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Sample records for bk990025 cobe trima

  1. COBE Sea Surface Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The COBE-SST is a gridded 1x1 resolution SST monitoring dataset. It is used as input for the JMA Climate Data Assimilation System (JCDAS) and the Japanese 25-year...

  2. COBE: A Radiological Analysis

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-10-01

    Full Text Available The COBE Far Infrared Absolute Spectrophotometer (FIRAS operated from ~30 to ~3,000 GHz (1-95 cm$^{-1}$ and monitored, from polar orbit (~900 km, the ~3 K microwave background. Data released from FIRAS has been met with nearly universal admiration. However, a thorough review of the literature reveals significant problems with this instrument. FIRAS was designed to function as a differential radiometer, wherein the sky signal could be nulled by the reference horn, Ical. The null point occurred at an Ical temperature of 2.759 K. This was 34 mK above the reported sky temperature, 2.725$pm$0.001 K, a value where the null should ideally have formed. In addition, an 18 mK error existed between the thermometers in Ical, along with a drift in temperature of ~3 mK. A 5 mK error could be attributed to Xcal; while a 4 mK error was found in the frequency scale. A direct treatment of all these systematic errors would lead to a ~64 mK error bar in the microwave background temperature. The FIRAS team reported ~1 mK, despite the presence of such systematic errors. But a 1 mK error does not properly reflect the experimental state of this spectrophotometer. In the end, all errors were essentially transferred into the calibration files, giving the appearance of better performance than actually obtained. The use of calibration procedures resulted in calculated Ical emissivities exceeding 1.3 at the higher frequencies, whereas an emissivity of 1 constitutes the theoretical limit. While data from 30-60 GHz was once presented, these critical points are later dropped, without appropriate discussion, presumably because they reflect too much microwave power. Data obtained while the Earth was directly illuminating the sky antenna, was also discarded. From 300-660 GHz, initial FIRAS data had systematically growing residuals as frequencies increased. This suggested that the signal was falling too quickly in the Wien region of the spectrum. In later data releases, the

  3. COBE: A Radiological Analysis

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-10-01

    Full Text Available The COBE Far Infrared Absolute Spectrophotometer (FIRAS operated from 30 to 3,000 GHz (1–95 cm -1 and monitored, from polar orbit ( 900 km, the 3 K mi- crowave background. Data released from FIRAS has been met with nearly universal ad- miration. However, a thorough review of the literature reveals significant problems with this instrument. FIRAS was designed to function as a differential radiometer, wherein the sky signal could be nulled by the reference horn, Ical. The null point occurred at an Ical temperature of 2.759 K. This was 34 mK above the reported sky temperature, 2.725 0.001 K, a value where the null should ideally have formed. In addition, an 18 mK error existed between the thermometers in Ical, along with a drift in temper- ature of 3 mK. A 5 mK error could be attributed to Xcal; while a 4 mK error was found in the frequency scale. A direct treatment of all these systematic errors would lead to a 64 mK error bar in the microwave background temperature. The FIRAS team reported 1 mK, despite the presence of such systematic errors. But a 1 mK er- ror does not properly reflect the experimental state of this spectrophotometer. In the end, all errors were essentially transferred into the calibration files, giving the appear- ance of better performance than actually obtained. The use of calibration procedures resulted in calculated Ical emissivities exceeding 1.3 at the higher frequencies, whereas an emissivity of 1 constitutes the theoretical limit. While data from 30–60 GHz was once presented, these critical points are later dropped, without appropriate discussion, presumably because they reflect too much microwave power. Data obtained while the Earth was directly illuminating the sky antenna, was also discarded. From 300–660 GHz, initial FIRAS data had systematically growing residuals as frequencies increased. This suggested that the signal was falling too quickly in the Wien region of the spec- trum. In later data

  4. Medžių trimačių modelių generavimo įrankio kūrimas

    OpenAIRE

    Šukytė, Jolanta

    2010-01-01

    Bakalauro baigiamojo darbo tikslas – sukurti įrankį, generuojantį trimačių medžių modelius. Sukurtas medžių generatorius (įrankis) pritaikytas Lietuvos rinkai. Generuoja Lietuvoje augančių skirtingų rūšių, trimačių medžių modelius, pagal vartotojo įvestus parametrus. Generatorius realizuotas naudojantis 3ds Max programa ir jos sava MAXScript kalba. The purpose of this bachelor‘s work is creation of a tool, used for generation of three dimentional trees. The created tool is designed for Lit...

  5. COBE looks back to the Big Bang

    Science.gov (United States)

    Mather, John C.

    1993-01-01

    An overview is presented of NASA-Goddard's Cosmic Background Explorer (COBE), the first NASA satellite designed to observe the primeval explosion of the universe. The spacecraft carries three extremely sensitive IR and microwave instruments designed to measure the faint residual radiation from the Big Bang and to search for the formation of the first galaxies. COBE's far IR absolute spectrophotometer has shown that the Big Bang radiation has a blackbody spectrum, proving that there was no large energy release after the explosion.

  6. COBE-DMR-Normalized Dark Energy Cosmogony

    OpenAIRE

    Mukherjee, Pia; Banday, Anthony J.; Riazuelo, Alain; Górski, Krzysztof M.; Ratra, Bharat

    2003-01-01

    Likelihood analyses of the COBE-DMR sky maps are used to determine the normalization of the inverse-power-law-potential scalar field dark energy model. Predictions of the DMR-normalized model are compared to various observations to constrain the allowed range of model parameters. Although the derived constraints are restrictive, evolving dark energy density scalar field models remain an observationally-viable alternative to the constant cosmological constant model.

  7. Constraints from microlensing on the COBE bar

    Science.gov (United States)

    Zhao, H. S.

    Since the first review of converging evidences for a bar in the center of the Galaxy by de Zeeuw (1992) at the IAU Sym. 153 in Gent five years ago, the Galactic bar idea has been put on a solid footing by an influx of new data (COBE/DIRBE maps, star count data of bulge red clump giants, microlensing optical depth, and bulge stellar proper motions, etc.) and a burst of increasingly sophisticated theoretical models (triaxial luminosity models of Dwek et al. 1994, and Binney, Gerhard & Spergel 1997, steady state stellar bar dynamical model of Zhao 1996, combined luminosity, microlensing and gas kinematics models of Zhao, Rich & Spergel 1996, and Bissantz et al. 1997, etc.), which fit new data and improve upon earlier simple bulge/bar models (Kent 1992, Binney et al. 1991, Blitz & Spergel 1991). While research in this field shifts more and more to constraining the exact phase space and parameter space of the bar, both the non-uniqueness of and the mismatches among bars from different datasets start to show up. I compare the bar from microlensing data with the COBE bar and point out the effects the non-uniqueness.

  8. Inflation after COBE: Lectures on inflationary cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S. [Chicago Univ., IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)

    1992-12-31

    In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge-a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for and the fundamentals of inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the ``initial data`` for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models.

  9. COBE's search for structure in the Big Bang

    Science.gov (United States)

    Soffen, Gerald (Editor); Guerny, Gene (Editor); Keating, Thomas (Editor); Moe, Karen (Editor); Sullivan, Walter (Editor); Truszkowski, Walt (Editor)

    1989-01-01

    The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle.

  10. Assessment of Models of Galactic Thermal Dust Emission Using COBE/FIRAS and COBE/DIRBE Observations

    CERN Document Server

    Odegard, N; Chuss, D T; Miller, N J

    2016-01-01

    Accurate modeling of the spectrum of thermal dust emission at millimeter wavelengths is important for improving the accuracy of foreground subtraction for CMB measurements, for improving the accuracy with which the contributions of different foreground emission components can be determined, and for improving our understanding of dust composition and dust physics. We fit four models of dust emission to high Galactic latitude COBE/FIRAS and COBE/DIRBE observations from 3 millimeters to 100 microns and compare the quality of the fits. We consider the two-level systems model because it provides a physically motivated explanation for the observed long wavelength flattening of the dust spectrum and the anticorrelation between emissivity index and dust temperature. We consider the model of Finkbeiner, Davis, and Schlegel because it has been widely used for CMB studies, and the generalized version of this model recently applied to Planck data by Meisner and Finkbeiner. For comparison we have also fit a phenomenologic...

  11. Bone marrow processing for transplantation using Cobe Spectra cell separator.

    Science.gov (United States)

    Veljković, Dobrila; Nonković, Olivera Šerbić; Radonjić, Zorica; Kuzmanović, Miloš; Zečević, Zeljko

    2013-06-01

    Concentration of bone marrow aspirates is an important prerequisite prior to infusion of ABO incompatible allogeneic marrow and prior to cryopreservation and storage of autologous marrow. In this paper we present our experience in processing 15 harvested bone marrow for ABO incompatible allogeneic and autologous bone marrow (BM) transplantation using Cobe Spectra® cell separator. BM processing resulted in the median recovery of 91.5% CD34+ cells, erythrocyte depletion of 91% and volume reduction of 81%. BM processing using cell separator is safe and effective technique providing high rate of erythrocyte depletion and volume reduction, and acceptable recovery of the CD34+ cells.

  12. Comparison of performance of Trima and Amicus blood cell separators%Trima与Amicus两种血细胞分离机的性能比较

    Institute of Scientific and Technical Information of China (English)

    王彦; 陈麟凤; 师红梅; 李卉; 汪德清

    2015-01-01

    Objective To contrastively analyze the performance of two kinds of blood cell separators for apheresis platelets . Methods 80 blood donors were selected from 4 234 healthy apheresis platelet donors and their data before and after apheresis platelets were respectively collected by using two kinds of different blood cell separators Trima and Amicus .The product quality during the collection process ,residual WBC and RBC count ,acquisition time ,collection efficiency ,scrapping situation and safety were performed the comparative analysis between the two kinds of blood cell separator .Results In the case of the difference of the basic parameters before apheresis platelet having no statistical significance ,the two kinds of blood cell separator had no differences in the aspects of product quality ,processing blood amount and the use amount of anticoagulants(P>0 .05);but there were statisti‐cal differences in the aspects of acquisition time ,collection efficiency and pipeline residual blood amount (P<0 .05) .Conclusion Two kinds of blood cell separators have their own advantages and disadvantages during the use process ,so the blood cell separator should be selected according to the physical quality and their own characteristics of blood donors .%目的:对比分析两种血细胞分离机单采血小板的性能。方法从健康机采血小板献血员4234名中,选取80名献血员前后使用两种不同血细胞分离机T rima和Amicus采集数据,比较分析两种不同的血细胞分离机采集过程中的产品质量、残余白细胞和红细胞计数、采集时间、采集效率、报废情况及安全性等方面。结果在两种血细胞分离机的献血员采集前基本参数差异无统计学意义的情况下,两种血细胞分离机采集的产品质量方面、处理血量和抗凝剂使用量方面差异无统计学意义(P>0.05);但是两种血细胞分离机在采集时间、采集效率和管道残余血量方面进行比

  13. Assessment of Models of Galactic Thermal Dust Emission Using COBE/FIRAS and COBE/DIRBE Observations

    Science.gov (United States)

    Odegard, N.; Kogut, A.; Chuss, D. T.; Miller, N. J.

    2016-09-01

    Accurate modeling of the spectrum of thermal dust emission at millimeter wavelengths is important for improving the accuracy of foreground subtraction for cosmic microwave background (CMB) measurements, for improving the accuracy with which the contributions of different foreground emission components can be determined, and for improving our understanding of dust composition and dust physics. We fit four models of dust emission to high Galactic latitude COBE/FIRAS and COBE/DIRBE observations from 3 mm to 100 μm and compare the quality of the fits. We consider the two-level systems (TLS) model because it provides a physically motivated explanation for the observed long wavelength flattening of the dust spectrum and the anti-correlation between emissivity index and dust temperature. We consider the model of Finkbeiner et al. because it has been widely used for CMB studies, and the generalized version of this model that was recently applied to Planck data by Meisner and Finkbeiner. For comparison we have also fit a phenomenological model consisting of the sum of two graybody components. We find that the two-graybody model gives the best fit and the FDS model gives a significantly poorer fit than the other models. The Meisner and Finkbeiner model and the TLS model remain viable for use in Galactic foreground subtraction, but the FIRAS data do not have a sufficient signal-to-noise ratio to provide a strong test of the predicted spectrum at millimeter wavelengths.

  14. The COBE normalization for standard cold dark matter

    Science.gov (United States)

    Bunn, Emory F.; Scott, Douglas; White, Martin

    1995-01-01

    The Cosmic Background Explorer Satellite (COBE) detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. This normalization is usually given for an n = 1 spectrum, including only the anisotropy caused by the Sachs-Wolfe effect. This is certainly not a good approximation for a model containing any reasonable amount of baryonic matter. In fact, even tilted Sachs-Wolfe spectra are not a good fit to models like cold dark matter (CDM). Here, we normalize standard CDM (sCDM) to the two-year COBE data and quote the best amplitude in terms of the conventionally used measures of power. We also give normalizations for some specific variants of this standard model, and we indicate how the normalization depends on the assumed values on n, Omega(sub B) and H(sub 0). For sCDM we find the mean value of Q = 19.9 +/- 1.5 micro-K, corresponding to sigma(sub 8) = 1.34 +/- 0.10, with the normalization at large scales being B = (8.16 +/- 1.04) x 10(exp 5)(Mpc/h)(exp 4), and other numbers given in the table. The measured rms temperature fluctuation smoothed on 10 deg is a little low relative to this normalization. This is mainly due to the low quadrupole in the data: when the quadrupole is removed, the measured value of sigma(10 deg) is quite consistent with the best-fitting the mean value of Q. The use of the mean value of Q should be preferred over sigma(10 deg), when its value can be determined for a particular theory, since it makes full use of the data.

  15. Report on 3- and 4-Point Correlation Statistics in COBE DMR Anisotropy Maps

    Science.gov (United States)

    Hinshaw, Gary; Gorski, Krzystof M.; Bennett, Charles L.; Banday, Anthony J.

    1996-01-01

    As part of the work performed under this contract, we have computed the 3- and 4-point correlation functions of the COBE-DMR 2-year and 4-year anisotropy maps. The results of our work showed that the 3-point correlation function is consistent with zero and that the 4-point function is not a very sensitive probe of non-Gaussian behavior in the COBE-DMR data.

  16. Reappraising foreground contamination in the COBE-DMR data

    CERN Document Server

    Banday, A J; Davies, R D; Davis, R J; Górski, K M

    2003-01-01

    With the advent of all-sky H-Alpha surveys it is possible to determine a reliable free-free template of the diffuse interstellar medium (Dickinson, Davies & Davis 2003) which can be used in conjunction with the synchrotron and dust templates to correct CMB observations for diffuse Galactic foregrounds. We have used the COBE-DMR data at 31.5, 53 and 90 GHz and employed cross- correlation techniques to re-evaluate the foreground contributions, particularly that due to dust which is known to be correlated with H-Alpha (and free-free) emission. The DMR microwave maps are found to contain, as well as the expected synchrotron and free-free components, a component tightly correlated to the 140 micron dust maps of DIRBE. At 31.5, 53 and 90 GHz this emission is 6.3 +/- 0.6, 2.4 +/- 0.4 and 2.2 +/- 0.4 microK/(MJy/sr) at 140 microns respectively. When corrected for the contribution from thermal dust following model 7 of Finkbeiner, Davis & Schlegel (1999), a strong anomalous dust emission component remains, whi...

  17. Wiener filtering of the COBE Differential Microwave Radiometer data

    Science.gov (United States)

    Bunn, Emory F.; Fisher, Karl B.; Hoffman, Yehuda; Lahav, Ofer; Silk, Joseph; Zaroubi, Saleem

    1994-01-01

    We derive an optimal linear filter to suppress the noise from the cosmic background explorer satellite (COBE) Differential Microwave Radiometer (DMR) sky maps for a given power spectrum. We then apply the filter to the first-year DMR data, after removing pixels within 20 deg of the Galactic plane from the data. We are able to identify particular hot and cold spots in the filtered maps at a level 2 to 3 times the noise level. We use the formalism of constrained realizations of Gaussian random fields to assess the uncertainty in the filtered sky maps. In addition to improving the signal-to-noise ratio of the map as a whole, these techniques allow us to recover some information about the cosmic microwave background anisotropy in the missing Galactic plane region. From these maps we are able to determine which hot and cold spots in the data are statistically significant, and which may have been produced by noise. In addition, the filtered maps can be used for comparison with other experiments on similar angular scales.

  18. Cosmological-constant cold dark matter models and the cobe two-year Sky maps

    CERN Document Server

    Bunn, E F; Emory F Bunn; Naoshi Sugiyama

    1994-01-01

    Abstract. We compare the two-year COBE DMR sky maps with the predictions of cosmological-constant cold dark matter models. Using a Bayesian analysis, we find that the most likely value of the cosmological constant in such a model is Lambda = 0. The data set an upper limit on Lambda of 0.71 (0.78) at 90% confidence, and 0.78 (0.86) at 95% confidence with (without) the quadrupole anisotropy.

  19. The COBE cosmic 3 K anisotropy experiment: A gravity wave and cosmic string probe

    Science.gov (United States)

    Bennett, Charles L.; Smoot, George F.

    1989-01-01

    Among the experiments to be carried into orbit next year, by the COBE satellite, are differential microwave radiometers. They will make sensitive all-sky maps of the temperature of the cosmic microwave background radiation at three frequencies, giving dipole, quadrupole, and higher order multipole measurements of the background radiation. The experiment will either detect, or place significant constraints on, the existence of cosmic strings and long wavelength gravity waves.

  20. On the Origins of the CMB: Insight from the COBE, WMAP, and Relikt-1 Satellites

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2007-01-01

    Full Text Available The powerful “Cosmic Microwave Background (CMB” signal currently associated with the origins of the Universe is examined from a historical perspective and relative to the experimental context in which it was measured. Results from the COBE satellite are reviewed, with particular emphasis on the systematic error observed in determining the CMB temperature. The nature of the microwave signal emanating from the oceans is also discussed. From this analysis, it is demonstrated that it is improper for the COBE team to model the Earth as a 285 K blackbody source. The assignment of temperatures to objects that fail to meet the requirements set forth in Kirchhoff’s law constitutes a serious overextension of the laws of thermal emission. Using this evidence, and the general rule that powerful signals are associated with proximal sources, the CMB monopole signal is reassigned to the oceans. In turn, through the analysis of COBE, WMAP, and Relikt-1 data, the dipole signal is attributed to motion through a much weaker microwave field present both at the position of the Earth and at the second Lagrange point.

  1. An IDL-based analysis package for COBE and other skycube-formatted astronomical data

    Science.gov (United States)

    Ewing, J. A.; Isaacman, Richard B.; Gales, J. M.

    1992-01-01

    UIMAGE is a data analysis package written in IDL for the Cosmic Background Explorer (COBE) project. COBE has extraordinarily stringent accuracy requirements: 1 percent mid-infrared absolute photometry, 0.01 percent submillimeter absolute spectrometry, and 0.0001 percent submillimeter relative photometry. Thus, many of the transformations and image enhancements common to analysis of large data sets must be done with special care. UIMAGE is unusual in this sense in that it performs as many of its operations as possible on the data in its native format and projection, which in the case of COBE is the quadrilateralized sphereical cube ('skycube'). That is, after reprojecting the data, e.g., onto an Aitoff map, the user who performs an operation such as taking a crosscut or extracting data from a pixel is transparently acting upon the skycube data from which the projection was made, thereby preserving the accuracy of the result. Current plans call for formatting external data bases such as CO maps into the skycube format with a high-accuracy transformation, thereby allowing Guest Investigators to use UIMAGE for direct comparison of the COBE maps with those at other wavelengths from other instruments. It is completely menu-driven so that its use requires no knowledge of IDL. Its functionality includes I/O from the COBE archives, FITS files, and IDL save sets as well as standard analysis operations such as smoothing, reprojection, zooming, statistics of areas, spectral analysis, etc. One of UIMAGE's more advanced and attractive features is its terminal independence. Most of the operations (e.g., menu-item selection or pixel selection) that are driven by the mouse on an X-windows terminal are also available using arrow keys and keyboard entry (e.g., pixel coordinates) on VT200 and Tektronix-class terminals. Even limited grey scales of images are available this way. Obviously, image processing is very limited on this type of terminal, but it is nonetheless surprising how

  2. A New Blackbody Radiation Law Based on Fractional Calculus and its Application to NASA COBE Data

    OpenAIRE

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-01-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter $(q-1)$, a formula proposed by Ertik et al. with a fractional parameter $(\\alpha-1)$, and our new formula including a parameter $(p-1)$, as well as the Bose-Einstein distribution with a dimensionless chemical potential $\\mu$. It can be said that on...

  3. Limits on the cosmic infrared background from clustering in COBE/DIRBE maps

    CERN Document Server

    Kashlinsky, A; Odenwald, S

    1997-01-01

    We discuss a new method of estimating the cosmic infrared background (CIB) from the spatial properties of infrared maps and give the limits on the CIB from applying it to the COBE/DIRBE maps. The strongest limits are obtained at mid- to far-IR where foregrounds are bright, but smooth. If the CIB comes from matter clustered like galaxies, the smoothness of the maps implies CIB levels less than $\\sim$(10-15) nW/m$^2$/sr over this wavelength range.

  4. Signal-to-noise eigenmode analysis of the two-year cobe maps

    CERN Document Server

    Bond, J R

    1994-01-01

    To test a theory of cosmic microwave background fluctuations, it is natural to expand an anisotropy map in an uncorrelated basis of linear combinations of pixel amplitudes --- statistically-independent for both the noise and the signal. These S/N-eigenmodes are indispensible for rapid Bayesian analyses of anisotropy experiments, applied here to the recently-released two-year COBE {\\it dmr} maps and the {\\it firs} map. A 2-parameter model with an overall band-power and a spectral tilt \

  5. Report on 3 and 4-point correlation statistics in the COBE DMR anisotrophy maps

    Science.gov (United States)

    Hinshaw, Gary (Principal Investigator); Gorski, Krzystof M.; Banday, Anthony J.; Bennett, Charles L.

    1996-01-01

    As part of the work performed under NASA contract # NAS5-32648, we have computed the 3-point and 4-point correlation functions of the COBE-DNIR 2-year and 4-year anisotropy maps. The motivation for this study was to search for evidence of non-Gaussian statistical fluctuations in the temperature maps: skewness or asymmetry in the case of the 3-point function, kurtosis in the case of the 4-point function. Such behavior would have very significant implications for our understanding of the processes of galaxy formation, because our current models of galaxy formation predict that non-Gaussian features should not be present in the DMR maps. The results of our work showed that the 3-point correlation function is consistent with zero and that the 4-point function is not a very sensitive probe of non-Gaussian behavior in the COBE-DMR data. Our computation and analysis of 3-point correlations in the 2-year DMR maps was published in the Astrophysical Journal Letters, volume 446, page L67, 1995. Our computation and analysis of 3-point correlations in the 4-year DMR maps will be published, together with some additional tests, in the June 10, 1996 issue of the Astrophysical Journal Letters. Copies of both of these papers are attached as an appendix to this report.

  6. The implications of the COBE diffuse microwave radiation results for cosmic strings

    Science.gov (United States)

    Bennett, David P.; Stebbins, Albert; Bouchet, Francois R.

    1992-01-01

    We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to those predicted by cosmic string theories. We use an analytic model for the Delta T/T power spectrum that is based on our previous numerical simulations of strings, under the assumption that cosmic strings are the sole source of the measured anisotropy. This implies a value for the string mass per unit length of 1.5 +/- 0.5 x 10 exp -6 C-squared/G. This is within the range of values required for cosmic strings to successfully seed the formation of large-scale structures in the universe. These results clearly encourage further studies of Delta T/T and large-scale structure in the cosmic string model.

  7. Cold dark matter and degree-scale cosmic microwave background anisotropy statistics after COBE

    Science.gov (United States)

    Gorski, Krzysztof M.; Stompor, Radoslaw; Juszkiewicz, Roman

    1993-01-01

    We conduct a Monte Carlo simulation of the cosmic microwave background (CMB) anisotropy in the UCSB South Pole 1991 degree-scale experiment. We examine cold dark matter cosmology with large-scale structure seeded by the Harrison-Zel'dovich hierarchy of Gaussian-distributed primordial inhomogeneities normalized to the COBE-DMR measurement of large-angle CMB anisotropy. We find it statistically implausible (in the sense of low cumulative probability F lower than 5 percent, of not measuring a cosmological delta-T/T signal) that the degree-scale cosmological CMB anisotropy predicted in such models could have escaped a detection at the level of sensitivity achieved in the South Pole 1991 experiment.

  8. A new blackbody radiation law based on fractional calculus and its application to NASA COBE data

    Science.gov (United States)

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-12-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter (q - 1) , a formula proposed by Ertik et al. with a fractional parameter (α - 1) , and our new formula including a parameter (p - 1) , as well as the Bose-Einstein distribution with a dimensionless chemical potential μ. It can be said that one role of the fractional parameter (p - 1) is almost the same as that of chemical potential (μ) as well as that of the parameter (q - 1) in the non-extensive approach.

  9. Crystallization and preliminary structure analysis of CobE, an essential protein of cobalamin (vitamin B12) biosynthesis

    International Nuclear Information System (INIS)

    P. aeruginosa CobE, a protein implicated in vitamin B12 biosynthesis, has been crystallized and data on the native and SeMet forms recorded to resolutions of 1.9 and 1.7 Å, respectively. The anomalous measurements will be used for phasing. CobE, a protein implicated in vitamin B12 biosynthesis, from Pseudomonas aeruginosa has been overexpressed in Escherichia coli, purified and crystallized using hanging-drop vapour diffusion. The crystals belong to the primitive orthorhombic space group P212121, with unit-cell parameters a = 31.86, b = 41.07, c = 87.41 Å. The diffraction extends to a resolution of 1.9 Å. There is one molecule per asymmetric unit and the estimated solvent content is 35%. SeMet-labelled CobE has been prepared and crystallizes under the same conditions as the native protein with diffraction to 1.7 Å. The anomalous measurements will be used for phasing

  10. Search for unresolved sources in the COBE-DMR two-year sky maps

    Science.gov (United States)

    Kogut, A.; Banday, A. J.; Bennett, C. L.; Hinshaw, G.; Loewenstein, K.; Lubin, P.; Smoot, G. F.; Wright, E. L.

    1994-01-01

    We have searched the temperature maps from the Cosmic Background Explorer (COBE) Differential Microwave Radiometers (DMR) first two years of data for evidence of unresolved sources. The high-latitude sky (absolute value of b greater than 30 deg) contains no sources brighter than 192 microKelvin thermodynamic temperature (322 Jy at 53 GHz). The cumulative count of sources brighter than threshold T, N(greater than T), is consistent with a superposition of instrument noise plus scale-invariant spectrum of cosmic temperature fluctuations normalized to Q(sub rms-PS) = 17 microKelvin. We examine the temperature maps toward nearby clusters and find no evidence for any Sunyaev-Zel'dovich effect, delta y less than 7.3 x 10(exp -6) (95% CL) averaged over the DMR beam. We examine the temperature maps near the brightest expected radio sources and detect no evidence of significant emission. The lack of bright unresolved sources in the DMR maps, taken with anisotropy measurements on smaller angular scales, places a weak constraint on the integral number density of any unresolved Planck-spectrum sources brighter than flux density S, n(greater than S) less than 2 x 10(exp 4)/(S/1 Jy)(exp 2)/sr.

  11. Collection of peripheral progenitor cells: a comparison between Amicus and Cobe-Spectra blood cell separators.

    Science.gov (United States)

    Adorno, Gaspare; Del Proposto, Gianpaolo; Palombi, Francesca; Bruno, Antonio; Ballatore, Giovanna; Postorino, Massimiliano; Tendas, Andrea; Del Poeta, Giovanni; Isacchi, Giancarlo; Amadori, Sergio

    2004-04-01

    The authors compared the efficiency of two different blood cell separators (Amicus and Cobe-Spectra) in collecting peripheral blood progenitor cells for autologous or homologous transplantation. A total number of 129 procedures were performed, 36 with Spectra, 93 with Amicus. There was no difference between Spectra and Amicus efficiencies for CD34+ cell collection (46.685% vs 46.235%; p=n.s) but the platelet efficiencies were 17.31% and 12.54% respectively (p=0.04) and, if autologous and allogeneic collections were considered separately, a marked difference resulted in allogeneic platelet efficiency between 6 Spectra and 23 Amicus procedures (26.83% vs 8.68%, p=0.0004). The authors were able to demonstrate that in 70 Amicus autologous collections there was a different platelet efficiency, if peripheral count was considered: 12 procedures performed with a platelet count > 100 x 10(9)/l had a very low efficiency (6.86%), but this value increased if platelet count lowered (13.02% if between 100 and 50 x 10(9)/l, 22.63% if between 50 and 0 x 10(9)/l, 23 and 35 procedures respectively). The study is preliminary and the number of collections is little, but the overall data suggest that Spectra (AutoPBSC, V 6.0) and Amicus separators have the same efficiency for collecting CD34+ cells while Amicus procedures have a very low platelet contamination, especially with donors.

  12. Genus and spot density in the COBE DMR first year anisotropy maps

    CERN Document Server

    Torres, S; Martínez-González, E; Sanz, J L; Torres, S; Cayon, L; Martinez-Gonzalez, E; Sanz, J L

    1995-01-01

    A statistical analysis of texture on the {\\it COBE}-DMR first year sky maps based on the genus and spot number is presented. A generalized \\chi^2 statistic is defined in terms of ``observable'' quantities: the genus and spot density that would be measured by different cosmic observers. This strategy together with the use of Monte Carlo simulations of the temperature fluctuations, including all the relevant experimental parameters, represent the main difference with previous analyses. Based on the genus analysis we find a strong anticorrelation between the quadrupole amplitude Q_{rms-PS} and the spectral index n of the density fluctuation power spectrum at recombination of the form Q_{rms-PS}= 22.2 \\pm 1.7 - (4.7 \\pm 1.3) \\times n\\ \\muK for fixed n, consistent with previous works. The result obtained based on the spot density is consistent with this Q_{rms-PS} (n) relation. In addition to the previous results we have determined, using Monte Carlo simulations, the minimum uncertainty due to cosmic variance for ...

  13. Cosmic Ray Exposure & Linear-Energy-Transfer Evaluations for the COBE Mission

    Science.gov (United States)

    Stassinopoulos, E. G.; Barth, J. M.

    1984-01-01

    Magnetospherically attenuated, orbit integrated, surface incident cosmic ray fluxes of galactic origin were determined for the COBE mission. All heavy ions up to Nickel (z=28) were considered in this, evaluation. In order to provide worst case approximations, estimates were based on solar minimum conditions. Transport and material shielding calculations were then performed for these vehicle encountered particles, for a simple spherical 3-D aluminum geometry, and the materially attenuated cosmic ray distributions emerging behind selected shield thicknesses were obtained. Finally, Linear-Energy-Transfer (LET) spectra were evaluated for the energy spectra of each ion specie and these were, in turn, integrated into the sum-total LET distribution contained in this report. The results are presented in tabular and graphical form for eight (8) different shield thicknesses from.01 to 10.0 gm/cm2 of aluminum. They show most conclusively, and not unexpectedly, that material shielding has virtually no 'effect on the final LET spectrum, at least not for aluminum shields. This was predictable. Please note that in the LET graphs, two curves were plotted. Of these, please ignore the one labeled "grazing" and use only the one labeled "normal". Again, it should be remembered that the end results contain contributions from all elements up to Nickel (z=28).

  14. The Relativistic Effect of the Deviation between the CMB Temperatures Obtained by the COBE Satellite

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2007-01-01

    Full Text Available The Far-Infrared Absolute Spectrophotometer (FIRAS on the COBE satellite, gives different temperatures of the Cosmic Microwave Background. This deviation has a theoretical explanation in the Doppler effect on the dipole (weak component of the radiation, the true microwave background of the Universe that moves at 365 km/sec, if the monopole (strong component of the radiation is due to the Earth. Owing to the Doppler effect, the dipole radiation temperature (determined by the 1st derivative of the monopole is lower than the monopole radiation temperature, with a value equal to the observed deviation. By this theory, the WMAP and PLANCK satellites, targeting the L2 point in the Sun-Earth-Moon system, should be insensitive to the monopole radiation. In contrast to the launched WMAP satellite, the PLANCK satellite will have on board absolute instruments which will not be able to detect the measured temperature of the Cosmic Microwave Background. That the monopole (strong component of the observed Cosmic Microwave Background is generated by the Earth is given a complete theoretical proof herein.

  15. On the Non-Gaussianity Observed in the COBE-DMR Sky Maps

    CERN Document Server

    Banday, A J; Górski, K M

    1999-01-01

    In this paper we pursue the origin of the non-Gaussianity determined by a bispectrum analysis of the COBE-DMR 4-year sky maps. The robustness of the statistic is demonstrated by the rebinning of the data into 12 coordinate systems. By computing the bispectrum statistic as a function of various data partitions - by channel, frequency, and time interval, we show that the observed non-Gaussian signal is driven by the 53 GHz data. This frequency dependence strongly rejects the hypothesis that the signal is cosmological in origin. A jack-knife analysis of the coadded 53 and 90 GHz sky maps reveals those sky pixels to which the bispectrum statistic is particularly sensitive. We find that by removing data from the 53 GHz sky maps for periods of time during which a known systematic effect perturbs the 31 GHz channels, the amplitudes of the bispectrum coefficients become completely consistent with that expected for a Gaussian sky. We conclude that the non-Gaussian signal detected by the normalised bispectrum statistic...

  16. Comments on the statistical analysis of excess variance in the COBE differential microwave radiometer maps

    Science.gov (United States)

    Wright, E. L.; Smoot, G. F.; Kogut, A.; Hinshaw, G.; Tenorio, L.; Lineweaver, C.; Bennett, C. L.; Lubin, P. M.

    1994-01-01

    Cosmic anisotrophy produces an excess variance sq sigmasky in the Delta maps produced by the Differential Microwave Radiometer (DMR) on cosmic background explorer (COBE) that is over and above the instrument noise. After smoothing to an effective resolution of 10 deg, this excess sigmasky(10 deg), provides an estimate for the amplitude of the primordial density perturbation power spectrum with a cosmic uncertainty of only 12%. We employ detailed Monte Carlo techniques to express the amplitude derived from this statistic in terms of the universal root mean square (rms) quadrupole amplitude, (Q sq/RMS)0.5. The effects of monopole and dipole subtraction and the non-Gaussian shape of the DMR beam cause the derived (Q sq/RMS)0.5 to be 5%-10% larger than would be derived using simplified analytic approximations. We also investigate the properties of two other map statistics: the actual quadrupole and the Boughn-Cottingham statistic. Both the sigmasky(10 deg) statistic and the Boughn-Cottingham statistic are consistent with the (Q sq/RMS)0.5 = 17 +/- 5 micro K reported by Smoot et al. (1992) and Wright et al. (1992).

  17. Statistics and topology of the COBE differential microwave radiometer first-year sky maps

    Science.gov (United States)

    Smoot, G. F.; Tenorio, L.; Banday, A. J.; Kogut, A.; Wright, E. L.; Hinshaw, G.; Bennett, C. L.

