{alpha}-PPAR{gamma} heterodimer. Charge reversal mutants of RXR{alpha} (RXR{alpha}{sub E395K}, RXR{alpha}{sub K422E}) and PPAR{gamma} (PPAR{gamma}{sub E405K}, PPAR{gamma}{sub K432E}) show impaired ability to form heterodimers with wild-type PPAR{gamma} and RXR{alpha}, respectively. However, pairs of mutants with balanced charge changes, i.e., RXR{alpha}{sub E395K} with PPAR{gamma}{sub K432E} and RXR{alpha}{sub K422E} with PPAR{gamma}{sub E405K}, are able to form dimers. Ligand response is preserved in the PPAR{gamma} mutants, indicating the mutation does not result in major structural derangement of the protein. These results establish the importance of salt bridges between these residues in the heterodimerization of nuclear receptors, and offer a technical approach to generating functional NR mutants with directed heterodimerization specificity. Such mutants will be valuable tools in the genetic analysis of NR function.

  20. β-reciprocal polynomials

    NASA Astrophysics Data System (ADS)

    Withers, Christopher S.; Nadarajah, Saralees

    2016-07-01

    A new class of polynomials pn(x) known as β-reciprocal polynomials is defined. Given a parameter ? that is not a root of -1, we show that the only β-reciprocal polynomials are pn(x) ≡ xn. When β is a root of -1, other polynomials are possible. For example, the Hermite polynomials are i-reciprocal, ?.

  1. Reciprocating pellet press

    DOEpatents

    Jones, Charles W.

    1981-04-07

    A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

  2. Fermi Large Area Telescope Observations of the Cosmic-Ray Induced

    SciTech Connect

    Abdo, A.

    2012-02-29

    We report on measurements of the cosmic-ray induced {gamma}-ray emission of Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The LAT has observed the Earth during its commissioning phase and with a dedicated Earth-limb following observation in September 2008. These measurements yielded {approx} 6.4 x 10{sup 6} photons with energies > 100 MeV and {approx} 250 hours total livetime for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission - often referred to as Earth albedo gamma-ray emission - has a power-law shape up to 500 GeV with spectral index {Lambda} = 2.79 {+-} 0.06.

  3. X-ray induced photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Xiang, Liangzhong; Han, Bin; Carpenter, Colin; Pratx, Guillem; Kuang, Yu; Xing, Lei

    2013-03-01

    X-ray induced photoacoustic tomography, also called X-ray acoustic computer tomography (XACT) is investigated in this paper. Short pulsed (μs-range) X-ray beams from a medical linear accelerator were used to generate ultrasound. The ultrasound signals were collected with an ultrasound transducer (500 KHz central frequency) positioned around an object. The transducer, driven by a computer-controlled step motor to scan around the object, detected the resulting acoustic signals in the imaging plane at each scanning position. A pulse preamplifier, with a bandwidth of 20 KHz-2 MHz at -3 dB, and switchable gains of 40 and 60 dB, received the signals from the transducer and delivered the amplified signals to a secondary amplifier. The secondary amplifier had bandwidth of 20 KHz-30 MHz at -3 dB, and a gain range of 10-60 dB. Signals were recorded and averaged 128 times by an oscilloscope. A sampling rate of 100 MHz was used to record 2500 data points at each view angle. One set of data incorporated 200 positions as the receiver moved 360°. The x-ray generated acoustic image was then reconstructed with the filtered back projection algorithm. The twodimensional XACT images of the lead rod embedded in chicken breast tissue were found to be in good agreement with the shape of the object. This new modality may be useful for a number of applications, such as providing the location of a fiducial, or monitoring x-ray dose distribution during radiation therapy.

  4. Reciprocity in directed networks

    NASA Astrophysics Data System (ADS)

    Yin, Mei; Zhu, Lingjiong

    2016-04-01

    Reciprocity is an important characteristic of directed networks and has been widely used in the modeling of World Wide Web, email, social, and other complex networks. In this paper, we take a statistical physics point of view and study the limiting entropy and free energy densities from the microcanonical ensemble, the canonical ensemble, and the grand canonical ensemble whose sufficient statistics are given by edge and reciprocal densities. The sparse case is also studied for the grand canonical ensemble. Extensions to more general reciprocal models including reciprocal triangle and star densities will likewise be discussed.

  5. Reciprocal NUT spacetimes

    NASA Astrophysics Data System (ADS)

    Momeni, Davood; Chattopadhyay, Surajit; Myrzakulov, Ratbay

    2015-05-01

    In this paper, we study the Ehlers' transformation (sometimes called gravitational duality rotation) for reciprocal static metrics. First, we introduce the concept of reciprocal metric. We prove a theorem which shows how we can construct a certain new static solution of Einstein field equations using a seed metric. Later, we investigate the family of stationary spacetimes of such reciprocal metrics. The key here is a theorem from Ehlers', which relates any static vacuum solution to a unique stationary metric. The stationary metric has a magnetic charge. The spacetime represents Newman-Unti-Tamburino (NUT) solutions. Since any stationary spacetime can be decomposed into a 1 + 3 time-space decomposition, Einstein field equations for any stationary spacetime can be written in the form of Maxwell's equations for gravitoelectromagnetic fields. Further, we show that this set of equations is invariant under reciprocal transformations. An additional point is that the NUT charge changes the sign. As an instructive example, by starting from the reciprocal Schwarzschild as a spherically symmetric solution and reciprocal Morgan-Morgan disk model as seed metrics we find their corresponding stationary spacetimes. Starting from any static seed metric, performing the reciprocal transformation and by applying an additional Ehlers' transformation we obtain a family of NUT spaces with negative NUT factor (reciprocal NUT factors).

  6. Reciprocating Linear Electric Motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, M. P.

    1984-01-01

    Features include structural simplicity and good force/displacement characteristics. Reciprocating motor has simple, rugged construction, relatively low reciprocating weight, improved power delivery, and improved force control. Wear reduced by use of magnetic bearings. Intended to provide drivers for long-lived Stirling-cycle cryogenic refrigerators, concept has less exotic applications, such as fuel pumps.

  7. The Value of Reciprocity

    ERIC Educational Resources Information Center

    Molm, Linda D.; Schaefer, David R.; Collett, Jessica L.

    2007-01-01

    The value of reciprocity in social exchange potentially comprises both instrumental value (the value of the actual benefits received from exchange) and communicative or symbolic value (the expressive and uncertainty reduction value conveyed by features of the act of reciprocity itself). While all forms of exchange provide instrumental value, we…

  8. The Structure of Reciprocity

    ERIC Educational Resources Information Center

    Molm, Linda D.

    2010-01-01

    Reciprocity is one of the defining features of social exchange and social life, yet exchange theorists have tended to take it for granted. Drawing on work from a decade-long theoretical research program, I argue that reciprocity is structured and variable across different forms of exchange, that these variations in the structure of reciprocity…

  9. Centrifugal reciprocating compressor

    NASA Technical Reports Server (NTRS)

    High, W. H.

    1980-01-01

    Efficient compressor uses centrifugal force to compress gas. System incorporates two coupled dc motors, each driving separate centrifugal reciprocating-compressor assembly. Motors are synchronized to accelerate and decelerate alternately.

  10. Hidden patterns of reciprocity.

    PubMed

    Syi

    2014-03-21

    Reciprocity can help the evolution of cooperation. To model both types of reciprocity, we need the concept of strategy. In the case of direct reciprocity there are four second-order action rules (Simple Tit-for-tat, Contrite Tit-for-tat, Pavlov, and Grim Trigger), which are able to promote cooperation. In the case of indirect reciprocity the key component of cooperation is the assessment rule. There are, again, four elementary second-order assessment rules (Image Scoring, Simple Standing, Stern Judging, and Shunning). The eight concepts can be formalized in an ontologically thin way we need only an action predicate and a value function, two agent concepts, and the constant of goodness. The formalism helps us to discover that the action and assessment rules can be paired, and that they show the same patterns. The logic of these patterns can be interpreted with the concept of punishment that has an inherent paradoxical nature. PMID:24368125

  11. Direct reciprocity on graphs

    PubMed Central

    Ohtsuki, Hisashi; Nowak, Martin A.

    2008-01-01

    Direct reciprocity is a mechanism for the evolution of cooperation based on the idea of repeated encounters between the same two individuals. Here we examine direct reciprocity in structured populations, where individuals occupy the vertices of a graph. The edges denote who interacts with whom. The graph represents spatial structure or a social network. For birth-death or pairwise comparison updating, we find that evolutionary stability of direct reciprocity is more restrictive on a graph than in a well-mixed population, but the condition for reciprocators to be advantageous is less restrictive on a graph. For death-birth and imitation updating, in contrast, both conditions are easier to fulfill on a graph. Moreover, for all four update mechanisms, reciprocators can dominate defectors on a graph, which is never possible in a well-mixed population. We also study the effect of an error rate, which increases with the number of links per individual; interacting with more people simultaneously enhances the probability of making mistakes. We provide analytic derivations for all results. PMID:17466339

  12. Series of Reciprocal Triangular Numbers

    ERIC Educational Resources Information Center

    Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

    2013-01-01

    Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

  13. Reciprocal Predicates in Japanese.

    ERIC Educational Resources Information Center

    Ishii, Yasuo

    A study of reciprocals in Japanese compares two kinds: (1) a verbal suffix "aw"; and (2) an NP argument "otagai." Although "otagai" appears to be taken care of by syntactic binding theory, it is proposed that there is no evidence for the existence of a syntactic position of the object NP in the case of "aw." The suffix can be characterized as…

  14. Terahertz wave reciprocal imaging

    NASA Astrophysics Data System (ADS)

    Xu, Jingzhou; Zhang, X.-C.

    2006-04-01

    A reciprocal imaging technology with an encoding/decoding image readout method allows a single detector (such as a heterodyne detector) to produce a two dimensional (2D) image simultaneously. Applying it in a pulsed terahertz imaging system could create a 2D terahertz image with 100pixels per frame which produces the same signal to noise ratio as a signal spot measurement.

  15. Cascaded Gamma Rays as a Probe of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Murase, Kohta

    2014-06-01

    Very-high-energy (VHE) and ultra-high-energy (UHE) gamma rays from extragalactic sources experience electromagnetic cascades during their propagation in intergalactic space. Recent gamma-ray data on TeV blazars and the diffuse gamma-ray background may have hints of the cascade emission, which are especially interesting if it comes from UHE cosmic rays. I show that cosmic-ray-induced cascades can be discriminated from gamma-ray-induced cascades with detailed gamma-ray spectra. I also discuss roles of structured magnetic fields, which suppress inverse-Compton pair halos/echoes but lead to guaranteed signals - synchrotron pair halos/echoes.

  16. Reciprocity relations in aerodynamics

    NASA Technical Reports Server (NTRS)

    Heaslet, Max A; Spreiter, John R

    1953-01-01

    Reverse flow theorems in aerodynamics are shown to be based on the same general concepts involved in many reciprocity theorems in the physical sciences. Reciprocal theorems for both steady and unsteady motion are found as a logical consequence of this approach. No restrictions on wing plan form or flight Mach number are made beyond those required in linearized compressible-flow analysis. A number of examples are listed, including general integral theorems for lifting, rolling, and pitching wings and for wings in nonuniform downwash fields. Correspondence is also established between the buildup of circulation with time of a wing starting impulsively from rest and the buildup of lift of the same wing moving in the reverse direction into a sharp-edged gust.

  17. Fermi large area telescope observations of the cosmic-ray induced γ-ray emission of the Earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; de Palma, F.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hays, E.; Horan, D.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Rodriguez, A. Y.; Roth, M.; Sadrozinski, H. F.-W.; Sander, A.; Saz Parkinson, P. M.; Sgrò, C.; Share, G. H.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.

    2009-12-01

    We report on measurements of the cosmic-ray induced γ-ray emission of Earth’s atmosphere by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The Large Area Telescope has observed the Earth during its commissioning phase and with a dedicated Earth limb following observation in September 2008. These measurements yielded ˜6.4×106 photons with energies >100MeV and ˜250 hours total live time for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission—often referred to as Earth albedo gamma-ray emission—has a power-law shape up to 500 GeV with spectral index Γ=2.79±0.06.

  18. Reciprocating magnetic refrigerator

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.

    1985-01-01

    A 4 to 15 K magnetic refrigerator to test as an alternative to the Joule-Thomson circuit as the low temperature stage of a 4 to 300 K closed-cycle refrigerator was developed. The reciprocating magnetic refrigerator consists of two matrices of gadolinium gallium garnet spheres located in tandem on a single piston which alternately moves each matrix into a 7 telsa magnetic field. A separate helium gas circuit is used as the heat exchange mechanism for the low and the high temperature extremes of the magnetic refrigerator. Details of the design and results of the initial refrigerator component tests are presented.

  19. High pressure reciprocating pump

    SciTech Connect

    Besic, D.

    1990-05-01

    This patent describes an improvement in a reciprocating pump having a plunger and a pumping chamber. It comprises: the plunger having a bore communicating with an intersection opening and wherein the plunger incudes a central axis; a suction valve and a discharge valve, each having an axis of actuation parallel to a central axis of the plunger; the suction valve comprising a cylindrical core having a central passageway, and the core is slidably received by a seating member and resiliently biased to the seating member.

  20. The principle of reciprocity.

    PubMed

    Hoult, D I

    2011-12-01

    The circumstances surrounding the realisation that NMR signal reception could be quantified in a simple fundamental manner using Lorentz's Principle of Reciprocity are described. The poor signal-to-noise ratio of the first European superconducting magnet is identified as a major motivating factor, together with the author's need to understand phenomena at a basic level. A summary is then given of the thought processes leading to the very simple pseudo-static formula that has been the basis of signal-to-noise calculations for over a generation. PMID:21889377

  1. 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.

  2. Reciprocal relations in electroacoustics

    SciTech Connect

    Chassagne, C.; Bedeaux, D.

    2014-07-28

    In a colloidal suspension, one can generate sound waves by the application of an alternating electric field (Electrokinetic Sonic Amplitude, i.e., ESA). Another phenomenon is electrophoresis (Electrophoretic Mobility, i.e., EM) where a colloidal particle moves relative to the solvent in an electric field. Vice versa one can generate electric fields or electric currents by sound waves (Colloid Vibration Potential/Current, i.e., CVP/CVI). In 1988 and 1990, O’Brien [J. Fluid Mech. 190, 71–86 (1988) and O’Brien, J. Fluid Mech. 212, 81–93 (1990)] derived a reciprocal relation between the proportionality coefficients of the EM and CVI phenomena. In this paper, we will generalize his proof by constructing the relevant entropy production from which the linear force-flux relations follow. General relations are derived for electrolyte solutions, of which colloidal suspensions are a particular case. The relations between CVI, CVP, EM, and ESA are discussed. O’Brien's reciprocal relation then follows as an Onsager relation. The relation is valid for any applied electric field frequency, particle surface charge and particle concentration (even in the presence of particle-particle interactions) provided the system is isotropic.

  3. Toward a Behavior of Reciprocity

    PubMed Central

    Gernsbacher, Morton Ann

    2014-01-01

    It is frequently believed that autism is characterized by a lack of social or emotional reciprocity. In this article, I question that assumption by demonstrating how many professionals—researchers and clinicians—and likewise many parents, have neglected the true meaning of reciprocity. Reciprocity is “a relation of mutual dependence or action or influence,” or “a mode of exchange in which transactions take place between individuals who are symmetrically placed.” Assumptions by clinicians and researchers suggest that they have forgotten that reciprocity needs to be mutual and symmetrical—that reciprocity is a two-way street. Research is reviewed to illustrate that when professionals, peers, and parents are taught to act reciprocally, autistic children become more responsive. In one randomized clinical trial of “reciprocity training” to parents, their autistic children's language developed rapidly and their social engagement increased markedly. Other demonstrations of how parents and professionals can increase their behavior of reciprocity are provided. PMID:25598865

  4. High Resolution X-ray-Induced Acoustic Tomography.

    PubMed

    Xiang, Liangzhong; Tang, Shanshan; Ahmad, Moiz; Xing, Lei

    2016-01-01

    Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology, and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray. PMID:27189746

  5. X-ray induced photoconductivity in Vanadium Dioxide samples

    NASA Astrophysics Data System (ADS)

    Dietze, Sebastian; Mohanty, Jyoti; Marsh, Moses; Kim, Jong Woo; West, Kevin; Schuller, Ivan K.; Shpyrko, Oleg G.

    2011-03-01

    Vanadium Dioxide (VO2) goes through a first-order phase transition at approximately 340K, exhibiting both an insulator to metal transition (IMT) and a structural phase transition (SPT), with a monoclinic (M1) insulating phase at low temperatures and a rutile (R) metallic phase at high temperatures. We show an anomalous behavior of x-ray induced persistent photoconductivity (PPC) well below the temperature induced phase transition in VO2 devices. We present conductivity and X-ray Diffraction (XRD) measurements, revealing a large enhancement of conductivity due to photo-induced carriers. Moreover, with the addition of nominal electric fields, we are able to fully transition into the rutile metallic phase at room temperature. This effect is completely reversible, allowing the monoclinic insulating phase to be recovered via annealing.

  6. High Resolution X-ray-Induced Acoustic Tomography

    NASA Astrophysics Data System (ADS)

    Xiang, Liangzhong; Tang, Shanshan; Ahmad, Moiz; Xing, Lei

    2016-05-01

    Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology, and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray.

  7. High Resolution X-ray-Induced Acoustic Tomography

    PubMed Central

    Xiang, Liangzhong; Tang, Shanshan; Ahmad, Moiz; Xing, Lei

    2016-01-01

    Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology, and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray. PMID:27189746

  8. Reciprocating linear motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, Michael P. (Inventor)

    1987-01-01

    A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

  9. Reciprocating wind engine

    SciTech Connect

    Van Mechelen, B.

    1980-12-09

    A reciprocating wind engine is described which utilizes plural, movably mounted sets of panels to form pistons. Cooperating first and second pistons may be spaced from each other on either side of a central crankshaft. As the wind strikes the surface of a first set of panels, the first piston is moved toward the crankshaft and the second piston is pulled toward the crankshaft from the opposite side. When both pistons are adjacent the crankshaft, the panels on the first or windward piston open to allow the wind to pass therethrough into contact with the panels of the second piston which are closed to present a uniform surface to the wind. The pistons are forced away from the crankshaft to complete one cycle of operation. The output from the crankshaft may be utilized to generate electricity, or for any other suitable purpose. Plural engine segments may be cooperatively joined together to form a bank of such units.

