bluuebunny/crossref_metadata_2025 huggingface dataset:
New Approaches to Develop Recyclable Catalysts for the Synthesis of Chiral Epoxides
Authors: Kureshy R. I. , Khan N. H. , Abdi S. H. R. , Jasra R. V.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Allylation Reactions
Authors: Hoffmann Reinhard W.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Homogeneous and Heterogeneous Catalysis with Metalloporphyrins
Authors: Simonneaux G. , Le Maux P. , Ferrand Y. , Rault‐Berthelot J.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Catalysis for the Construction of Quaternary Carbon Centers: Nucleophilic Addition on Ketones and Ketimines
Authors: Riant Olivier , Hannedouche Jerome
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Palladium Complexes of N‐Heterocyclic Carbenes as Catalysts for Cross‐Coupling Reactions — A Synthetic Chemist′s Perspective
Authors: Kantchev Eric Assen B. , O'Brien Christopher J. , Organ Michael G.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Taking up to Cudgels for Perchlorates: Uses and Applications in Organic Reactions under Mild Conditions
Authors: Bartoli Giuseppe , Locatelli Manuela , Melchiorre Paolo , Sambri Letizia
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of the Telomerase Inhibitors UCS1025A
Authors: Rueping Magnus
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Formamide Chemistry and the Origin of Informational Polymers
Authors: Saladino Raffaele , Crestini Claudia , Ciciriello Fabiana , Costanzo Giovanna , Di Mauro Ernesto
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhenium‐Linked Multiporphyrin Assemblies — Synthesis and Properties
Authors: Hupp Joseph T.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Azocalixarenes: Synthesis, Characterization, Complexation, Extraction, Absorption Properties and Thermal Behavior
Authors: Deligoz Hasalettin
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Influence of Bacillus subtilis on the growth of calcium oxalate
Authors: Chen Long , Xie Anjian , Jia Rong , Shen Yuhua , Tang Wenzhong , Li Chuanhao
Published: June 2007

The influence of the bacteria Bacillus subtilis (B. subtilis) on the nucleation, growth and aggregation of calcium oxalate (CaOx) crystals in aqueous solution has been studied. The crystals obtained were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X‐ray powder diffractometry. The results show that, in the presence of B. subtilis, quasi‐hexagonal calcium oxalate monohydrate (COM) crystals are obtained after 24 hours of reaction at a temperature of 30°C ± 1K. However, without the presence of the bacteria, irregular CaOx crystals were obtained which contain two crystal phases: COM and calcium oxalate dihydrate (COD). This suggests that B. subtilis may promote the crystallization of COM, the major component of urinary stone. The formation mechanism of CaOx crystals in the presence of B. subtilis is explored, indicating that the cell walls and extracellular proteins of the bacteria may act as templates to induce the nucleation, growth and aggregation of CaOx crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Keine Konjunktur im Wohnungsbau mehr?
Authors: Rast Ronald
Published: June 2007

Seit ein paar Tagen liegen die gesicherten statistischen Angaben zur Absatzentwicklung der Mauersteinindustrie im Geschäftsjahr 2006 vor. Danach hat die deutsche Mauersteinindustrie 17,1 Mio. m3 Mauersteine in den Markt abgesetzt. Das sind stolze 8,9 Prozent mehr als im Vorjahr. Was für ein Jahr!
Different and similar at the same time: when the activation of dissimilarity makes people look more similar
Authors: Ruys Kirsten I. , Spears Russell , Gordijn Ernestine H.
Published: June 2007

Whether two people are presented as similar or different may have a strong impact on the outcome of their comparison. In the present research, we examined the counterintuitive hypothesis that activating dissimilarity increases the perception of similarities between people, in other words increases perceived feature overlap, during the comparison process. We investigated this prediction by asking people to judge the perceived similarity between two faces with a suboptimally related or unrelated morph inserted in between (to influence joint categorization), and with similar or different facial expressions (to vary the salience of similar or different features). The results confirmed our expectations: In the similarity (joint categorization) condition, two faces that differed in expression were perceived as more dissimilar than faces with the same expression. More important for our prediction, in the dissimilarity condition two faces with different expressions were no longer perceived as more dissimilar than two faces with the same expression. We discuss implications of these findings for the mechanisms underlying comparisons between people. Copyright © 2007 John Wiley & Sons, Ltd.
Quarterly GPPA earnings data: Time‐series properties and predictive ability results in the airlines industry
Authors: Hillison W. A. , Hopwood W. S. , Lorek K. S.
Published: July 2007

