Science.gov

Sample records for beta sources

  1. Bremsstrahlung from cylindrical beta sources.

    NASA Technical Reports Server (NTRS)

    Harris, D. W.; Silverman, J.

    1972-01-01

    Refined experimental measurements of the bremsstrahlung number and energy fluxes from thick cylindrical sources of several nuclides are presented, dose rates calculated from experimental energy fluxes are compared with theoretical results based on Wyard's thick-target approximation, and experiments are correlated with both thick- and thin-target bremsstrahlung theory to obtain accurate values of bremsstrahlung yields. The data presented should prove useful for the design of radioisotope power supplies, particularly those used in spacecraft and in biological applications.

  2. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply superficial...

  3. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply superficial...

  4. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply superficial...

  5. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply superficial...

  6. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply superficial...

  7. Beta-cryptoxanthin as a source of vitamin A.

    PubMed

    Burri, Betty J

    2015-07-01

    Beta-cryptoxanthin is a common carotenoid that is found in fruit, and in human blood and tissues. Foods that are rich in beta-cryptoxanthin include tangerines, persimmons and oranges. Beta-cryptoxanthin has several functions that are important for human health, including roles in antioxidant defense and cell-to-cell communication. Most importantly, beta-cryptoxanthin is a precursor of vitamin A, which is an essential nutrient needed for eyesight, growth, development and immune response. We evaluate the evidence for beta-cryptoxanthin as a vitamin A-forming carotenoid in this paper. Observational, in vitro, animal model and human studies suggest that beta-cryptoxanthin has greater bioavailability from its common food sources than do alpha- and beta-carotene from theirs. Although beta-cryptoxanthin appears to be a poorer substrate for beta-carotene 15,15' oxygenase than is beta-carotene, animal model and human studies suggest that the comparatively high bioavailability of beta-cryptoxanthin from foods makes beta-cryptoxanthin-rich foods equivalent to beta-carotene-rich foods as sources of vitamin A. These results mean that beta-cryptoxanthin-rich foods are probably better sources of vitamin A, and more important for human health in general, than previously assumed. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  8. The genus Rhodosporidium: a potential source of beta-carotene.

    PubMed

    de Miguel, T; Calo, P; Díaz, A; Villa, T G

    1997-03-01

    Four wild-type species of the genus Rhodosporidium have been studied as as possible sources for the industrial production of beta-carotene. HPLC-based studies showed that their carotenoid composition consisted of almost pure beta-carotene at concentrations ranging from 226 to 685 micrograms/g of dried yeast biomass. These results are consistent with those obtained by spectrophotometry at 480 nm.

  9. Dose distributions in regions containing beta sources: Irregularly shaped source distributions in homogeneous media

    SciTech Connect

    Werner, B.L. )

    1991-11-01

    Methods are introduced by which dose rate distributions due to nonuniform, irregularly shaped distributions of beta emitters can be calculated using dose rate distributions for uniform, spherical source distributions. The dose rate distributions can be written in the MIRD formalism.

  10. Radioactive check sources for alpha and beta sensitive radiological instrumentation

    SciTech Connect

    Barnett, J.M.; Kane, J.E. II

    1994-06-01

    Since 1991, the Westinghouse Hanford Company has examined the construction and use of alpha and beta radioactive check sources for calibrating instruments and for performing response checks of instruments used for operational and environmental radiation detection. The purpose of using a radioactive check source is to characterize the response of a radiation monitoring instrument in the presence of radioactivity. To accurately calibrate the instrument and check its response, the check source used must emulate as closely as possible the actual physical and isotopic conditions being monitored. The isotope employed and the physical methods used to fabricate the check source (among other factors) determine instrument response. Although information from applicable national and international standards, journal articles, books, and government documents was considered, empirical data collected is most valuable when considering the type of source to use for a particular application. This paper presents source construction methods, use considerations, and standard recommendations. The results of a Hanford Site evaluation of several types of alpha and beta sources are also given.

  11. Beta-Cryptoxanthin as a source of Vitamin A.

    USDA-ARS?s Scientific Manuscript database

    Beta-cryptoxanthin is a common carotenoid that is found in fruit, and in human blood and tissues. Foods that are rich in beta-cryptoxanthin include tangerines, persimmons, and oranges. Beta-cryptoxanthin has several functions that are important for human health, including roles in antioxidant defens...

  12. Single Molecule Source Reagents for CVD of Beta Silicon Carbide

    DTIC Science & Technology

    1991-06-30

    Beta silicon carbide is an excellent candidate semiconductor material for demanding applications in high power and high temperature electronic...devices due to its high breakdown voltage, relatively large band gap, high thermal conductivity and high melting point. Use of silicon carbide thin films is...equipment has been used in the CVD systems, but small disparities remain between successive deposited films. The production of practical beta silicon carbide devices

  13. Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis

    USGS Publications Warehouse

    Welch, Alan H.

    1995-01-01

    Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements.Although40K and228Ra appear to be the primary sources of beta activity in ground water, the sum of40K plus228Ra appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities > 10 pCi/L, where these 2 radionuclides account for less than one-half the measured ross-beta activity. One exception is groundwater from the Coastal Plain of New Jersey, where40K plus228Ra generally contribute most of the gross-beta activity. In contrast,40K and228Ra generally contribute most of beta activity in ground water with gross-beta activities < 1 pCi/L.The gross-beta technique does not measure all beta activity in ground water. Although3H contributes beta activity to some ground water, it is driven from the sample before counting and therefore is not detected by gross-beta measurements. Beta-emitting radionuclides with half-lives shorter than a few days can decay to low values between sampling and counting. Although little is known about concentrations of most short-lived beta-emitting radionuclides in environmental ground water (water unaffected by direct releases from nuclear facilities and weapons tests), their

  14. Evaluation of the beta energy spectrum from a distributed uranium mill tailings source

    SciTech Connect

    Reif, R.H.; Martz, D.E.; Carlson, D.S.; Turner, J.B. )

    1993-10-01

    The beta energy spectra from uranium mill tailings, 90Sr with different absorber thicknesses, and a uranium metal slab were measured and compared to select an appropriate beta source for calibrating a personal dosimeter to measure shallow dose equivalent when exposed to uranium mill tailings. The measured beta energy spectrum from the 90Sr source, with a 111 mg cm-2 cover thickness, was selected as a possible calibration source for a personnel dosimeter. The dose equivalent rate to the skin at 1 cm from a distributed tailings source of infinite thickness, with a 226Ra activity of 56 Bq g-1 (1.5 x 10(3) pCi g-1), was measured to be 0.024 mSv h-1 (2.4 mrem h-1).

  15. Evaluation of the beta energy spectrum from a distributed uranium mill tailings source.

    PubMed

    Reif, R H; Martz, D E; Carlson, D S; Turner, J B

    1993-10-01

    The beta energy spectra from uranium mill tailings, 90Sr with different absorber thicknesses, and a uranium metal slab were measured and compared to select an appropriate beta source for calibrating a personal dosimeter to measure shallow dose equivalent when exposed to uranium mill tailings. The measured beta energy spectrum from the 90Sr source, with a 111 mg cm-2 cover thickness, was selected as a possible calibration source for a personnel dosimeter. The dose equivalent rate to the skin at 1 cm from a distributed tailings source of infinite thickness, with a 226Ra activity of 56 Bq g-1 (1.5 x 10(3) pCi g-1), was measured to be 0.024 mSv h-1 (2.4 mrem h-1).

  16. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    SciTech Connect

    Burns, R.E. Jr.; O`Brien, J.M. Jr.

    1993-12-31

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison.

  17. Beta4 tubulin identifies a primitive cell source for oligodendrocytes in the mammalian brain.

    PubMed

    Wu, Chuanshen; Chang, Ansi; Smith, Maria C; Won, Roy; Yin, Xinghua; Staugaitis, Susan M; Agamanolis, Dimitri; Kidd, Grahame J; Miller, Robert H; Trapp, Bruce D

    2009-06-17

    We have identified a novel population of cells in the subventricular zone (SVZ) of the mammalian brain that expresses beta4 tubulin (betaT4) and has properties of primitive neuroectodermal cells. betaT4 cells are scattered throughout the SVZ of the lateral ventricles in adult human brain and are significantly increased in the SVZs bordering demyelinated white matter in multiple sclerosis brains. In human fetal brain, betaT4 cell densities peak during the latter stages of gliogenesis, which occurs in the SVZ of the lateral ventricles. betaT4 cells represent <2% of the cells present in neurospheres generated from postnatal rat brain but >95% of cells in neurospheres treated with the anti-mitotic agent Ara C. betaT4 cells produce oligodendrocytes, neurons, and astrocytes in vitro. We compared the myelinating potential of betaT4-positive cells with A2B5-positive oligodendrocyte progenitor cells after transplantation (25,000 cells) into postnatal day 3 (P3) myelin-deficient rat brains. At P20, the progeny of betaT4 cells myelinated up to 4 mm of the external capsule, which significantly exceeded that of transplanted A2B5-positive progenitor cells. Such extensive and rapid mature CNS cell generation by a relatively small number of transplanted cells provides in vivo support for the therapeutic potential of betaT4 cells. We propose that betaT4 cells are an endogenous cell source that can be recruited to promote neural repair in the adult telencephalon.

  18. Investigation of the effect of beta source and phosphors on photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Yürük, Reyyan Kavak; Tütüncüler, Hayriye

    2017-02-01

    In this study, conversion of kinetic energy from the decay of a radioactive isotope to electricity is investigated by using the direct and the indirect conversion methods. In this context, simple nuclear battery models are designed. Analysis for the effect of low-activity radiation from Pm147 and Sr90 beta sources on photovoltaic Si solar cell is presented. Beta radioluminescence nuclear battery models consist of a beta source, a phosphor layer and a solar cell. Phosphor layers with different mass thicknesses are prepared from ZnS:CuCl and SrAl2O4:Eu2+,Dy3+ phosphors. Both the influence of beta sources and the phosphor layers on battery performance is analyzed separately. Effect of beta sources, phosphors are observed on solar cell by measuring the short circuit current and open circuit voltage. The efficiency of the battery models is determined with the obtained results. Furthermore, short circuit current values are analyzed at various times during the irradiation.

  19. Effects of purified dietary fiber sources on beta-carotene utilization by the chick.

    PubMed

    Erdman, J W; Fahey, G C; White, C B

    1986-12-01

    Effects of various purified dietary fiber components on beta-carotene utilization by the chick were investigated in two experiments (expt.). Eight-day-old Columbian X New Hampshire male (expt. 1) or female (expt. 2) chicks were fed a vitamin A-deficient diet for 1 wk and then fed beta-carotene-supplemented diets containing 0% fiber, 7% arenaceous flour or 7% of a purified fiber source for 4 wk. Results of expt. 1 showed that hemicellulose, lignin and citrus pectin, but not arenaceous flour or polygalacturonic acid, depressed beta-carotene utilization by the chick, as measured by percentage of consumed beta-carotene stored in liver as vitamin A relative to the 0% fiber control. In expt. 2, effects of the methoxyl content of pectin were studied. High and medium methoxyl apple pectin, citrus pectin and polygalacturonic acid reduced storage of vitamin A in liver. Low methoxyl apple pectin had no significant effect on beta-carotene utilization. Thus, several purified forms of dietary fiber significantly reduced beta-carotene utilization by chicks when fed at the 7% supplementary level. Moreover, with pectin, there was an inverse relationship between methoxyl content of pectin and beta-carotene utilization.

  20. Synthesis of labeled compounds using recovered tritium from expired beta light sources

    SciTech Connect

    Matei, L.; Postolache, C.; Bubueanu, G.; Podina, C.

    2008-07-15

    In this paper, the technological procedures for extracting tritium from beta light source are highlighted. The recovered tritium was used in the synthesis of organically labeled compounds and in the preparation of tritiated water (HTO) with high specific activity. Technological procedures for treatment of beta light sources consist of: envelope breaking into evacuated enclosure, the radioactive gaseous mixture pumping and its storage on metallic sodium. The mixtures of T{sub 2} and {sup 3}He were used in the synthesis of tritium labeled steroid hormones, nucleosides analogues and for the preparation of HTO with high radioactivity concentrations. (authors)

  1. A novel method for the activity measurement of large-area beta reference sources.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ioan, M R

    2016-03-01

    A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ((60)Co and (137)Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity.

  2. Single Molecule Source Reagents for CVD of Beta Silicon Carbide

    DTIC Science & Technology

    1991-08-31

    silicon carbide is an excellent candidate semiconductor material for demanding applications in high power and high temperature electronic devices due to its high breakdown voltage, relatively large band gap, high thermal conductivity and high melting point. Use of silicon carbide thin films is hampered, however, by the inability to reproducibly grow stoichiometric films free from excess silicon or carbon. The principal difficulty is that absolutely reproducible flows of the source gases cannot be provided with existing gas flow control equipment. The

  3. Microwaves as an energy source for producing beta-SiC.

    PubMed

    Aguilar, J; Rodríguez, J; Hinojosa, M

    2001-01-01

    This work describes the production of silicon carbide using microwaves as the energy source, which was supplied by means of variable power, up to 2000 Watts, magnetron operating at 2.45 GHz. The obtained samples were analyzed by means of X-ray diffraction and observed with electron microscopy (SEM). Temperatures achieved were around 2000 degrees C, which is the upper limit for the beta-SiC growth regime, before getting other SiC polytypes. Analysis of different portions of the sample showed that beta-SiC was the only formed compound, although free SiO2 and graphite were also present. Observations made by SEM demonstrated different crystal growth regime, meaning that thermal conditions were not totally uniform. The amount of beta-SiC found and the relative simplicity of the device prove that production of this material from silica and graphite is possible by applying microwaves as an energy source.

  4. Reconstruction of external dose from beta radiation sources of nuclear weapon origin.

    PubMed

    Barss, Neil M; Weitz, Ronald L

    2006-10-01

    In response to requests from the Department of Veterans Affairs, a methodology was developed to assess the external dose accrued by personnel in the vicinity of beta radiation sources of nuclear weapon origin. This methodology has been applied in support of the Nuclear Test Personnel Review (NTPR) Program implemented by the Department of Defense. As required by the Code of Federal Regulations (Title 32, Part 218 and Title 38, Part 3.311), the NTPR Program must evaluate radiological hazards from nuclear testing activities that include alpha particle, beta particle, neutron, and photon emissions from radionuclides. Prior to the development of this methodology, only photon and neutron radiations were explicitly quantified for external dose assessments in this program. Alpha radiation of external origin presents no risk for biological effects due to external dose potential to skin tissue because of the particle's very limited range. However, beta particles are sufficiently penetrating to have such potential. Methods are provided to quantify ionizing radiation doses to the skin and lens of the eye from beta radiation sources of nuclear weapon origin located external to the body. This formulation allows the estimation of beta dose from a film badge (gamma) dose or from an equivalent reconstructed gamma dose.

  5. Numerical modeling of large-area beta sources constructed from anodized-aluminum foils.

    PubMed

    Stanga, D

    2012-09-01

    The numerical modeling of large-area beta sources constructed from anodized-aluminum foils is described in this paper. Based on a realistic model for the activity depth distribution, theoretical lower and upper bounds for the efficiency and the transmission coefficient were calculated and used to analyze the comparison method recommended by ISO 8769 for measuring the surface emission rate. The analysis shows that this method can provide measurement results with relative standard uncertainties smaller than 3% for high energy beta emitters such as (90)Sr-(90)Y, (36)Cl and (204)Tl.

  6. Spatial analysis and source profiling of beta-agonists and sulfonamides in Langat River basin, Malaysia.

    PubMed

    Sakai, Nobumitsu; Yusof, Roslan Mohd; Sapar, Marni; Yoneda, Minoru; Mohd, Mustafa Ali

    2016-04-01

    Beta-agonists and sulfonamides are widely used for treating both humans and livestock for bronchial and cardiac problems, infectious disease and even as growth promoters. There are concerns about their potential environmental impacts, such as producing drug resistance in bacteria. This study focused on their spatial distribution in surface water and the identification of pollution sources in the Langat River basin, which is one of the most urbanized watersheds in Malaysia. Fourteen beta-agonists and 12 sulfonamides were quantitatively analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A geographic information system (GIS) was used to visualize catchment areas of the sampling points, and source profiling was conducted to identify the pollution sources based on a correlation between a daily pollutant load of the detected contaminant and an estimated density of human or livestock population in the catchment areas. As a result, 6 compounds (salbutamol, sulfadiazine, sulfapyridine, sulfamethazine, sulfadimethoxine and sulfamethoxazole) were widely detected in mid catchment areas towards estuary. The source profiling indicated that the pollution sources of salbutamol and sulfamethoxazole were from sewage, while sulfadiazine was from effluents of cattle, goat and sheep farms. Thus, this combination method of quantitative and spatial analysis clarified the spatial distribution of these drugs and assisted for identifying the pollution sources. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Beta planar source quality assurance with the Fricke xylenol gel dosimeter

    NASA Astrophysics Data System (ADS)

    Alva-Sánchez, Mirko S.; de Oliveira, Lucas N.; Petchevist, Paulo C.; Moreira, Marco V.; de Almeida, Adelaide

    2014-03-01

    Beta therapy is employed in post surgery to treat lesions such as pterygia, keloid and glioblastoma. The beta source most used for these purposes is 90/90Y, whose quality assurance is a challenge, because the detectors currently used for this evaluation do not satisfy the spatial resolution, the effective atomic number and the tissue equivalent conditions. The Fricke xylenol gel (FXG) has been used in several applications in radiotherapy due to its better characteristics. This dosimeter is associated with the Fe(II) to Fe(III) oxidation, post ionizing irradiation, being the final Fe(III) concentration linearly depended on the absorbed dose. The goal of this present work is to show that the FXG, with atomic effective number (Zeff) of 7.75 and high resolution (<1 mm), accomplishes quality assurance for rectangular and square planar 90Sr/90Y sources. In order to demonstrate the quality assurance, calibration curves, percentage depth dose and beam profile from exposed FXG samples were analyzed and from these results, we demonstrate the potential use of the FXG dosimeter for beta source quality control.

  8. Doses from radon progeny as a source of external beta and gamma radiation.

    PubMed

    Markovic, V M; Krstic, D; Nikezic, D; Stevanovic, N

    2012-11-01

    Great deal of work has been devoted to determine doses from alpha particles emitted by (222)Rn and its progeny. In contrast, contribution of beta particles and following gamma radiation to total dose has mostly been neglected so far. The present work describes a study of the detriment of (222)Rn progeny for humans due to external exposure. Doses and dose conversion factors (DCFs) were determined for beta and gamma radiation in main organs and remainder tissue of the Oak Ridge National Laboratory phantom, taking into account (222)Rn progeny (214)Pb and (214)Bi distributed in the middle of a standard or typical room with dimensions 4 m × 5 m × 2.8 m. The DCF was found to be 7.37 μSv/WLM. Skin and muscle tissue from remainder tissue receives largest dose. Beta and gamma radiation doses from external exposure were compared with alpha, beta, and gamma doses from internal exposure where the source of radioactivity was the lungs. Total doses received in all main organs and remainder tissues were obtained by summing up the doses from external and internal exposure and the corresponding DCF was found to be 20.67 μSv/WLM.

  9. Terrestrial isopods congregate under a low-level beta-emitter source.

    PubMed

    Kanao, Tomoko; Miyachi, Yukihisa; Yamada, Takeshi

    2002-01-01

    Ionizing radiation is ubiquitous, but very few experiments have investigated the biological effects of the natural background radiation at very low doses (>10 mGy/yr). We examined whether the background radiation, or radiation of a slightly higher level, has a role in evoking changes in behaviors of terrestrial isopods (woodlice). Upon exposure to a source giving 15 times the background level placed at one end of a box, a significant increase in the number of woodlice gathering under the beta-source was observed with time, as compared with the sham control. Terrestrial isopods have chemoreceptors (the olfactory system) on the terminal segment of their antennae. An additional experiment confirmed the involvement of these antennae in the radiation effect on behavior. After the excision of the antennae, no beta-taxis response was observed. The behavior of the group exposed to the source giving 30 times the background tended to decrease gradually in the area of the source, and the individuals aggregated in the area away from the source. Thus, the olfactory sensor in the antennae may be an important organ involved in the prompt response to radiation exposure, and the discrimination of the radiation field strengths of radioisotopes.

  10. Dose distributions in regions containing beta sources: Uniform spherical source regions in homogeneous media

    SciTech Connect

    Werner, B.L.; Rahman, M.; Salk, W.N. ); Kwok, C.S. )

    1991-11-01

    The energy-averaged transport model for the calculation of dose rate distributions is applied to uniform, spherical source distributions in homogeneous media for radii smaller than the electron range. The model agrees well with Monte Carlo based calculations for source distributions with radii greater than half the continuous slowing down approximation range. The dose rate distributions can be written in the medical internal radiation dose (MIRD) formalism.

  11. Marine ciliates as a widespread source of tetrahymanol and hopan-3. beta. -ol in sediments

    SciTech Connect

    Harvey, H.R.; McManus, G.B. )

    1991-11-01

    The authors observed tetrahymanol (gammaceran-3{beta}-ol) as a principal neutral lipid in eight marine ciliate species, most of which were scuticociliates, a group of ciliates that feeds mainly on bacteria. Tetrahymanol abundance in pure cultures and field samples (sediment traps, water column particulates, and enrichments from coastal and estuarine environments) shows good agreement with ciliate biovolume (R{sup 2} = 0.89), suggesting that tetrahymanol is a specific marker for marine ciliates that feed on bacteria. Hopan-3{beta}-ol was also positively identified in several ciliates, but did not occur in all species examined. Because of their widespread distribution in modern marine systems, these organisms provide a likely source for the common appearance of tetrahymanol in many marine sediments. By analogy, the presumed presence of ciliates in ancient seas may explain the occurrence of its diagenetic product, gammacerane, in more mature sediments and crude oils.

  12. Determination of the direction to a source of antineutrinos via inverse beta decay in Double Chooz

    NASA Astrophysics Data System (ADS)

    Nikitenko, Ya.

    2016-11-01

    To determine the direction to a source of neutrinos (and antineutrinos) is an important problem for the physics of supernovae and of the Earth. The direction to a source of antineutrinos can be estimated through the reaction of inverse beta decay. We show that the reactor neutrino experiment Double Chooz has unique capabilities to study antineutrino signal from point-like sources. Contemporary experimental data on antineutrino directionality is given. A rigorous mathematical approach for neutrino direction studies has been developed. Exact expressions for the precision of the simple mean estimator of neutrinos' direction for normal and exponential distributions for a finite sample and for the limiting case of many events have been obtained.

  13. Analysis and experimental verification of neutron-activated LiF as a stable matrix for tritium beta sources

    NASA Astrophysics Data System (ADS)

    Nullmeyer, Bradley R.; Kwon, Jae W.; Gahl, John M.; Dobey, Ronald J.; Gunn, Gregory; Flagg, Michael; Herbold, Carl

    2017-03-01

    Tritium (3H) has long been considered a useful radioisotope for many purposes due to its low-energy and pure beta decay. However, due to its aggressive migration, solid-state retention of tritium for use as a beta radiation source is challenging. Bulk-level infusion of tritium in a solid is often employed as a solution to effusion and outgassing but limits the beta radiation output due to the use of high-Z materials. This letter presents experimental and simulated analysis regarding the production and efficacy of a low-Z, solid-state tritium beta source. Single-crystal lithium fluoride (LiF) is used as a host matrix for tritium radionuclides, which are generated by the 6Li(n,α)3H reaction when the crystal is exposed to thermal neutron irradiation. The experimental findings present negligible outgassing of tritium from the material, while the simulation results suggest thickness optimization of the LiF/3H beta source. Moreover, the simulation results indicate significantly enhanced beta output efficiency compared to palladium tritide, which is a state-of-the-art tritium host. With proper thickness, the tritium-filled LiF matrix is a stable low energy beta source, which can be easily produced and incorporated into a variety of applications.

  14. Development of A phantom for ophthalmic beta source applicator quality control using TL dosimetry

    NASA Astrophysics Data System (ADS)

    Barbosa, N. A.; da Rosa, L. A. R.; Braz, D.

    2015-11-01

    Concave eye applicators with 90Sr/90Y and 106Ru/106Rh beta ray sources are usually used in brachytherapy for the treatment of superficial intraocular tumors as uveal melanoma with thickness up to 5 mm. The calculation of the dose delivered to the eye is carried out based on the data present in the beta source calibration certificate. Therefore, it would be interesting to have a system that could evaluate that dose. In this work, an eye phantom to be used with 106Ru/106Rh betatherapy applicators was developed in solid water. This phantom can hold nine micro-cube thermoluminescent (TL) dosimeters, TLD-100. The characteristics of the TL response of the dosimeters, namely reproducibility and individual sensitivity, were determined for a 60Co source. Using Monte Carlo code MCNPX, the dose to a water eye was determined at different depths. Exposing the eye phantom with TL dosimeters to the 106Ru/106Rh applicator, it is possible to assess calibration factors using the dose values obtained by Monte Carlo simulation to each depth. Using mean calibration factors, dose values obtained by TL dosimetry were compared to the data present in the applicators certificate. Mean differences for both applicators were lower than ±10%, maximum value 17% and minimum value 0.08%. Considering that the certificate values present an uncertainty of ±20%, the calibration procedure and the developed phantom are validated and can be applied.

  15. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    SciTech Connect

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  16. Monte Carlo calculated TG-60 dosimetry parameters for the {beta}{sup -} emitter {sup 153}Sm brachytherapy source

    SciTech Connect

    Sadeghi, Mahdi; Taghdiri, Fatemeh; Hamed Hosseini, S.; Tenreiro, Claudio

    2010-10-15

    Purpose: The formalism recommended by Task Group 60 (TG-60) of the American Association of Physicists in Medicine (AAPM) is applicable for {beta} sources. Radioactive biocompatible and biodegradable {sup 153}Sm glass seed without encapsulation is a {beta}{sup -} emitter radionuclide with a short half-life and delivers a high dose rate to the tumor in the millimeter range. This study presents the results of Monte Carlo calculations of the dosimetric parameters for the {sup 153}Sm brachytherapy source. Methods: Version 5 of the (MCNP) Monte Carlo radiation transport code was used to calculate two-dimensional dose distributions around the source. The dosimetric parameters of AAPM TG-60 recommendations including the reference dose rate, the radial dose function, the anisotropy function, and the one-dimensional anisotropy function were obtained. Results: The dose rate value at the reference point was estimated to be 9.21{+-}0.6 cGy h{sup -1} {mu}Ci{sup -1}. Due to the low energy beta emitted from {sup 153}Sm sources, the dose fall-off profile is sharper than the other beta emitter sources. The calculated dosimetric parameters in this study are compared to several beta and photon emitting seeds. Conclusions: The results show the advantage of the {sup 153}Sm source in comparison with the other sources because of the rapid dose fall-off of beta ray and high dose rate at the short distances of the seed. The results would be helpful in the development of the radioactive implants using {sup 153}Sm seeds for the brachytherapy treatment.

  17. Experimental evidence for beta-decay as a source of chirality by enantiomer analysis

    NASA Technical Reports Server (NTRS)

    Bonner, W. A.

    1984-01-01

    Earlier experiments testing the Vester-Ulbricht beta-decay hypothesis for the origin of molecular chirality are reviewed, followed by descriptions of experiments involving attempted asymmetric radiolysis of DL-amino acids using quantitative gas chromotography as a probe for optical activity. The radiation sources included Sr-90-Y-90, C-14, and P-32 Bremsstrahlen, longitudinally polarized electrons from a linear accelerator and longitudinally polarized protons from a cyclotron. With the possible exception of the linear accelerator irradiations, these experiments failed to produce g.c.-detectable enantiomeric excesses, even at 50-70 percent gross radiolysis. Thus no unambiguous support for the Vester-Ulbricht hypothesis is found in any of the attempted asymmetric radiolyses performed to date. Radioracemization, a possible reason for these failures, is discussed.

  18. Experimental evidence for beta-decay as a source of chirality by enantiomer analysis.

    PubMed

    Bonner, W A

    1984-01-01

    Earlier experiments testing the Vester-Ulbricht beta-decay hypothesis for the origin of molecular chirality are reviewed, followed by descriptions of our own experiments involving attempted asymmetric radiolysis of DL-amino acids using quantitative gas chromotography as a probe for optical activity. Our radiation sources included 90Sr-90Y, 14C and 32P Bremsstrahlen, longitudinally polarized electrons from a linear accelerator and longitudinally polarized protons from a cyclotron. With the possible exception of the linear accelerator irradiations, these experiments failed to produce g.c.-detectable enantiomeric excesses, even at 50-70% gross radiolysis. We thus find no unambiguous support for the Vester-Ulbricht hypothesis in any of the attempted asymmetric radiolyses performed to date. Radioracemization, a possible reason for these failures, is discussed.

  19. Determination of half-value thickness of aluminum foils for different beta sources by using fractional calculus

    NASA Astrophysics Data System (ADS)

    Şen, Mürsel; Çalık, Abdullah Engin; Ertik, Hüseyin

    2014-09-01

    Reduction of beta-ray intensity with respect to thickness of absorber material exhibits a non-exponential behavior due to the different types of the energy loss processes and many different fractal-like paths followed by beta particles in material. According to Caputo formalism of fractional calculus, the reduction process of beta-ray intensity is governed by using a simple fractional differential equation of order α ≈ 0.31. The solution is obtained in terms of Mittag-Leffler function which depends on a mass attenuation coefficient μm and a fractional order α that can be considered as a measure of fractality of absorbing material. In the experimental part of the study, 99Tc, 36Cl, 14C, 210Pb and 147Pm radioisotopes have been used as beta sources. In the framework of fractional calculus approach, the experimental and calculated half-value thicknesses of all samples have been obtained in agreement with each other.

  20. Adult pancreatic alpha-cells: a new source of cells for beta-cell regeneration.

    PubMed

    Chung, Cheng-Ho; Levine, Fred

    2010-01-01

    Beta-cell deficit is the major pathological feature in type 1 and type 2 diabetes patients, and plays a key role in disease progression. In principle, beta-cell regeneration can occur by replication of pre-existing beta-cells, or by beta-cell neogenesis from stem/progenitors. Unfortunately, beta-cell replication is limited by the almost complete absence of beta-cells in patients with type 1 diabetes, and the increasing recognition that the beta-cell replicative capacity declines severely with age. Therefore, beta-cell neogenesis has received increasing interest. Many different cell types within the pancreas have been suggested as potential beta-cell stem/progenitor cells, but the data have been conflicting. In some cases, this may be due to different regeneration models. On the other hand, different results have been obtained with similar regeneration models, leading to confusion about the nature and existence of beta-cell neogenesis in adult animals. Here, we review the major candidates for adult regeneration pathways, and focus on the recent discovery that alpha-cells can function as a novel beta-cell progenitor. Of note, this is a pathway that appears to be unique to beta-cell neogenesis in the adult, as the embryonic pathway of beta-cell neogenesis does not proceed through a glucagon-positive intermediate. We conclude that beta-cell neogenesis from alpha-cells is a new pathway of potential therapeutic significance, making it of high importance to elucidate the molecular events in alpha- to beta-cell conversion.

  1. Beta-globin haplotype analysis suggests that a major source of Malagasy ancestry is derived from Bantu-speaking Negroids.

    PubMed

    Hewitt, R; Krause, A; Goldman, A; Campbell, G; Jenkins, T

    1996-06-01

    The origins of the inhabitants of Madagascar have not been fully resolved. Anthropological studies and preliminary genetic data point to two main sources of ancestry of the Malagasy, namely, Indonesian and African, with additional contributions from India and Arabia. The sickle-cell (beta s) mutation is found in populations of African and Indian origin. The frequency of the beta s-globin gene, derived from 1,425 Malagasy individuals, varies from 0 in some highland populations to .25 in some coastal populations. The beta s mutation is thought to have arisen at least five times, on the basis of the presence of five distinct beta s-associated haplotypes, each found in a separate geographic area. Twenty-five of the 35 Malagasy beta s haplotypes were of the typical "Bantu" type, 1 "Senegal" haplotype was found, and 2 rare or atypical haplotypes were observed; the remaining 7 haplotypes were consistent with the Bantu haplotype. The Bantu beta s mutation is thought to have been introduced into Madagascar by Bantu-speaking immigrants (colonists or slaves) from central or east Africa. The Senegal beta s mutation may have been introduced to the island via Portuguese naval explorers. This study provides the first definitive biological evidence that a major component of Malagasy ancestry is derived from African populations, in particular, Bantu-speaking Negroids. beta A haplotypes are also consistent with the claim for a significant African contribution to Malagasy ancestry but are also suggestive of Asian/Oceanic and Caucasoid admixture within the Malagasy population.

  2. Effects of carbon source and Vitreoscilla hemoglobin (VHb) on the production of beta-galactosidase in Enterobacter aerogenes.

    PubMed

    Khleifat, Khaled M; Abboud, Muayad M; Al-Mustafa, Ahmed H; Al-Sharafa, Khalid Y

    2006-10-01

    At fixed concentration (0.5%), lactose and galactose acted as inducers while glucose and other tested carbon sugars showed repression effects on beta-galactosidase production in Enterobacter aerogenes strain. The expression of Vitreoscilla hemoglobin gene (vgb) in this bacterial strain managed to overcome the repression effects as well as improving the induction of beta-galactosidase formation by carbon sources. In parallel, the bacterial O(2) consumption was increased correspondingly to the vgb induction of beta-galactosidase synthesis. When Enterobacter aerogenes strains were grown at the incubation temperature 42 degrees C, about 5-fold higher enzyme productivity was obtained than with a similar incubation at 37 degrees C. The bacterial growth expressed as biomass yield had a different optimum temperature and was not influenced to the same extent by variations in the carbon sources. These data are discussed in terms of proposed enhancement in beta-galactosidase productivity by vgb expression as well as its significance to improve the technology of whey processing.

  3. Highly enantioselective alpha-chlorination of cyclic beta-ketoesters catalyzed by N,N'-dioxide using NCS as the chlorine source.

    PubMed

    Cai, Yunfei; Wang, Wentao; Shen, Ke; Wang, Jun; Hu, Xiaolei; Lin, Lili; Liu, Xiaohua; Feng, Xiaoming

    2010-02-28

    A simple and highly efficient N,N'-dioxide organocatalyst system was developed for the asymmetric alpha-chlorination of cyclic beta-ketoesters using easily available NCS as the chlorine source to provide a series of optically active alpha-chloro-beta-ketoesters in excellent yields with 90-98% ee.

  4. A methodology for efficiency optimization of betavoltaic cell design using an isotropic planar source having an energy dependent beta particle distribution.

    PubMed

    Theirrattanakul, Sirichai; Prelas, Mark

    2017-09-01

    Nuclear batteries based on silicon carbide betavoltaic cells have been studied extensively in the literature. This paper describes an analysis of design parameters, which can be applied to a variety of materials, but is specific to silicon carbide. In order to optimize the interface between a beta source and silicon carbide p-n junction, it is important to account for the specific isotope, angular distribution of the beta particles from the source, the energy distribution of the source as well as the geometrical aspects of the interface between the source and the transducer. In this work, both the angular distribution and energy distribution of the beta particles are modeled using a thin planar beta source (e.g., H-3, Ni-63, S-35, Pm-147, Sr-90, and Y-90) with GEANT4. Previous studies of betavoltaics with various source isotopes have shown that Monte Carlo based codes such as MCNPX, GEANT4 and Penelope generate similar results. GEANT4 is chosen because it has important strengths for the treatment of electron energies below one keV and it is widely available. The model demonstrates the effects of angular distribution, the maximum energy of the beta particle and energy distribution of the beta source on the betavoltaic and it is useful in determining the spatial profile of the power deposition in the cell. Copyright © 2017. Published by Elsevier Ltd.

  5. Characterization of the Theta to Beta Ratio in ADHD: Identifying Potential Sources of Heterogeneity

    ERIC Educational Resources Information Center

    Loo, Sandra K.; Cho, Alexander; Hale, T. Sigi; McGough, James; McCracken, James; Smalley, Susan L.

    2013-01-01

    Objective: The goal of this study is to characterize the theta to beta ratio (THBR) obtained from electroencephalogram (EEG) measures, in a large sample of community and clinical participants with regard to (a) ADHD diagnosis and subtypes, (b) common psychiatric comorbidities, and (c) cognitive correlates. Method: The sample includes 871…

  6. Characterization of the Theta to Beta Ratio in ADHD: Identifying Potential Sources of Heterogeneity

    ERIC Educational Resources Information Center

    Loo, Sandra K.; Cho, Alexander; Hale, T. Sigi; McGough, James; McCracken, James; Smalley, Susan L.

    2013-01-01

    Objective: The goal of this study is to characterize the theta to beta ratio (THBR) obtained from electroencephalogram (EEG) measures, in a large sample of community and clinical participants with regard to (a) ADHD diagnosis and subtypes, (b) common psychiatric comorbidities, and (c) cognitive correlates. Method: The sample includes 871…

  7. Source Analysis of Beta-Synchronisation and Cortico-Muscular Coherence after Movement Termination Based on High Resolution Electroencephalography

    PubMed Central

    Hellriegel, Helge; Deuschl, Günther; Raethjen, Jan

    2012-01-01

    We hypothesized that post-movement beta synchronization (PMBS) and cortico-muscular coherence (CMC) during movement termination relate to each other and have similar role in sensorimotor integration. We calculated the parameters and estimated the sources of these phenomena. We measured 64-channel EEG simultaneously with surface EMG of the right first dorsal interosseus muscle in 11 healthy volunteers. In Task1, subjects kept a medium-strength contraction continuously; in Task2, superimposed on this movement, they performed repetitive self-paced short contractions. In Task3 short contractions were executed alone. Time-frequency analysis of the EEG and CMC was performed with respect to the offset of brisk movements and averaged in each subject. Sources of PMBS and CMC were also calculated. High beta power in Task1, PMBS in Task2-3, and CMC in Task1-2 could be observed in the same individual frequency bands. While beta synchronization in Task1 and PMBS in Task2-3 appeared bilateral with contralateral predominance, CMC in Task1-2 was strictly a unilateral phenomenon; their main sources did not differ contralateral to the movement in the primary sensorimotor cortex in 7 of 11 subjects in Task1, and in 6 of 9 subjects in Task2. In Task2, CMC and PMBS had the same latency but their amplitudes did not correlate with each other. In Task2, weaker PMBS source was found bilaterally within the secondary sensory cortex, while the second source of CMC was detected in the premotor cortex, contralateral to the movement. In Task3, weaker sources of PMBS could be estimated in bilateral supplementary motor cortex and in the thalamus. PMBS and CMC appear simultaneously at the end of a phasic movement possibly suggesting similar antikinetic effects, but they may be separate processes with different active functions. Whereas PMBS seems to reset the supraspinal sensorimotor network, cortico-muscular coherence may represent the recalibration of cortico-motoneuronal and spinal systems. PMID

  8. Source analysis of beta-synchronisation and cortico-muscular coherence after movement termination based on high resolution electroencephalography.

    PubMed

    Muthuraman, Muthuraman; Tamás, Gertrúd; Hellriegel, Helge; Deuschl, Günther; Raethjen, Jan

    2012-01-01

    We hypothesized that post-movement beta synchronization (PMBS) and cortico-muscular coherence (CMC) during movement termination relate to each other and have similar role in sensorimotor integration. We calculated the parameters and estimated the sources of these phenomena.We measured 64-channel EEG simultaneously with surface EMG of the right first dorsal interosseus muscle in 11 healthy volunteers. In Task1, subjects kept a medium-strength contraction continuously; in Task2, superimposed on this movement, they performed repetitive self-paced short contractions. In Task3 short contractions were executed alone. Time-frequency analysis of the EEG and CMC was performed with respect to the offset of brisk movements and averaged in each subject. Sources of PMBS and CMC were also calculated.High beta power in Task1, PMBS in Task2-3, and CMC in Task1-2 could be observed in the same individual frequency bands. While beta synchronization in Task1 and PMBS in Task2-3 appeared bilateral with contralateral predominance, CMC in Task1-2 was strictly a unilateral phenomenon; their main sources did not differ contralateral to the movement in the primary sensorimotor cortex in 7 of 11 subjects in Task1, and in 6 of 9 subjects in Task2. In Task2, CMC and PMBS had the same latency but their amplitudes did not correlate with each other. In Task2, weaker PMBS source was found bilaterally within the secondary sensory cortex, while the second source of CMC was detected in the premotor cortex, contralateral to the movement. In Task3, weaker sources of PMBS could be estimated in bilateral supplementary motor cortex and in the thalamus. PMBS and CMC appear simultaneously at the end of a phasic movement possibly suggesting similar antikinetic effects, but they may be separate processes with different active functions. Whereas PMBS seems to reset the supraspinal sensorimotor network, cortico-muscular coherence may represent the recalibration of cortico-motoneuronal and spinal systems.

  9. A screening system for carbon sources enhancing beta-N-acetylglucosaminidase formation in Hypocrea atroviridis (Trichoderma atroviride).

    PubMed

    Seidl, Verena; Druzhinina, Irina S; Kubicek, Christian P

    2006-07-01

    To identify carbon sources that trigger beta-N-acetylglucosaminidase (NAGase) formation in Hypocrea atroviridis (anamorph Trichoderma atroviride), a screening system was designed that consists of a combination of Biolog Phenotype MicroArray plates, which contain 95 different carbon sources, and specific enzyme activity measurements using a chromogenic substrate. The results revealed growth-dependent kinetics of NAGase formation and it was shown that NAGase activities were enhanced on carbon sources sharing certain structural properties, especially on alpha-glucans (e.g. glycogen, dextrin and maltotriose) and oligosaccharides containing galactose. Enzyme activities were assessed in the wild-type and a H. atroviridis Deltanag1 strain to investigate the influence of the two NAGases, Nag1 and Nag2, on total NAGase activity. Reduction of NAGase levels in the Deltanag1 strain in comparison to the wild-type was strongly carbon-source and growth-phase dependent, indicating the distinct physiological roles of the two proteins. The transcript abundance of nag1 and nag2 was increased on carbon sources with elevated NAGase activity, indicating transcriptional regulation of these genes. The screening method for the identification of carbon sources that induce enzymes or a gene of interest, as presented in this paper, can be adapted for other purposes if appropriate enzyme or reporter assays are available.

  10. New estimates of asymmetric decomposition of racemic mixtures by natural beta-radiation sources

    NASA Technical Reports Server (NTRS)

    Hegstrom, R. A.; Rich, A.; Van House, J.

    1985-01-01

    Some recent calculations that appeared to invalidate the Vester-Ulbricht hypothesis, which suggests that the chirality of biological molecules originates from the beta-radiolysis of prebiotic racemic mixtures, are reexamined. These calculations apparently showed that the radiolysis-induced chiral polarization can never exceed the chiral polarization produced by statistical fluctuations. It is here shown that several overly restrictive conditions were imposed on these calculations which, when relaxed, allow the radiolysis-induced polarization to exceed that produced by statistical fluctuations, in accordance with the Vester-Ulbricht hypothesis.

  11. New estimates of asymmetric decomposition of racemic mixtures by natural beta-radiation sources

    NASA Technical Reports Server (NTRS)

    Hegstrom, R. A.; Rich, A.; Van House, J.

    1985-01-01

    Some recent calculations that appeared to invalidate the Vester-Ulbricht hypothesis, which suggests that the chirality of biological molecules originates from the beta-radiolysis of prebiotic racemic mixtures, are reexamined. These calculations apparently showed that the radiolysis-induced chiral polarization can never exceed the chiral polarization produced by statistical fluctuations. It is here shown that several overly restrictive conditions were imposed on these calculations which, when relaxed, allow the radiolysis-induced polarization to exceed that produced by statistical fluctuations, in accordance with the Vester-Ulbricht hypothesis.

  12. Pairwise beta diversity resolves an underappreciated source of confusion in calculating species turnover.

    PubMed

    Marion, Zachary H; Fordyce, James A; Fitzpatrick, Benjamin M

    2017-01-30

    Beta diversity is an important metric in ecology quantifying differentiation or disparity in composition among communities, ecosystems, or phenotypes. To compare systems with different sizes (N, number of units within a system), beta diversity is often converted to related indices such as turnover or local/regional differentiation. Here we use simulations to demonstrate that these naive measures of dissimilarity depend on sample size and design. We show that when N is the number of sampled units (e.g., quadrats) rather than the "true" number of communities in the system (if such exists), these differentiation measures are biased estimators. We propose using average pairwise dissimilarity as an intuitive solution. That is, instead of attempting to estimate an N-community measure, we advocate estimating the expected dissimilarity between any random pairs of communities (or sampling units)-especially when the "true" N is unknown or undefined. Fortunately, measures of pairwise dissimilarity or overlap have been used in ecology for decades, and their properties are well known. Using the same simulations, we show that average pairwise metrics give consistent and unbiased estimates regardless of the number of survey units sampled. We advocate pairwise dissimilarity as a general standardization to ensure commensurability of different study systems. This article is protected by copyright. All rights reserved.

  13. A primary standard for the measurement of alpha and beta particle surface emission rate from large area reference sources.

    PubMed

    Ravindra, Anuradha; Kulkarni, D B; Joseph, Leena; Kulkarni, M S; Babu, D A R

    2016-01-01

    A large area windowless gas flow multi wire proportional counting system for the calibration of large area reference sources has been developed as a primary standard at Bhabha Atomic Research Centre (BARC). The counting system consists of a multi wire proportional counter (MWPC), vacuum system, gas flow system and pulse processing units. The MWPC detector assembly consists of a vacuum tight aluminum enclosure, multi wire grid and sliding source tray. Various detector characteristics like operating characteristics curve, Fe-55 spectrum for beta discriminator threshold setting and dead time of the measurement system were studied and determined in order to achieve an optimized detection capability. The surface emission rates of different source strengths were measured and their relative combined standard uncertainties were determined. Large Area Sources Comparison Exercise (LASCE) was organized by International Committee on Radionuclide Metrology (ICRM) working group and coordinated by National Institute for Ionising Radiation Metrology (ENEA), Italy, to demonstrate equivalence of surface emission rate measurements at the international platform. BARC participated in the programme and the results of LASCE are also discussed in this paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Neisseria lactamica and Neisseria polysaccharea as possible sources of meningococcal beta-lactam resistance by genetic transformation.

    PubMed

    Saez-Nieto, J A; Lujan, R; Martinez-Suarez, J V; Berron, S; Vazquez, J A; Viñas, M; Campos, J

    1990-11-01

    We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria polysaccharea, to penicillin, ampicillin, and several cephalosporins. The MICs of penicillin, ampicillin, cephalothin, and cefuroxime for moderately resistant meningococci have increased two- to sixfold in relation to MICs for susceptible strains. For these strains of meningococci, N. lactamica, and N. polysaccharea, penicillin, ampicillin, cephalothin, and cefuroxime MICs for 50 and 90% of strains were similar. By genetic transformation of a penicillin-susceptible strain of N. meningitidis to low-level penicillin resistance with DNA from penicillin-resistant strains of N. meningitidis, N. lactamica, N. polysaccharea, and N. gonorrhoeae, isogenic strains with the same pattern of resistance to beta-lactams were obtained, suggesting that these commensal Neisseria spp. could be the source of meningococcal resistance genes.

  15. Neisseria lactamica and Neisseria polysaccharea as possible sources of meningococcal beta-lactam resistance by genetic transformation.

    PubMed Central

    Saez-Nieto, J A; Lujan, R; Martinez-Suarez, J V; Berron, S; Vazquez, J A; Viñas, M; Campos, J

    1990-01-01

    We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria polysaccharea, to penicillin, ampicillin, and several cephalosporins. The MICs of penicillin, ampicillin, cephalothin, and cefuroxime for moderately resistant meningococci have increased two- to sixfold in relation to MICs for susceptible strains. For these strains of meningococci, N. lactamica, and N. polysaccharea, penicillin, ampicillin, cephalothin, and cefuroxime MICs for 50 and 90% of strains were similar. By genetic transformation of a penicillin-susceptible strain of N. meningitidis to low-level penicillin resistance with DNA from penicillin-resistant strains of N. meningitidis, N. lactamica, N. polysaccharea, and N. gonorrhoeae, isogenic strains with the same pattern of resistance to beta-lactams were obtained, suggesting that these commensal Neisseria spp. could be the source of meningococcal resistance genes. PMID:2127349

  16. Biosynthesis of poly-beta-hydroxybutyrate and exopolysaccharides on Azotobacter chroococcum strain 6B utilizing simple and complex carbon sources.

    PubMed

    Quagliano, J C; Miyazaki, S S

    1999-12-01

    Coproduction of poly-beta-hydroxybutyrate (PHB) and exopolysaccharides (EPS) was investigated with Azotobacter chroococcum strain 6B isolated from soil samples. The bacterium was cultured using various carbon sources solely or with 0.1 g/L of ammonium sulfate. Ammonium addition resulted in reduced PHB and EPS production with glucose, fructose, and sucrose media, but cellular mass remained constant except for sucrose. Protein was nearly twofold higher in ammonium-grown cultures. Glucose and fructose alone biosynthesized high amounts of EPS (maximum 2.1 and 1.1 g/L, respectively, at 72 h), whereas PHB was accumulated only in glucose-grown cells. Sucrose almost did not produce EPS. Conversely, PHB content was the highest obtained from all experimented conditions (1.1 g/L at 48 h, 40% cell dry wt). When a complex carbon source such as sugar cane molasses was utilized, PHB was accumulated concomitant with EPS production from the initial time to 48 h (0.75 g/L, 37% cell dry wt and 0.6 g/L, respectively), and then PHB decayed at 72 h (0.2 g/L). On the other hand, EPS continued to be biosynthesized (1.1 g/L, 72 h). PHB fractions of total intra- and extracellular biopolymers were calculated. Sucrose-modified Burk's medium without ammonium addition is suggested as a medium capable of diverting the carbon source for the production of intracellular PHB rather than EPS with A. chroococcum 6B.

  17. Influence of carbon and nitrogen sources and temperature on hyperproduction of a thermotolerant beta-glucosidase from synthetic medium by Kluyveromyces marxianus.

    PubMed

    Rajoka, M I; Khan, Samia; Latif, Farooq; Shahid, Riaz

    2004-05-01

    The effect of carbon source and its concentration, inoculum size, yeast extract concentration, nitrogen source, pH of the fermentation medium, and fermentation temperature on beta-glucosidase production by Kluyveromyces marxianus in shake-flask culture was investigated. These were the independent variables that directly regulated the specific growth and beta-glucosidase production rate. The highest product yield, specific product yield, and productivity of beta-glucosidase occurred in the medium (pH 5.5) inoculated with 10% (v/v) inoculum of the culture. Cellobiose (20 g/L) significantly improved beta-glucosidase production measured as product yield (YP/S) and volumetric productivity (QP) followed by sucrose, lactose, and xylose. The highest levels of productivity (144 IU/[L.h]) of beta-glucosidase occurred on cellobiose in the presence of CSL at 35 degrees C and are significantly higher than the values reported by other researchers on almost all other organisms. The thermodynamics and kinetics of beta-glucosidase production and its deactivation are also reported. The enzyme was substantially stable at 60 degrees C and may find application in some industrial processes.

  18. Yellow maize with high beta-carotene is an effective source of vitamin A in healthy Zimbabwean men

    USDA-ARS?s Scientific Manuscript database

    The bioconversion efficiency of yellow maize beta-carotene to retinol in humans is unknown. Thus, the objective of this study was to determine the vitamin A value of yellow maize beta-carotene in humans. A high beta-carotene containing yellow maize was grown in a hydroponic medium with 23 atom% 2H2O...

  19. Yellow maize with high (beta)-carotene is an effective source of vitamin A in healthy Zimbabwean men

    USDA-ARS?s Scientific Manuscript database

    BACKGROUND: The bioconversion efficiency of yellow maize Beta-carotene to retinol in humans is unknown. OBJECTIVE: The objective of this study was to determine the vitamin A value of yellow maize Beta-carotene in humans. DESIGN: High Beta-carotene-containing yellow maize was grown in a hydroponic...

  20. Late gestation increase in 11beta-hydroxysteroid dehydrogenase 1 expression in human fetal membranes: a novel intrauterine source of cortisol.

    PubMed

    Alfaidy, Nadia; Li, Wei; MacIntosh, Tracy; Yang, Kaiping; Challis, John

    2003-10-01

    Late human gestation is associated with an increase in the concentration of cortisol (F) in the fetal circulation and amniotic fluid. It had been assumed that most of the F measured in the amniotic fluid came from the fetal adrenal gland. However, local production of F can also occur in human intrauterine tissues from inactive cortisone under the influence of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1. Recent studies have shown that 11beta-HSD 1 activity is up-regulated by prostaglandins (PG) E2 and F2alpha, hormones that are produced in the fetal membranes (FM) at term. In the present study, we hypothesized that 11beta-HSD 1 expression would increase in FM during pregnancy and at labor, creating the potential for local increase in F production at term. We examined 11beta-HSD 1 expression in placenta and FM obtained during normal pregnancy from nonlaboring women [26-28 wk (n = 3); 29-30 wk (n = 3); 32-33 wk (n = 3); 35-36 wk (n = 3)] and from uncomplicated term pregnancies after elective cesarean section (n = 6). 11beta-HSD 1 expression was also examined in amnion and chorionic tissues in relation to term labor (n = 12). Immunohistochemistry and Western blot analysis were used to examine 11beta-HSD 1 localization and expression. 11beta-HSD 1 activity was also measured in microsomal fractions prepared from whole fetal membranes. At term, immunoreactive 11beta-HSD 1 expression was localized predominantly to the chorion trophoblast cells, attached decidua, and amnion epithelial cells. 11beta-HSD 1 expression in FM increased with gestational age and reflected increased enzyme reductase activity. No change in 11beta-HSD 1 expression was found in placental tissue from the same patients. There was a significant increase in 11beta-HSD 1 expression in amnion but not in chorion with the onset of labor. We suggest that increases in 11beta-HSD 1 expression/activity by intrauterine membranes during late gestation may result in increased potential for a

  1. Development of a (147)Pm source for beta-backscatter thickness gauge applications.

    PubMed

    Kumar, Manoj; Udhayakumar, J; Nuwad, J; Shukla, Rakesh; Pillai, C G S; Dash, Ashutosh; Venkatesh, Meera

    2011-03-01

    This paper describes a method for the preparation of (147)Pm sources, utilized in the determination of graphite coating thickness on the inner surface of the zircaloy cladding tube of nuclear fuels. (147)Pm was adsorbed on a limited surface area [1.5mm (ϕ)×2mm (l)] of a cylindrical aluminum rod [1.5mm (ϕ)×10mm (l)]. In brief, the selected tip area [1.5mm (ϕ)×2mm (l)] was anodized at a current density of 15mA/cm(2) at 15°C in 3M·H(2)SO(4) for 2h followed by immersion of this area in 10μL of (147)Pm solution containing 37MBq (1mCi) of activity at pH 6.0 for 24h. The radioactive area was subsequently covered with a thin layer of Polymethyl Methacrylate (PMMA) to prevent leaching of (147)Pm from the source. The quantity of incorporated (147)Pm activity was assayed in a calibrated ion chamber. Quality control tests were carried out to ensure nonleachability, uniform distribution of activity and stability of the sources. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Low dose beta-emitter source induces sexual reproduction instead of fragmentation in an earthworm, Enchytraeus japonensis.

    PubMed

    Miyachi, Yukihisa; Kanao, Tomoko; Okamoto, Takehito

    2005-01-01

    We examined whether background radiation, or radiation at a slightly higher level, plays a role in the reproduction of a terrestrial earthworm. Enchytraeus japonensis a recently described terrestrial oligochaete, reproduces asexually by fragmentation and subsequent regeneration. Following radiation exposure in which the worms were subjected to a 32P beta-emitter source at 15 times the background dose rate (4.5 microGy/h), a statistically significant decrease in the number of fragmentations was observed as compared with the sham controls. At that time, in a stained preparation with haematoxylin and eosin (HE), sexual reproduction occurred instead of asexual fragmentation, and mature oocytes were observed in the body of grown worms. However, increasing the radiation dose rate by 30 microGy/h resulted in the complete disappearance of the radiation-induced effects, i.e., fragmentation again occurred after 14 h. The results of this study indicate that a lower dose of radiation may be essential to achieve sexual reproduction, inducing an inhibition of fragmentation (asexual reproduction), but at higher, more cytotoxic doses of radiation these effects are negated.

  3. Dosimetric consequences of manual pullback procedure for coronary artery radiotherapy with 90Sr/90Y beta-source.

    PubMed

    Iftimia, Ileana; Devlin, Phillip M; Martin, Andre-Guy; Shakur, Rameen; Almonacid, Alexandra; Kazakin, Julia; Chin, Lee M; Cormack, Robert A

    2004-01-01

    This work presents a quantitative dosimetric analysis of the Novoste (90)Sr/(90)Y beta-source cardiovascular brachytherapy treatments using a manual pullback technique for patients with in-stent restenosis. Based on our previous measurements, a model was developed to estimate the dose in the middle of the junction region for tandem irradiation expressed as fraction of prescription dose (FPD) and dosimetric overlap length (DOL) receiving more/less than a threshold dose. The overlap/gap size was measured using the digital cine images recorded during treatment and then FPD and DOL were quantified. Statistical analysis of 55 patients showed that the overlap size and the FPD at 2 mm radial distance were in range of 0 to 23 mm and 13-200% of prescription dose (Rx), respectively. Four gaps out of 76 pullback cases were found, but their size was at most 5 mm. Use of a 5 mm overlap avoided underdosed regions in the vast majority of the cases. These results are the first step towards an analysis of the clinical outcome of these patients.

  4. Characteristics of a 85Kr beta-particle source applied in Series 1 reference irradiations of DIS-1 direct ion storage dosemeters.

    PubMed

    Hakanen, A T; Sipilä, P M; Sahla, T T

    2007-01-01

    Characteristics necessary to specify an ISO 6980 Series 1 reference radiation field were determined for a commercially available 85Kr beta-particle source, using a BEAM EGS4 Monte Carlo code. The characteristics include residual maximum beta energy, E(res), and the uniformity of the dose rate over the calibration area. The E(res) and the uniformity were also determined experimentally, using an extrapolation ionization chamber (EC) and a 0.2 cm3 parallel plate ionization chamber, respectively. The depth-dose curve measured with the EC gave a value 0.62 MeV for the E(res). Series 2 90Sr + 90Y and Series 1(85) Kr beta-particle sources calibrated for H(p)(0.07) at the secondary standard dosimetry laboratory (SSDL) of STUK were used to determine the energy and angular responses of DIS-1 direct ion storage dosemeters. The averaged zero angle H(p)(0.07) responses to the 90Sr + 90Y and 85Kr reference radiations were 135 and 80%, respectively. The responses were normalized to 100%, H(p)(0.07) response to 137Cs photon radiation.