  10. Trust, Respect, and Reciprocity

    PubMed Central

    Phong, Tran Viet; Nhan, Le Nguyen Thanh; Dung, Nguyen Thanh; Ngan, Ta Thi Dieu; Kinh, Nguyen Van; Parker, Michael; Bull, Susan

    2015-01-01

    International science funders and publishers are driving a growing trend in data sharing. There is mounting pressure on researchers in low- and middle-income settings to conform to new sharing policies, despite minimal empirically grounded accounts of the ethical challenges of implementing the policies in these settings. This study used in-depth interviews and focus group discussions with 48 stakeholders in Vietnam to explore the experiences, attitudes, and expectations that inform ethical and effective approaches to sharing clinical research data. Distinct views on the role of trust, respect, and reciprocity were among those that emerged to inform culturally appropriate best practices. We conclude by discussing the challenges that authors of data-sharing policies should consider in this unique context. PMID:26297747

  11. Simpler valve for reciprocating engines

    NASA Technical Reports Server (NTRS)

    Akkerman, J. W.

    1978-01-01

    Simpler design eliminating camshafts, cams, and mechanical springs should improve reliability of hydrazine powered reciprocating engines. Valve is expected to improve efficiency, and reduce weight of engines in range up to 50 horsepower.

  12. X-ray-induced changes in growth of Mozambique tilapia

    SciTech Connect

    Jana, B.B.; Basu, M.

    1995-01-01

    Early fry (30 d postfertilization) and 7-8-week-old Mozambique tilapias (Tilapia mossambica) were exposed to X rays in dosages of 50, 100, 200, 300, 400 or 500 roentgens and reared in outdoor culture tanks between May 1981 and October 1988. Fish of either sex that were irradiated as fry grew faster than controls at all test X-ray doses. Among fish irradiated at 7-8 weeks, males grew significantly faster, but females grew significantly slower, than controls at all test doses. X-ray-induced changes in growth were dose-dependent: growth rates of fry (both sexes) and of juvenile males rose relative to those of controls with increased radiation dose. The growth increase per unit of radiation dose was higher for fry than for older juveniles. The length-weight regression was steeper for irradiated males than for controls. The average weights of F{sub 1} offspring of irradiated fish were greatly reduced as compared with controls, which suggests the transfer of the detrimental effects of X rays from irradiated parents to their offspring. 39 refs., 3 figs., 3 tabs.

  13. X-ray-induced cell death: Apoptosis and necrosis

    SciTech Connect

    Nakano, Hisako; Shinohara, Kunio

    1994-10-01

    X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis. 27 refs., 8 figs., 1 tab.

  14. Innovations in X-ray-induced electron emission spectroscopy (XIEES)

    SciTech Connect

    Pogrebitsky, K. Ju. Sharkov, M. D.

    2010-06-15

    Currently, a pressing need has arisen for controlling the local atomic and electron structure of materials irrespective of their aggregate state. Efficient approaches to the studies of short-range order are based on phenomena accompanied by interference of secondary electrons excited by primary X-ray radiation. The set of such approaches are commonly referred to as the X-ray absorption fine structure (XAFS) methods. In reality, the XAFS methods are based on the use of synchrotron radiation and applied to structural studies in two modes of measurements, transmission analysis and recording of secondary effects. Only two such effects-specifically, the X-ray fluorescence an d X-ray-induced electron emission effect-are commonly discussed. Access to synchrotron accelerators is problematic for most researchers, so a demand is created for designing laboratory systems that make direct access possible. Since the power of laboratory systems is much lower than that of synchrotrons, it is essential to use much more efficient detectors of secondary electrons. In addition, it is of interest to analyze energy characteristics with a high spatial resolution. Channel multipliers and multichannel boards are incapable of providing such a possibility. For this reason, an improved electron detector has been developed to analyze the photoemission effect in an accelerating field.

  15. Moral assessment in indirect reciprocity

    PubMed Central

    Sigmund, Karl

    2012-01-01

    Indirect reciprocity is one of the mechanisms for cooperation, and seems to be of particular interest for the evolution of human societies. A large part is based on assessing reputations and acting accordingly. This paper gives a brief overview of different assessment rules for indirect reciprocity, and studies them by using evolutionary game dynamics. Even the simplest binary assessment rules lead to complex outcomes and require considerable cognitive abilities. PMID:21473870

  16. Group formation through indirect reciprocity

    NASA Astrophysics Data System (ADS)

    Oishi, Koji; Shimada, Takashi; Ito, Nobuyasu

    2013-03-01

    The emergence of group structure of cooperative relations is studied in an agent-based model. It is proved that specific types of reciprocity norms lead individuals to split into two groups only inside of which they are cooperative. The condition for the evolutionary stability of the norms is also obtained. This result suggests reciprocity norms, which usually promote cooperation, can cause society's separation into multiple groups.

  17. Muon content of gamma ray induced EAS from Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Blake, P. R.; Nash, W. F.; Saich, M. R.; Stanley, G. B.

    1985-01-01

    During 1984 the Leeds group (Lambert et al, OG 2,1-6) have observed emission above 5 times 10 to the 14th power eV in July, September and October at phi approximately 0.6. These observations were made with an array which included the Nottingham 10 sq m muon detector. A search for muons in events at the phase peak and off source has yielded the following results: (1) for 42 on source events we find an average muon density of 0.63 muons m(-2) at a mean core distance Bar R = 32 m and mean primary energy approximately 25 times 10 to the 15th power eV; (2) for 21 off source events average muon density = 1.6 m(-2), Bar R = 32 m with mean primary energy approximately 2.0 x 10 to the 15th power eV; (3) for 11 of the 42 on source events, zero muons were recorded in the 10 sq ms. For these events Bar R = 41 m and mean primary energy approximately 1.5 x 10 to the 15th power eV; (4) for 8 of the 21 off source events, zero muons were recorded in the 10 sq ms. For these events Bar R = 37 m and mean primary energy approximately 1.5 times 10 to the 15th power eV. For all the events the mean zenith angle was approximately 16 deg. A more detailed comparison of on source and further off source events will be presented.

  18. Nucleus substitution between Petunia species using gamma ray-induced androgenesis.

    PubMed

    Raquin, C; Cornu, A; Farcy, E; Maizonnier, D; Pelletier, G; Vedel, F

    1989-09-01

    The ovaries of two different Petunia species: Petunia hybrida (hort) and Petunia parodii (Steere) were irradiated with τ-ray doses ranging from 50 to 1,000 Gy before pollination. Seed setting occurred after 4 days preculture on a non-sterile medium. Ovaries transformed into fruits were then cultivated aseptically with the following results: (1) τ-ray doses ranging from 200 to 1,000 Gy led to the development of two types of plants: haploids 2n=x=7 and overdiploids 2n>2x=14. (2) The androgenetic origin of haploids was ascertained by using genetic markers. The origin of overdiploids is discussed. (3) Androgenetic haploids contained the chloroplasts of the irradiated female parent. No visible change of cp DNA patterns was observed after irradiation. (4) The four possible androgenetic events were successfully obtained between the two Petunia species: hybrida haploids with hybrida or parodii cytoplasm, and parodii haploids with parodii or hybrida cytoplasm. PMID:24227238

  19. Laser- and gamma-ray induced crystallization of IR-transmitting calcium gallate glass

    NASA Astrophysics Data System (ADS)

    Nishida, T.; Kubuki, S.; Takashima, Y.; Mikami, M.; Yagi, T.

    1994-12-01

    Ar+-laser ( λ=488 nm) irradiation of calcium gallate (CG) glass with the composition of 60CaO·39Ga2O3·Fe2O3 resulted in a distinct decrease in the IR transmittance ( T) due to the formation of crystalline CaGa2O4 and CaGa4O9 phases. The Mössbauer spectrum of non-irradiated glass comprised a broad doublet due to distorted Fe3+(Td) with δ, Δ, and Γ of 0.20, 1.33, and 1.00 mm s-1, respectively. An additional doublet due to Fe3+(Td) was observed in the Ar+-irradiated glass and δ, Δ, and Γ were 0.17, 1.32, and 0.75 mm s-1, respectively. A decrease in T was also observed after the60Co γ-ray irradiation with doses ≥105Gy, and the precipitation of CaO, Ga2O3, and CaGa4O7 phases was confirmed by X-ray diffraction.

  20. Search for Cosmic-Ray-induced Gamma-Ray Emission in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Chaves, R. C. G.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hayashida, M.; Hewitt, J.; Hughes, R. E.; Jeltema, T. E.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Llena Garde, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Ruan, J.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Storm, E.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vianello, G.; Vitale, V.; Winer, B. L.; Wood, K. S.; Zimmer, S.; Fermi-LAT Collaboration; Pinzke, A.; Pfrommer, C.

    2014-05-01

    Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into γ rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended γ-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke & Pfrommer. We find an excess at a significance of 2.7σ, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters).Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R 200, to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the γ-ray flux from individual clusters in our sample.

  1. Search for cosmic-ray-induced gamma-ray emission in galaxy clusters

    SciTech Connect

    Ackermann, M.; Buehler, R.; Ajello, M.; Albert, A.; Allafort, A.; Bechtol, K.; Bloom, E. D.; Bottacini, E.; Atwood, W. B.; Baldini, L.; Ballet, J.; Bastieri, D.; Buson, S.; Bellazzini, R.; Bregeon, J.; Bonamente, E.; Brandt, T. J.; Brigida, M.; Bruel, P. E-mail: zimmer@fysik.su.se E-mail: apinzke@fysik.su.se [Laboratoire Leprince-Ringuet, École polytechnique, CNRS Collaboration: Fermi-LAT Collaboration; and others

    2014-05-20

    Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into γ rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended γ-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke and Pfrommer. We find an excess at a significance of 2.7σ, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters).Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R {sub 200}, to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the γ-ray flux from individual clusters in our sample.

  2. Indirect Reciprocity; A Field Experiment

    PubMed Central

    van Apeldoorn, Jacobien; Schram, Arthur

    2016-01-01

    Indirect reciprocity involves cooperative acts towards strangers, either in response to their kindness to third parties (downstream) or after receiving kindness from others oneself (upstream). It is considered to be important for the evolution of cooperative behavior amongst humans. Though it has been widely studied theoretically, the empirical evidence of indirect reciprocity has thus far been limited and based solely on behavior in laboratory experiments. We provide evidence from an online environment where members can repeatedly ask and offer services to each other, free of charge. For the purpose of this study we created several new member profiles, which differ only in terms of their serving history. We then sent out a large number of service requests to different members from all over the world. We observe that a service request is more likely to be rewarded for those with a profile history of offering the service (to third parties) in the past. This provides clear evidence of (downstream) indirect reciprocity. We find no support for upstream indirect reciprocity (in this case, rewarding the service request after having previously received the service from third parties), however. Our evidence of downstream indirect reciprocity cannot be attributed to reputational effects concerning one’s trustworthiness as a service user. PMID:27043712

  3. Direct reciprocity in structured populations

    PubMed Central

    van Veelen, Matthijs; García, Julián; Rand, David G.; Nowak, Martin A.

    2012-01-01

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that “indirect invasions” remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies. PMID:22665767

  4. Influence of reciprocal links in social networks.

    PubMed

    Zhu, Yu-Xiao; Zhang, Xiao-Guang; Sun, Gui-Quan; Tang, Ming; Zhou, Tao; Zhang, Zi-Ke

    2014-01-01

    How does reciprocal links affect the function of real social network? Does reciprocal link and non-reciprocal link play the same role? Previous researches haven't displayed a clear picture to us until now according to the best of our knowledge. Motivated by this, in this paper, we empirically study the influence of reciprocal links in two representative real datasets, Sina Weibo and Douban. Our results demonstrate that the reciprocal links play a more important role than non-reciprocal ones in information diffusion process. In particular, not only coverage but also the speed of the information diffusion can be significantly enhanced by considering the reciprocal effect. We give some possible explanations from the perspectives of network connectivity and efficiency. This work may shed some light on the in-depth understanding and application of the reciprocal effect in directed online social networks. PMID:25072242

  5. Influence of Reciprocal Links in Social Networks

    PubMed Central

    Zhu, Yu-Xiao; Zhang, Xiao-Guang; Sun, Gui-Quan; Tang, Ming; Zhou, Tao; Zhang, Zi-Ke

    2014-01-01

    How does reciprocal links affect the function of real social network? Does reciprocal link and non-reciprocal link play the same role? Previous researches haven't displayed a clear picture to us until now according to the best of our knowledge. Motivated by this, in this paper, we empirically study the influence of reciprocal links in two representative real datasets, Sina Weibo and Douban. Our results demonstrate that the reciprocal links play a more important role than non-reciprocal ones in information diffusion process. In particular, not only coverage but also the speed of the information diffusion can be significantly enhanced by considering the reciprocal effect. We give some possible explanations from the perspectives of network connectivity and efficiency. This work may shed some light on the in-depth understanding and application of the reciprocal effect in directed online social networks. PMID:25072242

  6. Hierarchical Classification by Multi-Level Reciprocity

    ERIC Educational Resources Information Center

    McQuitty, Louis L.

    1970-01-01

    A method is developed and illustrated which relaxes the principle of reciprocity in relation to characteristics of data and classifies in terms of successive levels of reciprocity, using two versions: (a) successive linkages, and (b) core assignments. (Author/RF)

  7. Do infants detect indirect reciprocity?

    PubMed

    Meristo, Marek; Surian, Luca

    2013-10-01

    In social interactions involving indirect reciprocity, agent A acts prosocially towards B and this prompts C to act prosocially towards A. This happens because A's actions enhanced its reputation in the eyes of third parties. Indirect reciprocity may have been of central importance in the evolution of morality as one of the major mechanisms leading to the selection of helping and fair attitudes. Here we show that 10-month-old infants expect third parties to act positively towards fair donors who have distributed attractive resources equally between two recipients, rather than toward unfair donors who made unequal distributions. Infants' responses were dependent on the reciprocator's perceptual exposure to previous relevant events: they expected the reciprocator to reward the fair donor only when it had seen the distributive actions performed by the donors. We propose that infants were able to generate evaluations of agents that were based on the fairness of their distributive actions and to generate expectations about the social preferences of informed third parties. PMID:23887149

  8. Reciprocity principle and crack identification

    NASA Astrophysics Data System (ADS)

    Andrieux, Stéphane; Ben Abda, Amel; Duong Bui, Huy

    1999-02-01

    In this paper we are concerned with the planar crack identification problem defined by a unique complete elastostatic overdetermined boundary datum. Based on the reciprocity gap principle, we give a direct process for locating the host plane and we establish a new constuctive identifiability result for 3D planar cracks.

  9. Reciprocating Saw for Silicon Wafers

    NASA Technical Reports Server (NTRS)

    Morrison, A. D.; Collins, E. R., Jr.

    1985-01-01

    Concept increases productivity and wafer quality. Cutting wafers from silicon ingots produces smooth wafers at high rates with reduced blade wear. Involves straight reciprocating saw blade and slight rotation of ingot between cutting strokes. Many parallel blades combined to cut many wafers simultaneously from ingot.

  10. Thermal-powered reciprocating pump

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1972-01-01

    Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.

  11. Capuchin Monkeys Judge Third-Party Reciprocity

    ERIC Educational Resources Information Center

    Anderson, James R.; Takimoto, Ayaka; Kuroshima, Hika; Fujita, Kazuo

    2013-01-01

    Increasing interest is being shown in how children develop an understanding of reciprocity in social exchanges and fairness in resource distribution, including social exchanges between third parties. Although there are descriptions of reciprocity on a one-to-one basis in other species, whether nonhumans detect reciprocity and violations of…

  12. Reciprocal Teaching: Critical Reflection on Practice

    ERIC Educational Resources Information Center

    McAllum, Ruth

    2014-01-01

    This paper highlights reciprocal teaching as an inclusive instructional strategy that has been shown to improve reading comprehension and metacognitive skills. It provides a conceptual background to reciprocal teaching and examines its purpose, strengths and weaknesses. The notion of reciprocal teaching as an evidence-based practice is also…

  13. Marmoset monkeys evaluate third-party reciprocity

    PubMed Central

    Kawai, Nobuyuki; Yasue, Miyuki; Banno, Taku; Ichinohe, Noritaka

    2014-01-01

    Many non-human primates have been observed to reciprocate and to understand reciprocity in one-to-one social exchanges. A recent study demonstrated that capuchin monkeys are sensitive to both third-party reciprocity and violation of reciprocity; however, whether this sensitivity is a function of general intelligence, evidenced by their larger brain size relative to other primates, remains unclear. We hypothesized that highly pro-social primates, even with a relatively smaller brain, would be sensitive to others' reciprocity. Here, we show that common marmosets discriminated between human actors who reciprocated in social exchanges with others and those who did not. Monkeys accepted rewards less frequently from non-reciprocators than they did from reciprocators when the non-reciprocators had retained all food items, but they accepted rewards from both actors equally when they had observed reciprocal exchange between the actors. These results suggest that mechanisms to detect unfair reciprocity in third-party social exchanges do not require domain-general higher cognitive ability based on proportionally larger brains, but rather emerge from the cooperative and pro-social tendencies of species, and thereby suggest this ability evolved in multiple primate lineages. PMID:24850892

  14. Kinetic Modeling of the X-ray-induced Damage to a Metalloprotein

    PubMed Central

    Davis, Katherine M.; Kosheleva, Irina; Henning, Robert W.; Seidler, Gerald T.; Pushkar, Yulia

    2013-01-01

    It is well known that biological samples undergo x-ray-induced degradation. One of the fastest occurring x-ray-induced processes involves redox modifications (reduction or oxidation) of redox-active cofactors in proteins. Here we analyze room temperature data on the photoreduction of Mn ions in the oxygen evolving complex (OEC) of photosystem II, one of the most radiation damage sensitive proteins and a key constituent of natural photosynthesis in plants, green algae and cyanobacteria. Time-resolved x-ray emission spectroscopy with wavelength-dispersive detection was used to collect data on the progression of x-ray-induced damage. A kinetic model was developed to fit experimental results, and the rate constant for the reduction of OEC MnIII/IV ions by solvated electrons was determined. From this model, the possible kinetics of x-ray-induced damage at variety of experimental conditions, such as different rates of dose deposition as well as different excitation wavelengths, can be inferred. We observed a trend of increasing dosage threshold prior to the onset of x-ray-induced damage with increasing rates of damage deposition. This trend suggests that experimentation with higher rates of dose deposition is beneficial for measurements of biological samples sensitive to radiation damage, particularly at pink beam and x-ray FEL sources. PMID:23815809

  15. Reciprocal food sharing in the vampire bat

    NASA Astrophysics Data System (ADS)

    Wilkinson, Gerald S.

