136 research outputs found

    Morphology and systematic position of some Anomalinid foraminifera

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    Morphological studies of the following species are the basis for a partial revision of the Family Anomalinadae: Anomalina acuta Plummer, A. midwayensis (Plummer), A. pseudopapillosa Carsey, A. vulgaris (Plummer), Anomalinoides pinguis (Jennings), Cibicides alleni (Plummer), C. beaumontianus (d’Orbigny), c. harperi (Sandidge), Cibicidina danvillensis (Howe and Wallace), Planulina correcta (Carsey), and P. dumblei (Applin); a description of Stensioina americana Cushman and Dorsey, discorbid foraminifer, is included for comparison. The classificatory position and incomplete content of the family are: Superfamily Discorbidea; Family Anomalinidae; Subfamily Anomalininae (revised) -- with ventral supplementary apertures: Anomalina , Planulina ; Subfamily Cibicidinae -- with dorsal supplementary apertures: Cibicides , Cibicidina , Anomalinoides . The anomalinid wall consists of radially crystalline calcium carbonate, deposited in successive enveloping lamellae, characteristic for the superfamily. In detail, the basic structure of the anomalinid and discorbid wall consists of (1) external and internal chitinoid films that also line the pores; (2) the lamellar calcareous wall; and (3) a black line within the septum and varyingly within the outer wall, composed of organic and calcareous particles. Mural pores are large, but of variable size, in the Anomalinidae; in pores large enough for the details to be seen, each is covered by a finely perforate sieve plate, near its external opening. Specific contributions of this report are: (1) emendation of the Anomalininae; (2) confirming presence of supplementary apertures in Anomalina and Planulina ; (3) transfer of Anomalinoides to the Cibicidinae; (4) synonymizing Gavelinella with Anomalina ; (5) transfer of Cibicides vulgaris to Anomalina ; (6) discovery of the detailed wall structure in anomalinid and discorbid species; (7) recognition of sieve plates in the Anomalinidae; and (8) recognition that Hofker’s “deuteropores” are simply large pores with contained sieve plates --Abstract, pages 1-2

    Outlawry: Another Gothic Column in North Carolina

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    A New Interpretation of Flux Quantization

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    We study the effect of Aharonov-Bohm flux on the superconducting state in metallic cylinders. Although Byers and Yang attributed flux quantization to the flux-dependent minimum of kinetic energies of the Cooper pairs, it is shown that kinetic energies do not produce any discernible oscillations in the free energy of the superconducting state (relative to that of normal state) as a function of the flux. This result is indeed anticipated by the observation of persistent current in normal metal rings at low temperature. Instead, we have found that pairing interaction depends on the flux, leading to flux quantization. When the flux (Φ(\Phi) is given by Φ=nĂ—hc/2e\Phi=n\times hc/2e (with integer n), the pairing interaction and the free energy become unchanged (even n) or almost unchanged (odd n), due to degenerate-state pairing resulting from the energy level crossing. As a result, flux quantization and Little-Parks oscillations follow.Comment: Revtex, 10 pages, 6 figures, For more information, send me an e-mail at [email protected]

    Validation of MIPAS IMK/IAA methane profiles

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    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is an infrared (IR) limb emission spectrometer on the Envisat platform. It measures trace gas distributions during day and night, pole-to-pole, over an altitude range from 6 to 70 km in nominal mode and up to 170 km in special modes, depending on the measurement mode, producing more than 1000 profiles day-1. We present the results of a validation study of methane, version V5R-CH4-222, retrieved with the IMK/IAA (Institut für Meteorologie und Klimaforschung, Karlsruhe/Instituto de Astrofisica de Andalucia, Grenada) MIPAS scientific level 2 processor. The level 1 spectra are provided by the ESA (European Space Agency) and version 5 was used. The time period covered is 2005-2012, which corresponds to the period when MIPAS measured trace gas distributions at a reduced spectral resolution of 0.0625 cm-1. The comparison with satellite instruments includes the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), the HALogen Occultation Experiment (HALOE), the Solar Occultation For Ice Experiment (SOFIE) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). Furthermore, comparisons with MkIV balloon-borne solar occultation measurements and with air sampling measurements performed by the University of Frankfurt are presented. The validation activities include bias determination, assessment of stability, precision validation, analysis of histograms and comparison of corresponding climatologies. Above 50 km altitude, MIPAS methane mixing ratios agree within 3 % with ACE-FTS and SOFIE. Between 30 and 40 km an agreement within 3 % with SCIAMACHY has been found. In the middle stratosphere, there is no clear indication of a MIPAS bias since comparisons with various instruments contradict each other. In the lower stratosphere (below 25 km) MIPAS CH4 is biased high with respect to satellite instruments, and the most likely estimate of this bias is 14 %. However, in the comparison with CH4 data obtained from cryogenic whole-air sampler (cryosampler) measurements, there is no evidence of a high bias in MIPAS between 20 and 25 km altitude. Precision validation is performed on collocated MIPAS-MIPAS pairs and suggests a slight underestimation of its uncertainties by a factor of 1.2. No significant evidence of an instrumental drift has been found. © Author(s) 2015

