bluuebunny/crossref_metadata_2025 huggingface dataset:
France Reopens the Constitutional Debate
Authors: Pierce Roy
Published: May 2006

Less than six years have passed since the Constitution of the Fourth Republic was put into operation, yet every political group in France with the exception of the Communist Party, which has its own special plans for France's future, is currently participating in a movement for constitutional revision. Since July, 1950, no candidate for the post of Prime Minister has neglected to assert in his ministerial declaration the need for constitutional reform. The parties of the Third Force majority of the first legislature of the Fourth Republic set into motion for the first time, in November, 1950, the machinery for the amendment of the Constitution. The momentum which the revisionist movement had already gathered was given greater impetus by the elections of June, 1951, which reinforced markedly the political groups opposed to the Constitution at its inception. These groups had been able to muster only 106 votes in the Second Constituent Assembly of 1946. Later, in the first legislature but after the formation of a Gaullist parliamentary group, their strength rose to approximately 160 seats. And as a result of the elections of June, 1951, the same groups now command 300 seats in the second legislature.
The Direct Primary and Party Structure: A Study of State Legislative Nominations
Authors: Key V. O.
Published: May 2006

Some analysts blame the direct primary for the supposedly parlous state of the American party system; others assert that nominating procedures do not affect parties at all. The literature abounds with more or less judicious, and conflicting, estimates of the consequences of the primary mode of nomination. In fact, our present knowledge provides little basis for confident appraisal of the effects of the direct primary. This article reports an attack on a small part of the problem, viz., state legislative nominations in two-party states, by explicit methods of analysis, whose use may both make possible a minor substantive contribution as well as demonstrate the appalling amount of work necessary for a provisional solution of even the smallest aspect of the broad problem.

To cope with questions about the consequences of particular institutional arrangements requires both a working theory and a means of observation to determine whether it fits the facts. For lack of a better concept, the problem of the effects of the primary method of nomination may be regarded as a special case of the broader question of the nature of the interaction between formal and informal organization.
“Neutralism” in Asia
Authors: Scalapino Robert A.
Published: May 2006

Many Americans view “neutralism” as a new type of social disease. Its probable causes: intimacy in some form with communism; its symptoms: mental confusion and moral dereliction; its cure: unknown. This is a somber diagnosis, filled with implications of doom for the “victims.” But our warnings and protests have been to little avail. Most “neutralists” have deliberately rejected them, and the “disease”—if that be its proper designation—has approached epidemic proportions in many areas. Among the centers of infection, Asia is certainly the region where “neutralism” has shown its most consistent strength and taken its most diverse forms. And however much they may lament it, Americans must recognize the fact that Asian “neutralism” can be neither ignored nor talked out of existence. In our own interests, therefore, we should seek a more complete understanding of this highly complex force—its causes and effects, and possibly its implications for future American policy. Understanding does not necessarily mean acceptance; it does permit a more accurate calculation of alternative risks, and this is the vital element in decision making.

At the outset, the problems of definition and terminology must be raised. It is not easy to define or describe “neutralism” in such manner as to obtain the largest measure of agreement from all parties concerned. Frequently, the word is intended as an epithet, with connotations similar to those suggested in our opening sentences.
Legislative Politics in Connecticut
Authors: Lockard W. Duane
Published: May 2006

Although there is a voluminous literature on the organization and procedure of state legislatures, material on their politics is relatively sparse. The classic work of A. Lawrence Lowell, now more than a half-century old, still appears to be the chief reliance of scholars in the field. Lowell's thesis was that parties were relatively insignificant in state legislatures; virtually the whole of the subsequent literature agrees with this. In the case of the Connecticut legislature, it would seem that parties, far from being relatively insignificant, play a dominating role.

The study of party influence in a legislature necessitates a two-level approach: analysis of the role of the party leadership and of the voting behavior of the party membership. Several questions must be answered with regard to the party leadership. Are the party leaders an identifiable and cohesive group? Do they develop a definite program for legislative consideration? Is their authority shared with factional leaders capable of frequent disruption of the party program? Are committee chairmen or party leaders in the stronger position for actually forming legislative policy? Do pressure group leaders work through the formal party leaders or do they attempt to build ad hoc legislative majorities for their bills through independent action?
Partisanship and County Office: The Case of Ohio
Authors: Key V. O.
Published: May 2006

The textbooks contain singularly little systematic analysis of the role of party in local government. They abstract the relevant statutes. They expound more or less orthodox suppositions. Voting on local candidates corresponds closely with presidential voting. Party groups compete for control of local government more or less as they do on the national level. Or, the contrary notion is argued that party has little place in local politics. Personal followings or essentially non-party courthouse cliques determine all. This paper represents a modest attempt, by analysis of Ohio data, to test a few of the standard suppositions and to suggest lines of inquiry that might be fruitful in the study of local politics.