    1984-03-01

    Behavioural reciprocity can be evolutionarily stable1-3. Initial increase in frequency depends, however, on reciprocal altruists interacting predominantly with other reciprocal altruists either by associating within kin groups or by having sufficient memory to recognize and not aid nonreciprocators. Theory thus suggests that reciprocity should evolve more easily among animals which live in kin groups. Data are available separating reciprocity from nepotism only for unrelated nonhuman animals4. Here, I show that food sharing by regurgitation of blood among wild vampire bats (Desmodus rotundus) depends equally and independently on degree of relatedness and an index of opportunity for recipro cation. That reciprocity operates within groups containing both kin and nonkin is supported further with data on the availability of blood-sharing occasions, estimates of the economics of shar ing blood, and experiments which show that unrelated bats will reciprocally exchange blood in captivity.

  16. Piston reciprocating compressed air engine

    SciTech Connect

    Cestero, L.G.

    1987-03-24

    A compressed air engine is described comprising: (a). a reservoir of compressed air, (b). two power cylinders each containing a reciprocating piston connected to a crankshaft and flywheel, (c). a transfer cylinder which communicates with each power cylinder and the reservoir, and contains a reciprocating piston connected to the crankshaft, (d). valve means controlled by rotation of the crankshaft for supplying compressed air from the reservoir to each power cylinder and for exhausting compressed air from each power cylinder to the transfer cylinder, (e). valve means controlled by rotation of the crankshaft for supplying from the transfer cylinder to the reservoir compressed air supplied to the transfer cylinder on the exhaust strokes of the pistons of the power cylinders, and (f). an externally powered fan for assisting the exhaust of compressed air from each power cylinder to the transfer cylinder and from there to the compressed air reservoir.

  17. Reciprocal uniparental disomy in yeast

    PubMed Central

    Andersen, Sabrina L.; Petes, Thomas D.

    2012-01-01

    In the diploid cells of most organisms, including humans, each chromosome is usually distinguishable from its partner homolog by multiple single-nucleotide polymorphisms. One common type of genetic alteration observed in tumor cells is uniparental disomy (UPD), in which a pair of homologous chromosomes are derived from a single parent, resulting in loss of heterozygosity for all single-nucleotide polymorphisms while maintaining diploidy. Somatic UPD events are usually explained as reflecting two consecutive nondisjunction events. Here we report a previously undescribed mode of chromosome segregation in Saccharomyces cerevisiae in which one cell division produces daughter cells with reciprocal UPD for the same pair of chromosomes without an aneuploid intermediate. One pair of sister chromatids is segregated into one daughter cell and the other pair is segregated into the other daughter cell, mimicking a meiotic chromosome segregation pattern. We term this process “reciprocal uniparental disomy.” PMID:22665764

  18. An Autonomously Reciprocating Transmembrane Nanoactuator.

    PubMed

    Watson, Matthew A; Cockroft, Scott L

    2016-01-22

    Biological molecular machines operate far from equilibrium by coupling chemical potential to repeated cycles of dissipative nanomechanical motion. This principle has been exploited in supramolecular systems that exhibit true machine behavior in solution and on surfaces. However, designed membrane-spanning assemblies developed to date have been limited to simple switches or stochastic shuttles, and true machine behavior has remained elusive. Herein, we present a transmembrane nanoactuator that turns over chemical fuel to drive autonomous reciprocating (back-and-forth) nanomechanical motion. Ratcheted reciprocating motion of a DNA/PEG copolymer threaded through a single α-hemolysin pore was induced by a combination of DNA strand displacement processes and enzyme-catalyzed reactions. Ion-current recordings revealed saw-tooth patterns, indicating that the assemblies operated in autonomous, asymmetric cycles of conformational change at rates of up to one cycle per minute. PMID:26661295

  19. Genetic Architecture of Reciprocal CNVs

    PubMed Central

    Golzio, Christelle; Katsanis, Nicholas

    2013-01-01

    Copy number variants (CNVs) represent a frequent type of lesion in human genetic disorders that typically affects numerous genes simultaneously. This has raised the challenge of understanding which genes within a CNV drive clinical phenotypes. Although CNVs can arise by multiple mechanisms, a subset is driven by local genomic architecture permissive to recombination events that can lead to both deletions and duplications. Phenotypic analyses of patients with such reciprocal CNVs have revealed instances in which the phenotype is either identical or mirrored; strikingly, molecular studies have revealed that such phenotypes are often driven by reciprocal dosage defects of the same transcript. Here we explore how these observations can help the dissection of CNVs and inform the genetic architecture of CNV-induced disorders. PMID:23747035

  20. Reciprocal relations between kinetic curves

    NASA Astrophysics Data System (ADS)

    Yablonsky, G. S.; Gorban, A. N.; Constales, D.; Galvita, V. V.; Marin, G. B.

    2011-01-01

    We study coupled irreversible processes. For linear or linearized kinetics with microreversibility, \\dot{x}=Kx , the kinetic operator K is symmetric in the entropic inner product. This form of Onsager's reciprocal relations implies that the shift in time, exp(Kt), is also a symmetric operator. This generates the reciprocity relations between the kinetic curves. For example, for the Master equation, if we start the process from the i-th pure state and measure the probability pj(t) of the j-th state (j≠i), and, similarly, measure pi(t) for the process, which starts at the j-th pure state, then the ratio of these two probabilities pj(t)/pi(t) is constant in time and coincides with the ratio of the equilibrium probabilities. We study similar and more general reciprocal relations between the kinetic curves. The experimental evidence provided as an example is from the reversible water gas shift reaction over iron oxide catalyst. The experimental data are obtained using Temporal Analysis of Products (TAP) pulse-response studies. These offer excellent confirmation within the experimental error.

  1. Best compression: Reciprocating or rotary?

    SciTech Connect

    Cahill, C.

    1997-07-01

    A compressor is a device used to increase the pressure of a compressible fluid. The inlet pressure can vary from a deep vacuum to a high positive pressure. The discharge pressure can range from subatmospheric levels to tens of thousands of pounds per square inch. Compressors come in numerous forms, but for oilfield applications there are two primary types, reciprocating and rotary. Both reciprocating and rotary compressors are grouped in the intermittent mode of compression. Intermittent is cyclic in nature, in that a specific quantity of gas is ingested by the compressor, acted upon and discharged before the cycle is repeated. Reciprocating compression is the most common form of compression used for oilfield applications. Rotary screw compressors have a long history but are relative newcomers to oilfield applications. The rotary screw compressor-technically a helical rotor compressor-dates back to 1878. That was when the first rotary screw was manufactured for the purpose of compressing air. Today thousands of rotary screw compression packages are being used throughout the world to compress natural gas.

  2. Monte-Carlo gamma response simulation of fast/thermal neutron interactions with soil elements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil elemental analysis using characteristic gamma rays induced by neutrons is an effective method of in situ soil content determination. The nuclei of soil elements irradiated by neutrons issue characteristic gamma rays due to both inelastic neutron scattering (e.g., Si, C) and thermal neutron capt...

  3. Evolution of spite through indirect reciprocity.

    PubMed Central

    Johnstone, Rufus A.; Bshary, Redouan

    2004-01-01

    How can cooperation persist in the face of a temptation to 'cheat'? Several recent papers have suggested that the answer may lie in indirect reciprocity. Altruistic individuals may benefit by eliciting altruism from observers, rather than (as in direct reciprocity) from the recipient of the aid they provide. Here, we point out that indirect reciprocity need not always favour cooperation; by contrast, it may support spiteful behaviour, which is costly for the both actor and recipient. Existing theory suggests spite is unlikely to persist, but we demonstrate that it may do so when spiteful individuals are less likely to incur aggression from observers (a negative form of indirect reciprocity). PMID:15347514

  4. Reciprocating motion of active deformable particles

    NASA Astrophysics Data System (ADS)

    Tarama, M.; Ohta, T.

    2016-05-01

    Reciprocating motion of an active deformable particle in a homogeneous medium is studied theoretically. For generality, we employ a simple model derived from symmetry considerations for the center-of-mass velocity and elliptical and triangular deformations in two dimensions. We carry out, for the first time, a systematic investigation of the reciprocating motion of a self-propelled particle. It is clarified that spontaneous breaking of the front-rear asymmetry is essential for the reciprocating motion. Moreover, two routes are found for the formation of the reciprocating motion. One is a bifurcation from a motionless stationary state. The other is destabilisation of an oscillatory rectilinear motion.

  5. Search for X-ray induced decay of the 31-yr isomer of 178Hf using synchrotron radiation

    SciTech Connect

    Ahmad, I; Banar, J C; Becker, J A; Bredeweg, T A; Cooper, J R; Gemmell, D S; Kraemer, A; Mashayekhi, A; McNabb, D P; Miller, G G; Moore, E F; Palmer, P; Pangault, L N; Rundberg, R S; Schiffer, J P; Shastri, S D; Wang, T F; Wilhelmy, J B

    2004-09-13

    Isomeric {sup 178}Hf (t{sub 1/2} = 31 yr, E{sub x} = 2.446 MeV, J{sup {pi}} = 16{sup +}) was bombarded by a white beam of x-rays from the Advanced Photon Source at Argonne National Laboratory. A search was made for x-ray induced decay of the isomer by detecting prompt and delayed {gamma} rays associated with the decay. No induced decay was observed. Upper limits for such a process for x-ray energies between 7-100 keV were set. The limits between 7 and 30 keV are below {approx} 3 x 10{sup -27} cm{sup 2}-keV for induced decay that bypasses the 4-s isomer and {approx} 5 x 10{sup -27} cm{sup 2}-keV for induced decay that is delayed through this isomer, orders of magnitude below values at which induced decay was reported previously. These limits are consistent with what is known about the properties of atomic nuclei.

  6. Retinoid protection against x-ray-induced chromatid damage in human peripheral blood lymphocytes.

    PubMed Central

    Sanford, K K; Parshad, R; Price, F M; Tarone, R E; Kraemer, K H

    1992-01-01

    Oral administration of isotretinoin (13-cis retinoic acid) was shown previously (Kraemer, K. H., J. J. DiGiovanna, A. N. Moshell, R. E. Tarone, and G. L. Peck. 1988. N. Engl. J. Med. 318:1633-1637) to reduce the frequency of skin cancers in xeroderma pigmentosum (XP) patients. The mechanism of protection was unclear. In the present study, x-ray-induced chromatid damage in PHA-stimulated blood lymphocytes from five XP patients receiving isotretinoin was approximately half that in blood samples from the same patients before or subsequent to treatment. The x-ray-induced chromatid damage in blood lymphocytes from a normal control was reduced significantly by cocultivation with blood or plasma from an XP patient receiving isotretinoin or by addition of 10(-6) M isotretinoin to cultures 1 h before x-irradiation. A similar reduction in x-ray-induced chromatid damage was reported previously by adding to the culture medium, mannitol, a scavenger of the free hydroxyl radical, or catalase, which decomposes hydrogen peroxide; both of these products are generated during ionizing radiation. The present observations suggest that isotretinoin acts as a scavenger of such radiation products, thereby providing protection against x-ray-induced chromatid damage. PMID:1430230

  7. DNA sequence analysis of X-ray induced Adh null mutations in Drosophila melanogaster

    SciTech Connect

    Mahmoud, J.; Fossett, N.G.; Arbour-Reily, P.; McDaniel, M.; Tucker, A.; Chang, S.H.; Lee, W.R. )

    1991-01-01

    The mutational spectrum for 28 X-ray induced mutations and 2 spontaneous mutations, previously determined by genetic and cytogenetic methods, consisted of 20 multilocus deficiencies (19 induced and 1 spontaneous) and 10 intragenic mutations (9 induced and 1 spontaneous). One of the X-ray induced intragenic mutations was lost, and another was determined to be a recombinant with the allele used in the recovery scheme. The DNA sequence of two X-ray induced intragenic mutations has been published. This paper reports the results of DNA sequence analysis of the remaining intragenic mutations and a summary of the X-ray induced mutational spectrum. The combination of DNA sequence analysis with genetic complementation analysis shows a continuous distribution in size of deletions rather than two different types of mutations consisting of deletions and point mutations'. Sequencing is shown to be essential for detecting intragenic deletions. Of particular importance for future studies is the observation that all of the intragenic deletions consist of a direct repeat adjacent to the breakpoint with one of the repeats deleted.

  8. Indirect reciprocity with trinary reputations.

    PubMed

    Tanabe, Shoma; Suzuki, Hideyuki; Masuda, Naoki

    2013-01-21

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs have been examined in great details. Most previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by analyzing a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equilibria composed of a homogeneous population or a heterogeneous population containing two types of players. Some results derived for the trinary reputation model are direct extensions of those for the binary model. However, we find that the trinary model allows cooperation under image scoring under some mild conditions. PMID:23123557

  9. Bipropellant propulsion with reciprocating pumps

    NASA Astrophysics Data System (ADS)

    Whitehead, John C.

    1993-06-01

    A pressure regulated gas generator rocket cycle with alternately pressurized pairs of reciprocating pumps offers thrust-on-demand operation with significantly lower inert mass than conventional spacecraft liquid propulsion systems. The operation of bipropellant feed systems with reciprocating pumps is explained, with consideration for both short and long term missions. There are several methods for startup and shutdown of this self-starting pump-fed system, with preference determined by thrust duty cycle and mission duration. Progress to date includes extensive development testing of components unique to this type of system, and several live tests with monopropellant hydrazine. Pneumatic pump control valves which render pistons and bellows automatically responsive to downstream liquid demand are significantly simpler than those described previously. A compact pumpset mounted to central liquid manifolds has a pair of oxidizer pumps pneumatically slaved to a pair of fuel pumps to reduce vibration. A warm gas pressure reducer for tank expulsion can eliminate any remaining need for inert gas storage.

  10. Hybrid internal combustion reciprocating engine

    SciTech Connect

    Gonzalez, C.

    1988-08-23

    This patent describes a hybrid type reciprocating internal combustion turbine fuel engine with combined spark ignition, torch-assisted to compression ignition modes comprising: a cylinder; a cylinder head mounted on the cylinder having a substantially planar inner surface; exhaust and inlet valves positioned in the head connected to corresponding exhaust and unthrottled inlet passages; a piston reciprocally mounted within the cylinder having a top surface thereon which surface in the top dead center position of the piston is in close proximity with the inner surface of the cylinder head; a substantially spherical precombustion chamber located in the head; a lineal passage tangentially joining the precombustion chamber with the inner surface of the cylinder head; a pilot fuel injector means and an igniter means both located in the precombustion chamber which inject and ignite a precharge; a main fuel injector means in the cylinder head; a bowl-shaped recess comprising the main combustion chamber located in the top surface of the piston in close proximity with the main injector means in the top dead center position with the lineal passage tangentially aligned with the main combustion chamber, whereby the burning gases exiting the precombustion chamber are directed into the main combustion chamber causing ignition therein.

  11. Hybrid internal combustion reciprocating engine

    SciTech Connect

    Gonzales, C.

    1986-06-17

    A hybrid type reciprocating internal combustion engine is described which consists of: a cylinder, a cylinder head mounted on the cylinder having a substantially planar inner surface; exhaust and inlet valves positioned in the head connected to corresponding exhaust and unthrottled inlet passages; a piston reciprocally mounted within the cylinder having a top surface thereon which surface in the top dead center position of the piston is in close proximity with the inner surface of the head; a precombustion chamber located in the head; a lineal passage tangentially joining the precombustion chamber with the inner surface of the cylinder head; a pilot fuel injector means and an igniter means both located in the precombustion chamber which inject and ignite a precharge; a main fuel injector means in the cylinder head; a bowl shaped recess comprising the main combustion chamber non-concentrically located in the top surface of the piston in close proximity with the main injector means in the top dead center position; a first ramp means located in the top surface of the piston tangentially joining the main combustion chamber recess and substantially aligned with the lineal passage, when the piston is approximately at the top dead center position, whereby the burning gases exiting the precombustion chamber are directed into the main combustion recess; and a second ramp means in the top surface of the piston laterally joining the first ramp means.

  12. Are there x-ray induced signature mutations in human cells?

    SciTech Connect

    Nelson, S.L.; Giver, C.R.; Grosovsky, A.J.

    1994-12-31

    Investigations of mutational spectra generally have two primary objectives: identification of mutagen specific hallmark mutations, and insight into mutagenic mechanisms. In order to address these two crucial issues we have examined the spectrum of 116 x-ray induced, and 78 spontaneous, HPRT{sup -} mutants derived from the human B lymphoblastoid cell line TK6. Multiplex PCR analysis demonstrated that the overall representation of large deletions was not significantly different in the 2 spectra, although highly significant differences were observed for specific deletion types. Total gene deletions represented 41/78 (.53) of x-ray induced, but only 7/43 (.16) of spontaneous, deletions (p < .0001). In contrast, 5{prime} terminal deletions were significantly more common among spontaneous (17/43, .40) than x-ray induced (13/78, .17) large deletions (p=.0079). Chromosomal scale investigation of x-ray induced and spontaneous hprt total deletion mutants was also performed using cytogenetic examination, and X-linked PCR probes. The types of point mutations induced by x-ray exposure were very diverse, including all classes of transitions and transversions, tandem base substitutions, frameshifts, and a deletion/insertion compound mutation. Compared to spontaneous data, radiation induced point mutations exhibited a significantly reduced number of transitions, and an increased representation of small deletions. Small deletions were uniformly surrounded by direct sequence repeats. The distribution of x-ray induced point mutations was characterized by a cluster of 8 mutants within a 30 base region of exon 8. Thirteen HPRT{sup -} point mutants exhibited aberrant splicing, 4 of which were attributable to coding sequence alterations within exons 4 and 8. These results suggest that it may be possible to identify hallmark mutations associated with x-ray exposure of human cells.

  13. 78 FR 53792 - Draft Guidance for Reciprocity

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... COMMISSION Draft Guidance for Reciprocity AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG; request... for reciprocity. The NRC is requesting public comment on draft NUREG-1556, Volume 19, Revision 1...@nrc.gov . The draft NUREG-1556, Volume 19, Revision 1, is available under ADAMS Accession...

