elements total half-lives: Topics by Science.gov

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Large-scale evaluation of β -decay rates of r -process nuclei with the inclusion of first-forbidden transitions

NASA Astrophysics Data System (ADS)

Marketin, T.; Huther, L.; Martínez-Pinedo, G.

2016-02-01

Background: r -process nucleosynthesis models rely, by necessity, on nuclear structure models for input. Particularly important are β -decay half-lives of neutron-rich nuclei. At present only a single systematic calculation exists that provides values for all relevant nuclei making it difficult to test the sensitivity of nucleosynthesis models to this input. Additionally, even though there are indications that their contribution may be significant, the impact of first-forbidden transitions on decay rates has not been systematically studied within a consistent model. Purpose: Our goal is to provide a table of β -decay half-lives and β -delayed neutron emission probabilities, including first-forbidden transitions, calculated within a fully self-consistent microscopic theoretical framework. The results are used in an r -process nucleosynthesis calculation to asses the sensitivity of heavy element nucleosynthesis to weak interaction reaction rates. Method: We use a fully self-consistent covariant density functional theory (CDFT) framework. The ground state of all nuclei is calculated with the relativistic Hartree-Bogoliubov (RHB) model, and excited states are obtained within the proton-neutron relativistic quasiparticle random phase approximation (p n -RQRPA). Results: The β -decay half-lives, β -delayed neutron emission probabilities, and the average number of emitted neutrons have been calculated for 5409 nuclei in the neutron-rich region of the nuclear chart. We observe a significant contribution of the first-forbidden transitions to the total decay rate in nuclei far from the valley of stability. The experimental half-lives are in general well reproduced for even-even, odd-A , and odd-odd nuclei, in particular for short-lived nuclei. The resulting data table is included with the article as Supplemental Material. Conclusions: In certain regions of the nuclear chart, first-forbidden transitions constitute a large fraction of the total decay rate and must be taken into account consistently in modern evaluations of half-lives. Both the β -decay half-lives and β -delayed neutron emission probabilities have a noticeable impact on the results of heavy element nucleosynthesis models.
β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.

PubMed

Lorusso, G; Nishimura, S; Xu, Z Y; Jungclaus, A; Shimizu, Y; Simpson, G S; Söderström, P-A; Watanabe, H; Browne, F; Doornenbal, P; Gey, G; Jung, H S; Meyer, B; Sumikama, T; Taprogge, J; Vajta, Zs; Wu, J; Baba, H; Benzoni, G; Chae, K Y; Crespi, F C L; Fukuda, N; Gernhäuser, R; Inabe, N; Isobe, T; Kajino, T; Kameda, D; Kim, G D; Kim, Y-K; Kojouharov, I; Kondev, F G; Kubo, T; Kurz, N; Kwon, Y K; Lane, G J; Li, Z; Montaner-Pizá, A; Moschner, K; Naqvi, F; Niikura, M; Nishibata, H; Odahara, A; Orlandi, R; Patel, Z; Podolyák, Zs; Sakurai, H; Schaffner, H; Schury, P; Shibagaki, S; Steiger, K; Suzuki, H; Takeda, H; Wendt, A; Yagi, A; Yoshinaga, K

2015-05-15

The β-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.
Observation of New Spontaneous Fission Activities from Elements 100 TO 105.

NASA Astrophysics Data System (ADS)

Somerville, Lawrence Patrick

Several new Spontaneous Fission (SF) activities have been found. Their half-lives and production cross sections in several reactions have been measured by collecting and transporting recoils at known speed past mica track detectors. No definite identification could be made for any of the new SF activities; however, half-lives and possible assignments to element-104 isotopes consistent with several cross bombardments include ('257)Rf(3.8 s, 14% SF), ('258)Rf(13 ms), ('259)Rf((TURN)3 s, 8% SF), ('260)Rf((TURN)20 ms), and ('262)Rf((TURN)50ms). The 80-ms SF activity claimed by the Dubna group for the discovery of element 104 (('260)104) was not observed. A difficulty exists in the interpretation that ('260)Rf is a (TURN)20-ms SF activity: in order to be correct, for example, the SF activities with half-lives between 14 and 24 ms produced in the reactions 109- to 119-MeV ('18)O + ('248)Cm, 88- to 100-MeV ('15)N + ('249)Bk, and 96-MeV ('18)O + ('249)Cf must be other nuclides due to their large production cross sections, or the cross sections for production of ('260)Rf must be enhanced by unknown mechanisms. Based on calculated total production cross sections a possible (TURN)1% electron-capture branch in ('258)Lr(4.5 s) to the SF emitter ('258)No(1.2 ms) and an upper limit of 0.05% for SF branching in ('254)No(55 s) were determined. Other measured half-lives from unknown nuclides produced in respective reactions include (TURN)1.6 s (('18)O + ('248)Cm), indications of a (TURN)47-s SF activity (75-MeV ('12)C + ('249)Cf), and two or more SF activities with 3 s (LESSTHEQ) T(, 1/2) (LESSTHEQ) 60 s (('18)O + ('249)Bk). The most exciting conclusion of this work is that if the tentative assignments to even-even element -104 isotopes are correct, there would be a sudden change in the SF half-life systematics at element 104 which has been predicted theoretically by Randrup et al. and Baran et al. and attributed to the disappearance of the second hump of the double-humped fission barrier. This disappearance of the second barrier also explains the tentative low hindrance factors compared to lighter elements for SF of the odd -mass isotopes ('257)Rf((TURN)4 x 10('3)) and ('259)Rf((TURN)2 x 10('3)). On the basis of recent odd-mass alpha-decay energy data, the 152-neutron sub-shell effect is probably weaker for element 104 than for element 102, confirming predictions of Randrup et al., and not strong enough to significantly alter the SF half-life predictions. This weakening sub-shell effect is in contrast to the continuing strong effect assumed in the Ghiorso half-life systematics. The possibilities of enhanced stability against SF with 157 neutrons for ('261)RF(65 s) and theoretical arguments concerning the SF-mass distributions for element-104 nuclei are discussed.
The generalized liquid drop model alpha-decay formula: Predictability analysis and superheavy element alpha half-lives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasgupta-Schubert, N.; Reyes, M.A.

2007-11-15

The predictive accuracy of the generalized liquid drop model (GLDM) formula for alpha-decay half-lives has been investigated in a detailed manner and a variant of the formula with improved coefficients is proposed. The method employs the experimental alpha half-lives of the well-known alpha standards to obtain the coefficients of the analytical formula using the experimental Q{sub {alpha}} values (the DSR-E formula), as well as the finite range droplet model (FRDM) derived Q{sub {alpha}} values (the FRDM-FRDM formula). The predictive accuracy of these formulae was checked against the experimental alpha half-lives of an independent set of nuclei (TEST) that span approximatelymore » the same Z, A region as the standards and possess reliable alpha spectroscopic data, and were found to yield good results for the DSR-E formula but not for the FRDM-FRDM formula. The two formulae were used to obtain the alpha half-lives of superheavy elements (SHE) and heavy nuclides where the relative accuracy was found to be markedly improved for the FRDM-FRDM formula, which corroborates the appropriateness of the FRDM masses and the GLDM prescription for high Z, A nuclides. Further improvement resulted, especially for the FRDM-FRDM formula, after a simple linear optimization over the calculated and experimental half-lives of TEST was used to re-calculate the half-lives of the SHE and heavy nuclides. The advantage of this optimization was that it required no re-calculation of the coefficients of the basic DSR-E or FRDM-FRDM formulae. The half-lives for 324 medium-mass to superheavy alpha decaying nuclides, calculated using these formulae and the comparison with experimental half-lives, are presented.« less
Theoretical and experimental α decay half-lives of the heaviest odd-Z elements and general predictions

NASA Astrophysics Data System (ADS)

Zhang, H. F.; Royer, G.

2007-10-01

Theoretical α decay half-lives of the heaviest odd-Z nuclei are calculated using the experimental Qα value. The barriers in the quasimolecular shape path are determined within a Generalized Liquid Drop Model (GLDM) and the WKB approximation is used. The results are compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The calculations provide consistent estimates for the half-lives of the α decay chains of these superheavy elements. The experimental data stand between the GLDM calculations and VSS ones in the most time. Predictions are provided for the α decay half-lives of other superheavy nuclei within the GLDM and VSS approaches using the recent extrapolated Qα of Audi, Wapstra, and Thibault [Nucl. Phys. A729, 337 (2003)], which may be used for future experimental assignment and identification.
Fission in the landscape of heaviest elements: Some recent examples

NASA Astrophysics Data System (ADS)

Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; Ackermann, D.; Andersson, L.-L.; Block, M.; Brand, H.; Even, J.; Forsberg, U.; Hartmann, W.; Herzberg, R.-D.; Heßberger, F. P.; Hoffmann, J.; Hübner, A.; Jäger, E.; Jeppsson, J.; Kindler, B.; Kratz, J. V.; Krier, J.; Kurz, N.; Lommel, B.; Maiti, M.; Minami, S.; Rudolph, D.; Runke, J.; Sarmiento, L. G.; Schädel, M.; Schausten, B.; Steiner, J.; Heidenreich, T. Torres De; Uusitalo, J.; Wiehl, N.; Yakusheva, V.

2016-12-01

The fission process still remains a main factor that determines the stability of the atomic nucleus of heaviest elements. Fission half-lives vary over a wide range, 10-19-1024 s. Present experimental techniques for the synthesis of the superheavy elements that usually measure α-decay chains are sensitive only in a limited range of half-lives, often 10-5-103 s. In the past years, measurement techniques for very short-lived and very long-lived nuclei were significantly improved at the gas-filled recoil separator TASCA at GSI Darmstadt. Recently, several experimental studies of fission-related phenomena have successfully been performed. In this paper, results on 254-256Rf and 266Lr are presented and corresponding factors for retarding the fission process are discussed.
alpha-decay half-lives and Q{sub a}lpha values of superheavy nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong Jianmin; Graduate University of Chinese Academy of Sciences, Beijing 100049; School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000

2010-06-15

The alpha-decay half-lives of recently synthesized superheavy nuclei (SHN) are investigated by employing a unified fission model (UFM) where a new method to calculate the assault frequency of alpha emission is used. The excellent agreement with the experimental data indicates the UFM is a useful tool to investigate these alpha decays. It is found that the alpha-decay half-lives become more and more insensitive to the Q{sub a}lpha values as the atomic number increases on the whole, which is favorable for us to predict the half-lives of SHN. In addition, a formula is proposed to compute the Q{sub a}lpha values formore » the nuclei with Z>=92 and N>=140 with a good accuracy, according to which the long-lived SHN should be neutron rich. Several weeks ago, two isotopes of a new element with atomic number Z=117 were synthesized and their alpha-decay chains have been observed. The Q{sub a}lpha formula is found to work well for these nuclei, confirming its predictive power. The experimental half-lives are well reproduced by employing the UFM with the experimental Q{sub a}lpha values. This fact that the experimental half-lives are compatible with experimental Q{sub a}lpha values supports the synthesis of a new element 117 and the experimental measurements to a certain extent.« less
Theoretical and experimental {alpha} decay half-lives of the heaviest odd-Z elements and general predictions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, H. F.; Royer, G.

Theoretical {alpha} decay half-lives of the heaviest odd-Z nuclei are calculated using the experimental Q{sub {alpha}} value. The barriers in the quasimolecular shape path are determined within a Generalized Liquid Drop Model (GLDM) and the WKB approximation is used. The results are compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The calculations provide consistent estimates for the half-lives of the {alpha} decay chains of these superheavy elements. The experimental data stand between the GLDM calculations and VSS ones in the most time. Predictions are provided for the {alpha} decay half-lives of other superheavymore » nuclei within the GLDM and VSS approaches using the recent extrapolated Q{sub {alpha}} of Audi, Wapstra, and Thibault [Nucl. Phys. A729, 337 (2003)], which may be used for future experimental assignment and identification.« less
Nuclear half-lives for {alpha}-radioactivity of elements with 100 {<=} Z {<=} 130

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chowdhury, P. Roy; Samanta, C.; Physics Department, Gottwald Science Center, University of Richmond, Richmond, VA 23173

2008-11-15

Theoretical estimates for the half-lives of about 1700 isotopes of heavy elements with 100 {<=} Z {<=} 130 are tabulated using theoretical Q-values. The quantum mechanical tunneling probabilities are calculated within a WKB framework using microscopic nuclear potentials. The microscopic nucleus-nucleus potentials are obtained by folding the densities of interacting nuclei with a density-dependent M3Y effective nucleon-nucleon interaction. The {alpha}-decay half-lives calculated in this formalism using the experimental Q-values were found to be in good agreement over a wide range of experimental data spanning about 20 orders of magnitude. The theoretical Q-values used for the present calculations are extracted frommore » three different mass estimates viz. Myers-Swiatecki, Muntian-Hofmann-Patyk-Sobiczewski, and Koura-Tachibana-Uno-Yamada.« less
Theoretical prediction of probable isotopes of superheavy nuclei of Z = 122

NASA Astrophysics Data System (ADS)

Manjunatha, H. C.

2016-11-01

We have studied the α-decay half-life and spontaneous fission half-lives of isotopes of superheavy element Z = 122 in the range 275 ≤ A ≥ 326. A comparison of calculated alpha half-lives with the literature [D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 83 (2011) 014601, D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 85 (2012) 034615] and the analytical formulas of Royer [G. Royer, J. Phys. G; Nucl. Part. Phys. 26 (2000) 1149] shows good agreement with each other. To identify the mode of decay of these isotopes, the spontaneous-fission half-lives were also evaluated using the semiempirical relation given by [C. Xu, Z. Ren and Y. Guo, Phys. Rev. C 78 (2008) 044329]. A comparative study on the competition of alpha decay versus spontaneous fission of superheavy nuclei (SHN) reveals that around eight isotopes (307-314122) survive fission and have alpha decay channel as the prominent mode of decay and hold the possibility to be synthesized in the laboratory. The alpha decay half-lives and spontaneous fission half-lives of SHN with Z = 122, A = 299-306, with Z = 120, A = 294-300, and with Z = 119, A = 292-297 are also studied. The present study will be useful in the synthesis of superheavy elements Z > 118 by using the actinide based reactions with stable projectiles heavier than 48Ca.
Decay properties of 256-339Ds superheavy nuclei

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2017-09-01

The decay properties of 84 isotopes of darmstadtium superheavy nuclei ( Z = 110) have been studied using various theoretical models. The proton emission half-lives, the alpha decay half-lives, the spontaneous fission half-lives and the cluster decay half-lives of all the isotopes are evaluated. The one-proton emission half-lives and the alpha decay half-lives are predicted using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated alpha half-lives are compared with the available experimental results as well as with the predictions of other theoretical models. The predicted half-lives matches well with the experimental results. The one-proton half-lives are also compared with the predictions using other formalisms. The shell-effect-dependent formula of Santhosh et al. has been employed for calculating the spontaneous fission half-lives. A theoretical comparison of spontaneous fission half-lives with four different formalisms is performed. By comparing the one-proton emission half-lives, the alpha decay half-lives and the spontaneous fission half-lives decay modes are predicted for all the isotopes of Ds. It is seen that the isotopes within the range 256 ≤ A ≤ 263 and 279 ≤ A ≤ 339 decay through spontaneous fission and the isotopes 264 ≤ A ≤ 278 exhibit alpha decay. Cluster decay half-lives are calculated using different models including the Coulomb and proximity potential (CPPM), for determining the magicities in the superheavy region. The effect of magicity at N = 184 and N = 202 were confirmed from the plot of log_{10}T_{1/2} versus neutron number of the daughter nuclei for the emission of different clusters. We hope that the systematic and detailed study of all the possible decay modes of 256-339Ds using various theoretical models will be helpful in the experimental identification of the isotopes of the element in the future.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Pritychenko, B.

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 T 2v 1/2 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.
RADIOACTIVE ELEMENTS IN THE STANDARD ATOMIC WEIGHTS TABLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holden, N.E.; Holden, N.; Holden,N.E.

2011-07-27

In the 1949 Report of the Atomic Weights Commission, a series of new elements were added to the Atomic Weights Table. Since these elements had been produced in the laboratory and were not discovered in nature, the atomic weight value of these artificial products would depend upon the production method. Since atomic weight is a property of an element as it occurs in nature, it would be incorrect to assign an atomic weight value to that element. As a result of that discussion, the Commission decided to provide only the mass number of the most stable (or longest-lived) known isotopemore » as the number to be associated with these entries in the Atomic Weights Table. As a function of time, the mass number associated with various elements has changed as longer-lived isotopes of a particular element has been found in nature, or as improved half-life values of an element's isotopes might cause a shift in the longest-lived isotope from one mass to another. In the 1957 Report of the Atomic Weights Commission, it was decided to discontinue the listing of the mass number in the Atomic Weights Table on the grounds that the kind of information supplied by the mass number is inconsistent with the primary purpose of the Table, i.e., to provide accurate values of 'these constants' for use in various chemical calculations. In addition to the Table of Atomic Weights, the Commission included an auxiliary Table of Radioactive Elements for the first time, where the entry would be the isotope of that element which was the most stable, i.e., the one with the longest known half-life. In their 1973 Report, the Commission noted that the users of the main Table of Atomic Weights were dissatisfied with the omission of values for some elements in that Table and it was decided to reintroduce the mass number for the radioactive elements into the main Table. In their 1983 Report, the Commission decided that radioactive elements were considered to lack a characteristic terrestrial isotopic composition, from which an atomic weight value could be calculated to five or more figure accuracy, without prior knowledge of the sample involved. These elements were again listed in the Atomic Weights Table with no further information, i.e., with no mass number or atomic weight value. For the elements, which have no stable characteristic terrestrial isotopic composition, the data on the half-lives and the relative atomic masses for the nuclides of interest for those elements have been evaluated. The values of the half-lives with their uncertainties are listed in the table. The uncertainties are given for the last digit quoted of the half-life and are given in parentheses. A half-life entry for the Table having a value and an uncertainty of 7 {+-} 3 is listed in the half-life column as 7 (3). The criteria to include data in this Table, is to be the same as it has been for over sixty years. It is the same criteria, which are used for all data that are evaluated for inclusion in the Standard Table of Atomic Weights. If a report of data is published in a peer-reviewed journal, that data is evaluated and considered for inclusion in the appropriate table of the biennial report of the Atomic Weights Commission. As better data becomes available in the future, the information that is contained in either of the Tables of Standard Atomic Weights or in the Table of Radioactive Elements may be modified. It should be noted that the appearance of any datum in the Table of the Radioactive Elements is merely for the purposes of calculating an atomic mass value for any sample of a radioactive material, which might have a variety of isotopic compositions and it has no implication as to the priority for claiming discovery of a given element and is not intended to. The atomic mass values have been taken primarily from the 2003 Atomic Mass Table. Mass values for those radioisotopes that do not appear in the 2003 Atomic mass Table have been taken from preliminary data of the Atomic Mass Data Center. Most of the quoted half-lives.« less
Contribution of fission to heavy-element nucleosynthesis in an astrophysical r-process

NASA Astrophysics Data System (ADS)

Korneev, I. Yu.; Panov, I. V.

2011-12-01

During the formation of heavy elements in the neutron star merger (NSM) scenario with a fairly long duration of the r-process, most of the seed nuclei rapidly burn out at the initial stage. The nucleosynthesis wave rapidly reaches the region of actinoids, where beta-delayed, neutron-induced, and spontaneous fission are the main reaction channels. The fission products of transuranium elements are again drawn into the r-process as new seed nuclei to form the yields of elements with mass numbers A > 100. The contribution from the various types of fission to the formation of heavy and superheavy nuclei is investigated. The proposed r-process model applied to the NSM scenario describes well the observed abundances of chemical elements, which confirms the formation of the main r-process component in the NSM scenario. Simple extrapolations of the spontaneous fission half-lives are shown to be inapplicable for the region of nuclei with N ˜ 184, because the formulas do not reflect the increase in half-life when the shell structure changes as the number of neutrons approaches 184. The formation of superheavy elements in the r-process is possible, but their survival depends to a large extent on how reliable the predictions of nuclear parameters, including the half-lives of the forming nuclei from the island of long-lived isotopes, are. The contributions from various types of fission—neutron-induced, beta-delayed, and spontaneous one—to the formation of heavy elements in the main r-process have been determined.
Synthesis of rutherfordium isotopes in the 238U(26Mg, xn)264-xRf reaction and study of their decay properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gates, Jacklyn M; Gates, J.M.; Garcia, M.A.

2008-01-15

Isotopes of rutherfordium (258-261Rf) were produced in irradiations of 238U targets with 26Mg beams. Excitation functions were measured for the 4n, 5n and 6n exit channels. Production of 261Rf in the 3n exit channel with a cross section of 28+92-26 pb was observed. Alpha decay of 258Rf was observed for the first time with an alpha-particle energy of 9.05+-0.03 MeV and an alpha/total decay branching ratio of 0.31+-0.11. In 259Rf, the electron capture/total decay branching ratio was measured to be 0.15+-0.04. The measured half-lives for 258Rf, 259Rf and 260Rf were 14.7+1.2-1.0 ms, 2.5+0.4-0.3 s and 22.2+3.0-2.4 ms, respectively, in agreementmore » with literature data. The systematics of the alpha decay Q values and of the partial spontaneous fission half-lives were evaluated for even-even nuclides in the region of the N = 152, Z = 100 deformed shell. The influence of the N = 152 shell on the alpha decay Q values for rutherfordium was observed to be similar to that of the lighter elements (96<_ Z<_ 102). However, the N = 152 shell does not stabilize the rutherfordium isotopes against spontaneous fission, as it does in the lighter elements (96<_ Z<_102).« less
Predictions on the modes of decay of even Z superheavy isotopes within the range 104 ≤ Z ≤ 136

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2018-01-01

The decay modes and half lives of all the even Z isotopes of superheavy elements within the range 104 ≤ Z ≤ 136 have been predicted by comparing the alpha decay half-lives with the spontaneous fission half-lives. The Coulomb and proximity potential model for deformed nuclei (CPPMDN) and the shell-effect-dependent formula of Santhosh et al. are used to calculate the alpha half-lives and spontaneous fission half-lives respectively. For theoretical comparison the alpha decay half-lives are also calculated using Coulomb and proximity potential model (CPPM), the Viola-Seaborg-Sobiczewski semi-empirical (VSS) relation, the universal (UNIV) curve of Poenaru et al., the analytical formula of Royer and the universal decay law (UDL) of Qi et al. Another tool used for the evaluation of spontaneous fission half-lives is the semi-empirical formula of Xu et al. The nuclei with alpha decay half-lives less than spontaneous fission half-lives will survive fission and hence decay through alpha emission. The predicted half lives and decay modes are compared with the available experimental results. The one-proton and two-proton separation energies of all the isotopes are calculated to find nuclei which lie beyond the proton drip line. Among 1119 even Z nuclei within the range 104 ≤ Z ≤ 136, 164 nuclei show sequential alpha emission followed by subsequent spontaneous fission. Since the isotopes decay through alpha decay chain and the half-lives are in measurable range, these isotopes are predicted to be synthesized and detected in laboratory via alpha decay. 2 nuclei will decay by alpha decay followed by proton emission, 54 nuclei show full alpha chains, 642 nuclei will decay through spontaneous fission, 166 nuclei exhibit proton decay and 91 isotopes are found to be stable against alpha decay. All the isotopes are tabulated according to their decay modes. The study is intended to enhance further experimental investigations in superheavy region.
β-decay Rates for Exotic Nuclei and r-process Nucleosynthesis up to Thorium and Uranium

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Shibagaki, Shota; Yoshida, Takashi; Kajino, Toshitaka; Otsuka, Takaharu

2018-06-01

Beta-decay rates for exotic nuclei with neutron magic number of N = 126 relevant to r-process nucleosynthesis are studied up to Z = 78 by shell-model calculations. The half-lives for the waiting-point nuclei obtained, which are short compared to a standard finite-range-droplet model, are used to study r-process nucleosynthesis in core-collapse supernova (CCSN) explosions and binary neutron star mergers. The element abundances are obtained up to the third peak as well as beyond the peak region up to thorium and uranium. The position of the third peak is found to be shifted toward a higher mass region in both CCSN explosions and neutron star mergers. We find that thorium and uranium elements are produced more with the shorter shell-model half-lives and their abundances come close to the observed values in CCSN explosions. In the case of binary neutron star mergers, thorium and uranium are produced consistently with the observed values independent of the half-lives.
Beyond mean-field description of Gamow-Teller resonances and β-decay

NASA Astrophysics Data System (ADS)

Niu, Yifei; Colò, Gianluca; Vigezzi, Enrico; Bai, Chunlin; Niu, Zhongming; Sagawa, Hiroyuki

2018-02-01

β-decay half-lives set the time scale of the rapid neutron capture process, and are therefore essential for understanding the origin of heavy elements in the universe. The random-phase approximation (RPA) based on Skyrme energy density functionals is widely used to calculate the properties of Gamow-Teller (GT) transitions, which play a dominant role in β-decay half-lives. However, the RPA model has its limitations in reproducing the resonance width and often overestimates β-decay half-lives. To overcome these problems, effects beyond mean-field can be included on top of the RPA model. In particular, this can be obtained by taking into account the particle-vibration coupling (PVC). Within the RPA+PVC model, we successfully reproduce the experimental GT resonance width and β-decay half-lives in magic nuclei. We then extend the formalism to superfluid nuclei and apply it to the GT resonance in 120Sn, obtaining a good reproduction of the experimental strength distribution. The effect of isoscalar pairing is also discussed.
``Sleeping reactor`` irradiations: Shutdown reactor determination of short-lived activation products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jerde, E.A.; Glasgow, D.C.

1998-09-01

At the High-Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, the principal irradiation system has a thermal neutron flux ({phi}) of {approximately} 4 {times} 10{sup 14} n/cm{sup 2} {center_dot} s, permitting the detection of elements via irradiation of 60 s or less. Irradiations of 6 or 7 s are acceptable for detection of elements with half-lives of as little as 30 min. However, important elements such as Al, Mg, Ti, and V have half-lives of only a few minutes. At HFIR, these can be determined with irradiation times of {approximately} 6 s, but the requirement of immediate countingmore » leads to increased exposure to the high activity produced by irradiation in the high flux. In addition, pneumatic system timing uncertainties (about {+-} 0.5 s) make irradiations of < 6 s less reliable. Therefore, the determination of these ultra-short-lived species in mixed matrices has not generally been made at HFIR. The authors have found that very short lived activation products can be produced easily during the period after reactor shutdown (SCRAM), but prior to the removal of spent fuel elements. During this 24- to 36-h period (dubbed the ``sleeping reactor``), neutrons are produced in the beryllium reflector by the reaction {sup 9}Be({gamma},n){sup 8}Be, the gamma rays principally originating in the spent fuel. Upon reactor SCRAM, the flux drops to {approximately} 1 {times} 10{sup 10} n/cm{sup 2} {center_dot} s within 1 h. By the time the fuel elements are removed, the flux has dropped to {approximately} 6 {times} 10{sup 8}. Such fluxes are ideal for the determination of short-lived elements such as Al, Ti, Mg, and V. An important feature of the sleeping reactor is a flux that is not constant.« less
Calculated half-lives and kinetic energies for spontaneous emission of heavy ions from nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poenaru, D.N.; Greiner, W.; Depta, K.

The most probable decays by spontaneous emission of heavy ions are listed for nuclides with Z = 47--106 and total half-lives>1 ..mu..sec. Partial half-lives, branching ratios relative to ..cap alpha.. decay, kinetic energies, and Q values are estimated by using the analytical superasymmetric fission model, a semiempirical formula for those ..cap alpha..-decay lifetimes which have not been measured, and the new Wapstra--Audi mass tables. Numerous ''stable'' nuclides with Z>40 are found to be metastable with respect to the new decay modes. The current experimental status is briefly reviewed.

94 β-Decay Half-Lives of Neutron-Rich _{55}Cs to _{67}Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation.

PubMed

Wu, J; Nishimura, S; Lorusso, G; Möller, P; Ideguchi, E; Regan, P-H; Simpson, G S; Söderström, P-A; Walker, P M; Watanabe, H; Xu, Z Y; Baba, H; Browne, F; Daido, R; Doornenbal, P; Fang, Y F; Gey, G; Isobe, T; Lee, P S; Liu, J J; Li, Z; Korkulu, Z; Patel, Z; Phong, V; Rice, S; Sakurai, H; Sinclair, L; Sumikama, T; Tanaka, M; Yagi, A; Ye, Y L; Yokoyama, R; Zhang, G X; Alharbi, T; Aoi, N; Bello Garrote, F L; Benzoni, G; Bruce, A M; Carroll, R J; Chae, K Y; Dombradi, Z; Estrade, A; Gottardo, A; Griffin, C J; Kanaoka, H; Kojouharov, I; Kondev, F G; Kubono, S; Kurz, N; Kuti, I; Lalkovski, S; Lane, G J; Lee, E J; Lokotko, T; Lotay, G; Moon, C-B; Nishibata, H; Nishizuka, I; Nita, C R; Odahara, A; Podolyák, Zs; Roberts, O J; Schaffner, H; Shand, C; Taprogge, J; Terashima, S; Vajta, Z; Yoshida, S

2017-02-17

The β-decay half-lives of 94 neutron-rich nuclei ^{144-151}Cs, ^{146-154}Ba, ^{148-156}La, ^{150-158}Ce, ^{153-160}Pr, ^{156-162}Nd, ^{159-163}Pm, ^{160-166}Sm, ^{161-168}Eu, ^{165-170}Gd, ^{166-172}Tb, ^{169-173}Dy, ^{172-175}Ho, and two isomeric states ^{174m}Er, ^{172m}Dy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β-decay half-lives are observed at neutron-number N=97 for _{58}Ce, _{59}Pr, _{60}Nd, and _{62}Sm, and N=105 for _{63}Eu, _{64}Gd, _{65}Tb, and _{66}Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. r-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.
Predictions on the modes of decay of odd Z superheavy isotopes within the range 105 ≤ Z ≤ 135

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2018-05-01

The decay modes of 1051 odd Z superheavy nuclei within the range 105 ≤ Z ≤ 135, and their daughter nuclei are studied by comparing the alpha decay half-lives with the spontaneous fission half-lives. The alpha decay half-lives are calculated using the Coulomb and proximity potential model for deformed nuclei (CPPMDN) proposed by Santhosh et al. (2011) and the spontaneous fission half-lives are obtained with the shell-effect dependent formula of Santhosh et al. (Santhosh and Nithya, 2016). For a theoretical comparison, the alpha decay half-lives are also computed with the Coulomb and proximity potential model (CPPM), Viola-Seaborg-Sobiczewski semi-empirical relation (VSS), Universal curve of Poenaru et al. (UNIV), the analytical formula of Royer, and the Universal decay law of Qi et al. (UDL). The predicted decay modes and half-lives were compared with the available experimental results. The proton and neutron separation energies are calculated to identify those nuclei, which decay through proton and neutron emission. From the entire study of odd Z superheavy elements, it is seen that among 1051 nuclei, 233 nuclei exhibit proton emission and 18 nuclei exhibit neutron emission. 56 nuclei are stable against alpha decay with negative Q value for the decay. 92 nuclei show alpha decay followed by spontaneous fission and 9 nuclei show alpha decay followed by proton emission. 39 nuclei decay through full alpha chain and 595 nuclei decay through spontaneous fission. We hope that the study will be very useful for the future experimental investigations in this field.
α -decay chains of the superheavy nuclei Rg-350255

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2017-05-01

The decay modes and half-lives of 96 isotopes of the superheavy element roentgenium (Rg) within the range of 255 ≤A ≤350 come under investigation in the present paper. The isotopes which lie beyond the proton drip line are identified by calculating the one-proton and two-proton separation energies. The α -decay half-lives are calculated using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). For a theoretical comparison the α half-lives are also evaluated using the Viola-Seaborg semiempirical relation, the universal curve of Poenaru et al., the analytical formula of Royer, and the universal decay law of Qi et al. Spontaneous fission half-lives are computed with the shell-effect-dependent formula of Santhosh and Nithya and the semiempirical formula of Xu et al. The decay modes are predicted by comparing the α -decay half-lives within the CPPMDN with the corresponding spontaneous fission half-lives computed by the shell-effect-dependent formula of Santhosh and Nithya. In our paper it is seen that the isotopes 255-271,273Rg lie beyond the proton drip line and hence decay through proton emission. The isotopes 272,274-277Rg exhibit long α chains. Three α chains are predicted from the isotopes Rg-282278. The isotopes Rg-345283 decay through spontaneous fission. The isotopes Rg-350346 are found to be stable against α decay. The theoretical results are compared with the available experimental results and are seen to be matching well. We hope that our predictions will be useful in future experimental investigations.
Beta-Decay Rates for Exotic Nuclei and R-Process Nucleosynthesis up to Th and U

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Yoshida, Takashi; Shibagaki, Shota; Kajino, Toshitaka; Otsuka, Takaharu

Beta-decay rates for exotic nuclei with N = 126 relevant to r-process nucleosynthesis are studied up to Z = 78 by shell-model calculations. The half-lives for the waiting-point nuclei obtained, which are short compared to a standard FRDM, are used to study r-process nucleosynthesis in neutrino-driven winds and magneto-hydrodynamic jets of core-collapse supernova explosions as well as in binary neutron star mergers. The element abundances are obtained up to the third peak as well as beyond the peak region up to thorium and uranium. Thorium and uranium are found to be produced more with the shorter shell-model half-lives and their abundances come closer to the observed values in core-collapse supernova explosions, while in case of binary neutron star mergers they are produced as much as the observed values rather independent of the half-lives.
Instrumental activation analysis of coal and fly ash with thermal and epithermal neutrons and short-lived nuclides

USGS Publications Warehouse

Steinnes, E.; Rowe, J.J.

1976-01-01

Instrumental neutron activation analysis is applied to the determination of about 25 elements in coals and fly ash by means of nuclides with half-lives of less than 48 h ; thermal and epithermal irradiations are used. The results indicate that epithermal activation is preferable for twelve of the elements (Ga, As, Br, Sr, In, Cs, Ba, La, Sm, Ho, W and U). Data for SRM 1632 (coal) and SRM 1633 (fly ash) compare favorably with the results obtained by other investigators. ?? 1976.
94 β -Decay Half-Lives of Neutron-Rich Cs 55 to Ho 67 : Experimental Feedback and Evaluation of the r -Process Rare-Earth Peak Formation

DOE PAGES

Wu, J.; Nishimura, S.; Lorusso, G.; ...

2017-02-16

The β-decay half-lives of 94 neutron-rich nuclei 144 $-$ 151Cs, 146 $-$ 154Ba, 148 $-$ 156La, 1 50 $-$ 158Ce, 153 $-$160Pr, 156 $-$ 162 Nd, 159 $-$ 163Pm, 160 $-$ 166Sm, 161 $-$ 168Eu , 165 $-$ 170Gd, 166 $-$ 172Tb, 169 $-$ 173Dy, 172 $-$ 175Ho, and two isomeric states 174 mEr, 172 mDy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β -decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd , and 62Sm, and N = 105 for 63Eu,more » 64Gd, 65Tb, and 66Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. In conclusion, $r$-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.« less
Abundance of live 244Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis

PubMed Central

Wallner, A.; Faestermann, T.; Feige, J.; Feldstein, C.; Knie, K.; Korschinek, G.; Kutschera, W.; Ofan, A.; Paul, M.; Quinto, F.; Rugel, G.; Steier, P.

2015-01-01

Half of the heavy elements including all actinides are produced in r-process nucleosynthesis, whose sites and history remain a mystery. If continuously produced, the Interstellar Medium is expected to build-up a quasi-steady state of abundances of short-lived nuclides (with half-lives ≤100 My), including actinides produced in r-process nucleosynthesis. Their existence in today’s interstellar medium would serve as a radioactive clock and would establish that their production was recent. In particular 244Pu, a radioactive actinide nuclide (half-life=81 My), can place strong constraints on recent r-process frequency and production yield. Here we report the detection of live interstellar 244Pu, archived in Earth’s deep-sea floor during the last 25 My, at abundances lower than expected from continuous production in the Galaxy by about 2 orders of magnitude. This large discrepancy may signal a rarity of actinide r-process nucleosynthesis sites, compatible with neutron-star mergers or with a small subset of actinide-producing supernovae. PMID:25601158
DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, J.; Nishimura, S.; Lorusso, G.

The β-decay half-lives of 94 neutron-rich nuclei 144$-$151Cs, 146$-$154Ba, 148$-$156La, 150$-$158Ce, 153$-$160Pr, 156$-$162Nd, 159$-$163Pm, 160$-$166Sm, 161$-$168Eu, 165$-$170Gd, 166$-$172Tb, 169$-$173Dy, 172$-$175Ho, and two isomeric states 174mEr, 172mDy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β-decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd, and 62Sm, and N = 105 for 63Eu, 64Gd, 65Tb, and 66Dy. Lastly, features in the data mirror the interplay between pairing effects and microscopic structure. r-process network calculations performed for a range of mass models and astrophysical conditionsmore » show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system« less
DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, J.; Nishimura, S.; Lorusso, G.

The β-decay half-lives of 94 neutron-rich nuclei 144 $-$ 151Cs, 146 $-$ 154Ba, 148 $-$ 156La, 1 50 $-$ 158Ce, 153 $-$160Pr, 156 $-$ 162 Nd, 159 $-$ 163Pm, 160 $-$ 166Sm, 161 $-$ 168Eu , 165 $-$ 170Gd, 166 $-$ 172Tb, 169 $-$ 173Dy, 172 $-$ 175Ho, and two isomeric states 174 mEr, 172 mDy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β -decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd , and 62Sm, and N = 105 for 63Eu,more » 64Gd, 65Tb, and 66Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. In conclusion, $r$-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.« less
Applications of a global nuclear-structure model to studies of the heaviest elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moeller, P.; Nix, J.R.

1993-10-01

We present some new results on heavy-element nuclear-structure properties calculated on the basis of the finite-range droplet model and folded-Yukawa single-particle potential. Specifically, we discuss calculations of nuclear ground-state masses and microscopic corrections, {alpha}-decay properties, {beta}-decay properties, fission potential-energy surfaces, and spontaneous-fission half-lives. These results, obtained in a global nuclear-structure approach, are particularly reliable for describing the stability properties of the heaviest elements.
Kinetics of removal of intravenous testosterone pulses in normal men.

PubMed

Veldhuis, Johannes D; Keenan, Daniel M; Liu, Peter Y; Takahashi, Paul Y

2010-04-01

Testosterone is secreted into the bloodstream episodically, putatively distributing into total, bioavailable (bio) nonsex hormone-binding globulin (nonSHBG-bound), and free testosterone moieties. The kinetics of total, bio, and free testosterone pulses are unknown. Design Adrenal and gonadal steroidogenesis was blocked pharmacologically, glucocorticoid was replaced, and testosterone was infused in pulses in four distinct doses in 14 healthy men under two different paradigms (a total of 220 testosterone pulses). Testosterone kinetics were assessed by deconvolution analysis of total, free, bioavailable, SHBG-bound, and albumin-bound testosterone concentration-time profiles. Independently of testosterone dose or paradigm, rapid-phase half-lives (min) of total, free, bioavailable, SHBG-bound, and albumin-bound testosterone were comparable at 1.4+/-0.22 min (grand mean+/-S.E.M. of geometric means). Slow-phase testosterone half-lives were highest for SHBG-bound testosterone (32 min) and total testosterone (27 min) with the former exceeding that of free testosterone (18 min), bioavailable testosterone (14 min), and albumin-bound testosterone (18 min; P<0.001). Collective outcomes indicate that i) the rapid phase of testosterone disappearance from point sampling in the circulation is not explained by testosterone dose; ii) SHBG-bound testosterone and total testosterone kinetics are prolonged; and iii) the half-lives of bioavailable, albumin-bound, and free testosterone are short. A frequent-sampling strategy comprising an experimental hormone clamp, estimation of hormone concentrations as bound and free moieties, mimicry of physiological pulses, and deconvolution analysis may have utility in estimating the in vivo kinetics of other hormones, substrates, and metabolites.
Project Physics Text 6, The Nucleus.

ERIC Educational Resources Information Center

Harvard Univ., Cambridge, MA. Harvard Project Physics.

Nuclear physics fundamentals are presented in this sixth unit of the Project Physics text for use by senior high students. Included are discussions of radioactivity, taking into account Bacquerel's discovery, radioactive elements, properties of radiations, radioactive transformations, decay series, and half-lives. Isotopes are analyzed in…
Evaluated activation cross sections of longer-lived radionuclides produced by deuteron-induced reactions on natural copper

NASA Astrophysics Data System (ADS)

Takács, S.; Tárkányi, F.; Király, B.; Hermanne, A.; Sonck, M.

2006-09-01

Activation cross sections for deuteron-induced reactions on natural copper were measured by using a standard stacked foil technique up to 50 MeV deuteron bombarding energy. Reaction products with half-life longer than half an hour were studied. Experimental elemental cross sections were determined and compared with earlier measured data for 62,63,65Zn, 64Cu, 57,65Ni, 57,58,60Co and 59Fe isotopes.
In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

William F. Bauer; Brian K. Schuetz; Gary M. Huestis

2012-09-01

Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dosemore » estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.« less
Quantification of 60Fe atoms by MC-ICP-MS for the redetermination of the half-life.

PubMed

Kivel, Niko; Schumann, Dorothea; Günther-Leopold, Ines

2013-03-01

In many scientific fields, the half-life of radionuclides plays an important role. The accurate knowledge of this parameter has direct impact on, e.g., age determination of archeological artifacts and of the elemental synthesis in the universe. In order to derive the half-life of a long-lived radionuclide, the activity and the absolute number of atoms have to be analyzed. Whereas conventional radiation measurement methods are typically applied for activity determinations, the latter can be determined with high accuracy by mass spectrometric techniques. Over the past years, the half-lives of several radionuclides have been specified by means of multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) complementary to the earlier reported values mainly derived by accelerator mass spectrometry. The present paper discusses all critical aspects (amount of material, radiochemical sample preparation, interference correction, isotope dilution mass spectrometry, calculation of measurement uncertainty) for a precise analysis of the number of atoms by MC-ICP-MS exemplified for the recently published half-life determination of 60Fe (Rugel et al, Phys Rev Lett 103:072502, 2009).
Radioisotopes: Today's Applications.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC. Nuclear Energy Office.

Radioisotopes are useful because of their three unique characteristics: (1) radiation emission; (2) predictable radioactive lives; and (3) the same chemical properties as the nonradioactive atoms of that element. Researchers are able to "order" a radioisotope with the right radiation, half-life, and chemical property to perform a given task with…
Alpha-decay chains of superheavy nuclei 292-296118

NASA Astrophysics Data System (ADS)

Singh, U. K.; Kumawat, M.; Saxena, G.; Kaushik, M.; Jain, S. K.

2018-05-01

We have employed relativistic mean-field plus BCS (RMF+BCS) approach for the study of even-even superheavy nuclei with Z = 118 which is the last and recent observed element in the periodic chart so far. Our study includes binding energies, Qα values, alpha-decay half-lives and spontaneous decay half-lives along with comparison of available experimental data and the results of FRDM calculations. We find an excellent match with the only known decay chain of 294118 for Z = 118 so far and predict decay chain of 292118 and 296118 in consistency with known experimental decay chains and FRDM results. These results may provide a very helpful insight to conduct experiments for realizing the presence of nuclei with Z = 118.
IUPAC Periodic Table of Isotopes for the Educational Community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holden N. E.; Holden,N.E.; Coplen,T.B.

2012-07-15

John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in thismore » area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).« less
Americium-241 and plutonium-237 turnover in mussels ( Mytilus galloprovincialis) living in field enclosures

NASA Astrophysics Data System (ADS)

Guary, J. C.; Fowler, S. W.

1981-02-01

Loss of 241Am and 237Pu from contaminated mussels ( Mytilus galloprovincialis) living in situ in the Mediterranean Sea is described as the sum of three exponential functions. In the case of 241Am, two short-lived compartments representing a total of 80% of the incorporated radionuclide turned over rapidly with biological half-lives of 2 and 3 weeks. The remaining fraction of 241Am, associated with a long-lived compartment, was lost at an extremely slow rate ( Tb1/2=1·3 years). Plutonium-237 turnover in the two short-lived compartments (containing 70% of the Pu) was more rapid ( Tb1/2=1-2 days and 2 weeks) than that of 241Am; however, there was some indication that subsequent loss rates of the two radionuclides in long-lived compartments may be similar if determined over comparable periods of time. Loss rates of 241Am differed for the various tissues, with the most rapid rates occurring in gill, viscera and shell. Abrupt changes in loss observed in muscle and mantle suggested a translocation of 241Am to muscle and mantle during depuration. Whole shell contained by far the largest fraction (˜90%) of both 241Am and 237Pu taken up; in addition, these radionuclides are not irreversibly bound to mussel shell but readily leach into the water. These observations suggest that mollusc shell may influence the biogeochemistry of transuranic elements in littoral zones.
The Next Big Thing We Won't Be Able to Live Without? Fulbright's Half-Life Theory Gives Us Some Ideas

ERIC Educational Resources Information Center

Fulbright, Ron

2015-01-01

My great-grandparents lived one-half of their lives without electricity. My grandparents lived one-half of their lives without a telephone. My parents lived one-half of their lives without a television. My sister has lived one-half of her life without a computer and I have lived one-half of my life without Google. Today, we could not imagine life…

Teaching Management: A Field Guide for Professors, Consultants, and Corporate Trainers

ERIC Educational Resources Information Center

Clawson, James G. S.; Haskins, Mark E.

2006-01-01

How can every management class be a dynamic, unforgettable experience? This much-needed book distills over half a century of the authors' combined experience as university professors, consultants, and advisors to corporate training departments. In a lively, hands-on fashion, it describes the fundamental elements in every learning situation,…
Evaluated activation cross sections of longer-lived radionuclides produced by deuteron induced reactions on natural nickel

NASA Astrophysics Data System (ADS)

Takács, S.; Tárkányi, F.; Király, B.; Hermanne, A.; Sonck, M.

2007-07-01

Activation cross sections for deuteron induced nuclear reactions on natural nickel target were studied by using a standard stacked foil technique and gamma spectrometry up to 50 MeV deuteron bombarding energy. Reaction products with half life of at least half an hour were studied. Experimental elemental activation cross sections were determined for reactions on nickel resulting in 61,64Cu, 56,57Ni, 55,56,57,58,60,61Co, 52,54,56Mn and 51Cr radionuclides and were compared with earlier measured data.
Decay properties of {sup 265}Sg(Z=106) and {sup 266}Sg(Z=106)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuerler, A.; Dressler, R.; Eichler, B.

1998-04-01

The presently known most neutron-rich isotopes of element 106 (seaborgium, Sg), {sup 265}Sg and {sup 266}Sg, were produced in the fusion reaction {sup 22}Ne+{sup 248}Cm at beam energies of 121 and 123 MeV. Using the On-Line Gas chemistry Apparatus OLGA, a continuous separation of Sg was achieved within a few seconds. Final products were assayed by {alpha}-particle and spontaneous fission (SF) spectrometry. {sup 265}Sg and {sup 266}Sg were identified by observing time correlated {alpha}-{alpha}-({alpha}) and {alpha}-SF decay chains. A total of 13 correlated decay chains of {sup 265}Sg (with an estimated number of 2.8 random correlations) and 3 decay chainsmore » of {sup 266}Sg (0.6 random correlations) were identified. Deduced decay properties were T{sub 1/2}=7.4{sub {minus}2.7}{sup +3.3} s (68{percent} c.i.) and E{sub {alpha}}=8.69 MeV (8{percent}), 8.76 MeV (23{percent}), 8.84 MeV (46{percent}), and 8.94 MeV (23{percent}) for {sup 265}Sg; and T{sub 1/2}=21{sub {minus}12}{sup +20} s (68{percent} c.i.) and E{sub {alpha}}=8.52 MeV (33{percent}) and 8.77 MeV (66{percent}) for {sup 266}Sg. The resolution of the detectors was between 50{endash}100 keV (full width at half maximum). Upper limits for SF of {le}35{percent} and {le}82{percent} were established for {sup 265}Sg and {sup 266}Sg, respectively. The upper limits for SF are given with a 16{percent} error probability. Using the lower error limits of the half-lives of {sup 265}Sg and {sup 266}Sg, the resulting lower limits for the partial SF half-lives are T{sub 1/2}{sup SF}({sup 265}Sg){ge}13 s and T{sub 1/2}{sup SF}({sup 266}Sg){ge}11 s. Correspondingly, the partial {alpha}-decay half-lives are between T{sub 1/2}{sup {alpha}}({sup 265}Sg)=4.7{endash}16.5 s (68{percent} c.i.) and T{sub 1/2}{sup {alpha}}({sup 266}Sg)=9{endash}228 s (68{percent} c.i.), using the upper and lower error limits of the half-lives of {sup 265}Sg and {sup 266}Sg. The lower limit on the partial SF half-life of {sup 266}Sg is in good agreement with theoretical predictions. Production cross sections of about 240 pb and 25 pb for the {alpha}-decay branch in {sup 265}Sg and {sup 266}Sg were estimated, respectively. {copyright} {ital 1998} {ital The American Physical Society}« less
Studies of Flerovium and Element 115 Homologs with Macrocyclic Extractants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Despotopulos, John D.

2015-03-12

Study of the chemistry of the heaviest elements, Z ≥ 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extractionmore » chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high-purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): natIn(p,n) 113Sn, natSn(p,n) 124Sb, and Au(p,n) 197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the 232U parent to generate 212Pb and 212Bi. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies; crown ethers show high selectivity for metal ions. Finally. a potential chemical system for Fl was established based on the Eichrom Pb resin, and insight to an improved system based on thiacrown ethers is presented.« less
Unique first-forbidden β-decay rates for neutron-rich nickel isotopes in stellar environment

NASA Astrophysics Data System (ADS)

Nabi, Jameel-Un; Stoica, Sabin

2014-02-01

In astrophysical environments, allowed Gamow-Teller (GT) transitions are important, particularly for β-decay rates in presupernova evolution of massive stars, since they contribute to the fine-tuning of the lepton-to-baryon content of the stellar matter prior to and during the collapse of a heavy star. In environments where GT transitions are unfavored, first-forbidden transitions become important especially in medium heavy and heavy nuclei. Particularly in case of neutron-rich nuclei, first-forbidden transitions are favored primarily due to the phase-space amplification for these transitions. In this work the total β-decay half-lives and the unique first-forbidden (U1F) β-decay rates for a number of neutron-rich nickel isotopes, 72-78Ni, are calculated using the proton-neutron quasi-particle random phase approximation (pn-QRPA) theory in stellar environment for the first time. For the calculation of the β-decay half-lives both allowed and unique first-forbidden transitions were considered. Comparison of the total half-lives is made with measurements and other theoretical calculations where it was found that the pn-QRPA results are in better agreement with experiments and at the same time are suggestive of inclusion of rank 0 and rank 1 operators in first-forbidden rates for still better results.
Chemical experiments with superheavy elements.

PubMed

Türler, Andreas

2010-01-01

Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.
Neutron activation analyses and half-life measurements at the usgs triga reactor

NASA Astrophysics Data System (ADS)

Larson, Robert E.

Neutron activation of materials followed by gamma spectroscopy using high-purity germanium detectors is an effective method for making measurements of nuclear beta decay half-lives and for detecting trace amounts of elements present in materials. This research explores applications of neutron activation analysis (NAA) in two parts. Part 1. High Precision Methods for Measuring Decay Half-Lives, Chapters 1 through 8 Part one develops research methods and data analysis techniques for making high precision measurements of nuclear beta decay half-lives. The change in the electron capture half-life of 51Cr in pure chromium versus chromium mixed in a gold lattice structure is explored, and the 97Ru electron capture decay half-life are compared for ruthenium in a pure crystal versus ruthenium in a rutile oxide state, RuO2. In addition, the beta-minus decay half-life of 71mZn is measured and compared with new high precision findings. Density Functional Theory is used to explain the measured magnitude of changes in electron capture half-life from changes in the surrounding lattice electron configuration. Part 2. Debris Collection Nuclear Diagnostic at the National Ignition Facility, Chapters 9 through 11 Part two explores the design and development of a solid debris collector for use as a diagnostic tool at the National Ignition Facility (NIF). NAA measurements are performed on NIF post-shot debris collected on witness plates in the NIF chamber. In this application NAA is used to detect and quantify the amount of trace amounts of gold from the hohlraum and germanium from the pellet present in the debris collected after a NIF shot. The design of a solid debris collector based on material x-ray ablation properties is given, and calculations are done to predict performance and results for the collection and measurements of trace amounts of gold and germanium from dissociated hohlraum debris.
Estimating biodegradation half-lives for use in chemical screening.

PubMed

Aronson, Dallas; Boethling, Robert; Howard, Philip; Stiteler, William

2006-06-01

Biodegradation half-lives are needed for many applications in chemical screening, but these data are not available for most chemicals. To address this, in phase one of this work we correlated the much more abundant ready and inherent biodegradation test data with measured half-lives for water and soil. In phase two, we explored the utility of the BIOWIN models (in EPI Suite) and molecular fragments for predicting half-lives. BIOWIN model output was correlated directly with measured half-lives, and new models were developed by re-regressing the BIOWIN fragments against the half-lives. All of these approaches gave the best results when used for binary (fast/slow) classification of half-lives, with accuracy generally in the 70-80% range. In the last phase, we used the collected half-life data to examine the default half-lives assigned by EPI Suite and the PBT Profiler for use as input to their level III multimedia models. It is concluded that estimated half-lives should not be used for purposes other than binning or prioritizing chemicals unless accuracy improves significantly.
Beta-Decay Rates for Exotic Nuclei and R-Process Nucleosynthesis

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Yoshida, Takashi; Wanajo, Shinya; Kajino, Toshitaka; Otsuka, Takaharu

Beta-decay rates for exotic nuclei at N = 126 relevant to r-process nucleosynthesis are studied by shell-model calculations. The half-lives obtained are used to study r-process nucleosynthesis in core-collapse supernova explosions and binary neutron star mergers. The element abundances are obtained up to the third peak as well as beyond the peak region up to uranium.
Gas Phase Chromatography of some Group 4, 5, and 6 Halides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sylwester, Eric Robert

1998-10-01

Gas phase chromatography using The Heavy Element Volatility Instrument (HEVI) and the On Line Gas Apparatus (OLGA III) was used to determine volatilities of ZrBr 4, HfBr 4, RfBr 4, NbBr 5, TaOBr 3, HaCl 5, WBr 6, FrBr, and BiBr 3. Short-lived isotopes of Zr, Hf, Rf, Nb, Ta, Ha, W, and Bi were produced via compound nucleus reactions at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory and transported to the experimental apparatus using a He gas transport system. The isotopes were halogenated, separated from the other reaction products, and their volatilities determined by isothermal gas phase chromatography.more » Adsorption Enthalpy (ΔH a) values for these compounds were calculated using a Monte Carlo simulation program modeling the gas phase chromatography column. All bromides showed lower volatility than molecules of similar molecular structures formed as chlorides, but followed similar trends by central element. Tantalum was observed to form the oxybromide, analogous to the formation of the oxychloride under the same conditions. For the group 4 elements, the following order in volatility and ΔH a was observed: RfBr 4 > ZrBr 4 > HfBr 4. The ΔH a values determined for the group 4, 5, and 6 halides are in general agreement with other experimental data and theoretical predictions. Preliminary experiments were performed on Me-bromides. A new measurement of the half-life of 261Rf was performed. 261Rf was produced via the 248Cm( 18O, 5n) reaction and observed with a half-life of 74 -6 +7 seconds, in excellent agreement with the previous measurement of 78 -6 +11 seconds. We recommend a new half-life of 75±7 seconds for 261Rf based on these two measurements. Preliminary studies in transforming HEVI from an isothermal (constant temperature) gas phase chromatography instrument to a thermochromatographic (variable temperature) instrument have been completed. Thermochromatography is a technique that can be used to study the volatility and ΔH a of longer-lived isotopes off-line, Future work will include a comparison between the two techniques and the use of thermochromatography to study isotopes in a wider range of half-lives and molecular structures.« less
Combining Optical Reporter Proteins with Different Half-lives to Detect Temporal Evolution of Hypoxia and Reoxygenation in Tumors

PubMed Central

Danhier, Pierre; Krishnamachary, Balaji; Bharti, Santosh; Kakkad, Samata; Mironchik, Yelena; Bhujwalla, Zaver M.

2015-01-01

Here we have developed a hypoxia response element driven imaging strategy that combined the hypoxia-driven expression of two optical reporters with different half-lives to detect temporal changes in hypoxia and hypoxia inducible factor (HIF) activity. For this purpose, human prostate cancer PC3 cells were transfected with the luciferase gene fused with an oxygen-dependent degradation domain (ODD-luc) and a variant of the enhanced green fluorescent protein (EGFP). Both ODD-luciferase and EGFP were under the promotion of a poly-hypoxia-response element sequence (5xHRE). The cells constitutively expressed tdTomato red fluorescent protein. For validating the imaging strategy, cells were incubated under hypoxia (1% O2) for 48 hours and then reoxygenated. The luciferase activity of PC3-HRE-EGFP/HRE-ODD-luc/tdtomato cells detected by bioluminescent imaging rapidly decreased after reoxygenation, whereas EGFP levels in these cells remained stable for several hours. After in vitro validation, PC3-HRE-EGFP/HRE-ODD-luc/tdtomato tumors were implanted subcutaneously and orthotopically in nude male mice and imaged in vivo and ex vivo using optical imaging in proof-of-principle studies to demonstrate differences in optical patterns between EGFP expression and bioluminescence. This novel "timer" imaging strategy of combining the short-lived ODD-luciferase and the long-lived EGFP can provide a time frame of HRE activation in PC3 prostate cancer cells and will be useful to understand the temporal changes in hypoxia and HIF activity during cancer progression and following treatments including HIF targeting strategies. PMID:26696369
High-precision half-life measurements of the T =1 /2 mirror β decays 17F and 33Cl

NASA Astrophysics Data System (ADS)

Grinyer, J.; Grinyer, G. F.; Babo, M.; Bouzomita, H.; Chauveau, P.; Delahaye, P.; Dubois, M.; Frigot, R.; Jardin, P.; Leboucher, C.; Maunoury, L.; Seiffert, C.; Thomas, J. C.; Traykov, E.

2015-10-01

Background: Measurements of the f t values for T =1 /2 mirror β+ decays offer a method to test the conserved vector current hypothesis and to determine Vud, the up-down matrix element of the Cabibbo-Kobayashi-Maskawa matrix. In most mirror decays used for these tests, uncertainties in the f t values are dominated by the uncertainties in the half-lives. Purpose: Two precision half-life measurements were performed for the T =1 /2 β+ emitters, 17F and 33Cl, in order to eliminate the half-life as the leading source of uncertainty in their f t values. Method: Half-lives of 17F and 33Cl were determined using β counting of implanted radioactive ion beam samples on a moving tape transport system at the Système de Production d'Ions Radioactifs Accélérés en Ligne low-energy identification station at the Grand Accélérateur National d'Ions Lourds. Results: The 17F half-life result, 64.347 (35) s, precise to ±0.05 % , is a factor of 5 times more precise than the previous world average. The half-life of 33Cl was determined to be 2.5038 (22) s. The current precision of ±0.09 % is nearly 2 times more precise compared to the previous world average. Conclusions: The precision achieved during the present measurements implies that the half-life no longer dominates the uncertainty of the f t values for both T =1 /2 mirror decays 17F and 33Cl.
Manganese-stabilized austenitic stainless steels for fusion applications

DOEpatents

Klueh, Ronald L.; Maziasz, Philip J.

1990-08-07

An austenitic stainless steel that is comprised of Fe, Cr, Mn, C but no Ni or Nb and minimum N. To enhance strength and fabricability minor alloying additions of Ti, W, V, B and P are made. The resulting alloy is one that can be used in fusion reactor environments because the half-lives of the elements are sufficiently short to allow for handling and disposal.
A Cultural Resources Evaluation of the Pammel Creek Site (47Lc61): An Oneota Occupation at La Crosse, Wisconsin

DTIC Science & Technology

1984-05-01

1 1 chrysemys/Gratemys sp. 1 - Small turtle sp. 2 - Fishes Estimated Total Live Weipht(kg) Lepisosteus sp. 3 1 .5 Amia calva 1 1 - Esox sp. 1 1 .2...Amphib. Gastropods 4 4 Feature 3 Estimated Total Fishes Live Weight(kg) Amia calva 1 1 2.3 Ictaluridae 2 1 •9 Feature 4 4 Freshwater Mussels Quadrula...Remains by Feature Number of Elements MNI 6 F.9 (cont.) Estimated Total Fishes Live Weight(kg) Lepisosteus sp. 5 1 .5 Amia calva 3 - - Catosom6i ae 1
Evaluating the environmental parameters that determine aerobic biodegradation half-lives of pesticides in soil with a multivariable approach.

PubMed

Wang, Yuxin; Lai, Adelene; Latino, Diogo; Fenner, Kathrin; Helbling, Damian E

2018-06-14

Aerobic biodegradation half-lives (half-lives) are key parameters used to evaluate pesticide persistence in soil. However, half-life estimates for individual pesticides often span several orders of magnitude, reflecting the impact that various environmental or experimental parameters have on half-lives in soil. In this work, we collected literature-reported half-lives for eleven pesticides along with associated metadata describing the environmental or experimental conditions under which they were derived. We then developed a multivariable framework to discover relationships between the half-lives and associated metadata. We first compared data for the herbicide atrazine collected from 95 laboratory and 65 field studies. We discovered that atrazine application history and soil texture were the parameters that have the largest influence on the observed half-lives in both types of studies. We then extended the analysis to include ten additional pesticides with data collected exclusively from laboratory studies. We found that, when data were available, pesticide application history and biomass concentrations were always positively associated with half-lives. The relevance of other parameters varied among the pesticides, but in some cases the variability could be explained by the physicochemical properties of the pesticides. For example, we found that the relative significance of the organic carbon content of soil for determining half-lives depends on the relative solubility of the pesticide. Altogether, our analyses highlight the reciprocal influence of both environmental parameters and intrinsic physicochemical properties for determining half-lives in soil. Copyright © 2018 Elsevier Ltd. All rights reserved.
Combining Optical Reporter Proteins with Different Half-lives to Detect Temporal Evolution of Hypoxia and Reoxygenation in Tumors.

PubMed

Danhier, Pierre; Krishnamachary, Balaji; Bharti, Santosh; Kakkad, Samata; Mironchik, Yelena; Bhujwalla, Zaver M

2015-12-01

Here we have developed a hypoxia response element driven imaging strategy that combined the hypoxia-driven expression of two optical reporters with different half-lives to detect temporal changes in hypoxia and hypoxia inducible factor (HIF) activity. For this purpose, human prostate cancer PC3 cells were transfected with the luciferase gene fused with an oxygen-dependent degradation domain (ODD-luc) and a variant of the enhanced green fluorescent protein (EGFP). Both ODD-luciferase and EGFP were under the promotion of a poly-hypoxia-response element sequence (5xHRE). The cells constitutively expressed tdTomato red fluorescent protein. For validating the imaging strategy, cells were incubated under hypoxia (1% O2) for 48 hours and then reoxygenated. The luciferase activity of PC3-HRE-EGFP/HRE-ODD-luc/tdtomato cells detected by bioluminescent imaging rapidly decreased after reoxygenation, whereas EGFP levels in these cells remained stable for several hours. After in vitro validation, PC3-HRE-EGFP/HRE-ODD-luc/tdtomato tumors were implanted subcutaneously and orthotopically in nude male mice and imaged in vivo and ex vivo using optical imaging in proof-of-principle studies to demonstrate differences in optical patterns between EGFP expression and bioluminescence. This novel "timer" imaging strategy of combining the short-lived ODD-luciferase and the long-lived EGFP can provide a time frame of HRE activation in PC3 prostate cancer cells and will be useful to understand the temporal changes in hypoxia and HIF activity during cancer progression and following treatments including HIF targeting strategies. Copyright © 2015 Nencki Institute of Experimental Biology, Polish Academy of Sciences,. Published by Elsevier Inc. All rights reserved.
A momentum-space formulation without partial wave decomposition for scattering of two spin-half particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fachruddin, Imam, E-mail: imam.fachruddin@sci.ui.ac.id; Salam, Agus

2016-03-11

A new momentum-space formulation for scattering of two spin-half particles, both either identical or unidentical, is formulated. As basis states the free linear-momentum states are not expanded into the angular-momentum states, the system’s spin states are described by the product of the spin states of the two particles, and the system’s isospin states by the total isospin states of the two particles. We evaluate the Lippmann-Schwinger equations for the T-matrix elements in these basis states. The azimuthal behavior of the potential and of the T-matrix elements leads to a set of coupled integral equations for the T-matrix elements in twomore » variables only, which are the magnitude of the relative momentum and the scattering angle. Some symmetry relations for the potential and the T-matrix elements reduce the number of the integral equations to be solved. A set of six spin operators to express any interaction of two spin-half particles is introduced. We show the spin-averaged differential cross section as being calculated in terms of the solution of the set of the integral equations.« less
U.S. War Costs: Two Parts Temporary, One Part Permanent.

PubMed

Edwards, Ryan D

2014-05-01

Military spending, fatalities, and the destruction of capital, all of which are immediately felt and are often large, are the most overt costs of war. They are also relatively short-lived. But the costs of war borne by combatants and their caretakers, which includes families, communities, and the modern welfare state, tend instead to be lifelong. In this paper I show that a significant component of the budgetary costs associated with U.S. wars is long-lived. One third to one half of the total present value of historical war costs are benefits distributed over the remaining life spans of veterans and their dependents. Even thirty years after the end of hostilities, typically half of all benefits remain to be paid. Estimates of the costs of injuries and deaths suggest that the private burden of war borne by survivors, namely the uncompensated costs of service-related injuries, are also large and long-lived.
U.S. War Costs: Two Parts Temporary, One Part Permanent

PubMed Central

Edwards, Ryan D.

2014-01-01

Military spending, fatalities, and the destruction of capital, all of which are immediately felt and are often large, are the most overt costs of war. They are also relatively short-lived. But the costs of war borne by combatants and their caretakers, which includes families, communities, and the modern welfare state, tend instead to be lifelong. In this paper I show that a significant component of the budgetary costs associated with U.S. wars is long-lived. One third to one half of the total present value of historical war costs are benefits distributed over the remaining life spans of veterans and their dependents. Even thirty years after the end of hostilities, typically half of all benefits remain to be paid. Estimates of the costs of injuries and deaths suggest that the private burden of war borne by survivors, namely the uncompensated costs of service-related injuries, are also large and long-lived. PMID:25221367
β -decay of very neutron-rich Pd and Ag nuclei

NASA Astrophysics Data System (ADS)

Smith, Karl; S323 / S410 Collaboration

2013-10-01

The astrophysical origin of about half of the elements heavier than iron have been attributed to the rapid neutron capture process. The modeling of such a process requires not only the correct astrophysical conditions but also reliable nuclear physics. The properties of neutron-rich nuclei in the region just below the N = 82 shell closure are of particular interest as they are responsible for the A = 130 peak in the solar abundance pattern. An experiment to investigate half-lives and β-delayed neutron emission branching ratios of very neutron-rich Pd and Ag isotopes was performed at the GSI projectile FRagment Separator (FRS). The FRS was used to separate products from in-flight fission of a 900 MeV/u 238U beam. Ions of interest were then implanted in the Silicon IMplantation detector and Beta Absorber (SIMBA) array. The high pixelation of the implantation detectors allowed for time-position correlation of the order of several seconds between implants and decays. Neutrons emitted during the decay were detected by the BEta deLayEd Neutron detector (BELEN) which surrounded the SIMBA array. Resulting analysis of half-lives and neutron emission branching ratios including a time-dependent background will be presented.

High-temperature brushless DC motor controller

DOEpatents

Cieslewski, Crzegorz; Lindblom, Scott C.; Maldonado, Frank J.; Eckert, Michael Nathan

2017-05-16

A motor control system for deployment in high temperature environments includes a controller; a first half-bridge circuit that includes a first high-side switching element and a first low-side switching element; a second half-bridge circuit that includes a second high-side switching element and a second low-side switching element; and a third half-bridge circuit that includes a third high-side switching element and a third; low-side switching element. The motor controller is arranged to apply a pulse width modulation (PWM) scheme to switch the first half-bridge circuit, second half-bridge circuit, and third half-bridge circuit to power a motor.
Suitability of regulatory data to predict micropollutant degradation in rivers

NASA Astrophysics Data System (ADS)

Honti, Mark; Bischoff, Fabian; Moser, Andreas; Stamm, Christian; Fenner, Kathrin

2017-04-01

For many chemicals a certain loss to surface water bodies over their life-cycle is unavoidable. These include pesticides, human pharmaceuticals, biocides, industrial chemicals, and veterinary medicines. Since most of them possess an intentional biological activity, they bear the potential to harm non-target organisms in the environment. The actual exposure to a chemical in the environment after emission is determined by its persistence, i.e., by the rate at which it is removed by biological and chemical degradation processes. For surface water systems, major transformation processes include chemical hydrolysis, direct and indirect photo-transformation and microbial biotransformation. Laboratory-based test systems play an important role in evaluating chemical transformation for regulatory purposes due to their replicability, their lower costs compared to field tests, and the better representation of environmental systems compared to lower tier biodegradability and hydrolysis tests. The OECD 308 and 309 test systems are relevant for evaluation of microbial biotransformation of chemicals in surface waters. Degradation half-lives derived from these experiments are typically used in exposure modeling and persistence assessment. These "simulation" tests have been severely criticized for yielding results strongly specific to the experimental systems and for therefore being irrelevant for most environmental conditions. Our objective was to check the relation between degradation half-lives measured in regulatory tests and half-lives observed in actual surface water bodies. We used the Rhine river catchment and the results of a field campaign carried out in 2011 (Ruff et al. 2015, Water Research). 7 pharmaceuticals were selected, including a conservative benchmark substance. Laboratory degradation half-lives were extracted from OECD 308 data. A GIS model was set up to simulate the accumulation of chemicals from the wastewater treatment plants of the catchment and the behavior of the chemicals in the river Rhine. For substances with OECD 308 data, predictions using compartment-specific degradation half-lives were found to be in accordance with measured concentrations, but not much different from simulations assuming no degradation. This suggests that the usually fairly long water half-lives dominated the compounds' behavior in the river Rhine. Besides this, it highlighted that the shorter total system half-lives derived from OECD 308 are indeed irrelevant for assessing persistence in medium to large river systems. For two substances, it was not possible to tune modelled concentration patterns to be in agreement with observed data, even when assuming different extents of degradation. This underlined the influence of input uncertainty (e.g. consumption in different countries and regions). Finally, the model was used to investigate what kind of water half-lives would result in an observable degradation along the Rhine. Substances with half-lives shorter than 9 days would show spatial concentration patterns that are clearly different from those of a conservative benchmark chemical, given the typical measurement, model and input uncertainty. Besides learning the inadequacy of certain indicators from laboratory simulation studies for assessment of environmental persistence, our results suggest that emissions of many organic micropollutants showing observable degradation in the laboratory are transferred almost without loss to the sea, even from such a large river basin as the Rhine.
Multiple CP non-conserving mechanisms of ( ββ)0 ν -decay and nuclei with largely different nuclear matrix elements

NASA Astrophysics Data System (ADS)

Meroni, A.; Petcov, S. T.; Šimkovic, F.

2013-02-01

We investigate the possibility to discriminate between different pairs of CP non-conserving mechanisms inducing the neutrinoless double beta ( ββ)0 ν -decay by using data on ( ββ)0 ν -decay half-lives of nuclei with largely different nuclear matrix elements (NMEs). The mechanisms studied are: light Majorana neutrino exchange, heavy left-handed (LH) and heavy right-handed (RH) Majorana neutrino exchanges, lepton charge non-conserving couplings in SUSY theories with R-parity breaking giving rise to the "dominant gluino exchange" and the "squark-neutrino" mechanisms. The nuclei considered are 76Ge, 82Se, 100Mo, 130Te and 136Xe. Four sets of nuclear matrix elements (NMEs) of the decays of these five nuclei, derived within the Self-consistent Renormalized Quasiparticle Random Phase Approximation (SRQRPA), were employed in our analysis. While for each of the five single mechanisms discussed, the NMEs for 76Ge, 82Se, 100Mo and 130Te differ relatively little, the relative difference between the NMEs of any two nuclei not exceeding 10%, the NMEs for 136 Xe differ significantly from those of 76Ge, 82 Se, 100Mo and 130Te, being by a factor ~ (1.3 - 2.5) smaller. This allows, in principle, to draw conclusions about the pair of non-interfering (interfering) mechanisms possibly inducing the ( ββ)0 ν -decay from data on the half-lives of 136 Xe and of at least one (two) more isotope(s) which can be, e.g., any of the four, 76 Ge, 82 Se, 100 Mo and 130 Te. Depending on the sets of mechanisms considered, the conclusion can be independent of, or can depend on, the NMEs used in the analysis. The implications of the EXO lower bound on the half-life of 136 Xe for the problem studied are also exploited.
WE-AB-206-03: Workshop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Z.

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less
WE-AB-206-01: Diagnostic Ultrasound Imaging Quality Assurance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zagzebski, J.

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less
Separation efficiency of the MASHA facility for short-lived mercury isotopes

NASA Astrophysics Data System (ADS)

Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Kliman, J.; Kondratiev, N. A.; Krupa, L.; Novoselov, A. S.; Oganessian, Yu. Ts.; Podshibyakin, A. V.; Salamatin, V. S.; Siváček, I.; Stepantsov, S. V.; Vanin, D. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Granja, C.; Pospisil, S.