Relation of voting for county and presidential candidates. Contrary to the belief that the presidential tide almost invariably carries with it the local candidates of the winning party, the Ohio record indicates a fairly high degree of independence of national party trends in the selection of county officers. Although in most instances a Republican county presidentially chooses Republican county officers and a Democratic county, Democratic county officers, the departures from this consistency are of sufficient magnitude to excite attention.
How Much Is Majority Status in the U.S. Congress Worth?
Authors: Cox Gary W. , Magar Eric
Published: May 2006

A key premise of partisan theories of congressional organization is that majority status confers substantial procedural advantages. In this article, we take advantage of changes in party control of the House and Senate, such as that following the Republicans' historic victory in the midterm elections of 1994, to assess the value of majority status in terms of contributions from access-seeking political action committees (PACs). We estimate that majority status in the House was worth about $36,000 per member in receipts from corporate and trade PACs circa 1994—even controlling for the usual factors cited in the literature as affecting members' ability to raise money (such as committee assignments and voting record). The value of majority status in the Senate is even larger in absolute terms, although smaller in proportion to the total amount of money raised. Our results show that majority status is a valuable asset, one worth considerable collective effort to attain.
“Killer” Amendments in Congress
Authors: Wilkerson John D.
Published: May 2006

For more than three decades, social choice theorists and legislative scholars have studied how legislative outcomes in Congress can be manipulated through strategic amendments and voting. I address the central limitation of this research, a virtual absence of systematic empirical work, by examining 76 “killer” amendments considered during the 103d and 104th congresses. I trace the effects of these amendments on their related bills using archival sources, test for strategic voting using NOMINATE as the baseline measure of legislator preferences across a range of issues, and explore with OLS regression why some killer amendments are more strategically important than others. The findings indicate that successful killer amendments and identifiable strategic voting are extremely rare. In none of the cases examined could the defeat of a bill be attributed to adoption of an alleged killer amendment.
Organized Interests and the Decision of Whom to Lobby in Congress
Authors: Hojnacki Marie , Kimball David C.
Published: May 2006

In a departure from previous research, we focus on the dyadic relationship between lobbyists and committee members in the House of Representatives in order to test hypotheses about what factors shape the decisions of individual groups to lobby individual committee members. Our primary assumption is that organized interests seek to expand their supportive coalitions and affect the content and fate of bills referred to committees. In order to accomplish these goals, they give highest priority to lobbying their legislative allies in committee; allies may lobby other members of Congress on a group's behalf and shape legislation to conform with a group's preferences. But organizations with access to a strong resource base can move beyond their allies and work directly to expand support among undecided committee members and legislative opponents. Our empirical analysis provides evidence to support our expectations.
Observations of Rhodium‐Containing Reaction Intermediates using HPLC with ICP‐MS and ESI‐MS Detection
Authors: Welch Christopher J. , Tu Qiang , Wang Tiebang , Raab Conrad , Wang Peng , Jia Xiujuan , Bu Xiaodong , Bykowski Darren , Hohenstaufen Benjamin , Doyle Michael P.
Published: May 2006

HPLC with ICP‐MS or ESI‐MS detection has been used to investigate metal‐containing reaction intermediates in the ligand exchange process leading to formation of the well known Rh2(MEPY)4 catalyst. A variety of intermediates are observed along the pathway to formation of the desired tetrasubstituted product, including isomeric species from di‐, tri‐, or tetrasubstitution that were previously believed to be absent.
2‐(2‐Haloalkenyl)‐aryl Halides as Substrates for Palladium‐Catalysed Tandem CN Bond Formation: Efficient Synthesis of 1‐Substituted Indoles
Authors: Willis Michael C. , Brace Gareth N. , Findlay Thomas J. K. , Holmes Ian P.
Published: May 2006

2‐(2‐Haloalkenyl)‐aryl halides, conveniently prepared in a single step from the corresponding o‐halobenzaldehydes, are combined with amines under Pd catalysis to provide 1‐substituted indoles. All combinations of Br and Cl leaving groups can be employed, and a range of substituents on the arene, alkene and amine, can all be tolerated. The use of 1,3‐dichloro‐substituted arenes allows a third amination process to take place; these three‐component processes deliver the corresponding 4‐aminoindoles in good yields.
Effect of ionic strength on folding and aggregation of the hemolytic peptide melittin in solution
Authors: Raghuraman H. , Chattopadhyay Amitabha
Published: May 2006

Melittin is a cationic, amphipathic, hemolytic peptide composed of 26 amino acid residues. It is intrinsically fluorescent due to the presence of a single tryptophan residue, which has been shown to be crucial for its hemolytic activity. It undergoes a structural transition from a random coil monomer to an α‐helical tetramer at high ionic strength. Although the aggregation behavior of melittin in solution is well characterized, dynamic information associated with the aggregation of melittin is lacking. In this paper, we have monitored the effect of ionic strength on the dynamics and aggregation behavior of melittin in aqueous solution by utilizing sensitive fluorescence approaches, which include the red edge excitation shift (REES) approach. Importantly, we demonstrate that REES is sensitive to the self‐association of melittin induced by ionic strength. The change in environment experienced by melittin tryptophan(s) is supported by changes in fluorescence emission maximum, polarization, and lifetime. In addition, the accessibility of the tryptophan residue was probed by fluorescence quenching experiments using acrylamide and trichloroethanol as soluble and hydrophobic quenchers, respectively. Circular dichroism studies confirm the ionic strength–induced change in the secondary structure of melittin. Taken together, these results constitute the first report showing that REES could be used as a sensitive tool to monitor the aggregation behavior of melittin in particular and other proteins and peptides in general. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 111–121, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Personal cytometers: Slow flow or no flow?
Authors: Shapiro Howard M. , Perlmutter Nancy G.
Published: May 2006

Background:

Although some manufacturers have optimistically described instruments with prices in the US$40,000 range as “personal cytometers”, analogy with the personal computer suggests that the target price for a true “personal” cytometer should be under $5,000. Since such an apparatus could find a wide range of applications in cytomics in both developing and developed countries, it seemed desirable to consider its technical and economic feasibility.