  14. Implementing Reciprocal Teaching: Was It Effective?

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.; And Others

    This study was conducted to explore the relationship between teaching methods and students' grades at the college level. Subjects, 58 undergraduate students enrolled in 2 introductory education courses, were organized into groups and exposed to one of two teaching methods: the lecture format and reciprocal teaching. Reciprocal teaching engages…

  15. Reciprocal Tutoring: Design with Cognitive Load Sharing

    ERIC Educational Resources Information Center

    Chou, Chih-Yueh; Chan, Tak-Wai

    2016-01-01

    "Reciprocal tutoring," as reported in "Exploring the design of computer supports for reciprocal tutoring" (Chan and Chou 1997), has extended the meaning and scope of "intelligent tutoring" originally implemented in stand alone computers. This research is a follow-up to our studies on a "learning companion…

  16. An Introduction to the Onsager Reciprocal Relations

    ERIC Educational Resources Information Center

    Monroe, Charles W.; Newman, John

    2007-01-01

    The Onsager reciprocal relations are essential to multicomponent transport theory. A discussion of the principles that should be used to derive flux laws for coupled diffusion is presented here. Fluctuation theory is employed to determine the reciprocal relation for transport coefficients that characterize coupled mass and heat transfer in binary…

  17. Reciprocal Contracting with Families of Adolescents.

    ERIC Educational Resources Information Center

    Lipinski, Judith M.; Lawrence, P. Scott

    The use of reciprocal behavior contracts with families of behavior-problem adolescents was investigated. Most family contracting to date has involved one-way contracts; that is, the child agrees to certain responsibilities for which he will be reinforced by the parents. A reciprocal contract requires the parents, in addition to the child, to agree…

  18. Education, Gift and Reciprocity: A Preliminary Discussion

    ERIC Educational Resources Information Center

    Sabourin, Eric

    2013-01-01

    This paper analyzes the importance and role of the reciprocity relationship in education. It presents a review on the mobilization of the principle of reciprocity--in the anthropological but also sociological and economic senses--in educational processes, especially in adult education. The study is divided into three parts. The first part analyzes…

  19. Reciprocal Teaching. Information Capsule. Volume 0609

    ERIC Educational Resources Information Center

    Blazer, Christie

    2007-01-01

    Reciprocal teaching is an instructional approach designed to increase students' reading comprehension at all grade levels and in all subject areas. Students are taught cognitive strategies that help them construct meaning from text and simultaneously monitor their reading comprehension. This Information Capsule summarizes reciprocal teaching's…

  20. Apollo orbital geochemistry: Gamma rays

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.

    1973-01-01

    Lunar gamma ray spectra obtained during Apollo-15 and -16 flights show a natural radioactivity due to potassium, thorium, and uranium as well as a cosmic ray induced activity in the lunar surface due to high neutron interactions produced by (p,n) reaction in the lunar surface. The radioactivity is at a low in the highlands on the backside of the moon; most of the radioactivity is confined to the Oceanus Procellarum/Mare Imbrium region and to the Van de Graff area on the lunar backside.

  1. Cosmic-ray-induced photodestruction of interstellar molecules in dense clouds

    SciTech Connect

    Sternberg, A.; Dalgarno, A.; Lepp, S.

    1987-09-01

    The ultraviolet spectrum of radiation generated by cosmic rays inside dense molecular clouds is presented, and the resulting rates of photodissociation for a variety of interstellar molecules are estimated. The effects of this radiation on the chemistry of dense molecular clouds are discussed, and it is argued that the cosmic-ray-induced photons will significantly inhibit the production of complex molecular species. 30 references.

  2. Pump-probe spectrometer for measuring x-ray induced strain.

    PubMed

    Loether, A; Adams, B W; DiCharia, A; Gao, Y; Henning, R; Walko, D A; DeCamp, M F

    2016-05-01

    A hard x-ray pump-probe spectrometer using a multi-crystal Bragg reflector is demonstrated at a third generation synchrotron source. This device derives both broadband pump and monochromatic probe pulses directly from a single intense, broadband x-ray pulse centered at 8.767 keV. We present a proof-of-concept experiment which directly measures x-ray induced crystalline lattice strain. PMID:27128053

  3. Ultraintense X-Ray Induced Ionization, Dissociation, and Frustrated Absorption in Molecular Nitrogen

    SciTech Connect

    Hoener, M.; Fang, L.; Murphy, B.; Berrah, N.; Kornilov, O.; Gessner, O.; Pratt, S. T.; Kanter, E. P.; Guehr, M.; Bucksbaum, P. H.; Cryan, J.; Glownia, M.; McFarland, B.; Petrovic, V.; Blaga, C.; DiMauro, L.; Bostedt, C.; Bozek, J. D.; Coffee, R.; Messerschmidt, M.

    2010-06-25

    Sequential multiple photoionization of the prototypical molecule N{sub 2} is studied with femtosecond time resolution using the Linac Coherent Light Source (LCLS). A detailed picture of intense x-ray induced ionization and dissociation dynamics is revealed, including a molecular mechanism of frustrated absorption that suppresses the formation of high charge states at short pulse durations. The inverse scaling of the average target charge state with x-ray peak brightness has possible implications for single-pulse imaging applications.

  4. Ultraintense x-ray induced ionization, dissociation and frustrated absorption in molecular nitrogen.

    SciTech Connect

    Hoener, M.; Fang, L.; Kornilov, O.; Gessner, O.; Pratt, S. T.; Guhr, M.; Kanter, E. P.; Blaga, C.; Bostedt, C.; Bozek, J. D.; Bucksbaum, P. H.; Buth, C.; Chen, M.; Coffee, R.; Cryan, J.; DiMauro, L.; Glownia, M.; Hosler, E.; Kukk, E.; Leone, S. R.; McFarland, B.; Messerschmidt, M.; Murphy, B.; Petrovic, V.; Rolles, D.; Berrah, N.; Chemical Sciences and Engineering Division; Western Michigan Univ.; LBNL; Ohio State Univ.; Louisiana State Univ.; LLNL; Univ. of Turku; Univ. of California at Berkeley; Max Planck Advanced Study Group, CFEL; LCLS

    2010-06-23

    Sequential multiple photoionization of the prototypical molecule N2 is studied with femtosecond time resolution using the Linac Coherent Light Source (LCLS). A detailed picture of intense x-ray induced ionization and dissociation dynamics is revealed, including a molecular mechanism of frustrated absorption that suppresses the formation of high charge states at short pulse durations. The inverse scaling of the average target charge state with x-ray peak brightness has possible implications for single-pulse imaging applications.

  5. Reciprocity and Ethical Tuberculosis Treatment and Control.

    PubMed

    Silva, Diego S; Dawson, Angus; Upshur, Ross E G

    2016-03-01

    This paper explores the notion of reciprocity in the context of active pulmonary and laryngeal tuberculosis (TB) treatment and related control policies and practices. We seek to do three things: First, we sketch the background to contemporary global TB care and suggest that poverty is a key feature when considering the treatment of TB patients. We use two examples from TB care to explore the role of reciprocity: isolation and the use of novel TB drugs. Second, we explore alternative means of justifying the use of reciprocity through appeal to different moral and political theoretical traditions (i.e., virtue ethics, deontology, and consequentialism). We suggest that each theory can be used to provide reasons to take reciprocity seriously as an independent moral concept, despite any other differences. Third, we explore general meanings and uses of the concept of reciprocity, with the primary intention of demonstrating that it cannot be simply reduced to other more frequently invoked moral concepts such as beneficence or justice. We argue that reciprocity can function as a mid-level principle in public health, and generally, captures a core social obligation arising once an individual or group is burdened as a result of acting for the benefit of others (even if they derive a benefit themselves). We conclude that while more needs to be explored in relation to the theoretical justification and application of reciprocity, sufficient arguments can be made for it to be taken more seriously as a key principle within public health ethics and bioethics more generally. PMID:26797512

  6. Reciprocity of agonistic support in ravens

    PubMed Central

    Fraser, Orlaith N.; Bugnyar, Thomas

    2012-01-01

    Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim’s likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals. PMID:22298910

  7. Reciprocity of agonistic support in ravens.

    PubMed

    Fraser, Orlaith N; Bugnyar, Thomas

    2012-01-01

    Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim's likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals. PMID:22298910

  8. Two distinct neural mechanisms underlying indirect reciprocity.

    PubMed

    Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

    2014-03-18

    Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards. PMID:24591599

  9. Two distinct neural mechanisms underlying indirect reciprocity

    PubMed Central

    Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

    2014-01-01

    Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards. PMID:24591599

  10. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)

    SciTech Connect

    Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

    2005-12-01

    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  11. Self-reciprocating radioisotope-powered cantilever

    NASA Astrophysics Data System (ADS)

    Li, Hui; Lal, Amit; Blanchard, James; Henderson, Douglass

    2002-07-01

    A reciprocating cantilever utilizing emitted charges from a millicurie radioisotope thin film is presented. The actuator realizes a direct collected-charge-to-motion conversion. The reciprocation is obtained by self-timed contact between the cantilever and the radioisotope source. A static model balancing the electrostatic and mechanical forces from an equivalent circuit leads to an analytical solution useful for device characterization. Measured reciprocating periods agree with predicted values from the analytical model. A scaling analysis shows that microscale arrays of such cantilevers provide an integrated sensor and actuator platform.

  12. Electronic controller for reciprocating rotary crystallizer

    NASA Technical Reports Server (NTRS)

    Kroes, Roger L.; Reiss, Donald A.; Hester, Howard B.

    1988-01-01

    An electronic controller for a reciprocating rotary crystallizer is described. The heart of this system is the electronic timer circuit. A schematic along with a detailed description of its operation is given.

  13. 30 CFR 57.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  14. 30 CFR 57.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  15. 32 CFR 148.1 - Intergency reciprocal acceptance .

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Intergency reciprocal acceptance . 148.1 Section... Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency reciprocal acceptance of security policies and procedures for approving, accrediting, and maintaining...

  16. 32 CFR 148.1 - Intergency reciprocal acceptance .

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Intergency reciprocal acceptance . 148.1 Section... Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency reciprocal acceptance of security policies and procedures for approving, accrediting, and maintaining...

  17. Principles of femtosecond X-ray/optical cross-correlation with X-ray induced transient optical reflectivity in solids

    SciTech Connect

    Eckert, S. E-mail: martin.beye@helmholtz-berlin.de; Beye, M. E-mail: martin.beye@helmholtz-berlin.de; Pietzsch, A.; Quevedo, W.; Hantschmann, M.; Ochmann, M.; Huse, N.; Ross, M.; Khalil, M.; Minitti, M. P.; Turner, J. J.; Moeller, S. P.; Schlotter, W. F.; Dakovski, G. L.; Föhlisch, A.

    2015-02-09

    The discovery of ultrafast X-ray induced optical reflectivity changes enabled the development of X-ray/optical cross correlation techniques at X-ray free electron lasers worldwide. We have now linked through experiment and theory the fundamental excitation and relaxation steps with the transient optical properties in finite solid samples. Therefore, we gain a thorough interpretation and an optimized detection scheme of X-ray induced changes to the refractive index and the X-ray/optical cross correlation response.

  18. Constraining X-ray-Induced Photoevaporation of Protoplanetary Disks Orbiting Low-Mass Stars

    NASA Astrophysics Data System (ADS)

    Punzi, Kristina M.; Kastner, Joel H.; Rodriguez, David; Principe, David A.; Vican, Laura

    2016-01-01

    Low-mass, pre-main sequence stars possess intense high-energy radiation fields as a result of their strong stellar magnetic activity. This stellar UV and X-ray radiation may have a profound impact on the lifetimes of protoplanetary disks. We aim to constrain the X-ray-induced photoevaporation rates of protoplanetary disks orbiting low-mass stars by analyzing serendipitous XMM-Newton and Chandra X-ray observations of candidate nearby (D < 100 pc), young (age < 100 Myr) M stars identified in the GALEX Nearby Young-Star Survey (GALNYSS).

  19. X-ray-Induced Shortwave Infrared Biomedical Imaging Using Rare-Earth Nanoprobes

    PubMed Central

    2015-01-01

    Shortwave infrared (SWIR or NIR-II) light provides significant advantages for imaging biological structures due to reduced autofluorescence and photon scattering. Here, we report on the development of rare-earth nanoprobes that exhibit SWIR luminescence following X-ray irradiation. We demonstrate the ability of X-ray-induced SWIR luminescence (X-IR) to monitor biodistribution and map lymphatic drainage. Our results indicate X-IR imaging is a promising new modality for preclinical applications and has potential for dual-modality molecular disease imaging. PMID:25485705

  20. Influence of caffeine on X-ray-induced killing and mutation in V79 cells

    SciTech Connect

    Bhattacharjee, S.B.; Bhattacharyya, N.; Chatterjee, S.

    1987-02-01

    Effects produced by caffeine on X-irradiated Chinese hamster V79 cells depended on the growth conditions of the cells. For exponentially growing cells, nontoxic concentrations of caffeine decreased the shoulder width from the survival curve, but the slope remained unchanged. The yield of mutants under the same conditions also remained unaffected. In case of density-inhibited cells, delaying trypsinization for 24 h after X irradiation increased the survival and decreased the yield of mutants. The presence of caffeine during this incubation period inhibited such recovery and significantly increased the yield of X-ray-induced mutants.

  1. X-ray-induced chromosome aberrations in Down lymphocytes: an explanation of their increased sensitivity

    SciTech Connect

    Preston, R.J.

    1981-01-01

    Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray--induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosomes aberrations, and hence higher aberration frequencies in Down than normal cells.

  2. X-ray-induced chromosome aberrations in Down lymphocytes: an explanation of their increased sensitivity

    SciTech Connect

    Preston, R.J.

    1981-01-01

    Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray-induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosome aberrations, and hence higher aberration frequencies in Down than normal cells.

  3. The Evaluational Consequences of Topic Reciprocity and Self-Disclosure Reciprocity.

    ERIC Educational Resources Information Center

    Hosman, Lawrence A.

    1987-01-01

    Investigates the hypothesis that messages reciprocating both topic and intimacy would be more positively evaluated than those reciprocating neither. Results support the hypothesis for initial low intimacy messages, and partially support it for initial high intimacy messages. Examines results in terms of competing interactional goals in a…

  4. Accurate analytical modelling of cosmic ray induced failure rates of power semiconductor devices

    NASA Astrophysics Data System (ADS)

    Bauer, Friedhelm D.

    2009-06-01

    A new, simple and efficient approach is presented to conduct estimations of the cosmic ray induced failure rate for high voltage silicon power devices early in the design phase. This allows combining common design issues such as device losses and safe operating area with the constraints imposed by the reliability to result in a better and overall more efficient design methodology. Starting from an experimental and theoretical background brought forth a few yeas ago [Kabza H et al. Cosmic radiation as a cause for power device failure and possible countermeasures. In: Proceedings of the sixth international symposium on power semiconductor devices and IC's, Davos, Switzerland; 1994. p. 9-12, Zeller HR. Cosmic ray induced breakdown in high voltage semiconductor devices, microscopic model and possible countermeasures. In: Proceedings of the sixth international symposium on power semiconductor devices and IC's, Davos, Switzerland; 1994. p. 339-40, and Matsuda H et al. Analysis of GTO failure mode during d.c. blocking. In: Proceedings of the sixth international symposium on power semiconductor devices and IC's, Davos, Switzerland; 1994. p. 221-5], an exact solution of the failure rate integral is derived and presented in a form which lends itself to be combined with the results available from commercial semiconductor simulation tools. Hence, failure rate integrals can be obtained with relative ease for realistic two- and even three-dimensional semiconductor geometries. Two case studies relating to IGBT cell design and planar junction termination layout demonstrate the purpose of the method.

  5. X-ray induced stellar mass loss near active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Voit, G. Mark; Shull, J. Michael

    1988-01-01

    The effects of UV and X-ray radiation on stars in active galactic nuclei (AGN) are critically evaluated. Mass loss rates in X-ray-induced winds are evaluated for realistic red giant models, and the effects of the ablation of stellar envelopes by radiation pressure are considered. The importance of X-ray-induced mass loss in the standard quasar model is evaluated and whether it can provide a source of accretion fuel or emission-line clouds is discussed. It is concluded that thermal winds driven by X-ray heating are a minor total supply of mass to AGN, but that thermal plus line-driven winds and stellar ablation may increase the mass loss and improve the chances for supplying a fraction of the necessary mass supply to the central object. It is speculated that when steady winds are inefficient, complex time-dependent processes due to X-ray energy injection deep into a stellar atmosphere could still release significant mass from stars.

  6. Gamma ray induced thermoluminescence properties of Eu{sup 3+} doped SnO{sub 2} phosphor

    SciTech Connect

    Chowdhury, M.; Sharma, S.K.; Lochab, S.P.

    2015-10-15

    Highlights: • TL properties of SnO{sub 2}:Eu{sup 3+} were reported upon γ-ray irradiation. • Effect of doping, irradiation dose and heating rate on TL properties were studied in detail. • The kinetic parameters associated with TL were calculated for first time in SnO{sub 2}:Eu{sup 3+}. • Existence of second-order kinetics indicates the occurrence of retrapping phenomena. • Retrapping of electrons at deep traps occurred due to thermal energy stimulation. - Abstract: This paper reports the thermoluminescence properties of Eu{sup 3+} doped SnO{sub 2} phosphors synthesized by combustion method. The thermoluminescence (TL) studies were carried out after irradiating the sample by γ-rays in the dose range 100 Gy to 1 KGy. The glow curves of γ-irradiated phosphors were resolved into two peaks, one centred at 116 °C and other at 300 °C. Intensity of the glow peak increases linearly in the studied dose range of γ-rays. Kinetic parameters such as order of kinetics, trap depth and frequency factor associated with the glow peak were calculated by various glow curve methods.

  7. Theory of reciprocating contact for viscoelastic solids

    NASA Astrophysics Data System (ADS)

    Putignano, Carmine; Carbone, Giuseppe; Dini, Daniele

    2016-04-01

    A theory of reciprocating contacts for linear viscoelastic materials is presented. Results are discussed for the case of a rigid sphere sinusoidally driven in sliding contact with a viscoelastic half-space. Depending on the size of the contact, the frequency and amplitude of the reciprocating motion, and on the relaxation time of the viscoelastic body, we establish that the contact behavior may range from the steady-state viscoelastic solution, in which traction forces always oppose the direction of the sliding rigid punch, to a more elaborate trend, which is due to the strong interaction between different regions of the path covered during the reciprocating motion. Practical implications span a number of applications, ranging from seismic engineering to biotechnology.

  8. Reciprocation and altruism in social cooperation.

    PubMed

    Safin, Vasiliy; Arfer, Kodi B; Rachlin, Howard

    2015-07-01

    Altruistic behavior benefits other individuals at a cost to oneself. The purpose of the present experiment was to study altruistic behavior by players (P) in 2-person iterated prisoner's dilemma games in which reciprocation by the other player (OP) was impossible, and this impossibility was clear to P. Altruism by P could not therefore be attributed to expectation of reciprocation. The cost to P of altruistic behavior was constant throughout the study, but the benefit to OP from P's cooperation differed between groups and conditions. Rate of cooperation was higher when benefit to OP was higher. Thus altruism (not attributable to expectation of reciprocation) can be a significant factor in interpersonal relationships as studied in iterated prisoner's dilemma games, and needs to be taken into account in their analysis. PMID:25907149

  9. Modelling fluid flow in a reciprocating compressor

    NASA Astrophysics Data System (ADS)

    Tuhovcak, Jan; Hejčík, Jiří; Jícha, Miroslav

    2015-05-01

    Efficiency of reciprocating compressor is strongly dependent on the valves characteristics, which affects the flow through the suction and discharge line. Understanding the phenomenon inside the compressor is necessary step in development process. Commercial CFD tools offer wide capabilities to simulate the flow inside the reciprocating compressor, however they are too complicated in terms of computational time and mesh creation. Several parameters describing compressor could be therefore examined without the CFD analysis, such is valve characteristic, flow through the cycle and heat transfer. The aim of this paper is to show a numerical tool for reciprocating compressor based on the energy balance through the cycle, which provides valve characteristics, flow through the cycle and heat losses from the cylinder. Spring-damping-mass model was used for the valve description. Boundary conditions were extracted from the performance test of 4-cylinder semihermetic compressor and numerical tool validation was performed with indicated p-V diagram comparison.