  5. Effects of sertraline on brain current source of the high beta frequency band: analysis of electroencephalography during audiovisual erotic stimulation in males with premature ejaculation.

    PubMed

    Kwon, O Y; Kam, S C; Choi, J H; Do, J M; Hyun, J S

    2011-01-01

    To identify the effects of sertraline, a selective serotonin reuptake inhibitor, for the treatment of premature ejaculation (PE), changes in brain current-source density (CSD) of the high beta frequency band (22-30 Hz) induced by sertraline administration were investigated during audiovisual erotic stimulation. Eleven patients with PE (36.9±7.8 yrs) and 11 male volunteers (24.2±1.9 years) were enrolled. Scalp electroencephalography (EEG) was conducted twice: once before sertraline administration and then again 4 h after the administration of 50 mg sertraline. Statistical non-parametric maps were obtained using the EEG segments to detect the current-density differences in the high beta frequency bands (beta-3, 22-30 Hz) between the EEGs before and after sertraline administration in the patient group and between the patient group and controls after the administration of sertraline during the erotic video sessions. Comparing between before and after sertraline administration in the patients with PE, the CSD of the high beta frequency band at 4 h after sertraline administration increased significantly in both superior frontal gyri and the right medial frontal gyrus (P<0.01). The CSD of the beta-3 band of the patients with PE were less activated significantly in the middle and superior temporal gyrus, lingual and fusiform gyrus, inferior occipital gyrus and cuneus of the right cerebral hemisphere compared with the normal volunteers 4 h after sertraline administration (P<0.01). In conclusion, sertraline administration increased the CSD in both the superior frontal and right middle temporal gyrus in patients with PE. The results suggest that the increased neural activity in these particular cerebral regions after sertraline administration may be associated with inhibitory effects on ejaculation in patients with PE.

  6. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes.

    PubMed

    Cerf, Marlon E

    2013-10-01

    Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.

  7. Effect of Sertraline on Current-Source Distribution of the High Beta Frequency Band: Analysis of Electroencephalography under Audiovisual Erotic Stimuli in Healthy, Right-Handed Males.

    PubMed

    Lee, Seung Hyun; Hyun, Jae Seog; Kwon, Oh-Young

    2010-08-01

    The purpose of this study was to examine the cerebral changes in high beta frequency oscillations (22-30 Hz) induced by sertraline and by audiovisual erotic stimuli in healthy adult males. Scalp electroencephalographies (EEGs) were conducted twice in 11 healthy, right-handed males, once before sertraline intake and again 4 hours thereafter. The EEGs included four sessions recorded sequentially while the subjects were resting, watching a music video, resting, and watching an erotic video for 3 minutes, 5 minutes, 3 minutes, and 5 minutes, respectively. We performed frequency-domain analysis using the EEGs with a distributed model of current-source analysis. The statistical nonparametric maps were obtained from the sessions of watching erotic and music videos (p<0.05). The erotic stimuli decreased the current-source density of the high beta frequency band in the middle frontal gyrus, the precentral gyrus, the postcentral gyrus, and the supramarginal gyrus of the left cerebral hemisphere in the baseline EEGs taken before sertraline intake (p<0.05). The erotic stimuli did not induce any changes in current-source distribution of the brain 4 hours after sertraline intake. It is speculated that erotic stimuli may decrease the function of the middle frontal gyrus, the precentral gyrus, the postcentral gyrus, and the supramarginal gyrus of the left cerebral hemisphere in healthy adult males. This change may debase the inhibitory control of the brain against erotic stimuli. Sertraline may reduce the decrement in inhibitory control.

  8. Comparison of two different types of LiF:Mg,Cu,P thermoluminescent dosimeters for detection of beta rays (beta-TLDs) from 90Sr/90Y, 85Kr and 147Pm sources.

    PubMed

    Grassi, Elisa; Sghedoni, Roberto; Piccagli, Vando; Fioroni, Federica; Borasi, Giovanni; Iori, Mauro

    2011-05-01

    Targeted radionuclide therapies in nuclear medicine departments increasingly depend on using unsealed beta radiation sources in the labeling of peptides and antibodies. Monitoring doses received by the fingers and hands during these procedures is best accomplished with TLD dosimeters that can be located at the fingertips. The present study examines the response of two TLD dosimeters (MCP-Ns and GR200A) to 90Sr/90Y, 85Kr, and 147Pm. The dosimeters were supplied by two different services, and all irradiations were performed at the PTB Institute in Germany. Each dosimetry service evaluated the dosimeters without knowledge that they had been purposefully irradiated. The accuracy and precision of the dosimeters were evaluated as a function of delivered dose, energy of beta particles and angular incidence. The results are compared to performance measures recommended by the IEC. Both dosimeter types displayed significant energy dependence. Angular dependence was moderate. Accuracy and precision as a function of dose (linearity) differed between the two systems, with the MCP-Ns being noticeably better than the GR200A. The superior precision makes the MCP-Ns much more useful for extremity dose measurements. The differences between these two dosimeter systems reinforce the need to evaluate a dosimeter carefully before using it in the daily work routine.

  9. Beta-Carotene

    USDA-ARS?s Scientific Manuscript database

    Beta-carotene is a pigment that occurs naturally in many photosynthetic plants and organisms and one of the most abundant carotenoids found in human blood. The richest dietary sources of beta-carotene are yellow, orange, and leafy green fruits and vegetables, such as carrots, spinach, sweet potatoes...

  10. Thermoluminescence studies of Nd doped Bi4Ge3O12 crystals irradiated by UV and beta sources.

    PubMed

    Karabulut, Y; Canimoglu, A; Ekdal, E; Ayvacikli, M; Can, N; Karali, T

    2016-07-01

    Thermoluminescence (TL) glow curves of pure and rare earth doped bismuth germanate (BGO) were investigated under UV and beta radiation. The glow curves of pure BGO crystal present different patterns for both kinds of radiation. The TL glow curves of BGO crystals doped with Nd ions are similar to that of pure BGO under UV radiation. The kinetic parameters, kinetic order (b), activation energy (E) and frequency factor (s) of the TL glow curves of pure BGO crystal have been determined by peak shape method. Activation energies of 3 peaks obtained by PS were found to be 1.81, 1.15 and 1.78, respectively.

  11. Systematic comparison of saturation effects and afterglow properties of Sr4Al14O25:Eu, Dy phosphor excited by alpha and beta ionizing sources and UV light

    NASA Astrophysics Data System (ADS)

    Havasi, Viktor; Tátrai, Dávid; Szabó, Gábor; Sipos, György; Kónya, Zoltán; Kukovecz, Ákos

    2017-07-01

    This study reports on the radioactive- and photo-charging effects related afterglow properties of the long-afterglow Sr4Al14O25:Eu, Dy phosphor (SAED). Saturation and oversaturation behavior, trapping and de-trapping sequences, decay profiles and resistivity of SAED to alpha, beta and UV excitations are detailed. Thermoluminescence and afterglow measurements were performed on SAED subjected to different irradiation dose/time. In order to determine the saturation point of SAED, phosphors were charged by 0.5-800 Gy dose using radioactive alpha and beta sources and for 0.02-900 min by near UV light. By radioactive excitations only a saturation tendency was observed, whereas clear indication of oversaturation was found for photo-charging. Different saturation tendencies were also observed as a function of average SAED particle size due to the different penetration depth and efficiency of the excitation radiations. A uniform de-trapping sequence, but an opposite trapping sequence was found for ionizing radiation and for UV charging due to secondary excitation effects of high-energy irradiation. After the saturation point, a slight reduction of charge carrier concentration and PL intensity were observed. This was evidenced by the shifting dominant components of the modeled afterglow and TL curves. Repeated charging by ionizing radiation does not effected the afterglow properties of SAED adversely. On the other hand, thermal exposure up to 350 °C reduced photoluminescence intensity even in inert atmosphere.

  12. [Effect of carbon and nitrogen sources on the accumulation of poly-beta-hydroxybutyrate by purple non-sulfur photosynthetic bacteria].

    PubMed

    Wu, Guang-xue; Guan, Yun-tao; Wang, Jian-qiu; Jiang, Zhan-peng

    2004-11-01

    The effect of carbon and nitrogen sources on the accumulation of Poly-beta-Hydroxybutyrate (PHB) by purple non-sulfur photosynthetic bacteria (PNSB)was investigated. The results showed that ammonia nitrogen and organic nitrogen could benefit the PNSB accumulating PHB; under certain ratio of carbon and nitrogen low carbon concentration can accumulate more PHB, but high carbon concentration is better for PNSB accumulating PHB with the growth of PNSB. As to different substrates, butyrate is the best for accumulating of PHB, but acetate is better and propionate is the poorest. Mixed substrate with butyrate as the main content are better than single substrate; carbon dioxide have certain effect on the PNSB accumulating PHB, and high carbon dioxide concentration can improve PHB content when using acetate or butyrate as substrate.

  13. Carbon, Nitrogen, and Nutrient Interactions in Beta vulgaris L. as Influenced by Nitrogen Source, NO3- versus NH4+

    PubMed Central

    Raab, T. K.; Terry, N.

    1995-01-01

    Sugar beets (Beta vulgaris L. cv F58-554H1) were grown hydroponically in a 16-h light, 8-h dark period (photosynthetic photon flux density of 0.5 mmol m-2 s-1) for 4 weeks from sowing in half-strength Hoagland nutrient solution containing 7.5 mM nitrate. Half of the plants were then transferred to 7.5 mM ammonium N; the rest remained in solution with 7.5 mM nitrate N. Upon transfer from nitrate to ammonium, the total N concentration decreased sharply in the fibrous roots and petiole/midribs and increased substantially in the leaf blades. This was because of the decreased nitrate concentrations in fibrous roots and petioles and a concomitant increase in amino acid/amide-N and protein N in leaf blades. Sugar beets acclimated to ammonium partly by a 2.5-fold increase in glutamine synthase activity in fibrous roots and a 1.7-fold increase in leaf blades. Rapid ammonium assimilation into glutamine consumed carbon skeletons, leading to a depletion of foliar starch, sucrose, and maltose. Ammonium treatment stimulated activities of some glycolytic/Krebs cycle enzymes, e.g. pyruvate dehydrogenase. Nitrate-fed leaf blades contained substantially larger concentrations of osmolytes (i.e. nitrate, cations, and sucrose), which may have contributed to the faster rates of leaf expansion in nitrate-fed compared to ammonium-fed plants. PMID:12228383

  14. Detection of beta-class variability in Black Hole source GRS 1915+105 by Astrosat Scanning Sky Monitor

    NASA Astrophysics Data System (ADS)

    Ramadevi, M. C.; Ravishankar, B. T.; Nandi, Anuj; Girish, V.; Singh, Brajpal; Jain, Anand; Agrawal, Vivek Kumar; Agarwal, Anil; Bhattacharya, Dipankar; Seetha, S.; Sharma, M. Ramakrishna; Sharan, Vaishali; Babu, V. C.; Yadav, Reena; Meena, G.; Murthy, N. Sitarama; Kumar; Ashoka, B. N.; Kulkarni, Ravi; Iyer, Nirmal; Radhika, D.; Kushwaha, Ankur; Balaji, K.; Nagesh, G.; Kumar, Manoj; Gaan, Dhruti Ranjan; Kulshresta, Prashanth; Agarwal, Pankaj; Sebastin, Matthew; Rajarajan, A.; Rao, S. V. S. Subba; Pandiyan; R.; Rao, K. Subba; Rao, Chaitra; Sarma, K. Suryanarayana

    2015-10-01

    The Scanning Sky Monitor (SSM) on board ASTROSAT was made operational on October 12th, 2015, the 15th day after launch (September 28th, 2015). After initial observations of the Crab Nebula, on October 14th 2015, the SSM was maneuvered for a stare at the galactic Black Hole source GRS 1915+105.

  15. Special Analysis for the Disposal of the Lawrence Livermore National Laboratory Low Activity Beta/Gamma Sources Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

    SciTech Connect

    Shott, Gregory J.

    2015-06-01

    This special analysis (SA) evaluates whether the Lawrence Livermore National Laboratory (LLNL) Low Activity Beta/Gamma Sources waste stream (BCLALADOEOSRP, Revision 0) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The LLNL Low Activity Beta/Gamma Sources waste stream consists of sealed sources that are no longer needed. The LLNL Low Activity Beta/Gamma Sources waste stream required a special analysis because cobalt-60 (60Co), strontium-90 (90Sr), cesium-137 (137Cs), and radium-226 (226Ra) exceeded the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015). The results indicate that all performance objectives can be met with disposal of the LLNL Low Activity Beta/Gamma Sources in a SLB trench. The LLNL Low Activity Beta/Gamma Sources waste stream is suitable for disposal by SLB at the Area 5 RWMS. However, the activity concentration of 226Ra listed on the waste profile sheet significantly exceeds the action level. Approval of the waste profile sheet could potentially allow the disposal of high activity 226Ra sources. To ensure that the generator does not include large 226Ra sources in this waste stream without additional evaluation, a control is need on the maximum 226Ra inventory. A limit based on the generator’s estimate of the total 226Ra inventory is recommended. The waste stream is recommended for approval with the control that the total 226Ra inventory disposed shall not exceed 5.5E10 Bq (1.5 Ci).

  16. [Comparative study of the biological utilization of beta-carotene from synthetic and natural sources in rats].

    PubMed

    Baracaldo Barrera, Cesar Mauricio; Rozo, Camilo; Castro de Navarro, Lucía

    2002-12-01

    The purpose of this study was to evaluate the change in concentration of retinol and beta-carotene (BC) in blood serum and liver tissue of rats, after supplementation with synthetic BC and commonly consumed carotenoid-rich vegetables (carrot and spinach). Weanling male Wistar rats were randomly assigned in four groups of 16 rats each. The four groups of rats were supplemented according to the following feeding treatments: 1) Control group (0G), 0.2 mL corn oil; 2) Pure BC group (BCG), 60 micrograms RE in 0.2 mL corn oil; 3) Carrot group (CG), 60 micrograms RE in 0.2 mL corn oil; 4) Spinach group (SG), 60 micrograms RE in 0.2 mL corn oil. Analysis of retinol and BC contents in serum and liver was performed by HPLC procedures. The variance analysis showed no significant differences (a = 0.05) in the increase of weight of the animals and in the increase of retinol and BC levels in serum and in liver of the four treatments during the four weeks of supplementation. The correlation analysis between levels of retinol and BC in serum and in liver showed no relation between these two parameters. A regression analysis of liver BC levels in the four treatments showed the following slopes of the regression lines: BCG, 0.909; CG, 0.451; SG, 0.444, and 0G, 0.203. These results indicate that the highest BC absorption was in the BCG treatment, whereas the BC absorption in the CG and SG treatments was approximately one half.

  17. Development of a low-energy and high-current pulsed neutral beam injector with a washer-gun plasma source for high-beta plasma experiments.

    PubMed

    Ii, Toru; Gi, Keii; Umezawa, Toshiyuki; Asai, Tomohiko; Inomoto, Michiaki; Ono, Yasushi

    2012-08-01

    We have developed a novel and economical neutral-beam injection system by employing a washer-gun plasma source. It provides a low-cost and maintenance-free ion beam, thus eliminating the need for the filaments and water-cooling systems employed conventionally. In our primary experiments, the washer gun produced a source plasma with an electron temperature of approximately 5 eV and an electron density of 5 × 10(17) m(-3), i.e., conditions suitable for ion-beam extraction. The dependence of the extracted beam current on the acceleration voltage is consistent with space-charge current limitation, because the observed current density is almost proportional to the 3/2 power of the acceleration voltage below approximately 8 kV. By optimizing plasma formation, we successfully achieved beam extraction of up to 40 A at 15 kV and a pulse length in excess of 0.25 ms. Its low-voltage and high-current pulsed-beam properties enable us to apply this high-power neutral beam injection into a high-beta compact torus plasma characterized by a low magnetic field.

  18. SNS Medium Beta Cryomodule Performance

    SciTech Connect

    Isidoro Campisi; Edward Daly; G. Davis; Jean Delayen; Christiana Grenoble; John Hogan; Lawrence King; Thomas Powers; Joseph Preble; Mircea Stirbet; Haipeng Wang; Mark Wiseman

    2003-09-01

    Thomas Jefferson National Accelerating Facility (Jefferson Lab) is producing 24 Superconducting Radio Frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) cold linac. This includes one medium-beta (0.61) prototype, 11 medium-beta production, and 12 high-beta (0.81) production cryomodules. Each of the medium-beta cryomodules is scheduled to undergo complete operational performance testing at Jefferson Laboratory before shipment to ORNL. To date, the prototype and three production models of the medium beta cryomodule have been tested. The performance results of the tested cryomodules will be discussed.

  19. Biosynthesis of poly-beta-hydroxyalkanoate by Brevundimonas vesicularis LMG P-23615 and Sphingopyxis macrogoltabida LMG 17324 using acid-hydrolyzed sawdust as carbon source.

    PubMed

    Silva, Johanna A; Tobella, Lorena M; Becerra, José; Godoy, Félix; Martínez, Miguel A

    2007-06-01

    Poly-beta-hydroxyalkanoate (PHA) is a biodegradable polymer accumulated in intracellular granules by different bacterial species. Its physical and chemical properties are similar to those of petroleum-derived plastics. Material generated by the acid hydrolysis of wood was evaluated for use in the bacterial synthesis of PHA. Acid-hydrolyzed sawdust was prepared and adjusted to pH 7. Mineral salts with carbon:nitrogen (C:N) proportions of 100:1, 100:3.5, 100:10, 100:30, or 100:50 and trace elements were added and these solutions were inoculated with a bacterial strain Brevundimonas vesicularis LMG P-23615 or Sphingopyxis macrogoltabida LMG 17324. The percentage of cells accumulating PHA was evaluated by flow cytometry. The hydrolyzed sawdust composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). The organic material (601.5 mg l(-1)) contained 112.5 mg l(-1) sugars. Over 96% of these sugars were consumed and more than 90% of the bacterial cells accumulated PHA. The 100:3.5 C:N proportion was optimal for growth and PHA synthesis, with yields ranging from 64% to 72% of the dry cell weight. The results suggest that acid-hydrolyzed sawdust can be used by bacteria as a carbon source for growth and PHA production. This forestry by sub-product offers a low-cost alternative for obtaining biodegradable plastics (e.g., PHA) synthesized by bacteria.

  20. Functional characterisation and cell specificity of BvSUT1, the transporter that loads sucrose into the phloem of sugar beet (Beta vulgaris L.) source leaves.

    PubMed

    Nieberl, P; Ehrl, C; Pommerrenig, B; Graus, D; Marten, I; Jung, B; Ludewig, F; Koch, W; Harms, K; Flügge, U-I; Neuhaus, H E; Hedrich, R; Sauer, N

    2017-05-01

    Sugar beet (Beta vulgaris L.) is one of the most important sugar-producing plants worldwide and provides about one third of the sugar consumed by humans. Here we report on molecular characterisation of the BvSUT1 gene and on the functional characterisation of the encoded transporter. In contrast to the recently identified tonoplast-localised sucrose transporter BvTST2.1 from sugar beet taproots, which evolved within the monosaccharide transporter (MST) superfamily, BvSUT1 represents a classical sucrose transporter and is a typical member of the disaccharide transporter (DST) superfamily. Transgenic Arabidopsis plants expressing the β-GLUCURONIDASE (GUS) reporter gene under control of the BvSUT1-promoter showed GUS histochemical staining of their phloem; an anti-BvSUT1-antiserum identified the BvSUT1 transporter specifically in phloem companion cells. After expression of BvSUT1 cDNA in bakers' yeasts (Saccharomyces cerevisiae) uptake characteristics of the BvSUT1 protein were studied. Moreover, the sugar beet transporter was characterised as a proton-coupled sucrose symporter in Xenopus laevis oocytes. Our findings indicate that BvSUT1 is the sucrose transporter that is responsible for loading of sucrose into the phloem of sugar beet source leaves delivering sucrose to the storage tissue in sugar beet taproot sinks.

  1. Extended-Spectrum beta (β)-Lactamases and Antibiogram in Enterobacteriaceae from Clinical and Drinking Water Sources from Bahir Dar City, Ethiopia.

    PubMed

    Abera, Bayeh; Kibret, Mulugeta; Mulu, Wondemagegn

    2016-01-01

    The spread of Extended-Spectrum beta (β)-Lactamases (ESBL)-producing Enterobacteriaceae has become a serious global problem. ESBL-producing Enterobacteriaceae vary based on differences in antibiotic use, nature of patients and hospital settings. This study was aimed at determining ESBL and antibiogram in Enterobacteriaceae isolates from clinical and drinking water sources in Bahir Dar City, Northwest Ethiopia. Enterobacteriaceae species were isolated from clinical materials and tap water using standard culturing procedures from September 2013 to March 2015. ESBL-producing-Enterobacteriaceae were detected using double-disk method by E-test Cefotaxim/cefotaxim+ clavulanic acid and Ceftazidime/ceftazidime+ clavulanic acid (BioMerieux SA, France) on Mueller Hinton agar (Oxoid, UK). Overall, 274 Enterobacteriaceae were isolated. Of these, 210 (44%) were from patients and 64 (17.1%) were from drinking water. The median age of the patients was 28 years. Urinary tract infection and blood stream infection accounted for 60% and 21.9% of Enterobacteriaceae isolates, respectively. Klebsiella pneumoniae was isolated from 9 (75%) of neonatal sepsis. The overall prevalence of ESBL-producing Enterobacteriaceae in clinical and drinking water samples were 57.6% and 9.4%, respectively. The predominant ESBL-producers were K. pneumoniae 34 (69.4%) and Escherichia coli 71 (58.2%). Statistically significant associations were noted between ESBL-producing and non- producing Enterobacteriaceae with regard to age of patients, infected body sites and patient settings (P = 0.001). ESBL-producing Enterobacteriaceae showed higher levels of resistance against chloramphenicol, ciprofloxacin and cotrimoxazole than non-ESBL producers (P = 0.001). ESBL-producing Enterobacteriaceae coupled with high levels of other antimicrobials become a major concern for treatment of patients with invasive infections such as blood stream infections, neonatal sepsis and urinary tract infections. ESBL

  2. Contaminated sinks in intensive care units: an underestimated source of extended-spectrum beta-lactamase-producing Enterobacteriaceae in the patient environment.

    PubMed

    Roux, D; Aubier, B; Cochard, H; Quentin, R; van der Mee-Marquet, N

    2013-10-01

    Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) outbreaks in intensive care units (ICUs) associated with contaminated handwashing sinks have been reported. To conduct a regional study to assess whether handwashing sinks in 135 ICU patient rooms are a potential source of contamination, and to identify factors associated with an increased risk of sink contamination. A multicentre study was conducted in 13 ICUs, including microbiological testing for ESBLE contamination at 185 sinks. The micro-organisms isolated were analysed using randomly amplified polymorphic DNA analysis to assess clonal spread in ICUs. Data were collected to document the use of each sink, factors that may contribute to contamination of clinical areas near to the sinks, and routine cleansing procedures for the sinks. Fifty-seven sinks were contaminated (31%) with ESBLE, mostly Klebsiella (N = 33) and Enterobacter (N = 18). In two ICUs, a high contamination rate was associated with clonal spread of an epidemic isolate. Risk factors for contamination of and by handwashing sinks were frequent: 81 sinks (44%) were used for handwashing as well as the disposal of body fluids; splash risk was identified for 67 sinks (36%), among which 23 were contaminated by ESBLE. Routine sink disinfection was frequent (85%), mostly daily (75%), and involved quaternary ammonium compounds (41%) or bleach (21%). A lower sink contamination rate was significantly associated with use of the sink being restricted to handwashing and to daily sink disinfection using bleach. In ICUs, contaminated sinks are a potential source of ESBLE in the environment of the patient, a problem that may be underestimated by ICU teams. Relatively simple measures may result in a rapid improvement of the situation, and a significant decrease of the risk of exposure of ICU patients to multiresistant Enterobacteriaceae. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  3. Extended-Spectrum beta (β)-Lactamases and Antibiogram in Enterobacteriaceae from Clinical and Drinking Water Sources from Bahir Dar City, Ethiopia

    PubMed Central

    Abera, Bayeh; Kibret, Mulugeta; Mulu, Wondemagegn

    2016-01-01

    Background The spread of Extended-Spectrum beta (β)-Lactamases (ESBL)-producing Enterobacteriaceae has become a serious global problem. ESBL-producing Enterobacteriaceae vary based on differences in antibiotic use, nature of patients and hospital settings. This study was aimed at determining ESBL and antibiogram in Enterobacteriaceae isolates from clinical and drinking water sources in Bahir Dar City, Northwest Ethiopia. Methods Enterobacteriaceae species were isolated from clinical materials and tap water using standard culturing procedures from September 2013 to March 2015. ESBL-producing-Enterobacteriaceae were detected using double-disk method by E-test Cefotaxim/cefotaxim+ clavulanic acid and Ceftazidime/ceftazidime+ clavulanic acid (BioMerieux SA, France) on Mueller Hinton agar (Oxoid, UK). Results Overall, 274 Enterobacteriaceae were isolated. Of these, 210 (44%) were from patients and 64 (17.1%) were from drinking water. The median age of the patients was 28 years. Urinary tract infection and blood stream infection accounted for 60% and 21.9% of Enterobacteriaceae isolates, respectively. Klebsiella pneumoniae was isolated from 9 (75%) of neonatal sepsis. The overall prevalence of ESBL-producing Enterobacteriaceae in clinical and drinking water samples were 57.6% and 9.4%, respectively. The predominant ESBL-producers were K. pneumoniae 34 (69.4%) and Escherichia coli 71 (58.2%). Statistically significant associations were noted between ESBL-producing and non- producing Enterobacteriaceae with regard to age of patients, infected body sites and patient settings (P = 0.001). ESBL-producing Enterobacteriaceae showed higher levels of resistance against chloramphenicol, ciprofloxacin and cotrimoxazole than non-ESBL producers (P = 0.001) Conclusions ESBL-producing Enterobacteriaceae coupled with high levels of other antimicrobials become a major concern for treatment of patients with invasive infections such as blood stream infections, neonatal sepsis and urinary

  4. Beta experiment

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A focused laser doppler velocimeter (LDV) system was developed for the measurement of atmospheric backscatter (beta) from aerosols at infrared wavelengths. A Doppler signal generator was used in mapping the coherent sensitive focal volume of a focused LDV system. System calibration data was analyzed during the flight test activity scheduled for the Beta system. These analyses were performed to determine the acceptability of the Beta measurement system's performance.

  5. Regeneration of pancreatic beta cells.

    PubMed

    Jun, Hee-Sook

    2008-05-01

    Diabetes mellitus results from inadequate mass of insulin-producing pancreatic beta cells. Type 1 diabetes is characterized by absolute loss of beta cells due to autoimmune-mediated destruction. Type 2 diabetes is characterized by relative deficiency of beta cells due to lack of compensation for insulin resistance. Restoration of deficient beta cell mass by transplantation from exogenous sources or by endogenous regeneration of insulin-producing cells would be therapeutic options. Mature beta cells have an ability to proliferate; however, it has been shown to be difficult to expand adult beta cells in vitro. Alternatively, regeneration of beta cells from embryonic and adult stem cells and pancreatic progenitor cells is an attractive method to restore islet cell mass. With information obtained from the biology of pancreatic development, direct differentiation of stem and progenitor cells toward a pancreatic beta cell phenotype has been tried using various strategies, including forced expression of beta cell-specific transcription factors. Further research is required to understand how endogenous beta cells differentiate and to develop methods to regenerate beta cells for clinically applicable therapies for diabetes.

  6. Spectral parameters modulation and source localization of blink-related alpha and low-beta oscillations differentiate minimally conscious state from vegetative state/unresponsive wakefulness syndrome.

    PubMed

    Bonfiglio, Luca; Piarulli, Andrea; Olcese, Umberto; Andre, Paolo; Arrighi, Pieranna; Frisoli, Antonio; Rossi, Bruno; Bergamasco, Massimo; Carboncini, Maria Chiara

    2014-01-01

    Recently, the cortical source of blink-related delta oscillations (delta BROs) in resting healthy subjects has been localized in the posterior cingulate cortex/precuneus (PCC/PCu), one of the main core-hubs of the default-mode network. This has been interpreted as the electrophysiological signature of the automatic monitoring of the surrounding environment while subjects are immersed in self-reflecting mental activities. Although delta BROs were directly correlated to the degree of consciousness impairment in patients with disorders of consciousness, they failed to differentiate vegetative state/unresponsive wakefulness syndrome (VS/UWS) from minimally conscious state (MCS). In the present study, we have extended the analysis of BROs to frequency bands other than delta in the attempt to find a biological marker that could support the differential diagnosis between VS/UWS and MCS. Four patients with VS/UWS, 5 patients with MCS, and 12 healthy matched controls (CTRL) underwent standard 19-channels EEG recordings during resting conditions. Three-second-lasting EEG epochs centred on each blink instance were submitted to time-frequency analyses in order to extract the normalized Blink-Related Synchronization/Desynchronization (nBRS/BRD) of three bands of interest (low-alpha, high-alpha and low-beta) in the time-window of 50-550 ms after the blink-peak and to estimate the corresponding cortical sources of electrical activity. VS/UWS nBRS/BRD levels of all three bands were lower than those related to both CTRL and MCS, thus enabling the differential diagnosis between MCS and VS/UWS. Furthermore, MCS showed an intermediate signal intensity on PCC/PCu between CTRL and VS/UWS and a higher signal intensity on the left temporo-parieto-occipital junction and inferior occipito-temporal regions when compared to VS/UWS. This peculiar pattern of activation leads us to hypothesize that resting MCS patients have a bottom-up driven activation of the task positive network and thus are

  7. Spectral Parameters Modulation and Source Localization of Blink-Related Alpha and Low-Beta Oscillations Differentiate Minimally Conscious State from Vegetative State/Unresponsive Wakefulness Syndrome

    PubMed Central

    Bonfiglio, Luca; Piarulli, Andrea; Olcese, Umberto; Andre, Paolo; Arrighi, Pieranna; Frisoli, Antonio; Rossi, Bruno; Bergamasco, Massimo; Carboncini, Maria Chiara

    2014-01-01

    Recently, the cortical source of blink-related delta oscillations (delta BROs) in resting healthy subjects has been localized in the posterior cingulate cortex/precuneus (PCC/PCu), one of the main core-hubs of the default-mode network. This has been interpreted as the electrophysiological signature of the automatic monitoring of the surrounding environment while subjects are immersed in self-reflecting mental activities. Although delta BROs were directly correlated to the degree of consciousness impairment in patients with disorders of consciousness, they failed to differentiate vegetative state/unresponsive wakefulness syndrome (VS/UWS) from minimally conscious state (MCS). In the present study, we have extended the analysis of BROs to frequency bands other than delta in the attempt to find a biological marker that could support the differential diagnosis between VS/UWS and MCS. Four patients with VS/UWS, 5 patients with MCS, and 12 healthy matched controls (CTRL) underwent standard 19-channels EEG recordings during resting conditions. Three-second-lasting EEG epochs centred on each blink instance were submitted to time-frequency analyses in order to extract the normalized Blink-Related Synchronization/Desynchronization (nBRS/BRD) of three bands of interest (low-alpha, high-alpha and low-beta) in the time-window of 50–550 ms after the blink-peak and to estimate the corresponding cortical sources of electrical activity. VS/UWS nBRS/BRD levels of all three bands were lower than those related to both CTRL and MCS, thus enabling the differential diagnosis between MCS and VS/UWS. Furthermore, MCS showed an intermediate signal intensity on PCC/PCu between CTRL and VS/UWS and a higher signal intensity on the left temporo-parieto-occipital junction and inferior occipito-temporal regions when compared to VS/UWS. This peculiar pattern of activation leads us to hypothesize that resting MCS patients have a bottom-up driven activation of the task positive network and thus

  8. Imported chicken meat as a potential source of quinolone-resistant Escherichia coli producing extended-spectrum beta-lactamases in the UK.

    PubMed

    Warren, R E; Ensor, V M; O'Neill, P; Butler, V; Taylor, J; Nye, K; Harvey, M; Livermore, D M; Woodford, N; Hawkey, P M

    2008-03-01

    Escherichia coli producing CTX-M-15 enzyme began to rapidly spread in the UK from around 2003 but other types also occur, notably CTX-M-14. We examined breasts from UK-reared (n = 62) and imported (n = 27) chickens as potential sources of quinolone-resistant E. coli with bla(CTX-M) genes. A further 40 samples for which the country of rearing could not be identified were examined. During 2006, 129 fresh and frozen chicken breast fillets were purchased from retail outlets in the West Midlands. These were cultured for E. coli on CLED agar containing 8 mg/L ciprofloxacin and carrying a 10 microg cefpodoxime disc. Resistant isolates were identified and typed by RAPD fingerprinting; bla(CTX-M) was identified by PCR and genotyped by reverse-line hybridization. The country of rearing was identified from the packaging for 89 of 129 purchased samples. Only one of the 62 UK-reared chicken samples carried E. coli producing a CTX-M-1 enzyme, whereas 10 of 27 samples reared overseas had E. coli with CTX-M enzymes. Specifically, 4/10 Brazilian, 3/4 Brazilian/Polish/French, and 2/2 Dutch samples had E. coli with CTX-M-2 enzymes. Six of 40 samples for which the country of rearing was not known had producers of CTX-M enzymes, 5 of them with CTX-M-14. Quinolone-resistant E. coli with various CTX-M beta-lactamase genes that are common in human infections worldwide were found in imported chicken breasts, indicating a possible source for gut colonization. Samples from Brazil were commonly positive for E. coli with CTX-M-2, the dominant bla(CTX-M) genotype from human infections in South America, which is currently rare in clinical infections in the UK. CTX-M-15, the dominant CTX-M type in human infections in the UK, was not found in chicken isolates, suggesting that the UK-reared chickens are not a reservoir of CTX-M-15.

  9. Beta in Streamers

    NASA Technical Reports Server (NTRS)

    Suess, Steven T.; Gary G. A.; Nerney, S. F.

    1999-01-01

    Streamers are often described as regions of the corona in which the density is higher than in coronal holes because the plasma is trapped by closed loops of magnetic flux. In contrast, Magnetohydrodynamics (MHD) models of the global corona show that the plasma beta identically equal to 8(pi)p/B(exp 2) > 1 in streamers above approximately 1.2Rs heliocentric height (p=pressure, B=magnetic field strength). There are three recent contributions to this topic. The first is that heating near the cusp further drives Beta up and can result in release of new slow solar wind from the top of the streamer. The second is SOHO/UVCS observations, in combination with a potential field/source surface model of the magnetic field, show beta > 1 above 1.2Rs in a streamer observed near solar sunspot minimum. The third is a magnetic field reconstruction technique (using field deforming algorithms) which was applied both to an isolated active region (AR 7999) and to the Pneuman & Kopp global MHD model. In the active region, beta becomes larger than unity at approximately 1.2Rs. In the Pneuman & Kopp model, beta = 1.0 at the base of the streamer and rises with increasing height, becoming 15-20 at 1.6Rs and 35-55 at 1.7RS. The collective implication of these three results is that beta > 1 everywhere in streamers above approximately 1.2 Rs. Global simulations go on to show that the reason streamers do not simply explode under such high beta conditions is that they are held down by pressure from the sides due to the magnetic fields (and low beta) in adjacent coronal holes. The main role of the closed magnetic loops near the cusp is to keep the streamer from continuously leaking plasma, as otherwise happens in a magnetic pinch which is similar but has no closed loops. The purpose of this note is to summarize the results implying that beta > 1 is a general property of streamers above 1.2 Rs.

  10. Dynamic radioactive particle source

    DOEpatents

    Moore, Murray E; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  11. Beta measurements

    NASA Technical Reports Server (NTRS)

    Schotland, R. M.; Warren, A. J.; Funariu, O. M.

    1991-01-01

    The second year's results of the BETA project research are presented. The program is divided into two areas, aerosol modification and climatology in the trade wind region and the climatology of BETA (CO2) on remote mountain top locations. Limited data is available on the aerosol climatology of the marine free troposphere (MFT) in the trade wind region. In order to study the effects of cumulus convection on the MFT values of BETA, a cloud model was developed to simulate the evolution of a typical Pacific trade wind cumulus cloud. The stages involved in this development are outlined. The assembly of the major optical components of the lidar was made. Tests were run of the spectral bandwidth of the Synrad laser when a portion of the beam is mixed with a component which has traveled 450 meters corresponding to a delay of 1.5 microsecs. The bandwidth of the beat signal was measured to be 3 KHz. The data processing system based on a parallel processing filter bank analyzer using true time squaring detectors at each filter was completed.

  12. Model Beta 5M: A potential instrumental counterpart to Method 5 for the continuous measurement of particulate matter emissions from combustion and other sources using isokinetic sample extraction technology followed by beta ray attenuation mass measurement techniques

    SciTech Connect

    Griguoli, F.T.

    1997-12-31

    For many years opacity and other values available from optical devices have been used in an attempt to assess and often quantify particulate matter emissions from stationary sources, particularly combustion sources using coal. These opacity values have also been used to obtain mass concentration data. Today`s reality is such that pollution abatement technologies have become better and better, dry or wet, and most processes are subject to a variety of conditions no longer suitable, in the author`s opinion, for the use of optical devices or derivatives of them. This paper describes a continuous extractive technique to measure particulate matter which has been used in Europe and around the world for more than 10 years. This technique works very well in changing particulate matter conditions, low particulate concentrations, small diameter stacks, and stacks/ducts with high water vapor content in the flue gas.

  13. [Sensitivity to beta-lactam and aminoglycoside antibiotics of clinical Proteus strains as dependent upon on their species classification and the source of their isolation].

    PubMed

    Shvidenko, I G

    1987-11-01

    Sensitivity of 130 Proteus clinical strains was studied. Among beta-lactam antibiotics cefotaxime showed marked advantages with respect to various Proteus species. All the isolates of Proteus mirabilis were sensitive to cefuroxime. Cefamezin and cephapirin were inferior by their activity to cefotaxime and cefuroxime. They were characterized by close antibacterial activity and almost complete cross resistance. Ampicillin and carbenicillin proved to be the least efficient among the tested beta-lactam antibiotics. Isolates of Proteus vulgaris and Proteus penneri were more resistant to the penicillins and cephalosporins than the cultures of Proteus mirabilis. Sensitivity of separate Proteus species to gentamicin, tobramycin, sisomicin and amikacin was close. No cross resistance to the aminoglycosides was detected. Studies on the effect of different doses of the antibiotics revealed pronounced heterogeneity of Proteus by the feature of sensitivity to the tested antibiotics. The level of the heterogeneity was not the same for separate antibiotics. Cultures of Proteus mirabilis resistant to ampicillin, carbenicillin, cefamezin and cephapirin were more frequent in patients with urogenital infections as compared to patients with intestinal infections and suppurative-inflammatory processes of other localization.

  14. BETA-SILICON CARBIDE AND ITS POTENTIAL FOR DEVICES

    DTIC Science & Technology

    BETA- SILICON CARBIDE AND ITS POTENTIAL FOR DEVICES. GROWTH OF BETA SIC CRYSTALS FROM SOLUTION USING MOLTEN SI AS SOLVENT. INCREASED RESISTIVITY (FROM 0.5 TO 3.8 OHM/CM) ACCOMPANIED DECREASE IN N CONTAMINATION SOURCES.

  15. Beta particle monitor for surfaces

    DOEpatents

    MacArthur, D.W.

    1997-10-21

    A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means. 2 figs.

  16. Beta particle monitor for surfaces

    DOEpatents

    MacArthur, Duncan W.

    1997-01-01

    A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means.

  17. Study of influence of plastic scintillators thicknesses to detect Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources

    SciTech Connect

    Cardenas, Jose Patricio Nahuel; Filho, Tufic Madi; Pereira, Maria da Conceicao Costa; Santos, Brianna B. dos; Correa, Eduardo de L.; Santos, Lucas Rodrigues dos; Lopes, Anderson Figueredo; Silva, Alexandre F.P. da; Santos, Diogo F. dos; Camilo, Douglas de S.; Purgato, Rafael T.; Aredes, Vitor O.G.

    2015-07-01

    The Nuclear and Energy Research Institute - IPEN, offers post-graduate programs, namely: Nuclear Technology - Applications (TNA), Nuclear Technology - Materials (TNM), Nuclear Technology - Reactors (TNR). The Institute programs mission is to form expert technicians, physicists and engineers with a strong knowledge in their discipline to work in the nuclear area. The course: 'Theoretical Fundamentals and Practices of the Instrumentation used in Nuclear Data Acquisition' covers the use of laboratory nuclear instrumentation and the accomplishment of experiments to obtain nuclear parameters. One of these experimental exercises is object of this work: 'Study of influence of plastic scintillators to detect Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources'. The use of scintillators plastic for the detection has the advantage of low cost, high mechanical strength, is not hygroscopic and can be manufactured in large volumes. This work aims to present the analysis of relative efficiency of detection of plastic scintillators of various thicknesses for beta particles and gamma radiation by the spectrum of {sup 137}Cs and {sup 90}Sr. Due to lack of resolution of the detectors plastic scintillators we worked with relative efficiency. The evaluation was done by reading deposited energy, using the software MAESTRO, for each detector thickness. For beta particles was observed an ideal thickness around 3 mm and the better photon efficiency was observed with increasing the thickness of the detector. The present experiment does not intend to establish a new technique for this subject: it solely aims student's practical exercises in nuclear properties of elements and detectors being part of the nuclear experimental course. (authors)

  18. Neutron Induced Beta Radiography

    SciTech Connect

    Shaikh, A. M.; Shylaja, D.

    2011-07-15

    In the present paper we give a new methodology named, 'neutron induced beta radiography-NIBR' which makes use of neutron activated Dy or In foils as source of (3-radiation. Radiographs are obtained with an aluminium cassette containing image plate, a sample under inspection and the activated Dy or In foil kept in tight contact. The sensitivity of the technique to thickness was evaluated for different materials in the form of step wedges. Some radiographs are presented to demonstrate potential of method to inspect thin samples.

  19. Shielding for beta-gamma radiation.

    PubMed

    Fletcher, J J

    1993-06-01

    The build-up factor, B, for lead was expressed as a polynominal cubic function of the relaxation length, mu x, and incorporated in a "general beta-gamma shielding equation." A computer program was written to determine shielding thickness for polyenergetic beta-gamma sources without resorting to the conventional "add-one-HVL" method.

  20. Oxalate content of silver beet leaves (Beta vulgaris var. cicla) at different stages of maturation and the effect of cooking with different milk sources.

    PubMed

    Simpson, Thomas S; Savage, Geoffrey P; Sherlock, Robert; Vanhanen, Leo P

    2009-11-25

    The work presented here indicates that people who have a tendency to develop kidney stones should avoid consuming regrowth and developed silver beet (Beta vulgaris var. cicla) leaves. Soluble oxalate contents of leaves range from 58% of the total oxalate for the mature leaves up to 89% for the regrowth tissue, with regrowth tissue containing the highest levels of soluble oxalate at 7267+/-307 mg/100 g of dry matter (DM). Leaves cooked in milk contained significantly (p<0.05) lower levels of soluble oxalate compared to the leaves that were cooked in water. Leaves cooked in low fat milk contained significantly lower levels (p<0.05) of soluble oxalate (1.9%) than leaves cooked in standard milk (5.3%) or cream (6.3%). To maximize the reduction of soluble oxalate during the cooking of high oxalate foods such as spinach and silver beet, a low fat milk cooking medium with neutral pH should be utilized.

  1. Beta cell device using icosahedral boride compounds

    DOEpatents

    Aselage, Terrence L.; Emin, David

    2002-01-01

    A beta cell for converting beta-particle energies into electrical energy having a semiconductor junction that incorporates an icosahedral boride compound selected from B.sub.12 As.sub.2, B.sub.12 P.sub.2, elemental boron having an .alpha.-rhombohedral structure, elemental boron having a .beta.-rhombohedral structure, and boron carbides of the chemical formula B.sub.12-x C.sub.3-x, where 0.15beta radiation source, and means for transmitting electrical energy to an outside load. The icosahedral boride compound self-heals, resisting degradation from radiation damage.

  2. Scintillator based beta batteries

    NASA Astrophysics Data System (ADS)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  3. Method for treating beta-spodumene ceramics

    DOEpatents

    Day, J. Paul; Hickman, David L.

    1994-09-27

    A vapor-phase method for treating a beta-spodumene ceramic article to achieve a substitution of exchangeable hydrogen ions for the lithium present in the beta-spodumene crystals, wherein a barrier between the ceramic article and the source of exchangeable hydrogen ions is maintained in order to prevent lithium contamination of the hydrogen ion source and to generate highly recoverable lithium salts, is provided.

  4. Interplanetary Lyman-beta emissions

    NASA Technical Reports Server (NTRS)

    Paresce, F.

    1973-01-01

    Derivation of the intensity of the diffuse hydrogen Lyman-beta glow at 1025 A which is due to resonance scattering of the solar H I 1025 A line by interstellar and interplanetary hydrogen. Two sources of neutral hydrogen are considered: the local interstellar medium interacting with the solar system, and the dust deionization of the H(+) component of the solar wind. It is shown that if the dust geometrical factor is less than or equal to five quintillionths per cm, observations of backscattered Lyman-beta radiation will provide a unique determination of the density and temperature of the local interstellar medium.

  5. Cereal beta-glucans

    USDA-ARS?s Scientific Manuscript database

    Cereal beta-glucans occur predominantly in oats and barley, but can be found in other cereals. Beta-glucan structure is a mixture of single beta-1,3-linkages and consecutive beta-1,4-linkages, and cellotriosyl and cellotetraosyl units typically make up 90-95% of entire molecule. Lichenase can hydr...

  6. beta-Hexachlorocyclohexane (beta-HCH)

    Integrated Risk Information System (IRIS)

    beta - Hexachlorocyclohexane ( beta - HCH ) ; CASRN 319 - 85 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Asses

  7. The Beta Cage: Screening Low Radioactive Backgrounds

    NASA Astrophysics Data System (ADS)

    Poinar, K.; Akerib, D.; Grant, D.; Schnee, R.; Shutt, T.; Golwala, S.; Ahmed, Z.

    2006-10-01

    The beta cage is a proposed multi-wire proportional chamber that will be the most sensitive device available to screen low-energy (200 keV) betas emitted at rates as low as 10-5 counts keV^1 cm-2 day-1 (of order 10-4 Bq/m^2). The expected sensitivity and details of the construction and commissioning of its prototype chamber are presented. The prototype beta cage is a 50x50x25 cm frame gridded by stacked wire planes contained in a chamber of gas. To reduce background, the chamber contains only enough mass to stop betas of interest. Samples are placed beneath the grid; the wires multiply the betas and collect their electron avalanche. Readouts allow discrimination of its events from background and determination of the beta (or alpha) source. The beta cage has potential use in carbon or tritium dating, with ^3H/^1H sensitivity of 10-20 and ^ 14C/ ^12C sensitivity of 10-18. Its design was motivated by CDMS, whose sensitivity to the dark matter candidate WIMPs is currently limited by low-energy beta contamination.

  8. Cellular pathways to beta-cell replacement.

    PubMed

    Fellous, Tariq G; Guppy, Naomi J; Brittan, Mairi; Alison, Malcolm R

    2007-02-01

    In the twenty-first century, diabetic patients are likely to be one of the major beneficiaries from the advancement of regenerative medicine through cellular therapies. Though the existence of a specific self-renewing stem cell within the pancreas is still far from clear, a surprising variety of cells within the pancreas can differentiate towards a beta-cell phenotype: ductular cells, periductular mesenchymal cells and beta-cells themselves can all give rise to new beta-cells. Extra-pancreatic adult somatic stem cells, in particular, those originating from bone marrow may also be capable of differentiating to beta-cells, though equally well the beneficial effects of bone marrow cells may reside in their contribution to the damaged islet vasculature. Forced expression of the beta-cell-specific transcription factor Pdx1 in hepatocytes also holds promise as a therapeutic strategy to increase insulin levels in diabetic individuals. Embryonic stem (ES) cells are clearly another possible source for generating beta-cells, but ES cells are beyond the scope of this review, which focuses on adult stem and progenitor cells capable of producing beta-cells. Despite considerable endeavour, we still have much to learn in the field of pancreatic regeneration prior to any clinically applicable therapy based upon adult stem cells.

  9. Modeling the transmission of beta rays through thin foils in planar geometry.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ionescu, E

    2016-01-01

    This paper is concerned with the modeling of the transmission of beta rays through thin foils in planar geometry based on the plane source concept, using Monte Carlo simulation of electron transport and least squares fitting. Applications of modeling results for calculating the efficiency of large-area beta sources, transmission coefficient of beta rays through thin foils and the beta detection efficiency of large-area detectors used in surface contamination measurements are also presented.

  10. Carotenoids: more than just beta-carotene.

    PubMed

    Gellenbeck, K W

    1998-12-01

    Fruits and vegetables of the human diet contain many of the over 600 carotenoid pigments that have been identified in plants. Led by work with beta-carotene, researchers have constantly been learning more about the metabolism of these compounds in the human body. Research work is now expanding beyond beta-carotene in an effort to understand what happens to all the pigments found in the human diet. This discussion briefly looks at research results on the carotenoids found in human serum as well as the effects of supplementation. Recent confusing results from large intervention trials with beta-carotene and lung cancer incidence are emphasized in relation to supplementation doses and beta-carotene source (synthetic vs. natural). The summation of results emphasizes the importance of the broad spectrum of carotenoids in the diet and relates to supplementation products currently being designed for the marketplace.

  11. Search for {beta}-delayed fission of {sup 228}Ac

    SciTech Connect

    Xu Yanbing; Ding Huajie; Yuan Shuanggui; Yang Weifan; Niu Yanning; Li Yingjun; Xiao Yonghou; Zhang Shengdong; Lu Xiting

    2006-10-15

    Radium was radiochemically separated from natural thorium. Thin {sup 228}Ra{yields}{beta}{sup -228}Ac sources were prepared and exposed to mica fission track detectors, and measured by an HPGe {gamma}-ray detector. The {beta}-delayed fission events of {sup 228}Ac were observed and its {beta}-delayed fission probability was found to be (5{+-}2)x10{sup -12}.

  12. Reprogramming of human exocrine pancreas cells to beta cells.

    PubMed

    Staels, Willem; Heremans, Yves; Heimberg, Harry

    2015-12-01

    One of the key promises of regenerative medicine is providing a cure for diabetes. Cell-based therapies are proving their safety and efficiency, but donor beta cell shortages and immunological issues remain major hurdles. Reprogramming of human pancreatic exocrine cells towards beta cells would offer a major advantage by providing an abundant and autologous source of beta cells. Over the past decade our understanding of transdifferentiation processes greatly increased allowing us to design reprogramming protocols that fairly aim for clinical trials.

  13. Critical role for interleukin-1beta (IL-1beta) during Chlamydia muridarum genital infection and bacterial replication-independent secretion of IL-1beta in mouse macrophages.

    PubMed

    Prantner, Daniel; Darville, Toni; Sikes, James D; Andrews, Charles W; Brade, Helmut; Rank, Roger G; Nagarajan, Uma M

    2009-12-01

    Recent findings have implicated interleukin-1beta (IL-1beta) as an important mediator of the inflammatory response in the female genital tract during chlamydial infection. But how IL-1beta is produced and its specific role in infection and pathology are unclear. Therefore, our goal was to determine the functional consequences and cellular sources of IL-1beta expression during a chlamydial genital infection. In the present study, IL-1beta(-/-) mice exhibited delayed chlamydial clearance and decreased frequency of hydrosalpinx compared to wild-type (WT) mice, implying an important role for IL-1beta both in the clearance of infection and in the mediation of oviduct pathology. At the peak of IL-1beta secretion in WT mice, the major producers of IL-1beta in vivo are F4/80(+) macrophages and GR-1(+) neutrophils, but not CD45(-) epithelial cells. Although elicited mouse macrophages infected with Chlamydia muridarum in vitro secrete minimal IL-1beta, in vitro prestimulation of macrophages by Toll-like receptor (TLR) ligands such as lipopolysaccharide (LPS) purified from Escherichia coli or C. trachomatis L2 prior to infection greatly enhanced secretion of IL-1beta from these cells. By using LPS-primed macrophages as a model system, it was determined that IL-1beta secretion was dependent on caspase-1, potassium efflux, and the activity of serine proteases. Significantly, chlamydia-induced IL-1beta secretion in macrophages required bacterial viability but not growth. Our findings demonstrate that IL-1beta secreted by macrophages and neutrophils has important effects in vivo during chlamydial infection. Additionally, prestimulation of macrophages by chlamydial TLR ligands may account for the elevated levels of pro-IL-1beta mRNA observed in vivo in this cell type.

  14. The selectivity of beta-adrenoceptor antagonists at the human beta1, beta2 and beta3 adrenoceptors.

    PubMed

    Baker, Jillian G

    2005-02-01

    Beta-adrenoceptor antagonists ("beta-blockers") are one of the most widely used classes of drugs in cardiovascular medicine (hypertension, ischaemic heart disease and increasingly in heart failure) as well as in the management of anxiety, migraine and glaucoma. Where known, the mode of action in cardiovascular disease is from antagonism of endogenous catecholamine responses in the heart (mainly at beta1-adrenoceptors), while the worrisome side effects of bronchospasm result from airway beta2-adrenoceptor blockade. The aim of this study was to determine the selectivity of beta-antagonists for the human beta-adrenoceptor subtypes. (3)H-CGP 12177 whole cell-binding studies were undertaken in CHO cell lines stably expressing either the human beta1-, beta2- or the beta3-adrenoceptor in order to determine the affinity of ligands for each receptor subtype in the same cell background. In this study, the selectivity of well-known subtype-selective ligands was clearly demonstrated: thus, the selective beta1 antagonist CGP 20712A was 501-fold selective over beta2 and 4169-fold selective over beta3; the beta2-selective antagonist ICI 118551 was 550- and 661-fold selective over beta1 and beta3, respectively, and the selective beta3 compound CL 316243 was 10-fold selective over beta2 and more than 129-fold selective over beta1. Those beta2-adrenoceptor agonists used clinically for the treatment of asthma and COPD were beta2 selective: 29-, 61- and 2818-fold for salbutamol, terbutaline and salmeterol over beta1, respectively. There was little difference in the affinity of these ligands between beta1 and beta3 adrenoceptors. The clinically used beta-antagonists studied ranged from bisoprolol (14-fold beta1-selective) to timolol (26-fold beta2-selective). However, the majority showed little selectivity for the beta1- over the beta2-adrenoceptor, with many actually being more beta2-selective. This study shows that the beta1/beta2 selectivity of most clinically used beta-blockers is

  15. Protein beta-turn prediction using nearest-neighbor method.

    PubMed

    Kim, Saejoon

    2004-01-01

    With the emerging success of protein secondary structure prediction through the applications of various statistical and machine learning techniques, similar techniques have been applied to protein beta-turn prediction. In this study, we perform protein beta-turn prediction using a k-nearest neighbor method, which is combined with a filter that uses predicted protein secondary structure information. Traditional beta-turn prediction from k-nearest neighbor method is modified to account for the unbalanced ratio of the natural occurrence of beta-turns and non-beta-turns. Our prediction scheme is tested on a set of 426 non-homologous protein sequences. The prediction scheme consists of two stages: k-nearest neighbor method stage and filtering stage. Variations of the k-nearest neighbor method were used to take property of beta-turns into consideration. Our filtering method uses beta-turn/non-beta-turn estimates from the k-nearest neighbor method stage and predicted protein secondary structure information from PSI-PRED in order to get new beta-turn/non-beta-turn estimate. Our result is compared with the previously best known beta-turn prediction method on the dataset of 426 non-homologous protein sequences and is shown to give slightly superior performance at significantly lower computational complexity. Contact the author for information on the source code of the programs used.

  16. Respiratory effects of beta-adrenergic receptor blockers.

    PubMed

    Antonelli-Incalzi, Raffaele; Pedone, Claudio

    2007-01-01

    Antagonists of the beta-adrenergic receptor (beta-AR antagonists) are a heterogeneous class of drugs. Selected members of this class are highly recommended in congestive heart failure (HF) and after acute myocardial infarction. Hydrosolubility, half life and prevalent route of excretion define the pharmacokinetic profile of individual drugs, whereas the respective degree of affinity for beta1-AR and beta2-AR, the level of coexistent agonist properties and several beta-AR independent properties (e. g. antioxidant, direct vasodilating effect) contribute to shape the pharmacodynamic profile. Genetically determined differences in the response to beta-AR antagonists and, probably, age-related changes in the neuroautonomic system are further source of variability in the effect of beta-AR antagonists on bronchial tone. Patients with chronic obstructive pulmonary disease (COPD) are theoretically at risk of worsening respiratory flows and symptoms caused by beta-AR antagonists prescribed for concurrent HF or myocardial infarction. Most of these patients, however, do not experience side effects, maybe because the improved haemodynamic due to beta-AR antagonists therapy may in turn improve the respiratory function. Occasional patients can develop untoward respiratory effects of beta-AR antagonists, and this risk is higher for those with severe COPD or active asthma. We provide some simple common sense rules for selecting patients with COPD or asthma that are suitable for beta-AR antagonists therapy while minimizing the risk of adverse respiratory effects.

  17. Alpha and beta thalassemia.

    PubMed

    Muncie, Herbert L; Campbell, James

    2009-08-15

    The thalassemias are a group of inherited hematologic disorders caused by defects in the synthesis of one or more of the hemoglobin chains. Alpha thalassemia is caused by reduced or absent synthesis of alpha globin chains, and beta thalassemia is caused by reduced or absent synthesis of beta globin chains. Imbalances of globin chains cause hemolysis and impair erythropoiesis. Silent carriers of alpha thalassemia and persons with alpha or beta thalassemia trait are asymptomatic and require no treatment. Alpha thalassemia intermedia, or hemoglobin H disease, causes hemolytic anemia. Alpha thalassemia major with hemoglobin Bart's usually results in fatal hydrops fetalis. Beta thalassemia major causes hemolytic anemia, poor growth, and skeletal abnormalities during infancy. Affected children will require regular lifelong blood transfusions. Beta thalassemia intermedia is less severe than beta thalassemia major and may require episodic blood transfusions. Transfusion-dependent patients will develop iron overload and require chelation therapy to remove the excess iron. Bone marrow transplants can be curative for some children with beta thalassemia major. Persons with thalassemia should be referred for preconception genetic counseling, and persons with alpha thalassemia trait should consider chorionic villus sampling to diagnose infants with hemoglobin Bart's, which increases the risk of toxemia and postpartum bleeding. Persons with the thalassemia trait have a normal life expectancy. Persons with beta thalassemia major often die from cardiac complications of iron overload by 30 years of age.