2014-06-01

The mass-separator MASHA built to identify Super Heavy Elements by their mass-to-charge ratios is described. The results of the off- and on-line measurements of its separation efficiency are presented. In the former case four calibrated leaks of noble gases were used. In the latter the efficiency was measured via 284 MeV Ar beam and with using the hot catcher. The ECR ion source was used in both cases. The -radioactive isotopes of mercury produced in the complete fusion reaction Ar+SmHg+xn were detected at the mass-separator focal plane. The half-lives and the separation efficiency for the short-lived mercury isotopes were measured. Potentialities of the MEDIPIX detector system have been demonstrated for future use at the mass-separator MASHA.
Mesonic enhancement of the weak axial charge and its effect on the half-lives and spectral shapes of first-forbidden J+↔J- decays

NASA Astrophysics Data System (ADS)

Kostensalo, Joel; Suhonen, Jouni

2018-06-01

The effects of the enhancement of the axial-charge matrix element γ5 were studied in medium heavy and heavy nuclei for first-forbidden J+ ↔J- decay transitions using the nuclear shell model. Noticeable dependence on the enhancement ɛMEC of the axial-charge matrix element, as well as on the value of the axial-vector coupling constant gA was found in the spectral shapes of 93Y, 95Sr, and 97Y. The importance of the spectrum of 138Cs in the determination of gA is discussed. Half-life analyses in the A ≈ 95 and A ≈ 135 regions were done, and consistent results gA ≈ 0.90, 0.75, and 0.65, corresponding to the three enhancement scenarios ɛMEC = 1.4, 1.7, and 2.0, were obtained. Connection to the reactor-antineutrino anomaly is pointed out.
Indoor Air Quality Management for Operations and Maintenance Personnel

DTIC Science & Technology

1991-09-01

short-lived radioisotopes collectively referred to as radon " daughters ." The first four of these daughters-polonium- 218, lead-214, bismuth-214, and...that can damage cells, increasing the risk of lung cancer. The radiation dose from inhaled radon daughters makes up about half the total dose from
Canada's Indians. Revised Edition.

ERIC Educational Resources Information Center

Wilson, James

Over a half million people in Canada today are identifiably of Native ancestry, legally categorized as Inuit (Eskimos), status Indians, or nonstatus Indians. Status Indians comprise 573 bands with total membership of about 300,000 people, most of whom live on 2,242 reserves. They are the direct responsibility of the federal government and have…
Congenital cardiac disease in childhood x socioeconomic conditions: a relationship to be considered in public health?

PubMed

Barros, Thayanny Lopes do Vale; Dias, Marly de Jesus Sá; Nina, Rachel Vilela de Abreu Haickel

2014-01-01

Congenital heart defects, cardiac malformations that occur in the embryonic period, constitute a serious health problem. They cover a proportion of 8-10 per 1000 live births and contribute to infant mortality. To identify the socioeconomic status of children undergoing cardiac surgery at the Hospital Universitário da Universidade Federal do Maranhão, in São Luis, the existence of material elements that contribute to worsening conditions. We conducted a retrospective study with a quantitative approach, descriptive and reflective, from the interviews conducted by the Social Service Social with families of children with heart disease from January 2011 to July 2012. A total of 95 interviews, the results reveal that (75.79%) of children have elements that suggest poor socioeconomic conditions. It also shows that only 66.33% lived in brick house, while (31.73%) in mud, adobe and straw houses. With regard to income, it showed that only 4.08% received 1-2 minimum wages, while the remaining (95.9%) with benchmarks oscillating half the minimum wage (27.55%), 1/4 of the minimum wage and (24.48%) and income below 70 dollars per person, featuring extreme poverty. On the social security situation prevailing at children with no ties to 61.22%. With respect to benefits, we found that only (12.24%) of children were in the enjoyment of the Continuous Cash Benefit - CCB. Poor socioeconomic conditions listed as major obstacles in meeting the needs, resulting in the maintenance of health conditions and even allowing the aggravation of an existing pathology.
Atomic weights of the elements 1999

USGS Publications Warehouse

Coplen, T.B.

2001-01-01

The biennial review of atomic-weight, Ar(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements: Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic-mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999. Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or atomic-weight values are included in this report for the information of the interested scientific community.
Role of constant value of surface diffuseness in alpha decay half-lives of superheavy nuclei

NASA Astrophysics Data System (ADS)

Dehghani, V.; Alavi, S. A.; Benam, Kh.

2018-05-01

By using WKB method and considering deformed Woods-Saxon nuclear potential, deformed Coulomb potential, and centrifugal potential, the alpha decay half-lives of 68 superheavy alpha emitters have been calculated. The effect of the constant value of surface diffuseness parameter in the range of 0.1 ≤ a ≤ 0.9 (fm) on the potential barrier, tunneling probability, assault frequency, and alpha decay half-lives has been investigated. Significant differences were observed for alpha decay half-lives and decay quantities in this range of surface diffuseness. Good agreement between calculated half-lives with fitted surface diffuseness parameter a = 0.54 (fm) and experiment was observed.
α-decay systematics for superheavy elements

NASA Astrophysics Data System (ADS)

Duarte, S. B.; Teruya, N.

2012-01-01

In this Brief Report we extend the α-decay half-life calculation to the superheavy emitter region to verify whether these nuclei satisfy the recently observed systematics [D. N. Poenaru , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.83.014601 83, 014601 (2011);C. Qi , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.80.044326 80, 044326 (2009)]. To establish the systematics, we have used the α-cluster potential description, which was originally developed to study α decay in connection with nuclear energy level structure [B. Buck , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.51.559 51, 559 (1995)]. The quantum-mechanical tunneling calculation has been employed to obtain the half-lives, showing that with this treatment the systematics are well reproduced in the region of heavy nuclei. Finally, the half-life calculation has been extended to the superheavy emitters to verify whether the systematics can still be observed.
Half-Lives of 101Rh and 108m Ag

NASA Astrophysics Data System (ADS)

Norman, Eric; Browne, Edgardo; Shugart, Howard

2014-09-01

Half-lives of short-lived nuclei can easily be measured by direct counting techniques, whereas those of long-lived naturally-occurring nuclei are usually determined by specific activity measurements. However, half-lives in the range of 1 - 1,000,000 years are notoriously difficult to determine. For example, published values for the half-life of 101Rh range from 3.0 +/- 0.4 years to 10 +/- 1 years, and for 108m Ag published values range from 127 +/- 21 years to 438 +/- 9 years. In order to resolve the issues of what the half-lives of these isotopes actually are, we set up two separate long-term gamma-ray counting experiments. Gamma-ray data were collected in time bins using high-purity Ge detectors and ORTEC PC-based data acquisition systems. We counted in this manner for a period of approximately 5 years for 101Rh and 3 years for 108mAg. In this talk we will describe the details of these experiments and will present the final results for the half-lives of 101Rh and 108mAg determined from these measurements. Half-lives of short-lived nuclei can easily be measured by direct counting techniques, whereas those of long-lived naturally-occurring nuclei are usually determined by specific activity measurements. However, half-lives in the range of 1 - 1,000,000 years are notoriously difficult to determine. For example, published values for the half-life of 101Rh range from 3.0 +/- 0.4 years to 10 +/- 1 years, and for 108m Ag published values range from 127 +/- 21 years to 438 +/- 9 years. In order to resolve the issues of what the half-lives of these isotopes actually are, we set up two separate long-term gamma-ray counting experiments. Gamma-ray data were collected in time bins using high-purity Ge detectors and ORTEC PC-based data acquisition systems. We counted in this manner for a period of approximately 5 years for 101Rh and 3 years for 108mAg. In this talk we will describe the details of these experiments and will present the final results for the half-lives of 101Rh and 108mAg determined from these measurements. This work was supported in part by the U. S. Dept. of Energy under Contract Numbers DE-AC02-05CH11231 and DE-NA0000979.
Data-Driven Molecular Engineering of Solar-Powered Windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Jacqueline M.

Buildings are the centerpiece of modern living, with more than half of the world’s population now living in urban environments. This demographic evolution has led to building use be-coming the main drain of our energy resources. According to the US Energy Information Administration, in 2016, 40 percent of the total energy consumption in the United States came from building use. However, we could overcome this energy drain by embedding new environmental technologies into future cities to realize energy-sustainable buildings.
Data-Driven Molecular Engineering of Solar-Powered Windows

DOE PAGES

Cole, Jacqueline M.

2018-02-14

Buildings are the centerpiece of modern living, with more than half of the world’s population now living in urban environments. This demographic evolution has led to building use be-coming the main drain of our energy resources. According to the US Energy Information Administration, in 2016, 40 percent of the total energy consumption in the United States came from building use. However, we could overcome this energy drain by embedding new environmental technologies into future cities to realize energy-sustainable buildings.
The predictive accuracy of analytical formulas and semiclassical approaches for α decay half-lives of superheavy nuclei

NASA Astrophysics Data System (ADS)

Zhao, T. L.; Bao, X. J.; Guo, S. Q.

2018-02-01

Systematic calculations on the α decay half-lives are performed by using three analytical formulas and two semiclassical approaches. For the three analytical formulas, the experimental α decay half-lives and {Q}α values of the 66 reference nuclei have been used to obtain the coefficients. We get only four adjustable parameters to describe α decay half-lives for even-even, odd-A, and odd-odd nuclei. By comparison between the calculated values from ten analytical formulas and experimental data, it is shown that the new universal decay law (NUDL) foumula is the most accurate one to reproduce the experimental α decay half-lives of the superheavy nuclei (SHN). Meanwhile it is found that the experimental α decay half-lives of SHN are well reproduced by the Royer formula although many parameters are contained. The results show that the NUDL formula and the generalized liquid drop model (GLDM2) with consideration of the preformation factor can give fairly equivalent results for the superheavy nuclei.
Deformed shell model results for neutrinoless positron double beta decay of nuclei in the A = 60-90 region

NASA Astrophysics Data System (ADS)

Sahu, R.; Srivastava, P. C.; Kota, V. K. B.

2013-09-01

Nuclear transition matrix elements (NTME) for neutrinoless positron double beta decay (0νβ+β+ and 0νβ+EC) of 64Zn, 74Se, 78Kr and 84Sr nuclei, which are in the A = 60-90 region, are calculated within the framework of the deformed shell model (DSM) based on Hartree-Fock states. For 64Zn, GXPF1A interaction in 1f7/2, 2p3/2, 1f5/2 and 2p1/2 space with 40Ca as the core is employed. Similarly for 74Se, 78Kr and 84Sr nuclei, 56Ni is taken as the inert core employing a modified Kuo interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space. After ensuring that the DSM gives a good description of the spectroscopic properties of low-lying levels in the four nuclei considered, the NTME are calculated. The half-lives deduced with these NTME, assuming the neutrino mass is 1 eV, are smallest for 78Kr with the half-life for β+EC decay being ˜1027 yr. For all others, the half-lives are in the range of ˜1028-1029 yr.
β -decay studies of very neutron-rich Pd and Ag isotopes

NASA Astrophysics Data System (ADS)

Smith, Karl

2014-03-01

The rapid-neutron capture process (r-process) is attributed as the source of nearly half the elements heavier than iron. To gain insight into the r-process nucleosynthesis, uncertainties such as the nuclear physics involved must be minimized. An experiment was performed to measure properties of neutron-rich nuclei just below the N = 82 shell closure believed to be responsible for production of the A = 130 peak in the solar r-process abundance pattern. β-decay half-lives and neutron branching ratios, Pn values, were measured for Pd and Ag isotopes at the GSI Fragment Separator (FRS). The FRS provided in-flight separation and identification of fission fragments produced by a 900 MeV/u 238U beam. Ions of interest were implanted in the Silicon Implantation detector and Beta Absorber (SIMBA) array. The large pixelation of the array allowed for position-time correlation between implants and the corresponding β-decays. The parent nucleus may decay to an excited state in the daughter, above the neutron separation energy emitting a neutron. These neutrons were moderated and detected in Beta deLayEd Neutron (BELEN) detector surrounding SIMBA. Resulting analysis of half-lives and neutron emission branching ratios including a time-dependent background will be presented.
Population-Based Surveillance of Birth Defects Potentially Related to Zika Virus Infection - 15 States and U.S. Territories, 2016.

PubMed

Delaney, Augustina; Mai, Cara; Smoots, Ashley; Cragan, Janet; Ellington, Sascha; Langlois, Peter; Breidenbach, Rebecca; Fornoff, Jane; Dunn, Julie; Yazdy, Mahsa; Scotto-Rosato, Nancy; Sweatlock, Joseph; Fox, Deborah; Palacios, Jessica; Forestieri, Nina; Leedom, Vinita; Smiley, Mary; Nance, Amy; Lake-Burger, Heather; Romitti, Paul; Fall, Carrie; Prado, Miguel Valencia; Barton, Jerusha; Bryan, J Michael; Arias, William; Brown, Samara Viner; Kimura, Jonathan; Mann, Sylvia; Martin, Brennan; Orantes, Lucia; Taylor, Amber; Nahabedian, John; Akosa, Amanda; Song, Ziwei; Martin, Stacey; Ramlal, Roshan; Shapiro-Mendoza, Carrie; Isenburg, Jennifer; Moore, Cynthia A; Gilboa, Suzanne; Honein, Margaret A

2018-01-26

Zika virus infection during pregnancy can cause serious birth defects, including microcephaly and brain abnormalities (1). Population-based birth defects surveillance systems are critical to monitor all infants and fetuses with birth defects potentially related to Zika virus infection, regardless of known exposure or laboratory evidence of Zika virus infection during pregnancy. CDC analyzed data from 15 U.S. jurisdictions conducting population-based surveillance for birth defects potentially related to Zika virus infection.* Jurisdictions were stratified into the following three groups: those with 1) documented local transmission of Zika virus during 2016; 2) one or more cases of confirmed, symptomatic, travel-associated Zika virus disease reported to CDC per 100,000 residents; and 3) less than one case of confirmed, symptomatic, travel-associated Zika virus disease reported to CDC per 100,000 residents. A total of 2,962 infants and fetuses (3.0 per 1,000 live births; 95% confidence interval [CI] = 2.9-3.2) (2) met the case definition. † In areas with local transmission there was a non-statistically significant increase in total birth defects potentially related to Zika virus infection from 2.8 cases per 1,000 live births in the first half of 2016 to 3.0 cases in the second half (p = 0.10). However, when neural tube defects and other early brain malformations (NTDs) § were excluded, the prevalence of birth defects strongly linked to congenital Zika virus infection increased significantly, from 2.0 cases per 1,000 live births in the first half of 2016 to 2.4 cases in the second half, an increase of 29 more cases than expected (p = 0.009). These findings underscore the importance of surveillance for birth defects potentially related to Zika virus infection and the need for continued monitoring in areas at risk for Zika.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parrado, G., E-mail: gparrado@sgc.gov.co; Cañón, Y.; Peña, M., E-mail: mlpena@sgc.gov.co

The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes withmore » medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.« less
Improvement of analytical capabilities of neutron activation analysis laboratory at the Colombian Geological Survey

NASA Astrophysics Data System (ADS)

Parrado, G.; Cañón, Y.; Peña, M.; Sierra, O.; Porras, A.; Alonso, D.; Herrera, D. C.; Orozco, J.

2016-07-01

The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes with medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.
Biodegradation in seawater of PAH and alkylphenols from produced water of a North Sea platform.

PubMed

Lofthus, Synnøve; Almås, Inger K; Evans, Peter; Pelz, Oliver; Brakstad, Odd Gunnar

2018-09-01

Operational planned discharges of produced water (PW) to the marine environment from offshore oil production installations, contain low concentrations of dispersed oil compounds, like polycyclic aromatic hydrocarbons (PAHs) and alkylated phenols (APs). Biotransformation in natural seawater (SW) of naphthalenes/PAHs and phenol/APs in field-collected PW from a North Sea platform was investigated in this biodegradation study. The PW was diluted in SW from a Norwegian fjord, and the biodegradation study was performed in slowly rotating carousels at 13 °C over a period of 62 days. Naphthalenes/PAHs and phenol/APs biotransformation was determined by first-order rate kinetics, after normalization against the recalcitrant biomarker 17α(H),21β(H)-Hopane. The results from this study showed total biotransformation half-lives ranging from 10 to 19 days for groups of naphthalenes and PAHs, while half-lives for APs (C0- to C9-alkylated) were 10-14 days. Biotransformation half-lives of single compounds ranged from 8 to >100 days for naphthalenes and PAHs (median 16 days), and from 5 to 70 days (median 15 days) for phenols and APs. Four of the tested PAHs (chrysene, benzo(b)fluoranthene, benzo(e)pyrene, benzo(g,h,i)perylene) and one AP (4-tert-butylphenol) showed biotransformation half-lives >50 days. This is one of a few studies that has investigated the potential for biodegradation of PW in natural SW. Methods and data from this study may be used as a part of Risk Based Approaches (RBA) for assessments of environmental fate of PW released to the marine environment and as part of the persistence related to risk. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.
2013 Review of Neutron and Non-Neutron Nuclear Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holden, N. E.

2014-05-23

The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature over the past three years since the ISRD-14 Symposium has been performed and the highlights are presented. Included in the data review are the status of new chemical elements, new measurements of the isotopic composition for many chemical elements and the resulting change in the atomic weight values. New half-life measurements for both short-lived and longlived nuclides, some alpha decay and double beta decay measurements for quasistable nuclides are discussed. The latest evaluation of atomic masses has been published. Data from newmore » measurements on the very heavy (trans-meitnerium) elements are discussed and tabulated. Data on various recent neutron cross section and resonance integral measurements are discussed and tabulated.« less
Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, April - September 1989

USGS Publications Warehouse

Taylor, R. Lynn; Ferreira, Rodger F.

1995-01-01

Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during April-September 1989. Benthic macroinvertebrate, periphyton, and phytoplankton communities were sampled at three sites along the Olmos Creek/San Antonio River system. Total mean densities of benthic macroinvertebrates for the three sites ranged from 670 to 10,000 organisms per square meter. The most abundant macroinvertebrates were the class Insecta (insects). Total densities of periphyton ranged from 2,900 to 110,000 cells per square millimeter. Cyanophyta (blue-green algae) and Bacillariophyta (diatoms) were the predominant periphyton organisms. Total densities of phyto- plankton ranged from 5,000 to 47,000 cells per square milliliter. Blue-green algae accounted for more than one- half of the phytoplankton in each sample. Hardness ranged from 160 to 250 milligrams per liter as calcium carbonate, and alkalinity ranged from 130 to 220 milligrams per liter as calcium carbonate. The largest dissolved nitrite concentration was 0.038 milligram per liter. The largest total phosphorus concentration was 0.150 milligram per liter, over one-half of which was dissolved orthophosphate. Total aluminum and total iron were the only trace elements in water to exceed the reporting threshold by large concen- trations. Total aluminum concentrations ranged from 70 to 280 micrograms per liter, and total iron concentrations ranged from 70 to 340 micrograms per liter. Lead was the most prominent trace element in bottom-material samples, with concentrations ranging from 30 to 230 micrograms per gram.
WE-AB-206-02: ACR Ultrasound Accreditation: Requirements and Pitfalls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, J.

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less
WE-AB-206-00: Diagnostic QA/QC Hands-On Workshop

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less
Influence of deformed surface diffuseness on alpha decay half-lives of actinides and lanthanides

NASA Astrophysics Data System (ADS)

Dahmardeh, S.; Alavi, S. A.; Dehghani, V.

2017-07-01

By using semiclassical WKB method and taking into account the Bohr-Sommerfeld quantization condition, the alpha decay half-lives of some deformed lanthanide (with 151 ≤ A ≤ 160 and 66 ≤ Z ≤ 73) and rare-earth nuclei (with 217 ≤ A ≤ 261 and 92 ≤ Z ≤ 104) have been calculated. The effective potential has been considered as sum of deformed Woods-Saxon nuclear potential, deformed Coulomb potential, and centrifugal potential. The influence of deformed surface diffuseness on the potential barrier, transmission coefficient at each angle, assault frequency, and alpha decay half-lives has been investigated. Good agreement between calculated half-lives with deformed surface diffuseness and experiment is observed. Relative differences between calculated half-lives with deformed surface diffuseness and with constant surface diffuseness were significant.
Calculations on the half-lives of Cluster decay in two-potential approach

NASA Astrophysics Data System (ADS)

Soylu, A.

The half-lives of the cluster decay (CD) from the isotopes having the known experimental values, the half-lives of the α-decay (AD) of same nuclei and also the branching ratios are obtained, within the framework of two-potential approach with cosh potential including with and without the isospin effects. Using two-potential approach and taking into account the isospin effects in the calculations decrease the rms values and they improve the results. The obtained branching ratios are in good agreement with the experimental ones for some isotopes. It is obtained that the isospin-dependent potentials have an influence on the half-lives of the cluster decays of nuclei. Present calculations would be important for predicting the experimental half-lives and branching ratios for the cluster decays of different types of isotopes.
Latino Child Poverty in the United States.

ERIC Educational Resources Information Center

Miranda, Leticia C.

Poverty among Latino children has soared during the past decade, accounting for half of the total growth in the number of American children who are poor. One in three Latino children was living in poverty as of 1989. Many Latino children are poor despite their parents' best efforts to pull their families out of poverty and despite the fact that…
Study of ^{14}C Cluster Decay Half-Lives of Heavy Deformed Nuclei

NASA Astrophysics Data System (ADS)

Shamami, S. Rahimi; Pahlavani, M. R.

2018-01-01

A theoretical model based on deformed Woods-Saxon, Coulomb and centrifugal terms are constructed to evaluate the half-lives for the cluster radioactivity of various super heavy nuclei. Deformation have been applied on all parts of their potential containing nuclear barrier for cluster decay. Also, both parent and daughter nuclei are considered to be deformed. The calculated results of ^{14}C cluster radioactivity half-lives are compared with available experimental data. A satisfactory agreement between theoretical and measured data is achieved. Also, obtained half-lives for each decay family is agreed with Geiger-Nuttall law.
Beta-decay half-lives for short neutron rich nuclei involved into the r-process

NASA Astrophysics Data System (ADS)

Panov, I.; Lutostansky, Yu; Thielemann, F.-K.

2018-01-01

The beta-strength function model based on Finite Fermi-Systems Theory is applied for calculations of the beta-decay half-lives for short neutron rich nuclei involved into the r- process. It is shown that the accuracy of beta-decay half-lives of short-lived neutron-rich nuclei is improving with increasing neutron excess and can be used for modeling of nucleosynthesis of heavy nuclei in the r-process.
Nuclear fuel in a reactor accident.

PubMed

Burns, Peter C; Ewing, Rodney C; Navrotsky, Alexandra

2012-03-09

Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.
Search for long lived heaviest nuclei beyond the valley of stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chowdhury, P. Roy; Samanta, C.; Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000

2008-04-15

The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and {alpha}-decay processes. According to microscopic nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide the extra stability to such SHN to have long enough lifetime to be observed. To investigate whether the so-called 'stability island' could really exist around the above Z, N values, the {alpha}-decay half-lives along with the spontaneous fission and {beta}-decay half-lives of such nuclei are studied. The {alpha}-decay half-lives of SHN with Z=102-120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using Q{sub {alpha}}more » values from three different mass formulas prescribed by Koura-Uno-Tachibana-Yamada (KUTY), Myers-Swiatecki (MS), and Muntian-Hofmann-Patyk-Sobiczewski (MMM). Calculation of spontaneous fission (SF) half-lives for the same SHN are carried out using a phenomenological formula and compared with SF half-lives predicted by Smolanczuk et al. A possible source of discrepancy between the calculated {alpha}-decay half-lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN, is discussed. In the region of Z=106-108 with N{approx}160-164, the {beta}-stable SHN {sub 106}{sup 268}Sg{sub 162} is predicted to have highest {alpha}-decay half-life (T{sub {alpha}}{approx}3.2 h) using Q{sub {alpha}} value from MMM. Interestingly, it is much greater than the recently measured T{sub {alpha}} ({approx}22 s) of deformed doubly magic {sub 108}{sup 270}Hs{sub 162} nucleus. A few fission-survived long-lived SHN which are either {beta}-stable or having large {beta}-decay half-lives are predicted to exist near {sup 294}110{sub 184}, {sup 293}110{sub 183}, {sup 296}112{sub 184}, and {sup 298}114{sub 184}. These nuclei might decay predominantly through {alpha}-particle emission.« less
β-Decay Half-Lives of Co76,77, Ni79,80, and Cu81: Experimental Indication of a Doubly Magic Ni78

NASA Astrophysics Data System (ADS)

Xu, Z. Y.; Nishimura, S.; Lorusso, G.; Browne, F.; Doornenbal, P.; Gey, G.; Jung, H.-S.; Li, Z.; Niikura, M.; Söderström, P.-A.; Sumikama, T.; Taprogge, J.; Vajta, Zs.; Watanabe, H.; Wu, J.; Yagi, A.; Yoshinaga, K.; Baba, H.; Franchoo, S.; Isobe, T.; John, P. R.; Kojouharov, I.; Kubono, S.; Kurz, N.; Matea, I.; Matsui, K.; Mengoni, D.; Morfouace, P.; Napoli, D. R.; Naqvi, F.; Nishibata, H.; Odahara, A.; Şahin, E.; Sakurai, H.; Schaffner, H.; Stefan, I. G.; Suzuki, D.; Taniuchi, R.; Werner, V.

2014-07-01

The half-lives of 20 neutron-rich nuclei with Z =27-30 have been measured at the RIBF, including five new half-lives of Co76(21.7-4.9+6.5 ms), Co77(13.0-4.3+7.2 ms), Ni79(43.0-7.5+8.6 ms), Ni80(23.9-17.2+26.0 ms), and Cu81(73.2±6.8 ms). In addition, the half-lives of Co73-75, Ni74-78, Cu78-80, and Zn80-82 were determined with higher precision than previous works. Based on these new results, a systematic study of the β-decay half-lives has been carried out, which suggests a sizable magicity for both the proton number Z =28 and the neutron number N=50 in Ni78.
Beta decay of 187Re and cosmochronology

NASA Astrophysics Data System (ADS)

Ashktorab, K.; Jänecke, J. W.; Becchetti, F. D.

1993-06-01

Uncertainties which limit the use of the 187-187Os isobaric pair as a cosmochronometer for the age of the galaxy and the universe include those of the partial half-lives of the continuum and bound-state decays of 187Re. While the total half-life of the decay is well established, the partial half-life for the continuum decay is uncertain, and several previous measurements are not compatible with each other. A high-temperature quartz proportional counter has been used in this work to remeasure the continuum decay of 187Re by introducing a metallo-organic rhenium compound into the counting gas. The measured beta end-point energy for the continuum decay of neutral 187Re to singly ionized 187Os of 2.70+/-0.09 keV agrees with earlier results. However, the present half-life measurement of (45+/-3) Gyr agrees within the quoted uncertainties only with the earlier measurement of Payne [Ph.D. thesis, University of Glasgow, 1965 (unpublished)] and Drever (private communication). The new half-life for the continuum decay and the total half-life of (43.5+/-1.3) Gyr, as reported by Linder et al. [Nature (London) 320, 246 (1986)] yield a branching ratio for the bound-state decay into discrete atomic states of (3+/-6)%. This is in agreement with the most recent calculated theoretical branching ratio of approximately 1%.
HALO--a Java framework for precise transcript half-life determination.

PubMed

Friedel, Caroline C; Kaufmann, Stefanie; Dölken, Lars; Zimmer, Ralf

2010-05-01

Recent improvements in experimental technologies now allow measurements of de novo transcription and/or RNA decay at whole transcriptome level and determination of precise transcript half-lives. Such transcript half-lives provide important insights into the regulation of biological processes and the relative contributions of RNA decay and de novo transcription to differential gene expression. In this article, we present HALO (Half-life Organizer), the first software for the precise determination of transcript half-lives from measurements of RNA de novo transcription or decay determined with microarrays or RNA-seq. In addition, methods for quality control, filtering and normalization are supplied. HALO provides a graphical user interface, command-line tools and a well-documented Java application programming interface (API). Thus, it can be used both by biologists to determine transcript half-lives fast and reliably with the provided user interfaces as well as software developers integrating transcript half-life analysis into other gene expression profiling pipelines. Source code, executables and documentation are available at http://www.bio.ifi.lmu.de/software/halo.
The use of dual-energy X-ray absorptiometry to estimate the dissected composition of lamb carcasses.

PubMed

Mercier, J; Pomar, C; Marcoux, M; Goulet, F; Thériault, M; Castonguay, F W

2006-06-01

A total of 140 male and female Dorset and Suffolk lambs were slaughtered according to four live weight classes (36-39kg, 41-44kg, 46-49kg and 51-54kg). Total tissue, fat and lean masses, and bone mineral content measured by dual-energy X-ray absorptiometry (DXA) were used to predict dissected tissue weights. The DXA total weights accurately predict half-carcasses and primal cuts weights (shoulder, leg, loin and flank) (R(2)>0.99, CVe<1.3%). The prediction of the half-carcass dissected fat percentage is weaker (R(2)=0.77, CVe=10.4%). Fatness prediction accuracy is equivalent for the shoulder, leg and loin (R(2) between 0.68 and 0.78, CVe between 10% and 13%). The R(2) obtained when predicting dissected lean content from DXA variables is 0.93 for the half-carcass and higher than 0.83 for all cuts other than flank (CVe are between 3.5% and 6.5%, except for the flank, which is 9.1%). The prediction of bone weight using the bone mineral content is not very accurate for the half-carcass, shoulder and leg (R(2): 0.48, 0.47 and 0.43; CVe: 10.2%, 12.0% and 11.6%, respectively). The situation improves, however, for the loin (R(2)=0.70, CVe=10.7%). In conclusion, DXA is an effective technology for predicting total weight and the amount of lean and fat in lamb carcasses and their primal cuts.
Half-life measurements of isomeric states populated in projectile fragmentation

NASA Astrophysics Data System (ADS)

Bowry, M.; Podolyák, Zs.; Kurcewicz, J.; Pietri, S.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Allegro, P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Gerl, J.; Gorska, M.; Gottardo, A.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Litvinov, Y. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Kurz, N.; Denis Bacelar, A. M.; Bruce, A. M.; Farrelly, G. F.; Alkhomashi, N.; Al-Dahan, N.; Scheidenberger, C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Takeda, H.; Tanihata, I.; Terashima, S.; Valiente Dobon, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.

2012-10-01

The half-lives of excited isomeric states observed in 195Au, 201Tl and 215Rn are reported for the first time. Delayed γ-rays were correlated with nuclei produced in the projectile fragmentation of relativistic 238U ions, unambiguously identified in terms of their atomic number (Z) and mass-to-charge ratio (A/Q) after traversing an in-flight separator. The observation of a long-lived isomeric state in 195Au with t1/2 = 16-4+8 μs is presented. Two shorter-lived isomeric states were detected in 201Tl and 215Rn with t1/2 = 95-21+39 and 57-12+21 ns respectively. In total 24 isomeric states were identified in different nuclei from Pt to Rn (A ˜ 200) during the current study, the majority of which were previously reported. The wealth of spectroscopic data provides the opportunity to determine the isomeric ratios over a wide range of Z, A and angular momentum (I ħ) of the reaction products. In particular, high-spin states with I ≳ 18 ħ provide a robust test of theoretical models of fragmentation.
Measurement of the most exotic beta-delayed neutron emitters at N=50 and N=126

NASA Astrophysics Data System (ADS)

Dillmann, Iris

2017-09-01

Beta-delayed neutron (βn)-emission will be the dominant decay mechanism of neutron-rich nuclei and plays an important role in the stellar nucleosynthesis of heavy elements in the ``r process''. It leads to a detour of the material β-decaying back to stability and the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. Thus the neutron branching ratio of very neutron-rich isotopes is a crucial parameter in astrophysical simulations. In addition, β-decay half-lives can be deduced from the time-dependent detection of βn's. I will talk about two recent experimental campaigns. The neutron detector BELEN was used at GSI Darmstadt to measure half-lives and neutron-branching ratios of the heaviest presently accessible βn-emitters at N=126. For isotopes between 204Au and 220Bi nine half-lives and eight neutron-branching ratios were measured for the first time and provide an important input for benchmarking theoretical models in this mass region. Its successor is the BRIKEN detector (``Beta-delayed neutron measurements at RIKEN for nuclear structure, astrophysics, and applications''), the most efficient neutron detector used so far for nuclear structure studies. In conjunction with two clover detectors and the ``Advanced Implantation Detector Array'' (AIDA) the setup has been used a few months ago to measure the most neutron-rich isotopes around 78Ni, 132Sn, and the Rare Earth Region. Some preliminary results are shown from the campaign covering the 78Ni region where the neutron-branching ratio of 78Ni and 28 more isotopes were measured for the first time, as well as the half-lives of 20 isotopes. The BRIKEN campaign aims to (re-)measure almost all βn-emitters between 76Co and 167Eu, many of them for the first time. An extension of the campaign to lighter masses is planned. This work has been supported by the NSERC and NRC in Canada, the US DOE, the Spanish Ministerio de Economia y Competitividad, and the European Commission under the FP7/EURATOM CHANDA program.

Ten-year observations on pruned ponderosa and jeffrey pine

Treesearch

Donald T. Gordon

1959-01-01

In 1956 Hallinl reported some observed effects of pruning ponderosa and Jeffrey pine based on the response after 5 years. This report is an extension of those observations, after a 10-year reexamination of the experiment. Hallin suggested that half the live crown, or six-tenths of total height of the tree could be pruned without adverse effects on growth. Pruning out...
Three-Dimensional Nuclear Chart--Understanding Nuclear Physics and Nucleosynthesis in Stars

ERIC Educational Resources Information Center

Koura, Hiroyuki

2014-01-01

Three-dimensional (3D) nuclear charts were created using toy blocks, which represent the atomic masses per nucleon number and the total half-lives for each nucleus in the entire region of the nuclear mass. The bulk properties of the nuclei can be easily understood by using these charts. Subsequently, these charts were used in outreach activities…
Synthesis, characterization and in vitro hydrolysis of a gemfibrozil-nicotinic acid codrug for improvement of lipid profile.

PubMed

Qandil, Amjad M; Rezigue, Meriem M; Tashtoush, Bassam M

2011-06-14

Combination therapy of fibrates and nicotinic acid has been reported to be synergistic. Herein, we describe a covalent codrug of gemfibrozil (GEM) and nicotinic acid (NA) that was synthesized and characterized by (1)H NMR, (13)C NMR, FT-IR, MS analysis and elemental analysis. A validated HPLC method was developed that allows for the accurate quantitative determination of the codrug and its hydrolytic products that are formed during the in vitro chemical and enzymatic hydrolysis. The physico-chemical properties of codrug were improved compared to its parent drugs in term of water solubility and partition coefficient. The kinetics of hydrolysis of the codrug was studied using accelerated hydrolysis experiments at high temperatures in aqueous phosphate buffer solution in pH 1.2, 6.8 and 7.4. Using the Arrhenius equation, the extrapolated half-life at 37°C were 289 days at pH 1.2 for the codrug and 130 and 20,315 days at pH 6.8 for the codrug and gemfibrozil 2-hydroxyethyl ester (GHEE), respectively. The shortest half-lives were at pH 7.4; 42 days for the codrug and 5837 days for GHEE, respectively. The hydrolysis of the latter was studied, alone, at 80°C and pH 1.2 and compared to its hydrolysis when it is produced from the codrug using similar conditions. The k(obs) was found in both cases to be 1.60×10(-3)h(-1). The half-lives in plasma were 35.24 min and 26.75 h for the codrug and GHEE, respectively. With regard to liver homogenate, the hydrolysis half-lives were 1.96 min and 48.13 min for the codrug and GHEE, respectively. It can be expected that in vivo, the codrug will liberate NA immediately in plasma then GEM will be liberated from its 2-hydroxyethyl ester in the liver. Copyright © 2011 Elsevier B.V. All rights reserved.
Considerations of temperature in the context of the persistence classification in the EU.

PubMed

Matthies, Michael; Beulke, Sabine

2017-01-01

Simulation degradation studies for industrial chemicals, biocidal products and plant protection products are required in the EU to estimate half-lives in soil, water and sediment for the comparison to persistence criteria for hazard (P/vP) assessment, and for use in exposure assessments. There is a discrepancy between European regulatory approaches regarding the temperature at which degradation half-lives should be (1) measured in simulation degradation testing of environmental compartments, and (2) compared to the P/vP criteria. In this paper, an opinion is provided on the options for the experimental temperature and extrapolation to other conditions. A review of the historical development of persistence criteria did not give conclusive evidence of the temperature at which the half-lives that underpin the P-criteria were measured, but room temperature is likely. Half-lives measured at 20 °C are in line with the intentions of some international agreements, but in the EU there is a continued political debate regarding the relevant temperature for comparison with persistence criteria. Measuring degradation at 20 °C has the advantage that metabolites/transformation products can be identified with greater accuracy, and that kinetic fits to determine half-lives for parent compounds and metabolites carry less uncertainty. Extrapolation of half-lives to lower temperatures is possible for assessing environmental exposure, but the uncertainty of the persistence classification is smaller when measured half-lives are used for direct comparison with P/vP criteria, without extrapolation. Model simulations demonstrate the pattern of concentrations that can be expected for realistic worst case climate scenarios in the EU based on the half-life of 120 days in soil at 20 °C and of 40 days in water at 20 °C, and their temporal and spatial variability.
Alpha Decay Potential Barriers and Half-Lives and Analytical Formula Predictions for Superheavy Nuclei

NASA Astrophysics Data System (ADS)

Royer, Guy; Zhang, Hongfei

The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault.
Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator.

PubMed

Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A

2014-05-13

Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5'-leader region of the Mg(2+) transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg(2+) availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators.
First chemical separation and identification of Seaborgium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuerler, A.; Eichler, B.; Jost, D.T.

1997-12-31

The chemical properties of element 106 (Seaborgium, Sg) were successfully studied using the On-line Gas Chromatography Apparatus (OLGA III). After chemical separation of Sg in the form of volatile oxichlorides the nuclides {sup 265}Sg and {sup 266}Sg were unambiguously identified and their half-lives were determined for the first time. The Sg nuclides were produced from the {sup 248}Cm({sup 22}Ne, 4,5n){sup 266,265}Sg reaction at the GSI Darmstadt UNILAC accelerator. Simultaneously, short-lived W nuclides were produced from a small admixture of {sup 152}Gd to the Cm target material. As predicted by relativistic calculations and by extrapolations of chemical properties, it was demonstratedmore » that Sg oxichlorides are indeed less volatile than their lighter homologue W- and Mo-oxichlorides.« less
Hybrid systems analysis of the control of burst duration by low-voltage-activated calcium current in leech heart interneurons.

PubMed

Olypher, Andrey; Cymbalyuk, Gennady; Calabrese, Ronald L

2006-12-01

The leech heartbeat CPG is paced by the alternating bursting of pairs of mutually inhibitory heart interneurons that form elemental half-center oscillators. We explore the control of burst duration in heart interneurons using a hybrid system, where a living, pharmacologically isolated, heart interneuron is connected with artificial synapses to a model heart interneuron running in real-time, by focusing on a low-voltage-activated (LVA) calcium current I(CaS). The transition from silence to bursting in this half-center oscillator occurs when the spike frequency of the bursting interneuron declines to a critical level, f(Final), at which the inhibited interneuron escapes owing to a build-up of the hyperpolarization-activated cation current, I(h). We varied I(CaS) inactivation time constant either in the living heart interneuron or in the model heart interneuron. In both cases, varying I(CaS) inactivation time constant did not affect f(Final) of either interneuron, but in the varied interneuron, the time constant of decline of spike frequency during bursts to f(Final) and thus the burst duration varied directly and nearly linearly with I(CaS) inactivation time constant. Bursts of the opposite, nonvaried interneuron did not change. We show also that control of burst duration by I(CaS) inactivation does not require synaptic interaction by reconstituting autonomous bursting in synaptically isolated living interneurons with injected I(CaS). Therefore inactivation of LVA calcium current is critically important for setting burst duration and thus period in a heart interneuron half-center oscillator and is potentially a general intrinsic mechanism for regulating burst duration in neurons.
Half-life Measurements of Excited Levels in Fission Products around Mass Number 150

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojima, Y., E-mail: kojima.yasuaki@f.mbox.nagoya-u.ac.jp; Shima, Y.; Hayashi, H.

2014-06-15

A spectrometer to measure nuclear level half-lives has been installed at the on-line isotope separator of the Kyoto University Reactor. This spectrometer consists of a LaBr3 scintillator, a thin plastic scintillator and an HPGe detector. Half-lives are deduced using the β-γ-γ delayed coincidence method. The prompt-time distribution curves measured with the spectrometer give a time resolution (FWHM) of 600 ps for 100-keV γ rays. This resolution means that half-lives down to the subnanosecond range or shorter can be measured. We reported recent measurements of the half-life of {sup 149}Pr and {sup 149}Nd. Some of the more interesting results include themore » first determination of the half-lives of {sup 149}Pr levels at 86.5 and 125.6 keV, which are 4.2(5) ns and 1.0(2) ns, respectively. In addition, the data indicate that the half-life of the 270.8-keV level in {sup 149}Nd is not 5.1(3) ns as reported previously, but 0.42(3) ns.« less
Occurrence, temporal trends, and half-lives of perfluoroalkyl acids (PFAAs) in occupational workers in China

PubMed Central

Fu, Jianjie; Gao, Yan; Cui, Lin; Wang, Thanh; Liang, Yong; Qu, Guangbo; Yuan, Bo; Wang, Yawei; Zhang, Aiqian; Jiang, Guibin

2016-01-01

Paired serum and urine samples were collected from workers in a fluorochemical plant from 2008 to 2012 (n = 302) to investigate the level, temporal trends, and half-lives of PFAAs in workers of a fluorochemical plant. High levels of perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonate (PFOS) were detected in serum with median concentrations of 764, 427, and 1725 ng mL−1, respectively. The half-lives of PFAAs in workers were estimated by daily clearance rates and annual decline rates of PFAAs in serum by a first-order model. The geometric mean and median value for PFHxS, PFOA, and PFOS were 14.7 and 11.7, 4.1 and 4.0, 32.6 and 21.6 years, respectively, by the daily clearance rates, and they were 3.6, 1.7, and 1.9 years estimated by annual decline rates. The half-lives estimated by the limited clearance route information could be considered as the upper limits for PFAAs, however, the huge difference between two estimated approaches indicated that there were other important elimination pathways of PFAAs other than renal clearance in human. The half-lives estimated by annual decline rates in the present study were the shortest values ever reported, and the intrinsic half-lives might even shorter due to the high levels of ongoing exposure to PFAAs. PMID:27905562
Occurrence, temporal trends, and half-lives of perfluoroalkyl acids (PFAAs) in occupational workers in China

NASA Astrophysics Data System (ADS)

Fu, Jianjie; Gao, Yan; Cui, Lin; Wang, Thanh; Liang, Yong; Qu, Guangbo; Yuan, Bo; Wang, Yawei; Zhang, Aiqian; Jiang, Guibin

2016-12-01

Paired serum and urine samples were collected from workers in a fluorochemical plant from 2008 to 2012 (n = 302) to investigate the level, temporal trends, and half-lives of PFAAs in workers of a fluorochemical plant. High levels of perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonate (PFOS) were detected in serum with median concentrations of 764, 427, and 1725 ng mL-1, respectively. The half-lives of PFAAs in workers were estimated by daily clearance rates and annual decline rates of PFAAs in serum by a first-order model. The geometric mean and median value for PFHxS, PFOA, and PFOS were 14.7 and 11.7, 4.1 and 4.0, 32.6 and 21.6 years, respectively, by the daily clearance rates, and they were 3.6, 1.7, and 1.9 years estimated by annual decline rates. The half-lives estimated by the limited clearance route information could be considered as the upper limits for PFAAs, however, the huge difference between two estimated approaches indicated that there were other important elimination pathways of PFAAs other than renal clearance in human. The half-lives estimated by annual decline rates in the present study were the shortest values ever reported, and the intrinsic half-lives might even shorter due to the high levels of ongoing exposure to PFAAs.
Optimal sampling designs for estimation of Plasmodium falciparum clearance rates in patients treated with artemisinin derivatives

PubMed Central

2013-01-01

Background The emergence of Plasmodium falciparum resistance to artemisinins in Southeast Asia threatens the control of malaria worldwide. The pharmacodynamic hallmark of artemisinin derivatives is rapid parasite clearance (a short parasite half-life), therefore, the in vivo phenotype of slow clearance defines the reduced susceptibility to the drug. Measurement of parasite counts every six hours during the first three days after treatment have been recommended to measure the parasite clearance half-life, but it remains unclear whether simpler sampling intervals and frequencies might also be sufficient to reliably estimate this parameter. Methods A total of 2,746 parasite density-time profiles were selected from 13 clinical trials in Thailand, Cambodia, Mali, Vietnam, and Kenya. In these studies, parasite densities were measured every six hours until negative after treatment with an artemisinin derivative (alone or in combination with a partner drug). The WWARN Parasite Clearance Estimator (PCE) tool was used to estimate “reference” half-lives from these six-hourly measurements. The effect of four alternative sampling schedules on half-life estimation was investigated, and compared to the reference half-life (time zero, 6, 12, 24 (A1); zero, 6, 18, 24 (A2); zero, 12, 18, 24 (A3) or zero, 12, 24 (A4) hours and then every 12 hours). Statistical bootstrap methods were used to estimate the sampling distribution of half-lives for parasite populations with different geometric mean half-lives. A simulation study was performed to investigate a suite of 16 potential alternative schedules and half-life estimates generated by each of the schedules were compared to the “true” half-life. The candidate schedules in the simulation study included (among others) six-hourly sampling, schedule A1, schedule A4, and a convenience sampling schedule at six, seven, 24, 25, 48 and 49 hours. Results The median (range) parasite half-life for all clinical studies combined was 3.1 (0.7-12.9) hours. Schedule A1 consistently performed the best, and schedule A4 the worst, both for the individual patient estimates and for the populations generated with the bootstrapping algorithm. In both cases, the differences between the reference and alternative schedules decreased as half-life increased. In the simulation study, 24-hourly sampling performed the worst, and six-hourly sampling the best. The simulation study confirmed that more dense parasite sampling schedules are required to accurately estimate half-life for profiles with short half-life (≤three hours) and/or low initial parasite density (≤10,000 per μL). Among schedules in the simulation study with six or fewer measurements in the first 48 hours, a schedule with measurements at times (time windows) of 0 (0–2), 6 (4–8), 12 (10–14), 24 (22–26), 36 (34–36) and 48 (46–50) hours, or at times 6, 7 (two samples in time window 5–8), 24, 25 (two samples during time 23–26), and 48, 49 (two samples during time 47–50) hours, until negative most accurately estimated the “true” half-life. For a given schedule, continuing sampling after two days had little effect on the estimation of half-life, provided that adequate sampling was performed in the first two days and the half-life was less than three hours. If the measured parasitaemia at two days exceeded 1,000 per μL, continued sampling for at least once a day was needed for accurate half-life estimates. Conclusions This study has revealed important insights on sampling schedules for accurate and reliable estimation of Plasmodium falciparum half-life following treatment with an artemisinin derivative (alone or in combination with a partner drug). Accurate measurement of short half-lives (rapid clearance) requires more dense sampling schedules (with more than twice daily sampling). A more intensive sampling schedule is, therefore, recommended in locations where P. falciparum susceptibility to artemisinins is not known and the necessary resources are available. Counting parasite density at six hours is important, and less frequent sampling is satisfactory for estimating long parasite half-lives in areas where artemisinin resistance is present. PMID:24225303
Optimal sampling designs for estimation of Plasmodium falciparum clearance rates in patients treated with artemisinin derivatives.

PubMed

Flegg, Jennifer A; Guérin, Philippe J; Nosten, Francois; Ashley, Elizabeth A; Phyo, Aung Pyae; Dondorp, Arjen M; Fairhurst, Rick M; Socheat, Duong; Borrmann, Steffen; Björkman, Anders; Mårtensson, Andreas; Mayxay, Mayfong; Newton, Paul N; Bethell, Delia; Se, Youry; Noedl, Harald; Diakite, Mahamadou; Djimde, Abdoulaye A; Hien, Tran T; White, Nicholas J; Stepniewska, Kasia

2013-11-13

The emergence of Plasmodium falciparum resistance to artemisinins in Southeast Asia threatens the control of malaria worldwide. The pharmacodynamic hallmark of artemisinin derivatives is rapid parasite clearance (a short parasite half-life), therefore, the in vivo phenotype of slow clearance defines the reduced susceptibility to the drug. Measurement of parasite counts every six hours during the first three days after treatment have been recommended to measure the parasite clearance half-life, but it remains unclear whether simpler sampling intervals and frequencies might also be sufficient to reliably estimate this parameter. A total of 2,746 parasite density-time profiles were selected from 13 clinical trials in Thailand, Cambodia, Mali, Vietnam, and Kenya. In these studies, parasite densities were measured every six hours until negative after treatment with an artemisinin derivative (alone or in combination with a partner drug). The WWARN Parasite Clearance Estimator (PCE) tool was used to estimate "reference" half-lives from these six-hourly measurements. The effect of four alternative sampling schedules on half-life estimation was investigated, and compared to the reference half-life (time zero, 6, 12, 24 (A1); zero, 6, 18, 24 (A2); zero, 12, 18, 24 (A3) or zero, 12, 24 (A4) hours and then every 12 hours). Statistical bootstrap methods were used to estimate the sampling distribution of half-lives for parasite populations with different geometric mean half-lives. A simulation study was performed to investigate a suite of 16 potential alternative schedules and half-life estimates generated by each of the schedules were compared to the "true" half-life. The candidate schedules in the simulation study included (among others) six-hourly sampling, schedule A1, schedule A4, and a convenience sampling schedule at six, seven, 24, 25, 48 and 49 hours. The median (range) parasite half-life for all clinical studies combined was 3.1 (0.7-12.9) hours. Schedule A1 consistently performed the best, and schedule A4 the worst, both for the individual patient estimates and for the populations generated with the bootstrapping algorithm. In both cases, the differences between the reference and alternative schedules decreased as half-life increased. In the simulation study, 24-hourly sampling performed the worst, and six-hourly sampling the best. The simulation study confirmed that more dense parasite sampling schedules are required to accurately estimate half-life for profiles with short half-life (≤ three hours) and/or low initial parasite density (≤ 10,000 per μL). Among schedules in the simulation study with six or fewer measurements in the first 48 hours, a schedule with measurements at times (time windows) of 0 (0-2), 6 (4-8), 12 (10-14), 24 (22-26), 36 (34-36) and 48 (46-50) hours, or at times 6, 7 (two samples in time window 5-8), 24, 25 (two samples during time 23-26), and 48, 49 (two samples during time 47-50) hours, until negative most accurately estimated the "true" half-life. For a given schedule, continuing sampling after two days had little effect on the estimation of half-life, provided that adequate sampling was performed in the first two days and the half-life was less than three hours. If the measured parasitaemia at two days exceeded 1,000 per μL, continued sampling for at least once a day was needed for accurate half-life estimates. This study has revealed important insights on sampling schedules for accurate and reliable estimation of Plasmodium falciparum half-life following treatment with an artemisinin derivative (alone or in combination with a partner drug). Accurate measurement of short half-lives (rapid clearance) requires more dense sampling schedules (with more than twice daily sampling). A more intensive sampling schedule is, therefore, recommended in locations where P. falciparum susceptibility to artemisinins is not known and the necessary resources are available. Counting parasite density at six hours is important, and less frequent sampling is satisfactory for estimating long parasite half-lives in areas where artemisinin resistance is present.
A new criterion for predicting rolling-element fatigue lives of through-hardened steels

NASA Technical Reports Server (NTRS)

Chevalier, J. L.; Zaretsky, E. V.; Parker, R. J.

1972-01-01

A carbide factor was derived based upon a statistical analysis which related rolling-element fatigue life to the total number of residual carbide particles per unit area, median residual carbide size, and percent residual carbide area. An equation was experimentally determined which predicts material hardness as a function of temperature. The limiting temperatures of all of the materials studied were dependent on initial room temperature hardness and tempering temperature. An equation was derived combining the effects of material hardness, carbide factor, and bearing temperature to predict rolling-element bearing life.
Hair-to-blood ratio and biological half-life of mercury: experimental study of methylmercury exposure through fish consumption in humans.

PubMed

Yaginuma-Sakurai, Kozue; Murata, Katsuyuki; Iwai-Shimada, Miyuki; Nakai, Kunihiko; Kurokawa, Naoyuki; Tatsuta, Nozomi; Satoh, Hiroshi

2012-02-01

The hair-to-blood ratio and biological half-life of methylmercury in a one-compartment model seem to differ between past and recent studies. To reevaluate them, 27 healthy volunteers were exposed to methylmercury at the provisional tolerable weekly intake (3.4 µg/kg body weight/week) for adults through fish consumption for 14 weeks, followed by a 15-week washout period after the cessation of exposure. Blood was collected every 1 or 2 weeks, and hair was cut every 4 weeks. Total mercury (T-Hg) concentrations were analyzed in blood and hair. The T-Hg levels of blood and hair changed with time (p < 0.001). The mean concentrations increased from 6.7 ng/g at week 0 to 26.9 ng/g at week 14 in blood, and from 2.3 to 8.8 µg/g in hair. The mean hair-to-blood ratio after the adjustment for the time lag from blood to hair was 344 ± 54 (S.D.) for the entire period. The half-lives of T-Hg were calculated from raw data to be 94 ± 23 days for blood and 102 ± 31 days for hair, but the half-lives recalculated after subtracting the background levels from the raw data were 57 ± 18 and 64 ± 22 days, respectively. In conclusion, the hair-to-blood ratio of methylmercury, based on past studies, appears to be underestimated in light of recent studies. The crude half-life may be preferred rather than the recalculated one because of the practicability and uncertainties of the background level, though the latter half-life may approximate the conventional one.
Polynomial response of 2,4-D mineralization to temperature in soils at varying soil moisture contents, slope positions and depths.

PubMed

Shymko, Janna L; Farenhorst, Annemieke; Zvomuya, Francis

2011-01-01

The herbicide 2,4-D [2,4-(dichlorophenoxy) acetic acid] is a widely used broadleaf control agent in cereal production systems. Although 2,4-D soil-residual activity (half-lives) are typically less than 10 days, this herbicide also has as a short-term leaching potential due to its relatively weak retention by soil constituents. Herbicide residual effects and leaching are influenced by environmental variables such as soil moisture and temperature. The objective of this study was to determine impacts of these environmental variables on the magnitude and extent of 2,4-D mineralization in a cultivated undulating Manitoba prairie landscape. Microcosm incubation experiments were utilized to assess 2,4-D half-lives and total mineralization using a 4 × 4 × 3 × 2 factorial design (with soil temperature at 4 levels: 5, 10, 20 and 40°C; soil moisture at 4 levels: 60, 85, 110, 135 % of field capacity; slope position at 3 levels: upper-, mid- and lower-slopes; and soil depth at 2 levels: 0-5 cm and 5-15 cm). Half-lives (t(½)) varied from 3 days to 51 days with the total 2,4-D mineralization (M(T)) ranging from 5.8 to 50.9 %. The four-way interaction (temperature × moisture × slope × depth) significantly (p < 0.001) influenced both t(½) and M(T). Second-order polynomial equations best described the relations of temperature with t(½) and M(T) as was expected from a biological system. However, the interaction and variability of t(½) and M(T) among different temperatures, soil moistures, slope positions, and soil depth combinations indicates that the complex nature of these interacting factors should be considered when applying 2,4-D in agricultural fields and in utilizing these parameters in pesticide fate models.
Hepatic drug acetylation and oxidation: effects of aging in man.

PubMed Central

Farah, F; Taylor, W; Rawlins, M D; James, O

1977-01-01

The half lives of acetanilide and isoniazid ("model" substrates for oxidation and acetylation respectively) were measured in populations of young (aged 20-35 years) and elderly (aged over 65 years) people. Whereas acetanilide half lives were significantly longer in the elderly, isoniazid half lives were distributed similarly in both populations. The results suggest that liver function does not decline uniformly with age and that heterozygotes for acetylation do not possess survival advantages during their middle years of life. PMID:871823
Intermittent Drug Dosing Intervals Guided by the Operational Multiple Dosing Half Lives for Predictable Plasma Accumulation and Fluctuation

PubMed Central

Grover, Anita; Benet, Leslie Z.

2013-01-01

Intermittent drug dosing intervals are usually initially guided by the terminal pharmacokinetic half life and are dependent on drug formulation. For chronic multiple dosing and for extended release dosage forms, the terminal half life often does not predict the plasma drug accumulation or fluctuation observed. We define and advance applications for the operational multiple dosing half lives for drug accumulation and fluctuation after multiple oral dosing at steady-state. Using Monte Carlo simulation, our results predict a way to maximize the operational multiple dosing half lives relative to the terminal half life by using a first-order absorption rate constant close to the terminal elimination rate constant in the design of extended release dosage forms. In this way, drugs that may be eliminated early in the development pipeline due to a relatively short half life can be formulated to be dosed at intervals three times the terminal half life, maximizing compliance, while maintaining tight plasma concentration accumulation and fluctuation ranges. We also present situations in which the operational multiple dosing half lives will be especially relevant in the determination of dosing intervals, including for drugs that follow a direct PKPD model and have a narrow therapeutic index, as the rate of concentration decrease after chronic multiple dosing (that is not the terminal half life) can be determined via simulation. These principles are illustrated with case studies on valproic acid, diazepam, and anti-hypertensives. PMID:21499748
High-efficiency and low-background multi-segmented proportional gas counter for β-decay spectroscopy

NASA Astrophysics Data System (ADS)

Mukai, M.; Hirayama, Y.; Watanabe, Y. X.; Schury, P.; Jung, H. S.; Ahmed, M.; Haba, H.; Ishiyama, H.; Jeong, S. C.; Kakiguchi, Y.; Kimura, S.; Moon, J. Y.; Oyaizu, M.; Ozawa, A.; Park, J. H.; Ueno, H.; Wada, M.; Miyatake, H.

2018-03-01

A multi-segmented proportional gas counter (MSPGC) with high detection efficiency and low-background event rate has been developed for β-decay spectroscopy. The MSPGC consists of two cylindrically aligned layers of 16 counters (32 counters in total). Each counter has a long active length and small trapezoidal cross-section, and the total solid angle of the 32 counters is 80% of 4 π. β-rays are distinguished from the background events including cosmic-rays by analyzing the hit patterns of independent counters. The deduced intrinsic detection efficiency of each counter was almost 100%. The measured background event rate was 0.11 counts per second using the combination of veto counters for cosmic-rays and lead block shields for background γ-rays. The MSPGC was applied to measure the β-decay half-lives of 198Ir and 199mPt. The evaluated half-lives of T1/2 = 9 . 8(7) s and 12.4(7) s for 198Ir and 199mPt, respectively, were in agreement with previously reported values. The estimated absolute detection efficiency of the MSPGC from GEANT4 simulations was consistent with the evaluated efficiency from the analysis of the β- γ spectroscopy of 199Pt, saturating at approximately 60% for Qβ > 4 MeV.
When do star clusters become multiple star systems? II. Toward a half-life formalism with four bodies

NASA Astrophysics Data System (ADS)

Ibragimov, Timur; Leigh, Nathan W. C.; Ryu, Taeho; Panurach, Teresa; Perna, Rosalba

2018-03-01

We present a half-life formalism for describing the disruption of gravitationally-bound few-body systems, with a focus on binary-binary scattering. For negative total encounter energies, the four-body problem has three possible decay products in the point particle limit. For each decay product and a given set of initial conditions, we obtain directly from numerical scattering simulations the half-life for the distribution of disruption times. As in radioactive decay, the half-lives should provide a direct prediction for the relative fractions of each decay product. We test this prediction with simulated data and find good agreement with our hypothesis. We briefly discuss applications of this feature of the gravitational four-body problem to populations of black holes in globular clusters. This paper, the second in the series, builds on extending the remarkable similarity between gravitational chaos at the macroscopic scale and radioactive decay at the microscopic scale to larger-N systems.

When do star clusters become multiple star systems? II. Towards a half-life formalism with four bodies

NASA Astrophysics Data System (ADS)

Ibragimov, Timur; Leigh, Nathan W. C.; Ryu, Taeho; Panurach, Teresa; Perna, Rosalba

2018-07-01

We present a half-life formalism for describing the disruption of gravitationally bound few-body systems, with a focus on binary-binary scattering. For negative total encounter energies, the four-body problem has three possible decay products in the point-particle limit. For each decay product and a given set of initial conditions, we obtain directly from numerical scattering simulations the half-life for the distribution of disruption times. As in radioactive decay, the half-lives should provide a direct prediction for the relative fractions of each decay product. We test this prediction with simulated data and find good agreement with our hypothesis. We briefly discuss applications of this feature of the gravitational four-body problem to populations of black holes in globular clusters. This paper, the second in the series, builds on extending the remarkable similarity between gravitational chaos at the macroscopic scale and radioactive decay at the microscopic scale to larger-N systems.
Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models.

PubMed

Chi, Yulang; Zhang, Huanteng; Huang, Qiansheng; Lin, Yi; Ye, Guozhu; Zhu, Huimin; Dong, Sijun

2018-02-01

Environmental risks of organic chemicals have been greatly determined by their persistence, bioaccumulation, and toxicity (PBT) and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor (BCF) and octanol-water partition coefficient (Kow), which frequently displays a substantial correlation with the sediment sorption coefficient (Koc). Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship (QSAR) estimation models are indispensable for predicting environmental fate and health effects in the absence of field- or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon (TOC) degradation, and two widely accepted and highly used QSAR estimation models (i.e., EPI Suite and PBT Profiler) were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment. However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants. Copyright © 2016. Published by Elsevier B.V.
Gear Performance Improved by Coating

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.

2004-01-01

Gears, bearings, and other mechanical elements transmit loads through contacting surfaces. Even if properly designed, manufactured, installed, and maintained, gears and bearings will eventually fail because of the fatigue of the working surfaces. Economical means for extending the fatigue lives of gears and bearings are highly desired, and coatings offer the opportunity to engineer surfaces to extend the fatigue lives of mechanical components. A tungsten-containing diamondlike-carbon coating exhibiting high hardness, low friction, and good toughness was evaluated for application to spur gears. Fatigue testing was done at the NASA Glenn Research Center on both uncoated and coated spur gears. The results showed that the coating extended the surface fatigue lives of the gears by a factor of about 5 relative to the uncoated gears. For the experiments, a lot of spur test gears made from AISI 9310 gear steel were case-carburized and ground to aerospace specifications. The geometries of the 28-tooth, 8-pitch gears were verified as meeting American Gear Manufacturing Association (AGMA) quality class 12. One-half of the gears were randomly selected for coating. The method of coating was selected to achieve desired adherence, toughness, hardness, and low-friction characteristics. First the gears to be coated were prepared by blasting (vapor honing) with Al2O3 particles and cleaning. Then, the gears were provided with a thin adhesion layer of elemental chromium followed by magnetron sputtering of the outer coating consisting of carbon (70 at.%), hydrogen (15 at.%), tungsten (12 at.%), and nickel (3 at.%) (atomic percent at the surface). In total, the coating thickness was about 2.5 to 3 microns. As compared with the steel substrate, the coated surface was harder by a factor of about 2 and had a smaller elastic modulus. All gears were tested using a 5-centistoke synthetic oil, a 10,000-rpm rotation speed, and a hertzian contact stress of at least 1.7 GPa (250 ksi). Tests were run until either surface fatigue occurred or 300 million stress cycles were completed. Tests were run using either a pair of uncoated gears or a pair of coated gears (coated gears mated with uncoated gears were not evaluated). The fatigue test results, shown on Weibull coordinates in the graph, demonstrate that the coating provided substantially longer fatigue lives even though some of the coated gears endured larger stresses. The increase in fatigue life was a factor of about 5 and the statistical confidence for the improvement is high (greater than 99 percent). Examination of the tested gears revealed substantial reductions of total wear for coated gears in comparison to uncoated gears. The coated gear surface topography changed with running, with localized areas of the tooth surface becoming smoother with running. Theories explaining how coatings can extend gear fatigue lives are research topics for coating, tribology, and fatigue specialists. This work was done as a partnership between NASA, the U.S. Army Research Laboratory, United Technologies Research Corporation, and Sikorsky Aircraft.
Determination of the energy transitions and half-lives of Rubidium nuclei

NASA Astrophysics Data System (ADS)

Biçer, Ahmet; Manisa, Kaan; Engin Çalık, Abdullah; Erdoğan, Mehmet; Şen, Mürsel; Bircan, Hasan; Dapo, Haris; Boztosun, Ismail

2018-03-01

The photonuclear reactions, first extensively studied in the 1970's and performed using the gamma rays obtained via bremsstrahlung, are a standard nuclear physics experiment. In this study, a non-enriched Rubidium sample was irradiated with photons produced by a clinical linear electron accelerator (cLINACs) with energies up to 18 MeV with the aim of activating it through photonuclear reactions. The activated sample was measured with a high purity germanium detector (HPGe) with the aim of measuring the transition energies and half-lives. The spectroscopic analysis performed on the obtained data yielded high quality results for the transition energies with precision matching or surpassing the literature data. For the half-lives the results were consistent with the literature, most notably the half-life of 84mRb decay was determined as 20.28(2) m. The results for both energies and half-lives further show that the clinical linear accelerators can be successfully used as an efficient tool in experimental nuclear research endeavors.
Changes in ambient dose equivalent rates around roads at Kawamata town after the Fukushima accident.

PubMed

Kinase, Sakae; Sato, Satoshi; Sakamoto, Ryuichi; Yamamoto, Hideaki; Saito, Kimiaki

2015-11-01

Changes in ambient dose equivalent rates noted through vehicle-borne surveys have elucidated ecological half-lives of radioactive caesium in the environment. To confirm that the ecological half-lives are appropriate for predicting ambient dose equivalent rates within living areas, it is important to ascertain ambient dose equivalent rates on/around roads. In this study, radiation monitoring on/around roads at Kawamata town, located about 37 km northwest of the Fukushima Daiichi Nuclear Power Plant, was performed using monitoring vehicles and survey meters. It was found that the ambient dose equivalent rates around roads were higher than those on roads as of October 2012. And withal the ecological half-lives on roads were essentially consistent with those around roads. With dose predictions using ecological half-lives on roads, it is necessary to make corrections to ambient dose equivalent rates through the vehicle-borne surveys against those within living areas. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Analysis of Metal Element Distributions in Rice (Oryza sativa L.) Seeds and Relocation during Germination Based on X-Ray Fluorescence Imaging of Zn, Fe, K, Ca, and Mn

PubMed Central

Lu, Lingli; Tian, Shengke; Liao, Haibing; Zhang, Jie; Yang, Xiaoe; Labavitch, John M.; Chen, Wenrong

2013-01-01

Knowledge of mineral localization within rice grains is important for understanding the role of different elements in seed development, as well as for facilitating biofortification of seed micronutrients in order to enhance seeds’ values in human diets. In this study, the concentrations of minerals in whole rice grains, hulls, brown rice, bran and polished rice were quantified by inductively coupled plasma mass spectroscopy. The in vivo mineral distribution patterns in rice grains and shifts in those distribution patterns during progressive stages of germination were analyzed by synchrotron X-ray microfluorescence. The results showed that half of the total Zn, two thirds of the total Fe, and most of the total K, Ca and Mn were removed by the milling process if the hull and bran were thoroughly polished. Concentrations of all elements were high in the embryo regions even though the local distributions within the embryo varied between elements. Mobilization of the minerals from specific seed locations during germination was also element-specific. High mobilization of K and Ca from grains to growing roots and leaf primordia was observed; the flux of Zn to these expanding tissues was somewhat less than that of K and Ca; the mobilization of Mn or Fe was relatively low, at least during the first few days of germination. PMID:23451212
A half-metallic half-Heusler alloy having the largest atomic-like magnetic moment at optimized lattice constant

DOE PAGES

Zhang, R. L.; Damewood, L.; Fong, C. Y.; ...

2016-11-02

For half-Heusler alloys, the general formula is XYZ, where X can be a transition or alkali metal element, Y is another transition metal element, typically Mn or Cr, and Z is a group IV element or a pnicitide. The atomic arrangements within a unit-cell show three configurations. Before this study, most of the predictions of half-metallic properties of half-Heusler alloys at the lattice constants differing from their optimized lattice constant. Based on the electropositivity of X and electronegativity of Z for half-Heusler alloys, we found that one of the configurations of LiCrS exhibits half-metallic properties at its optimized lattice constantmore » of 5.803Å, and has the maximum atomic-like magnetic moment of 5μ B. In conclusion, the challenges of its growth and the effects of the spin-orbit effect in this alloy will be discussed.« less
Apparent Half-Lives of Dioxins, Furans, and Polychlorinated Biphenyls as a Function of Age, Body Fat, Smoking Status, and Breast-Feeding

PubMed Central

Milbrath, Meghan O’Grady; Wenger, Yvan; Chang, Chiung-Wen; Emond, Claude; Garabrant, David; Gillespie, Brenda W.; Jolliet, Olivier

2009-01-01

Objective In this study we reviewed the half-life data in the literature for the 29 dioxin, furan, and polychlorinated biphenyl congeners named in the World Health Organization toxic equivalency factor scheme, with the aim of providing a reference value for the half-life of each congener in the human body and a method of half-life estimation that accounts for an individual’s personal characteristics. Data sources and extraction We compared data from > 30 studies containing congener-specific elimination rates. Half-life data were extracted and compiled into a summary table. We then created a subset of these data based on defined exclusionary criteria. Data synthesis We defined values for each congener that approximate the half-life in an infant and in an adult. A linear interpolation of these values was used to examine the relationship between half-life and age, percent body fat, and absolute body fat. We developed predictive equations based on these relationships and adjustments for individual characteristics. Conclusions The half-life of dioxins in the body can be predicted using a linear relationship with age adjusted for body fat, smoking, and breast-feeding. Data suggest an alternative method based on a linear relationship between half-life and total body fat, but this approach requires further testing and validation with individual measurements. PMID:19337517
Half-lives of 132La and 135La

NASA Astrophysics Data System (ADS)

Abel, E. P.; Clause, H. K.; Fonslet, J.; Nickles, R. J.; Severin, G. W.

2018-03-01

The half-lives of 135La and 132La were determined via serial gamma spectroscopy, and the half-life of 135La was further determined by a high-precision ionization-chamber measurement. The results are 18.91(2) hr for 135La and 4.59(4) hr for 132La compared with the previously compiled values of 19.5(2) hr and 4.8(2) hr, respectively. These lanthanum isotopes comprise a medically interesting system with positron emitter 132La and Auger-electron emitter 135La forming a theranostic pair for internal diagnostics and therapeutics. The precise half-lives are necessary for proper evaluation of their value in medicine and for a more representative tabulation of nuclear data.
Barriers to access to care reported by women living with HIV across 27 countries.

PubMed

Johnson, Margaret; Samarina, Anna; Xi, He; Valdez Ramalho Madruga, José; Hocqueloux, Laurent; Loutfy, Mona; Fournelle, Marie-Josée; Norton, Michael; Van Wyk, Jean; Zachry, Woodie; Martinez, Marisol

2015-01-01

Increased access to successful antiretroviral therapy (ART) is necessary in order to achieve an AIDS-free generation. Importantly, slightly over half of the people living with HIV are women. Small studies have described many barriers to accessing treatment and care among women living with HIV. This cross-sectional, non-interventional, epidemiological study assessed the prevalence of barriers to accessing care for women living with HIV across 27 countries, divided into four global regions. HIV-positive women attending routine clinical visits were offered the opportunity to participate in the study. Data describing the study sites and demographic characteristics of the participating women were collected. Participating women filled out questionnaires including the Barriers to Care Scale (BACS) questionnaire, on which they reported the extent to which they found each of the 12 potential barriers to accessing health care problematic. A total of 1931 women living with HIV were included in the study: 760 from Western Europe and Canada (WEC), 532 from Central and Eastern Europe (CEE), 519 from Latin America (LA), and 120 from China. The mean age of participating women was 40.1 ± 11.4 years. A total of 88.2% were currently taking ART. A total of 81.8% obtained HIV treatment under a government health plan. The most prevalent barrier to care was community HIV/AIDS stigma. Community HIV/AIDS knowledge, lack of supportive/understanding work environments, lack of employment opportunities, and personal financial resources were also highly prevalent barriers to accessing care. These findings indicate that, more than 30 years after the start of the AIDS epidemic, stigma is still a major issue for women living with HIV. Continued efforts are needed to improve community education on HIV/AIDS in order to maximize access to health care among women living with HIV.
Barriers to access to care reported by women living with HIV across 27 countries

PubMed Central

Johnson, Margaret; Samarina, Anna; Xi, He; Valdez Ramalho Madruga, José; Hocqueloux, Laurent; Loutfy, Mona; Fournelle, Marie-Josée; Norton, Michael; Van Wyk, Jean; Zachry, Woodie; Martinez, Marisol

2015-01-01

Increased access to successful antiretroviral therapy (ART) is necessary in order to achieve an AIDS-free generation. Importantly, slightly over half of the people living with HIV are women. Small studies have described many barriers to accessing treatment and care among women living with HIV. This cross-sectional, non-interventional, epidemiological study assessed the prevalence of barriers to accessing care for women living with HIV across 27 countries, divided into four global regions. HIV-positive women attending routine clinical visits were offered the opportunity to participate in the study. Data describing the study sites and demographic characteristics of the participating women were collected. Participating women filled out questionnaires including the Barriers to Care Scale (BACS) questionnaire, on which they reported the extent to which they found each of the 12 potential barriers to accessing health care problematic. A total of 1931 women living with HIV were included in the study: 760 from Western Europe and Canada (WEC), 532 from Central and Eastern Europe (CEE), 519 from Latin America (LA), and 120 from China. The mean age of participating women was 40.1 ± 11.4 years. A total of 88.2% were currently taking ART. A total of 81.8% obtained HIV treatment under a government health plan. The most prevalent barrier to care was community HIV/AIDS stigma. Community HIV/AIDS knowledge, lack of supportive/understanding work environments, lack of employment opportunities, and personal financial resources were also highly prevalent barriers to accessing care. These findings indicate that, more than 30 years after the start of the AIDS epidemic, stigma is still a major issue for women living with HIV. Continued efforts are needed to improve community education on HIV/AIDS in order to maximize access to health care among women living with HIV. PMID:26168817
Systematic study on the competition between α-decay and spontaneous fission of superheavy nuclei

NASA Astrophysics Data System (ADS)

Zhang, Y. L.; Wang, Y. Z.

