Distribution by Scientific Domains

Kinds of States.

  • unite states.

  • Selected Abstracts


    ECONOMIC INQUIRY, Issue 4 2008
    This paper explores the widely accepted view that Wal-Mart causes significant harm to the traditional, small "mom and pop" business sector of the U.S. economy. We present the first rigorous econometric investigation of this issue by examining the rate of self-employment and the number of small employer establishments using both time series and cross-sectional data. We also examine alternative measures and empirical techniques for robustness. Contrary to popular belief, our results suggest that the process of creative destruction unleashed by Wal-Mart has had no statistically significant long-run impact on the overall size and profitability of the small business sector in the United States. (JEL L81, D59, C21) [source]

    Introduction to therapy of hepatitis C

    HEPATOLOGY, Issue S1 2002
    Karen L. Lindsay M.D.
    Since the 1997 National Institutes of Health Consensus Development Conference on management of hepatitis C there have been several important advances that significantly impact its therapy; notably the availability of sensitive, specific, and standardized assays for identifying hepatitis C virus (HCV) RNA in the serum, the addition of ribavirin to alpha interferon, the pegylation of alpha interferon, and the demonstration that sustained virological response (SVR) is the optimal surrogate endpoint of treatment. Using pegylated interferon and ribavirin, virological response with relapse and nonresponse are less common, but remain poorly understood. Current studies are evaluating nonvirological endpoints of treatment, namely biochemical response and histological response. To date, definitive treatment trials have primarily been conducted in adult patients with elevated aminotransferase levels, clinically compensated chronic liver disease, and no other significant medical disorder. Limited data are available from studies of other patient populations, and the safety of interferon-based treatment has not yet been established in several patient groups. Future research is needed to elucidate the mechanisms of viral response and clearance, to develop effective therapies for interferon nonresponse or intolerance, to define the role of complementary and alternative medicine and other nonspecific therapies, and to develop strategies for the optimal management and treatment of special patient populations who probably represent the majority of persons with chronic hepatitis C in the United States. (HEPATOLOGY 2002;36:S114,S120). [source]

    Assigning priority to environmental policy interventions in a heterogeneous world

    Paul J. Ferraro
    Failure to consider costs as well as benefits is common in many policy initiatives and analyses, particularly in the environmental arena. Economists and other policy scientists have demonstrated that integrating both cost and benefit information explicitly into the policy process can be vital to ensuring that scarce funds go as far as they can toward achieving policy objectives. The costs of acquiring and analyzing such information, however, can be substantial. The objective of this paper is to help policy analysts and practitioners identify the conditions under which integrating cost and benefit information is likely to be vital to effective decisionmaking, and the conditions under which failing to use both cost and benefit data would result in little, if any, loss in efficiency. These points are illustrated through a conceptual discussion and an empirical analysis of a conservation initiative in the United States. © 2003 by the Association for Public Policy Analysis and Management. [source]

    Effecting science, affecting medicine: Homosexuality, the Kinsey reports, and the contested boundaries of psychopathology in the United States, 1948,1965

    Howard Hsueh-Hao Chiang
    Despite the well-documented intensive battle between Alfred Kinsey and American psychiatrists around the mid-twentieth century, this paper argues that Kinsey's work, in fact, played a significant role in transforming mental health experts' view of homosexuality starting as far back as the late 1940s and extending all the way through the mid-1960s. After analyzing the way in which Kinsey's work pushed American psychiatrists to re-evaluate their understanding of homosexuality indirectly through the effort of clinical psychologists, I then focus to a greater extent on examples that illustrate how the Kinsey reports directly influenced members of the psychiatric community. In the conclusion, using a Foucauldian conception of "discourse," I propose that in order to approach the struggle around the pathological status of homosexuality in the 1950s and the 1960s, thinking in terms of a "politics of knowledge" is more promising than simply in terms of a "politics of diagnosis." Central to the struggle was not merely the matter of medical diagnosis, but larger issues regarding the production of knowledge at an intersection of science and medicine where the parameters of psychopathology were disputed in the context of mid-twentieth-century United States. © 2008 Wiley Periodicals, Inc. [source]