  18. MOON for neutrino-less {beta}{beta} decays and {beta}{beta} nuclear matrix elements

    SciTech Connect

    Ejiri, H.

    2009-11-09

    The MOON project aims at spectroscopic 0v{beta}{beta} studies with the v-mass sensitivity of 100-30 meV by measuring two beta rays from {sup 100}Mo and/or {sup 82}Se. The detector is a compact super-module of multi-layer PL scintillator plates. R and D works made by the pro to-type MOON-1 and the small PL plate show the possible energy resolution of around {sigma}{approx}2.2%, as required for the mass sensitivity. Nuclear matrix elements M{sup 2v} for 2v{beta}{beta} are shown to be given by the sum {sigma}{sub L}M{sub k} of the 2v{beta}{beta} matrix elements M{sub k} through intermediate quasi-particle states in the Fermi-surface, where Mi is obtained experimentally by using the GT(J{sup {pi}} = 1{sup +}) matrix elements of M{sub i}(k) and M{sub f}(k) for the successive single-{beta} transitions through the k-th intermediate state.

  19. Beta blockers in hypertension.

    PubMed

    Thadani, U

    1983-11-10

    Beta-adrenoceptor antagonists are effective in the management of patients with mild-to-moderate hypertension. Noncardioselective agents, cardioselective agents and beta blockers with intrinsic sympathomimetic activity (ISA) are equally effective, provided they are used in equipotent doses. Beta blockers can be used as first-line therapy in the management of hypertension and can be safely combined with diuretics, vasodilators, or both, for a better control of blood pressure. The exact mechanism by which beta blockers decrease blood pressure remains speculative, but they all reduce cardiac output during long-term therapy; drugs with ISA lower cardiac output and heart rate less than do drugs without ISA. Pharmacokinetic properties of beta blockers differ widely; drugs metabolized by the liver have shorter plasma half-lives than drugs primarily excreted by the kidneys. Although many of the side effects of various beta blockers are similar, differences in water and lipid solubility account for a higher incidence of central nervous system side effects with lipid-soluble drugs (such as propranolol and metoprolol) than with hydrophilic drugs (such as atenolol and timolol). The incidence of cold extremities has been reported to be less with drugs with ISA, and the incidence of bronchospasm less with cardioselective drugs. In the management of uncomplicated mild-to-moderate hypertension, all beta blockers are equally effective and produce less troublesome side effects than alternative antihypertensive agents. For effective therapy beta blockers can be used in 2 divided daily doses or even once daily.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Beta-cryptoxanthin: A vitamin A-forming carotenoid

    USDA-ARS?s Scientific Manuscript database

    Beta-cryptoxanthin is a common carotenoid. It is generally the fourth most abundant in human blood but can achieve high concentrations especially in Japanese and Spanish populations. Its richest food sources include mandarin oranges, persimmons, oranges, papayas, pumpkin, and red sweet peppers. Beta...

  1. Propagating structure of alzheimer's {beta}-amyloid is parallel {beta}-sheet with residues in exact register.

    SciTech Connect

    Benzinger, T. L. S.; Gregory, D. M.; Burkoth, T. S.; Miller-Auer, H.; Lynn, D. G.; Botto, R. E.; Meredith, S. C.; Chemistry; Univ. of Chicago

    1998-11-10

    The pathognomonic plaques of Alzheimer's disease are composed primarily of the 39- to 43-aa {beta}-amyloid (A{beta}) peptide. Crosslinking of A{beta} peptides by tissue transglutaminase (tTg) indicates that Gln15 of one peptide is proximate to Lys16 of another in aggregated A{beta}. Here we report how the fibril structure is resolved by mapping interstrand distances in this core region of the A{beta} peptide chain with solid-state NMR. Isotopic substitution provides the source points for measuring distances in aggregated A{beta}. Peptides containing a single carbonyl 13C label at Gln15, Lys16, Leu17, or Val18 were synthesized and evaluated by NMR dipolar recoupling methods for the measurement of interpeptide distances to a resolution of 0.2 Angstrom. Analysis of these data establish that this central core of A{beta} consists of a parallel {beta}-sheet structure in which identical residues on adjacent chains are aligned directly, i.e., in register. Our data, in conjunction with existing structural data, establish that the A{beta} fibril is a hydrogen-bonded, parallel {beta}-sheet defining the long axis of the A{beta} fibril propagation.

  2. Rapid synthesis of beta zeolites

    DOEpatents

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  3. Beta Absorption Mass Monitoring of Particulates - A Review

    NASA Technical Reports Server (NTRS)

    Lilienfeld, Pedro

    1971-01-01

    The theory and application of beta-radiation absorption for the measurement and monitoring of airborne particulates are discussed. The use of this technique, both for source testing and for ambient air quality monitoring is reviewed. Various particle collection methods used in conjunction with beta absorption sensing configurations are considered. State of the art and current developments of instrumentation approaches for the automated measurement of mass concentration and size distribution of aerosols by beta absorption are discussed. Methods for electronic signal processing and recording are presented. The Beta absorption technique appears as a powerful tool for the unattended measurement of the mass of particulate pollution, compatible with telemetry and central data processing methods.

  4. Beta adrenergic receptors in human cavernous tissue

    SciTech Connect

    Dhabuwala, C.B.; Ramakrishna, C.V.; Anderson, G.F.

    1985-04-01

    Beta adrenergic receptor binding was performed with /sup 125/I iodocyanopindolol on human cavernous tissue membrane fractions from normal tissue and transsexual procedures obtained postoperatively, as well as from postmortem sources. Isotherm binding studies on normal fresh tissues indicated that the receptor density was 9.1 fmoles/mg. with a KD of 23 pM. Tissue stored at room temperature for 4 to 6 hours, then at 4C in saline solution for 19 to 20 hours before freezing showed no significant changes in receptor density or affinity, and provided evidence for the stability of postmortem tissue obtained within the same time period. Beta receptor density of 2 cavernous preparations from transsexual procedures was not significantly different from normal control tissues, and showed that high concentrations of estrogen received by these patients had no effect on beta adrenergic receptor density. Displacement of /sup 125/iodocyanopindolol by 5 beta adrenergic agents demonstrated that 1-propranolol had the greatest affinity followed by ICI 118,551, zinterol, metoprolol and practolol. When the results of these displacement studies were subjected to Scatfit, non- linear regression line analysis, a single binding site was described. Based on the relative potency of the selective beta adrenergic agents it appears that these receptors were of the beta 2 subtype.

  5. Purification and properties of beta-galactosidase from Aspergillus nidulans.

    PubMed

    Díaz, M; Pedregosa, A M; de Lucas, J R; Torralba, S; Monistrol, I F; Laborda, F

    1996-12-01

    Beta-Galactosidase from mycelial extract of Aspergillus nidulans has been purified by substrate affinity chromatography and used to obtain anti-beta-galactosidase polyclonal antibodies. A. nidulans growing in lactose as carbon source synthesizes one active form of beta-galactosidase which seems to be a multimeric enzyme of 450 kDa composed of monomers with 120 and 97 kDa. Although the enzyme was not released to the culture medium, some enzymatic activity was detected in a cell-wall extract, thus suggesting that it can be an extracellular enzyme. Beta-Galactosidase of A. nidulans is a very unstable enzyme with an optimum pH value of 7.5 and an optimum temperature of 30 degrees C. It was only active against beta-galactoside substrates like lactose and p-nitrophenyl-beta-D-galactoside (PNPG).

  6. Delta 5-3beta-hydroxysteroid dehydrogenase (3 beta HSD) from Digitalis lanata. Heterologous expression and characterisation of the recombinant enzyme.

    PubMed

    Herl, Vanessa; Frankenstein, Jördis; Meitinger, Nadine; Müller-Uri, Frieder; Kreis, Wolfgang

    2007-06-01

    During the biosynthesis of cardiac glycosides, Delta (5)-3beta-hydroxysteroid dehydrogenase (3 beta HSD, EC 1.1.1.51) converts pregnenolone (5-pregnen-3beta-ol-20-one) to isoprogesterone (5-pregnene-3,20-dione). A 3 beta HSD gene was isolated from leaves of Digitalis lanata. It consisted of 870 nucleotides containing a 90 nucleotide long intron. A full-length cDNA clone that encodes 3 beta HSD was isolated by RT-PCR from the same source. A SPH I /KPN I 3 beta HSD cDNA was cloned into the pQE30 vector and then transferred into E. COLI strain M15[pREP4]. 3 beta HSD cDNA was functionally expressed as a His-tagged fusion protein (pQ3 beta HSD) composed of 273 amino acids (calculated molecular mass 28,561 Da). pQ3 beta HSD was purified by metal chelate affinity chromatography on Ni-NTA. Pregnenolone and other 3beta-hydroxypregnanes but not cholesterol were 3beta-oxidised by pQ3 beta HSD when NAD was used as the co-substrate. Testosterone (4-androsten-17beta-ol-3-one) was converted to 4-androstene-3,17-dione indicating that the pQ3 beta HSD has also 17beta-dehydrogenase activity. pQ3 beta HSD was able to reduce 3-keto steroids to their corresponding 3beta-hydroxy derivatives when NADH was used as the co-substrate. For comparison, 3 beta HSD genes were isolated and sequenced from another 6 species of the genus DIGITALIS. Gene structure and the deduced 3 beta HSD proteins share a high degree of similarity.

  7. Beta scattering and beta back-scattering from a thin target

    SciTech Connect

    Bafandeh, H.R.

    1992-01-01

    An experimental and theoretical technique is presented to determine the distribution of transmitted and back scattered beta particles as a function of angle of incident radiation on a target. Scatterers used consisted of metallic foils of various thicknesses and atomic number, such as Al, Zn, Fe, Ag, and Zr. Three pure beta-emitting radionuclides, [sup 32]P, [sup 204]Tl, and [sup 147]Pm characterized by end-point energies of 1.71 Mev, 0.769 Mev, and 0.225 Mev, respectively, were prepared as individual sources and used in the experimental work. A scintillation detector used in conjunction with the target scatterer and a specially designed fixture that allowed rotation about its vertical rotation axis provided the proper geometry and shielding for this experiment. Finally, the author attempted to compare experimental results with computer calculations and derived an algebraic equation to predict the intensity of beta particle back-scattered radiation as a function of energy of the source material, the scattering angle, scatterer thickness, and the material of the target scatterer. Unlike the case of heavy charged particles such as alpha particles, the effects of beta particle back scattering on dose calculations cannot be ignored. Scattering effects also have important implications with respect to the measurement of beta-emitting radionuclides and the measurements of beta radiation dose.

  8. Beta Cell Breakthroughs

    MedlinePlus

    ... says Douglas Melton, PhD, a biologist at the Harvard Stem Cell Institute. Fluctuating blood glucose levels do ... journal Cell, Melton reported that his team at Harvard managed to turn human stem cells into beta ...

  9. Beta-carotene

    MedlinePlus

    ... disease, rheumatoid arthritis, schizophrenia, and skin disorders including psoriasis and vitiligo. Beta-carotene is also in used ... Depression. Epilepsy. Headaches. Heartburn. Hypertension. Infertility. ... Rheumatoid arthritis. Schizophrenia. Other conditions. More evidence is ...

  10. Beta experiment flight report

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A focused laser Doppler velocimeter system was developed for the measurement of atmospheric backscatter (beta) from aerosols at infrared wavelengths. The system was flight tested at several different locations and the results of these tests are summarized.

  11. [Internal and external sources of the radiation induce the blocking of the proliferation of the human endothelial cells in culture. G2-block is induced by beta-particle 3H-thymidine and gamma-rays 137Cs].

    PubMed

    Gil'iano, N Ia; Konevega, L V; Stepanov, S I; Semenova, E G; Noskin, L A

    2007-01-01

    We found that low doses (0.12-0.46Gy) of (methyl-) 3H-thymidine incorporated into human endothelial cells induce the accumulation cells in G2-phase of the cell cycle. Temperate doses of (1-6 Gy) gamma-rays 137Cs were less effective in the G2-block estimated by flow cytometry analysis of DNA content. Furthermore, the induced the high level of the chromosome aberrations (bridges and fragments in anaphases). 1Gy of gamma-ray 137Cs and 0.005 Gy of beta-rays induced the same per cent of the aberrant anaphases. Apparently, that the damages of the cellular hereditary structures are responsible for the blocking of the cellular proliferation in G2-phase. We suggest, that the disposition 3H-thymidine into radiosensitive target (DNA) defines the high cytotoxic of the beta-rays.

  12. A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

    SciTech Connect

    A Kolyada; C Lee; A De Biasio; N Beglova

    2011-12-31

    {beta}2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of {beta}2GPI generated by anti-{beta}2GPI antibodies is pathologically important, in contrast to monomeric {beta}2GPI which is abundant in plasma. We created a dimeric inhibitor, A1-A1, to selectively target {beta}2GPI in {beta}2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of {beta}2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of {beta}2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of {beta}2GPI present in human serum, {beta}2GPI purified from human plasma and the individual domain V of {beta}2GPI. We demonstrated that when {beta}2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of {beta}2GPI to cardiolipin, regardless of the source of {beta}2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of {beta}2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-{beta}2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric {beta}2GPI to cardiolipin. Our results suggest that the approach of using a dimeric inhibitor to block {beta}2GPI in the pathological multivalent {beta}2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.

  13. Genetics Home Reference: beta-ureidopropionase deficiency

    MedlinePlus

    ... down N-carbamyl-beta-alanine to beta-alanine, ammonia, and carbon dioxide. Both beta-aminoisobutyric acid and ... beta-ureidopropionase deficiency Merck Manual Professional Version: Pyrimidine Metabolism Disorders Orphanet: Beta-ureidopropionase deficiency Patient Support and ...

  14. The beta cell immunopeptidome.

    PubMed

    Dudek, Nadine L; Purcell, Anthony W

    2014-01-01

    Type 1 diabetes results from the autoimmune-mediated destruction of insulin-secreting beta cells, leading to beta cell loss and insulin deficiency. Presentation of peptides derived from beta cell proteins to autoreactive lymphocytes is critical for the development of disease, and the list of antigens recognized is increasing. A number of these proteins are found within the beta cell secretory granules, which are transiently exposed to the immune system during normal cellular function. How the interplay of environmental and genetic determinants culminates in destructive autoimmunity remains to be clearly defined. Nonconventional presentation of peptide ligands, posttranslational modification of peptides, and the role of the gut microbiome in the development of the immune system are all considered central topics in disease pathogenesis. Each of these may provide a mechanism by which presentation of antigenic peptides in the target tissue differs from presentation in the thymus, allowing autoreactive cells to escape tolerance induction. The high metabolic demand on pancreatic islets, the high concentration of granule proteins, and the susceptibility of islets to cellular stress may all contribute to the presentation of abnormal ligands in the pancreas. Moreover, the finding that small molecules can alter the repertoire of peptides presented by major histocompatibility complex molecules provides a tantalizing hypothesis for the presentation of autoantigenic peptides in the presence of microbial or endogenous metabolites. In this chapter, we provide an overview of the immunopeptidome of beta cells and the key factors that may influence presentation of beta cell antigens to the immune system.

  15. New precision measurements of free neutron beta decay with cold neutrons

    DOE PAGES

    Baeßler, Stefan; Bowman, James David; Penttilä, Seppo I.; ...

    2014-10-14

    Precision measurements in free neutron beta decay serve to determine the coupling constants of beta decay, and offer several stringent tests of the standard model. This study describes the free neutron beta decay program planned for the Fundamental Physics Beamline at the Spallation Neutron Source at Oak Ridge National Laboratory, and finally puts it into the context of other recent and planned measurements of neutron beta decay observables.

  16. Boosted Beta Regression

    PubMed Central

    Schmid, Matthias; Wickler, Florian; Maloney, Kelly O.; Mitchell, Richard; Fenske, Nora; Mayr, Andreas

    2013-01-01

    Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1). Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures. PMID:23626706

  17. Autoradiographic localization of beta-adrenoceptors in asthmatic human lung

    SciTech Connect

    Spina, D.; Rigby, P.J.; Paterson, J.W.; Goldie, R.G. )

    1989-11-01

    The autoradiographic distribution and density of beta-adrenoceptors in human non-diseased and asthmatic bronchi were investigated using (125I)iodocyanopindolol (I-CYP). Analysis of the effects of the beta-adrenoceptor antagonists on I-CYP binding demonstrated that betaxolol (20 nM, beta 1-selective) had no significant effect on specific grain density in either nonasthmatic or asthmatic human bronchus, whereas ICI-118551 (20 nM, beta 2-selective) inhibited I-CYP binding by 85 +/- 9% and 89 +/- 3%, respectively. Thus, homogeneous populations of beta 2-adrenoceptors existed in bronchi from both sources. Large populations of beta-adrenoceptors were localized to the bronchial epithelium, submucosal glands, and airway smooth muscle. Asthmatic bronchial tissue featured epithelial damage with exfoliated cells associated with luminal mucus plugs. A thickened basement membrane and airway smooth muscle hyperplasia were also evident. High levels of specific I-CYP binding were also detected over asthmatic bronchial smooth muscle, as assessed by autoradiography and quantitation of specific grain densities. Isoproterenol and fenoterol were 10- and 13-fold less potent, respectively, in bronchi from asthmatic lung than in those from nonasthmatic lung. However, this attenuated responsiveness to beta-adrenoceptor agonists was not caused by reduced beta-adrenoceptor density in asthmatic airways. A defect may exist in the coupling between beta-adrenoceptors and postreceptor mechanisms in severely asthmatic lung.

  18. IO SUBSYSTEM 1 BETA

    SciTech Connect

    Sjaardema, Greg

    2002-08-21

    "IO Subsystem Ver. 1.0 Beta" uses standard object-oriented principles to minimize dependencies between the underlying input or output database format and the client code (i.e., Sierra) using the io subsystem. The interface and priciples are simolar to the Facade pattern described in the "Design Patterns" book by Gamma, et.al. The software uses data authentication algorithms to ensure data input/output is consistent with model being defined. "IO Subsystem Ver. 1.0 Beta" is a database independent input/output library for finite element analysis, preprocessing, post processing, and translation programs.

  19. Expression of TGF-beta 1, -beta 2 and -beta 3 in localized and systemic scleroderma.

    PubMed

    Querfeld, C; Eckes, B; Huerkamp, C; Krieg, T; Sollberg, S

    1999-09-01

    Scleroderma is a generalized or localized disorder which leads to fibrosis of the affected organs. TGF-beta has been implicated as a causal agent in its pathogenesis. In mammals, TGF-beta comprises a family of three members, beta 1, beta 2 and beta 3. Since cutaneous wound healing is thought to result either in formation of a scar or in scar-free tissue regeneration, depending on the relative amounts of the beta 3 isoform, the expression of all three isoforms was studied in skin biopsies of patients with either localized or systemic scleroderma. mRNA for all three isoforms was detected in inflammatory skin areas of both disease forms, but never in sclerotic or healthy skin. Immunohistochemical analysis confirmed expression of beta1 and beta 2 proteins in inflammatory skin of patients, whereas beta 3 protein appeared to be present in the subepidermal area and also found throughout the dermis of patients and healthy dermis as well.

  20. Variability in the BETA Science Fields

    NASA Astrophysics Data System (ADS)

    Stevens, Jamie; Johnston, Simon; Bannister, Keith

    2011-04-01

    We propose to observe the Fornax BETA test field over a period of 6 months to characterise the variability of sources in the field. The resultant outcomes will (a) provide unique science, (b) contribute vital information for BETA observations, including calibration and imaging and (c) help refine the VAST science case. We will use novel on-the-fly mapping and CABB's increased bandwidth to cover 30 square degrees to 0.1 mJy sensitivity. We expect to detect in excess of 100 variable sources, providing us with insight into the structure of both the interstellar and intergalactic mediums. We have the potential to detect true transients and characterise them over the electromagnetic spectrum via ToO follow-ups.

  1. beta-Chloronaphthalene

    Integrated Risk Information System (IRIS)

    beta - Chloronaphthalene ; CASRN 91 - 58 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  2. Trichoderma .beta.-glucosidase

    DOEpatents

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  3. beta-Propiolactone

    Integrated Risk Information System (IRIS)

    beta - Propiolactone ; CASRN 57 - 57 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  4. Applied Beta Dosimetry

    SciTech Connect

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  5. Venus - Beta Regio

    NASA Image and Video Library

    1996-02-05

    This portion of NASA Magellan radar image strip shows a small region on Venus 20 kilometers 12.4 miles wide and 75 km 50 miles long on the east flank of a major volcanic upland called Beta Regio. http://photojournal.jpl.nasa.gov/catalog/PIA00206

  6. Measuring the skin dose protection afforded by protective apparel with a beta spectrometer

    SciTech Connect

    Martz, D.E.; Rich, B.L.; Johnson, L.O. )

    1986-10-01

    This paper reports that the protective apparel worn by radiation workers to avoid skin contamination also provides measurable protection against external beta sources. The beta contribution to the skin dose rate depends on the residual energy spectrum of the beta particles after they have penetrated the protective apparel. The shift in the beta energy spectra and consequent reduction in the shallow dose rates afforded by various items of protective apparel were investigated for a few laboratory beta sources using a beta spectrometer that is capable of dose calculations. The results presented here indicate that significant dose rates to the skin can occur despite the presence of protective apparel if high energy beta emitting isotopes are present.

  7. Interferon Beta-1b Injection

    MedlinePlus

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course ... and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications ...

  8. Misleading Betas: An Educational Example

    ERIC Educational Resources Information Center

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  9. Accumulation of Poly (beta-Hydroxybutyrate) by Halobacteria.

    PubMed

    Fernandez-Castillo, R; Rodriguez-Valera, F; Gonzalez-Ramos, J; Ruiz-Berraquero, F

    1986-01-01

    Some species of extremely halophilic archaebacteria, Halobacteriaceae, have been shown to accumulate large amounts of poly (beta-hydroxybutyrate) under conditions of nitrogen limitation and abundant carbon source. The production of poly (beta-hydroxybutyrate), at least in large quantities, was restricted to two carbohydrate-utilizing species, Halobacterium mediterranei and H. volcanii. In addition to the nutrients in the media, the salt concentration also influenced poly (beta-hydroxybutyrate) accumulation, which was greater at lower salt concentrations. The possible application of these microorganisms for the production of biodegradable plastics is discussed.

  10. Production and catabolite repression of Penicillium italicum beta-glucanases.

    PubMed Central

    Santos, T; Villanueva, J R; Nombela, C

    1977-01-01

    The filamentous fungus Penicillium italicum, grown in a defined liquid medium, produced beta-1,3-glucanase, which remained essentially bound to the cells, and beta-1,6-glucanase, an essentially extracellular enzyme. When glucose was depleted from the medium, when a limited concentration of glucose (0.2%) was maintained, or when the carbon source was galactose (3%) or lactose (3%), a significant increase in the specific activity of beta-1,3-glucanase, in cell extracts, took place. This was paralleled by a very slow rate of growth, and under glucose limitation, the appearance of beta-1,3-glucanase in the medium was also observed. On the other hand, when an excess of glucose, fructose, or sucrose was present, the specific activity remained constant and active growth was promoted. Laminarin, cellobiose, gentiobiose, and isolated Penicillium italicum walls were not capable of significantly inducing beta-1,3-glucanase synthesis to a level beyond that attained by glucose limitation. A similar behavior was observed for beta-1,6-glucanase. beta-1,3-Glucanase and beta-1,6-glucanase are therefore constitutive enzymes subjected to catabolite repression. The results are discussed in the context of the possible functions that have been suggested for glucanases and related enzymes. PMID:830646

  11. Efficiency transfer method applied to surface beta contamination measurements.

    PubMed

    Stanga, D; De Felice, P; Capogni, M

    2017-08-09

    In this paper, the application of the efficiency transfer method to the evaluation of the surface beta contamination is described. Using efficiency transfer factors, the reference calibration factor of contamination monitors is corrected, to obtain the calibration factor for an actual contamination source. The experimental part of the paper illustrates the applicability of the method to the direct measurement of the surface beta contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... beta or gamma-emitting material or 0.37 MBq (10 µCi) or less of alpha-emitting material; (4) Seeds of... brachytherapy sources, except for gamma stereotactic radiosurgery sources, shall conduct a semi-annual physical...

  13. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... beta or gamma-emitting material or 0.37 MBq (10 µCi) or less of alpha-emitting material; (4) Seeds of... brachytherapy sources, except for gamma stereotactic radiosurgery sources, shall conduct a semi-annual physical...

  14. SCALING PARAMETERS FOR HOT-PARTICLE BETA DOSIMETRY.

    PubMed

    Mangini, Colby D; Hamby, David M

    2016-12-01

    Scaling of dose-point kernel (DPK) values for beta particles transmitted by high-Z sources will overestimate dose at shallow depths while underestimating dose at greater depths due to spectral hardening. A new model has been developed based on a determination of the amount of monoenergetic electron absorption that occurs in a given source thickness through the use of EGSnrc (Electron Gamma Shower) Monte Carlo simulations. Integration over a particular beta spectrum provides the beta-particle DPK following self-absorption as a function of source thickness and radial depth in water, thereby accounting for spectral hardening that may occur in higher-Z materials. Beta spectra of varying spectral shapes and endpoint energies were used to test the model for select source materials with 7.42 ≤ Z ≤ 94. The results demonstrate that significant improvements can be made to DPK-based dosimetry models when dealing with high-Z volumetric sources. This new scaling model is currently being used to improve the accuracy of the beta-dosimetry calculations in VARSKIN 5.

  15. Rearrangement of beta-amino alcohols and application to the synthesis of biologically active compounds.

    PubMed

    Cossy, Janine; Pardo, Domingo Gomez; Dumas, Cécile; Mirguet, Olivier; Déchamps, Ingrid; Métro, Thomas-Xavier; Burger, Benjamin; Roudeau, Rémi; Appenzeller, Jérôme; Cochi, Anne

    2009-10-01

    Beta-amino alcohols derived from natural amino acids have been used extensively as a powerful source of chirality. Transformation of the hydroxy group of these beta-amino alcohols into a good leaving group, by using trifluoroacetic anhydride, led to rearranged beta-amino alcohols in good yields and with high enantiomeric excesses. This rearrangement has allowed the transformation of substituted prolinols to substituted 3-hydroxypiperidines and linear beta-amino alcohols, issued from natural amino acids, to rearranged beta-amino alcohols.

  16. Beta-rolls, beta-helices, and other beta-solenoid proteins.

    PubMed

    Kajava, Andrey V; Steven, Alasdair C

    2006-01-01

    Beta-rolls and beta-helices belong to a larger group of topologically similar proteins with solenoid folds: because their regular secondary structure elements are exclusively beta-strands, they are referred to as beta-solenoids. The number of beta-solenoids whose structures are known is now large enough to support a systematic analysis. Here we survey the distinguishing structural features of beta-solenoids, also documenting their notable diversity. Appraisal of these structures suggests a classification based on handedness, twist, oligomerization state, and coil shape. In addition, beta-solenoids are distinguished by the number of chains that wind around a common axis: the majority are single-stranded but there is a recently discovered subset of triple-stranded beta-solenoids. This survey has revealed some relationships of the amino acid sequences of beta-solenoids with their structures and functions-in particular, the repetitive character of the coil sequences and conformations that recur in tracts of tandem repeats. We have proposed the term beta-arc for the distinctive turns found in beta-solenoids and beta-arch for the corresponding strand-turn-strand motifs. The evolutionary mechanisms underlying these proteins are also discussed. This analysis has direct implications for sequence-based detection, structural prediction, and de novo design of other beta-solenoid proteins. The abundance of virulence factors, toxins and allergens among beta-solenoids, as well as commonalities of beta-solenoids with amyloid fibrils, imply that this class of folds may have a broader role in human diseases than was previously recognized. Thus, identification of genes with putative beta-solenoid domains promises to be a fertile direction in the search for viable targets in the development of new antibiotics and vaccines.

  17. Beta-thalassemia.

    PubMed

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  18. Investigation of horizon Beta.

    PubMed

    Windisch, C C; Leyden, R J; Worzel, J L; Saito, T; Ewing, J

    1968-12-27

    Horizon beta is a subbottom reflector in the North Atlantic deep ocean sediments that extends over a large portion of the North America basin. Cores from an outcrop of beta contained shallow-water Aptian-Albian sediments and deep-water Cenomanian sediments. A core near an outcrop of a deeper horizon, horizon B, contained shallow-water Lower Cretaceous (Barremian-Hauterivian) sediments. These cores can be interpreted to support extensive subsidence of the eastern portion of the basin in early Cretaceous time. It is equally likely that the shallow-water deposits are a result of sediments slumping into an already deep basin. A reconciliation of these interpretations depends upon the JOIDES project.

  19. Beta-thalassemia

    PubMed Central

    2010-01-01

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  20. Trafficking of cell surface beta-amyloid precursor protein: retrograde and transcytotic transport in cultured neurons

    PubMed Central

    1995-01-01

    Amyloid beta-protein (A beta), the principal constituent of senile plaques seen in Alzheimer's disease (AD), is derived by proteolysis from the beta-amyloid precursor protein (beta PP). The mechanism of A beta production in neurons, which are hypothesized to be a rich source of A beta in brain, remains to be defined. In this study, we describe a detailed localization of cell surface beta PP and its subsequent trafficking in primary cultured neurons. Full-length cell surface beta PP was present primarily on perikarya and axons, the latter with a characteristic discontinuous pattern. At growth cones, cell surface beta PP was inconsistently detected. By visualizing the distribution of beta PP monoclonal antibodies added to intact cultures, beta PP was shown to be internalized from distal axons or terminals and retrogradely transported back to perikarya in organelles which colocalized with fluid-phase endocytic markers. Retrograde transport of beta PP was shown in both hippocampal and peripheral sympathetic neurons, the latter using a compartment culture system that isolated cell bodies from distal axons and terminals. In addition, we demonstrated that beta PP from distal axons was transcytotically transported to the surface of perikarya from distal axons in sympathetic neurons. Indirect evidence of this transcytotic pathway was obtained in hippocampal neurons using antisense oligonucleotide to the kinesin heavy chain to inhibit anterograde beta PP transport. Taken together, these results demonstrate novel aspects of beta PP trafficking in neurons, including retrograde axonal transport and transcytosis. Moreover, the axonal predominance of cell surface beta PP is unexpected in view of the recent report of polarized sorting of beta PP to the basolateral domain of MDCK cells. PMID:7721945

  1. Wind-Forced Baroclinic Beta-Plumes

    NASA Astrophysics Data System (ADS)

    Belmadani, A.; Maximenko, N. A.; Melnichenko, O.; Schneider, N.; Di Lorenzo, E.

    2011-12-01

    A planetary beta-plume is a classical example of oceanic circulation induced by a localized vorticity source or sink that allows an analytical description in simplistic cases. Its barotropic structure is a zonally-elongated, gyre-like cell governed by the Sverdrup circulation on the beta-plane. The dominant zonal currents, found west of the source/sink, are often referred to as zonal jets. This simple picture describes the depth-integrated flow. Previous studies have investigated beta-plumes in a reduced-gravity framework or using other simple models with a small number of vertical layers, thereby lacking representation of the vertical structure. In addition, most previous studies use a purely linear regime without considering the role of eddies. However, these jets are often associated with strong lateral shear that makes them unstable under increased forcing. The circulation in such a nonlinear regime may involve eddy-mean flow interactions, which modify the time-averaged circulation. Here, the baroclinic structures of linear and nonlinear wind-forced beta-plumes are studied using a continuously-stratified, primitive equation, eddy-permitting ocean model (ROMS). The model is configured in an idealized rectangular domain for the subtropical ocean with a flat bottom. The surface wind forcing is a steady anticyclonic Gaussian wind vortex, which provides a localized vorticity source in the center of the domain. The associated wind stress curl and Ekman pumping comprise downwelling in the vortex center surrounded by a ring of weaker upwelling. Under weak forcing, the simulated steady-state circulation corresponds well with a theoretical linear beta-plume. While its depth-integrated transport exhibits a set of zonal jets, consistent with Sverdrup theory, the baroclinic structure of the plume is remarkably complex. Relatively fast westward decay of the surface currents occurs simultaneously with the deepening of the lower boundary of the plume. This deepening suggests

  2. Thermophilic Beta-Glycosidase

    NASA Technical Reports Server (NTRS)

    Grogan, Dennis W.

    1992-01-01

    Report describes identification of thermophilic Beta-glycosidase enzyme from isolate of Sulfolobus solfataricus, sulfur-metabolizing archaebacteria growing aerobically and heterotrophically to relatively high cell yields. Enzyme useful in enzymatic conversion of cellulose to D-glucose and important in recycling of biomass. Used for removal of lactose from milk products. Offers promise as model substance for elucidation of basic principles of structural stabilization of proteins.

  3. Thermophilic Beta-Glycosidase

    NASA Technical Reports Server (NTRS)

    Grogan, Dennis W.

    1992-01-01

    Report describes identification of thermophilic Beta-glycosidase enzyme from isolate of Sulfolobus solfataricus, sulfur-metabolizing archaebacteria growing aerobically and heterotrophically to relatively high cell yields. Enzyme useful in enzymatic conversion of cellulose to D-glucose and important in recycling of biomass. Used for removal of lactose from milk products. Offers promise as model substance for elucidation of basic principles of structural stabilization of proteins.

  4. TGF-beta and osteoarthritis.

    PubMed

    Blaney Davidson, E N; van der Kraan, P M; van den Berg, W B

    2007-06-01

    Cartilage damage is a major problem in osteoarthritis (OA). Growth factors like transforming growth factor-beta (TGF-beta) have great potential in cartilage repair. In this review, we will focus on the potential therapeutic intervention in OA with TGF-beta, application of the growth factor TGF-beta in cartilage repair and on the side effects of TGF-beta treatment that could occur. This review summarizes peer-reviewed articles published in the PubMed database before November 2006. In addition, this review is supplemented with recent data of our own group on the use of TGF-beta as a cartilage reparative factor in OA. TGF-beta is crucial for cartilage maintenance and lack there of results in OA-like changes. Moreover, TGF-beta supplementation can enhance cartilage repair and is therefore a potential therapeutic tool. However, application of TGF-beta supplementation provides problems in other tissues of the joint and results in fibrosis and osteophyte formation. This can potentially be overcome by local inhibition of TGF-beta at sites of unwanted side-effects or by blocking downstream mediators of TGF-beta that are important for the induction of fibrosis or osteophyte formation. Current understanding of TGF-beta suggests that it essential for cartilage integrity and that it is a powerful tool to prevent or repair cartilage damage. The side-effects that occur with TGF-beta supplementation can be overcome by local inhibition of TGF-beta itself or downstream mediators.

  5. Synthesis and characterization of novel polymers from non-petroleum sources for use in enhanced oil recovery. Progress report, July 1,1981-June 30, 1982. [Starch-g-polyacrylamide; polysaccharides and acrylamides; Schardinger-. beta. -dextrin and acrylamide

    SciTech Connect

    Butler, G.B.; Hogen-Esch, T.E.

    1982-01-01

    Annual progress reports are presented for the following tasks: (1) synthesis and structural characterization of polysaccharide-based graft copolymers for use in tertiary oil recovery; (2) determination of physical properties of the polymers and their solutions, and screening of the polymers to determine their utility in oil recovery. Over the past year synthesis and characterization studies have continued in the following five areas: (1) starch-g-polyacrylamide (ST-g-PAM) copolymers; (2) graft copolymers of other polysaccharides (gum arabic, yellow dextrin, pectin, okra polysaccharide, and guar gum) and acrylamides; (3) a naturally occurring polysaccharide extracted from okra (Akro); (4) graft copolymers of Schardinger-..beta..-dextrin and acrylamide (SD-g-PAM); (5) chemical degradation of ST-g-PAM and SD-g-PAM copolymers. For physical properties studies, the following areas were investigated: (1) characterization of copolymers by ultracentrifugation, size exclusion chromatography and nucleophore membrane filtration; (2) rheological studies on copolymers; and (3) statistical analysis of variables in graft copolymerization. (ATT)

  6. Beta* and beta-waist measurement and control at RHIC

    SciTech Connect

    Ptitsyn,V.; Della Penna, A.; Litvinenko, V.N.; Malitsky, N.; Satogata, T.

    2009-05-04

    During the course of last RHIC runs the beta-functions at the collision points ({beta}*) have been reduced gradually to 0.7m. In order to maximize the collision luminosity and ensure the agreement of the actual machine optics with the design one, more precise measurements and control of {beta}* value and {beta}-waist location became necessary. The paper presents the results of the implementation of the technique applied in last two RHIC runs. The technique is based on well-known relation between the tune shift and the beta function and involves precise betatron tune measurements using BBQ system as well as specially developed knobs for {beta}-waist location control.

  7. The Hubble Source Catalog

    NASA Astrophysics Data System (ADS)

    Lubow, S.; Allam, S.; Budavari, T.; Quick, L.; Strolger, L.; White, R. L.; Whitmore, B.

    2015-09-01

    We have continued development of the Hubble Source Catalog (HSC). The catalog was initially based on Hubble Space Telescope (HST) observations taken with the ACS/WFC and WFPC2 detectors. We have recently added observations from the WFC3/IR and WFC3/UVIS detectors. The catalog is available as a Beta 0.3 release at archive.stsci.edu/hst/hsc/. The catalog is produced by cross matching by position in the sky the Hubble Legacy Archive (HLA) Source Extractor source lists for these detectors using algorithms described in Budavári & Lubow (2012). The source lists describe properties of source detections within an HST visit (pointing). To carry out the cross matching, we improve the astrometry for the source lists. To do this, we first use a histogram method for cross matching the brightest sources against the Pan-STARRS, SDSS, and 2MASS catalogs. To further improve the alignment, we apply a different method that is highly efficient for approximately aligned source lists (less than a few tenths of an arc-sec). With that method, we cross match the brightest sources in overlapping source lists against each other and adjust the source list astrometry to minimize the offsets of matched sources. All the sources in the overlapping source lists are then cross matched to produce the HSC. The HSC provides time and muti-wavelength information. We have carried out some preliminary investigations of its capabilities through some use cases.

  8. Nuclear electric power sources

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1978-01-01

    Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

  9. A potential instrumental counterpart to Method 5 for the continuous measurement of particulate matter emissions from combustion and other sources using isokinetic sample extraction technology followed by beta ray attenuation mass measurements

    SciTech Connect

    Griguoli, F.T.

    1997-12-31

    For many years opacity and other values available from optical devices have been used in an attempt to assess and often quantify particulate matter emissions from stationary sources, particularly combustion sources using coal. These opacity values have also been used to obtain mass concentration data. Today`s reality is such that pollution abatement technologies have become better and better, dry or wet, and most processes are subject to a variety of conditions no longer suitable, in the author`s opinion, for the use of optical devices or derivatives of them. This paper describes a continuous extractive technique to measure particulate matter which has been used in Europe and around the word for more than 10 years. This technique works very well in changing particulate matter conditions, low particulate concentrations, small diameter stacks, and stacks/ducts with high water vapor content in the flue gas. 2 refs., 2 figs.

  10. Current and future searches for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Dolinski, Michelle J.

    2016-09-01

    With the discovery of neutrino oscillations and neutrino mass, it has become a pressing question whether neutrinos have distinct antiparticle states. The most practical experimental approach to answering this question is the search for neutrinoless double beta decay, a version of a rare nuclear process that would violate lepton number conservation. The observation of neutrinoless double beta decay would prove that neutrinos are their own antiparticles. Neutrinoless double beta decay experiments deploy large source masses consisting of a select few (usually enriched) isotopes of interest. Detectors must achieve extremely low levels of radioactive background to detect this rare decay. I will report on recent searches for neutrinoless double beta decay and discuss the technical challenges that the next generation of experiments will overcome.

  11. High-beta extended MHD simulations of stellarators

    NASA Astrophysics Data System (ADS)

    Bechtel, T. A.; Hegna, C. C.; Sovinec, C. R.; Roberds, N. A.

    2016-10-01

    The high beta properties of stellarator plasmas are studied using the nonlinear, extended MHD code NIMROD. In this work, we describe recent developments to the semi-implicit operator which allow the code to model 3D plasma evolution with better accuracy and efficiency. The configurations under investigation are an l=2, M=5 torsatron with geometry modeled after the Compact Toroidal Hybrid (CTH) experiment and an l=2, M=10 torsatron capable of having vacuum rotational transform profiles near unity. High-beta plasmas are created using a volumetric heating source and temperature dependent anisotropic thermal conduction and resistivity. To reduce computation expenses, simulations are initialized from stellarator symmetric pseudo-equilibria by turning on symmetry breaking modes at finite beta. The onset of MHD instabilities and nonlinear consequences are monitored as a function of beta as well as the fragility of the magnetic surfaces. Research supported by US DOE under Grant No. DE-FG02-99ER54546.

  12. Beta Crateris - Another Sirius system in the solar neighbourhood

    NASA Technical Reports Server (NTRS)

    Fleming, T. A.; Schmitt, J. H. M. M.; Barstow, M. A.; Mittaz, J. P. D.

    1991-01-01

    The star Beta Crt (A2 IV; mv = 4.48) has been detected in the Rosat all-sky survey. The Rosat X-ray and EUV data in conjunction with already published optical data suggest that the source of the X-ray emission is not the A star Beta Crt A, but rather a hitherto unknown white dwarf companion Beta Crt B, just like the well-known case of Sirius A and B. However, unlike Sirius B, Beta Crt B is too close to its primary to be resolved and/or studied optically. The temperature and atmospheric composition of the white dwarf companion are estimated and the similarities between this system and Sirius is discussed.

  13. Simultaneous beta and gamma spectroscopy

    DOEpatents

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  14. Feasibility of EBT Gafchromic films for comparison exercises among standard beta radiation fields.

    PubMed

    Benavente, J A; Meira-Belo, L C; Reynaldo, S R; da Silva, T A

    2012-12-01

    The feasibility of using radiochromic films to verify the metrological coherence among standard beta radiation fields was evaluated. Exercises were done between two Brazilian metrology laboratories in beta fields from (90)Sr/(90)Y, (85)Kr and (147)Pm radiation sources. Results showed that the radiochromic film was useful for field mapping aiming uniformity and alignment verification and it was not reliable for absorbed dose measurements only for (147)Pm beta field.

  15. Beta skin dose determination using TLDs, Monte-Carlo calculations, and extrapolation chamber.

    PubMed

    Ben-Shachar, B; Levine, S H; Hoffman, J M

    1989-12-01

    The beta doses produced by 90Sr-Y and 204 Tl beta sources were determined using three methods: Monte-Carlo calculations, measurements with TLDs, and measurements with an extrapolation chamber. Excellent agreement was obtained by all three methods, except a TLD nonlinear response to beta s was observed, which gives doses approximately 20% high for the 90Sr-Y source and 5% low for the 204Tl source. Also, analyses performed with low-energy beta s using these methods can determine errors in shield thickness covering TLD elements. Direct measurement of skin dose is not possible by the TLDs because the minimum shield thickness for the elements is 13 mg cm-2. A thinner shield for the elements must be used or the data must be extrapolated. Presently, thinner shields for TLD elements are not available, and the thick shields can lead to significant errors in skin dose when exposed to low-energy beta s.

  16. Cyclic modular beta-sheets.

    PubMed

    Woods, R Jeremy; Brower, Justin O; Castellanos, Elena; Hashemzadeh, Mehrnoosh; Khakshoor, Omid; Russu, Wade A; Nowick, James S

    2007-03-07

    The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low (

  17. Bremsstrahlung dosimetric parameters of beta-emitting therapeutic radionuclides

    NASA Astrophysics Data System (ADS)

    Manjunatha, H. C.

    2016-03-01

    Dosimetric parameters such as efficiency of bremsstrahlung, probability of energy loss of beta during bremsstrahlung production, intensity and dose rate of high, medium and low-energy beta-emitting therapeutic radionuclides in different tissues of human organs are computed. These parameters are lower in adipose tissue than all other studied tissues. The efficiency, intensity and dose rate of bremsstrahlung increases with maximum energy of the beta nuclide (Emax) and modified atomic number (Zmod) of the target tissue. The estimated bremsstrahlung efficiency, intensity and dose rate are useful in the calculations of photon track-length distributions. These parameters are useful to determine the quality and quantity of the bremsstrahlung radiation (known as the source term). Precise estimation of this source term is very important in planning for radiotherapy and diagnosis.

  18. Amyloid Beta Mediates Memory Formation

    ERIC Educational Resources Information Center

    Garcia-Osta, Ana; Alberini, Cristina M.

    2009-01-01

    The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

  19. Amyloid Beta Mediates Memory Formation

    ERIC Educational Resources Information Center

    Garcia-Osta, Ana; Alberini, Cristina M.

    2009-01-01

    The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

  20. RAVEN Beta Release

    SciTech Connect

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  1. Superallowed Fermi beta decay

    SciTech Connect

    Hardy, J. C.; Towner, I. S.

    1998-12-21

    Superallowed 0{sup +}{yields}0{sup +} nuclear beta decay provides a direct measure of the weak vector coupling constant, G{sub V}. We survey current world data on the nine accurately determined transitions of this type, which range from the decay of {sup 10}C to that of {sup 54}Co, and demonstrate that the results confirm conservation of the weak vector current (CVC) but differ at the 98% confidence level from the unitarity condition for the Cabibbo-Kobayashi-Maskawa (CKM) matrix. We examine the reliability of the small calculated corrections that have been applied to the data, and assess the likelihood of even higher quality nuclear data becoming available to confirm or deny the discrepancy. Some of the required experiments depend upon the availability of intense radioactive beams. Others are possible today.

  2. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  3. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  4. Beta systems error analysis

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The atmospheric backscatter coefficient, beta, measured with an airborne CO Laser Doppler Velocimeter (LDV) system operating in a continuous wave, focussed model is discussed. The Single Particle Mode (SPM) algorithm, was developed from concept through analysis of an extensive amount of data obtained with the system on board a NASA aircraft. The SPM algorithm is intended to be employed in situations where one particle at a time appears in the sensitive volume of the LDV. In addition to giving the backscatter coefficient, the SPM algorithm also produces as intermediate results the aerosol density and the aerosol backscatter cross section distribution. A second method, which measures only the atmospheric backscatter coefficient, is called the Volume Mode (VM) and was simultaneously employed. The results of these two methods differed by slightly less than an order of magnitude. The measurement uncertainties or other errors in the results of the two methods are examined.

  5. Just a beta....

    PubMed Central

    Lytle, K. S.; Bailey, D. W.; Dorman, K. F.; Moos, M. K.

    1999-01-01

    Traditional implementation of clinical information systems follows a predictable project management process. The selection, development, implementation, and evaluation of the system and the project management aspects of those phases require considerable time and effort. The purpose of this paper is to describe the beta site implementation of a knowledge-based clinical information system in a specialty area of a southeastern hospital that followed a less than traditional approach to implementation. Highlighted are brief descriptions of the hospital's traditional process, the nontraditional process, and key findings from the experience. Preliminary analysis suggests that selection of an implementation process is contextual. Selection of elements from each of these methods may provide a more useful process. The non-traditional process approached the elements of communication, areas of responsibility, training, follow-up and leadership differently. These elements are common to both processes and provide a focal point for future research. PMID:10566425

  6. Beta measurement evaluation and upgrade

    SciTech Connect

    Murphy, D.W.; Faust, L.G.; Selby, J.M.; Essig, T.H.; Vallario, E.J.

    1983-01-01

    The Department of Energy (DOE), Office of Nuclear Safety, initiated a program to evaluate dosimeters and instruments used at DOE laboratories in the determination of personnel beta dose. The program focuses on significant problems which affect field measurements and is involved in the development and evaluation of new beta dosimetry systems (both dosimeters and instruments). Currently the program is reviewing systems and practices; developing calibration systems and procedures for the calibration of instruments and dosimeters; and developing new concepts which may improve beta dosimetry. The program has been designed to provide a continuing effort for resolution of problems of assessing personnel beta dose at DOE facilities. The current personnel beta dosimetry practices at DOE facilities are being surveyed.

  7. Absorption of Beta Particles in Different Materials: An Undergraduate Experiment

    ERIC Educational Resources Information Center

    La Rocca, Paola; Riggi, Francesco

    2009-01-01

    The absorption of beta rays from a radioactive source in different materials was investigated by the use of a simple setup based on a Geiger counter and a set of absorber sheets. The number of electrons traversing the material was measured as a function of its thickness. Detailed GEANT simulations were carried out to reproduce the obtained…

  8. Absorption of Beta Particles in Different Materials: An Undergraduate Experiment

    ERIC Educational Resources Information Center

    La Rocca, Paola; Riggi, Francesco

    2009-01-01

    The absorption of beta rays from a radioactive source in different materials was investigated by the use of a simple setup based on a Geiger counter and a set of absorber sheets. The number of electrons traversing the material was measured as a function of its thickness. Detailed GEANT simulations were carried out to reproduce the obtained…

  9. Preparation of {alpha},{beta}-unsaturated carboxylic acids and esters

    DOEpatents

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.

    1998-09-15

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  10. Preparation of {alpha}, {beta}-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Tustin, G.C.

    1998-01-20

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  11. Preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters

    DOEpatents

    Gogate, Makarand Ratnakar; Spivey, James Jerry; Zoeller, Joseph Robert

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  12. Preparation of .alpha., .beta.-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, James Jerry; Gogate, Makarand Ratnakav; Zoeller, Joseph Robert; Tustin, Gerald Charles

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  13. Intravenous glucose preparation as the source of an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae infections in the neonatal unit of a regional hospital in KwaZulu-Natal.

    PubMed

    Moodley, Prashini; Coovadia, Yacoob M; Sturm, A Willem

    2005-11-01

    In the last week of May 2005, staff at Mahatma Gandhi Memorial Hospital in KwaZulu-Natal realised that many babies in the high-care nursery ward had bloodstream infections involving Klebsiella pneumoniae bacteria. Attempts to identify a common source of infection failed. The ward was therefore closed and new babies needing high care were admitted to another empty ward. Despite this, babies still became infected. This resulted in a request for assistance from the Department of Medical Microbiology of the Nelson R Mandela School of Medicine. A search for common factors through case history studies of the 26 infected babies showed that blood cultures of the babies remained positive despite the administration of appropriate antibiotics. Different options that could explain this were investigated. The organism was found in intravenous glucose preparations used for multiple dosing. Unopened vials of the same medication were sterile. The nursery was found to lack proper hand-wash facilities and to be overcrowded and understaffed. Reinforcement of hand hygiene and a ban on the multiple dosing of medicines stopped the outbreak. In conclusion, this outbreak resulted from a combination of factors among which lack of hand hygiene and multiple dosing of an intravenous glucose preparation were most significant.

  14. Beta Cell Regeneration in Adult Mice: Controversy Over the Involvement of Stem Cells.

    PubMed

    Yu, Ke; Fischbach, Shane; Xiao, Xiangwei

    2016-01-01

    Islet transplantation is an effective therapy for severe diabetes. Nevertheless, the short supply of donor pancreases constitutes a formidable obstacle to its extensive clinical application. This shortage heightens the need for alternative sources of insulin-producing beta cells. Since mature beta cells have a very slow proliferation rate, which further declines with age, great efforts have been made to identify beta cell progenitors in the adult pancreas. However, the question whether facultative beta cell progenitors indeed exist in the adult pancreas remains largely unresolved. In the current review, we discuss the problems in past studies and review the milestone studies and recent publications.

  15. High Temperature Stability of Potassium Beta Alumina

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Kisor, A.; Ryan, M. A.

    1996-01-01

    None. From Objectives section: Evaluate the stability of potassium beta alumina under potassium AMTEC operating conditions. Evaluate the stability regime in which potassium beta alumina can be fabricated.

  16. Evaluation of meat, fruit and vegetables from retail stores in five United Kingdom regions as sources of extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli.

    PubMed

    Randall, L P; Lodge, M P; Elviss, N C; Lemma, F L; Hopkins, K L; Teale, C J; Woodford, N

    2017-01-16

    We determined the prevalence and types of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli in raw retail beef, chicken, pork, fruit and vegetables in five UK regions in 2013-14. Raw meat (n=397), and fruit and vegetable samples (n=400) were purchased from retail stores in London, East Anglia, North West England, Scotland and Wales. Samples were tested for the presence of ESBL-producing E. coli by plating enriched samples on CHROMagar CTX and CHROMagar ESBL, for AmpC-type E. coli by plating on "CHROMagar FOX" (CHROMagar ECC+16mg/L cefoxitin), and for carbapenem-resistant E. coli by plating on CHROMagar KPC. Additionally, pre-enrichment counts were performed on the above agars, and on CHROMagar ECC. Isolates of interest were characterised by MALDI-ToF to confirm identification, by PCR for blaCIT,blaCTX-M,blaOXA, blaSHV and blaTEM genes; ESBL or blaCIT genes were sequenced. Only 1.9% and 2.5% of beef and pork samples, respectively were positive for ESBL-producing E. coli after enrichment compared with 65.4% of chicken samples. 85.6% positive samples from chicken meat carried blaCTX-M-1; blaCTX-M-15 was not detected. None of the fruits or vegetables yielded ESBL-producing E. coli and none of the meat, fruit or vegetable samples yielded carbapenem-resistant E. coli. Retail chicken was more frequently a source of ESBL-producing E. coli than were beef, pork, fruit or vegetables. None of the foodstuffs yielded E. coli with CTX-M-15 ESBL, which dominates in human clinical isolates in the UK, and none yielded carbapenem-resistant E. coli. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  17. Determination of the efficiency of commercially available dose calibrators for beta-emitters.

    PubMed

    Valley, Jean-François; Bulling, Shelley; Leresche, Michel; Wastiel, Claude

    2003-03-01

    The goals of this investigation are to determine whether commercially available dose calibrators can be used to measure the activity of beta-emitting radionuclides used in pain palliation and to establish whether manufacturer-supplied calibration factors are appropriate for this purpose. Six types of commercially available dose calibrators were studied. Dose calibrator response was controlled for 5 gamma-emitters used for calibration or typically encountered in routine use. For the 4 most commonly used beta-emitters ((32)P, (90)Sr, (90)Y, and (169)Er) dose calibrator efficiency was determined in the syringe geometry used for clinical applications. Efficiency of the calibrators was also measured for (153)Sm and (186)Re, 2 beta-emitters with significant gamma-contributions. Source activities were traceable to national standards. All calibrators measured gamma-emitters with a precision of +/-10%, in compliance with Swiss regulatory requirements. For beta-emitters, dose calibrator intrinsic efficiency depends strongly on the maximal energy of the beta-spectrum and is notably low for (169)Er. Manufacturer-supplied calibration factors give accurate results for beta-emitters with maximal beta-energy in the middle-energy range (1 MeV) but are not appropriate for use with low-energy ((169)Er) or high-energy ((90)Y) beta-emitters. beta-emitters with significant gamma-contributions behave like gamma-emitters. Commercially available dose calibrators have an intrinsic efficiency that is sufficient for the measurement of beta-emitters, including beta-emitters with a low maximum beta-energy. Manufacturer-supplied calibration factors are reliable for gamma-emitters and beta-emitters in the middle-energy range. For low- and high-energy beta-emitters, the use of manufacturer-supplied calibration factors introduces significant measurement inaccuracy.

  18. Detailed transcriptome atlas of the pancreatic beta cell.

    PubMed

    Kutlu, Burak; Burdick, David; Baxter, David; Rasschaert, Joanne; Flamez, Daisy; Eizirik, Decio L; Welsh, Nils; Goodman, Nathan; Hood, Leroy

    2009-01-15

    Gene expression patterns provide a detailed view of cellular functions. Comparison of profiles in disease vs normal conditions provides insights into the processes underlying disease progression. However, availability and integration of public gene expression datasets remains a major challenge. The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing beta cell gene expression, the Beta Cell Gene Atlas (BCGA). We performed Massively Parallel Signature Sequencing (MPSS) analysis of human pancreatic islet samples and microarray analyses of purified rat beta cells, alpha cells and INS-1 cells, and compared the information with available array data in the literature. MPSS analysis detected around 7600 mRNA transcripts, of which around a third were of low abundance. We identified 2000 and 1400 transcripts that are enriched/depleted in beta cells compared to alpha cells and INS-1 cells, respectively. Microarray analysis identified around 200 transcription factors that are differentially expressed in either beta or alpha cells. We reanalyzed publicly available gene expression data and integrated these results with the new data from this study to build the BCGA. The BCGA contains basal (untreated conditions) gene expression level estimates in beta cells as well as in different cell types in human, rat and mouse pancreas. Hierarchical clustering of expression profile estimates classify cell types based on species while beta cells were clustered together. Our gene atlas is a valuable source for detailed information on the gene expression distribution in beta cells and pancreatic islets along with insulin producing cell lines. The BCGA tool, as well as the data and code used to generate the Atlas are available at the T1Dbase website (T1DBase.org).

  19. Variants of beta-glucosidase

    DOEpatents

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2009-12-29

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  20. Variants of beta-glucosidase

    SciTech Connect

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2015-07-14

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  1. Variants of beta-glucosidases

    SciTech Connect

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2014-10-07

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  2. Variants of beta-glucosidases

    DOEpatents

    Fidantsef, Ana; Lamsa, Michael; Clancy, Brian Gorre

    2008-08-19

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  3. Immune-modulatory effects of dietary Yeast Beta-1,3/1,6-D-glucan

    PubMed Central

    2014-01-01

    Beta-glucans are a heterogeneous group of natural polysaccharides mostly investigated for their immunological effects. Due to the low systemic availability of oral preparations, it has been thought that only parenterally applied beta-glucans can modulate the immune system. However, several in vivo and in vitro investigations have revealed that orally applied beta-glucans also exert such effects. Various receptor interactions, explaining possible mode of actions, have been detected. The effects mainly depend on the source and structure of the beta-glucans. In the meantime, several human clinical trials with dietary insoluble yeast beta-glucans have been performed. The results confirm the previous findings of in vivo studies. The results of all studies taken together clearly indicate that oral intake of insoluble yeast beta-glucans is safe and has an immune strengthening effect. PMID:24774968

  4. Venus - Beta Regio

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This portion of a Magellan radar image strip shows a small region on Venus 20 kilometers (12.4 miles) wide and 75 km (50 miles) long on the east flank of a major volcanic upland called Beta Regio. The image is centered at 23 degrees north latitude and 286.7 degrees east longitude. The ridge and valley network in the middle part of the image is formed by intersecting faults which have broken the Venusian crust into a complex, deformed type of surface called tessera, the Latin word for tile. The parallel mountains and valleys resemble the Basin and Range Province in the western United States. The irregular dark patch near the top of the image is a smooth surface, probably formed by lava flows in a region about 10 km (6 miles) across. Similar dark surfaces within the valleys indicate lava flows that are younger than the tessera giving an indication of the geologic time relationships of the events that formed the present surface. The image has a resolution of 120 meters (400 feet).