Methods:

Using resolution targets and a variety of fluorescent bead standards immobilized on filters and/or slides, we evaluated high‐intensity LEDs as fluorescence excitation sources, relatively inexpensive CCD cameras as detectors, and 35 mm camera lenses and plastic low‐power microscope optics for light collection in a simple, inexpensive low‐resolution imaging cytometer.

Results:

The components tested could be combined toproduce an instrument capable of detecting fewer than 10,000 molecules of cell‐associated fluorescent label, and thus applicable to a broad range of cytometric tasks.

Conclusions:

Given the requirements for light sources, detectors, optics, mechanics, electronics and data analysis hardware and software, and the components presently available, it should be easier to reach the desired $5,000 price point with an image cytometer than with a flow cytometer. © 2006 International Society for Analytical Cytology
Extracting quantitative information from tissue—An industrial perspective
Authors: Van Osta Peter
Published: May 2006

The focus of this article is to provide an overview of the current technologies for the pharmaceutical and biotech industry. Disease processes express themselves in the functional and structural disturbance of cellular systems. Cells and their metabolites constitute the building blocks of tissues and entire organisms. Studying the spatial and temporal phenotype of disease processes in tissues at the cellular level reveals a multitude of information about the progress and status of a disease. Detailed exploration of tissues by slide‐based cytometry is an important source of information about disease processes. Technological and analytical advances allow us to shed a new light on tissues and to come to a better understanding of the complexity of disease processes. Dealing with complex multidimensional datasets from tissue samples requires an advanced approach to image processing and data management. The increase in computing power and the continuing research into imaging algorithms allow us to improve the exploration of the data content of tissues. © 2006 International Society for Analytical Cytology
Effects of Ionic Liquids on Pd‐Catalysed Carbon–Carbon Bond Formation
Authors: Calò Vincenzo , Nacci Angelo , Monopoli Antonio
Published: May 2006

A comparative study of the effects exerted by different ionic liquids on catalyst stability, reaction rates and regio‐ and stereoselectivity in carbon–carbon coupling reactions points to the superiority of the quaternary ammonium halides over pyridinium‐ and imidazolium‐derived ionic liquids. The influence of ionic liquids on the Heck and Suzuki reactions emerges as being associated with the Coulombic interaction between the cations and anions in ILs as well as the nucleophilicity of the anions. In the tetraalkylammonium halides and acetate, the bulkiness of tetrahedral tetraalkylammonium cations, which forces the anions away from the cation, renders these anions available for a good activity and stability of the palladium catalysts. On the contrary, the planar structures of imidazolium and pyridinium cations, due to a strong Coulombic interaction that binds the anions tightly, decrease their availability for stabilisation and activity of the catalysts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Regulatory fit and cognitive performance: the interactive effect of chronic and situationally induced self‐regulatory mechanisms on test performance
Authors: Keller Johannes , Bless Herbert
Published: May 2006

Two studies examined the impact of chronic and situational self‐regulatory mechanisms on cognitive test performance. In both studies, test performance was enhanced when situationally induced regulatory mechanisms matched the chronic self‐regulatory focus of the test taker. These results support the regulatory fit hypothesis put forward in regulatory focus theory and point to the importance of compatibility between chronic and situationally induced self‐regulatory states when it comes to cognitive test performance. Copyright © 2006 John Wiley & Sons, Ltd.
Biomechanical and surface physico‐chemical analyses of used osteosynthesis plates and screws—Potential for reuse in developing countries?
Authors: Magetsari Rahadyan , van der Houwen Eduard B. , Bakker Martine T. J. , van der Mei Henny C. , Verkerke Gijsbertus J. , Rakhorst Gerhard , Hilmy Chehab R. , van Horn Jim R. , Busscher Henk J.
Published: May 2006

Reprocessing of single‐use devices is an upcoming issue in the Western world, but has been for many years in developing countries. In developing countries, the number of bone fractures due to traffic or industrial accidents is high. Patients often need an osteosynthesis with plates and screws, but most patients, however, cannot afford this because of the costs involved and have to rely on the application of used plates and screws. This study aims to determine whether used plates can be safely reused in another patient from a biomechanical, surface physico‐chemical, and biological point‐of‐view. Osteosynthesis plates weakened in a predictable way during use, regardless of the history, presumably because tests were conducted under extreme conditions in the absence of clinically applied load‐sharing between bone and plate. Surface physico‐chemical analyses indicated that used plates and screws were more hydrophilic than new ones; had increased amounts of calcium‐phosphates at their surfaces and possessed higher number of scratches. Pitting corrosion could be seen on SEM micrographs. Simple cleaning methods, as available in developing countries, including toothbrush, water, detergent and bleach yielded elemental surface compositions, and hydrophobicities similar to those of new ones, while biologically thus cleaned screws were not cytotoxic according to ISO‐10993–5 and endotoxin release according to USP‐27‐NF‐22 was within the requirements of the FDA. It is concluded that the reuse of osteosynthesis plates and screws are not necessarily unsafe, although preferably a register should be kept of all previous users to limit the number of reuses as mechanical weakening does occur. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Changes in scattering and absorption properties of esthetic filling materials after aging
Authors: Lee Yong‐Keun , Lim Bum‐Soon , Rhee Sang‐Hoon , Yang Hyeong‐Cheol , Lim Yong‐Kyu
Published: May 2006

Objectives

Assuming that color changes after aging are related to changes in translucency of materials, the purpose of the present study was to determine the correlation between the changes in color and the changes in scattering and absorption properties after accelerated aging with representative dental esthetic restorative materials: glass ionomer, resin‐modified glass ionomer, compomer, and resin composite.