    DSM-III and the revolution in the classification of mental illness

    Rick Mayes
    A revolution occurred within the psychiatric profession in the early 1980s that rapidly transformed the theory and practice of mental health in the United States. In a very short period of time, mental illnesses were transformed from broad, etiologically defined entities that were continuous with normality to symptom-based, categorical diseases. The third edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III) was responsible for this change. The paradigm shift in mental health diagnosis in the DSM-III was neither a product of growing scientific knowledge nor of increasing medicalization. Instead, its symptom-based diagnoses reflect a growing standardization of psychiatric diagnoses. This standardization was the product of many factors, including: (1) professional politics within the mental health community, (2) increased government involvement in mental health research and policymaking, (3) mounting pressure on psychiatrists from health insurers to demonstrate the effectiveness of their practices, and (4) the necessity of pharmaceutical companies to market their products to treat specific diseases. This article endeavors to explain the origins of DSM-III, the political struggles that generated it, and its long-term consequences for clinical diagnosis and treatment of mental disorders in the United States. © 2005 Wiley Periodicals, Inc. [source]

    Language preference and its relationship with reading skills in English and Spanish

    Michele H. Brenneman
    A dearth of research has investigated the language preference of bilingual childhood populations and its subsequent relationship to reading skills. The current study evaluated how a sequential bilingual student's choice of language, in a particular environmental context, predicted reading ability in English and Spanish. The participants were Latino children ranging in age from 7 years, 5 months, to 11 years, 6 months, with 43% born in the United States. Results showed a relationship between a child's higher English language preference for media and for communication with others outside the family and better reading skills in English. Language preference differences predicted reading abilities better for English than for Spanish. Results suggested that sequential bilingual children's language preference may be a useful marker of English language (second language [L2]) facility and use that is related to their reading proficiency or influences the development of English reading skills in such bilingual children in the United States. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 171,181, 2007. [source]

    Clinical Practice Guidelines for the Use of Axillary Sentinel Lymph Node Biopsy in Carcinoma of the Breast: Current Update

    THE BREAST JOURNAL, Issue 2 2004
    Gordon F. Schwartz MD, MBAArticle first published online: 10 MAR 200
    Abstract: Axillary sentinel lymph node biopsy (SLNB) has been adopted as a suitable alternative to traditional level I and II axillary dissection in the management of clinically node-negative (N0) breast cancers. There are two current techniques used to identify the sentinel node(s): radiopharmaceutical, technetium sulfur colloid, and isosulfan blue dye (used in the United States) and technetium-labeled albumin and patent blue dye (used in Europe). (The labeled albumin is not U.S. Food and Drug Administration [FDA] approved in the United States.) SLNB to replace axillary dissection should only be performed by surgeons and patient management teams with appropriate training and experience. Although both radiocolloid and blue dye are used together by most surgeons, and training should be in both techniques, some experienced surgeons use one or the other almost exclusively. In addition, surgical pathologists must recognize the need to examine these small specimens with great care, using a generally adopted protocol. Imprint cytology or frozen sections may be used, followed by additional sections for light microscopy. Immunochemical staining with cytokeratin or other techniques to identify "submicroscopic" metastasis is often used, but the results should not be used to influence clinical decisions with respect to adjuvant therapy. "Failed" SLNB implies the surgeon's failure to identify the sentinel nodes, in which case a complete dissection is performed. A "false-negative" SLNB implies the finding of metastasis in the excised sentinel nodes by light microscopy after a negative frozen section examination. Whether a false-negative SLNB mandates completion axillary dissection is controversial, with clinical trials currently under way to answer this question. Although SLNB was initiated to accompany breast-conserving treatment, it is equally useful in patients undergoing mastectomy. It is more difficult to perform with mastectomy. When using blue dye only, SLNB may require a separate incision because of time constraints between injection and identification of the blue-stained nodes; radiocolloid usually does not. Completion axillary dissection after false-negative SLNB is more difficult after mastectomy. SLNB is a useful procedure that may save 70% of women with clinically negative (N0) axillae and all of those with pathologically negative axillae from the morbidity of complete axillary dissection. Ideally the sentinel nodes should be able to identified in more than 95% of patients, with a false-negative rate of less than 5%. Until these rates can be achieved consistently, however, surgeons should not abandon traditional axillary dissection., [source]