This paper provides preliminary results regarding the impact of general purchasing power adjustments (GPPA) on quarterly earnings for 24 firms from the airlines industry. Findings indicated that GPPA transformations do not substantially alter the time‐series properties of quarterly earnings data. Two Box‐Jenkins models, (100) × (100) and (100) × (110) were identified as possible parsimonious models for the airlines industry. It is recommended that these structures be considered as viable candidates for earnings expectations models in market studies testing for informational content of GPPA earnings. The predictive findings demonstrated that predictions of historical cost quarterly earnings were significantly more accurate than GPPA predictions for four of the five horizons tested.
Protective effects of isothiocyanates alone or in combination with vitamin C towards N‐nitrosodibutylamine or N‐nitrosopiperidine‐induced oxidative DNA damage in the single‐cell gel electrophoresis (SCGE)/HepG2 assay
Authors: García Almudena , Haza Ana I. , Arranz Nuria , Rafter Joseph , Morales Paloma
Published: June 2007

The aim of this study was to investigate the protective effect of isothiocyanates alone or in combination with vitamin C towards N‐nitrosodibutylamine (NDBA) or N‐nitrosopiperidine (NPIP)‐induced oxidative DNA damage in the single cell gel electrophoresis (SCGE)/HepG2 assay. Phenethyl isothiocyanate (PEITC) and indole‐3‐carbinol (I3C) alone showed a weak protective effect towards NDBA (0.1 µm, 26–27%, respectively) or NPIP (1 µm, 26–28%, respectively)‐induced oxidative DNA damage. Allyl isothiocyanate (AITC) alone did not attenuate the genotoxic effect provoked by NDBA or NPIP. In contrast, HepG2 cells simultaneously treated with PEITC, I3C and AITC in combination with vitamin C showed a stronger inhibition of oxidative DNA‐damage induced by NDBA (0.1 µm, 67%, 42%, 32%, respectively) or NPIP (1 µm, 50%, 73%, 63%, respectively) than isothiocyanates (ITCs) alone. One feasible mechanism by which ITCs alone or in combination with vitamin C exert their protective effects towards N‐nitrosamine‐induced oxidative DNA damage could be by the inhibition of their cytochrome P450 dependent bioactivation. PEITC and I3C strongly inhibited the p‐nitrophenol hydroxylation (CYP2E1) activity (0.1 µm, 66–50%, respectively), while the coumarin hydroxylase (CYP2A6) activity was slightly reduced (0.1 µm, 25–37%, respectively). However, the ethoxyresorufin O‐deethylation (CYP1A1) activity was only inhibited by PEITC (1 µm, 55%). The results indicate that PEITC and I3C alone or PEITC, I3C and AITC in combination with vitamin C protects human‐derived cells against the oxidative DNA damaging effects of NDBA and NPIP, two food carcinogenic compounds. Copyright © 2007 John Wiley & Sons, Ltd.
Chronic ethanol intake inhibits in vitro osteogenesis induced by osteoblasts differentiated from stem cells
Authors: Rosa Maria L. , Beloti Marcio M. , Prando Natalia , Queiroz Regina H. C. , Oliveira Paulo T. de , Rosa Adalberto L.
Published: June 2007

The study investigated whether chronic ethanol (ETH) intake and subsequent ETH exposure of cell cultures affects osteoblast differentiation by evaluating key parameters of in vitro osteogenesis. Rats were treated with 5–20% (0.85–3.43 mm) ETH, increasing by 5% per week for a period of 4 weeks (habituation), after which the 20% level was maintained for 15 days (chronic intake). Bone‐marrow stem cells from control (CONT) or ETH‐treated rats were cultured in osteogenic medium which was either supplemented (ETH) or not supplemented (CONT) with 1.3 mm ethanol. Thus, four groups relating to rat treatment/culture supplementation were evaluated: (1) CONT/CONT, (2) ETH/CONT, (3) CONT/ETH and (4) ETH/ETH. Cell morphology, proliferation and viability, total protein content, alkaline phosphatase (ALP) activity and bone‐like nodule formation were evaluated. Chronic ethanol intake significantly reduced both food and liquid consumption and body weight gain. No difference was seen in cell morphology among treatments. Cell number was affected at 7 and 10 days as follows: CONT/CONT = CONT/ETH < ETH/CONT = ETH/ETH. Doubling time between 3 and 10 days was greater in groups of CONT animals: ETH/ETH = ETH/CONT < CONT/ETH = CONT/CONT. Cell viability and ALP activity were not affected by either animal treatment or culture exposure to ethanol. At day 21, the total protein content was affected as follows: ETH/ETH = CONT/ETH < ETH/CONT = CONT/CONT. Bone‐like nodule formation was affected as follows: ETH/ETH < CONT/ETH < ETH/CONT < CONT/CONT. These results show that chronic ethanol intake, followed by the exposure of osteoblasts to ethanol, inhibited the differentiation of osteoblasts, as indicated by an increased proliferation rate and reduced bone‐like nodule formation. Copyright © 2007 John Wiley & Sons, Ltd.
Decentralization and district development planning in Zimbabwe
Authors: Mutizwa‐Mangiza N. D.
Published: July 2007