2017-10-01

The competition between α-decay and spontaneous fission (SF) of Z = 112 isotopes are studied. The α-decay half-lives are estimated by the generalized liquid-drop model (GLDM) and several sets of analytic formulas. These formulas include the Royer formula, Viola-Seaborg semiempirical (VSS) formula and universal decay law (UDL). For the SF, its half-lives are calculated by using the Xu, Ren, Karpov and Santhosh formulas. It is shown that the predicted α-decay half-lives by different approaches are more or less identical. However, the SF half-lives are highly sensitive to models. To test the accuracies of different SF formulas, the half-lives of 56 even-even heavy nuclei are calculated by these formulas. By comparing with the experimental data, it is found that the Xu formula is the most accurate one to reproduce the experimental SF half-lives. This allows us to make a systematic prediction on the competition between α-decay and SF of even-even superheavy nuclei (SHN) with Z = 104- 120 by using the Xu formula and the above mentioned models on α-decay. The calculations suggest that 258,260104, 268-276110, 270-280112, 272-286114, 274-294116, 284-302118 and 292-308120 have smaller α-decay half-lives than those of SF. Thus these nuclei can be synthesized and identified via α-decay in the laboratory. In addition, it is observed that N = 162, 178, 184 and 196 may be the submagic or magic numbers. Finally, an extensive study on the possible α-decay chains for Z = 120 isotopes is performed. It is predicted that six sequential α-decay chains can be observed from 292-296120, four α-decay chains from 298120, three α-decay chains from 300,302120, two α-decay chains from 304,306120, and only one α-decay chain from 308120. These nuclei are the most likely candidates to be synthesized experimentally via α-decay in the near future.
Divergent Binding and Transactivation by Two Related Steroid Receptors at the Same Response Element*

PubMed Central

Tesikova, Martina; Dezitter, Xavier; Nenseth, Hatice Z.; Klokk, Tove I.; Mueller, Florian; Hager, Gordon L.; Saatcioglu, Fahri

2016-01-01

Transcription factor (TF) recruitment to chromatin is central to activation of transcription. TF-chromatin interactions are highly dynamic, which are evaluated by recovery half time (t1/2) in seconds, determined by fluorescence recovery experiments in living cells, and chromatin immunoprecipitation (ChIP) analysis, measured in minutes. These two states are related: the larger the t1/2, the longer the ChIP occupancy resulting in increased transcription. Here we present data showing that this relationship does not always hold. We found that histone deacetylase inhibitors (HDACis) significantly increased t1/2 of green fluorescent protein (GFP) fused androgen receptor (AR) on a tandem array of positive hormone response elements (HREs) in chromatin. This resulted in increased ChIP signal of GFP-AR. Unexpectedly, however, transcription was inhibited. In contrast, the GFP-fused glucocorticoid receptor (GR), acting through the same HREs, displayed a profile consistent with current models. We provide evidence that these differences are mediated, at least in part, by HDACs. Our results provide insight into TF action in living cells and show that very closely related TFs may trigger significantly divergent outcomes at the same REs. PMID:27056330
Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator

PubMed Central

Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A.

2014-01-01

Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5′-leader region of the Mg2+ transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg2+ availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators. PMID:24778260
The Role of Parental Stress, Mother's Childhood Abuse and Perceived Consequences of Violence in Predicting Attitudes and Attribution in Favor of Corporal Punishment

ERIC Educational Resources Information Center

Clement, Marie-Eve; Chamberland, Claire

2009-01-01

We investigate maternal attitudes toward corporal punishment and the attribution of blame to the child on the basis of data gathered from a population survey of a representative sample of mothers and mother figures. A total of 3,148 women living at least half of the time with a child participated in a telephone survey. The independent variables…
Deformed shell model calculations of half lives for β+/EC decay and 2ν β+β+/β+EC/ECEC decay in medium-heavy N~Z nuclei

NASA Astrophysics Data System (ADS)

Mishra, S.; Shukla, A.; Sahu, R.; Kota, V. K. B.

2008-08-01

The β+/EC half-lives of medium heavy N~Z nuclei with mass number A~64-80 are calculated within the deformed shell model (DSM) based on Hartree-Fock states by employing a modified Kuo interaction in (2p3/2,1f5/2,2p1/2,1g9/2) space. The DSM model has been quite successful in predicting many spectroscopic properties of N~Z medium heavy nuclei with A~64-80. The calculated β+/EC half-lives, for prolate and oblate shapes, compare well with the predictions of the calculations with Skyrme force by Sarriguren Going further, following recent searches, half-lives for 2ν β+β+/β+EC/ECEC decay for the nucleus Kr78 are calculated using DSM and the results compare well with QRPA predictions.
Critical and systematic evaluation of data for estimating human exposures to 2,4-dichlorophenoxyacetic acid (2,4-D) - quality and generalizability.

PubMed

LaKind, Judy S; Burns, Carol J; Naiman, Daniel Q; O'Mahony, Cian; Vilone, Giulia; Burns, Annette J; Naiman, Joshua S

2017-01-01

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been commercially available since the 1940's. Despite decades of data on 2,4-D in food, air, soil, and water, as well as in humans, the quality the quality of these data has not been comprehensively evaluated. Using selected elements of the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument (temporal variability, avoidance of sample contamination, analyte stability, and urinary methods of matrix adjustment), the quality of 156 publications of environmental- and biomonitoring-based 2,4-D data was examined. Few publications documented steps were taken to avoid sample contamination. Similarly, most studies did not demonstrate the stability of the analyte from sample collection to analysis. Less than half of the biomonitoring publications reported both creatinine-adjusted and unadjusted urine concentrations. The scope and detail of data needed to assess temporal variability and sources of 2,4-D varied widely across the reviewed studies. Exposures to short-lived chemicals such as 2,4-D are impacted by numerous and changing external factors including application practices and formulations. At a minimum, greater transparency in reporting of quality control measures is needed. Perhaps the greatest challenge for the exposure community is the ability to reach consensus on how to address problems specific to short-lived chemical exposures in observational epidemiology investigations. More extensive conversations are needed to advance our understanding of human exposures and enable interpretation of these data to catch up to analytical capabilities. The problems defined in this review remain exquisitely difficult to address for chemicals like 2,4-D, with short and variable environmental and physiological half-lives and with exposures impacted by numerous and changing external factors.
Modification of apparent fission yields by Chemical Fractionation following Fission (CFF)

NASA Astrophysics Data System (ADS)

Hohenberg, Charles; Meshik, Alex

2008-04-01

Grain-by-grain studies of the 2 billion year old Oklo natural reactor, using laser micro-extraction^1,2, yield detailed information about Oklo, a water-moderated pulsed reactor, cycle times, total neutron fluence and duration, but it also demonstrates Chemical Fractionation following Fission. In the CFF process, members of an isobaric yield chain with long half-lives are subject to migration before decay can occur. Of particular interest is the 129 isobar where 17 million ^129I can migrate out of the host grain before decay, and iodine compounds are water soluble. This is amply demonstated by the variation of Xe spectra between micron-sized uranium-bearing minerals and adjacent uranium-free minerals. Fission 129 yields for the spontaneous fission of ^238U generally come from measured ^129Xe in pitchblend^2, ores emplaced by aqueous activity, and are incorrect due to the CFF process. ^238U yields for the 131 and 129 chains, reported in Hyde^3, as 0.455 +- .02 and < 0.012, respectively, the latter being anomalously low. ^1A Meshik, C Hohenberg and O Pravdivtesva, PRL 93, 182302 (2004); A Meshik Sci. Am. Nov (2005), 55; ^2E K Hyde, Nucl Prop of Heavy Elements III (1964).
RNA degradation in Archaea and Gram-negative bacteria different from Escherichia coli.

PubMed

Evguenieva-Hackenberg, Elena; Klug, Gabriele

2009-01-01

Exoribonucleolytic and endoribonucleolytic activities are important for controlled degradation of RNA and contribute to the regulation of gene expression at the posttranscriptional level by influencing the half-lives of specific messenger RNAs. The RNA half-lives are determined by the characteristics of the RNA substrates and by the availability and the properties of the involved proteins-ribonucleases and assisting polypeptides. Much is known about RNA degradation in Eukarya and Bacteria, but there is limited information about RNA-degrading enzymes and RNA destabilizing or stabilizing elements in the domain of the Archaea. The recent progress in the understanding of the structure and function of the archaeal exosome, a protein complex with RNA-degrading and RNA-tailing capabilities, has given some first insights into the mechanisms of RNA degradation in the third domain of life and into the evolution of RNA-degrading enzymes. Moreover, other archaeal RNases with degrading potential have been described and a new mechanism for protection of the 5'-end of RNA in Archaea was discovered. Here, we summarize the current knowledge on RNA degradation in the Archaea. Additionally, RNA degradation mechanisms in Rhodobacter capsulatus and Pseudomonas syringae are compared to those in the major model organism for Gram-negatives, Escherichia coli, which dominates our view on RNA degradation in Bacteria.
Whole-remnant and maximum-voxel SPECT/CT dosimetry in {sup 131}I-NaI treatments of differentiated thyroid cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mínguez, Pablo, E-mail: pablo.minguezgabina@osakid

Purpose: To investigate the possible differences between SPECT/CT based whole-remnant and maximum-voxel dosimetry in patients receiving radio-iodine ablation treatment of differentiated thyroid cancer (DTC). Methods: Eighteen DTC patients were administered 1.11 GBq of {sup 131}I-NaI after near-total thyroidectomy and rhTSH stimulation. Two patients had two remnants, so in total dosimetry was performed for 20 sites. Three SPECT/CT scans were performed for each patient at 1, 2, and 3–7 days after administration. The activity, the remnant mass, and the maximum-voxel activity were determined from these images and from a recovery-coefficient curve derived from experimental phantom measurements. The cumulated activity was estimatedmore » using trapezoidal-exponential integration. Finally, the absorbed dose was calculated using S-values for unit-density spheres in whole-remnant dosimetry and S-values for voxels in maximum-voxel dosimetry. Results: The mean absorbed dose obtained from whole-remnant dosimetry was 40 Gy (range 2–176 Gy) and from maximum-voxel dosimetry 34 Gy (range 2–145 Gy). For any given patient, the activity concentrations for each of the three time-points were approximately the same for the two methods. The effective half-lives varied (R = 0.865), mainly due to discrepancies in estimation of the longer effective half-lives. On average, absorbed doses obtained from whole-remnant dosimetry were 1.2 ± 0.2 (1 SD) higher than for maximum-voxel dosimetry, mainly due to differences in the S-values. The method-related differences were however small in comparison to the wide range of absorbed doses obtained in patients. Conclusions: Simple and consistent procedures for SPECT/CT based whole-volume and maximum-voxel dosimetry have been described, both based on experimentally determined recovery coefficients. Generally the results from the two approaches are consistent, although there is a small, systematic difference in the absorbed dose due to differences in the S-values, and some variability due to differences in the estimated effective half-lives, especially when the effective half-life is long. Irrespective of the method used, the patient absorbed doses obtained span over two orders of magnitude.« less

Average and recommended half-life values for two neutrino double beta decay: Upgrade-2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barabash, A. S.

2013-12-30

All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 100}Mo−{sup 100}Ru (0{sub 1}{sup +}), {sup 116}Cd, {sup 130}Te, {sup 136}Xe, {sup 150}Nd, {sup 150}Nd−{sup 150}Sm (0{sub 1}{sup +}) and {sup 238}U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of {sup 128}Te and {sup 130}Ba are proposed. I recommend the use of these results as the most currently reliable values for half-lives.
PCA and multidimensional visualization techniques united to aid in the bioindication of elements from transplanted Sphagnum palustre moss exposed in the Gdańsk City area.

PubMed

Astel, Aleksander; Astel, Karolina; Biziuk, Marek

2008-01-01

During the last decades, a technique for assessing atmospheric deposition of heavy elements was developed based on the principle that samples of moss are able to accumulate elements and airborne particles from rain, melting snow and dry deposition. Despite a broad interest in bioindication there are still ongoing works aimed at the preparation of a standard procedure allowing for a comparison of research carried out in various areas. This is why the comparison of living and dry moss of the same species and growth site seems to be interesting, logical and promising. A most reliable approach seems to be the application of bioindication connected with multivariate statistics and efficient visualization techniques in the interpretation of monitoring data. The aim of this study was: (i) to present cumulative properties of transplanted Sphagnum palustre moss with differentiation into dry and living biomaterial; (ii) to determine and geographically locate types of pollution sources responsible for a structure of the monitoring data set; (iii) to visualize geographical distribution of analytes in the Gdańsk metropolitan area and to identify the high-risk areas which can be targeted for environmental hazards and public health. A six month air pollution study based on Sphagnum palustre bioindication is presented and a simplified procedure of the experiment is given. The study area was located at the mouth of the Vistula River on the Baltic Sea, in Gdańsk City (Poland). Sphagnum palustre was selected for research because of its extraordinary morphological properties and its ease in being raised. The capability of dry and living moss to accumulate elements characteristic for anthropogenic and natural sources was shown by application of Principal Component Analysis. The high-risk areas and pollution profiles are detected and visualized using surface maps based on Kriging algorithm. The original selection of elements included all those that could be reliably determined by Neutron Activation Analysis in moss samples. Elimination of variables covered the elements whose concentrations in moss were lower than the reported detection limits for INAA for most observations or in cases where particular elements did not show any variation. Eighteen elements: a, Ca, Sc, Fe, Co, Zn, As, Br, Mo, Sb, Ba, La, Ce, Sm, Yb, Lu, Hf, Th, were selected for the research presented. Two runs of PCA were performed since, in the first-run a heavy polluted location (Stogi - 'Sto') understood as outlier in the term of PCA approach was detected and results in the form of block diagrams and surface maps were presented. As ensues from the first-run PCA analysis, the factor layout for both indicators is similar but not identical due to the differences in the elements accumulation mechanism. Three latent factors ('phosphatic fertilizer plant impact', 'urban impact' and 'marine impact') explain over 89% and 82% of the total variance for dry and living moss respectively. In the second-run PCA three latent factors are responsible for the data structure in both moss materials. However, in the case of dry moss analysis these factors explain 85% of the total variance but they are rather hard to interpret. On the other hand living moss shows the same pattern as in first-run PCA. Three latent factors explain over 84% of the total variance in this case. The pollution profiles extracted in PCA of dry moss data differ tremendously between both runs, while no deterioration was found after removal of Stogi from data set in case of living moss. Performance of the second-run PCA with exception of Stogi as a heavy polluted location has led to the conclusion that living moss shows better indication properties than dry one. While using moss as wet and dry deposition sampier it is not possible to calculate deposition values since the real volume of collected water and dust is hard to estimate due to a splash effect and irregular surface. Therefore, accumulation values seam to be reasonable for moss-based air pollution surveys. Both biomaterials: dry and living Sphagnum palustre show cumulative properties relative to elements under interest. Dry moss has a very loose collection of the atmospheric particles, which can also easily get lost upon rinsing with rainwater running through exposed dry moss material. The living moss may, on the contrary, incorporate the elements in its tissue, thus being less susceptible to rinsing and thus better reflecting the atmospheric conditions. Despite the differences in element uptake and uphold capabilities dry and living moss reflect characteristic anthropogenic and natural profiles. Visible differences in impacts' map coverage exist mostly due to the accumulation mechanisms differentiating dry from living moss. However, in case of each indicator 'phosphatic fertilizer plant impact' is recognized as the strongest pollution source present in examined region. General types of pollution sources responsible for a structure of monitoring data set were determined as high-risk/low-risk areas and visualized in form of geographic distribution maps. These locations can be targeted for environmental hazards and public health. Chemometric results in the form of easy defined surface maps can became a powerful instrument in hands of decision-makers working in the field of sustainable development implementation.
The detectability half-life in arthropod predator-prey research: what it is, why we need it, how to measure it, and how to use it.

PubMed

Greenstone, Matthew H; Payton, Mark E; Weber, Donald C; Simmons, Alvin M

2014-08-01

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Most assays produce only qualitative results, with each predator testing either positive or negative for target prey remains. Nevertheless, they have yielded important insights into community processes. For example, they have confirmed the long-hypothesized role of generalist predators in retarding early-season build-up of pest populations prior to the arrival of more specialized predators and parasitoids and documented the ubiquity of secondary and intraguild predation. However, raw qualitative gut-content data cannot be used to assess the relative impact of different predator taxa on prey population dynamics: they must first be weighted by the relative detectability periods for molecular prey remains for each predator-prey combination. If this is not carried out, interpretations of predator impact will be biased towards those with the longest detectabilities. We review the challenges in determining detectability half-lives, including unstated assumptions that have often been ignored in the performance of feeding trials. We also show how detectability half-lives can be used to properly weight assay data to rank predators by their importance in prey population suppression, and how sets of half-lives can be used to test hypotheses concerning predator ecology and physiology. We use data from 32 publications, comprising 97 half-lives, to generate and test hypotheses on taxonomic differences in detectability half-lives and discuss the possible role of the detectability half-life in interpreting qPCR and next-generation sequencing data. © 2013 John Wiley & Sons Ltd.
Off-site movement of endosulfan from irrigated cotton in New South Wales.

PubMed

Kennedy, I R; Sánchez-Bayo, F; Kimber, S W; Hugo, L; Ahmad, N

2001-01-01

The fate and transport of endosulfan (6,7,8,9,10,10-hexachloro-1,5, 5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide) applied to cotton (Gossypium hirsutum L.) fields were studied throughout three consecutive years on two selected locations in New South Wales (Australia). Rates of dissipation from foliage and soil, volatilization from the field, and transport of residues in irrigation and/or storm runoff waters were measured in order to estimate a total field balance. Dissipation of endosulfan from both foliage and soil is best explained by a two-phase process rather than by a first-order decay. Half-lives of total endosulfan toxic residues (alpha- and beta-endosulfan and the sulfate product) in the first phase were 1.6 d in foliage and 7.1 d in soil, and could be explained by the rapid volatilization of the parent isomers in the first 5 d (up to 70% of endosulfan volatilizes). In the second phase, half-lives were 9.5 d in foliage and 82 d in soil, mostly due to the persistence of the sulfate product. Concentration of endosulfan residues in runoff water varied from 45 to 2.5 microg L(-1) depending on the residue levels present on field soil at the time of the irrigation or storm events. These in turn are related to the total amounts applied, the cotton canopy cover at application, and the time since last spraying. Most of the endosulfan in runoff was found in the water phase (80%), suggesting it was bound to colloidal matter. Total endosulfan residues in runoff for a whole season accounted for no more than 2% of the pesticide applied on-field.
All half-lives are wrong, but some half-lives are useful.

PubMed

Wright, J G; Boddy, A V

2001-01-01

The half-life of a drug, which expresses a change in concentration in units of time, is perhaps the most easily understood pharmacokinetic parameter and provides a succinct description of many concentration-time profiles. The calculation of a half-life implies a linear, first-order, time-invariant process. No drug perfectly obeys such assumptions, although in practise this is often a valid approximation and provides invaluable quantitative information. Nevertheless, the physiological processes underlying half-life should not be forgotten. The concept of clearance facilitates the interpretation of factors affecting drug elimination, such as enzyme inhibition or renal impairment. Relating clearance to the observed concentration-time profile is not as naturally intuitive as is the case with half-life. As such, these 2 approaches to parameterising a linear pharmacokinetic model should be viewed as complementary rather than alternatives. The interpretation of pharmacokinetic parameters when there are multiple disposition phases is more challenging. Indeed, in any pharmacokinetic model, the half-lives are only one component of the parameters required to specify the concentration-time profile. Furthermore, pharmacokinetic parameters are of little use without a dose history. Other factors influencing the relevance of each disposition phase to clinical end-points must also be considered. In summarising the pharmacokinetics of a drug, statistical aspects of the estimation of a half-life are often overlooked. Half-lives are rarely reported with confidence intervals or measures of variability in the population, and some approaches to this problem are suggested. Half-life is an important summary statistic in pharmacokinetics, but care must be taken to employ it appropriately in the context of dose history and clinically relevant pharmacodynamic end-points.
Chemical Research--Radiochemistry Report for Month Ending April 17, 1943

DOE R&D Accomplishments Database

Franck, J. Division Director

1952-01-01

1. A continuation of the detailed analysis of beta and soft and hard gamma activity associated with all fission product elements in a nitrate bombardment is presented. The ?cooling? time has been extended to 170 days. The data for the individual elements are presented in tables as counts/min and in figures as percentage of total beta, soft gamma, and hard gamma radiations. 2. Calculations and graphs have been made on the heat generated by the longer-lived fission products. The method of analysis is presented. 3. Two new short-lived Rh fission product activities have been found. They are probably the daughters of the two long-lived Ru activities (30d, 200d). Re-evaluation of data on 43 leads to the conclusion that the longest lived 43 activity in measureable yields is the 6.1h (formerly 6.6h). New parent-daughter relationships in the rare-earth activities are given. 4. Theoretical beta absorption curves have been made using the Fermi distribution function and linear absorption curves for small energy intervals. A Feather analysis of the absorption curve leads to the theoretical maximum energy.
Pesticide nonextractable residue formation in soil: insights from inverse modeling of degradation time series.

PubMed

Loos, Martin; Krauss, Martin; Fenner, Kathrin

2012-09-18

Formation of soil nonextractable residues (NER) is central to the fate and persistence of pesticides. To investigate pools and extent of NER formation, an established inverse modeling approach for pesticide soil degradation time series was evaluated with a Monte Carlo Markov Chain (MCMC) sampling procedure. It was found that only half of 73 pesticide degradation time series from a homogeneous soil source allowed for well-behaved identification of kinetic parameters with a four-pool model containing a parent compound, a metabolite, a volatile, and a NER pool. A subsequent simulation indeed confirmed distinct parameter combinations of low identifiability. Taking the resulting uncertainties into account, several conclusions regarding NER formation and its impact on persistence assessment could nonetheless be drawn. First, rate constants for transformation of parent compounds to metabolites were correlated to those for transformation of parent compounds to NER, leading to degradation half-lives (DegT50) typically not being larger than disappearance half-lives (DT50) by more than a factor of 2. Second, estimated rate constants were used to evaluate NER formation over time. This showed that NER formation, particularly through the metabolite pool, may be grossly underestimated when using standard incubation periods. It further showed that amounts and uncertainties in (i) total NER, (ii) NER formed from the parent pool, and (iii) NER formed from the metabolite pool vary considerably among data sets at t→∞, with no clear dominance between (ii) and (iii). However, compounds containing aromatic amine moieties were found to form significantly more total NER when extrapolating to t→∞ than the other compounds studied. Overall, our study stresses the general need for assessing uncertainties, identifiability issues, and resulting biases when using inverse modeling of degradation time series for evaluating persistence and NER formation.
Total Solar Eclipse of 2008 August 01

NASA Technical Reports Server (NTRS)

Espenak, F.; Anderson, J.

2007-01-01

On 2008 August 01, a total eclipse of the Sun is visible from within a narrow corridor that traverses half the Earth. The path of the Moon's umbral shadow begins in northern Canada and extends across Greenland, the Arctic, central Russia, Mongolia, and China. A partial eclipse is seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, most of Europe and Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 308 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.
Attitudes of old people towards old age homes in Hong Kong.

PubMed

Kwok, T; Luk, J K; Lau, E; Woo, J

1998-01-01

The attitudes of older people towards old age homes (OAH) in Hong Kong and the factors which influenced their attitudes were investigated. A total of 197 non-institutionalised older subjects were interviewed with a standard questionnaire. A quarter of them admitted to having thought about going into an OAH, though most had never visited one. Half of them would consider an OAH if they lived alone with no family support, while only a few would consider it if they were living with family. If they became disabled and required help from family, a third would consider an OAH. If family support was not available, two-thirds would consider an OAH, while a few opted for social services. If advised to go into an OAH by doctors or family, about a half of the subjects would comply. On stepwise logistic regression, independent predictors of the desire for an OAH were agreeing with OAH placement if it was affordable and if one was living alone with visits from family, admitting to be happy in an OAH, and previous experience with an OAH. We concluded that older people in Hong Kong were not in favour of an OAH unless there were physical disabilities and lack of family support. They were, however, vulnerable to external pressures.
Living anew - About possibilities of contemporary adaptations of flats carried out in industrialised technologies in Poland

NASA Astrophysics Data System (ADS)

Kłopotowski, Maciej

2017-10-01

Around the half of Polish population currently live in the buildings constructed in the second half of the twentieth century in industrialized technologies. Economic conditions indicate that this state will not change substantially over the next decade. This situation forces people who deal with shaping housing space to take action that will raise the value of existing, technically and morally degrading, housing substance. As a result of conducted research, the author of this study pointed out that the so-called revitalization of the housing environment is carried out at the level of residents, administrators of buildings and housing estates. Their effects are often not correlated or even contradictory. He also emphasized the importance of comprehensive measures and the need for systemic solutions that integrate legislation, administration and contracting. As an important element of these actions he pointed out the need to develop a catalogue illustrating the possibility of reconstruction of housing. The article will present the results of research aimed at developing a strategy of remodelling flats, considered today unattractive, located in buildings constructed in OW-T technology. The analyses were carried out on a group of flats (about 85 m²) completed at the turn of 70s and 80s. During the construction period they were intended to be settled by families of minimum 6 people and were the largest. Their structure consists of a number of relatively small rooms (including very small bathrooms and kitchens). The author made a critical analysis of this housing offer. He defined contemporary needs of investors who are involved in buying flats of such size - they are families with one or two children. Measurable results of the work carried out are the schemes of housing conversion plans. The article presents four specific design solutions that show the direction of possible actions. According to the author, popularizing the possibility of reconstructing such flats should be one of the elements of the strategy of renovation and improvement of the quality of the Polish housing environment implemented in the second half of the 20th century.
New isotopic clues to solar system formation

NASA Technical Reports Server (NTRS)

Lee, T.

1979-01-01

The presence of two new extinct nuclides Al-26 and Pd-107 with half lives of approximately one million years in the early solar system implies that there were nucleosynthetic activities involving a great many elements almost at the instant of solar system formation. Rate gas and oxygen isotopic abundance variations ('anomalies') relative to the 'cosmic' composition were observed in a variety of planetary objects, which indicates that isotopic heterogeneities caused by the incomplete mixing of distinct nucleosynthesis components permeate the entire solar system. These new results have major implications for cosmochronology, nucleosynthesis theory, star formation, planetary heating, and the genetic relationship between different planetary bodies
Parallel and series FED microstrip array with high efficiency and low cross polarization

NASA Technical Reports Server (NTRS)

Huang, John (Inventor)

1995-01-01

A microstrip array antenna for vertically polarized fan beam (approximately 2 deg x 50 deg) for C-band SAR applications with a physical area of 1.7 m by 0.17 m comprises two rows of patch elements and employs a parallel feed to left- and right-half sections of the rows. Each section is divided into two segments that are fed in parallel with the elements in each segment fed in series through matched transmission lines for high efficiency. The inboard section has half the number of patch elements of the outboard section, and the outboard sections, which have tapered distribution with identical transmission line sections, terminated with half wavelength long open-circuit stubs so that the remaining energy is reflected and radiated in phase. The elements of the two inboard segments of the two left- and right-half sections are provided with tapered transmission lines from element to element for uniform power distribution over the central third of the entire array antenna. The two rows of array elements are excited at opposite patch feed locations with opposite (180 deg difference) phases for reduced cross-polarization.
Dissipation, half-lives, and mass spectrometric identification of chlorpyrifos and its two metabolites on field-grown collard and kale.

PubMed

Antonious, George F; Turley, Eric T; Abubakari, Mutari; Snyder, John C

2017-04-03

The persistence and fate of chlorpyrifos and its two metabolites, chlorpyrifos-oxon and the 3, 5, 6-trichloro-2-pyridinol (TCP) break-down product were investigated on kale and collard leaves under field conditions. A simultaneous extraction and quantification procedure was developed for chrorpyrifos and its two main metabolites. Residues of chlorpyrifos, chlorpyrifos oxon, and TCP were determined using a gas chromatograph (GC) equipped with an electron capture detector (GC/ECD). Chlorpyrifos metabolites were detectable up to 23 days following application. Residues were confirmed using a GC equipped with a mass selective detector (GC/MSD) in total ion mode. Initial residues of chlorpyrifos were greater on collard (14.5 µg g -1 ) than kale (8.2 µg g -1 ) corresponding to half-lives (T 1/2 ) values of 7.4 and 2.2 days, respectively. TCP, the hydrolysis product, was more persistent on collards with an estimated T 1/2 of 6.5 days compared to kale (T 1/2 of 1.9 days).
A combined experimental and finite element approach to analyse the fretting mechanism of the head-stem taper junction in total hip replacement.

PubMed

Bitter, Thom; Khan, Imran; Marriott, Tim; Lovelady, Elaine; Verdonschot, Nico; Janssen, Dennis

2017-09-01

Fretting corrosion at the taper interface of modular hip implants has been implicated as a possible cause of implant failure. This study was set up to gain more insight in the taper mechanics that lead to fretting corrosion. The objectives of this study therefore were (1) to select experimental loading conditions to reproduce clinically relevant fretting corrosion features observed in retrieved components, (2) to develop a finite element model consistent with the fretting experiments and (3) to apply more complicated loading conditions of activities of daily living to the finite element model to study the taper mechanics. The experiments showed similar wear patterns on the taper surface as observed in retrievals. The finite element wear score based on Archard's law did not correlate well with the amount of material loss measured in the experiments. However, similar patterns were observed between the simulated micromotions and the experimental wear measurements. Although the finite element model could not be validated, the loading conditions based on activities of daily living demonstrate the importance of assembly load on the wear potential. These findings suggest that finite element models that do not incorporate geometry updates to account for wear loss may not be appropriate to predict wear volumes of taper connections.
Half-lives of α -decaying nuclei in the medium-mass region within the transfer matrix method

NASA Astrophysics Data System (ADS)

Wu, Shuangxiang; Qian, Yibin; Ren, Zhongzhou

2018-05-01

The α -decay half-lives of even-even nuclei from Sm to Th are systematically studied based on the transfer matrix method. For the nuclear potential, a type of cosh-parametrized form is applied to calculate the penetration probability. Through a least-squares fit to experimental half-lives, we optimize the parameters in the potential and the α preformation factor P0. During this process, P0 is treated as a constant for each parent nucleus. Eventually, the calculated half-lives are found to agree well with the experimental data, which verifies the accuracy of the present approach. Furthermore, in recent studies, P0 is regulated by the shell and paring effects plus the nuclear deformation. To this end, P0 is here associated with the structural quantity, i.e., the microscopic correction of nuclear mass (Emic). In this way, the agreement between theory and experiment is greatly improved by more than 20%, validating the appropriate treatment of P0 in the scheme of Emic.
Effect of filtration on rolling-element-bearing life in contaminated lubricant environment

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.; Sherlock, J. J.

1978-01-01

Fatigue tests were conducted on groups of 65 millimeter-bore ball bearings under four levels of filtration with and without a contaminated MIL-L-23699 lubricant. The baseline series used noncontaminated oil with 49 micron absolute filtration. In the remaining tests contaminants of the composition found in aircraft engine filters were injected into the filter's supply line at a constant rate of 125 milligrams per bearing-hour. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns (0.45, 10, 30, and 70 microns nominal), respectively. Bearings were tested at 15,000 rpm under 4580 newtons radial load. Bearing life and running tract condition generally improved with finer filtration. The 3 and 30 micron filter bearings in a contaminated lubricant had statistically equivalent lives, approaching those from the baseline tests. The experimental lives of 49 micron bearings were approximately half the baseline bearing's lives. Bearings tested with the 105 micron filter experienced wear failures. The degree of surface distress, weight loss, and probable failure mode were found to be dependent on filtration level, with finer filtration being clearly beneficial.
Reproductive cancer risk factors among Alaska Native women: the Alaska Education and Research Towards Health (EARTH) Study.

PubMed

Redwood, Diana G; Lanier, Anne P; Johnston, Janet M; Murphy, Neil; Murtaugh, Maureen A

2012-01-01

The purpose of this study was to provide estimates for the prevalence of reproductive cancer risk factors among Alaska Native (AN) women who enrolled in the Alaska Education and Research Towards Health (EARTH) Study from 2004 to 2006. A total of 2,315 AN women 18 years or older completed reproductive health questions as part of a comprehensive health history questionnaire. The reproductive health section included menstrual status (age at menarche and menopause), pregnancy and live birth history, use of hormonal contraception, hormone replacement therapy, and history of hysterectomy and/or oophorectomy. A total of 463 (20%) of women experienced menarche before age 12 with a decline in mean age at menarche by age cohort. More than 86% had been pregnant (mean number of pregnancies, 3.8; mean number of live births, 2.9). More than one half of women (58%) had their first live birth between the ages of 18 and 24. Almost 28% of participants had completed menopause, of whom 24% completed menopause after age 52. Fewer than half (43%) reported ever using hormone replacement therapy. Almost two thirds (62%) reported ever using oral contraceptives, and fewer reported ever using birth control shots (30%) or implants (10%). This study is unique in reporting reproductive health factors among a large group of AN women. These data show that AN women have selective protective factors for reproductive cancers, including low nulliparity rates, low use of menopausal estrogens, and common use of contraceptive hormones. However, analysis by age cohorts indicates decreasing age at menarche that might increase the risk for reproductive cancers among AN women in the future. Copyright © 2012 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.
Retention of elements absorbed by juvenile fish (Menidia menidia, Menidia Beryllina) from zooplankton prey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinfelder, J.R.; Fisher, N.S.

1994-12-01

Radiolabeled copepods (Acartia spp.) were fed to juvenile silversides (Menidia menidia and Menidia beryllina) to study element absorption in the fish. Copepods were reared from nauplii in the presence of different radiotracers ({sup 14}C,{sup 109}Cd,{sup 57}Co,{sup 32}P,{sup 35}S,{sup 75}Se, o;r {sup 65}Zn) and were analyzed for relative concentrations of these elements in their tissue fractions. Copepod exoskeletons contained nearly all of the trace metals (>97%), 60% of the Se, and less than half of the C,P, and S accumulated by the copepods. Within the nonexoskeleton tissues of the copepods, nonpolar (CHCl{sub 3} extractable) material contained 34 and 24% of themore » total C and P, but only 8 and 2% of the total S and Se. Absorption efficiencies of trace metals in juvenile silversides (2.7% for Cd, 2.1% for Co, 6.2% for Zn) were an order of magnitude lower than those for nonmetals (29% for Se, 50% for S and C, 60% for P). The absorption efficiencies in the juvenile silversides of all seven elements studied were directly related to the percent of each element in the nonexoskeleton fractions of the copepod prey, indicating that the fish absorbed the soft tissues of the copepods and egested the chitinous exoskeleton and its associated elements. 32 refs., 1 fig., 2 tabs.« less
Recent α decay half-lives and analytic expression predictions including superheavy nuclei

NASA Astrophysics Data System (ADS)

Royer, G.; Zhang, H. F.

2008-03-01

New recent experimental α decay half-lives have been compared with the results obtained from previously proposed formulas depending only on the mass and charge numbers of the α emitter and the Qα value. For the heaviest nuclei they are also compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The correct agreement allows us to make predictions for the α decay half-lives of other still unknown superheavy nuclei from these analytic formulas using the extrapolated Qα of G. Audi, A. H. Wapstra, and C. Thibault [Nucl. Phys. A729, 337 (2003)].
Topology and Oligomerization of Mono- and Oligomeric Proteins Regulate Their Half-Lives in the Cell.

PubMed

Mallik, Saurav; Kundu, Sudip

2018-06-05

To find additional structural constraints (besides disordered segments) that regulate protein half-life in the cell, we herein assess the influence of native topology of monomeric and sequestration of oligomeric proteins into multimeric complexes in yeast, human, and mouse. Native topology acts as a molecular marker of globular protein's mechanical resistance and consequently captures their half-life variations on genome scale. Sequestration into multimeric complexes elongates oligomeric protein half-life in the cell, presumably by burying ubiquitinoylation sites and disordered segments required for proteasomal recognition. The latter effect is stronger for proteins associated with multiple complexes and for those binding early during complex self-assembly, including proteins that oligomerize with large proportions of surface buried. After gene duplication, diversification of topology and sequestration into non-identical sets of complexes alter half-lives of paralogous proteins during the course of evolution. Thus, native topology and sequestration into multimeric complexes reflect designing principles of proteins to regulate their half-lives. Copyright © 2018 Elsevier Ltd. All rights reserved.

α -decay chains of superheavy Mt-279265 isotopes

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2017-10-01

The α -decay chains of the isotopes Mt-279265 are predicted by comparing the α half-lives calculated within the Coulomb and proximity potential model for deformed nuclei of Santhosh et al. [Nucl. Phys. A 850, 34 (2011)], 10.1016/j.nuclphysa.2010.12.002 with the spontaneous fission half-lives using the shell-effect-dependent formula of Santhosh and Nithya [Phys. Rev. C 94, 054621 (2016)], 10.1103/PhysRevC.94.054621. α half-lives also are calculated using different theoretical formalisms for comparison. The predicted half-lives and decay modes match well with the experimental results. The use of four different mass tables for calculating the α - decay energies indicates that the mass table of Wang et al. [Chin. Phys. C 41, 030003 (2017)], 10.1088/1674-1137/41/3/030003, which is based on the AME2016 atomic mass evaluation, is in better agreement with experimental results. The paper predicts long α chains from 265,267-269,271-273MT with half-lives within experimental limits. The isotopes 274-276,278Mt exhibit 2α chains followed by spontaneous fission. The 2α chain of 266Mt and the 4α chain of 270Mt end with electron capture. The isotopes Mt,279277 decay via spontaneous fission. We hope that the paper will open up new areas in this field.
Gas-phase polychlorinated biphenyl and hexachlorocyclohexane concentrations near the Great Lakes: a historical perspective.

PubMed

Buehler, Stephanie S; Basu, Ilora; Hites, Ronald A

2002-12-01

The Integrated Atmospheric Deposition Network (IADN) has been measuring gas-phase, polychlorinated biphenyl (PCB) concentrations at sites near Lakes Michigan and Superior for over a decade. Data through 2000 were used in this study to investigate PCB temporal trends in the Great Lakes atmosphere. Decreasing trends were found at both sites, and half-lives of approximately 20 yr were calculated using IADN data. However, when these data were supplemented by historical data for Lakes Michigan and Superior dating back to 1977, half-lives dropped to 10 and 6 yr, respectively. These latter half-lives agreed well with half-lives in other environmental compartments. Exponential curves fitted to the historical and IADN data indicated little decline in PCB concentrations in the basin since the mid-1990s. A similar historical analysis of alpha-and gamma-hexachlorocyclohexane (HCH) data indicated that IADN data were the best predictor of trends, resulting in half-lives of around 4 yr for both compounds. Gamma-HCH concentrations, however, have shown little decline in recent years, most likely because of its continuing use. PCB and alpha-HCH temporal trends indicated that bans on these substances have helped to remove them from the atmosphere. This work also showed that decades of data may be necessary to properly interpret long-term temporal trends in gas-phase organochlorine concentrations.
Comparisons of discrete and integrative sampling accuracy in estimating pulsed aquatic exposures.

PubMed

Morrison, Shane A; Luttbeg, Barney; Belden, Jason B

2016-11-01

Most current-use pesticides have short half-lives in the water column and thus the most relevant exposure scenarios for many aquatic organisms are pulsed exposures. Quantifying exposure using discrete water samples may not be accurate as few studies are able to sample frequently enough to accurately determine time-weighted average (TWA) concentrations of short aquatic exposures. Integrative sampling methods that continuously sample freely dissolved contaminants over time intervals (such as integrative passive samplers) have been demonstrated to be a promising measurement technique. We conducted several modeling scenarios to test the assumption that integrative methods may require many less samples for accurate estimation of peak 96-h TWA concentrations. We compared the accuracies of discrete point samples and integrative samples while varying sampling frequencies and a range of contaminant water half-lives (t 50 = 0.5, 2, and 8 d). Differences the predictive accuracy of discrete point samples and integrative samples were greatest at low sampling frequencies. For example, when the half-life was 0.5 d, discrete point samples required 7 sampling events to ensure median values > 50% and no sampling events reporting highly inaccurate results (defined as < 10% of the true 96-h TWA). Across all water half-lives investigated, integrative sampling only required two samples to prevent highly inaccurate results and measurements resulting in median values > 50% of the true concentration. Regardless, the need for integrative sampling diminished as water half-life increased. For an 8-d water half-life, two discrete samples produced accurate estimates and median values greater than those obtained for two integrative samples. Overall, integrative methods are the more accurate method for monitoring contaminants with short water half-lives due to reduced frequency of extreme values, especially with uncertainties around the timing of pulsed events. However, the acceptability of discrete sampling methods for providing accurate concentration measurements increases with increasing aquatic half-lives. Copyright © 2016 Elsevier Ltd. All rights reserved.
Feasibility of protein turnover studies in prototroph Saccharomyces cerevisiae strains.

PubMed

Martin-Perez, Miguel; Villén, Judit

2015-04-07

Quantitative proteomics studies of yeast that use metabolic labeling with amino acids rely on auxotrophic mutations of one or more genes on the amino acid biosynthesis pathways. These mutations affect yeast metabolism and preclude the study of some biological processes. Overcoming this limitation, it has recently been described that proteins in a yeast prototrophic strain can also be metabolically labeled with heavy amino acids. However, the temporal profiles of label incorporation under the different phases of the prototroph's growth have not been examined. Labeling trajectories are important in the study of protein turnover and dynamics, in which label incorporation into proteins is monitored across many time points. Here we monitored protein labeling trajectories for 48 h after a pulse with heavy lysine in a yeast prototrophic strain and compared them with those of a lysine auxotrophic yeast. Labeling was successful in prototroph yeast during exponential growth phase but not in stationary phase. Furthermore, we were able to determine the half-lives of more than 1700 proteins during exponential phase of growth with high accuracy and reproducibility. We found a median half-life of 2 h in both strains, which corresponds with the cellular doubling time. Nucleolar and ribosomal proteins showed short half-lives, whereas mitochondrial proteins and other energy production enzymes presented longer half-lives. Except for some proteins involved in lysine biosynthesis, we observed a high correlation in protein half-lives between prototroph and auxotroph strains. Overall, our results demonstrate the feasibility of using prototrophs for proteomic turnover studies and provide a reliable data set of protein half-lives in exponentially growing yeast.
Stability of immobilized amyloglucosidase in the process of Cassava starch saccharification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zanin, G.M.; De Moraes, F.F.

1995-12-31

The half-life of immobilized amyloglucosidase was determined in a fluidized-bed reactor operating continuously with a 30% w/v liquefied cassava starch solution at pH 4.5 and temperatures from 50 to 70{degrees}C. For the higher temperatures: 60, 65, and 70{degrees}C, thermal deactivation gives half-lives of 127, 38 and 7.3 h, respectively, in close agreement with corn starch data. For the lower temperatures: 55 and 60{degrees}C, the deposition of impurities over the immobilized enzyme particle contributes significantly to deactivation, lowering expected half-lives to 32.6 and 13.2 d, respectively. Commercial exploitation of this process would then require low temperature of operation, thorough purification ofmore » the substrate solution, and control of microbial contamination to achieve sufficiently long half-lives.« less
Prehension of Half-Full and Half-Empty Glasses: Time and History Effects on Multi-Digit Coordination

PubMed Central

Sun, Yao; Zatsiorsky, Vladimir M.; Latash, Mark L.

2011-01-01

We explored how digit forces and indices of digit coordination depend on the history of getting to a particular set of task parameters during static prehension tasks. The participants held in the right hand an instrumented handle with a light-weight container attached on top of the handle. At the beginning of each trial, the container could be empty, filled to the half with water (0.4 l) or filled to the top (0.8 l). The water was pumped in/out of the container at a constant, slow rate over 10 s. At the end of each trial, the participants always held a half-filled container that has just been filled (Empty-Half), emptied (Full-Half), or stayed half-filled throughout the trial (Half-Only). Indices of co-variation (synergy indices) of elemental variables (forces and moments of force produced by individual digits) stabilizing such performance variables as total normal force, total tangetial force, and total moment of force were computed at two levels of an assumed control hierarchy. At the upper level, the task is shared between the thumb and virtual finger (an imagined digit with the mechanical action equal to that of the four fingers), while at the lower level, action of the virtual finger is shared among the actual four fingers. Filling or emptying the container led to a drop in the safety margin (proportion of grip force over the slipping threshold) below the values observed in the Half-Only condition. Synergy indices at both levels of the hierarchy showed changes over the Full-Half and Empty-Half condition. These changes could be monotonic (typical of moment of force and normal force) or non-monotonic (typical of tangential force). For both normal and tangential forces, higher synergy indices at the higher level of the hierarchy corresponded to lower indices at the lower level. Significant differences in synergy indices across conditions were seen at the final steady-state showing that digit coordination during steady holding an object is history dependent. The observations support an earlier hypothesis on a trade-off between synergies at the two levels of a hierarchy. They also suggest that, when a change in task parameters is expected, the neural strategy may involve producing less stable (easier to change) actions. The results suggest that synergy indices may be highly sensitive to changes in a task variable and that effects of such changes persist after the changes are over. PMID:21331525
Genome-wide gene expression and RNA half-life measurements allow predictions of regulation and metabolic behavior in Methanosarcina acetivorans

DOE PAGES

Peterson, Joseph R.; Thor, ShengShee; Kohler, Lars; ...

2016-11-16

Here, while a few studies on the variations in mRNA expression and half-lives measured under different growth conditions have been used to predict patterns of regulation in bacterial organisms, the extent to which this information can also play a role in defining metabolic phenotypes has yet to be examined systematically. Here we present the first comprehensive study for a model methanogen. As a result, we use expression and half-life data for the methanogen Methanosarcina acetivorans growing on fast- and slow-growth substrates to examine the regulation of its genes. Unlike Escherichia coli where only small shifts in half-lives were observed, wemore » found that most mRNA have significantly longer half-lives for slow growth on acetate compared to fast growth on methanol or trimethylamine. Interestingly, half-life shifts are not uniform across functional classes of enzymes, suggesting the existence of a selective stabilization mechanism for mRNAs. Using the transcriptomics data we determined whether transcription or degradation rate controls the change in transcript abundance. Degradation was found to control abundance for about half of the metabolic genes underscoring its role in regulating metabolism. Genes involved in half of the metabolic reactions were found to be differentially expressed among the substrates suggesting the existence of drastically different metabolic phenotypes that extend beyond just the methanogenesis pathways. By integrating expression data with an updated metabolic model of the organism (iST807) significant differences in pathway flux and production of metabolites were predicted for the three growth substrates. In conclusion, this study provides the first global picture of differential expression and half-lives for a class II methanogen, as well as provides the first evidence in a single organism that drastic genome-wide shifts in RNA half-lives can be modulated by growth substrate. We determined which genes in each metabolic pathway control the flux and classified them as regulated by transcription (e.g. transcription factor) or degradation (e.g. post-transcriptional modification). We found that more than half of genes in metabolism were controlled by degradation. Our results suggest that M. acetivorans employs extensive post-transcriptional regulation to optimize key metabolic steps, and more generally that degradation could play a much greater role in optimizing an organism’s metabolism than previously thought.« less
Genome-wide gene expression and RNA half-life measurements allow predictions of regulation and metabolic behavior in Methanosarcina acetivorans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Joseph R.; Thor, ShengShee; Kohler, Lars

Here, while a few studies on the variations in mRNA expression and half-lives measured under different growth conditions have been used to predict patterns of regulation in bacterial organisms, the extent to which this information can also play a role in defining metabolic phenotypes has yet to be examined systematically. Here we present the first comprehensive study for a model methanogen. As a result, we use expression and half-life data for the methanogen Methanosarcina acetivorans growing on fast- and slow-growth substrates to examine the regulation of its genes. Unlike Escherichia coli where only small shifts in half-lives were observed, wemore » found that most mRNA have significantly longer half-lives for slow growth on acetate compared to fast growth on methanol or trimethylamine. Interestingly, half-life shifts are not uniform across functional classes of enzymes, suggesting the existence of a selective stabilization mechanism for mRNAs. Using the transcriptomics data we determined whether transcription or degradation rate controls the change in transcript abundance. Degradation was found to control abundance for about half of the metabolic genes underscoring its role in regulating metabolism. Genes involved in half of the metabolic reactions were found to be differentially expressed among the substrates suggesting the existence of drastically different metabolic phenotypes that extend beyond just the methanogenesis pathways. By integrating expression data with an updated metabolic model of the organism (iST807) significant differences in pathway flux and production of metabolites were predicted for the three growth substrates. In conclusion, this study provides the first global picture of differential expression and half-lives for a class II methanogen, as well as provides the first evidence in a single organism that drastic genome-wide shifts in RNA half-lives can be modulated by growth substrate. We determined which genes in each metabolic pathway control the flux and classified them as regulated by transcription (e.g. transcription factor) or degradation (e.g. post-transcriptional modification). We found that more than half of genes in metabolism were controlled by degradation. Our results suggest that M. acetivorans employs extensive post-transcriptional regulation to optimize key metabolic steps, and more generally that degradation could play a much greater role in optimizing an organism’s metabolism than previously thought.« less
Inter-laboratory comparisons of short-lived gamma-emitting radionuclides in nuclear reactor water.

PubMed

Klemola, S K

2008-01-01

Inter-laboratory comparisons of gamma-emitting nuclides in nuclear power plant coolant water have been carried out in Finland since 1994. The reactor water samples are taken and prepared by one of the two nuclear power plants and delivered to the participants. Since all the participants get their sample within just a few hours it has been possible to analyse and compare results of nuclides with half-lives shorter than 1h. The total number of short-lived nuclides is 26. All the main nuclides are regularly identified and the activities have been obtained with reasonable accuracy throughout the years. The overall deviation of the results has decreased in 13 years. The effects of true coincidence summing and discrepancies in nuclear data have been identified as potential sources of remaining discrepancies. All the participants have found this type of comparison very useful.
Caring for people living with, and beyond, cancer: an online survey of GPs in England.

PubMed

Walter, Fiona M; Usher-Smith, Juliet A; Yadlapalli, Suresh; Watson, Eila

2015-11-01

Increasing numbers of people are living with, and beyond, cancer. They are at risk of long-term morbidity and premature mortality due to the consequences of their disease and its treatment. Primary care can contribute to providing ongoing care. To determine the current practice and views of GPs in England regarding cancer survivorship care. Online survey of a sample of 500 GPs, stratified by NHS region in England. The survey included questions adapted from prior surveys assessing physician knowledge and attitudes regarding care of patients with cancer. In total, 500 GPs responded; approximately half reported often providing care to people living beyond cancer for treatment-related side effects (51%), psychological symptoms (65%), and lifestyle advice (55%). Only 29% felt very confident managing treatment-related side effects compared with 46% and 65% for psychological symptoms and lifestyle advice respectively. Half reported usually receiving cancer treatment summaries and survivorship care plans but most of the sample felt these would improve their ability to provide care (76%). Only 53% were convinced of the usefulness of cancer care reviews. Although most felt that primary and specialist care should share responsibility for managing bone (81%) and cardiovascular (77%) health consequences, fewer than half reported often taking previous history of cancer or cancer treatment into consideration when assessing bone health; only one-fifth did this in relation to cardiovascular health. Most responders were interested in receiving education to improve their knowledge and expertise. GPs have a potentially important role to play in caring for people following cancer treatment. This study has highlighted areas where further support and education are needed to enable GPs to optimise their role in cancer survivorship care. © British Journal of General Practice 2015.
Nectar, not colour, may lure insects to their death

PubMed Central

Bennett, Katherine F.; Ellison, Aaron M.

2009-01-01

We experimentally demonstrate in the field that prey of the carnivorous plant Sarracenia purpurea are attracted to sugar, not to colour. Prey capture (either all taxa summed or individual common taxa considered separately) was not associated with total red area or patterning on pitchers of living pitcher plants. We separated effects of nectar availability and coloration using painted ‘pseudopitchers’, half of which were coated with sugar solution. Unsugared pseudopitchers captured virtually no prey, whereas pseudopitchers with sugar solution captured the same amount of prey as living pitchers. In contrast to a recent study that associated red coloration with prey capture but that lacked controls for nectar availability, we infer that nectar, not colour, is the primary means by which pitcher plants attract prey. PMID:19429649
Nectar, not colour, may lure insects to their death.

PubMed

Bennett, Katherine F; Ellison, Aaron M

2009-08-23

We experimentally demonstrate in the field that prey of the carnivorous plant Sarracenia purpurea are attracted to sugar, not to colour. Prey capture (either all taxa summed or individual common taxa considered separately) was not associated with total red area or patterning on pitchers of living pitcher plants. We separated effects of nectar availability and coloration using painted 'pseudopitchers', half of which were coated with sugar solution. Unsugared pseudopitchers captured virtually no prey, whereas pseudopitchers with sugar solution captured the same amount of prey as living pitchers. In contrast to a recent study that associated red coloration with prey capture but that lacked controls for nectar availability, we infer that nectar, not colour, is the primary means by which pitcher plants attract prey.
G-III Aircraft from NASA Armstrong Provides Live TV Coverage of Solar Eclipse Across America

NASA Image and Video Library

2017-08-13

For the first time in 99 years, a total solar eclipse will cross the entire nation Monday, Aug. 21. A total solar eclipse occurs when the sun is completely obscured by the moon. The lunar shadow enters the United States near Lincoln City, Oregon, at 9:05 a.m. PDT. Totality, where the moon completely covers the sun, begins in Lincoln City around 10:16 a.m. PDT. During totality, there will be up to two and a half minutes of darkness. The G-III aircraft was modified with upgraded windows and communications equipment to enable high-definition video to be streamed to NASA TV during the eclipse enabling citizen science. The aircraft will be flying at 25,000 feet over the coast of Oregon, near Lincoln City during the eclipse on August 21, 2017.
Recent {alpha} decay half-lives and analytic expression predictions including superheavy nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royer, G.; Zhang, H. F.

New recent experimental {alpha} decay half-lives have been compared with the results obtained from previously proposed formulas depending only on the mass and charge numbers of the {alpha} emitter and the Q{sub {alpha}} value. For the heaviest nuclei they are also compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The correct agreement allows us to make predictions for the {alpha} decay half-lives of other still unknown superheavy nuclei from these analytic formulas using the extrapolated Q{sub {alpha}} of G. Audi, A. H. Wapstra, and C. Thibault [Nucl. Phys. A729, 337 (2003)].
A novel approach for extracting viscoelastic parameters of living cells through combination of inverse finite element simulation and Atomic Force Microscopy.

PubMed

Wei, Fanan; Yang, Haitao; Liu, Lianqing; Li, Guangyong

2017-03-01

Dynamic mechanical behaviour of living cells has been described by viscoelasticity. However, quantitation of the viscoelastic parameters for living cells is far from sophisticated. In this paper, combining inverse finite element (FE) simulation with Atomic Force Microscope characterization, we attempt to develop a new method to evaluate and acquire trustworthy viscoelastic index of living cells. First, influence of the experiment parameters on stress relaxation process is assessed using FE simulation. As suggested by the simulations, cell height has negligible impact on shape of the force-time curve, i.e. the characteristic relaxation time; and the effect originates from substrate can be totally eliminated when stiff substrate (Young's modulus larger than 3 GPa) is used. Then, so as to develop an effective optimization strategy for the inverse FE simulation, the parameters sensitivity evaluation is performed for Young's modulus, Poisson's ratio, and characteristic relaxation time. With the experiment data obtained through typical stress relaxation measurement, viscoelastic parameters are extracted through the inverse FE simulation by comparing the simulation results and experimental measurements. Finally, reliability of the acquired mechanical parameters is verified with different load experiments performed on the same cell.
Risk Communication of Groundwater Quality in Northern Malawi, Africa

NASA Astrophysics Data System (ADS)

Holm, R.

2011-12-01

Malawi lies in Africa's Great Rift Valley. Its western border is defined by Lake Malawi, the third largest lake in Africa. Over 80% of Malawians live in rural areas and 90% of the labor force is associated with agriculture. More than half of the population lives below the poverty line. Area characteristics indicate a high likelihood of nitrate and total coliform in community drinking water. Infants exposed to high nitrate are at risk of developing methemoglobinemia. In addition, diarrheal diseases from unsafe drinking water are one of the top causes of mortality in children under five. Without sufficient and sustainable supplies of clean water, these challenges will continue to threaten Malawi's ability to overcome the devastating impact of diarrheal diseases on its population. Therefore, Malawi remains highly dependent on outside assistance and influence to reduce or eliminate the threat posed by unsafe drinking water. This research presents a literature review of nitrate and total coliform groundwater quality and a proposed risk communication plan for drinking water in northern Malawi.
Half-lives of 101Rh g and 108Ag m

DOE PAGES

Shugart, Howard A.; Browne, Edgardo; Norman, Eric B.

2018-02-20

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rh g and 108Ag m have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are then compared with previously reported values.
Half-lives of 101Rh g and 108Ag m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shugart, Howard A.; Browne, Edgardo; Norman, Eric B.

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rh g and 108Ag m have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are then compared with previously reported values.
Half-lives of 101 Rh g and 108 Ag m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shugart, H.; Browne, E.; Norman, E.

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rhg and 108Agm have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are compared with previously reported values.
β-decay half-lives of new neutron-rich rare-earth isotopes 159Pm,162Sm, and 166Gd

NASA Astrophysics Data System (ADS)

Ichikawa, S.; Asai, M.; Tsukada, K.; Haba, H.; Nagame, Y.; Shibata, M.; Sakama, M.; Kojima, Y.

2005-06-01

The new neutron-rich rare-earth isotopes 159Pm, 162Sm, and 166Gd produced in the proton-induced fission of 238U were identified using the JAERI on-line isotope separator (JAERI-ISOL) coupled to a gas-jet transport system. The half-lives of 159Pm, 162Sm, and 166Gd were determined to be 1.5 ± 0.2, 2.4 ± 0.5, and 4.8 ± 1.0 s respectively. The partial decay scheme of 166Gd was constructed from γγ-coincidence data. A more accurate half-life value of 25.6 ± 2.2 s was obtained for the previously identified isotope 166Tb. The half-lives measured in the present study are in good agreement with the theoretical predictions calculated by the second generation of the gross theory with the atomic masses evaluated by Audi and Wapstra.

The Use of Gene Ontology Term and KEGG Pathway Enrichment for Analysis of Drug Half-Life

PubMed Central

Chen, Lei; Lu, Jing; Kong, XiangYin; Huang, Tao; Li, HaiPeng

2016-01-01

A drug’s biological half-life is defined as the time required for the human body to metabolize or eliminate 50% of the initial drug dosage. Correctly measuring the half-life of a given drug is helpful for the safe and accurate usage of the drug. In this study, we investigated which gene ontology (GO) terms and biological pathways were highly related to the determination of drug half-life. The investigated drugs, with known half-lives, were analyzed based on their enrichment scores for associated GO terms and KEGG pathways. These scores indicate which GO terms or KEGG pathways the drug targets. The feature selection method, minimum redundancy maximum relevance, was used to analyze these GO terms and KEGG pathways and to identify important GO terms and pathways, such as sodium-independent organic anion transmembrane transporter activity (GO:0015347), monoamine transmembrane transporter activity (GO:0008504), negative regulation of synaptic transmission (GO:0050805), neuroactive ligand-receptor interaction (hsa04080), serotonergic synapse (hsa04726), and linoleic acid metabolism (hsa00591), among others. This analysis confirmed our results and may show evidence for a new method in studying drug half-lives and building effective computational methods for the prediction of drug half-lives. PMID:27780226
Local and global influences on protein turnover in neurons and glia

PubMed Central

Dörrbaum, Aline R; Kochen, Lisa

2018-01-01

Regulation of protein turnover allows cells to react to their environment and maintain homeostasis. Proteins can show different turnover rates in different tissue, but little is known about protein turnover in different brain cell types. We used dynamic SILAC to determine half-lives of over 5100 proteins in rat primary hippocampal cultures as well as in neuron-enriched and glia-enriched cultures ranging from <1 to >20 days. In contrast to synaptic proteins, membrane proteins were relatively shorter-lived and mitochondrial proteins were longer-lived compared to the population. Half-lives also correlate with protein functions and the dynamics of the complexes they are incorporated in. Proteins in glia possessed shorter half-lives than the same proteins in neurons. The presence of glia sped up or slowed down the turnover of neuronal proteins. Our results demonstrate that both the cell-type of origin as well as the nature of the extracellular environment have potent influences on protein turnover. PMID:29914620
Kinetics of intraventricularly injected trace amines and their deuterated isotopomers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durden, D.A.; Nguyen, T.V.; Boulton, A.A.

Intraventricular injection into the rat brain of four trace amines and a catecholamine resulted in rapid exponential loss of the amines in the first 30 minutes after injection. The half-lives were: phenylethylamine 3.8 min, para-tyramine 5.1 min, meta-tyramine 7.4 min and dopamine 8.0 min. Tryptamine showed a biphasic loss with half-lives of 4.7 min (over the 5 to 10 min period) and 14.1 min (10 to 30 min). The half-lives were substantially increased by deuterium labeling at the alpha carbon position: phenylethylamine 4.8 min, para-tyramine 8.8 min, meta-tyramine 14.1 min, dopamine 13.0 min and tryptamine 6.0 min (5 to 10more » min period) and 28.7 min (10 to 20 min). The loss of the amines was reduced by monoamine oxidase inhibition by pargyline hydrochloride and the deuterium isotope effect was abolished. It is noteworthy that the half-life of dopamine was similar to those of the trace amines in this time period and that the trace amine half-lives after i.v. injection was longer than those obtained from measurements of increases of concentrations of endogenous amines after MAOI in vivo and that of dopamine shorter than values calculated from turnover measurements.« less
Half-lives of 221Fr, 217At, 213Bi, 213Po and 209Pb from the 225Ac decay series.

PubMed

Suliman, G; Pommé, S; Marouli, M; Van Ammel, R; Stroh, H; Jobbágy, V; Paepen, J; Dirican, A; Bruchertseifer, F; Apostolidis, C; Morgenstern, A

2013-07-01

The half-lives of (221)Fr, (217)At, (213)Bi, (213)Po, and (209)Pb were measured by means of an ion-implanted planar Si detector for alpha and beta particles emitted from weak (225)Ac sources or from recoil sources, which were placed in a quasi-2π counting geometry. Recoil sources were prepared by collecting atoms from an open (225)Ac source onto a glass substrate. The (221)Fr and (213)Bi half-lives were determined by following the alpha particle emission rate of recoil sources as a function of time. Similarly, the (209)Pb half-life was determined from the beta particle count rate. The shorter half-lives of (217)At and (213)Po were deduced from delayed coincidence measurements on weak (225)Ac sources using digital data acquisition in list mode. The resulting values: T1/2((221)Fr)=4.806 (6) min, T1/2((217)At)=32.8 (3)ms, T1/2((213)Bi)=45.62 (6)min, T1/2((213)Po)=3.708 (8) μs, and T1/2((209)Pb)=3.232 (5)h were in agreement only with the best literature data. Copyright © 2013 Elsevier Ltd. All rights reserved.
Biodegradation kinetics for pesticide exposure assessment.

PubMed

Wolt, J D; Nelson, H P; Cleveland, C B; van Wesenbeeck, I J

2001-01-01

Understanding pesticide risks requires characterizing pesticide exposure within the environment in a manner that can be broadly generalized across widely varied conditions of use. The coupled processes of sorption and soil degradation are especially important for understanding the potential environmental exposure of pesticides. The data obtained from degradation studies are inherently variable and, when limited in extent, lend uncertainty to exposure characterization and risk assessment. Pesticide decline in soils reflects dynamically coupled processes of sorption and degradation that add complexity to the treatment of soil biodegradation data from a kinetic perspective. Additional complexity arises from study design limitations that may not fully account for the decline in microbial activity of test systems, or that may be inadequate for considerations of all potential dissipation routes for a given pesticide. Accordingly, kinetic treatment of data must accommodate a variety of differing approaches starting with very simple assumptions as to reaction dynamics and extending to more involved treatments if warranted by the available experimental data. Selection of the appropriate kinetic model to describe pesticide degradation should rely on statistical evaluation of the data fit to ensure that the models used are not overparameterized. Recognizing the effects of experimental conditions and methods for kinetic treatment of degradation data is critical for making appropriate comparisons among pesticide biodegradation data sets. Assessment of variability in soil half-life among soils is uncertain because for many pesticides the data on soil degradation rate are limited to one or two soils. Reasonable upper-bound estimates of soil half-life are necessary in risk assessment so that estimated environmental concentrations can be developed from exposure models. Thus, an understanding of the variable and uncertain distribution of soil half-lives in the environment is necessary to estimate bounding values. Statistical evaluation of measures of central tendency for multisoil kinetic studies shows that geometric means better represent the distribution in soil half-lives than do the arithmetic or harmonic means. Estimates of upper-bound soil half-life values based on the upper 90% confidence bound on the geometric mean tend to accurately represent the upper bound when pesticide degradation rate is biologically driven but appear to overestimate the upper bound when there is extensive coupling of biodegradation with sorptive processes. The limited data available comparing distribution in pesticide soil half-lives between multisoil laboratory studies and multilocation field studies suggest that the probability density functions are similar. Thus, upper-bound estimates of pesticide half-life determined from laboratory studies conservatively represent pesticide biodegradation in the field environment for the purposes of exposure and risk assessment. International guidelines and approaches used for interpretations of soil biodegradation reflect many common elements, but differ in how the source and nature of variability in soil kinetic data are considered. Harmonization of approaches for the use of soil biodegradation data will improve the interpretative power of these data for the purposes of exposure and risk assessment.
Internal exposure to trace elements in non-smoking residents living in a northern Taiwan industrial city.

PubMed

Lin, Tser-Sheng; Wu, Chin-Ching

2011-12-01

A total of 94 (54 males, 40 females) healthy adult residents living in an industrial city in northern Taiwan were recruited to study their exposure to industrial metals by measuring their blood levels of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W. All participants were non-smokers without obvious direct occupational exposure to these elements, although by working in administrative sectors in industrial facilities their indirect or potential exposure was increased. The average concentrations of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W in blood were 0.30, 1.49, 15.1, 3.84, 2.73, 21.1, 204, 3.2, 0.76, 51.1, and 0.40 ng/mL, respectively. These values were significantly higher than reference values reported for the general population, in some cases exceeding those of occupationally exposed workers. The principal component and correlation analyses among blood element levels suggested that the predominant sources of exposure were glass manufacturing and traffic-related sources. Despite of some limitations, the study demonstrates that the residents in this industrial area may suffer adverse chronic health effects attributable to exposures to these elements.
The A=96 system in ββ decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alanssari, M.

2015-10-28

Properties of the single and double beta decays of {sup 96}Zr are discussed. It is argued that the single beta decay can provide important information to the neutrinoless variant of β β decay, as it provides a test of theories aimed at calculating the nuclear matrix elements (NME) for both decays. An experimental extraction of the NME for the single β decay requires a measurement of the decay Q-value and half-life. It is shown that the present Q-value of the {sup 96}Zr single β decay is insufficiently well known and requires a re-measurement, preferentially using high-precision ion traps. We alsomore » describe the geochemical method to determine the total half-life of {sup 96}Zr, from which to set a limit on the single β -decay half-life at a level of ≈15 × 10{sup 19}yr. Further, the geochemical analysis will allow setting a limit on a rather exotic quadruple β decay of {sup 96}Zr.« less
Modelling the behaviour of unemployment rates in the US over time and across space

NASA Astrophysics Data System (ADS)

Holmes, Mark J.; Otero, Jesús; Panagiotidis, Theodore

2013-11-01

This paper provides evidence that unemployment rates across US states are stationary and therefore behave according to the natural rate hypothesis. We provide new insights by considering the effect of key variables on the speed of adjustment associated with unemployment shocks. A highly-dimensional VAR analysis of the half-lives associated with shocks to unemployment rates in pairs of states suggests that the distance between states and vacancy rates respectively exert a positive and negative influence. We find that higher homeownership rates do not lead to higher half-lives. When the symmetry assumption is relaxed through quantile regression, support for the Oswald hypothesis through a positive relationship between homeownership rates and half-lives is found at the higher quantiles.
A high-resolution study of ultra-heavy cosmic-ray nuclei (A0178)

NASA Technical Reports Server (NTRS)

Osullivan, D.; Thompson, A.; Oceallaigh, C.; Domingo, V.; Wenzel, K. P.

1984-01-01

The main objective of the experiment is a detailed study of the charge spectra of ultraheavy cosmic-ray nuclei from zinc (Z = 30) to uranium (Z = 92) and beyond using solid-state track detectors. Special emphasis will be placed on the relative abundances in the region Z or - 65, which is thought to be dominated by r-process nucleosynthesis. Subsidiary objectives include the study of the cosmic-ray transiron spectrum a search for the postulated long-lived superheavy (SH) nuclei (Z or = 110), such as (110) SH294, in the contemporary cosmic radiation. The motivation behind the search for super-heavy nuclei is based on predicted half-lives that are short compared to the age of the Earth but long compared to the age of cosmic rays. The detection of such nuclei would have far-reaching consequences for nuclear structure theory. The sample of ultraheavy nuclei obtained in this experiment will provide unique opportunities for many tests concerning element nucleosynthesis, cosmic-ray acceleration, and cosmic-ray propagation.
Total Solar Eclipse of 2006 March 29

NASA Technical Reports Server (NTRS)

Espenak, F.; Anderson, J.

2004-01-01

On 2006 March 29, a total eclipse of the Sun will be visible from within a narrow corridor which traverses half the Earth. The path of the Moon's umbral shadow begins in Brazil and extends across the Atlantic, northern Africa, and central Asia where it ends at sunset in western Mongolia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the northern two thirds of Africa, Europe, and central Asia.Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.
Valuing the non-market benefits of estuarine ecosystem services in a river basin context: Testing sensitivity to scope and scale

NASA Astrophysics Data System (ADS)

Pinto, R.; Brouwer, R.; Patrício, J.; Abreu, P.; Marta-Pedroso, C.; Baeta, A.; Franco, J. N.; Domingos, T.; Marques, J. C.

2016-02-01

A large scale contingent valuation survey is conducted among residents in one of the largest river basins in Portugal to estimate the non-market benefits of the ecosystem services associated with implementation of the European Water Framework Directive (WFD). Statistical tests of public willingness to pay's sensitivity to scope and scale are carried out. Decreasing marginal willingness to pay (WTP) is found when asking respondents to value two water quality improvement scenarios (within sample comparison), from current moderate water quality conditions to good and subsequently excellent ecological status. However, insensitivity to scale is found when asking half of the respondents to value water quality improvements in the estuary only and the other half in the whole basin (between sample comparison). Although respondents living outside the river basin value water quality improvements significantly less than respondents inside the basin, no spatial heterogeneity can be detected within the basin between upstream and downstream residents. This finding has important implications for spatial aggregation procedures across the population of beneficiaries living in the river basin to estimate its total economic value based on public WTP for the implementation of the WFD.
Insecticide dissipation from soil and plant surfaces in tropical horticulture of southern Benin, West Africa.

PubMed

Rosendahl, Ingrid; Laabs, Volker; Atcha-Ahowé, Cyrien; James, Braima; Amelung, Wulf

2009-06-01

In Sub-Saharan Africa, horticulture provides livelihood opportunities for millions of people, especially in urban and peri-urban areas. Although the vegetable agroecosystems are often characterized by intensive pesticide use, risks resulting therefrom are largely unknown under tropical horticultural conditions. The objective of this study therefore was to study the fate of pesticides in two representative horticultural soils (Acrisol and Arenosol) and plants (Solanum macrocarpon L.) after field application and thus to gain first insight on environmental persistence and dispersion of typical insecticides used in vegetable horticulture in Benin, West Africa. On plant surfaces, dissipation was rapid with half lives ranging from 2 to 87 h (alpha-endosulfan < beta-endosulfan < deltamethrin). Soil dissipation was considerably slower than dissipation from plant surfaces with half-lives ranging from 3 (diazinon) to 74 d (total endosulfan), but persistence of pesticides in soil was still reduced compared to temperate climates. Nevertheless, for deltamethrin and endosulfan, a tendency for mid-term accumulation in soil upon repeated applications was observed. The soil and plant surface concentrations of the metabolite endosulfan sulfate increased during the entire trial period, indicating that this compound is a potential long-term pollutant even in tropical environments.
A 32-channel lattice transmission line array for parallel transmit and receive MRI at 7 tesla.

PubMed

Adriany, Gregor; Auerbach, Edward J; Snyder, Carl J; Gözübüyük, Ark; Moeller, Steen; Ritter, Johannes; Van de Moortele, Pierre-François; Vaughan, Tommy; Uğurbil, Kâmil

2010-06-01

Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra-high-field MR. Transmit coil arrays enable such techniques as B(1) (+) shimming to substantially improve transmit B(1) homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imaging performance and SNR. Concentric coil arrangements hold promise for developing transceiver arrays incorporating large numbers of coil elements. At magnetic field strengths of 7 tesla and higher where the Larmor frequencies of interest can exceed 300 MHz, the coil array design must also overcome the problem of the coil conductor length approaching the RF wavelength. In this study, a novel concentric arrangement of resonance elements built from capacitively-shortened half-wavelength transmission lines is presented. This approach was utilized to construct an array with whole-brain coverage using 16 transceiver elements and 16 receive-only elements, resulting in a coil with a total of 16 transmit and 32 receive channels. (c) 2010 Wiley-Liss, Inc.
Uptake and loss of dissolved 109Cd and 75Se in estuarine macroinvertebrates.

