bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal polymerization of arylacetylenes: spectroscopic and thermal studies
Authors: Grenier-Loustalot Marie-Florence
Published: August 2002

The reaction mechanisms and kinetics of endcapped ethynyl polyethers were studies in the temperature range 150-220C. The results obtained by '3C and 'H NMR, FrTIR, HPLC and DSC indicate reactivity differences and competing reactions. These materials were cured and their thermal properties evaluated.
Polyimide foams derived from poly(4,4'-oxydiphenylpyromellitimide) and poly(α-methylstyrene)
Authors: Hedrick J L , DiPietro R , Charlier Y , Jerome R
Published: August 2002

An alternative route for the synthesis of high- Tg thermally stable polymer foams with pore sizes substantially smaller than those produced by other methods is described, using compositionally asymmetric microphase-separated block copolymers where the minor component, poly(α-methylstyrene), is thermally labile and the major component, a polyimide derived from poly(4,4'-oxydiphenylpyromellitimide), is thermally stable. Upon thermal treatment, the thermally unstable block can unzip to the monomer, leaving behind pores, the size and shape of which should, in principle, be identical to the initial block copolymer morphology. Triblock copolymers were prepared where the imide component was derived from poly(amic alfkyl ester) precursor using either the meta- or para-isomers with 4,4'-oxydianiline, and the α-methylstyrene component comprising the outside block of the ABA architecture. Dynamic mechanica] analysis confirmed microphase-separated morphologies for each of the copolymers. The decomposition of the α-methylstyrene block was studied by thermogravimetric, dynamic mechanical and thermomechanical analysis. Mild decomposition conditions were required to avoid rapid depolymerization of the α-methylstyrene and subsequent plasticization of the imide block. The resulting foams showed the expected reduction in density with pore sizes ranging from ∼200Å to ∼1 µm in size, depending on the synthetic route and processing conditions employed.
Study of the polymerization of high-performance polymers by electrons and x-rays: 1. The case of polypropargylic-butanedioldimethacrylate systems
Authors: Grenier-Loustalot Marie-Florence , Denizot Vincent , Beziers Daniel
Published: August 2002

We have investigated the polymerization of polypropargylic butanedioldimeth-acrylate derivatives using electron and x-ray irradiation. The results obtained with the pure resin and carbon-fibre-based composites were compared in terms of kinetics, mechanisms and properties with those obtained by thermal polymerization.

Data gathered using a panoply of solid state physicochemical techniques have shown that these polymers are good systems for obtaining composites having high thermal stability at temperatures higher than 350°C.
Blends of an aromatic poly(etherimide) with acetylene-terminated polyisoimides
Authors: Mercer Frank W , Reddy Vijay N , McKenzie Martin T
Published: August 2002

A series of novel semi-interpenetrating networks (semi-1PNS) has been prepared and characterized. The semi-TPNs were prepared by blending a commercially available polyetherimide with commercially available acetylene-terminated polyisoimides. Thermal treatment of the polyetherimide/acetylene-terminated polyisoimide blends causes the acetylene-terminated polyisoimide to concurrently rearrange to a polyimide and to crosslink. The resulting semi-IPNs exhibit excellent mechanical performance and chemical resistance. The preparation and characterization of this system are described.
Preparation and properties of poly(etber ketone)s derived from 2,6-naphthalenedicarboxylic acid chloride
Authors: Tokai Masaya , Sakaguchi Yoshimitsu , Kato Yasuo
Published: August 2002

Poly(ether ketone)s derived from diphenyl ether and mixed diacid chlorides containing 2,6-naphthalenedicarboxyliUc acid chloride (NDC) with terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC) were prepared by Friedel-Crafts acylation in 1,2-dichloroethane with aluminium trichloride as a catalyst. Their thermal properties were widely controlled by changing the composition of diacid chlorides; the glass transision temperature was in the range of 156-203 °C and the melting temperature was 235-390 °C. The order of the structural effect of acid chlorides in increasing the glass transition temperature was NDC > TPC> IPC, and that in decreasing the gas permeability was IPC — NDC > TPC.
Synthesis of novel organic-soluble high-temperature aromatic polymers
Authors: Imai Yoshio
Published: August 2002