  10. Reciprocating Feed System Development Status

    NASA Technical Reports Server (NTRS)

    Trewek, Mary (Technical Monitor); Blackmon, James B.; Eddleman, David E.

    2005-01-01

    The reciprocating feed system (RFS) is an alternative means of providing high pressure propellant flow at low cost and system mass, with high fail-operational reliability. The RFS functions by storing the liquid propellants in large, low-pressure tanks and then expelling each propellant through two or three small, high-pressure tanks. Each RFS tank is sequentially filled, pressurized, expelled, vented, and refilled so as to provide a constant, or variable, mass flow rate to the engine. This type of system is much lighter than a conventional pressure fed system in part due to the greatly reduced amount of inert tank weight. The delivered payload for an RFS is superior to that of conventional pressure fed systems for conditions of high total impulse and it is competitive with turbopump systems, up to approximately 2000 psi. An advanced version of the RFS uses autogenous pressurization and thrust augmentation to achieve higher performance. In this version, the pressurization gases are combusted in a small engine, thus making the pressurization system, in effect, part of the propulsion system. The RFS appears to be much less expensive than a turbopump system, due to reduced research and development cost and hardware cost, since it is basically composed of small high- pressure tanks, a pressurization system, and control valves. A major benefit is the high reliability fail-operational mode; in the event of a failure in one of the three tank-systems, it can operate on the two remaining tanks. Other benefits include variable pressure and flow rates, ease of engine restart in micro-gravity, and enhanced propellant acquisition and control under adverse acceleration conditions. We present a system mass analysis tool that accepts user inputs for various design and mission parameters and calculates such output values payload and vehicle weights for the conventional pressure fed system, the RFS, the Autogenous Pressurization Thrust Augmentation (APTA) RFS, and turbopump systems

  11. Feasibility analysis of reciprocating magnetic heat pumps

    NASA Technical Reports Server (NTRS)

    Larson, A. V.; Hartley, J. G.; Shelton, Sam V.; Smith, M. M.

    1989-01-01

    A reciprocating gadolinium core in a regeneration fluid column in the warm bore of a superconducting solenoidal magnet is considered for magnetic refrigeration in 3.517 MW (1000 ton) applications. A procedure is presented to minimize the amount of superconducting cable needed in the magnet design. Estimated system capital costs for an ideal magnetic refrigerator of this type become comparable to conventional chillers as the frequency of reciprocation approaches 10 Hertz. A 1-D finite difference analysis of a regenerator cycling at 0.027 Hertz is presented which exhibits some of the features seen in the experiments of G. V. Brown.

  12. [The experience in employing reciprocal gait orthoses].

    PubMed

    Radło, W; Miklaszewski, K; Gasińska, M; Michno, P

    1999-01-01

    The paper presents the experience of the authors in employing reciprocal gait orthoses in a group of 23 patients age 3-25 years (mean age 7.8 years). The orthoses were indicated in patients with flaccid paresis (17 children with myelodysplasia and 3 patients with traumatic paraplegia) and with arthrogryposis (3 patients). The follow-up period was 6 months to 5 years (mean 2.4 years). The authors discuss the principles of construction and operation of reciprocal gait orthoses and types of patients in whom they are recommended. The principles of learning walking and using the orthosis are also presented. PMID:10367535

  13. From Born Reciprocity to Reciprocal Relativity: A Paradigm for Space-Time Physics

    NASA Astrophysics Data System (ADS)

    Jarvis, Peter

    Born's principle of reciprocity -- the exchangeability of relativistic energy-momentum and time-position -- can be seen as a discrete element of a continuous group of symmetry transformations which transcend relativity. Invariance under the semi-direct product of the Weyl-Heisenberg group H(4) of canonical commutation relations with the non-compact unitary group U(3, 1) -- the so-called quaplectic group U(3, 1) ⋉ H(4) -- has been considered by Low as an extension of Born reciprocity to a fundamental symmetry principle of `reciprocal relativity' for the physics of non-inertial frames and high energy processes...

  14. Effect of caffeine on the expression of a major X-ray induced protein in human tumor cells

    SciTech Connect

    Hughes, E.N.; Boothman, D.A. )

    1991-03-01

    We have examined the effect of caffeine on the concomitant processes of the repair of potentially lethal damage (PLD) and the synthesis of X-ray-induced proteins in the human malignant melanoma cell line, Ul-Mel. Caffeine administered at a dose of 5mM after X radiation not only inhibited PLD repair but also markedly reduced the level of XIP269, a major X-ray-induced protein whose expression has been shown to correlate with the capacity to repair PLD. The expression of the vast majority of other cellular proteins, including seven other X-ray-induced proteins, remained unchanged following caffeine treatment. A possible role for XIP269 in cell cycle delay following DNA damage by X irradiation is discussed.

  15. Tuition Reciprocity in the United States

    ERIC Educational Resources Information Center

    Stewart, Gregory; Wright, Dianne Brown; Kennedy, Angelica

    2008-01-01

    Reciprocity agreements are contracts between two or more parties whereby students pay reduced tuition rates. The rate of reduction is determined by the parameters set forth in each individual state's agreement but may range from a modest reduction in fees to a waiver of full non-resident tuition. In addition to providing tuition relief,…

  16. Evolving the ingredients for reciprocity and spite

    PubMed Central

    Hauser, Marc; McAuliffe, Katherine; Blake, Peter R.

    2009-01-01

    Darwin never provided a satisfactory account of altruism, but posed the problem beautifully in light of the logic of natural selection. Hamilton and Williams delivered the necessary satisfaction by appealing to kinship, and Trivers showed that kinship was not necessary as long as the originally altruistic act was conditionally reciprocated. From the late 1970s to the present, the kinship theories in particular have been supported by considerable empirical data and elaborated to explore a number of other social interactions such as cooperation, selfishness and punishment, giving us what is now a rich description of the nature of social relationships among organisms. There are, however, two forms of theoretically possible social interactions—reciprocity and spite—that appear absent or nearly so in non-human vertebrates, despite considerable research efforts on a wide diversity of species. We suggest that the rather weak comparative evidence for these interactions is predicted once we consider the requisite socioecological pressures and psychological mechanisms. That is, a consideration of ultimate demands and proximate prerequisites leads to the prediction that reciprocity and spite should be rare in non-human animals, and common in humans. In particular, reciprocity and spite evolved in humans because of adaptive demands on cooperation among unrelated individuals living in large groups, and the integrative capacities of inequity detection, future-oriented decision-making and inhibitory control. PMID:19805432

  17. Reciprocal Teaching. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2013

    2013-01-01

    "Reciprocal teaching" is an instructional method designed to help teach reading comprehension skills to students with adequate decoding proficiency. During initial instructional sessions, the teacher introduces four comprehension strategies: summarizing, questioning, clarifying, and predicting. Then, the teacher and student read several…

  18. Development of Trust and Reciprocity in Adolescence

    ERIC Educational Resources Information Center

    van den Bos, Wouter; Westenberg, Michiel; van Dijk, Eric; Crone, Eveline A.

    2010-01-01

    We investigate the development of two types of prosocial behavior, trust and reciprocity, as defined using a game-theoretical task that allows investigation of real-time social interaction, among 4 age groups from 9 to 25 years. By manipulating the possible outcome alternatives, we could distinguish among important determinants of trust and…

  19. Note: Loading method of molecular fluorine using x-ray induced chemistry

    SciTech Connect

    Pravica, Michael Sneed, Daniel; White, Melanie; Wang, Yonggang

    2014-08-15

    We have successfully loaded molecular fluorine into a diamond anvil cell at high pressure using the synchrotron x-ray induced decomposition of perfluorohexane (C{sub 6}F{sub 14}). “White” x-ray radiation from the Advanced Photon Source was used to initiate the chemical decomposition of C{sub 6}F{sub 14}, which resulted in the in situ production of F{sub 2} as verified via Raman spectroscopy. Due to the toxic nature of fluorine, this method will offer significant advantages in the ability to easily load a relatively nontoxic and inert substance into a chamber (such as a diamond anvil cell) that, when sealed with other reactants and irradiate with hard x-rays (>7 keV), releases highly reactive and toxic fluorine into the sample/reaction chamber to enable novel chemical synthesis under isolated and/or extreme conditions.

  20. Cosmic-Ray-Induced Ship-Effect Neutron Measurements and Implications for Cargo Scanning at Borders

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Seifert, Allen; Siciliano, Edward R.; Weier, Dennis R.; Windsor, Lindsay K.; Woodring, Mitchell L.; Borgardt, James D.; Buckley, Elise D.; Flumerfelt, Eric L.; Oliveri, Anna F.; Salvitti, Matthew

    2008-03-11

    Neutron measurements are used as part of the interdiction process for illicit nuclear materials at border crossings. Even though the natural neutron background is small, its variation can impact the sensitivity of detection systems. The natural background of neutrons that is observed in monitoring instruments arises almost entirely from cosmic ray induced cascades in the atmosphere and the surrounding environment. One significant source of variation in the observed neutron background is produced by the “ship effect” in large quantities of cargo that transit past detection instruments. This paper reports on results from measurements with typical monitoring equipment of ship effect neutrons in various materials. One new result is the “neutron shadow shielding” effect seen with some low neutron density materials.

  1. Familial Reciprocity and Subjective Well-Being in Ghana

    ERIC Educational Resources Information Center

    Tsai, Ming-Chang; Dzorgbo, Dan-Bright S.

    2012-01-01

    The authors investigated variations in reciprocity and the impact of reciprocity on well-being in a West African society. They hypothesized that household size and income diversity encourage reciprocity, which in turn enhances subjective well-being. In empirical testing of these hypotheses the authors used the data of the Core Welfare Indicators…

  2. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  3. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  4. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  5. 27 CFR 28.23 - Reciprocating foreign countries.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Reciprocating foreign... Lading for Use on Certain Vessels and Aircraft § 28.23 Reciprocating foreign countries. The appropriate... other countries, which it is claimed reciprocate similar privileges to aircraft of the United...

  6. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  7. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  8. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  9. Isochronal annealing study of X-ray induced defects in single- and double-walled carbon nanotubes

    SciTech Connect

    Murakami, Toshiya; Yamamoto, Yuki; Itoh, Chihiro; Kisoda, Kenji

    2013-09-21

    X-ray induced defects in single-walled (SWCNTs) and double-walled carbon nanotubes (DWCNTs) were characterized by Raman scattering spectroscopy. Frenkel defects, interstitial-vacancy pairs, were revealed to form in both SWCNTs and DWCNTs after X-ray irradiation because these defects were entirely healed by thermal annealing. In order to clarify the structure of the X-ray induced defect in SWCNT and DWCNT, isochronal-annealing experiments were performed on the irradiated samples and the activation energy for defect healing was estimated. The intensity of D band (defect induced band) on Raman spectra was used as a measure of the density of X-ray induced defects. The experimental results were in good agreement with the simulated values using second order reaction model, which indicated that the defect healing was determined by the migration energy of interstitials on the carbon layer. We also found that the activation energy for defect healing of SWCNT and DWCNT were around 0.5 eV and 0.32 eV, respectively. The X-ray induced defects in SWCNTs were more stable than those in DWCNTs. Compared these estimated activation energies to previous theoretical reports, we concluded that bridge and/or dumbbell interstitials are formed in both SWCNT and DWCNT by X-ray irradiation.

  10. Thermodynamic Constraints on Reflectance Reciprocity and Kirchhoff's Law.

    PubMed

    Snyder, W C; Wan, Z; Li, X

    1998-06-01

    Contrary to common belief, neither reciprocity of the bidirectional reflectance distribution function (BRDF) nor the directional form of Kirchhoff's electromagnetic radiation law can be demonstrated on the basis of energy conservation. The BRDF is generally considered reciprocal as an extension of Helmholtz reciprocity, but Helmholtz reciprocity does not always hold. We describe the flaw in a thermodynamic demonstration of reciprocity that uses an enclosure calculation. Some conclusions can be drawn from the enclosure calculation, but reciprocity requires more restrictive conditions. We conclude that, although they can be violated, reciprocity and the directional form of Kirchhoff's law generally hold because of the quantum-mechanical principle of time-reversal invariance, which applies to most materials. PMID:18273310

  11. Condition monitoring of reciprocating seal based on FBG sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Xiuxu; Zhang, Shuanshuan; Wen, Pengfei; Zhen, Wenhan; Ke, Wei

    2016-07-01

    The failure of hydraulic reciprocating seals will seriously affect the normal operation of hydraulic reciprocating machinery, so the potential fault condition monitoring of reciprocating seals is very important. However, it is extremely difficult because of the limitation of reciprocating motion and the structure constraints of seal groove. In this study, an approach using fiber Bragg grating (FBG) sensors is presented. Experimental results show that the contact strain changes of a reciprocating seal can be detected by FBG sensors in the operation process of the hydraulic cylinders. The failure condition of the reciprocating seal can be identified by wavelet packet energy entropy, and the center frequency of power spectrum analysis. It can provide an effective solution for the fault prevention and health management of reciprocating hydraulic rod seals.

  12. Induced Background in the Mars Observer Gamma-Ray Spectrometer

    NASA Technical Reports Server (NTRS)

    Boynton, William V.; Evans, Larry G.; Starr, Richard; Bruekner, Johnnes; Bailey, S. H.; Trombka, Jacob I.

    1997-01-01

    Gamma-Ray Spectrometers in space must necessarily work in an environment of a background of lines due to natural and cosmic-ray induced radioactivity and lines due to prompt emission following nuclear reactions caused by primary and secondary cosmic rays. The Gamma-Ray Spectrometer (GRS) on the Mar Observer mission has provided important data allowing one to estimate for future missions the extent of the background due to cosmic rays. These data will help in the design of instruments and in calculation of realistic background intensities that may effect the sensitivity of determining the intensity of lines of interest.

  13. Reciprocity in Adolescent and Caregiver Violence

    PubMed Central

    Bartle-Haring, Suzanne; Slesnick, Natasha; Carmona, Jasmin

    2014-01-01

    Over a 2-year period, with assessments every six months, the reciprocity in violent behaviors (verbal and physical) was investigated in a sample of 161 adolescents, who met the criteria for substance or alcohol abuse or dependence, and their caregivers, who participated in a clinical trial for family treatment for adolescent substance abuse. Using observed variables in a structural equation model with panel data, there was very little stability in violent behaviors across time from the perspectives of both the adolescents and caregivers. Evidence for violence reciprocity between adolescent and caregiver was demonstrated toward the end of the study period. The results are discussed in the context of previous literature about adolescent-to-parent violence. PMID:25684856

  14. Interdependent network reciprocity in evolutionary games

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Szolnoki, Attila; Perc, Matjaž

    2013-01-01

    Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent networks is not disturbed.

  15. Reciprocal Suffering: Caregiver Concerns During Hospice Care

    PubMed Central

    Wittenberg-Lyles, Elaine; Demiris, George; Oliver, Debra Parker; Burt, Stephanie

    2010-01-01

    Context For many hospice caregivers, the constancy and difficulty of caregiving impact their physical quality of life and cause depression, psychological distress, guilt, loneliness, and restrictions on social activities. Objectives Deviating from traditional unidimensional research on hospice caregivers, this study explored the transactional nature of reciprocal suffering by examining caregiver concerns through four dimensions: physical, psychological, social, and spiritual. Methods Researchers analyzed audiotapes of intervention discussions between hospice caregivers and research social workers. Results Results indicated that of the 125 pain talk utterances, the majority referenced psychological concern (49%), followed by physical (28%), social (22%), and spiritual (2%). Reflections on concerns revealed a global perspective of caregiving, which highlighted the patient’s needs juxtaposed to the caregiver’s recognized limitations. Conclusion By examining the reciprocal nature of suffering for caregivers, this study reinforced the need for assessing caregivers in hospice care, with specific emphasis on the importance of providing caregiver education on pain management. PMID:21146356

  16. Microelectromechanical reciprocating-tooth indexing apparatus

    SciTech Connect

    Allen, J.J..

    1999-09-28

    An indexing apparatus is disclosed that can be used to rotate a gear or move a rack in a precise, controllable manner. The indexing apparatus, based on a reciprocating shuttle driven by one or more actuators, can be formed either as a micromachine, or as a millimachine. The reciprocating shuttle of the indexing apparatus can be driven by a thermal, electrostatic or electromagnetic actuator, with one or more wedge-shaped drive teeth of the shuttle being moveable to engage and slide against indexing teeth on the gear or rack, thereby moving the gear or rack. The indexing apparatus can be formed by either surface micromachining processes or LIGA processes, depending on the size of the apparatus that is to be formed.

  17. Microelectromechanical reciprocating-tooth indexing apparatus

    DOEpatents

    Allen, James J.

    1999-01-01

    An indexing apparatus is disclosed that can be used to rotate a gear or move a rack in a precise, controllable manner. The indexing apparatus, based on a reciprocating shuttle driven by one or more actuators, can be formed either as a micromachine, or as a millimachine. The reciprocating shuttle of the indexing apparatus can be driven by a thermal, electrostatic or electromagnetic actuator, with one or more wedge-shaped drive teeth of the shuttle being moveable to engage and slide against indexing teeth on the gear or rack, thereby moving the gear or rack. The indexing apparatus can be formed by either surface micromachining processes or LIGA processes, depending on the size of the apparatus that is to be formed.

  18. Dynamic Reciprocity in the Wound Microenvironment

    PubMed Central

    Schultz, Gregory S.; Davidson, Jeffrey M.; Kirsner, Robert S.; Bornstein, Paul; Herman, Ira M.

    2011-01-01

    Here, we define dynamic reciprocity (DR) as an ongoing, bidirectional interaction amongst cells and their surrounding microenvironment. In the review, we posit that DR is especially meaningful during wound healing as the DR-driven biochemical, biophysical and cellular responses to injury play pivotal roles in regulating tissue regenerative responses. Such cell-extracellular matrix interactions not only guide and regulate cellular morphology, but cellular differentiation, migration, proliferation, and survival during tissue development, including e.g. embryogenesis, angiogenesis, as well as during pathologic processes including cancer diabetes, hypertension and chronic wound healing. Herein, we examine DR within the wound microenvironment while considering specific examples across acute and chronic wound healing. This review also considers how a number of hypotheses that attempt to explain chronic wound pathophysiology, which may be understood within the DR framework. The implications of applying the principles of dynamic reciprocity to optimize wound care practice and future development of innovative wound healing therapeutics are also briefly considered. PMID:21362080

  19. Cosmic-Ray-Induced Ionization in Molecular Clouds Adjacent to Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Schuppan, F.; Becker, J. K.; Black, J. H.; Casanova, S.; Mandelartz, M.