PubMed

Alquezar, Ralph; Markich, Scott J; Twining, John R

2007-04-01

Semaphore crabs (Heloecius cordiformis), soldier crabs (Mictyris platycheles), ghost shrimps (Trypaea australiensis), pygmy mussels (Xenostrobus securis), and polychaetes (Eunice sp.), key benthic prey items of predatory fish commonly found in estuaries throughout southeastern Australia, were exposed to dissolved (109)Cd and (75)Se for 385 h at 30 k Bq/l (uptake phase), followed by exposure to radionuclide-free water for 189 h (loss phase). The whole body uptake rates of (75)Se by pygmy mussels, semaphore crabs and soldier crabs were 1.9, 2.4 and 4.1 times higher than (109)Cd, respectively. There were no significant (P>0.05) differences between the uptake rates of (75)Se and (109)Cd for ghost shrimps and polychaetes. The uptake rates of (109)Cd and (75)Se were highest in pygmy mussels; about six times higher than in soldier crabs for (109)Cd and in polychaetes for (75)Se - the organisms with the lowest uptake rates. The loss rates of (109)Cd and (75)Se were highest in semaphore crabs; about four times higher than in polychaetes for (109)Cd and nine times higher than in ghost shrimps for (75)Se - the organisms with the lowest loss rates. The loss of (109)Cd and (75)Se in all organisms was best described by a two (i.e. short and a longer-lived) compartment model. In the short-lived, or rapidly exchanging, compartment, the biological half-lives of (75)Se (16-39 h) were about three times greater than those of (109)Cd (5-12h). In contrast, the biological half-lives of (109)Cd in the longer-lived, or slowly exchanging compartment(s), were typically greater (1370-5950 h) than those of (75)Se (161-1500 h). Semaphore crabs had the shortest biological half-lives of both radionuclides in the long-lived compartment, whereas polychaetes had the greatest biological half-life for (109)Cd (5950 h), and ghost shrimps had the greatest biological half-life for (75)Se (1500 h). This study provides the first reported data for the biological half-lives of Se in estuarine decapod crustaceans. Moreover, it emphasises the importance of determining metal(loid) accumulation and loss kinetics in keystone prey items, which consequently influences their trophic transfer potential to higher-order predators.
Food-related advertising geared toward Mexican children.

PubMed

Ramírez-Ley, Karla; De Lira-García, Cynthia; Souto-Gallardo, María de las Cruces; Tejeda-López, María Fernanda; Castañeda-González, Lidia Magdalena; Bacardí-Gascón, Montserrat; Jiménez-Cruz, Arturo

2009-09-01

Overweight and obesity have dramatically increased in recent years. In 2006, the prevalence of overweight and obesity among 6- to 12-year-old children was 26% in Mexico. Food advertising has shown to be a contributor to childhood obesity. The purpose of this study was to evaluate the frequency and types of food advertisements geared toward children living in Baja California. Two local channels and three national channels, during a period of 7 h on weekday afternoons and 6 h on weekend mornings, were recorded for 7 days. A total of 235 h were recorded and analyzed. A total of 8299 advertisements were registered; 22% were food-related and 50% were geared toward children. The average of food-related advertisements (FRAs) per half an hour was 4, and half of them were geared toward children. During the time that children may be watching television, 50% of all FRAs were potato and corn chips, desserts and cakes, juices, sweetened cereals, candies, cookies, sweetened beverages and fast foods, which comprises a higher percentage of adult-oriented FRA (32 versus 22%). Children are systematically more exposed than adults to advertisements for high-energy-dense foods.
Do radioactive half-lives vary with the Earth-to-Sun distance?

PubMed

Hardy, J C; Goodwin, J R; Iacob, V E

2012-09-01

Recently, Jenkins, Fischbach and collaborators have claimed evidence that radionuclide half-lives vary systematically over a ±0.1% range as a function of the oscillating distance between the Earth and the Sun, based on multi-year activity measurements. We have avoided the time-dependent instabilities to which such measurements are susceptible by directly measuring the half-life of (198)Au (t(1/2)=2.695 d) on seven occasions spread out in time to cover the complete range of Earth-Sun distances. We observe no systematic oscillations in half-life and can set an upper limit on their amplitude of ±0.02%. Copyright © 2012 Elsevier Ltd. All rights reserved.
Consideration on the Long Ecological Half-Life Component of (137)Cs in Demersal Fish Based on Field Observation Results Obtained after the Fukushima Accident.

PubMed

Tagami, Keiko; Uchida, Shigeo

2016-02-16

Radiocesium concentrations in most marine fish collected off the coast of Fukushima and surrounding prefectures have decreased with time, and four years after the Fukushima Daiichi Nuclear Power Plant accident occurred, radiocesium concentrations have generally fallen below the detectable level (ca. < 10 Bq kg(-1)-raw). Only in some demersal fish species have detectable concentration levels still been found, and even these species have showed slow radiocesium decreases. The food web was considered as the major factor causing this phenomenon; however, slow elimination rates of radiocesium from these fish species also could be the cause. The latter effect was examined by considering that the (137)Cs concentration decreasing trend in fish could be fit with a set of three exponentially decreasing components; that is, having short, intermediate, and long biological half-lives. The long ecological half-life component was calculated using a 400-1500 d period of monitoring results for Japanese rockfish (Sebastes cheni) and compared with previous reported laboratory results for biological half-life. The obtained ecological half-lives ranged from 274-365 d, and these values agreed with the biological half-life of this fish species. This result implied that the long biological half-lives of radiocesium in some demersal fish species made their radiocesium contamination periods longer.
Determination of the kinetics of degradation of 13-cis-retinoic acid and all-trans-retinoic acid in solution.

PubMed

Tan, X; Meltzer, N; Lindenbaum, S

1993-09-01

The degradations of 13-cis-retinoic acid and all-trans-retinoic acid in an organic solvent were determined with an HPLC assay. The degradation curves at 70, 50 and 37 degrees C all showed autocatalytic characteristics for both isomers. For this kind of complex reaction, the usual method cannot be used to estimate the shelf-lives and half-lives at room temperature. In this work a new method was developed to directly calculate the shelf-lives and half-lives. From this equation the activation energy was found to change as the multiple step reaction progressed.
Interplay of quasiparticle-vibration coupling and pairing correlations on β-decay half-lives

NASA Astrophysics Data System (ADS)

Niu, Y. F.; Niu, Z. M.; Colò, G.; Vigezzi, E.

2018-05-01

The nuclear β-decay half-lives of Ni and Sn isotopes, around the closed shell nuclei 78Ni and 132Sn, are investigated by computing the distribution of the Gamow-Teller strength using the Quasiparticle Random Phase Approximation (QRPA) with quasiparticle-vibration coupling (QPVC), based on ground-state properties obtained by Hartree-Fock-Bogoliubov (HFB) calculations. We employ the effective interaction SkM* and a zero-range effective pairing force. The half-lives are strongly reduced by including the QPVC. We study in detail the effects of isovector (IV) and isoscalar (IS) pairing. Increasing the IV strength tends to increase the lifetime for nuclei in the proximity of, but lighter than, the closed-shell ones in QRPA calculations, while the effect is significantly reduced by taking into account the QPVC. On the contrary, the IS pairing mainly plays a role for nuclei after the shell closure. Increasing its strength decreases the half-lives, and the effect at QRPA and QRPA+QPVC level is comparable. The effect of IS pairing is particularly pronounced in the case of the Sn isotopes, where it turns out to be instrumental to obtain good agreement with experimental data.
{beta}-decay half-lives of new neutron-rich rare-earth isotopes {sup 159}Pm,{sup 162}Sm, and {sup 166}Gd

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ichikawa, S.; Asai, M.; Tsukada, K.

The new neutron-rich rare-earth isotopes {sup 159}Pm, {sup 162}Sm, and {sup 166}Gd produced in the proton-induced fission of {sup 238}U were identified using the JAERI on-line isotope separator (JAERI-ISOL) coupled to a gas-jet transport system. The half-lives of {sup 159}Pm, {sup 162}Sm, and {sup 166}Gd were determined to be 1.5 {+-} 0.2, 2.4 {+-} 0.5, and 4.8 {+-} 1.0 s respectively. The partial decay scheme of {sup 166}Gd was constructed from {gamma}{gamma}-coincidence data. A more accurate half-life value of 25.6 {+-} 2.2 s was obtained for the previously identified isotope {sup 166}Tb. The half-lives measured in the present study aremore » in good agreement with the theoretical predictions calculated by the second generation of the gross theory with the atomic masses evaluated by Audi and Wapstra.« less

Half-life determination for {sup 108}Ag and {sup 110}Ag

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zahn, Guilherme S.; Genezini, Frederico A.

2014-11-11

In this work, the half-life of the short-lived silver radionuclides {sup 108}Ag and {sup 110}Ag were measured by following the activity of samples after they were irradiated in the IEA-R1 reactor. The results were then fitted using a non-paralizable dead time correction to the regular exponential decay and the individual half-life values obtained were then analyzed using both the Normalized Residuals and the Rajeval techniques, in order to reach the most exact and precise final values. To check the validity of dead-time correction, a second correction method was also employed by means of counting a long-lived {sup 60}Co radioactive sourcemore » together with the samples as a livetime chronometer. The final half-live values obtained using both dead-time correction methods were in good agreement, showing that the correction was properly assessed. The results obtained are partially compatible with the literature values, but with a lower uncertainty, and allow a discussion on the last ENSDF compilations' values.« less
NUCLEAR AND HEAVY ION PHYSICS: α-decay half-lives of superheavy nuclei and general predictions

NASA Astrophysics Data System (ADS)

Dong, Jian-Min; Zhang, Hong-Fei; Wang, Yan-Zhao; Zuo, Wei; Su, Xin-Ning; Li, Jun-Qing

2009-08-01

The generalized liquid drop model (GLDM) and the cluster model have been employed to calculate the α-decay half-lives of superheavy nuclei (SHN) using the experimental α-decay Q values. The results of the cluster model are slightly poorer than those from the GLDM if experimental Q values are used. The prediction powers of these two models with theoretical Q values from Audi et al. (QAudi) and Muntian et al. (QM) have been tested to find that the cluster model with QAudi and QM could provide reliable results for Z > 112 but the GLDM with QAudi for Z <= 112. The half-lives of some still unknown nuclei are predicted by these two models and these results may be useful for future experimental assignment and identification.
Systematic study of α-decay half-lives using Royer and related formula

NASA Astrophysics Data System (ADS)

Akrawy, Dashty T.; Hassanabadi, H.; Hosseini, S. S.; Santhosh, K. P.

2018-03-01

The alpha decay half-lives of 356 isotopes were studied using the Royer and related Formula and are compared with experimental data. The study shows that the predicted half-lives match well with experimental data over a wide range for each (Z , N) parity of the parent nuclei. We have calculated the standard deviation of log10 ⁡Tα (s), for each formula and our study indicate that, for alpha decay studies, generally, analytical ℓ-dependent formula proposed by Royer, with σRB = 0.4373, is the best model followed by the formula proposed by Denisov and Khudenko (DK), σDK = 0.4743 for all 356 nuclei. We hope the present study is a clear indicator of the predictive power of Royer and related formula.
Assessing the impact of atmospheric chemistry on the fate, transport, and transformation of adulticides in an urban atmosphere

NASA Astrophysics Data System (ADS)

Guberman, S.; Yoon, S.; Guagenti, M. C.; Sheesley, R. J.; Usenko, S.

2017-12-01

Urban areas are literal hot spots of mosquito-borne disease transmission and air pollution during the summer months. Public health authorities release aerosolized adulticides to target adult mosquitoes directly in to the atmosphere to control mosquito populations and reduce the threat of diseases (e.g. Zika). Permethrin and malathion are the primary adulticides for controlling adult mosquito populations in Houston, TX and are typically sprayed at night. After being released into the atmosphere adulticides are subject to atmospheric oxidation initiated by atmospheric oxidants (e.g. O3 and NO3) which are driven by anthropogenic air pollutants (e.g. NOx; NO and NO2). Particulate matter (PM) samples were measured at both application and downwind locations. Sampling sites were determined using the combination of atmospheric plume transport models and adulticide application data provided by Harris County Public Health Mosquito Division. Atmospheric PM samples were taken using a Mobile Laboratory, equipped with total suspended PM and PM2.5 (PM with diameter <2.5 um) samplers, as well as real-time instruments that made congruent measurements of O3, NOx, and wind speed and direction. Nighttime atmospheric half-lives of malathion were calculated to be 40-90% lower than malathion half-lives measured in previous studies; these half-lives were determined using diurnal atmospheric concentrations of malathion and its oxidation product, malaoxon. Interestingly, during malathion-use periods, atmospheric malaoxon concentrations measured in the PM2.5 samples were similar to corresponding TSP samples. This suggests that the majority of the malathion (and malaoxon) was associated with fine PM. During permethrin-use periods, atmospheric permethrin concentrations measured in the PM2.5 samples were an order and half lower in magnitude. This suggests that permethrin may be undergoing less volatilization into the gas phase after application as compared to malathion (and or malaoxon). Unlike permethrin, malathion was not sprayed with a carrier or a synergistic compound. As a result, malathion may be more prone to volatilization. The atmospheric oxidation and migration to fine PM may result in decreased efficacy and increase atmospheric transport, both of which have environmental and human health consequences.
Atomic weights of the elements 1999

USGS Publications Warehouse

Coplen, T.B.

2001-01-01

The biennial review of atomic-weight, Ar(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements: from to nitrogen 14.006 74??0.000 07 14.0067??0.0002 sulfur 32.066??0.006 32.065??0.005 chlorine 35.4527??0.0009 35.453??0.002 germanium 72.61??0.02 72.64??0.01 xenon 131.29??0.02 131.293??0.006 erbium 167.26??0.03 167.259??0.003 uranium 238.0289??0.0001 238.028 91??0.000 03 Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999. Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or atomic-weight values are included in this report for the information of the interested scientific community. ?? 2001 American Institute of Physics.
Epidemiological study of sleep habits among four-and-a-half-year-old children in Japan.

PubMed

Ikeda, Maki; Kaneita, Yoshitaka; Kondo, Shuji; Itani, Osamu; Ohida, Takashi

2012-08-01

To date, only limited epidemiological data on the sleep habits of young children in Japan have been available. This study used representative samples to examine the sleep habits of four-and-a-half-year-old children in Japan. We used data from a nationwide cross-sectional survey. A member of each subject's family was asked to complete the questionnaire. The questionnaire included personal characteristics, sleep habits, and lifestyle. The data for 39,813 subject children (collection rate: 74.3%) were analyzed. The mean value of total sleep duration, night-time sleep duration, and daytime napping duration was 10 h 40 min 30 s, 9 h 53 min 0 s, and 46 min 24 s, respectively. The prevalence of daytime napping was 45.8%. Those whose total sleep duration was less than 10h accounted for 13.7% of the sample. The factors associated with high odds ratios for shorter total sleep duration were: living in a less populated area, long hours spent watching television, longer maternal work hours, and attending preschool. In attempting to devise ways of improving the sleep habits of young children, the lifestyles of both the children and their parents must be considered. Copyright © 2012 Elsevier B.V. All rights reserved.
Unravelling the magnetism, high spin polarization and thermoelectric efficiency of ZrFeSi half-Heusler

NASA Astrophysics Data System (ADS)

Yousuf, Saleem; Gupta, D. C.

2018-04-01

We report the systematic investigation of structural properties, occupancy of density of states, nature of bonding and thermoelectric efficiency of half-Heusler ZrFeSi. The band structure analysis predicts the hybridization of Zr-d and Fe-d metal atoms resulting in occupation of density of states above the Fermi level (EF) while Fe-p and Si-p occupy the lower energy states below the EF. Thermoelectric transport coefficients are predicted using the Boltzmann transport theory under constant relaxation approximation, where Seebeck coefficient (S), total thermal conductivity and figure of merit are calculated. The negative value of total S as -14.02 μV/K predicts the material as n-type with thermoelectric figure of merit (zT) of 0.5 at 800 K. The lattice thermal conductivity decreases with increasing temperature with room temperature value of 4.18 W/mK and shows a significant reduction towards higher temperatures. In view of above elements, structural stability, high zT, ZrFeSi alloy have the capabilities to stimulate experimental verification as a promising materials for high temperature power generation and spintronic device fabrications.
Tracking the metal of the goblins: cobalt's cycle of use.

PubMed

Harper, E M; Kavlak, G; Graedel, T E

2012-01-17

Cobalt is a vital element in many technological applications, which, together with its increasing end-use in batteries, makes it important to quantify its cycle of use. We have done so for the planet as a whole and for the three principal cobalt-using countries - China, Japan, and the United States - for 2005. Together, China, Japan, and the United States accounted for approximately 65% of the cobalt fabricated and manufactured into end-use products (a total of 37 Gg Co). A time residence model allowed calculations of in-use stock accumulation and recycled and landfilled flows. China had the largest accumulation of in-use stock at some 4.3 Gg Co, over half of which was comprised of consumer battery stock. More than half of the stock accumulation in the United States was estimated to be in aircraft, rocket, and gas turbine engines, with a total in-use stock accumulation of approximately 3 Gg Co. The largest amounts of cobalt landfilled in China, the United States, and the planet were from the "chemical and other uses" category, and Japan's largest landfilled flow was in consumer batteries.
On the absence of young white dwarf companions to five technetium stars

NASA Technical Reports Server (NTRS)

Smith, Verne V.; Lambert, David L.

1987-01-01

A search for hot companions to five stars of type MS and S has been carried out using the IUE satellite. No hot companions were detected for the MS stars HR 85, 4647, 6702, and 8062, and the S star HR 8714. Limits on the luminosities of possible white dwarf companions provide lower limits of 2-5x10 to the 8th yr to the ages of any degenerate companions. All five stars exhibit strong Tc I lines, and the presence of technetium, with a half-life of 2.1x10 to the 5th yr, signifies recent nucleosynthesis. The limits on the ages of possible white dwarf companions that are equal to or greater than 1000 half-lives of Tc exclude the possibility that the s-process elemental enhancement seen in these MS and S stars resulted from mass transfer from a more highly evolved companion (as is probably the mechanism by which barium stars are created). These MS and S stars represent a sample of true thermally pulsing asymptotic giant-branch stars.
Evolution of E 2 transition strength in deformed hafnium isotopes from new measurements on 172Hf,174Hf, and 176Hf

NASA Astrophysics Data System (ADS)

Rudigier, M.; Nomura, K.; Dannhoff, M.; Gerst, R.-B.; Jolie, J.; Saed-Samii, N.; Stegemann, S.; Régis, J.-M.; Robledo, L. M.; Rodríguez-Guzmán, R.; Blazhev, A.; Fransen, Ch.; Warr, N.; Zell, K. O.

2015-04-01

Background: The available data for E 2 transition strengths in the region between neutron-deficient hafnium and platinum isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, particularly in heavy-mass regions, which should be highly complex, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf as a representative case. Purpose: We remeasure the 21+ half-lives of 172,174,176Hf, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths. Method: The half-lives were measured using γ -γ and conversion-electron-γ delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations. Results: The measured 21+ half-lives disagree with results from earlier γ -γ fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the 41+ and 61+ states were measured, as well as a lower limit for the 81+ states. Conclusions: This work shows the importance of a mass-dependent effective boson charge in the interacting boson model for the description of E 2 transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New experimental values on transition rates in nuclei from neighboring isotopic chains could support these studies.
Predictive Value of Social Skills in Living Together at Primary School. Analysis in a Cultural Diversity Context

ERIC Educational Resources Information Center

Herrera Torres, Lucía; Bravo Antonio, Iván

2012-01-01

Coexistence at school stands out as one of the main goals in today's education (Carretero, 2008; Ortega, 2007). The aim of this study developed within a cultural diversity context is to identify the specific dimensions of social skills through which the different elements favouring or hindering coexistence at school can be predicted. A total of…
Total Solar Eclipse of 1999 August 11

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

1997-01-01

On 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon's umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India, where it ends at sunset in the Bay of Bengal. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, all of Europe, northern Africa, and the western half of Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 1400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.
Investigation of the feasibility of a small scale transmutation device

NASA Astrophysics Data System (ADS)

Sit, Roger Carson

This dissertation presents the design and feasibility of a small-scale, fusion-based transmutation device incorporating a commercially available neutron generator. It also presents the design features necessary to optimize the device and render it practical for the transmutation of selected long-lived fission products and actinides. Four conceptual designs of a transmutation device were used to study the transformation of seven radionuclides: long-lived fission products (Tc-99 and I-129), short-lived fission products (Cs-137 and Sr-90), and selective actinides (Am-241, Pu-238, and Pu-239). These radionuclides were chosen because they are major components of spent nuclear fuel and also because they exist as legacy sources that are being stored pending a decision regarding their ultimate disposition. The four designs include the use of two different devices; a Deuterium-Deuterium (D-D) neutron generator (for one design) and a Deuterium-Tritium (D-T) neutron generator (for three designs) in configurations which provide different neutron energy spectra for targeting the radionuclide for transmutation. Key parameters analyzed include total fluence and flux requirements; transmutation effectiveness measured as irradiation effective half-life; and activation products generated along with their characteristics: activity, dose rate, decay, and ingestion and inhalation radiotoxicity. From this investigation, conclusions were drawn about the feasibility of the device, the design and technology enhancements that would be required to make transmutation practical, the most beneficial design for each radionuclide, the consequence of the transmutation, and radiation protection issues that are important for the conceptual design of the transmutation device. Key conclusions from this investigation include: (1) the transmutation of long-lived fission products and select actinides can be practical using a small-scale, fusion driven transmutation device; (2) the transmutation of long-lived fission products could result in an irradiation effective half-life of a few years with a three order magnitude increase in the on-target neutron flux accomplishable through a combination of technological enhancements to the source and system design optimization; (3) the transmutation of long-lived fission products requires a thermal-slow energy spectrum to prevent the generation of activation products with half-lives even longer than the original radionuclide; (4) there is no benefit in trying to transmute short-lived fission products due to the ineffectiveness of the transmutation process and the generation of a multiplicity of counterproductive activation products; (5) for actinides, irradiation effective half-lives of < 1 year can be achieved with a four orders magnitude increase in the on-target flux; (6) the ideal neutron energy spectra for transmuting actinides is highly dependent on the particular radionuclide and its fission-to-capture ratio as they determine the generationrate of other actinides; and (7) the methodology developed in this dissertation provides a mechanism that can be used for studying the feasibility of transmuting other radionuclides, and its application can be extended to studying the production of radionuclides of interest in a transmutation process. Although large-scale transmutation technology is presently being researched world-wide for spent fuel management applications, such technology will not be viable for a couple of decades. This dissertation investigated the concept of a small-scale transmutation device using present technology. The results of this research show that with reasonable enhancements, transmutation of specific radionuclides can be practical in the near term.
The prediction of disability by self-reported physical frailty components of the Tilburg Frailty Indicator (TFI).

PubMed

Gobbens, R J J; van Assen, M A L M; Schalk, M J D

2014-01-01

Disability is an important health outcome for older persons; it is associated with impaired quality of life, future hospitalization, and mortality. Disability also places a high burden on health care professionals and health care systems. Disability is regarded as an adverse outcome of physical frailty. The main objective of this study was to assess the predictive validity of the eight individual self-reported components of the physical frailty subscale of the TFI for activities of daily living (ADL) and instrumental activities of daily living (IADL) disability. This longitudinal study was carried out with a sample of Dutch citizens. At baseline the sample consisted at 429 people aged 65 years and older and a subset of all respondents participated again two and a half years later (N=355, 83% response rate). The respondents completed a web-based questionnaire comprising the TFI and the Groningen Activity Restriction Scale (GARS) for measuring disability. Five components together (unintentional weakness, weakness, poor endurance, slowness, low physical activity), referring to the phenotype of Fried et al., predicted disability, even after controlling for previous disability and other background characteristics. The other three components of the physical frailty subscale of the TFI (poor balance, poor hearing, poor vision) together did not predict disability. Low physical activity predicted both total and ADL disability, and slowness both total and IADL disability. In conclusion, self-report assessment using the physical subscale of the TFI aids the prediction of future ADL and IADL disability in older persons two and a half years later. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Half-life of the electron-capture decay of {sup 97}Ru: Precision measurement shows no temperature dependence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodwin, J. R.; Golovko, V. V.; Iacob, V. E.

2009-10-15

We have measured the half-life of the electron-capture (ec) decay of {sup 97}Ru in a metallic environment, both at low temperature (19 K), and also at room temperature. We find the half-lives at both temperatures to be the same within 0.1%. This demonstrates that a recent claim that the ec decay half-life for {sup 7}Be changes by 0.9%{+-}0.2% under similar circumstances certainly cannot be generalized to other ec decays. Our results for the half-life of {sup 97}Ru, 2.8370(14) d at room temperature and 2.8382(14) d at 19 K, are consistent with, but much more precise than, previous room-temperature measurements. Inmore » addition, we have also measured the half-lives of the {beta}{sup -}-emitters {sup 103}Ru and {sup 105}Rh at both temperatures, and found them also to be unchanged.« less
Estimation of the alpha decay of Platinum isotopes using different versions of theoretical formula

NASA Astrophysics Data System (ADS)

Hosseini, S. S.; Hassanabadi, H.; Sobhani, H.

The alpha decay half-lives of even-even and even-odd Platinum (Pt) nuclei have been studied within the Coulomb and proximity potential model (CPPM). The present study is restricted to even-even nuclei with A = 166-198. The results are compared with other calculations such as the Semi-empirical formula (SemFIS) from Poenaru et al. based on fission theory of alpha decay, the Viola-Seaborg (VS), Royer (R) and Brown formulae. Also, the alpha decay half-lives have been calculated using the Scaling law of Brown (SLB), the Universal Decay Law (UDL) of Qi et al., the Scaling Law of Horoi et al. (SLH), and Akrawy-Dorin formula (ADF) of Akrawy and Poenaru, which are the Royer modified formula for alpha decay half-live by adding asymmetry term.
Fragile Families in the American Welfare State

PubMed Central

Garfinkel, Irwin; Zilanawala, Afshin

2016-01-01

The proportion of children born out of wedlock is now over 40 percent. At birth, about half of these parents are co-habiting. This paper examines data from the Fragile Families and Child Wellbeing study (N = 4,271) to describe for the first time the role of welfare state benefits in the economic lives of married, cohabiting, and single parent families with young children. Surprisingly, total welfare state benefits received by the three family types are relatively similar. Nearly half of the full incomes of fragile families come from welfare state transfers. For single parent families the proportion is slightly more than two thirds. Though aggregate welfare state transfers are approximately equal across family type and thus change very little as marital status changes, these transfers and the taxes required to finance them cushion family status changes and substantially narrow the gap in full income between married and fragile families. PMID:27114616
Analysis of medical screening and surveillance in 21 Occupational Safety and Health Administration standards: support for a generic medical surveillance standard.

PubMed

Silverstein, M

1994-09-01

Twenty-one Occupational Safety and Health Act (OSHA) standards were identified which contain medical service provisions intended to help in the identification and control of harmful health effects of workplace exposures. The utility and effectiveness of these provisions have not previously been evaluated. All 21 standards were reviewed and assigned numerical scores for each of 24 potential medical program elements. Several of these elements were combined to calculate Quality Control, Screening Utility, and Surveillance Utility scores for each standard. Total scores varied greatly, suggesting a lack of consistency and uniformity which was even more obvious when the actual regulatory language was examined. The mean Quality score was only 26% of potential points. Seventeen of 21 standards received less than half the total possible Quality score. When arrayed on a two by two matrix only two standards scored above 50% for both Screening and Surveillance Utility. It was concluded that the medical service provisions in OSHA standards are lacking in consistency and coherence. Two major shortcomings are the lack of quality control elements and the absence of surveillance features which would permit medical program results to be utilized for prevention activities including the identification and control of workplace hazards. A generic occupational medical surveillance standard could address these current weaknesses. Elements of such a generic standard are proposed.
Simplified half-life methods for the analysis of kinetic data

NASA Technical Reports Server (NTRS)

Eberhart, J. G.; Levin, E.

1988-01-01

The analysis of reaction rate data has as its goal the determination of the order rate constant which characterize the data. Chemical reactions with one reactant and present simplified methods for accomplishing this goal are considered. The approaches presented involve the use of half lives or other fractional lives. These methods are particularly useful for the more elementary discussions of kinetics found in general and physical chemistry courses.
α -decay chains of superheavy nuclei with Z =125

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2018-04-01

The decay properties of the isotopes of Z =125 within the range 303 ≤ A ≤ 339 are investigated. The calculation of proton separation energies reveals that isotopes 125-309303 may decay through proton emission. Four different mass tables are used to show the sensitivity of the mass models used to calculate the Q values as well as the α-decay half-lives. α -decay chains are predicted by comparing the α half-lives calculated within the Coulomb and proximity potential model for deformed nuclei (CPPMDN) [Nucl. Phys. A 850, 34 (2011), 10.1016/j.nuclphysa.2010.12.002] with the spontaneous fission half-lives using the shell-effect-dependent formula [Phys. Rev. C 94, 054621 (2016), 10.1103/PhysRevC.94.054621]. It is seen that isotopes 125,311310 show 6α chains. 5α chains can be seen from isotopes 125-318312. Isotopes 125,320319 exhibit 2α chains and 323125 exhibits 1α chain. All the other isotopes, that is, 125 321 ,322 ,324 -339 may decay through spontaneous fission. The α half-lives using CPPMDN are compared with five other theoretical formalisms and are seen to be matching with each other. We hope that our studies will be helpful in designing future experiments to explore the island of stability.

Transition-metal alloying of γ'-Ni3Al : Effects on the ideal uniaxial compressive strength from first-principles calculations

NASA Astrophysics Data System (ADS)

Wen, Minru; Wang, Chong-Yu

2018-01-01

The addition of transition-metal (TM) elements into the γ' precipitate phase of a Ni-based single-crystal superalloy can significantly affect its mechanical properties, including the intrinsic mechanical property of compressive strength. Using first-principles density functional calculations, the effects of 3 d (Sc-Zn), 4 d (Y-Cd), and 5 d (Hf-Au) TM alloying elements on the ideal uniaxial compressive strength of γ'-Ni3Al were investigated. The stress-strain relationships of pure Ni3Al under [100], [110], and [111] compressive loads and the site occupancy behavior of TM elements in Ni3Al were previously studied using a total-energy method based on density functional theory. Our results showed that the capacity of TM elements for strengthening the ideal compressive strength was associated with the d -electron number. The alloying elements with half-filled d bands (i.e., Cr, Mo, W, Tc, and Re) manifested the greatest efficacy for improving the ideal strength of Ni3Al under a deformation along the weakest compressive direction. Furthermore, the charge redistribution of Ni3Al doped with 5 d elements were also analyzed to understand the strengthening mechanisms of TM elements in the γ'-Ni3Al phase.
Treatment strategies and cumulative live birth rates in WHO-II ovulation disorders.

PubMed

Braam, Sanne C; de Bruin, Jan Peter; Buisman, Erato T I A; Brandes, Monique; Nelen, Willianne L D M; Smeenk, Jesper M J; van der Steeg, Jan Willem; Mol, Ben Willem J; Hamilton, Carl J C M

2018-04-10

To assess the live birth rate in women with WHO II anovulation and the proportion of women that need second or third line treatments if the initial therapy fails. In this multicenter cohort study we included couples with unfulfilled child wish who were referred to three fertility clinics in the Netherlands and selected women with a WHO II ovulation disorder as the only final infertility diagnosis (n = 468). The cumulative live birth rate of the total group was 82% (383/468). The majority started with clomiphene-citrate as first-line treatment (n = 378) resulting in 180 (48%) live births. There were 153 couples (40%) who underwent a second-line treatment (recombinant-FSH or laparoscopic electrocoagulation of the ovaries, LEO) and 52 couples (14%) a third-line treatment (IVF/ICSI), resulting in 44% and 63% treatment dependent live births rates, respectively. Of all couples, 92 (20%) conceived naturally, 186 (40%) after clomiphene-citrate, 60 (13%) after recombinant-FSH, nine (2%) after LEO and 36 (8%) after IVF. Subfertile women with a WHO II ovulation disorder have a good prognosis on live birth, and most did so after ovulation induction with clomiphene-citrate. If first-line ovulation induction has failed ovulation induction with gonadotrophins or IVF still result in a live birth in about half of the cases. Copyright © 2018 Elsevier B.V. All rights reserved.
An automatic generation of non-uniform mesh for CFD analyses of image-based multiscale human airway models

NASA Astrophysics Data System (ADS)

Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long

2014-11-01

The authors have developed a method to automatically generate non-uniform CFD mesh for image-based human airway models. The sizes of generated tetrahedral elements vary in both radial and longitudinal directions to account for boundary layer and multiscale nature of pulmonary airflow. The proposed method takes advantage of our previously developed centerline-based geometry reconstruction method. In order to generate the mesh branch by branch in parallel, we used the open-source programs Gmsh and TetGen for surface and volume meshes, respectively. Both programs can specify element sizes by means of background mesh. The size of an arbitrary element in the domain is a function of wall distance, element size on the wall, and element size at the center of airway lumen. The element sizes on the wall are computed based on local flow rate and airway diameter. The total number of elements in the non-uniform mesh (10 M) was about half of that in the uniform mesh, although the computational time for the non-uniform mesh was about twice longer (170 min). The proposed method generates CFD meshes with fine elements near the wall and smooth variation of element size in longitudinal direction, which are required, e.g., for simulations with high flow rate. NIH Grants R01-HL094315, U01-HL114494, and S10-RR022421. Computer time provided by XSEDE.
Sunlight photolysis of benzotriazoles - Identification of transformation products and pathways.

PubMed

Weidauer, Cindy; Davis, Caroline; Raeke, Julia; Seiwert, Bettina; Reemtsma, Thorsten

2016-07-01

Benzotriazoles (BTs) are widely used corrosion inhibitors, incompletely removed in municipal wastewater treatment. The photochemical fate of the three BTs 1H-benzotriazole (1H-BT), 4-methyl-1H-benzotriazole (4Me-BT) and 5-methyl-1H-benzotriazole (5Me-BT) and of three microbial metabolites, was studied under simulated sunlight (290-800 nm) at neutral pH in aqueous solution for 24 h. The half-life, the quantum yield and the reaction rate were determined and a total of 36 photolysis products were detected and identified using liquid chromatography-high resolution-mass spectrometry. The half-lives of all six BTs were in the range of 6-24 h under the experimental conditions. Though the quantum yields were comparatively low (0.0007-0.0021), the environmental half-lives ranged from 2.4 to 8 d, suggesting that sunlight photolysis is still a relevant degradation process of BTs in surface waters. The photolysis pathway of 1H-BT under simulated sunlight differed from that suggested for UV-radiation, in that aminophenol is formed directly rather than via aniline. Similar pathways were found for the other BTs, except for 4-hydroxy-1H-benzotriazole (4OH-BT). Most identified transformation products of the BTs showed a high reactivity and appear not to persist in the environment. Upon co-photolysis of BTs with dissolved organic matter (DOM), however, series of reaction products were determined by Fourier transform - ion cyclotron resonance - mass spectrometry (FTICR-MS) which are formed by reaction of photolysis intermediates of the BTs with DOM. Copyright © 2016 Elsevier Ltd. All rights reserved.
Prevalence and Attitude of Cigarette Smoking Among Indian Expatriates Living in Jeddah, Kingdom of Saudi Arabia

PubMed Central

Ahmad, Mohammad Sami

2015-01-01

Background: The objective was to determine the prevalence and attitudes of smoking among expatriate Indian workers living in Jeddah, Saudi Arabia. Methods: A cross-sectional analytical study was done. All the data were collected using a questionnaire-based interview. Results: A total of 421 people were interviewed. Almost half (42%) of the participants were between 31 and 40 years old and 7% were over 51 years. The majority of participants (63%) reported to be non-smokers. The maximum number of smokers was between 41 and 50 years old (42%) and most of them were regular smokers. Almost a third of the subjects (30%) had a higher secondary level of education, and 7% were illiterate. There was a significant association between the prevalence of smoking and the level of education (P < 0.001). Among smokers, half of them smoked more than 21 cigarettes/day. More than half, 238 (57%) of participants agreed that the tobacco was harmful to their health, and 50% agreed that tobacco sales should be banned. Among all, 92% were concerned about their health and 98% accepted that the tobacco causes diseases. The majority of smokers cited stress, loneliness financial responsibilities and a lack of socializing as reasons for their smoking habit. Conclusion: Although the prevalence was relatively high, the majority was aware of the harmful effects of smoking and was keen to have the sale of tobacco banned. Due to their possible loneliness and stress, many felt that smoking helped ease their stress and tension. PMID:26124592
Prevalence and Attitude of Cigarette Smoking Among Indian Expatriates Living in Jeddah, Kingdom of Saudi Arabia

PubMed Central

Ahmad, Mohammad Sami

2015-01-01

Background: The objective was to determine the prevalence and attitudes of smoking among expatriate Indian workers living in Jeddah, Saudi Arabia. Methods: A cross-sectional analytical study was done. All the data were collected using a questionnaire-based interview. Results: A total of 421 people were interviewed. Almost half (42%) of the participants were between 31 and 40 years old and 7% were over 51 years. The majority of participants (63%) reported to be non-smokers. The maximum number of smokers was between 41 and 50 years old (42%) and most of them were regular smokers. Almost a third of the subjects (30%) had a higher secondary level of education, and 7% were illiterate. There was a significant association between the prevalence of smoking and the level of education (P < 0.001). Among smokers, half of them smoked more than 21 cigarettes/day. More than half, 238 (57%) of participants agreed that the tobacco was harmful to their health, and 50% agreed that tobacco sales should be banned. Among all, 92% were concerned about their health and 98% accepted that the tobacco causes diseases. The majority of smokers cited stress, loneliness financial responsibilities and a lack of socializing as reasons for their smoking habit. Conclusion: Although the prevalence was relatively high, the majority was aware of the harmful effects of smoking and was keen to have the sale of tobacco banned. Due to their possible loneliness and stress, many felt that smoking helped ease their stress and tension. PMID:25954065
Isomer pattern and elimination of dioxins in workers exposed at a municipal waste incineration plant

PubMed Central

YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

2015-01-01

The aim of this study was to clarify patterns of serum concentrations of dioxins in the employees of a waste incineration plant and to estimate elimination rates and half-lives of serum dioxin isomers, and the maximum serum concentrations of dioxin isomers at the time of plant shutdown. Sixteen subjects participating 3 times or more in annual health examinations during an 8-yr period from 2000 to 2007 were recruited for this study. Serum concentrations of dioxins expressed as TEQ/g lipid decreased gradually after plant shutdown with the highest decrease observed in polychlorinated dibenzofurans (PCDFs) followed by polychlorinated deibenzo-p-dioxins (PCDDs) and then coplanar PCBs. The serum toxic equivalency (TEQ) concentrations of PCDF and PCDD congeners in the employees were higher than those in the general population survey by the Ministry of the Environment, Japan, whereas the serum concentrations of coplanar PCBs were similar to those in the general population. The estimated half-lives and elimination rates of PCDDs and PCDFs in the highly exposed workers increased compared with the moderately exposed workers. The estimated geometric mean serum concentrations of PCDDs, PCDFs and total dioxins at the time of plant shutdown were 35, 53 and 107 pg TEQ/g lipid, respectively. PMID:26118856
Use of newborn screening program blood spots for exposure assessment: declining levels of perluorinated compounds in New York State infants.

PubMed

Spliethoff, Henry M; Tao, Lin; Shaver, Shannon M; Aldous, Kenneth M; Pass, Kenneth A; Kannan, Kurunthachalam; Eadon, George A

2008-07-15

Temporal biomonitoring studies can assess changes in population exposures to contaminants, but collection of biological specimens with adequate representation and sufficient temporal resolution can be resource-intensive. Newborn Screening Programs (NSPs) collect blood as dried spots on filter paper from nearly all infants born in the United States (U.S.). In this study, we investigated the use of NSP blood spots for temporal biomonitoring by analyzing perfluorooctane sulfonate (PFOS), perfluorooctane sulfonamide (PFOSA), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) in 110 New York State (NYS) NSP blood spot composite specimens collected between 1997 and 2007, representing a total of 2640 infants. All analytes were detected in > or =90% of the specimens. Concentrations of PFOS, PFOSA, PFHxS, and PFOA exhibited significant exponential declines after the year 2000, coinciding with the phase-out in PFOS production in the U.S. Calculated disappearance half-lives for PFOS, PFHxS, and PFOA (4.4, 8.2, and 4.1 years, respectively) were similar to biological half-lives reported for retired fluorochemical workers. Our results suggest sharp decreases in perinatal exposure of NYS infants to PFOS, PFOSA, PFHxS, and PFOA and demonstrate, for the first time, the utility of NSP blood spots for assessment of temporal trends in exposure.
Half-Lives of Proton Emitters With a Deformed Density-Dependent Model

NASA Astrophysics Data System (ADS)

Qian, Yi-Bin; Ren, Zhong-Zhou; Ni, Dong-Dong; Sheng, Zong-Qiang

2010-11-01

Half-lives of proton radioactivity are investigated with a deformed density-dependent model. The single folding potential which is dependent on deformation and orientation is employed to calculate the proton decay width through the deformed potential barrier. In addition, the spectroscopic factor is taken into account in the calculation, which is obtained in the relativistic mean field theory with NL3. The calculated results of semi-spherical nuclei are found to be in good agreement with the experimental data, and the results of well-deformed nuclei are also satisfactory. Moreover, a formula for the spherical proton emission half-life based on the Gamow quantum tunneling theory is presented.
Terrestrial ages of Antarctic meteorites: Implications for concentration mechanisms

NASA Technical Reports Server (NTRS)

Schultz, L.

1986-01-01

Antarctic meteorites differ from meteorites fallen in other places in their mean terrestrial ages. Boeckl estimated the terrestrial half-life for the disintegration of stone meteorites by weathering under the climatic conditions of the Western United States to be about 3600 years. Antarctic meteorites, however, have terrestrial ages up to 70000 years, indicating larger weathering half-lives. The terrestrial ages of meteorites are determined by their concentration of cosmic-ray-produced radionuclides with suitable half-lives (C-14, Al-26, and Cl-36). These radionuclides have yielded reliable ages for the Antarctic meteorites. The distribution of terrestrial ages of Allan Hills and Yamato meteorites are examined.
Intra-annual changes in biomass, carbon, and nitrogen dynamics at 4-year old switchgrass field trials in West Tennessee, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, Jr, C. T.; Smith, Jeffery L.; Tyler, Donald D.

2010-02-15

Switchgrass is a potential bioenergy crop that could promote soil C sequestration in some environments. We compared four cultivars on a well-drained Alfisol to test for differences in biomass, C, and N dynamics during the fourth growing season. There was no difference (P > 0.05) among cultivars and no significant cultivar x time interaction in analyses of dry mass, C stocks, or N stocks in aboveground biomass and surface litter. At the end of the growing season, mean (±SE) aboveground biomass was 2.1±0.13 kg m-2, and surface litter dry mass was approximately 50% of aboveground biomass. Prior to harvest, themore » live root:shoot biomass ratio was 0.76. There was no difference (P > 0.05) among cultivars for total biomass, C, and N stocks belowground. Total belowground biomass (90-cm soil depth) as well as coarse (greater than or equal to 1 mm diameter) and fine (< 1 mm diameter) live root biomass increased from April to October. Dead roots were less than 7% of live root biomass to a depth of 90 cm. Net production of total belowground biomass (505 ±132 g m-2) occurred in the last half of the growing season. The increase in total live belowground biomass (426 ±139 g m-2) was more or less evenly divided among rhizomes, coarse, and fine roots. The N budget for annual switchgrass production was closely balanced with 6.3 g N m-2 removed by harvest of aboveground biomass and 6.7 g N m-2 supplied by fertilization. At the location of our study in west Tennessee, intra-annual changes in biomass, C, and N stocks belowground were of greater importance to crop management for C sequestration than were differences among cultivars.« less
Potential impacts of seasonal variation on atrazine and metolachlor persistence in andisol soil.

PubMed

Jaikaew, Piyanuch; Boulange, Julien; Thuyet, Dang Quoc; Malhat, Farag; Ishihara, Satoru; Watanabe, Hirozumi

2015-12-01

To estimate the potential effect of seasonal variation on the fate of herbicides in andisol soil, atrazine and metolachlor residues were investigated through the summer and winter seasons during 2013 and 2014 under field condition. The computed half-lives of atrazine and metolachlor in soil changed significantly through the two seasons of the trial. The half-lives were shorter in summer season with 16.0 and 23.5 days for atrazine and metolachlor, respectively. In contrast, the half-lives were longer during the winter season with 32.7 and 51.8 days for atrazine and metolachlor, respectively. The analysis of soil water balance suggested that more pesticide was lost in deeper soil layers through infiltration in summer than in winter. In addition, during the summer season, metolachlor was more likely to leach into deeper soil layer than atrazine possibly due to high water solubility of metolachlor.
The pharmacokinetics of commonly used antiepileptic drugs in immature CD1 mice

PubMed Central

Markowitz, Geoffrey J.; Kadam, Shilpa D.; Boothe, Dawn M.; Irving, Natasha D.; Comi, Anne M.

2010-01-01

Rodents eliminate antiepileptic drugs (AEDs) faster than humans, creating challenges for designing clinically-relevant protocols. Half-lives of AEDs in immature mice are unknown. The pharmacokinetics of commonly-used AEDs were examined in CD1 mice using a single-dose protocol at post-natal day 19. Following intraperitoneal therapeutic dosing, blood serum concentrations spanning 1–48 hours post-administration and corresponding brain tissue concentrations at 4 hours were analyzed. Half-lives of valproate, phenobarbital, diazepam (and metabolites), phenytoin, and levetiracetam were 2.6, 15.8, 22.3, 16.3, and 3.2 hours respectively, compared to 0.8, 7.5, 7.7, 16.0, and 1.5 hours reported for adult mice. Brain-to-blood ratios were comparable to adult ratios. AEDs tested had longer half-lives and maintained therapeutic plasma concentrations longer than reported in mature mice, making clinically-relevant protocols feasible. PMID:20848732
Assessing theoretical uncertainties in fission barriers of superheavy nuclei

DOE PAGES

Agbemava, S. E.; Afanasjev, A. V.; Ray, D.; ...

2017-05-26

Here, theoretical uncertainties in the predictions of inner fission barrier heights in superheavy elements have been investigated in a systematic way for a set of state-of-the-art covariant energy density functionals which represent major classes of the functionals used in covariant density functional theory. They differ in basic model assumptions and fitting protocols. Both systematic and statistical uncertainties have been quantified where the former turn out to be larger. Systematic uncertainties are substantial in superheavy elements and their behavior as a function of proton and neutron numbers contains a large random component. The benchmarking of the functionals to the experimental datamore » on fission barriers in the actinides allows to reduce the systematic theoretical uncertainties for the inner fission barriers of unknown superheavy elements. However, even then they on average increase on moving away from the region where benchmarking has been performed. In addition, a comparison with the results of non-relativistic approaches is performed in order to define full systematic theoretical uncertainties over the state-of-the-art models. Even for the models benchmarked in the actinides, the difference in the inner fission barrier height of some superheavy elements reaches $5-6$ MeV. This uncertainty in the fission barrier heights will translate into huge (many tens of the orders of magnitude) uncertainties in the spontaneous fission half-lives.« less
Total Radiosynthesis: Thinking outside "the box".

PubMed

Liang, Steven H; Vasdev, Neil

2015-09-01

The logic of total synthesis transformed a stagnant state of medicinal and synthetic organic chemistry when there was a paucity of methods and reagents to synthesize drug molecules and/or natural products. Molecular imaging by positron emission tomography (PET) is now experiencing a renaissance in the way radiopharmaceuticals for molecular imaging are synthesized, however, a paradigm shift is desperately needed in the discovery pipeline to accelerate in vivo imaging studies. A significant challenge in radiochemistry is the limited choice of labeled reagents (or building blocks) available for the synthesis of novel radiopharmaceuticals with the most commonly used short-lived radionuclides carbon-11 ( 11 C; half-life ~20 minutes) and fluorine-18 ( 18 F; half-life ~2 hours). In fact, most drugs cannot be labeled with 11 C or 18 F due to a lack of efficient and diverse radiosynthetic methods. In general, routine radiopharmaceutical production relies on the incorporation of the isotope at the last or penultimate step of synthesis, ideally within one half-life of the radionuclide, to maximize radiochemical yields and specific activities thereby reducing losses due to radioactive decay. Reliance on radiochemistry conducted within the constraints of an automated synthesis unit ("box") has stifled the exploration of multi-step reactions with short-lived radionuclides. Radiopharmaceutical synthesis can be transformed by considering logic of total synthesis to develop novel approaches for 11 C- and 18 F-radiolabeling complex molecules via retrosynthetic analysis and multi-step reactions. As a result of such exploration, new methods, reagents and radiopharmaceuticals for in vivo imaging studies are discovered. A new avenue to develop radiotracers that were previously unattainable due to the lack of efficient radiosynthetic methods is necessary to work towards our ultimate, albeit impossible goal - the concept we term total radiosynthesis - to radiolabel virtually any molecule. As with the vast majority of drugs, most radiotracers also fail, therefore expeditious evaluation of tracers in preclinical models prior to optimization or derivatization of the lead molecules/drugs is necessary. Furthermore the exact position of the 11 C and 18 F radionuclide in tracers is often critical for metabolic considerations, and flexible methodologies to introduce the radiolabel are needed. Using the principles of total synthesis our laboratory and others have shown that multi-step radiochemical reactions are indeed suitable for preclinical and even clinical use. As the goal of total synthesis is to be concise, we have also simplified the syntheses of radiopharmaceuticals. We are presently developing new strategies via [ 11 C]CO 2 fixation which has enabled library radiosynthesis as well as labeling non-activated arenes using [ 18 F]fluoride via iodonium ylides. Both of which have proven to be suitable for human PET imaging. We concurrently utilize state-of-the-art automation technologies including microfluidic flow chemistry and rapid purification strategies for radiopharmaceutical production. In this account we highlight how total radiosynthesis has impacted our radiochemistry program, with prominent examples from others, focusing on its impact towards preclinical and clinical research studies.
Total Radiosynthesis: Thinking outside “the box”

PubMed Central

Liang, Steven H.; Vasdev, Neil

2016-01-01

The logic of total synthesis transformed a stagnant state of medicinal and synthetic organic chemistry when there was a paucity of methods and reagents to synthesize drug molecules and/or natural products. Molecular imaging by positron emission tomography (PET) is now experiencing a renaissance in the way radiopharmaceuticals for molecular imaging are synthesized, however, a paradigm shift is desperately needed in the discovery pipeline to accelerate in vivo imaging studies. A significant challenge in radiochemistry is the limited choice of labeled reagents (or building blocks) available for the synthesis of novel radiopharmaceuticals with the most commonly used short-lived radionuclides carbon-11 (11C; half-life ~20 minutes) and fluorine-18 (18F; half-life ~2 hours). In fact, most drugs cannot be labeled with 11C or 18F due to a lack of efficient and diverse radiosynthetic methods. In general, routine radiopharmaceutical production relies on the incorporation of the isotope at the last or penultimate step of synthesis, ideally within one half-life of the radionuclide, to maximize radiochemical yields and specific activities thereby reducing losses due to radioactive decay. Reliance on radiochemistry conducted within the constraints of an automated synthesis unit (“box”) has stifled the exploration of multi-step reactions with short-lived radionuclides. Radiopharmaceutical synthesis can be transformed by considering logic of total synthesis to develop novel approaches for 11C- and 18F-radiolabeling complex molecules via retrosynthetic analysis and multi-step reactions. As a result of such exploration, new methods, reagents and radiopharmaceuticals for in vivo imaging studies are discovered. A new avenue to develop radiotracers that were previously unattainable due to the lack of efficient radiosynthetic methods is necessary to work towards our ultimate, albeit impossible goal – the concept we term total radiosynthesis - to radiolabel virtually any molecule. As with the vast majority of drugs, most radiotracers also fail, therefore expeditious evaluation of tracers in preclinical models prior to optimization or derivatization of the lead molecules/drugs is necessary. Furthermore the exact position of the 11C and 18F radionuclide in tracers is often critical for metabolic considerations, and flexible methodologies to introduce the radiolabel are needed. Using the principles of total synthesis our laboratory and others have shown that multi-step radiochemical reactions are indeed suitable for preclinical and even clinical use. As the goal of total synthesis is to be concise, we have also simplified the syntheses of radiopharmaceuticals. We are presently developing new strategies via [11C]CO2 fixation which has enabled library radiosynthesis as well as labeling non-activated arenes using [18F]fluoride via iodonium ylides. Both of which have proven to be suitable for human PET imaging. We concurrently utilize state-of-the-art automation technologies including microfluidic flow chemistry and rapid purification strategies for radiopharmaceutical production. In this account we highlight how total radiosynthesis has impacted our radiochemistry program, with prominent examples from others, focusing on its impact towards preclinical and clinical research studies. PMID:27512156
People diagnosed with dementia in Sweden: What type of home care services and housing are they granted? A cross-sectional study.

PubMed

Odzakovic, Elzana; Hydén, Lars-Christer; Festin, Karin; Kullberg, Agneta

2018-02-01

This study aims to examine what types of home care services and housing are granted to people with a dementia diagnosis and how these types are associated with socio-demographic factors (sex, age, marital status, native or foreign born, and regional area). A cross-sectional study of all people diagnosed with dementia in three Swedish counties was conducted from the medical records in 2012. Logistic regression analysis was carried out to investigate associations between home care services and housing and socio-demographic variables. In total, 17,405 people had a dementia diagnosis, and the majority were women, aged 80+ years, and unmarried. Some 72% were living in ordinary housing and 28% lived in special housing. Of those who lived in ordinary housing, 50% did not receive any home care service. Not receiving any type of home care services was less common for older people and was also associated with being married and living in rural municipalities. The most common home care services granted were home help and personal care. Special housing was more common for older people, unmarried persons, and those living in rural municipalities. Most people with a dementia diagnosis were living in ordinary housing, and, surprisingly, half of those did not receive any type of home care service. This knowledge is essential for making the living conditions and needs of people living with dementia more visible and to provide good home care services for people with dementia and their families.
Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants.

PubMed

Smith, Kirk R; Jerrett, Michael; Anderson, H Ross; Burnett, Richard T; Stone, Vicki; Derwent, Richard; Atkinson, Richard W; Cohen, Aaron; Shonkoff, Seth B; Krewski, Daniel; Pope, C Arden; Thun, Michael J; Thurston, George

2009-12-19

In this report we review the health effects of three short-lived greenhouse pollutants-black carbon, ozone, and sulphates. We undertook new meta-analyses of existing time-series studies and an analysis of a cohort of 352,000 people in 66 US cities during 18 years of follow-up. This cohort study provides estimates of mortality effects from long-term exposure to elemental carbon, an indicator of black carbon mass, and evidence that ozone exerts an independent risk of mortality. Associations among these pollutants make drawing conclusions about their individual health effects difficult at present, but sulphate seems to have the most robust effects in multiple-pollutant models. Generally, the toxicology of the pure compounds and their epidemiology diverge because atmospheric black carbon, ozone, and sulphate are associated and could interact with related toxic species. Although sulphate is a cooling agent, black carbon and ozone could together exert nearly half as much global warming as carbon dioxide. The complexity of these health and climate effects needs to be recognised in mitigation policies. Copyright 2009 Elsevier Ltd. All rights reserved.
Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants

PubMed Central

Smith, Kirk R.; Jerrett, Michael; Anderson, H Ross; Burnett, Richard T.; Stone, Vicki; Derwent, Richard; Atkinson, Richard W.; Cohen, Aaron; Shonkoff, Seth B.; Krewski, Daniel; Pope, C. Arden; Thun, Michael J.; Thurston, George

2014-01-01

In this report we review the health effects of three short-lived greenhouse pollutants—black carbon, ozone, and sulphates. We undertook new meta-analyses of existing time-series studies and an analysis of a cohort of 352 000 people in 66 US cities during 18 years of follow-up. This cohort study provides estimates of mortality effects from long-term exposure to elemental carbon, an indicator of black carbon mass, and evidence that ozone exerts an independent risk of mortality. Associations among these pollutants make drawing conclusions about their individual health effects difficult at present, but sulphate seems to have the most robust effects in multiple-pollutant models. Generally, the toxicology of the pure compounds and their epidemiology diverge because atmospheric black carbon, ozone, and sulphate are associated and could interact with related toxic species. Although sulphate is a cooling agent, black carbon and ozone could together exert nearly half as much global warming as carbon dioxide. The complexity of these health and climate effects needs to be recognised in mitigation policies. PMID:19942276
Perspectives concerning living wills in medical staff of a main regional hospital in Japan.

PubMed

Maeda, Yoshitaka; Shintani, Shuzo

2015-01-01

Living wills, written types of advanced directives, are now widespread in western countries, but in Japan, their recognition still remains restricted to a small part of the population. As an initial step to introduction of such patient-oriented medicine, we surveyed present recognition and acceptance patterns concerning living wills in a main regional hospital located in a suburban area of Tokyo. Without any preceding guidance on living wills, the questionnaire on living wills was distributed to all the staff working at JA Toride Medical Center in September 2013, and their responses were collected for analysis within one month. Questionnaires were distributed to all hospital staff, 843 in total, and 674 responses (80.0% of distributed) were obtained. The term of living will was known by 304 (45.1%) of the respondents, and introduction of living wills to patients was accepted in 373 (55.3%) of the respondents, meanwhile, 286 (42.4%) respondents did not indicate their attitude toward living wills. As to styles of document form, 332 respondents (49.3%) supported selection of wanted or unwanted medical treatments and care from a prepared list, and 102 respondents (15.1%) supported description of living wills in free form. As preferred treatment options that should be provided as a checklist, cardiac massage (chest compression) and a ventilator were selected by more than half of the respondents. Based on their responses, we developed an original type of living wills available to patients visiting the hospital. Although not all the respondents were aware of living wills even in this main regional hospital, introduction of living wills to patients was accepted by many of the hospital staff. Awareness programs or information campaigns are needed to introduce living wills to support patient-centered medicine.

Contamination status and accumulation profiles of organotins in sea otters (Enhydra lutris) found dead along the coasts of California, Washington, Alaska (USA), and Kamchatka (Russia)

USGS Publications Warehouse

Murata, S.; Takahashi, S.; Agusa, T.; Thomas, N.J.; Kannan, K.; Tanabe, S.

2008-01-01

Organotin compounds (OTs) including mono- to tri-butyltins, -phenyltins, and -octyltins were determined in the liver of adult sea otters (Enhydra lutris) found dead along the coasts of California, Washington, and Alaska in the USA and Kamchatka, Russia. Total concentrations of OTs in sea otters from California ranged from 34 to 4100 ng/g on a wet weight basis. The order of concentrations of OTs in sea otters was total butyltins ??? total octyltins ??? total phenyltins. Elevated concentrations of butyltins (BTs) were found in some otters classified under 'infectious-disease' mortality category. Concentrations of BTs in few of these otters were close to or above the threshold levels for adverse health effects. Total butyltin concentrations decreased significantly in the livers of California sea otters since the 1990s. Based on the concentrations of organotins in sea otters collected from 1992 to 2002, the half-lives of tributyltin and total butyltins in sea otters were estimated to be approximately three years. ?? 2008 Elsevier Ltd. All rights reserved.
DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products.

PubMed

Turkec, Aydin; Kazan, Hande; Karacanli, Burçin; Lucas, Stuart J

2015-08-01

In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products.
Viscoelastic properties of tablets from Osborne fractions, pentosans, flour and bread evaluated by creep tests

NASA Astrophysics Data System (ADS)

Escalante-Aburto, Anayansi; de Dios Figueroa-Cárdenas, Juan; Véles-Medina, José Juan; Ponce-García, Néstor; Hernández-Estrada, Zorba Josué; Rayas-Duarte, Patricia; Simsek, Senay

2017-07-01

Little attention has been given to the influence of non-gluten components on the viscoelastic properties of wheat flour dough, bread making process and their products. The aim of this study was to evaluate by creep tests the viscoelastic properties of tablets manufactured from Osborne solubility fractions (globulins, gliadins, glutenins, albumins and residue), pentosans, flour and bread. Hard and soft wheat cultivars were used to prepare the reconstituted tablets. Sintered tablets (except flour and bread) showed similar values to those obtained from the sum of the regression coefficients of the fractions. Gliadins and albumins accounted for about 54% of the total elasticity. Gliadins contributed with almost half of the total viscosity (45.7%), and showed the highest value for the viscosity coefficient of the viscous element. When the effect of dilution was evaluated, the residue showed the highest instantaneous elastic modulus (788.2 MPa). Retardation times of the first element (λ1 3.5 s) were about 10 times lower than the second element (λ2 39.3 s). The analysis of compliance of data corrected by protein content in flour showed that the residue fraction presented the highest values. An important contribution of non-gluten components (starch, albumins and globulins) on the viscoelastic performance of sintered tablets from Osborne fractions, flour and bread was found.
High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s.

PubMed

Wieser, Wolfgang; Draxinger, Wolfgang; Klein, Thomas; Karpf, Sebastian; Pfeiffer, Tom; Huber, Robert

2014-09-01

We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin.
High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s

PubMed Central

Wieser, Wolfgang; Draxinger, Wolfgang; Klein, Thomas; Karpf, Sebastian; Pfeiffer, Tom; Huber, Robert

2014-01-01

We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin. PMID:25401010
A Novel Observation-Guided Approach for Evaluating Mesoscale Convective Systems Simulated by the DOE ACME Model

NASA Astrophysics Data System (ADS)

Feng, Z.; Ma, P. L.; Hardin, J. C.; Houze, R.

2017-12-01

Mesoscale convective systems (MCSs) are the largest type of convective storms that develop when convection aggregates and induces mesoscale circulation features. Over North America, MCSs contribute over 60% of the total warm-season precipitation and over half of the extreme daily precipitation in the central U.S. Our recent study (Feng et al. 2016) found that the observed increases in springtime total and extreme rainfall in this region are dominated by increased frequency and intensity of long-lived MCSs*. To date, global climate models typically do not run at a resolution high enough to explicitly simulate individual convective elements and may not have adequate process representations for MCSs, resulting in a large deficiency in projecting changes of the frequency of extreme precipitation events in future climate. In this study, we developed a novel observation-guided approach specifically designed to evaluate simulated MCSs in the Department of Energy's climate model, Accelerated Climate Modeling for Energy (ACME). The ACME model has advanced treatments for convection and subgrid variability and for this study is run at 25 km and 100 km grid spacings. We constructed a robust MCS database consisting of over 500 MCSs from 3 warm-season observations by applying a feature-tracking algorithm to 4-km resolution merged geostationary satellite and 3-D NEXRAD radar network data over the Continental US. This high-resolution MCS database is then down-sampled to the 25 and 100 km ACME grids to re-characterize key MCS properties. The feature-tracking algorithm is adapted with the adjusted characteristics to identify MCSs from ACME model simulations. We demonstrate that this new analysis framework is useful for evaluating ACME's warm-season precipitation statistics associated with MCSs, and provides insights into the model process representations related to extreme precipitation events for future improvement. *Feng, Z., L. R. Leung, S. Hagos, R. A. Houze, C. D. Burleyson, and K. Balaguru (2016), More frequent intense and long-lived storms dominate the springtime trend in central US rainfall, Nat Commun, 7, 13429, doi: 10.1038/ncomms13429.
Does co-residence with adult children associate with better psychological well-being among the oldest old in China?

PubMed

Wang, Jinfeng; Chen, Tianyong; Han, Buxin

2014-03-01

Embedded in a traditional culture where filial piety was honored, living with adult children once had been the most prevalent living arrangement and the best option for Chinese elderly people. This study examined whether co-residence with adult children would be still beneficial to the psychological well-being (PWB) among the oldest old (aged 80 and above) in China today. Using data from the fifth wave of the Chinese Longitudinal Healthy Longevity Survey conducted in 2008, the authors examined the living arrangements among the total sample (n = 12,213) and the association between living arrangement and PWB among a subsample (n = 7037) of respondents with normal cognition. (1) More than half (67.1%) of the unmarried oldest old reported being co-resided with their children; while for the married oldest old, the majority of the respondents (62.4%) lived with a spouse only. (2) For the widowed, co-residence with adult children was associated with better PWB compared to living alone; but for the married, co-residence did not bring additional benefits to the PWB. (3) Co-residence of the widowed and children was associated with better life satisfaction compared to living with a spouse only, while it was associated with lower emotional well-being compared to living with a spouse (with or without a child). These findings suggest that living arrangements of Chinese oldest old are partially getting westernized, and a majority of them adapt it well. Government programs need to be developed to assist the Chinese oldest old (especially widowed) to live independently.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Marketin, Tomislav, E-mail: marketin@phy.hr; Petković, Jelena; Paar, Nils

Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied inmore » more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.« less
Beta decay rates of neutron-rich nuclei

NASA Astrophysics Data System (ADS)

Marketin, Tomislav; Huther, Lutz; Martínez-Pinedo, Gabriel

2015-10-01

Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei.
Beta decay rates of neutron-rich nuclei

NASA Astrophysics Data System (ADS)

Marketin, Tomislav; Huther, Lutz; Petković, Jelena; Paar, Nils; Martínez-Pinedo, Gabriel

2016-06-01

Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.
Differences in the half-lives of some mitochondrial rat liver enzymes may derive partially from hepatocyte heterogeneity.

PubMed

Vargas, J L; Roche, E; Knecht, E; Grisolía, S

1987-11-16

The different turnover rates of rat liver mitochondrial enzymes make autophagy unlikely to be the main mechanism for degradation of mitochondria. Although alternatives have been presented, hepatocyte heterogeneity has not been considered. Lighter hepatocytes isolated in a discontinuous Percoll gradient contain more glutamate dehydrogenase (GDH) (half-life 1 day) and a more active autophagic system than heavier hepatocytes. The latter contain more carbamoyl phosphate synthase (CPS) and ornithine carbamoyl transferase (OTC) (half-lives 8 days) but less lysosomal activity. As expected, isolated autophagic vacuoles contain, relative to the mitochondrial content, 3-times less OTC and CPS than GDH, probably reflecting a faster lysosomal engulfment of mitochondria in the light hepatocytes (which contain more GDH). These data may explain some of the half-life differences of the enzymes studied.
Self-Recognition in Live Videos by Young Children: Does Video Training Help?

ERIC Educational Resources Information Center

Demir, Defne; Skouteris, Helen

2010-01-01

The overall aim of the experiment reported here was to establish whether self-recognition in live video can be facilitated when live video training is provided to children aged 2-2.5 years. While the majority of children failed the test of live self-recognition prior to video training, more than half exhibited live self-recognition post video…
Radiogenic Isotopes in Weathering and Hydrology

NASA Astrophysics Data System (ADS)

Blum, J. D.; Erel, Y.

2003-12-01

There are a small group of elements that display variations in their isotopic composition, resulting from radioactive decay within minerals over geological timescales. These isotopic variations provide natural fingerprints of rock-water interactions and have been widely utilized in studies of weathering and hydrology. The isotopic systems that have been applied in such studies are dictated by the limited number of radioactive parent-daughter nuclide pairs with half-lives and isotopic abundances that result in measurable differences in daughter isotope ratios among common rocks and minerals. Prior to their application to studies of weathering and hydrology, each of these isotopic systems was utilized in geochronology and petrology. As in the case of their original introduction into geochronology and petrology, isotopic systems with the highest concentrations of daughter isotopes in common rocks and minerals and systems with the largest observed isotopic variations were introduced first and have made the largest impact on our understanding of weathering and hydrologic processes. Although radiogenic isotopes have helped elucidate many important aspects of weathering and hydrology, it is important to note that in almost every case that will be discussed in this chapter, our fundamental understanding of these topics came from studies of variations in the concentrations of major cations and anions. This chapter is a "tools chapter" and thus it will highlight applications of radiogenic isotopes that have added additional insight into a wide spectrum of research areas that are summarized in almost all of the other chapters of this volume.The first applications of radiogenic isotopes to weathering processes were based on studies that sought to understand the effects of chemical weathering on the geochronology of whole-rock samples and geochronologically important minerals (Goldich and Gast, 1966; Dasch, 1969; Blaxland, 1974; Clauer, 1979, 1981; Clauer et al., 1982); as well as on the observation that radiogenic isotopes are sometimes preferentially released compared to nonradiogenic isotopes of the same element during acid leaching of rocks ( Hart and Tilton, 1966; Silver et al., 1984; Erel et al., 1991). A major finding of these investigations was that weathering often results in anomalously young Rb-Sr isochron ages, and discordant Pb-Pb ages. Rubidium is generally retained relative to strontium in whole-rock samples, and in some cases radiogenic strontium and lead are lost preferentially to common strontium and lead from weathered minerals.The most widely utilized of these isotopic systems is Rb-Sr, followed by U-Pb. The K-Ar system is not directly applicable to most studies of rock-water interaction, because argon is a noble gas, and upon release during mineral weathering mixes with atmospheric argon, limiting its usefulness as a tracer in most weathering applications. Argon and other noble gas isotopes have, however, found important applications in hydrology (see Chapter 5.15). Three other isotopic systems commonly used in geochronology and petrology include Sm-Nd, Lu-Hf, and Re-Os. These parent and daughter elements are in very low abundance and concentrated in trace mineral phases. Sm-Nd, Lu-Hf, and Re-Os have been used in a few weathering studies but have not been utilized extensively in investigations of weathering and hydrology.The decay of 87Rb to 87Sr has a half-life of 48.8 Gyr, and this radioactive decay results in natural variability in the 87Sr/86Sr ratio in rubidium-bearing minerals (e.g., Blum, 1995). The trace elements rubidium and strontium are geochemically similar to the major elements potassium and calcium, respectively. Therefore, minerals with high K/Ca ratios develop high 87Sr/86Sr ratios over geologic timescales. Once released into the hydrosphere, strontium retains its isotopic composition without significant fractionation by geochemical or biological processes, and is therefore a good tracer for sources and cycling of calcium. The decay of 235U to 207Pb, 238U to 206Pb, and 232Th to 208Pb have half-lives of 0.704 Gyr, 4.47 Gyr, and 14.0 Gyr, respectively, and result in variations in the 207Pb/204Pb, 206Pb/204Pb, and 208Pb/204Pb ratios (e.g., Blum, 1995). Uranium-234 has a half-life of 0.25 Myr and the ratio 234U/238U approaches a constant secular equilibrium value in rocks and minerals if undisturbed for ˜1 Myr. Differences in this ratio are often observed in solutions following rock-water interaction and have been used in studies of weathering and hydrology. Uranium and thorium tend to be highly concentrated in the trace accessory minerals such as zircon, monazite, apatite, and sphene, which therefore develop high 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios. Once released into the hydrosphere, lead retains its isotopic composition without significant geochemical or biological fractionation and tends to generally follow the chemistry of iron in soils and aqueous systems (Erel and Morgan, 1992). The use of the U-Th disequilibrium series as a dating tool falls outside the scope of this chapter and is reviewed in Chapters 6.14 and 6.17 as well as Chapter 3.15. The decay of 147Sm to 143Nd, 176Lu to 176Hf, and 187Re to 187Os have half-lives of 106 Gyr, 35.7 Gyr, and 42.3 Gyr, respectively, and result in natural variability in the 144Nd/143Nd, 176Hf/177Hf, and 187Os/188Os ratios (e.g., Blum, 1995). Neodymium is a rare earth element (REE), hafnium is a transition metal with chemical similarities to zirconium, and osmium is a platinum group element. The geochemical behaviors of these elements in the hydrosphere are largely determined by these chemical affinities.
Observations on the influence of water and soil pH on the persistence of insecticides.

PubMed

Chapman, R A; Cole, C M

1982-01-01

The pH-disappearance rate profiles were determined at ca. 25 degrees C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water-ethanol (99:1 v/v). Half-lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (greater than 1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1-2 days for trichlorfon and oxamyl to greater than 1 year for fensulfothion and cypermethrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.
Self-Alining, Latching Joint For Folding Structural Elements

NASA Technical Reports Server (NTRS)

Bush, H. G.; Wallsom, R. E.

1982-01-01

Structural column elements assembled quickly and easily with aid of new center joint. Joint alines column elements automatically and fastens them together securely. Tapered half columns are stacked like paper cups, unfolded, and connected to other similar elements to form truss structures.
Successional changes in live and dead wood carbon stores: implications for net ecosystem productivity.

PubMed

Janisch, J E; Harmon, M E

2002-02-01

If forests are to be used in CO2 mitigation projects, it is essential to understand and quantify the impacts of disturbance on net ecosystem productivity (NEP; i.e., the change in ecosystem carbon (C) storage with time). We examined the influence of live tree and coarse woody debris (CWD) on NEP during secondary succession based on data collected along a 500-year chronosequence on the Wind River Ranger District, Washington. We developed a simple statistical model of live and dead wood accumulation and decomposition to predict changes in the woody component of NEP, which we call NEP(w). The transition from negative to positive NEP(w), for a series of scenarios in which none to all wood was left after disturbance, occurred between 0 and 57 years after disturbance. The timing of this transition decreased as live-tree growth rates increased, and increased as CWD left after disturbance increased. Maximum and minimum NEP(w) for all scenarios were 3.9 and -14.1 Mg C ha-1 year-1, respectively. Maximum live and total wood C stores of 319 and 393 Mg C ha(-1), respectively, were reached approximately 200 years after disturbance. Decomposition rates (k) of CWD ranged between 0.013 and 0.043 year-1 for individual stands. Regenerating stands took 41 years to attain a mean live wood mass equivalent to the mean mass of CWD left behind after logging, 40 years to equal the mean CWD mass in 500-year-old forest, and more than 150 years to equal the mean total live and dead wood in an old-growth stand. At a rotation age of 80 years, regenerating stands stored approximately half the wood C of the remaining nearby old-growth forests (predominant age 500 years), indicating that conversion of old-growth forests to younger managed forests results in a significant net release of C to the atmosphere.
Chimeric RNase H–Competent Oligonucleotides Directed to the HIV-1 Rev Response Element

PubMed Central

Prater, Chrissy E.; Saleh, Anthony D.; Wear, Maggie P.; Miller, Paul S.