One of the most important dimensions of rural development policy in Zimbabwe since independence has been rural local government reform, in particular decentralization policy. Evidence from a number of recent studies is used to present a comprehensive review of Zimbabwe's experience of local government decentralization during the first eight years of independence, 1980 to 1988. Section 2 presents a brief outline of some basic concepts on decentralization which have guided the discussion. Section 3 contains a short account of the local government system inherited from the colonial era. Section 4 outlines the major post‐independence reforms, that is: the 1980 District Councils Act; the 1984‐85 Prime Minister's Directive on Decentralization; the 1985 Provincial Councils and Administration Act; and the 1988 Rural District Councils Act. Section 5 presents an assessment of these reforms, paying particular attention to organizational, financial and planning issues. While some important improvements have been achieved in rural Communal Areas‐in particular the extension of services and increases in local revenues and popular participation‐the system of local government and administration remains a dual one. Other problems include the gap between the planning and budgeting processes, continued financial dependence of district councils on central government, and a lack of serious effort by central government to make use of provincial and district development plans.
Managerial thinking. A study of public managers from developing countries
Authors: Rahman Syedur , Norling Frederick
Published: July 2007

The field of comparative public administration/management in the United States has been criticized for theoretical underdevelopment and methodological narrowness. Utilizing advances made in comparative business management and taking into consideration the assertion that an agenda based empirical research programme in comparative public administration should highlight managerial processes, the individual, and group‐level behaviours, this paper focuses on examining the attitudes of public managers towards their own organizations. It analyses the responses of 110 public sector managers from 58 different countries of the world while they were in residence for professional development at 12 major universities in the United States. Examining public managers outside their own working environment makes this research on public sector managers to some extent unusual. For purposes of data collection a stratified sample was utilized. The principal instrument consisted of 79 items. Managers were asked to state their attitudes towards problem‐solving and decision‐making, leadership, job challenge, change, and organizational culture. Primarily descriptive statistics are used to analyse the data. Limited use is made of the One‐way ANOVA test. Results show that public managers from developing countries tend to view themselves somewhat differently from the traditional western perspective, especially as it relates to organizational innovativeness and job challenge. Public managers also confirm the earlier held western perspective that personnel in the public sector are more concerned with their personal welfare rather than organizational welfare and that their leadership is more directive. While one has to be careful interpreting the data, the emerging profile of public managers should influence future policy makers in both developing and developed nations of the world.
Ghana and South Korea: Lessons from world bank case studies
Authors: Werlin Herbert
Published: July 2007

In 1957, Ghana and South Korea had about the same annual per capita GDP. Thirty years later, South Korea's annual purchasing power per head was about 10 times that of Ghana's for reasons explained by World Bank case studies. Ghana's economic retrogression stemmed from allowing hyperinflation, over‐regulation, production disincentives, institutional demoralization, and deterioration of human services. Since 1983, Ghana has embarked upon an Economic Recovery Programme, including realistic exchange rates, decontrol of prices, and administrative reforms. While this programme has led to real GDP growth, Ghana remains dependent upon the international price of cocoa and foreign aid.

Under President Park, beginning in the mid‐1960s, South Korea successfully introduced an export‐oriented economy by developing export pride, national leadership, market sustaining incentives, labour incentives, research, and technical education. While both Ghana and South Korea have used state‐owned enterprises, only South Korea has done so successfully, with a Performance Evaluation System. This system can be introduced elsewhere with sufficient political will to overcome inevitable problems and opposition.
Reducing poverty
Authors: Salmen Lawrence
Published: July 2007

Since the early 1970s, the World Bank has recognized that economic growth alone will not reduce poverty. Yet it has not fully accepted the fact that effective poverty reduction requires a ‘learning process approach’, rather than the ‘blueprint approach’ commonly used by development agencies. To facilitate the learning process approach, the Bank should consider using qualified intermediary, grass‐roots, and non‐governmental organizations (NGOs); stimulating pluralism and competition; and encouraging cooperation between central and local institutions. However, helping the poor is going to require more administrative resources than heretofore provided, making funds available for careful and flexible project design, staff exposure to poverty conditions and programmes, training in and recruitment of appropriate interdisciplinary fields, monitoring and evaluation, and continual project revision.

This article was initially written as a Working Paper: Salmen, L. (1990). Institutional Dimensions of Poverty Reduction. World Bank, Washington, D.C.
Assessing the impact of decentralization on governance: A comparative methodological approach and application to Tunisia
Authors: Vengroff Richard , Salem Hatem Ben
Published: July 2007