    Fluxoid dynamics in superconducting thin film rings

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    We have measured the dynamics of individual magnetic fluxoids entering and leaving photolithographically patterned thin film rings of the underdoped high-temperature superconductor Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta}, using a variable sample temperature scanning SQUID microscope. These results can be qualitatively described using a model in which the fluxoid number changes by thermally activated nucleation of a Pearl vortex in, and transport of the Pearl vortex across, the ring wall.Comment: 9 pages, 10 figures, fixed typo

    Quantization of Superflow Circulation and Magnetic Flux with a Tunable Offset

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    Quantization of superflow-circulation and of magnetic-flux are considered for systems, such as superfluid 3^3He-A and unconventional superconductors, having nonscalar order parameters. The circulation is shown to be the anholonomy in the parallel transport of the order parameter. For multiply-connected samples free of distributed vorticity, circulation and flux are predicted to be quantized, but generically to nonintegral values that are tunably offset from integers. This amounts to a version of Aharonov-Bohm physics. Experimental settings for testing these issues are discussed.Comment: 5 two-column pages, ReVTeX, figure available upon request (to [email protected]

    Effects of Microgravity or Simulated Launch on Testicular Function in Rats

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    Testes from flight rats on COSMOS 2044 and simulated-launch, vivarium, or caudal-elevation control rats (5/group) were analyzed by subjective and quantitative methods. On the basis of observations of fixed tissue, it was evident that some rats had testicular abnormalities unassociated with treatment and probably existing when they were assigned randomly to the four treatment groups. Considering rats without preexisting abnormalities, diameter of seminiferous tubules and numbers of germ cells per tubule cross section were lower (P less than 0.05) in flight than in simulated-launch or vivarium rats. However, ratios of germ cells to each other or to Sertoli cells and number of homogenization-resistant spermatids did not differ from values for simulated-launch or vivarium controls. Expression of testis-specific gene products was not greatly altered by flight. Furthermore, there was no evidence for production of stress-inducible transcripts of the hsp7O or hsp9O genes. Concentration of receptors for rat luteinizing hormone in testicular tissue and surface density of smooth endoplasmic reticulum in Leydig cells were similar in flight and simulated-launch rats. However, concentrations of testosterone in testicular tissue or peripheral blood plasma were reduced (P less than 0.05) in flight rats to less than 20% of values for simulated-launch or vivarium controls. Thus spermatogenesis was essentially normal in flight rats, but production of testosterone was severely depressed. Exposure to microgravity for more than 2 wk might result in additional changes. Sequelae of reduced androgen production associated with microgravity on turnover of muscle and bone should be considered

    Metacognitions about desire thinking predict the severity of binge eating in a sample of Italian women

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    In this study, our principal aim was to investigate whether metacognitions about desire thinking predict the severity of binge eating in women and, if so, whether this relationship is independent of age, self-reported body mass index (BMI), negative affect, irrational food beliefs and craving. One hundred and four women, consisting of 32 consecutive patients with binge eating disorder undergoing initial assessment for cognitive therapy for eating disorders, 39 moderate binge eaters, and 33 non-binge eaters (both from the general population), completed the following measures: Self-reported BMI, Hospital Anxiety and Depression Scale, Irrational Food Beliefs Scale, General Craving Scale, Metacognitions about Desire Thinking Questionnaire, and Binge Eating Scale. A series of Spearman's rho correlation analyses revealed that self-reported BMI, anxiety, depression, irrational food beliefs, craving, and all three factors of the metacognitions about desire thinking questionnaire were significantly associated with the severity of binge eating. A stepwise regression analysis identified self-reported BMI, craving, and negative metacognitions about desire thinking as significant predictors of the severity of binge eating. These results, taken together, highlight the possible role of metacognitions about desire thinking in predicting the severity of binge eating. The clinical implications of these findings are discussed

    Dilation of the Giant Vortex State in a Mesoscopic Superconducting Loop

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    We have experimentally investigated the magnetisation of a mesoscopic aluminum loop at temperatures well below the superconducting transition temperature TcT_{c}. The flux quantisation of the superconducting loop was investigated with a μ\mu-Hall magnetometer in magnetic field intensities between ±100Gauss\pm 100 {Gauss}. The magnetic field intensity periodicity observed in the magnetization measurements is expected to take integer values of the superconducting flux quanta Φ0=h/2e\Phi_{0}=h/2e. A closer inspection of the periodicity, however, reveal a sub flux quantum shift. This fine structure we interpret as a consequence of a so called giant vortex state nucleating towards either the inner or the outer side of the loop. These findings are in agreement with recent theoretical reports.Comment: 12 pages, 5 figures. Accepted for publication in Phys. Rev.
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