  5. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  6. Chemical and rheological properties of the beta-glucan produced by Pediococcus parvulus 2.6.

    PubMed

    Velasco, Susana E; Areizaga, Javier; Irastorza, Ana; Dueñas, Maria T; Santamaria, Antxon; Muñoz, María E

    2009-03-11

    Some physicochemical and rheological properties of the exopolysaccharide (EPS) produced by Pediococcus parvulus 2.6 were examined. Structural characterization by NMR ((1)H and 2D-COSY) showed that the same EPS, a 2-substituted (1,3)-beta-D-glucan, was synthesized irrespective of sugar source used for growth (glucose, fructose, or maltose). The molecular masses of these beta-glucans were always very high (>10(6) Da) and influenced by the culture medium or sugar source. The steady shear rheological experiments showed that all concentrations of the beta-glucan aqueous solutions exhibited a pseudoplastic behavior at high shear rates. Viscoelastic behavior of beta-glucan solutions was determined by dynamic oscillatory analysis. A critical concentration of 0.35% associated with the appearance of entanglements was calculated. The beta-glucan adopts an ordered hydrogen bond dependent helical conformation in neutral and slightly alkaline aqueous solutions, which was partly denatured under more alkaline conditions.

  7. Evolution of outer membrane beta-barrels from an ancestral beta beta hairpin.

    PubMed

    Remmert, M; Biegert, A; Linke, D; Lupas, A N; Söding, J

    2010-06-01

    Outer membrane beta-barrels (OMBBs) are the major class of outer membrane proteins from Gram-negative bacteria, mitochondria, and plastids. Their transmembrane domains consist of 8-24 beta-strands forming a closed, barrel-shaped beta-sheet around a central pore. Despite their obvious structural regularity, evidence for an origin by duplication or for a common ancestry has not been found. We use three complementary approaches to show that all OMBBs from Gram-negative bacteria evolved from a single, ancestral beta beta hairpin. First, we link almost all families of known single-chain bacterial OMBBs with each other through transitive profile searches. Second, we identify a clear repeat signature in the sequences of many OMBBs in which the repeating sequence unit coincides with the structural beta beta hairpin repeat. Third, we show that the observed sequence similarity between OMBB hairpins cannot be explained by structural or membrane constraints on their sequences. The third approach addresses a longstanding problem in protein evolution: how to distinguish between a very remotely homologous relationship and the opposing scenario of "sequence convergence." The origin of a diverse group of proteins from a single hairpin module supports the hypothesis that, around the time of transition from the RNA to the protein world, proteins arose by amplification and recombination of short peptide modules that had previously evolved as cofactors of RNAs.

  8. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  9. Beta-Testing Agreement | FNLCR

    Cancer.gov

    Beta-Testing Agreements are appropriate forlimited term evaluation and applications development of new software, technology, or equipment platforms by the Frederick National Labin collaboration with an external commercial partner. It may

  10. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  11. A new approach in evaluating the surface beta contamination using the direct method of measurement.

    PubMed

    Stanga, D; De Felice, P; Capogni, M

    2017-11-01

    This paper describes a new approach in evaluating the surface beta contamination using the direct method of measurement. It makes use of previous results obtained in numerical modeling of electron transport in planar geometry and is mainly based on the estimation of the efficiency of contamination sources for beta radiation and its standard uncertainty using the available information concerning the component materials of the sources and their main parameters. Experimental results illustrate the appropriateness of the new approach for surface beta contamination measurements. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Apollo applications of beta fiber glass

    NASA Technical Reports Server (NTRS)

    Naimer, J.

    1971-01-01

    The physical characteristics of Beta fiber glass are discussed. The application of Beta fiber glass for fireproofing the interior of spacecraft compartments is described. Tests to determine the flammability of Beta fiber glass are presented. The application of Beta fiber glass for commercial purposes is examined.

  13. Expression of transforming growth factor-beta (TGF-beta) receptors, TGF-beta 1 and TGF-beta 2 production and autocrine growth control in osteosarcoma cells.

    PubMed

    Kloen, P; Jennings, C L; Gebhardt, M C; Springfield, D S; Mankin, H J

    1994-08-01

    Transforming growth factor-beta (TGF-beta) is a polypeptide with multiple physiological functions. Isoforms of this growth factor have important roles in control of the cell cycle, in regulation of cell-cell interactions and in growth and development. Malignant transformation has been shown to be associated with increased expression of TGF-beta. Since bone is the largest storage site and producer of TGF-beta, we speculated on the existence of an autocrine mechanism in osteosarcoma, a malignant bone tumor. Expression of TGF-beta cell surface receptors, effects on growth of TGF-beta and TGF-beta antibodies and production of 2 TGF-beta isoforms were studied in a panel of 7 osteosarcoma cell lines. In contrast to most previous reports on the effects of TGF-beta on osteosarcoma cell growth, we found a mitogenic effect of TGF-beta 1 in 4 of 7 osteosarcoma cell lines. Receptor profiles for TGF-beta were aberrant in 5 of the 7 cell lines tested, and production of TGF-beta 1 and TGF-beta 2 varied among cell lines. Addition of anti-TGF-beta antagonized the effects of endogenous TGF-beta. Our results suggest a potential role of TGF-beta in autocrine growth control of osteosarcoma cells.

  14. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    DOEpatents

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Standardization of immunoassays for antiphospholipid antibodies with beta 2GPI and role of other phospholipid cofactors.

    PubMed

    Amiral, J; Larrivaz, I; Cluzeau, D; Adam, M

    1994-01-01

    Presence of beta 2 Glycoprotein I (beta 2GPI), in addition to phospholipids, is an absolute requirement for binding APA. This binding is frequently observed with beta 2GPI coated alone, however many APA react only with beta 2GPI complexed to phospholipids, but not with phospholipids alone. We demonstrate that a subgroup of rabbit polyclonal antibodies to human beta 2GPI binds to this protein only when it is coated on a solid surface, but not if it is in solution. In addition, beta 2GPI present in goat serum is strongly fixed by the coated phospholipids and the complexes formed bind as well APA as the rabbit antibodies to beta 2GPI. The diluent used for testing APA, has a strong incidence on APA's reactivity as it can be a source of beta 2GPI. Antibody binding to beta 2GPI, Prothrombin, Protein S, and Annexin V, coated in the presence or in the absence of phospholipids, was tested in 55 patients with the antiphospholipid syndrome. The strongest binding of antibodies was observed in 39 plasma to a mixture of phospholipids and purified human beta 2GPI, however 17 samples also presented a significant reactivity to beta 2GPI alone. Nine plasmas contained antibodies to Prothrombin, 4 to Protein S, 3 to Annexin V, and 1 to Protein C. We conclude that most of the APA are directed to a complex of beta 2GPI and phospholipids although in some patients antibodies to beta 2GPI alone or to other phospholipid binding proteins are present.

  16. Differential gene expression in response to transforming growth factor-beta1 by fetal and postnatal dermal fibroblasts.

    PubMed

    Rolfe, Kerstin J; Irvine, Laurie M; Grobbelaar, Addie O; Linge, Claire

    2007-01-01

    The multipotent growth factor transforming growth factor (TGF)-beta1 is consistently linked with fibrosis and scarring. The perfect (scarless) healing of cutaneous wounds in early gestational age fetuses is proposed to be due to this tissue's predominance of the TGF-beta3 isoform over the profibrotic TGF-beta1 and 2. Nevertheless, TGF-beta1 is present during wound healing in the early fetus and recently we demonstrated that relevant intracellular signaling pathways are activated (albeit transiently) on TGF-beta1 stimulation. This study aimed to determine whether TGF-beta1 has different effects on gene transcription in human fetal (<14 weeks) vs. human postnatal dermal fibroblasts, using real-time polymerase chain reaction. The regulation pattern of a number of TGF-beta response genes differed dramatically between the two cell sources. The typical autocrine loop of TGF-beta1 autoinduction did not occur in fetal fibroblasts and genes that are normally up-regulated, connective tissue growth factor and collagen type I were actually down-regulated. Furthermore, other response genes responded in a delayed fashion (TGF-beta3) compared with that seen in the more developmentally mature postnatal fibroblasts. Finally, genes unaltered by TGF-beta stimulation in postnatal cells, TGF-beta2 and collagen III, were up-regulated in fetal cells. These developmentally related differences in fibroblast response to TGF-beta1 may influence wound-healing outcome, i.e., perfect regeneration or fibrosis.

  17. Monte-Carlo simulation of beta particle induced bremsstrahlung doses.

    PubMed

    Mrdja, Dusan; Bikit, Kristina; Bikit, Istvan; Slivka, Jaroslav; Forkapic, Sofija; Knezevic, Jovana

    2017-10-11

    It is well known that the protection from external irradiation produced by beta emitters is simpler than the corresponding shielding of radioactive sources that emit gamma radiation. This is caused by relatively strong absorption (i.e. short range) of electrons in different materials. However, for strong beta sources specific attention should be devoted to the bremsstrahlung radiation induced in the source encapsulation (matrix), especially for emitters with relatively high beta-endpoint energy (1 MeV), that are frequently used in nuclear medicine. In the present work, the bremsstrahlung spectra produced in various materials by the following beta emitters Sr-90 (together with its daughter Y-90), P-32, and Bi-210 were investigated by Monte-Carlo simulations, using Geant4 software. In these simulations, it is supposed that the point radioactive sources are surrounded by cylindrically shaped capsules made from different materials: Pb, Cu, Al, glass, and plastic. For the case of Sr-90(Y-90) in cylindrical lead and aluminum capsules, the dimensions of these capsules have also been varied. The absorbed dose rates from bremsstrahlung radiation were calculated for cases where the encapsulated point source is placed at the distance of 30 mm from the surface of a water cylinder with a mass of 75 kg (approximately representing the human body). The bremsstrahlung dose rate and bremsstrahlung spectrum from the Y-90(Sr-90) point source encapsulated in an Al capsule, were also measured experimentally and compared with the corresponding simulation results. In addition, the bremsstrahlung radiation risk for medical staff in therapies using Y-90 was considered in simulations, relating to finger dose as well as whole body dose during preparation and injection of this radioisotope. The corresponding annual doses were obtained for medical workers for specified numbers of Y-90 applications to patients. © 2017 IOP Publishing Ltd.

  18. [Beta-glucan content and hydration properties of filamentous fungi].

    PubMed

    Kiianko, M V; Canel, R S; Ludemann, V; Pose, G; Wagner, J R

    2013-01-01

    The aim of this work was to isolate and identify filamentous fungi from several sources to study the dietary fiber and beta-glucan content. The fungal hydration properties such as water absorption and water holding capacities were also evaluated. Total dietary fiber of isolates exhibited a noticeable variability from 16 to 53% and the highest values were obtained for the genera Paecilomyces and Penicillium, a fact consistent with a higher content of beta-glucans (24 and 17%, respectively), higher than previously reported for Basidiomycetes and yeast. We observed a large decrease (75%) in the water holding capacity when the mycelia were dried. Isolates of filamentous fungi with greater water holding capacity also exhibited greater absorption capacity. Paecilomyces variotii and Penicillium nalgiovense had the best hydration properties. Our results contribute to the search for new unconventional ingredients providing a high protein and beta-glucans content. The addition of these dried mycelia could change the hydration properties in the food system.

  19. The dust properties of the Beta Pictoris disk

    NASA Astrophysics Data System (ADS)

    Augereau, J.-C.

    2014-09-01

    The dust grains in orbit around Beta Pictoris are an essential source of information about its planetary system. Their spatial distribution and properties tell us about the dynamics and composition of their parent, km-sized bodies, and how they interact with the planet(s). Since its discovery, thirty years ago, the Beta Pictoris disk has been intensively observed with a wealth of technics that probed the dust grains at different spatial scales and different wavelengths: broad-band photometry, (infrared) spectroscopy, scattered light and thermal emission direct imaging, polarimetry, optical and millimeter interferometry... In this talk, I will try to take stock of the knowledge accumulated over the last thirty years on dust in the planetary system of Beta Pictoris. Specific emphasis will be placed on the numerous remaining uncertainties.

  20. Cardiovascular and metabolic alterations in mice lacking both beta1- and beta2-adrenergic receptors.

    PubMed

    Rohrer, D K; Chruscinski, A; Schauble, E H; Bernstein, D; Kobilka, B K

    1999-06-11

    The activation state of beta-adrenergic receptors (beta-ARs) in vivo is an important determinant of hemodynamic status, cardiac performance, and metabolic rate. In order to achieve homeostasis in vivo, the cellular signals generated by beta-AR activation are integrated with signals from a number of other distinct receptors and signaling pathways. We have utilized genetic knockout models to test directly the role of beta1- and/or beta2-AR expression on these homeostatic control mechanisms. Despite total absence of beta1- and beta2-ARs, the predominant cardiovascular beta-adrenergic subtypes, basal heart rate, blood pressure, and metabolic rate do not differ from wild type controls. However, stimulation of beta-AR function by beta-AR agonists or exercise reveals significant impairments in chronotropic range, vascular reactivity, and metabolic rate. Surprisingly, the blunted chronotropic and metabolic response to exercise seen in beta1/beta2-AR double knockouts fails to impact maximal exercise capacity. Integrating the results from single beta1- and beta2-AR knockouts as well as the beta1-/beta2-AR double knock-out suggest that in the mouse, beta-AR stimulation of cardiac inotropy and chronotropy is mediated almost exclusively by the beta1-AR, whereas vascular relaxation and metabolic rate are controlled by all three beta-ARs (beta1-, beta2-, and beta3-AR). Compensatory alterations in cardiac muscarinic receptor density and vascular beta3-AR responsiveness are also observed in beta1-/beta2-AR double knockouts. In addition to its ability to define beta-AR subtype-specific functions, this genetic approach is also useful in identifying adaptive alterations that serve to maintain critical physiological setpoints such as heart rate, blood pressure, and metabolic rate when cellular signaling mechanisms are perturbed.

  1. From Beta Cell Replacement to Beta Cell Regeneration

    PubMed Central

    Liu, Chengcheng

    2014-01-01

    Diabetes is affecting more than 25.8 million people in the United States, causing huge burden on the health care system and economy. Insulin injection, which is the predominant treatment for diabetes, is incapable of replenishing the lost insulin-producing beta cell in patients. Restoring beta cell mass through replacement therapy such as islet transplantation or beta cell regeneration through in vitro and in vivo strategies has attracted particular attentions in the field due to its potential to cure diabetes. In the aspect of islet transplantation, gene therapy, stem cell therapy, and more biocompatible immunosuppressive drugs have been tested in various preclinical animal models to improve the longevity and function of human islets against the posttransplantation challenges. In the islet regeneration aspect, insulin-producing cells have been generated through in vitro transdifferentiation of stem cells and other types of cells and demonstrated to be capable of glycemic control. Moreover, several biomarkers including cell-surface receptors, soluble factors, and transcriptional factors have been identified or rediscovered in mediating the process of beta cell proliferation in rodents. This review summarizes the current progress and hurdles in the preclinical efforts in resurrecting beta cells. It may provide some useful insights into the future drug discovery for antidiabetic purposes. PMID:25355714

  2. High beta plasmas in the PBX tokamak

    SciTech Connect

    Bol, K.; Buchenauer, D.; Chance, M.; Couture, P.; Fishman, H.; Fonck, R.; Gammel, G.; Grek, B.; Ida, K.; Itami, K.

    1986-04-01

    Bean-shaped configurations favorable for high ..beta.. discharges have been investigated in the Princeton Beta Experiment (PBX) tokamak. Strongly indented bean-shaped plasmas have been successfully formed, and beta values of over 5% have been obtained with 5 MW of injected neutral beam power. These high beta discharges still lie in the first stability regime for ballooning modes, and MHD stability analysis implicates the external kink as responsible for the present ..beta.. limit.

  3. Monte Carlo calculation of the sensitivity of a commercial dose calibrator to gamma and beta radiation.

    PubMed

    Laedermann, Jean-Pascal; Valley, Jean-François; Bulling, Shelley; Bochud, François O

    2004-06-01

    The detection process used in a commercial dose calibrator was modeled using the GEANT 3 Monte Carlo code. Dose calibrator efficiency for gamma and beta emitters, and the response to monoenergetic photons and electrons was calculated. The model shows that beta emitters below 2.5 MeV deposit energy indirectly in the detector through bremsstrahlung produced in the chamber wall or in the source itself. Higher energy beta emitters (E > 2.5 MeV) deposit energy directly in the chamber sensitive volume, and dose calibrator sensitivity increases abruptly for these radionuclides. The Monte Carlo calculations were compared with gamma and beta emitter measurements. The calculations show that the variation in dose calibrator efficiency with measuring conditions (source volume, container diameter, container wall thickness and material, position of the source within the calibrator) is relatively small and can be considered insignificant for routine measurement applications. However, dose calibrator efficiency depends strongly on the inner-wall thickness of the detector.

  4. (Depth-dose curves of the beta reference fields (147)Pm, (85)Kr and (90)Sr/(90)Y produced by the beta secondary standard BSS2.

    PubMed

    Brunzendorf, Jens

    2012-08-01

    The most common reference fields in beta dosimetry are the ISO 6980 series 1 radiation fields produced by the beta secondary standard BSS2 and its predecessor BSS. These reference fields require sealed beta radiation sources ((147)Pm, (85)Kr or (90)Sr/(90)Y) in combination with a source-specific beam-flattening filter, and are defined only at a given distance from the source. Every radiation sources shipped with the BSS2 is sold with a calibration certificate of the Physikalisch-Technische Bundesanstalt. The calibration workflow also comprises regular depth-dose measurements. This work publishes complete depth-dose curves of the series 1 sources (147)Pm, (85)Kr and (90)Sr/(90)Y in ICRU tissue up to a depth of 11 mm,when all electrons are stopped. For this purpose, the individual depth-dose curves of all BSS2 sources calibrated so far have been determined, i.e. the complete datasets of all BSS2 beta sources have been re-evaluated. It includes 191 depth-dose curves of 116 different sources comprising more than 2200 data points in total. Appropriate analytical representations of the nuclide-specific depth-dose curves are provided for the first time.

  5. Adaptation to beta-myrcene catabolism in Pseudomonas sp. M1: an expression proteomics analysis.

    PubMed

    Santos, Pedro M; Sá-Correia, Isabel

    2009-11-01

    Beta-myrcene, a monoterpene widely used as a fragrance and flavoring additive, also possesses analgesic, anti-mutagenic, and tyrosinase inhibitory properties. In order to get insights into the molecular mechanisms underlying the ability of Pseudomonas sp. M1 to catabolize beta-myrcene, an expression proteomics approach was used in this study. Results indicate that the catabolic enzyme machinery for beta-myrcene utilization (MyrB, MyrC, and MyrD and other uncharacterized proteins) is strongly induced when beta-myrcene is present in the growth medium. Since an M1 mutant, lacking a functional 2-methylisocitrate dehydratase, is not able to grow in mineral medium with beta-myrcene or propionic acid as the sole C-source, and also based on the expression proteomic analysis carried out in this study, it is suggested that the beta-myrcene catabolic intermediate propionyl-CoA is channeled into the central metabolism via the 2-methylcitrate cycle. Results also suggest that the major alteration occurring in the central carbon metabolism of cells growing in beta-myrcene-containing media is related with the redistribution of the metabolic fluxes leading to increased oxaloacetate production. Other up-regulated proteins are believed to prevent protein misfolding and aggregation or to play important structural roles, contributing to the adaptive alteration of cell wall and membrane organization and integrity, which are essential features to allow the bacterium to cope with the highly lipophilic beta-myrcene as C-source.

  6. Analysis of betaS and betaA genes in a Mexican population with African roots.

    PubMed

    Magaña, María Teresa; Ongay, Zoyla; Tagle, Juan; Bentura, Gilberto; Cobián, José G; Perea, F Javier; Casas-Castañeda, Maricela; Sánchez-López, Yoaly J; Ibarra, Bertha

    2002-01-01

    To investigate the origin of the beta(A) and beta(S) genes in a Mexican population with African roots and a high frequency of hemoglobin S, we analyzed 467 individuals (288 unrelated) from different towns in the states of Guerrero and Oaxaca in the Costa Chica region. The frequency of the sickle-cell trait was 12.8%, which may represent a public health problem. The frequencies of the beta-haplotypes were determined from 350 nonrelated chromosomes (313 beta(A) and 37 beta(S)). We observed 15 different beta(A) haplotypes, the most common of which were haplotypes 1 (48.9%), 2 (13.4%), and 3 (13.4%). The calculation of pairwise distributions and Nei's genetic distance analysis using 32 worldwide populations showed that the beta(A) genes are more closely related to those of Mexican Mestizos and North Africans. Bantu and Benin haplotypes and haplotype 9 were related to the beta(S) genes, with frequencies of 78.8, 18.2, and 3.0%, respectively. Comparison of these haplotypes with 17 other populations revealed a high similitude with the population of the Central African Republic. These data suggest distinct origins for the beta(A) and beta(S) genes in Mexican individuals from the Costa Chica region.

  7. Time reversal violation in radiative beta decay: experimental plans

    NASA Astrophysics Data System (ADS)

    Behr, J. A.; McNeil, J.; Anholm, M.; Gorelov, A.; Melconian, D.; Ashery, D.

    2017-01-01

    Some explanations for the excess of matter over antimatter in the universe involve sources of time reversal violation (TRV) in addition to the one known in the standard model of particle physics. We plan to search for TRV in a correlation between the momenta of the beta, neutrino, and the radiative gamma sometimes emitted in nuclear beta decay. Correlations involving three (out of four) momenta are sensitive at lowest order to different TRV physics than observables involving spin, such as electric dipole moments and spin-polarized beta decay correlations. Such experiments have been done in radiative kaon decay, but not in systems involving the lightest generation of quarks. An explicit low-energy physics model being tested produces TRV effects in the Fermi beta decay of the neutron, tritium, or some positron-decaying isotopes. We will present plans to measure the TRV asymmetry in radiative beta decay of laser-trapped 38mK at better than 0.01 sensitivity, including suppression of background from positron annihilation. Supported by NSERC, D.O.E., Israel Science Foundation. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

  8. Tetrahydro-beta-carboline-3-carboxylic acid compounds in fish and meat: possible precursors of co-mutagenic beta-carbolines norharman and harman in cooked foods.

    PubMed

    Herraiz, T

    2000-10-01

    The presence of tetrahydro-beta-carbolines and beta-carbolines was studied in raw, cooked and smoked fish and meat. 1,2,3,4-Tetrahydro-beta-carboline-3-carboxylic acid (THCA) usually was the major beta-carboline found, whereas 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) appeared in smoked and 'well done' cooked samples. THCA was detected in raw fish (nd-2.52 micrograms/g), cooked fish (nd-6.43 micrograms/g), cooked meats (nd-0.036 microgram/g), smoked fish (0.19-0.67 microgram/g) and smoked meats (0.02-1.1 micrograms/g). Smoked and cooked samples contained higher amounts of THCA and MTCA than raw products. Deep cooking of fish and meat increased both THCA and MTCA, and this was accompanied by the formation of more beta-carbolines, norharman and harman. The tetrahydro-beta-carbolines THCA and MTCA were chemical precursors of the co-mutagens norharman and harman during cooking. These and previous results confirm that foods are an important source of beta-carbolines in humans.

  9. Remote Sensing of Alpha and Beta Sources - Modeling Summary

    SciTech Connect

    Dignon, J; Frank, M; Cherepy, N

    2005-10-20

    Evaluating the potential for optical detection of the products of interactions of energetic electrons or other particles with the background atmosphere depends on predictions of change in atmospheric concentrations of species which would generate detectable spectral signals within the range of observation. The solar blind region of the spectrum, in the ultra violet, would be the logical band for outdoor detection (see Figure 1). The chemistry relevant to these processes is composed of ion-molecule reactions involving the initially created N{sub 2}{sup +} and O{sub 2}{sup +} ions, and their subsequent interactions with ambient trace atmospheric constituents. Effective modeling of the atmospheric chemical system acted upon by energetic particles requires knowledge of the dominant mechanism that exchange charge and associate it with atmospheric constituents, kinetic parameters of the individual processes (see e.g. Brasseur and Solomon, 1995), and a solver for the coupled differential equations that is accurate for the very stiff set of time constants involved. The LLNL box model, VOLVO, simulates the diel cycle of trace constituent photochemistry for any point on the globe over the wide range of time scales present using a stiff Gear-type ODE solver, i.e. LSODE. It has been applied to problems such as tropospheric and stratospheric nitrogen oxides, stratospheric ozone production and loss, and tropospheric hydrocarbon oxidation. For this study we have included the appropriate ion flux.

  10. Beta-blockers for hypertension

    PubMed Central

    Wiysonge, Charles S; Bradley, Hazel A; Volmink, Jimmy; Mayosi, Bongani M; Opie, Lionel H

    2017-01-01

    Background Beta-blockers refer to a mixed group of drugs with diverse pharmacodynamic and pharmacokinetic properties. They have shown long-term beneficial effects on mortality and cardiovascular disease (CVD) when used in people with heart failure or acute myocardial infarction. Beta-blockers were thought to have similar beneficial effects when used as first-line therapy for hypertension. However, the benefit of beta-blockers as first-line therapy for hypertension without compelling indications is controversial. This review is an update of a Cochrane Review initially published in 2007 and updated in 2012. Objectives To assess the effects of beta-blockers on morbidity and mortality endpoints in adults with hypertension. Search methods The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to June 2016: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 6), MEDLINE (from 1946), Embase (from 1974), and ClinicalTrials.gov. We checked reference lists of relevant reviews, and reference lists of studies potentially eligible for inclusion in this review, and also searched the the World Health Organization International Clinical Trials Registry Platform on 06 July 2015. Selection criteria Randomised controlled trials (RCTs) of at least one year of duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults. Data collection and analysis We selected studies and extracted data in duplicate, resolving discrepancies by consensus. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and conducted fixed-effect or random-effects meta-analyses, as appropriate. We also used GRADE to assess the certainty of the evidence. GRADE classifies the certainty of evidence as high (if we are confident that the true effect lies

  11. The Sine _beta β operator

    NASA Astrophysics Data System (ADS)

    Valkó, Benedek; Virág, Bálint

    2017-07-01

    We show that Sine$_\\beta$, the bulk limit of the Gaussian $\\beta$-ensembles is the spectrum of a self-adjoint random differential operator \\[ f\\to 2 {R_t^{-1}} \\left[ \\begin{array}{cc} 0 &-\\tfrac{d}{dt} \\tfrac{d}{dt} &0 \\end{array} \\right] f, \\qquad f:[0,1)\\to \\mathbb R^2, \\] where $R_t$ is the positive definite matrix representation of hyperbolic Brownian motion with variance $4/\\beta$ in logarithmic time. The result connects the Montgomery-Dyson conjecture about the Sine$_2$ process and the non-trivial zeros of the Riemann zeta function, the Hilbert-P\\'olya conjecture and de Brange's attempt to prove the Riemann hypothesis. We identify the Brownian carousel as the Sturm-Liouville phase function of this operator. We provide similar operator representations for several other finite dimensional random ensembles and their limits: finite unitary or orthogonal ensembles, Hua-Pickrell ensembles and their limits, hard-edge $\\beta$-ensembles, as well as the Schr\\"odinger point process. In this more general setting, hyperbolic Brownian motion is replaced by a random walk or Brownian motion on the affine group. Our approach provides a unified framework to study $\\beta$-ensembles that has so far been missing in the literature. In particular, we connect It\\^o's classification of affine Brownian motions with the classification of limits of random matrix ensembles.

  12. Purification and molecular characterization of the cardiac beta-adrenergic receptor

    SciTech Connect

    Robinson, D.A.; Venter, J.C.; Fraser, C.M.

    1986-05-01

    The porcine ventricle cardiac beta-adrenergic receptor (..beta..AR) is predominantly of the ..beta../sub 2/ subtype. Sucrose density gradient purified porcine ventricle membranes exhibit a high ..beta..AR density of 1 pmol per mg and a K/sub d/ for /sup 125/I-iodocyanopindolol of 180 pM. Digitonin solubilized receptor exhibits ligand binding characteristics identical to those of membrane bound receptor. Stability studies indicate that the solubilized cardiac ..beta..AR has a t/sub 1/2/ of 92 hours. Solubilized receptor is stabilized by occupation with antagonists. Isoelectric focusing indicates a pI = 5.0, in agreement with results obtained for both ..beta../sub 1/AR and ..beta../sub 2/AR isolated from other sources. The cardiac ..beta../sub 1/AR has been purified to homogeneity by affinity chromatography and size exclusion HPLC (2 TSK 2000, 1 TSK 3000). Autoradiograms of purified, radioiodinated receptor preparations subjected to SDS-PAGE revealed a single band with an apparent subunit molecular mass (M/sub r/) of 68 kDa. This subunit M/sub r/ was confirmed in membranes photoaffinity labeled with /sup 125/I-iodocyanopindolol diazirine. A single band was specifically labeled, as evidenced by blocking of photoincorporation by (-) and (+) propranolol with typical ..beta..AR stereoselectivity.

  13. Beta Cell Replacement in Mice Using Human Type 1 Diabetes Nuclear Transfer Embryonic Stem Cells.

    PubMed

    Sui, Lina; Danzl, Nichole; Campbell, Sean R; Viola, Ryan; Williams, Damian; Xing, Yuan; Wang, Yong; Phillips, Neil; Poffenberger, Greg; Johannesson, Bjarki; Oberholzer, Jose; Powers, Alvin C; Leibel, Rudolph L; Chen, Xiaojuan; Sykes, Megan; Egli, Dieter

    2017-09-20

    Beta cells derived from stem cells hold great promise for cell replacement therapy for diabetes. Here we examine the ability of nuclear transfer embryonic stem cells (NT-ES) derived from a type 1 diabetes patient to differentiate into beta cells, and provide a source of autologous islets for cell replacement. NT-ES cells differentiate in vitro with an average efficiency of 55% into C-peptide-positive cells, expressing markers of mature beta cells, including MAFA and NKX6.1. Upon transplantation in immunodeficient mice, grafted cells form vascularized islet-like structures containing MAFA/C-peptide-positive cells. These beta cells adapt insulin secretion to ambient metabolite status and show normal insulin processing. Importantly, NT-ES-beta cells maintain normal blood glucose levels after ablation of the mouse's endogenous beta cells. Cystic structures, but no teratomas, were observed in NT-ES-beta cell grafts. Isogenic induced pluripotent stem cell lines showed greater variability in beta cell differentiation. Even though different methods of somatic cell reprogramming result in stem cell lines that are molecularly indistinguishable, full differentiation competence is more common in ES cell lines than in iPS cell lines. These results demonstrate the suitability of NT-ES-beta for cell replacement for type 1 diabetes, and provide proof of principle for therapeutic cloning combined with cell therapy. © 2017 by the American Diabetes Association.

  14. Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay

    SciTech Connect

    Iachello, F.; Barea, J.

    2011-05-06

    A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.

  15. beta (+)-Thalassaemia in the Po river delta region (northern Italy): genotype and beta globin synthesis.

    PubMed Central

    Del Senno, L; Pirastu, M; Barbieri, R; Bernardi, F; Buzzoni, D; Marchetti, G; Perrotta, C; Vullo, C; Kan, Y W; Conconi, F

    1985-01-01

    Six beta(+)-thalassaemic patients from the Po river delta region have been studied. Using synthetic oligonucleotides as specific hybridisation probes, the beta(+) IVS I mutation (G----A at position 108) was demonstrated. This lesion and the enzyme polymorphism pattern in the subjects examined are the same as have been described for other Mediterranean beta(+)-thalassaemias. Antenatal diagnosis through DNA analysis of beta(+)-thalassaemia is therefore possible. The production of beta globin in a beta(+), homozygote and in a beta (+), beta(0) 39 (nonsense mutation at codon 39) double heterozygote is approximately 20% and 10% respectively of total non-alpha globin synthesis. Despite some overlapping of the results, similar beta globin synthesis levels have been obtained in 43 beta(+)-thalassaemia patients. This suggests that in the Po river delta region the most common thalassaemic genes are beta(0) 39 and beta(+) IVS I. Images PMID:2580095

  16. Beta 1-adrenoreceptors regulate resting metabolic rate.

    PubMed

    Lamont, L S; Romito, R A; Finkelhor, R S; Kalhan, S C

    1997-06-01

    This was a randomized, cross-over experiment designed to determine which beta-adrenergic receptors, beta 1, beta 2, or both, regulate metabolic rate in humans. All subjects (3 women, 4 men) were administered a 7-d therapeutic dose of a selective beta 1-antagonist (atenolol 50 mg BID), a combined beta 1, beta 2-antagonist (propranolol 80 mg BID), and a placebo control (BID). Indirect calorimetry was determined before and after 1 h of submaximal exercise. Exercise was performed at 50% of the trial specific VO2peak because maximal exercise was significantly decreased in the presence of the nonselective beta 1, beta 2-antagonist (VO2peak placebo: 44.90 +/- 4.40 mL.kg-1.min-1 vs beta 1, beta 2-antagonism: 39.20 +/- 3.00 mL.kg-1.min-1; P < 0.05). Both the beta 1 and the combined beta 1, beta 2-adrenoreceptor antagonists reduced resting oxygen consumption to a similar extent (0.247 +/- 0.007 L.min-1 placebo, vs 0.218 +/- 0.007 L.min-1 beta 1-antagonism, vs 0.226 +/- 0.007 L.min-1 beta 1, beta 2-antagonism; P < 0.05). However, the 30-min and 60-min excess post-exercise oxygen consumption (mean EPOC) remained unchanged. It is concluded that the beta 1-receptors are regulating the effects of the sympathetic nervous system on resting but not exercise recovery metabolic rate. These metabolic side effects may suggest that changes need to be made in the nutritional requirements of patients using beta-adrenergic antagonists.

  17. Beta ray flux measuring device

    DOEpatents

    Impink, Jr., Albert J.; Goldstein, Norman P.

    1990-01-01

    A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

  18. BETA-GAMMA PERSONNEL DOSIMETER

    DOEpatents

    Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

    1961-01-17

    A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

  19. sin 2 beta + gamma Measurements

    SciTech Connect

    Therin, G; /Paris U., VI-VII

    2005-06-24

    I report on the most recent measurements done to constrain sin(2{beta}+{gamma}) with neutral B mesons. Direct measurements of 2{beta} + {gamma} will provide a precise test of the standard model predictions with higher statistics. Present constraints come from studies of B {yields} D{sup (*){+-}}{pi}{sup {-+}}/{rho}{sup {-+}} decays done by BABAR and Belle collaborations with full and inclusive techniques to reconstruct B mesons. B {yields} D{sup 0(*)}K{sup 0} decays are also very promising but statistics are too low to give any constraint at the moment.

  20. The microbial oxidation of (-)-beta-pinene by Botrytis cinerea.

    PubMed

    Farooq, Afgan; Choudhary, M Iqbal; Tahara, Satoshi; Rahman, Atta-ur; Başer, K Hüsnü Can; Demirci, Fatih

    2002-01-01

    (-)-beta-pinene, a flavor and fragrance monoterpene is an important constituent of essential oils of many aromatic plants. It was oxidized by a plant-pathogenic fungus, Botrytis cinerea to afford four metabolites characterized as (-)-6a-hydroxy-beta-pinene, (-)-4beta,5beta-dihydroxy-beta-pinene, (-)-2beta,3beta-dihydroxypinane, and (-)-4beta-hydroxy-beta-pinene-6-one by detailed spectroscopic studies along with other known metabolites.

  1. Beta thalassaemia mutations in Turkish Cypriots.

    PubMed Central

    Sozuoz, A; Berkalp, A; Figus, A; Loi, A; Pirastu, M; Cao, A

    1988-01-01

    Using oligonucleotide hybridisation or restriction endonuclease analysis, we have characterised the molecular defect in 94 patients with thalassaemia major and four with thalassaemia intermedia of Turkish Cypriot descent. We found that four mutations, namely beta+ IVS-1 nt 110, beta zero IVS-1 nt, beta+ IVS-1 nt 6, and beta+ IVS-2 nt 745 were prevalent, accounting for 69.9%, 11.7%, 8.7%, and 5.6% respectively of the beta thalassaemia chromosomes. This information may help in the organisation of a large scale prevention programme based on fetal diagnosis of beta thalassaemia by DNA analysis in the Turkish population. PMID:3236356

  2. Transforming growth factor type. beta. can act as a potent competence factor for AKR-2B cells

    SciTech Connect

    Goustin, A.S.; Nuttall, G.A.; Leof, E.B.; Ranganathan, G.; Moses, H.L. )

    1987-10-01

    Transforming growth factor type {beta} (TGF{beta}) is a pleiotropic regulator of cell growth with specific high-affinity cell-surface receptors on a large number of cells; its mechanism of action, however, is poorly defined. In this report, the authors utilized the mouse fibroblast line AKR-2B to explore the question of the temporal requirements during the cell cycle in regard to both the growth inhibitory and the growth stimulatory action of TGF{beta}. The results indicate that AKR-2B cells are most sensitive to the inhibitory action of TGF{beta} during early to mid-G{sub 1}. In addition, TGF{beta} need be present only briefly in order to exert its inhibitory effect on EGF-induced DNA synthesis. Likewise, the stimulatory effect of TGF{beta} in the absence of EGF requires only an equally brief exposure to TGF{beta}. Use of homogeneous {sup 125}I-labeled TGF{beta} in a cell-binding assay demonstrates that TGF{beta} bound to cell-surface receptors can readily exchange into the culture medium, helping to rule out the possibility that persistent receptor-bound TGF{beta} is the source of a continuous stimulus. The data indicate that TGF{beta} exposure induces a stable state in the cell similar to but distinct from the state of competence induced by platelet-derived growth factor (PDGF).

  3. Production of poly-(beta-hydroxybutyric-co-beta-hydroxyvaleric) acids.

    PubMed Central

    Ramsay, B A; Lomaliza, K; Chavarie, C; Dubé, B; Bataille, P; Ramsay, J A

    1990-01-01

    Alcaligenes latus, Alcaligenes eutrophus, Bacillus cereus, Pseudomonas pseudoflava, Pseudomonas cepacia, and Micrococcus halodenitrificans were found to accumulate poly-(beta-hydroxybutyric-co-beta-hydroxyvaleric) acid [P(HB-co-HV)] copolymer when supplied with glucose (or sucrose in the case of A. latus) and propionic acid under nitrogen-limited conditions. A fed-batch culture of A. eutrophus produced 24 g of poly-beta-hydroxybutyric acid (PHB) liter-1 under ammonium limitation conditions. When the glucose feed was replaced with glucose and propionic acid during the polymer accumulation phase, 17 g of P(HB-co-HV) liter-1 was produced. The P(HB-co-HV) contained 5.0 mol% beta-hydroxyvaleric acid (HV). Varying the carbon-to-nitrogen ratio at a dilution rate of 0.15 h-1 in a chemostat culture of A. eutrophus resulted in a maximum value of 33% (wt/wt) PHB in the biomass. In comparison, A. latus accumulated about 40% (wt/wt) PHB in chemostat culture under nitrogen-limited conditions at the same dilution rate. When propionic acid was added to the first stage of a two-stage chemostat, A. latus produced 43% (wt/wt) P(HB-co-HV) containing 18.5 mol% HV. In the second stage, the P(HB-co-HV) increased to 58% (wt/wt) with an HV content of 11 mol% without further addition of carbon substrate. The HV composition in P(HB-co-HV) was controlled by regulating the concentration of propionic acid in the feed. Poly-beta-hydroxyalkanoates containing a higher percentage of HV were produced when pentanoic acid replaced propionic acid. PMID:2117877

  4. Screening of beta-glucan contents in commercially cultivated and wild growing mushrooms.

    PubMed

    Sari, Miriam; Prange, Alexander; Lelley, Jan I; Hambitzer, Reinhard

    2017-02-01

    Mushrooms have unique sensory properties and nutritional values as well as health benefits due to their bioactive compounds, especially beta-glucans. Well-known edible and medicinal mushroom species as well as uncommon or unknown species representing interesting sources of bioactive beta-glucans have been widely studied. Commercially cultivated and wild growing mushrooms were analysed for their beta-glucan contents. Enzymatic determinations of all glucans, alpha-glucans and beta-glucans in 39 mushrooms species were performed, leading to very remarkable results. Many wild growing species present high beta-glucan contents, especially Bracket fungi. The well-known cultivated species Agaricus bisporus, Lentinula edodes and Cantharellus cibarius as well as most screened wild growing species show higher glucan contents in their stipes than caps. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. One-step purification and characterization of an intracellular beta-glucosidase from Metschnikowia pulcherrima.

    PubMed

    González-Pombo, Paula; Pérez, Gabriel; Carrau, Francisco; Guisán, José Manuel; Batista-Viera, Francisco; Brena, Beatriz M

    2008-08-01

    A collection of 60 non-Saccharomyces yeasts isolated from grape musts in Uruguayan vineyards was screened for beta-glucosidase activity and Metschnikowia pulcherrima was the best source of this enzyme activity. Its major beta-glucosidase was successfully purified to homogeneity by ion-exchange chromatography on amino-agarose gel. The enzyme exhibited an optimum catalytic activity at 50 degrees C and pH 4.5 and was active against (1 --> 4)-beta and (1 --> 2)-beta glycosidic linkages. In spite of preserving 100% of its activity and stability in the presence of 12% (v/v) ethanol and 5 g glucose/l, the enzyme was unstable below pH 4. We characterized the beta-glucosidase from M. pulcherrima with a view to its potential applications in wine-making.

  6. The mammalian beta-tubulin repertoire: hematopoietic expression of a novel, heterologous beta-tubulin isotype

    PubMed Central

    1986-01-01

    We describe the structure of a novel and unusually heterologous beta- tubulin isotype (M beta 1) isolated from a mouse bone marrow cDNA library, and a second isotype (M beta 3) isolated from a mouse testis cDNA library. Comparison of M beta 1 and M beta 3 with the completed (M beta 4, M beta 5) or extended (M beta 2) sequence of three previously described beta-tubulin isotypes shows that each includes a distinctive carboxy-terminal region, in addition to multiple amino acid substitutions throughout the polypeptide chain. In every case where a mammalian interspecies comparison can be made, both the carboxy- terminal and internal amino acid substitutions that distinguish one isotype from another are absolutely conserved. We conclude that these characteristic differences are important in determining functional distinctions between different kinds of microtubule. The amino acid homologies between M beta 2, M beta 3, M beta 4, and M beta 5 are in the range of 95-97%; however the homology between M beta 1 and all the other isotypes is very much less (78%). The dramatic divergence in M beta 1 is due to multiple changes that occur throughout the polypeptide chain. The overall level of expression of M beta 1 is low, and is restricted to those tissues (bone marrow, spleen, developing liver and lung) that are active in hematopoiesis in the mouse. We predict that the M beta 1 isotype is functionally specialized for assembly into the mammalian marginal band. PMID:3782288

  7. Caliber Schools. Caliber: Beta Academy

    ERIC Educational Resources Information Center

    EDUCAUSE, 2015

    2015-01-01

    Caliber: Beta Academy is reimagining education as we know it, with the belief that the innovations in its model will allow 100% of its students to graduate ready to attend and succeed in a competitive four-year college and beyond. The academic model of the school features personalized learning plans, blended learning for English and math,…

  8. Caliber Schools. Caliber: Beta Academy

    ERIC Educational Resources Information Center

    EDUCAUSE, 2015

    2015-01-01

    Caliber: Beta Academy is reimagining education as we know it, with the belief that the innovations in its model will allow 100% of its students to graduate ready to attend and succeed in a competitive four-year college and beyond. The academic model of the school features personalized learning plans, blended learning for English and math,…

  9. Cellular localization of transforming growth factor-beta expression in bleomycin-induced pulmonary fibrosis.

    PubMed Central

    Zhang, K.; Flanders, K. C.; Phan, S. H.

    1995-01-01

    Bleomycin-induced pulmonary fibrosis is associated with increased lung transforming growth factor-beta (TGF-beta) gene expression, but cellular localization of the source of this expression has not been unequivocally established. In this study, lung fibrosis was induced in rats by endotracheal bleomycin injection on day 0 and, on selected days afterwards, lungs were harvested for in situ hybridization, immunohistochemical and histochemical analyses for TGF-beta 1 mRNA and protein expression, and cell identification. The results show that control lungs express essentially no detectable TGF-beta 1 mRNA or protein in the parenchyma. Before day 3 after bleomycin treatment, scattered bronchiolar epithelial cells, mononuclear cells, and eosinophils expressed elevated levels of TGF-beta 1. Between days 3 and 14, there was a major increase in the number of eosinophils, myofibroblasts, and fibroblasts strongly expressing TGF-beta 1 mRNA and protein. TGF-beta 1-producing cells were predominantly localized within areas of injury and active fibrosis. After day 14, the intensity and number of TGF-beta 1-expressing cells significantly declined and were predominantly found in fibroblasts in fibrotic areas. The expression of TGF-beta 1 protein was generally coincident with that for mRNA with the exception of bronchiolar epithelial cells in which strong protein expression was unaccompanied by a commensurate increase in mRNA. The study demonstrates that myofibroblasts, fibroblasts, and eosinophils represent the major sources of increased lung TGF-beta 1 expression in this model of pulmonary fibrosis. Images Figure 2 Figure 3 Figure 4 PMID:7543734

  10. How Do Beta Blocker Drugs Affect Exercise?

    MedlinePlus

    ... Blockers and Physical Activity Interestingly, beta blockers and exercise have some similar effects on the body. “Your blood pressure and heart rate are similarly changed by exercise and beta blockers,” said Gerald Fletcher, M.D., ...

  11. [Treatment of glaucoma with beta receptor blockers].

    PubMed

    Demmler, N

    1980-06-19

    We report the possibility of treatment with beta-adrenergic blocking agents in glaucoma-therapy. In open-angle glaucoma the therapy with beta-adrenergic blocking agents is often the best one. The combination of beta-adrenergic blocking agents with miotics is the therapy of choice in the treatment of closure-angle glaucoma. In special forms of glaucoma it is necessary to decide if the best therapy is the treatment with beta-adrenergaic blocking agents alone or a combined treatment of beta-adrenergic blocking agents with miotics. The beta-adrenergic blocking agent timolol (Chibro-Timoptol) and bupranolol (Ophtorenin) lower in the intraocular pressure to a greater extent than other beta-adrenergic blocking agents. Timolol eye drops and bupranolol eye drops are therefore the best beta-adrenergic blocking agents in therpay of glaucoma.

  12. Genetics Home Reference: beta-mannosidosis

    MedlinePlus

    ... beta-mannosidosis . The MANBA gene provides instructions for making the enzyme beta-mannosidase. This enzyme works in the lysosomes , which are compartments that digest and recycle materials in the cell. Within lysosomes, the enzyme helps ...

  13. Neutron beta decay studies with Nab

    NASA Astrophysics Data System (ADS)

    Baeßler, S.; Alarcon, R.; Alonzi, L. P.; Balascuta, S.; Barrón-Palos, L.; Bowman, J. D.; Bychkov, M. A.; Byrne, J.; Calarco, J. R.; Chupp, T.; Cianciolo, T. V.; Crawford, C.; Frlež, E.; Gericke, M. T.; Glück, F.; Greene, G. L.; Grzywacz, R. K.; Gudkov, V.; Harrison, D.; Hersman, F. W.; Ito, T.; Makela, M.; Martin, J.; McGaughey, P. L.; McGovern, S.; Page, S.; Penttilä, S. I.; Počanić, D.; Rykaczewski, K. P.; Salas-Bacci, A.; Tompkins, Z.; Wagner, D.; Wilburn, W. S.; Young, A. R.

    2013-10-01

    Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.

  14. Can Beta Blockers Cause Weight Gain?

    MedlinePlus

    Diseases and Conditions High blood pressure (hypertension) Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol (Tenormin) ...

  15. Interferon Beta-1a Intramuscular Injection

    MedlinePlus

    Interferon beta-1a intramuscular injection is used to reduce the number of episodes of symptoms and slow ... and problems with vision, speech, and bladder control). Interferon beta-1a is in a class of medications ...

  16. Interferon Beta-1a Subcutaneous Injection

    MedlinePlus

    Interferon beta-1a subcutaneous injection is used to reduce episodes of symptoms and slow the development of ... and problems with vision, speech, and bladder control). Interferon beta-1a is in a class of medications ...

  17. Simulation of the dose rate per activity of beta-emitting radionuclides.

    PubMed

    Behrens, R

    2015-12-01

    The dose rate per activity was simulated for 10 beta-emitting radionuclides and for different activity distributions (point source, areal sources and a semi-infinite volume source). The results are given for 7 different distances from the source (from 0.01 to 2 m) for both contributions: the beta- and electron-emission, and the X- and gamma-emission. Data are provided for both operational quantities and organ doses: Hp(0.07), Hp(3), Hp(10), Hskin and Hlens. Finally, a software applicaton to interpolate the dose rate per activity due to the beta-emission of arbitrary radionuclides is presented and a simple superposition of these data and of gamma-ray dose constants to calculate the total dose rate is described.

  18. Beta and low-energy photon irradiation of several commercial phosphors

    NASA Astrophysics Data System (ADS)

    Fix, J. J.; Holbrook, K. L.; Soldat, K. L.

    1983-02-01

    Several commercially available thermoluminescent phosphors were evaluated with respect to their observed response to selected beta sources and K-fluorescent X rays. Phosphor responses were determined for in-air and on-phantom irradiations. Similar irradiations were done using a 137Cs source. Phosphor glow curves were recorded using a Harshaw Model 2080 TL Picoprocessor.

  19. Beta- and gamma-range human lower limb corticomuscular coherence

    PubMed Central

    Gwin, Joseph T.; Ferris, Daniel P.

    2012-01-01

    Coherence between electroencephalography (EEG) recorded on the scalp above the motor cortex and electromyography (EMG) recorded on the skin of the limbs is thought to reflect corticospinal coupling between motor cortex and muscle motor units. Beta-range (13–30 Hz) corticomuscular coherence has been extensively documented during static force output while gamma-range (31–45 Hz) coherence has been linked to dynamic force output. However, the explanation for this beta-to-gamma coherence shift remains unclear. We recorded 264-channel EEG and 8-channel lower limb EMG while eight healthy subjects performed isometric and isotonic, knee, and ankle exercises. Adaptive mixture independent component analysis (AMICA) parsed EEG into models of underlying source signals. We computed magnitude squared coherence between electrocortical source signals and EMG. Significant coherence between contralateral motor cortex electrocortical signals and lower limb EMG was observed in the beta- and gamma-range for all exercise types. Gamma-range coherence was significantly greater for isotonic exercises than for isometric exercises. We conclude that active muscle movement modulates the speed of corticospinal oscillations. Specifically, isotonic contractions shift corticospinal oscillations toward the gamma-range while isometric contractions favor beta-range oscillations. Prior research has suggested that tasks requiring increased integration of visual and somatosensory information may shift corticomuscular coherence to the gamma-range. The isometric and isotonic tasks studied here likely required similar amounts of visual and somatosensory integration. This suggests that muscle dynamics, including the amount and type of proprioception, may play a role in the beta-to-gamma shift. PMID:22973219

  20. Recombinant GST-I-A beta 28-induced efficient serum antibody against A beta 42.

    PubMed

    Huang, Xuemei; Wang, Jiapeng; Cui, Lili; Zou, Xiaohuan; Zhang, Yingjiu

    2010-01-30

    Six recombinant proteins GST-A beta 28/A beta 35/A beta 42 and GST-I-A beta 28/A beta 35/A beta 42 [I was the abbreviation for an immunostimulatory sequence that consisted of pan HLA DR binding epitope (PADRE) and Tetanus toxin epitope (TT)] were used as antigens after expressed and purified to immunize mice. The strongest antibody response against A beta 42 (titer 1:3200) was achieved by GST-I-A beta 28 or GST-A beta 42 immunization. However, IgG1 and IgG2b were the predominant serum antibody isotype responses by GST-I-A beta 28 immunization, whereas did IgG2a by GST-A beta 42 immunization. Thus, it indicated that GST-I-A beta 28 immunization in a mouse mainly evoked a stronger Th-2-type response; whereas, GST-A beta 42 immunization mainly elicited a Th-1-type response. Moreover, GST-I-A beta 28-induced serum antibodies had higher specificity to A beta 42 monomers and oligomers than to protofibrils and mature fibrils and exhibited the highest efficacy to block A beta 42 aggregation or fibrillogenesis and to disassemble A beta 42 aggregates in vitro. GST-I-A beta 28-induced serum antibodies also showed the most protective and restorative effects on target cells in vitro by inhibiting or neutralizing A beta 42-induced cytotoxicity. All of the above results indicated that A beta 28 could be speculated to substitute for A beta 42 and would become a better antigenic peptide for Alzheimer's disease immunotherapy in the presence of additional Th-cell epitopes such as the immunostimulatory sequence (I) applied in this study. (c) 2009 Elsevier B.V. All rights reserved.

  1. Heterogeneity of the Pancreatic Beta Cell

    PubMed Central

    Gutierrez, Giselle Dominguez; Gromada, Jesper; Sussel, Lori

    2017-01-01

    The pancreatic beta cell functions as a key regulator of blood glucose levels by integrating a variety of signals in response to changing metabolic demands. Variations in beta cell identity that translate into functionally different subpopulations represent an interesting mechanism to allow beta cells to efficiently respond to diverse physiological and pathophysiological conditions. Recently, there is emerging evidence that morphological and functional differences between beta cells exist. Furthermore, the ability of novel single cell technologies to characterize the molecular identity of individual beta cells has created a new era in the beta cell field. These studies are providing important novel information about the origin of beta cell heterogeneity, the type and proportions of the different beta cell subpopulations, as well as their intrinsic properties. Furthermore, characterization of different beta cell subpopulations that could variably offer protection from or drive progression of diabetes has important clinical implications in diabetes prevention, beta cell regeneration and stem cell treatments. In this review, we will assess the evidence that supports the existence of heterogeneous populations of beta cells and the factors that could influence their formation. We will also address novel studies using islet single cell analysis that have provided important information toward understanding beta cell heterogeneity and discuss the caveats that may be associated with these new technologies. PMID:28321233

  2. beta. -decay asymmetry of the free neutron

    SciTech Connect

    Bopp, P.; Dubbers, D.; Klemt, E.; Last, J.; Schuetze, H.; Weibler, W.; Freedman, S.J.; Schaerpf, O.

    1983-01-01

    The ..beta..-decay of polarized neutrons has been studied with the new superconducting spectrometer PERKEO at the ILL. The energy dependence of the ..beta..-decay asymmetry has been measured for the first time. From the measured ..beta..-asymmetry parameter we obtain a new value for the ratio of weak coupling constants g/sub A//g/sub V/. 11 references.

  3. Beta measurements at Department of Energy facilities

    SciTech Connect

    Rathbun, L.A.; Swinth, K.L.; Haggard, D.L.

    1987-08-01

    Pacific Northwest Laboratory performed a two-step process to characterize the current beta measurement practices at DOE facilities. PNL issued a survey questionnaire on beta measurement practices to DOE facilities and reported the results. PNL measured beta doses and spectra at seven selected DOE facilities and compared selected measurement techniques in the facility environment. This report documents the results of the radiation field measurements and the comparison of measurement techniques at the seven facilities. Data collected included beta dose and spectral measurements at seven DOE facilities that had high beta-to-gamma ratios (using a silicon surface barrier spectrometer, a plastic scintillator spectrometer, and a multielement beta dosimeter). Other dosimeters and survey meters representative of those used at DOE facilities or under development were also used for comparison. Field spectra were obtained under two distinct conditions. Silicon- and scintillation-based spectrometer systems were used under laboratory conditions where high beta-to-gamma dose ratios made the beta spectra easier to observe and analyze. In the second case, beta spectrometers were taken into actual production and maintenance areas of DOE facilities. Analyses of beta and gamma spectra showed that /sup 234/Th- /sup 234m/Pa, /sup 231/Th, /sup 137/Cs, and /sup 90/Sr//sup 90/Y were the major nuclides contributing to beta doses at the facilities visited. Beta doses from other fission products and /sup 60/Co were also measured, but the potential for exposure was less significant. 21 refs., 64 figs., 18 tabs.

  4. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Effects of beta-glucan addition to a probiotic containing yogurt.

    PubMed

    Vasiljevic, T; Kealy, T; Mishra, V K

    2007-09-01

    This study investigated the effects of addition of beta-glucan from 2 different cereal sources (oat and barley) on growth and metabolic activity of Bifidobacterium animalis ssp. lactis (Bb-12) as determined by plating on a selective medium in yogurt during prolonged cold storage. These yogurt batches were compared to unsupplemented and inulin supplemented controls. All batches were also assessed for syneresis. Oat beta-glucan addition resulted in improved probiotic viability and stability comparable to that of inulin. It also enhanced lactic and propionic acid production. The barley beta-glucan addition suppressed proteolytic activity more than that from oat. These improvements were hindered by greater syneresis caused likely by thermodynamic incompatibility. Small amplitude oscillatory measurements of acidified model mixture of beta-glucan/skim milk solids showed formation of casein gel within the beta-glucan network. Binary mixtures of beta-glucan and skim milk solids had apparent pseudoplastic and non-Newtonian behavior governed mainly by beta-glucan contribution. Above critical concentrations, the mixtures underwent phase separation with the lower phase rich in protein. The phase diagram also showed that the addition of beta-glucan may be possible at or below 0.24 w/w%.