The relationship between decentralization and governance has not been adequately explored in the literature. Many past studies have failed to assess fully the impact of decentralization because of the lack of a set of independent, comparative indicators of the quality of decentralization being implemented in a given country. The authors adopt the working hypothesis that decentralization, both as a process and as an end state in terms of organization and operations, is closely related to the quality of governance in developing countries. In order to provide an empirical basis for a comparative assessment, the authors have developed a model based on the scope, intensity and commitment to decentralization in a country. Each of these concepts is operationalized in terms of a set of empirically measurable variables. The method is then applied to the case of Tunisia and assessed as a tool for the comparative study of decentralization and governance. Decentralization in Tunisia is shown to have an important relationship to the quality of governance in that country. The methodology developed here for the analysis of the quality of decentralization appears, based on the examination of a significant case, to be worth pursuing cross‐nationally.
Methods and mindsets: Towards an understanding of the tyranny of methodology
Authors: Bell Simon
Published: July 2007

This article attempts to examine familiar things through a different comparative focus. The results given here are preliminary and intended for comment and further development. The article takes as its basis the tradition which has arisen from the export of methods to developing countries in all manner of scientific and technical development projects. In the area of global development the traditions of technology transfer and development intervention by donor agencies and their related consultancy groups is well documented. Not so well covered in the literature is the related issue pertaining to the export of the methods which accompany and, to some extent, confer respectability upon all manner of technology, intervention and work towards nation building. The article is concerned with what might be called the ‘tyranny of methods’, which, it is argued, are applied often uncritically in development work. The mindsets which are invoked by traditional western scientific methods are reviewed using a psychological model. Following from this, the article investigates two areas of existing experience in the adoption of methods and then goes on to develop a critical perspective of one particular form of information systems development method, drawing on the experiences related. The article briefly investigates traditional, linear methods and makes links to the experiences of fanning systems research and rapid rural appraisal. Although no definitive conclusions are made, observations relating to an action plan are provided. The core of this relates to self‐analysis and points to be conscious of in the export of any method.
Structure of the Nucleons
Authors: Latal H. , Urban P. , Zingl H.
Published: July 2007

Some of the recent developments in the theory of the structure of nucleons are surveyed including discussions on experimental verifications of theoretical treatments.
Antiproton Annihilation into Two Mesons and Higher Symmetries
Authors: Makarov A. A. , van Hieu Nguyen , Winternitz P.
Published: July 2007

The annihilation of antiprotons on nucleons is investigated assuming various symmetry groups. The general structure of the transition amplitude is found for the unitary symmetry and the higher symmetries SL (6, C) and U (6, 6) are applied to annihilations at rest. The relations between matrix elements, amplitudes and cross sections, following from various symmetries are compared with each other and with experiments. It is shown that all SL (6, C) predictions, that can be compared with experiments, are in good agreement, whereas the stronger results of the U (6, 6) symmetry contradict experiments.
Complex Angular Momentum Theory in Particle Physics
Authors: Drechsler Wolfgang
Published: July 2007

A critical review of the techniques of complex angular momenta used at present in the Regge theory of strong interactions is presented. After discussing the kinematical singularities of helicity amplitudes, their crossing properties as well as the constraints they satisfy, the reggeization procedure for two‐body helicity amplitudes is reviewed in detail. The properties of the generalized Froissart‐Gribov continuation are investigated. The factorization properties of Regge pole contributions to a general two‐body scattering amplitude are studied and the various mechanisms producing the dip structure of differential cross‐sections are discussed. The complications of the reggeization for amplitudes describing unequal‐mass reactions at high energies in the forward direction are discussed and a survey of the status of “conspiracies” of singularities in the complex angular momentum plane is given. Both, the group theoretical and the analytical methods are discussed in treating the conspiracy problem. Finally, a review of the present situation is given regarding the influence of branch cuts in the complex angular momentum plane and their phenomenological consideration in various multiple scattering models. It is shown that the multiple scattering correction in the Glauber‐eikonal type of approach correspond to cuts in the angular momentum plane which represent absorptive corrections to the single Regge exchanges. It is clear from this discussion that cuts in the complex j‐plane, describing multi‐Regge pole exchanges, cannot be neglected.
Would‐Be Local Fields
Authors: Hindle C. M.
Published: July 2007

General quantum field theory is formulated for the case when the Wightman distributions can grow in momentum space as the exponential of a covariant polynomial. Appropriate spaces of test functions are introduced, and it is shown that the vacuumexpectation values can be written in terms of various associated tempered distributions, which enjoy some of the properties of ordinary Wightman distributions; in particular, they can be represented as boundary values of functions holomorphic in the usual extended tubes. Notions of locality for the tempered distributions can be introduced, which are sufficient to imply the PCT theorem and theorems on the connection between spin and statistic for the non‐tempered fields. It is shown how a Haag‐Ruelle theory of asymptotic states and fields may be set up. A possible line of generalisation is illustrated by the special example of fields of the type χ (□) A (x), where A is a tempered field, and χ an entire analytic function of finite exponential order.
ππ Scattering Amplitudes that Satisfy Inelastic Unitarity Constraints
Authors: Kupsch J.
Published: July 2007

We construct amplitudes which are represented by a Mandelstam representation with a finite number of subtractions and that satisfy ππ crossing symmetry and the unitarity constraints Im flI(s) ≧|flI (s)|2, l=0, 1, 2,…, for all energies above threshold s > 4, in the three isospin channels I=0, 1, 2.