    1994-01-01

    We use statistical and topological quantities to test the Cosmic Background Explorer (COBE) Differential Microwave Radiometer (DMR) first-year sky maps against the hypothesis that the observed temperature fluctuations reflect Gaussian initial density perturbations with random phases. Recent papers discuss specific quantities as discriminators between Gaussian and non-Gaussian behavior, but the treatment of instrumental noise on the data is largely ignored. The presence of noise in the data biases many statistical quantities in a manner dependent on both the noise properties and the unknown cosmic microwave background temperature field. Appropriate weighting schemes can minimize this effect, but it cannot be completely eliminated. Analytic expressions are presented for these biases, and Monte Carlo simulations are used to assess the best strategy for determining cosmologically interesting information from noisy data. The genus is a robust discriminator that can be used to estimate the power-law quadrupole-normalized amplitude, Q(sub rms-PS), independently of the two-point correlation function. The genus of the DMR data is consistent with Gaussian initial fluctuations with Q(sub rms-PS) = (15.7 +/- 2.2) - (6.6 +/- 0.3)(n - 1) micro-K, where n is the power-law index. Fitting the rms temperature variations at various smoothing angles gives Q(sub rms-PS) = 13.2 +/- 2.5 micro-K and n = 1.7(sup (+0.3) sub (-0.6)). While consistent with Gaussian fluctuations, the first year data are only sufficient to rule out strongly non-Gaussian distributions of fluctuations.

  18. A Search for Resonant Structures in the Zodiacal Cloud with COBE DIRBE: The Mars Wake and Jupiter's Trojan Clouds

    OpenAIRE

    Kuchner, Marc J.; Reach, William T.; Brown, Michael E.

    2000-01-01

    We searched the COBE DIRBE Sky and Zodi Atlas for a wake of dust trailing Mars and for Trojan dust near Jupiter's L5 Lagrange point. We compare the DIRBE images to a model Mars wake based on the empirical model of the Earth's wake as seen by the DIRBE and place a 3-sigma upper limit on the fractional overdensity of particles in the Mars wake of 18% of the fractional overdensity trailing the Earth. We place a 3-sigma upper limit on the effective emitting area of large (10-100 micron diameter) ...

  19. One-way return-link Doppler navigation with the Tracking and Data Satellite System (TDRSS) - The ultrastable oscillator (USO) experiment on the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Dunham, J. B.; Nemesure, M.; Teles, J.; Brown-Conwell, E. R.; Jackson, J. A.; Reamy, V. L.; Maher, M. J.; Elrod, B. D.

    1990-01-01

    The principal objectives of the USO experiment on the COBE spacecraft are defined, and results of space qualification studies for the COBE USO experiment are summarized. The principal objectives of the experiment are: (1) to determine flight performance of the USO coupled to the second-generation TDRSS transponder; (2) space qualify TDRSS noncoherent one-way return-link Doppler tracking; and (3) analyze algorithms for one-way navigation with real data. The three objectives of the experiment have been met in the first stage of the experiment analysis.

  20. On the radiative and thermodynamic properties of the Cosmic Microwave Background radiation using COBE FIRAS instrument data

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Use formulas to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density in the finite range of frequencies are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.728 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant are calculated. In the case of the dipole spectrum, the constants a and the Stefan-Bol...

  1. The gravitational wave contribution to cosmic microwave background anisotropies and the amplitude of mass fluctuations from COBE results

    Science.gov (United States)

    Lucchin, Francesco; Matarrese, Sabino; Mollerach, Silvia

    1992-01-01

    A stochastic background of primordial gravitational waves may substantially contribute, via the Sachs-Wolfe effect, to the large-scale cosmic microwave background (CMB) anisotropies recently detected by COBE. This implies a bias in any resulting determination of the primordial amplitude of density fluctuations. We consider the constraints imposed on n is less than 1 ('tilted') power-law fluctuation spectra, taking into account the contribution from both scalar and tensor waves, as predicted by power-law inflation. The gravitational wave contribution to CMB anisotropies generally reduces the required rms level of mass fluctuation, thereby increasing the linear bias parameter, even in models where the spectral index is close to the Harrison-Zel'dovich value n = 1. This 'gravitational wave bias' helps to reconcile the predictions of CDM models with observations on pairwise galaxy velocity dispersion on small scales.

  2. The effect of Community Based Education and Service (COBES) on medical graduates’ choice of specialty and willingness to work in rural communities in Ghana

    OpenAIRE

    Amalba, Anthony; van Mook, Walther Nicolaas Karel Anton; Mogre, Victor; Scherpbier, Albert Jakob Johannus Antonius

    2016-01-01

    Background Career choices and placements of healthcare professionals in rural areas are a major problem worldwide, and their recruitment and retention to these areas have become a challenge to the health sector. The purpose of this study was to investigate the effect of Community Based Education and Service (COBES) on medical graduates' choice of specialty and willingness to work in a rural area. Method This cross sectional survey was conducted among 56 pioneering graduates that followed a Pr...

  3. On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: III. Galactic far-infrared radiation

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Using the three-component spectral model describing the FIRAS average continuum spectra, the analytical expressions for the temperature dependence of the thermodynamic and radiative functions of the galactic far-infrared radiation are obtained. The COBE FIRAS instrument data in the 0.15 - 2.88 THz frequency interval at the mean temperatures T = 17.72 K, T = 14 K, and T =6.73 K are used for calculating the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, total emissivity, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume and pressure for the warm, intermediate-temperature and very cold components of the Galactic continuum spectra. The generalized Stefan-Boltzmann laws for the warm, intermediate-temperature and very cold components are constructed. This result is important when we construct the cosmological models of radiative transfer in the inner Galaxy. Within the framework of the three- com...

  4. Re-Analysis of Michelson-Morley Experiments Reveals Agreement with COBE Cosmic Background Radiation Preferred Frame so Impacting on Interpretation of General Relativity

    CERN Document Server

    Cahill, R T; Cahill, Reginald T.; Kitto, Kirsty

    2003-01-01

    We report a re-analysis of the old results from the Michelson-Morley interferometer experiments that were designed to detect absolute motion. We build upon a recent (1998) re-analysis of the original data by Munera, which revealed small but significant effects after allowing for several systematic errors in the original analyses. The further re-analysis here reveals that a genuine effect of absolute motion is expected, in what is essentially a quantum interference experiment, but only if the photons travel in the interferometer at speeds V < c. This is the case if the interferometer operates in a dielectric, such as air, or helium as was the case of the Illingworth (1927) Michelson-Morley experiment. The re-analysis here of the Illingworth experimental data correcting for the refractive index effect of the helium, reveals an absolute speed of the Earth of v=369+/-123 km/s, which is in agreement with the speed of v=365+/-18 km/s determined from the dipole fit, in 1991, to the NASA COBE satellite Cosmic Back...

  5. Clustering of the Diffuse Infrared Light from the COBE DIRBE maps; 3, Power spectrum analysis and excess isotropic component of fluctuations

    CERN Document Server

    Kashlinsky, A; Odenwald, S

    1999-01-01

    The cosmic infrared background (CIB) radiation is the cosmic repository for energy release throughout the history of the universe. Using the all-sky data from the COBE DIRBE instrument at wavelengths 1.25 - 100 mic we attempt to measure the CIB fluctuations. In the near-IR, foreground emission is dominated by small scale structure due to stars in the Galaxy. There we find a strong correlation between the amplitude of the fluctuations and Galactic latitude after removing bright foreground stars. Using data outside the Galactic plane ($|b| > 20\\deg$) and away from the center ($90\\deg< l <270\\deg$) we extrapolate the amplitude of the fluctuations to cosec$|b|=0$. We find a positive intercept of $\\delta F_{\\rm rms} = 15.5^{+3.7}_{-7.0},5.9^{+1.6}_{-3.7}, 2.4^{+0.5}_{-0.9}, 2.0^{+0.25}_{-0.5}$ nW/m2/sr at 1.25, 2.2,3.5 and 4.9 mic respectively, where the errors are the range of 92% confidence limits. For color subtracted maps between band 1 and 2 we find the isotropic part of the fluctuations at $7.6^{+1.2}_...

  6. Hemopoietic stem cell processing: comparison of progenitor cell recovery using the Cobe 2991 cell washer and the Haemonetics V50 apheresis system.

    Science.gov (United States)

    Preti, R A; Ahmed, T; Ayello, J; Helson, L; Argani, I; Wuest, D; Ciavarella, D

    1992-05-01

    Using 24 bone marrow (BM) harvests intended for cryopreservation and transplantation, we compared the use of the Cobe 2991 cell washer (2991) and the Haemonetics V50 apheresis system (HV50) for automated BM processing. Our in vitro data indicate that while the mononuclear cell (MNC) concentration of the HV50 product was significantly greater than that of the 2991, the overall MNC recovery of the two products was equivalent. In addition, although the concentration of CFU-GM and BFU-E in the products was equivalent, recovery of these progenitors in the 2991 product was significantly greater than those of the HV50 product. There was no significant difference in either the final product concentration or the overall recovery of cells bearing the primitive myeloid antigens, CD33 or CD34, between the two methods. The HV50 product volume, the red cell and the granulocyte mass were significantly lower than those of the 2991. We conclude that the advantages gained through the use of each machine should be evaluated within the context of the specific intention for the graft. Future advances in the identification and understanding of the primitive stem cell will aid in attempts to evaluate the methods used to isolate these cells.

  7. [Erythrocyte removal from bone marrow by density gradient separation using the COBE 2991 cell processor with the triple-bag processing set].

    Science.gov (United States)

    Cappellesso-Fleury, S; Rage, C; Tschaggeny, F; Gaudé, J; Gomez, M; Bourin, P

    2009-03-01

    ABO-incompatible bone marrow transplantation requires red blood cell depletion. Lots of laboratory adopted the technique of density gradient centrifugation (Ficoll-hypaque) using the COBE 2991 cell processor with simple-bag processing set. However, tubing of this set is not adapted to the currently available peristaltic pumps. Moreover, two other sets are required: one for the buffy-coat and one for postgradient cell washing. We developed a method using triple-bag processing set to conduct whole-step procedure (concentration, Ficoll and washing). Peristaltic PVC tubing is provided in one line of the set allowing a safe processing without several connections thus reducing risks of microbial contamination. First, we used buffy-coat of total blood for training, then, we carried out red cell depletion of healthy bone marrow donors. The red blood cell depletion was 97.9+/-1.1% and CD34+ recovery was 89.6+/-8.7%. These results are very close to those obtained with the simple-bag set (red cell depletion.=94.0+/-6.8% and CD34+ recovery=95.9+/-20.3%). We conclude that the triple-bag system, very little used in France, is practical, simplified the manipulation and is more safety than the simple-bag set.

  8. WINNICOTT Y HEIDEGGER: LA APERTURA DEL MUNDO Y EL CO-ESTAR // WINNICOTT AND HEIDEGGER: OPENING UP OF WORLD AND CO-BEING

    Directory of Open Access Journals (Sweden)

    Julieta Bareiro

    2013-06-01

    Full Text Available Este trabajo integra la investigación de la tesis doctoral defendida en la Facultad de Psicología (UBA y tiene por propósito establecer un diálogo entre Winnicott y Heidegger respecto de la apertura del mundo y los otros. En efecto, ambos pensadores desde sus respectivas disciplinas han reflexionado sobre la experiencia del ser y el existir. Winnicott desde el ámbito de la clínica psicoanalítica y Heidegger desde la fenomenología hermenéutica. El hecho de que la apertura del mundo en el filósofo alemán sea compartida, permite una mayor comprensión del rol materno en el proceso del desarrollo del niño winnicottiano. A partir de la afirmación de que el Dasein es esencialmente ser con otros, co-estar, (Mitsein y que los otros son ahí con el Dasein, es posible pensar que el desarrollo de la subjetividad winnicottiana tiene el rasgo de la co-existencia. // This work integrates the research of the doctoral thesis defended at the Faculty of Psychology (UBA and aims to establish a dialogue between Winnicott and Heidegger regarding the opening up of world and the others. Indeed, both thinkers, from their respective disciplines, have thought about the experience of being and existing. Winnicott from the field of psychoanalytic clinic and Heidegger from the hermeneutic phenomenology. The fact that opening up of world in the German philosopher is shared allows a better understanding of the maternal role in the Winnicottian child development process. From the statement that Dasein is essentially being with others, co-being, (Mitsein and that others are there with the Dasein, it is conceivable that the development of the Winnicottian subjectivity has the trait of coexistence.

  9. COBE-DIRBE observations of the Earth's resonant ring.

    Science.gov (United States)

    Jayaraman, S.; Dermott, S. F.

    The marked trailing/leading asymmetry of the zodiacal cloud, first detected in the IRAS (Infrared Astronomical Satellite) data by Dermott et al. (1988), has since been confirmed by DIRBE (Reach et al., 1995). The authors' analysis of the DIRBE data shows that the asymmetry exists in a range of wavebands from 4.5 to 60 μm as well as at different solar elongations. The authors proposed (Dermott et al., 1994) that this asymmetry is caused by a trailing cloud of asteroidal dust particles that corotates with the Earth in a circumsolar ring of particles trapped in mean motion resonances. Here, the authors compare predictions derived from this model with the DIRBE observations and discuss the implications of the results for the sizes of the particles near the Earth, and their origin, and for the overall structure of the zodiacal cloud.

  10. COBE-SST2 Sea Surface Temperature and Ice

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A new sea surface temperature (SST) analysis on a centennial time scale is presented. The dataset starts in 1850 with monthly 1x1 means and is periodically updated....

  11. A new blackbody radiation law based on fractional calculus and its application to NASA COBE data

    OpenAIRE

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-01-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA CODE data by means of a non-extensive formula with a parameter (q - 1), a formula proposed by Ertik et al. with a fractional parameter (alpha - 1), and our new formula including a parameter (p - 1), as well as the Bose-Einstein distribution with a dimensionless chemical potential mu. It can be said that one ro...

  12. Reconciling cold dark matter with COBE/IRAS plus solar and atmospheric neutrino data

    CERN Document Server

    Joshipura, A S; Joshipura, A S; Valle, J W F

    1994-01-01

    We present a model where an unstable MeV Majorana tau neutrino can naturally reconcile the cold dark matter model (CDM) with cosmological observations of large and small scale density fluctuations and, simultaneously, with data on solar and atmospheric neutrinos. The solar neutrino deficit is explained through long wavelength, so-called {\\sl just-so} oscillations involving conversions of \

  13. COBE,A Milestone in Cosmology: Comments on Nobel Prize in Physics 2006%COBE:宇宙学的一块里程碑——2006年诺贝尔物理学奖解读

    Institute of Scientific and Technical Information of China (English)

    俞允强

    2006-01-01

    瑞典皇家科学院将2006年诺贝尔物理学奖授予美国科学家约翰·马瑟和乔治·斯穆特,以表彰他们发现了宇宙微波背景辐射的黑体形式和各向异性.扼要地阐述了COBE的两个重要成果的物理含义.

  14. Trimatės vartotojo sąsajos, kuriamos atkuriamosios grafikos priemonėmis

    OpenAIRE

    Vižinienė, Asta

    2007-01-01

    Atkuriamosios grafikos priemonės leidžia sukurti trimatę vartotojo sąsają, panaudojant įvarius trimačius modelius. Darbo tikslas: Trimačių modelių aprašymo kalbų analizė ir trimatės vartotojo sąsajos modelio sukūrimas. Darbo uždaviniai: išnagrinėti literatūrą apie trimatės vartotojo sąsajos kūrimą, atlikti atkuriamosios grafikos priemonių, skirtų kurti trimačius objektus, analizę bei pagrindinių virtualios realybės aprašymo kalbų analizę, pasinaudojant atkuriamosios grafikos priemonėmis sukur...

  15. The infrared and submillimetre sky after COBE; Proceedings of the NATO Advanced Study Institute, Les Houches, France, Mar. 20-30, 1991

    Science.gov (United States)

    Signore, Monique; Dupraz, Christophe

    The present conference discusses first-order cosmological inflation, the great attractor and the anisotropies of the relic radiation, the role of string theory in cosmology, the cosmic microwave background radiation, dark matter candidates and candidate detection methods, and the thermal history of the cosmological gas. Also discussed are Galactic IR emission, sources of cosmic IR-to-submillimeter background radiation, cosmic background anisotropies in the millimetric region, and linear and nonlinear gravitational effects on the cosmic microwave background.

  16. MOLIŠKI HRVATI. Rekonstrukcija kreiranja i reprezentacije jednog etničkog identiteta

    OpenAIRE

    Perinić, Ana

    2006-01-01

    Rad govori o moliškim Hrvatima, najmanjom i najstarijom hrvatskom dijasporom u Europi, koja se nalazi u trima selima južne talijanske pokrajine Molise. Na primjeru ove zajednice vidljiva je kompleksnost i konstruiranje identiteta, koji izmiče probranim, stvarnim, objektivnim sličnostima i različitostima zajednice iznesenima u šest kriterija potrebnih za njegovu tvorbu prema A. D. Smithu.

  17. Perception and valuations of community-based education and service by alumni at Makerere University College of Health Sciences

    Directory of Open Access Journals (Sweden)

    Mbalinda Scovia

    2011-03-01

    Full Text Available Abstract Background Training of health professionals can be deliberately structured to enhance rural recruitment by exposing the trainees to the realities of rural life and practice through Community-Based Education and Service (COBE programs. Few studies have surveyed the alumni of these programs to establish their post-university views and whether the positive impact of COBE programs endures into the post-university life. This study surveyed the alumni of COBE at Makerere to obtain their perceptions of the management and administration of COBE and whether COBE had helped develop their confidence as health workers, competence in primary health care and willingness and ability to work in rural communities. Objectives • To assess the efficiency of the management and administration of COBES. • To obtain the views of the impact of COBES on its alumni. Methods A mixed qualitative and quantitative study was conducted using focus group discussions (FGD and a telephone administered questionnaire. From a total of 300 COBES alumni 150 were contacted. Twenty four Alumni (13 females and 11 males were purposefully selected by discipline, gender and place of work, and invited for the focus group discussion. The discussions were transcribed and analyzed using a manifest content analysis table. The thematic issues from the FGDs were used to develop a structured questionnaire which was administered by telephone by the authors. The data were entered into Microsoft excel template and exported to Stata for analysis. The findings of the telephone survey were used to cross-match the views expressed during the focus group discussions. Results The alumni almost unanimously agree that the initial three years of COBES were very successful in terms of administration and coordination. COBES was credited for contributing to development of confidence as health workers, team work, communication skills, competence in primary health care and willingness to work in rural

  18. Zbrinjavanje medicinskog otpada - zakonodavstvo i njegova provedba

    OpenAIRE

    Marinković, Natalija; Vitale, Ksenija; Janev Holcer, Nataša; Džakula, Aleksandar

    2006-01-01

    Gospodarenje medicinskim otpadom, koji po svojim svojstvima može biti opasan i/ili inertan, u Hrvatskoj je regulirano trima temeljnim pravnim aktima: Zakonom o otpadu, Pravilnikom o vrstama otpada te Naputkom o postupanju s otpadom koji nastaje pri pružanju zdravstvene zaštite. Uz njih još su i Zakon o prijevozu opasnih tvari i Zakon o otrovima akti koji podupiru provedbu ovih propisa. Slijedom razvoja suvremenih cjelovitih sustava za gospodarenje otpadom razvijen je i cjeloviti sustav za gos...

  19. Reply to comment on: "Cobeñas, G., Thouret, J.-C., Bonadonna, C., Boivin, P., 2012. The c.2030 yr BP Plinian eruption of El Misti volcano, Peru: Eruption dynamics and hazard implications. Journal of Volcanology and Geothermal Research 241-242, 105-120." by Harpel et al., JVGR 2013

    Science.gov (United States)

    Cobeñas, Gisela; Thouret, Jean-Claude; Bonadonna, Costanza; Boivin, Pierre

    2014-04-01

    The comment provided by Harpel et al. challenges our interpretation of the most recent Plinian eruption of El Misti c.2070 yr BP* situated near the city of Arequipa, Peru (*revised age from our previously stated date of c.2030 BP). In our view, the sequence of deposits points to another example of a Plinian (pumice-rich) tephra fall followed by lithic-rich pyroclastic density currents (PDCs). Locally, late rockslide avalanches have emplaced mass-flow deposits on top of PDCs, while elsewhere post-eruption lahars have led to their remobilization. One of the main criticisms from Harpel et al. was in our interpretation of the deposits as being of PDC origin, rather than post-eruption lahars. We revise each of the diagnostic features that Harpel et al. have used for attributing the deposits to lahars. We present two tables of the revised age of the eruption and criteria based on lithofacies, lithological components, grain-size distribution and statistical indices for each of the c.2070 yr BP-old PDC, lahar and mass-flow deposits. Our maps and simulations of PDCs and lahars, based on two numerical codes with volume inputs from identified deposits around El Misti, do not "fall short" of the hazard assessment goal.

  20. Remembering when the big bang seemed so simple

    CERN Multimedia

    Johnson, George

    2006-01-01

    Fourteen years ago, an astronomer at Berkeley declared that he and his satellite, COBE, had detected the astrophysical equivalent of the fingerprints of God, his euphoria was easy to understand. (1 page)

  1. Analysis of different norms and corresponding Lipschitz constants for global optimization

    OpenAIRE

    Paulavičius, Remigijus; Žilinskas, Julius

    2006-01-01

    Šiam tikslui buvo įvertintos įvairias normas atitinkančios Lipšico konstantos. Šakų ir rėžių algoritmas buvo naudojamas globalaus maksimumo paieškai. Eksperimento rezultatai parodė, kad geriausi rezultatai gaunami, kai Lipšico viršutiniam rėžiui įvertinti naudojamas kraštinių (begalinės ir pirmosios) normų junginys dvimačiam atvejui ir jų junginys su euklidine norma trimačiam atvejui. The paper discusses how the used norm and corresponding Lipschitz constant influence the speed of algorith...

  2. Nobel Lecture: From the Big Bang to the Nobel Prize and beyond

    Science.gov (United States)

    Mather, John C.

    NASA’s Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the cosmic microwave background radiation and discovering the cosmic infrared background radiation. I describe the history of the COBE project, its scientific context, the people who built it, and the scientific results. The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post Big Bang objects is twice as great as previously believed. The COBE concept was developed by a Mission Definition Study Team appointed by NASA in 1976, based on three competing proposals submitted in 1974. The COBE was built in-house by Goddard Space Flight Center, with a helium cryostat provided by Ball Aerospace, and was launched on a Delta rocket built by McDonnell Douglas. It is in a circular orbit 900km above the Earth, in a plane inclined 99° to the equator and roughly perpendicular to the line to the Sun. It carried three instruments, a far infrared absolute spectrophotometer (FIRAS), a differential microwave radiometer with three channels (DMR), and a diffuse infrared background experiment (DIRBE). The helium cryostat cooled the FIRAS and DIRBE for 10months until the helium was exhausted, but operations continued for a total of 4years . Subsequent observations have confirmed the COBE results and led to measurements of the main cosmological parameters with a precision of a few percent.

  3. Effective asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate to ethyl (R)-4-chloro-3-hydroxybutanoate by recombinant E. coli CCZU-A13 in [Bmim]PF6-hydrolyzate media.

    Science.gov (United States)

    He, Yu-Cai; Tao, Zhi-Cheng; Di, Jun-Hua; Chen, Liang; Zhang, Lin-Bing; Zhang, Dan-Ping; Chong, Gang-Gang; Liu, Feng; Ding, Yun; Jiang, Chun-Xia; Ma, Cui-Luan

    2016-08-01

    It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3wt%)-soaking rice straw at 30°C was used to form [Bmim]PF6-hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (>99% e.e.) with recombinant E. coli CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20mM) was employed to improve the reductase activity. Moreover, Hp-β-cyclodextrin (0.01mol Hp-β-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of (R)-CHBE from COBE by E. coli CCZU-A13 whole-cells. The yield of (R)-CHBE (>99% e.e.) from 800mM COBE was obtained at 100% in the [Bmim]PF6-hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20mM) and Hp-β-CD (8mM). In conclusion, an effective strategy for the biosynthesis of (R)-CHBE was successfully demonstrated.

  4. Planck early results. II. The thermal performance of Planck

    DEFF Research Database (Denmark)

    Bréelle, E.; Bucher, M.; Delabrouille, J.;

    2011-01-01

    detector technologies with widely different temperature and cooling needs. Active coolers could satisfy these needs; a helium cryostat, as used by previous cryogenic space missions (IRAS, COBE, ISO, Spitzer, AKARI), could not. Radiative cooling is provided by three V-groove radiators and a large telescope...

  5. Large Deployable Reflector Science and Technology Workshop. Volume 3: Systems and Technology Assessment. Conclusions

    Science.gov (United States)

    1984-01-01

    The physical parameters of the Large Deployable Reflector (LDR) required to achieve the anticipated astronomical objectives are reviewed briefly. System parameters and performance requirements for the LDR are enumerated. The LDR was compared with the Cosmic Background Experiment (COBE), the Infrared Astronomical Satellite (IRAS), and the Space Infrared Telescope Facility (SIRTF). Angular resolution and high resolution spectroscopy requirements for LDR were considered.

  6. Cosmic background radiation anisotropy in an open inflation, cold dark matter cosmogony

    Science.gov (United States)

    Kamionkowski, Marc; Ratra, Bharat; Spergel, David N.; Sugiyama, Naoshi

    1994-01-01

    We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At Omega(sub 0) is approximately 0.3-0.4, the Cosmic Background Explorer (COBE) normalized open model appears to be consistent with most observations.

  7. COBRAS/SAMBA: The European space mission to map the CBR anisotropy

    DEFF Research Database (Denmark)

    Bersanelli, M.; Mandolesi, N.; Cesarsky, C.;

    1996-01-01

    COBRAS/SAMBA is an ESA mission designed for extensive, accurate mapping of the anisotropies of the Cosmic Background Radiation, with angular sensitivity from sub-degree scales up to and overlapping with the COBE-DMR resolution. This will allow a fun identification of the primordial density pertur...

  8. Design of Effective Energy Efficiency Policies : An analysis in the frame of target setting, monitoring and evaluation

    NARCIS (Netherlands)

    Schlomann, B.

    2014-01-01

    Energy efficiency (EE) is widely acknowledged as the most important strategy for achieving global energy and climate targets. Apart from its contribution to the reduction of energy consumption and energy-related greenhouse gas emissions (GHG), improving energy efficiency can deliver a range of co-be

  9. Effective asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate to ethyl (R)-4-chloro-3-hydroxybutanoate by recombinant E. coli CCZU-A13 in [Bmim]PF6-hydrolyzate media.

    Science.gov (United States)

    He, Yu-Cai; Tao, Zhi-Cheng; Di, Jun-Hua; Chen, Liang; Zhang, Lin-Bing; Zhang, Dan-Ping; Chong, Gang-Gang; Liu, Feng; Ding, Yun; Jiang, Chun-Xia; Ma, Cui-Luan

    2016-08-01

    It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3wt%)-soaking rice straw at 30°C was used to form [Bmim]PF6-hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (>99% e.e.) with recombinant E. coli CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20mM) was employed to improve the reductase activity. Moreover, Hp-β-cyclodextrin (0.01mol Hp-β-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of (R)-CHBE from COBE by E. coli CCZU-A13 whole-cells. The yield of (R)-CHBE (>99% e.e.) from 800mM COBE was obtained at 100% in the [Bmim]PF6-hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20mM) and Hp-β-CD (8mM). In conclusion, an effective strategy for the biosynthesis of (R)-CHBE was successfully demonstrated. PMID:27155796

  10. Evaluation of storage performance of special plastic blood bags for apheresis platelets%血小板保存专用塑料血袋的储存性能评价

    Institute of Scientific and Technical Information of China (English)

    王捷熙; 韩颖; 周倩; 刘敏霞; 王艳; 柴丽娜; 卓海龙; 易晓阳; 周建伟; 王建卫

    2015-01-01

    Objective To evaluate the storage performance of storage bags for apheresis platelets produced by Shandong Weigao Group Medical Polymer Co .,Ltd ( experimental bags ) with Trima set platelet storage bags produced by the U .S. Gambro BCT as the control .Method One unit of apheresis platelets was divided into two equal parts , added to control blood bags and experimental blood bags respectively .All samples were stored at ( 22 ±2 )℃ with consecutive oscillation . The platelets′count, mean volume, aggregate activity (ADP, THR), pH, glucose, lactate concentration, lactate dehydro-genase concentration , hypotonic shock reaction , expression of CD62P and phosphatidyl serine on surface of cell membrane were detected at 0,3,5 and 7 d respectively.Results There was no significant difference in platelet quality after five days of storage between the experimental group and the control group (t-test, P>0.05).Conclusion Two types of platelet stor-age blood bags have similar storage performance for apheresis platelets .%目的:以美国Gambro BCT公司生产的Trima set血小板保存袋为对照,评价山东威高集团医用高分子制品股份有限公司生产的血小板保存袋对单采血小板的储存性能。方法将1U单采血小板平分成两份,分别加入实验血袋和对照血袋中,于血小板恒温振荡保存箱中保存。分别于保存0、3、5、7d取样,比较分析两组的血小板含量和血小板平均体积、pH值、体外聚集活性、氧分压和二氧化碳分压、葡萄糖、乳酸和乳酸脱氢酶浓度、低渗休克反应、血小板活化和凋亡、血小板形态结构及细菌培养试验。结果两种保存袋保存的血小板在保存期内,相同保存时间实验组与对照组之间各项检测结果差异无统计学意义(P>0.05);无菌试验均为阴性。结论国产血小板专用塑料血袋与美国Trima set血小板保存袋对该实验使用的15份单采血小板具有相似的储存性能。

  11. Evalutation of efficiency of dynamic laser magnetic stimulation of eye drainage system of patients with open angle glaucomatosis

    Directory of Open Access Journals (Sweden)

    Sidelnikova V.S.

    2014-06-01

    Full Text Available The purpose of the study is to develop a comprehensive treatment aimed at improving uveoscleral outflow in the application of dynamic laser magnetic stimulation of the drainage system of the eye and evaluation of its effectiveness in treating patients with primary open-angle glaucoma (POAG. Material. 106 patients diagnosed POAG I, II, III stages were examined. Group 1 consisted of 62 patients treated with medical therapy and dynamic laser magnetic stimulation of the drainage system of the eye using the "AMO-ATOS-ICL", produced by JSC "TRIMA", Saratov. Group 2 consisted of 64 patients who received only medical therapy. Comprehensive survey including standard eye examination, static perimetry, visual evoked potentials study, the study of intraocular blood flow was conducted to all patients. Analysis of the results of the complex therapeutic effects showed that as the result of treatment 73% of patients had a decrease of intraocular pressure and the ease factor outflow increase. 52% of patients had a decrease in the number and area of relative. 63% of patients had activation of intraocular blood flow. These indices remained stable for three months. Conclusion. The treatment with the technique of dynamic laser magnetic stimulation of the drainage system of the eye of patients with primary open-angle glaucoma leads to lower intraocular pressure, and to the improvement of dopple-rographic and perimetric indications.

  12. Simulation on stern-rudder independent control for submarine motion in vertical plane%尾舵独立控制的潜艇垂直面运动仿真

    Institute of Scientific and Technical Information of China (English)

    颜俐; 许建; 马运义

    2013-01-01

    To independent control the submarine depth and trim,a fuzzy control method on stern-rudder is proposed,and the advantage of single stern-rudder in low noise control is elaborated.According to the character of single stern-rudder,the fuzzy controller is designed.The simulation result showed that the algorithm had very good control precision,which decreased the rudder and radiated noise greatly.%提出一种由尾舵独立控制潜艇深度和纵倾的模糊控制方法,阐述单尾舵在低噪声控制中的优势.针对单尾舵控制特点,设计了模糊控制器.仿真结果表明,该算法具有很好的控制精度,能大大降低潜艇的打舵噪声和辐射噪声.

  13. Bounds on QCD axion mass and primordial magnetic field from CMB $\\mu$-distortion

    CERN Document Server

    Ejlli, Damian

    2014-01-01

    Oscillation of CMB photons into axions can cause CMB spectral distortion in presence of large scale magnetic fields. With COBE limit on $\\mu$ parameter and homogeneous magnetic field strength $B\\lesssim 3.2$ nG at horizon scale, constraint on axion mass is found to be $4.8\\times 10^{-5}$ eV $\\lesssim m_a$ for the KSVZ axion model. On the other hand using experimental limit on axion mass $3.5\\times 10^{-6}$ eV $\\lesssim m_a$ from ADMX experiment together with COBE $\\mu$ bound, is found $B\\lesssim 53$ nG (KSVZ axion model) and $B\\lesssim 141$ nG (DFSZ axion model) for homogeneous magnetic field with coherence length at present $\\lambda_B\\sim 1.3$ Mpc. Limits on $B$ and $m_a$ for PIXIE/PRISM expected bound on $\\mu$ are derived.

  14. The Far Infrared and Submillimeter Diffuse Extragalactic Background

    CERN Document Server

    Hauser, M G

    2001-01-01

    The cosmic infrared background (CIB) radiation was a long-sought fossil of energetic processes associated with structure formation and chemical evolution since the Big Bang. The COBE Diffuse Infrared Background Experiment (DIRBE) and Far Infrared Absolute Spectrophotometer (FIRAS) were specifically designed to search for this background from 1.25 microns to millimeter wavelengths. These two instruments provided high quality, absolutely calibrated all-sky maps which have enabled the first detections of the CIB, initially at far infrared and submillimeter wavelengths, and more recently in the near infrared as well. The aim of this paper is to review the status of determinations of the CIB based upon COBE measurements. The results show that the energy in the CIB from far infrared to millimeter wavelengths is comparable to that in the integrated light of galaxies from UV to near infrared wavelengths: the universe had a luminous but dusty past. On the assumption that nucleosynthesis in stars is the energy source f...

  15. Tests of the particle physics-physical cosmology interface

    International Nuclear Information System (INIS)

    Three interrelated interfaces of particle physics and physical cosmology are discussed: (1) inflation and other phase transitions; (2) Big Bang Nucleosynthesis (and also the quark-hadron transition); and (3) structure formation (including dark matter). Recent observations that affect each of these topics are discussed. Topic number 1 is shown to be consistent with the COBE observations but not proven and it may be having problems with some age-expansion data. Topic number 2 has now been well-tested and is an established ''pillar'' of the Big Bang. Topic number 3 is the prime arena of current physical cosmological activity. Experiments to resolve the current exciting, but still ambiguous, situation following the COBE results are discussed

  16. From the Big Bang to the Nobel Prize and the JWST

    Science.gov (United States)

    Mather, John C.

    2007-01-01

    I will describe the history of the universe, from the Big Bang to 2013, when the JWST is to be launched to look back towards our beginnings. I will discuss how the COBE results led to the Nobel Prize, how the COBE results have been confirmed and extended, and their implications for future observations. The James Webb Space Telescope will be used to examine every part of our history from the first stars and galaxies to the formation of individual stars and planets and the delivery of life-supporting materials to the Earth. I will describe the plans for the JWST and how observers may use it. With luck, the JWST may produce a Nobel Prize for some discovery we can only guess today.

  17. Can the Local Supercluster explain the low CMB multipoles?

    OpenAIRE

    Abramo, L. Raul; Sodre Jr., L.