Methods

Color was measured according to the CIELAB color scale in the transmittance and reflectance modes and used to calculate changes in color (ΔE*ab), color coordinates (ΔL*, Δa*, and Δb*), translucency parameter (ΔTP), scattering coefficient (ΔS), absorption coefficient (ΔK), and light reflectivity (ΔRI) after accelerated aging. Simple correlations between each pair of the changes in optical values were calculated, and multiple regression analysis was used to determine the parameters influencing the changes in color and color coordinates (p = 0.05).

Results

In the resin composite and compomer, ΔS, ΔK, and ΔRI values were approximately zero, whereas ΔS was as high as 8.9 in the glass ionomer. For most comparisons, correlation coefficient (r) was between 0.700 and 0.997. ΔL* was found to have a major influence on color changes, and ΔS, ΔTP, and ΔRI influenced ΔL*. Therefore, changes in scattering and absorption properties, after aging, were closely correlated with changes in color and color coordinates, especially in glass ionomer‐based filling materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Surface modification of titanium‐based alloys with bioactive molecules using electrochemically fixed nucleic acids
Authors: Michael J. , Beutner R. , Hempel U. , Scharnweber D. , Worch H. , Schwenzer B.
Published: May 2006

A new method of surface modification for titanium (alloys) with bioactive molecules was developed with the intention of providing a new basis of implant adaptation for particular requirements of certain medical indications. Nucleic acid single strands are fixed electrochemically via their termini (regiospecifically) by growing an oxide layer on Ti6Al7Nb anodically. It could be shown that they are accessible to subsequent hybridization with complementary strands at physiological pH. Amount of nucleic acids immobilized and hybridized were determined radioanalytically using 32P‐labelled nucleic acids. Stable fixation was attained at and above potentials of 4 VSCE. Up to 4 pmol/cm2 of nucleic acid single strands could be immobilized and hybridization efficiencies up to 1.0 were reached. Hybridization efficiency was found to depend on surface density of immobilized oligonucleotides, while hybridization rates increased when MgCl2 was added. A conjugate consisting of an oligonucleotide complementary to the immobilized strand and the hexapeptide GRGDSP with RGD as an integrin recognition site was synthesized. This conjugate was able to bind to integrins on osteoblasts. It was shown that this conjugate binds to the anchor strand fixed on Ti6Al7Nb to an extent comparable with the unconjugated complementary strand. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Bovine prion (PrP) and Doppel (Dpl) proteins expression after in vitro leukocyte activation or Dpl/PrP blocking
Authors: Paltrinieri Saverio , Spagnolo Valentina , Giordano Alessia , Gelmetti Daniela , Comazzi Stefano
Published: May 2006

It has been postulated that Doppel (Dpl) and Prion (PrP) proteins have yet undetermined interactions, since Dpl is overexpressed in transgenic PrP‐deficient mice. In this study we investigated the expression levels of Dpl and PrP on lymphocytes, monocytes and neutrophils (PMNs) isolated from bovine blood and incubated (2 and 18 h) with TNFα, IL‐1, IL‐2, IL‐8, C5a, IFNγ, anti‐PrP, and anti‐Dpl antibodies by flow cytometry. The isolation procedures yielded cell populations with high purity, viability and recovery rates. After 2 h incubation, expression of PrP or Dpl was altered only in PMNs. These cells overexpressed PrP when incubated with TNFα and IFNγ, and both PrP and Dpl when incubated with C5a; incubation with TNFα, IL‐8 and IFNγ led to down‐regulation of Dpl. Lymphocytes incubated for 18 h with IL‐2 and with IFNγ overexpressed Dpl. Incubation with the anti‐PrP antibody induced down‐regulation of Dpl in PMNs after 2 h and overexpression of Dpl in lymphocytes after 18 h. The differences recorded after 2 h were likely due to redistribution of pre‐existing PrP or Dpl molecules, while those seen at 18 h were most probably due to increased protein synthesis. The variations seen using the different activators depend on different receptors and/or signaling pathways. These results demonstrate that is possible to alter the expression of Dpl and PrP in blood cells in vitro by incubation with either cytokines or anti‐PrP antibodies. This opens an interesting opportunity to study the biology of these proteins using in vitro systems. J. Cell. Physiol. 208: 446–450, 2006. © 2006 Wiley‐Liss, Inc.
Robust stochastic seasonal precipitation scenarios
Authors: Kioutsioukis Ioannis , Rapsomanikis Spyridon , Loupa Rea
Published: May 2006

In this paper, a stochastic statistical forecasting methodology is employed for long‐term predictions of winter precipitation over Greece. Lagged climatic indices and North Atlantic (NA) sea‐level pressure (SLP) field are explored as potential predictors of the teleconnection. Rather than employing traditional stationary models, two dynamic regression‐modelling schemes are analysed and validated and their parameter variation is interpreted. Dynamic regression models, in contrast to static (constant parameter) regression models, have time variable parameters (TVPs) evaluated through recursive optimisation and are suitable for analysis of non‐stationary phenomena like most atmospheric processes.