  8. Isozymes of beta-N-Acetylhexosaminidase from Pea Seeds (Pisum sativum L.).

    PubMed

    Harley, S M; Beevers, L

    1987-12-01

    Four isozymes of beta-N-acetylhexosaminidase (beta-NAHA) from pea seeds (Pisum sativum L.) have been separated, with one, designated beta-NAHA-II, purified to apparent homogeneity by means of an affinity column constructed by ligating p-aminophenyl-N-acetyl-beta-d-thioglucosaminide to Affi-Gel 202. The other three isozymes have been separated and purified 500- to 1750-fold by chromatography on Concanavalin A-Sepharose, Zn(2+) charged immobilized metal affinity chromatography, hydrophobic chromatography, and ion exchange chromatography on CM-Sephadex. All four isozymes are located in the protein bodies of the cotyledons. The molecular weight of each isozyme is 210,000. beta-NAHA-II is composed of two heterogenous subunits. The subunits are not held together by disulfide bonds, but sulfhydryl groups are important for catalysis. All four isozymes release p-nitrophenol from both p-nitrophenyl-N-acetyl-beta-d-glucosaminide and p-nitrophenyl-N-acetyl-beta-d-galactosaminide. The ratio of activity for hydrolysis of the two substrates is pH dependent. The K(m) value for the two substrates and pH optima of the isozymes are comparable to beta-NAHAs from other plant sources.

  9. Synthesis of new 10 beta-propargylic and 11 beta-allenic steroidal spirolactones.

    PubMed

    Faraj, H; Aumelas, A; Claire, M; Rondot, A; Auzou, G

    1991-11-01

    As part of continuing studies on the synthesis of new, biologically interesting 11 beta-substituted steroidal spirolactones, we describe here the competition between 10 beta-propargylation and 11 beta-allenylation. Grignard addition of allenyl magnesium bromide to an appropriate 5,10-epoxy-9(11)-olefin provides 10 beta-propargylation or 11 beta-allenylation. The role of the catalytic effect of copper chloride and of the solvent is evaluated. Confirmation of the structural assignments of these new 3,3-ethylenethioxy-10 beta-propargyl (or 11 beta-allenyl)-19-nor-17 alpha-pregna-4,9-diene-21,17-carbolactones is reported.

  10. [Microbial sources of pigments].

    PubMed

    Cañizares-Villanueva, R O; Ríos-Leal, E; Olvera Ramírez, R; Ponce Noyola, T; Márquez Rocha, F

    1998-01-01

    Pigments from natural sources has been obtained since long time ago, and their interest has increased due to the toxicity problems caused by those of synthetic origin. In this way the pigments from microbial sources are a good alternative. Some of more important natural pigments, are the carotenoids, flavonoids (anthocyanins) and some tetrapirroles (chloropyls, phycobilliproteins). Another group less important are the betalains and quinones. The carotenoids are molecules formed by isoprenoids units and the most important used as colorant are the alpha and beta carotene which are precursors of vitamin A, and some xantophylls as astaxanthin. The pigment more used in the industry is the beta-carotene which is obtained from some microalgae and cyanobacteria. The astaxanthin another important carotenoid is a red pigment of great commercial value, and it is used in the pharmaceutical feed and acuaculture industries. This pigments is mainly obtained from Phaffia rhodozyma and Haematococcus pluvialis and other organisms. The phycobilliproteins obtained from cyanobacteria and some group of algae, have recently been increased on the food industries. In the last years it has been used as fluorescent marker in biochemical assays. Our research group have carried out studies about the factors that improve the production of these pigments obtained from different microbial species as well as the methods for their extraction and application.

  11. Cytoplasmic tails of beta 1, beta 2, and beta 7 integrins differentially regulate LFA-1 function in K562 cells.

    PubMed Central

    Lub, M; van Vliet, S J; Oomen, S P; Pieters, R A; Robinson, M; Figdor, C G; van Kooyk, Y

    1997-01-01

    The beta 2 integrin lymphocyte function-associated antigen 1 (LFA-1) mediates activation-dependent adhesion of lymphocytes. To investigate whether lymphocyte-specific elements are essential for LFA-1 function, we expressed LFA-1 in the erythroleukemic cell line K562, which expresses only the integrin very late antigen 5. We observed that LFA-1-expressing K562 cannot bind to intercellular adhesion molecule 1-coated surfaces when stimulated by phorbol 12-myristate 13-acetate (PMA), whereas the LFA-1-activating antibody KIM185 markedly enhanced adhesion. Because the endogenously expressed beta 1 integrin very late antigen 5 is readily activated by PMA, we investigated the role of the cytoplasmic domain of distinct beta subunits in regulating LFA-1 function. Transfection of chimeric LFA-1 receptors in K562 cells reveals that replacement of the beta 2 cytoplasmic tail with the beta 1 but not the beta 7 cytoplasmic tail completely restores PMA responsiveness of LFA-1, whereas a beta 2 cytoplasmic deletion mutant of LFA-1 is constitutively active. Both deletion of the beta 2 cytoplasmic tail or replacement by the beta 1 cytoplasmic tail alters the localization of LFA-1 into clusters, thereby regulating LFA-1 activation and LFA-1-mediated adhesion to intercellular adhesion molecule 1. These data demonstrate that distinct signaling routes activate beta 1 and beta 2 integrins through the beta-chain and hint at the involvement of lymphocyte-specific signal transduction elements in beta 2 and beta 7 integrin activation that are absent in the nonlymphocytic cell line K562. Images PMID:9247650

  12. Alpha, beta, or gamma: where does all the diversity go?

    NASA Technical Reports Server (NTRS)

    Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

    1988-01-01

    Global taxonomic richness is affected by variation in three components: within-community, or alpha, diversity, between-community, or beta, diversity; and between-region, or gamma, diversity. A data set consisting of 505 faunal lists distributed among 40 stratigraphic intervals and six environmental zones was used to investigate how variation of alpha and beta diversity influenced global diversity through the Paleozoic, and especially during the Ordovician radiations. As first shown by Bambach (1977), alpha diversity increased by 50 to 70 percent in offshore marine environments during the Ordovician and then remained essentially constant of the remainder of the Paleozoic. The increase is insufficient, however, to account for the 300 percent rise observed in global generic diversity. It is shown that beta diversity among level, soft-bottom communities also increased significantly during the early Paleozoic. This change is related to enhanced habitat selection, and presumably increased overall specialization, among diversifying taxa during the Ordovician radiations. Combined with alpha diversity, the measured change in beta diversity still accounts for only about half of the increase in global diversity. Other sources of increase are probably not related to variation in gamma diversity but rather to appearance and/or expansion of organic reefs, hardground communities, bryozoan thickets, and crinoid gardens during the Ordovician.

  13. The Majorana Demonstrator Neutrinoless Double-beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Guiseppe, V. E.

    2012-03-01

    Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in ^76Ge. Our proposed method uses the well-established technique of searching for neutrinoless double-beta decay in high purity Ge-diode radiation detectors that play both roles of source and detector. The use of p-type point contact Ge detectors present advances in background rejection and a significantly lower energy threshold than conventional Ge detectors. The lower energy threshold opens up a broader and exciting physics program including searches for dark matter and axions concurrent with the double-beta decay search. Initially, Majorana is constructing a prototype module to demonstrate the potential of a future 1-tonne experiment. The status and potential physics reach of the Majorana Demonstrator module will be presented.

  14. Calculating Capstone depleted uranium aerosol concentrations from beta activity measurements.

    PubMed

    Szrom, Frances; Falo, Gerald A; Parkhurst, Mary Ann; Whicker, Jeffrey J; Alberth, David P

    2009-03-01

    Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the DU source term for the subsequent Human Health Risk Assessment (HHRA) of Capstone aerosols. Establishing a calibration curve between beta activity measurements and uranium mass measurements is straightforward if the uranium isotopes are in equilibrium with their immediate short-lived, beta-emitting progeny. For DU samples collected during the Capstone study, it was determined that the equilibrium between the uranium isotopes and their immediate short-lived, beta-emitting progeny had been disrupted when penetrators had perforated target vehicles. Adjustments were made to account for the disrupted equilibrium and for wall losses in the aerosol samplers. Values for the equilibrium fraction ranged from 0.16 to 1, and the wall loss correction factors ranged from 1 to 1.92. This paper describes the process used and adjustments necessary to calculate uranium mass from proportional counting measurements.

  15. Beta-cell replacement for type I diabetes.

    PubMed

    Stock, Peter G; Bluestone, Jeffrey A

    2004-01-01

    The ability to achieve insulin independence with either solid-organ pancreas or islet transplantation has increased the number of patients seeking beta-cell replacement as an alternative to insulin therapy. Despite dramatic improvements in the ability to achieve insulin independence following solid-organ pancreas transplantation, the secondary complications of long-standing diabetes are frequently irreversible by the time surgical intervention is justified based on the risk of this procedure. Pancreatic islet transplantation provides a safer and less invasive alternative for beta-cell replacement that could be justified earlier in the course of diabetes to prevent the development of secondary complications. Recent advances in the technology of islet isolation, as well as the ability to prevent the alloimmune and recurrent autoimmune response following islet transplantation with immunosuppressive regimens that are not toxic to beta cells, have rekindled an interest in this field. Widespread application of islet transplantation will depend on further improvements in selective immunosuppression, development of immunologic tolerance, and finding new sources of beta cells.

  16. Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements

    SciTech Connect

    Szrom, Fran; Falo, Gerald A.; Parkhurst, MaryAnn; Whicker, Jeffrey J.; Alberth, David P.

    2009-03-01

    Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols. Establishing a calibration curve between beta activity measurements and uranium mass measurements is straightforward if the uranium isotopes are in equilibrium with their immediate short-lived, beta-emitting progeny. For DU samples collected during the Capstone study, it was determined that the equilibrium between the uranium isotopes and their immediate short lived, beta-emitting progeny had been disrupted when penetrators had perforated target vehicles. Adjustments were made to account for the disrupted equilibrium and for wall losses in the aerosol samplers. Correction factors for the disrupted equilibrium ranged from 0.16 to 1, and the wall loss correction factors ranged from 1 to 1.92.

  17. Alpha-beta coordination method for collective search

    DOEpatents

    Goldsmith, Steven Y.

    2002-01-01

    The present invention comprises a decentralized coordination strategy called alpha-beta coordination. The alpha-beta coordination strategy is a family of collective search methods that allow teams of communicating agents to implicitly coordinate their search activities through a division of labor based on self-selected roles and self-determined status. An agent can play one of two complementary roles. An agent in the alpha role is motivated to improve its status by exploring new regions of the search space. An agent in the beta role is also motivated to improve its status, but is conservative and tends to remain aggregated with other agents until alpha agents have clearly identified and communicated better regions of the search space. An agent can select its role dynamically based on its current status value relative to the status values of neighboring team members. Status can be determined by a function of the agent's sensor readings, and can generally be a measurement of source intensity at the agent's current location. An agent's decision cycle can comprise three sequential decision rules: (1) selection of a current role based on the evaluation of the current status data, (2) selection of a specific subset of the current data, and (3) determination of the next heading using the selected data. Variations of the decision rules produce different versions of alpha and beta behaviors that lead to different collective behavior properties.

  18. Beta-particle spectroscopy with active gamma-ray discrimination

    SciTech Connect

    Higginbotham, J.F.

    1987-01-01

    A spectrometer was developed which was capable of measuring a beta-particle energy distribution while simultaneously (actively) rejecting the system's response to gamma rays. A two detector configuration was used, where the first detector was a thin, pancake type, gas-flow counter, positioned in front of the entrance window to a BC-400 plastic scintillator. The gas-flow counter was designed to be insensitive to gamma rays so that it could act as a sensor which would gate the spectrometer to accept only those pulses induced by beta-particle interactions in the scintillator. The gamma-ray rejection capability of the spectrometer was a linear function of gamma-ray energy. Various spectrometer design and response considerations were investigated to determine their effect on either the spectrometer's discrimination capabilities or on its ability to accurately measure the incident beta-particle energy distribution. The spectrometer was used to measure the energy distribution of the photoelectric and Compton recoil electrons which are produced by gamma ray interaction in thin metal foils. In addition, the energy distributions of each component of a radiation field consisting of beta particles and gamma rays were measured for several radiation sources.

  19. Transforming growth factor beta in Alzheimer's disease.

    PubMed Central

    Chao, C C; Hu, S; Frey, W H; Ala, T A; Tourtellotte, W W; Peterson, P K

    1994-01-01

    Alzheimer's disease (AD) has been hypothesized to be an inflammatory condition. We hypothesized that anti-inflammatory cytokines, such as transforming growth factor beta (TGF-beta), counteract the inflammatory process. In the present study, we found that TGF-beta levels were elevated in both cerebrospinal fluid and serum samples obtained from AD patients < 6 h after death. Serum TGF-beta levels were also markedly elevated before death. These results suggest that elevated TGF-beta levels in AD may represent a protective host response to immunologically mediated neuronal injury. PMID:7496909

  20. Beta genus papillomaviruses and skin cancer.

    PubMed

    Howley, Peter M; Pfister, Herbert J

    2015-05-01

    A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Beta Genus Papillomaviruses and Skin Cancer

    PubMed Central

    Howley, Peter M.; Pfister, Herbert J.

    2015-01-01

    A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor. PMID:25724416

  2. Molecular basis for amyloid-[beta] polymorphism

    SciTech Connect

    Colletier, Jacques-Philippe; Laganowsky, Arthur; Landau, Meytal; Zhao, Minglei; Soriaga, Angela B.; Goldschmidt, Lukasz; Flot, David; Cascio, Duilio; Sawaya, Michael R.; Eisenberga, David

    2011-10-19

    Amyloid-beta (A{beta}) aggregates are the main constituent of senile plaques, the histological hallmark of Alzheimer's disease. A{beta} molecules form {beta}-sheet containing structures that assemble into a variety of polymorphic oligomers, protofibers, and fibers that exhibit a range of lifetimes and cellular toxicities. This polymorphic nature of A{beta} has frustrated its biophysical characterization, its structural determination, and our understanding of its pathological mechanism. To elucidate A{beta} polymorphism in atomic detail, we determined eight new microcrystal structures of fiber-forming segments of A{beta}. These structures, all of short, self-complementing pairs of {beta}-sheets termed steric zippers, reveal a variety of modes of self-association of A{beta}. Combining these atomic structures with previous NMR studies allows us to propose several fiber models, offering molecular models for some of the repertoire of polydisperse structures accessible to A{beta}. These structures and molecular models contribute fundamental information for understanding A{beta} polymorphic nature and pathogenesis.

  3. Estimating beta-mixing coefficients

    PubMed Central

    McDonald, Daniel J.; Shalizi, Cosma Rohilla; Schervish, Mark

    2015-01-01

    The literature on statistical learning for time series assumes the asymptotic independence or “mixing” of the data-generating process. These mixing assumptions are never tested, and there are no methods for estimating mixing rates from data. We give an estimator for the beta-mixing rate based on a single stationary sample path and show it is L1-risk consistent. PMID:26279742

  4. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  5. [Beta-adrenergic receptor blocker poisoning].

    PubMed

    Reingardiene, Dagmara

    2007-01-01

    Beta-adrenergic receptor blocking drugs are used in the treatment of hypertension, angina, myocardial infarction, cardiac dysrhythmia, cardiomyopathy, migraine headache, thyrotoxicosis, and glaucoma. beta-adrenergic receptor blocking agents are competitive antagonist at beta(1), beta(2), or both types of adrenergic receptors. Overdoses of beta-adrenergic receptor blockers are uncommon, but are associated with significant morbidity and mortality. This review article discusses the properties of beta-adrenergic receptor blockers, presents the doses of these drugs causing toxicity and doses, after ingestion of which, referral to an emergency department is recommended. Clinical presentation of overdose (the cardiovascular, neurologic manifestations, pulmonary and other complications), diagnosis, and treatment (gastrointestinal decontamination; the usage of atropine, phosphodiesterase inhibitors, glucagon, insulin; indications for cardiac pacing, extracorporeal procedures of drug removal, etc.) are analyzed. In addition, this article focuses on clinical course and prognosis of beta-blocker overdose.

  6. Basal Ganglia Beta Oscillations Accompany Cue Utilization

    PubMed Central

    Leventhal, Daniel K.; Gage, Gregory J.; Schmidt, Robert; Pettibone, Jeffrey R.; Case, Alaina C.; Berke, Joshua D.

    2012-01-01

    SUMMARY Beta oscillations in cortical-basal ganglia (BG) circuits have been implicated in normal movement suppression and motor impairment in Parkinson’s disease. To dissect the functional correlates of these rhythms we compared neural activity during four distinct variants of a cued choice task in rats. Brief beta (~20 Hz) oscillations occurred simultaneously throughout the cortical-BG network, both spontaneously and at precise moments of task performance. Beta phase was rapidly reset in response to salient cues, yet increases in beta power were not rigidly linked to cues, movements, or movement suppression. Rather, beta power was enhanced after cues were used to determine motor output. We suggest that beta oscillations reflect a postdecision stabilized state of cortical-BG networks, which normally reduces interference from alternative potential actions. The abnormally strong beta seen in Parkinson’s Disease may reflect overstabilization of these networks, producing pathological persistence of the current motor state. PMID:22325204

  7. Hemoglobinopathies among the Gond tribal groups of central India; interaction of alpha- and beta-thalassemia with beta chain variants.

    PubMed

    Gupta, R B; Tiwary, R S; Pande, P L; Kutlar, F; Oner, C; Oner, R; Huisman, T H

    1991-01-01

    We have investigated the frequencies and types of alpha-thal, beta-thal, and Hb variants among nearly 200 inhabitants of villages in the Mandla and Jabalpur districts of Madhya Pradesh in Central India. Over 85% were tribals of the Gond group. alpha-Thal, as -alpha 3.7/and -alpha 4.2/, and the nondeletional Koya Dora mutation were present at the combined frequency of 0.54. There were indications for the presence of other nondeletional types of alpha-thal. alpha-Globin gene triplications were not observed. Four of the six beta-thal alleles observed were in the tribal groups; two (G----C at codon 30 and G----A at IVS-I-1) were found for the first time. The simultaneous presence of an alpha-thal (-alpha/alpha alpha or -alpha/-alpha) greatly improved the clinical and hematological condition of the patients with Hb S-beta(+)-thal (IVS-I-5; G----C). The lower frequency of alpha-thal among the beta-thal heterozygotes (f = 0.32) may indicate that some of the beta-thal alleles in the tribal populations originated from an outside source. Forty-one subjects had SS; all but one had beta S with haplotype #31, while one chromosome had haplotype #17. The presence of an alpha-thal-2 (f = 0.53) in the SS patients did not affect hematological data. The Hb F levels varied between 7.5% and 42.5% with high G gamma values. No difference in Hb F level between males and females was observed. Lower Hb F levels were present in 10 SS patients with an alpha-thal-2 homozygosity (average 16% versus 23.5% for eight SS patients with alpha alpha/alpha alpha) suggesting a decreased formation of alpha gamma dimers in severe alpha chain deficiency. Several younger SS patients (less than 10 years) also had high Hb F levels (32-42%). Variations in the sequence at -530 of the beta-globin gene; i.e. in the so-called silencer sequence, were present in all beta S chromosomes with haplotype #31, but were not considered important for understanding the variability in the Hb F level. gamma-Globin gene

  8. Determination of beta activity in water

    USGS Publications Warehouse

    Barker, F.B.; Robinson, B.P.

    1963-01-01

    Many elements have one or more naturally radioactive isotopes, and several hundred other radionuclides have been produced artificially. Radioactive substances may be present in natural water as a result of geochemical processes or the release of radioactive waste and other nuclear debris to the environment. The Geological Survey has developed methods for measuring certain of these .radioactive substances in water. Radioactive substances often are present in water samples in microgram quantities or less. Therefore, precautions must be taken to prevent loss of material and to assure that the sample truly represents its source at the time of collection. Addition of acids, complexing agents, or stable isotopes often aids in preventing loss of radioactivity on container walls, on sediment, or on other solid materials in contact with the sample. The disintegration of radioactive atoms is a random process subject to established methods of statistical analysis. Because many water samples contain small amounts of radioactivity, low-level counting techniques must be used. The usual assumption that counting data follow a Gaussian distribution is invalid under these conditions, and statistical analyses must be based on the Poisson distribution. The gross beta activity in water samples is determined from the residue left after evaporation of the sample to dryness. Evaporation is accomplished first in a teflon dish, then the residue is transferred with distilled water to a counting planchet and again is reduced to dryness. The radioactivity on the planchet is measured with an anticoincidence-shielded, low-background, beta counter and is compared with measurements of a strontium-90-yttrium-90 standard prepared and measured in the same manner. Control charts are used to assure consistent operation of the counting instrument.

  9. Mammalian. beta. /sub 1/- and. beta. /sub 2/-adrenergic receptors: immunological and structural comparison

    SciTech Connect

    Moxham, C.P.; George, S.T.; Graziano, M.P.; Brandwein, H.J.; Malbon, C.C.

    1986-11-05

    ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors, pharmacologically distinct proteins, have been reported to be structurally dissimilar. In the present study three techniques were employed to compare the nature of mammalian ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors. Antibodies against each of the receptor subtypes were raised separately. Polyclonal antisera against ..beta../sub 1/-receptors of rat fat cells were raised in mice, and antisera against ..beta../sub 2/-receptors of guinea pig lung were raised in rabbits. Receptors purified from rat fat cells (..beta../sub 1/-), S49 mouse lymphoma cells (..beta../sub 2/-), and rat liver (..beta../sub 2/-) were probed with these antisera. Each anti-receptor antisera demonstrated the ability to immunoprecipitate purified receptors of both ..beta../sub 1/- and ..beta../sub 2/-subtypes. The mobility of ..beta..-receptors subjected to polyacrylamide gel electrophoresis was probed using antireceptor antibodies and nitrocellulose blots of the gels. Fat cell ..beta../sub 1/-adrenergic receptors display M/sub r/ = 67,000 under reducing conditions and M/sub r/ = 54,000 under nonreducing conditions, as previously reported. Both ..beta../sub 1/- and ..beta../sub 2/-receptors displayed this same shift in electrophoretic mobility observed in the presence as compared to the absence of disulfide bridge-reducing agents, as detected both by autoradiography of the radiolabeled receptors and by immunoblotting of native receptors. Finally, isoelectric focusing of purified radioiodinated ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors revealed identical isoelectric points. These data are the first to provide analyses of immunological, structural, and biochemical features of ..beta../sub 1/- and ..beta../sub 2/-subtypes in tandem and underscore the structural similarities that exist between these pharmacologically distinct receptors.

  10. Role of ROS-mediated TGF beta activation in laser photobiomodulation

    NASA Astrophysics Data System (ADS)

    Arany, Praveen R.; Chen, Aaron Chih-Hao; Hunt, Tristan; Mooney, David J.; Hamblin, Michael

    2009-02-01

    The ability of laser light to modulate specific biological processes has been well documented but the precise mechanism mediating these photobiological interactions remains an area of intense investigation. We recently published the results of our clinical trial with 30 patients in an oral tooth-extraction wound healing model using a 904nm GaAs laser (Oralaser 1010, Oralia, Konstnaz, Germany), assessing healing parameters using routine histopathology and immunostaining (Arany et al Wound Rep Regen 2007, 15, 866). We observed a better organized healing response in laser irradiated oral tissues that correlated with an increased expression of TGF-beta1 immediately post laser irradiation. Our data suggested the source of latent TGF-beta1 might be from the degranulating platelets in the serum, an abundant source of in vivo latent TGF-beta, in the freshly wounded tissues. Further, we also demonstrated the ability of the low power near-infrared laser irradiation to activate the latent TGF-beta complexes in vitro at varying fluences from 10sec (0.1 J/cm2) to 600secs (6 J/cm2). Using serum we observed two isoforms, namely TGF-beta1 and TGF-beta3, were capable of being activated by laser irradiation using an isoform-specific ELISA and a reporter based (p3TP) assay system. We are presently pursuing the precise photomolecular mechanisms focusing on potential chromophores, wavelength and fluence parameters affecting the Latent TGF-beta activation process in serum. As ROS mediated TGF-beta activation has been previously demonstrated and we are also exploring the role of Laser generated-ROS in this activation process. In summary, we present evidence of a potential molecular mechanism for laser photobiomodulation in its ability to activate latent TGF-beta complexes.

  11. Synergistic mobilization of hemopoietic progenitor cells using concurrent beta1 and beta2 integrin blockade or beta2-deficient mice.

    PubMed

    Papayannopoulou, T; Priestley, G V; Nakamoto, B; Zafiropoulos, V; Scott, L M; Harlan, J M

    2001-03-01

    The hierarchy of cytoadhesion molecules involved in hematopoietic/stem progenitor cell mobilization has not yet been delineated. Previous studies have suggested an important role for alpha4beta1 integrin in this process. To test whether mobilization involves dynamic interactions of alpha4beta1 with other integrins on hematopoietic cells, especially the beta2 integrins, mice and primates were treated with anti-beta1 or anti-beta2 antibodies alone or in combination. A single injection of anti-alpha4beta1 antibody elicited reproducible mobilization in contrast to other antibodies, and 3 injections yielded higher mobilization efficiency than each of the other antibodies. When the anti-beta2 (anti-CD11a or anti-CD18) or anti-alpha5/beta1 integrin antibody was combined with anti-alpha4, an augmentation in mobilization was seen that was either additive or synergistic, depending on the potency of the antibody used. Synergy between anti-alpha4 and anti-CD18 (beta(2)) antibody blockade was seen in primates and confirmed in anti-alpha4-treated CD18-deficient mice. In the latter, there was a 49-fold increase in mobilization with anti-alpha4, much higher than in littermate control animals, in CD18 hypomorphic mice, or in other strains of mice tested. Data from both the antibody blockade and gene-targeted mice suggest that the cooperativity of alpha4beta1 with beta2 integrins becomes evident when they are concurrently inhibited. It is unclear whether this cooperativity is exerted at the stage of reversible adhesion versus migration, and enhancement of and whether the 2 integrins work in a sequential or parallel manner. Whatever the mechanism, the data provide a novel example of beta1 and beta2 integrin crosstalk in stem/progenitor cell mobilization.

  12. Development of downstream processing to minimize beta-glucan impurities in GMP-manufactured therapeutic antibodies.

    PubMed

    Vigor, Kim; Emerson, John; Scott, Robert; Cheek, Julia; Barton, Claire; Bax, Heather J; Josephs, Debra H; Karagiannis, Sophia N; Spicer, James F; Lentfer, Heike

    2016-11-01

    The presence of impurities or contaminants in biological products such as monoclonal antibodies (mAb) could affect efficacy or cause adverse reactions in patients. ICH guidelines (Q6A and Q6B) are in place to regulate the level of impurities within clinical drug products. An impurity less often reported and, therefore, lacking regulatory guideline is beta-glucan. Beta-glucans are polysaccharides of d-glucose monomers linked by (1-3) beta-glycosidic bonds, and are produced by prokaryotic and eukaryotic organisms, including plants. They may enter manufacturing processes via raw materials such as cellulose-based membrane filters or sucrose. Here we report the detection of beta-glucan contamination of a monoclonal IgE antibody (MOv18), manufactured in our facility for a first-in-human, first-in-class clinical trial in patients with cancer. Since beta-glucans have potential immunostimulatory properties and can cause symptomatic infusion reactions, it was of paramount importance to identify the source of beta-glucans in our product and to reduce the levels to clinically insignificant concentrations. We identified beta-glucans in sucrose within the formulation buffer and within the housing storage buffer of the virus removal filter. We also detected low level beta-glucan contamination in two of four commercially available antibodies used in oncology. Both formulation buffers contained sucrose. We managed to reduce levels of beta-glucan in our product 10-fold, by screening all sucrose raw material, filtering the sucrose by Posidyne® membrane filtration, and by incorporating extra wash steps when preparing the virus removal filter. The beta-glucan levels now lie within a range that is unlikely to cause clinically significant immunological effects. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1494-1502, 2016.

  13. Association of heterocellular HPFH, beta(+)-thalassaemia, and delta beta(0)-thalassaemia: haematological and molecular aspects.

    PubMed Central

    Cianetti, L; Care, A; Sposi, N M; Giampaolo, A; Calandrini, M; Petrini, M; Massa, A; Marinucci, M; Mavilio, F; Ceccanti, M

    1984-01-01

    An Italian family in which heterocellular hereditary persistence of fetal haemoglobin (HPFH) interacts with both beta(+)- and delta beta-thalassaemia is described. The index case was an 8 year old girl who was presumed to inherit both heterocellular HPFH and beta (+)-thalassaemia from her mother and delta beta-thalassaemia from her father. She was healthy and never needed blood transfusions. The possible contribution of heterocellular HPFH to the less severe expression of the compound delta beta/beta(+)-thalassaemia heterozygosity is discussed. By DNA analysis the specific delta beta-thalassaemia defect on the gamma delta beta globin gene region has been established. In addition, a previously unreported association of a polymorphic restriction site haplotype with a beta (+)-thalassaemia mutation has been observed. PMID:6208362

  14. beta-Endorphin-induced analgesia is inhibited by synthetic analogs of beta-endorphin.

    PubMed Central

    Nicolas, P; Hammonds, R G; Li, C H

    1984-01-01

    Competitive antagonism of human beta-endorphin (beta h-EP)-induced analgesia by synthetic beta h-EP analogs with high in vitro opiate receptor binding to in vivo analgesic potency ratio has been demonstrated. A parallel shift of the dose-response curve for analgesia to the right was observed when either beta h-EP or [ Trp27 ] -beta h-EP was coinjected with various doses of [Gln8, Gly31 ]-beta h-EP-Gly-Gly-NH2, [Arg9,19,24,28,29]-beta h-EP, or [ Cys11 ,26, Phe27 , Gly31 ]-beta h-EP. It was estimated that the most potent antagonist, [Gln8, Gly31 ]-beta h-EP-Gly-NH2, is at least 200 times more potent than naloxone. PMID:6328494

  15. De novo design of monomeric beta-hairpin and beta-sheet peptides.

    PubMed

    Pantoja-Uceda, David; Santiveri, Clara M; Jiménez, M Angeles

    2006-01-01

    Since the first report in 1993 (JACS 115, 5887-5888) of a peptide able to form a monomeric beta-hairpin structure in aqueous solution, the design of peptides forming either beta-hairpins (two-stranded antiparallel beta-sheets) or three-stranded antiparallel beta-sheets has become a field of intense interest. These studies have yielded great insights into the principles governing the stability and folding of beta-hairpins and antiparallel beta-sheets. This chapter reviews briefly those principles and describes a protocol for the de novo design of beta-sheet-forming peptides based on them. Criteria to select appropriate turn and strand residues and to avoid aggregation are provided. Because nuclear magnetic resonance is the most appropriate technique to check the success of new designs, the nuclear magnetic resonance parameters characteristic of beta-hairpins and three-stranded antiparallel beta-sheets are given.

  16. TGF-{beta} modulates {beta}-Catenin stability and signaling in mesenchymal proliferations

    SciTech Connect

    Amini Nik, Saeid; Ebrahim, Rasoul Pour; Dam, Kim van; Cassiman, Jean-Jacques; Tejpar, Sabine . E-mail: sabine.tejpar@med.kuleuven.be

    2007-08-01

    Here for the first time we showed, despite the oncogenic mutations in {beta}-Catenin, that TGF-{beta} is a modulator of {beta}-Catenin levels in tumoral fibroblasts as well as non-tumoral fibroblasts. The results show that the TGF-{beta} pathway is active in desmoids cells and in in situ tumors. A dose dependent increase in {beta}-Catenin protein levels was observed after TGF-{beta} treatment in combination with an increased repression of GSK-3{beta} both in normal and tumoral fibroblasts. TGF-{beta} stimulation also led to an altered - up to 5 fold - transcriptional activity of {beta}-Catenin responsive promoters, such as IGFBP6 as well as increase of TOPflash activity. TGF-{beta} stimulation increased cell proliferation and BrdU incorporation 2.5 times. Taken together, we propose that TGF-{beta} is a modulator of {beta}-Catenin levels in tumoral fibroblasts and non-tumoral fibroblasts, despite the oncogenic mutations already present in this gene in tumoral fibroblasts of desmoid tumors. This modulation of {beta}-Catenin levels by TGF-{beta} may be involved in determining the tumoral phenotype of the cells.

  17. Ultraviolet observations of beta Canis majoris and beta Cephei

    NASA Technical Reports Server (NTRS)

    Fischel, D.; Sparks, W. M.

    1972-01-01

    Ultraviolet spectra of the two variables exhibit periodic variations in the H I, Si IV, and C IV resonance lines. Later scans of the beta Cep atmosphere show that the C IV line disappeared for short periods. Three possible mechanisms for this effect are: a beat phenomenon, shock waves, or tidal distortions. It is concluded that a tidal distortion is possible if the period of revolution is 12 days and if the inclination is sufficiently small to keep one tidal bulge out of sight and large enough to keep the secondary from eclipsing the primary bulge.

  18. A method for isolating beta-casein.

    PubMed

    Ward, L S; Bastian, E D

    1996-08-01

    A new method was developed for obtaining pure beta-CN. Calcium caseinate (3%) was reconstituted, renneted to form a gel, cooled (4 degrees C) to allow beta-CN dissociation from the caseinate gel, and centrifuged. The supernatant was warmed to 30 degrees C, precipitating pure beta-CN from solution. Large quantities of beta-CN were recovered by scaling-up this procedure, but these beta-CN preparations were less pure than the beta-CN that was prepared on a smaller scale. Chromatography (FPLC) and urea-PAGE showed beta-CN to be the main component in the precipitate. Chymosin, used to form the caseinate gel, did not extensively hydrolyze beta-CN under the conditions of these experiments. Calcium concentration, cooling time, and caseinate concentration influenced the recovery of beta-CN. Maximum recovery of beta-CN, under the experimental conditions used, occurred at 10 mM calcium, 48 h of cooling, and 3% caseinate concentration.

  19. Developments for the 6He beta - nu angular correlation experiment

    NASA Astrophysics Data System (ADS)

    Zumwalt, David W.

    This thesis describes developments toward the measurement of the angular correlation between the beta and the antineutrino in the beta decay of 6He. This decay is a pure Gamow-Teller decay which is described in the Standard Model as a purely axial vector weak interaction. The angular correlation is characterized by the parameter abetanu = -1/3 in the Standard Model. Any deviation from this value would be evidence for tensor components in the weak interaction and would constitute new physics. A new method will be used to measure the parameter a betanu from 6He decays, featuring a magneto-optical trap that will measure the beta particle in coincidence with the recoiling 6Li daughter ion. This neutral atom trapping scheme provides cold, tightly confined atoms which will reduce systematic uncertainties related to the initial position of the decay. By knowing the initial position of the decay and measuring the time of flight of the recoiling 6Li daughter ion in coincidence with the beta, the angular correlation between the beta and the antineutrino can be deduced. We aim to measure a betanu first to the level of 1%, and eventually to the 0.1% level, which would represent an order of magnitude improvement in precision over past experiments. Towards this goal, we have designed, built, and successfully tested a liquid lithium target to provide >2×10. {10} 6He atoms/sto a low-background environment, which is the most intense source of 6He presently available. This allowed for an additional measurement of the 6He half-life (806.89 +/- 0.11stat +0.23-0.19syst ms) to be made with unprecedented precision, resolving discrepancies in past measurements. We have also tested our trapping and detection apparatus and have begun to record preliminary coincidence events.

  20. Microbial flora analysis for the degradation of beta-cypermethrin.

    PubMed

    Qi, Zhang; Wei, Zhang

    2017-03-01

    In the Xinjiang region of Eurasia, sustained long-term and continuous cropping of cotton over a wide expanse of land is practiced, which requires application of high levels of pyrethroid and other classes of pesticides-resulting in high levels of pesticide residues in the soil. In this study, soil samples were collected from areas of long-term continuous cotton crops with the aim of obtaining microbial resources applicable for remediation of pyrethroid pesticide contamination suitable for the soil type and climate of that area. Soil samples were first used to culture microbial flora capable of degrading beta-cypermethrin using an enrichment culture method. Structural changes and ultimate microbial floral composition during enrichment were analyzed by high-throughput sequencing. Four strains capable of degrading beta-cypermethrin were isolated and preliminarily classified. Finally, comparative rates and speeds of degradation of beta-cypermethrin between relevant microbial flora and single strains were determined. After continuous subculture for 3 weeks, soil sample microbial flora formed a new type of microbial flora by rapid succession, which showed stable growth by utilizing beta-cypermethrin as the sole carbon source (GXzq). This microbial flora mainly consisted of Pseudomonas, Hyphomicrobium, Dokdonella, and Methyloversatilis. Analysis of the microbial flora also permitted separation of four additional strains; i.e., GXZQ4, GXZQ6, GXZQ7, and GXZQ13 that, respectively, belonged to Streptomyces, Enterobacter, Streptomyces, and Pseudomonas. Under culture conditions of 37 °C and 180 rpm, the degradation rate of beta-cypermethrin by GXzq was as high as 89.84% within 96 h, which exceeded that achieved by the single strains GXZQ4, GXZQ6, GXZQ7, and GXZQ13 and their derived microbial flora GXh.

  1. Synthetic glycosylation of peptides using unprotected saccharide beta-glycosylamines.

    PubMed

    Wong, S Y; Guile, G R; Rademacher, T W; Dwek, R A

    1993-06-01

    Glycopeptides can be valuable tools in determining the influence of carbohydrate moieties on the intrinsic properties of glycoproteins. However, glycopeptides of sufficient quantity and purity are as yet not readily available from biological sources. The chemical coupling of a beta-glycosylamino group of an unprotected carbohydrate with an activated aspartic acid residue of an unprotected peptide is a simple method for synthesizing asparagine-linked glycopeptides. In this report we demonstrate that the use of this method is not restricted to beta-glycosylamines of simple monosaccharides or short aspartic acid-containing pentapeptides. This is illustrated by the syntheses of several glycopentapeptides containing N,N'-diacetylchitobiose, a glutamine-linked glycopentapeptide containing a biantennary complex oligosaccharide, and glycosylated variants of two analogs of a polypeptide hormone, atriopeptin, containing N,N'-diacetylchitobiose.

  2. Precision Nuclear Beta Spectroscopy as a Probe for BSM Physics

    NASA Astrophysics Data System (ADS)

    Sprow, Aaron

    2017-01-01

    The shape of nuclear beta decay spectra is sensitive to new physics such as scalar and tensor currents, and weak magnetism. By selecting an appropriate nuclear species, it is possible to disentangle these effects. 45Ca, which undergoes a predominantly Gamow-Teller transition with an end-point energy of 256 keV, is an excellent probe for tensor couplings. Recently, the 45Ca beta decay spectrum was measured in the Caltech/UCNA 4 π magnetic spectrometer instrumented with large, highly-pixelated Si detectors at the Los Alamos National Laboratory UCN facility. This detection system, in conjunction with an extremely thin foil source preparation, allows for a full reconstruction of events to build a precise spectrum. Preliminary results of the analysis of this data will be presented.

  3. Beta

    USDA-ARS?s Scientific Manuscript database

    This chapter covers the use of wild beets in sugar beet improvement, including the basic botany of the species, its distribution; geographical locations of genetic diversity; morphology; cytology and karyotype; genome size; taxonomic position; agricultural status (model plant/weeds/invasive species/...

  4. Transradial coronary brachytherapy with the Novoste Beta-Rail system.

    PubMed

    Bertrand, Olivier F; De Larochellière, Robert; Gleeton, Onil; Plante, Sylvain; Tessier, Michel; Guimond, Jean

    2002-03-01

    We report our initial experience in 10 consecutive patients who underwent transradial coronary brachytherapy for in-stent restenosis using a 90Sr/Y source and the Novoste Beta-Rail system. In all patients, procedures were successfully completed using a right transradial approach. We performed the procedures with the Beta-Rail catheter using 7 Fr (Zuma II, Medtronic, MN; n = 5) or 8 Fr (Cordis, Miami, FL; n = 5) guiding catheters. All lesions were successfully dilated and no additional stent was inserted. We used a 40 mm source (n = 3) or a 60 mm source (n = 7) with manual stepping in four cases. In three cases, we did one stepping, and in one case, we did three steppings. The mean dwell time was 195 plus minus 44 sec. The mean delivered dose was 23 +/- 3 Gy at 2 mm distance from the source. No radiation treatment was interrupted. Mean fluoroscopy time was 26 +/- 13 min. Procedural success was achieved in all patients. Three patients had mild CK elevations (< 3 times upper normal limit). All patients were pretreated with clopidogrel (300 mg) and combined treatment with aspirin + clopidogrel is to be continued for at least 1 year. Clinical follow-up up to 3 months has not yielded any complication and all patients have remained free from angina.

  5. Superconducting Prototype Cavities for the Spallation Neutron Source (SNS) Project

    SciTech Connect

    Gianluigi Ciovati

    2001-09-01

    The Spallation Neutron Source project includes a superconducting linac section in the energy range from 186 MeV to 1000 MeV. For this energy range two types of cavities are needed with geometrical {beta} values of {beta} = 0.61 and {beta} = 0.81. An aggressive cavity prototyping program is being pursued at Jefferson Lab, which calls for fabricating and testing four {beta} = 0.61 cavities and two {beta} = 0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler on each beam pipe and a port for a high power coaxial input coupler. Three of the four {beta} = 0.61 cavities will be used for a cryomodule test in early 2002. At this time four medium beta cavities and one high beta cavity have been completed at JLab. The first tests on the {beta} = 0.61 and {beta} = 0.81 exceeded the design values for gradient and Q value: E{sub acc} = 10.1 MV/m and Q = 5 x 10{sup 9} at 2.1K for the {beta} = 0.61 and E{sub acc} = 12.3 MV/m and Q = 5 x 10{sup 9} at 2.1 K for the {beta} = 0.81. One of the medium beta cavities has been equipped with an integrated helium vessel and measurements of the static Lorentz force detuning have been done and compared to the ''bare'' cavities. In addition two single cell cavities have been fabricated, equipped with welded-on HOM couplers. They are being used to evaluate the HOM couplers with respect to multipacting, fundamental mode rejection and HOM damping as far as possible in a single cell. This paper describes the cavity design with respect to electromagnetic and mechanical features, the fabrication efforts and the results obtained with the different cavities existing at the time of this workshop.

  6. Bovine haemoglobin beta A Zebu, beta A43(CD3)Ser----Thr: an intermediate globin type between the beta A and beta D Zambia is present in Indian zebu cattle.

    PubMed

    Namikawa, T; Nagai, A; Takenaka, O; Takenaka, A

    1987-01-01

    Two bovine haemoglobin beta chains, electrophoretically identical with the beta A chain of Herefords, were obtained from Ongole and Banteng, Bos javanicus, cattle. The amino acid residue differences of the two beta chains were compared by electrophoresis, cation-exchange and reverse-phase chromatography, amino acid analyses, and Edman degradation in comparison with beta A chain. The results showed that two beta chains differed from the beta A chain of the Hereford breed by the substitution of serine with threonine at the beta 43 position. No other difference was found between the two chains and beta A. This new beta chain type was termed beta A Zebu, which forms a possible evolutionarily transitional type between the beta A and the rare variant beta D Zambia found previously in African zebu cattle. The beta A Zebu differentiates from the previous beta B by at least four amino acid substitutions involving five codon-base changes.

  7. Nonstochastic effects of different energy beta emitters on pig skin.

    PubMed

    Peel, D M; Hopewell, J W; Wells, J; Charles, M W

    1984-08-01

    Circular areas of pig skin from 1- to 40-mm diameter were irradiated with beta emitters of high, medium, and low energies, 90Sr, 170Tm, and 147Pm, respectively. The study provides information for radiological protection problems of localized skin exposures. During the first 16 weeks after irradiation 90Sr produced a first reaction due to epithelial cell death followed by a second reaction attributable to damage to the dermal blood vessels. 170Tm and 147Pm produced the epithelial reaction only. The epithelial dose response varied as a function of beta energy. The doses required to produce moist desquamation in 50% of 15- to 22.5-mm fields (ED50) were 30-45 Gy from 90Sr, approximately 80 Gy from 170Tm, and approximately 500 Gy from 147Pm. A model involving different methods of epithelial repopulation is proposed to explain this finding. An area effect was observed in the epithelial response to 90Sr irradiation. The ED50 for moist desquamation ranged from approximately 25 Gy for a 40-mm source to approximately 450 Gy for a 1-mm source. The 5-, 9-, and 19-mm 170Tm sources all produced an ED50 of approximately 80 Gy, while the value for the 2-mm source was approximately 250 Gy. It is also suggested that the area effects could be explained by different modes of epithelial repopulation after irradiation. After high energy beta irradiation repopulation would be mainly from the field periphery, while after lower energy irradiation repopulation from hair follicle epithelium would predominate.

  8. Reorganization of axoplasmic organelles following beta, beta'- iminodipropionitrile administration

    PubMed Central

    1981-01-01

    beta, beta'-Iminodipropionitrile (IDPN), a synthetic compound that selectively impairs slow axonal transport, produced a rearrangement of the axonal cytoskeleton, smooth endoplasmic reticulum, and mitochondria. Immunoperoxidase staining using an antiserum to the 68,000-dalton neurofilament subunit demonstrated a displacement of neurofilaments toward the periphery of the axons of IDPN-treated rats. This change occurred simultaneously along the entire length of the sciatic nerve. Ultrastructural morphometry of the axonal organelles confirmed the peripheral relocation of neurofilaments and also showed a displacement of microtubules, smooth endoplasmic reticulum, and mitochondria to the center of the axons. The overall density of axonal mitochondria was increased, whereas those of other organelles were not significantly changed. Axons were reduced in size by 10--24%, the large axons being more affected than the small ones. The observed rearrangement of axonal organelles may be due to an effect of IDPN on microtubule-neurofilament interactions, which could in turn explain the impairment of the slow transport. Axons in IDPN intoxication are a useful model to study the organization of the axoplasm and the mechanism of axonal transport. PMID:7199048

  9. Secondary prevention of type 1 diabetes mellitus: stopping immune destruction and promoting beta-cell regeneration.

    PubMed

    Couri, C E B; Foss, M C; Voltarelli, J C

    2006-10-01

    Type 1 diabetes mellitus results from a cell-mediated autoimmune attack against pancreatic beta-cells. Traditional treatments involve numerous daily insulin dosages/injections and rigorous glucose control. Many efforts toward the identification of beta-cell precursors have been made not only with the aim of understanding the physiology of islet regeneration, but also as an alternative way to produce beta-cells to be used in protocols of islet transplantation. In this review, we summarize the most recent studies related to precursor cells implicated in the regeneration process. These include embryonic stem cells, pancreas-derived multipotent precursors, pancreatic ductal cells, hematopoietic stem cells, mesenchymal stem cells, hepatic oval cells, and mature beta-cells. There is controversial evidence of the potential of these cell sources to regenerate beta-cell mass in diabetic patients. However, clinical trials using embryonic stem cells, umbilical cord blood or adult bone marrow stem cells are under way. The results of various immunosuppressive regimens aiming at blocking autoimmunity against pancreatic beta-cells and promoting beta-cell preservation are also analyzed. Most of these regimens provide transient and partial effect on insulin requirements, but new regimens are beginning to be tested. Our own clinical trial combines a high dose immunosuppression with mobilized peripheral blood hematopoietic stem cell transplantation in early-onset type 1 diabetes mellitus.

  10. Organic dust induced pulmonary disease - the role of mould derived beta-glucan.

    PubMed

    Rylander, Ragnar

    2010-01-01

    The objective of the study was to evaluate the role of the mould cell wall agent beta-glucan in environmentally related pulmonary disease. All published articles where beta-glucan was administered by the airways, either as intratracheal injection or as inhalation were utilised as data sources. Data reporting consisted of analysis of data reports concerning the effects of beta-glucan on the immune system on the cellular level, particularly on the aggregation of inflammatory cells or production of inflammatory cytokines. High doses of soluble and particulate beta-glucan cause an inflammatory response characterized by cytokine activation and neutrophil invasion in the lung tissue. At lower doses, closer to environmental exposure levels, the predominant effect is an influence on the response to antigens, the reactivity of eosinophils and other Th2 driven immune responses. It is concluded that, beta-glucan can induce Th1 as well asTh2 driven immune responses. The pathology of atopy/allergy, hypersensitivity pneumonitis, and toxic penumonitis might be induced by exposure to beta-glucan. Measurements of beta-glucan in different environments are useful for risk control and prevention.

  11. Asymmetrically acting lycopene beta-cyclases (CrtLm) from non-photosynthetic bacteria.

    PubMed

    Tao, L; Picataggio, S; Rouvière, P E; Cheng, Q

    2004-03-01

    Carotenoids have important functions in photosynthesis, nutrition, and protection against oxidative damage. Some natural carotenoids are asymmetrical molecules that are difficult to produce chemically. Biological production of carotenoids using specific enzymes is a potential alternative to extraction from natural sources. Here we report the isolation of lycopene beta-cyclases that selectively cyclize only one end of lycopene or neurosporene. The crtLm genes encoding the asymmetrically acting lycopene beta-cyclases were isolated from non-photosynthetic bacteria that produced monocyclic carotenoids. Co-expression of these crtLm genes with the crtEIB genes from Pantoea stewartii (responsible for lycopene synthesis) resulted in the production of monocyclic gamma-carotene in Escherichia coli. The asymmetric cyclization activity of CrtLm could be inhibited by the lycopene beta-cyclase inhibitor 2-(4-chlorophenylthio)-triethylamine (CPTA). Phylogenetic analysis suggested that bacterial CrtL-type lycopene beta-cyclases might represent an evolutionary link between the common bacterial CrtY-type of lycopene beta-cyclases and plant lycopene beta- and epsilon-cyclases. These lycopene beta-cyclases may be used for efficient production of high-value asymmetrically cyclized carotenoids.

  12. beta. -adrenergic relaxation of smooth muscle: differences between cells and tissues

    SciTech Connect

    Scheid, C.R.

    1987-09-01

    The present studies were carried out in an attempt to resolve the controversy about the Na/sup +/ dependence of ..beta..-adrenergic relaxation in smooth muscle. Previous studies on isolated smooth muscle cells from the toad stomach had suggested that at least some of the actions of ..beta..-adrenergic agents, including a stimulatory effect on /sup 45/Ca efflux, were dependent on the presence of a normal transmembrane Na/sup +/ gradient. Studies by other investigators using tissues derived from mammalian sources had suggested that the relaxing effect of ..beta..-adrenergic agents was Na/sup +/ independent. Uncertainty remained as to whether these discrepancies reflected differences between cells and tissues or differences between species. Thus, in the present studies, the authors utilized both tissues and cells from the same source, the stomach muscle of the toad Bufo marinus, and assessed the Na/sup +/ dependence of ..beta..-adrenergic relaxation. They found that elimination of a normal Na/sup +/ gradient abolished ..beta..-adrenergic relaxation of isolated cells. In tissues, however, similar manipulations had no effect on relaxation. The reasons for this discrepancy are unclear but do not appear to be attributable to changes in smooth muscle function following enzymatic dispersion. Thus the controversy concerning the mechanisms of ..beta..-adrenergic relaxation may reflect inherent differences between tissues and cells.

  13. Human globin gene analysis for a patient with beta-o/delta beta-thalassemia.

    PubMed Central

    Ottolenghi, S; Lanyon, W G; Williamson, R; Weatherall, D J; Clegg, J B; Pitcher, C S

    1975-01-01

    Complementary DNA (cDNA) was prepared with RNA-dependent DNA polymerase from human globin messenger RNA (mRNA). Annealing and translation experimenta with total mRNA from circulating cells from a patient with heterozygous beta/heterozygous beta-delta-o thalassemia (beta-o/delta beta-o-thalassemia) demonstrated no detectable mRNA for beta-globin. cDNA enriched in sequences homologous to beta-globin mRNA was prepared by hydroxylapatite fractionation of hybrids formed between beta-o/delta beta-o-thalassemic mRNA and cDNA made from mRNA from a patient with alpha-thalassemia (hemoglobin H disease). The rate of annealing of this beta-enriched cDNA to normal human nuclear DNA was that of a sequence present as only a single copy per haploid genome. The beta-enriched cDNA annealed to the beta-o-delta beta-o-thalassemia total DNA with approximately the same kinetics as to normal DNA, indicating that no total gene deletion of beta-globin genes from the diploid genome has occurred, although the accuracy of the technique could not exclude with certainty a partial deletion or a deletion of a beta-globin gene from only one of the haploid genomes. This demonstrates that at least one of the beta-o- or the delta beta-o-thalassemia haploid genomes in this case contains a substantially intact beta-globin gene. PMID:49057

  14. Beta adrenergic receptor blockade of feline myocardium. Cardiac mechanics, energetics, and beta adrenoceptor regulation.

    PubMed Central

    Cooper, G; Kent, R L; McGonigle, P; Watanabe, A M

    1986-01-01

    Myocardial oxygen consumption is regulated by interrelated mechanical and inotropic conditions; there is a parallel increase in the aerobic metabolism and inotropic state during beta-adrenergic stimulation under fixed mechanical conditions. In contrast, there is some evidence that beta-blockade may reduce oxygen consumption through effects independent of its influence on mechanical conditions and contractile state, and that prolonged beta-blockade may sensitize the myocardium to beta-adrenergic stimulation. To clarify these two points, the present study examined the relationship of myocardial energetics to mechanics and inotropism during acute beta-blockade and after the withdrawal of long-term beta-blockade, whereupon the basis for any effect observed was sought by characterizing the number, affinity, and affinity states of the beta-receptors as well as the coupling of activated beta-receptors to cyclic AMP generation. Studies of right ventricular papillary muscles from control and chronically beta-blocked cats demonstrated contractile and energetic properties as well as dose-response behavior and inotropic specificity suggestive of an increase in myocardial sensitivity to beta-adrenoceptor stimulation in the latter group. Assays of cardiac beta-adrenoceptors from further groups of control and pretreated cats, both in cardiac tissue and in isolated cardiac muscle cells, failed to define a difference between the two groups either in terms of receptor number and affinity or in terms of the proportion of receptors in the high-affinity state. However, coupling of the activated beta-adrenoceptors to cyclic AMP generation was enhanced in cardiac muscle cells from chronically beta-blocked cats. These data demonstrate that beta-adrenoceptor blockade (a) produces parallel effects on inotropic state and oxygen consumption without an independent effect on either and (b) increases myocardial sensitivity to beta-adrenergic stimulation after beta-blockade withdrawal, not by "up

  15. Binding of TEM-1 beta-lactamase to beta-lactam antibiotics by frontal affinity chromatography.

    PubMed

    Chen, Xiu; Li, Yuhua; Zhang, Yan; Yang, Jianting; Bian, Liujiao

    2017-04-15

    TEM-1 beta-lactamases can accurately catalyze the hydrolysis of the beta-lactam rings in beta-lactam antibiotics, which make beta-lactam antibiotics lose its activity, and the prerequisite for the hydrolysis procedure in the binding interaction of TEM-1 beta-lactamases with beta-lactam antibiotics is the beta-lactam rings in beta-lactam antibiotics. Therefore, the binding of TEM-1 beta-lactamase to three beta-lactam antibiotics including penicillin G, cefalexin as well as cefoxitin was explored here by frontal affinity chromatography in combination with fluorescence spectra, adsorption and thermodynamic data in the temperature range of 278-288K under simulated physiological conditions. The results showed that all the binding of TEM-1 beta-lactamase to the three antibiotics were spontaneously exothermic processes with the binding constants of 8.718×10(3), 6.624×10(3) and 2.244×10(3) (mol/L), respectively at 288K. All the TEM-1 beta-lactamases were immobilized on the surface of the stationary phase in the mode of monolayer and there existed only one type of binding sites on them. Each TEM-1 beta-lactamase bound with only one beta-lactam antibiotic and hydrogen bond interaction and Van der Waals force were the main forces between them. This work provided an insight into the binding interactions between TEM-1 beta-lactamases and beta-lactam antibiotics, which may be beneficial for the designing and developing of new substrates resistant to TEM-1 beta-lactamases. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. [Heterocygous beta thalassaemia (author's transl)].

    PubMed

    Méndez Aparicio, F

    1978-01-01

    Two girls with an heterocigotic beta-thalassemy are presented in this study. Case 1 has an hypochromic and microtic anaemia with an enormous splenomegaly, increased osmotic resistence of red blood cells in salted solution and increase of A2 hemoglobin. This situation is associated with an increase of the glucolitic intraerythrocitic enzimes. Case 2 showed increase of A2 hemoglobine, but this anomaly was associated with decrease of intraerythrocitic enzimatic rate. First clinical signs of erythrocitic disturbances was an acute hemolytic crisis developed by the supply of the sulphometoxipiridacine. The erythroquinetic study showed a decrease of the average life of the red blood cells in both patients.

  17. Neutrino Factories and Beta Beams

    SciTech Connect

    Zisman, Michael S.

    2006-06-21

    In this paper we briefly review the concepts of Neutrino Factories and Beta Beam facilities, and indicate the main challenges in terms of beam performance and technological developments. We also describe the worldwide organizations that have embarked on defining and carrying out the necessary R&D on component design, beam simulations of facility performance, and benchmarking of key subsystems via actual beam tests. Currently approved subsystem tests include the Muon Ionization Cooling Experiment (MICE), under construction at Rutherford Appleton Laboratory, and the Mercury Intense Target (MERIT) experiment, to be carried out at CERN. These experiments are briefly described, and their schedules are indicated.

  18. Experiment M408: Beta spectrometer

    NASA Technical Reports Server (NTRS)

    Marbach, J. R.

    1971-01-01

    The beta spectrometer functioned as planned throughout the Gemini 10 mission. The cool temperatures that were recorded from the instrument during the mission were indicative that the evaporative cooler, coupled with apparently lower-than-expected spacecraft-adapter temperatures, maintained ideal operating conditions. The data facilitate a good analysis of the electron directional distribution. The omnidirectional flux that was calculated is apparently consistent with previous measurements. Representative electron spectra, measured during the Gemini 12 mission, established the apparent decay of the artificially injected electrons (from the Starfish high altitude nuclear test) to such low levels that natural trapped electrons were becoming detectable.

  19. Evaluation of the instrument correction factors needed in beta dosimetry

    SciTech Connect

    Swinth, K.L.; Sisk, D.R.; Selby, J.M.; Vallario, E.J.

    1987-11-01

    Generally, the same survey instruments used for the measurement of gamma dose rates are used for monitoring beta fields by making measurements with and without a shield over the detector to separate the penetrating and nonpenetrating components of the radiation field. Survey meters are calibrated using fields that uniformly irradiate the detector volume with the center of the volume used as a reference point. However, under field survey conditions, sources are frequently encountered that have irregular shape and large or small dimensions compared with the detector volume. When the distance from the source to the detector volume (reference point) is small such sources produce non-uniform radiation fields in the detector. Similarly, low energy beta sources cause non-uniform irradiation of the volume due to attenuation of the radiation. In addition, when survey meters are used close to the source, the surveyor is generally interested in dose rates at contact or within a few centimeters of the source. In these cases the reference point is the center front surface of the detector. The resulting readings from such fields are based on an average of the uneven distribution of energy deposition occurring within the detector. In general, this reading would be significantly less than the actual dose existing at the surface of the meter entrance window. To compensate for this discrepancy, correction factors are applied to the readings to give the actual dose. These factors can be in excess of a factor of 100. This paper summarizes observations on energy, angular and source geometry response of survey instruments.