The following types of solutions are derived.

The amplitudes have a positive double spectral function ϱ(s, t) ≧ 0. The total cross section decreases like σT(s) ∼ (log s)‐δ for arbitrary δ ≧ 1, including the limiting case δ=1.

The amplitudes are dominated by Regge poles, the total cross section can reach a constant asymptotic value, σT(s) → const.

The amplitudes are dominated by Regge cuts, the total cross section can increase logarithmically σT(s) → log s.
Local Operator Products and Field Equations in P(φ)2 Theories
Authors: Schrader Robert
Published: July 2007

In P(φ)2 theories with small coupling constants, local fields exist which are obtained from normal ordering of Euclidean fields. Normal ordering with respect to the free measure and the physical measure leads to the same family of fields. The coefficients of the two resulting field equations are related by a fixed point problem. Conditions are exhibited under which there is a unique solution.
ΔI = 1/2‐Rule and Fierz‐, SU(3)‐ and Colour SU(3)‐Crossing Eigenvectors of the Current‐Current Quark Interaction
Authors: Körner J. G.
Published: July 2007

In this review we study the SU(3) transformation behaviour of the hadronic current‐current quark interaction Hamiltonian for the different cases of possible quark statistics. By expanding the current‐current quark Hamiltonian along the crossing‐even and ‐odd eigenvectors of the appropiate Fierz‐, SU(3)‐ and colour SU(3)‐crossing matrices, resp., we arrive at a transparent classification of the possible forms of the current‐current quark interaction that lead to octet behaviour. In some instances, octet behaviour can be established directly for the interaction Hamiltonian, in others, simplifications occur if one makes reference to the two basic types of diagrams that occur in the evaluation of nonleptonic transitions.
Modification of Dispersion Relations and Generalization of the Hartree‐Fock Method for Hard‐Core Interactions in Nuclear Matter
Authors: Winter J.
Published: July 2007

The influence of a hard‐core part in the interaction on dispersion relations for the generalized optical potential (mass operator) and the T‐matrix of nuclear matter is investigated in the frame‐work of the A00‐approximation. The model is based on the two‐nucleon scattering problem in vacuo, for which a hard‐core generalization of the Low equation is derived. As a consequence, T‐matrix and mass operator are shown to split into a polynomial of the first order in the energy variable and a dispersion integral generalized by a limiting process, so that dispersion relations of the twice subtracted type result.

Restriction to a self‐consistent calculation of the non‐dispersive term of the mass operator leads to a close analogue of the Hartree‐Fock equations for non‐singular interactions. This simple approximation which avoids the full‐nucleon problem is shown to yield a qualitatively correct density dependence of the ground‐state energy possibly to be improved by more realistic interactions. A formulation as an eigenvalue problem for finite nuclei is also given.
Quantum Field Theory of Crystals and Dislocations
Authors: Wadati M. , Matsumoto H. , Takahashi Y. , Umezawa H.
Published: July 2007

We present a quantum field theoretical treatment of crystals from the view point of the spontaneous breakdown of the spatial translation invariance. It is proved that at least three massless Goldstone particles exist and they are identified as the acoustic phonons.

We carry out the boson transformation to show that the classical phenomenological theory of crystals can be derived. The classical momentum and stress tensor are expressed in terms of the classical displacement field.

The method is extended to a microscopic derivation of the theory of crystal dislocations. It is shown that the Burgers vector is quantized and is a special case of the so‐called topological quantum number. An explicit expression of a general solution of the dislocation is obtained.
Quantum Field Theory with Soliton Conservation Laws
Authors: Schroer B.
Published: July 2007

Field theories with soliton conservation laws are the most promising candidates for explicitly constructable models. We exemplify in the case of the massive Thirring model how the old S matrix bootstrap idea, supplemented with a soliton factorization property, may be used as a systematic starting point for the construction of the S matrix, form factors and (hopefully) correlation functions.
Neutral Currents and P‐Odd Effects in Processes with Participation of Leptons
Authors: Bilenky S. M. , Bilenkaya S. I. , Motz G. B.
Published: July 2007

The present article is a detailed review on P‐odd effects in deep‐inelastic and elastic scattering of polarized leptons on nucleons. The contribution from neutral currents into the cross sections of processes e+ + e− → l+ + l−(l = e, μ) for the case of unpolarized initial particles is also considered.
On the 1‐Loop Renormalization of the Electroweak Standard Model and its Application to Leptonic Processes
Authors: Böhm M. , Spiesberger H. , Hollik W.
Published: July 2007

A renormalization scheme for the electroweak standard model is presented in which the electric charge and the masses of the gauge bosons, Higgs particle and fermions are used as physical parameters. The photon is treated such that quantum electrodynamics is contained as a simple substructure. Field renormalization respecting the gauge symmetry gives finite propagators and vertex functions. The Ward identities between the Green functions of the unphysical sector allow a renormalization that maintains the simple pole structure of the propagators in the t'Hooft‐Feynman gauge. We give a complete list of self energies and all renormalization constants also in the unphysical Higgs and ghost sector. Explicit results are given for the renormalized self energies, vertex functions and boxes that enter the evaluation of 1‐loop radiative corrections to fermionic processes.