    Energetic gamma rays (GeV to TeV photon energy) have been detected toward several supernova remnants (SNR) that are associated with molecular clouds. If the gamma rays are produced mainly by hadronic processes rather than leptonic processes like bremsstrahlung, then the flux of energetic cosmic ray nuclei (>1GeV) required to produce the gamma rays can be inferred at the site where the particles are accelerated in SNR shocks. It is of great interest to understand the acceleration of the cosmic rays of lower energy (<1GeV) that accompany the energetic component. These particles of lower energy are most effective in ionizing interstellar gas, which leaves an observable imprint on the interstellar ion chemistry. A correlation of energetic gamma radiation with enhanced interstellar ionization can thus be used to support the hadronic origin of the gamma rays and to constrain the acceleration of ionizing cosmic rays in SNR. Using observational gamma ray data, the primary cosmic ray proton spectrum can be modeled for E>1GeV, and careful extrapolation of the spectrum to lower energies offers a method to calculate the ionization rate of the molecular cloud.

  20. Feasibility analysis of reciprocating magnetic heat pumps

    NASA Technical Reports Server (NTRS)

    Larson, A. V.; Hartley, J. G.; Shelton, S. V.; Smith, M. M.

    1986-01-01

    The conceptual design selected for detailed system analysis and optimization is the reciprocating gadolinium core in a regenerative fluid column within the bore of a superconducting magnet. The thermodynamic properties of gadolinium are given. A computerized literature search for relevant papers was conducted and is being analyzed. Contact was made with suppliers of superconducting magnets and accessories, magnetic materials, and various types of hardware. A description of the model for the thermal analysis of the core and regenerator fluids is included.

  1. Reciprocal allopreening in the Brownheaded Nuthatch

    USGS Publications Warehouse

    Barbour, D.B.; DeGange, A.R.

    1982-01-01

    In his extensive reviews of allopreening, Harrison (1965, 1969) did not record this behavior for the Sittidae, nor did Kilham (1968, 1972, 1973) mention observing this behavior in either White-breasted (Sitta carolinensis) or Red-breasted (S. canadensis) nuthatches. Norris (1958: 187), however, mentioned the occurrence of allopreening in Brown-headed Nuthatches (S. pusilia), in passing. Here we relate our observations of reciprocal allopreening between two Brown-headed Nuthatches.

  2. Variable-Aperture Reciprocating Reed Valve

    NASA Technical Reports Server (NTRS)

    Lindner, Jeffrey L. (Inventor); Myers, W. Neill (Inventor); Kelley, Anthony R. (Inventor); Yang, Hong Q. (Inventor)

    2015-01-01

    A variable-aperture reciprocating reed valve includes a valve body defining a through hole region having a contoured-profile portion. A semi-rigid plate is affixed on one side thereof to the valve body to define a cantilever extending across the through hole region. At least one free edge of the cantilever opposes the contoured-profile portion of the through hole region in a non-contact relationship.

  3. Time Domain Modelling of a Reciprocating Engine

    NASA Astrophysics Data System (ADS)

    Li, H.; Stone, B. J.

    1999-01-01

    This paper describes the application of a time domain systems approach to the modelling of a reciprocating engine. The engine model includes the varying inertia effects resulting from the motion of the piston and con-rod. The cylinder pressure measured under operating conditions is used to force the model and the resulting motion compared with the measured response. The results obtained indicate that the model is very good.

  4. Nutating spider crank reciprocating piston machine

    SciTech Connect

    Shaffer, J.E.

    1991-07-02

    This patent describes reciprocating piston apparatus. It comprises a housing; a shaft journalled on the housing for rotation about a shaft axis; a plurality of cylinders each having a central longitudinal axis and disposed parallel to the shaft axis and located on the housing at positions angularly-spaced circumferentially about the shaft; a plurality of double-acting pistons having piston axes and centers, each the piston having a transverse bore therein and being respectively mounted for reciprocation within corresponding ones of the cylinders, each the bore having a longitudinal central axis normal to the respective cylinder axis; a mutating spider having a central hub portion mounted on the shaft obliquely of the shaft axis, and having a plurality of branches extending radially outward from the hub portion and terminating at terminal ends; and means directly connecting the terminal ends centrally to corresponding ones of the bores for transferring motion between reciprocation of the pistons and rotation of the shaft, and for restraining the spider from rotating with the shaft.

  5. Compression ratio control in reciprocating piston engines

    SciTech Connect

    Doundoulakis, G.J.

    1989-08-29

    The patent describes compression ratio control for reciprocating piston engines. It comprises: a reciprocating engine crankcase; a plurality of compression/expansion cylinders rigidly attached to the crankcase; each of the cylinders including a curved surface and a cylinder head; a fuel mixture in-taken in the cylinders; a piston reciprocating along each cylinder's curved surface for providing compression/expansion to the fuel mixture; a crank mechanism including a crankshaft rotating about an axial line that is substantially equidistant from the heads, crankcheek lobes radially extending from the crankshaft, crankpins inside and in contact with crankpin bearings, axially extending between the crankcheek lobes, and crankshaft journal bearings for providing low frictional support to the crankshaft; a connecting rod for each of the cylinders connecting the piston with the crankpin; crankshaft positioning; a first transmission gear, a crankshaft gear for meshing with the transmission gear, and a slot cut on the crankcase; wherein the constraint in the displacement of the crankshaft in the horizontal sense is provided by the vertical edges of the slot, and wherein the vertical edges of the slot are preferably being curved with a radius of curvature substantially equal to the average pitch diameter of the crankshaft gear and thee first transmission gear for accurate meshing of the gears.

  6. The role of metal ions in X-ray-induced photochemistry

    NASA Astrophysics Data System (ADS)

    Stumpf, V.; Gokhberg, K.; Cederbaum, L. S.

    2016-03-01

    Metal centres in biomolecules are recognized as being particularly sensitive to radiation damage by X-ray photons. This results in such molecules being both susceptible to an effective X-ray-induced loss of function and problematic to study using X-ray diffraction methods, with reliable structures of the metal centres difficult to obtain. Despite the abundance of experimental evidence, the mechanistic details of radiation damage at metal centres are unclear. Here, using ab initio calculations, we show that the absorption of X-rays by microsolvated Mg2+ results in a complicated chain of ultrafast electronic relaxation steps that comprise both intra- and intermolecular processes and last for a few hundred femtoseconds. At the end of this cascade the metal reverts to its original charge state, the immediate environment becomes multiply ionized and large concentrations of radicals and slow electrons build up in the metal's vicinity. We conclude that such cascades involving metal ions are essential to our understanding of radiation chemistry and radiation damage in biological environments.

  7. X-ray Induced Luminescence Spectroscopy of Samarium Doped Barium Sulfate Prepared by Sintering Method

    NASA Astrophysics Data System (ADS)

    Kumeda, T.; Maeda, K.; Shirano, Y.; Fujiwara, K.; Sakai, K.; Ikari, T.

    2015-06-01

    X-ray induced luminescence (XL) properties of phosphor materials made of samarium doped barium sulfate have been investigated. The samples were prepared by sintering method heated at 900-1250 °C for 3 hours in air from the mixture of BaSO4 and Sm2O3. The concentration of Sm were prepared from 0.01-6 at.%. In as-prepared sample, the Sm3+ was detected by photoluminescence (PL). The PL intensity is maximum about 2 at.% with Sm, and then starts decreasing. The PL intensity showed concentration quenching. The XL observed Sm2+ and Sm3+ ions. The XL was shown from the sample sintered up to 1200 °C. The XL intensity increased with Sm concentration up to 1 at.%. The intensity was almost constant larger than 1 at.% Sm. These concentration dependences is different since the X-ray energy absorbed to the host material at once, and the energy transferred to both Sm3+ and Sm2+ ions. Sm doped BaSO4 is found a host for XL phosphor materials.

  8. Study of single and combined mass-sensitive observables of cosmic ray induced extensive air showers

    NASA Astrophysics Data System (ADS)

    Rastegarzadeh, G.; Nemati, M.

    2016-03-01

    In this study, combinations of the global arrival time, (Δτ_{global}), pseudorapidity, and lateral density distribution (ρ_{μ}) of muons, which are three mass-sensitive observables of cosmic ray induced extensive air showers, have been used as new parameters to study the primary mass discrimination around the knee energies (100 TeV-10 PeV). This is a simulation-based study and the simulations have been performed for the KASCADE array at Karlsruhe and the Alborz-I array at Tehran to study the effect of the altitude on the quality of the primary mass discrimination. The merit factors of the single and combined three mass-sensitive observables have been calculated to compare the discrimination power of combined and single observables. We have used the CORSIKA 7.4 code to simulate the extensive air showers (EASs) sample sets. Considering all aspects of our study, it is found that the ratio of the global time to the lateral density distribution of the muons gives better results than other ratios; also in the case of single observables, the muon density gives better results compared with the other observables. Also it is shown that below 1 PeV primary energies, the ratio of the muon global time to the muon density (Δτ_{global}/ρ_{μ}) results in a better mass discrimination relative to the muon density only.

  9. Measurements and simulations of the cosmic-ray-induced neutron background

    NASA Astrophysics Data System (ADS)

    Becchetti, M. F.; Flaska, M.; Clarke, S. D.; Pozzi, S. A.

    2015-03-01

    The cosmic-ray-induced neutron background at ground level has been measured and simulated in conjunction with EJ-309 organic liquid scintillators with an approximate deposited energy range of 0.5-6 MeV. Specifically, the pulse height distributions, net neutron count rates, and angular dependences were obtained. The simulations were carried out using the Monte Carlo transport code MCNPX-PoliMi combined with the (Cosmic-Ray Shower Generator) CRY source subroutine that returns secondary particles produced by cosmic rays. A scaling formula from literature was also implemented in the simulation. The angular dependence of the neutron count rate was measured by collimating the liquid scintillator with polyethylene to attain 18° angular resolution from 0° downwards to 72° horizontally. The neutron count rate was measured to be 23.10±1.69 h-1 sr-1 at 0°, and 7.20±0.78 h-1 sr-1 at 72°. The simulations and measurements compare well and show similar cosine anisotropy for the angular distribution. The study thus shows that the neutron background response in detector systems can be efficiently and accurately simulated using the procedures described.

  10. Neural correlate of human reciprocity in social interactions

    PubMed Central

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions

  11. X-ray-induced photo-chemistry and X-ray absorption spectroscopy of biological samples

    PubMed Central

    George, Graham N.; Pickering, Ingrid J.; Pushie, M. Jake; Nienaber, Kurt; Hackett, Mark J.; Ascone, Isabella; Hedman, Britt; Hodgson, Keith O.; Aitken, Jade B.; Levina, Aviva; Glover, Christopher; Lay, Peter A.

    2012-01-01

    As synchrotron light sources and optics deliver greater photon flux on samples, X-ray-induced photo-chemistry is increasingly encountered in X-ray absorption spectroscopy (XAS) experiments. The resulting problems are particularly pronounced for biological XAS experiments. This is because biological samples are very often quite dilute and therefore require signal averaging to achieve adequate signal-to-noise ratios, with correspondingly greater exposures to the X-ray beam. This paper reviews the origins of photo-reduction and photo-oxidation, the impact that they can have on active site structure, and the methods that can be used to provide relief from X-ray-induced photo-chemical artifacts. PMID:23093745

  12. Reciprocal invisibility cloak based on complementary media

    NASA Astrophysics Data System (ADS)

    Yang, J. J.; Huang, M.; Yang, C. F.; Yu, J.

    2011-02-01

    The first invisibility cloak was proposed by Pendry et al. [Science 312, 1780 (2006)]. But the object enclosed in this original cloak is "blind", that is, it cannot see the outside world, since no electromagnetic waves can reach within the cloaked space. Based on the concept of complementary media, we propose a reciprocal invisibility cloak, in which the hidden object can see the outside world, but its presence cannot be detected by electromagnetic wave. The performance of the cloak has been verified by full-wave simulations.

  13. Designing topological bands in reciprocal space.

    PubMed

    Cooper, N R; Moessner, R

    2012-11-21

    Motivated by new capabilities to realize artificial gauge fields in ultracold atomic systems, and by their potential to access correlated topological phases in lattice systems, we present a new strategy for designing topologically nontrivial band structures. Our approach is simple and direct: it amounts to considering tight-binding models directly in reciprocal space. These models naturally cause atoms to experience highly uniform magnetic flux density and lead to topological bands with very narrow dispersion, without fine-tuning of parameters. Further, our construction immediately yields instances of optical Chern lattices, as well as band structures with Chern numbers of magnitude larger than one. PMID:23215598

  14. X-ray-induced sterility in Aedes albopictus (Diptera: Culicidae) and male longevity following irradiation.

    PubMed

    Yamada, H; Parker, A G; Oliva, C F; Balestrino, F; Gilles, J R L

    2014-07-01

    The mosquito Aedes albopictus (Skuse, 1895) is a potent vector of several arboviral diseases, most notably chikungunya and dengue fever. In the context of the sterile insect technique (SIT), the sterilization of the male mosquitoes before their release can be achieved by gamma-ray irradiation. As gamma-ray irradiators are becoming increasingly problematic to purchase and transport, the suitability of an X-ray irradiator as an alternative for the sterilization of Ae. albopictus males was studied. The sterilization of up to 200,000 pupae at one time can be achieved with relative ease, and the sterility results obtained were comparable with those achieved by gamma irradiation, where 99% sterility is induced with a dose of 40 Gy. A significant reduction of longevity was observed in the latter stages of the males' life after irradiation treatments, especially at doses > 40 Gy, which is consistent with the negative effects on longevity induced by similar radiation doses using gamma rays. Females irradiated at 40 Gy were not only 100% sterile, but also failed to oviposit entirely, i.e., all of the females laid 0 eggs. Overall, it was found that the X-ray irradiator is generally suitable for the sterilization process for sterile insect technique programs, as it showed a high processing capacity, practicality, high effectiveness, and reproducibility. PMID:25118413

  15. Role of x-ray-induced transcripts in adaptive responses following x-rays

    SciTech Connect

    Boothman, D.A.

    1992-01-01

    Potentially lethal damage repair (PLDR) and sublethal damage repair, may be the same manifestations of a series of common enzymatic steps. PLDR, has two distinct phases based upon DNA lesion repair and survival recovery studies. The first phase of PLDR occurs very quickly (t{sub {1/2}}:2--20 mins) to increase the survival of X-irradiated cells by mending the vast array of DNA lesions created by ionizing radiation. The second slower phase of PLDR proceeds much later (i.e., >1--2 hrs) following X-irradiation, during which the remaining double-stranded DNA breaks are completely repaired. This second phase of repair closely corresponds to the restructuring of gross chromosomal damage, and can be partially blocked in some human cells by inhibiting protein synthesis. This slower phase of PLDR correlated with a rapid decline in X-ray-induced transformation of normal cells. The fast component of PLDR may be due to constitutively synthesized DNA ligases, topoisomerases, or polymerases, which act immediately to repair damaged, DNA. In contrast, the slow phase of PLDR in human cells may require the induction of specific genes and gene product's involved in the repair of potentially lethal or carcinogenic DNA lesions. Induced gene products (i.e., proteins) specifically synthesized in response to physiological doses of ionizing radiation in radioresistant human melanoma (U1-Mel) cells, and in a variety of other human normal and cancer-prone cells, were identified using two-dimensional gel electrophoresis. We identified and partially characterized ten proteins synthesized by U1-Mel cells. The synthesis of eight of these proteins were specifically induced by ionizing radiation and two proteins were repressed Neither heat shock, UV-irradiation, nor bifunctional alkylating agent treatments resulted in the induction of these proteins. The expression of one protein, XIP269, correlated very well with PLDR capacity.

  16. Genetics of x-ray induced double strand break repair in saccharomyces cerevisiae

    SciTech Connect

    Budd, M.E.

    1982-07-01

    The possible fates of x-ray-induced double-strand breaks in Saccharomyces cerevisiae were examined. One possible pathway which breaks can follow, the repair pathway, was studied by assaying strains with mutations in the RAD51, RAD54, and RAD57 loci for double-strand break repair. In order of increasing radiation sensitivity one finds: rad57-1(23/sup 0/)> rad51-1(30/sup 0/)> rad54-3(36/sup 0/). At 36/sup 0/, rad54-3 cells cannot repair double-strand breaks, while 23/sup 0/, they can. Strains with the rad57-1 mutation can rejoin broken chromosomes at both temperatures. However, the low survival at 36/sup 0/ shows that the assay is not distinguishing large DNA fragments which allow cell survival from those which cause cell death. A rad51-1 strain could also rejoin broken chromosomes, and was thus capable of incomplete repair. The data can be explained with the hypothesis that rad54-3 cells are blocked in an early step of repair, while rad51-1 and rad57-1 strains are blocked in a later step of repair. The fate of double-strand breaks when they are left unrepaired was investigated with the rad54-3 mutation. If breaks are prevented from entering the RAD54 repair pathway they become uncommitted lesions. These lesions are repaired slower than the original breaks. One possible fate for an uncommitted lesion is conversion into a fixed lesion, which is likely to be an unrepairable or misrepaired double-strand break. The presence of protein synthesis after irradiation increases the probability that a break will enter the repair pathway. Evidence shows that increased probability of repair results from enhanced synthesis of repair proteins shortly after radiation. (ERB)

  17. Reciprocating magnetic refrigerator employing tandem porous matrices within a reciprocating displacer

    NASA Technical Reports Server (NTRS)

    Johnson, D. L. (Inventor)

    1985-01-01

    Disclosed is a method and apparatus for a magnetic refrigeration system. A continuously reciprocating displacer houses at least a pair of paramagnetic substances each of which is alternately driven into and out of a magnetic field. Two separate bidirectional pumping systems flow helium gas through the displacer and through both paramagnetic substances to create heat exchange conditions at two separate temperature extremes.

  18. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem

    PubMed Central

    2016-01-01

    Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner’s dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system. PMID:27248493

  19. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem.