    2003-01-01

    We show that the thermal Sunyaev-Zeldovich effect caused by hot electrons in the Local Supercluster (LSC) can explain the abnormal quadrupole and octopole of the cosmic microwave background (CMB) that were measured by WMAP and COBE. The distortion needed to account for the low observed quadrupole is a spot in the direction of the LSC with a temperature decrease of order \\Delta T \\approx - 7 \\mu K for \

  18. Improved Ways to Compare Simulations to Data

    OpenAIRE

    Primack, Joel R.

    1995-01-01

    Theoretical models for structure formation with Gaussian initial fluctuations have been worked out in considerable detail and compared with observations on various scales. It is on nonlinear scales $\\lsim 10 \\ h^{-1}\\ {\\rm Mpc}$ that the greatest differences exist between $\\Omega=1$ models that have been normalized to agree on the largest scales with the COBE data; here especially there is a need for better statistical tests which are simultaneously {\\it robust}, {\\it discriminatory}, and {\\i...

  19. Cosmological Perturbations of Quantum-Mechanical Origin and Anisotropy of the Microwave Background

    CERN Document Server

    Grishchuk, L P

    1993-01-01

    Cosmological perturbations generated quantum-mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution of the produced temperature fluctuations of the CMBR is quite specific. An exact formula is derived for the angular correlation function of the temperature fluctuations caused by squeezed gravitational waves. The predicted angular pattern can, in principle, be revealed by the COBE-type observations.

  20. Assessing community perspectives of the community based education and service model at Makerere University, Uganda: a qualitative evaluation

    OpenAIRE

    Okullo Isaac; Oria Hussein; Mwanika Andrew; Kaye Dan; Burnham Gilbert; Plover Colin M; Mbalinda Scovia N; Muhwezi Wilson; Groves Sara

    2011-01-01

    Abstract Background Community partnerships are defined as groups working together with shared goals, responsibilities, and power to improve the community. There is growing evidence that these partnerships contribute to the success and sustainability of community-based education and service programs (COBES), facilitating change in community actions and attitudes. Makerere University College of Health Sciences (MakCHS) is forging itself as a transformational institution in Uganda and the region...

  1. Catalyst Architecture

    DEFF Research Database (Denmark)

    Kiib, Hans; Marling, Gitte; Hansen, Peter Mandal

    2014-01-01

    How can architecture promote the enriching experiences of the tolerant, the democratic, and the learning city - a city worth living in, worth supporting and worth investing in? Catalyst Architecture comprises architectural projects, which, by virtue of their location, context and their combinatio...... meaningful for everyone. The exhibited works are designed by SANAA, Diller Scofidio + Renfro, James Corner Field Operation, JBMC Arquitetura e Urbanismo, Atelier Bow-Wow, Ateliers Jean Nouvel, COBE, Transform, BIG, Topotek1, Superflex, and by visual artist Jane Maria Petersen....

  2. Local Pancake Defeats Axis of Evil

    OpenAIRE

    Vale, Chris

    2005-01-01

    Among the biggest surprises revealed by COBE and confirmed by WMAP measurements of the temperature anisotropy of the CMB are the anomalous features in the 2-point angular correlation function on very large angular scales. In particular, the $\\ell = 2$ quadrupole and $\\ell = 3$ octopole terms are surprisingly planar and aligned with one another, which is highly unlikely for a statistically isotropic Gaussian random field, and the axis of the combined low-$\\ell$ signal is perpendicular to eclip...

  3. Effective pretreatment of sugarcane bagasse with combination pretreatment and its hydrolyzates as reaction media for the biosynthesis of ethyl (S)-4-chloro-3-hydroxybutanoate by whole cells of E. coli CCZU-K14.

    Science.gov (United States)

    He, Yu-Cai; Zhang, Dan-Ping; Di, Jun-Hua; Wu, Yin-Qi; Tao, Zhi-Cheng; Liu, Feng; Zhang, Zhi-Jun; Chong, Gang-Gang; Ding, Yun; Ma, Cui-Luan

    2016-07-01

    In this study, sugarcane bagasse (SB) was pretreated with combination pretreatment (e.g., sequential KOH extraction and ionic liquid soaking, sequential KOH extraction and Fenton soaking, or sequential KOH extraction and glycerol soaking). After the enzymatic hydrolysis of pretreated SBs, it was found that all these three concentrated hydrolyzates could be used for the asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE]. Compared with glucose, arabinose and cellobiose couldn't promote the initial reaction rate, and xylose could increase the intracellular NADH content. Moreover, it was the first report that hydrolyzates could be used for the effective biosynthesis of (S)-CHBE (∼500g/L; 98.0% yield) from 3000 COBE by whole cells of Escherichia coli CCZU-K14 in the presence of β-CD (0.4mol β-CD/mol COBE), l-glutamine (200mM) and glycine (500mM). In conclusion, it is a new alternative to utilize bioresource for the synthesis of key chiral intermediate (S)-CHBE. PMID:27060248

  4. Information and communication technology and community-based health sciences training in Uganda: perceptions and experiences of educators and students.

    Science.gov (United States)

    Chang, Larry W; Mwanika, Andrew; Kaye, Dan; Muhwezi, Wilson W; Nabirye, Rose C; Mbalinda, Scovia; Okullo, Isaac; Kennedy, Caitlin E; Groves, Sara; Sisson, Stephen D; Burnham, Gilbert; Bollinger, Robert C

    2012-01-01

    Information and communication technology (ICT) has been advocated as a powerful tool for improving health education in low-resource settings. However, few evaluations have been performed of ICT perceptions and user experiences in low-resource settings. During late 2009, an internet-based survey on ICT was administered to students, tutors, and faculty members associated with a Community-Based Education and Service (COBES) program in Uganda. 255 surveys were completed. Response rates varied (students, 188/684, 27.5%; tutors, 14/27, 51.9%; faculty, 53/335, 15.8%). Most respondents owned mobile phones (98%). Students were less likely (p students' COBES experiences. Free text responses found that respondents valued ICT access for research, learning, and communication purposes. In summary, ICT penetration in this population is primarily manifest by extensive mobile phone ownership. Internet access in rural educational sites is still lacking, but students and educators appear eager to utilize this resource if availability improves. ICT may offer a unique opportunity to improve the quality of teaching and learning for COBES participants. PMID:21332303

  5. Cosmic microwave background and first molecules in the early universe

    Energy Technology Data Exchange (ETDEWEB)

    Signore, Monique [LERMA, Observatoire de Paris, Paris (France); Puy, Denis [University of Montpellier II, CNRS UMR 5024, GRAAL CC72, Montpellier (France)

    2009-01-15

    Besides the Hubble expansion of the universe, the main evidence in favor of the big-bang theory was the discovery, by Penzias and Wilson, of the cosmic microwave background (hereafter CMB) radiation. In 1990, the COBE satellite (Cosmic Background Explorer) revealed an accurate black-body behavior with a temperature around 2.7 K. Although the microwave background is very smooth, the COBE satellite did detect small variations - at the level of one part in 100 000 - in the temperature of the CMB from place to place in the sky. These ripples are caused by acoustic oscillations in the primordial plasma. While COBE was only sensitive to long-wavelength waves, the Wilkinson Microwave Anisotropy Probe (WMAP) - with its much higher resolution - reveals that the CMB temperature variations follow the distinctive pattern predicted by cosmological theory. Moreover, the existence of the microwave background allows cosmologists to deduce the conditions present in the early stages of the big bang and, in particular, helps to account for the chemistry of the universe. This report summarizes the latest measurements and studies of the CMB with the new calculations about the formation of primordial molecules. The PLANCK mission - planned to be launched in 2009 - is also presented. (orig.)

  6. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    Science.gov (United States)

    Mather, John C.

    2009-01-01

    The history of the universe in a nutshell, from the Big Bang to now, and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA s Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein s biggest mistake, show how Edwin Hubble discovered the expansion of the universe, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA s plans for the next great telescope in space, the James Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where stars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  7. From the Big Bang to the Nobel Prize and on to the James Webb Space Telescope

    Science.gov (United States)

    Mather, John C.

    2008-01-01

    The history of the universe in a nutshell, from the Big Bang to now. and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA's Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein's biggest mistake, show how Edwin Hubble discovered the expansion of the univerre, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA's plans for the next great telescope in space, the Jarnes Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where rtars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  8. Community-Oriented Biodiversity Environmental education: Its effect on knowledge, values, and behavior among rural fifth- and sixth-grade students in northeastern Thailand

    Science.gov (United States)

    Ratanapojnard, Sorrayut

    The goals of this study were to (a) develop and implement Community-Orient Biodiversity Environmental Education (COBEE) program in Buriram, northeastern Thailand; and (b) determine its effect on biodiversity-related knowledge, values, and behavior among rural fifth- and sixth-grade students. Local teachers, community leaders, and the author, in association with Thailand's Ministry of Education, together developed a multidisciplinary curriculum to study the community of Satuk, Buriram---its history, lifestyles, and economy, and how these were interconnected with biodiversity issues. The COBEE program provided intensive and ongoing teacher training workshops, supervisory visits, and support group meetings for teachers. Over the 1996--1997 academic year, teachers delivered the COBEE curriculum using both indoor and outdoor activities, including community studies, interviews with local people, developing a species inventory with descriptions of biology, habitats, and uses, and field trips to agricultural fields, local forests, and protected areas. Seven primary schools were randomly assigned as four experimental and three control schools. There were 218 and 198 fifth- and sixth-grade students in the experimental and control schools respectively. The Solomon four-group research design was used to compare students before and after the COBEE program. A set of survey instruments was developed to gather quantitative data. Qualitative data were collected from interviews, participant observations, and students' schoolwork. Three major findings are: (1) An environmental education program can be designed and implemented to produce positive effects not only on objectives identified as the foundation of environmental education (e.g., knowledge, attitudes, and behavior), but also on students' other academic attitudes and development. (2) Based on qualitative data, the relative success of COBEE indicates that curriculum, instruction, nature experience, and other facilitating

  9. Polimerinių implantų, skirtų širdies ir kraujagyslių chirurgijai, formavimas tiesioginio lazerinio rašymo metodu

    Directory of Open Access Journals (Sweden)

    Paulius DANILEVIČIUS

    2012-06-01

    Full Text Available Per pastaruosius porą dešimtmečių sparčiai tobulėja tiesioginio lazerinio rašymo, paremto selektyviai tūryje lokalizuota fotojautrios medžiagos modifikacija, technologija, skirta trimačių mikro- ir nanostruktūrizuotų polimerinių darinių gamybai. Šiame darbe pristatoma galimybė tiesioginio lazerinio rašymo būdu formuoti didelių matmenų (iki cm3 eilės mikroporėtus kamieninėms ląstelėms auginti skirtus karkasus, kurie gali būti taikomi ir širdies bei kraujagyslių chirurgijoje. Lyginant įvairių impulsų trukmių lazerines spinduliuotes, nustatyta, kad, naudojant femtosekundinius lazerius ir derinant spinduliuotės intensyvumą, galima labiau modifikuoti formavimo skyrą, tačiau audinių inžinerijai reikalingai darinių kokybei pasiekti tinka ir pikosekundiniai lazeriai.Tai sudaro palankesnes sąlygas ateityje diegti pigesnes, praktiniams taikymams skirtas tiesioginio lazerinio rašymo polimeruose sistemas.  Karkasų gamybai naudotos keturios skirtingos medžiagos – hibridiniai organiniai-neorganiniai polimerai SZ2080 ir „Ormoclear“, biologiškai skaidus PEG-DA-258 bei akrilatinis AKRE. In vitro ir in vivo tyrimais nustatyta, kad visi keturi polimerai yra biologiškai sutaikomi, nepasižymi citotoksiškumu, todėl gali būti naudojami audinių inžinerijoje. Adekvačių karkasų gamybos našumui paspartinti buvo pritaikytas replikavimas PDMS minkštąja litografija. Tai leido 2 % tikslumu atkartoti replikuojamo darinio paviršiaus šiurkštumą bei keliomis eilėmis sutrumpinti 15´15 mm2 ploto pavyzdinių dvimačių karkasų gamybos trukmę. Taip pat pateikiama suformuotų trimačių polimerinių karkasų pavyzdžių, kurie yra pakankamai didelių matmenų, kad būtų tinkami praktiškai naudoti chirurgijoje. Jų geometrija ir mikrostruktūrizavimo kokybė įvertinta elektronų skenuojamuoju elektroniniu mikroskopu. Šie tiesioginio lazerinio rašymo būdu gauti dirbtiniai karkasai išsiskiria tiksliai

  10. Comparison of plateletpheresis on three continuous flow cell separators

    Directory of Open Access Journals (Sweden)

    Tendulkar Anita

    2009-01-01

    Full Text Available Introduction: Platelet concentrate (PC remains one of the most important support measures in thrombocytopenic patients. An efficient cell separator is a prerequisite for an optimally functioning apheresis setup. Donor blood count may undergo a temporary reduction after the procedure. Aim: The aim was to find the extent of reduction in donor blood count (hemoglobin, hematocrit, white blood cell, and platelet after plateletpheresis and to evaluate the cell separator for collection efficiency, processing time, and leukoreduction. Study Design and Methods: Two hundred and thirty seven procedures performed on the Amicus (N = 121, Fenwal CS-3000 Plus (N = 50 and Cobe spectra (N = 66 in a one year period were evaluated. The procedures performed on the continuous flow centrifugation (CFC cell separators and donor blood counts (pre and post donation done were included in the study. Results: The percent reduction in hemoglobin (HB, hematocrit (HCT, white blood cell (WBC and platelet count ((PLT ct was 2.9, 3.1, 9, 30.7 (Mean, N = 237 respectively after the procedure. The post donation PLT ct reduced to < 100x109/L (range 80-100 in five donors (N = 5/237, Amicus. The pre donation PLT ct in them was 150-200x109/L. Collection efficiency (percent of Amicus (79.3 was better as compared to the other two machines (CS: 62.5, Cobe: 57.5. PC collected on Cobe spectra had < 1x106 WBC. The donor pre donation PLT levels had a positive correlation to the product PLT yield (r = 0.30, P = 0.000. Conclusion: Monitoring donor blood counts helps to avoid pheresis induced adverse events. A cautious approach is necessary in donors whose pre donation PLT ct is 150-200x109/L. The main variable in PLT yield is donor PLT ct (pre donation. High collection efficiency is a direct measure of an optimally functioning cell separator.

  11. Cluster evolution as a probe of primordial density fluctuations

    Science.gov (United States)

    Bond, J. Richard; Myers, Steven T.

    1993-01-01

    Although COBE's detection of large angle microwave background anisotropies fixes the amplitude of density fluctuations on length scales k exp -1 approximately = (300-6000) h(exp -1)Mpc, what is crucial for the level of large scale clustering is the amplitude of density fluctuations on scales (5-50) h(exp -1)Mpc. The level of dynamical clustering is usually parameterized by the size of the mass fluctuations in 8 h exp -1 Mpc spheres, sigma sub 8. For the cold dark matter model, COBE gives sigma sub 8 approximately = 1, while models with extra large scale power give sigma sub 8 approximately = 1/2. The most massive clusters of galaxies (greater than or approximately = 10 exp 15 solar mass) form from rare 'peak patches' found in the initial mass density distribution. Their abundance as a function of redshift is a sensitive probe of the wave number band k(exp -1) approx. (3-8) h(exp -1)Mpc, hence of sigma sub 8, and so cluster evolution can discriminate among models allowed by the COBE results. We use our Hierarchical Peaks Method, which accurately reproduces the results of P3M N-body simulations, to calculate the evolution of cluster x-ray flux counts, luminosity, and temperature functions as a function of sigma sub 8 for CDM models and those with more large scale power. We find that the EMSS and Edge et al. cluster samples support sigma sub 8 in the range from approx. 0.6-0.9, and that models with more large scale power (and hence flatter fluctuation spectra in the cluster regime) fit the x-ray bright end better.

  12. An Astrosocial Observation: The Nobel Connection to the Space Program

    Science.gov (United States)

    Ng, Edward W.; Nash, Rebecca L.

    2007-01-01

    The 2006 Nobel Prize in Physics was heralded by some in the press as the 'First Nobel Prize for Space Exploration.' Indeed the Nobel Foundation's announcement specifically cited the Cosmic Background Explorer (COBE) satellite launched by NASA in 1989 as the prime-enabling instrument It elaborated further, 'The COBE results provided increased support for the Big Bang scenario for the origin of the Universe... These measurements also marked the inception of cosmology as a precise science.' NASA also seized this unique moment of fame to honor its favorite son, the first Nobel scientist of the agency, John Mather, of the Goddard Space Flight Center, who shared the honor with Professor G. Smoot of the University of California, the Principal Investigator of the COBE measurement. It is without any dispute that the Nobel Prize is the highest scientific honor and best-known award of admiration and inspiration to the public and educational sectors. Unfortunately in the American culture, youths are mostly exposed to success icons in the sports, entertainment, and business domains. Science icons (of either gender) are largely unknown to them. We sincerely hope that success stories of Nobel scientists will become part of the learning curriculum in the K-16 educational experience. In this paper, we examine the pedigree of a number of Nobel Prizes over the years, and discuss their interactions with, and connections to, the space program. It is advantageous for the context of educational and public outreach to see such connections, because in a number of public surveys, one important customer expectation for the space program is the search for new knowledge, to which the Nobel Prize is a prominent benchmark.

  13. Science with CMB spectral distortions

    CERN Document Server

    Chluba, Jens

    2014-01-01

    The measurements of COBE/FIRAS have shown that the CMB spectrum is extremely close to a perfect blackbody. There are, however, a number of processes in the early Universe that should create spectral distortions at a level which is within reach of present day technology. In this talk, I will give a brief overview of recent theoretical and experimental developments, explaining why future measurements of the CMB spectrum will open up an unexplored window to early-universe and particle physics with possible non-standard surprises but also several guaranteed signals awaiting us.

  14. The CMB Dipole: The Most Recent Measurement And Some History

    OpenAIRE

    Lineweaver, Charles H.

    1996-01-01

    The largest anisotropy in the cosmic microwave background (CMB) is the $\\approx 3$ mK dipole assumed to be due to our velocity with respect to the CMB. Over the past ten years the precision of our knowledge of the dipole has increased by a factor of ten. We discuss the most recent measurement of this dipole obtained from the four year COBE Differential Microwave Radiometers (DMR) as reported by Lineweaver \\etal (1996). The inferred velocity of the Local Group is $v_{LG}= 627 \\pm 22$ km/s in t...

  15. Assessing community perspectives of the community based education and service model at Makerere University, Uganda: a qualitative evaluation

    Directory of Open Access Journals (Sweden)

    Okullo Isaac

    2011-03-01

    Full Text Available Abstract Background Community partnerships are defined as groups working together with shared goals, responsibilities, and power to improve the community. There is growing evidence that these partnerships contribute to the success and sustainability of community-based education and service programs (COBES, facilitating change in community actions and attitudes. Makerere University College of Health Sciences (MakCHS is forging itself as a transformational institution in Uganda and the region. The College is motivated to improve the health of Ugandans through innovative responsive teaching, provision of service, and community partnerships. Evaluating the COBES program from the community perspective can assist the College in refining an innovative and useful model that has potential to improve the health of Ugandans. Methods A stratified random sample of 11 COBES sites was selected to examine the community’s perception of the program. Key Informant Interviews of 11 site tutors and 33 community members were completed. The data was manually analyzed and themes developed. Results Communities stated the students consistently engaged with them with culturally appropriate behaviour. They rated the student’s communication as very good even though translators were frequently needed. Half the community stated they received some feedback from the students, but some communities interpreted any contact after the initial visit as feedback. Communities confirmed and appreciated that the students provided a number of interventions and saw positive changes in health and health seeking behaviours. The community reflected that some programs were more sustainable than others; the projects that needed money to implement were least sustainable. The major challenges from the community included community fatigue, and poor motivation of community leaders to continue to take students without compensation. Conclusions Communities hosting Makerere students valued the

  16. Brane in the Relativistic Theory of Gravitation

    CERN Document Server

    Naboulsi, R

    2003-01-01

    It was proven that Logunov RTG predicts a cyclic Universe with no singularities. It is shown in this paper that an additional exotic density term will not affect this important characteristic of the Universe evolution. We assume that this later varies with time according to the law m^2 propto frac{dot{R}^2}{R}. The graviton mass and the density term are of order of Hubble's constant. The classical Einstein's cosmological parameter is excluded to converse the logical structure of the RTG. The age of the Universe and the deceleration parameter agree with recent observational data from BOOMERANG, MAXIMA and COBE.

  17. Strong constraint on ever-present Λ

    International Nuclear Information System (INIS)

    We show that the causal-set approach to creating an ever-present cosmological 'constant' in the expanding universe is strongly constrained by the isotropy of the microwave background. Fluctuations generated by stochastic lambda generation which are consistent with COBE and WMAP observations are far too small to dominate the expansion dynamics at z<1000 and so cannot explain the observed late-time acceleration of the universe. We also discuss other observational constraints from the power spectrum of galaxy clustering and show that the theoretical possibility of ever-present lambda arises only in 3+1 dimensional space-times

  18. A Strong Constraint on Ever-Present Lambda

    CERN Document Server

    Barrow, J D

    2006-01-01

    We show that the causal set approach to creating an ever-present cosmological 'constant' in the expanding universe is strongly constrained by the isotropy of the microwave background. Fluctuations generated by stochastic lambda generation which are consistent with COBE and WMAP observations are far too small to dominate the expansion dynamics at z<1000 and so cannot explain the observed late-time acceleration of the universe. We also discuss other observational constraints from the power spectrum of galaxy clustering and show that the theoretical possibility of ever-present lambda arises only in 3+1 dimensional space-times.

  19. Cold dark matter confronts the cosmic microwave background - Large-angular-scale anisotropies in Omega sub 0 + lambda 1 models

    Science.gov (United States)

    Gorski, Krzysztof M.; Silk, Joseph; Vittorio, Nicola

    1992-01-01

    A new technique is used to compute the correlation function for large-angle cosmic microwave background anisotropies resulting from both the space and time variations in the gravitational potential in flat, vacuum-dominated, cold dark matter cosmological models. Such models with Omega sub 0 of about 0.2, fit the excess power, relative to the standard cold dark matter model, observed in the large-scale galaxy distribution and allow a high value for the Hubble constant. The low order multipoles and quadrupole anisotropy that are potentially observable by COBE and other ongoing experiments should definitively test these models.

  20. Some Heuristics and Results for Small Cycles of the Discrete Logarithm

    OpenAIRE

    Holden, Joshua; Moree, Pieter

    2004-01-01

    Brizolis asked the question: does every prime p have a pair (g,h) such that h is a fixed point for the discrete logarithm with base g? The first author previously extended this question to ask about not only fixed points but also two-cycles, and gave heuristics (building on work of Zhang, Cobeli, Zaharescu, Campbell, and Pomerance) for estimating the number of such pairs given certain conditions on g and h. In this paper we extend these heuristics and prove results for some of them, building ...

  1. New Conjectures and Results for Small Cycles of the Discrete Logarithm

    OpenAIRE

    Holden, Joshua; Moree, Pieter

    2003-01-01

    Brizolis asked the question: does every prime p have a pair (g,h) such that h is a fixed point for the discrete logarithm with base g? The first author previously extended this question to ask about not only fixed points but also two-cycles, and gave heuristics (building on work of Zhang, Cobeli, Zaharescu, Campbell, and Pomerance) for estimating the number of such pairs given certain conditions on $g$ and $h$. In this paper we give a summary of conjectures and results which follow from these...

  2. Distribution of the Error in Estimated Numbers of Fixed Points of the Discrete Logarithm

    OpenAIRE

    Holden, Joshua

    2004-01-01

    Brizolis asked the question: does every prime p have a pair (g,h) such that h is a fixed point for the discrete logarithm with base g? The author and Pieter Moree, building on work of Zhang, Cobeli, and Zaharescu, gave heuristics for estimating the number of such pairs and proved bounds on the error in the estimates. These bounds are not descriptive of the true situation, however, and this paper is a first attempt to collect and analyze some data on the distribution of the actual error in the...

  3. Estimación de variables dasométricas del bosque templado de Hidalgo, México mediante datos espectrales y del Inventario Nacional Forestal.

    OpenAIRE

    Muñoz RuIz, Miguel Ángel

    2012-01-01

    Los métodos basados en la percepción remota son herramientas importantes para la medición de variables biofísicas del bosque a un costo menor y a una escala espacial y temporal mayor. En este trabajo se analiza la relación existente entre datos del Inventario Nacional Forestal y de Suelos (INFyS) y datos espectrales provenientes de imágenes de la plataforma SPOT correspondientes al bosque templado y bosque mesófilo de Hidalgo, México. Las estimaciones del área basal (AB), volumen (VOL) y cobe...

  4. Exact Solution in the New Inflation Scenario with Induced Gravity

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Fu

    2001-01-01

    Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution which is inflation for end, and develops smoothly towards radiation-like evolution for ≥ end. The inflation is driven by the evolution of the field with inflation potential, V( ) = λ 2 v2)2.density, ns, is computed and ns lies well inside the limits set by the cosmic background explorer (COBE) satellite.the dex of the scalar effective cosmological constant Aeff tends to zero when inflation ends.``

  5. Open and closed CDM isocurvature models contrasted with the CMB data

    CERN Document Server

    Enqvist, Kari; Valiviita, J; Enqvist, Kari; Kurki-Suonio, Hannu; Valiviita, Jussi

    2002-01-01

    We consider pure isocurvature CDM models in the case of open and closed universe. We allow for a large spectral tilt and scan the 6-dimensional parameter space for the best fit to the COBE, Boomerang, and Maxima-1 data. Taking into account constraints from large-scale structure and big bang nucleosynthesis, we find a best fit with $\\chi^2 = 121$, which is to be compared to $\\chi^2 = 44$ of a flat adiabatic reference model. Hence the current data strongly disfavour pure isocurvature perturbations.

  6. Basic Space Science; United Nations/European Space Agency Workshops for Developing Countries, 2nd, Bogota, Colombia, November 9-13, 1992

    Science.gov (United States)

    Haubold, Hans J. (Editor); Torres, Sergio (Editor)

    1994-01-01

    The conference primarily covered astrophysical and astronomical topics on stellar and solar modeling and processes, high magnetic field influence on stellar spectra, cosmological topics utilizing Cosmic Background Explorer (COBE) data and radioastronomic mapping as well as cosmic gravitational instability calculations, astrometry of open clusters amd solar gravitational focusing, extremely energetic gamma rays, interacting binaries, and balloon-borne instrumentation. Other papers proposed an active Search for Extraterrestrial Intelligence (SETI) communication scheme to neighboring solar-like systems and more direct involvement of and with the public in astronomy and space exploration projects.

  7. On the origin of the cosmic microwave background anisotropies

    OpenAIRE

    Follop, Ria; Rassat, Anais; Cooray, Asantha; Abdalla, Filipe B.

    2007-01-01

    Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a correlate-by-eye exercise was attempted by overlaying the CMB map from Wilkinson Microwave Anisotropy Probe on a topographical map of Earth. Remarkably, several hot spots in the CMB map are found to be well aligned with either large cities on Earth or region...

  8. Innovative design to prevent reversal of roller blood pump rotation in the event of electromechanical failure: an easy solution to a devastating problem.

    Science.gov (United States)

    Skoletsky, Jennifer S; White, Brian T; Austin, Jon W

    2007-06-01

    Despite the advanced technologies of battery back-up for heart-lung consoles and the availability of system-wide generators, electromechanical failure is still occurring. Several heart-lung machine manufacturers still provide unsafe handcranking devices to use in the case of an emergency while using a roller blood pump. A new design has been engineered to eliminate safety and quality issues for the perfusionist and the patient when the need for handcranking presents itself. A ratchet-style handcranking device was fabricated by means of a steel plate with adjustable pins. The adjustable pins allow for use with different models of the Cobe, Stockert, and Jostra heart-lung consoles, which contain roller pumps with 1800 roller heads. Additional modifications such as a 1:2 transmission and fluorescent markers are also used in the design. This innovative design is an improvement in safety compared with the current handcrank provided by Cobe, Stockert, and Jostra. With this modified handcranking device, accidental reverse rotation of the roller pump head cannot occur. Fluorescent markers will improve visualization of the pump head in low-light situations. The ergonomic design improves efficiency by reducing fatigue. Most importantly, a "safe" safety device will replace the current design provided by these manufacturers, thus improving the quality of care by health care providers.

  9. The extragalactic background and its fluctuations in the far-infrared wavelengths

    CERN Document Server

    Lagache, G; Abergel, A; Bouchet, F R; Boulanger, F; Ciliegi, P; Clements, D L; Césarsky, C J; Désert, F X; Dole, H; Elbaz, D; Franceschini, A; Gispert, R; Guiderdoni, B; Haffner, L M; Harwit, M; Laureijs, R J; Lemke, D; Moorwood, A F M; Oliver, S; Reach, W T; Reynolds, R J; Rowan-Robinson, M; Stickel, M; Tufte, S L

    2000-01-01

    A Cosmic Far-InfraRed Background (CFIRB) has long been predicted that wouldtraces the intial phases of galaxy formation. It has been first detected byPuget et al.(1996) using COBE data and has been later confirmed by severalrecent studies (Fixsen et al. 1998, Hauser et al. 1998, Lagache et al. 1999).We will present a new determination of the CFIRB that uses for the first time,in addition to COBE data, two independent gas tracers: the HI survey ofLeiden/Dwingeloo (hartmann, 1998) and the WHAM H$_{\\alpha}$ survey (Reynolds etal 1998). We will see that the CFIRB above 100 micron is now very wellconstrained. The next step is to see if we can detect its fluctuations. Tosearch for the CFIRB fluctuations, we have used the FIRBACK observations.FIRBACK is a deep cosmological survey conducted at 170 micron with ISOPHOT(Dole et al., 2000). We show that the emission of unresolved extra-galacticsources clearly dominates, at arcminute scales, the background fluctuations inthe lowest galactic emission regions. This is the f...

  10. Exchange transfusion for severe malaria: A comparison of red cell exchange with whole blood exchange

    Directory of Open Access Journals (Sweden)

    Udani S

    2003-01-01

    Full Text Available Aim: To compare exchange transfusions done for severe malaria using the traditional whole blood exchange method with therapeutic red cell exchange (TREX done using a Cobe spectra cell separator. Methods: 6 children with acute, severe malaria and parasitic infestation rates (IR >50% with multi organ failure, were subjected to exchange transfusions. 3 had whole blood single volume exchanges and 3 had TREX using the Cobe-Spectra cell separator. The two groups were compared for difficulties encountered, time taken, complications, quantity of blood products used, metabolic and hematological derangements and fall in IR. Results: The TREX took less time per 100 ml of blood exchanged, resulted in a 24% more efficient decrease in the IR and required less donor plasma. 3/3 tolerated the TREX well whereas one child had complications of hypocalcemia and acidosis with the whole blood exchange. The rise in hemoglobin/hematocrit was comparable in both and the platelet count was not significantly altered in either group. There was no significant alteration in the DIC profile in either group. All 6 children recovered within comparable time frames. Conclusion: The TREX was safer, more efficacious and less time consuming. This procedure is recommended whenever available for red cell exchange in malaria.

  11. CMB Science: Opportunities for a Cryogenic Filter-Bank Spectrometer

    Science.gov (United States)

    Tartari, A.; Battistelli, E. S.; Piat, M.; Prêle, D.

    2016-08-01

    Cosmic microwave background (CMB) spectral science is experiencing a renewed interest after the impressive result of COBE-FIRAS in the early Nineties. In 2011, the PIXIE proposal contributed to reopen the prospect of measuring deviations from a perfect 2.725 K planckian spectrum. Both COBE-FIRAS and PIXIE are differential Fourier transform spectrometers (FTSes) capable to operate in the null condition across ˜ 2 frequency decades (in the case of PIXIE, the frequency span is 30 GHz-6 THz). We discuss a complementary strategy to observe CMB spectral distortions at frequencies lower than 250 GHz, down to the Rayleigh-Jeans tail of the spectrum. The throughput advantage that makes the FTS capable of achieving exquisite sensitivity via multimode operation becomes limited at lower frequencies. We demonstrate that an array of 100 cryogenic planar filter-bank spectrometers coupled to single mode antennas, on a purely statistical ground, can perform better than an FTS between tens of GHz and 200 GHz (a relevant frequency window for cosmology) in the hypothesis that (1) both instruments have the same frequency resolution and (2) both instruments are operated at the photon noise limit (with the FTS frequency band extending from ˜ tens of GHz up to 1 THz). We discuss possible limitations of these hypotheses, and the constraints that have to be fulfilled (mainly in terms of efficiency) in order to operate a cryogenic filter-bank spectrometer close to its ultimate sensitivity limit.

  12. A map of the temperature of interstellar dust in the Milky Way Galaxy

    Science.gov (United States)

    2002-01-01

    A map of the temperature of interstellar dust in the Milky Way Galaxy derived from FIRAS sub-millimeter data. The map is a projection of the full sky in Galactic coordinates. The plane of the Milky Way is horizontal in the middle of the map with the Galactic center at the center. At high frequencies, the continuum in a FIRAS spectrum is dominated by thermal dust emission; at low frequencies, the cosmic microwave background dominates. A single-temperature dust model (with 1.55 adopted as the emissivity spectral index) was used to make this map. Different models can be used and assumptions made, and corresponding temperature and optical depth maps can be derived straightforwardly from the FIRAS Continuum Spectrum Maps (see 'About the Data Products' in the FIRAS section of the COBE Home Page). Reach et al. ( 1995, ApJ, 451, 188, 'Far-Infrared Spectral Observations of the Galaxy by COBE'), for example, report evidence for a ubiquitous cold (5 K) dust component.

  13. Cold dark matter. 2: Spatial and velocity statistics

    Science.gov (United States)

    Gelb, James M.; Bertschinger, Edmund

    1994-01-01

    We examine high-resolution gravitational N-body simulations of the omega = 1 cold dark matter (CDM) model in order to determine whether there is any normalization of the initial density fluctuation spectrum that yields acceptable results for galaxy clustering and velocities. Dense dark matter halos in the evolved mass distribution are identified with luminous galaxies; the most massive halos are also considered as sites for galaxy groups, with a range of possibilities explored for the group mass-to-light ratios. We verify the earlier conclusions of White et al. (1987) for the low-amplitude (high-bias) CDM model-the galaxy correlation function is marginally acceptable but that there are too many galaxies. We also show that the peak biasing method does not accurately reproduce the results obtained using dense halos identified in the simulations themselves. The Cosmic Background Explorer (COBE) anisotropy implies a higher normalization, resulting in problems with excessive pairwise galaxy velocity dispersion unless a strong velocity bias is present. Although we confirm the strong velocity bias of halos reported by Couchman & Carlberg (1992), we show that the galaxy motions are still too large on small scales. We find no amplitude for which the CDM model can reconcile simultaneously and galaxy correlation function, the low pairwise velocity dispersion, and the richness distribution of groups and clusters. With the normalization implied by COBE, the CDM spectrum has too much power on small scales if omega = 1.

  14. Modeling of the Zodiacal Emission for the AKARI/IRC Mid-infrared All-sky Diffuse Maps

    Science.gov (United States)

    Kondo, Toru; Ishihara, Daisuke; Kaneda, Hidehiro; Nakamichi, Keichiro; Takaba, Sachi; Kobayashi, Hiroshi; Ootsubo, Takafumi; Pyo, Jeonghyun; Onaka, Takashi

    2016-03-01

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.