    A Hallucinogenic Tea, Laced with Controversy: Ayahuasca in the Amazon and the United States. by Marlene Dobkin de Rios and Roger Rumrrill

    John R. Baker
    No abstract is available for this article. [source]

    Widespread distribution of knockdown resistance mutations in the bed bug, Cimex lectularius (Hemiptera: Cimicidae), populations in the United States

    Fang Zhu
    Abstract We previously reported high deltamethrin resistance in bed bugs, Cimex lectularius, collected from multiple areas of the United States (Romero et al., 2007). Recently, two mutations, the Valine to Leucine mutation (V419L) and the Leucine to Isoleucine mutation (L925I) in voltage-gated sodium channel ,-subunit gene, had been identified to be responsible for knockdown resistance (kdr) to deltamethrin in bed bugs collected from New York (Yoon et al., 2008). The current study was undertaken to investigate the distribution of these two kdr mutations in 110 bed bug populations collected in the United States. Out of the 17 bed bug populations that were assayed for deltamethrin susceptibility, two resistant populations collected in the Cincinnati area and three deltamethrin-susceptible lab colonies showed neither of the two reported mutations (haplotype A). The remaining 12 populations contained L925I or both V419L and L925I mutations in voltage-gated sodium channel ,-subunit gene (haplotypes B&C). In 93 populations that were not assayed for deltamethrin susceptibility, 12 contained neither of the two mutations (haplotype A) and 81 contained L925I or V419L or both mutations (haplotypes B-D). Thus, 88% of the bed bug populations collected showed target-site mutations. These data suggest that deltamethrin resistance conferred by target-site insensitivity of sodium channel is widely spread in bed bug populations across the United States. © 2010 Wiley Periodicals, Inc. [source]

    LambdaXtreme® transport system: R&D of a high capacity system for low cost, ultra long haul DWDM transport

    Daniel A. Fishman
    The LambdaXtreme® Transport System, Lucent Technologies' ultra long haul high-capacity transport product, leverages leading edge innovations in optics and applied physics as well as computational and computer science. In this paper, we provide a detailed view of the research and development efforts that resulted in a lightwave transmission system that is now being used in backbone national networks in the United States. © 2006 Lucent Technologies Inc. [source]

    Low temperature hydrothermal growth and optical properties of ZnO nanorods

    J. H. Yang
    Abstract Well-faceted hexagonal ZnO nanorods have been synthesized by a simple hydrothermal method at relative low temperature (90°C) without any catalysts or templates. Zinc oxide (ZnO) nanorods were grown in an aqueous solution that contained Zinc chloride (ZnCl2, Aldrich, purity 98%) and ammonia (25%). Most of the ZnO nanorods show the perfect hexagonal cross section and well-faceted top and side surfaces. The diameter of ZnO nanorods decreased with the reaction time prolonging. The samples have been characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurement. XRD pattern confirmed that the as-prepared ZnO was the single-phase wurtzite structure formation. SEM results showed that the samples were rod textures. The surface-related optical properties have been investigated by photoluminescence (PL) spectrum and Raman spectrum. Photoluminescence measurements showed each spectrum consists of a weak band ultraviolet (UV) band and a relatively broad visible light emission peak for the samples grown at different time. It has been found that the green emission in Raman measurement may be related to surface states. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Issues related to the diagnosis and treatment of autism spectrum disorders,

    Paul T. Shattuck
    Abstract This paper explores issues and implications for diagnosis and treatment, stemming from the growing number of children identified with autism spectrum disorders (ASDs). Recent developments and innovations in special education and Medicaid programs are emphasized. Eligibility determination policies, innovations in diagnostic practices, the cost and financing of assessment, variability among programs in diagnostic criteria, and racial/ethnic disparities in the timing of diagnosis all influence the capacity of service systems to provide diagnoses in a timely, coordinated, accurate, economical, and equitable manner. There are several barriers to the more widespread provision of intensive intervention for children with ASDs, including lack of strong evidence of effectiveness in scaled-up public programs, uncertainty about the extent of obligations to provide services under the Individuals with Disabilities Education Act, high cost of intervention, and variability among states in their willingness to fund intensive intervention via Medicaid. Innovative policy experiments with respect to financing intensive intervention through schools and Medicaid are being conducted in a number of states. © 2007 Wiley-Liss, Inc. MRDD Research Reviews 2007;13:129,135. [source]