We calculate the 1‐loop radiative corrections to purely leptonic reactions like μ decay, vμμe scattering and μ pair production in e+e−annihilation. A test of the standard model is performed by comparing these low energy data with the results of the PP collider experiments for the W and Z boson masses.
Reversal of resistance to pyriproxyfen in the Q biotype of Bemisia tabaci (Hemiptera: Aleyrodidae)
Authors: Wilson Margaret , Moshitzky Pnina , Laor Einat , Ghanim Murad , Rami Horowitz A , Morin Shai
Published: June 2007

Pyriproxyfen, a juvenile hormone (JH) mimic, is a biorational insecticide that disrupts insect development. It is one of the principal insecticides being used to control Bemisia tabaci (Gennadius) on cotton, and has many environmentally positive attributes that make it compatible with integrated pest management (IPM) programs. In Israel, a high level of resistance to pyriproxyfen has been observed in several isolated regions. Here, tests were conducted to establish whether temporal refuges from exposure to pyriproxyfen could be useful for restoring the effectiveness of the compound. Resistance was found to decrease by a factor of 8 when exposure to pyriproxyfen was ceased for 13 generations. Reversal of resistance was accompanied with increased biotic fitness of the revertant colony. By incorporating experimental estimates of nymph survival, sex ratio, fecundity, egg hatching rate and developmental time, the seasonal cost per generation for resistant insects was estimated to be 25%. A genetic simulation model, optimized by empirical data from bioassays, predicted fitness cost per generation of 19% for resistant homozygous (RR) females and hemizygous (R) males, and produced rates of reversal similar to the experimental results. The model also predicted that, even after 5 years (∼55 generations) without pyriproxyfen treatments, the frequency of the resistance allele (R) will still remain high (0.02). It is therefore concluded, on the basis of experimental and modeling results, that the effectiveness of temporal refuges for reversing development of resistance to pyriproxyfen in B. tabaci may be limited. Copyright © 2007 Society of Chemical Industry
Humidity acceleration factor for plastic packaged electronic devices
Authors: Klinger David J.
Published: July 2007

Failure mechanisms associated with the effects of humidity on plastic packaged devices are briefly reviewed. Relevant experimental and theoretical work on these failure mechanisms is then considered, pointing to an incomplete understanding as to why relative humidity is the appropriate variable, along with temperature to use in acceleration factor models. The BET equation (Brunauer, Emmett and Teller), is invoked to provide a theoretical underpinning to the use of relative humidity in such acceleration factor models. The BET equation provides such a connection by relating surface concentration of water to vapour pressure of water. Using the BET equation as a starting point, we derive a relation between surface concentration of water and relative humidity that has no explicit temperature dependence.

We then consider a simple kinetic model for a corrosion reaction leading to failure. The result is an acceleration factor that is a typical Arrhenius form, multiplied by a simple function of relative humidity. This form is similar to other power‐law acceleration factor models that have been developed empirically. Now a physical derivation is offered as a theoretical basis for power‐law models of the effects of humidity on plastic packaged device reliability.
The influence of temperature on integrated circuit failure mechanisms
Authors: Pecht Michael , Lall Pradeep , Hakim Edward B.
Published: July 2007

Temperature is generally considered to be a key parameter in the design of electronic equipment, and cautions concerning temperature and its relationship to reliability are widely documented. While some studies suggest that temperature is the most critical stress influence on microelectronic device failures, the actual failure mechanisms have generally not been quantified in terms of whether a steady state temperature, temperature change, rate of temperature change, or spatial temperature gradient induced failure. In this paper, the influence of temperature on major integrated circuit failure mechanisms is discussed, with emphasis placed on those failure mechanisms which occur in the temperature range of ‐55°C to 125°C. This paper shows that no simple expression can adequately describe temperature as a failure accelerator for all integrated circuit failure mechanisms. In fact, a generic statement that can be attributed to temperature is lacking. This suggests that a much deeper level of insight into temperature dependencies is necessary to achieve reliable equipment and avoid unnecessary thermal design complexities. Thermal management in electronic equipment can involve additional costs and system complexities that can be of consequential importance, and temperature control should not be routinely employed without close study and justification.
Plastic encapsulated ic reliability prediction modelling: Principal results
Authors: Nallino M. , Digout R. , Deleuze G. , Brizoux M.
Published: July 2007