  15. MODELING OF THE ZODIACAL EMISSION FOR THE AKARI/IRC MID-INFRARED ALL-SKY DIFFUSE MAPS

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Toru; Ishihara, Daisuke; Kaneda, Hidehiro; Nakamichi, Keichiro; Takaba, Sachi; Kobayashi, Hiroshi [Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Ootsubo, Takafumi [Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902 (Japan); Pyo, Jeonghyun [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Onaka, Takashi, E-mail: kondo@u.phys.nagoya-u.ac.jp, E-mail: ishihara@u.phys.nagoya-u.ac.jp [Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2016-03-15

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.

  16. Modeling of the zodiacal emission for the AKARI/IRC mid-infrared all-sky diffuse maps

    CERN Document Server

    Kondo, T; Kaneda, H; Nakamichi, K; Takaba, S; Kobayashi, H; Ootsubo, T; Pyo, J; Onaka, T

    2016-01-01

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our Solar System, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. We therefore aim to improve the IPD cloud model based on Kelsall et al. 1998, using the AKARI 9 and 18 micron all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest ...

  17. The distribution of the ISM in the Milky Way A three-dimensional large-scale model

    CERN Document Server

    Misiriotis, A; Papamastorakis, J; Boumis, P; Goudis, C D

    2006-01-01

    We use the COBE/DIRBE (1.2, 2.2, 60, 100, 140, and 240 $\\mu$m) maps and the COBE/FIRAS spectra (for the wavelength range 100 - 1000 $\\mu$m) to constrain a model for the spatial distribution of the dust, the stars, and the gas in the Milky Way. By assuming exponential axisymmetric distributions for the dust and the stars and by performing the corresponding radiative transfer calculations we closely (given the simple geometry of the model) reproduce the FIR and NIR maps of the Milky Way. Similar distributions for the atomic and molecular hydrogen in the disk are used (with an inner cut-off radius for the atomic hydrogen) to fit the gas data. The star formation rate as a function of the Galactic radius is derived from the FIR emission and is well in agreement with existing estimates from various star formation tracers. The gas surface density is plotted against the star formation rate density and an ``intrinsic'' Galactic Schmidt law is derived with excellent agreement with the ``external'' Schmidt law found for...

  18. Nobel Connection to the Space Program

    Science.gov (United States)

    Ng, Edward W.; Nash, Rebecca

    2007-09-01

    The 2006 Nobel Prize in Physics was heralded by some in the press as the "First Nobel Prize for Space Exploration." Indeed the Nobel Foundation's announcement specifically cited the Cosmic Background Explorer (COBE) satellite launched by NASA in 1989 as the prime-enabling instrument It elaborated further, "The COBE results provided increased support for the Big Bang scenario for the origin of the Universe... These measurements also marked the inception of cosmology as a precise science." NASA also seized this unique moment of fame to honor its favorite son, the first Nobel scientist of the agency, John Mather, of the Goddard Space Flight Center, who shared the honor with Professor G. Smoot of the University of California, the Principal Investigator of the COBE measurement. It is without any dispute that the Nobel Prize is the highest scientific honor and best-known award of admiration and inspiration to the public and educational sectors. Unfortunately in the American culture, youths are mostly exposed to success icons in the sports, entertainment, and business domains. Science icons (of either gender) are largely unknown to them. We sincerely hope that success stories of Nobel scientists will become part of the learning curriculum in the K-16 educational experience. In this paper, we examine the pedigree of a number of Nobel Prizes over the years, and discuss their interactions with, and connections to, the space program. It is advantageous for the context of educational and public outreach to see such connections, because in a number of public surveys, one important customer expectation for the space program is the search for new knowledge, to which the Nobel Prize is a prominent benchmark. We have organized this paper into nine, fairly independent sections for ease of reading: I. "Michael Jordan or Mia Hamm" - Introduction and Background II. "Connecting the Dots Between the Heavens and Earth" - From Newton to Bethe III. "From Cosmic Noise to the Big Bang" - The

  19. The Nobel Connection to the Space Program

    Science.gov (United States)

    Ng, E. N.; Nash, R. L.

    2007-09-01

    The 2006 Nobel Prize in Physics was heralded by some in the press as the "First Nobel Prize for Space Exploration." Indeed the Nobel Foundation's announcement specifically cited the Cosmic Background Explorer (COBE) satellite launched by NASA in 1989 as the prime-enabling instrument It elaborated further, "The COBE results provided increased support for the Big Bang scenario for the origin of the Universe. These measurements also marked the inception of cosmology as a precise science." NASA also seized this unique moment of fame to honor its favorite son, the first Nobel scientist of the agency, John Mather, of the Goddard Space Flight Center, who shared the honor with Professor G. Smoot of the University of California, the Principal Investigator of the COBE measurement. It is without any dispute that the Nobel Prize is the highest scientific honor and best-known award of admiration and inspiration to the public and educational sectors. Unfortunately in the American culture, youths are mostly exposed to success icons in the sports, entertainment, and business domains. Science icons are largely unknown to them. We sincerely hope that success stories of Nobel scientists will become part of the learning curriculum in the K-16 educational experience. In this paper, we examine the pedigree of a number of Nobel Prizes over the years, and discuss their interactions with, and connections to, the space program. It is advantageous for the context of educational and public outreach to see such connections, because in a number of public surveys, one important customer expectation for the space program is the search for new knowledge, to which the Nobel Prize is a prominent benchmark. We have organized this lengthy paper into nine, fairly independent sections for ease of reading:1."Michael Jordan or Mia Hamm" - Introduction and Background2."Connecting the Dots Between the Heavens and Earth" - From Newton to Bethe3."From Cosmic Noise to the Big Bang" - The First Nobel

  20. 采集后6小时与72小时制备的冰冻单采血小板质量研究%A comparative study on qualities of frozen platelets prepared 6 h and 72 h after collection

    Institute of Scientific and Technical Information of China (English)

    刘利明; 陈蓉; 詹鹏飞; 邹志强; 杨湘辉; 江顺琴; 陈雪丽

    2008-01-01

    Objective To offer evidence for preparation criteria of frozen platelet preparation by means of comparison of a number of quality parameters between the frozen platelets prepared at 6 hour and 72 hour time point after collection.Methods Frozen platelet preparation was made 6 h and 72 h after collection of blood platelets gathered in bags by Trima Blood Corpuscle Machine.A week later, the frozen platelet preparation was dissolved and sampled for detection of PLT,MPV,PCT,PDW, platelet adhesiveness,P-selectin,PF3A,PF4,pH value,blood clot contractibility(clot retraction test).Results There were no significant differences in a series of quality parameters between the frozen platelets prepared at 6 hours and 72 hours after collection.Under the different conservation conditions.PF3A kept available activity.When the blood platelets were conserved under the conditions at22℃or at-80℃,the expressions of PF3A and p-Selection were increased,there was no difference of PF3A and p-Selection expression between the frozen platelets prepared at 6 hours and 72 hours after collection.During three days of routine conservation,no change appeared in the conglutinate function and clot contractibility;however,the above parameters were significantly decreased,and the activity of platelets was markedly datined under congealing.Conclusion There are no significant differences in a series of quality parameters between the frozen platelet preparation prepared with gathered blood by Trima Blood Corpuscle Machine at 6 hours and 72 hours after collection,and both of the frozen platelet preparation can effectively improve or control the hemorrhagic tendency of patients suffered urgent massive hemorrhage.%目的 通过比较采集后6 h和72 h制备的冰冻单采血小板制品的多项质量参数,为冰冻单采血小板的制备标准提供依据.方法 以美国产Trims血细胞分离机配套全密闭7 d保存袋采集的单采血小板,分别于采集后6 h和72 h

  1. Stray light analysis of the Diffuse Infrared Background Experiment (DIRBE)

    Science.gov (United States)

    Breault, R. P.

    1984-01-01

    The straylight analysis of the diffuse infrared background experiment (DIRBE) on the cosmic background explorer (COBE) mission is discussed. From the statement of work (SOW), the purpose of DIRBE is to measure, or set upper limits on, the spectral and spatial character of the diffuse extra galactic infrared radiation. Diffuse infrared sources within our own galaxy are measured. The required reduction of the unwanted radiation imposes severe design and operating restrictions on the DIRBE instrument. To accomplish its missions, it will operate at a multitude of wavelengths ranging from 1.25 um out to 200 to 300 microns. The operating bands and the required point source normalized irradiance transmittance (PSNIT) are shown. The important straylight concepts in the DIRBE design are reviewed. The model and assumptions used in APART analysis are explained. The limitations due to the scalar theory used in the analysis are outlined.

  2. Cosmological constraints on neutrinos with Planck data

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, M. [Laboratoire de l’Accélérateur Linéaire, Bat.200, 91400 Orsay (France)

    2015-07-15

    Neutrinos take part in the dance of the evolving Universe influencing its history from leptogenesis, to Big Bang nucleosynthesis, until late time structure formation. This makes cosmology, and in particular one of its primary observables the Cosmic Microwave Background (CMB), an unusual but valuable tool for testing Neutrino Physics. The best measurement to date of full-sky CMB anisotropies comes from the Planck satellite launched in 2009 by the European Space Agency (ESA) and successful follower of COBE and WMAP. Testing Planck data against precise theoretical predictions allow us to shed light on various interesting open questions such as the value of the absolute scale of neutrino masses or their energy density. We revise here the results concerning neutrinos obtained by the Planck Collaboration in the 2013 data release.

  3. Polylogarithmic representation of radiative and thermodynamic properties of thermal radiation in a given spectral range: I. Blackbody radiation

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Using polylogarithm functions the exact analytical expressions for the radiative and thermodynamic properties of blackbody radiation, such as the Wien displacement law, Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies are constructed. The obtained expressions allow us to tabulate these functions in various finite frequency bands at different temperatures for practical applications. As an example, the radiative and thermodynamic functions using experimental data for the monopole spectrum of the Cosmic Microwave Background (CMB) radiation measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.725 K are calculated. The expressions obtained for the radiative and thermodynamic functions can be easily presented in wavelength and wavenumber domains.

  4. Asymmetric reduction carbonyl compounds to chiral alcohols by baker's yeast%面包酵母催化羰基不对称还原合成手性醇的研究

    Institute of Scientific and Technical Information of China (English)

    黄和; 杨忠华; 姚善泾

    2004-01-01

    以2-辛酮和4-氯乙酰乙酸乙酯(COBE)为模型底物分别考察了酵母细胞对直链甲基酮和β-羰基酯中的羰基不对称还原情况.实验发现不对称还原2-辛酮的产物主要是S型的2-辛醇,且对映体选择性很高.不对称还原COBE生成的主要是S(D)-型产物,反应COBE的转化率、光学选择性都比较高.同时发现COBE的浓度和产物对不对称还原都有一定负面的影响.

  5. The inflationary energy scale

    Science.gov (United States)

    Liddle, Andrew R.

    1994-01-01

    The energy scale of inflation is of much interest, as it suggests the scale of grand unified physics, governs whether cosmological events such as topological defect formation can occur after inflation, and also determines the amplitude of gravitational waves which may be detectable using interferometers. The COBE results are used to limit the energy scale of inflation at the time large scale perturbations were imprinted. An exact dynamical treatment based on the Hamilton-Jacobi equations is then used to translate this into limits on the energy scale at the end of inflation. General constraints are given, and then tighter constraints based on physically motivated assumptions regarding the allowed forms of density perturbation and gravitational wave spectra. These are also compared with the values of familiar models.

  6. Measurements of very low-sidelobe conical horn antennas

    Science.gov (United States)

    Toral, Marco A.; Ratliff, Roger B.; Lecha, Maria C.; Maruschak, John G.; Bennett, Charles L.

    1989-01-01

    A description is given of conical corrugated-horn antennas that were designed for millimeter-wave radiometers with a 7 degree field of view, namely the Differential Microwave Radiometers (DMRs) that will measure the large-angular-scale anisotropy of the cosmic background radiation that is generally thought to be the remnant of the primeval explosion, the Big Bang. The DMRs will be part of the Cosmic Background Explorer (COBE) satellite. Measured test results for three radiometers at 31.4, 53, and 90 GHz are reported along with those of a circular polarization orthomode transducer designed and characterized at 31.4 GHz. The measurement techniques and facilities are described, including an outdoor far-field facility where measurements down to levels 90 dB below the main beam maximum were achieved. The goal of achieving very low-sidelobe antennas with good symmetry has been demonstrated.

  7. Introduction and Overview CMB Sessions

    CERN Document Server

    Smoot, G F

    1998-01-01

    This is a very exciting time for the CMB field. It is widely recognized that precision measurements of the CMB can provide a definitive test of cosmological models and determine their parameters accurately. At present observations give us the first rough results but ongoing experiments promise new and improved results soon and eventually satellite missions (MAP and COBRAS/SAMBA now named Planck) are expected to provide the requisite precision measurements. Other areas such as observations of the spectrum and Sunyaev-Zeldovich effect are also making significant progress. There has long been anticipation that cosmic microwave background (CMB) radiation would provide significant information about the early Universe due to its early central role and its general lack of interaction in the later epochs. Though there have been many observations of the CMB since its discovery by Penzias and Wilson in 1964, the Cosmic Background Explorer satellite, COBE, provided two watershed observations: (1) the CMB is extremely we...

  8. IRSI-DARWIN How to see through the interplanetary dust cloud

    CERN Document Server

    Landgraf, M; Flury, W; Fridlund, M; Karlsson, A M; Léger, A

    2001-01-01

    ESA has identified interferometry as one of the major goals of the Horizon 2000+ programme. Infrared interferometers are a highly sensitive astronomical instruments that enable us to observe terrestrial planets around nearby stars. In this context the Infrared Space Interferometry Mission (IRSI)/ DARWIN is studied. The current design calls for a constellation of 6 free flying telescopes using 1.5m mirrors, plus one hub and one master spacecraft. As the baseline trajectory an orbit about the second collinear libration point of the Earth-Sun system has been selected. The thermal radiation from the interplanetary dust cloud that surrounds the Sun, the so-called zodiacal infrared foreground, is a major concern for any high-sensitivity infrared mission. The most reliable information about this radiation comes from the measurements by NASA's Cosmic Background Explorer (COBE) mission. There are various ways to detect faint terrestrial planets despite the bright foreground. We find that, using integration times in th...

  9. Did the universe recombine? New spectral constraints on reheating

    CERN Document Server

    Tegmark, M; Tegmark, Max; Silk, Joseph

    1994-01-01

    One still cannot conclusively assert that the universe underwent a neutral phase, despite the new COBE FIRAS limit y<0.000025 on Compton y-distortions of the cosmic microwave background. Although scenarios where the very early (z=1000) ionization is thermal, caused by IGM temperatures exceeding 10000K, are clearly ruled out, there is a significant loophole for cosmologies with typical CDM parameters if the dominant ionization mechanism is photoionization. If the ionizing radiation has a typical quasar spectrum, then the y-constraint implies roughly h^{3/2}\\Omega_b Omega_0^{-1/4}<0.1 for fully ionized models. This means that BDM models with Omega_0 around 0.15 and reionization at about z=1000 are strongly constrained even in this very conservative case, and can survive the y test only if most of the baryons form BDM around the reionization epoch.

  10. An Upper Limit on the Finescale Anisotropy of the Cosmic Background Radiation at 800-MICRONS

    Science.gov (United States)

    Church, S. E.; Lasenby, A. N.; Hills, R. E.

    1993-04-01

    In some models of the early Universe, radiation is reprocessed into the submillimetre and far-infrared by high-redshift dust, without violating COBE limits on the CBR spectrum, but producing secondary anisotropies which should be detectable with ground-based submillimetre telescopes. We describe an attempt to measure these anisotropies at 800 microns using the JCMT. A careful analysis to reduce position-dependent systematics was carried out and we show that, for this experiment, chopping the telescope beam in azimuth rather than RA produces lower systematics. Bayesian likelihood analysis is then used to set an upper limit on CBR fluctuations of {DELTA} T/T Kreysa & Chini in 1988 with the IBM 30-m telescope at 1300 microns are reanalysed in the same way to enable a comparison to be made. The results are used to set limits on the generation of cosmic backgrounds from primeval dust.

  11. The music of the Big Bang the cosmic microwave background and the new cosmology

    CERN Document Server

    Balbi, Amedeo

    2008-01-01

    The cosmic microwave background radiation is the afterglow of the big bang: a tenuous signal, more than 13 billion years old, which carries the answers to many of the questions about the nature of our Universe. It was serendipitously discovered in 1964, and thoroughly investigated in the last four decades by a large number of experiments. Two Nobel Prizes in Physics have already been awarded for research on the cosmic background radiation: one in 1978 to Arno Penzias and Robert Wilson, who first discovered it, the other in 2006, to George Smoot and John Mather, for the results of the COBE satellite. Most cosmological information is encoded in the cosmic background radiation by acoustic oscillations in the dense plasma that filled the primordial Universe: a "music" of the big bang, which cosmologists have long been trying to reconstruct and analyze, in order to distinguish different cosmological models, much like one can distinguish different musical instruments by their timbre and overtones. Only lately, this...

  12. Questions of Modern Cosmology Galileo's Legacy

    CERN Document Server

    D'Onofrio, Mauro

    2009-01-01

    Are we living in the "golden age" of cosmology? Are we close to understanding the nature of the unknown ingredients of the currently most accepted cosmological model and the physics of the early Universe? Or are we instead approaching a paradigm shift? What is dark matter and does it exist? How is it distributed around galaxies and clusters? Is the scientific community open to alternative ideas that may prompt a new scientific revolution - as the Copernican revolution did in Galileo's time? Do other types of supernovae exist that can be of interest for cosmology? Why have quasars never been effectively used as standard candles? Can you tell us about the scientific adventure of COBE? How does the extraction of the Cosmic Microwave Background anisotropy depend on the subtraction of the various astrophysical foregrounds? These, among many others, are the astrophysical, philosophical and sociological questions surrounding modern cosmology and the scientific community that Mauro D'Onofrio and Carlo Burigana pose t...

  13. Supermassive black holes formed by direct collapse of inflationary perturbations

    CERN Document Server

    Nakama, Tomohiro; Yokoyama, Jun'ichi

    2016-01-01

    We propose a mechanism of producing a new type of primordial perturbations which collapse to primordial black holes whose mass can be as large as necessary for them to grow to the supermassive black holes observed at high redshifts, without contradicting COBE/FIRAS upper limits on cosmic microwave background (CMB) spectral distortions. In our model, the observable Universe consists of two kinds of many small patches which experienced different expansion histories during inflation. Large amplitudes of primordial perturbations enough to form primordial black holes are realized on patches that experienced more Hubble expansion than the others. By making these patches the minor component, the rarity of supermassive black holes can be explained. On the other hand, most regions of the Universe experienced the standard history and hence have only standard almost scale-invariant adiabatic perturbations confirmed by observations of CMB or large-scale structures of the universe. Thus our mechanism can evade the constra...

  14. Science and the media alternative routes in scientific communication

    CERN Document Server

    Bucchi, Massimiano

    1998-01-01

    In the days of global warming and BSE, science is increasingly a public issue. This book provides a theoretical framework which allows us to understand why and how scientists address the general public. The author develops the argument that turning to the public is not simply a response to inaccurate reporting by journalists or to public curiosity, nor a wish to gain recognition and additional funding. Rather, it is a tactic to which the scientific community are pushed by certain "internal" crisis situations. Bucchi examines three cases of scientists turning to the public: the cold fusion case, the COBE/Big Bang issue and Louis Pasteur's public demonstration of the anthrax vaccine, a historical case of "public science." Finally, Bucchi presents his unique model of communications between science and the public, carried out through the media. This is a thoughtful and wide-ranging treatment of complex contemporary issues, touching upon the history and sociology of science, communication and media studies. Bucchi...

  15. Archeops: an instrument for present and future cosmology

    CERN Document Server

    Tristram, M

    2003-01-01

    Archeops is a balloon-borne instrument dedicated to measure the cosmic microwave background (CMB) temperature anisotropies. It has, in the millimetre domain (from 143 to 545 GHz), a high angular resolution (about 10 arcminutes) in order to constrain high l multipoles, as well as a large sky coverage fraction (30%) in order to minimize the cosmic variance. It has linked, before WMAP, Cobe large angular scales to the first acoustic peak region. From its results, inflation motivated cosmologies are reinforced with a flat Universe (Omega_tot=1 within 3%). The dark energy density and the baryonic density are in very good agreement with other independent estimations based on supernovae measurements and big bang nucleosynthesis. Important results on galactic dust emission polarization and their implications for Planck are also addressed.

  16. Constraints on hidden photons from current and future observations of CMB spectral distortions

    CERN Document Server

    Kunze, Kerstin E

    2015-01-01

    A variety of beyond the standard model scenarios contain very light hidden sector U(1) gauge bosons undergoing kinetic mixing with the photon. The resulting oscillation between ordinary and hidden photons leads to spectral distortions of the cosmic microwave background. We update the bounds on the mixing parameter $\\chi_0$ and the mass of the hidden photon $m_{\\gamma'}$ for future experiments measuring CMB spectral distortions, such as PIXIE and PRISM/COrE. For $10^{-14}\\;{\\rm eV}\\lesssim m_{\\gamma'}\\lesssim 10^{-13}\\;{\\rm eV}$, we find the kinetic mixing angle $\\chi_0$ has to be less than $10^{-8}$ at 95\\% CL. These bounds are more than an order of magnitude stronger than those derived from the COBE/FIRAS data.

  17. Astronomical data analysis software and systems I; Proceedings of the 1st Annual Conference, Tucson, AZ, Nov. 6-8, 1991

    Science.gov (United States)

    Worrall, Diana M. (Editor); Biemesderfer, Chris (Editor); Barnes, Jeannette (Editor)

    1992-01-01

    Consideration is given to a definition of a distribution format for X-ray data, the Einstein on-line system, the NASA/IPAC extragalactic database, COBE astronomical databases, Cosmic Background Explorer astronomical databases, the ADAM software environment, the Groningen Image Processing System, search for a common data model for astronomical data analysis systems, deconvolution for real and synthetic apertures, pitfalls in image reconstruction, a direct method for spectral and image restoration, and a discription of a Poisson imagery super resolution algorithm. Also discussed are multivariate statistics on HI and IRAS images, a faint object classification using neural networks, a matched filter for improving SNR of radio maps, automated aperture photometry of CCD images, interactive graphics interpreter, the ROSAT extreme ultra-violet sky survey, a quantitative study of optimal extraction, an automated analysis of spectra, applications of synthetic photometry, an algorithm for extra-solar planet system detection and data reduction facilities for the William Herschel telescope.

  18. The Polarized Radiation Imaging and Spectroscopy Mission

    CERN Document Server

    André, Philippe; Banday, Anthony; Barbosa, Domingos; Barreiro, Belen; Bartlett, James; Bartolo, Nicola; Battistelli, Elia; Battye, Richard; Bendo, George; Benoȋt, Alain; Bernard, Jean-Philippe; Bersanelli, Marco; Béthermin, Matthieu; Bielewicz, Pawel; Bonaldi, Anna; Bouchet, François; Boulanger, François; Brand, Jan; Bucher, Martin; Burigana, Carlo; Cai, Zhen-Yi; Camus, Philippe; Casas, Francisco; Casasola, Viviana; Castex, Guillaume; Challinor, Anthony; Chluba, Jens; Chon, Gayoung; Colafrancesco, Sergio; Comis, Barbara; Cuttaia, Francesco; D'Alessandro, Giuseppe; Da Silva, Antonio; Davis, Richard; de Avillez, Miguel; de Bernardis, Paolo; de Petris, Marco; de Rosa, Adriano; de Zotti, Gianfranco; Delabrouille, Jacques; Désert, François-Xavier; Dickinson, Clive; Diego, Jose Maria; Dunkley, Joanna; Enßlin, Torsten; Errard, Josquin; Falgarone, Edith; Ferreira, Pedro; Ferrière, Katia; Finelli, Fabio; Fletcher, Andrew; Fosalba, Pablo; Fuller, Gary; Galli, Silvia; Ganga, Ken; García-Bellido, Juan; Ghribi, Adnan; Giard, Martin; Giraud-Héraud, Yannick; Gonzalez-Nuevo, Joaquin; Grainge, Keith; Gruppuso, Alessandro; Hall, Alex; Hamilton, Jean-Christophe; Haverkorn, Marijke; Hernandez-Monteagudo, Carlos; Herranz, Diego; Jackson, Mark; Jaffe, Andrew; Khatri, Rishi; Kunz, Martin; Lamagna, Luca; Lattanzi, Massimiliano; Leahy, Paddy; Lesgourgues, Julien; Liguori, Michele; Liuzzo, Elisabetta; Lopez-Caniego, Marcos; Macias-Perez, Juan; Maffei, Bruno; Maino, Davide; Mangilli, Anna; Martinez-Gonzalez, Enrique; Martins, Carlos J.A.P.; Masi, Silvia; Massardi, Marcella; Matarrese, Sabino; Melchiorri, Alessandro; Melin, Jean-Baptiste; Mennella, Aniello; Mignano, Arturo; Miville-Deschênes, Marc-Antoine; Monfardini, Alessandro; Murphy, Anthony; Naselsky, Pavel; Nati, Federico; Natoli, Paolo; Negrello, Mattia; Noviello, Fabio; O'Sullivan, Créidhe; Paci, Francesco; Pagano, Luca; Paladino, Rosita; Palanque-Delabrouille, Nathalie; Paoletti, Daniela; Peiris, Hiranya; Perrotta, Francesca; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Pollo, Agnieszka; Ponthieu, Nicolas; Remazeilles, Mathieu; Ricciardi, Sara; Roman, Matthieu; Rosset, Cyrille; Rubino-Martin, Jose-Alberto; Salatino, Maria; Schillaci, Alessandro; Shellard, Paul; Silk, Joseph; Starobinsky, Alexei; Stompor, Radek; Sunyaev, Rashid; Tartari, Andrea; Terenzi, Luca; Toffolatti, Luigi; Tomasi, Maurizio; Trappe, Neil; Tristram, Matthieu; Trombetti, Tiziana; Tucci, Marco; Van de Weijgaert, Rien; Van Tent, Bartjan; Verde, Licia; Vielva, Patricio; Wandelt, Ben; Watson, Robert; Withington, Stafford; Cabrera, Nicolas

    2014-01-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM

  19. Superconducting Cosmic String with Propagating Torsion

    CERN Document Server

    Ferreira, C N; Garcia de Andrade, L C

    2000-01-01

    We show that it is possible to construct a consistent model describing a current-carrying cosmic string endowed with torsion. The torsion contribution to the gravitational force and geodesics of a test-particle moving around the SCCS are analyzed. In particular, we point out two interesting astrophysical phenomena in which the higher magnitude force we derived may play a critical role: the dynamics of compact objects orbiting the torsioned SCCS and accretion of matter onto it. The deficit angle associated to the SCCS can be obtained and compared with data from the Cosmic Background Explorer (COBE) satellite. We also derived a value for the torsion contribution to matter density fluctuations in the early Universe.

  20. Cosmological constraints on neutrinos with Planck data

    International Nuclear Information System (INIS)

    Neutrinos take part in the dance of the evolving Universe influencing its history from leptogenesis, to Big Bang nucleosynthesis, until late time structure formation. This makes cosmology, and in particular one of its primary observables the Cosmic Microwave Background (CMB), an unusual but valuable tool for testing Neutrino Physics. The best measurement to date of full-sky CMB anisotropies comes from the Planck satellite launched in 2009 by the European Space Agency (ESA) and successful follower of COBE and WMAP. Testing Planck data against precise theoretical predictions allow us to shed light on various interesting open questions such as the value of the absolute scale of neutrino masses or their energy density. We revise here the results concerning neutrinos obtained by the Planck Collaboration in the 2013 data release

  1. Counting Fixed Points, Two-Cycles, and Collisions of the Discrete Exponential Function using p-adic Methods

    CERN Document Server

    Holden, Joshua

    2011-01-01

    Brizolis asked for which primes p greater than 3 does there exist a pair (g, h) such that h is a fixed point of the discrete exponential map with base g, or equivalently h is a fixed point of the discrete logarithm with base g. Zhang (1995) and Cobeli and Zaharescu (1999) answered with a "yes" for sufficiently large primes and gave estimates for the number of such pairs when g and h are primitive roots modulo p. In 2000, Campbell showed that the answer to Brizolis was "yes" for all primes. The first author has extended this question to questions about counting fixed points, two-cycles, and collisions of the discrete exponential map. In this paper, we use p-adic methods, primarily Hensel's lemma and p-adic interpolation, to count fixed points, two cycles, collisions, and solutions to related equations modulo powers of a prime p.

  2. Confrontation of a Double Inflationary Cosmological Model with Observations

    CERN Document Server

    Gottlöber, S; Starobinsky, A A; Gottloeber, Stefan; Muecket, Jan P.

    1994-01-01

    CDM models with non-scale-free step-like spectra of adiabatic perturbations produced in a realistic double inflationary model are compared with recent observational data. The model contains two additional free parameters relatively to the standard CDM model with the flat ($n=1$) initial spectrum. Results of the COBE experiment are used for the determination of a free overall spectrum normalization. Then predictions for the galaxy biasing parameter, the variance for "counts in cells", the galaxy angular correlation function, bulk flow peculiar velocities and the Mach number test are obtained. Also considered are conditions for galaxy and quasar formation. Observational data strongly restricts allowed values for the two remaining model parameters. However, a non-empty region for them satisfying all considered tests is found.

  3. All-Sky Observational Evidence for An Inverse Correlation Between Dust Temperature and Emissivity Spectral Index

    Science.gov (United States)

    Liang, Z.; Fixsen, D. J.; Gold, B.

    2012-01-01

    We show that a one-component variable-emissivity-spectral-index model (the free- model) provides more physically motivated estimates of dust temperature at the Galactic polar caps than one- or two-component fixed-emissivity-spectral-index models (fixed- models) for interstellar dust thermal emission at far-infrared and millimeter wavelengths. For the comparison we have fit all-sky one-component dust models with fixed or variable emissivity spectral index to a new and improved version of the 210-channel dust spectra from the COBE-FIRAS, the 100-240 micrometer maps from the COBE-DIRBE and the 94 GHz dust map from the WMAP. The best model, the free-alpha model, is well constrained by data at 60-3000 GHz over 86 per cent of the total sky area. It predicts dust temperature (T(sub dust)) to be 13.7-22.7 (plus or minus 1.3) K, the emissivity spectral index (alpha) to be 1.2-3.1 (plus or minus 0.3) and the optical depth (tau) to range 0.6-46 x 10(exp -5) with a 23 per cent uncertainty. Using these estimates, we present all-sky evidence for an inverse correlation between the emissivity spectral index and dust temperature, which fits the relation alpha = 1/(delta + omega (raised dot) T(sub dust) with delta = -.0.510 plus or minus 0.011 and omega = 0.059 plus or minus 0.001. This best model will be useful to cosmic microwave background experiments for removing foreground dust contamination and it can serve as an all-sky extended-frequency reference for future higher resolution dust models.

  4. Towards understanding the dynamics of the bar/bulge region in our Galaxy

    Directory of Open Access Journals (Sweden)

    Athanassoula E.

    2012-02-01

    Full Text Available I review some of the work on bars which is closely linked to the bar/bulge system in our Galaxy. Several independent studies, using totally independent methods, come to the same results about the 3D structure of a bar, i.e., that a bar is composed of a vertically thick inner part and a vertically thin outer part. I give examples of this from simulations and substantiate the discussion with input from orbital structure analysis and from observations. The thick part has a considerably shorter radial extent than the thin part. I then see how this applies to our Galaxy, where two bars have been reported, the COBE/DIRBE bar and the Long bar. Comparing their extents and making the reasonable and necessary assumption that our Galaxy has properties similar to those of other galaxies of similar type, leads to the conclusion that these two bars can not form a standard double bar system. I then discuss arguments in favour of the two bars being simply different parts of the same bar, the COBE/DIRBE bar being the thick inner part and the Long bar being the thin outer part of this bar. I also very briefly discuss some related new results. I first consider bar formation and evolution in disc galaxies with a gaseous component – including star formation, feedback and evolution – and a triaxial halo. Then I consider bar formation in a fully cosmological context using hydrodynamical LCDM simulations, where the host galaxies grow, accrete matter and significantly evolve during the formation and evolution of the bar.

  5. Search for pseudoscalar cold dark matter

    Energy Technology Data Exchange (ETDEWEB)

    van Bibber, K.; Stoeffl, W.; LLNL Collaborators

    1992-05-29

    AH dynamical evidence points to the conclusion that the predominant form of matter in the universe is in a non-luminous form. Furthermore, large scale deviations from uniform Hubble flow, and the recent COBE reports of inhomogeneities in the cosmic microwave background strongly suggest that we live in an exactly closed universe. If this is true, then ordinary baryonic matter could only be a minority component (10% at most) of the missing mass, and that what constitutes the majority of the dark matter must involve new physics. The axion is one of very few well motivated candidates which may comprise the dark matter. Additionally it is a `cold` dark-matter candidate which is preferred by the COBE data. We propose to construct and operate an experiment to search for axions which may constitute the dark matter of our own galaxy. As proposed by Sikivie, dark-matter axions may be detected by their stimulated conversion into monochromatic microwave photons in a tunable high-Q cavity inside a strong magnetic field. Our ability to mount an experiment quickly and take data within one year is due to a confluence of three factors. The first is the availability of a compact high field superconducting magnet and a local industrial partner, Wang NMR, who can make a very thermally efficient and economical cryostat for it. The second is an ongoing joint venture with the Institute for Nuclear Research of the Russian Academy of Sciences to do R&D on metalized precision-formed ceramic microwave cavities for the axion search, and INR has commited to providing all the microwave cavity arrays for this experiment, should this proposal be approved. The third is a commitment of very substantial startup capital monies from MIT for all of the state-of-the-art ultra-low noise microwave electronics, to one of our outstanding young collaborators who is joining their faculty.

  6. PLANCK, the Satellite: a New Experimental Test of General Relativity

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2008-04-01

    Full Text Available If the origin of a microwave background (EMB is the Earth, what would be its density and associated dipole anisotropy measured at different altitudes from the surface of the Earth? The mathematical methods of the General Theory of Relativity are applied herein to answer these questions. The density of the EMB is answered by means of Einstein's equations for the electromagnetic field of the Earth. The dipole anisotropy, which is due to the rapid motion of the source (the Earth in the weak intergalactic field, is analysed by using the geodesic equations for light-like particles (photons, which are mediators for electromagnetic radiation. It is shown that the EMB decreases with altitude so that the density of its energy at the altitude of the COBE orbit (900km is 0.68 times less than that at the altitude of a U2 aeroplane (25km. Furthermore, the density at the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites should be only 10$^{-7}$ of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the EMB doesn't depend on altitude from the surface of the Earth, it should be the same irrespective of the altitude at which measurements are taken. This result is in support to the experimental and observational analysis conducted by P.-M.Robitaille, according to which the 2.7K microwave background, first observed by Penzias and Wilson, is not of cosmic origin, but of the Earth, and is generated by the oceans. WMAP indicated the same anisotropy of the microwave background at the 2nd Lagrange point that near the Earth. Therefore when PLANCK, which is planned on July, 2008, will manifest the 2.7K monopole microwave signal deceased at the 2nd Langrange point, it will be a new experimental verification of Einstein's theory.