The analysis of the spectrum with non‐stationary models points out that the most influential seasonal components of the winter precipitation anomalies have periods of 14 and 3.5 years, explain 40% of its variance, possess significant amplitude change and correlate significantly with the North Atlantic Oscillation Index Anomaly (NAOIA) and Southern Oscillation Index Anomaly, indicating their climatic origin. Furthermore, the forecasting skill of the dynamic models (R2 = 0.71), in addition to reproducing the peaks, was found superior even to the hindcasting skill of the stationary model (R2 = 0.55). Copyright © 2006 Royal Meteorological Society
Comparative study of degenerate four‐wave mixing and cavity ringdown signal intensities of formaldehyde in a molecular beam
Authors: Tulej M. , Meisinger M. , Knopp G. , Walser A. M. , Beaud P. , Gerber T. , Radi P. P.
Published: May 2006

A comparison of degenerate four‐wave mixing (DFWM) and cavity ring‐down (CRD) spectroscopy is made on jet‐cooled formaldehyde under identical expansion conditions. We show that both methods are applicable to the low‐density environment of a molecular beam. However, a slightly superior signal‐to‐noise ratio for the background‐free DFWM method is observed for our experimental configurations. Absorption spectra simulated by applying an asymmetric rotor model are used to deduce Boltzmann temperatures of the rotational population distribution by a nonlinear least‐squares fit to the experimental data. In addition, partial interconversion of the nuclear spin upon supersonic expansion is observed. Consequently, a second fit parameter, describing the para/ortho concentration ratio in the molecular beam, is introduced. The resulting simulated spectra are in favorable agreement with the relative CRD intensities. A simple model for the reduction of the DFWM signal intensities to population is applied yielding absorption‐like spectra in accordance with both the simulations and the CRD measurements. We conclude that DFWM spectroscopy is applicable to deduce population distributions of an asymmetric rotor molecule under free‐jet conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Coherent bichromatic spectroscopy of Rb vapor with a femtosecond laser
Authors: Akimov A. V. , Matveev A. N. , Sokolov A. V. , Tereshenko E. O. , Kondratjev D. A. , Sorokin V. N. , Kanorsky S. I. , Kolachevsky N. N.
Published: May 2006

We experimentally studied the narrow resonances of coherent population trapping (CPT) in a rubidium vapor cell with the help of a phase‐coherent bichromatic light source based on a mode‐locked femtosecond laser. We investigated the dependence of the contrast and the width of CPT resonance on the light power, as well as the sensitivity of the shape of the resonance to a magnetic field. Prospects of using the novel bichromatic source for phase‐coherent Raman spectroscopy of CPT resonances in atomic systems with a large energy separation of the lower levels are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Kinetics and mechanism of the oxidation of acetylacetone by permanganate ion
Authors: Jáky Miklós , Szammer János , Simon‐Trompler Edit
Published: May 2006

The kinetics and mechanism of permanganate ion oxidation of acetylacetone (Acac) was studied in acidic and alkaline media. The rate constants for keto, enol, and enolate anions were determined and discussed. Delocalization of the π‐electrons of the double bond by conjugation results in a slower oxidation rate of enol than can be usually observed for unsaturated compounds. In the case of the keto form, the acid‐catalyzed nucleophilic attack of permanganate ion occurs on the carbonyl‐C atom. For enolate anion a mechanism with basis‐catalyzed electron abstraction is suggested. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 444–450, 2006
Biodegradable Network Elastomeric Polyesters from Multifunctional Aliphatic Carboxylic Acids and Poly(ε‐caprolactone) Diols
Authors: Nagata Minoru , Kato Keisuke , Sakai Wataru , Tsutsumi Naoto
Published: May 2006

Summary: Biodegradable elastomeric network polyesters were prepared from multifunctional aliphatic carboxylic acids such as tricarballylic acid (Yt) or meso‐1,2,3,4‐butanetetracarboxylic acid (Xb) and poly(ε‐caprolactone) (PCL) diols with molecular weights of 530, 1 250 and 2 000 g · mol−1. Prepolymers prepared by a melt polycondensation were cast from DMF solution and postpolymerized at 280 °C for various periods of times to form a network. The resultant films were transparent, flexible and insoluble in organic solvents. The network polyesters obtained were characterized by IR absorption spectra, WAXS, density measurement, DSC, and tensile test. YtPCL1250, and XbPCL1250 network polyester films showed good elastomeric properties with high ultimate elongation (540–590%), and low Young's modulus (2.5–3.3 MPa). The enzymatic degradation was estimated by the weight loss of network films in a buffer solution with Rhizopus delemar lipase at 37 °C. The degree and rate of degradation were significantly affected by the molecular weight of PCL diol, chemical structures of multifunctional aliphatic carboxylic acids and the morphology of network films. The changes in the solid states of network films during the degradation were also estimated by the results of DSC and WAXS.