2007-01-01

Chimeric oligo-2′-O-methylribonucleotides containing centrally located patches of contiguous 2′-deoxyribonucleotides and terminating in a nuclease resistant 3′-methylphosphonate internucleotide linkage were prepared. The oligonucleotides were targeted to the 3′-side of HIV Rev response element (RRE) stem-loop IIB RNA, which is adjacent to the high affinity Rev protein binding site and is critical to virus function. Thermal denaturation experiments showed that chimeric oligonucleotides form very stable duplexes with a complementary single-stranded RNA, and gel electrophoretic mobility shift assays (EMSA) showed that they bind with high affinity and specificity to RRE stem-loop II RNA (KD approximately 200 nM). The chimeric oligonucleotides promote RNase H-mediated hydrolysis of RRE stem-loop II RNA and have half lives exceeding 24 h when incubated in cell culture medium containing 10% fetal calf serum. One of the chimeric oligonucleotides inhibited RRE mediated expression of chloramphenicol acetyl transferase (CAT) approximately 60% at a concentration of 300 nM in HEK 293T cells co-transfected with p-RRE/CAT and p-Rev mammalian expression vectors. PMID:17566743
Tables for simplifying calculations of activities produced by thermal neutrons

USGS Publications Warehouse

Senftle, F.E.; Champion, W.R.

1954-01-01

The method of calculation described is useful for the types of work of which examples are given. It is also useful in making rapid comparison of the activities that might be expected from several different elements. For instance, suppose it is desired to know which of the three elements, cobalt, nickel, or vanadium is, under similar conditions, activated to the greatest extent by thermal neutrons. If reference is made to a cross-section table only, the values may be misleading unless properly interpreted by a suitable comparison of half-lives and abundances. In this table all the variables have been combined and the desired information can be obtained directly from the values of A 3??, the activity produced per gram per second of irradiation, under the stated conditions. Hence, it is easily seen that, under similar circumstances of irradiation, vanadium is most easily activated even though the cross section of one of the cobalt isotopes is nearly five times that of vanadium and the cross section of one of the nickel isotopes is three times that of vanadium. ?? 1954 Societa?? Italiana di Fisica.
Face Liveness Detection Using Defocus

PubMed Central

Kim, Sooyeon; Ban, Yuseok; Lee, Sangyoun

2015-01-01

In order to develop security systems for identity authentication, face recognition (FR) technology has been applied. One of the main problems of applying FR technology is that the systems are especially vulnerable to attacks with spoofing faces (e.g., 2D pictures). To defend from these attacks and to enhance the reliability of FR systems, many anti-spoofing approaches have been recently developed. In this paper, we propose a method for face liveness detection using the effect of defocus. From two images sequentially taken at different focuses, three features, focus, power histogram and gradient location and orientation histogram (GLOH), are extracted. Afterwards, we detect forged faces through the feature-level fusion approach. For reliable performance verification, we develop two databases with a handheld digital camera and a webcam. The proposed method achieves a 3.29% half total error rate (HTER) at a given depth of field (DoF) and can be extended to camera-equipped devices, like smartphones. PMID:25594594
Nursing Homes

MedlinePlus

... our e-newsletter! Aging & Health A to Z Nursing Homes Basic Facts & Information Nursing homes have changed ... guide care in nursing homes. Who lives in nursing homes? Almost half of all people who live ...

Convective Transport of Very-short-lived Bromocarbons to the Stratosphere

NASA Technical Reports Server (NTRS)

Liang, Qing; Atlas, Elliot Leonard; Blake, Donald Ray; Dorf, Marcel; Pfeilsticker, Klaus August; Schauffler, Sue Myhre

2014-01-01

We use the NASA GEOS Chemistry Climate Model (GEOSCCM) to quantify the contribution of two most important brominated very short-lived substances (VSLS), bromoform (CHBr3) and dibromomethane (CH2Br2), to stratospheric bromine and its sensitivity to convection strength. Model simulations suggest that the most active transport of VSLS from the marine boundary layer through the tropopause occurs over the tropical Indian Ocean, the Western Pacific warm pool, and off the Pacific coast of Mexico. Together, convective lofting of CHBr3 and CH2Br2 and their degradation products supplies 8 ppt total bromine to the base of the Tropical Tropopause Layer (TTL, 150 hPa), similar to the amount of VSLS organic bromine available in the marine boundary layer (7.8-8.4 ppt) in the above active convective lofting regions. Of the total 8 ppt VSLS-originated bromine that enters the base of TTL at 150 hPa, half is in the form of source gas injection (SGI) and half as product gas injection (PGI). Only a small portion (< 10%) the VSLS-originated bromine is removed via wet scavenging in the TTL before reaching the lower stratosphere. On global and annual average, CHBr3 and CH2Br2, together, contribute 7.7 pptv to the present-day inorganic bromine in the stratosphere. However, varying model deep convection strength between maximum and minimum convection conditions can introduce a 2.6 pptv uncertainty in the contribution of VSLS to inorganic bromine in the stratosphere (BryVSLS). Contrary to the conventional wisdom, minimum convection condition leads to a larger BryVSLS as the reduced scavenging in soluble product gases, thus a significant increase in PGI (2-3 ppt), greatly exceeds the relative minor decrease in SGI (a few 10ths ppt.
Atomic Weights of the Elements 1999

NASA Astrophysics Data System (ADS)

Coplen, T. B.

2001-05-01

The biennial review of atomic-weight, Ar(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements: from to nitrogen 14.006 74±0.000 07¯r 14.0067±0.0002¯ sulfur 32.066±0.006 32.065±0.005 chlorine 35.4527±0.0009 35.453±0.002 germanium 72.61±0.02 72.64±0.01 xenon 131.29±0.02 131.293±0.006 erbium 167.26±0.03 167.259±0.003 uranium 238.0289±0.0001 238.028 91±0.000 03 Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999. Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or atomic-weight values are included in this report for the information of the interested scientific community.
Metolachlor and alachlor breakdown product formation patterns in aquatic field mesocosms

USGS Publications Warehouse

Graham, William H.; Graham, D.W.; DeNoyelles, Frank; Smith, Val H.; Larive, C.K.; Thurman, E.M.

1999-01-01

The transformation of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)- N-(2-methoxy-1-methyl)ethyl)acetamide] and alachlor [2-chloro-N-(2,6- diethylphenyl)-N-methoxymethyl)acetamide] in aquatic systems was investigated using outdoor tank mesocosms. Metolachlor and alachlor levels and their ethane sulfonic acid (ESA) and oxanillic acid breakdown products were monitored over time under five experimental treatments (each in quadruplicate). Background water conditions were identical in all treatments with each treatment differing based on the level and type(s) of herbicide present. Treatments included a noherbicide control, 10 ??g/L metolachlor, 25 ??g/L metolachlor, 25 ??g/L alachlor, and 25 ??g/L alachlor plus 25 ??g/L metolachlor in combination. The experiment was initiated by adding herbicide(s) to the units to the target concentrations; herbicide and breakdown product levels and other chemical parameters were then monitored for 85 days. In general, metolachlor half-lives were longer than alachlor half-lives under all treatments, although the differences were not statistically significant. Metolachlor half-lives (??95% confidence limits) ranged from 33.0 d (??14.1 d) to 46.2 d (??40.0 d), whereas alachlor half- lives ranged from 18.7 d (??3.5 d) to 21.0 d (??6.5 d) for different treatments. Formation patterns of ESA were similar in all treatments, whereas oxanillic acid formation differed for the two herbicides. Alachlor oxanillic acid was produced in larger quantities than metolachlor oxanillic acid and either ESA under equivalent conditions. Our results suggest that the transformation pathways for alachlor and metolachlor in aquatic systems are similar and resemble the acetochlor pathway in soils proposed by Feng (Pestic. Biochem. Physiol. 1991, 34, 136); however, the oxanillic acid branch of the pathway is favored for alachlor as compared with metolachlor.The transformation of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N- (2-methoxy-1-methylethy)acetamide] and alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] in aquatic systems was investigated using outdoor tank mesocosms. Metolachlor and alachlor levels and their ethane sulfonic acid (ESA) and oxanillic acid breakdown products were monitored over time under five experimental treatments (each in quadruplicate). Background water conditions were identical in all treatments with each treatment differing based on the level and type(s) of herbicide present. Treatments included a no-herbicide control, 10 ??g/L metolachlor, 25 ??g/L metolachlor, 25 ??g/L alachlor, and 25 ??g/L alachlor plus 25 ??g/L metolachlor in combination. The experiment was initiated by adding herbicide(s) to the units to the target concentrations; herbicide and breakdown product levels and other chemical parameters were then monitored for 85 days. In general, metolachlor half-lives were longer than alachlor half-lives under all treatments, although the differences were not statistically significant. Metolachlor half-lives (??95% confidence limits) ranged from 33.0 d (??14.1 d) to 46.2 d (??40.0 d), whereas alachlor half-lives ranged from 18.7 d (??3.5 d) to 21.0 d (??6.5 d) for different treatments. Formation patterns of ESA were similar in all treatments, whereas oxanillic acid formation differed for the two herbicides. Alachlor oxanillic acid was produced in larger quantities than metolachlor oxanillic acid and either ESA under equivalent conditions. Our results suggest that the transformation pathways for alachlor and metolachlor in aquatic systems are similar and resemble the acetochlor pathway in soils proposed by Feng; however, the oxanillic acid branch of the pathway is favored for alachlor as compared with metolachlor.
Thermal oxidation saves $500,000, lifts capacity, upholds compliance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harley, C.G.; Nagy, A.J.; Sendecki, M.

1985-12-01

The age and destruction of the heat recovery system dictated the replacement of the original fume incinerator at the Congoleum Resilient Flooring Division Plant in Trenton, NJ. The original unit, installed in 1967, had a conventional air-to-oil heat recovery system. Plant personnel placed high priority on finding a replacement with a higher thermal efficiency while still maintaining environmental integrity. A proprietary software program was used to obtain values for NPV (net pressure value) for several competitive equipment systems. The NPV allows simple comparison of equipment based on data such as purchase pgsrice, cost of installation, operating costs, and maintenance costsmore » for the predicted life span of each unit. Based on NPV analysis, a regenerative thermal oxidation unit was selected. To assure expansion capability, Congoleum opted for a 30,000 scfm system. The regenerative thermal oxidation unit consists of a central combustion chamber with five lobes extending radially outward. Each lobe is packed with ceramic refractory elements (saddles) which serve as heat exchange media. The elements are retained by perforated refractory blocks on the hot combustion chamber side and by a grating on the cold side. Estimated savings from the system, about a half million dollars the first year, are expected to significantly exceed Congoleum's original estimates. About half of the total savings will result from reduced consumption of natural gas since the unit is fueled mainly by the organic material in the process exhaust. The other half of the savings has resulted from improvements in production efficiency and the recycling of waste heat from the thermal oxidizer.« less
β -decay half-lives and β -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caballero-Folch, R.; Domingo-Pardo, C.; Agramunt, J.

Background: There have been measurements on roughly 230 nuclei that are β-delayed neutron emitters. They range from 8He up to 150La . Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A = 150 . Therefore, new data are needed, particularly in the region of heavy nuclei around N = 126 , in order to guide theoretical models and help understand the formation of the third r-process peak at A ~ 195. Purpose: To measure both β-decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bimore » isotopes beyond N = 126 . Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and β decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new β-decay half-lives are reported for 204-206Au, 208 – 211Hg, 211 – 216Tl , 215 – 218Pb, and 218 – 220Bi, nine of them for the first time. Neutron emission probabilities are reported for 210, 211Hg and 211 – 216Tl . Conclusions: The new β-decay half-lives are in good agreement with previous measurements on nuclei in this region. Lastly, the measured neutron emission probabilities are comparable to or smaller than values predicted by global models such as relativistic Hartree Bogoliubov plus the relativistic quasi-particle random phase approximation (RHB + RQRPA).« less
β -decay half-lives and β -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N =126

NASA Astrophysics Data System (ADS)

Caballero-Folch, R.; Domingo-Pardo, C.; Agramunt, J.; Algora, A.; Ameil, F.; Ayyad, Y.; Benlliure, J.; Bowry, M.; Calviño, F.; Cano-Ott, D.; Cortès, G.; Davinson, T.; Dillmann, I.; Estrade, A.; Evdokimov, A.; Faestermann, T.; Farinon, F.; Galaviz, D.; García, A. R.; Geissel, H.; Gelletly, W.; Gernhäuser, R.; Gómez-Hornillos, M. B.; Guerrero, C.; Heil, M.; Hinke, C.; Knöbel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Yu. A.; Maier, L.; Marganiec, J.; Marta, M.; Martínez, T.; Montes, F.; Mukha, I.; Napoli, D. R.; Nociforo, C.; Paradela, C.; Pietri, S.; Podolyák, Zs.; Prochazka, A.; Rice, S.; Riego, A.; Rubio, B.; Schaffner, H.; Scheidenberger, Ch.; Smith, K.; Sokol, E.; Steiger, K.; Sun, B.; Taín, J. L.; Takechi, M.; Testov, D.; Weick, H.; Wilson, E.; Winfield, J. S.; Wood, R.; Woods, P. J.; Yeremin, A.

2017-06-01

Background: There have been measurements on roughly 230 nuclei that are β -delayed neutron emitters. They range from 8He up to 150La. Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A =150 . Therefore, new data are needed, particularly in the region of heavy nuclei around N =126 , in order to guide theoretical models and help understand the formation of the third r -process peak at A ˜195 . Purpose: To measure both β -decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bi isotopes beyond N =126 . Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and β decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new β -decay half-lives are reported for Au-206204, Hg-211208,Tl-216211,Pb-218215 , and Bi-220218, nine of them for the first time. Neutron emission probabilities are reported for Hg,211210 and Tl-216211. Conclusions: The new β -decay half-lives are in good agreement with previous measurements on nuclei in this region. The measured neutron emission probabilities are comparable to or smaller than values predicted by global models such as relativistic Hartree Bogoliubov plus the relativistic quasi-particle random phase approximation (RHB + RQRPA).
β -decay half-lives and β -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126

DOE PAGES

Caballero-Folch, R.; Domingo-Pardo, C.; Agramunt, J.; ...

2017-06-23

Background: There have been measurements on roughly 230 nuclei that are β-delayed neutron emitters. They range from 8He up to 150La . Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A = 150 . Therefore, new data are needed, particularly in the region of heavy nuclei around N = 126 , in order to guide theoretical models and help understand the formation of the third r-process peak at A ~ 195. Purpose: To measure both β-decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bimore » isotopes beyond N = 126 . Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and β decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new β-decay half-lives are reported for 204-206Au, 208 – 211Hg, 211 – 216Tl , 215 – 218Pb, and 218 – 220Bi, nine of them for the first time. Neutron emission probabilities are reported for 210, 211Hg and 211 – 216Tl . Conclusions: The new β-decay half-lives are in good agreement with previous measurements on nuclei in this region. Lastly, the measured neutron emission probabilities are comparable to or smaller than values predicted by global models such as relativistic Hartree Bogoliubov plus the relativistic quasi-particle random phase approximation (RHB + RQRPA).« less
Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

PubMed

Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

2005-02-28

Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the cognate elements.
mRNA stability in mammalian cells.

PubMed Central

Ross, J

1995-01-01

This review concerns how cytoplasmic mRNA half-lives are regulated and how mRNA decay rates influence gene expression. mRNA stability influences gene expression in virtually all organisms, from bacteria to mammals, and the abundance of a particular mRNA can fluctuate manyfold following a change in the mRNA half-life, without any change in transcription. The processes that regulate mRNA half-lives can, in turn, affect how cells grow, differentiate, and respond to their environment. Three major questions are addressed. Which sequences in mRNAs determine their half-lives? Which enzymes degrade mRNAs? Which (trans-acting) factors regulate mRNA stability, and how do they function? The following specific topics are discussed: techniques for measuring eukaryotic mRNA stability and for calculating decay constants, mRNA decay pathways, mRNases, proteins that bind to sequences shared among many mRNAs [like poly(A)- and AU-rich-binding proteins] and proteins that bind to specific mRNAs (like the c-myc coding-region determinant-binding protein), how environmental factors like hormones and growth factors affect mRNA stability, and how translation and mRNA stability are linked. Some perspectives and predictions for future research directions are summarized at the end. PMID:7565413
Nutritional composition and total collagen content of three commercially important edible jellyfish.

PubMed

Khong, Nicholas M H; Yusoff, Fatimah Md; Jamilah, B; Basri, Mahiran; Maznah, I; Chan, Kim Wei; Nishikawa, Jun

2016-04-01

The study aimed to evaluate nutraceutical potential of three commercially significant edible jellyfish species (Acromitus hardenbergi, Rhopilema hispidum and Rhopilema esculentum). The bell and oral arms of these jellyfishes were analyzed for their proximate composition, calorific value, collagen content, amino acid profile, chemical score and elemental constituent. In general, all jellyfish possessed low calorific values (1.0-4.9 kcal/g D.W.) and negligible fat contents (0.4-1.8 g/100 g D.W.), while protein (20.0-53.9 g/100 g D.W.) and minerals (15.9-57.2g/100g D.W.) were found to be the richest components. Total collagen content of edible jellyfish varied from 122.64 to 693.92 mg/g D.W., accounting for approximately half its total protein content. The dominant amino acids in both bell and oral arms of all jellyfish studied includes glycine, glutamate, threonine, proline, aspartate and arginine, while the major elements were sodium, potassium, chlorine, magnesium, sulfur, zinc and silicon. Among the jellyfish, A. hardenbergi exhibited significantly higher total amino acids, chemical scores and collagen content (p<0.05) compared to R. hispidum and R. esculentum. Having good protein quality and low calories, edible jellyfish is an appealing source of nutritive ingredients for the development of oral formulations, nutricosmetics and functional food. Copyright © 2015 Elsevier Ltd. All rights reserved.
Total quality in acute care hospitals: guidelines for hospital managers.

PubMed

Holthof, B

1991-08-01

Quality improvement can not focus exclusively on peer review and the scientific evaluation of medical care processes. These essential elements have to be complemented with a focus on individual patient needs and preferences. Only then will hospitals create the competitive advantage needed to survive in an increasingly market-driven hospital industry. Hospital managers can identify these patients' needs by 'living the patient experience' and should then set the hospital's quality objectives according to its target patients and their needs. Excellent quality program design, however, is not sufficient. Successful implementation of a quality improvement program further requires fundamental changes in pivotal jobholders' behavior and mindset and in the supporting organizational design elements.
Modeling Radioactive Decay Chains with Branching Fraction Uncertainties

DTIC Science & Technology

2013-03-01

moments methods with transmutation matrices. Uncertainty from both half-lives and branching fractions is carried through these calculations by Monte...moment methods, method for sampling from normal distributions for half- life uncertainty, and use of transmutation matrices were leveraged. This...distributions for half-life and branching fraction uncertainties, building decay chains and generating the transmutation matrix (T-matrix
A list of nuclear medicine radionuclides and potential contaminants for operators of in-vivo counters.

PubMed

Stabin, M; Schlafke-Stelson, A

1991-09-01

Operators of in-vivo counters often encounter unusual photopeaks, some of which may be attributed to nuclear medicine radiopharmaceuticals recently received by the subject. This article lists the most common radiopharmaceuticals used in nuclear medicine, their common uses, their half-lives and principal decay energies, and the half-lives and decay energies of any contaminants or daughter products they may contain. The purpose is to help the in-vivo counter operator track down and eliminate causes of such unusual photopeaks.
Spatial relations between sympatric coyotes and red foxes in North Dakota

USGS Publications Warehouse

Sargeant, A.B.; Allen, S.H.; Hastings, J.O.

1987-01-01

Spatial relations between coyotes (Canis latrans) and red foxes (Vulpes vulpes) on a 360-km2 area in North Dakota were studied during 1977-78. Coyote families occupied large (mean = 61.2 km2), relatively exclusive territories that encompassed about one-half of the study area. Fox families occupied much smaller (mean = 11.9 km2), relatively exclusive, territories that overlapped perimeters of coyote territories and/or encompassed area unoccupied by coyotes. No fox family lived totally within a coyote territory, but 3 fox families lived within the 153.6-km2 home range of an unattached yearling male coyote. Both coyotes and foxes, from families with overlapping territories, tended to use their overlap areas less than was expected by amount of overlap. Encounters between radio-equipped coyotes and foxes from families with overlapping territories occurred less often than was expected by chance. Foxes living near coyotes exhibited considerable tenacity to their territories, and no monitored fox was killed by coyotes during 2,518 fox-days of radio surveillance. A hypothesis for coyote-induced fox population declines, based largely on fox avoidance mechanisms, is presented.
A wideband fast multipole boundary element method for half-space/plane-symmetric acoustic wave problems

NASA Astrophysics Data System (ADS)

Zheng, Chang-Jun; Chen, Hai-Bo; Chen, Lei-Lei

2013-04-01

This paper presents a novel wideband fast multipole boundary element approach to 3D half-space/plane-symmetric acoustic wave problems. The half-space fundamental solution is employed in the boundary integral equations so that the tree structure required in the fast multipole algorithm is constructed for the boundary elements in the real domain only. Moreover, a set of symmetric relations between the multipole expansion coefficients of the real and image domains are derived, and the half-space fundamental solution is modified for the purpose of applying such relations to avoid calculating, translating and saving the multipole/local expansion coefficients of the image domain. The wideband adaptive multilevel fast multipole algorithm associated with the iterative solver GMRES is employed so that the present method is accurate and efficient for both lowand high-frequency acoustic wave problems. As for exterior acoustic problems, the Burton-Miller method is adopted to tackle the fictitious eigenfrequency problem involved in the conventional boundary integral equation method. Details on the implementation of the present method are described, and numerical examples are given to demonstrate its accuracy and efficiency.
Application of simple mathematical expressions to relate the half-lives of xenobiotics in rats to values in humans.

PubMed

Ward, Keith W; Erhardt, Paul; Bachmann, Kenneth

2005-01-01

Previous publications from GlaxoSmithKline and University of Toledo laboratories convey our independent attempts to predict the half-lives of xenobiotics in humans using data obtained from rats. The present investigation was conducted to compare the performance of our published models against a common dataset obtained by merging the two sets of rat versus human half-life (hHL) data previously used by each laboratory. After combining data, mathematical analyses were undertaken by deploying both of our previous models, namely the use of an empirical algorithm based on a best-fit model and the use of rat-to-human liver blood flow ratios as a half-life correction factor. Both qualitative and quantitative analyses were performed, as well as evaluation of the impact of molecular properties on predictability. The merged dataset was remarkably diverse with respect to physiochemical and pharmacokinetic (PK) properties. Application of both models revealed similar predictability, depending upon the measure of stipulated accuracy. Certain molecular features, particularly rotatable bond count and pK(a), appeared to influence the accuracy of prediction. This collaborative effort has resulted in an improved understanding and appreciation of the value of rats to serve as a surrogate for the prediction of xenobiotic half-lives in humans when clinical pharmacokinetic studies are not possible or practicable.
Remote-handled/special case TRU waste characterization summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Detamore, J.A.

1984-03-30

TRU wastes are those (other than high level waste) contaminated with specified quantities of certain alpha-emitting radionuclides of long half-life and high specific radiotoxicity. TRU waste is defined as /sup 226/Ra isotopic sources and those other materials that, without regard to source or form, are contaminated with transuranic elements with half-lives greater than 20 years, and have TRU alpha contamination greater than 100 nCi/g. RH TRU waste has high beta and gamma radiation levels, up to 30,000 R/hr, and thermal output may be a few hundred watts per container. The radiation levels in most of this remotely handled (RH) TRUmore » waste, however, are below 100 R/hr. Remote-handled wastes are stored at Los Alamos, Hanford, Oak Ridge, and the Idaho National Engineering Laboratory. This report presents a site by site discussion of RH waste handling, placement, and container data. This is followed by a series of data tables that were compiled in the TRU Waste Systems Office. These tables are a compendium of data that are the most up to date and accurate data available today. 10 tables.« less
Relationship among aqueous copper half-lives and responses of Pimephales promelas to a series of copper sulfate pentahydrate concentrations.

PubMed

Calomeni, Alyssa J; Kinley, Ciera M; Geer, Tyler D; Iwinski, Kyla J; Hendrikse, Maas; Rodgers, John H

2018-04-01

Copper algaecide exposures in situ are often of shorter duration than exposures for static toxicity experiments because aqueous concentrations in situ dissipate as a function of site-specific fate processes. Consequently, responses of organisms to static copper exposures may overestimate effects following in situ exposures. To understand the role of exposure duration for altering responses, Pimephales promelas survival was compared following static (96 h) and pulse (1.5, 4, 8, and 15 h half-lives) exposures of CuSO 4 •5H 2 O. Copper concentrations sorbed by fry indicated a consequence of different exposures. Responses of P. promelas to static exposures resulted in 96 h LC 50 s of 166 µgCu/L (95% confidence interval [CI], 142-189 µgCu/L) as soluble copper and 162 µgCu/L (CI, 140-183 µgCu/L) as acid soluble copper. Relative to static 96 h LC 50 s, exposures with half-lives of 1.5, 4 and 8 h resulted in LC 50 s 10, 3 and 2 times greater, respectively, for responses measured 96 h after exposure initiation. Copper concentrations extracted from fry exposed for 1.5, 4 and 8 h half-lives were less than the static experiment. However, copper sorbed by fry in the 15 h half-life experiment was not different than the static experiment. The relationship between 96 h LC 50 and 1/half-life was expressed using the equations y = 116 + 1360 × (R 2 = 0.97) for soluble copper and y = 147 + 1620 × (R 2 = 0.98) for acid soluble copper. Incorporation of exposure duration for predictions of P. promelas responses to copper pulse exposures increases prediction accuracy by an order of magnitude.
Absorbed dose estimates from a single measurement one to three days after the administration of 177Lu-DOTATATE/-TOC.

PubMed

Hänscheid, Heribert; Lapa, Constantin; Buck, Andreas K; Lassmann, Michael; Werner, Rudolf A

2017-01-01

To retrospectively analyze the accuracy of absorbed dose estimates from a single measurement of the activity concentrations in tumors and relevant organs one to three days after the administration of 177 Lu-DOTA-TATE/TOC assuming tissue specific effective half-lives. Activity kinetics in 54 kidneys, 30 neuroendocrine tumor lesions, 25 livers, and 27 spleens were deduced from series of planar images in 29 patients. After adaptation of mono- or bi-exponential fit functions to the measured data, it was analyzed for each fit function how precise the time integral can be estimated from fixed tissue-specific half-lives and a single measurement at 24, 48, or 72 h after the administration. For the kidneys, assuming a fixed tissue-specific half-life of 50 h, the deviations of the estimate from the actual integral were median (5 % percentile, 95 % percentile): -3 °% (-15 %>; +16 °%) for measurements after 24 h, +2 %> (-9 %>; +12 %>) for measurements after 48 h, and 0 % (-2 %; +12 %) for measurements after 72 h. The corresponding values for the other tissues, assuming fixed tissue-specific half-lives of 67 h for liver and spleen and 77 h for tumors, were +2 % (-25 %; +20 %) for measurements after 24 h, +2 °% (-16 %>; +17 %>) for measurements after 48 h, and +2 %> (-11 %>; +10 %>) for measurements after 72 h. Especially for the kidneys, which often represent the dose limiting organ, but also for liver, spleen, and neuroendocrine tumors, a meaningful absorbed dose estimate is possible from a single measurement after 2, more preferably 3 days after the administration of 177 Lu-DOTA-TATE/-TOC assuming fixed tissue specific effective half-lives. Schattauer GmbH.
Improved measurement of the half-life of the J π = 8 - nuclear isomer 152m2 Eu

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humby, Peter; Simon, Anna; Beausang, C. W.

2015-02-23

The standard γ-ray energy calibration source 152Eu is well known based on the 13.5 y decay of its ground state. Nevertheless, in addition to this decay 152Eu also has two relatively long-lived isomeric states: a 9 h J π=0 - state at E *=46 keV and a 96 min J π=8 - state at E *=148 keV. Here we report a new measurement of the half-lives of both of these isomeric states. Excited states in 152Eu were populated following the 154Sm (p,3n) reaction using a 25 MeV proton beam from the K-150 cyclotron at the Cyclotron Institute of Texas A&Mmore » University. Post irradiation, γ rays from the de-excitation of the long lived isomeric states were measured using the six BGO shielded high-purity germanium (HPGe) clover detectors that are part of the STARLiTeR array. The half-life of the J π=8 - isomer 152m2Eu was obtained by measuring the decrease in intensity of the 90 keV γ ray from the cascade to the ground state. The half-life of this state was measured to be 95.8(4) min which is in agreement with and significantly more precise than the previously measured value of 96(1) min. In a manner similar to the ground state the second long-lived isomer 151m1Eu, the J π=0 - state at 46 keV, β decays to excited states in 152Gd and 152Sm. Also, the half-life of this state was measured to be 9.39(7) h using five γ-ray transitions.« less

Circadian clock-dependent and -independent posttranscriptional regulation underlies temporal mRNA accumulation in mouse liver

PubMed Central

Wang, Jingkui; Yeung, Jake; Gobet, Cédric; Sobel, Jonathan; Lück, Sarah; Molina, Nacho; Naef, Felix

2018-01-01

The mammalian circadian clock coordinates physiology with environmental cycles through the regulation of daily oscillations of gene expression. Thousands of transcripts exhibit rhythmic accumulations across mouse tissues, as determined by the balance of their synthesis and degradation. While diurnally rhythmic transcription regulation is well studied and often thought to be the main factor generating rhythmic mRNA accumulation, the extent of rhythmic posttranscriptional regulation is debated, and the kinetic parameters (e.g., half-lives), as well as the underlying regulators (e.g., mRNA-binding proteins) are relatively unexplored. Here, we developed a quantitative model for cyclic accumulations of pre-mRNA and mRNA from total RNA-seq data, and applied it to mouse liver. This allowed us to identify that about 20% of mRNA rhythms were driven by rhythmic mRNA degradation, and another 15% of mRNAs regulated by both rhythmic transcription and mRNA degradation. The method could also estimate mRNA half-lives and processing times in intact mouse liver. We then showed that, depending on mRNA half-life, rhythmic mRNA degradation can either amplify or tune phases of mRNA rhythms. By comparing mRNA rhythms in wild-type and Bmal1−/− animals, we found that the rhythmic degradation of many transcripts did not depend on a functional BMAL1. Interestingly clock-dependent and -independent degradation rhythms peaked at distinct times of day. We further predicted mRNA-binding proteins (mRBPs) that were implicated in the posttranscriptional regulation of mRNAs, either through stabilizing or destabilizing activities. Together, our results demonstrate how posttranscriptional regulation temporally shapes rhythmic mRNA accumulation in mouse liver. PMID:29432155
Pharmacokinetics of lidocaine and bupivacaine following subarachnoid administration in surgical patients: simultaneous investigation of absorption and disposition kinetics using stable isotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burm, A.G.; Van Kleef, J.W.; Vermeulen, N.P.

1988-10-01

The pharmacokinetics of lidocaine and bupivacaine following subarachnoid administration were studied in 12 surgical patients using a stable isotope method. After subarachnoid administration of the agent to be evaluated, a deuterium-labelled analogue was administered intravenously. Blood samples were collected for 24 h. Plasma concentrations of the unlabelled and the deuterium-labelled local anesthetics were determined using a combination of capillary gas chromatography and mass fragmentography. Bi-exponential functions were fitted to the plasma concentration-time data of the deuterium-labelled local anesthetics. The progression of the absorption was evaluated using deconvolution. Mono- and bi-exponential functions were then fitted to the fraction absorbed versus timemore » data. The distribution and elimination half-lives of the deuterium-labelled analogues were 25 +/- 13 min (mean +/- SD) and 121 +/- 31 min for lidocaine and 19 +/- 10 min and 131 +/- 33 min for bupivacaine. The volumes of the central compartment and steady-state volumes of distribution were: lidocaine 57 +/- 10 l and 105 +/- 25 l, bupivacaine 25 +/- 6 l and 63 +/- 22 l. Total plasma clearance values averaged 0.97 +/- 0.21 l/min for lidocaine and 0.56 +/- 0.14 l/min for bupivacaine. The absorption of lidocaine could be described by a single first order absorption process, characterized by a half-life of 71 +/- 17 min in five out of six patients. The absorption of bupivacaine could be described adequately assuming two parallel first order absorption processes in all six patients. The half-lives, characterizing the fast and slow absorption processes of bupivacaine, were 50 +/- 27 min and 408 +/- 275 min, respectively. The fractions of the dose, absorbed in the fast and slow processes, were 0.35 +/- 0.17 and 0.61 +/- 0.16, respectively.« less
Creation of half-metallic f -orbital Dirac fermion with superlight elements in orbital-designed molecular lattice

NASA Astrophysics Data System (ADS)

Cui, Bin; Huang, Bing; Li, Chong; Zhang, Xiaoming; Jin, Kyung-Hwan; Zhang, Lizhi; Jiang, Wei; Liu, Desheng; Liu, Feng

2017-08-01

Magnetism in solids generally originates from the localized d or f orbitals that are hosted by heavy transition-metal elements. Here, we demonstrate a mechanism for designing a half-metallic f -orbital Dirac fermion from superlight s p elements. Combining first-principles and model calculations, we show that bare and flat-band-sandwiched (FBS) Dirac bands can be created when C20 molecules are deposited into a two-dimensional hexagonal lattice, which are composed of f -molecular orbitals (MOs) derived from s p -atomic orbitals (AOs). Furthermore, charge doping of the FBS Dirac bands induces spontaneous spin polarization, converting the system into a half-metallic Dirac state. Based on this discovery, a model of a spin field effect transistor is proposed to generate and transport 100% spin-polarized carriers. Our finding illustrates a concept to realize exotic quantum states by manipulating MOs, instead of AOs, in orbital-designed molecular crystal lattices.
Structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the quaternary Heusler compound FeCrRuSi: A first-principles study.

PubMed

Wang, Xiaotian; Khachai, Houari; Khenata, Rabah; Yuan, Hongkuan; Wang, Liying; Wang, Wenhong; Bouhemadou, Abdelmadjid; Hao, Liyu; Dai, Xuefang; Guo, Ruikang; Liu, Guodong; Cheng, Zhenxiang

2017-11-23

In this paper, we have investigated the structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the equiatomic quaternary Heusler (EQH) compound FeCrRuSi using the density functional theory (DFT) and the quasi-harmonic Debye model. Our results reveal that FeCrRuSi is a half-metallic material (HMM) with a total magnetic moment of 2.0 μ B in agreement with the well-known Slater-Pauling rule M t = Z t - 24. Furthermore, the origin of the half-metallic band gap in FeCrRuSi is well studied through a schematic diagram of the possible d-d hybridization between Fe, Cr and Ru elements. The half-metallic behavior of FeCrRuSi can be maintained in a relatively wide range of variations of the lattice constant (5.5-5.8 Å) under uniform strain and the c/a ratio (0.96-1.05) under tetragonal distortion. The calculated phonon dispersion, cohesive and formation energies, and mechanical properties reveal that FeCrRuSi is stable with an EQH structure. Importantly, the compound of interest has been prepared and is found to exist in an EQH type structure with the presence of some B2 disorder. Moreover, the thermodynamic properties, such as the thermal expansion coefficient α, the heat capacity C V , the Grüneisen constant γ, and the Debye temperature Θ D are calculated.
Clinically referred children and adolescents: fathers, family constellations, and other demographic factors.

PubMed

Phares, V; Lum, J J

1997-06-01

Investigated the likelihood that clinically referred youth have contact with their biological father. Family demographics such as family constellation, race/ethnicity, and socioeconomic status were also explored. Based on 356 consecutive therapy and assessment referrals to an outpatient clinic, slightly less than half (42.4%) of the children and adolescents referred due to psychological problems and more than half (67.8%) of the youth referred due to learning difficulties lived with both their biological mother and biological father. For those who did not live with both of their biological parents, 40.0% and 56.0%, respectively, had regular face-to-face contact with both biological parents. These figures suggest that, although the percentages of intact families are somewhat lower in treatment samples than in the general population or in a sample referred for learning difficulties, close to half of clinically referred youth continue to live with both of their biological parents. Future directions for the inclusion of fathers in clinical research are discussed.
Systematic analysis of protein turnover in primary cells.

PubMed

Mathieson, Toby; Franken, Holger; Kosinski, Jan; Kurzawa, Nils; Zinn, Nico; Sweetman, Gavain; Poeckel, Daniel; Ratnu, Vikram S; Schramm, Maike; Becher, Isabelle; Steidel, Michael; Noh, Kyung-Min; Bergamini, Giovanna; Beck, Martin; Bantscheff, Marcus; Savitski, Mikhail M

2018-02-15

A better understanding of proteostasis in health and disease requires robust methods to determine protein half-lives. Here we improve the precision and accuracy of peptide ion intensity-based quantification, enabling more accurate protein turnover determination in non-dividing cells by dynamic SILAC-based proteomics. This approach allows exact determination of protein half-lives ranging from 10 to >1000 h. We identified 4000-6000 proteins in several non-dividing cell types, corresponding to 9699 unique protein identifications over the entire data set. We observed similar protein half-lives in B-cells, natural killer cells and monocytes, whereas hepatocytes and mouse embryonic neurons show substantial differences. Our data set extends and statistically validates the previous observation that subunits of protein complexes tend to have coherent turnover. Moreover, analysis of different proteasome and nuclear pore complex assemblies suggests that their turnover rate is architecture dependent. These results illustrate that our approach allows investigating protein turnover and its implications in various cell types.
An interprofessional educational approach to oral health care in the geriatric population.

PubMed

Bonwell, Patricia Brown; Parsons, Pamela L; Best, Al M; Hise, Sabrina

2014-01-01

An interprofessional educational approach was used to provide five in-service training sessions for all direct health care providers in a long-term care facility, and one half-day seminar/live webinar for community-licensed health care professionals. Content included presentations by five disciplines: (a) periodontist: oral-systemic relationship, (b) oral pathologist: oral pathology, (c) pharmacist: oral health-pharmacological link, (d) dietitian: oral health-dietary link, and (e) occupational therapist: providing and practicing proper oral hygiene. Significant improvement in posttest scores for the five in-service training sessions and the half-day seminar/live webinar was revealed in t-test results, representing an increase in knowledge gained. Approximately 80% of the 145 participants indicated that they would make a change in patient care. Findings indicate that the in-service training sessions and half-day seminar/live webinar supported development of the geriatric work force by utilizing an interprofessional educational approach which will assist in meeting the oral health care needs of the geriatric population.
Coral settlement onto Halimeda opuntia: a fatal attraction to an ephemeral substrate?

NASA Astrophysics Data System (ADS)

Nugues, Maggy M.; Szmant, Alina M.

2006-11-01

Degraded reefs with a high abundance of macroalgae usually also have low densities of coral recruits. Few studies, however, have examined whether these algae affect coral larval settlement. This study demonstrates, experimentally, that larvae of the Caribbean coral Favia fragrum can settle on the green alga Halimeda opuntia even when another substrate more suitable for settlement is present. Larval settlement onto experimental substrates was quantified under three treatments: rubble only, rubble plus plastic algal mimic, and rubble plus live H. opuntia. Similar total larval settlement was observed in all treatments. No larvae settled on the algal mimic, but total settlement was similar on the rubble in the first two treatments, showing that the rubble alone offered sufficient substrate for high settlement success. About half the larvae in the live algal treatment settled on H. opuntia instead of on the rubble, showing that larvae did not reject this substrate as they did the algal mimic. This result raises the possibility that corals will settle on some macroalgae when their abundance is high. Most macroalgae, including H. opuntia, are ephemeral substrates unsuitable for post-settlement survival. Such unexpected settlement may therefore have significant consequences for coral recruitment success on algal-dominated reefs.
The effect of maternal substance abuse on the cost of neonatal care.

PubMed

Norton, E C; Zarkin, G A; Calingaert, B; Bradley, C J

1996-01-01

This study addresses the effect of maternal substance abuse on the cost of neonatal care in a sample of all singleton live births in Maryland in 1991. Most other cost studies have analyzed data from only one hospital; we analyzed data from 54 hospitals and therefore can control for individual hospital effects and correlation of observations within hospitals. We find that maternal drug abuse has a significant positive effect on total hospital charges, length of stay, and average daily charges, with the increase in length of stay being proportionally greater than the increase in average daily charges. Maternal alcohol abuse also has a positive effect on hospital charges and length of stay, but the effects are not statistically significant. About half the effect of drug abuse on total charges works indirectly through premature birth and other comorbidities.
Short Lived Fission Product Yield Measurements in 235U, 238U and 239Pu

NASA Astrophysics Data System (ADS)

Silano, Jack; Tonchev, Anton; Tornow, Werner; Krishichayan, Fnu; Finch, Sean; Gooden, Matthew; Wilhelmy, Jerry

2017-09-01

Yields of short lived fission products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about the fission process. Knowledge of short lived FPYs would contribute to existing data on longer lived FPY mass and charge distributions. Of particular interest are the relative yields between the ground states and isomeric states of FPYs since these isomeric ratios can be used to determine the angular momentum of the fragments. Over the past five years, a LLNL-TUNL-LANL collaboration has made precision measurements of FPYs from quasi-monoenergetic neutron induced fission of 235U, 238U and 239Pu. These efforts focused on longer lived FPYs, using a well characterized dual fission chamber and several days of neutron beam exposure. For the first time, this established technique will be applied to measuring short lived FPYs, with half lives of minutes to less than an hour. A feasibility study will be performed using irradiation times of < 1 hour, improving the sensitivity to short lived FPYs by limiting the buildup of long lived isotopes. Results from this exploratory study will be presented, and the implications for isomeric ratio measurements will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.
Amino acid racemization on Mars: implications for the preservation of biomolecules from an extinct martian biota

NASA Technical Reports Server (NTRS)

Bada, J. L.; McDonald, G. D.; Miller, S. L. (Principal Investigator)

1995-01-01

Using kinetic data, we have estimated the racemization half-lives and times for total racemization of amino acids under conditions relevant to the surface of Mars. Amino acids from an extinct martian biota maintained in a dry, cold (<250 K) environment would not have racemized significantly over the lifetime of the planet. Racemization would have taken place in environments where liquid water was present even for time periods of only a few million years following biotic extinction. The best preservation of both amino acid homochirality and nucleic acid genetic information associated with extinct martian life would be in the polar regions.
SIBLING CONFLICTS IN FULL- AND HALF-SIBLING HOUSEHOLDS IN THE UK.

PubMed

Tanskanen, Antti O; Danielsbacka, Mirkka; Jokela, Markus; Rotkirch, Anna

2017-01-01

Sibling relations are by nature ambivalent with high levels of both altruistic helping and competition. Higher relatedness is often assumed to reduce the occurrence of conflicts between siblings, but evidence of this has been scarce and mixed. Siblings typically compete over resources and parental attention, and parental constellations vary with sibship types. Since full-siblings compete over the same two biological parents, while half-siblings have only one shared biological parent and often a higher number of parents overall, it is hypothesized that conflicts are more common between full- than half-siblings. This study tested this assumption using the British Millennium Cohort Study (n=7527 children at age 11). Conflicts were measured as children's reports of how much siblings picked on and hurt each other. Households with full-siblings only, maternal half-siblings only, and both full- and maternal half-siblings were compared. The results show that children who were living with only their full-siblings were more likely to experience sibling conflicts compared with children living with their maternal half-siblings only. This was the case also after controlling for several potentially confounding variables. The results suggest that differential access to parental resources of available biological and step-parents may explain the higher amount of sibling conflict between full- compared with maternal half-siblings.
Measurement of the half-life of {sup 198}Au in a nonmetal: High-precision measurement shows no host-material dependence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodwin, J. R.; Nica, N.; Iacob, V. E.

2010-10-15

We have measured the half-life of the {beta}{sup -} decay of {sup 198}Au to be 2.6948(9) d, with the nuclide sited in an insulating environment. Comparing this result with the half-life we measured previously with a metallic environment, we find the half-lives in both environments to be the same within 0.04%, thus contradicting a prediction that screening from a ''plasma'' of quasifree electrons in a metal increases the half-life by as much as 7%.
Importance of neonatal FcR in regulating the serum half-life of therapeutic proteins containing the Fc domain of human IgG1: a comparative study of the affinity of monoclonal antibodies and Fc-fusion proteins to human neonatal FcR.

PubMed

Suzuki, Takuo; Ishii-Watabe, Akiko; Tada, Minoru; Kobayashi, Tetsu; Kanayasu-Toyoda, Toshie; Kawanishi, Toru; Yamaguchi, Teruhide

2010-02-15

The neonatal FcR (FcRn) binds to the Fc domain of IgG at acidic pH in the endosome and protects IgG from degradation, thereby contributing to the long serum half-life of IgG. To date, more than 20 mAb products and 5 Fc-fusion protein products have received marketing authorization approval in the United States, the European Union, or Japan. Many of these therapeutic proteins have the Fc domain of human IgG1; however, the serum half-lives differ in each protein. To elucidate the role of FcRn in the pharmacokinetics of Fc domain-containing therapeutic proteins, we evaluated the affinity of the clinically used human, humanized, chimeric, or mouse mAbs and Fc-fusion proteins to recombinant human FcRn by surface plasmon resonance analysis. The affinities of these therapeutic proteins to FcRn were found to be closely correlated with the serum half-lives reported from clinical studies, suggesting the important role of FcRn in regulating their serum half-lives. The relatively short serum half-life of Fc-fusion proteins was thought to arise from the low affinity to FcRn. The existence of some mAbs having high affinity to FcRn and a short serum half-life, however, suggested the involvement of other critical factor(s) in determining the serum half-life of such Abs. We further investigated the reason for the relatively low affinity of Fc-fusion proteins to FcRn and suggested the possibility that the receptor domain of Fc-fusion protein influences the structural environment of the FcRn binding region but not of the FcgammaRI binding region of the Fc domain.
Does Co-residence with Adult Children Associate with Better Psychological Well-being among the Oldest Old in China?

PubMed Central

WANG, Jinfeng; CHEN, Tianyong; HAN, Buxin

2014-01-01

Objectives Embedded in a traditional culture where filial piety was honored, living with adult children once had been the most prevalent living arrangement and the best option for Chinese elderly people. This study examined whether co-residence with adult children would be still beneficial to the psychological well-being (PWB) among the oldest old (aged 80 and above) in China today. Method Using data from the fifth wave of the Chinese Longitudinal Healthy Longevity Survey conducted in 2008, the authors examined living arrangements among the total sample (n = 12,213) and the association between living arrangement and PWB among a sub-sample (n = 7,037) of respondents with normal cognition. Results 1) More than half (67.1%) of the unmarried oldest old reported being co-resided with their children; while for the married oldest old, the majority of the respondents (62.4%) lived with a spouse only. 2) For the widowed, co-residence with adult children was associated with better PWB compared to living along; but for the married, co-residence did not bring additional benefits to the PWB. 3) Co-residence of the widowed and children was associated with better life satisfaction compared to living with a spouse only, while it was associated with lower emotional well-being compared to living with a spouse (with or without a child). Conclusion These findings suggest that living arrangements of Chinese oldest old are partially getting westernized, and the majority of them adapt it well. Government programs need to be developed to assist the Chinese oldest old (especially widowed) to live independently. PMID:24053437
[Knowledge and attitudes of the population about the living wills].

PubMed

Angel-López-Rey, Esther; Romero-Cano, Marta; Tébar-Morales, Juan Pablo; Mora-García, Cristina; Fernández-Rodríguez, Olga

2008-01-01

To evaluate knowledge of living wills and attitudes to these documents in the populations of two basic health areas in Toledo (Spain). We performed a descriptive, cross-sectional study in primary care centers. Participants consisted of the populations of two basic health areas selected by systematic stratified sampling. Inclusion criteria comprised age between 18 and 80 years, and absence of mental or terminal illnesses. The participants were contacted by telephone before a personal interview was carried out. Data on demographic variables and knowledge of living wills and attitudes to these documents were recorded. A total of 395 participants were interviewed (58% women) with a mean age of 46.22 years (SD: 17.13). The vast majority (88.6%) were unaware of living wills, with no significant differences in sex or religious beliefs. Most (67.8%) would sign a living will in the case of terminal illness whereas 56.3% would sign at the present moment, with no significant differences in sex or religious beliefs. More than half of the men (57.5%) would agree to modify the living will if requested by relatives versus 42.6% of the women. More than three-quarters (76.2%) believed that information on living wills was insufficient. One-third (34.5%) would allow a relative's organs to be donated even without the relative leaving express wishes, while 49.2% would donate their own organs. There was a huge lack of awareness on living wills in our population, which nevertheless proved to be highly receptive to, and in agreement with, the implications of these documents after receiving information on the topic.
Seasonal growth and duration of the parasitic life stage of the landlocked sea lamprey (Petromyzon marinus)

USGS Publications Warehouse

Bergstedt, Roger A.; Swink, William D.

1995-01-01

We used lengths and weights of 2367 live parasitic-phase sea lampreys (Petromyzon marinus) collected from Lake Huron, 1984–1990, to calculate their mean size at half-month intervals. Growth in weight was linear during June through September; increments averaged 11.1 g per half month. Growth increased sharply in October to several times the summer rate. We speculate that the increase in growth in October is explained partly by water temperature and partly by an increase in appetite related to the onset of gonadal development. The greater compression of biomass accumulation in autumn than has been previously demonstrated better explains the autumn pulse of sea lamprey induced host mortality. Based on the seasonal pattern of growth and on recaptures of marked sea lampreys, we conclude that landlocked individuals grow to adult size and mature in one parasitic growth year. Regressions of weight (grams) on total length (millimetres) differed significantly among months, and the season of collection must be considered in predicting weight from length.
Time–motion analysis and physiological data of elite under‐19‐year‐old basketball players during competition

PubMed Central

Abdelkrim, Nidhal Ben; Fazaa, Saloua El; Ati, Jalila El

2007-01-01

The physical demands of modern basketball were assessed by investigating 38 elite under‐19‐year‐old basketball players during competition. Computerised time–motion analyses were performed on 18 players of various positions. Heart rate was recorded continuously for all subjects. Blood was sampled before the start of each match, at half time and at full time to determine lactate concentration. Players spent 8.8% (1%), 5.3% (0.8%) and 2.1% (0.3%) of live time in high “specific movements”, sprinting and jumping, respectively. Centres spent significantly lower live time competing in high‐intensity activities than guards (14.7% (1%) v 17.1% (1.2%); p<0.01) and forwards (16.6% (0.8%); p<0.05). The mean (SD) heart rate during total time was 171 (4) beats/min, with a significant difference (p<0.01) between guards and centres. Mean (SD) plasma lactate concentration was 5.49 (1.24) mmol/l, with concentrations at half time (6.05 (1.27) mmol/l) being significantly (p<0.001) higher than those at full time (4.94 (1.46) mmol/l). The changes to the rules of basketball have slightly increased the cardiac efforts involved during competition. The game intensity may differ according to the playing position, being greatest in guards. PMID:17138630
Estimating Surface/Subsurface Sediment Mixing in Karst Settings Using 7Be Isotopes

NASA Astrophysics Data System (ADS)

Wicks, C. M.; Paylor, R. L.; Bentley, S. J.

2018-03-01

This study shows that the cosmogenic radionuclide beryllium-7 can be used to track sediment movement through caves. The activities of beryllium-7 and cesium-137 were measured in two different karst settings at both surface and subsurface sites before and after storm runoff events. At one site, 7Be-enriched sediment was detected up to 1.5 km along a stream conduit after a moderate storm event; however, the activity of 137Cs was too variable to show a meaningful pattern. The percentages of surface sediment that was found ranged from 0 to 52% along the entire 3 km cave stream and from 33 to 52% along the upper 1.5 km. At the other site, as much as 96% of the sediment initially discharged at the spring during a storm event was fresh surface material that had traveled into and through the cave stream. Moreover, during the 4 day runoff event, approximately 23% of the total suspended sediment flux was estimated to originate from surface erosion with 78% being reworked sediment from within the cave. The data in this study show that cosmogenic radionuclides with multiyear half-lives are too long-lived to track sediment origins in the caves; whereas, 7Be with a 53.2 day half-life, can be used to track movement of sediment along cave streams.
Photolytic dehalogenation of disinfection byproducts in water by natural sunlight irradiation.

PubMed

Abusallout, Ibrahim; Hua, Guanghui

2016-09-01

The aqueous photolysis of halogenated disinfection byproducts (DBPs) by natural sunlight irradiation was studied to determine their photolytic dehalogenation kinetics. Total organic halogen analysis was used to quantify the dehalogenation extents of DBPs during outdoor photolysis experiments. Dichloroacetamide, chloral hydrate, chloroform, dichloroacetonitrile, monochloro-, monobromo-, dichloro-, dibromo-, and trichloroacetic acids were generally resistant to photolytic dehalogenation and showed less than 10% reduction after 6 h sunlight irradiation. Monoiodoacetic acid, tribromoacetic acid, bromoform, dibromoacetonitrile, and trichloronitromethane showed moderate to high dehalogenation degrees with half-lives of 4.0-19.3 h. Diiodoacetic acid, triiodoacetic acid, and iodoform degraded rapidly under the sunlight irradiation and exhibited half-lives of 5.3-10.2 min. In general, the photosensitive cleavage of carbon-halogen bonds of DBPs increased with increasing number of halogens (tri- > di- > mono-halogenated) and size of the substituted halogens (I > Br > Cl). Nitrate, nitrite, and pH had little impact on the photodehalogenation of DBPs under typical levels in surface waters. The presence of natural organic matter (NOM) inhibited the photodehalogenation of DBPs by light screening. The NOM inhibiting effects were more pronounced for the fast degrading iodinated DBPs. The results of this study improve our understanding about the photolytic dehalogenation of wastewater-derived DBPs in surface waters during water reuse. Published by Elsevier Ltd.

Laboratory studies of 2H evaporator scale dissolution in dilute nitric acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L.

The rate of 2H evaporator scale solids dissolution in dilute nitric acid has been experimentally evaluated under laboratory conditions in the SRNL shielded cells. The 2H scale sample used for the dissolution study came from the bottom of the evaporator cone section and the wall section of the evaporator cone. The accumulation rate of aluminum and silicon, assumed to be the two principal elemental constituents of the 2H evaporator scale aluminosilicate mineral, were monitored in solution. Aluminum and silicon concentration changes, with heating time at a constant oven temperature of 90 deg C, were used to ascertain the extent ofmore » dissolution of the 2H evaporator scale mineral. The 2H evaporator scale solids, assumed to be composed of mostly aluminosilicate mineral, readily dissolves in 1.5 and 1.25 M dilute nitric acid solutions yielding principal elemental components of aluminum and silicon in solution. The 2H scale dissolution rate constant, based on aluminum accumulation in 1.5 and 1.25 M dilute nitric acid solution are, respectively, 9.21E-04 ± 6.39E-04 min{sup -1} and 1.07E-03 ± 7.51E-05 min{sup -1}. Silicon accumulation rate in solution does track the aluminum accumulation profile during the first few minutes of scale dissolution. It however diverges towards the end of the scale dissolution. This divergence therefore means the aluminum-to-silicon ratio in the first phase of the scale dissolution (non-steady state conditions) is different from the ratio towards the end of the scale dissolution. Possible causes of this change in silicon accumulation in solution as the scale dissolution progresses may include silicon precipitation from solution or the 2H evaporator scale is a heterogeneous mixture of aluminosilicate minerals with several impurities. The average half-life for the decomposition of the 2H evaporator scale mineral in 1.5 M nitric acid is 12.5 hours, while the half-life for the decomposition of the 2H evaporator scale in 1.25 M nitric acid is 10.8 hours. Based on averaging the two half-lives from the 2H scale acid dissolution in 1.25 and 1.5 M nitric acid solutions, a reasonable half-live for the dissolution of 2H scales in dilute nitric acid is 11.7 ± 1.3 hours. The plant operational time for chemically cleaning (soaking) the 2H evaporator with dilute nitric acid is 32 hours. It therefore may require about 3 half-lives or less to completely dissolve most of the scales in the Evaporator pot which come into contact with the dilute nitric acid solution. On a mass basis, the Al-to-Si ratio for the scale dissolution in 1.5 M nitric acid averaged 1.30 ± 0.20 and averaged 1.18 ± 0.10 for the 2H scale dissolution in 1.25 M nitric acid. These aluminum-to-silicon ratios are in fairly good agreement with ratios from previous studies. Therefore, there is still more aluminum in the 2H evaporator scales than silicon which implies that there are no significant changes in scale properties which will exclude nitric acid as a viable protic solvent for aluminosilicate scale buildup dissolution from the 2H evaporator. Overall, the monitoring of the scale decomposition reaction in 1.25 and 1.5 M nitric acid may be better ascertained through the determination of aluminum concentration in solution than monitoring silicon in solution. Silicon solution chemistry may lead to partial precipitating of silicon with time as the scale and acid solution is heated.« less
Neutron capture on short-lived nuclei via the surrogate (d,pγ) reaction

NASA Astrophysics Data System (ADS)

Cizewski, Jolie A.; Ratkiewicz, Andrew

2018-05-01

Rapid r-process nucleosynthesis is responsible for the creation of about half of the elements heavier than iron. Neutron capture on shortlived nuclei in cold processes or during freeze out from hot processes can have a significant impact on the final observed r-process abundances. We are validating the (d,pγ) reaction as a surrogate for neutron capture with measurements on 95Mo targets and a focus on discrete transitions. The experimental results have been analyzed within the Hauser-Feshbach approach with non-elastic breakup of the deuteron providing a neutron to be captured. Preliminary results support the (d,pγ) reaction as a valid surrogate for neutron capture. We are poised to measure the (d,pγ) reaction in inverse kinematics with unstable beams following the development of the experimental techniques.
Geochemical behaviour of PM10 aerosol constituents under the influence of succeeding anticyclonic/cyclonic situations: case of Sfax City, southern Tunisia.

PubMed

Bahloul, Moez; Chabbi, Iness; Dammak, Rim; Amdouni, Ridha; Medhioub, Khaled; Azri, Chafai

2015-12-01

The present study investigates the geochemical behaviour of PM10 aerosol constituents (Cl, Na, Si, Al, Ca, Fe, Mg, Mn, Pb, Zn, S) at Sfax City (Tunisia) under succeeding meteorological conditions, including short-lived anticyclonic, cyclonic and prolonged anticyclonic situations. The results revealed daily total concentrations fluctuating between 4.07 and 88.51 μg/m(3). The highest level recorded was noted to occur under the effect of the short-lived anticyclonic situation characterized by low wind speeds. It was 1.5 times higher than those recorded during cyclonic and long-lived anticyclonic situations characterized by moderate to high wind speeds. During the cyclonic situation, the marked increase of (Na and Cl) concentrations is associated with relatively high sea wind speeds (6 to 9 m/s), which are in turn responsible for a slight increase of crustal elements such as Al, Ca, Si, Fe and Mg, by the entrainment in the air of dust from roads and undeveloped areas. During the two anticyclonic situations, the simultaneous increase (due to communal transport) of crustal (Ca, Si, Al, Fe, Mg) and man-made (Mn, S, Pb, Zn) elements was noted to be associated with the dominance of terrigenious wind flows with speeds varying between 1.5 and 4 m/s. However, the significant contribution rates observed for Cl under the prevalence of such winds as compared to other crustal elements such as Fe suggested the influence of the sebkhas of Southern Tunisia.
An analysis of state legislation on community trails.

PubMed

Eyler, Amy; Lankford, Tina; Chriqui, Jamie; Evenson, Kelly R; Kruger, Judy; Tompkins, Nancy; Voorhees, Carolyn; Zieff, Susan; Aytur, Semra; Brownson, Ross

2010-03-01

Trails provide opportunities for recreation, transportation and activity. The purpose of this article is to describe state legislation related to community trails, to analyze legislation content, and to evaluate legislation on inclusion of evidence-informed elements. State trail legislation from 2001 to 2008 was identified using online legislative databases. An analysis of evidence-informed elements included in the legislation was conducted. These elements included: funding, liability, accessibility, connectivity, and maintenance. Of the total 991 trail bills, 516 (52.0%) were appropriations bills, of which 167 (32.2%) were enacted. We analyzed 475 (48%) nonappropriation trail bills of which 139 (29.3%) were enacted. The percentage of enactment of appropriations bills decreased over time while enactment of nonappropriations trail bills increased. Over half of the nonappropriations trail bills included at least 1 evidence-informed element, most commonly funding. Few bills contained liability, connectivity, accessibility, or maintenance. There is opportunity for providing evidence-informed information to policy-makers to potentially influence bill content. The number of bills with a funding element demonstrates that fiscal support for trails is an important policy lever that state legislatures may use to support trails. Lastly, trails should be considered in over-all state-level physical activity legislation to provide opportunities for communities to be active.
Mechanical end joint system for structural column elements

NASA Technical Reports Server (NTRS)

Bush, H. G.; Wallsom, R. E. (Inventor)

1982-01-01

A mechanical end joint system, useful for the transverse connection of strut elements to a common node, comprises a node joint half with a semicircular tongue and groove, and a strut joint half with a semicircular tongue and groove. The two joint halves are engaged transversely and the connection is made secure by the inherent physical property characteristics of locking latches and/or by a spring-actioned shaft. A quick release mechanism provides rapid disengagement of the joint halves.
Fungal Infections

MedlinePlus

... primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful. Some fungi reproduce through tiny spores ...
A combined application of boundary-element and Runge-Kutta methods in three-dimensional elasticity and poroelasticity

NASA Astrophysics Data System (ADS)

Igumnov, Leonid; Ipatov, Aleksandr; Belov, Aleksandr; Petrov, Andrey

2015-09-01

The report presents the development of the time-boundary element methodology and a description of the related software based on a stepped method of numerical inversion of the integral Laplace transform in combination with a family of Runge-Kutta methods for analyzing 3-D mixed initial boundary-value problems of the dynamics of inhomogeneous elastic and poro-elastic bodies. The results of the numerical investigation are presented. The investigation methodology is based on direct-approach boundary integral equations of 3-D isotropic linear theories of elasticity and poroelasticity in Laplace transforms. Poroelastic media are described using Biot models with four and five base functions. With the help of the boundary-element method, solutions in time are obtained, using the stepped method of numerically inverting Laplace transform on the nodes of Runge-Kutta methods. The boundary-element method is used in combination with the collocation method, local element-by-element approximation based on the matched interpolation model. The results of analyzing wave problems of the effect of a non-stationary force on elastic and poroelastic finite bodies, a poroelastic half-space (also with a fictitious boundary) and a layered half-space weakened by a cavity, and a half-space with a trench are presented. Excitation of a slow wave in a poroelastic medium is studied, using the stepped BEM-scheme on the nodes of Runge-Kutta methods.
Characterization of Mesoscale Convective Systems by Means of Composite Radar Reflectivity Data

NASA Technical Reports Server (NTRS)

Geerts, Bart

1998-01-01

A mesoscale convective system (MCS) is broadly defined as a cloud and precipitation system of mesoscale dimensions (often too large for most aircraft to circumnavigate) with deep-convective activity concentrated in at least part of the MCS, or present during part of its evolution. A large areal fraction of MCSs is stratiform in nature, yet estimates from MCSs over the Great Plains, the Southeast, and tropical waters indicate that at least half of the precipitation is of convective origin. The presence of localized convection is important, because within convective towers cloud particles and hydrometeors are carried upward towards the cloud top. Ice crystals then move over more stratiform regions, either laterally, or through in situ settling over decaying and spreading convection. These ice crystals then grow to precipitation-size particles in mid- to upper tropospheric mesoscale updrafts. The convective portion of a MCS is often a more or less continuous line of thunderstorms, and may be either short-lived or long-lived. Geerts (1997) presents a preliminary climatology of MCSs in the southeastern USA, using just one year of composite digital radar reflectivity data. In this study MCSs are identified and characterized by means of visual inspection of animated images. A total of 398 MCSs were identified. In the warm season MCSs were found to be about twice as frequent as in the cold season. The average lifetime and maximum length of MCSs are 9 hours, and 350 km, respectively, but some MCSs are much larger and more persistent. In the summer months small and short-lived MCSs are relatively more common, whereas in winter larger and longer-lived systems occur more frequently. MCSs occur more commonly in the afternoon, in phase with thunderstorm activity, but the amplitude of the diurnal cycle is small compared to that of observed thunderstorms. It is estimated that in the Southeast more than half of all precipitation and severe weather results from MCSs.
Selenium and other elements in juvenile striped bass from the San Joaquin Valley and San Francisco Estuary, California

USGS Publications Warehouse

Saiki, Michael K.; Palawski, Donald U.

1990-01-01

Concentrations of selenium and other trace elements were determined in 55 whole body samples of juvenile anadromous striped bass (Morone saxatilis) from the San Joaquin Valley and San Francisco Estuary, California. The fish (≤1 yr old—the predominant life stage in the San Joaquin Valley) were collected in September–December 1986 from 19 sites in the Valley and 3 sites in the Estuary, and analyzed for the following elements: aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), vanadium (V), and zinc (Zn). When compared to concentrations in whole freshwater fish measured by surveys from other waters, a few samples contained higher levels, of As, Cd, Cu, Pb, and Se. The median concentrations of Al, As, Cu, Fe, Mg, Se, and Sr also differed significantly (P⩽0.05) among sites. However, only Se concentrations were highest (up to 7.9 μg/g dry weight) in samples from Valley sites exposed to agricultural subsurface (tile) drainwater; concentrations were lower in samples collected elsewhere. Water quality variables—especially those strongly influenced by tile drainwater (conductivity, total dissolved solids, total alkalinity, and total hardness)—were also significantly correlated (P⩽0.05) with Se concentrations in fish. Selenium concentrations in striped bass from the Estuary were only one-fourth to one-half the concentrations measured in the most contaminated fish from the San Joaquin River.
Degradation of cyflumetofen and formation of its main metabolites in soils and water/sediment systems.

PubMed

Wang, Pingping; Li, Minmin; Liu, Xingang; Xu, Jun; Dong, Fengshou; Wu, Xiaohu; Zheng, Yongquan

2016-11-01

Cyflumetofen is a novel benzoyl acetonitrile acaricide without cross-resistance to existing acaricides. In the present study, for the first time, the environmental behaviors of cyflumetofen and the formation of its main metabolites, 2-(trifluoromethyl) benzoic acid (B-1) and 2-(trifluoromethyl) benzamide (B-3), in the four types of soil (black soil, sierozem, krasnozem, and fluvo-aquic soil) and three types of water/sediment systems (Northeast Lake, Hunan paddy field, and Beijng Shangzhuang reservoir) under aerobic and anaerobic conditions were investigated. The degradation dynamics of cyflumetofen followed first-order kinetics. Under aerobic environment, the half-lives of cyflumetofen in black soil, sierozem, krasnozem and fluvo-aquic soil were 11.2, 10.3, 12.4, and 11.4 days. Under water anaerobic conditions, the half-lives were 13.1, 10.8, 13.9, and 12.8 days. The effects of different conditions and soil types on the half-lives of cyflumetofen were studied using a one-way ANOVA test with post hoc comparison (Tukey's test). It was shown that the differences in black soil, krasnozem, and fluvo-aquic soil were extremely significant difference (p < 0.05) under aerobic and water anaerobic conditions. And there is a strong correlation between half-life and pH. Under aerobic environment, the half-lives of cyflumetofen in Northeast Lake, Hunan paddy field, and Beijng Shangzhuang reservoir were 15.4, 16.9, and 15.1 days. Under anaerobic conditions, they were 16.5, 17.3, and 16.1 days. Analyzing the differences of the half-lives under aerobic and anaerobic conditions, the difference only in Shangzhuang reservoir was extremely significant difference (p < 0.05). In soils, cyflumetofen degraded metabolites B-1 and B-3, from the first day 0.24 % B-1 was generated, while, only very low levels of B-3 generated at the same time. As time increased, B-3 gradually increased, cyflumetofen reduced gradually. Until 100 days, there were about 3.5 % B-1 and B-3 in the soils. In the water/sediment systems, from the first day, it degraded into B-1 in the sediment, and in the water mainly degraded into B-3.
Dasheng: a recently amplified nonautonomous long terminal repeat element that is a major component of pericentromeric regions in rice.

PubMed

Jiang, Ning; Bao, Zhirong; Temnykh, Svetlana; Cheng, Zhukuan; Jiang, Jiming; Wing, Rod A; McCouch, Susan R; Wessler, Susan R

2002-07-01

A new and unusual family of LTR elements, Dasheng, has been discovered in the genome of Oryza sativa following database searches of approximately 100 Mb of rice genomic sequence and 78 Mb of BAC-end sequence information. With all of the cis-elements but none of the coding domains normally associated with retrotransposons (e.g., gag, pol), Dasheng is a novel nonautonomous LTR element with high copy number. Over half of the approximately 1000 Dasheng elements in the rice genome are full length (5.6-8.6 kb), and 60% are estimated to have amplified in the past 500,000 years. Using a modified AFLP technique called transposon display, 215 elements were mapped to all 12 rice chromosomes. Interestingly, more than half of the mapped elements are clustered in the heterochromatic regions around centromeres. The distribution pattern was further confirmed by FISH analysis. Despite clustering in heterochromatin, Dasheng elements are not nested, suggesting their potential value as molecular markers for these marker-poor regions. Taken together, Dasheng is one of the highest-copy-number LTR elements and one of the most recent elements to amplify in the rice genome.
Analysis of the costs of veterinary education and factors associated with financial stress among veterinary students in Australia.

PubMed

Gregory, K P; Matthew, S M; Baguley, J A

2018-01-01

To investigate the course-related and other costs involved in obtaining a veterinary education in Australia and how these costs are met. The study also aimed to identify sociodemographic and course-related factors associated with increased financial stress. Students from seven Australian veterinary schools were surveyed using an online questionnaire. A total of 443 students participated (response rate 17%). Responses to survey items relating to finances, employment and course-related costs were compared with sociodemographic factors and prior research in the area of student financial stress. Respondents reported spending a median of A$300 per week on living costs and a median of A$2,000 per year on course-related expenses. Over half of respondents received the majority of their income from their parents or Youth Allowance (56%). A similar proportion (55%) reported that they needed to work to meet basic living expenses. Circumstances and sociodemographic factors linked to perceived financial stress included requiring additional finances to meet unexpected costs during the course; sourcing additional finances from external loans; an expected tuition debt at graduation over A$40,000; being 22 years or older; working more than 12 hours per week; living costs above A$300 per week; and being female. The costs involved in obtaining a veterinary education in Australia are high and over half of respondents are reliant on parental or Government income support. Respondents with certain sociodemographic profiles are more prone to financial stress. These findings may have implications for the psychological health, diversity and career plans of veterinary students in Australia. © 2017 Australian Veterinary Association.
Ethnobiology in the city: Embracing the urban ecological moment

Treesearch

Marla R. Emery; Patrick T. Hurley

2016-01-01

More than half the world's human population resides in cities (United Nations Economic and Social Affairs Population Division 2015)1. Unpacking this singular statistic, it becomes clear that people come to live in urban environments via numerous routes. Some have lived in cities all their lives and are descendants of city dwellers. In other...
Cultivating the Social, Emotional, and Inner Lives of Children and Teachers

ERIC Educational Resources Information Center

Lantieri, Linda

2012-01-01

Adults often feel the pressures of today's fast-paced world and think back longingly to a time when their daily lives were a lot less hectic. One third of the respondents in one study report that they are living with "extreme stress" and almost half feel that the level of stress in their lives has increased over the past five years. Children are…
77 FR 22217 - Drawbridge Operation Regulation; Snohomish River and Steamboat Slough, Everett and Marysville, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-13

.... This deviation is necessary to accommodate the Total Health Events Heros Half Marathon scheduled for... Total Health Events Heros Half Marathon. The Heros Half Marathon is a benefit run for the St. Jude...
In vivo kinetic approach reveals slow SOD1 turnover in the CNS

PubMed Central

Crisp, Matthew J.; Mawuenyega, Kwasi G.; Patterson, Bruce W.; Reddy, Naveen C.; Chott, Robert; Self, Wade K.; Weihl, Conrad C.; Jockel-Balsarotti, Jennifer; Varadhachary, Arun S.; Bucelli, Robert C.; Yarasheski, Kevin E.; Bateman, Randall J.; Miller, Timothy M.

2015-01-01

Therapeutic strategies that target disease-associated transcripts are being developed for a variety of neurodegenerative syndromes. Protein levels change as a function of their half-life, a property that critically influences the timing and application of therapeutics. In addition, both protein kinetics and concentration may play important roles in neurodegeneration; therefore, it is essential to understand in vivo protein kinetics, including half-life. Here, we applied a stable isotope-labeling technique in combination with mass spectrometric detection and determined the in vivo kinetics of superoxide dismutase 1 (SOD1), mutation of which causes amyotrophic lateral sclerosis. Application of this method to human SOD1-expressing rats demonstrated that SOD1 is a long-lived protein, with a similar half-life in both the cerebral spinal fluid (CSF) and the CNS. Additionally, in these animals, the half-life of SOD1 was longest in the CNS when compared with other tissues. Evaluation of this method in human subjects demonstrated successful incorporation of the isotope label in the CSF and confirmed that SOD1 is a long-lived protein in the CSF of healthy individuals. Together, the results of this study provide important insight into SOD1 kinetics and support application of this technique to the design and implementation of clinical trials that target long-lived CNS proteins. PMID:26075819
In vivo kinetic approach reveals slow SOD1 turnover in the CNS.