    Decanuclear Manganese Isobutyrate Clusters Featuring a Novel MnII8MnIII2 Core

    Iurii L. Malaestean
    Abstract Recrystallization of freshly prepared MnII isobutyrate from PrOH or from EtOH/MeCN mixtures containing pyrazole (pyr) yields neutral mixed-valence decanuclear manganese(II/III) complexes, [Mn10O2(O2CCHMe2)18(HO2CCHMe2)2(PrOH)2] (1) and [Mn10O2(O2CCHMe2)18(pyr)4] (2). The Mn10 metal core of both 1 and 2 consists of eight MnII and two MnIII centers and represents a new motif in the structural organization of polynuclear mixed-valence manganese clusters. Both, 1 and 2 exhibit a net antiferromagnetic exchange coupling resulting in singlet ground states. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

    The Role of Axial Ligation in Nitrate Reductase: A Model Study by DFT Calculations on the Mechanism of Nitrate Reduction

    Kuntal Pal
    Abstract The reactivity differences of the model anionic complexes [Mo(mnt)2(X)(PPh3)], [mnt2, = 1,2-dicyanoethylenedithiolate; X = SPh (1a), SEt (1b), Cl (1c), Br (1b)] towards oxygen atom transfer from nitrate, which is a key step performed by nitrate reductase, has been investigated by density functional theory calculations. Unlike complexes 1a and 1b, complexes 1c and 1d do not react with nitrate. Thermodynamically, all these complexes have a similar ability to generate the pentacoordinate active state [Mo(mnt)2(X)], by dissociation of PPh3, although the inaccessibility of the dxy orbital in 1c,d and the instability of the corresponding nitrate-bound enzyme substrate (ES) type complex contributes to their failure to reduce nitrate. The nature of the ES complex for 1a,b is described. The variation in the experimental data due to the change of axial ligation from SPh to SEt on the catalytic pathway has also been addressed. The gas-phase and solvent-corrected potential energy surface for the reaction of 1a,b with nitrate are established with fully optimized minima and transition states.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

    Designed Assembly and Structures and Photoluminescence of a New Class of Discrete ZnII Complexes of 1H -1,10-Phenanthroline-2-one

    Jie-Peng Zhang
    Abstract The hydrothermal reaction of 1H -1,10-phenanthroline-2-one (Hophen), zinc acetate, benzoic acid (Hba), and triethylamine (3.0 mL) yields the tetranuclear complex [Zn4(,3 -OH)2(ophen)4(ba)2] (2), which features a chair-like Zn4(,3 -OH)2 cluster with two ba ligands centrosymmetrically oriented. [(OAc){Zn3(,3 -OH)(ophen)3}(ox){Zn3(,3 -OH)(ophen)3}(OAc)] (3; ox = oxalate) was isolated when less triethylamine (1.0 mL) was used. Two Zn3(,3 -OH)(ophen)3 clusters in 3 are linked together by an oxalate to form a dumbbell-like structure in which the acetate and oxalate ligands point outward from the Zn3(,3 -OH)(ophen)3 cluster with an acute bending angle. A geometric analysis reveals that Zn3(,3 -OH)(ophen)3 and dicarboxylate with an obtuse bending angle cannot form an infinite zigzag chain, whereas the ring isomer can. With isophthalate (ipa), thiophene-2,5-dicarboxylate (tda), and 4,4,-oxybis(benzoate) (oba) instead of the acetate of 3 three new complexes, namely [{Zn3(,3 -OH)(ophen)3}(ipa)2{Zn3(,3 -OH)(ophen)3}]·0.5H2O (4), [{Zn3(,3 -OH)(ophen)3}(tda)2{Zn3(,3 -OH)(ophen)3}] (5), and [{Zn3(,3 -OH)(ophen)3}(oba)2{Zn3(,3 -OH)(ophen)3}] (6), were obtained in which two Zn3(,3 -OH)(ophen)3 clusters are linked by a pair of ipa, tda, or oba ligands to form isostructural, cluster-based 2:2 metallomacrocycles. Photoluminescence studies of 2,6 revealed that their luminescent properties are derived from ophen-based ,-,* excited states. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    The Fe-only nitrogenase and the Mo nitrogenase from Rhodobacter capsulatus