    PubMed

    Ozono, Hiroki; Kamijo, Yoshio; Shimizu, Kazumi

    2016-01-01

    Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner's dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system. PMID:27248493

  20. X-ray induced dimerization of cinnamic acid: Time-resolved inelastic X-ray scattering study

    PubMed Central

    Inkinen, Juho; Niskanen, Johannes; Talka, Tuomas; Sahle, Christoph J.; Müller, Harald; Khriachtchev, Leonid; Hashemi, Javad; Akbari, Ali; Hakala, Mikko; Huotari, Simo

    2015-01-01

    A classic example of solid-state topochemical reactions is the ultraviolet-light induced photodimerization of α-trans-cinnamic acid (CA). Here, we report the first observation of an X-ray-induced dimerization of CA and monitor it in situ using nonresonant inelastic X-ray scattering spectroscopy (NRIXS). The time-evolution of the carbon core-electron excitation spectra shows the effects of two X-ray induced reactions: dimerization on a short time-scale and disintegration on a long time-scale. We used spectrum simulations of CA and its dimerization product, α-truxillic acid (TA), to gain insight into the dimerization effects. From the time-resolved spectra, we extracted component spectra and time-dependent weights corresponding to CA and TA. The results suggest that the X-ray induced dimerization proceeds homogeneously in contrast to the dimerization induced by ultraviolet light. We also utilized the ability of NRIXS for direct tomography with chemical-bond contrast to image the spatial progress of the reactions in the sample crystal. Our work paves the way for other time-resolved studies on chemical reactions using inelastic X-ray scattering. PMID:26568420

  1. Dynamic Reciprocity in Cell-Scaffold Interactions

    PubMed Central

    Mauney, Joshua R.; Adam, Rosalyn M.

    2014-01-01

    Tissue engineering in urology has shown considerable promise. However, there is still much to understand, particularly regarding the interactions between scaffolds and their host environment, how these interactions regulate regeneration and how they may be enhanced for optimal tissue repair. In this review, we discuss the concept of dynamic reciprocity as applied to tissue engineering, i.e. how bi-directional signaling between implanted scaffolds and host tissues such as the bladder drives the process of constructive remodeling to ensure successful graft integration and tissue repair. The impact of scaffold content and configuration, the contribution of endogenous and exogenous bioactive factors, the influence of the host immune response and the functional interaction with mechanical stimulation are all considered. In addition, the temporal relationships of host tissue ingrowth, bioactive factor mobilization, scaffold degradation and immune cell infiltration, as well as the reciprocal signaling between discrete cell types and scaffolds are discussed. Improved understanding of these aspects of tissue repair will identify opportunities for optimization of repair that could be exploited to enhance regenerative medicine strategies for urology in future studies. PMID:25453262

  2. Reciprocating piston pump system with screw drive

    NASA Technical Reports Server (NTRS)

    Perkins, Gerald S. (Inventor); Moore, Nicholas R. (Inventor)

    1981-01-01

    A pump system of the reciprocating piston type is described, which facilitates direct motor drive and cylinder sealing. A threaded middle potion of the piston is engaged by a nut connected to rotate with the rotor of an electric motor, in a manner that minimizes loading on the rotor by the use of a coupling that transmits torque to the nut but permits it to shift axially and radially with respect to the rotor. The nut has a threaded hydrostatic bearing for engaging the threaded piston portion, with an oil-carrying groove in the nut being interrupted. A fluid emitting seal located at the entrance to each cylinder, can serve to center the piston within the cylinder, wash the piston, and to aid in sealing. The piston can have a long stroke to diameter ratio to minimize reciprocations and wear on valves at high pressures. The voltage applied to the motor can be reversed prior to the piston reaching the end of its stroke, to permit pressure on the piston to aid in reversing the motor.

  3. NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death

    SciTech Connect

    Liu Qing; He Xiaoqing; Liu Yongsheng; Du Bingbing; Wang Xiaoyan; Zhang Weisheng; Jia Pengfei; Dong Jingmei; Ma Jianxiu; Wang Xiaohu; Li Sha; Zhang Hong

    2008-12-19

    Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91{sup phox} was dose-dependent. Meanwhile, the cytoplasmic subunit p47{sup phox} was translocated to the cell membrane and localized with p22{sup phox} and gp91{sup phox} to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.

  4. Transient nature of cooperation by pay-it-forward reciprocity

    PubMed Central

    Horita, Yutaka; Takezawa, Masanori; Kinjo, Takuji; Nakawake, Yo; Masuda, Naoki

    2016-01-01

    Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainable. We carried out laboratory experiments of a pay-it-forward indirect reciprocity game (i.e., chained gift-giving game) on a large scale in terms of group size and time. We found that cooperation consistent with pay-it-forward reciprocity occurred only in a first few decisions per participant and that cooperation originated from inherent pro-sociality of individuals. In contrast, the same groups of participants showed persisting chains of cooperation in a different indirect reciprocity game in which participants earned reputation by cooperating. Our experimental results suggest that pay-it-forward reciprocity is transient and disappears when a person makes decisions repeatedly, whereas the reputation-based reciprocity is stable in the same situation. PMID:26786178

  5. Instructional Guidance in Reciprocal Peer Tutoring With Task Cards

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Elen, Jan; Behets, Daniel

    2010-01-01

    This article addresses the issue of instructional guidance in reciprocal peer tutoring with task cards as learning tools. Eighty-six Kinesiology students (age 17-19 years) were randomized across four reciprocal peer tutoring settings, differing in quality and quantity of guidance, to learn Basic Life Support (BLS) with task cards. The separate and…

  6. Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism

    PubMed Central

    Campennì, Marco

    2016-01-01

    Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated “social relationships” and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions. PMID:26998412

  7. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    ERIC Educational Resources Information Center

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; van der Werf, Greetje

    2012-01-01

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-lagged panel model of reciprocal effects between…

  8. 26 CFR 521.116 - Reciprocal administrative assistance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 19 2011-04-01 2010-04-01 true Reciprocal administrative assistance. 521.116... of Denmark and of Danish Corporations § 521.116 Reciprocal administrative assistance. (a) General. (1) By Article XVII of the convention, the United States and Denmark adopt the principle of exchange...

  9. Using Excel's Matrix Operations to Facilitate Reciprocal Cost Allocations

    ERIC Educational Resources Information Center

    Leese, Wallace R.; Kizirian, Tim

    2009-01-01

    The reciprocal method of service department cost allocation requires linear equations to be solved simultaneously. These computations are often so complex as to cause the abandonment of the reciprocal method in favor of the less sophisticated direct or step-down methods. Here is a short example demonstrating how Excel's sometimes unknown matrix…

  10. Reciprocal Borrowing Patterns in the North Suburban Library System.

    ERIC Educational Resources Information Center

    Able Consultants, DeKalb, IL.

    During a 5-day period in 1990, a total of 1,401 reciprocal borrowers in the North Suburban Library System (NSLS) received questionnaires asking about their choice of library and other aspects of borrowing behavior to provide data on the reciprocal borrowing characteristics and patterns within the system. This survey was designed to identify the…

  11. 2005 Reciprocity Agreements and Other Student Exchange Options

    ERIC Educational Resources Information Center

    Washington Higher Education Coordinating Board, 2005

    2005-01-01

    The Higher Education Coordinating Board (HECB) is required by state law to report to the governor and legislature every two years on the status of Washington's state-level reciprocity agreements with Idaho, Oregon, and British Columbia. Reciprocity agreements allow some Washington students to attend public colleges in other states and pay lower…

  12. Accepting Roles Created for Us: The Ethics of Reciprocity.

    ERIC Educational Resources Information Center

    Powell, Katrina M.; Takayoshi, Pamela

    2003-01-01

    Argues that seeing reciprocity as a context-based process of definition and re-definition of the relationship between participants and researchers helps them understand how research projects can benefit participants in ways that they desire. Considers the ethical dimensions of reciprocal research relationships. Uses the authors' own research…

  13. An Analysis of Direct Reciprocal Borrowing among Quebec University Libraries

    ERIC Educational Resources Information Center

    Duy, Joanna C.; Lariviere, Vincent

    2013-01-01

    An analysis of Quebec academic libraries' direct reciprocal borrowing statistics from 2005 to 2010 reveals that the physical distance separating universities plays an important role in determining the amount of direct reciprocal borrowing activity conducted between institutions. Significant statistical correlations were also seen between the…

  14. Similarity and Reciprocity in the Friendships of Elementary School Children.

    ERIC Educational Resources Information Center

    Clark, M. L.; Drewry, Debra L.

    1985-01-01

    Investigated the effect of similarity and reciprocity on dyadic friendship choices in third- and sixth-grade students. Reciprocal (mutual) friendships were more similar in proximity, popularity, and self-concept than those in nonreciprocal (nonmutual) dyads. Results are discussed in relation to the interpersonal attraction theories. (Author/DST)

  15. 47 CFR 51.711 - Symmetrical reciprocal compensation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Symmetrical reciprocal compensation. 51.711 Section 51.711 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Traffic § 51.711 Symmetrical reciprocal compensation. (a) Rates for transport and termination of...

  16. Rethinking natural altruism: simple reciprocal interactions trigger children's benevolence.

    PubMed

    Cortes Barragan, Rodolfo; Dweck, Carol S

    2014-12-01

    A very simple reciprocal activity elicited high degrees of altruism in 1- and 2-y-old children, whereas friendly but nonreciprocal activity yielded little subsequent altruism. In a second study, reciprocity with one adult led 1- and 2-y-olds to provide help to a new person. These results question the current dominant claim that social experiences cannot account for early occurring altruistic behavior. A third study, with preschool-age children, showed that subtle reciprocal cues remain potent elicitors of altruism, whereas a fourth study with preschoolers showed that even a brief reciprocal experience fostered children's expectation of altruism from others. Collectively, the studies suggest that simple reciprocal interactions are a potent trigger of altruism for young children, and that these interactions lead children to believe that their relationships are characterized by mutual care and commitment. PMID:25404334

  17. Does food sharing in vampire bats demonstrate reciprocity?

    PubMed

    Carter, Gerald; Wilkinson, Gerald

    2013-11-01

    Claims of reciprocity (or reciprocal altruism) in animal societies often ignite controversy because authors disagree over definitions, naturalistic studies tend to demonstrate correlation not causation, and controlled experiments often involve artificial conditions. Food sharing among common vampire bats has been a classic textbook example of reciprocity, but this conclusion has been contested by alternative explanations. Here, we review factors that predict food sharing in vampire bats based on previously published and unpublished data, validate previous published results with more precise relatedness estimates, and describe current evidence for and against alternative explanations for its evolutionary stability. Although correlational evidence indicates a role for both direct and indirect fitness benefits, unequivocally demonstrating reciprocity in vampire bats still requires testing if and how bats respond to non-reciprocation. PMID:24505498

  18. Quantitative genetically nonequivalent reciprocal crosses in cultivated plants.

    PubMed

    Aksel, R

    Quantitative expressions of character difference between reciprocal crosses have been studied by different researchers in a number of plant species, such as Epilobium, Zea mays, Oryza sativa, Hordeum sativum, Triticum aestivum, Trifolium hybridum, Linum usitatissimum, Nicotiana rustica, and others. In all cases it was found that the nonequivalence of reciprocal crosses manifested itself beginning with the F1 generation, with the exception of some flax crosses in which reciprocals differed beginning with the F2 generation. The nonequivalence of reciprocal crosses usually manifested itself in the inequality of their F1 and/or F2 or backcross means; however, there were instances in which their means were the same but the variances were different. Both matroclinous and patroclinous inheritances were reported in plants. Because of the casual complexity of reciprocal differences the experimental results often lack a simple explanation. PMID:1032105

  19. Reciprocal and unidirectional scattering of parity-time symmetric structures

    PubMed Central

    Jin, L.; Zhang, X. Z.; Zhang, G.; Song, Z.

    2016-01-01

    Parity-time symmetry is of great interest. The reciprocal and unidirectional features are intriguing besides the symmetry phase transition. Recently, the reciprocal transmission, unidirectional reflectionless and invisibility are intensively studied. Here, we show the reciprocal reflection/transmission in -symmetric system is closely related to the type of symmetry, that is, the axial (reflection) symmetry leads to reciprocal reflection (transmission). The results are further elucidated by studying the scattering of rhombic ring form coupled resonators with enclosed synthetic magnetic flux. The nonreciprocal phase shift induced by the magnetic flux and gain/loss break the parity and time-reversal symmetry but keep the parity-time symmetry. The reciprocal reflection (transmission) and unidirectional transmission (reflection) are found in the axial (reflection) -symmetric ring centre. The explorations of symmetry and asymmetry from symmetry may shed light on novel one-way optical devices and application of -symmetric metamaterials. PMID:26876806

  20. Linkage map construction involving a reciprocal translocation.

    PubMed

    Farré, A; Benito, I Lacasa; Cistué, L; de Jong, J H; Romagosa, I; Jansen, J

    2011-03-01

    This paper is concerned with a novel statistical-genetic approach for the construction of linkage maps in populations obtained from reciprocal translocation heterozygotes of barley (Hordeum vulgare L.). Using standard linkage analysis, translocations usually lead to 'pseudo-linkage': the mixing up of markers from the chromosomes involved in the translocation into a single linkage group. Close to the translocation breakpoints recombination is severely suppressed and, as a consequence, ordering markers in those regions is not feasible. The novel strategy presented in this paper is based on (1) disentangling the "pseudo-linkage" using principal coordinate analysis, (2) separating individuals into translocated types and normal types and (3) separating markers into those close to and those more distant from the translocation breakpoints. The methods make use of a consensus map of the species involved. The final product consists of integrated linkage maps of the distal parts of the chromosomes involved in the translocation. PMID:21153624

  1. Sleep and exercise: a reciprocal issue?

    PubMed

    Chennaoui, Mounir; Arnal, Pierrick J; Sauvet, Fabien; Léger, Damien

    2015-04-01

    Sleep and exercise influence each other through complex, bilateral interactions that involve multiple physiological and psychological pathways. Physical activity is usually considered as beneficial in aiding sleep although this link may be subject to multiple moderating factors such as sex, age, fitness level, sleep quality and the characteristics of the exercise (intensity, duration, time of day, environment). It is therefore vital to improve knowledge in fundamental physiology in order to understand the benefits of exercise on the quantity and quality of sleep in healthy subjects and patients. Conversely, sleep disturbances could also impair a person's cognitive performance or their capacity for exercise and increase the risk of exercise-induced injuries either during extreme and/or prolonged exercise or during team sports. This review aims to describe the reciprocal fundamental physiological effects linking sleep and exercise in order to improve the pertinent use of exercise in sleep medicine and prevent sleep disorders in sportsmen. PMID:25127157

  2. Balancing mechanism for reciprocating piston engine

    SciTech Connect

    Murata, N.; Ogino, T.

    1987-04-14

    This patent describes a balancing mechanism for a reciprocating piston internal combustion engine which includes a cylinder, a piston reciprocatable in the cylinder, a crankcase, a crankshaft mounted in the crankshaft, a crankpin connected to the piston, and a pair of crank arms bridging the crankshaft and crankpin. The crank arms and crankpin rotate with the crankshaft during operation and form a rotating mass. The balancing mechanism comprises at least one rotating counterweight attached to and rotating with the crankshaft, and eccentric journal means on the crankshaft adjacent the crank arms, rotating with the crankshaft. The journal means has an axis spaced to the side of the crankshaft axis which is opposite from the crankpin. The rotating counterweight and the eccentric journal means counterbalancing the rotating mass.

  3. Numerical analysis of flows in reciprocating engines

    NASA Astrophysics Data System (ADS)

    Takata, H.; Kojima, M.

    1986-07-01

    A numerical method of the analysis for three-dimensional turbulent flow in cylinders of reciprocating engines with arbitrary geometry is described. A scheme of the finite volume/finite element methods is used, employing a large number of small elements of arbitrary shapes to form a cylinder. The fluid dynamic equations are expressed in integral form for each element, taking into account the deformation of the element shape according to the piston movements, and are solved in the physical space using rectangular coordinates. The conventional k-epsilon two-equation model is employed to describe the flow turbulence. Example calculations are presented for simple pancake-type combustion chambers having an annular intake port at either center or asymmetric position of the cylinder head. The suction inflow direction is also changed in several ways. The results show a good simulation of overall fluid movements within the engine cylinder.

  4. An experimental reciprocating expander for cryocooler application

    NASA Technical Reports Server (NTRS)

    Minta, M.; Smith, J. L., Jr.

    1985-01-01

    An experimental reciprocating expander was designed with features appropriate for cryocooler cycles. The expander has a displacer piston, simple valves, and a hydraulic/pneumatic stroking mechanism. The expander has a valve in head configuration with the valves extending out the bottom of the vacuum enclosure while the piston extends out the top. The expander was tested using a CTI 1400 liquefier to supply 13 atm in the temperature range 4.2 to 12 K. Expander efficiency was measured in the range 84 to 93% while operating the apparatus as a supercritical wet expander and in the range 91 to 93% aa a single phase expander. The apparatus can also be modified to operate as a compressor for saturated helium vapor.

  5. Thermal Powered Reciprocating-Force Motor

    NASA Technical Reports Server (NTRS)

    Tatum, III, Paul F. (Inventor); McDow Elliott, Amelia (Inventor)

    2015-01-01

    A thermal-powered reciprocating-force motor includes a shutter switchable between a first position that passes solar energy and a second position that blocks solar energy. A shape memory alloy (SMA) actuator is coupled to the shutter to control switching thereof between the shutter's first and second position. The actuator is positioned with respect to the shutter such that (1) solar energy impinges on the SMA when the shutter is in its first position so that the SMA experiences contraction in length until the shutter is switched to its second position, and (2) solar energy is impeded from impingement on the SMA when the shutter is in its second position so that the SMA experiences extension in length. Elastic members coupled to the actuator apply a force to the SMA that aids in its extension in length until the shutter is switched to its first position.

  6. Reciprocal relativity of noninertial frames: quantum mechanics

    NASA Astrophysics Data System (ADS)

    Low, Stephen G.

    2007-04-01

    Noninertial transformations on time-position-momentum-energy space {t, q, p, e} with invariant Born-Green metric ds^{2}=-d t^{2}+\\frac{1}{c^{2}}\\,d q^{2}+\\frac{1}{b^{2}} \\big(d p^{2}-\\frac{1}{c^{2}}\\,d e^{2}\\big) and the symplectic metric -de ∧ dt + dp ∧ dq are studied. This {\\cal U}1,3) group of transformations contains the Lorentz group as the inertial special case and, in the limit of small forces and velocities, reduces to the expected Hamilton transformations leaving invariant the symplectic metric and the nonrelativistic line element ds2 = -dt2. The {\\cal U}( 1,3) transformations bound relative velocities by c and relative forces by b. Spacetime is no longer an invariant subspace but is relative to noninertial observer frames. In the limit of b → ∞, spacetime is invariant. Born was lead to the metric by a concept of reciprocity between position and momentum degrees of freedom and for this reason we call this reciprocal relativity. For large b, such effects will almost certainly only manifest in a quantum regime. Wigner showed that special relativistic quantum mechanics follows from the projective representations of the inhomogeneous Lorentz group. Projective representations of a Lie group are equivalent to the unitary representations of its central extension. The same method of projective representations for the inhomogeneous {\\cal U}( 1,3) group is used to define the quantum theory in the noninertial case. The central extension of the inhomogeneous {\\cal U}( 1,3) group is the cover of the quaplectic group {\\cal Q}( 1,3) ={\\cal U}( 1,3) \\otimes _{s}{\\cal H}(4) . {\\cal H}( 4) is the Weyl-Heisenberg group. The {\\cal H}( 4) group, and the associated Heisenberg commutation relations central to quantum mechanics, results directly from requiring projective representations. A set of second-order wave equations result from the representations of the Casimir operators.