The content of this paper is based on the study published at ESREF 91 in Bordeaux under the title ‘Plastic Encapsulated IC's in military equipments: reliability prediction modelling’. The first paper introduced the theoretical aspects of plastic encapsulated IC reliability prediction modelling. This paper presents the results of statistical studies done to complete the model with numerical data. Dependence of failure rates on year of manufacturing, dependence of thermo‐mechanical failure rate on die diagonal, distribution of the quality of ICs in the market, and environment factor defect values are the principal topics addressed in this paper.
Electromigration early resistance increase measurements
Authors: Niehof J. , Flinn P. A. , Maloney T. J.
Published: July 2007

An early resistance change measurement set‐up, using an AC bridge technique, has been developed, and measurements have been performed. Large sample‐to‐sample variations occur. The characteristic time for the resistance change curve is shorter for resistance increase (under current stress) than for resistance decay (during recovery).
Analysis of MOS SOI transistor degradation
Authors: Berland V. , Touboul A. , Flament O.
Published: July 2007

This study is related to the behaviour of hardened n‐MOS transistors (SOI‐SIMOX technology). These elementary components have been irradiated by X‐ray radiation after an electrical characterization. In addition to the electrical parameters such as the threshold voltage Vt, the transconductance gm and the leakage drain current Idfo, it appears interesting to observe the channel noise level shift before and after irradiation at different doses. The particular interest of this analysis is found in the behaviour of SOI‐SIMOX technology transistors.

This approach, on the basis of LF excess noise measurements, is an efficient and sensitive tool to understand the radiation‐induced mechanisms. The major effects of ionizing radiation on MOS transistors are identified as the increase of the fixed oxide charge (ΔQot) and of the interface state density (ΔQit), both mechanisms stemming from ionizing effects in the thin gate oxide. Of course, these densities control the channel current fluctuations and then the channel noise current.
Degradation behaviour of highly coherent 1‐55 μm long‐cavity multiple quantum well DFB lasers
Authors: Fukuda Mitsuo , Kano Fumiyoshi , Kurosaki Takeshi , Yoshida Jun‐Ichi
Published: July 2007

This paper examines the degradation behaviour of spectral characteristics, such as spectral line‐width and FM response, in a 1·55 μm highly coherent multiple quantum well (MQW) DFB laser with a long‐cavity. The possibility of long‐life MQW DFB lasers for use in optical coherent transmission systems is demonstrated by clarifying the degradation behaviours.
Very high temperature test of InP‐based laser diodes
Authors: Tesauri Monica , Chiorboli Giovanni , Cova Paolo , Fantini Fausto , Magistrali Fabrizio , Sala Danila
Published: July 2007

The reliability of DHBC and DFB InGaAsP/InP lasers has been evaluated by means of high‐temperature operating life tests between 80 and 110°C. The main failure mechanisms have been related to the stability of the active layer, thus demonstrating the applicability of these high temperatures to the evaluation of InP‐based lasers.
On the Astm electromigration test structure applied to Al–1%Si/TiN/Ti bamboo metal lines
Authors: de Munari Ilaria , Vanzi Massimo , Scorzoni Andrea , Fantini Fausto
Published: July 2007

The applicability of NIST‐ASTM electromigration test patterns when used to test ‘bamboo’ metal lines is discussed. Wafer level tests on passivated and non‐passivated samples employing the Al–1%Si/TiN/Ti metallization scheme were performed. Straight metal lines 1000 μm long and 0·9 μm or 1·4 μm wide were tested at two different current densities. j = 3 MA cm2 and j = 4·5 MA/cm2, at constant stress temperature (T = 230·C). The failures mainly occurred in the end‐segment areas and hindered the evaluation of the electromigration resistance of the ‘bamboo’ test lines. In order to avoid this problems, completely different test patterns based on different approaches must be designed.
An automaton decomposition method for program structure simplification
Authors: Hirakawa Yutaka , Okada Keiji
Published: July 2007

We propose a method of decomposing an automaton which represents the flow of a program into simpler automata. More specifically, we: (1) introduce a new automata model called paired synchronized automata; (2) present a polynomial time algorithm for decomposing an automaton into paired synchronized automata; (3) show the correctness proof of the algorithm; and (A) give an experimental result on the effect of the decomposition algorithm for a certain application. In the proposed model of paired synchronized automata, each automaton contains a synchronization symbol to describe the action of sending a signal to and receiving it from another automaton, and for any external input, multiple transitions are prohibited. The paired synchronized automata produced by the proposed decomposition method are much simpler than the automata produced by the previous method, and they are easy to be translated in a program.
Performance evaluation for buffer‐contained disk units
Authors: Mitsuishi Akitoshi , Mizoguchi Tetsuo
Published: July 2007