    FEBS JOURNAL, Issue 6 2002
    A comparative study on the redox properties of the metal clusters present in the dinitrogenase components
    The dinitrogenase component proteins of the conventional Mo nitrogenase (MoFe protein) and of the alternative Fe-only nitrogenase (FeFe protein) were both isolated and purified from Rhodobacter capsulatus, redox-titrated according to the same procedures and subjected to an EPR spectroscopic comparison. In the course of an oxidative titration of the MoFe protein (Rc1Mo) three significant S = 1/2 EPR signals deriving from oxidized states of the P-cluster were detected: (1) a rhombic signal (g = 2.07, 1.96 and 1.83), which showed a bell-shaped redox curve with midpoint potentials (Em) of ,195 mV (appearance) and ,30 mV (disappearance), (2) an axial signal (g|| = 2.00, g, = 1.90) with almost identical redox properties and (3) a second rhombic signal (g = 2.03, 2.00, 1.90) at higher redox potentials (> 100 mV). While the ,low-potential' rhombic signal and the axial signal have been both attributed to the one-electron-oxidized P-cluster (P1+) present in two conformationally different proteins, the ,high-potential' rhombic signal has been suggested rather to derive from the P3+ state. Upon oxidation, the FeFe protein (Rc1Fe) exibited three significant S = 1/2 EPR signals as well. However, the Rc1Fe signals strongly deviated from the MoFe protein signals, suggesting that they cannot simply be assigned to different P-cluster states. (a) The most prominent feature is an unusually broad signal at g = 2.27 and 2.06, which proved to be fully reversible and to correlate with catalytic activity. The cluster giving rise to this signal appears to be involved in the transfer of two electrons. The midpoint potentials determined were: ,80 mV (appearance) and 70 mV (disappearance). (b) Under weakly acidic conditions (pH 6.4) a slightly altered EPR signal occurred. It was characterized by a shift of the g values to 2.22 and 2.05 and by the appearance of an additional negative absorption-shaped peak at g = 1.86. (c) A very narrow rhombic EPR signal at g = 2.00, 1.98 and 1.96 appeared at positive redox potentials (Em = 80 mV, intensity maximum at 160 mV). Another novel S = 1/2 signal at g = 1.96, 1.92 and 1.77 was observed on further, enzymatic reduction of the dithionite-reduced state of Rc1Fe with the dinitrogenase reductase component (Rc2Fe) of the same enzyme system (turnover conditions in the presence of N2 and ATP). When the Rc1Mo protein was treated analogously, neither this ,turnover signal' nor any other S = 1/2 signal were detectable. All Rc1Fe -specific EPR signals detected are discussed and tentatively assigned with special consideration of the reference spectra obtained from Rc1Mo preparations. [source]

    Statistical theory of weak field thermoremanent magnetization in multidomain particle ensembles

    Karl Fabian
    SUMMARY A non-equilibrium statistical theory of multidomain thermoremanent magnetization (TRM) is developed, which describes thermal magnetization changes as continuous inhomogeneous Markov processes. The proposed theory relies on three very general physical properties of TRM: (a) The probability that a magnetization state Sj is transformed during an infinitesimal temperature change into state Si depends only on external conditions and on Sj, but not on previously assumed states. (b) Due to time inversion symmetry of the Maxwell equations, the magnetic energies are invariant with respect to inversion of all spins in zero field. (c) The probability that an energy barrier between two magnetization states is overcome during a thermal process is governed by Boltzmann statistics. From these properties, the linearity of TRM with field is derived for generic multidomain particle ensembles. The general validity of Thellier's law of additivity of partial TRM's in weak fields is established and a method for proving a large class of similar additivity laws is developed. The theory allows consistent treatment of blocking and unblocking of remanence in multidomain particle ensembles and naturally explains apparent differences between blocking and unblocking temperatures. [source]

    Brain region binding of the D2/3 agonist [11C]-(+)-PHNO and the D2/3 antagonist [11C]raclopride in healthy humans