  7. PLANCK, the Satellite: a New Experimental Test of General Relativity

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2008-04-01

    Full Text Available If the origin of a microwave background (EMB is the Earth, what would be its density and associated dipole anisotropy measured at different altitudes from the surface of the Earth? The mathematical methods of the General Theory of Relativity are applied herein to answer these questions. The density of the EMB is answered by means of Einstein’s equations for the electromagnetic field of the Earth. The dipole anisotropy, which is due to the rapid motion of the source (the Earth in the weak intergalactic field, is analysed by using the geodesic equations for light-like particles (photons, which are mediators for electromagnetic radiation. It is shown that the EMB decreases with altitude so that the density of its energy at the altitude of the COBE orbit (900km is 0.68 times less than that at the altitude of a U2 aeroplane (25 km. Furthermore, the density at the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites should be only 1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the EMB doesn’t depend on altitude from the surface of the Earth, it should be the same irrespective of the altitude at which measurements are taken. This result is in support to the experimental and observational analysis conducted by P.-M. Robitaille, according to which the 2.7 K microwave background, first observed by Penzias and Wilson, is not of cosmic origin, but of the Earth, and is generated by the oceans. WMAP indicated the same anisotropy of the microwave background at the 2nd Lagrange point that near the Earth. Therefore when PLANCK, which is planned on July, 2008, will manifest the 2.7 K monopole microwave signal deceased at the 2nd Langrange point, it will be a new experimental verification of Einstein’s theory.

  8. Application of haemocyte pheresis in adjunctive treatment of polycythemia vera using haemocyte separator%红细胞单采术辅助治疗真性红细胞增多症的应用

    Institute of Scientific and Technical Information of China (English)

    辛延; 李晓云

    2013-01-01

    目的 探讨应用COBE Spectra血细胞分离机进行红细胞单采术辅助治疗真性红细胞增多症的疗效.方法 应用COBE Spectra血细胞分离机对18例真性红细胞增多症进行红细胞单采术,共27次,单采后接受羟基脲口服;同时与32例单用羟基脲的真性红细胞增多症患者进行对比,观察疗效的时间为1个月.结果 ①在单采联合羟基脲治疗组,18例患者血红蛋白中位数210(179~ 261) g/L下降至165(155~220) g/L,颜面绛紫色好转,血压下降,与术前比较差异有统计学意义(P<0.01);②32例单用羟基脲的真性红细胞性增多症患者血红蛋白中位数209.5(158~242) g/L下降至183.5(124~228) g/L,颜面绛紫色有所好转,与用药前相比有统计学意义(P<0.01);③单采联合羟基脲组血红蛋白降低更加明显,每次单采后血红蛋白即刻下降,且血红蛋白下降的中位天数(10天)明显少于单用羟基脲组(4天),有统计学意义(P<0.05).结论 利用血细胞分离机进行红细胞单采术,其临床效果肯定,能迅速缓解症状,优于单用羟基脲治疗,且安全、可靠、不良反应小.

  9. Chaotic inflation limits for non-minimal models with a Starobinsky attractor

    CERN Document Server

    Mosk, Benjamin

    2014-01-01

    We investigate inflationary attractor points by analyzing non-minimally coupled single field inflation models in two opposite limits; the `flat' limit in which the first derivative of the conformal factor is small and the `steep' limit, in which the first derivative of the conformal factor is large. We consider a subset of models that yield Starobinsky inflation in the steep conformal factor, strong coupling, limit and demonstrate that they result in chaotic inflation in the opposite flat, weak coupling, limit. The suppression of higher order powers of the inflaton field in the potential is shown to be related to the flatness condition on the conformal factor. We stress that the chaotic attractor behaviour in the weak coupling limit is of a different, less universal, character than the Starobinsky attractor. Agreement with the COBE normalisation cannot be obtained in both attractor limits at the same time and in the chaotic attractor limit the scale of inflation depends on the details of the conformal factor,...

  10. On the origin of the cosmic microwave background anisotropies

    CERN Document Server

    Follop, Ria; Cooray, Asantha; Abdalla, Filipe B

    2007-01-01

    Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a correlate-by-eye exercise was attempted by overlaying the CMB map from Wilkinson Microwave Anisotropy Probe on a topographical map of Earth. Remarkably, several hot spots in the CMB map are found to be well aligned with either large cities on Earth or regions of high altitude. To further study the correlations between Earth and CMB, we performed a complicated cross-correlation analysis in the multipole space. The overall correlations are detected at more than 5 sigma confidence level. These results can be naively interpreted to suggest that large angular scale fluctuations in CMB are generated on Earth by a process that traces the altitude relative to a mean radius. Simply extending our analysis, we suggest that cross-correlations between CMB and any other map of a Solar sys...

  11. 3D Distribution of Molecular Gas in the Barred Milky Way

    CERN Document Server

    Pohl, Martin; Bissantz, Nicolai

    2007-01-01

    We present a new model of the three-dimensional distribution of molecular gas in the Milky Way Galaxy, based on CO line data. Our analysis is based on a gas-flow simulation of the inner Galaxy using smoothed-particle hydrodynamics (SPH) using a realistic barred gravitional potential derived from the observed COBE/DIRBE near-IR light distribution. The gas model prescribes the gas orbits much better than a simple circular rotation model and is highly constrained by observations, but it cannot predict local details. In this study, we provide a 3D map of the observed molecular gas distribution using the velocity field from the SPH model. A comparison with studies of the Galactic Center region suggests that the main structures are reproduced but somewhat stretched along the line-of-sight, probably on account of limited resolution of the underlying SPH simulation. The gas model will be publicly available and may prove useful in a number of applications, among them the analysis of diffuse gamma-ray emission as measu...

  12. Evaluation of ultrasound training in the problem based learning radiography curriculum at Makerere University, Uganda

    International Nuclear Information System (INIS)

    Introduction: The College of Health Sciences (CHS), Makerere University has been training health professionals since 1924. Six years ago, there was a curriculum change to Problem Based Learning/Community based Education and Service (PBL/COBES). A SPICES model (Student centered, problem based, integrated, community based, electives, systematic) was adopted and defined to suit the CHS environment. The radiography program is 3 years in length which involves Ultrasound as an important part of the training. It was a challenge to adopt the new PBL method of learning after having a lecture-based pedagogical method for over 80 years. Objective: To implement the training of ultrasound in the PBL radiography curriculum as well as evaluate the opinions of the staff and students about Ultrasound training in the new curriculum. Methodology: A participatory approach was used. Workshops were conducted and objectives for ultrasound courses refined. Scenarios were written for use in the PBL sessions. A retrospective review of student performance in the ultrasound courses was carried out. A cross-sectional survey involving teachers and current radiography students was also carried out to evaluate learning of ultrasound using the PBL approach. Results: Students have consistently excelled in ultrasound courses using the PBL approach of learning. Both teachers and students rated the teaching of ultrasound to radiography students as being highly important and supported the new approach to training. Conclusion: Ultrasound training using PBL has been successfully implemented. However, this is still an ongoing process and will require the total commitment of both students and teachers.

  13. Cosmological Density and Power Spectrum from Peculiar Velocities Nonlinear Corrections and PCA

    CERN Document Server

    Silberman, L; Eldar, A; Zehavi, I

    2001-01-01

    we allow for nonlinear effects in the likelihood analysis of galaxy peculiar velocities, and obtain ~35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be a flat LCDM model (h=0.65, n=1, COBE) with only Om_m as a free parameter. Since the likelihood is driven by the nonlinear regime, we "break" the power spectrum at k_b=0.2 h/Mpc and fit a power law at k>k_b. This allows for independent matching of the nonlinear behavior and an unbiased fit in the linear regime. The analysis assumes Gaussian fluctuations and errors, and a linear relation between velocity and density. Tests using mock catalogs that properly simulate nonlinear effects demonstrate that this procedure results in a reduced bias and a better fit. We find for the Mark3 and SFI data Om_m=0.32+-0.06 and 0.37+-0.09 respectively, with sigma_8*Om_m^0.6 =0.49+-0.06 and 0.63+-0.08, in agreement with constraints from other data. The quoted 90% erro...

  14. Diffuse Baryons in Groups and Clusters of Galaxies

    CERN Document Server

    Cavaliere, A; Tozzi, P

    1998-01-01

    To predict the X-ray observables associated to the diffuse baryons in clusters of galaxies, we develop a new physical approach to model such a hot intra-cluster plasma. Such approach is based on punctuated equilibria. and comprises the following blocks: Monte Carlo ``merging histories'' of dark matter potential wells; the central hydrostatic disposition for the ICP, reset to a new equilibrium after each merging episode; conditions of shock, or of closely adiabatic compression at the boundary with the external gas, preheated by stellar energy feedbacks. We predict the L-T relation, consistent with the data as for shape and scatter. This we combine with the mass distribution provided by the hierarchical clustering for different COBE-normalized CDM models, to predict the z-resolved luminosity functions, the source counts, the redshift distributions and contribution of the unresolved groups and clusters to the soft X-ray background. When compared with the recent ROSAT surveys, our results confirm that the critica...

  15. II José Plínio Baptista School of Cosmology

    CERN Document Server

    Piattella, Oliver; Rodrigues, Davi; Velten, Hermano; Zimdahl, Winfried

    2016-01-01

    The series of texts composing this book is based on the lectures presented during the II José Plínio Baptista School of Cosmology, held in Pedra Azul (Espírito Santo, Brazil) between 9 and 14 March 2014. This II JBPCosmo has been entirely devoted to the problem of understanding theoretical and observational aspects of Cosmic Background Radiation (CMB). The CMB is one of the most important phenomena in Physics and a fundamental probe of our Universe when it was only 400,000 years old. It is an extraordinary laboratory where we can learn from particle physics to cosmology; its discovery in 1965 has been a landmark event in the history of physics. The observations of the anisotropy of the cosmic microwave background radiation through the satellites COBE, WMAP and Planck provided a huge amount of data which are being analyzed in order to discover important information regarding the composition of our universe and the process of structure formation.

  16. The second coming of cold dark matter?

    Energy Technology Data Exchange (ETDEWEB)

    Zurek, W.H.; Warren, M.S. [Los Alamos National Lab., NM (United States); Quinn, P.J. [Mt. Stromlo Observatory, PB Weston Creek, Canberra, ACT (Australia) ; Salmon, J.K. [Caltech Concurrent Supercomputing Facility, Pasadena, CA (United States)

    1993-12-31

    In recent years standard cold dark matter (CDM) theory, which enjoyed a large following throughout much of the past decade, has been abandoned by virtually all of its early supporters. The most serious argument against CDM was the incompatibility between the relatively high value of the pairwise radial velocity dispersion between galaxies, {sigma}{sub v}, inferred from numerical simulation with the much lower observational estimates. We reexamine this argument in the light of our new, high-resolution, COBE-normalized simulations and conclude that {sigma}{sub v} is significantly overestimated in simulations which do not have sufficient resolution (i.e., which have masses of galaxies comparable to the mass of N-body particles) and that it is also difficult to reliably estimate {sigma}{sub v} from the observational catalogues used for this purpose. We conclude that inflationary cosmology and CDM are not -- contrary to the presently prevailing prejudice -- incompatible with the observations of small scale peculiar velocities, as characterized, for example, by {sigma}{sub v}.

  17. Cosmological Parameters from Cosmic Background Imager Observations and Comparisons with BOOMERANG, DASI, and MAXIMA

    CERN Document Server

    Sievers, J L; Cartwright, J K; Contaldi, C R; Mason, B S; Myers, S T; Padin, S; Pearson, T J; Pen, U L; Pogosyan, D; Prunet, S; Readhead, A C S; Shepherd, M C; Udomprasert, P S; Bronfman, L; Holzapfel, W L; May, J

    2003-01-01

    We report on the cosmological parameters derived from observations with the Cosmic Background Imager (CBI), covering 40 square degrees and the multipole range 300 <~ l <~ 3500. These unique, high-resolution observations show the seeds that gave rise to clusters of galaxies and also show damping in the power spectrum to l ~ 2000. Because the observations extend to much higher l the CBI results provide information complementary to that probed by the BOOMERANG, DASI, and MAXIMA experiments. When the CBI observations are used in combination with those from COBE-DMR, we find evidence for a flat universe, Omega(tot)=0.99 +/- 0.12 (1-sigma), a power law index of primordial fluctuations, n_s = 1.05(-0.08,+0.09), and densities in cold dark matter, Omega(cdm)h^2 = 0.17(-0.06,+0.08), and baryons, Omega(b)h^2 = 0.022(-0.009,+0.15). With the addition of large scale structure priors the Omega(cdm)h^2 value is sharpened to 0.12(-0.03,+0.03), and we find Omega(Lambda) = 0.64(-0.14,+0.11). In the l < 1000 overlap reg...

  18. Planck Early Results: The thermal performance of Planck

    CERN Document Server

    Ade, P A R; Arnaud, M; Ashdown, M; Aumont, J; Baccigalupi, C; Baker, M; Balbi, A; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoit, A; Bernard, J P; Bersanelli, M; Bhandari, P; Bhatia, R; Bock, J J; Bonaldi, A; Bond, J R; Borders, J; Borrill, J; Bouchet, F R; Bowman, B; Bradshaw, T; Breelle, E; Bucher, M; Burigana, C; Butler, R C; Cabella, P; Camus, P; Cantalupo, C M; Cappellini, B; Cardoso, J F; Catalano, A; Cayon, L; Challinor, A; Chamballu, A; Chambelland, J P; Charra, J; Charra, M; Chiang, L Y; Chiang, C; Christensen, P R; Clements, D L; Collaudin, B; Colombi, S; Couchot, F; Coulais, A; Crill, B P; Crook, M; Cuttaia, F; Damasio, C; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Gasperis, G; de Rosa, A; Delabrouille, J; Delouis, J M; Desert, F -X; Doerl, U; Dolag, K; Donzelli, S; Dore, O; Douspis, M; Dupac, X; Efstathiou, G; Enslin, T A; Eriksen, H K; Finelli, F; Foley, S; Forni, O; Fosalba, P; Fourmond, J J; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Gavila, E; Giard, M; Giardino, G; Giraud-Heraud, Y; Gonzalez-Nuevo, J; Gorski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Guyot, G; Harrison, D; Helou, G; Henrot-Versille, S; Hernandez-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Hoyland, R J; Huffenberger, K M; Israelsson, U; Jaffe, A H; Jones, W C; Juvela, M; Keihanen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knox, L; Kurki-Suonio, H; Lagache, G; Lamarre, J M; Lami, P; Lasenby, A; Laureijs, R J; Lawrence, C R; Leach, S; Leonardi, R; Leroy, C; Lilje, P B; Lopez-Caniego, M; Lubin, P M; Macias-Perez, J F; Maciaszek, T; MacTavish, C J; Maffei, B; Maino, D; Mandolesi, N; Mann, R; Maris, M; Martinez-Gonzalez, E; Masi, S; Matarrese, S; Matthai, F; Mazzotta, P; McGehee, P; Meinhold, P R; Melchiorri, A; Melot, F; Mendes, L; Mennella, A; Miville-Deschenes, M -A; Moneti, A; Montier, L; Mora, J; Morgante, G; Morisset, N; Mortlock, D; Munshi, D; Murphy, A; Naselsky, P; Nash, A; Natoli, P; Netterfield, C B; Novikov, D; Novikov, I; O'Dwyer, I J; Osborne, S; Pajot, F; Pasian, F; Patanchon, G; Pearson, D; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Plaszczynski, S; Platania, P; Pointecouteau, E; Polenta, G; Ponthieu, N; Poutanen, T; Prezeau, G; Prina, M; Prunet, S; Puget, J L; Rachen, J P; Rebolo, R; Reinecke, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Rubiino-Martin, J A; Rusholme, B; Sandri, M; Santos, D; Schaefer, B M; Scott, D; Seiffert, M D; Shellard, P; Smoot, G F; Starck, J -L; Stassi, P; Stivoli, F; Stolyarov, V; Stompor, R; Sudiwala, R; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Torre, J -P; Tristram, M; Tuovinen, J; Valenziano, L; Vibert, L; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Watson, C; White, S D M; Wilkinson, A; Wilson, P; Yvon, D; Zacchei, A; Zhang, B; Zonca, A

    2011-01-01

    The performance of the Planck instruments in space is enabled by their low operating temperatures, 20K for LFI and 0.1K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. Active coolers were chosen to minimize straylight on the detectors and to maximize lifetime. The scientific requirement for very broad frequency led to two detector technologies with widely different temperature and cooling needs. This made use of a helium cryostat, as used by previous cryogenic space missions (IRAS, COBE, ISO, SPITZER, AKARI), infeasible. Radiative cooling is provided by three V-groove radiators and a large telescope baffle. The active coolers are a hydrogen sorption cooler (<20K), a 4He Joule-Thomson cooler (4.7K), and a 3He-4He dilution cooler (1.4K and 0.1K). The flight system was at ambient temperature at launch and cooled in space to operating conditions. The bolometer plate of the High Frequency Instrument reached 93mK on 3 July 2009, 50 days after launch. The ...

  19. Diffuse Microwave Emission Survey

    Science.gov (United States)

    Shafer, R. A.; Mather, J.; Kogut, A.; Fixsen, D. J.; Seiffert, M.; Lubin, P. M.; Levin, S. M.

    1996-12-01

    The Diffuse Microwave Emission Survey (DIMES) is a mission concept selected by NASA in 1995 to answer fundamental questions about the content and history of the universe. DIMES will use a set of absolutely calibrated cryogenic radiometers from a space platform to measure the frequency spectrum of the cosmic microwave background (CMB) at wavelengths 15--0.3 cm (frequency 2--100 GHz) to precision 0.1 mK or better. Measurements at centimeter wavelengths probe different physical processes than the COBE-FIRAS spectra at shorter wavelengths, and complement the anisotropy measurements from DMR, balloon and ground-based instruments, and the planned MAP and COBRAS/SAMBA satellites. DIMES will observe the free-free signal from early photoionization to establish the precise epoch of structure formation, and will measure or limit energy release at redshift 10(4) theory and allowed by current measurement limits; even an upper limit at the expected sensitivity 10(-5) MJy/sr will place important constraints on the matter content, structure, and evolution of the universe. Detecting these distortions or showing that they do not exist constitutes the last frontier of CMB observations.

  20. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10-7, where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  1. COBRAS/SAMBA: the ESA Medium Size Mission for measurements of CBR anisotropy

    Science.gov (United States)

    Mandolesi, N.; Bersanelli, M.; Cesarsky, C.; Danese, L.; Efstathiou, G.; Griffin, M.; Lamarre, J. M.; Norgaard-Nielsen, H. U.; Pace, O.; Puget, J. L.; Raisanen, A.; Smoot, G. F.; Tauber, J.; Volonte, S.

    1995-02-01

    The COBRAS/SAMBA mission is designed for extensive, accurate mapping of the anisotropy of the Cosmic Background Radiation. with angular sensitivity from scales of a few arcminutes up to and overlapping with the > 7° COBE-DMR resolution. This will allow a full identification of the primordial density perturbations which grew to Corm the large-scale structures observed in the present universe. The COBRAS/SAMBA maps will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure. One of the main diffuse foreground emissions will be from interstellar dust, and the mission will provide relevant information on its components and emission properties. A combination of bolometric and radiometric detection techniques will ensure the sensitivity and wide spectral coverage required for accurate foreground discrimination. A far-Earth orbit has been selected to minimize the unwanted emission from the Earth as a source of contamination. The project is currently undergoing a feasibility study within the European Space Agency M3 programme.

  2. Measuring Galactic Extinction A Test

    CERN Document Server

    Arce, H G; Arce, Hector G.; Goodman, Alyssa A.

    1999-01-01

    We test the recently published all-sky reddening map of Schlegel, Finkbeiner & Davis (1998 [SFD]) using the extinction study of a region in the Taurus dark cloud complex by Arce & Goodman (1999 [AG]). In their study, AG use four different techniques to measure the amount and structure of the extinction toward Taurus, and all four techniques agree very well. Thus we believe that the AG results are a truthful representation of the extinction in the region and can be used to test the reliability of the SFD reddening map. The results of our test show that the SFD all-sky reddening map, which is based on data from COBE/DIRBE and IRAS/ISSA, overestimates the reddening by a factor of 1.3 to 1.5 in regions of smooth extinction with A_V > 0.5 mag. In some regions of steep extinction gradients the SFD map underestimates the reddening value, probably due to its low spatial resolution. We expect that the astronomical community will be using the SFD reddening map extensively. We offer this Letter as a cautionary n...

  3. Planck 2013 results. XIV. Zodiacal emission

    CERN Document Server

    Ade, P A R; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colley, J.-M.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Mottet, S.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; O'Sullivan, C.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polegre, A. M.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Smoot, G. F.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    The Planck satellite provides a set of all-sky maps at nine frequencies from 30 GHz to 857 GHz. Planets, minor bodies, and diffuse interplanetary dust emission (IPD) are all observed. The IPD can be separated from Galactic and other emissions because Planck views a given point on the celestial sphere multiple times, through different columns of IPD. We use the Planck data to investigate the behaviour of zodiacal emission over the whole sky at sub-millimetre and millimetre wavelengths. We fit the Planck data to find the emissivities of the various components of the COBE zodiacal model -- a diffuse cloud, three asteroidal dust bands, a circumsolar ring, and an Earth-trailing feature. The emissivity of the diffuse cloud decreases with increasing wavelength, as expected from earlier analyses. The emissivities of the dust bands, however, decrease less rapidly, indicating that the properties of the grains in the bands are different from those in the diffuse cloud. We fit the small amount of Galactic emission seen t...

  4. When scientists turn to the public alternative routes in science communication

    CERN Document Server

    Bucchi, M

    1998-01-01

    In the days of global warming and BSE, science is increasingly a public issue. But what should scientists communicate to the general public? To what extent can the public understand and be involved in scientific debate? How does this involvement affect the shaping and organisation of scientific activity? Why do scientists sometime turn to the media and publicize their findings rather than communicating their findings only with their peers? In this presentation, Massimiano Bucchi reviews the existing literature in this field and highlights the pitfalls of current approaches. He then develops his core argument that turning to the public is not simply a response to inaccurate reporting by journalists or to public curiosity, nor a wish to gain recognition and additional funding. Rather, it is a tactic to which the scientific community are pushed by certain ÒinternalÓ crisis situations. Three cases of scientists turning to the public are examined: the cold fusion case, the COBE/Big Bang issue and Louis PasteurÕ...

  5. Another look to distortions of the CMB spectrum

    CERN Document Server

    De Zotti, G; Castex, G; Lapi, A; Bonato, M

    2015-01-01

    We review aspects of cosmic microwave background spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by feedback from active galactic nuclei are investigated. Taking also into account the IGM heating associated to structure formation, we argue that values of the y parameter of several times 10^(-6), i.e. a factor of a few below the COBE/FIRAS upper limit, are to be expected. The Compton scattering by the re-ionized plasma also re-processes primordial Bose Einstein-type distortions, reshaping them; hence no pure Bose-Einstein-like distortions are to be expected. An assessment of Galactic and extragalactic foregrounds, taking into account the latest results from the Planck satellite as well as the contributions from the strong CII and CO lines from star-forming galaxies demonstrates that the foreground subtraction accurate enough to fully exploit the PIXIE sensitivity will be extremel...

  6. The Observational Mass Function of Nearby Galaxy Clusters

    CERN Document Server

    Girardi, M; Giuricin, G; Mardirossian, F; Mezzetti, M

    1998-01-01

    We present a new determination of the mass function of galaxy clusters, based on optical virial mass estimates for a large sample of 152 nearby (z M_lim)=(6.3\\pm 1.2) 10^{-6} (h^{-1} Mpc)^{-3} for cluster masses estimated within a 1.5 h^{-1} Mpc radius. Our mass function is intermediate between the two previous estimates by Bahcall & Cen (1993) and by Biviano et al. (1993). Based on the Press--Schechter approach, we use this mass function to constrain the amplitude of the fluctuation power spectrum at the cluster scale. After suitably convolving the PS predictions with observational errors on cluster masses and COBE--normalizing the fluctuation power spectrum, we find sigma_8=(0.60\\pm 0.04) Omega_0^{-0.46+0.09Omega_0} for flat low--density models and \\sigma_8=(0.60\\pm 0.04) Omega_0^{-0.48+0.17Omega_0} for open models (at the 90% c.l.).

  7. Phase Lags in the Optical-Infrared Light Curves of AGB Stars

    CERN Document Server

    Smith, B J; Moffett, A J; Smith, Beverly J.; Price, Stephan D.; Moffett, Amanda J.

    2005-01-01

    To search for phase lags in the optical-infrared light curves of asymptotic giant branch stars, we have compared infrared data from the COBE DIRBE satellite with optical light curves from the AAVSO and other sources. We found 17 examples of phase lags in the time of maximum in the infrared vs. that in the optical, and 4 stars with no observed lags. There is a clear difference between the Mira variables and the semi-regulars in the sample, with the maximum in the optical preceding that in the near-infrared in the Miras, while in most of the semi-regulars no lags are observed. Comparison to published theoretical models indicates that the phase lags in the Miras are due to strong titanium oxide absorption in the visual at stellar maximum, and suggests that Miras pulsate in the fundamental mode, while at least some semi-regulars are first overtone pulsators. There is a clear optical-near-infrared phase lag in the carbon-rich Mira V CrB; this is likely due to C2 and CN absorption variations in the optical.

  8. Annual parallax and a dimming event of a Mira variable star, FV Bootis

    Science.gov (United States)

    Kamezaki, Tatsuya; Nakagawa, Akiharu; Omodaka, Toshihiro; Inoue, Kan-ichiro; Chibueze, James O.; Nagayama, Takumi; Ueno, Yuji; Matsunaga, Noriyuki

    2016-10-01

    We present the first measurement of the trigonometric parallax of water masers associated with a Mira star, FV Bootis (FV Boo) using VLBI Exploration of Radio Astrometry (VERA). Based on our multi-epoch VERA observations, we derived the parallax to be 0.97 ± 0.06 mas, which corresponds to a distance of 1.03^{+0.07}_{-0.06} kpc. The water masers around FV Boo were spatially distributed over an area of 41 au × 41 au, and their internal motions indicate the presence of an outflow. Using the Kagoshima University 1 m optical/infrared telescope, we determined the period to be 305.6 d and the mean apparent magnitude to be +2.91 mag in the K'-band. On the period-luminosity plane, the obtained period and K'-band magnitude puts FV Boo slightly below the sequence of Miras, possibly due to circumstellar reddening. Combining our photometric data with COBE and 2MASS datasets spanning over 20 years, we found in the near infrared that FV Boo was significantly fainter in 2005 compared with preceding and later phases. Its color, however, did not show a large variation through this change. We infer that the dimming could be caused by an eclipse due to a cloud in a binary system.

  9. A Preferred-Direction Statistic for Sky Maps

    CERN Document Server

    Bunn, E F; Bunn, Emory F.; Scott, Douglas

    1999-01-01

    Large patterns could exist on the microwave sky as a result of various non-standard possibilities for the large-scale Universe -- rotation or shear, non-trivial topology, and single topological defects are specific examples. All-sky (or nearly all-sky) CMB data sets allow us, uniquely, to constrain such exotica, and it is therefore worthwhile to explore a wide range of statistical tests. We describe one such statistic here, which is based on determining gradients and is useful for assessing the level of 'preferred directionality' or 'stripiness' in the map. This method is more general than other techniques for picking out specific patterns on the sky, and it also has the advantage of being easily calculable for the mega-pixel maps which will soon be available. For the purposes of illustration, we apply this statistic to the four-year COBE DMR data. For future CMB maps we expect this to be a useful statistical test of the large-scale structure of the Universe. In principle, the same statistic could also be app...

  10. Theoretical Models of the Galactic Bulge

    CERN Document Server

    Shen, Juntai

    2015-01-01

    Near infrared images from the COBE satellite presented the first clear evidence that our Milky Way galaxy contains a boxy shaped bulge. Recent years have witnessed a gradual paradigm shift in the formation and evolution of the Galactic bulge. Bulges were commonly believed to form in the dynamical violence of galaxy mergers. However, it has become increasingly clear that the main body of the Milky Way bulge is not a classical bulge made by previous major mergers, instead it appears to be a bar seen somewhat end-on. The Milky Way bar can form naturally from a precursor disk and thicken vertically by the internal firehose/buckling instability, giving rise to the boxy appearance. This picture is supported by many lines of evidence, including the asymmetric parallelogram shape, the strong cylindrical rotation (i.e., nearly constant rotation regardless of the height above the disk plane), the existence of an intriguing X-shaped structure in the bulge, and perhaps the metallicity gradients. We review the major theor...

  11. Evaluation of ultrasound training in the problem based learning radiography curriculum at Makerere University, Uganda

    Energy Technology Data Exchange (ETDEWEB)

    Elsie, Kiguli-Malwadde [Makerere University, College of Health Sciences, Radiology Department, Kampala (Uganda); Gonzaga, Mubuuke A., E-mail: gmubuuke@gmail.co [Makerere University, College of Health Sciences, Radiology Department, Kampala (Uganda); Francis, Businge; Rebecca, Nakatudde; Stephen, Bule [Makerere University, College of Health Sciences, Radiology Department, Kampala (Uganda)

    2010-11-15

    Introduction: The College of Health Sciences (CHS), Makerere University has been training health professionals since 1924. Six years ago, there was a curriculum change to Problem Based Learning/Community based Education and Service (PBL/COBES). A SPICES model (Student centered, problem based, integrated, community based, electives, systematic) was adopted and defined to suit the CHS environment. The radiography program is 3 years in length which involves Ultrasound as an important part of the training. It was a challenge to adopt the new PBL method of learning after having a lecture-based pedagogical method for over 80 years. Objective: To implement the training of ultrasound in the PBL radiography curriculum as well as evaluate the opinions of the staff and students about Ultrasound training in the new curriculum. Methodology: A participatory approach was used. Workshops were conducted and objectives for ultrasound courses refined. Scenarios were written for use in the PBL sessions. A retrospective review of student performance in the ultrasound courses was carried out. A cross-sectional survey involving teachers and current radiography students was also carried out to evaluate learning of ultrasound using the PBL approach. Results: Students have consistently excelled in ultrasound courses using the PBL approach of learning. Both teachers and students rated the teaching of ultrasound to radiography students as being highly important and supported the new approach to training. Conclusion: Ultrasound training using PBL has been successfully implemented. However, this is still an ongoing process and will require the total commitment of both students and teachers.

  12. Axion production and CMB spectral distortion in cosmological tangled magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ejlli, Damian [INFN Laboratori Nazionali del Gran Sasso, Theory group, Assergi, L' Aquila (Italy); Novosibirsk State University, Department of Physics, Novosibirsk (Russian Federation)

    2015-08-15

    Axion production due to photon-axion mixing in tangled magnetic fields prior to the recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, the contribution of both processes to the CMB μ distortion in the case of resonant photon-axion mixing is studied. Assuming that the magnetic field power spectrum is approximated by a power law, P{sub B}(k)∝k{sup n} with spectral index n, it is shown that for magnetic field cut-off scales 172.5 pc ≤ λ{sub B} ≤ 4 x 10{sup 3} pc, the axion contribution to the CMB μ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using the COBE upper limit on μ and for the magnetic field scale λ{sub B} ≅ 415 pc, a weaker limit in comparison with other studies on the magnetic field strength (B{sub 0} ≤ 8.5 @ x 10{sup -8} G) up to a factor 10 for the DFSZ axion model and axion mass m{sub a} ≥ 2.6 @ x 10{sup -6} eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on μ is also presented. (orig.)

  13. Taking the Universe's Temperature with Spectral Distortions of the Cosmic Microwave Background.

    Science.gov (United States)

    Hill, J Colin; Battaglia, Nick; Chluba, Jens; Ferraro, Simone; Schaan, Emmanuel; Spergel, David N

    2015-12-31

    The cosmic microwave background (CMB) energy spectrum is a near-perfect blackbody. The standard model of cosmology predicts small spectral distortions to this form, but no such distortion of the sky-averaged CMB spectrum has yet been measured. We calculate the largest expected distortion, which arises from the inverse Compton scattering of CMB photons off hot, free electrons, known as the thermal Sunyaev-Zel'dovich (TSZ) effect. We show that the predicted signal is roughly one order of magnitude below the current bound from the COBE-FIRAS experiment, but it can be detected at enormous significance (≳1000σ) by the proposed Primordial Inflation Explorer (PIXIE). Although cosmic variance reduces the effective signal-to-noise ratio to 230σ, this measurement will still yield a subpercent constraint on the total thermal energy of electrons in the observable Universe. Furthermore, we show that PIXIE can detect subtle relativistic effects in the sky-averaged TSZ signal at 30σ, which directly probe moments of the optical depth-weighted intracluster medium electron temperature distribution. These effects break the degeneracy between the electron density and the temperature in the mean TSZ signal, allowing a direct inference of the mean baryon density at low redshift. Future spectral distortion probes will thus determine the global thermodynamic properties of ionized gas in the Universe with unprecedented precision. These measurements will impose a fundamental "integral constraint" on models of galaxy formation and the injection of feedback energy over cosmic time.

  14. Polylogarithmic Representation of Radiative and Thermodynamic Properties of Thermal Radiation in a Given Spectral Range: I. Blackbody Radiation

    Science.gov (United States)

    Fisenko, Anatoliy I.; Lemberg, Vladimir

    2015-07-01

    The thermodynamics of blackbody radiation has been constructed for the entire range of the spectrum. However, in practical applications, thermodynamic functions must be calculated within a finite range of frequencies. The analytical expressions for the radiative and thermodynamic properties of blackbody radiation over an arbitrary spectral range of the electromagnetic spectrum are obtained. The Wien displacement law, Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, and pressure are expressed in terms of the polylogarithm functions. These expressions are important when we build a theoretical model of radiative heat transfer, for example. The thermodynamic functions of blackbody radiation are calculated for various ranges of the spectrum at different temperatures. As an example of practical applications, thermodynamics of the cosmic microwave background radiation measured by the COBE FIRAS instrument is constructed. The expressions obtained for the radiative and thermodynamic functions of blackbody radiation can easily be presented in wavelength and wavenumber domains.