  20. [Plasma beta-2-microglobulin in rheumatoid arthritis].

    PubMed

    Fioravanti, A; Giordano, N; Loi, F; D'Amato, S; Castagna, M L; Frati, E; Marcolongo, R

    1984-09-30

    The beta 2 microglobulin (beta 2m) is a low molecular weight protein, recognized on the cellular membranes of numerous nucleated cells and strictly correlated to the antigens of Major Histocompatibility Complex. Many authors have demonstrated an increase of the plasmatic beta 2m in different inflammatory diseases and, particularly in rheumatic ones, as Rheumatoid Arthritis (RA), Reiter's syndrome, Ankylosing Spondylitis, Systemic lupus erythematosus. We have also investigated the behaviour of the plasmatic beta 2m in 52 RA patients and in 17 healthy subjects. The beta 2m was measured in serum, by radioimmunoassay. We have demonstrated that the plasmatic beta 2m has moderately increased in the serum of RA patients, even if there is not a significant difference when compared to the normal subjects.

  1. Computational Study of Bond Dissociation Enthalpies for Lignin Model Compounds: $\\beta$-5 Arylcoumaran

    SciTech Connect

    Beste, Ariana; Buchanan III, A C; Younker, Jarod M

    2012-01-01

    The biopolymer lignin is a potential source of valuable chemicals. The $\\beta$-5 linkage comprises $\\sim$10\\% of the linkages in lignin. Density Functional Theory (DFT) was used to calculate the $\\alpha$C-O and $\\alpha$C-$\\beta$C bond dissociation enthalpies (BDEs) for $\\beta$-5 models with varied substituents, which are important for understanding initial lignin decomposition. The $\\alpha$C-O ($\\alpha$C-$\\beta$C) BDEs were in the range of 40-44 (57-62) kcal/mol. The products resulting from either homolysis are bi-radicals with multi-determinant character in the singlet electronic state. Multiconfiguration self-consistent field (MCSCF) theory results were used to verify that unrestricted DFT and broken-symmetry DFT were sufficient to study these reactions.

  2. Is Transforming Stem Cells to Pancreatic Beta Cells Still the Holy Grail for Type 2 Diabetes?

    PubMed

    Kahraman, Sevim; Okawa, Erin R; Kulkarni, Rohit N

    2016-08-01

    Diabetes is a progressive disease affecting millions of people worldwide. There are several medications and treatment options to improve the life quality of people with diabetes. One of the strategies for the treatment of diabetes could be the use of human pluripotent stem cells or induced pluripotent stem cells. The recent advances in differentiation of stem cells into insulin-secreting beta-like cells in vitro make the transplantation of the stem cell-derived beta-like cells an attractive approach for treatment of type 1 and type 2 diabetes. While stem cell-derived beta-like cells provide an unlimited cell source for beta cell replacement therapies, these cells can also be used as a platform for drug screening or modeling diseases.

  3. IKK and (Beta) - Catenin in Breast Cancer

    DTIC Science & Technology

    2004-07-01

    activity is not due to a decrease in total beta-catenin protein levels, however, the dephosphorylated form of beta-catenin within the nucleus...2000. 19. Staal F J, Noort MM, Strous G J, and Clevers HC, Wnt signals are transmitted through N-terminally dephosphorylated beta-catenin. EMBO Rep. 3...catenin is phoshorylated sequentially by casein kinase 1 (CK1) and glycogen synthase kinase 3-P (GSK-313) (4,52); activation of frizzled receptors by Wnt

  4. Mode identification in Beta Cephei stars

    NASA Technical Reports Server (NTRS)

    Aizenmen, M. L.; Lesh, J. R.

    1980-01-01

    The essential observational characteristics related to mode identification are summarized. Major emphasis is placed on the following: both light and velocity amplitudes; typical periods in both light and radial velocity; the light curve for Beta Cephei stars in comparison to the classical Cepheids and RR Lyrae stars; the van Hoof effect with respect to the radial velocity curves in many Beta Cephei stars; and the line profiles of many Beta Cephei stars.

  5. Method for preparing Pb-. beta. ''-alumina ceramic

    DOEpatents

    Hellstrom, E.E.

    1984-08-30

    A process is disclosed for preparing impermeable, polycrystalline samples of Pb-..beta..''-alumina ceramic from Na-..beta..''-alumina ceramic by ion exchange. The process comprises two steps. The first step is a high-temperature vapor phase exchange of Na by K, followed by substitution of Pb for K by immersing the sample in a molten Pb salt bath. The result is a polycrystalline Pb-..beta..''-alumina ceramic that is substantially crack-free.

  6. Cholesterol-lowering effect of beta-glucan from oat bran in mildly hypercholesterolemic subjects may decrease when beta-glucan is incorporated into bread and cookies.

    PubMed

    Kerckhoffs, Daniëlle A J M; Hornstra, Gerard; Mensink, Ronald P

    2003-08-01

    Findings about the effects of beta-glucan on serum lipoproteins are conflicting. The study investigated the effects of beta-glucan from oat bran in bread and cookies (study 1) and in orange juice (study 2) on serum lipoproteins in mildly hypercholesterolemic subjects. In study 1, 48 subjects (21 men, 27 women) received for 3 wk control bread and cookies rich in wheat fiber. For the next 4 wk, by random assignment, 23 subjects continued to consume the control products, and 25 received bread and cookies rich in beta-glucan. Mean daily intake of beta-glucan was 5.9 g. Total dietary fiber intake did not differ significantly between the groups. In study 2, the same sources of control fiber and beta-glucan (5 g/d) as in study 1 were provided. For 2 wk, 25 of the original 48 subjects (10 men, 15 women) were randomly assigned to consume orange juice containing either wheat fiber (n = 13) or beta-glucan from oat bran (n = 12). After a washout period of 1 wk, dietary regimens were crossed over. In study 1, the change in LDL cholesterol did not differ significantly (-0.12 mmol/L; P = 0.173) between the 2 groups. In study 2, the drink rich in beta-glucan decreased LDL cholesterol by 0.26 +/- 0.07 mmol/L (6.7 +/- 1.8%; P = 0.001) and the ratio of total to HDL cholesterol by 0.26 +/- 0.11 (5.4 +/- 2.1%; P = 0.029) compared with the other drink. HDL-cholesterol and triacylglycerol concentrations did not change significantly. The food matrix or the food processing, or both, could have adverse effects on the hypocholesterolemic properties of oat beta-glucan.

  7. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)

  8. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)

  9. {beta} decay of {sup 95}Ag

    SciTech Connect

    Harissopulos, S.; Galanopoulos, S.; Skouras, L. D.; Doering, J.; Schmidt, K.; Gorska, M.; Grawe, H.; Hellstroem, M.; Kirchner, R.; Roeckl, E.; La Commara, M.; Mazzocchi, C.; Borcea, R.; Janas, Z.; Johnstone, I.P.; Schwengner, R.

    2005-08-01

    We studied the {beta}-decay properties of the N=Z+1 nucleus {sup 95}Ag by measuring {beta}-delayed {gamma} rays and {beta}-{gamma}-{gamma} coincidences with a plastic scintillator as {beta} detector and a Ge-detector array. The {sup 95}Ag nuclei were produced by means of the {sup 58}Ni({sup 40}Ca,p2n) reaction and separated with the GSI online mass separator. The previously reported level scheme of the {sup 95}Pd daughter nucleus was extended considerably. The deduced level scheme is compared with different shell-model calculations with or without breaking the {sup 100}Sn core.

  10. Gyrokinetic turbulence simulations at high plasma beta

    SciTech Connect

    Pueschel, M. J.; Kammerer, M.; Jenko, F.

    2008-10-15

    Electromagnetic gyrokinetic turbulence simulations employing Cyclone Base Case parameters are presented for {beta} values up to and beyond the kinetic ballooning threshold. The {beta} scaling of the turbulent transport is found to be linked to a complex interplay of linear and nonlinear effects. Linear investigation of the kinetic ballooning mode is performed in detail, while nonlinearly, it is found to dominate the turbulence only in a fairly narrow range of {beta} values just below the respective ideal limit. The magnetic transport scales like {beta}{sup 2} and is well described by a Rechester-Rosenbluth-type ansatz.

  11. Milk Intolerance, Beta-Casein and Lactose

    PubMed Central

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-01-01

    True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed. PMID:26404362

  12. Milk Intolerance, Beta-Casein and Lactose.

    PubMed

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-08-31

    True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

  13. Effect of training on beta1 beta2 beta3 adrenergic and M2 muscarinic receptors in rat heart.

    PubMed

    Barbier, Julie; Rannou-Bekono, Françoise; Marchais, Jérome; Berthon, Phanélie-Marie; Delamarche, Paul; Carré, François

    2004-06-01

    Physical training is known to alter several cardiovascular parameters. These adaptations are for a great part linked to an alteration of the myocardial responses to its autonomic nervous regulation. To further explain the parasympathetic and catecholamine effects, we hypothesized that endurance training could modify rat myocardial beta1, beta2, beta3 adrenoreceptors (AR) and M2 muscarinic cholinergic receptor (AchR) densities. Two groups of adults female Wistar rats were studied: controls (C) (N = 7) and trained (T) (N = 9). An 8-wk treadmill training protocol was performed, 5 d x wk and of 1 h x d. At the end of the training session, left ventricle and atria muscle were isolated and weighed. Then, quantification of beta1, beta2, beta3 AR and M2 AchR was performed using Western blot analysis. M2 AchR densities were not modified in left ventricle or in atria by training (respectively, 100 +/- 22%, C vs 101 +/- 14%, T and 100 +/- 23%, C vs 119 +/- 30%, T). Concerning the left ventricle beta AR isoforms, beta1AR density was decreased in T (80 +/- 10% T vs 100 +/- 14% C, P = 0.01), beta2AR was unaltered (102 +/- 12%, T vs 100 +/- 17%, C), and beta3 AR density was increased in T (139 +/- 38% T vs 100 +/- 15% C; P < 0.05). Our results show for the first time that in female rats an 8-wk treadmill training protocol alters specifically the left ventricle beta AR isoforms densities but not the M2 AchR one. These results could explain some of the beneficial cardiovascular adaptations of the physically trained heart.

  14. beta-Catenin associates with the actin-bundling protein fascin in a noncadherin complex

    PubMed Central

    1996-01-01

    Catenins were first characterized as linking the cytoplasmic domains of cadherin cell-cell adhesion molecules to the cortical actin cytoskeleton. In addition to their essential role in modulating cadherin adhesivity, catenins have more recently been indicated to participate in cell and developmental signaling pathways. beta-Catenin, for example, associates directly with at least two receptor tyrosine kinases and transduces developmental signals within the Wnt pathway. Catenins also complex with the tumor suppressor protein adenomatous polyposis coli (APC), which appears to have a role in regulating cell proliferation. We have used the yeast two-hybrid method to reveal that fascin, a bundler of actin filaments, binds to beta-catenin's central Armadillo repeat domain. Western blotting of immunoprecipitates from cell line and mouse and rat brain extracts indicate that this interaction exists in vivo. Fascin and beta-catenin's association was further substantiated in vitro using purified proteins isolated from recombinant bacterial and baculoviral sources. Immunoprecipitation analysis indicates that fascin additionally binds to plakoglobin, which is highly homologous to beta-catenin but not to p120cas, a newly described catenin which contains a more divergent Armadillo-repeat domain. Immunoprecipitation, in vitro competition, and domain-mapping experiments demonstrate that fascin and E-cadherin utilize a similar binding site within beta-catenin, such that they form mutually exclusive complexes with beta-catenin. Immunofluorescence microscopy reveals that fascin and beta-catenin colocalize at cell-cell borders and dynamic cell leading edges of epithelial and endothelial cells. In addition to cell-cell borders, cadherins were unexpectedly observed to colocalize with fascin and beta-catenin at cell leading edges. It is conceivable that beta-catenin participates in modulating cytoskeletal dynamics in association with the microfilament-bundling protein fascin, perhaps in a

  15. Neutrinoless double beta decay and neutrino mass

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.; Ejiri, H.; Šimkovic, F.

    2016-11-01

    The observation of neutrinoless double beta decay (DBD) will have important consequences. First it will signal that lepton number is not conserved and the neutrinos are Majorana particles. Second, it represents our best hope for determining the absolute neutrino mass scale at the level of a few tens of meV. To achieve the last goal, however, certain hurdles have to be overcome involving particle, nuclear and experimental physics. Particle physics is important since it provides the mechanisms for neutrinoless DBD. In this review, we emphasize the light neutrino mass mechanism. Nuclear physics is important for extracting the useful information from the data. One must accurately evaluate the relevant nuclear matrix elements (NMEs), a formidable task. To this end, we review the recently developed sophisticated nuclear structure approaches, employing different methods and techniques of calculation. We also examine the question of quenching of the axial vector coupling constant, which may have important consequences on the size of the NMEs. From an experimental point of view it is challenging, since the life times are extremely long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with good energy resolution and very low background.

  16. Imperfect World of beta beta-decay Nuclear Data Sets

    SciTech Connect

    Pritychenko, B.

    2015-01-03

    The precision of double-beta ββ-decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for ββ-decay T2v1/2 is consistent with large nuclear reaction and structure data sets and provides validation of experimental half-lives. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of-decay half-lives and nuclear matrix elements.

  17. Interaction of transforming growth factor beta (TGF beta) with proteinase 3.

    PubMed

    Kekow, J; Csernok, E; Szymkowiak, C; Gross, W L

    1997-01-01

    TGF beta is a multifunctional cytokine modulating onset and course of autoimmune diseases as shown in experimental models. Aim of this study was to investigate possible interactions of TGF beta with lysosomal enzymes identified as ANCA autoantigens (e.g. proteinase 3, PR3). This included TGF beta effects on the translocation the lysosomal enzymes to the cell surface of polymorphonuclear cells (PMN), and the presumabe activation of non bioactive, latent TGF beta by these enzymes. Flow cytometry analysis showed TGF beta 1 to be a potent translocation factor for PR3 comparable with other neutrophil activating factors such as interleukin 8 (IL8). The PR3 membrane expression on primed PMN increased by up to 51% after incubation with TGF beta 1. PR3 itself was revealed as a potent activator of latent TGF beta, thus mediating bioeffects of this cytokine. Patients with various types of systemic vasculitis (SV) showed marked TGF beta overexpression correlating with disease. Mean TGF beta 1 plasma levels in the ANCA associated vasculitis (AAV) patients ranged from 8.9 (Wegeners granulomatosis, WG) to 13.3 ng/ml (Churg-Strauss syndrome, CSS)(control: 4.2 ng/ml, p < 0.01) while TGF beta 2 levels were not elevated. Our findings, together with other features of TGF beta's such as induction of angiogenesis and its strong chemotactic capacity, indicate that TGF beta might serve as a proinflammatory factor in SV, especially in AAV.

  18. Pin1 promotes production of Alzheimer's amyloid {beta} from {beta}-cleaved amyloid precursor protein

    SciTech Connect

    Akiyama, Hirotada; Shin, Ryong-Woon; Uchida, Chiyoko; Kitamoto, Tetsuyuki; Uchida, Takafumi . E-mail: uchidat@cir.tohoku.ac.jp

    2005-10-21

    Here we show that prolyl isomerase Pin1 is involved in the A{beta} production central to the pathogenesis of Alzheimer's disease. Enzyme immunoassay of brains of the Pin1-deficient mice revealed that production of A{beta}40 and A{beta}42 was lower than that of the wild-type mice, indicating that Pin1 promotes A{beta} production in the brain. GST-Pin1 pull-down and immunoprecipitation assay revealed that Pin1 binds phosphorylated Thr668-Pro of C99. In the Pin1 {sup -/-} MEF transfected with C99, Pin1 co-transfection enhanced the levels of A{beta}40 and A{beta}42 compared to that without Pin1 co-transfection. In COS7 cells transfected with C99, Pin1 co-transfection enhanced the generation of A{beta}40 and A{beta}42, and reduced the expression level of C99, facilitating the C99 turnover. Thus, Pin1 interacts with C99 and promotes its {gamma}-cleavage, generating A{beta}40 and A{beta}42. Further, GSK3 inhibitor lithium blocked Pin1 binding to C99 by decreasing Thr668 phosphorylation and attenuated A{beta} generation, explaining the inhibitory effect of lithium on A{beta} generation.

  19. Plant and algal interference in bacterial beta-D-galactosidase and beta-D-glucuronidase assays.

    PubMed Central

    Davies, C M; Apte, S C; Peterson, S M; Stauber, J L

    1994-01-01

    Several commonly occurring freshwater and marine plants and algae were screened for beta-D-galactosidase and beta-D-glucuronidase activities by using a 60-min enzyme assay based on the hydrolysis by these enzymes of 4-methylumbelliferyl-beta-D-galactoside and 4-methylumbelliferyl- beta-glucuronide, respectively. All freshwater plant extracts tested showed beta-D-galactosidase activity several at relatively high levels, and a number also showed beta-D-glucuronidase activity. A number of the macroalgae showed no activity of either enzyme, but those showing beta-D-galactosidase activity also showed beta-D-glucuronidase activity. The majority of microalgae showed some beta-D-galactosidase activity, but few showed beta-D-glucuronidase activity. Further studies, using the commercial Colilert test and the marine water formulation of Colilert, revealed that 2 of 11 of the microalgal species and several of the plant extracts tested caused positive reactions. It was concluded that several plant extracts and algae could significantly interfere with the detection of coliform bacteria and Escherichia coli with the use of rapid assays, on the basis of their production of beta-D-galactosidase and beta-D-glucuronidase, respectively. The significance of the plant and algal interferences in tests such as Colilert is dependent on the levels of enzymes released under natural conditions, the dilution which they may undergo, and the numbers of algal cells present. This also applies to interferences in rapid enzyme assays.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7993085

  20. The role of beta1 and beta2 adrenoceptors in isoproterenol-induced drinking.

    PubMed

    Kirby, R F; Novak, C M; Thunhorst, R L; Johnson, A K

    1994-09-05

    The present study examined the contribution of beta1 and beta2 adrenoceptor activation to drinking behavior and the stimulation of plasma renin activity produced by the mixed beta adrenoceptor agonist, isoproterenol. The stimulation of drinking by beta adrenoceptor activation could occur via two independent pathways; by either directly stimulating renal beta1 adrenoceptors on the juxtaglomerular cells to release renin or by stimulating vascular beta2 adrenoceptors that would decrease blood pressure and activate afferent neural and humoral mechanisms. Selective pharmacological antagonism of each adrenoceptor type was achieved by administering atenolol (2.5 mg/kg), a beta1 adrenoceptor antagonist, or ICI 118,551 (1 mg/kg), a beta2 adrenoceptor antagonist, before treatment with isoproterenol (25 micrograms/kg). Neither adrenoceptor mechanism alone could account for all of the water intake or stimulation of plasma renin activity due to isoproterenol treatment. Cardiovascular recordings confirmed the selectivity of the antagonists to their respective receptor subtypes, with atenolol blocking the beta1 adrenoceptor-mediated heart rate increases and ICI 118,551 blocking the beta 2 adrenoceptor-mediated depressor response to isoproterenol. The results provide evidence that the stimulation of both beta1 and beta2 adrenoceptors by isoproterenol acts in a synergistic manner to induce drinking and renin-angiotensin system activation.

  1. Beta-glucosidase I variants with improved properties

    SciTech Connect

    Bott, Richard R.; Kaper, Thijs; Kelemen, Bradley; Goedegebuur, Frits; Hommes, Ronaldus Wilhelmus; Kralj, Slavko; Kruithof, Paulien; Nikolaev, Igor; Van Der Kley, Wilhelmus Antonious Hendricus; Van Lieshout, Johannes Franciscus Thomas; Van Stigt Thans, Sander

    2016-09-20

    The present disclosure is generally directed to enzymes and in particular beta-glucosidase variants. Also described are nucleic acids encoding beta-glucosidase variants, compositions comprising beta-glucosidase variants, methods of using beta-glucosidase variants, and methods of identifying additional useful beta-glucosidase variants.

  2. Cytoplasmic beta-catenin in esophageal cancers.

    PubMed

    Kimura, Y; Shiozaki, H; Doki, Y; Yamamoto, M; Utsunomiya, T; Kawanishi, K; Fukuchi, N; Inoue, M; Tsujinaka, T; Monden, M

    1999-04-20

    beta-Catenin has 2 distinct roles in E-cadherin-mediated cell adhesion and carcinogenesis through APC gene mutation. One occurs at cell-adhesion sites, where cadherins become linked to the actin-based cytoskeleton. The others occur in the cytoplasm and nuclei and are thought to regulate cell transformation. We studied these different beta-catenins and evaluated their significance in carcinogenesis. Fresh surgical specimens were obtained from 22 patients with squamous-cell carcinoma of the esophagus. beta-Catenin in the free soluble fraction and the insoluble fraction was immunoblotted separately. At the same time, its localization was observed by immuno-histochemical techniques. In the normal esophageal epithelium, 91% of beta-catenin was detected in the insoluble fraction and beta-catenin staining occurred at the cell membrane, in co-existence with E-cadherin. In cancerous tissues, the amount of soluble beta-catenin was significantly (about 4-fold) higher than in normal tissues. Also, in cancerous tissues with higher amounts of soluble beta-catenin, immuno-histochemical techniques revealed the presence of beta-catenin in the cytoplasm and nuclei, as well as in the cell membrane. However, in samples with lower amounts of beta-catenin, expression was found only at the cell boundaries. The amount of soluble beta-catenin was not associated with the clinico-pathological grading of the tumors. Our results show that the accumulation of free soluble beta-catenin in the cytoplasm and nuclei frequently occurs during carcinogenesis of the squamous epithelium of the esophagus.

  3. Thymosin beta4: actin regulation and more.

    PubMed

    Yarmola, Elena G; Klimenko, Evguenia S; Fujita, Go; Bubb, Michael R

    2007-09-01

    The intracellular function of thymosin beta(4) is not limited to simple sequestration of globular actin. Our recent studies revealed that thymosin beta(4) affects actin critical concentration and forms a ternary complex with actin and profilin. The consequences of this complex formation can be very significant. Our new data demonstrate that it is likely that profilin affects binding of thymosin beta(4) to actin in the ternary complex through allosteric changes in actin rather than through competition for the binding site. The N- and C-terminal thymosin beta(4) helices are known to be unstructured in aqueous solution and to adopt helical conformation in organic solvents or upon binding to actin. Osmolytes stabilize protein structure, and TMAO (trimethylamine N-oxide) specifically stabilizes hydrogen bonds. This increases affinity of intact thymosin beta(4) to actin significantly, but the increase is much less for thymosin beta(4) sulfoxide. Our data show that oxidation does not alter binding of profilin to form a ternary complex, and therefore it is very likely that there is no direct steric interference by methionine 6 of thymosin beta(4). Rather, since TMAO has little effect on thymosin beta(4) sulfoxide, this observation is consistent with the hypothesis that methionine oxidation prevents helix transition. The experiment with truncated versions of thymosin beta(4) also supports this hypothesis. Oxidation and formation of the helices are important for both intra- and extracellular properties of thymosin beta(4). We found that actin and, in lesser extent, profilin-actin complex protect thymosin beta(4) from oxidation.

  4. Verification of the VARSKIN beta skin dose calculation computer code.

    PubMed

    Sherbini, Sami; DeCicco, Joseph; Gray, Anita Turner; Struckmeyer, Richard

    2008-06-01

    The computer code VARSKIN is used extensively to calculate dose to the skin resulting from contaminants on the skin or on protective clothing covering the skin. The code uses six pre-programmed source geometries, four of which are volume sources, and a wide range of user-selectable radionuclides. Some verification of this code had been carried out before the current version of the code, version 3.0, was released, but this was limited in extent and did not include all the source geometries that the code is capable of modeling. This work extends this verification to include all the source geometries that are programmed in the code over a wide range of beta radiation energies and skin depths. Verification was carried out by comparing the doses calculated using VARSKIN with the doses for similar geometries calculated using the Monte Carlo radiation transport code MCNP5. Beta end-point energies used in the calculations ranged from 0.3 MeV up to 2.3 MeV. The results showed excellent agreement between the MCNP and VARSKIN calculations, with the agreement being within a few percent for point and disc sources and within 20% for other sources with the exception of a few cases, mainly at the low end of the beta end-point energies. The accuracy of the VARSKIN results, based on the work in this paper, indicates that it is sufficiently accurate for calculation of skin doses resulting from skin contaminations, and that the uncertainties arising from the use of VARSKIN are likely to be small compared with other uncertainties that typically arise in this type of dose assessment, such as those resulting from a lack of exact information on the size, shape, and density of the contaminant, the depth of the sensitive layer of the skin at the location of the contamination, the duration of the exposure, and the possibility of the source moving over various areas of the skin during the exposure period if the contaminant is on protective clothing.

  5. Problems with packaged sources in foreign countries

    SciTech Connect

    Abeyta, Cristy L; Matzke, James L; Zarling, John; Tompkin, J. Andrew

    2010-01-01

    The Global Threat Reduction Initiative's (GTRI) Off-Site Source Recovery Project (OSRP), which is administered by the Los Alamos National Laboratory (LANL), removes excess, unwanted, abandoned, or orphan radioactive sealed sources that pose a potential threat to national security, public health, and safety. In total, GTRI/OSRP has been able to recover more than 25,000 excess and unwanted sealed sources from over 825 sites. In addition to transuranic sources, the GTRI/OSRP mission now includes recovery of beta/gamma emitting sources, which are of concern to both the U.S. government and the International Atomic Energy Agency (IAEA). This paper provides a synopsis of cooperative efforts in foreign countries to remove excess and unwanted sealed sources by discussing three topical areas: (1) The Regional Partnership with the International Atomic Energy Agency; (2) Challenges in repatriating sealed sources; and (3) Options for repatriating sealed sources.

  6. X-ray absorption and diffraction studies of the metal binding sites in amyloid beta-peptide.

    PubMed

    Streltsov, Victor

    2008-03-01

    A major source of neurodegeneration observed in Alzheimer's disease is believed to be caused by the toxicity from reactive oxygen species produced in the brain mediated by the A beta protein and mainly copper species. An atomic model of an amyloid beta-peptide (A beta) Cu2+ complex or at least the structure of the metal binding site is of great interest. Accurate information about the Cu-binding site of A beta protein can facilitate simulation of redox chemistry using high level quantum mechanics. Complementary X-ray diffraction and X-ray absorption techniques can be employed to obtain such accurate information. This review provides a blend of X-ray diffraction results on amyloid structures and selected works on A beta Cu2+ binding based on spectroscopic measurements with emphasis on the X-ray absorption technique.

  7. Spectroscopic Studies of Double Beta Decays and MOON

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2007-10-01

    This is a brief review of future spectroscopic experiments of neutrino-less double beta decays (0νββ) and the MOON (Mo Observatory Of Neutrinos) project. Spectroscopic 0νββ experiments of MOON, SuperNEMO and DCBA are planned to study Majorana masses in the quasi-degenerate (QD) and inverted mass hierarchy (IH) regions. MOON aims at 0νββ studies with the ν-mass sensitivities of 100-30 meV by means of a super ensemble of multi-layer modules, each being consist of a scintillator plate, two tracking detector planes and a thin ββ source film.

  8. Spores, pollen, and microplankton from the horizon Beta outcrop.

    PubMed

    Habib, D

    1968-12-27

    Palynology was used for dating a pre-Pleistocene deep-sea organic lutite layer situated stratigraphically near seismic horizon beta, below horizon A. The spores and pollen are closely identified, quantitatively, with nonmarine and marine Middle Cretaceous assemblages (Albian-Cenomanian) on the continents, an age designation that is confirmed by the occurrence of dinoflagellate cysts, acritarchs, foraminifers, and coccoliths in the investigated cores. The abundance of these well-preserved, land-derived assemblages in an area far removed from a source suggests some tectonic displacement since their deposition.

  9. Values of the phase space factors for double beta decay

    SciTech Connect

    Stoica, Sabin Mirea, Mihai

    2015-10-28

    We report an up-date list of the experimentally most interesting phase space factors for double beta decay (DBD). The electron/positron wave functions are obtained by solving the Dirac equations with a Coulomb potential derived from a realistic proton density distribution in nucleus and with inclusion of the finite nuclear size (FNS) and electron screening (ES) effects. We build up new numerical routines which allow us a good control of the accuracy of calculations. We found several notable differences as compared with previous results reported in literature and possible sources of these discrepancies are discussed.

  10. (Confinement and heating of high beta plasmas. Annual progress report)

    SciTech Connect

    Not Available

    1986-01-01

    Final measurements have been made of flux surfaces and equilibrium pressure balance with improved magnetic probes on the ''steady'' hardcore system with 6 msec risetime. These measurements were made with the power crowbar on the main B/sub z/ and l = 1 stellarator fields. Pressure balance measurements show a ..beta.. distribution peaking at about 40% (centered on the ''bean''). Theoretical work that shows the equivalence of a hardcore shift of 2.5 cm (with respect to the l = 1 axis) and toroidal effects corresponding to aspect ratios >17. Some operational results of the coaxial slow source for compact toroids are described.

  11. Beta maritima: the Origin of Beets

    USDA-ARS?s Scientific Manuscript database

    Along the undisturbed shores, especially of the Mediterranean Sea and the European North Atlantic Ocean, is a widespread plant called Beta maritima (Beta vulgaris subspecies maritima) by the botanists, or more commonly sea beet. Nothing for the inexperienced observer's eye distinguishes it from surr...

  12. Beta-adrenergic blockade in clinical practice.

    PubMed

    Frishman, W H

    1982-09-01

    Although all beta-blocking agents have similar pharmacologic effects, they have vastly different pharmacokinetic properties, which can influence the clinical usefulness of a given beta blocker in an individual patient. The efficacy of these drugs in a host of disorders-both cardiovascular and noncardiovascular-and their modes of action in these clinical contexts are examined and discussed.

  13. Beta-agonists and animal welfare

    USDA-ARS?s Scientific Manuscript database

    The use of beta-agonists in animal feed is a high profile topic within the U.S. as consumers and activist groups continue to question its safety. The only beta-agonist currently available for use in swine is ractopamine hydrochloride (RAC). This is available as Paylean™ (Elanco Animal Health – FDA a...

  14. Modeling the beta diversity of coral reefs.

    PubMed

    Harborne, Alastair R; Mumby, Peter J; Zychaluk, Kamila; Hedley, John D; Blackwell, Paul G

    2006-11-01

    Quantifying the beta diversity (species replacement along spatiotemporal gradients) of ecosystems is important for understanding and conserving patterns of biodiversity. However, virtually all studies of beta diversity focus on one-dimensional transects orientated along a specific environmental gradient that is defined a priori. By ignoring a second spatial dimension and the associated changes in species composition and environmental gradients, this approach may provide limited insight into the full pattern of beta diversity. Here, we use remotely sensed imagery to quantify beta diversity continuously, in two dimensions, and at multiple scales across an entire tropical marine seascape. We then show that beta diversity can be modeled (0.852 > or = r2 > or = 0.590) at spatial scales between 0.5 and 5.0 km2, using the environmental variables of mean and variance of depth and wave exposure. Beta diversity, quantified within a "window" of a given size, is positively correlated to the range of environmental conditions within that window. For example, beta diversity increases with increasing variance of depth. By analyzing such relationships across seascapes, this study provides a framework for a range of disparate coral reef literature including studies of zonation, diversity, and disturbance. Using supporting evidence from soft-bottom communities, we hypothesize that depth will be an important variable for modeling beta diversity in a range of marine systems. We discuss the implications of our results for the design of marine reserves.

  15. Venus: Geology of Beta Regio rift system

    NASA Technical Reports Server (NTRS)

    Nikishin, A. M.; Borozdin, V. K.; Bobina, N. N.

    1992-01-01

    Beta Regio is characterized by the existence of rift structures. We compiled new geologic maps of Beta Regio according to Magellan data. There are many large uplifted tesserae on beta upland. These tesserae are partly buried by younger volcanic cover. We can conclude, using these observations, that Beta upland formed mainly due to lithospheric tectonic uplifting and was only partly constructed by volcanism. Theia Mons is the center of the Beta rift system. Many rift belts are distributed radially to Theia Mons. Typical widths of rifts are 40-160 km. Rift valleys are structurally represented by crustal grabens or half-grabens. There are symmetrical and asymmetrical rifts. Many rifts have shoulder uplifts up to 0.5-1 km high and 40-60 km wide. Preliminary analysis for rift valley structural cross sections lead to the conclusion that rifts originated due to 5-10 percent crustal extension. Many rifts traverse Beta upland and spread to the surrounding lowlands. We can assume because of these data that Beta rift system has an active-passive origin. It formed due to regional tectonic lithospheric extension. Rifting was accelerated by upper-mantle hot spot origination under the center of passive extension (under the Beta Regio).

  16. Fine mapping, transcriptome analysis, and marker development for Y2, the gene that conditions beta-carotene accumulation in carrot (Daucus carota L.)

    USDA-ARS?s Scientific Manuscript database

    Domesticated carrots, Daucus carota subsp. sativus, are the richest source of beta-carotene in the US diet, which when consumed is converted into vitamin A, an essential component of eye health and immunity. The Y2 locus plays a significant role in beta-carotene accumulation in carrot roots, but a c...

  17. PBX: the Princeton beta experiment

    SciTech Connect

    Bol, K.; Chance, M.; Dewar, R.

    1983-09-01

    A rearrangement of the divertor coils in PDX will enable a test in 1984 of the MHD stability properties of deeply indented bean-shaped plasmas. The goal is a beta of 10%. Indentation is expected to counter the deterioration of MHD stability against pressure driven modes that is occasioned by the larger aspect ratios typical of anticipated reactor oriented devices. Indeed, as shown by M. Chance et al., indentation may offer direct access to the second region of stability for ballooning modes, and numerical analyses with PEST show the internal kink to be stabilized completely with even relatively modest indentation. The internal kink is implicated in the loss of beam ions in PDX. In this report the theoretical basis for the forthcoming experiment, and the design considerations underlying the modification from PDX to PBX, are described in detail. Additional theoretical material, including an analysis of particle orbits in an indented tokamak plasma, is appended.

  18. The chromosphere of Beta Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Teays, Terry J.; Schmidt, Edward G.; Pasinetti Fracassini, Laura E.; Fracassini, Massimo

    1989-01-01

    High-resolution, long-wavelength IUE observations and ground-based photometry of the Delta Scuti star Beta Cas is reported. The ground-based observations were used together with previous results of Antonello et al. (1986) to ensure that the IUE observations were correctly phased relative to the photometric variation. Fluxes for the emission core of the Mg II k 2796-A line were obtained from the UV spectra over several cycles in 1986 and 1987. It is found that there is an increase in the emission during part of the cycle, but it occurs near minimum light in contrast to another Delta Scuti star, Rho Pup, and the classical Cepheids (where it occurs near maximum light). The mean level of chromospheric activity is comparable to other early F dwarfs.

  19. DREAM: Research to Operations Beta

    NASA Astrophysics Data System (ADS)

    Friedel, Reiner; Reeves, Geoffrey; Zaharia, Sorin; Koller, Josef; Chen, Yue; Henderson, Mike; Thomsen, Davis

    The Dynamic Radiation Environment Assimilation Model (DREAM) is a dataassimilative model of the Earth's radiation belts that has, until recently, been used primarily as a re-search tool to understand radiation belt dynamics and to develop Kalman filter techniques for application to magnetospheric modeling. More recently, the emphasis of the DREAM program has shifted toward implementation of an operational prototype for testing and validation at the Air Force Research Laboratory's (AFRL) Space Weather Forecast Laboratory (SWFL) and NASA's Community Coordinated Modeling Center (CCMC). The transition has required significant effort, funding, and shifting of priorities that serve as a recent example of the oppor-tunities and challenges of transitioning a model from research to operations (R2O). DREAM is still in the early stages of transition to operations but we do not see any significant obstacles to success. We present here the BETA version of this model, operating in real-time, using GOES energetic particle data as input.

  20. Generalized Beta Mixtures of Gaussians.

    PubMed

    Armagan, Artin; Dunson, David B; Clyde, Merlise

    2011-01-01

    In recent years, a rich variety of shrinkage priors have been proposed that have great promise in addressing massive regression problems. In general, these new priors can be expressed as scale mixtures of normals, but have more complex forms and better properties than traditional Cauchy and double exponential priors. We first propose a new class of normal scale mixtures through a novel generalized beta distribution that encompasses many interesting priors as special cases. This encompassing framework should prove useful in comparing competing priors, considering properties and revealing close connections. We then develop a class of variational Bayes approximations through the new hierarchy presented that will scale more efficiently to the types of truly massive data sets that are now encountered routinely.

  1. Expression pattern and localization of beta,beta-carotene 15,15'-dioxygenase in different tissues.

    PubMed Central

    Wyss, A; Wirtz, G M; Woggon, W D; Brugger, R; Wyss, M; Friedlein, A; Riss, G; Bachmann, H; Hunziker, W

    2001-01-01

    Beta,beta-carotene 15,15'-dioxygenase cleaves beta,beta-carotene into two molecules of retinal, and is the key enzyme in the metabolism of beta,beta-carotene to vitamin A. The enzyme has been known for more than 40 years, yet all attempts to purify the protein to homogeneity have failed. Recently, the successful cloning and sequencing of an enzyme with beta,beta-carotene 15,15'-dioxygenase activity from chicken, as well as from Drosophila, has been reported. Here, we describe in detail our attempt to enrich the chicken beta,beta-carotene 15,15'-dioxygenase to such an extent as to allow determination of partial amino acid sequences, which were then used to design degenerate oligonucleotides. Screening of a chicken duodenal expression library yielded a full-length clone containing a coding sequence of 1578 bp. Functional expression in Escherichia coli and in eukaryotic cell lines confirmed that we had cloned the first vertebrate dioxygenase that cleaves beta,beta-carotene at the central 15,15'-double bond. By performing a sequence homology search, the cDNA sequence of the mouse homologue was found as an expressed sequence tag (EST) in the gene bank. At the amino-acid level, the degree of homology between the chicken and mouse sequences is 81%. Thus beta,beta-carotene 15,15'-dioxygenase can be considered as being an enzyme that is evolutionarily rather well conserved. We established the expression pattern of beta,beta-carotene 15,15'-dioxygenase in chicken and mouse tissues with a combination of Northern blots and in situ hybridization. The mRNA for beta,beta-carotene 15,15'-dioxygenase was localized primarily in duodenal villi, as well as in liver and in tubular structures of lung and kidney. These new findings demonstrate that beta,beta-carotene 15,15'-dioxygenase is also expressed in epithelial structures, where it serves to provide the tissue-specific vitamin A supply. PMID:11237856

  2. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, G.G.; Kato, T.R.; Schonegg, E.

    1985-04-11

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed. 5 tabs.

  3. Gamma-ray blind beta particle probe

    DOEpatents

    Weisenberger, Andrew G.

    2001-01-01

    An intra-operative beta particle probe is provided by placing a suitable photomultiplier tube (PMT), micro channel plate (MCP) or other electron multiplier device within a vacuum housing equipped with: 1) an appropriate beta particle permeable window; and 2) electron detection circuitry. Beta particles emitted in the immediate vicinity of the probe window will be received by the electron multiplier device and amplified to produce a detectable signal. Such a device is useful as a gamma insensitive, intra-operative, beta particle probe in surgeries where the patient has been injected with a beta emitting radiopharmaceutical. The method of use of such a device is also described, as is a position sensitive such device.

  4. Beta-glucuronidase in physiology and disease.

    PubMed

    Basińska, Agnieszka; Floriańczyk, Bolesław

    2003-01-01

    beta-glucoronidase (EC 3.2.1.31) is a lysosomal enzyme catylysing the decomposition of beta-D-glucoronides--compounds arising as a result of the combination of beta-D-glucoronic acid and a number of compounds both exo- and endogenous, containing hydroxylic, carboxylic, amine, imine or thiol groups. The most common test evaluating the activity of the enzyme is that using phenolphtalein glucoronide as a biosynthetic substrate. The freed aglycons are colorimetrically assayed. The activity of beta-glucoronidase increases in many pathological conditions: liver infammations, cirrhosis of the liver, inflammations of other organs, cholestatic jaundice, tuberculosis, sarcoidosis and also in neoplasms. Many authors point to beta-glucoronidase as a sensitive indicator signalling cell damage.

  5. Precision measurements in 20F beta decay

    NASA Astrophysics Data System (ADS)

    Hughes, Maximilian; Naviliat-Cuncic, Oscar; Voytas, Paul; George, Elizabeth; Paulauskas, Stan; Huyan, Xueying

    2017-01-01

    Precision measurements of the shape of the beta particle energy spectrum provide a sensitive window to search for new interactions beyond the standard model. The decay of 20F offers an attractive system due to the simple decay scheme for a coincidence measurement. A beam of 20F ions, produced at the National Superconducting Cyclotron Laboratory, was implanted into a beta-detector. A gamma-ray detection system surrounded the beta detector to detect the beta-delayed gammas in coincidence to reduce the background. Preliminary analysis of these data focus on the half-life of 20F due to the statistical inconsistency of previous work. Monte Carlo simulations are ongoing to analyze the shape of the beta energy spectrum. Results of the analysis of the half-life will be presented. Supported by National Science Foundation Grant PHY-1102511.

  6. Singular points of protein beta-sheets.

    PubMed Central

    Liu, W. M.; Chou, K. C.

    1998-01-01

    Protein beta-sheets can be regarded as surfaces. Two surfaces can be connected along a common edge to form a larger surface, or two edges of a surface can coalesce to form a closed sheet such as a beta-barrel. Singular points are locations where these connections are not perfect. In protein beta-sheets, a singular point is characterized by a residue separating two beta-ladders. In this paper, we study the singular points of protein beta-sheets from the surface topologic viewpoint, summarize our search results from the protein structural data in the Protein Data Bank, and present examples where singular points are near the active sites and may contribute to forming the proper relative positions of catalytic residues. PMID:9827998

  7. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, Gifford G.; Kato, Takeo R.; Schonegg, Edward

    1986-10-07

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which have undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed.

  8. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, Gifford G.; Kato, Takeo R.; Schonegg, Edward

    1986-01-01

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which have undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed.

  9. Effect of finite. beta. on stellarator transport

    SciTech Connect

    Mynick, H.E.

    1984-04-01

    A theory of the modification of stellarator transport due to the presence of finite plasma pressure is developed, and applied to a range of stellarator configurations. For many configurations of interest, plasma transport can change by more than an order of magnitude in the progression from zero pressure to the equilibrium ..beta.. limit of the device. Thus, a stellarator with transport-optimized vacuum fields can have poor confinement at the desired operating ..beta... Without an external compensating field, increasing ..beta.. tends to degrade confinement, unless the initial field structure is very carefully chosen. The theory permits one to correctly determine this vacuum structure, in terms of the desired structure of the field at a prescribed operating ..beta... With a compensating external field, the deleterious effect of finite ..beta.. on transport can be partially eliminated.

  10. Beta Pictoris planet finally imaged?

    NASA Astrophysics Data System (ADS)

    2008-11-01

    A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc. With a projected distance from the star of only 8 times the Earth-Sun distance, this object is most likely the giant planet suspected from the peculiar shape of the disc and the previously observed infall of comets onto the star. It would then be the first image of a planet that is as close to its host star as Saturn is to the Sun. Sharpening Up Jupiter ESO PR Photo 42a/08 Beta Pictoris as seen in infrared light The hot star Beta Pictoris is one of the best-known examples of stars surrounded by a dusty 'debris' disc. Debris discs are composed of dust resulting from collisions among larger bodies like planetary embryos or asteroids. They are a bigger version of the zodiacal dust in our Solar System. Its disc was the first to be imaged -- as early as 1984 -- and remains the best-studied system. Earlier observations showed a warp of the disc, a secondary inclined disc and infalling comets onto the star. "These are indirect, but tell-tale signs that strongly suggest the presence of a massive planet lying between 5 and 10 times the mean Earth-Sun distance from its host star," says team leader Anne-Marie Lagrange. "However, probing the very inner region of the disc, so close to the glowing star, is a most challenging task." In 2003, the French team used the NAOS-CONICA instrument (or NACO [1]), mounted on one of the 8.2 m Unit Telescopes of ESO's Very Large Telescope (VLT), to benefit from both the high image quality provided by the Adaptive Optics system at infrared wavelengths and the good dynamics offered by the detector, in order to study the immediate surroundings of Beta Pictoris. Recently, a member of the team re-analysed the data in a different way to seek the trace of a companion to the star. Infrared wavelengths are indeed very well suited for such searches. "For this, the real challenge

  11. Ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  12. Withholding planned speech is reflected in synchronized beta-band oscillations

    PubMed Central

    Piai, Vitória; Roelofs, Ardi; Rommers, Joost; Dahlslätt, Kristoffer; Maris, Eric

    2015-01-01

    When engaged in a conversation, speakers sometimes have to withhold a planned response, for example, before it is their turn to speak. In the present study, using magnetoencephalography (MEG) outside of a conversational setting, we investigate the oscillatory brain mechanisms involved in the process of withholding a planned verbal response until it is time to speak. Our participants viewed a sequence of four random consonant strings and one pseudoword, which they had to pronounce when the fifth string (the imperative stimulus) was presented. The pseudoword appeared either as the fourth or fifth stimulus in the sequence, creating two conditions. In the withhold condition, the pseudoword was the fourth string and the verbal response was withheld until the imperative stimulus was presented. In the control condition, the fifth string was the pseudoword, so no response was withheld. We compared oscillatory responses to the withhold relative to the control condition in the time period preceding speech. Alpha-beta power (8–30 Hz) decreased over occipital sensors in the withhold condition relative to the control condition. Source-level analysis indicated a posterior source (i.e., occipital cortex) associated with the alpha-beta power decreases. This occipital alpha-beta desynchronization likely reflects attentional allocation to the upcoming imperative stimulus. Moreover, beta (12–20 Hz) power increased over frontal sensors. Source-level analysis indicated a frontal source (i.e., middle and superior frontal gyri) associated with the beta-power increases. We interpret the frontal beta synchronization to reflect a mechanism aiding the maintenance of the current motor or cognitive state. Our results provide a window into a possible oscillatory mechanism implementing the ability of speakers to withhold a planned verbal response until they have to speak. PMID:26528164

  13. Effect of storage and cooking on beta-carotene isomers in carrots ( Daucus carota L. cv. 'Stefano').

    PubMed

    Imsic, Michael; Winkler, Sonja; Tomkins, Bruce; Jones, Rod

    2010-04-28

    Carrots are one of the highest dietary sources of beta-carotene and are naturally high in the (all-E)-beta-carotene isomer, which has higher bioavailability, provitamin A activity, and antioxidant capacity compared to Z (cis) isomers. The objectives of the present study were to investigate the effects of storage temperature, time, and cooking (boiling for 15 min) on the levels of carotene isomers in 'Stefano' carrots. Storing carrots at either 4 degrees C to simulate long-term storage or 20 degrees C to simulate marketing practices resulted in increases in (all-E)-beta-carotene of 20.3% after 3 days at 4 degrees C and 34.4% after 14 days at 20 degrees C, respectively. The levels of Z isomers in raw carrots were low with (13Z)-beta-carotene and (9Z)-beta-carotene accounting for less that 1.8% of the total beta-carotene present. Levels of (9Z)-beta-carotene decreased during storage at either temperature, whereas storage at 4 degrees C resulted in a 109% increase in (13Z)-beta-carotene after 56 days. Cooking significantly increased the levels of (13Z)-beta-carotene and (9Z)-beta-carotene and resulted in the production of (15Z)-beta-carotene, which was absent in raw carrots. Storage at 4 degrees C for 15 days or more prior to cooking reduced the susceptibility of (all-E)-beta-carotene to thermal isomerization during cooking, resulting in lower levels of all three Z-beta-carotene isomers being generated, while storage at 20 degrees C for up to 21 days resulted in significantly higher levels of (all-E)-beta-carotene before and after cooking but had no effect on Z-isomer production during cooking. Consequently, we conclude that, for the greatest health benefit, fresh carrots can be stored for up to 21 days at 20 degrees C or at 4 degrees C for up to 56 days without significant reduction in (all-E)-beta-carotene and should be consumed raw or boiled for less than 15 min to limit Z-beta-carotene isomer formation.

  14. Complementation of subunits from different bacterial luciferases. Evidence for the role of the. beta. subunit in the bioluminescent mechanism

    SciTech Connect

    Meighen, E.A.; Bartlet, I.

    1980-12-10

    Complementation of the nonidentical subunits (..cap alpha.. and ..beta..) of luciferases isolated from two different bioluminescent strains, Beneckea harveyi and Photobacterium phosphoreum, has resulted in the formation of a functional hybrid luciferase (..cap alpha../sub h/..beta../sub p/) containing the ..cap alpha.. subunit from B. harveyi luciferase (..cap alpha../sub h/) and the ..beta.. subunit from P. phosphoreum luciferase (..beta../sub p/). The complementation was unidirectional; activity could not be restored by complementing the ..cap alpha.. subunit of P. phosphoreum luciferase with the ..beta.. subunit of B. harveyi luciferase, showing that the subunits from these luciferases were not identical. Kinetic parameters of the hybrid luciferase reflecting the intermediate and later steps of the bioluminescent reaction as well as the overall activity and specificity were essentially identical to the same kinetic parameters for B. harveyi luciferase, the source of the ..cap alpha.. subunit, and quite distinct from those of P. phosphoreum luciferase. However, kinetic parameters that reflected the initial step in the reaction involving interaction of FMNH/sub 2/ and luciferase were altered in the hybrid luciferase compared to both the parental luciferases, the K/sub d/ for FMNH/sub 2/ actually being closer to that observed for the P. phosphoreum luciferase (the source of the ..beta.. subunit). These results provide direct evidence that modification or alteration of the ..beta.. subunit in a dimeric luciferase molecule can affect the kinetic properties and indicates that the ..beta.. subunit plays a functional role in the bioluminescent mechanism. It is proposed that both the ..cap alpha.. and ..beta.. subunits are involved with the initial interaction with FMNH/sub 2/, whereas subsequent steps in the mechanism are dictated exclusively by the ..cap alpha.. subunit and are unaffected by alterations in the ..beta.. subunit.

  15. Maternal plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin throughout pregnancy.

    PubMed

    Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A

    1983-12-01

    Plasma beta-LPH, beta-EP and gamma-LPH concentrations were measured by radioimmunoassay in 10 pregnant women from 12 weeks gestation until term and in nine women in the early follicular phase of the cycle. There was a progressive and significant rise in the concentration of all three peptides throughout pregnancy and by 32 weeks the concentrations of beta-LPH and beta-EP were greater than the corresponding concentrations in the follicular phase: gamma-LPH was greater than in the follicular phase by the end of pregnancy in those women who were delivered after 40 weeks. The ratio of beta-LPH to gamma-LPH did not change significantly throughout pregnancy, but there was a progressive fall in the beta-LPH/beta-EP ratio. The possible presence of a 'big LPH' to explain this finding is discussed.

  16. Inverse Beta: Inverse cumulative density function (CDF) of a Beta distribution

    NASA Astrophysics Data System (ADS)

    Kipping, David

    2014-03-01

    The Beta Inverse code solves the inverse cumulative density function (CDF) of a Beta distribution, allowing one to sample from the Beta prior directly. The Beta distribution is well suited as a prior for the distribution of the orbital eccentricities of extrasolar planets; imposing a Beta prior on orbital eccentricity is valuable for any type of observation of an exoplanet where eccentricity can affect the model parameters (e.g. transits, radial velocities, microlensing, direct imaging). The Beta prior is an excellent description of the current, empirically determined distribution of orbital eccentricities and thus employing it naturally incorporates an observer’s prior experience of what types of orbits are probable or improbable. The default parameters in the code are currently set to the Beta distribution which best describes the entire population of exoplanets with well-constrained orbits.

  17. Impaired growth of pancreatic exocrine cells in transgenic mice expressing human activin {beta}E subunit

    SciTech Connect

    Hashimoto, Osamu . E-mail: ohashim@vmas.kitasato-u.ac.jp; Ushiro, Yuuki; Sekiyama, Kazunari; Yamaguchi, Osamu; Yoshioka, Kazuki; Mutoh, Ken-Ichiro; Hasegawa, Yoshihisa

    2006-03-10

    Activins, TGF-{beta} superfamily members, have multiple functions in a variety of cells and tissues. Recently, additional activin {beta} subunit genes, {beta}C and {beta}E, have been identified. To explore the role of activin E, we created transgenic mice overexpressing human activin {beta}E subunit. There were pronounced differences in the pancreata of the transgenic animals as compared with their wild-type counterparts. Pancreatic weight, expressed relative to total body weight, was significantly reduced. Histologically, adipose replacement of acini in the exocrine pancreas was observed. There was a significant decrease in the number of PCNA-positive cells in the acinar cells, indicating reduced proliferation in the exocrine pancreas of the transgenic mice. However, quantitative pancreatic morphometry showed that the total number and mass of the islets of the transgenic mice were comparable with those of the nontransgenic control mice. Our findings suggest a role for activin E in regulating the proliferation of pancreatic exocrine cells.

  18. The lipolytic effect of beta 1- and beta 2-adrenoceptor activation in healthy human volunteers.

    PubMed Central

    Haffner, C A; Kendall, M J; Maxwell, S; Hughes, B

    1993-01-01

    1. We investigated the effect of activation beta 1- and beta 2-adrenoceptors on the process of lipolysis in human volunteers. Ten male subjects underwent a single-blind randomized cross-over trial using infusions of terbutaline (a specific beta 2-adrenoceptor agonist), xamoterol (a partial beta 1-agonist with beta 2-adrenoceptor blocking activity) and saline (placebo control). The effect of these infusions on plasma potassium, glucose, free fatty acids (FFA) (total and individual) and insulin levels was studied. 2. Terbutaline infusion induced a significant rise in plasma glucose and a fall in plasma potassium in keeping with its beta 2-adrenoceptor stimulant properties. Xamoterol infusion had no significant effect on these values. Terbutaline infusion caused a greater rise in total and individual FFA than xamoterol, but both effects were significantly different from placebo. 3. The possible reasons for these results and their implications on the beta-adrenergic control of lipolysis are discussed. PMID:8383517

  19. Methods of Fabricating Scintillators with Radioisotopes for Beta Battery Applications

    NASA Technical Reports Server (NTRS)

    Rensing, Noa M.; Squillante, Michael R.; Tieman, Timothy C.; Higgins, William; Shiriwadkar, Urmila

    2013-01-01

    Technology has been developed for a class of self-contained, long-duration power sources called beta batteries, which harvest the energy contained in the radioactive emissions from beta decay isotopes. The new battery is a significant improvement over the conventional phosphor/solar cell concept for converting this energy in three ways. First, the thin phosphor is replaced with a thick scintillator that is transparent to its own emissions. By using a scintillator sufficiently thick to completely stop all the beta particles, efficiency is greatly improved. Second, since the energy of the beta particles is absorbed in the scintillator, the semiconductor photodetector is shielded from radiation damage that presently limits the performance and lifetime of traditional phosphor converters. Finally, instead of a thin film of beta-emitting material, the isotopes are incorporated into the entire volume of the thick scintillator crystal allowing more activity to be included in the converter without self-absorption. There is no chemical difference between radioactive and stable strontium beta emitters such as Sr-90, so the beta emitter can be uniformly distributed throughout a strontium based scintillator crystal. When beta emitter material is applied as a foil or thin film to the surface of a solar cell or even to the surface of a scintillator, much of the radiation escapes due to the geometry, and some is absorbed within the layer itself, leading to inefficient harvesting of the energy. In contrast, if the emitting atoms are incorporated within the scintillator, the geometry allows for the capture and efficient conversion of the energy of particles emitted in any direction. Any gamma rays associated with secondary decays or Bremsstrahlung photons may also be absorbed within the scintillator, and converted to lower energy photons, which will in turn be captured by the photocell or photodiode. Some energy will be lost in this two-stage conversion process (high-energy particle

  20. USE OF GREEN MANURE CROPS AND SUGAR BEET VARIETIES TO CONTROL HETERODERA BETAE.

    PubMed

    Raaijmakers, E

    2014-01-01

    Although it is less studied than the white beet cyst nematode (Heterodera schachtii), the yellow beet cyst nematode (H. betae) has been found in many countries in Europe. For example in The Netherlands, France and Spain. H. betae causes yield losses on sandy soils. A high infestation can result in loss of complete plants. In The Netherlands, this nematode is especially found in the south eastern and north eastern part, where it occurs on 18% and 5% of the fields, respectively. From a project of the Dutch Sugar beet Research Institute IRS (SUSY) on factors explaining differences in sugar yield, this nematode was one of the most important factors reducing sugar yields on sandy soils. Until 2008, the only way to control H. betae was by reducing the number of host crops in the crop rotation. Host crops are crops belonging to the families of Cruciferae, Chenopodiaceae, Polygonaceae, Caryophyllaceae and Leguminosea. In order to find more control measures, research was done to investigate the host status of different green manure crops and the resistance and tolerance of different sugar beet varieties to H. betae. White mustard (Sinapis alba) and oil seed radish (Raphanus sativus spp. oleiferus) varieties resistant to H. schachtii were investigated for their resistance against H. betae. A climate room trial and a field trial with white mustard and oil seed radish were conducted in 2007 and 2008, respectively. Results show that H. betae could multiply on susceptible white mustard and susceptible oil seed radish, but not on the H. schachtii resistant varieties. In climate room trials in 2009, 2010 and 2011 and field trials in 2010, 2011 and 2012, the effect of different sugar beet varieties on the multiplication of H. betae and the effect of H. betae on yield at different infestation levels was investigated. Sugar beet varieties with resistance genes to H. schachtii (from Beta procumbens or B. maritima) were selected. Varieties with resistance genes from these sources were

  1. Short-baseline electron neutrino disappearance, tritium beta decay, and neutrinoless double-beta decay

    SciTech Connect

    Giunti, Carlo; Laveder, Marco

    2010-09-01

    We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}. The combined fit gives {Delta}m{sup 2}(greater-or-similar sign)0.1 eV{sup 2} and 0.11(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.48 at 2{sigma}. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in {beta} decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin{sup 2}2{theta} below 0.10 at 2{sigma}. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives {Delta}m{sup 2}{approx_equal}2 eV and 0.01(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.13 at 2{sigma}. Assuming a hierarchy of masses m{sub 1}, m{sub 2}, m{sub 3}<beta} decay and neutrinoless double-{beta} decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at 2{sigma}. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a 2.6{sigma} indication of a mixing angle asymmetry.