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Liquid Pool Copolymerization of Propylene/1‐Butene with a MgCl2‐Supported Ziegler‐Natta Catalyst
Authors: Silva Fabricio M. , Melo Príamo A. , Nele Márcio , Lima Enrique L. , Pinto José Carlos
Published: May 2006

Summary: Liquid pool propylene/1‐butene copolymerizations were carried out in a batch reactor with a high activity Ziegler‐Natta catalyst system. Experimental runs were performed to evaluate the effect of the 1‐butene content on the crystallinity and melt temperature of the polymer resins. According to the results, 1‐butene can be significantly incorporated into the polymer chain at high polymerization rates over the whole range of copolymer compositions, leading to a decrease in the melting temperature (Tm) of the polymer, when compared to the poly(propylene) homopolymer, allowing for reduction of the sealing initiation temperature. It was observed by GPC and MFI measurements that the average molecular weights and the polydispersity index of the copolymer significantly decreased when compared to the ones obtained from poly(propylene). Despite high polymerization rates, polymer particles with good morphological features were produced in all cases. It was also observed that the absence of an external electron donor led to low crystallinity values for both the poly(propylene) homopolymer and for copolymers with different fractions of 1‐butene, when compared to literature values frequently reported for polymer resins based on 1‐butene and propylene. The obtained results indicate that a family of bulk propylene/1‐butene copolymer grades can be successfully developed for packaging and film applications.

Surface morphology and molecular weight distribution (deconvoluted into Schulz‐Flory distributions) of the propylene/1‐butene copolymer.

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Surface morphology and molecular weight distribution (deconvoluted into Schulz‐Flory distributions) of the propylene/1‐butene copolymer.
Occurrence of mycotoxins (ochratoxin A, deoxynivalenol) and toxigenic fungi in Moroccan wheat grains: impact of ecological factors on the growth and ochratoxin A production
Authors: Hajjaji Abdelouahed , El Otmani Mostafa , Bouya Driss , Bouseta Amina , Mathieu Florence , Collin Sonia , Lebrihi Ahmed
Published: May 2006

The aim of the present work was to evaluate the contamination of some samples, taken from Moroccan wheat grains, by ochratoxin A (OTA), deoxynivalenol (DON) and the associated toxigenic fungi. Moreover, we focused on the influence of environmental factors on both the growth and OTA production by three strains of Aspergillus. The results showed that only few samples were contaminated by the two mycotoxins (2 samples for OTA and 7 for DON). The main isolated fungi belong to the Aspergillus, Penicillium and Fusarium genus; 74 Aspergillus and 28 Penicillium isolates were tested for their ability to produce OTA. Only 2 A. alliaceus and 14 A. niger were able to synthesize OTA. However, none of Penicillium isolates can produce this toxin under the conditions mentioned. In respect of the effects of the temperature and water activity (aw), the optimal conditions for the growth and OTA production were different. While the optimal conditions of growth for A. alliaceus and A. terreus are 30°C and 0.98 aw, A. niger prefered 0.93–0.95 aw at 25°C, whereas the optimal production of OTA was observed at 30°C for both A. alliaceus and A. niger at 0.93 and 0.99 aw, respectively.
Modulation of neurosteroid production in human neuroblastoma cells by Alzheimer's disease key proteins
Authors: Schaeffer Véronique , Patte‐Mensah Christine , Eckert Anne , Mensah‐Nyagan Ayikoe G.
Published: May 2006

Studies performed with animals suggest neurosteroid involvement in neuroprotection. However in humans, the role of neurosteroidogenesis in the regulation of degenerative processes is unknown. To determine whether cellular factors intervening in degenerative mechanisms may interfere with the process of neurosteroidogenesis in humans, we combined pulse‐chase experiments with HPLC and continuous flow scintillation detection to compare neurosteroid production in normal and transfected SH‐SY5Y cells with key proteins involved in Alzheimer's disease (AD). Microscope analyses revealed that cell morphology was unchanged in stably transfected SH‐SY5Y cells overexpressing human native tau (hTau40), mutant tau (P301L), and wild‐type amyloid precursor protein (APPwt) compared to controls. Biochemical investigations showed that hTau40 enhanced progesterone (PROG), 17OHPROG, testosterone, and 3α‐androstanediol neosynthesis from pregnenolone. In contrast, tau with the pathogenic P301L mutation was devoid of action on neurosteroidogenesis. Overexpression of APPwt inhibited PROG formation, did not affect 17OHPROG and testosterone, but increased 3α‐androstanediol and estradiol synthesis. Extracellular treatment of control cells with aggregated amyloid peptide mimicked the action of APPwt expression on PROG but not on 3α‐androstanediol and estradiol production. Moreover, PROG biosynthesis in APPwt cells was up‐regulated in the presence of a γ‐secretase inhibitor. Our results provide the first evidence for the regulation of neurosteroid biosynthesis by key proteins involved in the etiology of AD. The data suggest that pathogenic factors may induce neurodegeneration in humans through the reduction of the synthesis of endogenous neuroprotective neurosteroids in nerve cells. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Interactions of the C2 domain of human factor V with a model membrane
Authors: Mollica Luca , Fraternali Franca , Musco Giovanna
Published: May 2006