  15. Cosmic Microwave Background Data Analysis

    Science.gov (United States)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    About 400,000 years after the Big Bang the temperature of the Universe fell to about a few thousand degrees. As a result, the previously free electrons and protons combined and the Universe became neutral. This released a radiation which we now observe as the cosmic microwave background (CMB). The tiny fluctuations* in the temperature and polarization of the CMB carry a wealth of cosmological information. These so-called temperature anisotropies were predicted as the imprints of the initial density perturbations which gave rise to the present large-scale structures such as galaxies and clusters of galaxies. This relation between the present-day Universe and its initial conditions has made the CMB radiation one of the most preferred tools to understand the history of the Universe. The CMB radiation was discovered by radio astronomers Arno Penzias and Robert Wilson in 1965 [72] and earned them the 1978 Nobel Prize. This discovery was in support of the Big Bang theory and ruled out the only other available theory at that time - the steady-state theory. The crucial observations of the CMB radiation were made by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite [86]- orbited in 1989-1996. COBE made the most accurate measurements of the CMB frequency spectrum and confirmed it as being a black-body to within experimental limits. This made the CMB spectrum the most precisely measured black-body spectrum in nature. The CMB has a thermal black-body spectrum at a temperature of 2.725 K: the spectrum peaks in the microwave range frequency of 160.2 GHz, corresponding to a 1.9mmwavelength. The results of COBE inspired a series of ground- and balloon-based experiments, which measured CMB anisotropies on smaller scales over the next decade. During the 1990s, the first acoustic peak of the CMB power spectrum (see Figure 5.1) was measured with increasing sensitivity and by 2000 the BOOMERanG experiment [26] reported

  16. Taking the Universe's Temperature with PIXIE

    CERN Document Server

    Hill, J Colin; Chluba, Jens; Ferraro, Simone; Schaan, Emmanuel; Spergel, David N

    2015-01-01

    The cosmic microwave background (CMB) energy spectrum is a near-perfect blackbody. The standard model of cosmology predicts small spectral distortions to this form, but no such distortion of the sky-averaged CMB spectrum has yet been measured. We calculate the largest expected distortion, which arises from the inverse Compton scattering of CMB photons off hot, ionized electrons in the universe, known as the thermal Sunyaev-Zel'dovich (tSZ) effect. We show that the predicted signal is roughly one order of magnitude below the current bound from the COBE-FIRAS experiment, but will be detected at enormous significance ($\\gtrsim 1000\\sigma$) by the proposed Primordial Inflation Explorer (PIXIE). Although cosmic variance reduces the effective signal-to-noise to $230\\sigma$, PIXIE will still yield a sub-percent constraint on the total thermal energy in electrons in the observable universe. Furthermore, we show that PIXIE will detect subtle relativistic effects in the sky-averaged tSZ signal at $30\\sigma$, which dire...

  17. Annual parallax and a dimming event of a Mira variable star, FV Bootis

    Science.gov (United States)

    Kamezaki, Tatsuya; Nakagawa, Akiharu; Omodaka, Toshihiro; Inoue, Kan-ichiro; Chibueze, James O.; Nagayama, Takumi; Ueno, Yuji; Matsunaga, Noriyuki

    2016-08-01

    We present the first measurement of the trigonometric parallax of water masers associated with a Mira star, FV Bootis (FV Boo) using VLBI Exploration of Radio Astrometry (VERA). Based on our multi-epoch VERA observations, we derived the parallax to be 0.97 ± 0.06 mas, which corresponds to a distance of 1.03^{+0.07}_{-0.06} kpc. The water masers around FV Boo were spatially distributed over an area of 41 au × 41 au, and their internal motions indicate the presence of an outflow. Using the Kagoshima University 1 m optical/infrared telescope, we determined the period to be 305.6 d and the mean apparent magnitude to be +2.91 mag in the K'-band. On the period-luminosity plane, the obtained period and K'-band magnitude puts FV Boo slightly below the sequence of Miras, possibly due to circumstellar reddening. Combining our photometric data with COBE and 2MASS datasets spanning over 20 years, we found in the near infrared that FV Boo was significantly fainter in 2005 compared with preceding and later phases. Its color, however, did not show a large variation through this change. We infer that the dimming could be caused by an eclipse due to a cloud in a binary system.

  18. Michelson-Morley Experiments Revisited and the Cosmic Background Radiation Preferred Frame

    CERN Document Server

    Cahill, R T; Cahill, Reginald T.; Kitto, Kirsty

    2002-01-01

    We report a simple re-analysis of the old results (1887) from the Michelson-Morley interferometer experiment that was designed to detect absolute motion. We build upon a recent (1998) re-analysis of the original data by Munera, which revealed a small but significant effect after allowing for several systematic errors in the original analysis. The further re-analysis here reveals that a genuine effect of absolute motion is expected, in what is essentially a quantum interference experiment, but only if the photons travel in the interferometer at speeds V< c. This is the case if the interferometer operates in a dielectric, such as air, as was the case, incidently, of the Michelson-Morley experiment. The re-analysis here of the Michelson-Morley experimental data, correcting for the refractive index effect of the air, reveals an absolute speed of the Earth of v=359+/-54 km/s, which is in excellent agreement with the speed of v=365+/-18 km/s determined from the dipole fit, in 1991, to the NASA COBE satellite Cos...

  19. Non-Linear Clustering in the Cold+Hot Dark Matter Model

    CERN Document Server

    Bonometto, S A; Ghigna, S; Klypin, A A; Primack, Joel R

    1993-01-01

    We use high resolution PM N-body simulations to follow the development of non-linear clustering in a flat Universe, dominated by Cold + Hot Dark Matter (CHDM) with 60% of CDM, 30% of HDM and 10% of baryons; a simulation box of 100 Mpc a side ($h=0.5$) is used. We analyze two CHDM simulations with $b =1.5$ (COBE normalization). We also compare them with CDM simulations with $b=1.5$ and $b=1$. We evaluate high-order correlation functions and the void-probability-function (VPF). Correlation functions are obtained both from counts in cells and counts of neighbors. The analysis is made for DM particles and for galaxies, identified as massive halos in the evolved density field. We also check the effects of dynamical evolution and redshift space distortions. We find that clustering of DM particles exhibits deviations from the hierarchical scaling, which decrease somewhat in redshift space. Galaxies follow hierarchical scaling far more closely, with coefficients S_3=2.5 and S_4=7.5, in general agreement with observat...

  20. CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane

    CERN Document Server

    Melbourne, J; Layden, A; Martins, D H; Melbourne, Jason; Sarajedini, Ata; Layden, Andrew; Martins, Donald H.

    2000-01-01

    We present CCD photometry for the Galactic globular cluster NGC 4833. Our BVI color magnitude diagrams (CMD) extend from above the red giant branch (RGB) tip to several magnitudes below the main sequence turnoff. The principal sequences of the cluster show the effects of differential reddening. We have created a local extinction map, consistent with IRAS and COBE/DIRBE dust maps of the region. We use our map to correct the colors and magnitudes of each star to the value at the cluster center. The cluster horizontal branch (HB) is predominately blueward of the instability strip with 13 confirmed RR Lyrae variables and 5 additional RR Lyrae candidates. Using the 11 confirmed RR Lyraes measured on our images, and the differential reddening corrected photometry we calculate V(HB) = 15.56 +/- 0.063. We have used the simultaneous reddening and metallicity method of Sarajedini (1994) to find the mean reddening of the cluster E(B-V) = 0.32 +/- 0.03, and the mean metallicity [Fe/H] = -1.83 +/- 0.14. As for the age of ...

  1. Constraints on gravitino decay and the scale of inflation using CMB spectral distortions

    Science.gov (United States)

    Dimastrogiovanni, Emanuela; Krauss, Lawrence M.; Chluba, Jens

    2016-07-01

    If local supersymmetry is the correct extension of the standard model of particle physics, then following inflation the early Universe would have been populated by gravitinos produced from scatterings in the hot plasma during reheating. Their abundance is directly related to the magnitude of the reheating temperature. The gravitino lifetime is fixed as a function of its mass, and for gravitinos with lifetimes longer than the age of the Universe at redshift z ≃2 ×1 06 (or roughly 6 ×1 06 s ), decay products can produce spectral distortion of the cosmic microwave background. Currently available COBE/FIRAS limits on spectral distortion can, in certain cases, already be competitive with respect to cosmological constraints from primordial nucleosynthesis for some gravitino decay scenarios. We show how the sensitivity limits on μ and y distortions that can be reached with current technology will improve constraints and possibly rule out a significant portion of the parameter space for gravitino masses and inflation reheating temperatures.

  2. Kurtosis, skewness, and non-Gaussian cosmological density perturbations

    Science.gov (United States)

    Luo, Xiaochun; Schramm, David N.

    1993-01-01

    Cosmological topological defects as well as some nonstandard inflation models can give rise to non-Gaussian density perturbations. Skewness and kurtosis are the third and fourth moments that measure the deviation of a distribution from a Gaussian. Measurement of these moments for the cosmological density field and for the microwave background temperature anisotropy can provide a test of the Gaussian nature of the primordial fluctuation spectrum. In the case of the density field, the importance of measuring the kurtosis is stressed since it will be preserved through the weakly nonlinear gravitational evolution epoch. Current constraints on skewness and kurtosis of primeval perturbations are obtained from the observed density contrast on small scales and from recent COBE observations of temperature anisotropies on large scales. It is also shown how, in principle, future microwave anisotropy experiments might be able to reveal the initial skewness and kurtosis. It is shown that present data argue that if the initial spectrum is adiabatic, then it is probably Gaussian, but non-Gaussian isocurvature fluctuations are still allowed, and these are what topological defects provide.

  3. Cosmological Implications of the PSCz PDF and its Moments

    CERN Document Server

    Plionis, M

    2001-01-01

    We compare the PDF and its low-order moments (variance and skewness) of the smoothed PSCz galaxy density field and of the corresponding simulated PSCz look-alikes, generated from N-body simulations of 6 different DM models; four structure normalized with $\\Gamma=0.25$ and $\\sigma_{8}=0.55 \\Omega_{\\circ}^{-0.6}$, one COBE normalized and the old SCDM. The galaxy distributions are smoothed with a Gaussian window at three different smoothing scales $R_{sm}=5$, 10 and $15 h^{-1}$ Mpc. We find that the simulation PSCz look-alike PDF's are sensitive only on the normalization of the power spectrum, probably due to shape similarity of the simulated galaxy power spectrum on the relevant scales. We find that the only models that are consistent, at a high significance level, with the observed PSCz PDF are models with a relatively low power spectrum normalization $(\\sigma_{8}=0.83)$. From the phenomenologically derived $\\sigma_{8}-moments$ relation, fitted from the simulation data, we find that the PSCz moments suggest $\\...

  4. DIRBE Comet Trails

    CERN Document Server

    Arendt, Richard G

    2014-01-01

    Re-examination of the COBE DIRBE data reveals the thermal emission of several comet dust trails. The dust trails of 1P/Halley, 169P/NEAT, and 3200 Phaethon have not been previously reported. The known trails of 2P/Encke, and 73P/Schwassmann-Wachmann 3 are also seen. The dust trails have 12 and 25 micron surface brightnesses of <0.1 and <0.15 MJy/sr, respectively, which is <1% of the zodiacal light intensity. The trails are very difficult to see in any single daily image of the sky, but are evident as rapidly moving linear features in movies of the DIRBE data. Some trails are clearest when crossing through the orbital plane of the parent comet, but others are best seen at high ecliptic latitudes as the Earth passes over or under the dust trail. All these comets have known associations with meteor showers. This re-examination also reveals one additional comet and 13 additional asteroids that had not previously been recognized in the DIRBE data.

  5. Preliminary Orbit Determination System (PODS) for Tracking and Data Relay Satellite System (TDRSS)-tracked target Spacecraft using the homotopy continuation method

    Science.gov (United States)

    Kirschner, S. M.; Samii, M. V.; Broaddus, S. R.; Doll, C. E.

    1988-09-01

    The Preliminary Orbit Determination System (PODS) provides early orbit determination capability in the Trajectory Computation and Orbital Products System (TCOPS) for a Tracking and Data Relay Satellite System (TDRSS)-tracked spacecraft. PODS computes a set of orbit states from an a priori estimate and six tracking measurements, consisting of any combination of TDRSS range and Doppler tracking measurements. PODS uses the homotopy continuation method to solve a set of nonlinear equations, and it is particularly effective for the case when the a priori estimate is not well known. Since range and Doppler measurements produce multiple states in PODS, a screening technique selects the desired state. PODS is executed in the TCOPS environment and can directly access all operational data sets. At the completion of the preliminary orbit determination, the PODS-generated state, along with additional tracking measurements, can be directly input to the differential correction (DC) process to generate an improved state. To validate the computational and operational capabilities of PODS, tests were performed using simulated TDRSS tracking measurements for the Cosmic Background Explorer (COBE) satellite and using real TDRSS measurements for the Earth Radiation Budget Satellite (ERBS) and the Solar Mesosphere Explorer (SME) spacecraft. The effects of various measurement combinations, varying arc lengths, and levels of degradation of the a priori state vector on the PODS solutions were considered.

  6. Chaotic inflation limits for non-minimal models with a Starobinsky attractor

    International Nuclear Information System (INIS)

    We investigate inflationary attractor points by analysing non-minimally coupled single field inflation models in two opposite limits; the 'flat' limit in which the first derivative of the conformal factor is small and the 'steep' limit, in which the first derivative of the conformal factor is large. We consider a subset of models that yield Starobinsky inflation in the steep conformal factor, strong coupling, limit and demonstrate that they result in φ2n-chaotic inflation in the opposite flat, weak coupling, limit. The suppression of higher order powers of the inflaton field in the potential is shown to be related to the flatness condition on the conformal factor. We stress that the chaotic attractor behaviour in the weak coupling limit is of a different, less universal, character than the Starobinsky attractor. Agreement with the COBE normalisation cannot be obtained in both attractor limits at the same time and in the chaotic attractor limit the scale of inflation depends on the details of the conformal factor, contrary to the strong coupling Starobinsky attractor

  7. Testing Cosmic Inflation

    Science.gov (United States)

    Chuss, David

    2010-01-01

    The Cosmic Microwave Background (CMB) has provided a wealth of information about the history and physics of the early Universe. Much progress has been made on uncovering the emerging Standard Model of Cosmology by such experiments as COBE and WMAP, and ESA's Planck Surveyor will likely increase our knowledge even more. Despite the success of this model, mysteries remain. Currently understood physics does not offer a compelling explanation for the homogeneity, flatness, and the origin of structure in the Universe. Cosmic Inflation, a brief epoch of exponential expansion, has been posted to explain these observations. If inflation is a reality, it is expected to produce a background spectrum of gravitational waves that will leave a small polarized imprint on the CMB. Discovery of this signal would give the first direct evidence for inflation and provide a window into physics at scales beyond those accessible to terrestrial particle accelerators. I will briefly review aspects of the Standard Model of Cosmology and discuss our current efforts to design and deploy experiments to measure the polarization of the CMB with the precision required to test inflation.

  8. Search for Anisotropic Light Propagation as a Function of Laser Beam Alignment Relative to the Earth's Velocity Vector

    Directory of Open Access Journals (Sweden)

    Navia C. E.

    2007-01-01

    Full Text Available A laser diffraction experiment was conducted to study light propagation in air. The experiment is easy to reproduce and it is based on simple optical principles. Two optical sensors (segmented photo-diodes are used for measuring the position of diffracted light spots with a precision better than 0.1 μ m. The goal is to look for signals of anisotropic light propagation as function of the laser beam alignment to the Earth’s motion (solar barycenter motion obtained by COBE. Two raster search techniques have been used. First, a laser beam fixed in the laboratory frame scans in space due to Earth’s rotation. Second, a laser beam mounted on a turntable system scans actively in space by turning the table. The results obtained with both methods show that the course of light rays are affected by the motion of the Earth, and a predominant first order quantity with a Δ c/c = − β (1 + 2 a cos θ signature with ˉ a = − 0.393 ± 0.032 describes well the experimental results. This result differs in amount of 21% from the Special Relativity Theory prediction and that supplies the value of a = − 1 2 (isotropy.

  9. Axion production and CMB spectral distortion in cosmological tangled magnetic field

    CERN Document Server

    Ejlli, Damian

    2015-01-01

    Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both processes to CMB $\\mu$ distortion in the case of resonant photon-axion mixing is studied. Assuming that magnetic field power spectrum is approximated by a power law $P_B(k)\\propto k^n$ with spectral index $n$, it is shown that for magnetic field cut-off scales $172.5$ pc $\\leq \\lambda_B\\leq 4\\times 10^3$ pc, axion contribution to CMB $\\mu$ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using COBE upper limit on $\\mu$ and for magnetic field scale $\\lambda_B\\simeq 415$ pc, weaker limit in comparison with other studies on the magnetic field strength ($B_0\\leq 8.5\\times 10^{-8}$ G) up to a factor 10 for the DFSZ axion model and axion mass $m_a\\geq 2.6\\times 10^{-6}$ eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on...

  10. Superconductivity, the Structure Scale of the Universe

    CERN Document Server

    Saam, R D

    1997-01-01

    A lattice and associated superconducting theory is postulated whereby electromagnetic and gravitational forces are mediated by a particle of mass (110.39 x electron mass) such that the established electron/proton mass is maintained, electron and proton charge is maintained and the universe radius is 1.5E28 cm, the universe mass is 2.00E56 gram, the universe density is 1.45E-29 g/cm3, the universe time or age is 1.57E10 years and the universe Hubble constant is 2.47E-18/sec (76 km/sec-million parsec). The calculated universe mass and density are based on an isotropic homogeneous media filling the vacuum of space analogous to the 'ether' referred to in the 19th century and could be considered a candidate for the 'dark matter' in present universe theories. In this context the COBE satellite universe background microwave black body radiation temperature is linked to universe dark matter superconducting temperature. Also, a reasonable value for the cosmological constant is derived having dimensions of the known un...

  11. Dynamics of the Galactic Bulge using Planetary Nebulae

    CERN Document Server

    Beaulieu, S F; Kálnay, A J; Saha, P; Zhao, H S; Beaulieu, Sylvie F.; Freeman, Kenneth C.; Kalnajs, Agris J.; Saha, Prasenjit; Zhao, HongSheng

    2000-01-01

    Evidence for a bar at the center of the Milky Way triggered a renewed enthusiasm for dynamical modelling of the Galactic bar-bulge. Our goal is to compare the kinematics of a sample of tracers, planetary nebulae, widely distributed over the bulge with the corresponding kinematics for a range of models of the inner Galaxy. Three of these models are N-body barred systems arising from the instabilities of a stellar disk (Sellwood, Fux and Kalnajs), and one is a Schwarzschild system constructed to represent the 3D distribution of the COBE/DIRBE near-IR light and then evolved as an N-body system for a few dynamical times (Zhao). For the comparison of our data with the models, we use a new technique developed by Saha (1998). The procedure finds the parameters of each model, i.e. the solar galactocentric distance R_o in model units, the orientation angle phi, the velocity scale (in km/s per model unit), and the solar tangential velocity which best fit the data.

  12. A review of the stochastic background of gravitational waves in f(R) gravity with WMAP constrains

    CERN Document Server

    Corda, Christian

    2009-01-01

    This paper is a review of previous works on the stochastic background of gravitational waves (SBGWs) which has been discussed in various peer-reviewed journals and international conferences. The SBGWs is analyzed with the aid of the Wilkinson Microwave Anisotropy Probe (WMAP) data. We emphasize that, in general, in previous works in the literature about the SBGWs, old Cosmic Background Explorer (COBE) data were used. After this, we want to face the problem of how the SBGWs and f(R) gravity (where f(R) is a function of the Ricci scalar R) can be related, showing, vice versa, that a revealed SBGWs could be a powerful probe for a given theory of gravity. In this way, it will also be shown that the conform treatment of SBGWs can be used to parametrize in a natural way f(R) theories. Some interesting examples which have been recently discussed in the literature will be also analysed. The presence and the potential detection of the SBGWs is quite important in the framework of the debate on high-frequency gravitatio...

  13. The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background

    CERN Document Server

    Geach, J E; Coppin, K E K; Dunlop, J S; Halpern, M; Smail, Ian; van der Werf, P; Serjeant, S; Farrah, D; Roseboom, I; Targett, T; Arumugam, V; Asboth, V; Blain, A; Chrysostomou, A; Clarke, C; Ivison, R J; Jones, S L; Karim, A; Mackenzie, T; Meijerink, R; Michalowski, M J; Scott, D; Simpson, J; Swinbank, A M; Alexander, D; Almaini, O; Aretxaga, I; Best, P; Chapman, S; Clements, D L; Conselice, C; Danielson, A L R; Eales, S; Edge, A C; Gibb, A; Hughes, D; Jenness, T; Knudsen, K K; Lacey, C; Marsden, G; McMahon, R; Oliver, S; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Spaans, M; Stevens, J; Webb, T M A; Willott, C; Wilson, C D; Zemcov, M

    2012-01-01

    The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin^2 of the COSMOS field, in the footprint of the HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate the number counts of 450um-selected galaxies with flux densities S_450>5mJy. The 8-arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at ~200um) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S_450>5mJy we resolve (7.4[+/-]0.7)x10^-2 MJy/sr of the CIB at 450um (equivalent to 16[+/-]7% of the absolute brightness measured by COBE at this wavelength) into point sources. A further ~40% of the CIB can be recovered through a statistical stack of 24um emitters in this field, indicating that the majority (~60%) o...

  14. Rapid Asymmetric Inflation and Early Cosmology in Theories with Sub-Millimeter Dimensions

    CERN Document Server

    Arkani-Hamed, N; Kaloper, Nemanja; March-Russell, John David; Arkani-Hamed, Nima; Dimopoulos, Savas; Kaloper, Nemanja; March-Russell, John

    2000-01-01

    It was recently pointed out that the fundamental Planck mass could be close to the TeV scale with the observed weakness of gravity at long distances being due the existence of new sub-millimeter spatial dimensions. In this picture the standard model fields are localized to a $(3+1)$-dimensional wall or ``3-brane''. We show that in such theories there exist attractive models of inflation that occur while the size of the new dimensions are still small. We show that it is easy to produce the required number of efoldings, and further that the density perturbations $\\delta\\rho/\\rho$ as measured by COBE can be easily reproduced, both in overall magnitude and in their approximately scale-invariant spectrum. In the minimal approach, the inflaton field is just the moduli describing the size of the internal dimensions, the role of the inflationary potential being played by the stabilizing potential of the internal space. We show that under quite general conditions, the inflationary era is followed by an epoch of contra...

  15. Dust-filled axially symmetric universes with a cosmological constant

    CERN Document Server

    Aguiar, P; Aguiar, Paulo; Crawford, Paulo

    2000-01-01

    Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic and homogeneous models: Kantowski-Sachs, Bianchi type-I and Bianchi type-III universes, with dust and a cosmological constant, in order to find out which are physically permitted. We find that these models undergo isotropization up to the point that the observations will not be able to distinguish between them and the standard model, except for the Kantowski-Sachs model $(\\Omega_{k_{0}}0)$ with $\\Omega_{\\Lambda_{0}}$ smaller than some critical value $\\Omega_{\\Lambda_{M}}$. Even if one imposes that the Universe should be nearly isotropic since the last scattering epoch ($z\\approx 1000$), meaning that the Universe should have approximately the same Hubble parameter in all directions (considering the COBE 4-Year data), there is still a large range for the matter density paramete...

  16. Interference of Light in Michelson-Morley Interferometer: A Quantum Optical Approach

    CERN Document Server

    Langangen, O; Vaskinn, A

    2011-01-01

    We investigate how the temporal coherence interference properties of light in a Michelson-Morley interferometer (MMI), using only a single-photon detector, can be understood in a quantum-optics framework in a straightforward and pedagogical manner. For this purpose we make use of elementary quantum field theory and Glaubers theory for photon detection in order to calculate the expected interference pattern in the MMI. If a thermal reference source is used in the MMI local oscillator port in combination with a thermal source in the signal port, the interference pattern revealed by such an intensity measurement shows a distinctive dependence on the differences in the temperature of the two sources. The MMI can therefore be used in order to perform temperature measurements. A related method was actually used to carry out high precision measurements of the cosmic micro-wave background radiation on board of the COBE satellite. The theoretical framework allows us to consider any initial quantum state. The interfere...

  17. Engineering of a novel carbonyl reductase with coenzyme regeneration in E. coli for efficient biosynthesis of enantiopure chiral alcohols.

    Science.gov (United States)

    Wei, Ping; Gao, Jia-Xin; Zheng, Gao-Wei; Wu, Hong; Zong, Min-Hua; Lou, Wen-Yong

    2016-07-20

    The novel anti-Prelog stereospecific carbonyl reductase from Acetobacter sp. CCTCC M209061 was successfully expressed in E. coli combined with glucose dehydrogenase (GDH) to construct an efficient whole-cell biocatalyst with coenzyme NADH regeneration. The enzymatic activity of GAcCR (AcCR with a GST tag) reached 304.9U/g-dcw, even 9 folds higher than that of wild strain, and the activity of GDH for NADH regeneration recorded 46.0U/mg-protein in the recombinant E. coli. As a whole-cell biocatalyst, the recombinant E. coli BL21(DE3)pLysS (pETDuet-gaccr-gdh) possessed a broad substrate spectrum for kinds of carbonyl compounds with encouraging yield and stereoselectivity. Besides, the asymmetric reduction of ethyl 4-chloroacetoacetate (COBE) to optically pure ethyl 4-chloro-3-hydroxybutyrate (CHBE) catalyzed by the whole-cell biocatalyst was systematically investigated. Under the optimal reaction conditions, the optical purity of CHBE was over 99% e.e. for (S)-enantiomer, and the initial rate and product yield reached 8.04μmol/min and 99.4%, respectively. Moreover, the space-time yield was almost 20 folds higher than that catalyzed by the wild strain. Therefore, a new, high efficiency biocatalyst for asymmetric reductions was constructed successfully, and the enantioselective reduction of prochiral compounds using the biocatalyst was a promising approach for obtaining enantiopure chiral alcohols. PMID:27211999

  18. Erythrocyte Fragment Count Predicts Hemolysis in Roller Pumps

    Institute of Scientific and Technical Information of China (English)

    FAN Jun-qiang; XU Shi-wei; CHEN Fang; DING Min-jun

    2007-01-01

    Hemolysis in blood pumps has been measured by various in vitro test methods, in which normalized index of hemolysis (NIH) was established. As NIH is complicated and difficult to calculate, erythrocyte fragment count is proposed in the present study to predict hemolysis in roller pumps. Methods: Five paired in vitro tests wereconducted using the POLYSTAN pediatric pump(group A) and COBE pump(group B). Ten whole blood samples (400 ml ) were circled in the roller pump for 16 h. Erythrocyte fragments count and plasma-free hemoglobin (FHb) were measured before pumping and every two hours through circulation after four-hour-pumping. The morphological changes of erythrocyte were observed by scanning electron microscope. Results: The two groups' EFC and FHb levels were increased linearly during a long duration of pumping and linear regression of erythrocyte fragments count and plasma-free hemoglobin were correlated. Conclusion: Erythrocyte fragments count could be used as an index in evaluating the in vitro hemolytic properties of blood pumps.

  19. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky

    CERN Document Server

    Andre, Philippe; Barbosa, Domingos; Bartlett, James; Bartolo, Nicola; Battistelli, Elia; Battye, Richard; Bendo, George; Bernard, Jean-Philippe; Bersanelli, Marco; Bethermin, Matthieu; Bielewicz, Pawel; Bonaldi, Anna; Bouchet, Francois; Boulanger, Francois; Brand, Jan; Bucher, Martin; Burigana, Carlo; Cai, Zhen-Yi; Casasola, Viviana; Castex, Guillaume; Challinor, Anthony; Chluba, Jens; Colafrancesco, Sergio; Cuttaia, Francesco; D'Alessandro, Giuseppe; Davis, Richard; de Avillez, Miguel; de Bernardis, Paolo; de Petris, Marco; de Rosa, Adriano; de Zotti, Gianfranco; Delabrouille, Jacques; Dickinson, Clive; Diego, Jose Maria; Falgarone, Edith; Ferreira, Pedro; Ferriere, Katia; Finelli, Fabio; Fletcher, Andrew; Fuller, Gary; Galli, Silvia; Ganga, Ken; Garcia-Bellido, Juan; Ghribi, Adnan; Gonzalez-Nuevo, Joaquin; Grainge, Keith; Gruppuso, Alessandro; Hall, Alex; Hernandez-Monteagudo, Carlos; Jackson, Mark; Jaffe, Andrew; Khatri, Rishi; Lamagna, Luca; Lattanzi, Massimiliano; Leahy, Paddy; Liguori, Michele; Liuzzo, Elisabetta; Lopez-Caniego, Marcos; Macias-Perez, Juan; Maffei, Bruno; Maino, Davide; Masi, Silvia; Mangilli, Anna; Massardi, Marcella; Matarrese, Sabino; Melchiorri, Alessandro; Melin, Jean-Baptiste; Mennella, Aniello; Mignano, Arturo; Miville-Deschenes, Marc-Antoine; Nati, Federico; Natoli, Paolo; Negrello, Mattia; Noviello, Fabio; Paci, Francesco; Paladino, Rosita; Paoletti, Daniela; Perrotta, Francesca; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Ricciardi, Sara; Roman, Matthieu; Rubino-Martin, Jose-Alberto; Salatino, Maria; Schillaci, Alessandro; Shellard, Paul; Silk, Joseph; Stompor, Radek; Sunyaev, Rashid; Tartari, Andrea; Terenzi, Luca; Toffolatti, Luigi; Tomasi, Maurizio; Trombetti, Tiziana; Tucci, Marco; Van Tent, Bartjan; Verde, Licia; Wandelt, Ben; Withington, Stafford

    2013-01-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in response to the Call for White Papers for the definition of the L2 and L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1) an imager with a 3.5m mirror (cooled to 4K for high performance in the far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and (2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS instrument but over three orders of magnitude more sensitive. Highlights of the new science (beyond the obvious target of B-modes from gravity waves generated during inflation) made possible by these two instruments working in tandem include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters extending to large redshift and measuring their peculiar velocities and temperatures (through the kSZ effect and relativistic corrections to the classic y-distortion spectrum, respectively) (2) a detailed investigation into the nature of the cosmic infrared back...

  20. Measurements of Diffuse Sky Emission Components in High Galactic Latitudes at 3.5 and 4.9 um Using DIRBE and WISE Data

    CERN Document Server

    Sano, K; Matsuura, S; Kataza, H; Arai, T; Matsuoka, Y

    2015-01-01

    Using all-sky maps obtained from COBE/DIRBE at 3.5 and 4.9 um, we present a reanalysis of diffuse sky emissions such as zodiacal light (ZL), diffuse Galactic light (DGL), integrated starlight (ISL), and isotropic residual emission including the extragalactic background light (EBL). Our new analysis, which includes an improved estimate of ISL using the Wide-field Infrared Survey Explorer (WISE) data, enabled us to find the DGL signal in a direct linear correlation between diffuse near-infrared and 100 um emission at high Galactic latitudes (|b| > 35 degree). At 3.5um, the high-latitude DGL result is comparable to the low-latitude value derived from the previous DIRBE analysis. In comparison with models of the DGL spectrum assuming a size distribution of dust grains composed of amorphous silicate, graphite, and polycyclic aromatic hydrocarbon (PAH), the measured DGL values at 3.5 and 4.9 um constrain the mass fraction of PAH particles in the total dust species to be more than ~ 2%. This was consistent with the ...

  1. Superconductivity, the Structure Scale of the Universe, Second Edition

    CERN Document Server

    Saam, R D

    1999-01-01

    A theoretical framework supported by experimental evidence is presented which indicates that superconductivity is a relativistic phenomenon. A lattice and associated superconducting theory is postulated whereby electromagnetic and gravitational forces are mediated by a particle of relativistic velocity transformed mass (110.39 x electron mass) such that the established electron/proton mass is maintained, electron and proton charge is maintained and the universe radius is 1.5E28 cm, the universe mass is 2.00E56 gram, the universe density is 1.45E-29 g/cm3, the universe time or age is 1.57E10 years and the universe Hubble constant is 2.47E-18/sec (76 km/sec-million parsec). The calculated universe mass and density are based on an isotropic homogeneous media filling the vacuum of space analogous to the 'aether' referred to in the 19th century and could be considered a candidate for the 'dark matter' in present universe theories. In this context the COBE satellite universe background microwave black body radiatio...

  2. Implications of Cosmic Microwave Background Anisotropies for Large Scale Variations in Hubble's Constant

    CERN Document Server

    Wang, Y; Turner, E L; Wang, Yun; Spergel, David N.; Turner, Edwin L.

    1998-01-01

    Low amplitude (linear regime) cosmic density fluctuations lead to spatial variations in the locally measurable value of $H_0$ (denoted as $H_L$), interval) in a sphere of 200$ h^{-1}$Mpc in diameter, and of order $1-2$% in a sphere of 400$ h^{-1}$Mpc in diameter, for three currently viable structure formation models (tilted CDM, $\\Lambda$CDM, and open CDM) as normalized by the 4 year COBE DMR data. However, the true matter distribution power spectrum may differ from any of the currently viable models. For example, it may contain sharp features which have escaped detection so far. The measured CMB dipole velocity (the Galaxy's peculiar velocity with respect to the CMB rest frame) provides additional constraints on the probability distribution of $\\delta_H$ that supplement our limited knowledge of the power spectrum. For a matter power spectrum which consists of the smooth power spectrum of a viable cosmological model plus a delta-function bump, we find that given the CMB dipole velocity, the 95% CL upper limit...

  3. Search for anisotropic light propagation as a function of laser beam alignment relative to the Earth's velocity vector

    CERN Document Server

    Navia, C E; Franceschini, D F; Robba, M B; Tsui, K H

    2006-01-01

    A laser diffraction experiment was conducted to study light propagation in air. The experiment is easy to reproduce and it is based on simple optical principles. Two optical sensors (segmented photo-diodes) are used for measuring the position of diffracted light spots with a precision better than $0.1 \\mu m$. The goal is to look for signals of anisotropic light propagation as function of the laser beam alignment to the Earth's motion (solar barycenter motion) obtained by COBE. Two raster search techniques have been used. First, a fixed laser beam in the laboratory frame that scans due to Earth's rotation. Second, an active rotation of the laser beam on a turntable system. The results obtained with both methods show that the course of the light rays are affected by the motion of the Earth, and a predominant quantity of first order with a $\\Delta c/c=-\\beta (1+2a)\\cos \\theta$ signature with $a=-0.4106\\pm 0.0225$ describes well the experimental results. This result differs in a amount of 18% from the Special Rel...

  4. Molecular Hydrogen in Infrared Cirrus

    CERN Document Server

    Gillmon, K; Gillmon, Kristen

    2006-01-01

    We combine data from our recent FUSE survey of interstellar molecular hydrogen absorption toward 50 high-latitude AGN with COBE-corrected IRAS 100 micron emission maps to study the correlation of infrared cirrus with H2. A plot of the H2 column density vs. IR cirrus intensity shows the same transition in molecular fraction, f_H2, as seen with total hydrogen column density, N_H. This transition is usually attributed to H2 self-shielding, and it suggests that many diffuse cirrus clouds contain H2 in significant fractions, f_H2 = 1-30%. These clouds cover approximately 50% of the northern sky at latitudes b > 30 degrees, at temperature-corrected 100 micron intensities D_100 > 1.5 MJy/sr. The sheetlike cirrus clouds, with hydrogen densities n_H > 30 cm^-3, may be compressed by dynamical processes at the disk-halo interface, and they are conducive to H2 formation on grain surfaces. Exploiting the correlation between N(H2) and 100 micron intensity, we estimate that cirrus clouds at b > 30 contain approximately 3000...