  2. Collective search by mobile robots using alpha-beta coordination

    SciTech Connect

    Goldsmith, S.Y.; Robinett, R. III

    1998-04-01

    One important application of mobile robots is searching a geographical region to locate the origin of a specific sensible phenomenon. Mapping mine fields, extraterrestrial and undersea exploration, the location of chemical and biological weapons, and the location of explosive devices are just a few potential applications. Teams of robotic bloodhounds have a simple common goal; to converge on the location of the source phenomenon, confirm its intensity, and to remain aggregated around it until directed to take some other action. In cases where human intervention through teleoperation is not possible, the robot team must be deployed in a territory without supervision, requiring an autonomous decentralized coordination strategy. This paper presents the alpha beta coordination strategy, a family of collective search algorithms that are based on dynamic partitioning of the robotic team into two complementary social roles according to a sensor based status measure. Robots in the alpha role are risk takers, motivated to improve their status by exploring new regions of the search space. Robots in the beta role are motivated to improve but are conservative, and tend to remain aggregated and stationary until the alpha robots have identified better regions of the search space. Roles are determined dynamically by each member of the team based on the status of the individual robot relative to the current state of the collective. Partitioning the robot team into alpha and beta roles results in a balance between exploration and exploitation, and can yield collective energy savings and improved resistance to sensor noise and defectors. Alpha robots waste energy exploring new territory, and are more sensitive to the effects of ambient noise and to defectors reporting inflated status. Beta robots conserve energy by moving in a direct path to regions of confirmed high status.

  3. Hanford beta-gamma personnel dosimeter prototypes and evaluation

    SciTech Connect

    Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

    1983-04-01

    Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips.

  4. Effect of toll-like receptor activation on thymosin beta-4 production by chicken macrophages

    USDA-ARS?s Scientific Manuscript database

    Thymosin beta 4 (Tb4) is an actin binding intracellular peptide that promotes wound healing, tissue remodeling, and angiogenesis. The regulation of Tb4 secretion to the extracellular environment is not understood. The macrophage is a rich source of Tb4 which also participates in wound healing proce...

  5. Production of poly(beta-L-malic acid) (PMA) from agricultural biomass substrates by Aureobasidium pullulans

    USDA-ARS?s Scientific Manuscript database

    We report here for the first time the production of poly(beta-L-malic acid) (PMA) from agricultural biomass substrates by the yeastlike fungus Aureobasidium pullulans. Strains NRRL Y 2311-1, NRRL 50382, NRRL 50383, and NRRL 50384, representing diverse isolation sources and phylogenetic clades, prod...

  6. Decay constants of heavy-light pseudoscalars: Results at. beta. = 6. 3

    SciTech Connect

    Bernard, C.; Heard, C.M. . Dept. of Physics); Labrenz, J.; Soni, A. )

    1992-01-01

    A lattice calculation of the pseudoscalar decay constant for heavy-light mesons is reported. Emphasis is placed on preliminary results obtained using wall-source propagators at {beta} = 6.3. The previously-observed discrepancy between the static and conventional approaches appears to be much reduced.

  7. Decay constants of heavy-light pseudoscalars: Results at {beta} = 6.3

    SciTech Connect

    Bernard, C.; Heard, C.M.; Labrenz, J.; Soni, A.

    1992-01-01

    A lattice calculation of the pseudoscalar decay constant for heavy-light mesons is reported. Emphasis is placed on preliminary results obtained using wall-source propagators at {beta} = 6.3. The previously-observed discrepancy between the static and conventional approaches appears to be much reduced.

  8. Quantitative analyses of beta-carotene and retinol in serum and feces in support of clinical bioavailability studies.

    PubMed

    Zhu, Dongwei; Wang, Yan; Pang, Yan; Liu, Ang; Guo, Jian; Bouwman, Carolien A; West, Clive E; van Breemen, Richard B

    2006-01-01

    Among more than 50 provitamin carotenoids, beta-carotene is the most metabolically active source of retinol. Despite diets rich in fruits and vegetables containing beta-carotene, vitamin A deficiency is the leading cause of blindness and childhood mortality in developing countries. In addition, the uncertainty of beta-carotene bioconversion into vitamin A suggests that new data are needed to update the nutritional guidelines in developed countries. Previously, we reported the development of a carotene/retinol plateau isotopic enrichment method (CarRet PIE) for the determination of beta-carotene bioavailability and bioconversion into retinol, which utilizes positive ion atmospheric pressure chemical ionization (APCI) liquid chromatography/mass spectrometry (LC/MS). While seeking to validate the CarRet PIE using a mass balance approach requiring fecal measurements of beta-carotene and retinol, interference was encountered that required substantial modifications of the LC/MS assay. Here we report a new LC/MS assay that is based on the detection of molecular anions of beta-carotene using negative ion APCI with a reversed-phase C30 column for HPLC separation. Sample preparation required saponification to eliminate interfering triglycerides. The limit of detection (LOD) of beta-carotene was 0.25 pmol calculated on the basis of an injection of 20 microL of 0.0125 microM beta-carotene, and the limit of quantitation (LOQ) was 1.0 pmol based on the injection of 20 microL of 0.050 microM beta-carotene. The linear range was 1.1 to 2179 pmol on-column. The wide linear range and low LOD and LOQ of this assay facilitated the sensitive and selective quantitative analysis of beta-carotene in both serum and fecal samples in support of an on-going clinical investigation of beta-carotene bioavailability and bioconversion into vitamin A.

  9. A novel phoswich imaging detector for simultaneous beta and coincidence-gamma imaging of plant leaves.

    PubMed

    Wu, Heyu; Tai, Yuan-Chuan

    2011-09-07

    To meet the growing demand for functional imaging technology for use in studying plant biology, we are developing a novel technique that permits simultaneous imaging of escaped positrons and coincidence gammas from annihilation of positrons within an intake leaf. The multi-modality imaging system will include two planar detectors: one is a typical PET detector array and the other is a phoswich imaging detector that detects both beta and gamma. The novel phoswich detector is made of a plastic scintillator, a lutetium oxyorthosilicate (LSO) array, and a position sensitive photomultiplier tube (PS-PMT). The plastic scintillator serves as a beta detector, while the LSO array serves as a gamma detector and light guide that couples scintillation light from the plastic detector to the PMT. In our prototype, the PMT signal was fed into the Siemens QuickSilver electronics to achieve shaping and waveform sampling. Pulse-shape discrimination based on the detectors' decay times (2.1 ns for plastic and 40 ns for LSO) was used to differentiate beta and gamma events using the common PMT signals. Using our prototype phoswich detector, we simultaneously measured a beta image and gamma events (in single mode). The beta image showed a resolution of 1.6 mm full-width-at-half-maximum using F-18 line sources. Because this shows promise for plant-scale imaging, our future plans include development of a fully functional simultaneous beta-and-coincidence-gamma imager with sub-millimeter resolution imaging capability for both modalities.

  10. Micellarization and intestinal cell uptake of beta-carotene and lutein from drumstick (Moringa oleifera) leaves.

    PubMed

    Pullakhandam, Raghu; Failla, Mark L

    2007-06-01

    The leaves and pods of the drumstick tree are used as food and medicine in some Asian and African countries. Although relatively high concentrations of beta-carotene and lutein have been reported in the leaves, the bioavailability of these carotenoids from this source is unknown. We have analyzed the digestive stability and bioaccessibility of carotenoids in fresh and lyophilized drumstick leaves using the coupled in vitro digestion/Caco-2 cell model. Beta-carotene and lutein were stable during simulated gastric and small intestinal digestion. The efficiency of micellarization of lutein during the small intestinal phase of digestion exceeded that of beta-carotene. Addition of peanut oil (5% vol/wt) to the test food increased micellarization of both carotenoids, and particularly beta-carotene. Caco-2 cells accumulated beta-carotene and lutein from micelles generated during digestion of drumstick leaves in a time- and concentration-dependent manner. The relatively high bioaccessibility of beta-carotene and lutein from drumstick leaves ingested with oil supports the potential use of this plant food for improving vitamin A nutrition and perhaps delaying the onset of some degenerative diseases such as cataracts.

  11. Peroxisomal beta-oxidation activities and gamma-decalactone production by the yeast Yarrowia lipolytica.

    PubMed

    Pagot, Y; Le Clainche, A; Nicaud, J M; Wache, Y; Belin, J M

    1998-03-01

    gamma-Decalactone is a peachy aroma compound resulting from the peroxisomal beta-oxidation of ricinoleic acid by yeasts. The expression levels of acyl-CoA oxidase (gene deletion) and 3-ketoacyl-CoA thiolase activities (gene amplification on replicative plasmids) were modified in the yeast Yarrowia lipolytica. The effects of these modifications on beta-oxidation were measured. Overexpression of thiolase activity did not have any effect on the overall beta-oxidation activity. The disruption of one of the acyl-CoA oxidase genes resulted in an enhanced activity. The enhancement led to an increase of overall beta-oxidation activity but reduced the gamma-decalactone production rates. This seemed to indicate a non-rate-limiting role for beta-oxidation in the biotransformation of ricinoleic acid to gamma-decalactone by the yeast Yarrowia lipolytica. All strains produced and then consumed gamma-decalactone. We checked the ability of the different strains to consume gamma-decalactone in a medium containing the lactone as sole carbon source. The consumption of the strain overexpressing acyl-CoA oxidase activity was higher than that of the wild-type strain. We concluded that peroxisomal beta-oxidation is certainly involved in gamma-decalactone catabolism by the yeast Y. lipolytica. The observed production rates probably depend on an equilibrium between production and consumption of the lactone.

  12. A novel phoswich imaging detector for simultaneous beta and coincidence-gamma imaging of plant leaves

    NASA Astrophysics Data System (ADS)

    Wu, Heyu; Tai, Yuan-Chuan

    2011-09-01

    To meet the growing demand for functional imaging technology for use in studying plant biology, we are developing a novel technique that permits simultaneous imaging of escaped positrons and coincidence gammas from annihilation of positrons within an intake leaf. The multi-modality imaging system will include two planar detectors: one is a typical PET detector array and the other is a phoswich imaging detector that detects both beta and gamma. The novel phoswich detector is made of a plastic scintillator, a lutetium oxyorthosilicate (LSO) array, and a position sensitive photomultiplier tube (PS-PMT). The plastic scintillator serves as a beta detector, while the LSO array serves as a gamma detector and light guide that couples scintillation light from the plastic detector to the PMT. In our prototype, the PMT signal was fed into the Siemens QuickSilver electronics to achieve shaping and waveform sampling. Pulse-shape discrimination based on the detectors' decay times (2.1 ns for plastic and 40 ns for LSO) was used to differentiate beta and gamma events using the common PMT signals. Using our prototype phoswich detector, we simultaneously measured a beta image and gamma events (in single mode). The beta image showed a resolution of 1.6 mm full-width-at-half-maximum using F-18 line sources. Because this shows promise for plant-scale imaging, our future plans include development of a fully functional simultaneous beta-and-coincidence-gamma imager with sub-millimeter resolution imaging capability for both modalities.

  13. Engineered Mononuclear Variants in Bacillus cereus Metallo-beta-lactamase BcII Are Inactive

    SciTech Connect

    Abriata,L.; Gonzalez, L.; Llarrull, L.; Tomatis, P.; Myers, W.; Costello, A.; Tierney, D.; Vila, A.

    2008-01-01

    Metallo-{beta}-lactamases (M{beta}Ls) are zinc enzymes able to hydrolyze almost all {beta}-lactam antibiotics, rendering them inactive, at the same time endowing bacteria high levels of resistance. The design of inhibitors active against all classes of M{beta}Ls has been hampered by their structural diversity and by the heterogeneity in metal content in enzymes from different sources. BcII is the metallo-{beta}-lactamase from Bacillus cereus, which is found in both the mononuclear and dinuclear forms. Despite extensive studies, there is still controversy about the nature of the active BcII species. Here we have designed two mutant enzymes in which each one of the metal binding sites was selectively removed. Both mutants were almost inactive, despite preserving most of the structural features of each metal site. These results reveal that neither site isolated in the M{beta}L scaffold is sufficient to render a fully active enzyme. This suggests that only the dinuclear species is active or that the mononuclear variants can be active only if aided by other residues that would be metal ligands in the dinuclear species.

  14. LOW HORIZONTAL BETA FUNCTION IN LONG STRAIGHTS OF THE NSLS-II LATTICE

    SciTech Connect

    Fanglei, L.; Bengtsson, J.; Guo, W.; Krinsky, S.; Li, Y.; Yang, L.

    2011-03-28

    The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 short straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this paper, we explore the possibility of maintaining three long straights with large horizontal beta function while providing the other 12 long straights with smaller horizontal beta function to optimize the brightness of insertion devices. Our study considers the possible linear lattice solutions as well as characterizing the nonlinear dynamics. Results are reported on optimization of dynamic aperture required for good injection efficiency and adequate Touschek lifetime. This paper discusses dynamic aperture optimization for the NSLS-II lattice with alternate high and low horizontal beta function in the long straights, which is proposed for the optimization of the brightness of insertion devices. The linear optics is optimized to meet the requirements of lattice function and source properties. Nonlinear optimization for a lattice with working point at (37.18, 16.2) is performed. Considering the realistic magnets errors and physical apertures, we calculate the frequency maps and plot the tune footprint. The results show that the lattice with high-low beta function has adequate dynamic aperture for good injection efficiency and sufficient Touschek lifetime.

  15. beta-subunits of Snf1 kinase are required for kinase function and substrate definition.

    PubMed

    Schmidt, M C; McCartney, R R

    2000-09-15

    The Snf1 kinase and its mammalian homolog, the AMP-activated protein kinase, are heterotrimeric enzymes composed of a catalytic alpha-subunit, a regulatory gamma-subunit and a beta-subunit that mediates heterotrimer formation. Saccharomyces cerevisiae encodes three beta-subunit genes, SIP1, SIP2 and GAL83. Earlier studies suggested that these subunits may not be required for Snf1 kinase function. We show here that complete and precise deletion of all three beta-subunit genes inactivates the Snf1 kinase. The sip1Delta sip2Delta gal83Delta strain is unable to derepress invertase, grows poorly on alternative carbon sources and fails to direct the phosphorylation of the Mig1 and Sip4 proteins in vivo. The SIP1 sip2Delta gal83Delta strain manifests a subset of Snf phenotypes (Raf(+), Gly(-)) observed in the snf1Delta 10 strain (Raf(-), Gly(-)), suggesting that individual beta-subunits direct the Snf1 kinase to a subset of its targets in vivo. Indeed, deletion of individual beta-subunit genes causes distinct differences in the induction and phosphorylation of Sip4, strongly suggesting that the beta-subunits play an important role in substrate definition.

  16. Granulocytes of reptilian sauropsids contain beta-defensin-like peptides: a comparative ultrastructural survey.

    PubMed

    Alibardi, Lorenzo

    2013-08-01

    The ability of lizards to withstand infections after wounding or amputation of the tail or limbs has suggested the presence of antimicrobial peptides in their tissues. Previous studies on the lizard Anolis carolinensis have identified several beta-defensin-like peptides that may potentially be involved in protection from infections. The present ultrastructural immunocytochemical study has analyzed tissues in different reptilian species in order to localize the cellular source of one of the more expressed beta-defensins previously sequenced in lizard indicated as AcBD15. Beta-defensin-like immunoreactivity is present in some of the larger, nonspecific granules of granulocytes in two lizard species, a snake, the tuatara, and a turtle. The ultrastructural study indicates that only heterophilic and basophilic granulocytes contain this defensin while other cell types from the epidermis, mesenchyme, and dermis, muscles, nerves, cartilage or bone are immunonegative. The study further indicates that not all granules in reptilian granulocytes contain the beta-defensin peptide, suggesting the presence of granules with different content as previously indicated for mammalian neutrophilic leucocytes. No immunolabeling was instead observed in granulocytes of the alligator and chick using this antibody. The present immunocytochemical observations suggest a broad cross-reactivity and conservation of beta-defensin-like sequence or steric motif across lepidosaurians and likely in turtles while archosaurian granulocytes may contain different beta-defensin-like or other peptides. Copyright © 2013 Wiley Periodicals, Inc.

  17. ION SOURCE

    DOEpatents

    Martina, E.F.

    1958-04-22

    An improved ion source particularly adapted to provide an intense beam of ions with minimum neutral molecule egress from the source is described. The ion source structure includes means for establishing an oscillating electron discharge, including an apertured cathode at one end of the discharge. The egress of ions from the source is in a pencil like beam. This desirable form of withdrawal of the ions from the plasma created by the discharge is achieved by shaping the field at the aperture of the cathode. A tubular insulator is extended into the plasma from the aperture and in cooperation with the electric fields at the cathode end of the discharge focuses the ions from the source,

  18. Purification of an isoflavonoid 7-O-beta-apiosyl-glucoside beta-glycosidase and its substrates from Dalbergia nigrescens Kurz.

    PubMed

    Chuankhayan, Phimonphan; Hua, Yanling; Svasti, Jisnuson; Sakdarat, Santi; Sullivan, Patrick A; Ketudat Cairns, James R

    2005-08-01

    A beta-glycosidase was purified from the seeds of Dalbergia nigescens Kurz based on its ability to hydrolyse p-nitrophenyl beta-glucoside and beta-fucoside. This enzyme did not hydrolyze various glycosidic substrates efficiently, so it was used to identify its own natural substrates. Two substrates were identified, isolated and their structures determined as: compound 1, dalpatein 7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside and compound 2, 6,2',4',5'-tetramethoxy-7-hydroxy-7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (dalnigrein7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside). The beta-glycosidase removes the sugar from these glycosides as a disaccharide, despite its initial identification as a beta-glucosidase and beta-fucosidase.

  19. The Evaluation of the 0.07 and 3 mm Dose Equivalent with a Portable Beta Spectrometer

    NASA Astrophysics Data System (ADS)

    Hoshi, Katsuya; Yoshida, Tadayoshi; Tsujimura, Norio; Okada, Kazuhiko

    Beta spectra of various nuclide species were measured using a commercially available compact spectrometer. The shape of the spectra obtained via the spectrometer was almost similar to that of the theoretical spectra. The beta dose equivalent at any depth was obtained as a product of the measured pulse height spectra and the appropriate conversion coefficients of ICRP Publication 74. The dose rates evaluated from the spectra were comparable with the reference dose rates of standard beta calibration sources. In addition, we were able to determine the dose equivalents with a relative error of indication of 10% without the need for complicated correction.

  20. Sequence swapping does not result in conformation swapping for the beta4/beta5 and beta8/beta9 beta-hairpin turns in human acidic fibroblast growth factor.

    PubMed

    Kim, Jaewon; Lee, Jihun; Brych, Stephen R; Logan, Timothy M; Blaber, Michael

    2005-02-01

    The beta-turn is the most common type of nonrepetitive structure in globular proteins, comprising ~25% of all residues; however, a detailed understanding of effects of specific residues upon beta-turn stability and conformation is lacking. Human acidic fibroblast growth factor (FGF-1) is a member of the beta-trefoil superfold and contains a total of five beta-hairpin structures (antiparallel beta-sheets connected by a reverse turn). beta-Turns related by the characteristic threefold structural symmetry of this superfold exhibit different primary structures, and in some cases, different secondary structures. As such, they represent a useful system with which to study the role that turn sequences play in determining structure, stability, and folding of the protein. Two turns related by the threefold structural symmetry, the beta4/beta5 and beta8/beta9 turns, were subjected to both sequence-swapping and poly-glycine substitution mutations, and the effects upon stability, folding, and structure were investigated. In the wild-type protein these turns are of identical length, but exhibit different conformations. These conformations were observed to be retained during sequence-swapping and glycine substitution mutagenesis. The results indicate that the beta-turn structure at these positions is not determined by the turn sequence. Structural analysis suggests that residues flanking the turn are a primary structural determinant of the conformation within the turn.

  1. Influence of food acidulants and antioxidant spices on the bioaccessibility of beta-carotene from selected vegetables.

    PubMed

    Veda, Supriya; Platel, Kalpana; Srinivasan, Krishnapura

    2008-09-24

    Four common food acidulants--amchur, lime, tamarind, and kokum--and two antioxidant spices--turmeric and onion--were examined for their influence on the bioaccessibility of beta-carotene from two fleshy and two leafy vegetables. Amchur and lime generally enhanced the bioaccessibility of beta-carotene from these test vegetables in many instances. Such an improved bioaccessibility was evident in both raw and heat-processed vegetables. The effect of lime juice was generally more pronounced than that of amchur. Turmeric significantly enhanced the bioaccessibility of beta-carotene from all of the vegetables tested, especially when heat-processed. Onion enhanced the bioaccessibility of beta-carotene from pressure-cooked carrot and amaranth leaf and from open-pan-boiled pumpkin and fenugreek leaf. Lime juice and the antioxidant spices turmeric and onion minimized the loss of beta-carotene during heat processing of the vegetables. In the case of antioxidant spices, improved bioaccessibility of beta-carotene from heat-processed vegetables is attributable to their role in minimizing the loss of this provitamin. Lime juice, which enhanced the bioaccessibility of this provitamin from both raw and heat-processed vegetables, probably exerted this effect by some other mechanism in addition to minimizing the loss of beta-carotene. Thus, the presence of food acidulants (lime juice/amchur) and antioxidant spices (turmeric/onion) proved to be advantageous in the context of deriving maximum beta-carotene from the vegetable sources.

  2. Bacterial infection of osteoblasts induces interleukin-1beta and interleukin-18 transcription but not protein synthesis.

    PubMed

    Marriott, Ian; Hughes, Francis M; Bost, Kenneth L

    2002-10-01

    A growing body of evidence has shown that bacterially challenged bone-forming osteoblasts are a significant source of an array of cytokines and chemokines that can support immune responses during bone disease. In the present study, Staphylococcus aureus and Salmonella, two common pathogens of bone, were investigated for their ability to induce production of two related inflammatory cytokines, interleukin-1beta (IL-1beta) and IL18, in osteoblasts. Cultured mouse osteoblasts were found to respond rapidly to either bacterial challenge by upregulation in the levels of mRNA encoding both IL-1beta and IL-18. Surprisingly, this mRNA expression did not translate into intracellular accumulation of IL-1beta or IL-18 precursor proteins or secretion of mature cytokines, despite the presence of detectable caspase-1 activity in these cells. These studies demonstrate that although osteoblasts can secrete a number of key proinflammatory mediators in response to bacterial pathogens, IL-1beta and IL-18 are not among this number. We suggest that osteoblasts are an unlikely source of these cytokines during the progression of bacterial infection of bone.

  3. Isolation of beta-mannanase from Cocos nucifera Linn haustorium and its application in the depolymerization of beta-(1,4)-linked D-mannans.

    PubMed

    Soumya, Rema S; Abraham, Emilia T

    2010-05-01

    Beta-mannanase was extracted from coconut (Cocos nucifera Linn) haustorium and purified through ammonium sulfate precipitation and sepharose 6B-lectin affinity chromatography. Coconut beta-mannanase is an acidic protein with a pI of 3.75. The molecular mass of coconut beta-mannanase (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) was found to be 44 kDa and was confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The optimum temperature and pH for enzyme activity was 70 degrees C and 5.2. The enzyme was used for the preparation of neutraceutical dietary supplement from galactomannans of guar gum and tender coconut kernel having a beta-(1,4)-linked D-mannose backbone. Depolymerized guar gum has 92% of oligosaccharides with a degree of polymerization of 3 and 7. Tender coconut kernel has a degree of polymerization of 9-39 oligosaccharides along with disaccharides and trisaccharides. Hence this mannanase will be useful to depolymerize beta-(1,4)-linked D-mannose polysaccharides from most plant sources to produce prebiotics in a cost-effective technique.

  4. Resistance exercise decreases beta-endorphin immunoreactivity.

    PubMed Central

    Pierce, E F; Eastman, N W; McGowan, R W; Tripathi, H; Dewey, W L; Olson, K G

    1994-01-01

    Previous research investigating the response of plasma beta-endorphins (beta-EP) to resistance exercise has resulted in equivocal findings. To examine further the effects of resistance exercise on beta-EP immunoreactivity, 10 male and 10 female college-age students participated in a series of controlled isotonic resistance exercises. The session consisted of three sets of eight repetitions at 80% of one repetition maximum (1-RM) for each of the following exercises: (1) bench press; (2) lateral pull-downs; (3) seated arm curls; and (4) military press. Blood plasma was sampled both before and after the lifting routine and beta-endorphin levels were determined by radioimmunoassay. A Students t test for paired samples indicated that mean(s.e.) plasma beta-endorphin levels after exercise (10.5(1.3) pg beta-EP ml-1) were significantly decreased as compared with pre-exercise (control) levels (16.5(1.2), P < 0.05). While the mechanism(s) contributing to the decrease in immunoreactivity is unclear, it may be the result of the synergistic effect of beta-EP clearance during rest intervals and changes in psychological states between sampling. PMID:8000813

  5. Latent TGF-[beta] structure and activation

    SciTech Connect

    Shi, Minlong; Zhu, Jianghai; Wang, Rui; Chen, Xing; Mi, Lizhi; Walz, Thomas; Springer, Timothy A.

    2011-09-16

    Transforming growth factor (TGF)-{beta} is stored in the extracellular matrix as a latent complex with its prodomain. Activation of TGF-{beta}1 requires the binding of {alpha}v integrin to an RGD sequence in the prodomain and exertion of force on this domain, which is held in the extracellular matrix by latent TGF-{beta} binding proteins. Crystals of dimeric porcine proTGF-{beta}1 reveal a ring-shaped complex, a novel fold for the prodomain, and show how the prodomain shields the growth factor from recognition by receptors and alters its conformation. Complex formation between {alpha}v{beta}6 integrin and the prodomain is insufficient for TGF-{beta}1 release. Force-dependent activation requires unfastening of a 'straitjacket' that encircles each growth-factor monomer at a position that can be locked by a disulphide bond. Sequences of all 33 TGF-{beta} family members indicate a similar prodomain fold. The structure provides insights into the regulation of a family of growth and differentiation factors of fundamental importance in morphogenesis and homeostasis.

  6. Beta adrenoceptors and regenerating corneal epithelium.

    PubMed

    Liu, G S; Trope, G E; Basu, P K

    1990-01-01

    Beta blockers inhibit corneal re-epithelialization. This may be due to beta-2 receptor controlled mechanisms. To investigate this possibility we performed a randomized, double-masked study involving 60 rabbit iatrogenic induced corneal ulcers produced with iodine vapour. Two beta specific drug compounds were tested, namely, betaxolol hydrochloride 0.25% (Alcon) (beta 1) and L132-468 (Sandoz, Basel) 0.25% (beta 2), and phosphate-buffered solution (PBS) as control. There was no statistical difference in the wound healing rates among all groups at 24 hours but there were significant differences at 48 hours (p less than 0.01). At 72 hours, the L132-468 treated groups showed significantly less healing than the betaxolol hydrochloride treated group. The PBS-treated group was healed at this time. By 20th post burning day, SEM revealed that betaxolol hydrochloride treated corneas were completely healed with normal epithelial microvilli. The L132-468 treated corneas were also healed but desquamation and abnormal cells were observed. In conclusion, beta-2 blockers inhibit corneal re-epithelialization more potently than beta-1 blockers.

  7. BACE2, a beta -secretase homolog, cleaves at the beta site and within the amyloid-beta region of the amyloid-beta precursor protein.

    PubMed

    Farzan, M; Schnitzler, C E; Vasilieva, N; Leung, D; Choe, H

    2000-08-15

    Production of amyloid-beta protein (Abeta) is initiated by a beta-secretase that cleaves the Abeta precursor protein (APP) at the N terminus of Abeta (the beta site). A recently identified aspartyl protease, BACE, cleaves the beta site and at residue 11 within the Abeta region of APP. Here we show that BACE2, a BACE homolog, cleaves at the beta site and more efficiently at a different site within Abeta. The Flemish missense mutation of APP, implicated in a form of familial Alzheimer's disease, is adjacent to this latter site and markedly increases Abeta production by BACE2 but not by BACE. BACE and BACE2 respond identically to conservative beta-site mutations, and alteration of a common active site Arg inhibits beta-site cleavage but not cleavage within Abeta by both enzymes. These data suggest that BACE2 contributes to Abeta production in individuals bearing the Flemish mutation, and that selective inhibition of these highly similar proteases may be feasible and therapeutically advantageous.

  8. Significance of alpha 9 beta 1 and alpha v beta 6 integrin expression in breast carcinoma.

    PubMed

    Arihiro, K; Kaneko, M; Fujii, S; Inai, K; Yokosaki, Y

    2000-01-01

    Both alpha 9 beta 1 and alpha v beta 6 integrins have been newly identified from the tracheal epithelium of guinea pig. It has been pointed out that alpha 9 beta 1 functions as a receptor for tenascin-C and osteopontin. As for the ligands of alpha v beta 6, fibronectin and tenascin-C have been identified. It has not been ascertained whether alpha 9 beta 1 and alpha v beta 6 are expressed in normal breast tissue, benign breast lesion or breast carcinoma. Immunohistochemical staining for alpha 9 beta 1 and alpha v beta 6 was performed in benign breast lesion and breast carcinoma specimens. Western blotting was carried out on 11 breast carcinoma cases. alpha 9 beta 1 was expressed in the cytoplasm of carcinoma cells in 23 of 90 cases (26%) and alpha v beta 6 in the membrane of carcinoma cells in 16 of 90 cases (18%). However, these findings of alpha 9 beta 1 and alpha v beta 6 did not correlate with any clinicopathological factors including the patients' age, tumor size, histological type of carcinoma, location of carcinoma cells and hormone receptor status. With regard to the histological grade of carcinoma, alpha v beta 6 and alpha 9 beta 1 expression did not statistically correlate, although no expression of alpha v beta 6 was observed in 14 cases of Grade I. On Western-blott analysis strong and weak bands consistent with alpha v beta 6 were noted in the membrane fraction extracted from breast carcinoma cells. On the other hand weak bands consistent with alpha 9 subunit were noted in the whole cell lysates of breast carcinoma cells and very weak or no bands consistent with alpha 9 subunit were noted in the membrane fraction extracted from the breast carcinoma cells. Significance of alpha 9 beta 1 and alpha v beta 6 integrins expression in breast carcinoma was still unknown on clinicopathological examination. The findings of Western blot analysis may indicate that the transportation system of glycoproteins such as integrins to the cell membrane of carcinoma cells is

  9. Serum alpha- and beta-carotene concentrations qualitatively respond to sustained carrot feeding.

    PubMed

    Tanumihardjo, Sherry A; Horvitz, Micah A; Dosti, Mandy Porter; Simon, Philipp W

    2009-11-01

    Beta-carotene is a predominant source of vitamin A in developing countries. Genetically selected "high carotene" carrots could have an impact on the vitamin A and antioxidant status of people if widely adopted. A 3 x 3 crossover study in humans (n = 10) evaluated the difference in uptake and clearance of alpha- and beta-carotene from carrots genetically selected and traditionally bred to have high, typical, or no carotene. Subjects were fed white (0 mg alpha- and beta-carotene/d), orange (1.8 mg alpha-carotene and 2.6 mg beta-carotene/d), or dark-orange (4 mg alpha-carotene and 7 mg beta-carotene/d) carrots in muffins for 11 d, with a 10-d washout phase between treatments. Serum carotenoid and retinol concentrations were measured by HPLC. C-reactive protein (CRP), an indicator of underlying inflammation or infection which may lower serum retinol, was measured at the beginning of each period. A significant treatment effect occurred for serum alpha- and beta-carotene concentrations (P < 0.001), and a trend towards a negative effect of subjects' BMI on concentrations (P= 0.08). A significant treatment by sequence interaction was observed (P = 0.038), which was attributable to a difference in serum alpha- and beta-carotene concentrations between carrot treatments in the first period. Serum retinol remained stable for the first 20 d of the intervention and then decreased (P = 0.02). CRP was not elevated in any subject. High carotene carrots provide more provitamin A carotenoids than the typical store-bought variety, without a change in flavor. The availability of high carotene carrots could readily increase consumption of beta-carotene and potentially impact the vitamin A status of those individuals who are deficient or at risk of depletion.

  10. Bioinformatics Knowledge Map for Analysis of Beta-Catenin Function in Cancer

    PubMed Central

    Arighi, Cecilia N.; Wu, Cathy H.

    2015-01-01

    Given the wealth of bioinformatics resources and the growing complexity of biological information, it is valuable to integrate data from disparate sources to gain insight into the role of genes/proteins in health and disease. We have developed a bioinformatics framework that combines literature mining with information from biomedical ontologies and curated databases to create knowledge “maps” of genes/proteins of interest. We applied this approach to the study of beta-catenin, a cell adhesion molecule and transcriptional regulator implicated in cancer. The knowledge map includes post-translational modifications (PTMs), protein-protein interactions, disease-associated mutations, and transcription factors co-activated by beta-catenin and their targets and captures the major processes in which beta-catenin is known to participate. Using the map, we generated testable hypotheses about beta-catenin biology in normal and cancer cells. By focusing on proteins participating in multiple relation types, we identified proteins that may participate in feedback loops regulating beta-catenin transcriptional activity. By combining multiple network relations with PTM proteoform-specific functional information, we proposed a mechanism to explain the observation that the cyclin dependent kinase CDK5 positively regulates beta-catenin co-activator activity. Finally, by overlaying cancer-associated mutation data with sequence features, we observed mutation patterns in several beta-catenin PTM sites and PTM enzyme binding sites that varied by tissue type, suggesting multiple mechanisms by which beta-catenin mutations can contribute to cancer. The approach described, which captures rich information for molecular species from genes and proteins to PTM proteoforms, is extensible to other proteins and their involvement in disease. PMID:26509276

  11. 10 CFR 39.35 - Leak testing of sealed sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Leak testing of sealed sources. 39.35 Section 39.35 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39... form; (4) Sources of beta- or gamma-emitting radioactive material with an activity of 3.7 MBq or less...

  12. 10 CFR 39.35 - Leak testing of sealed sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Leak testing of sealed sources. 39.35 Section 39.35 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39... form; (4) Sources of beta- or gamma-emitting radioactive material with an activity of 3.7 MBq or less...

  13. Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

    SciTech Connect

    Feng, Ying; Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min; Sun, Gui-yuan; Liu, Rui-tian

    2009-12-25

    Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

  14. Evidence for Novel [beta]-Sheet Structures in Iowa Mutant [beta]-Amyloid Fibrils

    SciTech Connect

    Tycko, Robert; Sciarretta, Kimberly L.; Orgel, Joseph P.R.O.; Meredith, Stephen C.

    2009-07-24

    Asp23-to-Asn mutation within the coding sequence of {beta}-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-A{beta}40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-A{beta}40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10{sup -3} min{sup -1} and 1.07 x 10{sup -4} min{sup -1} for D23N-A{beta}40 and the wild-type peptide WT-A{beta}40, respectively) and without a lag phase. Electron microscopy shows that D23N-A{beta}40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-{beta} pattern, with a sharp reflection at 4.7 {angstrom} and a broad reflection at 9.4 {angstrom}, which is notably smaller than the value for WT-A{beta}40 fibrils (10.4 {angstrom}). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-A{beta}40 fibrils containing the in-register, parallel {beta}-sheet structure commonly found in WT-A{beta}40 fibrils and most other amyloid fibrils. Antiparallel {beta}-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through 13C-13C and 15N-13C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-A{beta}40 fibrils and the unusual vasculotropic clinical picture in these patients.

  15. Comparison of the apoptotic processes induced by the oxysterols 7beta-hydroxycholesterol and cholesterol-5beta,6beta-epoxide.

    PubMed

    Ryan, L; O'Callaghan, Y C; O'Brien, N M

    2004-09-01

    Oxysterols have been shown to induce apoptosis in a variety of cell lines. The mechanism of oxysterol-induced apoptosis is mainly known at the post-mitochondrial level. The aim of the present study was to compare the pathway of apoptosis induced by the oxysterols 7beta-hydroxycholesterol (7beta-OH) and cholesterol-5beta,6beta-epoxide (beta-epoxide) in U937 cells. To this end, we employed a range of inhibitors of apoptosis; a broad-spectrum caspase inhibitor, a specific caspase-3 inhibitor and an inhibitor of cytochrome c release and the antioxidants; trolox, ebselen and resveratrol. The three inhibitors of apoptosis prevented cell death induced by 7beta-OH; however, in beta-epoxide-treated cells, the inhibitor of cytochrome c release did not protect against apoptosis. The cellular antioxidant glutathione was depleted in 7beta-OH-treated cells but not in cells incubated with beta-epoxide. Trolox, a water-soluble synthetic analogue of alpha-tocopherol, prevented 7beta-OH-induced apoptosis but did not protect against cell death induced by beta-epoxide. Ebselen and resveratrol did not protect U937 cells against apoptosis induced by either 7beta-OH or beta-epoxide. Our results suggest that differences occur in the pathways of apoptosis induced by 7beta-OH and beta-epoxide in U937 cells.

  16. Single Molecule Source Reagents for Chemical Vapor Deposition of B- Silicon Carbide

    DTIC Science & Technology

    1992-12-10

    vapor deposition of stoichiometric Beta silicon carbide . Four single molecule sources were synthesized, their decomposition pathways studied, and their...utility in Beta- silicon carbide CVD investigated. Dramatic differences in the CVD process resulted from small changes in the reagent structure. A...strained cyclic molecule, 1,3-disilacyclobutane, allowed growth of a Beta- silicon carbide film at a temperature >300 deg C lower than was possible with a

  17. Light Source

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

  18. Fabrication of thin layer beta alumina

    NASA Technical Reports Server (NTRS)

    Tennenhouse, G. J.

    1977-01-01

    Beta alumina tubes having walls 700 microns, 300 microns, and 140 microns were processed by extrusion and sintering utilizing Ford proprietary binder and fabrication systems. Tubes prepared by this method have properties similar to tubes prepared by isostatic pressing and sintering, i.e. density greater than 98% of theoretical and a helium leak rate less than 3 x 10 to the -9th power cc/sq cm/sec. Ford ultrasonic bonding techniques were used for bonding beta alumina end caps to open ended beta -alumina tubes prior to sintering. After sintering, the bond was hermetic, and the integrity of the bonded area was comparable to the body of the tube.

  19. Syntheses of stable isotope-labeled 6 beta-hydroxycortisol, 6 beta-hydroxycortisone, and 6 beta-hydroxytestosterone.

    PubMed

    Furuta, Takashi; Suzuki, Atsushi; Matsuzawa, Mitsuhiro; Shibasaki, Hiromi; Kasuya, Yasuji

    2003-09-01

    A method is described for the preparation of two types of multi-labeled 6 beta-hydroxycortisol containing either five deuterium atoms at C-19 methyl and C-1 methylene or four 13C atoms at C-1, C-2, C-4, and C-19 in addition to the five deuterium atoms for use as analytical internal standards for gas chromatography-mass spectrometry (GC-MS). BMD derivatives of [1,1,19,19,19-2H(5)]cortisone and [1,2,4,19-13C(4),1,1,19,19,19-2H(5)]cortisone (cortisone-2H(5)-BMD and cortisone-13C(4),2H(5)-BMD) were first synthesized via indan synthon method starting from optical active 11-oxoindanylpropionic acid and labeled isopropenyl anion ([1,1,3,3,3-2H(5)]- or [1,3-13C(2),1,1,3,3,3-2H(5)]isopropenyl anion). The labeled isopropenyl anion was prepared from commercially available [1,1,1,3,3,3-2H(6)]- or [1,3-13C(2),1,1,1,3,3,3-2H(6)]acetone. Ultraviolet (UV) irradiated autoxidation at C-6 position of 3-ethyl-3,5-dienol ether derivatives of the labeled cortisone-BMDs gave 6 beta-hydroxy-[1,1,19,19,19-2H(5)]cortisone-BMD and 6 beta-hydroxy-[1,2,4,19-13C(4),1,1,19,19,19-2H(5)]cortisone-BMD, respectively, as a mixture of 6 beta- and 6 alpha-epimers in a ratio of 4:1. Separation of 6 beta- and 6 alpha-epimers by thin-layer chromatography (TLC) and subsequent hydrolysis of the BMD group at C-17 gave pure labeled 6 beta-hydroxycortisone. After protecting the keto group at C-3 of the labeled 6 beta-hydroxycortisone-BMD as semicarbazone, reduction of 11-keto group with NaBH(4) and subsequent removal of the C-3 and C-17 protecting groups gave 6beta-hydroxy-[1,1,19,19,19-2H(5)]cortisol (6 beta-hydroxycortisol-2H(5)) and 6 beta-hydroxy-[1,2,4,19-13C(4),1,1,19,19,19-2H(5)]cortisol (6 beta-hydroxycortisol-13C(4),2H(5)), respectively, as a mixture of 6 beta- and 6 alpha-epimers (6 beta:6 alpha=4.4:1). The isotopic compositions of 6 beta-hydroxycortisol-2H(5) and 6 beta-hydroxycortisol-13C(4),2H(5) were 90.9 and 92.1 at.%, respectively. Furthermore, 6 beta-hydroxy-[1 alpha,16,16,17 alpha-2H(4

  20. Proton Source for Characterizing and Testing Charged Particle Silicon Detectors

    NASA Astrophysics Data System (ADS)

    Bass, Kevin

    2016-09-01

    Improvements in experimental design and equipment have increased our capability for future neutron beta decay measurements. The upcoming experiments have the potential to test the Standard Model at the same level as the superallowed nuclear beta decay measurements but without the need for nuclear corrections. Part of the improvement comes from new large-area pixelated silicon detector technology. The precision and accuracy that is demanded by the neutron beta decay experiments require detailed characterization of the detectors. Such characterization can be achieved using a low current, variable energy proton beam. The design and simulation of a proton beam from source through accelerator will be presented. University of Tennessee Physics Summer Fellowship.

  1. Beta-human chorionic gonadotropin producing osteosarcoma of the sacrum in a 26-year-old woman: a case report and review of the literature.

    PubMed

    Glass, Ryan; Asirvatham, Jaya Ruth; Kahn, Leonard; Aziz, Mohamed

    2015-01-01

    Ectopic secretion of beta-human chorionic gonadotropin is considered a poor prognostic marker in epithelial tumors. However, very few cases have been reported in sarcomas. We present the case of a 26-year-old female who presented with a metastatic osteosarcoma. She underwent usual testing prior to starting treatment and was found to have elevated levels of beta-human chorionic gonadotropin. As the patient was not pregnant, another source of beta-human chorionic gonadotropin secretion had to be considered. The tumor cells demonstrated positive staining for beta-human chorionic gonadotropin by immunohistochemistry, and serum levels of beta-human chorionic gonadotropin were used to monitor tumor progression and response to chemotherapy. We review the literature and discuss a potential role of beta-human chorionic gonadotropin in the treatment of such patients.

  2. Energetic, Structural, and Antimicrobial Analyses of [beta]-Lactam Side Chain Recognition by [beta]-Lactamases

    SciTech Connect

    Caselli, E.; Powers, R.A.; Blaszczak, L.C.; Wu, C.Y.E.; Prati, F.; Shoichet, B.K.

    2010-03-05

    Penicillins and cephalosporins are among the most widely used and successful antibiotics. The emergence of resistance to these {beta}-lactams, most often through bacterial expression of {beta}-lactamases, threatens public health. To understand how {beta}-lactamases recognize their substrates, it would be helpful to know their binding energies. Unfortunately, these have been difficult to measure because {beta}-lactams form covalent adducts with {beta}-lactamases. This has complicated functional analyses and inhibitor design. To investigate the contribution to interaction energy of the key amide (R1) side chain of {beta}-lactam antibiotics, eight acylglycineboronic acids that bear the side chains of characteristic penicillins and cephalosporins, as well as four other analogs, were synthesized. These transition-state analogs form reversible adducts with serine {beta}-lactamases. Therefore, binding energies can be calculated directly from K{sub i} values. The K{sub i} values measured span four orders of magnitude against the Group I {beta}-lactamase AmpC and three orders of magnitude against the Group II {beta}-lactamase TEM-1. The acylglycineboronic acids have K{sub i} values as low as 20 nM against AmpC and as low as 390 nM against TEM-1. The inhibitors showed little activity against serine proteases, such as chymotrypsin. R1 side chains characteristic of {beta}-lactam inhibitors did not have better affinity for AmpC than did side chains characteristic of {beta}-lactam substrates. Two of the inhibitors reversed the resistance of pathogenic bacteria to {beta}-lactams in cell culture. Structures of two inhibitors in their complexes with AmpC were determined by X-ray crystallography to 1.90 {angstrom} and 1.75 {angstrom} resolution; these structures suggest interactions that are important to the affinity of the inhibitors. Acylglycineboronic acids allow us to begin to dissect interaction energies between {beta}-lactam side chains and {beta}-lactamases. Surprisingly

  3. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  4. Ion Sources

    NASA Astrophysics Data System (ADS)

    Haseroth, Helmut; Hora, Heinrich

    1993-03-01

    Ion sources for accelerators are based on plasma configurations with an extraction system in order to gain a very high number of ions within an appropriately short pulse and of sufficiently high charge number Z for advanced research. Beginning with the duoplasmatron, all established ion sources are based on low-density plasmas, of which the electron beam ionization source (EBIS) and the electron cyclotron resonance (ECR) source are the most advanced; for example they result in pulses of nearly 6 × 108 fully stripped sulfur ions per pulse in the Super Proton Synchrotron (SPS) at CERN with energies of 200 GeV/u. As an example of a forthcoming development, we are reporting about the lead ion source for the same purpose. Contrary to these cases of low-density plasmas, where a rather long time is always necessary to generate sufficiently high charge states, the laser ion source uses very high density plasmas and therefore produced, for example in 1983, single shots of Au51+ ions of high directivity with energies above 300 MeV within 2 ns irradiation time of a gold target with a medium-to-large CO2 laser. Experiments at Dubna and Moscow, using small-size lasers, produced up to one million shots with 1 Hz sequence. After acceleration by a linac or otherwise, ion pulses of up to nearly 5 × 1010 ions of C4+ or Mg12+ with energies in the synchrotrons of up to 2 GeV/u were produced. The physics of the laser generation of the ions is most complex, as we know from laser fusion studies, including non-linear dynamic and dielectric effects, resonances, self-focusing, instabilities, double layers, and an irregular pulsation in the 20 ps range. This explains not only what difficulties are implied with the laser ion source, but also why it opens up a new direction of ion sources.

  5. beta-Adrenergic receptor polymorphisms: relationship to the beta-agonist controversy and clinical implications.

    PubMed

    Taylor, D Robin

    2007-12-01

    Aspects of the 'beta-agonist controversy' have recently re-emerged with the publication of data implicating the long-acting beta-agonist salmeterol in increased mortality from asthma. The reasons underlying the adverse effects of beta2-agonists as a class are unclear. Polymorphisms of the beta2 adrenoceptor (ADRB2), notably the variant associated with an arginine moiety at position 16 of the ADRB2 protein result in changes in in vitro receptor function. There is now consistent clinical evidence showing that, in vivo, patients with asthma harbouring the Arg-16 genotype may experience reduced lung function and an increased frequency of exacerbations when treated with regular short-acting beta-agonists. This may, in part, explain why beta-agonists have been associated with adverse outcomes in the past. ADRB2 genotyping of patients with severe or difficult-to-control asthma may shed light on a possible contributor to their clinical instability.

  6. Experiments on the origin of molecular chirality by parity non-conservation during beta-decay

    NASA Technical Reports Server (NTRS)

    Bonner, W. A.

    1974-01-01

    Experiments are described to test a theory for the origin of optical activity wherein the longitudinally polarized electrons resulting from parity violation during radioactive beta-decay, and their resulting circularly polarized bremsstrahlung, might interact asymmetrically with organic matter to yield optically active products. The historical background to this subject is briefly reviewed. Our experiments involve subjecting a number of racemic and optically active amino acid samples to a beta-radiation source for a period of 1.34 years (total dose: 411 Mrads), then examining them for any asymmetric effects by means of optical rotatory dispersion and analytical gas chromatography.

  7. Enantioselective Ring-Cleavage of meso- Epoxides with beta-Halodiisopinocampheylboranes.

    DTIC Science & Technology

    1988-05-17

    BETA -HALODII~V SO NCL)PDE VLA FAET N BETA HALODIISOPINOC C)PDE V AF AYETTE INfl RICHRRD B IETHERILL LAB N N JOSH! ET AL. 17 NAY 8S UNLSIFIED TR-3...ORGANIZATION j(if applicable) Office of Naval Research ________NOOl 4-86-K-0547 8 c. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS...either (+)- or (-)-ct- pinene . First we examined the reaction between cyclohexene oxide and dlpc 2 BX (the superscript "d" indicates that the reagent

  8. Measurement of the electron antineutrino mass from the beta spectrum of gaseous tritium

    SciTech Connect

    Knapp, D.A.

    1986-12-01

    A measurement has been made of the mass of the electron antineutrino using the beta spectrum from a source of gaseous molecular tritium, and an upper limit of 36 eV/c/sup 2/ has been set on this mass. This measurement is the first upper limit on neutrino mass that does not rely on assumptions about the atomic configuration after the beta decay, and it has significantly smaller systematic errors associated with it than do previous measurements. 130 refs., 83 figs., 8 tabs.

  9. Tracking electrons from double beta decay - How far can you push the TPC?

    NASA Astrophysics Data System (ADS)

    Moe, M. K.; Nelson, M. A.; Vient, M. A.

    New results are reported from time-projection-chamber measurements of the double beta decay of 100Mo and 150Nd. A previously-observed high-energy anomaly has been eliminated by improved energy resolution. Kurie plots of the two-neutrino spectra show end-point energies close to the reported parent-daughter mass differences. The 150Nd source has produced a new direct-counting 90% confidence neutrino-majoron coupling limit of < gν, χ> < 7.0 × 10 -5. The strengths and weaknesses of the TPC, and the feasibility of a larger TPC for neutrinoless double beta decay are discussed.

  10. A Sr-90/Y-90 field calibrator for performance testing of beta-gamma survey instruments

    SciTech Connect

    Olsher, R.H.; Haynie, J.S.

    1988-01-01

    ANSI and regulatory agency guidelines prescribe periodic performance tests for radiation protection instrumentation. Reference readings should be obtained for one point on each scale or decade normally used. A small and lightweight calibrator has been developed that facilitates field testing of beta-gamma survey instruments. The calibrator uses a 45 microcurie Sr-90/Y-90 beta source with a filter wheel to generate variable dose rates in the range from 4 to 400 mrad/hr. Thus, several ranges may be checked by dialing in appropriate filters. The design, use, and typical applications of the calibrator are described.

  11. Experiments on the origin of molecular chirality by parity non-conservation during beta-decay

    NASA Technical Reports Server (NTRS)

    Bonner, W. A.

    1974-01-01

    Experiments are described to test a theory for the origin of optical activity wherein the longitudinally polarized electrons resulting from parity violation during radioactive beta-decay, and their resulting circularly polarized bremsstrahlung, might interact asymmetrically with organic matter to yield optically active products. The historical background to this subject is briefly reviewed. Our experiments involve subjecting a number of racemic and optically active amino acid samples to a beta-radiation source for a period of 1.34 years (total dose: 411 Mrads), then examining them for any asymmetric effects by means of optical rotatory dispersion and analytical gas chromatography.

  12. Beta scaling of transport in microturbulence simulations

    SciTech Connect

    Candy, J.

    2005-07-15

    A systematic study of the beta ({beta}) scaling and spatial structure of thermal and particle transport in gyrokinetic turbulence simulations is presented. Here, {beta} is the ratio of the plasma kinetic pressure to the magnetic pressure. Results show that the nonlinear self-consistent temperature profiles exhibit a (statistically) time-stationary flattening in the vicinity of rational surfaces with a concomitant drop in the electrostatic components of the thermal diffusivity. Simultaneously, the increased magnetic fluctuation amplitude at these surfaces enhances the steady-state electromagnetic (flutter) component of the electron thermal diffusivity. The electromagnetic components of the ion transport coefficients remain close to zero, as expected on theoretical grounds. Only a weak dependence of ion energy transport on {beta} is observed, consistent with recent tokamak experiments [C. C. Petty et al., Phys. Plasmas 11, 2514 (2004)].

  13. Review of modern double beta decay experiments

    SciTech Connect

    Barabash, A. S.

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  14. Optical properties of {beta}-Sn films

    SciTech Connect

    Takeuchi, Katsuki; Adachi, Sadao

    2009-04-01

    Optical properties of white tin ({beta}-Sn) have been investigated using spectroscopic ellipsometry in the photon-energy range between 0.6 and 6.5 eV at room temperature. The {beta}-Sn films are deposited by vacuum evaporation on Si(001) substrates. The structural properties of the films are evaluated by x-ray diffraction and ex situ atomic force microscopy. The measured {epsilon}(E) spectra reveal distinct structures at several interband critical points in the Brillouin zone of {beta}-Sn. These spectra are analyzed on the basis of a simplified model of the interband transitions, including the free-carrier absorption between the filled and empty electronic states. Dielectric-related optical constants, such as the complex refractive index, absorption coefficient, and normal-incidence reflectivity, of bulk {beta}-Sn films are also presented.

  15. [Beta 3 adrenergic receptor polymorphism and obesity].

    PubMed

    Yoshida, T; Umekawa, T

    1998-07-01

    The beta 3-adrenoceptor plays a significant role in the control of lipolysis and thermogenesis in the brown adipose tissue of rodents and humans. In human beta 3-adrenoceptor, a Trp to Arg replacement has recently been discovered. This change which occurs at position 64, in the first coding exon, has been correlated with increased weight gain, difficulty in losing weight, insulin resistance syndrome, and worsened diabetic situation. Higher percentages of this mutation are observed in Pima Indians (over 30%) and Japanese (20%). The possible functional mechanism of Trp54Arg is reported using human HEK293 cell line stably expressing the wild type and the [Arg64] beta 3-adrenoceptor type. Beta 3-adrenoceptor agonists available for humans are been also developing. In this paper we describe these points up-to-date.

  16. A massive neutrino in nuclear beta decay

    SciTech Connect

    Norman, E.B.; Chan, Y. ); da Cruz, M.F. Physics Institute, University of Sao Paulo, Sao Paulo ); Garcia, A. ); Hindi, M.M. Physics Department, Tennessee Technological University, Cookeville, Tennessee ); Lesko, K.T.; Larimer, R.; Stokstad, R.G.; Sur, B. ); Wietfeldt, F.E. Physics Department, University of California, Berkeley, California ); Zlimen, I. (Nuclear Science Division, Lawrence Berke

    1992-02-01

    We have continued our studies of the [beta]-spectrum of [sup 14]C using a germanium detector doped with [sup 14]C. There is a feature in the [beta]-spectrum 17 keV below the endpoint which could be explained by the hypothesis that there is a heavy neutrino emitted in the [beta]-decay of [sup 14]C with a mass of 17[plus minus]1 keV and an emission probability of 1.26[plus minus]0.25%. However, we also have performed a high statistics measurement of the inner bremsstrahlung spectrum of [sup 55]Fe and find no indication of the emission of a 17-keV neutrino. We conclude that the origin of the kink'' that has been observed in some recent beta spectral measurements is not a neutrino.

  17. A massive neutrino in nuclear beta decay?

    SciTech Connect

    Norman, E.B.; Chan, Yuen-Dat; Garcia, A.; Lesko, K.T.; Larimer, R.M.; Stokstad, R.G. Sur, B.; Zlimen, I.; da Cruz, M.T.F. |; Hindi, M.M. |; Wietfeldt, F.E. |

    1992-09-01

    We have continued our studies of the {beta}-spectrum of {sup 14}C using a germanium detector doped with {sup l4}C. There is a feature in the {beta}-spectrum 17 keV below the endpoint which could be explained by the hypothesis that there is a heavy neutrino emitted in the {beta}-decay of {sup 14}C with a mass of 17{plus_minus}1 keV and an emission probability of 1.26{plus_minus}0.25%. However, we also have performed a high statistics measurement of the inner bremsstrahlung spectrum of {sup 55}Fe and find no indication of the emission of a {sup 17}-keV neutrino. We conclude that the origin of the ``kink`` that has been observed in some recent beta spectral measurements is not a neutrino.

  18. A massive neutrino in nuclear beta decay

    SciTech Connect

    Norman, E.B.; Chan, Yuen-Dat; Garcia, A.; Lesko, K.T.; Larimer, R.M.; Stokstad, R.G. Sur, B.; Zlimen, I. ); da Cruz, M.T.F. University of Sao Paulo, Sao Paulo, Brazil . Physics Institute); Hindi, M.M. Tennessee Technological Univ., Cookeville, TN (United Stat

    1992-09-01

    We have continued our studies of the [beta]-spectrum of [sup 14]C using a germanium detector doped with [sup l4]C. There is a feature in the [beta]-spectrum 17 keV below the endpoint which could be explained by the hypothesis that there is a heavy neutrino emitted in the [beta]-decay of [sup 14]C with a mass of 17[plus minus]1 keV and an emission probability of 1.26[plus minus]0.25%. However, we also have performed a high statistics measurement of the inner bremsstrahlung spectrum of [sup 55]Fe and find no indication of the emission of a [sup 17]-keV neutrino. We conclude that the origin of the kink'' that has been observed in some recent beta spectral measurements is not a neutrino.

  19. Beta-2 Microglobulin Kidney Disease Test

    MedlinePlus

    ... Serum or Urine Related tests: Albumin , Creatinine , BUN , Heavy Metals Were you looking for Beta-2 Microglobulin Tumor ... to high levels of cadmium and/or other heavy metals like mercury, such as may occur with occupational ...