  7. X-ray-induced cell death in the developing hippocampal complex involved neurons and requires protein synthesis

    SciTech Connect

    Ferrer, I.; Serrano, T.; Alcantara, S.; Tortosa, A.; Graus, F.

    1993-07-01

    Sprague-Dawley rats aged 1 or 15 days were irradiated with a single dose of 200 cGy X-rays and killed at different intervals from 3 to 48 hours (h). Dying cells were recognized by their shrunken and often fragmented nuclei and less damaged cytoplasm in the early stages. On the basis of immunocytochemical markers, dying cells probably represented a heterogeneous population which included neurons and immature cells. In rats aged 1 day the number of dying cells rapidly increased in the hippocampal complex with peak values 6 h after irradiation. This was following by a gentle decrease to reach normal values 48 h after irradiation. The most severely affected regions were the subplate and the cellular layer of the subiculum, gyrus dentatus and hilus, and the stratum oriens and pyramidale of the hippocampus (CA1 more affected than CA2, and this more affected than CA3). X-ray-induced cell death was abolished with an injection of cycloheximide (2 [mu]g/g i.p.) given at the time of irradiation. X-ray-induced cell death was not changed after the intraventicular administration of nerve growth factor (NGF; 10 [mu]g in saline) at the time of irradiation. Cell death was not induced by X-irradiation in rats aged 15 days. These results indicate that X-ray-induced cell death in the hippocampal complex of the developing rat is subjected to determinate temporal and regional patterns of vulnerability; it is an active process mediated by protein synthesis but probably not dependent on NGF. 60 refs., 5 figs.

  8. Near optimal graphene terahertz non-reciprocal isolator

    PubMed Central

    Tamagnone, Michele; Moldovan, Clara; Poumirol, Jean-Marie; Kuzmenko, Alexey B.; Ionescu, Adrian M.; Mosig, Juan R.; Perruisseau-Carrier, Julien

    2016-01-01

    Isolators, or optical diodes, are devices enabling unidirectional light propagation by using non-reciprocal optical materials, namely materials able to break Lorentz reciprocity. The realization of isolators at terahertz frequencies is a very important open challenge made difficult by the intrinsically lossy propagation of terahertz radiation in current non-reciprocal materials. Here we report the design, fabrication and measurement of a terahertz non-reciprocal isolator for circularly polarized waves based on magnetostatically biased monolayer graphene, operating in reflection. The device exploits the non-reciprocal optical conductivity of graphene and, in spite of its simple design, it exhibits almost 20 dB of isolation and only 7.5 dB of insertion loss at 2.9 THz. Operation with linearly polarized light can be achieved using quarter-wave plates as polarization converters. These results demonstrate the superiority of graphene with respect to currently used terahertz non-reciprocal materials and pave the way to a novel class of optimal non-reciprocal devices. PMID:27048760

  9. Near optimal graphene terahertz non-reciprocal isolator

    NASA Astrophysics Data System (ADS)

    Tamagnone, Michele; Moldovan, Clara; Poumirol, Jean-Marie; Kuzmenko, Alexey B.; Ionescu, Adrian M.; Mosig, Juan R.; Perruisseau-Carrier, Julien

    2016-04-01

    Isolators, or optical diodes, are devices enabling unidirectional light propagation by using non-reciprocal optical materials, namely materials able to break Lorentz reciprocity. The realization of isolators at terahertz frequencies is a very important open challenge made difficult by the intrinsically lossy propagation of terahertz radiation in current non-reciprocal materials. Here we report the design, fabrication and measurement of a terahertz non-reciprocal isolator for circularly polarized waves based on magnetostatically biased monolayer graphene, operating in reflection. The device exploits the non-reciprocal optical conductivity of graphene and, in spite of its simple design, it exhibits almost 20 dB of isolation and only 7.5 dB of insertion loss at 2.9 THz. Operation with linearly polarized light can be achieved using quarter-wave plates as polarization converters. These results demonstrate the superiority of graphene with respect to currently used terahertz non-reciprocal materials and pave the way to a novel class of optimal non-reciprocal devices.

  10. Near optimal graphene terahertz non-reciprocal isolator.

    PubMed

    Tamagnone, Michele; Moldovan, Clara; Poumirol, Jean-Marie; Kuzmenko, Alexey B; Ionescu, Adrian M; Mosig, Juan R; Perruisseau-Carrier, Julien

    2016-01-01

    Isolators, or optical diodes, are devices enabling unidirectional light propagation by using non-reciprocal optical materials, namely materials able to break Lorentz reciprocity. The realization of isolators at terahertz frequencies is a very important open challenge made difficult by the intrinsically lossy propagation of terahertz radiation in current non-reciprocal materials. Here we report the design, fabrication and measurement of a terahertz non-reciprocal isolator for circularly polarized waves based on magnetostatically biased monolayer graphene, operating in reflection. The device exploits the non-reciprocal optical conductivity of graphene and, in spite of its simple design, it exhibits almost 20 dB of isolation and only 7.5 dB of insertion loss at 2.9 THz. Operation with linearly polarized light can be achieved using quarter-wave plates as polarization converters. These results demonstrate the superiority of graphene with respect to currently used terahertz non-reciprocal materials and pave the way to a novel class of optimal non-reciprocal devices. PMID:27048760

  11. Advanced Natural Gas Reciprocating Engine(s)

    SciTech Connect

    Kwok, Doris; Boucher, Cheryl

    2009-09-30

    Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

  12. Reciprocity and gyrotropism in magnetic resonance transduction

    NASA Astrophysics Data System (ADS)

    Tropp, James

    2006-12-01

    We give formulas for transduction in magnetic resonance—i.e., the appearance of an emf due to Larmor precession of spins—based upon the modified Lorentz reciprocity principle for gyrotropic (also called “nonreciprocal”) media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields, oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e., (H1x±iH1y) , where, e.g., for a single transceive antenna, the H ’s are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are swapped

  13. Reciprocity and gyrotropism in magnetic resonance transduction

    SciTech Connect

    Tropp, James

    2006-12-15

    We give formulas for transduction in magnetic resonance - i.e., the appearance of an emf due to Larmor precession of spins - based upon the modified Lorentz reciprocity principle for gyrotropic (also called 'nonreciprocal') media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields, oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e. (H{sub 1x}{+-}iH{sub 1y}), where, e.g., for a single transceive antenna, the H's are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are

  14. Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry

    SciTech Connect

    Atri, Dimitra; Melott, Adrian L.; Thomas, Brian C. E-mail: melott@ku.edu

    2010-05-01

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV. An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV–1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.

  15. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    SciTech Connect

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  16. Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

    NASA Astrophysics Data System (ADS)

    Swiderski, L.; Moszyński, M.; Wolski, D.; Iwanowska, J.; Szczęśniak, T.; Schotanus, P.; Hurlbut, C.

    2011-10-01

    Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60- keVee and 4 MeVee. The measurements were carried out under irradiation from an intense 137Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.

  17. Accumulation of DSBs in {gamma}-H2AX domains fuel chromosomal aberrations

    SciTech Connect

    Scherthan, H. Hieber, L.; Braselmann, H.; Meineke, V.; Zitzelsberger, H.

    2008-07-11

    DNA double strand breaks (DSBs) pose a severe hazard to the genome as erroneous rejoining of DSBs can lead to mutation and cancer. Here, we have investigated the correlation between X irradiation-induced {gamma}-H2AX foci, theoretically induced DSBs, and the minimal number of mis-rejoined DNA breaks (MNB) in irradiated lymphocytes obtained from two healthy humans by painting of the whole chromosome complement by spectral karyotyping. There were less {gamma}-H2AX foci/dose than theoretically expected, while misrepair, as expressed by MNB/{gamma}-H2AX focus, was similar at 0.5 and 1 Gy but 3.6-fold up at 3 Gy. Hence, our results suggest that X-ray-induced {gamma}-H2AX foci in G0 lymphocyte nuclei contain more than one DSB and that the increasing number of DSBs per {gamma}-H2AX repair factory lead to an increased rate of misrepair.

  18. Reciprocal Paracrine Interactions Between Normal Human Epithelial and Mesenchymal Cells Protect Cellular DNA from Radiation-Induced Damage

    SciTech Connect

    Nakazawa, Yuka; Saenko, Vladimir Rogounovitch, Tatiana; Suzuki, Keiji; Mitsutake, Norisato; Matsuse, Michiko; Yamashita, Shunichi

    2008-06-01

    Purpose: To explore whether interactions between normal epithelial and mesenchymal cells can modulate the extent of radiation-induced DNA damage in one or both types of cells. Methods and Materials: Human primary thyrocytes (PT), diploid fibroblasts BJ, MRC-5, and WI-38, normal human mammary epithelial cells (HMEC), and endothelial human umbilical cord vein endothelial cells (HUV-EC-C), cultured either individually or in co-cultures or after conditioned medium transfer, were irradiated with 0.25 to 5 Gy of {gamma}-rays and assayed for the extent of DNA damage. Results: The number of {gamma}-H2AX foci in co-cultures of PT and BJ fibroblasts was approximately 25% lower than in individual cultures at 1 Gy in both types of cells. Reciprocal conditioned medium transfer to individual cultures before irradiation resulted in approximately a 35% reduction of the number {gamma}-H2AX foci at 1 Gy in both types of cells, demonstrating the role of paracrine soluble factors. The DNA-protected state of cells was achieved within 15 min after conditioned medium transfer; it was reproducible and reciprocal in several lines of epithelial cells and fibroblasts, fibroblasts, and endothelial cells but not in epithelial and endothelial cells. Unlike normal cells, human epithelial cancer cells failed to establish DNA-protected states in fibroblasts and vice versa. Conclusions: The results imply the existence of a network of reciprocal interactions between normal epithelial and some types of mesenchymal cells mediated by soluble factors that act in a paracrine manner to protect DNA from genotoxic stress.

  19. Focal plane scanner with reciprocating spatial window

    NASA Technical Reports Server (NTRS)

    Mao, Chengye (Inventor)

    2000-01-01

    A focal plane scanner having a front objective lens, a spatial window for selectively passing a portion of the image therethrough, and a CCD array for receiving the passed portion of the image. All embodiments have a common feature whereby the spatial window and CCD array are mounted for simultaneous relative reciprocating movement with respect to the front objective lens, and the spatial window is mounted within the focal plane of the front objective. In a first embodiment, the spatial window is a slit and the CCD array is one-dimensional, and successive rows of the image in the focal plane of the front objective lens are passed to the CCD array by an image relay lens interposed between the slit and the CCD array. In a second embodiment, the spatial window is a slit, the CCD array is two-dimensional, and a prism-grating-prism optical spectrometer is interposed between the slit and the CCD array so as to cause the scanned row to be split into a plurality of spectral separations onto the CCD array. In a third embodiment, the CCD array is two-dimensional and the spatial window is a rectangular linear variable filter (LVF) window, so as to cause the scanned rows impinging on the LVF to be bandpass filtered into spectral components onto the CCD array through an image relay lens interposed between the LVF and the CCD array.

  20. Experimental Assessment of the Reciprocating Feed System

    NASA Technical Reports Server (NTRS)

    Eddleman, David E.; Blackmon, James B.; Morton, Christopher D.

    2006-01-01

    The primary goal of this project was to design, construct, and test a full scale, high pressure simulated propellant feed system test bed that could evaluate the ability of the Reciprocating Feed System (RFS) to provide essentially constant flow rates and pressures to a rocket engine. The two key issues addressed were the effects of the transition of the drain cycle from tank to tank and the benefits of other hardware such as accumulators to provide a constant pressure flow rate out of the RFS. The test bed provided 500 psi flow at rates of the order of those required for engines in the 20,000 lbf thrust class (e.g., 20 to 40 lb/sec). A control system was developed in conjunction with the test article and automated system operation was achieved. Pre-test planning and acceptance activities such as a documented procedure and hazard analysis were conducted and the operation of the test article was approved by, and conducted in coordination with, appropriate NASA Marshall Space Flight Center personnel under a Space Act Agreement. Tests demonstrated successful control of flow rates and pressures.

  1. 19. View northwest of Tropic Chamber reciprocal compressors (typical), in ...

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

    19. View northwest of Tropic Chamber reciprocal compressors (typical), in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  2. Drift stabilizer for reciprocating free-piston devices

    DOEpatents

    Ward, William C.; Corey, John A.; Swift, Gregory W.

    2003-05-20

    A free-piston device has a stabilized piston drift. A piston having a frequency of reciprocation over a stroke length and with first and second sides facing first and second variable volumes, respectively, for containing a working fluid defining an acoustic wavelength at the frequency of reciprocation. A bypass tube waveguide connects the first and second variable volumes at all times during reciprocation of the piston. The waveguide has a relatively low impedance for steady flow and a relatively high impedance for oscillating flow at the frequency of reciprocation of the piston, so that steady flow returns fluid leakage from about the piston between the first and second volumes while oscillating flow is not diverted through the waveguide. Thus, net leakage about the piston is returned during each stroke of the piston while oscillating leakage is not allowed and pressure buildup on either the first or second side of the piston is avoided to provide a stable piston location.

  3. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DMV(s) per reciprocal agreements. In the absence of electronic communication technology, the... information on exchanging and obtaining information with civilian law enforcement agencies concerning... licensing authorities. Upon receipt of written or other official law enforcement communication relative...

  4. Effects of Reciprocal Peer Counseling on College Student Personality Development.

    ERIC Educational Resources Information Center

    McWilliams, Spencer A.

    1979-01-01

    This report describes a project in which college students were briefly trained to work as counselors in reciprocating peer relationships and compares the effectiveness of peer counseling with traditional professional counseling. (JD)

  5. Reciprocal Rights and Responsibilities in Parent-Child Relations

    ERIC Educational Resources Information Center

    Baumrind, Diana

    1978-01-01

    This article examines critically the case for protecting children's rights as against the case for protecting children's welfare. The principle of reciprocity in parent-child relations is rejected. (Author/AM)

  6. Research on networked manufacturing system for reciprocating pump industry

    NASA Astrophysics Data System (ADS)

    Wu, Yangdong; Qi, Guoning; Xie, Qingsheng; Lu, Yujun

    2005-12-01

    Networked manufacturing is a trend of reciprocating pump industry. According to the enterprises' requirement, the architecture of networked manufacturing system for reciprocating pump industry was proposed, which composed of infrastructure layer, system management layer, application service layer and user layer. Its main functions included product data management, ASP service, business management, and customer relationship management, its physics framework was a multi-tier internet-based model; the concept of ASP service integration was put forward and its process model was also established. As a result, a networked manufacturing system aimed at the characteristics of reciprocating pump industry was built. By implementing this system, reciprocating pump industry can obtain a new way to fully utilize their own resources and enhance the capabilities to respond to the global market quickly.

  7. 14 CFR 121.175 - Airplanes: Reciprocating engine-powered: Weight limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) No person may take off a reciprocating engine powered airplane from an airport located at an...) No person may take off a reciprocating engine powered airplane for an airport of intended destination... the reciprocating engine powered airplane concerned. (d) No person may take off a reciprocating...

  8. Bah humbug: Unexpected Christmas cards and the reciprocity norm.

    PubMed

    Meier, Brian P

    2016-01-01

    The reciprocity norm refers to the expectation that people will help those who helped them. A well-known study revealed that the norm is strong with Christmas cards, with 20% of people reciprocating a Christmas card received from a stranger. I attempted to conceptually replicate and extend this effect. In Study 1, 755 participants received a Christmas card supposedly from a more- versus less-similar stranger. The reciprocation rate was unexpectedly low (2%), which did not allow for a test of a similarity effect. Two potential reasons for this low rate were examined in Study 2 in which 494 participants reported their likelihood of reciprocating a Christmas card from a stranger as well as their felt suspicions/threat about the card and their frequency of e-mail use. Reciprocation likelihood was negatively correlated with perceived threat/suspicion and e-mail use. It appears that reciprocating a gift from a stranger in offline settings may be less likely than expected. PMID:26666577

  9. Indirect reciprocity in three types of social dilemmas.

    PubMed

    Nakamura, Mitsuhiro; Ohtsuki, Hisashi

    2014-08-21

    Indirect reciprocity is a key mechanism for the evolution of human cooperation. Previous studies explored indirect reciprocity in the so-called donation game, a special class of Prisoner's Dilemma (PD) with unilateral decision making. A more general class of social dilemmas includes Snowdrift (SG), Stag Hunt (SH), and PD games, where two players perform actions simultaneously. In these simultaneous-move games, moral assessments need to be more complex; for example, how should we evaluate defection against an ill-reputed, but now cooperative, player? We examined indirect reciprocity in the three social dilemmas and identified twelve successful social norms for moral assessments. These successful norms have different principles in different dilemmas for suppressing cheaters. To suppress defectors, any defection against good players is prohibited in SG and PD, whereas defection against good players may be allowed in SH. To suppress unconditional cooperators, who help anyone and thereby indirectly contribute to jeopardizing indirect reciprocity, we found two mechanisms: indiscrimination between actions toward bad players (feasible in SG and PD) or punishment for cooperation with bad players (effective in any social dilemma). Moreover, we discovered that social norms that unfairly favor reciprocators enhance robustness of cooperation in SH, whereby reciprocators never lose their good reputation. PMID:24721479

  10. Modeling high-energy cosmic ray induced terrestrial muon flux: A lookup table

    NASA Astrophysics Data System (ADS)

    Atri, Dimitra; Melott, Adrian L.

    2011-06-01

    On geological timescales, the Earth is likely to be exposed to an increased flux of high-energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma-ray bursts or by galactic shocks. Typical cosmic ray energies may be much higher than the ≤1GeV flux which normally dominates. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the radiation dose. Muons contribute 85% to the radiation dose from cosmic rays. This enhanced dose could be potentially harmful to the biosphere. This mechanism has been discussed extensively in literature but has never been quantified. Here, we have developed a lookup table that can be used to quantify this effect by modeling terrestrial muon flux from any arbitrary cosmic ray spectra with 10 GeV to 1 PeV primaries. This will enable us to compute the radiation dose on terrestrial planetary surfaces from a number of astrophysical sources.