PubMed

Crisp, Matthew J; Mawuenyega, Kwasi G; Patterson, Bruce W; Reddy, Naveen C; Chott, Robert; Self, Wade K; Weihl, Conrad C; Jockel-Balsarotti, Jennifer; Varadhachary, Arun S; Bucelli, Robert C; Yarasheski, Kevin E; Bateman, Randall J; Miller, Timothy M

2015-07-01

Therapeutic strategies that target disease-associated transcripts are being developed for a variety of neurodegenerative syndromes. Protein levels change as a function of their half-life, a property that critically influences the timing and application of therapeutics. In addition, both protein kinetics and concentration may play important roles in neurodegeneration; therefore, it is essential to understand in vivo protein kinetics, including half-life. Here, we applied a stable isotope-labeling technique in combination with mass spectrometric detection and determined the in vivo kinetics of superoxide dismutase 1 (SOD1), mutation of which causes amyotrophic lateral sclerosis. Application of this method to human SOD1-expressing rats demonstrated that SOD1 is a long-lived protein, with a similar half-life in both the cerebral spinal fluid (CSF) and the CNS. Additionally, in these animals, the half-life of SOD1 was longest in the CNS when compared with other tissues. Evaluation of this method in human subjects demonstrated successful incorporation of the isotope label in the CSF and confirmed that SOD1 is a long-lived protein in the CSF of healthy individuals. Together, the results of this study provide important insight into SOD1 kinetics and support application of this technique to the design and implementation of clinical trials that target long-lived CNS proteins.
Total suspended particulate matter and toxic elements indoors during cooking with yak dung

NASA Astrophysics Data System (ADS)

Kang, Shichang; Li, Chaoliu; Wang, Feiyue; Zhang, Qianggong; Cong, Zhiyuan

Many herders in the Tibetan Plateau still inherit the traditional lifestyle, including living in tents and burning yak dung for fuel. This short correspondence reports a pilot study on indoor air quality in the nomadic tents in the Nam Co region, inland Tibetan Plateau. The results showed very high concentrations of total suspended particles (TSP), averaging at 4.45 mg m -3 during the cooking/heating period (with daily value of 3.16 mg m -3). Elevated concentrations of toxic element Cd, As and Pb were also found within the tents, averaging 3.16 μg m -3, 35.00 μg m -3, and 81.39 μg m -3 for a day, respectively, which were not only far higher than those of WHO indoor air quality guidelines, but also more than 10 4-10 6 times higher than the outdoor air level in the Nam Co area. The study raises serious concerns over the health of Tibetan herders following their long-term exposure to the tent air.
Influence of ethacrynic acid on glutathione S-transferase pi transcript and protein half-lives in human colon cancer cells.

PubMed

Shen, H; Ranganathan, S; Kuzmich, S; Tew, K D

1995-10-12

Ethacrynic acid (EA) is a plant phenolic acid that is both an inhibitor and an inducer of glutathione S-transferase (GST) activity. To determine contributory factors in the increased GST activity caused by EA treatment, human colon carcinoma HT29 cells were compared with a cloned EA-resistant population (HT6-8) maintained in medium containing 72 microM EA. Several factors are involved in the increased expression of GST pi in HT6-8. For example, nuclear run-on experiments showed an approximately 2-fold increase in the rate of transcription of GST pi. In addition, the half-life of GST pi transcript was increased from 4.1 (wild type, HT29, HT4-1) to 8.4 hr. The half-life of GST pi protein was 1-2 hr in HT4-1 cells versus 8-9 hr in HT6-8 cells. When either human ovarian carcinoma cells (SKOV3) or human prostatic carcinoma cells (DU145) were treated with EA, the half-life of the GST pi transcript was also increased. The transcript half-lives of another thiol-metabolism enzyme, gamma-glutamylcysteine synthetase (gamma-GCS), and a phase II detoxification enzyme, dihydrodiol dehydrogenase (DDH), were also increased in HT6-8, SKOV3 and DU145 cells treated with EA. However, the half-lives of transcripts from "housekeeping genes," such as glyceraldehyde 3-phosphate dehydrogenase (G3PDH), beta-actin and beta-tubulin, were not changed in these cell lines following EA. Apparently, a number of coordinated factors are involved in EA-enhanced expression of GST pi and other detoxification enzymes.
Passive fault current limiting device

DOEpatents

Evans, Daniel J.; Cha, Yung S.

1999-01-01

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

Airborne particulate matter and spacecraft internal environments

NASA Technical Reports Server (NTRS)

Liu, Benjamin Y. H.; Rubow, Kenneth L.; Mcmurry, Peter H.; Kotz, Thomas J.; Russo, Dane

1991-01-01

Instrumentation, consisting of a Shuttle Particle Sampler (SPS) and a Shuttle Particle Monitor (SPM), has been developed to characterize the airborne particulate matter in the Space Shuttle cabin during orbital flight. The SPS size selectively collects particles in four size fractions (0-2.5, 2.5-10, 10-100, and greater than 100 microns) which are analyzed postflight for mass concentration and size distribution, elemental composition, and morphology. The SPM provides a continuous record of particle concentration through photometric light scattering. Measurements were performed onboard Columbia, OV-102, during the flight of STS-32 in January 1990. No significant changes were observed in the particle mass concentration, size distribution, or chemical composition in samples collected during flight-day 2 and flight-day 7. The total mass concentration was 56 microg/cu cm with approximately half of the particles larger than 100 microns. Elemental analysis showed that roughly 70 percent of the particles larger than 2.5 microns were carbonaceous with small amounts of other elements present. The SPM showed no temporal or spatial variation in particle mass concentration during the mission.
Passive fault current limiting device

DOEpatents

Evans, D.J.; Cha, Y.S.

1999-04-06

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.
Redox flow batteries having multiple electroactive elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei; Li, Liyu; Yang, Zhenguo

Introducing multiple redox reactions with a suitable voltage range can improve the energy density of redox flow battery (RFB) systems. One example includes RFB systems utilizing multiple redox pairs in the positive half cell, the negative half cell, or in both. Such RFB systems can have a negative electrolyte, a positive electrolyte, and a membrane between the negative electrolyte and the positive electrolyte, in which at least two electrochemically active elements exist in the negative electrolyte, the positive electrolyte, or both.
BioMetals: a historical and personal perspective.

PubMed

Silver, Simon

2011-06-01

Understanding of BioMetals developed basically from a starting point about 60 years ago to current mechanistic understanding of the biological behavior of many metal ions from protein structural and functional studies. Figure 1 shows a Biochemical Periodic Table, element by element, with requirements, roles and biochemistry of the specific ions indicated. With few exceptions, the biology is of the ions formed and not of the elemental state of each. Early BioMetals efforts defined nutritional growth needs for animals, plants and microbes for inorganic "macro-nutrients" such as magnesium, calcium, potassium, sodium, and phosphate and of "micronutrients" such as copper, iron, manganese and zinc. Surprises came early with regard to microbes, for example the finding that Escherichia coli (then and now the standard microbial model) grows happily in the apparent total absence of calcium, sodium, and chloride, which are certainly major animal nutrients. Some elements such as mercury and arsenic are never required by living cells, but are always toxic, often at very low levels. Therefore, the division into nutrient elements and toxic elements came soon. For most inorganic nutrients, excessive amounts can be toxic as well, for example for copper and iron.
Physical and chemical properties of pyrethroids.

PubMed

Laskowski, Dennis A

2002-01-01

The physical and chemical properties of the pyrethroids bifenthrin, cyfluthrin, cypermethrin (also zetacypermethrin), deltamethrin, esfenvalerate (also fenvalerate), fenpropathrin, lambda-cyhalothrin (also cyhalothrin), permethrin, and tralomethrin have been reviewed and summarized in this paper. Physical properties included molecular weight, octanol-water partition coefficient, vapor pressure, water solubility, Henry's law constant, fish biocencentration factor, and soil sorption, desorption, and Freundlich coefficients. Chemical properties included rates of degradation in water as a result of hydrolysis, photodecomposition, aerobic or anaerobic degradation by microorganisms in the absence of light, and also rates of degradation in soil incubated under aerobic or anaerobic conditions. Collectively, the pyrethroids display a highly nonpolar nature of low water solubility, low volatility, high octanol-water partition coefficients, and have high affinity for soil and sediment particulate matter. Pyrethroids have low mobility in soil and are sorbed strongly to the sediments of natural water systems. Although attracted to living organisms because of their nonpolar nature, their capability to bioconcentrate is mitigated by their metabolism and subsequent elimination by the organisms. In fish, bioconcentration factors (BCF) ranged from 360 and 6000. Pyrethroids in water solution tend to be stable at acid and neutral pH but [table: see text] become increasingly susceptible to hydrolysis at pH values beyond neutral. Exceptions at higher pH are bifenthrin (stable), esfenvalerate (stable), and permethrin (half-life, 240 d). Pyrethroids vary in susceptibility to sunlight. Cyfluthrin and tralomethrin in water had half-lives of 0.67 and 2.5 d; lambda-cyhalothrin, esfenvalerate, deltamethrin, permethrin, and cypermethrin were intermediate with a range of 17-110 d; and bifenthrin and fenpropathrin showed the least susceptibility with half-lives of 400 and 600 d, respectively. Pyrethroids on soil can also undergo photolysis, often at rates similar to that in water. Half-lives ranged from 5 to 170 d. [table: see text] Pyrethroids are degradable in soils with half-lives ranging from 3 to 96 d aerobically, and 5 to 430 d anaerobically. For those pyrethroids studied in water (cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, and lambda-cyhalothrin), aerobic and anaerobic degradation often continued at rates similar to that displayed in soil.
Severe 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) intoxication: kinetics and trials to enhance elimination in two patients.

PubMed

Geusau, Alexandra; Schmaldienst, Sabine; Derfler, Kurt; Päpke, Olaf; Abraham, Klaus

2002-06-01

In spring 1998, two women were diagnosed with severe 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) intoxication. Over the following 3 years, TCDD levels were monitored under various attempts to enhance its elimination, and the half-lives were evaluated. Olestra, a non-digestible, non-absorbable dietary fat substitute, was continuously administered to the patients either as pure substance or in potato-chips. Additionally, in the more severely contaminated patient, we studied whether low-density lipoprotein (LDL)-apheresis, an extracorporeal means of blood lipid elimination, was effective in reducing the TCDD body burden. The blood concentrations initially measured in spring 1998 were 144,000 pg/g blood fat in patient 1 and 26,000 pg/g in patient 2, the highest levels ever measured in adults. In March 2001, concentrations in blood fat were 35,900 and 9,500 pg/g, corresponding to overall elimination half-lives of 560 days (1.5 years) in patient 1 and 1050 days (2.9 years) in patient 2, which are considerably shorter than median values of 7-9 years reported for background and moderate exposure levels. Calculations of the TCDD half-lives and measurements of TCDD elimination via different routes allowed the calculation of an unidentified route of elimination, representing 78 and 62% of the overall elimination in patient 1 and 2, respectively, probably due to an induced hepatic metabolism caused by the high TCDD exposure. As previously reported, administration of olestra was found to be effective in increasing the fecal excretion of TCDD. Due to the short half-lives in our patients, the effect of olestra on the overall elimination was relatively small, but is expected to be much greater for 'normal' half-lives. LDL-apheresis was shown to eliminate TCDD, corresponding to the eliminated blood fat. When employed twice a week, the amount of TCDD excreted by this method was comparable to fecal excretion. In view of costs and time involved, LDL-apheresis does not seem to be justified for enhancement of TCDD elimination.
Prenatally fabricated autologous human living heart valves based on amniotic fluid derived progenitor cells as single cell source.

PubMed

Schmidt, Dörthe; Achermann, Josef; Odermatt, Bernhard; Breymann, Christian; Mol, Anita; Genoni, Michele; Zund, Gregor; Hoerstrup, Simon P

2007-09-11

A novel concept providing prenatally tissue engineered human autologous heart valves based on routinely obtained fetal amniotic fluid progenitors as single cell source is introduced. Fetal human amniotic progenitors were isolated from routinely sampled amniotic fluid and sorted using CD133 magnetic beads. After expansion and differentiation, cell phenotypes of CD133- and CD133+ cells were analyzed by immunohistochemistry and flowcytometry. After characterization, CD133- derived cells were seeded onto heart valve leaflet scaffolds (n=18) fabricated from rapidly biodegradable polymers, conditioned in a pulse duplicator system, and subsequently coated with CD133+ derived cells. After in vitro maturation, opening and closing behavior of leaflets was investigated. Neo-tissues were analyzed by histology, immunohistochemistry, and scanning electron microscopy (SEM). Extracellular matrix (ECM) elements and cell numbers were quantified biochemically. Mechanical properties were assessed by tensile testing. CD133- derived cells demonstrated characteristics of mesenchymal progenitors expressing CD44 and CD105. Differentiated CD133+ cells showed features of functional endothelial cells by eNOS and CD141 expression. Engineered heart valve leaflets demonstrated endothelialized tissue formation with production of ECM elements (GAG 80%, HYP 5%, cell number 100% of native values). SEM showed intact endothelial surfaces. Opening and closing behavior was sufficient under half of systemic conditions. The use of amniotic fluid as single cell source is a promising low-risk approach enabling the prenatal fabrication of heart valves ready to use at birth. These living replacements with the potential of growth, remodeling, and regeneration may realize the early repair of congenital malformations.
Short-lived non-coding transcripts (SLiTs): Clues to regulatory long non-coding RNA.

PubMed

Tani, Hidenori

2017-03-22

Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs). Although the importance of lncRNAs has been documented in previous reports, the biological and physiological functions of lncRNAs remain largely unknown. The role of lncRNAs seems an elusive problem. Here, I propose a clue to the identification of regulatory lncRNAs. The key point is RNA half-life. RNAs with a long half-life (t 1/2 > 4 h) contain a significant proportion of ncRNAs, as well as mRNAs involved in housekeeping functions, whereas RNAs with a short half-life (t 1/2 < 4 h) include known regulatory ncRNAs and regulatory mRNAs. This novel class of ncRNAs with a short half-life can be categorized as Short-Lived non-coding Transcripts (SLiTs). I consider that SLiTs are likely to be rich in functionally uncharacterized regulatory RNAs. This review describes recent progress in research into SLiTs.
Acylated heptapeptide binds albumin with high affinity and application as tag furnishes long-acting peptides

NASA Astrophysics Data System (ADS)

Zorzi, Alessandro; Middendorp, Simon J.; Wilbs, Jonas; Deyle, Kaycie; Heinis, Christian

2017-07-01

The rapid renal clearance of peptides in vivo limits this attractive platform for the treatment of a broad range of diseases that require prolonged drug half-lives. An intriguing approach for extending peptide circulation times works through a `piggy-back' strategy in which peptides bind via a ligand to the long-lived serum protein albumin. In accordance with this strategy, we developed an easily synthesized albumin-binding ligand based on a peptide-fatty acid chimera that has a high affinity for human albumin (Kd=39 nM). This ligand prolongs the elimination half-life of cyclic peptides in rats 25-fold to over seven hours. Conjugation to a peptide factor XII inhibitor developed for anti-thrombotic therapy extends the half-life from 13 minutes to over five hours, inhibiting coagulation for eight hours in rabbits. This high-affinity albumin ligand could potentially extend the half-life of peptides in human to several days, substantially broadening the application range of peptides as therapeutics.
Perfluorooctane Sulfonate Plasma Half-Life Determination and Long-Term Tissue Distribution in Beef Cattle (Bos taurus).

PubMed

Lupton, Sara J; Dearfield, Kerry L; Johnston, John J; Wagner, Sarah; Huwe, Janice K

2015-12-30

Perfluorooctane sulfonate (PFOS) is used in consumer products as a surfactant and is found in industrial and consumer waste, which ends up in wastewater treatment plants (WWTPs). PFOS does not breakdown during WWTP processes and accumulates in the biosolids. Common practices include application of biosolids to pastures and croplands used for feed, and as a result, animals such as beef cattle are exposed to PFOS. To determine plasma and tissue depletion kinetics in cattle, 2 steers and 4 heifers were dosed with PFOS at 0.098 mg/kg body weight and 9.1 mg/kg, respectively. Plasma depletion half-lives for steers and heifers were 120 ± 4.1 and 106 ± 23.1 days, respectively. Specific tissue depletion half-lives ranged from 36 to 385 days for intraperitoneal fat, back fat, muscle, liver, bone, and kidney. These data indicate that PFOS in beef cattle has a sufficiently long depletion half-life to permit accumulation in edible tissues.
Theoretical predictions for α -decay chains of 118 290 -298Og isotopes using a finite-range nucleon-nucleon interaction

NASA Astrophysics Data System (ADS)

Ismail, M.; Adel, A.

2018-04-01

The α -decay half-lives of the recently synthesized superheavy nuclei (SHN) are investigated by employing the density dependent cluster model. A realistic nucleon-nucleon (NN ) interaction with a finite-range exchange part is used to calculate the microscopic α -nucleus potential in the well-established double-folding model. The calculated potential is then implemented to find both the assault frequency and the penetration probability of the α particle by means of the Wentzel-Kramers-Brillouin (WKB) approximation in combination with the Bohr-Sommerfeld quantization condition. The calculated values of α -decay half-lives of the recently synthesized Og isotopes and its decay products are in good agreement with the experimental data. Moreover, the calculated values of α -decay half-lives have been compared with those values evaluated using other theoretical models, and it was found that our theoretical values match well with their counterparts. The competition between α decay and spontaneous fission is investigated and predictions for possible decay modes for the unknown nuclei 118 290 -298Og are presented. We studied the behavior of the α -decay half-lives of Og isotopes and their decay products as a function of the mass number of the parent nuclei. We found that the behavior of the curves is governed by proton and neutron magic numbers found from previous studies. The proton numbers Z =114 , 116, 108, 106 and the neutron numbers N =172 , 164, 162, 158 show some magic character. We hope that the theoretical prediction of α -decay chains provides a new perspective to experimentalists.
Eawag-Soil in enviPath: a new resource for exploring regulatory pesticide soil biodegradation pathways and half-life data.

PubMed

Latino, Diogo A R S; Wicker, Jörg; Gütlein, Martin; Schmid, Emanuel; Kramer, Stefan; Fenner, Kathrin

2017-03-22

Developing models for the prediction of microbial biotransformation pathways and half-lives of trace organic contaminants in different environments requires as training data easily accessible and sufficiently large collections of respective biotransformation data that are annotated with metadata on study conditions. Here, we present the Eawag-Soil package, a public database that has been developed to contain all freely accessible regulatory data on pesticide degradation in laboratory soil simulation studies for pesticides registered in the EU (282 degradation pathways, 1535 reactions, 1619 compounds and 4716 biotransformation half-life values with corresponding metadata on study conditions). We provide a thorough description of this novel data resource, and discuss important features of the pesticide soil degradation data that are relevant for model development. Most notably, the variability of half-life values for individual compounds is large and only about one order of magnitude lower than the entire range of median half-life values spanned by all compounds, demonstrating the need to consider study conditions in the development of more accurate models for biotransformation prediction. We further show how the data can be used to find missing rules relevant for predicting soil biotransformation pathways. From this analysis, eight examples of reaction types were presented that should trigger the formulation of new biotransformation rules, e.g., Ar-OH methylation, or the extension of existing rules, e.g., hydroxylation in aliphatic rings. The data were also used to exemplarily explore the dependence of half-lives of different amide pesticides on chemical class and experimental parameters. This analysis highlighted the value of considering initial transformation reactions for the development of meaningful quantitative-structure biotransformation relationships (QSBR), which is a novel opportunity offered by the simultaneous encoding of transformation reactions and corresponding half-lives in Eawag-Soil. Overall, Eawag-Soil provides an unprecedentedly rich collection of manually extracted and curated biotransformation data, which should be useful in a great variety of applications.
Studies on crude oil removal from pebbles by the application of biodiesel.

PubMed

Xia, Wen-xiang; Xia, Yan; Li, Jin-cheng; Zhang, Dan-feng; Zhou, Qing; Wang, Xin-ping

2015-02-15

Oil residues along shorelines are hard to remove after an oil spill. The effect of biodiesel to eliminate crude oil from pebbles alone and in combination with petroleum degrading bacteria was investigated in simulated systems. Adding biodiesel made oil detach from pebbles and formed oil-biodiesel mixtures, most of which remained on top of seawater. The total petroleum hydrocarbon (TPH) removal efficiency increased with biodiesel quantities but the magnitude of augment decreased gradually. When used with petroleum degrading bacteria, the addition of biodiesel (BD), nutrients (NUT) and BD+NUT increased the dehydrogenase activity and decreased the biodegradation half lives. When BD and NUT were replenished at the same time, the TPH removal efficiency was 7.4% higher compared to the total improvement of efficiency when BD and NUT was added separately, indicating an additive effect of biodiesel and nutrients on oil biodegradation. Copyright © 2014 Elsevier Ltd. All rights reserved.
Systematic shell-model study of β -decay properties and Gamow-Teller strength distributions in A ≈40 neutron-rich nuclei

NASA Astrophysics Data System (ADS)

Yoshida, Sota; Utsuno, Yutaka; Shimizu, Noritaka; Otsuka, Takaharu

2018-05-01

We perform large-scale shell-model calculations of β -decay properties for neutron-rich nuclei with 13 ≤Z ≤18 and 22 ≤N ≤34 , taking the first-forbidden transitions into account. The natural-parity and unnatural-parity states are calculated in the 0 ℏ ω and 1 ℏ ω model spaces, respectively, within the full s d +p f +s d g valence shell. The calculated β -decay half-lives and β -delayed neutron emission probabilities show good agreement with the experimental data. The first-forbidden transitions make a non-negligible contribution to the half-lives of N ≳28 nuclei. The low-lying Gamow-Teller strengths of even-even nuclei are considerably larger than those of the neighboring odd-A and odd-odd nuclei, strongly affecting the half-lives and neutron emission probabilities. It is shown that this even-odd effect is caused by the Jπ=1+ proton-neutron pairing interaction. We derive a formula to represent the positions of the Gamow-Teller giant resonances from the calculated strength distributions.
Deposition of gamma emitters from Chernobyl accident and their transfer in lichen-soil columns.

PubMed

Lehto, Jukka; Paatero, Jussi; Pehrman, Reijo; Kulmala, Seija; Suksi, Juhani; Koivula, Teija; Jaakkola, Timo

2008-10-01

Lichen-soil column samples were taken from several locations in the Southern Finland between 1986 and 2006. Columns were divided into three parts, upper lichen, lower lichen and underlying soil, and their gamma emitting radionuclides, 134Cs, 137Cs, 103Ru, 95Zr, 106Ru, 110mAg, 125Sb and 144Ce, were measured with gamma spectrometry. Deposition values were calculated as Bq/m2 for each sampling site. Distribution of various radionuclides in the three compartments as a function of time was determined. Both effective and ecological half-lives of all radionuclides were calculated for upper lichen, whole lichen and whole lichen-soil column. A linear relation was derived between the physical half-lives and effective half-lives for whole lichen and for whole lichen-soil column. Reindeer meat activity concentrations of various radionuclides and ensuing radiation doses to reindeer-herding people were also estimated for a hypothetical case where a similar high radioactive pollution, as was taken place in the Southern Finland, would have occurred in the reindeer-herding areas in the Finnish Lapland.
Trace element contamination in feather and tissue samples from Anna’s hummingbirds

USGS Publications Warehouse

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The results from this study provide a benchmark for the distribution of trace element concentrations in feather and tissue samples from hummingbirds and suggests a reference mark for exceeding normal. Lastly, pollinating avian species are minimally represented in the literature as bioindicators for environmental trace element contamination. Given that trace elements can move through food chains by a variety of routes, our study indicates that hummingbirds are possible bioindicators of environmental trace element contamination.
Concentrations of trace elements and PCDD/Fs around a municipal solid waste incinerator in Girona (Catalonia, Spain). Human health risks for the population living in the neighborhood.

PubMed

Rovira, Joaquim; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

2018-07-15

Previously to the modernization of the municipal solid waste incinerator (MSWI) of Campdorà (Girona, Catalonia, Spain) two sampling campaigns (2015 and 2016) were conducted. In each campaign, 8 soil and 4 air samples (PM 10 and total particle phase and gas phase) were collected. The levels of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl and V, and PCDD/Fs were analysed at different distances and wind directions around the MSWI. Environmental levels of trace elements and PCDD/Fs were used to assess exposure and health risks (carcinogenic and non-carcinogenic) for the population living around the facility. In soils, no significant differences were observed for trace elements and PCDD/Fs between both campaigns. In air, significant higher levels of As, Cd, Co, Mn, Ni, Pb, Tl and V were detected in 2016. Regarding soil levels, only Cd (distances) and As, Cu, Mn, and Ni (wind directions) showed significant differences. No differences were noted in the concentrations of trace elements and PCDD/Fs in air levels with respect to distances and directions to the MSWI. No differences were registered in air levels (elements and PCDD/Fs) between points influenced by MSWI emissions and background point. However some differences in congener profile were noted regarding from where back-trajectories come from (HYSPLIT model results), pointing some influence of Barcelona metropolitan area. The concentrations of trace elements and PCDD/Fs were similar -or even lower- than those reported around other MSWIs in Catalonia and various countries. Non-carcinogenic risks were below the safety limit (HQ<1). In turn, carcinogenic risks due to exposure to trace elements and PCDD/Fs were in acceptable ranges, according to national and international standard regulations. Copyright © 2018 Elsevier B.V. All rights reserved.
Spotlight: French Polynesia.

PubMed

May, J F

1988-01-01

French Polynesia is a group of 4 archipelagos in the South Pacific with an estimated 1987 population of 176,600. Its people are mainly Tahitians, Polynesians, Chinese, Europeans, and persons of mixed heritage. More than half of the population live in the Society Islands. About half of the population is less than 20 years old and slightly more than 5% is older than 60. Due to a recent decline in fertility, the rate of natural increase is moderate--about 2.5% annually. In the early 1980s, about two thirds of women in Tahiti aged 15-49 used a modern method of contraception. It remains to be seen whether this pattern will spread to the entire area. Projections by the World Bank, assuming little decline in mortality, yield a total population of 400,000 by the year 2030. The major challenge for French Polynesia is to develop the many small islands spread across an ocean territory half the size of the contiguous 48 states of the U.S. Tourist-related activities have replaced traditional income-generating such as production of coconuts, mother-of-pearl, and vanilla. The value of exports from the area make up only 5% of the value of imports. To extract the potentially huge food and mineral resources from the ocean, enormous infusions of capital will be necessary.
Influence of proton-skin thickness on the {{\\alpha }} decays of heavy nuclei

NASA Astrophysics Data System (ADS)

Seif, W. M.; Abdurrahman, A.

2018-01-01

We investigate the effect of proton-skin thickness on the α decay process. We consider 188 neutron-deficient nuclei belonging to the isotopic chains from Te (Z = 52) to Pb (Z = 82). The calculations of the half-life are carried out in the framework of the preformed cluster model, with the Wentzel-Kramers-Brillouin penetration probability and assault frequency. It is shown that the proton-skin thickness ({\\varDelta }{{p}}) of the daughter nucleus gives rise to a total α- daughter nucleus interaction potential of relatively wide deep internal pocket and a thinner Coulomb barrier of less height. This increases the penetration probability but decreases the assault frequency. The overall impact of the proton-skin thickness appears as a decrease in the decay half-life. The proton-skin thickness decreases the stability of the nucleus. The half-lives of the proton-skinned isotopes along the isotopic chain decrease exponentially with increasing the proton-skin thickness, whereas the {Q}α -value increases with {\\varDelta }{{p}}. α-decay manifests itself as the second favorite decay mode of neutron-deficient nuclei, next to the {β }+-decay and before proton-decay. It is indicated as main, competing, and minor decay mode, at 21%, 7%, and 57%, respectively, of the investigated nuclei.
Uptake of Cadmium, Lead and Arsenic by Tenebrio molitor and Hermetia illucens from Contaminated Substrates.

PubMed

van der Fels-Klerx, H J; Camenzuli, L; van der Lee, M K; Oonincx, D G A B

2016-01-01

Insects have potential as a novel source of protein in feed and food production in Europe, provided they can be used safely. To date, limited information is available on the safety of insects, and toxic elements are one of the potential hazards of concern. Therefore, we aimed to investigate the potential accumulation of cadmium, lead and arsenic in larvae of two insect species, Tenebrio molitor (yellow mealworm) and Hermetia illucens (black soldier fly), which seem to hold potential as a source of food or feed. An experiment was designed with 14 treatments, each in triplicate, per insect species. Twelve treatments used feed that was spiked with cadmium, lead or arsenic at 0.5, 1 and 2 times the respective maximum allowable levels (ML) in complete feed, as established by the European Commission (EC). Two of the 14 treatments consisted of controls, using non-spiked feed. All insects per container (replicate) were harvested when the first larva in that container had completed its larval stage. Development time, survival rates and fresh weights were similar over all treatments, except for development time and total live weight of the half of the maximum limit treatment for cadmium of the black soldier fly. Bioaccumulation (bioaccumulation factor > 1) was seen in all treatments (including two controls) for lead and cadmium in black soldier fly larvae, and for the three arsenic treatments in the yellow mealworm larvae. In the three cadmium treatments, concentrations of cadmium in black soldier fly larvae are higher than the current EC maximum limit for feed materials. The same was seen for the 1.0 and 2.0 ML treatments of arsenic in the yellow mealworm larvae. From this study, it can be concluded that if insects are used as feed materials, the maximum limits of these elements in complete feed should be revised per insect species.

Uptake of Cadmium, Lead and Arsenic by Tenebrio molitor and Hermetia illucens from Contaminated Substrates

PubMed Central

van der Fels-Klerx, H. J.; Camenzuli, L.; van der Lee, M. K.; Oonincx, D. G. A. B.

2016-01-01

Insects have potential as a novel source of protein in feed and food production in Europe, provided they can be used safely. To date, limited information is available on the safety of insects, and toxic elements are one of the potential hazards of concern. Therefore, we aimed to investigate the potential accumulation of cadmium, lead and arsenic in larvae of two insect species, Tenebrio molitor (yellow mealworm) and Hermetia illucens (black soldier fly), which seem to hold potential as a source of food or feed. An experiment was designed with 14 treatments, each in triplicate, per insect species. Twelve treatments used feed that was spiked with cadmium, lead or arsenic at 0.5, 1 and 2 times the respective maximum allowable levels (ML) in complete feed, as established by the European Commission (EC). Two of the 14 treatments consisted of controls, using non-spiked feed. All insects per container (replicate) were harvested when the first larva in that container had completed its larval stage. Development time, survival rates and fresh weights were similar over all treatments, except for development time and total live weight of the half of the maximum limit treatment for cadmium of the black soldier fly. Bioaccumulation (bioaccumulation factor > 1) was seen in all treatments (including two controls) for lead and cadmium in black soldier fly larvae, and for the three arsenic treatments in the yellow mealworm larvae. In the three cadmium treatments, concentrations of cadmium in black soldier fly larvae are higher than the current EC maximum limit for feed materials. The same was seen for the 1.0 and 2.0 ML treatments of arsenic in the yellow mealworm larvae. From this study, it can be concluded that if insects are used as feed materials, the maximum limits of these elements in complete feed should be revised per insect species. PMID:27846238
Space Shuttle Projects

NASA Image and Video Library

1981-01-01

The Space Shuttle main propulsion system includes three major elements. One of those elements is the External Tank (ET). The ET holds over one-half million gallons of liquid oxygen and liquid hydrogen that fuel the main engines.
Delayed blastulation, multinucleation, and expansion grade are independently associated with live-birth rates in frozen blastocyst transfer cycles.

PubMed

Desai, Nina; Ploskonka, Stephanie; Goodman, Linnea; Attaran, Marjan; Goldberg, Jeffrey M; Austin, Cynthia; Falcone, Tommaso

2016-11-01

To identify blastocyst features independently predictive of successful pregnancy and live births with vitrified-warmed blastocysts. Retrospective study. Academic hospital. Women undergoing a cycle with transfer of blastocysts vitrified using the Rapid-i closed carrier (n = 358). None. Clinical pregnancy and live-birth rates analyzed using logistic regression analysis. A total of 669 vitrified-warmed blastocysts were assessed. The survival rate was 95%. A mean of 1.7 ± 0.5 embryos were transferred. The clinical pregnancy, live-birth, and implantation rates were 55%, 46%, and 43%, respectively. The odds of clinical pregnancy (odds ratio [OR] 3.08; 95% confidence interval [CI], 1.88-5.12) and live birth (OR 2.93; 95% CI, 1.79-4.85) were three times higher with day-5 blastocysts versus slower-growing day-6 vitrified blastocysts, irrespective of patient age at cryopreservation. Blastocysts from multinucleated embryos were half as likely to result in a live birth (OR 0.46; 95% CI, 0.22-0.91). A four -fold increase in live birth was observed if an expanded blastocyst was available for transfer. The inner cell mass-trophectoderm score correlated to positive outcomes in the univariate analysis. The implantation rate was statistically significantly higher for day-5 versus day-6 vitrified blastocysts (50% vs. 29%, respectively). The blastocyst expansion grade after warming was predictive of successful outcomes independent of the inner cell mass or trophectoderm score. Delayed blastulation and multinucleation were independently associated with lower live-birth rates in frozen cycles. Implantation potential of the frozen blastocysts available should be included in the decision-making process regarding embryo number for transfer. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Development and testing of a CW-EPR apparatus for imaging of short-lifetime nitroxyl radicals in mouse head

NASA Astrophysics Data System (ADS)

Sato-Akaba, Hideo; Fujii, Hirotada; Hirata, Hiroshi

2008-08-01

This article describes a method for reducing the acquisition time in three-dimensional (3D) continuous-wave electron paramagnetic resonance (CW-EPR) imaging. To visualize nitroxyl spin probes, which have a short lifetime in living organisms, the acquisition time for a data set of spectral projections should be shorter than the lifetime of the spin probes. To decrease the total time required for data acquisition, the duration of magnetic field scanning was reduced to 0.5 s. Moreover, the number of projections was decreased by using the concept of a uniform distribution. To demonstrate this faster data acquisition, two kinds of nitroxyl radicals with different decay rates were measured in mice. 3D EPR imaging of 4-hydroxy-2,2,6,6-tetramethylpiperidine-d 17-1- 15N-1-oxyl in mouse head was successfully carried out. 3D EPR imaging of nitroxyl spin probes with a half-life of a few minutes was achieved for the first time in live animals.
Skin diseases among internally displaced Tawerghans living in camps in Benghazi, Libya.

PubMed

Elfaituri, Safa S

2016-09-01

Benghazi has received many internally displaced persons (IDPs) from other Libyan cities as a result of the armed conflict in Libya. These groups have significant health problems associated with their displacement, including skin diseases. This study aimed to determine the spectrum and frequency of skin diseases among people living in IDP camps in Benghazi. A total of 480 IDP camp residents with complaints of skin diseases were studied over a period of 6 months. All subjects were ethnic Tawerghans; about three-quarters were female and half were adults. The disease types found to occur at the highest frequencies were skin infections (40.0%), followed by xerosis (31.3%), eczema (18.3%), acne (17.0%), hair-related diseases (6.7%), and psychosomatic diseases (3.0%). People who are resident in IDP camps have skin problems similar to those of other populations in similar circumstances. They have increased vulnerability to infections, environment-associated disorders such as xerosis cutis and eczema, and diseases of psychosomatic origin. © 2015 The International Society of Dermatology.
Positive selection of Caenorhabditis elegans mutants with increased stress resistance and longevity.

PubMed Central

Muñoz, Manuel J; Riddle, Donald L

2003-01-01

We developed selective conditions for long-lived mutants of the nematode Caenorhabditis elegans by subjecting the first larval stage (L1) to thermal stress at 30 degrees for 7 days. The surviving larvae developed to fertile adults after the temperature was shifted to 15 degrees. A total of one million F(2) progeny and a half million F(3) progeny of ethyl-methanesulfonate-mutagenized animals were treated in three separate experiments. Among the 81 putative mutants that recovered and matured to the reproductive adult, 63 retested as thermotolerant and 49 (80%) exhibited a >15% increase in mean life span. All the known classes of dauer formation (Daf) mutant that affect longevity were found, including six new alleles of daf-2, and a unique temperature-sensitive, dauer-constitutive allele of age-1. Alleles of dyf-2 and unc-13 were isolated, and mutants of unc-18, a gene that interacts with unc-13, were also found to be long lived. Thirteen additional mutations define at least four new genes. PMID:12586705
First Compilation and Evaluation of Beta-Delayed Neutron Emission Probabilities and Associated Half-Lives for A ≤72 Nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birch, M.; Singh, B.; Abriola, D.

2014-06-01

After a comprehensive compilation and evaluation of beta-delayed neutron (β -n) emission probabilities, P n, and associated half-lives for A ≤ 72 nuclei has been performed for the first time. The recommended values have been used to analyze the systematics of β -nemission in this region. The ratio P n/T 1/2 is better correlated with the Q-value of the β -n decay mode than the previously proposed Kratz-Herrmann Formula (KHF). Moreover, the recommended values are also compared with theoretical quasi-particle random phase approximation (QRPA) calculations.
A tetraethylene glycol coat gives gold nanoparticles long in vivo half-lives with minimal increase in size

PubMed Central

Willett, Julian DS; Lawrence, Marlon G; Wilder, Jennifer C; Smithies, Oliver

2017-01-01

In this study, we describe the experiments determining whether coating gold nanoparticles with tetraethylene glycol (TEG) provides pharmacologically relevant advantages, such as increased serum half-life and resistance to protein adsorption. Monodisperse TEG-coated, NaBH4-reduced gold nanoparticles with a hydrodynamic size comparable to albumin were synthesized by reducing gold chloride with NaBH4 under alkaline conditions in the presence of TEG-SH. The particles were characterized by gel electrophoresis, column chromatography, and transmission electron microscopy. The nanoparticles were subsequently injected intravenously into mice, and their half-lives and final destinations were determined via photometric analysis, light microscopy (LM), and transmission electron microscopy. The TEG particles had a long half-life (~400 minutes) that was not influenced by splenectomy. After 500 minutes of injection, TEG particles were found in kidney proximal tubule cell vesicles and in spleen red and white pulp. The particles induced apoptosis in the spleen red pulp but not in white pulp or the kidney. Some of the TEG particles appeared to have undergone ligand exchange reactions that increased their charge. The TEG particles were shown to be resistant to nonspecific protein adsorption, as judged by gel electrophoresis and column chromatography. These results demonstrate that naturally monodisperse, small-sized gold nanoparticles coated with TEG have long in vivo plasma half-lives, are minimally toxic, and are resistant to protein adsorption. This suggests that a TEG coating should be considered as an alternative to a polyethylene glycol coating, which is polydisperse and of much larger size. PMID:28408825
Linking trace element variations with macronutrients and major cations in marine mussels Mytilus edulis and Perna viridis.

PubMed

Liu, Fengjie; Wang, Wen-Xiong

2015-09-01

Marine mussels have long been used as biomonitors of contamination of trace elements, but little is known about whether variation in tissue trace elements is significantly associated with those of macronutrients and major cations. The authors examined the variability of macronutrients and major cations and their potential relationships with bioaccumulation of trace elements. The authors analyzed the concentrations of macronutrients (C, N, P, S), major cations (Na, Mg, K, Ca), and trace elements (Al, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb) in the whole soft tissues of marine mussels Mytilus edulis and Perna viridis collected globally from 21 sites. The results showed that 12% to 84% of the variances in the trace elements was associated with major cations, and the tissue concentration of major cations such as Na and Mg in mussels was a good proxy for ambient seawater concentrations of the major cations. Specifically, bioaccumulation of most of the trace elements was significantly associated with major cations, and the relationships of major cations with trace cations and trace oxyanions were totally opposite. Furthermore, 14% to 69% of the variances in the trace elements were significantly associated with macronutrients. Notably, more than half of the variance in the tissue concentrations of As, Cd, V, Ba, and Pb was explained by the variance in macronutrients in one or both species. Because the tissue macronutrient concentrations were strongly associated with animal growth and reproduction, the observed coupling relationships indicated that these biological processes strongly influenced the bioaccumulation of some trace elements. The present study indicated that simultaneous quantification of macronutrients and major cations with trace elements can improve the interpretation of biomonitoring data. © 2015 SETAC.
Contribution of internal exposures to the radiological consequences of the Chernobyl accident.

PubMed

Balonov, M I; Anspaugh, L R; Bouville, A; Likhtarev, I A

2007-01-01

The main pathways leading to exposure of members of the general public due to the Chernobyl accident were external exposure from radionuclides deposited on the ground and ingestion of contaminated terrestrial food products. The collective dose to the thyroid was nearly 1.5 million man Gy in Belarus, Russia and Ukraine with nearly half received by children and adolescents. The collective effective dose received in 1986-2005 by approximately five million residents living in the affected areas of the three countries was approximately 50,000 man Sv with approximately 40% from ingestion. That contribution might have been larger if countermeasures had not been applied. The main radionuclide contributing to both external and internal effective dose is 137Cs with smaller contributions of 134Cs and 90Sr and negligible contribution of transuranic elements. The major demonstrated radiation-caused health effect of the Chernobyl accident has been an elevated incidence of thyroid cancer in children.
Experimental survey of the production of α -decaying heavy elements in 238U+232Th reactions at 7.5-6.1 MeV/nucleon

NASA Astrophysics Data System (ADS)

Wuenschel, S.; Hagel, K.; Barbui, M.; Gauthier, J.; Cao, X. G.; Wada, R.; Kim, E. J.; Majka, Z.; Płaneta, R.; Sosin, Z.; Wieloch, A.; Zelga, K.; Kowalski, S.; Schmidt, K.; Ma, C.; Zhang, G.; Natowitz, J. B.

2018-06-01

The production of α -particle decaying heavy nuclei in reactions of 7.5-6.1 MeV/nucleon 238U +232Th was explored using an in-beam detection array composed of YAP scintillators and gas ionization chamber-Si telescopes. Comparisons of α energies and half-lives for the observed products with those of the previously known isotopes and with theoretically predicted values indicate the observation of a number of previously unreported α emitters. α -particle decay energies reaching as high as 12 MeV are observed. Many of these are expected to be from decay of previously unseen relatively neutron rich products. While the contributions of isomeric states require further exploration and specific isotope identifications need to be made, the production of heavy isotopes with quite high atomic numbers is suggested by the data.
Nuclear spectroscopy of r-process nuclei around N = 126 using KISS

NASA Astrophysics Data System (ADS)

Hirayama, Y.; Watanabe, Y. X.; Miyatake, H.; Schury, P.; Wada, M.; Oyaizu, M.; Kakiguchi, Y.; Mukai, M.; Kimura, S.; Ahmed, M.; Jeong, S. C.; Moon, J. Y.; Park, J. H.

2017-09-01

The beta-decay properties and atomic mass of nuclei with neutron magic number of N = 126 are considered critical for understanding the production of heavy elements such as gold and platinum at astrophysical sites. We will produce and measure the half-lives and masses of the nuclei with Z = 74-77 around N = 126 by using the multinucleon transfer (MNT) reaction of ^{136} Xe/ ^{238} U beams and ^{198} Pt target system. For this purpose, we have constructed the KEK Isotope Separation System (KISS) at RIKEN RIBF facility. KISS consists of an argon gas cell based laser ion source (atomic number selection) and an isotope separation on-line (ISOL) (mass number selection), to produce pure low-energy beams of neutron-rich isotopes around N = 126 . We performed the on-line tests to study the basic properties of the KISS and, successfully extracted laser-ionized nuclei around N = 126.
Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manabe, K.; Endo, Akira; Eckerman, Keith F

2010-03-01

The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was foundmore » that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.« less
Pharmacokinetics of triptorelin after intravenous bolus administration in healthy males and in males with renal or hepatic insufficiency

PubMed Central

Müller, F. O.; Terblanchè, J.; Schall, R.; van Zyl Smit, R.; Tucker, T.; Marais, K.; Groenewoud, G.; Porchet, H. C.; Weiner, M.; Hawarden, D.

1997-01-01

Aims Triptorelin is a gonadotropin-releasing hormone (GnRH) analogue with enhanced affinity for GnRH receptors and a prolonged half-life due to its resistance to enzymatic degradation. The sustained-release formulation of this molecule is advantageous in conditions requiring chronic hormone suppression. Methods This was an open study to determine the pharmacokinetics of a single i.v. bolus dose of 0.5 mg triptorelin acetate in four groups of six male subjects; namely in healthy subjects (Group I), in patients with varying degrees of renal insufficiency (Groups II and III), and in patients with hepatic insufficiency (Group IV). Results The maximum concentrations of triptorelin were found to be similar for all four study groups (geometric mean Cmax between 41.6 mg ml−1 and 53.9 mg ml−1 ). The total clearance of triptorelin decreased with increasing renal impairment, and was even lower in patients with hepatic insufficiency (geometric mean CLtot: 210 ml min−1, 113 ml min−1, 86.8 ml min−1 and 57.3 ml min−1 for Groups I, II, III and IV, respectively). Serum triptorelin concentrations in all four groups were adequately described by a three-compartment model. The elimination half-life for patients with hepatic impairment was similar to that of patients with renal impairment (geometric mean t1/2, z: 6.6 h, 7.7 h and 7.6 h for Groups II, III and IV, respectively), but significantly longer than in healthy volunteers (2.8 h for Group I). The first and second distribution half-lives were similar for the four groups studied, with geometric mean distribution half-lives of about 0.1 h (6 min) and 0.75 h (45 min), respectively. Conclusions Although both renal and hepatic function are important for the clearance of triptorelin, the liver plays the predominant role in subjects suffering from some degree of renal impairment. PMID:9354307
Liberal Education in a Visual World

ERIC Educational Resources Information Center

Little, Deandra; Felten, Peter; Berry, Chad

2010-01-01

The past century's technological revolution has returned images to a central place in people's individual and collective lives. Photography became widely popular in the first half of the past century, creating new visual forms of high art, mass advertising, and amateur entertainment. During the latter half of the twentieth century, innovations in…
An improved method for determination of fumigant degradation half-life in soil

USDA-ARS?s Scientific Manuscript database

Using the current approach, measurement of fumigant degradation half-lives under realistic soil conditions is problematic due to the large headspace that is necessary above the soil during incubation. This results in a poor degree of contact between the fumigant and the soil’s degrading surfaces; di...
Nuclear resonant scattering experiment with fast time response: Photonuclear excitation of 201Hg

NASA Astrophysics Data System (ADS)

Yoshimi, A.; Hara, H.; Hiraki, T.; Kasamatsu, Y.; Kitao, S.; Kobayashi, Y.; Konashi, K.; Masuda, R.; Masuda, T.; Miyamoto, Y.; Okai, K.; Okubo, S.; Ozaki, R.; Sasao, N.; Sato, O.; Seto, M.; Schumm, T.; Shigekawa, Y.; Stellmer, S.; Suzuki, K.; Uetake, S.; Watanabe, M.; Yamaguchi, A.; Yasuda, Y.; Yoda, Y.; Yoshimura, K.; Yoshimura, M.

2018-02-01

Nuclear resonant excitation and detection of its decay signal for the 26.27-keV level of 201Hg is demonstrated with high-brilliance synchrotron radiation (SR) and a fast x-ray detector system. This SR-based photonuclear excitation scheme, known as nuclear resonant scattering (NRS) in the field of materials science, is also useful for investigating nuclear properties, such as the half-lives and radiative widths of excited nuclear levels. To date, because of the limited time response of the x-ray detector, the nuclear levels to which this method could be applied have been limited to the one whose half-lives are longer than ˜1 ns. The faster time response of the NRS measurement makes possible NRS experiments on nuclear levels with much shorter half-lives. We have fabricated an x-ray detector system that has a time resolution of 56 ps and a shorter tail function than that reported previously. With the implemented detector system, the NRS signal of the 26.27-keV state of 201Hg could be clearly discriminated from the electronic scattering signal at an elapsed time of 1 ns after the SR pulse. The half-life of the state was determined as 629 ± 18 ps, which has better precision by a factor of three compared with that reported to date obtained from nuclear decay spectroscopy.
29 CFR 553.20 - Introduction.

Code of Federal Regulations, 2010 CFR

2010-07-01

... element of flexibility to State and local government employers and an element of choice to their employees... not less than one and one-half hours of compensatory time for each hour of overtime work, just as the...
The Unresponsive Partner: Roles of Social Status, Auditory Feedback, and Animacy in Coordination of Joint Music Performance

PubMed Central

Demos, Alexander P.; Carter, Daniel J.; Wanderley, Marcelo M.; Palmer, Caroline

2017-01-01

We examined temporal synchronization in joint music performance to determine how social status, auditory feedback, and animacy influence interpersonal coordination. A partner’s coordination can be bidirectional (partners adapt to the actions of one another) or unidirectional (one partner adapts). According to the dynamical systems framework, bidirectional coordination should be the optimal (preferred) state during live performance. To test this, 24 skilled pianists each performed with a confederate while their coordination was measured by the asynchrony in their tone onsets. To promote social balance, half of the participants were told the confederate was a fellow participant – an equal social status. To promote social imbalance, the other half was told the confederate was an experimenter – an unequal social status. In all conditions, the confederate’s arm and finger movements were occluded from the participant’s view to allow manipulation of animacy of the confederate’s performances (live or recorded). Unbeknownst to the participants, half of the confederate’s performances were replaced with pre-recordings, forcing the participant into unidirectional coordination during performance. The other half of the confederate’s performances were live, which permitted bidirectional coordination between performers. In a final manipulation, both performers heard the auditory feedback from one or both of the performers’ parts removed at unpredictable times to disrupt their performance. Consistently larger asynchronies were observed in performances of unidirectional (recorded) than bidirectional (live) performances across all conditions. Participants who were told the confederate was an experimenter reported their synchrony as more successful than when the partner was introduced as a fellow participant. Finally, asynchronies increased as auditory feedback was removed; removal of the confederate’s part hurt coordination more than removal of the participant’s part in live performances. Consistent with the assumption that bidirectional coupling yields optimal coordination, an unresponsive partner requires the other member to do all the adapting for the pair to stay together. PMID:28261123
The location of displaced New Orleans residents in the year after Hurricane Katrina.

PubMed

Sastry, Narayan; Gregory, Jesse

2014-06-01

Using individual data from the restricted version of the American Community Survey, we examined the displacement locations of pre-Hurricane Katrina adult residents of New Orleans in the year after the hurricane. More than one-half (53 %) of adults had returned to-or remained in-the New Orleans metropolitan area, with just under one-third of the total returning to the dwelling in which they resided prior to Hurricane Katrina. Among the remainder, Texas was the leading location of displaced residents, with almost 40 % of those living away from the metropolitan area (18 % of the total), followed by other locations in Louisiana (12 %), the South region of the United States other than Louisiana and Texas (12 %), and elsewhere in the United States (5 %). Black adults were considerably more likely than nonblack adults to be living elsewhere in Louisiana, in Texas, and elsewhere in the South. The observed race disparity was not accounted for by any of the demographic or socioeconomic covariates in the multinomial logistic regression models. Consistent with hypothesized effects, we found that following Hurricane Katrina, young adults (aged 25-39) were more likely to move further away from New Orleans and that adults born outside Louisiana were substantially more likely to have relocated away from the state.

The Location of Displaced New Orleans Residents in the Year After Hurricane Katrina

PubMed Central

Sastry, Narayan; Gregory, Jesse

2014-01-01

Using individual data from the restricted version of the American Community Survey, we examined the displacement locations of pre–Hurricane Katrina adult residents of New Orleans in the year after the hurricane. More than one-half (53 %) of adults had returned to—or remained in—the New Orleans metropolitan area, with just under one-third of the total returning to the dwelling in which they resided prior to Hurricane Katrina. Among the remainder, Texas was the leading location of displaced residents, with almost 40 % of those living away from the metropolitan area (18 % of the total), followed by other locations in Louisiana (12 %), the South region of the United States other than Louisiana and Texas (12 %), and elsewhere in the United States (5 %). Black adults were considerably more likely than nonblack adults to be living elsewhere in Louisiana, in Texas, and elsewhere in the South. The observed race disparity was not accounted for by any of the demographic or socioeconomic covariates in the multinomial logistic regression models. Consistent with hypothesized effects, we found that following Hurricane Katrina, young adults (aged 25–39) were more likely to move further away from New Orleans and that adults born outside Louisiana were substantially more likely to have relocated away from the state. PMID:24599750
Biological half-life of gaseous elemental iodine deposited onto rice grains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uchida, S.; Muramatsu, Y.; Sumiya, M.

In order to obtain the biological half-life (Tb) of iodine deposited on rough rice grains, rice plants of four different growing stages--heading, milky, dough, and yellow ripe--were exposed to elemental gaseous iodine. After the exposure, the rough rice samples were collected at different intervals and analyzed for iodine to estimate the value of Tb. The average value of Tb obtained by the experiments at the dough and yellow ripe stages was about 200 d. This value is considerably larger than those for pasture grass and leafy vegetables.
Sexual dysfunction in women with ESRD requiring hemodialysis.

PubMed

Strippoli, Giovanni F M; Vecchio, Mariacristina; Palmer, Suetonia; De Berardis, Giorgia; Craig, Jonathan; Lucisano, Giuseppe; Johnson, David; Pellegrini, Fabio; Nicolucci, Antonio; Sciancalepore, Michela; Saglimbene, Valeria; Gargano, Letizia; Bonifati, Carmen; Ruospo, Marinella; Navaneethan, Sankar D; Montinaro, Vincenzo; Stroumza, Paul; Zsom, Marianna; Torok, Mariatta; Celia, Eduardo; Gelfman, Ruben; Bednarek-Skublewska, Anna; Dulawa, Jan; Graziano, Giusi; Gentile, Giorgio; Ferrari, Juan Nin; Santoro, Antonio; Zucchelli, Annalisa; Triolo, Giorgio; Maffei, Stefano; Hegbrant, Jörgen; Wollheim, Charlotta; De Cosmo, Salvatore; Manfreda, Valeria M

2012-06-01

The few existing studies of sexual dysfunction in women on hemodialysis are limited by small sample size. This large, cross-sectional study evaluated the prevalence and correlates of female sexual dysfunction in advanced kidney disease. DESIGN, SETTING, PARTICIPANTS, METHODS: A total of 1472 women with ESRD undergoing hemodialysis were recruited to a multinational, cross-sectional study conducted within a collaborative dialysis network in Europe and South America. Sexual dysfunction was identified by the Female Sexual Function Index. Correlates of self-reported sexual dysfunction were identified by regression analyses. Of the 1472 women, 659 completed questionnaires (45%). More than half (362 of 659 [55%]) lived with a partner, and 232 of 659 (35%) reported being sexually active. Of these 659 respondents, 555 (84%) reported sexual dysfunction. Women with a partner (282 of 362 [78%]) were less likely to report sexual dysfunction than those without a partner (273 of 297 [92%]) (P<0.001). Sexual dysfunction was independently associated with age, depressive symptoms, less education, menopause, diabetes, and diuretic therapy. Nearly all women who were not wait-listed for a kidney transplant and were living without a partner (249 of 260 [96%]) reported sexual dysfunction. More than half (128 of 232 [55%]) of sexually active women reported sexual dysfunction, associated with age, depressive symptoms, menopause, low serum albumin, and diuretic therapy. This descriptive study suggests most women on hemodialysis experience sexual problems. Additional research on the relevance of sexual dysfunction to symptom burden and quality of life in these women is needed.
Age and choice in health insurance: evidence from a discrete choice experiment.

PubMed

Becker, Karolin; Zweifel, Peter

2008-01-01

A uniform package of benefits and uniform cost sharing are elements of regulation inherent in most social health insurance systems. Both elements risk burdening the population with a welfare loss if preferences for risk and insurance attributes differ. This suggests the introduction of more choice in social health insurance packages may be advantageous; however, it is widely believed that this would not benefit the elderly.A representative telephone survey of 1000 people aged >24 years living in the German- and French-speaking parts of Switzerland was conducted. Participants were asked to compare the status quo (i.e. their current insurance contract) with ten hypothetical alternatives. In addition, participants were asked questions concerning utilization of healthcare services; overall satisfaction with the healthcare system, insurer and insurance policy; and a general preference for new elements in the insurance package. Socioeconomic variables surveyed were age, sex, total household income, education (seven categories ranging from primary school to university degree), place of residence, occupation, and marital status. To examine the relationship between age and willingness to pay (WTP) for additional options in Swiss social health insurance.A representative telephone survey of 1000 people aged >24 years living in the German- and French-speaking parts of Switzerland was conducted. Participants were asked to compare the status quo (i.e. their current insurance contract) with ten hypothetical alternatives. In addition, participants were asked questions concerning utilization of healthcare services; overall satisfaction with the healthcare system, insurer and insurance policy; and a general preference for new elements in the insurance package. Socioeconomic variables surveyed were age, sex, total household income, education (seven categories ranging from primary school to university degree), place of residence, occupation, and marital status. A discrete choice experiment was developed using six attributes (deductibles, co-payment, access to alternative medicines, medication choice, access to innovation, and monthly premium) that are currently in debate within the context of Swiss health insurance. These attributes have been shown to be important in the choice of insurance contract. Using statistical design optimization procedures, the number of choice sets was reduced to 27 and randomly split into three groups. One choice was included twice to test for consistency. Two random effects probit models were developed: a simple model where marginal utilities and WTP values were not allowed to vary according to socioeconomic characteristics, and a more complex model where the values were permitted to depend on socioeconomic variables.A representative telephone survey of 1000 people aged >24 years living in the German- and French-speaking parts of Switzerland was conducted. Participants were asked to compare the status quo (i.e. their current insurance contract) with ten hypothetical alternatives. In addition, participants were asked questions concerning utilization of healthcare services; overall satisfaction with the healthcare system, insurer and insurance policy; and a general preference for new elements in the insurance package. Socioeconomic variables surveyed were age, sex, total household income, education (seven categories ranging from primary school to university degree), place of residence, occupation, and marital status. All chosen elements proved relevant for choice in the simple model. Accounting for socioeconomic characteristics in the comprehensive model reveals preference heterogeneity for contract attributes, but also for the propensity to consider deviating from the status quo and choosing an alternative health insurance contract. The findings suggest that while the elderly do exhibit a stronger status quo bias than younger age groups, they require less rather than more specific compensation for selected cutbacks, indicating a potential for contracts that induce self-rationing in return for lower premiums.
Modelling and simulation of high-frequency (100 MHz) ultrasonic linear arrays based on single crystal LiNbO3.

PubMed

Zhang, J Y; Xu, W J; Carlier, J; Ji, X M; Nongaillard, B; Queste, S; Huang, Y P

2012-01-01

High-frequency ultrasonic transducer arrays are essential for high resolution imaging in clinical analysis and Non-Destructive Evaluation (NDE). However, the fabrication of conventional backing-layer structure, which requires a pitch (distance between the centers of two adjacent elements) of half wavelength in medium, is really a great challenge. Here we present an alternative buffer-layer structure with a silicon lens for volumetric imaging. The requirement for the size of the pitch is less critical for this structure, making it possible to fabricate high-frequency (100MHz) ultrasonic linear array transducers. Using silicon substrate also makes it possible to integrate the arrays with IC (Integrated Circuit). To compare with the conventional backing-layer structure, a finite element tool, COMSOL, is employed to investigate the performances of acoustic beam focusing, the influence of pitch size for the buffer-layer configuration, and to calculate the electrical properties of the arrays, including crosstalk effect and electrical impedance. For a 100MHz 10-element array of buffer-layer structure, the ultrasound beam in azimuth plane in water could be electronically focused to obtain a spatial resolution (a half-amplitude width) of 86μm at the focal depth. When decreasing from half wavelength in silicon (42μm) to half wavelength in water (7.5μm), the pitch sizes weakly affect the focal resolution. The lateral spatial resolution is increased by 4.65% when the pitch size decreases from 42μm to 7.5μm. The crosstalk between adjacent elements at the central frequency is, respectively, -95dB, -39.4dB, and -60.5dB for the 10-element buffer, 49-element buffer and 49-element backing arrays. Additionally, the electrical impedance magnitudes for each structure are, respectively, 4kΩ, 26.4kΩ, and 24.2kΩ, which is consistent with calculation results using Krimholtz, Leedom, and Matthaei (KLM) model. These results show that the buffer-layer configuration is a promising alternative for the fabrication of high-frequency ultrasonic linear arrays dedicated to volumetric imaging. Copyright © 2011 Elsevier B.V. All rights reserved.
Deriving persistence indicators from regulatory water-sediment studies – opportunities and limitations in OECD 308 data.

PubMed

Honti, Mark; Fenner, Kathrin

2015-05-19

The OECD guideline 308 describes a laboratory test method to assess aerobic and anaerobic transformation of organic chemicals in aquatic sediment systems and is an integral part of tiered testing strategies in different legislative frameworks for the environmental risk assessment of chemicals. The results from experiments carried out according to OECD 308 are generally used to derive persistence indicators for hazard assessment or half-lives for exposure assessment. We used Bayesian parameter estimation and system representations of various complexities to systematically assess opportunities and limitations for estimating these indicators from existing data generated according to OECD 308 for 23 pesticides and pharmaceuticals. We found that there is a disparity between the uncertainty and the conceptual robustness of persistence indicators. Disappearance half-lives are directly extractable with limited uncertainty, but they lump degradation and phase transfer information and are not robust against changes in system geometry. Transformation half-lives are less system-specific but require inverse modeling to extract, resulting in considerable uncertainty. Available data were thus insufficient to derive indicators that had both acceptable robustness and uncertainty, which further supports previously voiced concerns about the usability and efficiency of these costly experiments. Despite the limitations of existing data, we suggest the time until 50% of the parent compound has been transformed in the entire system (DegT(50,system)) could still be a useful indicator of persistence in the upper, partially aerobic sediment layer in the context of PBT assessment. This should, however, be accompanied by a mandatory reporting or full standardization of the geometry of the experimental system. We recommend transformation half-lives determined by inverse modeling to be used as input parameters into fate models for exposure assessment, if due consideration is given to their uncertainty.
Uncertainties in s -process nucleosynthesis in low mass stars determined from Monte Carlo variations

NASA Astrophysics Data System (ADS)

Cescutti, G.; Hirschi, R.; Nishimura, N.; den Hartogh, J. W.; Rauscher, T.; Murphy, A. St J.; Cristallo, S.

2018-05-01

The main s-process taking place in low mass stars produces about half of the elements heavier than iron. It is therefore very important to determine the importance and impact of nuclear physics uncertainties on this process. We have performed extensive nuclear reaction network calculations using individual and temperature-dependent uncertainties for reactions involving elements heavier than iron, within a Monte Carlo framework. Using this technique, we determined the uncertainty in the main s-process abundance predictions due to nuclear uncertainties link to weak interactions and neutron captures on elements heavier than iron. We also identified the key nuclear reactions dominating these uncertainties. We found that β-decay rate uncertainties affect only a few nuclides near s-process branchings, whereas most of the uncertainty in the final abundances is caused by uncertainties in neutron capture rates, either directly producing or destroying the nuclide of interest. Combined total nuclear uncertainties due to reactions on heavy elements are in general small (less than 50%). Three key reactions, nevertheless, stand out because they significantly affect the uncertainties of a large number of nuclides. These are 56Fe(n,γ), 64Ni(n,γ), and 138Ba(n,γ). We discuss the prospect of reducing uncertainties in the key reactions identified in this study with future experiments.
ELECTROLYTIC SEPARATION PROCESS AND APPARATUS

DOEpatents

McLain, M.E. Jr.; Roberts, M.W.

1962-03-01

A method is given for dissolving stainless steel-c lad fuel elements in dilute acids such as half normal sulfuric acid. The fuel element is made the anode in a Y-shaped electrolytic cell which has a flowing mercury cathode; the stainless steel elements are entrained in the mercury and stripped therefrom by a continuous process. (AEC)
Rural Villagers and Urban Residents Exposure to Poultry in China

PubMed Central

Shi, Ying; Liao, Qiaohong; Zhou, Hang; Zhou, Lei; Li, Leilei; Wu, Jiabing; Zhang, Shunxiang; Yu, Zhangda; Wu, Xiaomin; Ma, Hanwu; Lu, Jianhua; Cowling, Benjamin J.; Yu, Hongjie

2014-01-01

Patterns of poultry exposure in rural and urban areas in China have not been systematically evaluated and compared. The objective of our study is to investigate patterns in human exposure to poultry in rural and urban China. We conducted a two-stage household-based clustered survey on population exposure to live/sick/dead poultry in Xiuning and Shenzhen. Half of the rural households (51%) in Xiuning raised poultry, mostly (78%) free-range. Around half of those households (40%) allowed poultry to stay in their living areas. One quarter of villagers reported having contact with sick or dead poultry. In Shenzhen, 37% urban residents visited live poultry markets. Among these, 40% purchased live poultry and 16% touched the poultry or cages during purchase. Our findings indicated that human exposure to poultry was different in rural and urban areas in China. This discrepancy could contribute to the observed differences in epidemiologic characteristics between urban and rural cases of influenza A(H7N9) and A(H5N1) virus infection. PMID:24769673
Heavy element synthesis in the Universe

NASA Astrophysics Data System (ADS)

Ramirez-Ruiz, Enrico

2018-06-01

The source of about half of the heaviest elements in the Universe has been a mystery for a long time. Although the general picture of element formation is well understood, many questions about the nuclear physics processes and particularly the astrophysical details remain to be answered. Here I focus on recent advances in our understanding of the origin of the heaviest and rarest elements in the Universe
Results of adolescent health risk assesment on exposure to habitat water peroral factor in conditions of a large industrial city

NASA Astrophysics Data System (ADS)

Valeeva, E. R.; Stepanova, N. V.; Ismagilova, G. A.; Ziyatdinova, A. I.; Semanov, D. A.

2018-01-01

Results of the non-carcinogenic risk assessment on ingestion of chemical substances with drinking water showed that the risk value corresponded to the allowable level of the non-carcinogenic risk (HQ < 1) for the major part of elements in all zones. The excess of the allowable level is observed only in oil products in the 1st zone (2.05) and the 4th zone (1.04). However, the total hazard index (HI) on combined peroral ingestion of chemical compounds and elements with drinking water in selected zones of the city of Kazan implies a low risk level for adolescents living in the 1st and the 4th zones (3.7 and 3.59) correspondingly, and is dangerous for health. According to the results of analysis carried out in all zones, the following basic critical organs and systems were identified: blood, CNS, kidneys, endocrine system, cardiovascular system, skeletal system and teeth. The total hazard indices in the 1st and the 4th zones deserve particular attention. The following elements: oil products (29.7% - 54.0%), nitrates (in NO3), chloroform and fluorides make a major contribution to the value of risk. In all other zones, irrespective of the value of exposure factors, total hazard quotients indicate alarming and unacceptable risk levels at HIMe = from 4 to 8.67; and at HI 95th Perc = from 8.7 to 16.8.
Written informed consent for living liver donor evaluation: compliance with Centers for Medicare and Medicaid Services and Organ Procurement and Transplantation Network Guidelines and alibi offers.

PubMed

Thiessen, Carrie; Kim, Yunsoo A; Yoo, Peter S; Rodriguez-Davalos, Manuel; Mulligan, David; Kulkarni, Sanjay

2014-04-01

We examined written informed consent forms for living liver donor evaluations to determine whether they incorporated elements required by the Centers for Medicare and Medicaid Services (CMS) and suggested by the Organ Procurement and Transplantation Network (OPTN). We contacted each of the 41 US centers that performed at least 1 living donor liver transplant in 2011; 37 centers reported active living donor evaluation programs. Twenty-six centers shared their consent form for living donor evaluation (response rate = 70%). Each document was double-coded for consent element content. We found that 57% of the centers included the 9 mandated CMS elements. Although the OPTN guidelines are non-binding, 78% of the centers used consent forms that addressed at least two-thirds of the elements recommended by OPTN. Only 17% of the centers provided written offers of an alibi to donors who withdrew from the evaluation. On the basis of our findings, we offer suggestions that may be relevant to ongoing revisions to the OPTN living liver donor consent policy and may help centers to improve the clarity of their written consent forms. © 2014 American Association for the Study of Liver Diseases.
Deriving an atmospheric budget of total organic bromine using airborne in-situ measurements of brominated hydrocarbons in the Western Pacific during SHIVA

NASA Astrophysics Data System (ADS)

Sala, Stephan; Bönisch, Harald; Keber, Timo; Oram, Dave; Mills, Graham; Engel, Andreas

2014-05-01

Halogenated hydrocarbons play a major role as precursors for stratospheric ozone depletion. Released from the surface in the troposphere, the halocarbons reach the stratosphere via transport through the tropical tropopause layer. The contribution of the so called very short lived species (VSLS), having atmospheric lifetimes of less than half a year as sources gases for stratospheric bromine is significant. Source gas observations of long-lived bromine compounds and VSLS have so far not been able to explain the amount of bromine derived in the stratosphere from observations of BrO and modeling of the ratio of BrO to total bromine. Due to the short lifetimes and the high atmospheric variability, the representativeness of the available observations of VSLS source gases remains unclear, as these may vary with region and display seasonal variability. During the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) project an extensive dataset with over 700 samples of ambient air of all halogen species relevant for the atmospheric budget of total organic bromine (long lived halocarbons: H-1301, H-1211, H-1202, H-2402 and CH3Br, very short lived substances: CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CHBrCl) have been collected from onboard the FALCON aircraft in the West Pacific region. Measurements were performed with the newly developed fully-automated in-situ instrument GHOST-MS (Gas chromatograph for the Observation of Tracers - coupled with a Mass Spectrometer) by the Goethe University of Frankfurt and with the onboard whole-air sampler WASP with subsequent ground based state-of-the-art GC/MS analysis by the University of East Anglia. We will present the datasets, compare these to other observation, derive a bromine budget for the West Pacific and derive an estimate of the amount of bromine from VSLS reaching the stratosphere. Using the mean mixing ratios in the upper troposphere of the halocarbons mentioned above, the calculated budget of the total organic bromine is (20.01 ± 1.77) ppt and the total amount from VSLS is (4.35 ± 0.59) ppt. Regarding the entry of bromine in the stratosphere, the estimation of the bromine content at the LZRH gives a value of (18.54 ± 1.78) ppt and a value of (2.88 ± 0.60) ppt from VSLS, reflecting a fraction of 16% of the total bromine budget.
Validation of mega composite sampling and nationwide mass inventories for 26 previously unmonitored contaminants in archived biosolids from the U.S National Biosolids Repository

PubMed Central

Chari, Bipin P.; Halden, Rolf U.

2012-01-01

In the present study, archived U.S biosolids from the 2001 Environmental Protection Agency (EPA) National Sewage Sludge Survey were analyzed with an expanded U.S EPA Method 1694, to determine the occurrence of 26 previously unmonitored pharmaceuticals and personal care products (PPCPs) among a total of 120 analytes. The study further served to examine the reproducibility of a mega-composite approach for creating chemical mass inventories in biosolids based on pooled samples from wastewater treatment plants (WWTPs) nationwide. Five mega-composites reflecting 94 WWTPs in 32 states and the District of Columbia were constructed from archived biosolids and analyzed by LC/ESI-MS/MS using a newly introduced analytical method expanding upon U.S EPA Method 1694. In addition, soil-biosolids mixtures from a mesocosm setup were analyzed to experimentally determine the half-lives of biosolids-borne compounds applied on U.S land. Among 59 analytes detected, 33 had been reported previously, whereas 26 are reported in biosolids for the first time, at levels ranging from 1.65 to 673 μg kg−1 dry weight. Newly recognized biosolids constituents were identified as Ca2+ channel blockers, antidepressants, diuretics, β-blockers and analgesics. Using a mass balance approach, the total loading of these 26 pharmaceuticals to U.S soils from biosolids land application was estimated at 5–15 tons year−1. Past and present datasets for 30 pharmaceuticals and personal care products (PPCPs) were determined to be statistically indistinguishable (paired t-test; p = 0.01). This study expands the list of PPCPs reported in U.S biosolids, provides the first estimates of nationwide release rates to and environmental half-lives in U.S agricultural soils, and confirms the utility of using mega-composite sampling for economical tracking of chemical inventories in biosolids on a national scale. PMID:22789759
Characterisation of particulate exposure during fireworks displays

NASA Astrophysics Data System (ADS)

Joly, Alexandre; Smargiassi, Audrey; Kosatsky, Tom; Fournier, Michel; Dabek-Zlotorzynska, Ewa; Celo, Valbona; Mathieu, David; Servranckx, René; D'amours, Réal; Malo, Alain; Brook, Jeffrey

2010-11-01

Little is known about the level and content of exposure to fine particles (PM 2.5) among persons who attend fireworks displays and those who live nearby. An evaluation of the levels of PM 2.5 and their elemental content was carried out during the nine launches of the 2007 Montréal International Fireworks Competition. For each event, a prediction of the location of the firework plume was obtained from the Canadian Meteorological Centre (CMC) of the Meteorological Service of Canada. PM 2.5 was measured continuously with a photometer (Sidepak™, TSI) within the predicted plume location ("predicted sites"), and integrated samples were collected using portable personal samplers. An additional sampler was located on a nearby roof ("fixed site"). The elemental composition of the collected PM 2.5 samples from the "predicted sites" was determined using both a non-destructive energy dispersive ED-XRF method and an ICP-MS method with a near-total microwave-assisted acid digestion. The elemental composition of the "fixed site" samples was determined by the ICP-MS with the near-total digestion method. The highest PM 2.5 levels reached nearly 10 000 μg m -3, roughly 1000 times background levels. Elements such as K, Cl, Al, Mg and Ti were markedly higher in plume-exposed filters. This study shows that 1) persons in the plume and in close proximity to the launch site may be exposed to extremely high levels of PM 2.5 for the duration of the display and, 2) that the plume contains specific elements for which little is known of their acute cardio-respiratory toxicity.
Putting estates issues higher on the agenda.

PubMed

2014-06-01

In HEJ's May issue we reported on the first 'half' of a lively two-and-a-half-hour roundtable discussion jointly staged by IHEEM and building and engineering services association, the B&ES, in London, which sought both to determine 'the vexed question of why so many hospital buildings services engineering projects seem to be fraught with problems', with a particular focus on 'poor commissioning', and to identify some potential solutions. Here we report on the debate's 'second half'.
Consumption of materials in the United States, 1900-1995

USGS Publications Warehouse

Matos, G.; Wagner, L.

1998-01-01

The flows of nonfood and nonfuel materials through the economy have significant impact on our lives and the world around us. Growing populations and economies demand more goods, services, and infrastructure. Since the beginning of the twentieth century, the types of materials consumed in the United States have significantly changed. In 1900, on a per-weight basis, almost half of the materials consumed were from renewable resources, such as wood, fibers, and agricultural products, the rest being derived from nonrenewable resources. By 1995, the consumption of renewable resources had declined dramatically, to only 8% of total consumption. During this century, the quantity of materials consumed has grown, from 161 million metric tons in 1900 to 2.8 billion metric tons by 1995, an equivalent of 10 metric tons per person per year. Of all the materials consumed during this century, more than half were consumed in the last 25 years. This paper examines the general historical shifts in materials consumption and presents an analysis of different measurements of materials use and the significance of their trends.
A Preliminary Study of Temperament Among Malnourished Mayan Children.