    HUMAN BRAIN MAPPING, Issue 4 2008
    Ariel Graff-Guerrero
    Abstract The D2 receptors exist in either the high- or low-affinity state with respect to agonists, and while agonists bind preferentially to the high-affinity state, antagonists do not distinguish between the two states. [11C]-(+)-PHNO is a PET D2agonist radioligand and therefore provides a preferential measure of the D2high receptors. In contrast, [11C]raclopride is an antagonist radioligand and thus binds with equal affinity to the D2 high- and low-affinity states. The aim was to compare the brain uptake, distribution and binding characteristics between [11C]-(+)-PHNO and [11C]raclopride in volunteers using a within-subject design. Both radioligands accumulated in brain areas rich in D2/D3 -receptors. However, [11C]-(+)-PHNO showed preferential uptake in the ventral striatum and globus pallidus, while [11C]raclopride showed preferential uptake in the dorsal striatum. Mean binding potentials were higher in the putamen (4.3 vs. 2.8) and caudate (3.4 vs 2.1) for [11C]raclopride, equal in the ventral-striatum (3.4 vs. 3.3), and higher in the globus pallidus for [11C]-(+)-PHNO (1.8 vs. 3.3). Moreover [11C]-(+)-PHNO kinetics in the globus pallidus showed a slower washout than other regions. One explanation for the preferential binding of [11C]-(+)-PHNO in the globus pallidus and ventral-striatum could be the presence of a greater proportion of high- vs. low-affinity receptors in these areas. Alternatively, the observed distribution could also be explained by a preferential binding of D3 -over-D2 with [11C]-(+)-PHNO. This differential binding of agonist vs. antagonist radioligand, especially in the critically important region of the limbic striatum/pallidum, offers new avenues to investigate the role of the dopamine system in health and disease. Hum Brain Mapp 2008. © 2007 Wiley-Liss, Inc. [source]

    Emotion avoidance in patients with anorexia nervosa: Initial test of a functional model

    Jennifer E. Wildes PhD
    Abstract Objective: This study aimed to evaluate emotion avoidance in patients with anorexia nervosa (AN) and to examine whether emotion avoidance helps to explain (i.e., mediates) the relation between depressive and anxiety symptoms and eating disorder (ED) psychopathology in this group. Method: Seventy-five patients with AN completed questionnaires to assess study variables. Rates of emotion avoidance were compared to published data, and regression models were used to test the hypothesis that emotion avoidance mediates the relation between depressive and anxiety symptoms and ED psychopathology in AN. Results: Patients with AN endorsed levels of emotion avoidance that were comparable to or higher than other psychiatric populations and exceeded community controls. As predicted, emotion avoidance significantly explained the relations of depressive and anxiety symptoms to ED psychopathology. Discussion: Findings confirm that emotion avoidance is present in patients with AN and provide initial support for the idea that anorexic symptoms function, in part, to help individuals avoid aversive emotional states. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010 [source]

    Inverse Monte Carlo procedure for conformation determination of macromolecules

    Mark Bathe
    Abstract A novel numerical method for determining the conformational structure of macromolecules is applied to idealized biomacromolecules in solution. The method computes effective inter-residue interaction potentials solely from the corresponding radial distribution functions, such as would be obtained from experimental data. The interaction potentials generate conformational ensembles that reproduce thermodynamic properties of the macromolecule (mean energy and heat capacity) in addition to the target radial distribution functions. As an evaluation of its utility in structure determination, we apply the method to a homopolymer and a heteropolymer model of a three-helix bundle protein [Zhou, Y.; Karplus, M. Proc Natl Acad Sci USA 1997, 94, 14429; Zhou, Y. et al. J Chem Phys 1997, 107, 10691] at various thermodynamic state points, including the ordered globule, disordered globule, and random coil states. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 876,890, 2003 [source]

    Relativistic energy-consistent pseudopotentials,Recent developments

    Hermann Stoll
    Abstract The direct adjustment of two-component pseudopotentials (scalar-relativistic + spin-orbit potentials), to atomic total energy valence spectra derived from four-component multiconfiguration Dirac,Hartree,Fock all-electron calculations based on the Dirac,Coulomb,Breit Hamiltonian, has been made a routine tool for an efficient treatment of heavy main-group elements. Both large-core (nsp valence shell) and small-core ((n , 1)spd nsp valence shell) potentials have been generated for all the post- d elements of groups 13,17. At the example of lead and bismuth compounds (PbHal, BiH, BiO, BiHal (Hal = F, Cl, Br, I)), we show how small-core and large-core potentials can be combined in accurate, yet computationally economic, spin-free-state-shifted relativistic electronic structure calculations of molecular ground and excited states. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 767,778, 2002 [source]