Activated coagulation Factor V is an important cofactor of the coagulation cascade that catalyzes the formation of the prothrombinase complex on the surface of membranes rich in phosphatidyl‐l‐serine (PS). Here we report molecular dynamics simulations of the two crystallographic structures (the open and closed conformations) of domain C2 of coagulation Factor V (FaVC2). The calculations were performed in water (1.5 ns for each conformation) and in the presence of a neutral phospholipid bilayer model (POPE; 10 ns for each conformation) in order to describe the dynamics of the free (plasma circulating) and membrane bound forms of FaVC2. Water simulations confirmed the hypothesis that the plasma circulating form is in the closed conformation. In contrast, the membrane simulations showed that both conformations are energetically compatible with membrane binding. We have investigated the mechanism, the dynamics, and the energetics of the binding process. Our data are consistent with published estimates of the immersion depth of the aromatic residues (W26 and W27), and with mutagenesis studies involving specific residues located on the spikes at the bottom of the FaVC2 structure. Electrostatic interactions between the phospholipid head groups and hydrophilic residues at the bottom of the structure play a key role in the binding process by creating a large number of hydrogen bonds that anchor the protein to the membrane. The simulations identified a stable phospholipid binding pocket reminiscent of a previously suggested PS interaction site. Our structural data could contribute to the design of potential inhibitors able to disrupt membrane association. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Microstructure of multi‐layered interphases processed by temperature‐pulsing chemical vapor infiltration
Authors: Yuan M. , Huang Zh. R. , Dong Sh. M. , Zhu Y. Zh. , Jiang D. L.
Published: May 2006

We demonstrate for the first time to our knowledge the method of temperature‐pulsing chemical vapour infiltration to process multilayered interphases of the carbon/silicon carbide composites. Transmission electron microscopy was employed to investigate the microstructure of the interphases. Finely alternate layered microstructures in nanoscale were proved to be prepared successfully via the route. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A randomized on–line algorithm for thek–server problem on a line
Authors: Csaba Béla , Lodha Sachin
Published: May 2006

Thek–server problemis one of the most important and well‐studied problems in the area of on–line computation. Its importance stems from the fact that it models many practical problems like multi‐level memory paging encountered in operating systems, weighted caching used in the management of web caches, head motion planning of multi‐headed disks, and robot motion planning. In this paper, we investigate its randomized version for which Θ(logk)–competitiveness is conjectured and yet hardly any <kcompetitive algorithms are known, even for the simplest of metric spaces ofO(k) size.

We present a$O(n^{2/3}\log{n})$–competitive randomizedk–server algorithm against an oblivious adversary when the underlying metric space is given bynequally spaced points on a line$({\cal L}(n))$. This algorithm is <kcompetitive for$n = k + o\big(\big({k \over \log k}\big)^{3/2}\big)$. Thus, it provides a super–linear bound fornwitho(k)–competitiveness for the first time and improves the best results known so far for the range$n-k \in \big[o(k), o\big(\big({k \over \log k}\big)^{3/2}\big)\big]$on${\cal L}(n)$. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Assessment of changes in endometrial and subendometrial volume and vascularity during the normal menstrual cycle using three‐dimensional power Doppler ultrasound
Authors: Jokubkiene L. , Sladkevicius P. , Rovas L. , Valentin L.
Published: May 2006

Objectives

To describe changes in endometrial and subendometrial volume and vascularity during the normal menstrual cycle using three‐dimensional (3D) power Doppler ultrasonography.

Methods

Fourteen healthy volunteers, 24–44 years old with regular menstrual cycles, underwent serial transvaginal 3D power Doppler ultrasound examinations of the uterus on cycle day 2, 3 or 4, then daily from cycle day 9 until follicular rupture and 1, 2, 5, 7 and 12 days after follicular rupture. Endometrial and subendometrial volume (cm3), vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using the VOCAL™ (Virtual Organ Computer‐aided AnaLysis) software.

Results

Endometrial and subendometrial vascularity indices increased throughout the follicular phase, decreased to a nadir 2 days after follicular rupture and then increased again during the luteal phase. Endometrial and subendometrial volume increased rapidly during the follicular phase and then remained almost unchanged during the luteal phase.

Conclusions

Substantial changes occur in endometrial volume and vascularization during the normal menstrual cycle. There is the potential for 3D power Doppler ultrasonography to become a useful tool for assessing pathological changes associated with female subfertility and abnormal uterine bleeding. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Preparation and Characterization of Pt/Co‐Core Au‐Shell Magnetic Nanoparticles
Authors: Dai Jingtao , Du Yukou , Yang Ping
Published: May 2006

Pt/Co‐core Au‐shell nanoparticles were synthesized via a two‐step route using NaBH4 as a reducing agent. The nanoparticles are characterized by UV‐vis spectroscopy, transmission electron microscopy (TEM) and powder X‐ray diffraction (XRD). The results indicate that the as‐synthesized Pt/Co‐core Au‐shell nanoparticles have a disordered face centered cubic (fcc) structure, whereas the annealed Pt/Co‐core Au‐shell nanoparticles exhibit an ordered face centered tetragonal (fct) structure. Superconducting quantum interference device (SQUID) studies reveal that the coercivity of the annealed Pt/Co‐core Au‐shell nanoparticles increases to 510 Oe after heat treatment at 500 °C for 2 h.
The amino acid sensitive TOR pathway from yeast to mammals
Authors: Dann Stephen G. , Thomas George
Published: May 2006