PubMed

Galler, J R; Cervera, M D; Harrison, R H

1998-01-01

Temperament ratings using a modified Carey Infant Temperament Questionnaire were assessed in marginally malnourished and healthy comparison infants aged 7-13 months. The children were selected from a total of 81 children in this age range living in a rural region of southern Yucatan, Mexico. Eleven marginally malnourished infants whose weights fell between one-half and two standard deviations below local means and 14 comparison children whose weights fell one-half to two standard deviations above the local means were included in the study. Lengths did not differ between index and comparison groups. Related temperament categories were statistically grouped into two factors. Factor 1 (Difficult Child), which included approach, mood, threshold, adaptability and rhythmicity, showed a significant nutrition × sex interaction; Factor 2 (Activity) did not distinguish the groups. Comparison boys were viewed as significantly easier than marginally malnourished boys, and they were more adaptable to change and predictable in biological functions. Girls were similar regardless of nutritional status, and their scores were intermediate between those of malnourished and well-nourished boys. These findings were not significantly associated with environmental conditions in the home.
Patterns of natural mortality in stream-living brown trout (Salmo trutta)

USGS Publications Warehouse

Lobon-Cervia, J.; Budy, P.; Mortensen, E.

2012-01-01

We tested the hypothesis that lifetime mortality patterns and their corresponding rates and causal factors differ among populations of stream-living salmonids. To this end, we examined the lifetime mortality patterns of several successive cohorts of two stream-living brown trout (Salmo trutta) populations in Spain and Denmark. In the southern population, we observed a consistent two-phase pattern, in which mortality was negligible during the first half of the lifetime and severe during the rest of the lifetime. In contrast, the northern population demonstrated a three-phase pattern with an earlier phase varying from negligible to severe, followed by a second stage of weak mortality, and lastly by a third life stage of severe mortality. Despite substantial differences in the mortality patterns between the two populations, the combined effect of recruitment (as a proxy of the density-dependent processes occurring during the lifetime) and mean body mass (as a proxy of growth experienced by individuals in a given cohort) explained c. 89% of the total lifetime mortality rates across cohorts and populations. A comparison with other published data on populations of stream-living brown trout within its native range highlighted lifetime mortality patterns of one, two, three and four phases, but also suggested that common patterns may occur in populations that experience similar individual growth and population density. ?? 2011 Blackwell Publishing Ltd.
High Variability in Cellular Stoichiometry of Carbon, Nitrogen, and Phosphorus Within Classes of Marine Eukaryotic Phytoplankton Under Sufficient Nutrient Conditions.

PubMed

Garcia, Nathan S; Sexton, Julie; Riggins, Tracey; Brown, Jeff; Lomas, Michael W; Martiny, Adam C

2018-01-01

Current hypotheses suggest that cellular elemental stoichiometry of marine eukaryotic phytoplankton such as the ratios of cellular carbon:nitrogen:phosphorus (C:N:P) vary between phylogenetic groups. To investigate how phylogenetic structure, cell volume, growth rate, and temperature interact to affect the cellular elemental stoichiometry of marine eukaryotic phytoplankton, we examined the C:N:P composition in 30 isolates across 7 classes of marine phytoplankton that were grown with a sufficient supply of nutrients and nitrate as the nitrogen source. The isolates covered a wide range in cell volume (5 orders of magnitude), growth rate (<0.01-0.9 d -1 ), and habitat temperature (2-24°C). Our analysis indicates that C:N:P is highly variable, with statistical model residuals accounting for over half of the total variance and no relationship between phylogeny and elemental stoichiometry. Furthermore, our data indicated that variability in C:P, N:P, and C:N within Bacillariophyceae (diatoms) was as high as that among all of the isolates that we examined. In addition, a linear statistical model identified a positive relationship between diatom cell volume and C:P and N:P. Among all of the isolates that we examined, the statistical model identified temperature as a significant factor, consistent with the temperature-dependent translation efficiency model, but temperature only explained 5% of the total statistical model variance. While some of our results support data from previous field studies, the high variability of elemental ratios within Bacillariophyceae contradicts previous work that suggests that this cosmopolitan group of microalgae has consistently low C:P and N:P ratios in comparison with other groups.

Human semen as an early, sensitive biomarker of highly polluted living environment in healthy men: A pilot biomonitoring study on trace elements in blood and semen and their relationship with sperm quality and RedOx status.

PubMed

Bergamo, Paolo; Volpe, Maria Grazia; Lorenzetti, Stefano; Mantovani, Alberto; Notari, Tiziana; Cocca, Ennio; Cerullo, Stefano; Di Stasio, Michele; Cerino, Pellegrino; Montano, Luigi

2016-12-01

The Campania region in Italy is facing an environmental crisis due to the illegal disposal of toxic waste. Herein, a pilot study (EcoFoodFertility initiative) was conducted to investigate the use of human semen as an early biomarker of pollution on 110 healthy males living in various areas of Campania with either high or low environmental impact. The semen from the "high impact" group showed higher zinc, copper, chromium and reduced iron levels, as well as reduced sperm motility and higher sperm DNA Fragmentation Index (DFI). Redox biomarkers (total antioxidant capacity, TAC, and glutathione, GSH) and the activity of antioxidant enzymes in semen were lower in the "high impact" group. The percentage of immotile spermatozoa showed a significant inverse correlation with TAC and GSH. Overall, several semen parameters (reduced sperm quality and antioxidant defenses, altered chemical element pattern), which were associated with residence in a high polluted environment, could be used in a further larger scale study, as early biomarkers of environmental pollution. Copyright Â© 2016 Elsevier Inc. All rights reserved.
Demonstration of a radiation resistant, high efficiency SiC betavoltaic

NASA Astrophysics Data System (ADS)

Eiting, C. J.; Krishnamoorthy, V.; Rodgers, S.; George, T.; Robertson, J. David; Brockman, John

2006-02-01

A SiC p-i-n junction betavoltaic was fabricated, and electrical power output under irradiation from an 8.5GBq P33 source was monitored over a period of four half-lives of the radioisotope. The open-circuit voltage (VOC) of the device was 2.04±0.02V, and the peak power (Pout) was 0.58±0.02μW (2.1±0.2μW /cm2) at 1.60V. The conversion efficiency (ηconv) was 4.5%±0.3% and the normalized power output indicates no device degradation over more than 3months (four half-lives of the source).
A comparative analysis of alpha-decay half-lives for even-even 178Pb to 234U isotopes

NASA Astrophysics Data System (ADS)

Hosseini, S. S.; Hassanabadi, H.; Zarrinkamar, S.

2018-02-01

The feasibility for the alpha decay from the even-even transitions of 178Pb to 234U isotopes has been studied within the Coulomb and proximity potential model (CPPM). The alpha decay half-lives are considered from different theoretical approaches using Semi-empirical formula of Poenaru et al. (SemFIS), the Universal Decay law (UDL) of Qi et al., Akrawy-Dorin formula of Akrawy and Poenaru (ADF), the Scaling law of Brown (SLB) and the Scaling Law of Horoi et al. (SLH). The numerical results obtained by the CPPM and compared with other method as well the experimental data.
Recent Advances in GLP-1 Receptor Agonists for Use in Diabetes Mellitus.

PubMed

McBrayer, Dominic N; Tal-Gan, Yftah

2017-09-01

Preclinical Research Mimetics of Glucagon-like peptide 1 (GLP-1) represent a useful alternative or complementary treatment choice to insulin in the treatment of diabetes mellitus. The lack of hypoglycemia as a side effect when GLP-1 receptor agonists are used along with the tendency of these therapeutic agents to prevent or even reduce weight gain makes them valuable targets in therapy development. However, native GLP-1 and many of its early analogues have very short half-lives, requiring repeated treatment to maintain therapeutic levels. As all current treatments are injected subcutaneously, a large focus has been made on trying to extend the half-lives of GLP-1 analogues while retaining bioactivity. Most success in this regard has been achieved with the use of peptide-protein fusions, which are not as well suited for oral administration. However, recent work focused on the development of non-fusion peptides with increased half-lives that may be more appropriate for oral administration. This minireview discusses the structural characteristics of past and present analogues as well as the recent work conducted toward developing novel GLP-1 receptor agonists. Drug Dev Res 78 : 292-299, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Recovery of Coastal Fauna after the 2011 Tsunami in Japan as Determined by Bimonthly Underwater Visual Censuses Conducted over Five Years.

PubMed

Masuda, Reiji; Hatakeyama, Makoto; Yokoyama, Katsuhide; Tanaka, Masaru

2016-01-01

Massive tsunamis induce catastrophic disturbance in marine ecosystems, yet they can provide unique opportunities to observe the process of regeneration. Here, we report the recovery of fauna after the 2011 tsunami in northeast Japan based on underwater visual censuses performed every two months over five years. Both total fish abundance and species richness increased from the first to the second year after the tsunami followed by stabilization in the following years. Short-lived fish, such as the banded goby Pterogobius elapoides, were relatively abundant in the first two years, whereas long-lived species, such as the black rockfish Sebastes cheni, increased in the latter half of the survey period. Tropical fish species were recorded only in the second and third years after the tsunami. The body size of long-lived fish increased during the survey period resulting in a gradual increase of total fish biomass. The recovery of fish assemblages was slow at one site located in the inner bay, where the impact of the tsunami was the strongest. Apart from fish, blooms of the moon jellyfish Aurelia sp. occurred only in the first two years after the tsunami, whereas the abundances of sea cucumber Apostichopus japonicus and abalone Haliotis discus hannai increased after the second year. Although we lack quantitative data prior to the tsunami, we conclude that it takes approximately three years for coastal reef fish assemblages to recover from a heavy disturbance such as a tsunami and that the recovery is dependent on species-specific life span and habitat.
Recovery of Coastal Fauna after the 2011 Tsunami in Japan as Determined by Bimonthly Underwater Visual Censuses Conducted over Five Years

PubMed Central

Masuda, Reiji; Hatakeyama, Makoto; Yokoyama, Katsuhide; Tanaka, Masaru

2016-01-01

Massive tsunamis induce catastrophic disturbance in marine ecosystems, yet they can provide unique opportunities to observe the process of regeneration. Here, we report the recovery of fauna after the 2011 tsunami in northeast Japan based on underwater visual censuses performed every two months over five years. Both total fish abundance and species richness increased from the first to the second year after the tsunami followed by stabilization in the following years. Short-lived fish, such as the banded goby Pterogobius elapoides, were relatively abundant in the first two years, whereas long-lived species, such as the black rockfish Sebastes cheni, increased in the latter half of the survey period. Tropical fish species were recorded only in the second and third years after the tsunami. The body size of long-lived fish increased during the survey period resulting in a gradual increase of total fish biomass. The recovery of fish assemblages was slow at one site located in the inner bay, where the impact of the tsunami was the strongest. Apart from fish, blooms of the moon jellyfish Aurelia sp. occurred only in the first two years after the tsunami, whereas the abundances of sea cucumber Apostichopus japonicus and abalone Haliotis discus hannai increased after the second year. Although we lack quantitative data prior to the tsunami, we conclude that it takes approximately three years for coastal reef fish assemblages to recover from a heavy disturbance such as a tsunami and that the recovery is dependent on species-specific life span and habitat. PMID:27942028
Weight optimization of large span steel truss structures with genetic algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mojolic, Cristian; Hulea, Radu; Pârv, Bianca Roxana

2015-03-10

The paper presents the weight optimization process of the main steel truss that supports the Slatina Sport Hall roof. The structure was loaded with self-weight, dead loads, live loads, snow, wind and temperature, grouped in eleven load cases. The optimization of the structure was made using genetic algorithms implemented in a Matlab code. A total number of four different cases were taken into consideration when trying to determine the lowest weight of the structure, depending on the types of connections with the concrete structure ( types of supports, bearing modes), and the possibility of the lower truss chord nodes tomore » change their vertical position. A number of restrictions for tension, maximum displacement and buckling were enforced on the elements, and the cross sections are chosen by the program from a user data base. The results in each of the four cases were analyzed in terms of weight, element tension, element section and displacement. The paper presents the optimization process and the conclusions drawn.« less
National estimation of children in residential care institutions in Cambodia: a modelling study.

PubMed

Stark, Lindsay; Rubenstein, Beth L; Pak, Kimchoeun; Kosal, Sok

2017-01-16

The primary objective of this study was to collect baseline data on the number of children living in residential care institutions in Cambodia. The secondary objective was to describe the characteristics of the children (eg, age, sex, duration of stay, education and health). The data were intended to guide recent efforts by the Government of Cambodia to reduce the number of children living in residential care institutions and increase the number of children growing up in supportive family environments. Data were collected in Cambodia across 24 sites at the commune level. Communes-administrative divisions roughly equivalent to counties-were selected by the National Institute of Statistics using a two-stage sampling method. Government lists and key informant interviews were used to construct a complete roster of institutions across the 24 communes. All identified institutions were visited to count the number of children and gather data on their basic characteristics. The rate of children in residential care in the selected communes was calculated as a percentage of total population using a Poisson model. This rate was applied to all districts in Cambodia with at least one reported residential care institution. A total of 3588 children were counted across 122 institutions. A child living in a residential care institution was defined as anyone under the age of 18 years who was sleeping in the institution for at least four nights per week during the data collection period. There are an estimated 48 775 children living in residential care institutions in Cambodia. The vast majority of children have a living parent and are school-aged. More than half are between 13 and 17 years of age. Nearly 1 of every 100 children in Cambodia is living in residential care. This raises substantial concerns for child health, protection and national development. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
The impact of atmospheric dust deposition and trace elements levels on the villages surrounding the former mining areas in a semi-arid environment (SE Spain)

NASA Astrophysics Data System (ADS)

Sánchez Bisquert, David; Matías Peñas Castejón, José; García Fernández, Gregorio

2017-03-01

It is understood that particulate matter in the atmosphere from metallic mining waste has adverse health effects on populations living nearby. Atmospheric deposition is a process connecting the mining wasteswith nearby ecosystems. Unfortunately, very limited information is available about atmospheric deposition surrounding rural metallic mining areas. This article will focus on the deposition from mining areas, combined with its impact on nearby rural built areas and populations. Particle samples were collected between June 2011 and March 2013. They were collected according to Spanish legislation in ten specialised dust collectors. They were located near populations close to a former Mediterranean mining area, plus a control, to assess the impact of mining waste on these villages. This article and its results have been made through an analysis of atmospheric deposition of these trace elements (Mn, Zn, As, Cd and Pb). It also includes an analysis of total dust flux. Within this analysis it has considered the spatial variations of atmospheric deposition flux in these locations. The average annual level of total bulk deposition registered was 42.0 g m-2 per year. This was higher than most of the areas affected by a Mediterranean climate or in semi-arid conditions around the world. Regarding the overall analysis of trace elements, the annual bulk deposition fluxes of total Zn far exceeded the values of other areas. While Mn, Cd and Pb showed similar or lower values, and in part much lower than those described in other Mediterranean mining areas. This study confirmed some spatial variability of dust and trace elements, contained within the atmospheric deposition. From both an environmental and a public health perspective, environmental managers must take into account the cumulative effect of the deposition of trace elements on the soil and air quality around and within the villages surrounding metallic mining areas.
Socio-economic cultural transformations and Depression in elderly people.

PubMed

Stranieri, Giuseppe; Carabetta, Carmelo

2015-09-01

The socio-economic and cultural evolution in the last decades encouraged a significant process of transformation of the life conditions in advanced societies, particularly the average duration of the life of the elderly population, which since the second half of the past century has increased by about 60%, becoming from an average of fifty years to about eighty two for women and eighty for men. This phenomenon enables scholars and in particular demography scholars, to assume that in 2030 the number of elderly persons will reach about two billion worldwide. This development of an increasingly longer life expectancy, justifies the trust in the great progress that characterizes our society. The rapid growth of this segment of population, due to the improved living conditions and the related progress in science, technology and medicine, in addition to its positive aspects, also includes negative elements, which already affect the Welfare State and, more generally, the public administration that is called to fill the gaps that the transformation of the family and kinship networks have treated with indifference. The problems of the increasingly long-lived, is not freed from new elements of negativity related to the physical and mental decline that leads to the development of new diseases in addition to those already present, ans is increasingly motivated to seek the best remedies to shorten or eliminate the diseases of the elderly. In this context, Depression assumes a central dimension which will surely be a central concern for the economic, social and health impact and for the multitude of changes that put in crisis many of the traditional institutions. This work aims to analyze through a careful review of the scientific literature, the causes of the spread of this disease, the diagnostic difficulties and possible solutions for prevention and care.
Soil pollution in Central district of Saint-Petersburg (Russia)

NASA Astrophysics Data System (ADS)

Terekhina, Natalia; Ufimtseva, Margarita

2015-04-01

Analysis of soil samples of upper horizon for the content of chemical elements (Fe, Mn, Cu, Zn, Pb, Ni, Cr, Co, Cd, Ba, Sr) was carried out by atomic emission with inductively coupled plasma. A relative indicator of soil contamination degree is a concentration coefficient, representing the ratio of metal content in tested soil samples to the local background value of the corresponding element. Total pollution index is calculated by the concentration coefficients, which are greater than 1, taking into account the hazard class of metals (1 class - Zn, Pb ,Cd; 2 - class Cr, Ni, Cu ,Со; 3 class - Fe, Mn, Sr, Ba). Analysis of trace element of urban soils demonstrated mosaic patterns of pollution for Central district. The method of correlation sets constructing and factor analysis revealed three groups of chemical elements having a strong and significant association with each other: Pb-Cu-Cd-Zn-Ba, Ni-Cr-Co, Fe-Mn. Elements of the first group are characterized by high values of concentration coefficient and are the main pollutants - their average content is 3-11 times higher than background values. Strontium does not have strong correlation with the other elements, and its lowest concentration coefficient indicates that the element can not be regarded as a pollutant. The spatial distribution of the total pollution index identified several sources of pollution, the origin of which may be different. The main reason is probably the impact of vehicle emissions, although local pollution of soil is possible (the soils, contaminated during reconstruction of lawns, dumping of construction materials, etc.). Differentiated assessment of database shows that 48% of samples refer to dangerous pollution category, 37% - to moderately dangerous category, 15% - to allowable category. Thus, almost half of the district is characterized as dangerous in terms of soil contamination. Solution of the problem of soil contamination is recommended in three ways: reducing the intensity of vehicular traffic through the historic center of the city, improving the quality of transport emissions, removal of contaminated soil layers in particularly polluted areas and the introduction of clean soil, optimization of verdurization of the urban environment, as a means of reducing the flow of atmospheric pollutants in soil.
Thermoviscoplastic response of thin plates subjected to intense local heating

NASA Technical Reports Server (NTRS)

Byrom, Ted G.; Allen, David H.; Thornton, Earl A.

1992-01-01

A finite element method is employed to investigate the thermoviscoplastic response of a half-cylinder to intense localized transient heating. Thermoviscoplastic material behavior is characterized by the Bodner-Partom constitutive model. Structure geometry is modeled with a three-dimensional assembly of CST-DKT plate elements incorporating the large deflection von Karman assumptions. The paper compares the results of a dynamic analysis with a quasi-static analysis for the half-cylinder structure with a step-function transient temperature loading similar to that which may be encountered with shock wave interference on a hypersonic leading edge.
A Proposal for Assessing Study Quality: Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals (BEES-C) Instrument

EPA Science Inventory

The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals...
Ways in Analyzing and Responding to Literature.

ERIC Educational Resources Information Center

Rockas, Leo

Intended as a guide for students of literature, this book introduces literary analysis through discussion of forms, elements, and genres. The first half of the book focuses on theory, with each section preceded by literary passages and interpretative questions. The second half is devoted to practice, and contains three contrasting literary genre…
Subject-Specific Modeling of Muscle Force and Knee Contact in Total Knee Arthroplasty

PubMed Central

Navacchia, Alessandro; Rullkoetter, Paul J.; Schütz, Pascal; List, Renate B.; Fitzpatrick, Clare K.; Shelburne, Kevin B.

2017-01-01

Understanding the mechanical loading environment and resulting joint mechanics for activities of daily living in total knee arthroplasty is essential to continuous improvement in implant design. Although survivorship of these devices is good, a substantial number of patients report dissatisfaction with the outcome of their procedure. Knowledge of in vivo kinematics and joint loading will enable improvement in preclinical assessment and refinement of implant geometry. The purpose of this investigation was to describe the mechanics of total knee arthroplasty during a variety of activities of daily living (gait, walking down stairs, and chair rise/sit). Estimates of muscle forces, tibial contact load, location, and pressure distribution was performed through a combination of mobile fluoroscopy data collection, musculoskeletal modeling, and finite element simulation. For the activities evaluated, joint compressive load was greatest during walking down stairs; however, the highest contact pressure occurred during chair rise/sit. The joint contact moment in the frontal plane was mainly varus for gait and walking down stairs, while it was valgus during chair rise/sit. Excursion of the center of pressure on the tibial component was similar during each activity and between the medial and lateral sides. The main determinants of center of pressure location were internal–external rotation, joint load, and tibial insert conformity. PMID:26792665
@Astro_Wheels Tweetup

NASA Image and Video Library

2011-03-16

Astronaut Doug Wheelock discusses his experiences while living on the International Space Station during a tweetup at NASA Headquarters in Washington, Wednesday, March 16, 2011. Wheelock, who has accumulated a total of 178 days in space, assumed command of the International Space Station and the Expedition 25 crew. During Expedition 25, there were more than 120 microgravity experiments in human research; biology and biotechnology; physical and materials sciences; technology development; and Earth and space sciences. Wheelock also responded to an emergency shutdown of half of the station's external cooling system and supported three unplanned spacewalks to replace the faulty pump module that caused the shutdown. His efforts restored the station's critical cooling system to full function. The mission duration was 163 days. Photo Credit: (NASA/Paul E. Alers)
Education Development among Bedouin Tribes of the Negev Desert. [Paper and Discussion.

ERIC Educational Resources Information Center

Abu-Rabia, Aref

About 60,000 Bedouins live in the Negev Desert, which comprises 60% of Israel. Of these, about half live in towns, a third live in settlements of huts for all or part of the year, while a sixth continue to follow traditional nomadic practices. The number of Bedouin children enrolled in school has grown from 150 in 1950 to about 16,000 in 1986.…
Chemical Composition of Rainwater in Córdoba City, Argentina

NASA Astrophysics Data System (ADS)

López, M. L.; Asar, M. L.; Ceppi, S.; Bürgesser, R. E.; Avila, E.

2013-05-01

Sampling and chemical analysis of rainwater has proved to be a useful technique for studying its chemical composition and provides a greater understanding of local and regional dispersion of pollutants and their potential impacts to ecosystems through deposition processes. Samples of rainwater were collected during 2009-2012, in Córdoba city, Argentina. Two kind of sampling were performed: event-specific and sequential. The objective of the first of these was to determine the chemical concentration of the total rain, while the objective of the second one was to analyze the variability of the chemical concentration during an individual rain event. The total volume of each sample was divided in halves. One half was filtered through 0.45 μm membrane filter. After this, all the samples were reduced by evaporation to a final volume of 10 ml. The non-filtered samples were acidified and digested in accordance to the method 3050B of the Environmental Protection Agency (EPA) for acid digestion of sediments. Multi-elemental standard solutions in different concentrations were prepared by adequate dilutions. Gallium was added as an internal standard in all standard solutions and samples. Exactly 5 μL of these solutions were deposited on acrylic supports. When these droplets were dried, Synchrotron Radiation Total Reflection X-Ray Fluorescence technique was used for determining the chemical elements. Spectra were analyzed with the AXIL package for spectrum analysis. Due to the intrinsic characteristics of the total reflection technique, the background of the measurements is significantly reduced and there are no matrix effects, therefore quantification can be obtained from the linear correlation between fluorescence intensity and the concentration of the element of interest. The elements quantified were S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, and Pb. For all of them a calibration curve was performed in order to quantify their concentrations on the samples. The results show that the average pH in city rainwater was pH=6.5; the elements found in the samples were S, Ca, Cu, Cr, Sr, P, Fe, Mn, Pb, K, Ti, V, Zn and the average concentrations of these elements were below the limits established by World Health Organization for drinking water, and show a high natural variability. The temporal evolution of inorganic ion concentration during rain events was analyzed and the scavenging coefficients were calculated and compared with data from literature. A comparison was made between the rainwater chemical composition and chemical composition in the aerosols scavenging during the rain. This study is the first in Córdoba city to analyze the chemical composition of rainwater and constitute a base for future comparison of variability in pH and elemental composition.
Deformations resulting from the movements of a shear or tensile fault in an anisotropic half space

NASA Astrophysics Data System (ADS)

Sheu, Guang Y.

2004-04-01

Earlier solutions (Bull. Seismol. Soc. Amer. 1985; 75:1135-1154; Bull. Seismol. Soc. Amer. 1992; 82:1018-1040) of deformations caused by the movements of a shear or tensile fault in an isotropic half-space for finite rectangular sources of strain nucleus have been extended for a transversely isotropic half-space. Results of integrating previous solutions (Int. J. Numer. Anal. Meth. Geomech. 2001; 25(10): 1175-1193) of deformations due to a shear or tensile fault in a transversely isotropic half-space for point sources of strain nucleus over the fault plane are presented. In addition, a boundary element (BEM) model (POLY3D:A three-dimensional, polygonal element, displacement discontinuity boundary element computer program with applications to fractures, faults, and cavities in the Earth's crust. M.S. Thesis, Stanford University, Department of Geology, 1993; 62) is given. Different from similar researches (e.g. Thomas), the Akaike's view on Bayesian statistics (Akaike Information Criterion Statistics. D. Reidel Publication: Dordrecht, 1986) is applied for inverting deformations due to a fault to obtain displacement discontinuities on the fault plane.An example is given for checking displacements predicted by proposed analytical expressions. Another example is generated for the use of proposed BEM model. It demonstrates the effectiveness of this model in exploring displacement behaviours of a fault. Copyright
Annual report of the United States transuranium and uranium registries, October 1, 1988--September 30, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kathren, R.L.; Swint, M.J.; Dietert, S.E.

1990-04-01

This report summarizes the primary scientific activities of the United States Transuranium and Uranium Registries for the period October 1, 1988 through September 30, 1989. The Registries are parallel human tissue research programs devoted to the study of the actinide elements in man. The emphasis of the Transuranium Registry was directed toward evaluation of six whole body donations. In the five cases whose exposure was through inhalation, approximately half of the total body content of Pu-239 + 240 and a third of the Am-241 was found in the respiratory tract, suggesting that these nuclides are more avidly retained than predictedmore » by the current model of the International Commission on Radiological Protection. A significant fraction of these nuclides is found in soft tissues other than liver, and an uptake fraction of 0.2 is proposed for muscle, with a residence half-time of 10 years. Studies of these and routine autopsy cases indicate that more than 90% of the total respiratory tract plutonium or americium is in the lungs, with the remainder in the lymph nodes, and that a greater fraction is found in the lungs of smokers relative to the lymph nodes. Primary activities of the Uranium Registry centered around the acquisition of a whole body donation from a woman who had received an injection of colloidal thorium dioxide some 38 years prior to death.« less

Trends In Rhode Island Forests: A Half-Century of Change

Treesearch

Northeastern Research Station and Rhode Island Department of Environmental Management Division of Forest Environment

2002-01-01

Forests provide watershed protection, settings for recreation, wildlife habitat, biodiversity, wood and other products, and much more. Forests contribute to the quality of life of each Rhode Island resident making the State a better place in which to live. Some of the significant trends that have occurred in Rhode Island's forests over the last half century are...
Conservation of species, volume, and belief in patients with Alzheimer's disease: the issue of domain specificity and conceptual impairment.

PubMed

Zaitchik, Deborah; Solomon, Gregg E A

2009-09-01

Two studies investigated whether patients with Alzheimer's disease (AD) suffer high-level and category-specific impairment in the conceptual domain of living things. In Experiment 1, AD patients and healthy young and healthy elderly controls took part in three tasks: the conservation of species, volume, and belief. All 3 tasks required tracking an object's identity in the face of irrelevant but salient transformations. Healthy young and elderly controls performed at or near ceiling on all tasks. AD patients were at or near ceiling on the volume and belief tasks, but only about half succeeded on the species task. Experiment 2 demonstrated that the results were not due to simple task demands. AD patients' failure to conserve species indicates that they are impaired in their theoretical understanding of living things, and their success on the volume and belief tasks suggests that the impairment is domain-specific. Two hypotheses are put forward to explain the phenomenon: The first, a category-specific account, holds that the intuitive theory of biology undergoes pervasive degradation; the second, a hybrid domain-general/domain-specific account, holds that impairment to domain-general processes such as executive function interacts with core cognition, the primitive elements that are the foundation of domain-specific knowledge.
Conservation of species, volume, and belief in patients with Alzheimer’s disease: the issue of domain-specificity and conceptual impairment

PubMed Central

Zaitchik, Deborah; Solomon, Gregg E. A.

2009-01-01

Two studies investigated whether patients with Alzheimer’s disease (AD) suffer high-level and category-specific impairment in the conceptual domain of living things. In Study 1, AD patients and healthy young and healthy elderly controls took part in three tasks: the Conservation of Species, Volume, and Belief. All 3 tasks required tracking an object’s identity in the face of irrelevant but salient transformations. Healthy young and elderly controls performed at or near ceiling on all tasks. AD patients were at or near ceiling on the Volume and Belief tasks, but only about half succeeded on the Species task. Study 2 demonstrated that the results were not due to simple task demands. AD patients’ failure to conserve species indicates that they are impaired in their theoretical understanding of living things, and their success on the Volume and Belief tasks suggests that the impairment is domain-specific. Two hypotheses are put forward to explain the phenomenon: the first, a category-specific account, holds that the intuitive theory of biology undergoes pervasive degradation; the second, a hybrid domain-general/domain-specific account, holds that impairment to domain-general processes such as executive function interacts with core cognition, the primitive elements that are the foundation of domain-specific knowledge. PMID:20043252
Five-year follow-up of persons with brain injury entering the French vocational and social rehabilitation programme UEROS: Return-to-work, life satisfaction, psychosocial and community integration.

PubMed

Cogné, M; Wiart, L; Simion, A; Dehail, P; Mazaux, J-M

2017-01-01

Social and vocational reintegration of persons with brain injury is an important element in their rehabilitation. To evaluate the 5-year outcome of persons with brain injury included in 2008 in the Aquitaine Unit for Evaluation, Training and Social and Vocational Counselling programme (UEROS). 57 persons with brain injury were recruited from those who completed the 2008 UEROS programme. Five years later, an interview was done to assess family and vocational status, autonomy and life satisfaction. These results were compared with those from persons completing the 1997-1999 programme. The typical person entered the 2008 UEROS programme 6 years after a severe brain injury (42%) and was male, single and 35 years. At the 5-year follow-up, more persons lived with a partner (+23%) and lived in their own home (+21%). 47% were working vs 11% on entering the programme. Approximately half were satisfied or very satisfied with their quality of life. Having a job in 2013 was associated with a high education level, less cognitive sequelae, having a job in 2008 and no health condition. The UEROS programme is effective with regard to return-to-work and improvement of autonomy in persons with brain injury, irrespective of length of time from injury.
The Effect of Intensified Language Exposure on Accommodating Talker Variability.

PubMed

Antoniou, Mark; Wong, Patrick C M; Wang, Suiping

2015-06-01

This study systematically examined the role of intensified exposure to a second language on accommodating talker variability. English native listeners (n = 37) were compared with Mandarin listeners who had either lived in the United States for an extended period of time (n = 33) or had lived only in China (n = 44). Listeners responded to target words in an English word-monitoring task in which sequences of words were randomized. Half of the sequences were spoken by a single talker and the other half by multiple talkers. Mandarin listeners living in China were slower and less accurate than both English listeners and Mandarin listeners living in the United States. Mandarin listeners living in the United States were less accurate than English natives only in the more cognitively demanding mixed-talker condition. Mixed-talker speech affects processing in native and nonnative listeners alike, although the decrement is larger in nonnatives and further exaggerated in less proficient listeners. Language immersion improves listeners' ability to resolve talker variability, and this suggests that immersion may automatize nonnative processing, freeing cognitive resources that may play a crucial role in speech perception. These results lend support to the active control model of speech perception.
Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors.

PubMed

Chiba, Satoshi; Wakabayashi, Toshio; Tachi, Yoshiaki; Takaki, Naoyuki; Terashima, Atsunori; Okumura, Shin; Yoshida, Tadashi

2017-10-24

Transmutation of long-lived fission products (LLFPs: 79 Se, 93 Zr, 99 Tc, 107 Pd, 129 I, and 135 Cs) into short-lived or non-radioactive nuclides by fast neutron spectrum reactors without isotope separation has been proposed as a solution to the problem of radioactive wastes disposal. Despite investigation of many methods, such transmutation remains technologically difficult. To establish an effective and efficient transmutation system, we propose a novel neutron moderator material, yttrium deuteride (YD 2 ), to soften the neutron spectrum leaking from the reactor core. Neutron energy spectra and effective half-lives of LLFPs, transmutation rates, and support ratios were evaluated with the continuous-energy Monte Carlo code MVP-II/MVP-BURN and the JENDL-4.0 cross section library. With the YD 2 moderator in the radial blanket and shield regions, effective half-lives drastically decreased from 106 to 102 years and the support ratios reached 1.0 for all six LLFPs. This successful development and implementation of a transmutation system for LLFPs without isotope separation contributes to a the ability of fast spectrum reactors to reduce radioactive waste by consuming their own LLFPs.
OA27 Rural palliative care for low resource settings among marginalised communities in the south indian state of tamilnadu - a new venture with two and a half years of outcome.

PubMed

Thiagarajan, Mohanasundaram

2015-04-01

India with a total of 1.27 Billion (2014) population and over 73% of them are living in rural areas. Cancer remaining as the second cause of death in rural community and at any given time over 4 million cancer cases are living in our country and most of them are diagnosed at their advanced stages and suffering with intractable pain and 'total sufferings'. At present, time available for palliative care services is less than 1% for the needy, it is mostly spread out around the urban areas leaving the remaining 73% of rural sufferers in lack of availability, accessibility, acceptability and affordability. To identify the need for palliative care, in a particular Block of the district, and provide home based total care. Selection of 'Andanallur' village block with a population of nearly 100,000. Sensitisation of the health care staff, village members, self help groups and schools and through the Information, educative and communication methods. Conduction of a primary survey to identify the needy Examination and short listing cases for home based Palliative care Home based palliative care The project was started in 2011 January and 156 cases short listed; 121 cases started with home care and 52 cases had passed away, 8 cases were given end of life care. Palliative care reaching the sufferers directly Reaching the unreachable and under-privileged Need based 'total care' at their door steps Empowering and training the family members. © 2015, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
The Physical/Chemical Closed-Loop Life Support Research Project

NASA Technical Reports Server (NTRS)

Bilardo, Vincent J., Jr.

1990-01-01

The various elements of the Physical/Chemical Closed-Loop Life Support Research Project (P/C CLLS) are described including both those currently funded and those planned for implementation at ARC and other participating NASA field centers. The plan addresses the entire range of regenerative life support for Space Exploration Initiative mission needs, and focuses initially on achieving technology readiness for the Initial Lunar Outpost by 1995-97. Project elements include water reclamation, air revitalization, solid waste management, thermal and systems control, and systems integration. Current analysis estimates that each occupant of a space habitat will require a total of 32 kg/day of supplies to live and operate comfortably, while an ideal P/C CLLS system capable of 100 percent reclamation of air and water, but excluding recycling of solid wastes or foods, will reduce this requirement to 3.4 kg/day.
Comparative genome analysis of 52 fish species suggests differential associations of repetitive elements with their living aquatic environments.

PubMed

Yuan, Zihao; Liu, Shikai; Zhou, Tao; Tian, Changxu; Bao, Lisui; Dunham, Rex; Liu, Zhanjiang

2018-02-13

Repetitive elements make up significant proportions of genomes. However, their roles in evolution remain largely unknown. To provide insights into the roles of repetitive elements in fish genomes, we conducted a comparative analysis of repetitive elements of 52 fish species in 22 orders in relation to their living aquatic environments. The proportions of repetitive elements in various genomes were found to be positively correlated with genome sizes, with a few exceptions. More importantly, there appeared to be specific enrichment between some repetitive element categories with species habitat. Specifically, class II transposons appear to be more abundant in freshwater bony fish than in marine bony fish when phylogenetic relationship is not considered. In contrast, marine bony fish harbor more tandem repeats than freshwater species. In addition, class I transposons appear to be more abundant in primitive species such as cartilaginous fish and lamprey than in bony fish. The enriched association of specific categories of repetitive elements with fish habitats suggests the importance of repetitive elements in genome evolution and their potential roles in fish adaptation to their living environments. However, due to the restriction of the limited sequenced species, further analysis needs to be done to alleviate the phylogenetic biases.
Female married illiteracy as the most important continual determinant of total fertility rate among districts of Empowered Action Group States of India: Evidence from Annual Health Survey 2011-12.

PubMed

Kumar, Rajesh; Dogra, Vishal; Rani, Khushbu; Sahu, Kanti

2017-01-01

District level determinants of total fertility rate in Empowered Action Group states of India can help in ongoing population stabilization programs in India. Present study intends to assess the role of district level determinants in predicting total fertility rate among districts of the Empowered Action Group states of India. Data from Annual Health Survey (2011-12) was analysed using STATA and R software packages. Multiple linear regression models were built and evaluated using Akaike Information Criterion. For further understanding, recursive partitioning was used to prepare a regression tree. Female married illiteracy positively associated with total fertility rate and explained more than half (53%) of variance. Under multiple linear regression model, married illiteracy, infant mortality rate, Ante natal care registration, household size, median age of live birth and sex ratio explained 70% of total variance in total fertility rate. In regression tree, female married illiteracy was the root node and splits at 42% determined TFR <= 2.7. The next left side branch was again married illiteracy with splits at 23% to determine TFR <= 2.1. We conclude that female married illiteracy is one of the most important determinants explaining total fertility rate among the districts of an Empowered Action Group states. Focus on female literacy is required to stabilize the population growth in long run.
[Pharmacokinetic and clinical studies of ceftizoxime in newborn infants].

PubMed

Sato, H; Nakazawa, S; Narita, A; Nakazawa, S; Matsumoto, K; Suzuki, H; Nakanishi, Y; Chikaoka, H; Kamigaki, M; Niino, K

1988-08-01

Pharmacokinetic and clinical studies of ceftizoxime (CZX) were performed in infants given intravenously. The obtained results are summarized as follows. 1. Serum concentrations of CZX in 2 and 3 day-old mature infants given 20 mg/kg by one shot intravenous injection peaked at 49.0 and 57.9 micrograms/ml in 1 hour and decreased to 14.4 and 24.9 micrograms/ml in 8 hours after dosing, respectively. Half-lives were 3.9 and 5.6 hours, respectively. In 5 day-old or older mature infants, peak serum levels ranged from 20.9 to 38.0 micrograms/ml at 1 hour after the injection. Levels of CZX at 8 hours after injection were 1.31 to 7.32 micrograms/ml. Half-lives were 1.6-3.0 hours in all the infants except one. 2. In a 3 day-old premature infant given the same dose by a bolus intravenous injection, the serum level peaked at 45.7 micrograms/ml in 1 hour after the injection. The level at 8 hours after injection was 15.7 micrograms/ml. The half-life was 4.2 hours. In 5-15 day-old premature infants, half-lives were 2.3-3.1 hours in all the infants except one. 3. Serum concentrations of CZX in 1 and 2 day-old infants given 20 mg/kg by intravenous drip infusion peaked at 49.4 to 115.0 micrograms/ml in 1 hour after dosing. Half-lives were rather long, 4.0 and 5.1 hours, in the 2 infants. 4. Peak serum levels and half-lives tended to be lower and shorter in 5 day-old or older ones than in the 3 day-old or younger infants. 5. No changes in the serum concentration were observed even after dosing with 20 mg/kg of continuous one shot intravenous injection. 6. Urinary recovery rates during the first 8 hours (one is 6 hours, two is 9 hours) after 20 mg/kg intravenous bolus injection of CZX tended to be lower in 3 day-old or younger infants than in 5 day-old or older infants. 7. Eleven infants with various bacterial infections were given CZX by intravenous bolus injection or drip infusion. Dosage of CZX used in the present study were 36-148 mg/kg/day in 2-3 divided doses. Duration of treatment ranged from 3 to 12 days. Clinical efficacy of CZX was excellent or good in all the infants with acute bronchitis, acute pneumonia, suspected sepsis infected in uterine, acute otitis media, cellulitis, meningitis caused by Klebsiella pneumoniae and Escherichia coli, acute urinary tract infection and periproctic abscess except 1 case of acute bronchitis.(ABSTRACT TRUNCATED AT 250 WORDS)
Living in poverty in America today.

PubMed

Holosko, Michael J; Feit, Marvin D

2005-01-01

No statistician, social scientist or tarot card reader is needed to attest that the gap between the rich and poor in America is increasing. Further, most Americans don't care that much about it. There are also more rich people today living in the U.S. and there are more people living in poverty. Between 2000 and 2002, the number of Americans living in poverty increased by nearly 3 million to 34.6 million. Of these, 12% (or about one half a million persons) are living extreme poverty and many are children, with 16.7% likely to be poor (National Association of Social Workers, 2003).
Hyperthermophilic Composting Accelerates the Removal of Antibiotic Resistance Genes and Mobile Genetic Elements in Sewage Sludge.

PubMed

Liao, Hanpeng; Lu, Xiaomei; Rensing, Christopher; Friman, Ville Petri; Geisen, Stefan; Chen, Zhi; Yu, Zhen; Wei, Zhong; Zhou, Shungui; Zhu, Yongguan

2018-01-02

Composting is an efficient way to convert organic waste into fertilizers. However, waste materials often contain large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) that can reduce the efficacy of antibiotic treatments when transmitted to humans. Because conventional composting often fails to remove these compounds, we evaluated if hyperthermophilic composting with elevated temperature is more efficient at removing ARGs and MGEs and explored the underlying mechanisms of ARG removal of the two composting methods. We found that hyperthermophilic composting removed ARGs and MGEs more efficiently than conventional composting (89% and 49%, respectively). Furthermore, the half-lives of ARGs and MGEs were lower in hyperthermophilic compositing compared to conventional composting (67% and 58%, respectively). More-efficient removal of ARGs and MGEs was associated with a higher reduction in bacterial abundance and diversity of potential ARG hosts. Partial least-squares path modeling suggested that reduction of MGEs played a key role in ARG removal in hyperthermophilic composting, while ARG reduction was mainly driven by changes in bacterial community composition under conventional composting. Together these results suggest that hyperthermophilic composting can significantly enhance the removal of ARGs and MGEs and that the mechanisms of ARG and MGE removal can depend on composting temperature.
A Physical Health Profile of Youths Living with a “Hikikomori” Lifestyle

PubMed Central

Yan, Yoyo K. Y.; Tam, Wilson W. S.; So, Ka-Wing

2018-01-01

A cross-sectional study was designed to understand the impacts of “hikikomori” lifestyle on physical health. A total of 104 eligible hikikomori cases were recruited from the social services network of Hong Kong with a mean age of 19.02 ± 3.62 (ranged 13–31) year-old, and had completed the set of questionnaires and a series of anthropometric and physical health measurements. Despite SF36 score of 84.0 indicated good physical functioning in general, participants were lived sedentarily with high incidence of hypertension at 15.4% and prehypertension at 31.7%. Occurrence of hypertension and prehypertension in cases living as hikikomori >6 months were 3 times and 1.5 times higher than those newly onset cases, respectively. The blood pressure levels were correlated with age and all obesity index parameters measured including waist circumference and body mass index. Results also observed a shift of body weight from underweight to overweight and obesity along the hikikomori duration. Half of the hypertensive cases involved the elevation of systolic blood pressure, which suggested higher odds of cardiovascular complications. In conclusion, the hikikomori lifestyle could be a risk behavior that may harm the younger generation physically by promoting obesity and hypertension and probably other chronic illnesses. PMID:29439488
Performance profile of NCAA Division I men's basketball games and training sessions.

PubMed

Conte, D; Tessitore, A; Smiley, K; Thomas, C; Favero, T G

2016-06-01

This study aimed to analyse live and stoppage time phases, their ratio, and action played on half and full court in college basketball games. Differences were assessed for the entire games and between halves. Moreover, differences of the live/stoppage time ratio were analysed between games and game-based conditioning drills. Ten games as well as fifteen defensive, fourteen offensive and six scrimmage-type drills of the same division I men's college team (13 players) were analysed using time-motion analysis technique. Live and stoppage time were classified in five classes of duration: 1-20, 21-40, 41-60, 61-80, >80 seconds. Half court actions started and finished in the same half court. Full court actions were classified as transfer (TR) phases when at least 3 teammates crossed the mid-court line. TR phases were then classified in 5 classes of frequency: 1TR, 2TR, 3TR, 4TR, and >4TR. The results revealed no statistically significant differences between games or between halves for the considered parameters. The only significant difference was observed for live/stoppage time ratio between halves (p<0.001). Furthermore, a significant difference of the live/stoppage ratio was found between games and game-based drills (p<0.01). Post-hoc analysis demonstrated significant differences of scrimmage-type drills in comparison to games, and defensive and offensive drills (p<0.05), whereas no differences emerged for the other pairwise comparisons. The absence of differences between games in the analysed parameters might be important to characterize the model of performance in division I men's college games. Furthermore, these results encourage coaches to use game-based conditioning drills to replicate the LT/ST ratio documented during games.
40-MW(E) PROTOTYPE HIGH-TEMPERATURE GAS-COOLED REACTOR RESEARCH AND DEVELOPMENT PROGRAM. Quarterly Progress Report for the Period Ending June 30, 1962

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1963-10-31

Research and development progress specifically directed toward the construction of a 40-Mw(e) prototype power plant employing a high-temperature, gas-cooled, graphitemoderated reactor known as the HTGR is reported. Irradiation of element III-B in the in-pile loop continued satisfactorily. The element has generated a total of l36.3 Mw-hr of fission heat. The gross activity in the purge stream increased slightly to about 350 mu C/cm/sup 3/. By taking larger gas samples than were previously taken, a value of 0.02 VC/cm/sup 3/ was obtained for the gross activity of the primary loop. Element III-A, which was removed from the loop after generating 133more » Mw-hr of fission heat, was disassembled and examined. No fuel-compact damage of any type was visible. Determination of the distribution of fission products in the element is under way, Fissionproduct- release data for in-pile-loop element III-A were calculated. During the 133 Mw- hr of operation, the release fraction increased by approximately one order of magnitude. Also calculated were the xenon and krypton release data for the first 100 Mw-hr of III-B operation. The release rate for the longer-lived isotopes increased bv about a factor of 10 and that of the shorter-lived isotopes by about a factor of 100. A test was run in which the in-pileloop purge flow, was stopped. The primariy-loop activity level rose sharply during the first hour, increased at a slower rate for the next 11 hr, and then appeared to level off. When purge flow was resumed, the gross activity in the primary loop was cleaned up with a half life of about 2.2 hr. An attempt was made to identify Cs/sup 137/ and Ba/ sup 140/ plateout in portions of the in-pile loop. A very small amount of cesium (less than a monolayer) was found, but no barium could be detected. The validity of two basic assumptions made in the one-dimensional burnup code FEVER was investigated. As a result of extensive lifetime studies and power-distribution and temperaturecoefficient calculations, the initial fuel loading for the Peach Bottom core was specified. A series of control-rodworth calculations and a recalculation of the postulated rod-fall accident were made for this loading. The test of the prototype control rod and drive was satisfactorily coNonempleted during the quarter. During the course of the test the drive completed 590,641 starts and stops, 5,756 scrams, and more than 2.6 million inches of random regulating motion in helium at reactor temperatures. These totals far exceed the expected life requirements of the system. Preparations are being made for testing the prototype emergency shutdown rod and drive. The apparatus for the barium permeation experiment with a full-diameter sleeve was completed, and preliminary calibration runs were started. Following these runs, the system will be operated until an equilibrium distribution of barium is reached. At that time, a series of corings will be made on all of the compacts and the sleeve to evaluate the overall barium and strontium distribution. Other experiments on barium behavior, including permeation experiments with reducedscale fuel elements and exVeriments on the vaporization, sorption, and diffusion of barium, were continued, and the data are being analyzed. Measurements were made to compare the room-temperature back diffusion of argon, krypton, and xenon through a sample of sleeve graphite against a helium pressure difference. The results show that the difference between the effective back-diffusion coefficients of krypton and xenon seems to increase with increasing helium pressure difference across the sleeve. The argon and krypton back-diffusion data at an average pressure of 3 atm are essentially the same, A FORTRAN code was written to recalculate the retention of neutron poison material and fission products in the core as well as their condensation on and revaporization from the upper reflector following a complete loss-of-coolant-circulation accident. (auth)« less
Diabetes Self-Management and Education of People Living with Diabetes: A Survey in Primary Health Care in Muscat Oman

PubMed Central

Al-Maniri, Abdullah A.; Al-Shafaee, Mohammed A.; Wahlström, Rolf

2013-01-01

Background Although the prevalence of type 2 diabetes in Oman is high and rising, information on how people were self-managing their disease has been lacking. The objective of this study was therefore to assess diabetes self-management and education (DSME) among people living with type 2 diabetes in Oman. Methods A questionnaire survey was conducted in public primary health care centres in Muscat. Diabetes self-management and education was assessed by asking how patients recognized and responded to hypo- and hyperglycaemia, and if they had developed strategies to maintain stable blood glucose levels. Patients' demographic information, self-treatment behaviours, awareness of potential long-term complications, and attitudes concerning diabetes management were also recorded. Associations between these factors and diabetes self-management and education were analysed. Results In total, 309 patients were surveyed. A quarter (26%, n = 83) were unaware how to recognize hypoglycaemia or respond to it (26%, n = 81). Around half (49%, n = 151), could not recognize hyperglycaemia and more than half could not respond to it (60%, n = 184). Twelve percent (n = 37) of the patients did not have any strategies to stabilize their blood glucose levels. Patients with formal education generally had more diabetes self-management and education than those without (p<0.001), as had patients with longer durations of diabetes (p<0.01). Self-monitoring of blood glucose was practiced by 38% (n = 117) of the patients, and insulin was used by 22% (n = 67), of which about one third independently adjusted dosages. Patients were most often aware of complications concerning loss of vision, renal failure and cardiac problems. Many patients desired further health education. Conclusions Many patients displayed dangerous diabetes self-management and education knowledge gaps. The findings suggest a need for improving knowledge transfer to people living with diabetes in the Omani clinical setting. PMID:23451219
Applying GIS and fine-resolution digital terrain models to assess three-dimensional population distribution under traffic impacts.

PubMed

Wu, Chih-Da; Lung, Shih-Chun Candice

2012-01-01

Pollution exhibits significant variations horizontally and vertically within cities; therefore, the size and three-dimensional (3D) spatial distribution of population are significant determinants of urban health. This paper presents a novel methodology, 3D digital geography (3DIG) methodology, for investigating 3D spatial distributions of population in close proximity to traffic, thus the potential highly exposed population under traffic impacts. 3DIG applies geographic information system and fine-resolution (5 m) digital terrain models to obtain the number of building floors in residential zones of the Taipei metropolis; the vertical distribution of population at different floors was estimated based on demographic data in each census tract. In addition, population within 5, 10, 20, 50, and 100 m from the roadways was estimated. Field validation indicated that model results were reliable and accurate; the final population estimation differs only by 0.88% from the demographic database. The results showed that among the total 6.5 million Taipei residents, 0.8 (12.3%), 1.5 (22.9%), 2.3 (34.9), and 2.7 (41.1%) million residents live on the first or second floor within 5, 10, 20, and 50 m, respectively, of municipal roads. There are 22 census tracts with more than half of their residents living on the first or second floor within 5 m of municipal roads. In addition, half of the towns in Taipei city and county with >13.9% and 12.1% of residents live on the first and second floors within 5 m of municipal roads, respectively. These findings highlight the huge number of Taipei residents in close proximity to traffic and have significant implications for exposure assessment and environmental epidemiological studies. This study demonstrates that 3DIG is a versatile methodology for various research and policy planning in which 3D spatial population distribution is the central focus.
Microscopic description of fission properties for r-process nuclei

NASA Astrophysics Data System (ADS)

Giuliani, S. A.; Martínez-Pinedo, G.; Robledo, L. M.

2018-01-01

Fission properties of 886 even-even nuclei in the region 84 ≤ Z ≤ 120 and 118 ≤ Z ≤ 250 were computed using the Barcelona-Catania-Paris-Madrid energy density functional. An extensive study of both the potential energy surfaces and collectives inertias was performed. Spontaneous fission half-lives are computed using the semiclassical Wentzel-Kramers-Brillouin formalism. By comparing these three quantities we found that the stability of the nucleus against the fission process is driven by the interplay between both the potential energy and the collective inertias. In our calculations, nuclei with relative long half-lives were found in two regions around Z = 120, N = 182 and Z = 104, N = 222.
Nuclear isospin effect on α-decay half-lives

NASA Astrophysics Data System (ADS)

Akrawy, Dashty T.; Hassanabadi, H.; Hosseini, S. S.; Santhosh, K. P.

2018-07-01

The α-decay half-lives for the even-even, even-odd, odd-even and odd-odd of 356 nuclei in the range 52 ≤Zp ≤ 118 have been studied within the analytical formula of Royer and also within the modified analytical formula of Royer. We calculated the new coefficient of the Royer by fitting 356 isotopes. Also, we considered the Denisov and Khudenko formula and obtained the new coefficient for the modified Denisov and Khudenko formula. We calculated the standard deviation and the average deviation. Analytical results are compared with the experimental data. The results are in better agreement with the experimental data when the effect of the isospin considered for the parent nuclei.

Dispersibility and biotransformation of oils with different properties in seawater.

PubMed

Brakstad, Odd G; Farooq, Umer; Ribicic, Deni; Netzer, Roman

2018-01-01

Dispersants are used to remove oils slicks from sea surfaces and to generate small oil-droplet dispersions, which may result in enhanced biodegradation of the oil. In this study, dispersibility and biodegradation of chemically dispersed oils with different physical-chemical properties (paraffinic, naphthenic and asphaltenic oils) were compared in natural temperate SW at 13 °C. All selected oils were chemically dispersible when well-known commercial dispersants were used. However, interfacial tension (IFT) studies of the dispersed oils showed different IFT properties of the oils at 13 °C, and also different leaching of the dispersants from oil droplet surfaces. Biodegradation studies of the chemically dispersed oils were performed in a carousel system, with initial median droplet sizes <30 μm and oil concentrations of 2.5-2.8 mg/L. During biodegradation, oil droplet concentrations were rapidly reduced, in association with the emergence of macroscopic 'flocs'. Biotransformation results showed that half-lives of semivolatile total extractable organic carbon (TEOC), single target 2- to 4-ring PAH, and 22 oil compound groups used as input data in the oil spill contingency model OSCAR, did not differ significantly between the oils (P > 0.05), while n-alkanes half-lives differed significantly (P < 0.05). Biotransformation was associated with rapid microbial growth in all oil dispersions, in association with n-alkane and PAH biotransformation. These results have implications for the predictions of biodegradation of oil slicks treated with dispersants in temperate SW. Copyright © 2017 Elsevier Ltd. All rights reserved.
Death Obsession in Palestinians

ERIC Educational Resources Information Center

Abdel-Khalek, Ahmed M.; Al-Arja, Nahida S.; Abdalla, Taysir

2006-01-01

The authors explored death obsession level and correlates among a sample (N=601) of Palestinians living in the city of Beit Jala, the village of Al-Khader, and the Aida refugee camp in the Bethlehem area. They live in war conditions; the houses of half of them have been demolished. The Death Obsession Scale (DOS) was administered. Its alpha…
Experimental partitioning of Tc, Mo, Ru, and Re between solid and liquid during crystallization in Fe-Ni-S 1

NASA Astrophysics Data System (ADS)

Lazar, C.; Walker, D.; Walker, R. J.

2004-02-01

Technetium isotopes 97Tc, 98Tc and 99Tc decay to 97Mo, 98Ru and 99Ru, with half-lives of 2.6 My, 4.1 My, and 0.21 My respectively. If there were early solar system processes that resulted in significant fractionation of Tc from the daughter elements, decay of extant Tc could have led to the creation of Mo and Ru isotopic heterogeneities. To assess the potential of metallic core crystallization to fractionate these elements, we examine the partitioning behavior of Tc relative to Re, Mo and Ru in the Fe-Ni-S system between solid metal and liquid metal alloy. The experimental evidence shows that Tc behaves more like the modestly compatible siderophile element Ru than the more highly compatible siderophile element Re, and that Tc is substantially more compatible than Mo. We also demonstrate a pressure effect in the partitioning of Mo during the crystallization of Fe-Ni-S melts. For a sulfur concentration in the liquid fraction of the core of 10 wt% (16.3 at%), the Jones and Malvin (1990) parameter is -ln(1-2 × 1.09 × 0.163) ≅ 0.44, which yields: D(Re) ≅ 4.1; D(Ru) ≅ 2.3; D(Tc) ≅ 1.7; D(Mo) Lo-P ≅ 1.0;.and D(Mo) Hi-P ≅ 0.5. Our results suggest that detectable Tc-induced isotopic anomalies (≥0.1 ɛ unit) in Ru and Mo could only be produced by unrealistically extreme degrees of crystallization of metal during asteroidal core fractionation, regardless of the time scales and initial Tc abundances involved.
The production of transuranium elements by the r-process nucleosynthesis

NASA Astrophysics Data System (ADS)

Goriely, S.; Martínez Pinedo, G.

2015-12-01

The production of super-heavy transuranium elements by stellar nucleosynthesis processes remains an open question. The most promising process that could potentially give rise to the formation of such elements is the so-called rapid neutron-capture process, or r-process, known to be at the origin of approximately half of the A > 60 stable nuclei observed in nature. However, despite important efforts, the astrophysical site of the r-process remains unidentified. Here, we study the r-process nucleosynthesis in material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars. Neutron star mergers could potentially be the dominant r-process site in the Galaxy, but also due to the extreme neutron richness found in such environment, could potentially synthesise super-heavy elements. R-process nucleosynthesis during the decompression is known to be largely insensitive to the detailed astrophysical conditions because of efficient fission recycling, producing a composition that closely follows the solar r-abundance distribution for nuclei with mass numbers A > 140. During the neutron irradiation, nuclei up to charge numbers Z ≃ 110 and mass number A ≃ 340 are produced, with a major peak production at the N = 184 shell closure, i.e. around A ≃ 280. Super-heavy nuclei with Z > 110 can hardly be produced due to the efficient fission taking place along those isotopic chains. Long-lived transuranium nuclei are inevitably produced by the r-process. The predictions concerning the production of transuranium nuclei remain however very sensitive to the predictions of fission barrier heights for such super-heavy nuclei. More nuclear predictions within different microscopic approaches are needed.
Effects of washing on mineral composition of leaf samples of Lycium andersonii

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, A.; Romney, E.M.; Hunter, R.B.

1982-07-01

Leaves of Lycium andersonii A. Gray from 20 different shrubs from the northern Mojave Desert were collected. Half of each sample was washed in 1/10 N HCl followed with deionized water before analysis in triplicate by optical emission spectrometry, and the other half was analyzed unwashed. Washed samples contained 12, 35, 33, 40, 55, 47, 57, 8, 8, 9, and 20 percent, respectivey, less calcium, zinc, copper, iron, aluminum, silicon, titanium, strontium, barium, lithium, and lead than did unwashed leaves. The losses probably exceed contamination for some elements, because the results differed in some respects from those obtained for citrus.more » Statisticaly significant differences were not obtained for other elements analyzed. Even though 40 to 57 percent of the iron, aluminum, silicon, and titanium was washed from the leaves, cluster analyses grouped the four elements into a common cluster whether or not the leaves had been washed. Washing resulted in a lower coefficient of variation for some of the elements compared with unwashed leaves.« less
Biomonitoring of arsenic, cadmium, lead, manganese and mercury in urine and hair of children living near mining and industrial areas.

PubMed

Molina-Villalba, Isabel; Lacasaña, Marina; Rodríguez-Barranco, Miguel; Hernández, Antonio F; Gonzalez-Alzaga, Beatriz; Aguilar-Garduño, Clemente; Gil, Fernando

2015-04-01

Huelva (South West Spain) and its surrounding municipalities represent one of the most polluted estuaries in the world owing to the discharge of mining and industrial related pollutants in their proximity. A biomonitoring study was conducted to assess exposure to arsenic and some trace metals (cadmium, mercury, manganese and lead) in urine and scalp hair from a representative sample of children aged 6-9 years (n=261). This is the only study simultaneously analyzing those five metal elements in children urine and hair. The potential contribution of gender, water consumption, residence area and body mass index on urinary and hair metal concentrations was also studied. Urine levels of cadmium and total mercury in a proportion (25-50%) of our children population living near industrial/mining areas might have an impact on health, likely due to environmental exposure to metal pollution. The only significant correlation between urine and hair levels was found for mercury. Children living near agriculture areas showed increased levels of cadmium and manganese (in urine) and arsenic (in hair). In contrast, decreased urine Hg concentrations were observed in children living near mining areas. Girls exhibited significantly higher trace metal concentrations in hair than boys. The greatest urine arsenic concentrations were found in children drinking well/spring water. Although human hair can be a useful tool for biomonitoring temporal changes in metal concentrations, levels are not correlated with those found in urine except for total mercury, thus providing additional information. Copyright © 2014 Elsevier Ltd. All rights reserved.
Selenium and hazardous elements distribution in plant-soil-water system and human health risk assessment of Lower Cambrian, Southern Shaanxi, China.

PubMed

Du, Yajun; Luo, Kunli; Ni, Runxiang; Hussain, Rahib

2018-03-01

The natural selenium poisoning due to toxic Se levels in food chain had been observed in humans and animals in Lower Cambrian outcrop areas in Southern Shaanxi, China. To find out the distribution pattern of selenium and other hazardous elements in the plant, soil and water of Lower Cambrian in Southern Shaanxi, China, and their possible potential health risk, a total of 30 elements were analyzed and the health risk assessment of 18 elements was calculated. Results showed that the soil, plant and natural water of Lower Cambrian all had relatively high Se levels. In Lower Cambrian, the soil was enriched with Se, As, Ba, Cu, Mo, Ni, Zn, Ga, Cd and Cr (1.68 < I geo < 4.48, I geo ; geo-accumulation index). In same plants, the contents of Se, Cd and Zn (except Cd in corn and rice, Zn in potato and corn) of Lower Cambrian were higher than that of the other strata. Ba and Ga in natural water were higher than that of the other strata, while K and Cs were opposite. The health risk assessment results showed that the people living in outcrop areas of Lower Cambrian had both high total non-carcinogenic risk of 18 elements (HI = 16.12, acceptable range: < 1) and carcinogenic risk of As (3.98E-04, acceptable range: 10 -6 -10 -4 ). High contents of Se, As, Mo and Tl of Lower Cambrian may pose a health risk to local people, and food intake was the major pathway. For minimizing potential health risk, the local inhabitants should use the mix-imported food with local growing foods.
Evaluation of the 129I Half-Life Value Through Analyses of Primitive Meteorites

NASA Astrophysics Data System (ADS)

Pravdivtseva, Olga; Meshik, Alex; Hohenberg, Charles M.

The preserved record of decay of now-extinct 129I into 129Xe forms the basis of the I-Xe chronometer. Comparison of the high precision I-Xe and Pb-Pb ages of chondrules and pure mineral phases separated from eight meteorites suggests the 17.5 ÷ 14.6 Ma range for the 129I half-life, assuming that the 235U and 238U half-lives are correct. The mean value of 16 Ma indicates that the 15.7 Ma half-life of 129I used here for the I-Xe age calculations is most probably correct. Since the 129I half-life value only affects the relative I-Xe ages, the few Ma relative to the Shallowater standard, the absolute I-Xe ages are almost immune to this uncertainty in the 129I half-life.
Half-life measurement of the medical radioisotope 177Lu produced from the 176Yb(n,γ) reaction

NASA Astrophysics Data System (ADS)

Ferreira, K. M.; Collins, S. M.; Fenwick, A. J.

2017-09-01

177Lu is a medium energy beta-emitter commonly used in Nuclear Medicine for radiotherapeutic applications. In this work, the half-life of 177Lu has been measured using a re-entrant ionisation chamber over a period of 82 days (approximately 12 half-lives). Unlike the majority of previous studies, the material used in this work was produced via the 176Yb(n,γ)177Yb reaction followed by the β-decay to 177Lu, producing insignificant quantities of 177mLu. This has resulted in the most precise half-life measurement of 177Lu to date. A half-life of 6.6430 (11) days has been determined. This value is in statistical agreement with the currently recommended half-life of 6.6463 (15) days (z-score = 1.8).
Falls in very old people: the population-based Umeå 85+ study in Sweden.

PubMed

von Heideken Wågert, Petra; Gustafson, Yngve; Kallin, Kristina; Jensen, Jane; Lundin-Olsson, Lillemor

2009-01-01

The aim of this study was to describe incidences of falls and fall-related injuries, and to identify predisposing factors for falls in very old people in a prospective population-based follow-up study for falls. The study is part of the Umeå 85+ Study which includes half of the population aged 85, and the total population aged 90 and > or =95 (-103), in Umeå, Sweden. Of the 253 people interviewed, 220 (87%) were followed up for falls for 6 months, of whom 109 lived in ordinary and 111 in institutional housing. A comprehensive geriatric baseline assessment was made through interviews and testing during home visits. Forty percent of the participants did fall a total 304 times, corresponding to 2.17 falls per Person Year (PY). It occurred 0.83 injuries per PY, including 0.14 fractures per PY. In a Cox regression analysis, the independent explanatory risk factors for time to first fall were dependency in activities of daily living (ADL), thyroid disorders, treatment with selective serotonin reuptake inhibitors (SSRIs) and occurrence of falls in the preceding year. It could be predicted that every seventh participant and every third of the people who did fall would suffer a fracture within 1 year. ADL, thyroid disorders and treatment with SSRIs should be considered in fall prevention programmes.
Separation of Long-Lived Fission Products Tc-99 and I-129 from Synthetic Effluents by Crown Ethers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paviet-Hartmann, P.; Hartmann, T.

2006-07-01

To minimize significantly the radio-toxic inventory of nuclear geological repositories to come as well as to reduce the potential of radionuclides migration and to minimize long-term exposure, the concept of partitioning and transmutation (P/T) of nuclear waste is currently discussed. Transmutation offers the possibility to convert radio-toxic radionuclides with long half-lives into radionuclides of shorter half-lives, less toxic isotopes, or even into stable isotopes. Besides the most prominent isotopes of neptunium, plutonium, americium, and curium, the long-lived fission products Tc-99 and I-129 (half-lives of 2.13 x 10{sup 5} years, and 1.57 x 10{sup 7} years, respectively) are promising candidates formore » transmutation in order to prevent their migration from a nuclear repository. Partitioning and transmutation of the most radio-toxic radionuclides will not only minimize the nuclear waste load but most importantly will significantly reduce the long-term radio-toxic hazard of nuclear waste repositories to come. Prior to the deployment of partitioning and transmutation, selective extraction techniques are required to separate the radionuclides of concern. Since the discovery of crown ethers by C. Pedersen, various applications of crown ethers have drawn much attention. Although liquid-liquid extraction of alkali and alkali earth metals by crown ethers has been extensively studied, little data is available on the extraction of Tc-99 and I-129 by crown ethers. The methods developed herein for the specific extraction of Tc-99 and I-129 provide recommendations in support of their selectively extraction from liquid radioactive waste streams, mainly ILW. We report data on the solvent extraction of Tc-99 and I-129 from synthetic effluents by six crown ethers of varying cavity dimensions and derivatization. To satisfy the needs of new extractant systems we are demonstrating that crown ether (CE) based systems have the potential to serve as selective extractants for the separation of these long lived radionuclides from high level nuclear waste (HLW), intermediate level nuclear waste (ILW), and low level nuclear waste (LLW) streams. The experimental results show that dibenzo-18-crown-6 (DB 18C6) is highly selective towards Tc-99, and dicyclohexano-18-crown-6 (DC18C6) is highly selective towards I-129. The nature of the diluent was examined and was shown to be the most influential variable in controlling the extraction coefficients of Tc-99 and I-129. Therefore the addition of polar diluent acetone to non-polar diluent toluene enhanced the distribution coefficient of Tc-99 (DTc) was by a factor of 30. For I-129, the best extraction yield was obtained after introducing tetrachloroethane. Through the process, by a single extraction step, 85 % to 95 % of Tc-99 was extracted from synthetic effluents, while 84 % to 88 % of I-129 was extracted from different acidic media. The extraction by crown ether is a fairly rapid process and the total preparation time of the chemical separation takes about 20 minutes for a batch of eight samples. (authors)« less
Double-β decay within a consistent deformed approach

NASA Astrophysics Data System (ADS)

Delion, D. S.; Suhonen, J.

2015-05-01

In this paper we present a timely application of the proton-neutron deformed quasiparticle random-phase approximation (p n -dQRPA), designed to describe in a consistent way the 1+ Gamow-Teller states in odd-odd deformed nuclei. For this purpose we apply a projection before variation procedure by using a single-particle basis with projected angular momentum, provided by the diagonalization of a spherical mean field plus quadrupole-quadrupole interaction. The residual Hamiltonian contains pairing plus proton-neutron dipole terms in particle-hole and particle-particle channels, with constant strengths. As an example we describe the two-neutrino double-beta (2 ν β β ) decay of 150Nd to the ground state of 150Sm. The experimental (p ,n ) type of strength in 150Nd and the (n ,p ) type of strength in 150Sm are reasonably reproduced and the 2 ν β β decay matrix element depicts a strong dependence upon the particle-particle strength gp p. The experimental half-life is reproduced for gp p=0.05 . It turns out that the measured half-lives for 2 ν β β transitions between other deformed superfluid partners with mass numbers A =82 ,96,100,128,130,238 are reproduced with fairly good accuracy by using this value of gp p.
Bullying Prevention Is Crime Prevention. A Report by Fight Crime: Invest in Kids.

ERIC Educational Resources Information Center

Kass, David; Evans, Phil; Shah, Rita

Asserting that prevention and intervention efforts to reduce bullying can serve to reduce later criminal behavior and save lives, this report identifies programs that have reduced bullying by as much as half and cut future arrests in half, and urges schools to invest in these programs. Chapter 1 of the report defines bullying and presents…
Radium-223 in the treatment of osteoblastic metastases: a critical clinical review.

PubMed

Humm, John L; Sartor, Oliver; Parker, Chris; Bruland, Oyvind S; Macklis, Roger

2015-04-01

The element radium (Ra) was discovered by the Curies in 1898 and within a decade was in broad scientific testing for the management of several forms of cancer. The compound was known to give rise to a series of both high-energy particulate and penetrating γ-emissions. The latter found an important role in early 20th century brachytherapy applications, but the short-range α-particles seemed much less useful. Although highly cytotoxic when released within a few cell diameters of critical cell nuclei, the dense double-strand break damage was poorly repaired, and concerns regarding treatment-related toxicities and secondary malignancies halted clinical development. Moreover, the most common isotope of Ra has an exceptionally long half-life (>1600 years for (226)Ra) that proved daunting when aiming for a systemic cancer therapy. Fortunately, other radium isotopes have more convenient half-lives while still producing cytotoxic α particles. Radium-223 dichloride has a half-life of 11.4 days, and this isotope was identified as an excellent candidate for radionuclide therapy of cancers metastatic to bone. The calcium-mimetic chemical properties of the radium allowed intravenous infusion with rapid uptake to sites of new bone formation. The highly efficient bone localization suggested a potential therapeutic role for osteoblastic bone metastases, and a series of phase 1, 2, and 3 clinical trials was undertaken to explore this possibility. This series of clinical explorations culminated in the ALSYMPCA trial, an international, placebo-controlled, phase 3 study that accrued 921 symptomatic men with bone-metastatic, castrate-resistant prostate cancer. Results of this trial demonstrated a prolongation of overall survival, and regulatory agencies around the world have now approved this product as a treatment for advanced prostate cancer. Copyright © 2015 Elsevier Inc. All rights reserved.
Radium-223 in the Treatment of Osteoblastic Metastases: A Critical Clinical Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humm, John L.; Sartor, Oliver; Parker, Chris

2015-04-01

The element radium (Ra) was discovered by the Curies in 1898 and within a decade was in broad scientific testing for the management of several forms of cancer. The compound was known to give rise to a series of both high-energy particulate and penetrating γ-emissions. The latter found an important role in early 20th century brachytherapy applications, but the short-range α-particles seemed much less useful. Although highly cytotoxic when released within a few cell diameters of critical cell nuclei, the dense double-strand break damage was poorly repaired, and concerns regarding treatment-related toxicities and secondary malignancies halted clinical development. Moreover, themore » most common isotope of Ra has an exceptionally long half-life (>1600 years for {sup 226}Ra) that proved daunting when aiming for a systemic cancer therapy. Fortunately, other radium isotopes have more convenient half-lives while still producing cytotoxic α particles. Radium-223 dichloride has a half-life of 11.4 days, and this isotope was identified as an excellent candidate for radionuclide therapy of cancers metastatic to bone. The calcium-mimetic chemical properties of the radium allowed intravenous infusion with rapid uptake to sites of new bone formation. The highly efficient bone localization suggested a potential therapeutic role for osteoblastic bone metastases, and a series of phase 1, 2, and 3 clinical trials was undertaken to explore this possibility. This series of clinical explorations culminated in the ALSYMPCA trial, an international, placebo-controlled, phase 3 study that accrued 921 symptomatic men with bone-metastatic, castrate-resistant prostate cancer. Results of this trial demonstrated a prolongation of overall survival, and regulatory agencies around the world have now approved this product as a treatment for advanced prostate cancer.« less
The 80:20 phenomenon: help or hindrance to planning caries prevention programmes?