The rotation delay of a disk caused by RPS‐miss, which is larger than what is usually assumed to be, is nonnegligible in. systems of heavy load. A method is proposed to cope with this delay by improving the response time and throughput: a buffer‐contained disk unit. Its performance evaluation is shown by simulation. The buffer‐contained disk unit has a small amount of buffer (some tens of kB). Data transmission between a buffer and a disk control unit and disk rotation occur asynchronously, which considerably reduces the delay time. In writing operation, the seek time is overlapped by data transmission time, and seek and rotation delay time appear to be zero. In simulation, an access pattern of real system is used which is obtained by tracing the disk input/output operation. Hence, the response and throughput are clearly improved by 1.7±3.8 times and by 2.0±3.3 times, respectively. The method can be applied to a large variety of disks with great performance improvement and little add‐on hardware.
Descriptive powers of synchronized shuffle grammars and synchronized production systems
Authors: Araki Toshiro , Uoi Hirotaka , Kosai Shoji , Tokura Nobuki
Published: July 2007

As models to describe the concurrent systems with synchronized mechanism, synchronized shuffle grammar and synchronized production system (SPS) have been proposed. The synchronized shuffle grammar is defined by the triplet composed of a shuffle grammar G, synchronizing language LC and a homeomorphism h. The language generated by is defined as L(G) = h (L(G) LC). As a subclass of the synchronized shuffle grammar, this paper considers a class syncRSG (sync ERSG), where G is an (extended) regular shuffle grammar and Lc is an arbitrary regular language. SPS can also be defined as a pair of extended context‐free grammar and a state‐transition machine. This paper considers as its subclass, the context‐free SPS which is a pair of a context‐free grammar and a finite automaton. It is shown that there exist some subclass.es in syncRSG (sync ERSG) and context‐free SPS, which generate the same class of formal languages. It is also shown that there exists a certain hierarchical relation, and the full descriptive powers of syncRSG (syncERSG) and context‐free SPS are the equivalent to that of Petri net.
A class of SEC‐DED‐SBED codes for semiconductor memory
Authors: Kaneda Shigeo
Published: July 2007

The SEC‐DED‐SbED code is capable of correcting a single‐bit eror, detecting a random double‐bit error and detecting a b‐bit block error. It is expected to be widely used for highly reliable semiconductor memory systems composed of memory devices with b‐bit output.

In this paper a new theoretical construction method for SEC‐DED‐SbED codes is proposed. The proposed class of codes is so characterized that, with byte length b, it is constructed from conventional SEC‐DED‐SbED codes of byte length b/2 and the weight of the column vector of its parity check matrix H (the number of l's) is odd. The bit length n of the code is given as n _ b2(r‐b) . r/2Cb/2 bits, when the check bit length r and the byte length b are even. It has the longest bit length among the known code classes in a large range of byte lengths.
3‐D reconstruction of coronary artery from cine‐angiograms based on left ventricular model
Authors: Iwai Shinichi , Yachida Masahiko , Tsuji Saburo
Published: July 2007

There is an increasing demand for coronary angiography, corresponding to the recent increase of such ischemic cardiac diseases as myocardial infarction. At present, the obtained angiograms must be read by specialized doctors and require a large amount of time. Still it is usually difficult to arrive at a three‐dimensional understanding of the coronary artery. From such a point of view, this paper aims at the automatic analysis of the angiogram and describes a method which can determine the correspondence between vessels in the coronary artery angiograms taken along two directions. In the proposed system the three‐dimensional information is used in establishing the correspondence, which is difficult for human observers to utilize. As the first step, a straight line connecting a branch point of a vessel and the X‐ray source is considered and the projection of that line onto another image (called an epi‐polar line) is determined. Points close to that line are used as candidates for the correspondence. Then, using the vessels with established correspondences, a three‐dimensional model is constructed for determination of the correct candidates. Then a prohibited region in the three‐dimensional model is specified where there cannot exist a vessel. The vessels with established correspondence are represented in three dimensions and evaluation of the left ventricle is performed. From the results of experiment, the validity and the problems of the proposed system are pointed out.
A flexible structured multimicroprocessor using general‐purpose CPU chips
Authors: Taniguchi Tadakatsu
Published: July 2007

This paper discusses the design of a simple multimicroprocessor system to be built into the dedicated instrument, and also discusses the design for the system. The 8‐bit processor sometimes makes it difficult to realize the required function or necessitates a sophisticated technique or experience to realize the function. However, this paper demonstrates that there exist techniques that can easily be incorporated into the processor in the system to realize the required function and performance. The hardware discussed in this paper is flexible so that the result of functional analysis can be realized directly as the structure. The problems of parallel processing that will inevitably arise in this kind of approach are then solved by queue and synchronized registers. Hence, the hardware structure (number and connections of processors and memories) is determined according to the result of structured programming, and parallel processing programs are designed to be performed along the lines of the past single‐stream system. The performance of the system can be modified by modifying the number of processors and the hardware structure without completely changing the program, only by reassignment of the memory. From the practical viewpoint, 80‐type CPU (Intel 8085A), most widely used at present, is adopted. The result of experimental set‐up and simple application examples are shown.