    Highly stable electrochromic polyamides based on N,N -bis(4-aminophenyl)- N,,N,-bis(4- tert -butylphenyl)-1,4-phenylenediamine

    Sheng-Huei Hsiao
    Abstract A new triphenylamine-containing aromatic diamine monomer, N,N -bis(4-aminophenyl)- N,,N,-bis(4- tert -butylphenyl)-1,4-phenylenediamine, was synthesized by an established synthetic procedure from readily available reagents. A novel family of electroactive polyamides with di- tert -butyl-substituted N,N,N,,N,-tetraphenyl-1,4-phenylenediamine units were prepared via the phosphorylation polyamidation reactions of the newly synthesized diamine monomer with various aromatic or aliphatic dicarboxylic acids. All the polymers were amorphous with good solubility in many organic solvents, such as N -methyl-2-pyrrolidinone (NMP) and N,N -dimethylacetamide, and could be solution-cast into tough and flexible polymer films. The polyamides derived from aromatic dicarboxylic acids had useful levels of thermal stability, with glass-transition temperatures of 269,296 °C, 10% weight-loss temperatures in excess of 544 °C, and char yields at 800 °C in nitrogen higher than 62%. The dilute solutions of these polyamides in NMP exhibited strong absorption bands centered at 316,342 nm and photoluminescence maxima around 362,465 nm in the violet-blue region. The polyamides derived from aliphatic dicarboxylic acids were optically transparent in the visible region and fluoresced with a higher quantum yield compared with those derived from aromatic dicarboxylic acids. The hole-transporting and electrochromic properties were examined by electrochemical and spectro-electrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium-tin oxide-coated glass substrate exhibited two reversible oxidation redox couples at 0.57,0.60 V and 0.95,0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent elcterochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.2 V. These anodically coloring polymeric materials showed interesting electrochromic properties, such as high coloration efficiency (CE = 216 cm2/C for the green coloring) and high contrast ratio of optical transmittance change (,T%) up to 64% at 424 nm and 59% at 983 nm for the green coloration, and 90% at 778 nm for the blue coloration. The electroactivity of the polymer remains intact even after cycling 500 times between its neutral and fully oxidized states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2330,2343, 2009 [source]

    Optical properties of a novel fluorene-based thermally stable conjugated polymer containing pyridine and unsymmetric carbazole groups

    Der-Jang Liaw
    Abstract A new diiodo monomer containing heterocyclic pyridine and carbazole groups was synthesized via Chichibabin reaction and used in the preparation of a conjugated polymer via Suzuki coupling approach. The conjugated polymer was highly soluble in common organic solvents such as NMP, THF, dichloromethane, chloroform, toluene, xylene, and benzene at room temperature. The polymer had high glass transition temperature at 191 °C and Td10 at 434 °C in nitrogen atmosphere. The pristine polymer exhibited the UV,vis maximum absorption at 355 nm and shifted to 420 nm after protonation. The emission of the polymer in THF solution changed from the blue region with maximum peak at 400 nm to the yellow region with maximum peak at 540 nm after protonated by HCl, and the intensity of emission depended on the concentration of acid. The polymer also showed electrochromic behavior under applied voltage. The emission color of the polymer film changed from blue (435 nm) to yellow (570 nm) when 2.5 V bias voltage was applied. The polymer also exhibited write-once and read-many-times (WORM) polymer memory effect with tristable states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 991,1002, 2009 [source]

    Teachers' perceptions of policy influences on science instruction with culturally and linguistically diverse elementary students

    Annis Shaver
    Abstract This study asked elementary school teachers how educational policies affected their science instruction with a majority of English language learners. The study employed a questionnaire followed by focus group interviews with 43 third and fourth grade teachers from six elementary schools in a large urban school district with high populations of English language learners in the southeastern United States. Results indicate that teachers' opinions concerning all areas of policy evolved as the state enforced stronger measures of accountability during the 2-year period of the study. Although relatively positive regarding standards, their opinions became increasingly negative regarding statewide assessment, and even more so toward accountability measured by reading, writing, and mathematics. The results suggest that it is important to understand how teachers perceive the influence of policies, particularly those relating to English language learners, as science accountability becomes more imminent across the states. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 725,746, 2007 [source]