  20. Identification of residues in beta-lactamase critical for binding beta-lactamase inhibitory protein.

    PubMed

    Rudgers, G W; Palzkill, T

    1999-03-12

    beta-Lactamase inhibitory protein (BLIP) is a potent inhibitor of several beta-lactamases including TEM-1 beta-lactamase (Ki = 0.1 nM). The co-crystal structure of TEM-1 beta-lactamase and BLIP has been solved, revealing the contact residues involved in the interface between the enzyme and inhibitor. To determine which residues in TEM-1 beta-lactamase are critical for binding BLIP, the method of monovalent phage display was employed. Random mutants of TEM-1 beta-lactamase in the 99-114 loop-helix and 235-240 B3 beta-strand regions were displayed as fusion proteins on the surface of the M13 bacteriophage. Functional mutants were selected based on the ability to bind BLIP. After three rounds of enrichment, the sequences of a collection of functional beta-lactamase mutants revealed a consensus sequence for the binding of BLIP. Seven loop-helix residues including Asp-101, Leu-102, Val-103, Ser-106, Pro-107, Thr-109, and His-112 and three B3 beta-strand residues including Ser-235, Gly-236, and Gly-238 were found to be critical for tight binding of BLIP. In addition, the selected beta-lactamase mutants A113L/T114R and E240K were found to increase binding of BLIP by over 6- and 11-fold, respectively. Combining these substitutions resulted in 550-fold tighter binding between the enzyme and BLIP with a Ki of 0.40 pM. These results reveal that the binding between TEM-1 beta-lactamase and BLIP can be improved and that there are a large number of sequences consistent with tight binding between BLIP and beta-lactamase.

  1. Proteopedia: Rossmann Fold: A Beta-Alpha-Beta Fold at Dinucleotide Binding Sites

    ERIC Educational Resources Information Center

    Hanukoglu, Israel

    2015-01-01

    The Rossmann fold is one of the most common and widely distributed super-secondary structures. It is composed of a series of alternating beta strand (ß) and alpha helical (a) segments wherein the ß-strands are hydrogen bonded forming a ß-sheet. The initial beta-alpha-beta (ßaß) fold is the most conserved segment of Rossmann folds. As this segment…

  2. Proteopedia: Rossmann Fold: A Beta-Alpha-Beta Fold at Dinucleotide Binding Sites

    ERIC Educational Resources Information Center

    Hanukoglu, Israel

    2015-01-01

    The Rossmann fold is one of the most common and widely distributed super-secondary structures. It is composed of a series of alternating beta strand (ß) and alpha helical (a) segments wherein the ß-strands are hydrogen bonded forming a ß-sheet. The initial beta-alpha-beta (ßaß) fold is the most conserved segment of Rossmann folds. As this segment…

  3. Enzyme-catalyzed formation of beta-peptides: beta-peptidyl aminopeptidases BapA and DmpA acting as beta-peptide-synthesizing enzymes.

    PubMed

    Heck, Tobias; Kohler, Hans-Peter E; Limbach, Michael; Flögel, Oliver; Seebach, Dieter; Geueke, Birgit

    2007-09-01

    In recent studies, we discovered that the three beta-peptidyl aminopeptidases, BapA from Sphingosinicella xenopeptidilytica 3-2W4, BapA from S. microcystinivorans Y2, and DmpA from Ochrobactrum anthropi LMG7991, possess the unique feature of cleaving N-terminal beta-amino acid residues from beta- and alpha/beta-peptides. Herein, we investigated the use of the same three enzymes for the reverse reaction catalyzing the oligomerization of beta-amino acids and the synthesis of mixed peptides with N-terminal beta-amino acid residues. As substrates, we employed the beta-homoamino acid derivatives H-beta hGly-pNA, H-beta3 hAla-pNA, H-(R)-beta3 hAla-pNA, H-beta3 hPhe-pNA, H-(R)-beta3 hPhe-pNA, and H-beta3 hLeu-pNA. All three enzymes were capable of coupling the six beta-amino acids to oligomers with chain lengths of up to eight amino acid residues. With the enzyme DmpA as the catalyst, we observed very high conversion rates, which correspond to dimer yields of up to 76%. The beta-dipeptide H-beta3 hAla-beta3 hLeu-OH and the beta/alpha-dipeptide H-beta hGly-His-OH (carnosine) were formed with almost 50% conversion, when a five-fold excess of beta3-homoleucine or histidine was incubated with H-beta3 hAla-pNA and H-beta hGly-pNA, respectively, in the presence of the enzyme BapA from S. microcystinivorans Y2. BapA from S. xenopeptidilytica 3-2W4 turned out to be a versatile catalyst capable of coupling various beta-amino acid residues to the free N-termini of beta- and alpha-amino acids and even to an alpha-tripeptide. Thus, these aminopeptidases might be useful to introduce a beta-amino acid residue as an N-terminal protecting group into a 'natural' alpha-peptide, thereby stabilizing the peptide against degradation by other proteolytic enzymes.

  4. Expression of transforming growth factor-beta 1, -beta 2, and -beta 3 in human developing teeth: immunolocalization according to the odontogenesis phases.

    PubMed

    Sassá Benedete, Ana Paula; Sobral, Ana Paula Veras; Lima, Dirce Mary Correia; Kamibeppu, Leonardo; Soares, Fernando Augusto; Lourenço, Silvia Vanessa

    2008-01-01

    Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor that has several biological effects in vivo, including control of cell growth and differentiation, cell migration, lineage determination, motility, adhesion, apoptosis, and synthesis and degradation of extracellular matrix, and TGF-beta plays an important role in regulating tissue repair and regeneration. Our study analyzed the participation of TGF-beta 1, -beta 2, and -beta 3 in the different stages of morphogenesis and differentiation of human developing dental organ using immunohistochemistry. The maxillae and mandibles of 10 human embryos ranging from 8 to 23 weeks of gestation were employed, according to the approval of the ethical committee. Our study revealed that the TGF-beta subunits-beta 1, beta 2, and beta 3-were present in the various stages of tooth development, but the expression varied according to the differentiation stage, tissue, and TGF-beta subunit. Our results indicated that TGF-beta 1 is closely related to differentiation of enamel organ and initiation of matrix secretion, TGF-beta 2 to cellular differentiation, and TGF-beta 3 to mineral maturation matrix.

  5. Dose Rate Calibration of a Commercial Beta-Particle Irradiator Used In Archeological and Geological Dating

    SciTech Connect

    Bernal, S.M.

    2004-10-31

    The 801E Multiple Sample Irradiator, manufactured by Daybreak Nuclear Systems, is capable of exposing up to 30 samples to beta radiation by placing each sample one by one directly beneath a heavily shielded ceramic Sr-90/Y-90 source and opening a specially designed shutter. Daybreak Nuclear Systems does not provide the {sup 90}Sr/{sup 90}Y dose rate to the sample because of variations of up to 20% in the nominal activity of the beta sources (separately manufactured by AEA Technology). Thus it is left to the end user to determine. Here aluminum oxide doped with carbon (Al{sub 2}O{sub 3}:C), in the form of Landauer's Luxel{trademark}, was irradiated to different known doses using a calibrated {sup 90}Sr/{sup 90}Y beta particle irradiator, and the OSL signal monitored after each irradiation to generate a calibration curve. Comparison of the OSL Signal from the unknown 801E Irradiator dose with the calibration curve enabled the dose and therefore dose rate to be determined. The timing accuracy of the 801E Irradiator was also evaluated and found to be +/- 0.5 seconds. The dose rate of the beta source was found to be 0.147 +/- 0.007 Gy/s.

  6. Solid-state NMR analysis of the {beta}-strand orientation of the protofibrils of amyloid {beta}-protein

    SciTech Connect

    Doi, Takashi; Masuda, Yuichi; Irie, Kazuhiro; Akagi, Ken-ichi; Monobe, Youko; Imazawa, Takayoshi; Takegoshi, K.

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer The supramolecular structure of A{beta}42 protofibrils was analyzed by solid-state NMR. Black-Right-Pointing-Pointer The Ala-21 residue in the A{beta}42 protofibrils is included in a slightly disordered {beta}-strand. Black-Right-Pointing-Pointer The A{beta}42 protofibrils do not form intermolecular in-register parallel {beta}-sheets. -- Abstract: Alzheimer's disease (AD) is caused by abnormal deposition (fibrillation) of a 42-residue amyloid {beta}-protein (A{beta}42) in the brain. During the process of fibrillation, the A{beta}42 takes the form of protofibrils with strong neurotoxicity, and is thus believed to play a crucial role in the pathogenesis of AD. To elucidate the supramolecular structure of the A{beta}42 protofibrils, the intermolecular proximity of the Ala-21 residues in the A{beta}42 protofibrils was analyzed by {sup 13}C-{sup 13}C rotational resonance experiments in the solid state. Unlike the A{beta}42 fibrils, an intermolecular {sup 13}C-{sup 13}C correlation was not found in the A{beta}42 protofibrils. This result suggests that the {beta}-strands of the A{beta}42 protofibrils are not in an in-register parallel orientation. A{beta}42 monomers would assemble to form protofibrils with the {beta}-strand conformation, then transform into fibrils by forming intermolecular parallel {beta}-sheets.

  7. Beta/alpha continuous air monitor

    DOEpatents

    Becker, Gregory K.; Martz, Dowell E.

    1989-01-01

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinguishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts.

  8. [Transforming growth factor of beta-type].

    PubMed

    Stoĭka, R S

    1988-01-01

    Recent data about the structure and properties of the beta-type transforming growth factor as well as evidence about its influence on different target cells are presented. The regulatory action of the factor is shown to depend mainly on the type of tested cells, conditions of their culturing and the presence of other bioregulators of cell proliferation in the medium. The prospects of the beta-type transforming growth factor use in practice are considered.

  9. Giant impacts in the Beta Pic system

    NASA Astrophysics Data System (ADS)

    Jackson, A.

    2014-09-01

    One scenario that can potentially explain the brightness asymmetry in the Beta Pictoris debris disk in the mid-infrared and millimetre is that of a comparatively recent (< 1 Myr ago) impact between planetary scale bodies at an orbital distance of ˜85 AU, as discussed by Dent et al 2014. I will discuss the details of this model, how it applies to Beta Pictoris, and how it may be applied elsewhere.

  10. Stability of Beta Limited Thermonuclear Burn.

    DTIC Science & Technology

    1980-01-28

    critical value of beta is exceeded. For example, in tokamaks such a critical beta might result due to the onset of magnetohydrodynamic *instabilities. Since...generally accepted theoretical models for anoma- lous plasma loss in such devices as tokamaks are not available, we shall try to make as few...situation might result from the onset of magnetic field braiding in a tokamak ). In this case a 3 % a4 >> a 1 %,a2 (6) (Note that since the a terms are

  11. Beta/alpha continuous air monitor

    DOEpatents

    Becker, G.K.; Martz, D.E.

    1988-06-27

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinquishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts. 7 figs.

  12. N=1 supersymmetric {beta}-functions

    SciTech Connect

    Jones, D. R. T.

    1997-06-15

    Recent results on three-loop, four-loop and large-N{sub f}{beta}-functions in supersymmetric gauge theories are summarised. It is argued that the O(1/N{sub f})-corrected form of {beta}{sub g} in SQCD is consistent with the existence of the conformal window 3N{sub c}/2

  13. New osmoregulated beta(1-3),beta(1-6) glucosyltransferase(s) in Azospirillum brasilense.

    PubMed Central

    Altabe, S G; Iñón de Iannino, N; de Mendoza, D; Ugalde, R A

    1994-01-01

    A linear beta(1-3),beta(1-6) glucan was detected in the periplasm of Azospirillum brasilense cells growing in a medium of low osmotic strength. This glucan was produced in vitro by purified bacterial inner membranes with UDP-glucose as the sugar donor in the presence of Mg2+. Growth in a high-osmotic-strength medium strongly reduced the amount of this glucan accumulated in the periplasmic space, and the inhibition was associated with a reduction in the enzymatic activity of the beta(1-3),beta(1-6) glucosyltransferase(s). Images PMID:8051002

  14. 6-beta-Iodopenicillanate as a probe for the classification of beta-lactamases.

    PubMed Central

    De Meester, F; Frère, J M; Waley, S G; Cartwright, S J; Virden, R; Lindberg, F

    1986-01-01

    An inactivator of serine beta-lactamases, 6 beta-iodopenicillanate, can be utilized as a probe in the classification of beta-lactamases. It is a substrate for class-B Zn2+-containing beta-lactamase II. Although it inactivates enzymes from both classes A and C, it is much more efficient for the former group, with which it sometimes interacts following a branched pathway. On the basis of these observations, predictions are made concerning the class to which several enzymes belong. PMID:3030266

  15. AE activity during transient beta drops in high poloidal beta discharges

    NASA Astrophysics Data System (ADS)

    Huang, J.; Gong, X. Z.; Ren, Q. L.; Ding, S. Y.; Qian, J. P.; Pan, C. K.; Li, G. Q.; Heidbrink, W. W.; Garofalo, A. M.; McClenaghan, J.

    2016-10-01

    Enhanced AE activity has been observed during transient beta drops in high poloidal beta DIII-D discharges with internal transport barriers (ITBs). These drops in beta are believed to be caused by n=1 external kink modes. In some discharges, beta recovers within 200 ms but, in others, beta stays suppressed. A typical discharge has βP 3, qmin 3, and q95 12. The drop in beta affects both fast ions and thermal particles, and a drop is also observed in the density and rotation. The enhanced AE activity follows the instability that causes the beta drop, is largest at the lowest beta, and subsides as beta recovers. MHD stability analysis is planned. A database study of the plasma conditions associated with the collapse will be also presented. Supported in part by the US Department of Energy under DE-FC02-04ER54698, DE-AC05-06OR23100, and by the National Natural Science Foundation of China 11575249, and the National Magnetic Confinement Fusion Program of China No. 2015GB110005.

  16. Endogenous beta-cell CART regulates insulin secretion and transcription of beta-cell genes.

    PubMed

    Shcherbina, L; Edlund, A; Esguerra, J L S; Abels, M; Zhou, Y; Ottosson-Laakso, E; Wollheim, C B; Hansson, O; Eliasson, L; Wierup, N

    2017-05-15

    Impaired beta-cell function is key to the development of type 2 diabetes. Cocaine- and amphetamine-regulated transcript (CART) is an islet peptide with insulinotropic and glucagonostatic properties. Here we studied the role of endogenous CART in beta-cell function. CART silencing in INS-1 (832/13) beta-cells reduced insulin secretion and production, ATP levels and beta-cell exocytosis. This was substantiated by reduced expression of several exocytosis genes, as well as reduced expression of genes important for insulin secretion and processing. In addition, CART silencing reduced the expression of a network of transcription factors essential for beta-cell function. Moreover, in RNAseq data from human islet donors, CARTPT expression levels correlated with insulin, exocytosis genes and key beta-cell transcription factors. Thus, endogenous beta-cell CART regulates insulin expression and secretion in INS-1 (832/13) cells, via actions on the exocytotic machinery and a network of beta-cell transcription factors. We conclude that CART is important for maintaining the beta-cell phenotype. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Presynaptic beta-adrenoceptors in rat atria: evidence for the presence of stereoselective beta 1-adrenoceptors.

    PubMed Central

    Heimburger, M.; Montero, M. J.; Fougeres, V.; Beslot, F.; Davy, M.; Midol-Monnet, M.; Cohen, Y.

    1989-01-01

    1. Presynaptic beta-adrenoceptor activity was studied in rat isolated atria, previously loaded with [3H]-noradrenaline. The stimulation-induced release of 3H transmitter was measured in the presence of cocaine, and adrenaline was used as a facilitatory beta-adrenoceptor agonist. 2. Adrenaline (0.1 and 2 nM) increased, by about 50%, the evoked efflux of tritium. With phenoxybenzamine present, the same activity was shown with 10 nM adrenaline. 3. The beta 2-selective adrenoceptor blocking drugs: IPS 339 and ICI 118 551 caused a concentration-dependent decrease in the activity of adrenaline. Cardioselective beta-blocking drugs: acebutolol, beta-xolol, nebivolol and its isomers (R 67 138 and R 67 145) also reduced dose-dependently the agonistic action of adrenaline. The order of potency for nebivolol and its isomers was R 67 138 greater than nebivolol greater than R 67 145. The activity of pindolol was not concentration-dependent. The inhibitory effect of acebutolol was also observed in the presence of blockade of alpha-adrenoceptors. 4. The postsynaptic beta-adrenoceptor blocking activity of nebivolol and its isomers was studied in pithed rats. They reduced isoprenaline-induced tachycardia without altering hypotensive responses. The order of potency was: R 67 138 greater than nebivolol greater than R 67 145. 5. It is concluded that in rat isolated atria, presynaptic beta 2- and beta 1-adrenoceptors coexist and that facilitatory beta 1-adrenoceptors are stereospecific. PMID:2572291

  18. Beta-alanine and beta-aminoisobutyric acid levels in two siblings with dihydropyrimidinase deficiency.

    PubMed

    van Kuilenburg, A B P; Stroomer, A E M; Bosch, A M; Duran, M

    2008-06-01

    Dihydropyrimidinase (DHP) deficiency is an inborn error of the pyrimidine degradation pathway, affecting the hydrolytic ring opening of the dihydropyrimidines. In two siblings with a complete DHP deficiency and a variable clinical presentation, a normal concentration of beta-alanine and strongly decreased levels of beta-aminoisobutyric acid were observed in plasma, urine and CSF. No major differences were observed for the concentrations of the beta-amino acids in plasma and urine between the symptomatic and asymptomatic sibling. Thus, the relevance of the shortage of beta-aminoisobutyric acid for the onset of a clinical phenotype in patients with DHP deficiency remains to be established.

  19. Transcriptional upregulation of retinoic acid receptor beta (RAR beta) expression by phenylacetate in human neuroblastoma cells.

    PubMed

    Sidell, N; Chang, B; Yamashiro, J M; Wada, R K

    1998-02-25

    Sodium phenylacetate (NaPA) has been shown to synergize with retinoic acid (RA) in inducing the differentiation of human neuroblastoma cells. Our studies indicated that NaPA can impact on the RA differentiation program by upregulating nuclear retinoic acid receptor-beta (RAR beta) expression. We have found that NaPA does not alter the half-life of RAR beta mRNA; thus, increased stability of mRNA levels does not contribute to NaPA induction. In contrast, NaPA was able to specifically activate a reporter gene construct (delta SV beta RE-CAT) which contains a retinoic acid response element (RARE beta) that is located in the RAR beta promoter. Activation of delta SV beta RE-CAT by NaPA also occurred in neuroblastoma cells cotransfected with a nuclear retinoic acid receptor expression vector, demonstrating the independence of this activation on cellular RAR levels. Taken together, our findings suggest that induction of RAR beta by NaPA is regulated at the level of transcription and mediated through the retinoic acid response element, RARE beta. This effect may account, at least in part, for the strong synergy between NaPA and RA in promoting neuroblastoma differentiation.

  20. Expression of transforming growth factor-beta (TGF-beta) isoforms in osteosarcomas: TGF-beta3 is related to disease progression.

    PubMed

    Kloen, P; Gebhardt, M C; Perez-Atayde, A; Rosenberg, A E; Springfield, D S; Gold, L I; Mankin, H J

    1997-12-15

    Transforming growth factor-beta (TGF-beta) is a multipotent growth factor affecting development, homeostasis, and tissue repair. In addition, increased expression of TGF-beta has been reported in different malignancies, suggesting a role for this growth factor in tumorigenesis. Using immunohistochemistry, the expression, prevalence, and distribution of TGF-beta isoforms were evaluated in 25 high grade human osteosarcomas. The Cox proportional hazards models and Kaplan-Meier curves were calculated correlating disease free survival with TGF-beta expression. Expression of one or more TGF-beta isoforms was found in all the osteosarcomas. Immunoreactivity for TGF-beta1 and TGF-beta3 generally was stronger than for TGF-beta2. The cytoplasm of the tumor cells showed stronger staining than their surrounding extracellular stroma. Most notably, osteoclasts showed strong to intense staining for all three isoforms. In 11 of 25 specimens angiogenic activity was noted with staining of multiple small vessels in the tumor stroma. Expression of TGF-beta3, but not of TGF-beta2 or TGF-beta1, related to disease progression, such that there was a statistically significant decrease in the disease free interval as the immunoreactivity for TGF-beta3 increased. All osteosarcomas expressed TGF-beta in the cytoplasm of the tumor cells as well as in their extracellular stroma. The presence of TGF-beta in the endothelial and perivascular layers of small vessels in the tumor stroma suggests angiogenic activity of this growth factor. The expression of TGF-beta3 was correlated strongly with disease progression (P = 0.027). These data suggest that increased expression of TGF-beta isoforms, especially TGF-beta3, may play a role in osteosarcoma progression.

  1. Adsorption of beta blockers to environmental surfaces.

    PubMed

    Kibbey, Tohren C G; Paruchuri, Rajiv; Sabatini, David A; Chen, Lixia

    2007-08-01

    Beta-adrenergic blocking agents (beta blockers) are widely used pharmaceuticals which have been detected in the environment. Predicting the transport and ultimate fate of beta blockers in the environment requires understanding their adsorption to soils and sediments, something for which little information is currently available. The objective of this work was to examine the adsorption of three beta blockers, propranolol, metoprolol and nadolol, to a natural alluvial material, as well as to six minerals present as components of the alluvial material. Batch adsorption experiments indicate that, for most of the minerals studied, compound hydrophobicity is an important predictor of adsorption, with propranolol,the most hydrophobic compound studied, adsorbing to the greatest extent. Results further suggest that, for the minerals studied, electrostatic effects are not a good predictor of adsorption; adsorption extent was not well-predicted by either surface zeta potential or by the difference between experiment pH and point of zero charge, despite the cationic nature af the three beta blockers at experiment pH values. Experiments were conducted to examine the effect of an anionic surfactant, sodium dodecyl benzene sulfonate (SDBS), on adsorption. Results indicate that SDBS significantly increases the adsorption of propranolol to two different sorbents. This result is potentially important because surfactants such as SDBS are likely to be present in wastewater effluents with beta blockers and could influence their mobility in the environment.

  2. Peptidase activity of beta-lactamases.

    PubMed Central

    Rhazi, N; Galleni, M; Page, M I; Frère, J M

    1999-01-01

    Although beta-lactamases have generally been considered as being devoid of peptidase activity, a low but significant hydrolysis of various N-acylated dipeptides was observed with representatives of each class of beta-lactamases. The kcat/Km values were below 0.1 M(-1). s(-1), but the enzyme rate enhancement factors were in the range 5000-20000 for the best substrates. Not unexpectedly, the best 'peptidase' was the class C beta-lactamase of Enterobacter cloacae P99, but, more surprisingly, the activity was always higher with the phenylacetyl- and benzoyl-d-Ala-d-Ala dipeptides than with the diacetyl- and alpha-acetyl-l-Lys-d-Ala-d-Ala tripeptides, which are the preferred substrates of the low-molecular-mass, soluble dd-peptidases. A comparison between the beta-lactamases and dd-peptidases showed that it might be as difficult for a dd-peptidase to open the beta-lactam ring as it is for the beta-lactamases to hydrolyse the peptides, an observation which can be explained by geometric and stereoelectronic considerations. PMID:10393100

  3. Beta-blockers in hypertension.

    PubMed

    Ram, C Venkata S

    2010-12-15

    Beta blockers have been used in the treatment of cardiovascular conditions for decades. Despite a long history and status as a guideline-recommended treatment option for hypertension, recent meta-analyses have brought into question whether β blockers are still an appropriate therapy given outcomes data from other antihypertensive drug classes. However, β blockers are a heterogenous class of agents with diverse pharmacologic and physiologic properties. Much of the unfavorable data revealed in the recent meta-analyses were gleaned from studies involving nonvasodilating, traditional β blockers, such as atenolol. However, findings with traditional β blockers may not be extrapolated to other members of the class, particularly those agents with vasodilatory activity. Vasodilatory β blockers (i.e., carvedilol and nebivolol) reduce blood pressure in large part through reducing systemic vascular resistance rather than by decreasing cardiac output, as is observed with traditional β blockers. Vasodilating ability may also ameliorate some of the concerns associated with traditional β blockade, such as the adverse effects on metabolic and lipid parameters, including an increased risk for new-onset diabetes. Furthermore, vasodilating ability is physiologically relevant and important in treating a condition with common co-morbidities involving metabolic and lipid abnormalities such as hypertension. In patients with hypertension and diabetes or coronary artery disease, vasodilating β blockers provide effective blood pressure control with neutral or beneficial effects on important parameters for the co-morbid disease. In conclusion, it is time for a reexamination of the clinical evidence for the use of β blockers in hypertension, recognizing that there are patients for whom β blockers, particularly those with vasodilatory actions, are an appropriate treatment option.

  4. Flavonoids from Tephrosia major. A new prenyl-beta-hydroxychalcone.

    PubMed

    Gómez-Garibay, Federico; Téllez-Valdez, Oswaldo; Moreno-Torres, Gregorio; Calderón, José S

    2002-01-01

    The roots and aerial parts of Tephrosia major Micheli, afforded a new prenylated-beta-hydroxychalcone, characterized as 2',6'-dihydroxy-3'-prenyl-4'-methoxy-beta-hydroxychalcone. In addition, seven prenylated flavonoids, two rotenoids, beta-sitosterol, stigmasterol, lupeol and quercetin were isolated. The structure of the new beta-hydroxy chalcone was established by spectroscopic methods, including 2D NMR experiments.

  5. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-10-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Computational methods for analyzing the transmission characteristics of a beta particle magnetic analysis system

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1979-01-01

    Computational methods were developed to study the trajectories of beta particles (positrons) through a magnetic analysis system as a function of the spatial distribution of the radionuclides in the beta source, size and shape of the source collimator, and the strength of the analyzer magnetic field. On the basis of these methods, the particle flux, their energy spectrum, and source-to-target transit times have been calculated for Na-22 positrons as a function of the analyzer magnetic field and the size and location of the target. These data are in studies requiring parallel beams of positrons of uniform energy such as measurement of the moisture distribution in composite materials. Computer programs for obtaining various trajectories are included.

  7. A measurement system for alpha and beta surface emission rate using MWPC

    NASA Astrophysics Data System (ADS)

    Lin, Ye; Fang, Fang; Ren, Jia-Fu; He, Lin-Feng; Tang, Fang-Dong; Xu, Yi-He; Ding, Wei-Cheng

    2015-05-01

    We have developed a large area multi-wire proportional counter (MWPC) as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology (SIMT). To shorten the preparation time for chamber gas refilling, a self-designed gas control unit was adopted. Various characteristics of the system have been studied. The uncertainties were analysed. Three certified alpha plane sources (Am-241) and six certified beta plane sources (Tl-204 and Sr-90/Y-90) were measured by this system. The results show excellent agreement with the surface emission rate reported by the National Institute of Measuring, China (NIM) that En values of all measured sources are within ±1. Supported by National Natural Science Foundation of China (41204133)

  8. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  9. ION SOURCE

    DOEpatents

    Leland, W.T.

    1960-01-01

    The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

  10. Crowd Sourcing.

    PubMed

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish.

  11. Varietal differences in the bioaccessibility of beta-carotene from mango (Mangifera indica) and papaya (Carica papaya) fruits.

    PubMed

    Veda, Supriya; Platel, Kalpana; Srinivasan, K

    2007-09-19

    Mango and papaya, which are rich sources of beta-carotene, are widely consumed in India. In this study, beta-carotene content and its bioaccessibility were determined in six locally available varieties of mango, namely, Badami, Raspuri, Mallika, Malgoa, Totapuri, and Neelam, and two varieties of papaya, namely, Honey Dew and Surya. Varietal differences were evident in both beta-carotene content and its bioaccessibility in the case of mango. beta-Carotene content in ripe mango ranged from 0.55 +/- 0.03 mg/100 g in the Malgoa variety to 3.21 +/- 0.25 mg/100 g in the Badami variety. Similarly, in the Honey Dew and Surya varieties of papaya, beta-carotene contents were 0.70 +/- 0.10 and 0.74 +/- 0.12 mg/100 g, respectively. Bioaccessibility of beta-carotene ranged from 24.5% in Badami to 39.1% in Raspuri varieties of mango. Considering both the percent bioaccessibility and the inherent beta-carotene content, the amount of bioaccessible beta-carotene was highest in the Mallika variety (0.89 mg/100 g), followed by Badami (0.79 mg/100 g). Because mango and papaya are also consumed as a blend with milk, the influence of the presence of milk on the bioaccessibility of beta-carotene from these fruits was also examined. Addition of milk generally brought about a significant increase in the bioaccessibility of beta-carotene from mango, the increase ranging from 12 to 56%. Bioaccessibility of beta-carotene from the two varieties of papaya examined was similar (31.4-34.3%). Addition of milk increased this bioaccessibility by 19 and 38% in these two varieties. Considering the beta-carotene content of mango and papaya, the latter has to be consumed in amounts roughly 3 times that of mango to derive the same amount of beta-carotene. Thus, this study has indicated that varietal differences exist in the content and bioaccessibility of beta-carotene in mango and that the addition of milk is advantageous in deriving this provitamin A from the fruit pulp of mango and papaya.

  12. Resources (beta) | ECHO | US EPA

    EPA Pesticide Factsheets

    ECHO, Enforcement and Compliance History Online, provides compliance and enforcement information for approximately 800,000 EPA-regulated facilities nationwide. ECHO includes permit, inspection, violation, enforcement action, and penalty information about facilities regulated under the Clean Air Act (CAA) Stationary Source Program, Clean Water Act (CWA) National Pollutant Elimination Discharge System (NPDES), and/or Resource Conservation and Recovery Act (RCRA). Information also is provided on surrounding demographics when available.

  13. RADIATION SOURCES

    DOEpatents

    Brucer, M.H.

    1958-04-15

    A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

  14. NEUTRON SOURCE

    DOEpatents

    Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

    1959-01-13

    A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

  15. Isolation of cDNA clones coding for the beta subunit of human beta-hexosaminidase.

    PubMed Central

    O'Dowd, B F; Quan, F; Willard, H F; Lamhonwah, A M; Korneluk, R G; Lowden, J A; Gravel, R A; Mahuran, D J

    1985-01-01

    The major forms of beta-hexosaminidase (2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase, EC 3.2.1.30) occur as multimers of alpha and beta chains--hexosaminidase A (alpha beta a beta b) and hexosaminidase B 2(beta a beta b). To facilitate the investigation of beta-chain biosynthesis and the nature of mutation in Sandhoff disease, a human hexosaminidase beta-chain cDNA clone was isolated. Hexosaminidase B (10 mg) was treated with CNBr, five peptide fragments were isolated by reverse-phase HPLC, and their amino acid sequences were determined. One of these contained a string of six amino acids from which an oligonucleotide probe was defined. The simian virus 40-transformed human fibroblast cDNA library of Okayama and Berg was screened by colony hybridization with the radiolabeled probe. Thirteen probe-binding clones were selected out of 50,000 clones screened. Four of these designated pHex were shown to be identical at their 3' ends by restriction enzyme mapping, differing only in their 5' extensions (1.4-1.7 kilobases). The nucleotide sequence of a 174-base-pair segment contained the deduced amino acid sequence of two of the five CNBr peptides, indicating that the pHex clones encode the beta subunit of hexosaminidase. In addition, pHex cDNA was found homologous to multiple bands in digests of genomic human DNA totaling 43 kilobases (kb), all of which were mapped to chromosome 5 in somatic cell hybrids, as expected of the HEXB gene. The pHex cDNA also hybridized to a 2.2-kilobase RNA that apparently codes for the pre-beta-polypeptide of hexosaminidase. This RNA species was absent in the fibroblasts of one of three patients with Sandhoff disease examined. We anticipate that these clones will be of value to diagnosis and carrier detection of Sandhoff disease in affected families. Images PMID:2579389

  16. The turn sequence directs beta-strand alignment in designed beta-hairpins.

    PubMed Central

    de Alba, E.; Rico, M.; Jiménez, M. A.

    1999-01-01

    A previous NMR investigation of model decapeptides with identical beta-strand sequences and different turn sequences demonstrated that, in these peptide systems, the turn residues played a more predominant role in defining the type of beta-hairpin adopted than cross-strand side-chain interactions. This result needed to be tested in longer beta-hairpin forming peptides, containing more potentially stabilizing cross-strand hydrogen bonds and side-chain interactions that might counterbalance the influence of the turn sequence. In that direction, we report here on the design and 1H NMR conformational study of three beta-hairpin forming pentadecapeptides. The design consists of adding two and three residues at the N- and C-termini, respectively, of the previously studied decapeptides. One of the designed pentadecapeptides includes a potentially stabilizing R-E salt bridge to investigate the influence of this interaction on beta-hairpin stability. We suggest that this peptide self-associates by forming intermolecular salt bridges. The other two pentadecapeptides behave as monomers. A conformational analysis of their 1H NMR spectra reveals that they adopt different types of beta-hairpin structure despite having identical strand sequences. Hence, the beta-turn sequence drives beta-hairpin formation in the investigated pentadecapeptides that adopt beta-hairpins that are longer than the average protein beta-hairpins. These results reinforce our previous suggestion concerning the key role played by the turn sequence in directing the kind of beta-hairpin formed by designed peptides. PMID:10595526

  17. Single fiber beta detector for stereotactic biopsy and intraoperative lumpectomy of breast cancer

    SciTech Connect

    Atac, M.; Nalcioglu, O.; Roeck, W.W.

    1996-10-01

    We have developed an intraoperative probe for use in early detection of breast cancer and aiding lumpectomy. The probe consists of a small plastic scintillator, 0.8mm dia and 3mm long, coupled to a single clear optical-fiber strand, and solid state photomultiplier. Due to the small size of the probe, it can be placed inside of a small gauge biopsy needle. The scintillator is very efficient in detecting betas and positrons while being very in efficient to energetic gammas due to small size and low density. High quantum efficiency, 80%, and high gain obtainable, solid state photomultiplier makes the probe very low noise device in detecting beta particles. Intrinsic resolution of the probe is expected to be around 1 mm. Preliminary results using beta sources and a rat bearing R320 adenocarcinoma tumor were very successful.

  18. Plant-Derived Compounds Targeting Pancreatic Beta Cells for the Treatment of Diabetes

    PubMed Central

    Oh, Yoon Sin

    2015-01-01

    Diabetes is a global health problem and a national economic burden. Although several antidiabetic drugs are available, the need for novel therapeutic agents with improved efficacy and few side effects remains. Drugs derived from natural compounds are more attractive than synthetic drugs because of their diversity and minimal side effects. This review summarizes the most relevant effects of various plant-derived natural compounds on the functionality of pancreatic beta cells. Published data suggest that natural compounds directly enhance insulin secretion, prevent pancreatic beta cell apoptosis, and modulate pancreatic beta cell differentiation and proliferation. It is essential to continuously investigate natural compounds as sources of novel pharmaceuticals. Therefore, more studies into these compounds' mechanisms of action are warranted for their development as potential anti-diabetics. PMID:26587047

  19. Source Water Protection Basics

    EPA Pesticide Factsheets

    Defines drinking water sources (source water), identifies drinking water sources, and describes source water assessments and protection, roles of government and organizations in drinking water source protection

  20. Beta-1-Selective Beta-Blockers and Cognitive Functions in Patients With Coronary Artery Disease: A Cross-Sectional Study.

    PubMed

    Burkauskas, Julius; Noreikaite, Aurelija; Bunevicius, Adomas; Brozaitiene, Julija; Neverauskas, Julius; Mickuviene, Narseta; Bunevicius, Robertas

    2016-01-01

    The association between current beta-1-selective beta-blocker use and cognitive function was evaluated in 722 patients with coronary artery disease without dementia. Beta-1-selective beta-blocker use was associated with worse incidental learning independently of sociodemographic characteristics, clinical coronary artery disease severity, and depression/anxiety.

  1. Terahertz sources.

    PubMed

    Shumyatsky, Pavel; Alfano, Robert R

    2011-03-01

    We present an overview and history of terahertz (THz) sources for readers of the biomedical and optical community for applications in physics, biology, chemistry, medicine, imaging, and spectroscopy. THz low-frequency vibrational modes are involved in many biological, chemical, and solid state physical processes.

  2. Superluminal sources.

    PubMed Central

    Vermeulen, R C

    1995-01-01

    Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H0 and the deceleration parameter q0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities betaapp in the range 1-5 h-1, where h = H0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 10(22) m], occur with roughly equal frequency; higher values, up to betaapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The betaapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at gammab approximately 2 h-1 and a tail up to at least gammab approximately 10 h-1. There appears to be a clearly rising upper envelope to the betaapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources. PMID:11607604

  3. Superluminal Sources

    NASA Astrophysics Data System (ADS)

    Vermeulen, R. C.

    1995-12-01

    Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H_0 and the deceleration parameter q_0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities βapp in the range 1-5 h-1, where h = H_0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 1022 m], occur with roughly equal frequency; higher values, up to βapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The βapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at γ_b ≈ 2 h-1 and a tail up to at least γ_b ≈ 10 h-1. There appears to be a clearly rising upper envelope to the βapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources.

  4. Hydrothermal synthesis of alpha- and beta-HgS nanostructures

    NASA Astrophysics Data System (ADS)

    Galain, Isabel; María, Pérez Barthaburu; Ivana, Aguiar; Laura, Fornaro

    2017-01-01

    We synthesized HgS nanostructures by the hydrothermal method in order to use them as electron acceptors in hybrid organic-inorganic solar cells. We employed different mercury sources (HgO and Hg(CH3COO)2) and polyvinylpyrrolidone (PVP) or hexadecanethiol (HDT) as stabilizing/capping agent for controlling size, crystallinity, morphology and stability of the obtained nanostructures. We also used thiourea as sulfur source, and a temperature of 180 °C during 6 h. Synthesized nanostructures were characterized by powder X-Ray Diffraction, Diffuse Reflectance Infrared Fourier Transform and Transmission Electron Microscopy. When PVP acts as stabilizing agent, the mercury source has influence on the size -but not in morphology- of the beta-HgS obtained nansostructures. HDT has control over nanostructures' size and depending on the relation Hg:HDT, we obtained a mixture of alpha and beta HgS which can be advantageous in the application in solar cells, due their absorption in different spectral regions. The smallest nanostructures obtained have a mean diameter of 20 nm when using HDT as capping agent. Also, we deposited the aforementioned nanostructures onto flat glass substrates by the spin coating technique as a first approach of an active layer of a solar cell. The depositions were characterized by atomic force microscopy. We obtained smaller particle deposition and higher particle density -but a lower area coverage (5%) - in samples with HDT as capping agent. This work presents promising results on nanostructures for future application on hybrid solar cells. Further efforts will be focused on the deposition of organic-inorganic layers.

  5. Structural studies of dopamine. beta. -hydroxylase

    SciTech Connect

    Papadopoulos, N.J.

    1985-01-01

    Dopamine ..beta..-hydroxylase catalyzes the conversion of dopamine to norepinephrine, a ..beta..-hydroxylation reaction, utilizing ascorbic acid as reducing agent and molecular oxygen as cosubstrate. Modifications of the previously published purification procedure for D..beta..H have produced findings which show that (1) enzyme is inactivated by ascorbate autooxidation during the isolation procedure, (2) active as well as inactive D..beta..H co-purify throughout the entire purification procedure and (3) beef liver catalase totally protects against this time dependent inactivation. The stoichiometry of copper binding to the active sites of D..beta..H has been investigated using /sup 19/F-NMR and radioactive binding experiments. The data unequivocally show that homogeneous D..beta..H (isolated in the presence of catalase) specifically binds up to approx.8 copper atoms per enzyme tetramer. Distance determinations done using NMR relaxation rate theory show that anion activators of the catalytic reaction are bound at a fairly far distance from the Cu/sup 2 +/ centers. Spin-echo electron paramagnetic resonance spectroscopy indicates that at least one, possibly two, histidines are bound as equatorial ligands to each Cu/sup 2 +/ ion. The combined data indicate that highly purified dopamine ..beta..-hydroxylase contains a 2 copper atom active site, composed of magnetically non-interacting metal centers. Active site components are distant from the Cu/sup 2 +/ centers, suggesting a possible movement of active site residues or components after reduction of enzyme bound copper in order to achieve the insertion of 1 atom of oxygen into the benzylic C-H bond of dopamine.

  6. Beta-thalassaemia trait: haematological parameters.

    PubMed

    Yousafzai, Yasar M; Khan, Shahtaj; Raziq, Fazle

    2010-01-01

    Beta-Thalassaemia syndromes are a group of hereditary disorders characterised by a genetic deficiency in the synthesis of beta-globin chains due to a defect in beta-globin genes. The objective of this study was to determine the haematological features of beta-thalassaemia trait (BTT). and to determine the sensitivity of Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mentzer Index (ML) as a screening tool for beta-thalassaemia trait. A descriptive study was conducted in Hayatabad Medical Complex, Peshawar from May 2009 to May 2010 with 203 subjects having BTT. Blood samples were collected in EDTA anti-coagulated tubes. RBC indices were taken as part of complete blood count (CBC) by haematology analyser, and Haemoglobin (Hb) electrophoresis was done to determine the HbA2 percentage. The data was collected and analysed on statistical software for demographic details, RBC indices and HbA2 levels. Out of 203 patients, 92 (45%) were males and 111 (55%) were females. Most patients tested were in the 15-45 year age group. One-hundred-sixty (79%) patients had anaemia. MCV was lower than 76 fl in all the cases. Mean MCV was 59.1 fl. MCH was low, the mean MCH being 19.3 g/dl. MCH < 26 gave sensitivity of 99% in detecting BTT. We calculated MI for these cases and found out that it was < 12 in 75% of cases and < 15 in 197 (97%). Beta-thalassaemia traits present with a microcytic hypochromic blood picture, detected on simple haematology analysers as low MCV and MCH and MI which provide a useful screening tool for beta-thalassaemia trait.

  7. Comparison of ophthalmic beta-blocking agents.

    PubMed

    Lesar, T S

    1987-06-01

    Glaucoma is described, and the chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of betaxolol and levobunolol in comparison with timolol are reviewed. Betaxolol and levobunolol are two beta-adrenergic blocking agents being marketed as ophthalmic solutions for treatment of primary open-angle glaucoma (POAG) and ocular hypertension (OHT). Betaxolol is a relatively cardioselective beta-adrenergic blocker, while levobunolol is a nonselective beta-adrenergic blocking agent. Double-blind comparative trials have suggested that betaxolol has an equal to slightly lower efficacy and levobunolol has equal efficacy in reducing intraocular pressure (IOP) compared with timolol, the first ophthalmic beta blocker. A mean reduction in intraocular pressure of 15-35% occurs with both betaxolol and levobunolol and is reported to be maintained with prolonged use. Betaxolol is associated with a higher (25%) incidence of local ocular adverse reactions than timolol. However, betaxolol produces less systemic beta 2- and possibly beta 1-adrenergic receptor blockade than either timolol or levobunolol. Betaxolol may be relatively safer to use in patients with reactive airway disease than either timolol or levobunolol. Levobunolol causes a similar to greater incidence of local ocular adverse reactions and similar systemic beta blockade compared with timolol. Levobunolol may possibly be longer acting than timolol, allowing more patients to be controlled by once-daily dosing. Betaxolol and levobunolol appear to be similar to timolol in controlling IOP in patients with POAG and OHT; additional experience with these agents is needed to assess the advantages and disadvantages of each agent.

  8. The biology of beta human papillomaviruses.

    PubMed

    Tommasino, Massimo

    2017-03-02

    The beta genus comprises more than 50 beta human papillomavirus (HPV) types that are suspected to be involved, together with ultraviolet (UV) irradiation, in the development of non-melanoma skin cancer (NMSC), the most common form of human cancer. Two members of the genus beta, HPV5 and HPV8, were first identified in patients with a genetic disorder, epidermodysplasia verruciformis (EV), that confers high susceptibility to beta HPV infection and NMSC development. The fact that organ transplant recipients (OTRs) with an impaired immune system have an elevated risk of NMSC raised the hypothesis that beta HPV types may also be involved in skin carcinogenesis in non-EV patients. Epidemiological studies have shown that serological and viral DNA markers are weakly, but significantly, associated with history of NMSC in OTRs and the general population. Functional studies on mucosal high-risk (HR) HPV types have clearly demonstrated that the products of two early genes, E6 and E7, are the main viral oncoproteins, which are able to deregulate events closely linked to transformation, such as cell cycle progression and apoptosis. Studies on a small number of beta HPV types have shown that their E6 and E7 oncoproteins also have the ability to interfere with the regulation of key pathways/events associated with cellular transformation. However, the initial functional data indicate that the molecular mechanisms leading to cellular transformation are different from those of mucosal HR HPV types. Beta HPV types may act only at early stages of carcinogenesis, by potentiating the deleterious effects of other carcinogens, such as UV radiation.

  9. Response-Modality-Specific Encoding of Human Choices in Upper Beta Band Oscillations during Vibrotactile Comparisons

    PubMed Central

    Herding, Jan; Ludwig, Simon; Blankenburg, Felix

    2017-01-01

    Perceptual decisions based on the comparison of two vibrotactile frequencies have been extensively studied in non-human primates. Recently, we obtained corresponding findings from human oscillatory electroencephalography (EEG) activity in the form of choice-selective modulations of upper beta band amplitude in medial premotor areas. However, the research in non-human primates as well as its human counterpart was so far limited to decisions reported by button presses. Thus, here we investigated whether the observed human beta band modulation is specific to the response modality. We recorded EEG activity from participants who compared two sequentially presented vibrotactile frequencies (f1 and f2), and decided whether f2 > f1 or f2 < f1, by performing a horizontal saccade to either side of a computer screen. Contrasting time-frequency transformed EEG data between both choices revealed that upper beta band amplitude (∼24–32 Hz) was modulated by participants’ choices before actual responses were given. In particular, “f2 > f1” choices were always associated with higher beta band amplitude than “f2 < f1” choices, irrespective of whether the choice was correct or not, and independent of the specific association between saccade direction and choice. The observed pattern of beta band modulation was virtually identical to our previous results when participants responded with button presses. In line with an intentional framework of decision making, the most likely sources of the beta band modulation were now, however, located in lateral as compared to medial premotor areas including the frontal eye fields. Hence, we could show that the choice-selective modulation of upper beta band amplitude is on the one hand consistent across different response modalities (i.e., same modulation pattern in similar frequency band), and on the other hand effector specific (i.e., modulation originating from areas involved in planning and executing saccades). PMID:28360848

  10. SU-E-J-03: A Comprehensive Comparison Between Alpha and Beta Emitters for Cancer Radioimmunotherapy

    SciTech Connect

    Huang, C.Y.; Guatelli, S; Oborn, B; Allen, B

    2014-06-01

    Purpose: The purpose of this study is to perform a comprehensive comparison of the therapeutic efficacy and cytotoxicity of alpha and beta emitters for Radioimmunotherapy (RIT). For each stage of cancer development, specific models were built for the separate objectives of RIT to be addressed:a) kill isolated cancer cells in transit in the lymphatic and vascular circulation,b) regress avascular cell clusters,c) regress tumor vasculature and tumors. Methods: Because of the nature of short range, high LET alpha and long energy beta radiation and heterogeneous antigen expression among cancer cells, the microdosimetric approach is essential for the RIT assessment. Geant4 based microdosimetric models are developed for the three different stages of cancer progression: cancer cells, cell clusters and tumors. The energy deposition, specific energy resulted from different source distribution in the three models was calculated separately for 4 alpha emitting radioisotopes ({sup 211}At, {sup 213}Bi, {sup 223}Ra and {sup 225}Ac) and 6 beta emitters ({sup 32}P, {sup 33}P, {sup 67}Cu, {sup 90}Y, {sup 131}I and {sup 177}Lu). The cell survival, therapeutic efficacy and cytotoxicity are determined and compared between alpha and beta emitters. Results: We show that internal targeted alpha radiation has advantages over beta radiation for killing isolated cancer cells, regressing small cell clusters and also solid tumors. Alpha particles have much higher dose specificity and potency than beta particles. They can deposit 3 logs more dose than beta emitters to single cells and solid tumor. Tumor control probability relies on deep penetration of radioisotopes to cancer cell clusters and solid tumors. Conclusion: The results of this study provide a quantitative understanding of the efficacy and cytotoxicity of RIT for each stage of cancer development.

  11. Occurrence of high-beta superthermal plasma events in the close environment of Jupiter's bow shock as observed by Ulysses

    SciTech Connect

    Marhavilas, P. K.; Sarris, E. T.; Anagnostopoulos, G. C.

    2011-01-04

    The ratio of the plasma pressure to the magnetic field pressure (or of their energy densities) which is known as the plasma parameter 'beta'({beta}) has important implications to the propagation of energetic particles and the interaction of the solar wind with planetary magnetospheres. Although in the scientific literature the contribution of the superthermal particles to the plasma pressure is generally assumed negligible, we deduced, by analyzing energetic particles and magnetic field measurements recorded by the Ulysses spacecraft, that in a series of events, the energy density contained in the superthermal tail of the particle distribution is comparable to or even higher than the energy density of the magnetic field, creating conditions of high-beta plasma. More explicitly, in this paper we analyze Ulysses/HI-SCALE measurements of the energy density ratio (parameter {beta}{sub ep}) of the energetic ions'(20 keV to {approx}5 MeV) to the magnetic field's in order to find occurrences of high-beta ({beta}{sub ep}>1) superthermal plasma conditions in the environment of the Jovian magnetosphere, which is an interesting plasma laboratory and an important source of emissions in our solar system. In particular, we examine high-beta ion events close to Jupiter's bow shock, which are produced by two processes: (a) bow shock ion acceleration and (b) ion leakage from the magnetosphere.

  12. NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of beta-lactam production.

    PubMed

    Thykaer, Jette; Rueksomtawin, Kanchana; Noorman, Henk; Nielsen, Jens

    2008-04-01

    The interactions between the ammonium assimilatory pathways and beta-lactam production were investigated by disruption of the NADPH-dependent glutamate dehydrogenase gene (gdhA) in two industrial beta-lactam-producing strains of Penicillium chrysogenum. The strains used were an adipoyl-7-ADCA- and a penicillin-producing strain. The gdhA gene disruption caused a decrease in maximum specific growth rate of 26 % and 35 % for the adipoyl-7-ADCA-producing strain and the penicillin-producing strain, respectively, compared to the corresponding reference strains. Interestingly, no beta-lactam production was detected in either of the DeltagdhA strains. Supplementation with glutamate restored growth but no beta-lactam production was detected for the constructed strains. Cultures with high ammonium concentrations (repressing conditions) and with proline as nitrogen source (de-repressed conditions) showed continued beta-lactam production for the reference strains whereas the DeltagdhA strains remained non-productive under all conditions. By overexpressing the NAD-dependent glutamate dehydrogenase, the specific growth rate could be restored, but still no beta-lactam production was detected. The results indicate that the NADPH-dependent glutamate dehydrogenase may be directly or indirectly involved in the regulation of beta-lactam production in industrial strains of P. chrysogenum.

  13. In vitro reprogramming of pancreatic alpha cells towards a beta cell phenotype following ectopic HNF4α expression.

    PubMed

    Sangan, Caroline B; Jover, Ramiro; Heimberg, Harry; Tosh, David

    2015-01-05

    There is currently a shortage of organ donors available for pancreatic beta cell transplantation into diabetic patients. An alternative source of beta cells is pre-existing pancreatic cells. While we know that beta cells can arise directly from alpha cells during pancreatic regeneration we do not understand the molecular basis for the switch in phenotype. The aim of the present study was to investigate if hepatocyte nuclear factor 4 alpha (HNF4α), a transcription factor essential for a normal beta cell phenotype, could induce the reprogramming of alpha cells towards potential beta cells. We utilised an in vitro model of pancreatic alpha cells, the murine αTC1-9 cell line. We initially characterised the αTC1-9 cell line before and following adenovirus-mediated ectopic expression of HNF4α. We analysed the phenotype at transcript and protein level and assessed its glucose-responsiveness. Ectopic HNF4α expression in the αTC1-9 cell line induced a change in morphology (1.7-fold increase in size), suppressed glucagon expression, induced key beta cell-specific markers (insulin, C-peptide, glucokinase, GLUT2 and Pax4) and pancreatic polypeptide (PP) and enabled the cells to secrete insulin in a glucose-regulated manner. In conclusion, HNF4α reprograms alpha cells to beta-like cells.

  14. Oligomerization and toxicity of A{beta} fusion proteins

    SciTech Connect

    Caine, Joanne M.; Bharadwaj, Prashant R.; Sankovich, Sonia E.; Ciccotosto, Giuseppe D.; Streltsov, Victor A.; Varghese, Jose

    2011-06-10

    Highlights: {yields} We expressed amyloid-{beta} (A{beta}) peptide as a soluble maltose binding protein fusion (MBP-A{beta}42 and MBP-A{beta}16). {yields} The full length A{beta} peptide fusion, MBP-A{beta}42, forms oligomeric species as determined by SDS-PAGE gels, gel filtration and DLS. {yields} The MBP-A{beta}42, but not MBP-A{beta}16 or MBP alone, is toxic to both yeast and mammalian cells as determined by toxicity assays. -- Abstract: This study has found that the Maltose binding protein A{beta}42 fusion protein (MBP-A{beta}42) forms soluble oligomers while the shorter MBP-A{beta}16 fusion and control MBP did not. MBP-A{beta}42, but neither MBP-A{beta}16 nor control MBP, was toxic in a dose-dependent manner in both yeast and primary cortical neuronal cells. This study demonstrates the potential utility of MBP-A{beta}42 as a reagent for drug screening assays in yeast and neuronal cell cultures and as a candidate for further A{beta}42 characterization.

  15. Efficacy of beta-glucuronidase assay for identification of Escherichia coli by the defined-substrate technology.

    PubMed Central

    Rice, E W; Allen, M J; Edberg, S C

    1990-01-01

    In 1976, Kilian and Bulow described the association of beta-glucuronidase with the genus Escherichia (97% positive) and suggested that a beta-glucuronidase assay would be a useful identification test. Since that report, papers about the sensitivity and specificity of this enzyme for the identification of Escherichia coli from clinical sources, food, seawater, potable-water supplies, and various environmental sources have appeared. A study was undertaken to determine the efficacy and specificity of the defined-substrate technology beta-glucuronidase (Colilert) assay for the identification of this species from fecal samples. A total of 460 human, 105 cow, and 55 horse E. coli isolates were tested. Results showed 95.5% beta-glucuronidase-positive isolates in 24 h and 99.5% positive after 28 h of incubation. Only one E. coli isolate was negative. There were no significant differences in the percentage of beta-glucuronidase-positive isolates among the human or animal isolates. There were no non-E. coli isolates that were positive. All subjects carried beta-glucuronidase-positive E. coli. PMID:2187409

  16. Cytotoxic bis-3,4-dihydro-beta-carbolines and bis-beta-carbolines.

    PubMed

    Jiang, Wei-Qun; Charlet-Fagnère, Catherine; Sapi, Janos; Laronze, Jean-Yves; Renard, Pierre; Pfeiffer, Bruno; Léonce, Stéphane

    2002-12-01

    Ten bis-beta-carboline 1, 2 and bis-3,4-dihydro-beta-carboline 3, 4 derivatives, linked between carbons 1 and 1' by a polymethylene spacer, were synthesized from bistryptamine amides 9, 10. Some of them display a micromolar IC50 towards L-1210 cells.

  17. Beta-Lactamase Production and Resistance to Beta-Lactam Antibiotics in Nocardia

    PubMed Central

    Wallace, Richard J.; Vance, Paula; Weissfeld, Alice; Martin, R. Russell

    1978-01-01

    Although ampicillin has been suggested as a useful agent for the treatment of nocardiosis in man, little is known regarding the presence of beta-lactamase in Nocardia or its possible role in determining resistance to ampicillin and the other beta-lactam antibiotics. We have evaluated 55 isolates of Nocardia for susceptibility to five beta-lactam antibiotics and for the presence of beta-lactamase. Nocardia were resistant to penicillin G, cloxacillin, and cefazolin, but 27 and 62% were susceptible to 3.1 and 25 μg of ampicillin per ml, respectively. Almost 90% of these ampicillin-susceptible or intermediate strains were also susceptible to carbenicillin. The combination of ampicillin and cloxacillin was synergistic against many ampicillin-resistant strains. Beta-lactamase was detected in 89% of Nocardia isolates when intact cells were used and in six of six strains after cell fractionation. This beta-lactamase was most active against penicillin G and ampicillin, with lesser activity against carbenicillin and cephaloridine. These studies suggest that beta-lactamase may be present in all clinical isolates of Nocardia and that mechanisms of antimicrobial resistance other than or in addition to beta-lactamase are responsible for resistance of Nocardia to ampicillin and carbenicillin. PMID:310280

  18. Organocatalytic synthesis of beta-alkylaspartates via beta-lactone ring opening.

    PubMed

    Armstrong, Alan; Geldart, Stephen P; Jenner, Chloe R; Scutt, James N

    2007-10-12

    Cinchona alkaloid-catalyzed reaction of ethyl glyoxylate with substituted ketenes, formed in situ, gives disubstituted beta-lactones in moderate yield and high enantiomeric excess. Subsequent azide ring opening, reduction, and ester hydrolysis allows access to chiral beta-alkyl aspartates.

  19. Biochemical and immunochemical analysis of avian beta 1 and mammalian beta 2-adrenergic receptors.

    PubMed

    Chapot, M P; Cervantes, P; Kaveri, S; Durieu-Trautmann, O; Delavier-Klutchko, C; Emorine, L; Couraud, P O; Strosberg, A D

    1987-01-01

    We have studied the molecular properties of avian beta 1-adrenergic receptor and human beta 2-adrenergic receptor. The turkey erythrocytes beta 1-receptor has been solubilized in active form by digitonin and has been purified to homogeneity by affinity chromatography followed by electroelution from polyacrylamide gel. The photoactivable ligand, iodocyanopindololdiazirine, labels specifically a major 45 kDa and minor 55 kDa polypeptide in turkey erythrocytes, whereas in A431, it labels two polypeptides of molecular weights 65 kDa and 55 kDa. Both types of receptors are N- and possibly O-glycosylated but the turkey beta 1 receptor has only complex carbohydrates whereas the human beta 2 receptor has in addition oligo mannosidic polysaccharidic moiety. Polyclonal and monoclonal antibodies were raised against the beta 1- and beta 2-adrenergic receptors. Polyclonal antibodies were found to mimic beta-adrenergic agonists by stimulating adenylate cyclase upon binding to the receptors. The monoclonal antibodies precipitated both intact and affinity labeled receptors which they also revealed on immunoblots.

  20. Hemoglobinopathies in the Dogon Country: presence of beta S, beta C, and delta A' genes.

    PubMed

    Ducrocq, R; Bennani, M; Bellis, G; Baby, M; Traore, K; Nagel, R L; Krishnamoorthy, R; Chaventre, A

    1994-07-01

    The population of the Dogon, located in Mali, is divided in an endogamic Noble class and two endogamic servant castes (Tanners and Blacksmiths). We find that the polymorphic frequencies of beta c, beta S, and, unexpectedly, a mutation of the delta-chain (delta A'), are geographically (valley vs. plateau) as well as social status dependent.