The target of rapamycin (TOR) is an ancient effector of cell growth that integrates signals from growth factors and nutrients. Two downstream effectors of mammalian TOR, the translational components S6K1 and 4EBP1, are commonly used as reporters of mTOR activity. The conical signaling cascade initiated by growth factors is mediated by PI3K, PKB, TSC1/2 and Rheb. However, the process through which nutrients, i.e., amino acids, activate mTOR remains largely unknown. Evidence exists for both an intracellular and/or a membrane bound sensor for amino acid mediated mTOR activation. Research in eukaryotic models, has implicated amino acid transporters as nutrient sensors. This review describes recent advances in nutrient signaling that impinge on mTOR and its targets including hVps34, class III PI3K, a transducer of nutrient availability to mTOR.
Erythropoietin production: Molecular mechanisms of the antagonistic actions of cyclic adenosine monophosphate and interleukin‐1
Authors: Batmunkh Chimedtseren , Krajewski Jochen , Jelkmann Wolfgang , Hellwig-Bürgel Thomas
Published: May 2006

Erythropoietin (Epo) mRNA expression is suppressed by interleukin 1 (IL‐1). Cyclic adenosine monophosphate (cAMP) can increase Epo mRNA and Epo protein levels in IL‐1 treated HepG2 cells to some extent. To identify molecular mechanisms of this reaction we investigated three transcription factors (NF‐κB, GATA‐2 and HIF‐1) that control the Epo gene. Western blot analyses and electrophoretic mobility shift assays (EMSAs) revealed that IL‐1 strongly activated NF‐κB, which is a likely suppressor of the Epo promoter. Treatment of the cells with dibutyryl‐cAMP (Bt2‐cAMP) inhibited the activation of NF‐κB by IL‐1. Bt2‐cAMP increased GATA‐2 DNA binding. Since GATA‐2 is a suppressor of the Epo promoter, GATA‐2 activation was unlikely to cause the increase of Epo mRNA expression in IL‐1 treated cells. Furthermore, Western blots, EMSAs and reporter gene studies showed that Bt2‐cAMP was without effect on the hypoxia‐inducible transcription factor HIF‐1. Thus, NF‐κB is probably the primary transcription factor by which cAMP counteracts the inhibition of Epo gene expression by IL‐1.
Reynolds-number-independent instability of the boundary layer over a flat surface
Authors: Luchini Paolo
Published: May 2006

A three-dimensional mode of spatial instability, related to the temporal algebraic growth that determines lift-up in parallel flow, is found to occur in the two-dimensional boundary layer growing over a flat surface. This unstable perturbation can be framed within the limits of Prandtl's standard boundary-layer approximation, and therefore develops at any Reynolds number for which the boundary layer exists, in sharp contrast to all previously known flow instabilities which only occur beyond a sharply defined Reynolds-number threshold. It is thus a good candidate for the initial linear amplification mechanism that leads to bypass transition.
Die akute Hämoptoe
Authors: Schwizer
Published: May 2006

Hämoptoe ist ein lebensbedrohliches und für alle Beteiligten beängstigendes Symptom. Die Gefahr des Erstickens ist meist größer als die Verblutungsgefahr. Neben der Notfallanamnese und der Inspektion des Nasenrachen-Raumes bilden die Thorax-Radiologie und die Bronchoskopie die Grundpfeiler der Diagnostik. Eine engmaschige Zusammenarbeit zwischen Notfallarzt, Pneumologe, Radiologe und Thoraxchirurge ist Voraussetzung für eine optimale Versorgung dieser Patienten. Bei massiver Hämoptoe ist eine Doppellumen-Intubation oft lebensrettend. Die Bronchoskopie erlaubt gleichzeitig therapeutische Maßnahmen zur Blutstillung. Weitere therapeutische Maßnahmen sind das Bronchialarterien-Coiling und die Resektion des betroffenen Lungenabschnittes.
Reprocessing of a global GPS network
Authors: Steigenberger P. , Rothacher M. , Dietrich R. , Fritsche M. , Rülke A. , Vey S.
Published: May 2006

During the 10 years since the official start of the International GNSS Service (IGS) in 1994 considerable improvements in the processing strategies and modeling of global GPS solutions were achieved. Owing to changes at the individual IGS Analysis Centers during these years the resulting time series of global geodetic parameters are very inhomogeneous and inconsistent. A geophysical interpretation of these long series and the realization of a high‐accuracy global reference frame are therefore difficult and questionable. In view of these deficiencies, the Technical Universities of Munich and Dresden decided to perform a reprocessing of a global GPS network over the last decade in a joint effort. First results of the reprocessing of 11 years of data show significant improvements in the quality and homogeneity of the estimated parameters and will allow for new geodynamic and geophysical interpretations. In the early years an improvement of the coordinate repeatability by a factor of more than 2 could be achieved. The formal errors of subdaily Earth rotation parameters could be reduced by 30%. Advanced modeling approaches like a mapping function based on numerical weather models, consideration of second‐ and third‐order ionospheric corrections and absolute antenna phase center corrections for receivers and satellites were tested to achieve further improvements.