    Law, health and the European Union

    LEGAL STUDIES, Issue 2 2005
    Tamara K Hervey
    How does the European Union (EU) affect health law in its member states.? Having defined ,health law', this article takes a multilevel governance perspective of the EU und its legal order, aid considers, through selected examples, the various modes of governance used by the EU applicable in the health law field. The article presents N spectrum of the different types of effect that the EU has on health law: strong effect from health-specific measures; strong effect from general measures; marginal effect; slow convergence effect; little prospect for effect. [source]

    Deciphering the human nucleolar proteome,

    Yohann Couté
    Abstract Nucleoli are plurifunctional nuclear domains involved in the regulation of several major cellular processes such as ribosome biogenesis, the biogenesis of non-ribosomal ribonucleoprotein complexes, cell cycle, and cellular aging. Until recently, the protein content of nucleoli was poorly described. Several proteomic analyses have been undertaken to discover the molecular bases of the biological roles fulfilled by nucleoli. These studies have led to the identification of more than 700 proteins. Extensive bibliographic and bioinformatic analyses allowed the classification of the identified proteins into functional groups and suggested potential functions of 150 human proteins previously uncharacterized. The combination of improvements in mass spectrometry technologies, the characterization of protein complexes, and data mining will assist in furthering our understanding of the role of nucleoli in different physiological and pathological cell states. © 2005 Wiley Periodicals, Inc. Mass Spec Rev 25:215,234, 2006 [source]

    Magnetotunneling into Fock,Darwin-like quantum dot states: Lateral matrix elements and the role of selection rules

    Gerold Kießlich
    Abstract We study theoretically the magnetotunneling transport through quantum dots formed by thermal diffusion of charged manganese interstitials in the vicinity of a GaAs quantum well [Phys. Rev. Lett. 101, 226807 (2008)]. In particular, we examine the lateral matrix elements between Landau subbands in the contact and Fock,Darwin-like states of an individual dot at high magnetic fields. We explicitly demonstrate the effect of spatial deformation of the dot on the wave function's overlap. The comparison with measured data suggests a selection rule similar to angular momentum conservation for tunneling into perfect Fock,Darwin states. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Change in the magnetic properties of [FeII(phen)3](PF6)2 in the solid state by combining grinding and annealing

    T. Ohshita
    Abstract By grinding crystalline [FeII(phen)3](PF6)2, the effective magnetic moment, or ,MT, increased with simultaneous amorphization. Subsequent annealing further increased ,MT, despite the restoration of the crystallinity. This was explained by the recovery of the counterion, PF6,, from its strained state in the intact crystal to a less strained state towards higher spherical symmetry. The effects of annealing preceded by grinding suggest a novel method to control the magnetic states of coordination compounds without regard to their crystalline states. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Description of band structures of armchair nanotubes using the symmetry-adapted linear augmented cylindrical wave method

    P. N. D'yachkov
    Abstract Using a symmetry-adapted linear augmented cylindrical wave method, the total band structures and the densities of states of the armchair single-walled carbon nanotubes (SWNTs) (n,n) with 4 , n , 20, n = 30, 40, 60 and 100 are calculated. The approximations are made in the sense of muffin-tin potentials and density functional theory only. The electronic states are presented as the functions of the two quantum numbers, namely, the continuous wave vector k corresponding to the screw symmetry operations and an integer rotational quantum number L between 0 and n , 1. An account of rotational and helical symmetry properties of the armchair SWNTs and particularly an introduction of the quantum number L permit to elaborate a more detailed classification of the armchair SWNTs electronic states. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Exciton dephasing in quantum dots: Coupling to LO phonons via excited states

    E. A. Muljarov
    Abstract We have found a novel mechanism of spectral broadening and dephasing in quantum dots (QDs) due to the coupling to longitudinal-optical (LO) phonons. In theory, this mechanism comes into play only if the complete manifold of exciton levels (including those in the wetting-layer continuum) is taken into account. We demonstrate this nontrivial dephasing in different types of QDs, using the exactly solvable quadratic coupling model, here generalized to an arbitrary number of excitonic states. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]