PubMed

Tickle, Martin

2002-03-01

to compare the outcomes of population segmentation analyses according to caries experience using the distribution of dmft and the Super Profiles geodemographic classification. The study population consisted of all 15,747 children in seven districts in the North West Region, England who were examined in whole population surveys during the 1995/6 NHS epidemiological survey of 5-year-old children. Market penetration analyses were used to segment this population according to caries experience by their dmft score and by the Super Profiles geodemographic classification. Lorenz curves were plotted and Gini coefficients were calculated from the outputs. When dmft was used to segment the population approximately 80% of carious teeth were found in some 42% of the total population, producing a Lorenz Curve with a Gini coefficient of 66%. The population was then segmented using Super Profiles Target Markets. The target markets were ranked according to caries experience and the denominator population living in each of these area types. Some 81% of the total population dmft was found in the topmost ranked 73.8% of the total population. The resultant Lorenz curve produced a Gini coefficient of 16.2%. About half of the population disease was confined to a minority of the population but not to the extent of 80% of the disease in 20% of the population. Although these high risk children were more commonly found in underprivileged area types, they did not live exclusively in a small number of deprived areas. These findings shed doubt on the wisdom of a targeted approach to oral health promotion and disease prevention programmes.
Advocating for active living on the rural-urban fringe: a case study of planning in the Portland, Oregon, metropolitan area.

PubMed

Adler, Sy; Dobson, Noelle; Fox, Karen Perl; Weigand, Lynn

2008-06-01

This case study is about the politics of incorporating active-living elements into a concept plan for a new community of about 68,000 people on the edge of the Portland, Oregon, metropolitan area. Development on the rural-urban fringe is ongoing in metropolitan areas around the United States. In this article, we evaluate the product of the concept-planning process from the standpoint of the extent to which environmental elements conducive to active living were included. We also analyze four issues in which challenges to the incorporation of active-living features surfaced: choices related to transportation facilities, the design and location of retail stores, the location of schools and parks, and the location of a new town center. Overall, the Damascus/Boring Concept Plan positions the area well to promote active living. Analyses of the challenges that emerged yielded lessons for advocates regarding ways to deal with conflicts between facilitating active living and local economic development and related tax-base concerns and between active-living elements and school-district planning autonomy as well as the need for advocates to have the capacity to present alternatives to the usual financial and design approaches taken by private- and public-sector investors.
Systematic study of α decay of nuclei around the Z =82 , N =126 shell closures within the cluster-formation model and proximity potential 1977 formalism

NASA Astrophysics Data System (ADS)

Deng, Jun-Gang; Zhao, Jie-Cheng; Chu, Peng-Cheng; Li, Xiao-Hua

2018-04-01

In the present work, we systematically study the α decay preformation factors Pα within the cluster-formation model and α decay half-lives by the proximity potential 1977 formalism for nuclei around Z =82 ,N =126 closed shells. The calculations show that the realistic Pα is linearly dependent on the product of valance protons (holes) and valance neutrons (holes) NpNn . It is consistent with our previous works [Sun et al., Phys. Rev. C 94, 024338 (2016), 10.1103/PhysRevC.94.024338; Deng et al., Phys. Rev. C 96, 024318 (2017), 10.1103/PhysRevC.96.024318], in which Pα are model dependent and extracted from the ratios of calculated α half-lives to experimental data. Combining with our previous works, we confirm that the valance proton-neutron interaction plays a key role in the α preformation for nuclei around Z =82 ,N =126 shell closures whether the Pα is model dependent or microcosmic. In addition, our calculated α decay half-lives by using the proximity potential 1977 formalism taking Pα evaluated by the cluster-formation model can well reproduce the experimental data and significantly reduce the errors.
The persistence of pesticides in atmospheric particulate phase: An emerging air quality issue

NASA Astrophysics Data System (ADS)

Socorro, Joanna; Durand, Amandine; Temime-Roussel, Brice; Gligorovski, Sasho; Wortham, Henri; Quivet, Etienne

2016-09-01

The persistent organic pollutants (POPs) due to their physicochemical properties can be widely spread all over the globe; as such they represent a serious threat to both humans and wildlife. According to Stockholm convention out of 24 officially recognized POPs, 16 are pesticides. The atmospheric life times of pesticides, up to now were estimated based on their gas-phase reactivity. It has been only speculated that sorption to aerosol particles may increase significantly the half-lives of pesticides in the atmosphere. The results presented here challenge the current view of the half-lives of pesticides in the lower boundary layer of the atmosphere and their impact on air quality and human health. We demonstrate that semivolatile pesticides which are mostly adsorbed on atmospheric aerosol particles are very persistent with respect to the highly reactive hydroxyl radicals (OH) that is the self-cleaning agent of the atmosphere. The half-lives in particulate phase of difenoconazole, tetraconazole, fipronil, oxadiazon, deltamethrin, cyprodinil, permethrin, and pendimethalin are in order of several days and even higher than one month, implying that these pesticides can be transported over long distances, reaching the remote regions all over the world; hence these pesticides shall be further evaluated prior to be confirmed as POPs.
Efforts to estimate pesticide degradation rates in subsurface ...

EPA Pesticide Factsheets

When pesticides are used in real-world settings, the objective is to be effective in pest eradication at the site of application, but also it is desired that the pesticide have minimal persistence and mobility as it migrates away from the application site. At the site of application, sorption on soil and surface-soil degradation rates both factor into the pesticides' persistence. But once it migrates to the subsurface vadose zone and/or aquifers, subsurface degradation rate is a factor as well. Unfortunately, numerous soil properties that might affect pesticide degradation rate vary by orders of magnitude in the subsurface environment, both spatially and temporally, e.g., organic-carbon concentration, oxygen concentration, redox conditions, pH and soil mineralogy. Consequently, estimation of subsurface pesticide degradation rates and, in tum, pesticide persistence and mobility in the environment, has remained a challenge. To address this intransigent uncertainty, we surveyed peer-reviewed literature to identify > 100 data pairs in which investigators reported pesticide degradation rates in both surface and subsurface soils, using internally consistent experimental methods. These > 100 data pairs represented >30 separate pesticides. When the > 100 subsurface half-lives were plotted against surface half-lives, a limiting line could be defined for which all subsurface half-lives but three fe ll below the line. Of the three data points plotting above the limiting li

In-plane dynamic Green's functions for inclined and uniformly distributed loads in a multi-layered transversely isotropic half-space

NASA Astrophysics Data System (ADS)

Ba, Zhenning; Kang, Zeqing; Liang, Jianwen

2018-04-01

The dynamic stiffness method combined with the Fourier transform is utilized to derive the in-plane Green's functions for inclined and uniformly distributed loads in a multi-layered transversely isotropic (TI) half-space. The loaded layer is fixed to obtain solutions restricted in it and the corresponding reactions forces, which are then applied to the total system with the opposite sign. By adding solutions restricted in the loaded layer to solutions from the reaction forces, the global solutions in the wavenumber domain are obtained, and the dynamic Green's functions in the space domain are recovered by the inverse Fourier transform. The presented formulations can be reduced to the isotropic case developed by Wolf (1985), and are further verified by comparisons with existing solutions in a uniform isotropic as well as a layered TI half-space subjected to horizontally distributed loads which are special cases of the more general problem addressed. The deduced Green's functions, in conjunction with boundary element methods, will lead to significant advances in the investigation of a variety of wave scattering, wave radiation and soil-structure interaction problems in a layered TI site. Selected numerical results are given to investigate the influence of material anisotropy, frequency of excitation, inclination angle and layered on the responses of displacement and stress, and some conclusions are drawn.
Half-life of Xe120

NASA Astrophysics Data System (ADS)

Phillips, A. A.; Andreoiu, C.; Ball, G. C.; Bandyopadhyay, D.; Behr, J. A.; Chupp, T. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hayden, M. E.; Hyland, B.; Nuss-Warren, S. R.; Pearson, M. R.; Schumaker, M. A.; Smith, M. B.; Svensson, C. E.; Tardiff, E. R.; Valiente-Dobón, J. J.; Warner, T.

2006-08-01

We have measured the half-life of Xe120 using a high-purity germanium (HPGe) detector to monitor the 176, 178, and 762 keV γ rays from Xe120 β+ decay. The result, 46±0.6 min, differs significantly from the value 40±1 min reported by Andersson [Ark. Fys. 28, 37 (1964)]. We have also measured the half-lives of Cs120 and I120 to be 60±0.7 s and 82.1±0.6 min, respectively, both of which are consistent with previous measurements.
Tests of a Fast Plastic Scintillator for High-Precision Half-Life Measurements

NASA Astrophysics Data System (ADS)

Laffoley, A. T.; Dunlop, R.; Finlay, P.; Leach, K. G.; Michetti-Wilson, J.; Rand, E. T.; Svensson, C. E.; Grinyer, G. F.; Thomas, J. C.; Ball, G.; Garnsworthy, A. B.; Hackman, G.; Orce, J. N.; Triambak, S.; Williams, S. J.; Andreoiu, C.; Cross, D.

2013-03-01

A fast plastic scintillator detector is evaluated for possible use in an ongoing program of high-precision half-life measurements of short lived β emitters. Using data taken at TRI-UMF's Isotope Separator and Accelerator Facility with a radioactive 26Na beam, a detailed investigation of potential systematic effects with this new detector setup is being performed. The technique will then be applied to other β-decay half-life measurements including the superallowed Fermi β emitters 10C, 14O, and T = 1/2 decay of 15O.
Enhanced robustness of evolving open systems by the bidirectionality of interactions between elements.

PubMed

Ogushi, Fumiko; Kertész, János; Kaski, Kimmo; Shimada, Takashi

2017-08-01

Living organisms, ecosystems, and social systems are examples of complex systems in which robustness against inclusion of new elements is an essential feature. A recently proposed simple model has revealed a general mechanism by which such systems can become robust against inclusion of elements with totally random interactions when the elements have a moderate number of links. The interaction is, however, in many systems often intrinsically bidirectional like for mutual symbiosis and competition in ecology. This study reports the strong reinforcement effect of the bidirectionality of the interactions on the robustness of evolving systems. We show that the system with purely bidirectional interactions can grow with twofold average degree, in comparison with the purely unidirectional system. This drastic shift of the transition point comes from the reinforcement of each node, not from a change in structure of the emergent system. For systems with partially bidirectional interactions we find that the regime of the growing phase gets expanded. In the dense interaction regime, there exists an optimum proportion of bidirectional interactions for the growth rate at around 1/3. In the sparsely connected systems, small but finite fraction of bidirectional links can change the system's behaviour from non-growing to growing.
Sequence dependent N-terminal rearrangement and degradation of peptide nucleic acid (PNA) in aqueous solution

NASA Technical Reports Server (NTRS)

Eriksson, M.; Christensen, L.; Schmidt, J.; Haaima, G.; Orgel, L.; Nielsen, P. E.

1998-01-01

The stability of the PNA (peptide nucleic acid) thymine monomer inverted question markN-[2-(thymin-1-ylacetyl)]-N-(2-aminoaminoethyl)glycine inverted question mark and those of various PNA oligomers (5-8-mers) have been measured at room temperature (20 degrees C) as a function of pH. The thymine monomer undergoes N-acyl transfer rearrangement with a half-life of 34 days at pH 11 as analyzed by 1H NMR; and two reactions, the N-acyl transfer and a sequential degradation, are found by HPLC analysis to occur at measurable rates for the oligomers at pH 9 or above. Dependent on the amino-terminal sequence, half-lives of 350 h to 163 days were found at pH 9. At pH 12 the half-lives ranged from 1.5 h to 21 days. The results are discussed in terms of PNA as a gene therapeutic drug as well as a possible prebiotic genetic material.
Spectrum-shape method and the next-to-leading-order terms of the β -decay shape factor

NASA Astrophysics Data System (ADS)

Haaranen, M.; Kotila, J.; Suhonen, J.

2017-02-01

Effective values of the axial-vector coupling constant gA have lately attracted much attention due to the prominent role of gA in determining the half-lives of double β decays, in particular their neutrinoless mode. The half-life method, i.e., comparing the calculated half-lives to the corresponding experimental ones, is the most widely used method to access the effective values of gA. The present paper investigates the possibilities offered by a complementary method: the spectrum-shape method (SSM). In the SSM, comparison of the shapes of the calculated and measured β electron spectra of forbidden nonunique β decays yields information on the magnitude of gA. In parallel, we investigate the impact of the next-to-leading-order terms of the β -decay shape function and the radiative corrections on the half-life method and the SSM by analyzing the fourfold forbidden decays of 113Cd and 115In by using three nuclear-structure theory frameworks; namely, the nuclear shell model, the microscopic interacting boson-fermion model, and the microscopic quasiparticle-phonon model. The three models yield a consistent result, gA≈0.92 , when the SSM is applied to the decay of 113Cd for which β -spectrum data are available. At the same time the half-life method yields results which are in tension with each other and the SSM result.
A Case Controlled Examination of the Interpersonal Theory of Suicide in the Second Half of Life.

PubMed

Van Orden, Kimberly A; Smith, Phillip N; Chen, Tian; Conwell, Yeates

2016-07-02

The interpersonal theory of suicide proposes that the most proximal cause of suicide is the combination of thwarted belongingness and perceived burdensomeness coupled with a pre-existing vulnerability of reduced fear of death and increased pain tolerance. This pre-existing vulnerability develops in response to painful and provocative life events. According to the theory, empirically demonstrated risk factors for suicide operate by increasing the likelihood of one or more of the theory's constructs. The current study examined the relations of the major constructs of the interpersonal theory with suicide case status compared to living controls in the second half of life. The current study used a pre-existing psychological autopsy database to compare suicide decedents to living controls 50 years and older. Theory constructs were measured by composite scores of thwarted belongingness, perceived burdensomeness, and painful and provocative experiences using an a priori selection of items comprising each construct. Suicide decedents experienced greater levels of all three of the theory's constructs when examined independently compared to living controls. When examined simultaneously while also controlling for Major Depression, greater perceived burdensomeness and painful and provocative experiences were associated with suicide case status (vs. control). The interpersonal theory is a comprehensive framework that may be useful in understanding risk for death by suicide in the second half of life. Clinical management of suicide risk for adults in the second half of life could include a focus on perceived burdensomeness, as the IPTS proposes that this psychological state is amenable to change via therapeutic intervention.
90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans--WOMARS results.

PubMed

Povinec, Pavel P; Aarkrog, Asker; Buesseler, Ken O; Delfanti, Roberta; Hirose, Katsumi; Hong, Gi Hoon; Ito, Toshimichi; Livingston, Hugh D; Nies, Hartmut; Noshkin, Victor E; Shima, Shigeki; Togawa, Orihiko

2005-01-01

Under an IAEA's Co-ordinated Research Project "Worldwide Marine Radioactivity Studies (WOMARS)" 90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans have been investigated. The Pacific and Indian Oceans were divided into 17 latitudinal boxes according to ocean circulation, global fallout patterns and the location of nuclear weapons test sites. The present levels and time trends in radionuclide concentrations in surface water for each box were studied and the corresponding effective half-lives were estimated. For the year 2000, the estimated average 90Sr, 137Cs and (239,240)Pu concentrations in surface waters of the Pacific and Indian Oceans varied from 0.1 to 1.5 mBq/L, 0.1 to 2.8 mBq/L, and 0.1 to 5.2 microBq/L, respectively. The mean effective half-lives for 90Sr and 137Cs in surface water were 12+/-1 years for the North, 20+/-1 years for the South and 21+/-2 years for the Equatorial Pacific. For (239,240)Pu the corresponding mean effective half-lives were 7+/-1 years for the North, 12+/-4 years for the South and 10+/-2 years for the Equatorial Pacific. For the Indian Ocean the mean effective half-lives of 137Cs and (239,240)Pu were 21+/-2 years and 9+/-1 years, respectively. There is evidence that fallout removal rates before 1970 were faster than those observed during recent decades. The estimated surface water concentrations of 90Sr, 137Cs and (239,240)Pu in latitudinal belts of the Pacific and Indian Oceans for the year 2000 may be used as the average levels so that any new contribution from nuclear facilities, nuclear weapons test sites, radioactive waste dumping sites and from possible nuclear accidents can be identified.
Biodegradability relationships among propylene glycol substances in the Organization for Economic Cooperation and Development ready- and seawater biodegradability tests.

PubMed

West, Robert J; Davis, John W; Pottenger, Lynn H; Banton, Marcy I; Graham, Cynthia

2007-05-01

Eight propylene glycol substances, ranging from 1,2-propanediol to a poly(propylene glycol) (PPG) having number-average molecular weight (M(n)) of 2,700 (i.e., PPG 2700), were evaluated in the Organization for Economic Cooperation and Development (OECD) ready- and seawater biodegradability tests. Uniformity in test parameters, such as inoculum source/density and test substance concentrations, combined with frequent measurements of O2 consumption and CO2 evolution, revealed unexpected biodegradability trends across this family of substances. Biodegradability in both tests decreased with increased number of oxy-propylene repeating units (n = 1, 2, 3, 4) of the oligomeric propylene glycols (PGs). However, this trend was reversed for the PPG polymers, and increased biodegradability was observed with increases of average n to seven, 17, and 34 (M(n) = 425, 1,000, and 2,000, respectively). This relationship between molecular weight and biodegradability was reversed again when average n was incremented from 34 (PPG 2000) to 46 (PPG 2700). Six of the tested substances (n = 1, 2, 3, 7, 17, and 34) met the OECD-specified criteria for "ready biodegradability," whereas the tetrapropylene glycol (n = 4) and PPG 2700 substances failed to meet these criteria. Biodegradation half-lives for these eight substances ranged from 3.8 d (PPG 2000) to 33.2 d (PPG 2700) in the ready test, and from 13.6 (PG) to 410 d (PPG 2700) in seawater. Biodegradation half-lives in seawater were significantly correlated with half-lives determined in the ready test. However, half-lives in both tests were correlated poorly with molecular weight, water solubility, and log K(ow). It is speculated that the molecular conformation of these substances, perhaps more so than these other physicochemical properties, has an important role in influencing biodegradability of the propylene glycol substances.
Sensitivity tests on the rates of the excited states of positron decays during the rapid proton capture process of the one-zone X-ray burst model

NASA Astrophysics Data System (ADS)

Lau, Rita

2018-02-01

In this paper, we investigate the sensitivities of positron decays on a one-zone model of type-I X-ray bursts. Most existing studies have multiplied or divided entire beta decay rates (electron captures and beta decay rates) by 10. Instead of using the standard Fuller & Fowler (FFNU) rates, we used the most recently developed weak library rates [1], which include rates from Langanke et al.'s table (the LMP table) (2000) [2], Langanke et al.'s table (the LMSH table) (2003) [3], and Oda et al.'s table (1994) [4] (all shell model rates). We then compared these table rates with the old FFNU rates [5] to study differences within the final abundances. Both positron decays and electron capture rates were included in the tables. We also used pn-QRPA rates [6,7] to study the differences within the final abundances. Many of the positron rates from the nuclei's ground states and initial excited energy states along the rapid proton capture (rp) process have been measured in existing studies. However, because temperature affects the rates of excited states, these studies should have also acknowledged the half-lives of the nuclei's excited states. Thus, instead of multiplying or dividing entire rates by 10, we studied how the half-lives of sensitive nuclei in excited states affected the abundances by dividing the half-lives of the ground states by 10, which allowed us to set the half-lives of the excited states. Interestingly, we found that the peak of the final abundance shifted when we modified the rates from the excited states of the 105Sn positron decay rates. Furthermore, the abundance of 80Zr also changed due to usage of pn-QRPA rates instead of weak library rates (the shell model rates).
Use, non-use and perceived unmet needs of assistive technology among Swedish people in the third age.

PubMed

Löfqvist, Charlotte; Slaug, Björn; Ekström, Henrik; Kylberg, Marianne; Haak, Maria

2016-01-01

To describe the most prominent use of or perceived unmet need of assistive technology (AT) and to compare the characteristics of users, non-users and those expressing perceived unmet need with respect to overall health, independence in everyday life, environmental barriers and socio-demographic features. The study is based on data collected in the "Home and Health in the Third Age Project". In all, 371 individuals participated and data were collected during home visits in southern Sweden by interviewers trained specifically for this project. The data collection comprised well-proven self-report scales and observational formats on the home environment and health indicators as well as questions about basic demographics and socio-structural data. The proportion of users constituted almost half of the total sample. The most common types of AT used were for furnishing/adaptation (35%) and the highest perceived unmet need concerned AT for communication, in total 8%. Those cohabiting were to a higher extent users of AT for furnishing/adaptation, compared to those who lived alone. A higher perceived unmet need was seen among those who lived alone compared with cohabiting people. These findings are of importance for future planning and development of policy to improve health services for the new generation of elderly. Implications for Rehabilitation In order to support the ageing process, the need for assistive technology has to be monitored in the third age. Assistive technology for furnishings and adaptation are frequently used by individuals in their third age and are important to support ageing in the home. Not only do health aspects impact the use of assistive technology, but gender, living conditions and social situation also matter - older men especially need to be monitored thoroughly according to their perceived unmet needs as well as do older persons living alone.
Water and the city (Henry Darcy Medal Lecture)

NASA Astrophysics Data System (ADS)

Rosso, Renzo

2010-05-01

Total world population is about six billion, half living in cities, one third living in slums. This figure has doubled from 1960, when urban population was less than one billion out of the total figure of 3 billion; no more than one fifth was estimated to live in slums at that time. Demography experts predict that population will be around 9 billion in 2050, two thirds (6 billion) living in urban areas, and no reasonable prediction is available for slums. History shows that water is a key factor of urbanization: springs and rivers played a fundamental role in determining where one could settle, and where we are settled now. Water availability is expected to be a major control of man's life in the next future of planet Earth. The daily municipal water withdrawal ranges from 80 to 150 liters per person in China, India and Brazil cities; can they pretend to get more than 600 liters as a US citizen currently does? The impact of natural disasters such as storms and floods is strongly linked to increasing vulnerability associated with urbanization. Are state-of-the-art mitigation policies effective in reducing this impact in both terms of human casualties and economic damage? These and similar questions are fundamental to address hydrological science and engineering hydrology in next years. This talk will approach some open problems arising from the impact of increasing urbanization on the water cycle and, mostly, the associated feedback on human life. These include the need for an insight of nonstationarity, transients and feedback control of hydrological processes; the merging of the space-time scales of hydrological processes with the spatial scales of the city, and the temporal scale of lifestyles; and the way for water scientist and engineers to be involved in the design of cities and the search for life styles coherent with a sustainable development approach.
Regulatory motifs for CREB-binding protein and Nfe2l2 transcription factors in the upstream enhancer of the mitochondrial uncoupling protein 1 gene.

PubMed

Rim, Jong S; Kozak, Leslie P

2002-09-13

Thermogenesis against cold exposure in mammals occurs in brown adipose tissue (BAT) through mitochondrial uncoupling protein (UCP1). Expression of the Ucp1 gene is unique in brown adipocytes and is regulated tightly. The 5'-flanking region of the mouse Ucp1 gene contains cis-acting elements including PPRE, TRE, and four half-site cAMP-responsive elements (CRE) with BAT-specific enhancer elements. In the course of analyzing how these half-site CREs are involved in Ucp1 expression, we found that a DNA regulatory element for NF-E2 overlaps CRE2. Electrophoretic mobility shift assay and competition assays with the CRE2 element indicates that nuclear proteins from BAT, inguinal fat, and retroperitoneal fat tissue interact with the CRE2 motif (CGTCA) in a specific manner. A supershift assay using an antibody against the CRE-binding protein (CREB) shows specific affinity to the complex from CRE2 and nuclear extract of BAT. Additionally, Western blot analysis for phospho-CREB/ATF1 shows an increase in phosphorylation of CREB/ATF1 in HIB-1B cells after norepinephrine treatment. Transient transfection assay using luciferase reporter constructs also indicates that the two half-site CREs are involved in transcriptional regulation of Ucp1 in response to norepinephrine and cAMP. We also show that a second DNA regulatory element for NF-E2 is located upstream of the CRE2 region. This element, which is found in a similar location in the 5'-flanking region of the human and rodent Ucp1 genes, shows specific binding to rat and human NF-E2 by electrophoretic mobility shift assay with nuclear extracts from brown fat. Co-transfections with an Nfe2l2 expression vector and a luciferase reporter construct of the Ucp1 enhancer region provide additional evidence that Nfe2l2 is involved in the regulation of Ucp1 by cAMP-mediated signaling.
Tracking contributions to human body burden of environmental chemicals by correlating environmental measurements with biomarkers.

PubMed

Shin, Hyeong-Moo; McKone, Thomas E; Sohn, Michael D; Bennett, Deborah H

2014-01-01

The work addresses current knowledge gaps regarding causes for correlations between environmental and biomarker measurements and explores the underappreciated role of variability in disaggregating exposure attributes that contribute to biomarker levels. Our simulation-based study considers variability in environmental and food measurements, the relative contribution of various exposure sources (indoors and food), and the biological half-life of a compound, on the resulting correlations between biomarker and environmental measurements. For two hypothetical compounds whose half-lives are on the order of days for one and years for the other, we generate synthetic daily environmental concentrations and food exposures with different day-to-day and population variability as well as different amounts of home- and food-based exposure. Assuming that the total intake results only from home-based exposure and food ingestion, we estimate time-dependent biomarker concentrations using a one-compartment pharmacokinetic model. Box plots of modeled R2 values indicate that although the R2 correlation between wipe and biological (e.g., serum) measurements is within the same range for the two compounds, the relative contribution of the home exposure to the total exposure could differ by up to 20%, thus providing the relative indication of their contribution to body burden. The novel method introduced in this paper provides insights for evaluating scenarios or experiments where sample, exposure, and compound variability must be weighed in order to interpret associations between exposure data.
Long-term effects of mechanical harvesting of lugworms Arenicola marina on the zoobenthic community of a tidal flat in the Wadden Sea

NASA Astrophysics Data System (ADS)

Beukema, J. J.

More than half of the annual catch of about 30 million lugworms Arenicola marina from the Dutch Wadden Sea originates from digging machines which make 40-cm deep guilles in a few restricted tidal-flat areas (Texel, Balgzand) in the westernmost part of the Wadden Sea. Four successive years (1978-1982) of frequent disturbance by a lugworm dredge of one of the 15 sampling stations involved in a long-term study of the dynamics of the macrozoobenthos on Balgzand allowed a study of long-term effects of mechanical lugworm digging. Within an area of about 1 km 2, a near-doubling of the annual lugworm mortality rate resulted in a gradual and substantial decline of the local lugworm stock from more than twice the overall Balgzand mean at the start of the 4-year digging period to a value close to this mean at the end of the period (when the dredge moved to a richer area). Simultaneously, total zoobenthic biomass declined even more by the almost complete extinction of the population of larger gaper clams Mya arenaria that initially comprised half of the total biomass. Of the other, mostly short-lived, species only Heteromastus filiformis showed a clear reduction during the dredging period. Recovery of the biomass of the benthos took several years, particularly by the slow re-establishment of a Mya population with a normal size and age structure.
A minimum income for healthy living

PubMed Central

Morris, J; Donkin, A; Wonderling, D; Wilkinson, P; Dowler, E

2000-01-01

BACKGROUND—Half a century of research has provided consensual evidence of major personal requisites of adult health in nutrition, physical activity and psychosocial relations. Their minimal money costs, together with those of a home and other basic necessities, indicate disposable income that is now essential for health. METHODS—In a first application we identified such representative minimal costs for healthy, single, working men aged 18-30, in the UK. Costs were derived from ad hoc survey, relevant figures in the national Family Expenditure Survey, and by pragmatic decision for the few minor items where survey data were not available. RESULTS—Minimum costs were assessed at £131.86 per week (UK April 1999 prices). Component costs, especially those of housing (which represents around 40% of this total), depend on region and on several assumptions. By varying these a range of totals from £106.47 to £163.86 per week was detailed. These figures compare, 1999, with the new UK national minimum wage, after statutory deductions, of £105.84 at 18-21 years and £121.12 at 22+ years for a 38 hour working week. Corresponding basic social security rates are £40.70-£51.40 per week. INTERPRETATION—Accumulating science means that absolute standards of living, "poverty", minimal official incomes and the like, can now be assessed by objective measurement of the personal capacity to meet the costs of major requisites of healthy living. A realistic assessment of these costs is presented as an impetus to public discussion. It is a historical role of public health as social medicine to lead in public advocacy of such a national agenda.   Keywords: income; public health; lifestyle; nutrition; housing; exercise; social exclusion; inequalities PMID:11076983
Elimination kinetics of metals after an accidental exposure to welding fumes.

PubMed

Schaller, Karl H; Csanady, György; Filser, Johannes; Jüngert, Barbara; Drexler, Hans

2007-07-01

We had the opportunity to study the kinetics of metals in blood and urine samples of a flame-sprayer exposed to high accident-prone workplace exposure. We measured over 1 year, the nickel, aluminium, and chromium concentrations in blood and urine specimens after exposure. On this basis, we evaluated the corresponding half-lives. Blood and urine sampling were carried out five times after accidental exposure over a period of 1 year. The metals were analysed by graphite furnace atomic absorption spectrometry and Zeeman compensation with reliable methods. Either a mono-exponential or a bi-exponential function was fitted to the concentration-time courses of selected metals using weighted least squares non-linear regression analysis. The amount excreted in urine was calculated integrating the urinary decay curve and multiplying with the daily creatinine excretion. The first examination was carried out 15 days after exposure. The mean aluminium concentration in plasma was 8.2 microg/l and in urine, 58.4 microg/g creatinine. The mean nickel concentration in blood was 59.6 microg/l and the excretion in urine 700 microg/g creatinine. The mean chromium level in blood was 1.4 microg/l in urine, 7.4 microg/g creatinine. For the three elements, the metal concentrations in blood and urine exceeded the reference values at least in the initial phase. For nickel, the German biological threshold limit values (EKA) were exceeded. Aluminium showed a mono-exponential decay, whereas the elimination of chromium and nickel was biphasic in biological fluids of the accidentally exposed welder. The half-lives were as follows: for aluminium 140 days (urine) and 160 days (plasma); for chromium 40 and 730 days (urine); for nickel 25 and 610 days (urine) as well as 30 and 240 days (blood). The renal clearance of aluminium and nickel was about 2 l/h estimated for the last monitoring day.
American Indians and the Urban Experience. Contemporary Native American Communities 5.

ERIC Educational Resources Information Center

Lobo, Susan, Ed.; Peters, Kurt, Ed.

Over half of all American Indian people living in the United States now live in urban areas, but few books and little research have addressed urban Indian themes. This book compiles research, scholarly writing, poetry, prose, and artwork concerned with the Native urban experience. Of specific educational interest are chapters on the role of…
For Love "and" Money? The Impact of Family Structure on Family Income

ERIC Educational Resources Information Center

Thomas, Adam; Sawhill, Isabel

2005-01-01

What do the half-century decline in U.S. marriage and the attendant rise in single parenthood mean for the economic well-being of children, especially children living in single-parent families? Adam Thomas and Isabel Sawhill show how differing living arrangements can be expected to affect families' economic well-being. Married-parent and…
Identifying the Correlates and Barriers of Future Planning among Parents of Individuals with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Burke, Meghan; Arnold, Catherine; Owen, Aleksa

2018-01-01

Although individuals with intellectual and developmental disabilities (IDD) are living longer lives, fewer than half of parents of individuals with IDD conduct future planning. The correlates and barriers to future planning must be identified to develop targeted interventions to facilitate future planning. In this study, 388 parents of individuals…

Long-lived radionuclides as chronometers and tracers of environmental processes at the Xi'an Accelerator Mass Spectrometry center

NASA Astrophysics Data System (ADS)

Zhou, W.; Hou, X.; Du, Y.; Kong, X.; Cheng, P.; Zhang, L.; Fan, Y.; Zhang, L.; Niu, Z.; Dong, G.; Chen, N.; Li, M.; Zhu, Y.

2017-12-01

Long-lived radionuclides with half-lives ranging from 103 to 108 years have wide applications in geochronology and environmental tracer studies. A wide range of climatic, geologic, and environmental records preserved in diverse natural archives can be characterized by measuring their concentrations, using accelerator mass spectrometry (AMS). Relying on the operation of the Xi'an 3 MV multi-element AMS since 2006, multi-radionuclides such as 14C, 10Be, 26Al, and 129I have been widely used for the above studies. Here some representative works on the four radionuclides can be briefly summarized as (1) we have successfully obtained temporal and spatial distribution of fossil fuel CO2 in certain cities in China by analyzing Δ14C from atmospheric CO2 and one year growth plants respectively, providing direct scientific data for government's emission cutting policy; (2) we have mathematically disentangled geomagnetic field and precipitation signals in Chinese loess 10Be, and firstly confirmed that the timing of Brunhes-Matuyama (B/M) reversal in loess was synchronous with that of marine sediments; (3) we have explored the paired in situ 10Be and 26Al double dating methodology for exposure dating, which has been successfully applied in fluvial terraces investigations in Tibet and glacial evolution tracing in East Antarctica; and (4) we have evaluated the radiation risk after Fukushima nuclear accident based on the 129I observation. All the above mentioned progress has opened up the new directions in AMS applications and we hope to show more new results in the near future.
Determination of Rolling-Element Fatigue Life From Computer Generated Bearing Tests

NASA Technical Reports Server (NTRS)

Vlcek, Brian L.; Hendricks, Robert C.; Zaretsky, Erwin V.

2003-01-01

Two types of rolling-element bearings representing radial loaded and thrust loaded bearings were used for this study. Three hundred forty (340) virtual bearing sets totaling 31400 bearings were randomly assembled and tested by Monte Carlo (random) number generation. The Monte Carlo results were compared with endurance data from 51 bearing sets comprising 5321 bearings. A simple algebraic relation was established for the upper and lower L(sub 10) life limits as function of number of bearings failed for any bearing geometry. There is a fifty percent (50 percent) probability that the resultant bearing life will be less than that calculated. The maximum and minimum variation between the bearing resultant life and the calculated life correlate with the 90-percent confidence limits for a Weibull slope of 1.5. The calculated lives for bearings using a load-life exponent p of 4 for ball bearings and 5 for roller bearings correlated with the Monte Carlo generated bearing lives and the bearing data. STLE life factors for bearing steel and processing provide a reasonable accounting for differences between bearing life data and calculated life. Variations in Weibull slope from the Monte Carlo testing and bearing data correlated. There was excellent agreement between percent of individual components failed from Monte Carlo simulation and that predicted.
Measurements of I-129 in meteorites and lunar rock by tandem accelerator mass spectrometry

NASA Technical Reports Server (NTRS)

Nizhiizumi, K.; Arnold, J. R.; Elmore, D.; Gove, H. E.; Honda, M.

1983-01-01

Precise measurements of the half-life of I-129 in three different meteorites and one lunar surface rock are reported. The meteorite source of I-129 was produced by cosmic ray secondary neutron reactions on Te, while the source in lunar materials in spallation on barium and rare earth elements. The Abee, Allende, and Dhajala meteorites were examined, together with the lunar rock 14310. Details of the process used to extract the iodine are provided. The Abee and Allende samples exhibited a production of 0.5 atom/min per gm of Te from the (n,2n) reaction and 0.05 atom/min/gm for the (n,gamma) reaction. The I-129 is concluded to be a viable tool for long-lived cosmogenic nuclide studies. Further work to extend the data to include the constancy of the cosmic ray flux, the meteorite bombardment history, and the cosmic exposure age dating by means of the I-129 and Xe-129 method is indicated.
The Arabidopsis lyrata genome sequence and the basis of rapid genome size change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Tina T.; Pattyn, Pedro; Bakker, Erica G.

2011-04-29

In our manuscript, we present a high-quality genome sequence of the Arabidopsis thaliana relative, Arabidopsis lyrata, produced by dideoxy sequencing. We have performed the usual types of genome analysis (gene annotation, dN/dS studies etc. etc.), but this is relegated to the Supporting Information. Instead, we focus on what was a major motivation for sequencing this genome, namely to understand how A. thaliana lost half its genome in a few million years and lived to tell the tale. The rather surprising conclusion is that there is not a single genomic feature that accounts for the reduced genome, but that every aspectmore » centromeres, intergenic regions, transposable elements, gene family number is affected through hundreds of thousands of cuts. This strongly suggests that overall genome size in itself is what has been under selection, a suggestion that is strongly supported by our demonstration (using population genetics data from A. thaliana) that new deletions seem to be driven to fixation.« less
There are many ways to spin a photon: Half-quantization of a total optical angular momentum

PubMed Central

Ballantine, Kyle E.; Donegan, John F.; Eastham, Paul R.

2016-01-01

The angular momentum of light plays an important role in many areas, from optical trapping to quantum information. In the usual three-dimensional setting, the angular momentum quantum numbers of the photon are integers, in units of the Planck constant ħ. We show that, in reduced dimensions, photons can have a half-integer total angular momentum. We identify a new form of total angular momentum, carried by beams of light, comprising an unequal mixture of spin and orbital contributions. We demonstrate the half-integer quantization of this total angular momentum using noise measurements. We conclude that for light, as is known for electrons, reduced dimensionality allows new forms of quantization. PMID:28861467
Ecology and management of tansy ragwort (Senecio jacobaea L.)

Treesearch

Jim Jacobs; Sharlene Sing

2009-01-01

Tansy ragwort, a member of the Asteraceae taxonomic family, is a large biennial or short-lived perennial herb native to and widespread throughout Europe and Asia. Stems can grow to a height of 5.5 feet (1.75 meters), with the lower half simple and the upper half many-branched at the inflorescence. Reproductive stems produce up to 2,500 bright golden-yellow flowers....
@Astro_Wheels Tweetup

NASA Image and Video Library

2011-03-16

A tweetuup participant videotapes with her iPhone and tweets as astronaut Doug Wheelock discusses his experiences while living on the International Space Station during a tweetup at NASA Headquarters in Washington, Wednesday, March 16, 2011. Wheelock, who has accumulated a total of 178 days in space, assumed command of the International Space Station and the Expedition 25 crew. During Expedition 25, there were more than 120 microgravity experiments in human research; biology and biotechnology; physical and materials sciences; technology development; and Earth and space sciences. Wheelock also responded to an emergency shutdown of half of the station's external cooling system and supported three unplanned spacewalks to replace the faulty pump module that caused the shutdown. His efforts restored the station's critical cooling system to full function. The mission duration was 163 days. Photo Credit: (NASA/Paul E. Alers)
Dynamic PET/CT measurements of induced positron activity in a prostate cancer patient after 50-MV photon radiation therapy.

PubMed

Janek Strååt, Sara; Jacobsson, Hans; Noz, Marilyn E; Andreassen, Björn; Näslund, Ingemar; Jonsson, Cathrine

2013-01-23

The purpose of this work was to reveal the research interest value of positron emission tomography (PET) imaging in visualizing the induced tissue activity post high-energy photon radiation treatment. More specifically, the focus was on the possibility of retrieving data such as tissue composition and physical half-lives from dynamic PET acquisitions, as positron-emitting radionuclides such as 15O, 11C, and 13N are produced in vivo during radiation treatment with high-energy photons (>15 MeV). The type, amount, and distribution of induced positron-emitting radionuclides depend on the irradiated tissue cross section, the photon spectrum, and the possible perfusion-driven washout. A 62-year-old man diagnosed with prostate cancer was referred for palliative radiation treatment of the pelvis minor. A total dose of 8 Gy was given using high-energy photon beams (50 MV) with a racetrack microtron, and 7 min after the end of irradiation, the patient was positioned in a PET/computed tomography (CT) camera, and a list-mode acquisition was performed for 30 min. Two volumes of interests (VOIs) were positioned on the dynamic PET/CT images, one in the urinary bladder and the other in the subcutaneous fat. Analysis of the measured relative count rate was performed in order to compute the tissue compositions and physical half-lives in the two regions. Dynamic analysis from the two VOIs showed that the decay constants of activated oxygen and carbon could be deduced. Calculation of tissue composition from analyzing the VOI containing subcutaneous fat only moderately agreed with that of the tabulated International Commission on Radiation Units & Measurements (ICRU) data of the adipose tissue. However, the same analysis for the bladder showed a good agreement with that of the tabulated ICRU data. PET can be used in visualizing the induced activity post high-energy photon radiation treatment. Despite the very low count rate in this specific application, wherein 7 min after treatment was about 5% of that of a standard 18F-FDG PET scan, the distribution of activated tissue elements (15O and 11C) could be calculated from the dynamic PET data. One possible future application of this method could possibly be to measure and determine the tumor tissue composition in order to identify any hypoxic or necrotic region, which is information that can be used in the ongoing therapy planning process. The official name of the trial committee of this study is 'Regionala etikprövningsnämnden i Stockholm' (FE 289, Stockholm, SE-17177, Sweden). The unique identifying number is 2011/1789-31/2.
Application of a loading dose of colistin methanesulfonate in critically ill patients: population pharmacokinetics, protein binding, and prediction of bacterial kill.

PubMed

Mohamed, Ami F; Karaiskos, Ilias; Plachouras, Diamantis; Karvanen, Matti; Pontikis, Konstantinos; Jansson, Britt; Papadomichelakis, Evangelos; Antoniadou, Anastasia; Giamarellou, Helen; Armaganidis, Apostolos; Cars, Otto; Friberg, Lena E

2012-08-01

A previous pharmacokinetic study on dosing of colistin methanesulfonate (CMS) at 240 mg (3 million units [MU]) every 8 h indicated that colistin has a long half-life, resulting in insufficient concentrations for the first 12 to 48 h after initiation of treatment. A loading dose would therefore be beneficial. The aim of this study was to evaluate CMS and colistin pharmacokinetics following a 480-mg (6-MU) loading dose in critically ill patients and to explore the bacterial kill following the use of different dosing regimens obtained by predictions from a pharmacokinetic-pharmacodynamic model developed from an in vitro study on Pseudomonas aeruginosa. The unbound fractions of colistin A and colistin B were determined using equilibrium dialysis and considered in the predictions. Ten critically ill patients (6 males; mean age, 54 years; mean creatinine clearance, 82 ml/min) with infections caused by multidrug-resistant Gram-negative bacteria were enrolled in the study. The pharmacokinetic data collected after the first and eighth doses were analyzed simultaneously with the data from the previous study (total, 28 patients) in the NONMEM program. For CMS, a two-compartment model best described the pharmacokinetics, and the half-lives of the two phases were estimated to be 0.026 and 2.2 h, respectively. For colistin, a one-compartment model was sufficient and the estimated half-life was 18.5 h. The unbound fractions of colistin in the patients were 26 to 41% at clinical concentrations. Colistin A, but not colistin B, had a concentration-dependent binding. The predictions suggested that the time to 3-log-unit bacterial kill for a 480-mg loading dose was reduced to half of that for the dose of 240 mg.
Application of a Loading Dose of Colistin Methanesulfonate in Critically Ill Patients: Population Pharmacokinetics, Protein Binding, and Prediction of Bacterial Kill

PubMed Central

Karaiskos, Ilias; Plachouras, Diamantis; Karvanen, Matti; Pontikis, Konstantinos; Jansson, Britt; Papadomichelakis, Evangelos; Antoniadou, Anastasia; Giamarellou, Helen; Armaganidis, Apostolos; Cars, Otto; Friberg, Lena E.

2012-01-01

A previous pharmacokinetic study on dosing of colistin methanesulfonate (CMS) at 240 mg (3 million units [MU]) every 8 h indicated that colistin has a long half-life, resulting in insufficient concentrations for the first 12 to 48 h after initiation of treatment. A loading dose would therefore be beneficial. The aim of this study was to evaluate CMS and colistin pharmacokinetics following a 480-mg (6-MU) loading dose in critically ill patients and to explore the bacterial kill following the use of different dosing regimens obtained by predictions from a pharmacokinetic-pharmacodynamic model developed from an in vitro study on Pseudomonas aeruginosa. The unbound fractions of colistin A and colistin B were determined using equilibrium dialysis and considered in the predictions. Ten critically ill patients (6 males; mean age, 54 years; mean creatinine clearance, 82 ml/min) with infections caused by multidrug-resistant Gram-negative bacteria were enrolled in the study. The pharmacokinetic data collected after the first and eighth doses were analyzed simultaneously with the data from the previous study (total, 28 patients) in the NONMEM program. For CMS, a two-compartment model best described the pharmacokinetics, and the half-lives of the two phases were estimated to be 0.026 and 2.2 h, respectively. For colistin, a one-compartment model was sufficient and the estimated half-life was 18.5 h. The unbound fractions of colistin in the patients were 26 to 41% at clinical concentrations. Colistin A, but not colistin B, had a concentration-dependent binding. The predictions suggested that the time to 3-log-unit bacterial kill for a 480-mg loading dose was reduced to half of that for the dose of 240 mg. PMID:22615285
Initial performance of the CUORE-0 experiment

DOE PAGES

Artusa, D. R.; Avignone, F. T.; Azzolini, O.; ...

2014-08-01

CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130Te. We present the first data analysis with 7.1kg • y of total TeO 2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to 2.57MeV) and in the α background-dominated region (2.70 to 3.90MeV) have been measured to be 0.071±0.011 and 0.019±0.002counts/(keV • kg • y), respectively. The latter result represents a factor of 6 improvement from a predecessor experiment, Cuoricino. The results verify our understanding of themore » background sources in CUORE-0, which is the basis of extrapolations to the full CUORE detector. The obtained energy resolution (full width at half maximum) in the region of interest is 5.7keV. Based on the measured background rate and energy resolution in the region of interest, CUORE-0 half-life sensitivity is expected to surpass the observed lower bound of Cuoricino with one year of live time.« less
The analysis of predictability of recent alpha decay formulae and the alpha partial half-lives of some exotic nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasgupta-Schubert, N.; Reyes, M. A.; Tamez, V. A.

2009-04-20

Alpha decay is one of the two main decay modes of the heaviest nuclei, (SHE), and constitutes one of the dominant decay modes of highly neutron deficient medium mass nuclei ('exotics'). Thus identifying and characterizing the alpha decay chains form a crucial part of the identification of SHE. We report the extension of the previously developed method for the detailed and systematic investigation of the reliability of the three main extant analytical formulae of alpha decay half-lives: the generalized liquid drop model based formula of Royer et al. (FR), the Sobiczewski modified semi-empirical Viola-Seaborg formula (VSS) and the recent phenomenologicalmore » formula of Sobiczewski and Parkhomenko (SP)« less
Nuclear Decay Data for the International Reactor Dosimetry Library for Fission and Fusion (IRDFF): Updated Evaluations of the Half-Lives and Gamma Ray Intensities

NASA Astrophysics Data System (ADS)

Chechev, Valery P.; Kuzmenko, Nikolay K.

2016-02-01

Updated evaluations of the half-lives and prominent gamma ray intensities have been presented for 20 radionuclides - dosimetry reaction residuals. The new values of these decay characteristics recommended for the IRDFF library were obtained using the approaches and methodology adopted by the working group of the Decay Data Evaluation Project (DDEP) cooperation. The experimental data published up to 2014 were taken into account in updated evaluations. The list of radionuclides includes 3H, 18F, 22Na, 24Na, 46Sc, 51Cr, 54Mn, 59Fe, 57Co, 60Co, 57Ni, 64Cu, 88Y, 132Te, 131I, 140Ba, 140La, 141Ce, 182Ta, 198Au.
EXPLORER: Changing the molecular imaging paradigm with total-body PET/CT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cherry, Simon R.; Badawi, Ramsey D.; Jones, Terry

2016-04-01

Positron emission tomography (PET) is the highest sensitivity technique for human whole-body imaging studies. However, current clinical PET scanners do not make full use of the available signal, as they only permit imaging of a 15-25 cm segment of the body at one time. Given the limited sensitive region, whole-body imaging with clinical PET scanners requires relatively long scan times and subjects the patient to higher than necessary radiation doses. The EXPLORER initiative aims to build a 2-meter axial length PET scanner to allow imaging the entire subject at once, capturing nearly the entire available PET signal. EXPLORER will acquire data with ~40-fold greater sensitivity leading to a six-fold increase in reconstructed signal-to-noise ratio for imaging the total body. Alternatively, total-body images with the EXPLORER scanner will be able to be acquired in ~30 seconds or with ~0.15 mSv injected dose, while maintaining current PET image quality. The superior sensitivity will open many new avenues for biomedical research. Specifically for cancer applications, high sensitivity PET will enable detection of smaller lesions. Additionally, greater sensitivity will allow imaging out to 10 half-lives of positron emitting radiotracers. This will enable 1) metabolic ultra-staging with FDG by extending the uptake and clearance time to 3-5 hours to significantly improve contrast and 2) improved kinetic imaging with short-lived radioisotopes such as C-11, crucial for drug development studies. Frequent imaging studies of the same subject to study disease progression or to track response to therapy will be possible with the low dose capabilities of the EXPLORER scanner. The low dose capabilities will also open up new imaging possibilities in pediatrics and adolescents to better study developmental disorders. This talk will review the basis for developing total-body PET, potential applications, and review progress to date in developing EXPLORER, the first total-body PET scanner.
Helix coupling

DOEpatents

Ginell, W.S.

1982-03-17

A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the U sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.
Helix coupling

DOEpatents

Ginell, William S.

1989-04-25

A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.
The nonamer UUAUUUAUU is the key AU-rich sequence motif that mediates mRNA degradation.

PubMed Central

Zubiaga, A M; Belasco, J G; Greenberg, M E

1995-01-01

Labile mRNAs that encode cytokine and immediate-early gene products often contain AU-rich sequences within their 3' untranslated region (UTR). These AU-rich sequences appear to be key determinants of the short half-lives of these mRNAs, although the sequence features of these elements and the mechanism by which they target mRNAs for rapid decay have not been fully defined. We have examined the features of AU-rich elements (AREs) that are crucial for their function as determinants of mRNA instability in mammalian cells by testing the ability of various mutant c-fos AREs and synthetic AREs to direct rapid mRNA deadenylation and decay when inserted within the 3' UTR of the normally stable beta-globin mRNA. Evidence is presented that the pentamer AUUUA, which previously was suggested to be the minimal determinant of instability present in mammalian AREs, cannot direct rapid mRNA deadenylation and decay. Instead, the nonomer UUAUUUAUU is the elemental AU-rich sequence motif that destabilizes mRNA. Removal of one uridine residue from either end of the nonamer (UUAUUUAU or UAUUUAUU) results in a decrease of potency of the element, while removal of a uridine residue from both ends of the nonamer (UAUUUAU) eliminates detectable destabilizing activity. The inclusion of an additional uridine residue at both ends of the nonamer (UUUAUUUAUUU) does not further increase the efficacy of the element. Taken together, these findings suggest that the nonamer UUAUUUAUU is the minimal AU-rich motif that effectively destabilizes mRNA. Additional ARE potency is achieved by combining multiple copies of this nonamer in a single mRNA 3' UTR. Furthermore, analysis of poly(A) shortening rates for ARE-containing mRNAs reveals that the UUAUUUAUU sequence also accelerates mRNA deadenylation and suggests that the UUAUUUAUU motif targets mRNA for rapid deadenylation as an early step in the mRNA decay process. PMID:7891716
A systematic study of the disposition and metabolism of mercury species in mice after exposure to low levels of thimerosal (ethylmercury)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carneiro, Maria Fernanda Hornos, E-mail: mafehoca@fcfrp.usp.br; Oliveira Souza, Juliana Maria, E-mail: souza.jmo@gmail.com; Grotto, Denise, E-mail: denise.grotto@prof.uniso.br

Thimerosal (TM) is an ethylmercury (etHg)-containing preservative used in some vaccines despite very limited knowledge on the kinetics and direct interaction/effects in mammals' tissues after exposure. Thus, this study aimed to evaluate the kinetics of Hg species in mice in a time course analysis after intramuscular injection of TM, by estimating Hg half-lives in blood and tissues. Mice were exposed to one single intramuscular dose of 20 µg of Hg as TM. Blood, brain, heart, kidney and liver were collected at 0.5 hour (h), 1 h, 8 h, 16 h, 144 h, 720 h and 1980 h after TM exposuremore » (n=4). Hg species in animal tissues were identified and quantified by speciation analysis via liquid chromatography hyphenated with inductively coupled mass spectrometry (LC–ICP-MS). It was found that the transport of etHg from muscle to tissues and its conversion to inorganic Hg (inoHg) occur rapidly. Moreover, the conversion extent is modulated in part by the partitioning between EtHg in plasma and in whole blood, since etHg is rapidly converted in red cells but not in a plasma compartment. Furthermore, the dealkylation mechanism in red cells appears to be mediated by the Fenton reaction (hydroxyl radical formation). Interestingly, after 0.5 h of TM exposure, the highest levels of both etHg and inoHg were found in kidneys (accounting for more than 70% of the total Hg in the animal body), whereas the brain contributed least to the Hg body burden (accounts for <1.0% of total body Hg). Thirty days after TM exposure, most Hg had been excreted while the liver presented the majority of the remaining Hg. Estimated half-lives (in days) were 8.8 for blood, 10.7 for brain, 7.8 for heart, 7.7 for liver and 45.2 for kidney. Taken together, our findings demonstrated that TM (etHg) kinetics more closely approximates Hg{sup 2+} than methylmercury (meHg) while the kidney must be considered a potential target for etHg toxicity. - Highlights: • Ethylmercury is rapidly converted to inorganic mercury. • Hg substantially accumulates in kidney with a terminal half-life of 45.2 d. • The dealkylation of ethylmercury occurs in red blood cells but not in plasma. • Hydroxyl radical is probably the main effector of this dealkylation. • Kidney must be considered a potential target for ethylmercury toxicity.« less
Local Burn-Up Effects in the NBSR Fuel Element

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown N. R.; Hanson A.; Diamond, D.

2013-01-31

This study addresses the over-prediction of local power when the burn-up distribution in each half-element of the NBSR is assumed to be uniform. A single-element model was utilized to quantify the impact of axial and plate-wise burn-up on the power distribution within the NBSR fuel elements for both high-enriched uranium (HEU) and low-enriched uranium (LEU) fuel. To validate this approach, key parameters in the single-element model were compared to parameters from an equilibrium core model, including neutron energy spectrum, power distribution, and integral U-235 vector. The power distribution changes significantly when incorporating local burn-up effects and has lower power peakingmore » relative to the uniform burn-up case. In the uniform burn-up case, the axial relative power peaking is over-predicted by as much as 59% in the HEU single-element and 46% in the LEU single-element with uniform burn-up. In the uniform burn-up case, the plate-wise power peaking is over-predicted by as much as 23% in the HEU single-element and 18% in the LEU single-element. The degree of over-prediction increases as a function of burn-up cycle, with the greatest over-prediction at the end of Cycle 8. The thermal flux peak is always in the mid-plane gap; this causes the local cumulative burn-up near the mid-plane gap to be significantly higher than the fuel element average. Uniform burn-up distribution throughout a half-element also causes a bias in fuel element reactivity worth, due primarily to the neutronic importance of the fissile inventory in the mid-plane gap region.« less
Volcanic Evolution in the Galapagos: The Geochemistry and Petrology of Espanola Island

NASA Astrophysics Data System (ADS)

McGuire, M.; Varga, K. C.; Harpp, K. S.; Geist, D.; Hall, M. L.

2015-12-01

The Galapagos Archipelago consists of a series of volcanic islands located ~1,000 km west of South America that are thought to be the result of a mantle plume. The southeasternmost island, Espanola, is one of the smallest of the major islands, measuring only 7 by 14 km and reaching an elevation of 200 m. Espanola is also the oldest island in the chain, with K-Ar dates from 3.01 ± 0.11 to 3.31 ± 0.36 million years (Hall et al. 1983; White et al., 1993). The southern coast is defined by cliffs that exceed 100 m in height, made up of nearly flat-lying lavas that are each several meters thick. The northern coastline consists of lavas that dip gently toward the ocean from the highlands, as well as remnants of eroded cinder cones. Paleomagnetic measurements made in the field indicate that the western half of the island is reversely polarized, whereas most lavas measured across the eastern half are normally polarized. Major element analyses of samples from across the island indicate that fractional crystallization is the dominant process controlling chemical variations in Espanola lavas, suggesting a relatively long-lived magmatic plumbing system. Stratigraphically constrained chemical variations suggest the magma chamber may have experienced periodic replenishment by compositionally homogeneous primitive melts. Variable fluid-mobile trace element concentrations provide some evidence for contributions from ancient, recycled oceanic crust to the parental melts. Espanola lavas have more depleted Sr and Pb radiogenic isotope ratios than either Floreana or Fernandina, and lie on a mixing curve between the composition of the plume and that of the depleted upper mantle. Between ~3 and 8 Ma, the Galapagos Spreading Center was closer to the Galapagos plume than it is today. Given that Espanola was constructed during the same period, the depleted isotopic signatures suggest that plume-ridge interaction may have been a strong influence on the island's geochemical composition.

Living Day by Day: The Meaning of Living With HIV/AIDS Among Women in Lebanon.

PubMed

Kaplan, Rachel L; Khoury, Cynthia El; Field, Emily R S; Mokhbat, Jacques

2016-01-01

We examined the meaning of living with HIV/AIDS among women in Lebanon. Ten women living with HIV/AIDS (WLWHA) described their experiences via semistructured in-depth interviews. They navigated a process of HIV diagnosis acceptance that incorporated six overlapping elements: receiving the news, accessing care, starting treatment, navigating disclosure decisions, negotiating stigma, and maintaining stability. Through these elements, we provide a framework for understanding three major themes that were constructed during data analysis: Stand by my side: Decisions of disclosure; Being "sick" and feeling "normal": Interacting with self, others, and society; and Living day by day: focusing on the present. We contribute to the existing literature by providing a theoretical framework for understanding the process of diagnosis and sero-status acceptance among WLWHA. This was the first study of its kind to examine the meaning of living with HIV/AIDS among women in a Middle Eastern country.
Posttranscriptional Control of Photosynthetic mRNA Decay under Stress Conditions Requires 3′ and 5′ Untranslated Regions and Correlates with Differential Polysome Association in Rice1[W][OA

PubMed Central

Park, Su-Hyun; Chung, Pil Joong; Juntawong, Piyada; Bailey-Serres, Julia; Kim, Youn Shic; Jung, Harin; Bang, Seung Woon; Kim, Yeon-Ki; Do Choi, Yang; Kim, Ju-Kon

2012-01-01

Abiotic stress, including drought, salinity, and temperature extremes, regulates gene expression at the transcriptional and posttranscriptional levels. Expression profiling of total messenger RNAs (mRNAs) from rice (Oryza sativa) leaves grown under stress conditions revealed that the transcript levels of photosynthetic genes are reduced more rapidly than others, a phenomenon referred to as stress-induced mRNA decay (SMD). By comparing RNA polymerase II engagement with the steady-state mRNA level, we show here that SMD is a posttranscriptional event. The SMD of photosynthetic genes was further verified by measuring the half-lives of the small subunit of Rubisco (RbcS1) and Chlorophyll a/b-Binding Protein1 (Cab1) mRNAs during stress conditions in the presence of the transcription inhibitor cordycepin. To discern any correlation between SMD and the process of translation, changes in total and polysome-associated mRNA levels after stress were measured. Total and polysome-associated mRNA levels of two photosynthetic (RbcS1 and Cab1) and two stress-inducible (Dehydration Stress-Inducible Protein1 and Salt-Induced Protein) genes were found to be markedly similar. This demonstrated the importance of polysome association for transcript stability under stress conditions. Microarray experiments performed on total and polysomal mRNAs indicate that approximately half of all mRNAs that undergo SMD remain polysome associated during stress treatments. To delineate the functional determinant(s) of mRNAs responsible for SMD, the RbcS1 and Cab1 transcripts were dissected into several components. The expressions of different combinations of the mRNA components were analyzed under stress conditions, revealing that both 3′ and 5′ untranslated regions are necessary for SMD. Our results, therefore, suggest that the posttranscriptional control of photosynthetic mRNA decay under stress conditions requires both 3′ and 5′ untranslated regions and correlates with differential polysome association. PMID:22566494
"Move or Suffer": Is Age-Segregation the New Norm for Older Americans Living Alone?

PubMed

Portacolone, Elena; Halpern, Jodi

2016-08-01

Despite ethical claims that civic societies should foster intergenerational integration, age-segregation is a widespread yet understudied phenomenon. The purpose of this study was to understand the reasons that led community-dwelling older Americans to relocate into senior housing. Qualitative data were collected through participant observation and ethnographic interviews with 47 older adults living alone in San Francisco, California. Half of study participants lived in housing for seniors, the other half in conventional housing. Data were analyzed with standard qualitative methods. Findings illuminate the dynamics that favor age-segregation. Senior housing might be cheaper, safer, and offer more socializing opportunities than conventional housing. Yet, tenants of senior housing may also experience isolation, crime, and distress. Findings suggest that rather than individual preference, cultural, political, and economic factors inform the individual decision to relocate into age-segregated settings. Findings also call for an increased awareness on the ethical implications of societies increasingly segregated by age. © The Author(s) 2014.
Transposon-like properties of the major, long repetitive sequence family in the genome of Physarum polycephalum

PubMed Central

Pearston, Douglas H.; Gordon, Mairi; Hardman, Norman

1985-01-01

A family of long, highly-repetitive sequences, referred to previously as `HpaII-repeats', dominates the genome of the eukaryotic slime mould Physarum polycephalum. These sequences are found exclusively in scrambled clusters. They account for about one-half of the total complement of repetitive DNA in Physarum, and represent the major sequence component found in hypermethylated, 20-50 kb segments of Physarum genomic DNA that fail to be cleaved using the restriction endonuclease HpaII. The structure of this abundant repetitive element was investigated by analysing cloned segments derived from the hypermethylated genomic DNA compartment. We show that the `HpaII-repeat' forms part of a larger repetitive DNA structure, ∼8.6 kb in length, with several structural features in common with recognised eukaryotic transposable genetic elements. Scrambled clusters of the sequence probably arise as a result of transposition-like events, during which the element preferentially recombines in either orientation with target sites located in other copies of the same repeated sequence. The target sites for transposition/recombination are not related in sequence but in all cases studied they are potentially capable of promoting the formation of small `cruciforms' or `Z-DNA' structures which might be recognised during the recombination process. ImagesFig. 3.Fig. 4. PMID:16453652
Risk Assessment and Management for Medically Complex Potential Living Kidney Donors: A Few Deontological Criteria and Ethical Values

PubMed Central

Petrini, Carlo

2011-01-01

A sound evaluation of every bioethical problem should be predicated on a careful analysis of at least two basic elements: (i) reliable scientific information and (ii) the ethical principles and values at stake. A thorough evaluation of both elements also calls for a careful examination of statements by authoritative institutions. Unfortunately, in the case of medically complex living donors neither element gives clear-cut answers to the ethical problems raised. Likewise, institutionary documents frequently offer only general criteria, which are not very helpful when making practical choices. This paper first introduces a brief overview of scientific information, ethical values, and institutionary documents; the notions of “acceptable risk” and “minimal risk” are then briefly examined, with reference to the problem of medically complex living donors. The so-called precautionary principle and the value of solidarity are then discussed as offering a possible approach to the ethical problem of medically complex living donors. PMID:22174982
Rolling-element fatigue life of AMS 5749 corrosion resistant, high temperature bearing steel

NASA Technical Reports Server (NTRS)

Parker, R. J.; Hodder, R. S.

1977-01-01

The rolling element fatigue lives of AMS 5749 and AISI M-50 were compared in tests run in the five ball fatigue tester and the rolling contact fatigue tester. The effects of double vacuum melting and retained austenite on the life of AMS 5749 were determined in five ball fatigue tests. The double vacuum melting process consisted of induction vacuum melting followed by vacuum arc remelting (VIM-VAR). In the five ball tests, VIM-VAR AMS 5749 gave lives at least six times that of VIM-VAR AISI M-50. Similar tests in the rolling contact fatigue tester showed no significant difference in the lives of the two materials. The rolling element fatigue life of VIM-VAR AMS 5749 was at least 14 times that of vacuum induction melted AMS 5749. A trend toward increased rolling element fatigue life with decreased retained austenite is apparent, but the confidence that all experimental differences are significant is not great.
Disposition and metabolism of [(14)C] Sacubitril/Valsartan (formerly LCZ696) an angiotensin receptor neprilysin inhibitor, in healthy subjects.

PubMed

Flarakos, Jimmy; Du, Yancy; Bedman, Timothy; Al-Share, Qusai; Jordaan, Pierre; Chandra, Priya; Albrecht, Diego; Wang, Lai; Gu, Helen; Einolf, Heidi J; Huskey, Su-Er; Mangold, James B

2016-11-01

1. Sacubitril/valsartan (LCZ696) is an angiotensin receptor neprilysin inhibitor (ARNI) providing simultaneous inhibition of neprilysin (neutral endopeptidase 24.11; NEP) and blockade of the angiotensin II type-1 (AT1) receptor. 2. Following oral administration, [(14)C]LCZ696 delivers systemic exposure to valsartan and AHU377 (sacubitril), which is rapidly metabolized to LBQ657 (M1), the biologically active neprilysin inhibitor. Peak sacubitril plasma concentrations were reached within 0.5-1 h. The mean terminal half-lives of sacubitril, LBQ657 and valsartan were ∼1.3, ∼12 and ∼21 h, respectively. 3. Renal excretion was the dominant route of elimination of radioactivity in human. Urine accounted for 51.7-67.8% and feces for 36.9 to 48.3 % of the total radioactivity. The majority of the drug was excreted as the active metabolite LBQ657 in urine and feces, total accounting for ∼85.5% of the total dose. 4. Based upon in vitro studies, the potential for LCZ696 to inhibit or induce cytochrome P450 (CYP) enzymes and cause CYP-mediated drug interactions clinically was found to be low.
Living with HIV, disclosure patterns and partnerships a decade after the introduction of HIV programmes in rural South Africa

PubMed Central

Mkwanazi, Ntombizodumo B.; Rochat, Tamsen J.; Bland, Ruth M.

2015-01-01

Prevention of mother-to-child Transmission and HIV Treatment programmes were scaled-up in resource-constrained settings over a decade ago, but there is still much to be understood about women's experiences of living with HIV and their HIV disclosure patterns. This qualitative study explored women's experiences of living with HIV, 6–10 years after being diagnosed during pregnancy. The area has high HIV prevalence, and an established HIV treatment programme. Participants were enrolled in a larger intervention, “Amagugu”, that supported women (n = 281) to disclose their HIV status to their children. Post-intervention we conducted individual in-depth interviews with 20 randomly selected women, stratified by clinic catchment area, from the total sample. Interviews were entered into ATLAS.ti computer software for coding. Most women were living with their current sexual partner and half were still in a relationship with the child's biological father. Household exposure to HIV was high with the majority of women knowing at least one other HIV-infected adult in their household. Eighteen women had disclosed their HIV status to another person; nine had disclosed to their current partner first. Two main themes were identified in the analyses: living with HIV and the normalisation of HIV treatment at a family level; and the complexity of love relationships, in particular in long-term partnerships. A decade on, most women were living positively with HIV, accessing care, and reported experiencing little stigma. However, as HIV became normalised new challenges arose including concerns about access to quality care, and the need for family-centred care. Women's sexual choices and relationships were intertwined with feelings of love, loyalty and trust and the important supportive role played by partners and families was acknowledged, however, some aspects of living with HIV presented challenges including continuing to practise safe sex several years after HIV diagnosis. PMID:26616127
Projections of forest contributions to global carbon cycles

Treesearch

Michael E. Goerndt; Stephen R. Shifley; Patrick D. Miles; Dave Wear; Francisco X. Aguilar

2016-01-01

Forests cover 42 percent of the Northern United States, and collectively they store 13 billion tons of carbon in live trees (29 percent), roots (6 percent), forest floor (9 percent), dead trees (6 percent), and soils (50 percent). About half the biomass of a live tree (dry weight basis) is sequestered carbon (Woodall et al. 2011) - not the largest but the most dynamic...
A Guide to the Study of a Victorian Household.

ERIC Educational Resources Information Center

Hewett, Marie; MacAdam, Barbara

Designed to introduce secondary school students to a variety of historical resources on local, family, and 19th century cultural history, the primary materials presented in this guide provide insight into the lives of one family, the D. H. Osbornes, who lived in Victor, New York, from the 1850's through the first half of this century. Based on a…
Substance Use and Dependency Disorders in Adolescent Girls in Group Living Programs: Prevalence and Associations with Milieu Factors

ERIC Educational Resources Information Center

Baker, Amy J. L.; Ashare, Caryn; Charvat, Benjamin J.

2009-01-01

Fifty-three adolescent girls residing in community-based group-living child welfare programs were administered a standardized measure (SASS-2) in order to assess probability of a substance use/dependency disorder in this highly vulnerable population. Findings revealed that one third of the sample, and one half of the nonpregnant/parenting girls,…
Female married illiteracy as the most important continual determinant of total fertility rate among districts of Empowered Action Group States of India: Evidence from Annual Health Survey 2011–12

PubMed Central

Kumar, Rajesh; Dogra, Vishal; Rani, Khushbu; Sahu, Kanti

2017-01-01

Background: District level determinants of total fertility rate in Empowered Action Group states of India can help in ongoing population stabilization programs in India. Objective: Present study intends to assess the role of district level determinants in predicting total fertility rate among districts of the Empowered Action Group states of India. Material and Methods: Data from Annual Health Survey (2011-12) was analysed using STATA and R software packages. Multiple linear regression models were built and evaluated using Akaike Information Criterion. For further understanding, recursive partitioning was used to prepare a regression tree. Results: Female married illiteracy positively associated with total fertility rate and explained more than half (53%) of variance. Under multiple linear regression model, married illiteracy, infant mortality rate, Ante natal care registration, household size, median age of live birth and sex ratio explained 70% of total variance in total fertility rate. In regression tree, female married illiteracy was the root node and splits at 42% determined TFR <= 2.7. The next left side branch was again married illiteracy with splits at 23% to determine TFR <= 2.1. Conclusion: We conclude that female married illiteracy is one of the most important determinants explaining total fertility rate among the districts of an Empowered Action Group states. Focus on female literacy is required to stabilize the population growth in long run. PMID:29416999
Mobile element biology – new possibilities with high-throughput sequencing

PubMed Central

Xing, Jinchuan; Witherspoon, David J.; Jorde, Lynn B.

2014-01-01

Mobile elements compose more than half of the human genome, but until recently their large-scale detection was time-consuming and challenging. With the development of new high-throughput sequencing technologies, the complete spectrum of mobile element variation in humans can now be identified and analyzed. Thousands of new mobile element insertions have been discovered, yielding new insights into mobile element biology, evolution, and genomic variation. We review several high-throughput methods, with an emphasis on techniques that specifically target mobile element insertions in humans, and we highlight recent applications of these methods in evolutionary studies and in the analysis of somatic alterations in human cancers. PMID:23312846
Half-lives of 214Pb and 214Bi.

PubMed

Martz, D E; Langner, G H; Johnson, P R

1991-10-01

New measurements on chemically separated samples of 214Bi have yielded a mean half-life value of 19.71 +/- 0.02 min, where the error quoted is twice the standard deviation of the mean based on 23 decay runs. This result provides strong support for the historic 19.72 +/- 0.04 min half-life value and essentially excludes the 19.9-min value, both reported in previous studies. New measurements of the decay rate of 222Rn progeny activity initially in radioactive equilibrium have yielded a value of 26.89 +/- 0.03 min for the half-life of 214Pb, where the error quoted is twice the standard deviation of the mean based on 12 decay runs. This value is 0.1 min longer than the currently accepted 214Pb half-value of 26.8 min.
FUEL ELEMENT INTERLOCKING ARRANGEMENT

DOEpatents

Fortescue, P.; Nicoll, D.

1963-01-01

This patent relates to a system for mutually interlocking a multiplicity of elongated, parallel, coextensive, upright reactor fuel elements so as to render a laterally selfsupporting bundle, while admitting of concurrent, selective, vertical withdrawal of a sizeable number of elements without any of the remaining elements toppling, Each element is provided with a generally rectangular end cap. When a rank of caps is aligned in square contact, each free edge centrally defines an outwardly profecting dovetail, and extremitally cooperates with its adjacent cap by defining a juxtaposed half of a dovetail- receptive mortise. Successive ranks are staggered to afford mating of their dovetails and mortises. (AEC)
Piezoelectric drive circuit

DOEpatents

Treu, C.A. Jr.

1999-08-31

A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.
Development and Verification of a Weld Simulation Capability for VAST

DTIC Science & Technology

2012-06-01

midsurface -aligned and not contain any offsets (i.e., thickness is symmetric on either side of the midsurface ). Furthermore, for a given element...both above and below the midsurface – i.e., NT /2 elements representing half the thickness both above and below (Figure 35). This operation is easy for
Piezoelectric drive circuit

DOEpatents

Treu, Jr., Charles A.

1999-08-31

A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.
European Scientific Notes. Volume 34, Number 10,

DTIC Science & Technology

1980-10-31

vivo use because of its short half- According to Pfannenstiel there are life, its favorable photon emissions more than 50 different forms of known thy...of medical professionals from 3 ity, biological half-lives, dosimetry countries. (Moses A. Greenfield) (absorbed dose), and the differential di...for the Advancement The crash was a serious blow for of Siene wre tld hatther isa mjor European scientists including Britain’s ga tatisrapidly
BIPAD: A web server for modeling bipartite sequence elements

PubMed Central

Bi, Chengpeng; Rogan, Peter K

2006-01-01

Background Many dimeric protein complexes bind cooperatively to families of bipartite nucleic acid sequence elements, which consist of pairs of conserved half-site sequences separated by intervening distances that vary among individual sites. Results We introduce the Bipad Server [1], a web interface to predict sequence elements embedded within unaligned sequences. Either a bipartite model, consisting of a pair of one-block position weight matrices (PWM's) with a gap distribution, or a single PWM matrix for contiguous single block motifs may be produced. The Bipad program performs multiple local alignment by entropy minimization and cyclic refinement using a stochastic greedy search strategy. The best models are refined by maximizing incremental information contents among a set of potential models with varying half site and gap lengths. Conclusion The web service generates information positional weight matrices, identifies binding site motifs, graphically represents the set of discovered elements as a sequence logo, and depicts the gap distribution as a histogram. Server performance was evaluated by generating a collection of bipartite models for distinct DNA binding proteins. PMID:16503993

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