  5. Likelihood analysis of large-scale flows

    CERN Document Server

    Jaffe, A; Jaffe, Andrew; Kaiser, Nick

    1994-01-01

    We apply a likelihood analysis to the data of Lauer & Postman 1994. With P(k) parametrized by (\\sigma_8, \\Gamma), the likelihood function peaks at \\sigma_8\\simeq0.9, \\Gamma\\simeq0.05, indicating at face value very strong large-scale power, though at a level incompatible with COBE. There is, however, a ridge of likelihood such that more conventional power spectra do not seem strongly disfavored. The likelihood calculated using as data only the components of the bulk flow solution peaks at higher \\sigma_8, as suggested by other analyses, but is rather broad. The likelihood incorporating both bulk flow and shear gives a different picture. The components of the shear are all low, and this pulls the peak to lower amplitudes as a compromise. The velocity data alone are therefore {\\em consistent} with models with very strong large scale power which generates a large bulk flow, but the small shear (which also probes fairly large scales) requires that the power would have to be at {\\em very} large scales, which is...

  6. Mira variables in the Galactic bulge with OGLE-II data

    CERN Document Server

    Matsunaga, N; Nakada, Y

    2005-01-01

    We have extracted a total of 1968 Mira variables from the OGLE-II data base in the Galactic bulge region. Among them, 1960 are associated with 2MASS sources, and 1541 are further identified with MSX point sources. Their photometric properties are compared with those of Mira variables in the Large and Small Magellanic Clouds. We have found that mass-losing stars with circumstellar matter are reddened such that the colour dependence of the absorption coefficient is similar to that of interstellar matter. We also discuss the structure of the bulge. The surface number density of the bulge Mira variables is well correlated with the 2.2-micron surface brightness obtained by the COBE satellite. Using this relation, the total number of Mira variables in the bulge is estimated to be about 600,000. The logP-K relation of the Mira variables gives their space distribution which supports the well-known asymmetry of the bar-like bulge.

  7. Space and Earth Sciences, Computer Systems, and Scientific Data Analysis Support, Volume 1

    Science.gov (United States)

    Estes, Ronald H. (Editor)

    1993-01-01

    This Final Progress Report covers the specific technical activities of Hughes STX Corporation for the last contract triannual period of 1 June through 30 Sep. 1993, in support of assigned task activities at Goddard Space Flight Center (GSFC). It also provides a brief summary of work throughout the contract period of performance on each active task. Technical activity is presented in Volume 1, while financial and level-of-effort data is presented in Volume 2. Technical support was provided to all Division and Laboratories of Goddard's Space Sciences and Earth Sciences Directorates. Types of support include: scientific programming, systems programming, computer management, mission planning, scientific investigation, data analysis, data processing, data base creation and maintenance, instrumentation development, and management services. Mission and instruments supported include: ROSAT, Astro-D, BBXRT, XTE, AXAF, GRO, COBE, WIND, UIT, SMM, STIS, HEIDI, DE, URAP, CRRES, Voyagers, ISEE, San Marco, LAGEOS, TOPEX/Poseidon, Pioneer-Venus, Galileo, Cassini, Nimbus-7/TOMS, Meteor-3/TOMS, FIFE, BOREAS, TRMM, AVHRR, and Landsat. Accomplishments include: development of computing programs for mission science and data analysis, supercomputer applications support, computer network support, computational upgrades for data archival and analysis centers, end-to-end management for mission data flow, scientific modeling and results in the fields of space and Earth physics, planning and design of GSFC VO DAAC and VO IMS, fabrication, assembly, and testing of mission instrumentation, and design of mission operations center.

  8. The big bang

    Science.gov (United States)

    Silk, Joseph

    Our universe was born billions of years ago in a hot, violent explosion of elementary particles and radiation - the big bang. What do we know about this ultimate moment of creation, and how do we know it? Drawing upon the latest theories and technology, this new edition of The big bang, is a sweeping, lucid account of the event that set the universe in motion. Joseph Silk begins his story with the first microseconds of the big bang, on through the evolution of stars, galaxies, clusters of galaxies, quasars, and into the distant future of our universe. He also explores the fascinating evidence for the big bang model and recounts the history of cosmological speculation. Revised and updated, this new edition features all the most recent astronomical advances, including: Photos and measurements from the Hubble Space Telescope, Cosmic Background Explorer Satellite (COBE), and Infrared Space Observatory; the latest estimates of the age of the universe; new ideas in string and superstring theory; recent experiments on neutrino detection; new theories about the presence of dark matter in galaxies; new developments in the theory of the formation and evolution of galaxies; the latest ideas about black holes, worm holes, quantum foam, and multiple universes.

  9. The Lighter Side of Gravity

    Science.gov (United States)

    Narlikar, Jayant Vishnu

    1996-10-01

    From the drop of an apple to the stately dance of the galaxies, gravity is omnipresent in the Cosmos. Even with its high profile, gravity is the most enigmatic of all the known basic forces in nature. The Lighter Side of Gravity presents a beautifully clear and completely nontechnical introduction to the phenomenon of this force in all its manifestations. Astrophysicist Jayant Narlikar begins with an historical background to the discovery of the law of gravitation by Isaac Newton in the seventeenth century. Using familiar analogies, interesting anecdotes, and numerous illustrations to get across subtle effects and difficult points to readers, he goes on to describe the general theory of relativity and some of its strange and unfamiliar ideas such as curved spacetime, the bending of light, and black holes. Since first publication in 1982 (W.H. Freeman), Dr. Narlikar has brought his book completely up to date and expanded it to include the discovery of gigantic gravitational lenses in space, the findings of the Cosmic Background Explorer (COBE) satellite, the detection of dark matter in galaxies, the investigation of the very early Universe, and other new ideas in cosmology. This lucid and stimulating book presents a clear approach to the intriguing phenomenon of gravity for everyone who has ever felt caught in its grip. Jayant Narlikar is the winner of many astronomical prizes and the author of Introduction to Cosmology (Cambridge University Press, 1993).

  10. Testing Models for Structure Formation

    CERN Document Server

    Kaiser, N

    1993-01-01

    I review a number of tests of theories for structure formation. Large-scale flows and IRAS galaxies indicate a high density parameter $\\Omega \\simeq 1$, in accord with inflationary predictions, but it is not clear how this meshes with the uniformly low values obtained from virial analysis on scales $\\sim$ 1Mpc. Gravitational distortion of faint galaxies behind clusters allows one to construct maps of the mass surface density, and this should shed some light on the large vs small-scale $\\Omega$ discrepancy. Power spectrum analysis reveals too red a spectrum (compared to standard CDM) on scales $\\lambda \\sim 10-100$ $h^{-1}$Mpc, but the gaussian fluctuation hypothesis appears to be in good shape. These results suggest that the problem for CDM lies not in the very early universe --- the inflationary predictions of $\\Omega = 1$ and gaussianity both seem to be OK; furthermore, the COBE result severely restricts modifications such as tilting the primordial spectrum --- but in the assumed matter content. The power s...

  11. Detection of an exoplanet around the evolved K giant HD 66141

    CERN Document Server

    Lee, B -C; Han, I; Park, M -G; Kim, K -M

    2012-01-01

    Aims. We have been carrying out a precise radial velocity (RV) survey for K giants to search for and study the origin of the lowamplitude and long-periodic RV variations. Methods. We present high-resolution RV measurements of the K2 giant HD 66141 from December 2003 to January 2011 using the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory (BOAO). Results. We find that the RV measurements for HD 66141 exhibit a periodic variation of 480.5 +/- 0.5 days with a semi-amplitude of 146.2 +/- 2.7 m/s. The Hipparcos photometry and bisector velocity span (BVS) do not show any obvious correlations with RV variations. We find indeed 706.4 +/- 35.0 day variations in equivalent width (EW) measurements of H_alpha line and 703.0 +/- 39.4 day variations in a space-born measurements 1.25{\\mu} flux of HD 66141 measured during COBE/DIRBE experiment. We reveal that a mean value of long-period variations is about 705 +/- 53 days and the origin is a rotation period of the star ...

  12. Clinical Allograft Islets Post-transplant 1 Year for Type 1 Diabetes Mellitus with A Modified Edmonton Protocol%同种异体胰岛细胞移植治疗1型糖尿病的护理

    Institute of Scientific and Technical Information of China (English)

    张雯

    2015-01-01

    目的:总结同种异体胰岛细胞移植治疗1型糖尿病的护理研究。方法按JDRF标准筛选3例1型糖尿病患者(T1DM),并实施同种异体胰岛细胞移植。在GMP实验室内以Liberase 酶消化胰腺器官、COBE 2991细胞分离机分离、连续密度梯度纯化,获取高纯度与高活性的胰岛细胞。培养12h后,检测其达到移植标准,再经皮穿刺肝脏门静脉主干,经门静脉将胰岛细胞匀速移植到肝脏内。术后应用各种护理方法,密切观察病情变化和各种并发症的变化。结果2例完全脱离胰岛素治疗,1例胰岛素用量较术前减少60%以上。术后血糖稳定,C肽、糖化血红蛋白在正常范围,肾功能得以改善,无移植并发症、以及低血糖发作,患者掌握了术后自我管理的方法,总结出了个体化的护理经验。结论患者护理效果满意,初步建立同种异体胰岛细胞移植治疗1型糖尿病一整套护理方法。%Objective To investigate the pancreatic islet cell isolation technology,quality standards,and allograft islet cell transplantation in the treatment of type 1 diabetes safety and effectiveness. Methods According to Juvenile Diabetes Research Foundation (JDRF) standard screening method,three cases of type 1 diabetes (T1DM) were selected as allograft islet cells recipi-ents. Using Liberase enzyme digested pancreatic organs,COBE 2991 cell separator,and discontinuous density gradient purification-to obtained high purity and high activity of islet cells. All these procedures were conducted in our GMP facilities. Cultured after 12h,testing islets reached transplant standards,then performed percutaneous hepatic portal vein trunk of the recipients,islet cells were through the portal vein into the recipient liver site. After islet transplantation,using a modified Edmonton immunosuppressive protocol controlled rejection,and monitored of blood glucose,C peptide and glycate hemoglobin level changes regularly for 1-year followed

  13. Nursing of Allogeneic Donor Peripheral Blood Stem Cell Collection%异基因外周血造血干细胞供者采集术的护理

    Institute of Scientific and Technical Information of China (English)

    吕翠侠; 陈美珠; 黄爱勤

    2011-01-01

    Objective To probe nursing of donor peripheral blood stem cell collection, to provide sufficient peripheral blood stem cells,and to ensure successful transplantation of peripheral blood stem cell of providers. Methods Data from recipients during 2006 -2010 were analyzed. The peripheral blood stem cell mobilization regimen for recombinant human granulocyte colony stimulating factor( rhG-CSF) 300 μg.sc, 1 day,4 d,or continuously 5 d,as a result,white blood cells rose to 30 × 109/L. Then by COBE Spectra apheresis unit of whole blood cell the patient' s peripheral blood stem cells were collected and separated,and then input into the providers with leukemia. Throughout the entire process,a full range of care was conducted. Results 128 peripheral blood stem cells were collected from 107 donors. In the total cycle 9000-12 000 ml cases,80% or more WBC of peripheral blood stem cells were collected,and CD34 concentration more than 5 times than before collection. The cells were in security input into 107 recipients,and transplantation success rate was 99%. Conclusion Psychological,diet,basic care and a full range of professional care were provided for providers from the beginning to the end of the collection was a prerequisite for success, and was the key to success in transplantation of a peripheral blood stem cell.%目的 探讨供者外周造血干细胞采集术的护理,提供足够细胞数量的外周造血干细胞数,确保受者外周造血干细胞移植的成功.方法 分析2006~ 2010年供者资料,其外周血干细胞动员方案为粒系集落刺激因子或加用粒单核系集落刺激因皮下注射,1次/d,连续4d或5d,白细胞水平升至30×109/L,应用COBE Spectra全血细胞单采机采集和分离供者的外周血干细胞,输给白血病受者,整过程实行全方位的护理.结果 107例供者共采集了128次外周造血干细胞,在总循环9000~12 000 ml情况下,采集的外周血干细胞中的WBC 80%以上,CD34

  14. Effect of using pump on postoperative pleural effusion in the patients that underwent CABG

    Directory of Open Access Journals (Sweden)

    Mehmet Özülkü

    2015-08-01

    Full Text Available Abstract Objective: The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting. Methods: A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11. Results: The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump as compared to Group 2 (off-pump. But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893, P>0.05 for bilateral pleural effusion (P=0.780]. Left pleural effusion was encountered to be lower in Group 2 (off-pump. The difference was found to be statistically significant (P<0.05, P=0.006. Conclusion: Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.

  15. Intercomparison of an improved 20th Century reanalysis version 2c dataset spanning 1850 to 2012

    Science.gov (United States)

    Compo, G. P.; Whitaker, J. S.; Sardeshmukh, P. D.; Giese, B. S.; Brohan, P.

    2014-12-01

    The historical reanalysis dataset generated by NOAA ESRL and the University of Colorado CIRES, the Twentieth Century Reanalysis version 2 (20CRv2), is a comprehensive global atmospheric circulation dataset spanning 1871-2012, assimilating only surface pressure and using monthly Hadley Centre SST and sea ice distributions (HadISST1.1) as boundary conditions. It has been made possible through collaboration with GCOS, WCRP, and the ACRE initiative. It is chiefly motivated by a need to provide an observational validation dataset, with quantified uncertainties, for assessments of climate model simulations of the 20th century, with emphasis on the statistics of daily weather. It uses, together with an NCEP global numerical weather prediction (NWP) land/atmosphere model to provide background "first guess" fields, an Ensemble Kalman Filter (EnKF) data assimilation method. This yields a global analysis every 6 hours as the most likely state of the atmosphere, and also yields the uncertainty of that analysis. Improvements in the new version ("2c") include an extension back to 1850 and the specification of new boundary conditions. These come from new fields of monthly COBE-SST2 sea ice concentrations and an ensemble of daily Simple Ocean Data Assimilation with Sparse Input (SODAsi.2c) sea surface temperatures. SODAsi.2c itself was forced with 20CR, allowing these boundary conditions to be more consistent with the atmospheric reanalysis. Millions of additional pressure observations contained in the new International Surface Pressure Databank version 3 are also included. These improvements result in 20CR version "2c" having comparable or better analyses, as suggested by improved 24 hour forecast skill, more realistic uncertainty in near-surface air temperature, and a reduction in spurious centennial trends in the tropical and polar regions. An intercomparison with ERA-Interim, MERRA, and JRA-55 reanalyses that assimilate all available upper-air and satellite observations will

  16. The SPHEREx All-Sky Spectroscopic Survey

    Science.gov (United States)

    Unwin, Stephen C.; SPHEREx Science Team, SPHEREx Project Team

    2016-06-01

    SPHEREx is a mission to conduct an optical-near-IR survey of the entire sky with a spectrum at every pixel location. It was selected by NASA for a Phase A study in its Small Explorer Program; if selected, development would begin in 2016, and the observatory would start a 2-year prime mission in 2020. An all-sky spectroscopic survey can be used to tackle a wide range of science questions. The SPHEREx science team is focusing on three: (1) Probing the physics of inflation through measuring non-Gaussianity from the study of large-scale structure; (2) Studying the origin of water and biogenic molecules in a wide range of physical and chemical environments via ice absorption spectra; (3) Charting the history of star formation in the universe through intensity mapping of the large-scale spatial power. The instrument is a small wide-field telescope operating in the range of 0.75 - 4.8 µm at a spectral resolution of 41.5 in the optical and 150 at the long-wavelength end. It observes in a sun-sync low-earth orbit, covering the sky like WISE and COBE. SPHEREx is a simple instrument that requires no new technology. The Phase A design has substantial technical and resource margins and can be built with low risk. It is a partnership between Caltech and JPL, with Ball Aerospace and the Korea Astronomy and Space Science Institute as major partners. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. © 2016 California Institute of Technology. Government sponsorship acknowledged.

  17. Vom Urknall zum Durchknall

    Science.gov (United States)

    Unzicker, Alexander

    Lautstarker Applaus erhob sich im Salon III/IV des Marriott-Hotels von Crystal City im amerikanischen Bundesstaat Virginia. In dem überfüllten Konferenzraum starrten alle wie gebannt auf die Leinwand, wo nicht mehr zu sehen war als ein nüchternes Diagramm aus zahlreichen Punkten und einer geschwungenen Kurve. Nureine eigenartige Personengruppe konnte sich davon zu Emotionen hinreißen lassen - Physiker auf der Jahrestagung der Astronomischen Gesellschaft, die ihren Begeisterungssturm noch minutenlang fortsetzten. Was war geschehen? Die im Diagramm aufgetragenen Daten bestätigten mit einer nie da gewesenen Genauigkeit ein fundamentales Naturgesetz zur Wärmeabstrahlung von heißen Körpern. 1900 von Max Planck entdeckt, leuchtete es nun in geradezu mathematischer Reinheit auf. Noch sensationeller war der Ursprung der Daten - Mikrowellensignale verschiedener Frequenzen, die nicht aus einem irdischen Labor stammten, sondern von einem heißen Urzustand des Universums! Ein Feuerball aus Wasserstoff und Helium, noch ohne jegliche Strukturen, die irgendwann Leben ermöglichen sollten, ließ damals seinem Licht freien Lauf. Mehr als zehn Milliarden Jahre war es bis zu den Detektoren des vom Menschen gebauten Satelliten COBE unterwegs, der wenige Tage zuvor die Daten übertragen hatte. Wenn ich das alles wie einen Film in meiner Vorstellung ablaufen lasse, bekomme ich immer eine Gänsehaut, als würde ich die inzwischen extrem abgekühlte Strahlung tatsächlich spüren. Ihre Gleichverteilung im Raum macht uns auch deutlich, dass wir uns nicht einbilden dürfen, an einem besonderen Ort im Universum zu leben - intelligente Aliens könnten sich seitdem überall entwickelt haben! Sollten sie - was nicht wahrscheinlich ist - uns wirklich von Zeit zu Zeit über die Schulter schauen, dann hätten sie an jenem Nachmittag des 13. Januar 1990, als der Vortrag stattfand, bestimmt anerkennend mit ihrem großen Kopf genickt.

  18. Cosmology with Sunyaev-Zeldovich observations from space.

    Science.gov (United States)

    Aghanim, N.; de Luca, A.; Bouchet, F. R.; Gispert, R.; Puget, J. L.

    1997-09-01

    In order to assess the potential of future microwave anisotropy space experiments for detecting clusters by their Sunyaev-Zeldovich (SZ) thermal effect, we have simulated maps of the large scale distribution of their Compton parameter y and of the temperature anisotropy {DELTA}T/T induced by their proper motion. Our model is based on a predicted distribution of clusters per unit of redshift and flux density using a Press-Schecter approach (De Luca et al. 1995A&A...300..335D). These maps were used to create simulated microwave sky by adding them to the microwave contributions of the emissions of our Galaxy (free-free, dust and synchrotron) and the primary Cosmic Microwave Background (CMB) anisotropies (corresponding to a COBE-normalized standard Cold Dark Model scenario). In order to simulate measurements representative of what current technology should achieve, "observations" were performed according to the instrumental characteristics (number of spectral bands, angular resolutions and detector sensitivity) of the COBRAS/SAMBA space mission. These observations were separated into physical components by an extension of the Wiener filtering theory (Bouchet et al. 1996, in prep). We then analyzed the resulting y and {DELTA}T/T maps which now include both the primary anisotropies and those superimposed due to cluster motions. A cluster list was obtained from the recovered y maps, and their profiles compared with the input ones. Even for low y-values, the input and output profiles show good agreement, most notably in the outer parts of the profile where values as low as y=~3x10^-7^ are properly mapped. We also construct and optimize a spatial filter which is used to derive the accuracy on the measurement of the radial peculiar velocity of a detected cluster. We derive the accuracy of the mapping of the very large scale cosmic velocity field obtained from such measurements.

  19. 白细胞单采术治疗高白细胞急性白血病26例临床观察%Clinical analysis of 26 patients with leukapheresis in the treatment of hyperleukocytic acute leukemia

    Institute of Scientific and Technical Information of China (English)

    冯春锐; 蔡力生; 蔡云; 李明; 卓家才

    2013-01-01

    目的 探讨白细胞单采术治疗高白细胞急性白血病的疗效.方法 回顾性分析本院收治的26例高白细胞急性白血病患者的临床资料,观察化疗前行白细胞单采术治疗的效果.结果 26例患者中,25例临床症状缓解,外周血白细胞数显著下降,有效率达96.1%.结论 白细胞单采术能迅速降低患者外周血中白血病细胞数目,减少体内白血病细胞负荷,有效防止肿瘤溶解综合征的发生,是治疗高白细胞急性白血病的有效方法.%Objective To evaluate the efficacy of leukapheresis in the treatment of hyperleukocytic acute leukemia.Methods Twenty six patients,who were performed leukapheresis with COBE Spectra before chemotherapy were analyzed respectively.Results Among 26 cases,25 cases achieved remission in clinical features,and dramatic reduction of WBC counts with an overall response rate of 96.1%.Conclusion Leukapheresis could prevent tumor lysis syndrome through reduction of leukemia cells burdens.It is an effective method for hyperleukocytic acute leukemia.

  20. Clinico-serologic co-relation in bi-directional ABO incompatible hemopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Sabita Basu

    2015-01-01

    Full Text Available Background: The ABO blood group system is of prime significance in red cell transfusion and organ transplantation. However, ABO compatibility is not critical in allogenic hemopoietic stem cell transplantation (HSCT and approximately 40-50% of hemopoietic stem cell transplants are ABO incompatible. This incompatibility may be major, minor or bi-directional. Though there are descriptions of transfusion practice and protocols in ABO incompatible HSCT, there are considerable variations and transfusion support in these patients can be very challenging. Aims: The immunohematologic observations in two cases of bi-directional ABO incompatible HSCT have been described, and clinico-serologic correlation has been attempted. Materials and Methods: In both cases, peripheral blood stem cell harvests were obtained using the Cobe spectra cell separator. Immunohematologic assessments in the donor and recipient were done as a part of pre HSCT evaluation. Both the standard tube technique and column agglutination method (Ortho Biovue Micro Bead System was used. Antibody screen was done by column agglutination method using three cell panel (Surgiscreen cells. Isoagglutinin titration was done by the master dilution method and standard validated techniques were used. Results: The pattern of laboratory findings in the two cases was different and so were the clinical outcomes. Although there was early engraftment in the first case, the second case developed pure red cell aplasia and this was well-reflected in the immunohematologic assessments. Conclusion: Immunohematologic assessment correlated well with the clinical picture and could be used to predict clinical outcome and onset of complications in ABO incompatible HSCT.

  1. Cosmic microwave background theory.

    Science.gov (United States)

    Bond, J R

    1998-01-01

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  2. Cosmic microwave background theory

    Science.gov (United States)

    Bond, J. Richard

    1998-01-01

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in ℓ-space are consistent with a ΔT flat in frequency and broadly follow inflation-based expectations. That the levels are ∼(10−5)2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at ℓ ≳ 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Λ cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 ± 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 ± 0.08 for DMR plus the SK95 experiment; 1.00 ± 0.04 for DMR plus all smaller angle experiments; 1.00 ± 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Λ and moderate constraints on Ωtot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant. PMID:9419321

  3. The SPHEREx All-Sky Spectroscopic Survey

    Science.gov (United States)

    Unwin, Stephen C.; SPHEREx Science Team, SPHEREx Project Team

    2016-06-01

    SPHEREx is a mission to conduct an optical-near-IR survey of the entire sky with a spectrum at every pixel location. It was selected by NASA for a Phase A study in its Small Explorer Program; if selected, development would begin in 2016, and the observatory would start a 2-year prime mission in 2020. An all-sky spectroscopic survey can be used to tackle a wide range of science questions. The SPHEREx science team is focusing on three: (1) Probing the physics of inflation through measuring non-Gaussianity from the study of large-scale structure; (2) Studying the origin of water and biogenic molecules in a wide range of physical and chemical environments via ice absorption spectra; (3) Charting the history of star formation in the universe through intensity mapping of the large-scale spatial power. The instrument is a small wide-field telescope operating in the range of 0.75 - 4.8 µm at a spectral resolution of 41.5 in the optical and 150 at the long-wavelength end. It observes in a sun-sync low-earth orbit, covering the sky like WISE and COBE. SPHEREx is a simple instrument that requires no new technology. The Phase A design has substantial technical and resource margins and can be built with low risk. It is a partnership between Caltech and JPL, with Ball Aerospace and the Korea Astronomy and Space Science Institute as major partners. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  4. Hematopoietic SCT with cryopreserved grafts: adverse reactions after transplantation and cryoprotectant removal before infusion.

    Science.gov (United States)

    Shu, Z; Heimfeld, S; Gao, D

    2014-04-01

    Transplantation of hematopoietic stem cells (HSCs) has been successfully developed as a part of treatment protocols for a large number of clinical indications, and cryopreservation of both autologous and allogeneic sources of HSC grafts is increasingly being used to facilitate logistical challenges in coordinating the collection, processing, preparation, quality control testing and release of the final HSC product with delivery to the patient. Direct infusion of cryopreserved cell products into patients has been associated with the development of adverse reactions, ranging from relatively mild symptoms to much more serious, life-threatening complications, including allergic/gastrointestinal/cardiovascular/neurological complications, renal/hepatic dysfunctions, and so on. In many cases, the cryoprotective agent (CPA) used-which is typically dimethyl sulfoxide (DMSO)-is believed to be the main causal agent of these adverse reactions and thus many studies recommend depletion of DMSO before cell infusion. In this paper, we will briefly review the history of HSC cryopreservation, the side effects reported after transplantation, along with advances in strategies for reducing the adverse reactions, including methods and devices for removal of DMSO. Strategies to minimize adverse effects include medication before and after transplantation, optimizing the infusion procedure, reducing the DMSO concentration or using alternative CPAs for cryopreservation and removing DMSO before infusion. For DMSO removal, besides the traditional and widely applied method of centrifugation, new approaches have been explored in the past decade, such as filtration by spinning membrane, stepwise dilution-centrifugation using rotating syringe, diffusion-based DMSO extraction in microfluidic channels, dialysis and dilution-filtration through hollow-fiber dialyzers and some instruments (CytoMate, Sepax S-100, Cobe 2991, microfluidic channels, dilution-filtration system, etc.) as well. However

  5. Characterizing the Dust-Correlated Anomalous Emission in LDN 1622

    Science.gov (United States)

    Cleary, Kieran; Casassus, Simon; Dickinson, Clive; Lawrence, Charles; Sakon, Itsuki

    2008-03-01

    The search for 'dust-correlated microwave emission' was started by the surprising excess correlation of COBE-DMR maps, at 31.5, 53 and 91GHz, with DIRBE dust emission at 140 microns. It was first thought to be Galactic free-free emission from the Warm Ionized Medium (WIM). However, Leitch et al. (1997) ruled out a link with free-free by comparing with Halpha templates and first confirmed the anomalous nature of this emission. Since then, this emission has been detected by a number of experiments in the frequency range 5-60 GHz. The most popular explanation is emission from ultra-small spinning dust grains (first postulated by Erickson, 1957), which is expected to have a spectrum that is highly peaked at about 20 GHz. Spinning dust models appear to be broadly consistent with microwave data at high latitudes, but the data have not been conclusive, mainly due to the difficulty of foreground separation in CMB data. LDN 1622 is a dark cloud that lies within the Orion East molecular cloud at a distance of 120 pc. Recent cm-wave observations, in combination with WMAP data, have verified the detection of anomalous dust-correlated emission in LDN 1622. This mid-IR-cm correlation in LDN 1622 is currently the only observational evidence that very small grains VSG emit at GHz frequencies. We propose a programme of spectroscopic observations of LDN 1622 with Spitzer IRS to address the following questions: (i) Are the IRAS 12 and 25 microns bands tracing VSG emission in LDN 1622? (ii) What Mid-IR features and continuum bands best correlate with the cm-wave emission? and (iii) How do the dust properties vary with the cm-wave emission? These questions have important implications for high-sensitivity CMB experiments.

  6. On the Microwave Signal at the Second Lagrange Point.

    Science.gov (United States)

    Robitaille, Pierre-Marie; Borissova, Larissa; Rabounski, Dmitri

    2007-11-01

    It has been proposed that the 2.7 K Penzias-Wilson monopole is of oceanic origin. Under this scenario, the signal should be powerful near the Earth and rapidly fall in power away from our planet. As a result, the Penzias and Wilson signal is not expected to have any significant intensity at the second Lagrange point. In July 2008, the ESA will launch the PLANCK mission to this location. The low Frequency Instrument (LFI) on PLANCK is operating as a group of pseudo-correlation receivers. Since the 2.7 K signal will not be found at L2, an analytical analysis of the PLANCK LFI reveals that the knee frequency of the radiometers will rise to ˜50 mHz, well above the 3-7 mHz levels expected by the PLANCK team and substantially above the satellite spin frequency of ˜17 mHz. This will result in the production of significant stripes in the raw maps generated, potentially impacting the harvest from PLANCK. Calculations reveal that little difference exists in the intensity of the 2.7 K field, either at the position of a U2 plane (25 km), or in the COBE orbit (900 km). However, the density of the energy of the field drops to ˜10-7 of these near Earth values at the L2 point, rendering detection improbable. Since the LFI on PLANCK can operate either in absolute or difference mode and since the HFI operate as bolometers, PLANCK should unequivocally ascertain the origin of the 2.7K monopole.

  7. IYL Blog: Astronomers travel in time and space with light

    Science.gov (United States)

    Mather, John C.

    2015-01-01

    also using light to find out whether we are alone in the universe. The Kepler observatory showed that thousands of stars blink a little when their orbiting planets pass between us and them, and other observatories use light to measure the wobble of stars as their planets pull on them. Eventually, we will find out whether planets like Earth have atmospheres like Earth's too - with water, carbon dioxide, oxygen, methane, and other gases that would be evidence of photosynthetic life. I think in a few decades we will have evidence that some planets do have life, and it will be done using light for remote chemical analysis. Also, astronomers at the SETI project are using light (long wavelength light we can pick up with radio telescopes) to look for signals from intelligent civilizations. That's a harder project because we don't know what to look for. But if we wanted to send signals all the way across the Milky Way, we could do it with laser beams, and if somebody over there knew what to look for, he or she could decode the message. On with the search! Dr. John C. Mather is a Senior Astrophysicist and is the Senior Project Scientist for the James Webb Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, MD. His research centers on infrared astronomy and cosmology. With the Cosmic Background Explorer (COBE) team, he showed that the cosmic microwave background radiation has a blackbody spectrum within 50 parts per million, confirming the expanding universe model (aka the Big Bang Theory) to extraordinary accuracy, and initiating the study of cosmology as a precision science. The COBE team also made the first map of the hot and cold spots in the background radiation. The COBE maps have been confirmed and improved by two succeeding space missions, the Wilkinson Microwave Anisotropy Probe (WMAP, built by GSFC with Princeton University), and the Planck mission built by ESA. Based on these maps, astronomers have now developed a "standard model" of cosmology and have

  8. ESA scientist discovers a way to shortlist stars that might have planets

    Science.gov (United States)

    2002-02-01

    Traces of the disc surrounding our Solar System Credits: Michael Hauser (Space Telescope Science Institute), the COBE/DIRBE Science Team, and NASA Traces of the disc surrounding our Solar System Traces of the disc surrounding our Solar System. The blue band curving across this image is created by the dust disc surrounding our Solar System. Viewed from afar this would show up as a bright ring surrounding the Sun. The bright band running across the centre of the image is from dust in our Galaxy. This image, taken by the COBE satellite, is a composite of three far-infrared wavelengths (60, 100, and 240 microns). (Photo: Michael Hauser (Space Telescope Science Institute), the COBE/DIRBE Science Team, and NASA) Disc surrounding the Sun Credits: Brad Smith (University of Hawaii), Glenn Schneider (University of Arizona), and NASA Viewed from afar our Solar System would have a bright disc surrounding the Sun Viewed from afar our Solar System would have a bright dust disc surrounding the Sun similar to the disc surrounding this star. This image, taken with Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS), shows a dust ring around a star called HR 4796A. The image was taken on March 15, 1998. (Photo: Brad Smith (University of Hawaii), Glenn Schneider (University of Arizona), and NASA) Ulysses in flight configuration hi-res Size hi-res: 117 Kb Credits: ESA/Dave Hardy Ulysses at Jupiter encounter Ulysses in flight configuration passing by Jupiter. Remarkably, their discovery gives astronomers a way to determine which other stars in the Galaxy are most likely to harbour planets and allows mission planners to draw up a 'short-list' of stars to be observed by ESA's future planet-search missions, Eddington and Darwin. The discovery of the Solar System's dust ring strengthens the idea that such features around mature stars are signposts to planetary systems. The reason for this is that planetary systems are thought to condense from a cloud of gas and dust

  9. The Primordial Inflation Explorer (PIXIE)

    Science.gov (United States)

    Kogut, Alan; Chluba, Jens; Fixsen, Dale J.; Meyer, Stephan; Spergel, David

    2016-07-01

    The Primordial Inflation Explorer is an Explorer-class mission to open new windows on the early universe through measurements of the polarization and absolute frequency spectrum of the cosmic microwave background. PIXIE will measure the gravitational-wave signature of primordial inflation through its distinctive imprint in linear polarization, and characterize the thermal history of the universe through precision measurements of distortions in the blackbody spectrum. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning over 7 octaves in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded non-imaging optics feed a polarizing Fourier Transform Spectrometer to produce a set of interference fringes, proportional to the difference spectrum between orthogonal linear polarizations from the two input beams. Multiple levels of symmetry and signal modulation combine to reduce systematic errors to negligible levels. PIXIE will map the full sky in Stokes I, Q, and U parameters with angular resolution 2.6° and sensitivity 70 nK per 1° square pixel. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10-3 at 5 standard deviations. The PIXIE mission complements anticipated ground-based polarization measurements such as CMB- S4, providing a cosmic-variance-limited determination of the large-scale E-mode signal to measure the optical depth, constrain models of reionization, and provide a firm detection of the neutrino mass (the last unknown parameter in the Standard Model of particle physics). In addition, PIXIE will measure the absolute frequency spectrum to characterize deviations from a blackbody with sensitivity 3 orders of magnitude beyond the seminal COBE/FIRAS limits. The sky cannot be black at this level; the expected results will constrain physical processes ranging from

  10. SPHEREx: An All-Sky Spectral Survey

    Science.gov (United States)

    Bock, James; SPHEREx Science Team

    2016-01-01

    SPHEREx, a mission in NASA's Small Explorer (SMEX) program that was selected for Phase A in July 2015, is an all-sky survey satellite designed to address all three science goals in NASA's astrophysics division, in a single survey, with a single instrument. We will probe the physics of inflation by measuring non-Gaussianity by studying large-scale structure, surveying a large cosmological volume at low redshifts, complementing high-z surveys optimized to constrain dark energy. The origin of water and biogenic molecules will be investigated in all phases of planetary system formation - from molecular clouds to young stellar systems with protoplanetary disks - by measuring ice absorption spectra. We will chart the origin and history of galaxy formation through a deep survey mapping large-scale spatial power. Finally, SPHEREx will be the first all-sky near-infrared spectral survey, creating a legacy archive of spectra (0.75 - 4.8 um at R = 41.5 and 150) with high sensitivity using a cooled telescope with large mapping speed.SPHEREx will observe from a sun-synchronous low-earth orbit, covering the entire sky in a manner similar to IRAS, COBE and WISE. During its two-year mission, SPHEREx will produce four complete all-sky maps for constraining the physics of inflation. These same maps contain numerous high signal-to-noise absorption spectra to study water and biogenic ices. The orbit naturally covers two deep regions at the celestial poles, which we use for studying galaxy evolution. All aspects of the SPHEREx instrument and spacecraft have high heritage. SPHEREx requires no new technologies and carries large technical and resource margins on every aspect of the design. The projected instrument sensitivity, based on conservative performance estimates, meets the driving point source sensitivity requirement with 300 % margin.SPHEREx is a partnership between Caltech and JPL, following the successful management structure of the NuSTAR and GALEX SMEX missions. The spacecraft

  11. Spitzer and DIRBE Studies of the Infrared Background

    Science.gov (United States)

    Werner, Michael; Gorjian, Varoujan; Hauser, Michael; Wright, Edward; Arendt, Rick; Chary, Ranga-Ram; Levenson, Louis

    2011-05-01

    The extragalactic background light (EBL), defined as the sky surface brightness of all radiation arising from outside the Milky Way, carries in the 1-5um region the imprint of the nearby Universe, of red-shifted light from the first galaxies, and of any possible pre-galactic contributions. The DIRBE instrument on the COBE satellite has measured the total sky brightness, the Cosmic Infrared Background (CIRB), over the entire sky at 3.6um. The CIRB is the sum of the zodiacal light, galactic starlight, radiation from the ISM, and the EBL. Although the determinations of the EBL are presently limited by uncertainties in the zodiacal light model, experiments now under way can reduce those uncertainties. This Spitzer proposal prepares for that reduction by eliminating other uncertainties. We will use Spitzer to determine the point source components of CIRB at 3.6um, the wavelength of the minimum in the bright foreground from interplanetary dust. We will measure essentially all of the stellar contribution, and more than 80% of the integrated light from resolved galaxies; this can be extrapolated using other Spitzer data to determine IGL. The ultimate objective of this type of study is to search for a currently unknown diffuse component of EBL, DEBL. Symbolically, DEBL = EBL-IGL. In this program, we will execute the following steps aimed at reducing the uncertainties in DEBL once the zodiacal uncertainty in CIRB is minimized and a correction for ISM emission is applied: 1. Cross calibrating DIRBE and Spitzer so that EBL and IGL are on the same flux scale; 2. Reducing the uncertainties in EBL by measuring stars as faint as 19th mag at 3.6um. 3. Determining EBL and IGL at six widely separated positions so that the isotropy - and hence the cosmological significance - of any detection of DEBL can be assessed. We emphasize that this important investigation can be carried out only with Spitzer, and this scientific opportunity is perishable due to Spitzer's finite lifetime.

  12. How large is the cosmic dust flux into the Earth's atmosphere?

    Science.gov (United States)

    Plane, John; Janches, Diego; Gomez-Martin, Juan Carlos; Bones, David; Diego Carrillo-Sanchez, Juan; James, Sandy; Nesvorny, David; Pokorny, Petr

    2016-07-01

    Cosmic dust particles are produced in the solar system from the sublimation of comets as they orbit close to the sun, and also from collisions between asteroids in the belt between Mars and Jupiter. Current estimates of the magnitude of the cosmic dust input rate into the Earth's atmosphere range from 2 to well over 100 tons per day, depending on whether the measurements are made in space, in the middle atmosphere, or at the surface in polar ice cores. This nearly 2 order-of-magnitude discrepancy indicates that there are serious flaws in the interpretation of observations that have been used to make the estimates. Dust particles enter the atmosphere at hyperthermal velocities (11 - 72 km s ^{-1}), and mostly ablate at heights between 80 and 120 km in a region of the atmosphere known as the mesosphere/lower thermosphere (MLT). The resulting metal vapours (Fe, Mg, Si and Na etc.) then oxidize and recondense to form nm-size particles, termed "meteoric smoke". These particles are too small to sediment downwards. Instead, they are transported by the general circulation of the atmosphere, taking roughly 5 years to reach the surface. There is great interest in the role smoke particles play as condensation nuclei of noctilucent ice clouds in the mesosphere, and polar stratospheric clouds in the lower stratosphere. Various new estimates of the dust input will be discussed. The first is from a zodiacal dust cloud model which predicts that more than 90% of the dust entering the atmosphere comes from Jupiter Family Comets; this model is constrained by observations of the zodiacal cloud using the IRAS, COBE and Planck satellites. The cometary dust is predicted to mostly be in a near-prograde orbit, entering the atmosphere with an average velocity around 14 km s ^{-1}. The total dust input should then be about 40 t d ^{-1}. However, relatively few of these particles are observed, even by the powerful Arecibo 430 MHz radar. Coupled models of meteoroid differential ablation

  13. Cosmology comes of age

    International Nuclear Information System (INIS)

    This year's Nobel prize is welcome recognition for cosmology. Back in the 1960s, according to Paul Davies' new book The Goldilocks Enigma (see 'Seeking anthropic answers' in this issue), cynics used to quip that there is 'speculation, speculation squared - and cosmology'. Anyone trying to understand the origin and fate of the universe was, in other words, dealing with questions that were simply impractical - or even impossible - to answer. But that has all changed with the development of new telescopes, satellites and data-processing techniques - to the extent that cosmology is now generally viewed as a perfectly acceptable branch of science. If anyone was in any doubt of cosmology's new status, the Royal Swedish Academy of Sciences last month gave the subject welcome recognition with the award of this year's Nobel prize to John Mather and George Smoot (see pp6-7; print version only). The pair were the driving force behind the COBE satellite that in 1992 produced the now famous image of the cosmic microwave background. The mission's data almost certainly proved that the universe started with a Big Bang, while tiny fluctuations in the temperature signal between different parts of the sky were shown to be the seeds of the stars and galaxies we see today. These results are regarded by many as the start of a new era of 'precision cosmology'. But for cosmologists, the job is far from over. There are still massive holes in our understanding of the cosmos, notably the nature of dark matter and dark energy, which together account for over 95% of the total universe. Indeed, some regard dark energy and matter as just ad hoc assumptions needed to fit the data. (Hypothetical particles called 'axions' are one possible contender for dark matter (see pp20-23; print version only), but don't bet your house on it.) Some physicists even think it makes more sense to adjust Newtonian gravity rather than invoke dark matter. But the notion that cosmology is in crisis, as argued by some

  14. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

    International Nuclear Information System (INIS)

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The data obtained will allow us to precisely measure the absolute sky brightness and polarization of all the components of the sky emission in the observed frequency range, separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM, which include: (1) the ultimate galaxy cluster survey using the Sunyaev-Zeldovich (SZ) effect, detecting approximately 106 clusters extending to large redshift, including a characterization of the gas temperature of the brightest ones (through the relativistic corrections to the classic SZ template) as well as a peculiar velocity survey using the kinetic SZ effect that comprises our entire Hubble volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where the most of the star formation in the universe took place, the faintest population of which constitute the diffuse CIB (Cosmic Infrared Background); (3) a characterization of the B modes from primordial gravity waves generated during inflation

  15. Allograft islet cell transplantation and postoperatively modified Edmonton protocol for 3 cases of type 1 diabetes mellitus%同种胰岛细胞移植及采用改良Edmonton方案治疗1型糖尿病三例

    Institute of Scientific and Technical Information of China (English)

    黄孝伦; 姚豫桐; 罗兰云; 薛华; 邹海波; 魏玲玲; 杨卯竹; 骆乐; 王冠

    2014-01-01

    Objective To investigate the pancreatic islet cell isolation technology,quality standards,and safety and effectiveness of allograft islet cell transplantation and modified Edmonton protocol in the treatment of type 1 diabetes (T1DM).Method Three cases of T1DM received allograft islet cell transplantation.The pancreas was taken from adult organ donation after cardiac death donor.All pancreatic organs were digested by Liberase enzyme,COBE 2991 cell separator,and discontinuous density gradient purification,to obtain high purity and high activity of islet cells.All these procedures were conducted in our GMP facilities.After culture for 12 h,testing islets reached transplant standards.After the percutaneous puncture of hepatic portal vein trunk of the recipients,islet cells were transplanted evenly through the portal vein into the liver of recipients.After islet cell transplantation,a modified Edmonton immunosuppressive protocol containing antithymocyte globulin (ATG),tacrolimus and mycophenolate mofetil was used,and the changes in blood glucose,C peptide and glycate hemoglobin were monitored regularly during a follow-up period of one year.Result The transplanted islet cells of 3 recipients were 460 00(-505 200 IEQ,and islet purity and viability were 38.5%-49.7% and 95%-97% respectively.The stimulation index of human islet was 2.8-5.4.The glucose levels of 3 recipients in the normal diet were strictly controlled below 7.8 mmol/L.Two recipients remained insulin-independent after 3-5 months.The dosage of insulin was decreased by 60% in 1 patient after 12 months.The levels of C-peptide and HbA1c were all within normal range and renal functions were improved.No complications related to islet infusion including hypoglycemia,adverse drug reactions,acute rejection and infection were observed.Conclusion Our isolation techniques and methods of islet cells are reliable.Allograft islet cell transplantation and the improved Edmonton protocol in the short-term for

  16. 肾移植联合成人胰岛细胞移植治疗糖尿病肾病七例报告%Simultaneous adult islet-kidney transplantation in 7 patients of type 1 diabetes mellitus with end-stage renal failure

    Institute of Scientific and Technical Information of China (English)

    谭建明; 蔡锦全; 杨顺良; 吴卫真; 郭君其; 黄梁浒; 王庆华; 吴志贤; 陈津

    2009-01-01

    Objective To establish a new technique of isolating pancreatic islet of langerhans and glueoeortieoid-free immunosuppressive regimen and to evaluate the clinical efficacy and safety of simultaneous adult islet-kidney transplantation in the treatment of type 1 diabetes mellitus with endstage renal failure.Methods Pancreases were stored using the"2-layer method"of the oxygenated perfluoroehemieal and UW solution.The pancreases were digested by Liberase collagenase enzyme and purified using continuous gradients of Ficoll-diatrizoic acid on a refrigerated COBE 2991 centrifuge to separate the islets.Cadaver kidney was transplanted by conventional method and cultured islets were infused by surgical approach to the liver via portal vaseulature using glucocorticoid-free immunosuppressive regimen.Clinical metabolic data such as blood glucose,dose of insulin,C-peptide,HbAlc,liver function and renal function,were determined and compared with the pre-transplant data.ResuitsIslets of langerhans were isolated successfully in 23 pancreases.The average islet yield was 300000 islet equivalents(IEQ).Islet purity and viability were 91.6%,94.6%,respectively.The stimulation index as assessing function of human islet was 3.16 and etiology results in vivo were negative.Twelve islet transplant infusions were carried out in 7 patients after kidney transplantation.Three recipients received 2 islet infusions,1 patient had 3 transplants,and 3 patients received 1 transplant only.The average islet mass for infusion was 1 1 820 IEQ/kg.The immunosuppressive regimen glucocorticoid.During 18 months to 3 yearg follow-up,4 recipients had insulin independence,the dosage of insulin decreased by 70%in 3 patients.The level of blood glucose and H bAlc,liver and renal function were normal throughout follow-up period.C-peptide of all patients was positive after islet transplantation.No adverse effects and complications related to islet infusion procedure were found.Conclusions New technique has proved tO be

  17. The Physics of the Cosmic Microwave Background

    International Nuclear Information System (INIS)

    The award of the 2006 Nobel Prize for Physics is a reminder to non-specialists that the cosmic microwave background (CMB) has yielded astonishing advances in our understanding of cosmology. Mather and Smoot received their prize for work done with NASA's COBE satellite in the early 1990s, but the subject has if anything accelerated since then. The results from NASA's WMAP satellite, reported in 2003 and 2006, have proved COBE's equal in importance and have generated huge worldwide interest. There could therefore hardly be a better time to be writing a detailed textbook to explain what the fuss is all about to a new generation of research students. A comprehensive treatment of the physics of the CMB is not easy to achieve, because it is connected to so much else in cosmology. A student must have a background knowledge of the geometry and dynamics of an expanding universe, plus a deep exposure to the physics of quantum fields, in order to understand the modern 'inflationary' view in which the universe was set expanding by the tension of the vacuum, and was seeded with small inhomogeneities as a result of quantum fluctuations. Although the theory of inflation is not yet verified, the CMB has the potential to accomplish this; testing inflation is undoubtedly one of the principal aims of cosmology over the next decade. Even with this preparation, understanding the properties of the CMB is quite hard at the professional level, requiring the perturbation expansion of the relativistic Boltzmann equation. These technical difficulties are particularly strong in the frontier area of CMB polarization. Naselsky and his collaborators have allocated themselves a relatively brief 255 pages in which to meet these challenges, so some compromise is inevitable. Although the preface is not explicit about the assumed prior knowledge, no systematic material on background cosmology or on inflation is to be found. The former is reasonable in a graduate-level text (which this certainly is

  18. Obituary: Andrew Lange (1957-2010)

    Science.gov (United States)

    Kamionkowski, Marc

    2011-12-01

    The worlds of physics and astrophysics were stunned to learn on 22 January 2010 that Andrew Lange, the Marvin L. Goldberger Professor of Physics at Caltech, had taken his own life the night before. He had succumbed to the severe depression that he had suffered from for many years, unbeknownst to even his closest colleagues. Lange will perhaps be best remembered as the co-leader of Boomerang, the balloon-borne experiment that provided the first high-angular-resolution map of the cosmic microwave background (CMB). And while this was certainly his most notable achievement, Andrew amassed a record of accomplishment as an instrumentalist, leader, mentor, and communicator that extended much further. Andrew was born in Urbana, Illinois on July 23, 1957, the son of an architect and a librarian, and raised primarily in Connecticut. His family and early friends remember him as a serious and extremely intelligent child and young man. Andrew Lange's lifelong interest in the CMB was nurtured as an undergraduate at Princeton University by David Wilkinson, and he recalled fondly a summer spent working with John Mather at Goddard Space Flight Center. Andrew Lange went to graduate school in physics at Berkeley where he worked in Paul Richards' group. Although his thesis project, the Berkeley-Nagoya rocket experiment, showed an anomalous sub-millimeter excess in the CMB spectrum that was shortly thereafter shown by a later flight of the same rocket and COBE-FIRAS to be incorrect, Lange's talents were recognized by the physics department at Berkeley who appointed him shortly after his PhD (1987) to their faculty. While on the Berkeley faculty, Andrew obtained early detections of the Sunyaev-Zeldovich effect, upper limits to small-angle CMB fluctuations, and important infrared constraints to the interstellar medium. He also led a pioneering instrument operating 300 mK detectors for a small infrared satellite experiment. This early work showed high ambition and daring, and it pioneered

  19. 健康供者外周血造血干细胞动员的临床研究%Clinical study on peripheral blood stem cell mobilization in normal donors

    Institute of Scientific and Technical Information of China (English)

    章卫平; 王健民; 童书鹏; 宋献民; 钱宝华; 周虹; 李红梅; 丁晓勤

    2002-01-01

    目的:探讨造血生长因子(HGFs)对健康供者外周血干细胞(PBSC)的动员作用,并比较粒细胞集落刺激因子(G-CSF)单用及G-CSF联合粒-巨噬细胞集落刺激因子(GM-CSF)的动员效果.方法:52例健康供者分成G-CSF单用组(34例)及与GM-CSF合用组(18例),分别采用G-CSF(5 μg·kg-1·d-1)及G-CSF(3 μg·kg-1·d-1)+GM-CSF(2 μg·kg-1·d-1),连续皮下注射5~6 d动员,采集PBSC.动员前后动态检测外周血及采集物MNC、CD34+细胞、CFU-GM计数.52例血液病患者接受上述供体动员之PBSC并行异基因PBSC移植(Allo-PBSCT).结果:动员后CD34+细胞及CFU-GM分别较动员前增加10.83及8.7倍,并在第5~6天达到高峰;G-CSF单用及与GM-CSF合用均可有效动员CD34+细胞和CFU-GM,但合用较单用更有效(P<0.05);所有患者接受Allo-PBSCT后均满意获得造血重建;随访观察至今应用HGFs对健康供者无明显不良反应.结论:采用中小剂量G-CSF单用和与GM-CSF合用均能安全、有效动员健康供者PBSC,但以合用更为有效.%Objective: To explore the efficiency of hematopoietic growth factors (HGFs) on peripheral blood stem cell (PBSC) mobilization in normal donors. Methods: Granulocyte-colony stimulating factor (G-CSF, 5 μg·kg-1·d-1) was used subcutaneously in 34 donors and G-CSF (3 μg·kg-1·d-1) + granulocyte-macrophage-colony stimulating factor (GM-CSF,2 μg·kg-1·d-1) in 18 donors for 5-6 d. PBSC was harvested with CS-3000 Plus or COBE Spectra blood cell separator. The numbers of MNC, CD34+ cells and CFU-GM were determined during the mobilization. Fifty-two patients with hematologic disease received allogeneic peripheral blood stem cell transplantation (Allo-PBSCT). Results: After mobilization, CD34+ cells and CFU-GM yields increased by 10.83 and 8.7 folds, respectively, and peaked on day 5 of HGFs initiation. Both G-CSF alone and G-CSF + GM-CSF effectively mobilized PBSC, while G-CSF+GM-CSF mobilized CD34+cells and CFU-GM more efficiently than G

  20. Mobilization of peripheral blood stem cells with mitoxantrone and high-dose cytarabine chemotherapy and rhG-CSF in patients with hematopoietic malignancies%MAG方案对恶性血液病患者造血干细胞动员作用的研究

    Institute of Scientific and Technical Information of China (English)

    仇惠英; 吴德沛; 孙爱宁; 常伟荣; 金正明; 苗瞄; 唐晓文; 沈益明; 傅琤琤

    2004-01-01

    目的研究米托蒽醌(MTZ)联合大剂量阿糖胞苷(Ara-C)、重组人粒细胞集落刺激因子(rhG-CSF)组成MAG方案对恶性血液病患者外周血干细胞的动员作用.方法1995年12月至2003年4月,采用MAG方案对14例恶性淋巴瘤和29例急性白血病患者外周血干细胞进行动员,其用量为MTZ 10 mg/m2,第2,3天;Ara-C 2 g/m2,每12 h 1次,第1,2天;rhG-CSF 300μg/d.首先用MA方案联合化疗,白细胞<1.0×109/L时开始用rhG-CSF,白细胞回升时用CS 3000 plus或Cobe Spectra血细胞分离机采集外周血干细胞.结果14例恶性淋巴瘤患者除1例外周血干细胞采集失败外,其余13例均1次性采集成功,所得单个核细胞(MNC)(3.91±2.70)×108/kg,CD34+细胞(17.79±12.90)×106/kg.采集29例急性白血病患者外周血干细胞平均2.13次,24例采集成功,5例采集失败,所得MNC(3.62士2.89)×108/kg,CD34+细胞(7.37±6.60)×106/kg.rhG-CSF平均使用时间为7 d.经MAG方案动员后,除8例患者有胃肠道反应、14例患者骨髓抑制期合并感染外无明显不良反应,无动员相关死亡.MAG方案动员后进行微小残留病检测,部分病例转为阴性.结论MAG方案在恶性淋巴瘤和急性白血病患者外周血干细胞动员中安全、高效.

  1. Science Archives in the 21st Century: A NASA LAMBDA Report

    Science.gov (United States)

    Butterworth, P.; Greason, M.

    2007-01-01

    Lambda is a thematic data center that focuses on serving the cosmic microwave background (CMB) research community. LAMBDA is an active archive for NASA's Cosmic Background Explorer (COBE) and Wilkinson Microwave Anisotropy Probe (WMAP) mission data sets. In addition, LAMBDA provides analysis software, on-line tools, relevant ancillary data and important web links. LAMBDA also tries to preserve the most important ground-based and suborbital CMB data sets. CMB data is unlike other astrophysical data, consisting of intrinsically diffuse surface brightness photometry with a signal contrast of the order 1 part in 100,000 relative to the uniform background. Because of the extremely faint signal levels, the signal-to-noise ratio is relatively low and detailed instrument-specific knowledge of the data is essential. While the number of data sets being produced is not especially large, those data sets are becoming large and complex. That tendency will increase when the many polarization experiments currently being deployed begin producing data. The LAMBDA experience supports many aspects of the NASA data archive model developed informally over the last ten years-that small focused data centers are often more effective than larger more ambitious collections, for example; that data centers are usually best run by active scientists; that it can be particularly advantageous if those scientists are leaders in the use of the archived data sets; etc. LAMBDA has done some things so well that they might provide lessons for other archives. A lot of effort has been devoted to developing a simple and consistent interface to data sets, for example; and serving all the documentation required via simple 'more' pages and longer explanatory supplements. Many of the problems faced by LAMBDA will also not surprise anyone trying to manage other space science data. These range from persuading mission scientists to provide their data as quickly as possible, to dealing with a high volume of

  2. Wide-Field Infrared Survey Telescope (WFIRST) Interim Report

    Science.gov (United States)

    Green, J.; Schechter, P.; Baltay, C.; Bean, R.; Bennett, D.; Brown, R.; Conselice, C.; Donahue, M.; Gaudi, S.; Lauer, T.; Perlmutter, S.; Rauscher, B.; Rhodes, J.; Roellig, T.; Stern, D.; Sumi, T.; Gerhels, N.; Sambruna, R.; Barry, R. K.; Content, D.; Grady, K; Jackson, C.; Kruk, J.; Melton, M.; Rioux, N.

    2011-01-01

    Satellite (IRAS), the Cosmic Background Explorer (COBE), Herschel, Spitzer, and Wide-field Infrared Sur-vey Explorer (WISE) are all space missions that have produced stunning new scientific advances by going to space to observe in the infrared. This interim report describes progress as of June 2011 on developing a requirements flowdown and an evaluation of scientific performance. An Interim Design Reference Mission (IDRM) configuration is presented that is based on the specifications of NWNH with some refinements to optimize the design in accordance with the new scientific requirements. Analysis of this WFIRST IDRM concept is in progress to ensure the capability of the observatory is compatible with the science requirements. The SDT and Project will continue to refine the mission concept over the coming year as design, analysis and simulation work are completed, resulting in the SDT s WFIRST Design Reference Mission (DRM) by the end of 2012.

  3. Systematic Effects in Large Scale Angular Power Spectra and Implications for Constraining Primordial Non-gaussianity%宇宙大尺度结构和原初扰动非高斯性研究进展

    Institute of Scientific and Technical Information of China (English)

    杨圣

    2015-01-01

    宇宙微波背景辐射(CMB)探测和大尺度结构(LSS)巡天是两种研究宇宙演化的重要手段.近年来高精度的宇宙微波背景辐射实验和大尺度结构巡天可以对今天的宇宙学模型给出精确测量,比如宇宙曲率、暴胀模型参数和原初非高斯性等.宇宙大尺度结构的原初非高斯性揭示了在甚早期宇宙中引发大尺度结构的原初扰动的物理诱发机制,有效地对不同暴胀模型进行区分,是研究甚早期宇宙的有效工具和手段.但是最近的研究结果表明,很多大尺度结构巡天的数据被系统误差严重污染,如大气视宁度、天光背景等,这些误差导致由大尺度结构巡天数据给出的原初非高斯的研究结果与实际情况相差甚远.大尺度结构巡天数据的系统误差消除和它对限制宇宙原初非高斯性的改善,对更好地了解甚早期宇宙具有重要意义.%The cosmic microwave background radiation (CMBR) detection and the large scale structure (LSS) survey are two important tools to study on the evolution of the universe. The CMB experiment and the LSS detector could calculate and restrict on the cosmological parameters with very high precision, such as the curvature of the universe, the parameter of the inflation models and so on. The COBE satellite first showed the Non-Gaussianity among the observed CMB photons that in Gaussian distribution. The Primordial Non-Gaussianity (PNG) of the cosmic large scale structure explains the physical mechanism why there should exists a primordial perturbation and how it forms the large scale structure today in the very early universe. Also, it can help researcher to distinguish between different inflation models, and it is an effective tool for us to study very early universe. But recent research papers have shown that the large scale structure survey's data may be polluted badly by some systematic errors, such as seeing, airmass, sky brightness and so on, which would cause a

  4. Predicting the sky from 30 MHz to 800 GHz: the extended Global Sky Model

    Science.gov (United States)

    Liu, Adrian

    We propose to construct the extended Global Sky Model (eGSM), a software package and associated data products that are capable of generating maps of the sky at any frequency within a broad range (30 MHz to 800 GHz). The eGSM is constructed from archival data, and its outputs will include not only "best estimate" sky maps, but also accurate error bars and the ability to generate random realizations of missing modes in the input data. Such views of the sky are crucial in the practice of precision cosmology, where our ability to constrain cosmological parameters and detect new phenomena (such as B-mode signatures from primordial gravitational waves, or spectral distortions of the Cosmic Microwave Background; CMB) rests crucially on our ability to remove systematic foreground contamination. Doing so requires empirical measurements of the foreground sky brightness (such as that arising from Galactic synchrotron radiation, among other sources), which are typically performed only at select narrow wavelength ranges. We aim to transcend traditional wavelength limits by optimally combining existing data to provide a comprehensive view of the foreground sky at any frequency within the broad range of 30 MHz to 800 GHz. Previous efforts to interpolate between multi-frequency maps resulted in the Global Sky Model (GSM) of de Oliveira-Costa et al. (2008), a software package that outputs foreground maps at any frequency of the user's choosing between 10 MHz and 100 GHz. However, the GSM has a number of shortcomings. First and foremost, the GSM does not include the latest archival data from the Planck satellite. Multi-frequency models depend crucially on data from Planck, WMAP, and COBE to provide high-frequency "anchor" maps. Another crucial shortcoming is the lack of error bars in the output maps. Finally, the GSM is only able to predict temperature (i.e., total intensity) maps, and not polarization information. With the recent release of Planck's polarized data products, the

  5. The Cosmic Microwave Background & Inflation, Then & Now

    Science.gov (United States)

    Bond, J. Richard; Contaldi, Carlo; Pogosyan, Dmitry; Mason, Brian; Myers, Steve; Pearson, Tim; Pen, Ue-Li; Prunet, Simon; Readhead, Tony; Sievers, Jonathan

    2002-12-01

    The most recent results from the Boomerang, Maxima, DASI, CBI and VSA CMB experiments significantly increase the case for accelerated expansion in the early universe (the inflationary paradigm) and at the current epoch (dark energy dominance). This is especially so when combined with data on high redshift supernovae (SN1) and large scale structure (LSS), encoding information from local cluster abundances, galaxy clustering, and gravitational lensing. There are ``7 pillars of Inflation'' that can be shown with the CMB probe, and at least 5, and possibly 6, of these have already been demonstrated in the CMB data: (1) the effects of a large scale gravitational potential, demonstrated with COBE/DMR in 1992-96 (2) acoustic peaks/dips in the angular power spectrum of the radiation, which tell about the geometry of the Universe, with the large first peak convincingly shown with Boomerang and Maxima data in 2000, a multiple peak/dip pattern shown in data from Boomerang and DASI (2nd, 3rd peaks, first and 2nd dips in 2001) and from CBI (2nd, 3rd, 4th, 5th peaks, 3rd, 4th dips at 1-sigma in 2002) (3) damping due to shear viscosity and the width of the region over which hydrogen recombination occurred when the universe was 400000 years old (CBI 2002) (4) the primary anisotropies should have a Gaussian distribution (be maximally random) in almost all inflationary models, the best data on this coming from Boomerang; (5) secondary anisotropies associated with nonlinear phenomena subsequent to 400000 years, which must be there and may have been detected by CBI and another experiment, BIMA. Showing the 5 ``pillars'' involves detailed confrontation of the experimental data with theory; e.g., (5) compares the CBI data with predictions from two of the largest cosmological hydrodynamics simulations ever done. DASI, Boomerang and CBI in 2002, AMiBA in 2003, and many other experiments have the sensitivity to demonstrate the next pillar, (6) polarization, which must be there at the ~ 7

  6. Stem cell harvesting protocol research in autologous transplantation setting: Large volume vs. conventional cytapheresis

    Directory of Open Access Journals (Sweden)

    Balint Bela

    2008-01-01

    Full Text Available Background/Aim. The use of peripheral blood as a source of hematopoietic stem cells (SCs is progressively increasing and has nearly supplanted bone marrow transplantation. Interpatient variability in the degree and kinetics of SC mobilization into peripheral blood is an expected event after conventional chemotherapy-based treatment, followed by sequential administration of recombinant granulocyte-colony- stimulating factor (rHu-CSF. In this study, specific factors associated with the application of two different SC-harvesting approaches, including the use of large volume leukapheresis (LVL vs. repetitive conventional apheresis (RCA, were analyzed. The basic goal of the study was to evaluate the influence of apheresis protocol (collection timing, processed blood volume and cell yield upon the clinical outcome of transplantation. Methods. Results obtained by LVL (76 pts and RCA (20 pts - control group were compared. The SC mobilizing regimen used was cyclophosphamide (4-7 g/m2 or polychemotherapy and rHuG-CSF 10-16 μg/kg of body mess (bm per day. Cell harvesting was performed using COBE-Spectra (Caridian-BCT, USA. The volume of processed blood in LVL setting was ≥ 3.5 - fold of the patient's circulating blood quantity (ranged from 12.7 to 37.8 l. All patients tolerated well the use of intensive treatment, without any side or adverse effects. Our original controlled-rate cryopreservation was carried out with 10% dimethyl sulfoxide (DMSO using Planer R203/200R or Planer 560-16 equipments (Planer Products Ltd, UK. Total nucleated cell (NC and mononuclear cell (MNC counts were examined by flow cytometry (Advia-2120 Bayer, Germany; Technicon H-3 System, USA. The CD34+ cell surface antigen was investigated by the EPICS XL-MCL device (Coulter, Germany. Results. Performing LVL-apheresis, high-level MNC and CD34+ cell yields (7.6±4.6 × 108/kg bm and 11.8±6.5 × 106/kg bm, respectively were obtained. As a result, rapid hematopoietic reconstitution

  7. 银盘外区的翘曲结构%Warp of the Outer Region of the Galactic Disc

    Institute of Scientific and Technical Information of China (English)

    赵君亮

    2011-01-01

    .In addition to the population I objects, molecular clouds and interstellar dust have also been observed to study the large scale structure of the outer Galaxy, and some interesting conclusions have been obtained. For example, the ensemble of clouds shows the same warped shape and flaring thickness as shown by the outer Galaxy HI gas layer.Interstellar extinction remains a serious obstacle for observing stars near the Galactic plane. Since the extinction suffered in the near infrared is about an order of magnitudelower than in visible, the data provided recently by large scale infrared surveys, including IRAS, DENIS, DIRBE/COBE and 2MASS, have been used to investigate the warp and flare structure of our Galaxy. It is discovered from some studies that a feature of infrared point source counts can be interpreted as a signature of the warp in the Galactic older stellar disc. The warp is less obvious in stars than in the gas and it also shows different shapes of the disc at negative and positive longitudes.Up to date, it is not completely clear how the warped disc of the outer Galaxy was formed and whether the warp is a persistent feature of the Galaxy, or a transient phenomenon. Most recent work has focused on one of the following 3 possible mechanisms: (1) a satellite dwarf orbiting the Galaxy, such as the Large Magellanic Cloud or the Sagittarius dwarf galaxy, causes a warp by tidel interaction with the Galactic disc; (2) the warp is caused by infall and accretion of intergalactic medium onto the disc; (3) the warp can be formed by interaction between the outer Galactic disc and a triaxial or an oblate massive dark matter halo, misaligned with the disc. Anyway, further studies are needed to finally solve the puzzle of the formation mechanism of the Galactic warp.%银盘外区存在翘曲结构和近边增厚现象已是不争的观测事实.自20世纪50年代通过中性氢的射电观测发现此类结构以来,对不同示踪天体(包括各类星族1天体、分子云、

  8. PREFACE: The Sixth International Conference on Gravitation & Cosmology

    Science.gov (United States)

    Date, Ghanashyam; Souradeep, Tarun

    2008-07-01

    programme had 21 plenary talks on current theoretical, observational and experimental topics in Cosmology, General Relativity, detection of gravitational waves, and various approaches to Quantum gravity. The meeting also included three intensive parallel workshops focused on Cosmology, Classical General Relativity & Gravitational waves and Quantum Gravity, respectively. The workshops had around 75 oral presentations. The immensely rich and diverse scientific programme was highlighted in the concluding remarks by the late Professor Juergen Ehlers. A public lecture on `Oldest light in the Universe' by NASA scientist, Professor Gary Hinshaw, who is a member of the WMAP team (formerly, also a member of the COBE-DMR team that won the Nobel prize in 2006) was also organized as part of ICGC-07 and drew sizable audience from the public in Pune. The proceedings contains articles by the plenary speakers, the concluding remarks and a summary of each of the three workshops. We also include an obituary for Professor Juergen Ehlers, who passed away on 20 May 2008. The sentiments expressed in the obituary are shared by the editors and members of IAGRG. Professor Ehlers had participated very actively during the meeting and delivered an excellent concluding talk on the conference. We are indeed fortunate to able to include in this volume, what is perhaps, his last article. A possible reflection of the tight schedule of researchers in the booming period of research in Cosmology and Gravitation is the number of missing articles by plenary speakers. Due to various reasons, we were able to get only 11 of the 21 plenary talks for publication in this volume. In order to ensure that the volume is published within a year of the conference, we decided to publish the proceedings with the available articles. The meeting was financially supported by generous contribution from Indian organizations: ISRO, CSIR, DST, BNRS and IAGRG; and from Indian institutes: HRI (Allahabad), IIA (Bangalore), IMSc

  9. New water and remote galaxies complete ISO's observations

    Science.gov (United States)

    mapping parts of the sky at a wavelength of 200 microns. Activity concerning ISO will continue at the Villafranca ground station until the year 2001, long after the completion of the observational phase of the mission. During the space operations, the main objective was to make as many observations as possible. Thorough analysis and interpretation of the results will take several years. "We still have plenty to do," says Martin Kessler, ESA's project scientist for ISO. "Our team at Villafranca is preparing a complete archive of ISO data on 500-1000 compact disks, after reprocessing with improved software. We'll release part of this archive to the world-wide astronomical community in the autumn of this year, and the rest in 1999. We shall also advise the astronomers who have used ISO, about the particular requirements for handling the data from each instrument, and we'll be doing some astronomy ourselves. There are far more results still to come from ISO." Europe's infrared astronomers are already busy preparing ESA's FIRST and Planck missions, due for launch early in the new century. FIRST will observe long infrared wavelengths in the sub-millimetre range, while Planck will map the cosmic microwave background far more accurately than NASA's COBE mission did, to reveal the clumps of matter from which galaxies evolved. Also under study by ESA is a possible interferometer mission using a combination of infrared telescopes. In principle it might observe and characterize planets in orbit around other stars. Meanwhile, Europe's space astronomy programme continues apace in other directions. ESA's participation in the Hubble Space Telescope and its eventual successor assures access to those important instruments for Europe's astronomers. The release in 1997 of the catalogues from ESA's unique star-mapping mission Hipparcos provided all astronomer with amazingly precise data for sizing up the stars and the wider Universe. Next year will see the launch of ESA's XMM satellite to