This paper reviews our current work on the synthesis of new organic-soluble aromatic polyamides and polyimides having high glass transition temperatures above 300 °C. Our strategy to achieve this goal is to introduce a bulky pendant phenyl group along the polymer backbone and to incorporate a crank and twisted non-coplanar structure into the polymer main chain.
Synthesis and characterization of extended poly(phenylquinoxalines) containing carbonyl, ether and sulphide linking groups
Authors: Singh Rajendra K , Mehta Rooma Mago , Bass R G
Published: August 2002

A series of eight novel extended poly(phenylquinoxalines) (PPQs) containing carbonyl, ether and sulphide linking groups were prepared by polycondensation of 4,4'-bis(phenylglyoxalyl-4-phenoxy-4'-benzoyl)diphenyl sulphide, I-D, and 4,4'-bis(phenyl glyoxalyl-4-phenylthio-4'-benzoyl)diphenyl sulphide, 2-D, with four aromatic bis(o-diamines) in m-cresol. The primary objective of this study was to correlate the effect of these linkages on the various properties such as solubility, thermal stability and glass transition temperature of the PPQs. Polymerization of 1-D was carried out in an oil bath maintained at 195-200C whereas polymerization of 2-D was performed at ambient temperature. The polymers prepared were soluble in m-cresol. dimethylsulphoxide, N,N-dimethylacetamide, I-methyl-2-pyrrolidinone and chlorinated hydrocarbon solvents, and formed tough transparent, yellow fingernail-creasable films from chloroform solutions. The inherent viscosities ranged between 0.44 and 0.96 dl g' '. The glass transition temperatures were nearly identical for both systems and ranged from 217-231 'C for polymers prepared from l-D and from 215-233"C for polymers prepared from 2-D. The PPQs having carbonyl and stJlphide linking groups had higher thermal stability in comparison to PPQs having carbonyl, ether and sulphide linkages. The temperature of 10% weight loss for I-D ranged from 484-496 'C in air and 485-516"C in helium whereas those for 2-D ranged from 538-579 XC in air and 522-549 in helium.
Processing and Properties of IM7/LARCTM-SCI Composite
Authors: Hou T H , Bryant R G
Published: August 2002

LARCTM-SCI (Langley Research Center - Semi-Crystaline polyImide) is an aromatic polyimide based on 3,4′-oxydianiline and 3,3′,4,4′-biphenyl tetracarboxylic dianhydride. This polyimide was synthesized and evaluated for use as a neat resin and a matrix resin for advanced composites. Three 30% w/w solids polyamic acid/ N-methypyrrolidone solutions were prepared using 2, 3 and 4% stoichiometric imbalances end-capped with phthalic anhydride to provide polyimides with theoretical number average molecular weights of approximately 22 800, 15 100 and 11 400 g mol−1 respectively. Unidirectional IM7 carbon fibre prepreg was prepared from these three resins using the Langley multipurpose tape machine. Thermal and rheological properties and the solvent/volatile depletion rates along with crystallization kinetics were characterized for the resin scraps taken from the prepreg tapes. Processing characteristics of the LARCTM-SCI resin were thoroughly understood from these results, and a workable moulding cycle was designed for this composite. Composite laminates were moulded at 410 °C at either 200 or 300 psi, which consistently yielded good consolidation and high-quality panels as measured by C-scan, acid digestion and optical photomicrography. The composite mechanical properties were also obtained. Short beam shear strength was 15 ksi at RT. Longitudinal flexural strength was 295 ksi at RT and 200 ksi at 177 °C. Excellent fracture toughness of 6.9 in-lb/in2 was obtained. Excellent values of transverse flexural strength and longitudinal tensile strength indicated a good translation of fibre properties into the composite. Un-notched longitudinal compression strength of 163 ksi was comparable to typical thermoplastic composites. An open hole compression strength of 55 ksi suggested good damage tolerance for this composite.
Propargylic Terminated Prepolymers. 2. Molten State Mechanisms and Kinetics of Difunctional Systems
Authors: Genier-Loustalot M F , Sanglar C
Published: August 2002

We have synthesized five dipropargylic compounds containing electron donor and acceptor substituents between the two phenyl groups. Based on physicochemical data obtained it is shown that heat-induced polymerization depends on the nature of the substituent. Thus, reaction kinetics are modified while molten state mechanisms involved remain identical (principal reaction: intramolecular ring formation; secondary reaction: formation of phenolic entities). The physicochemical techniques used to obtain these results were Fourier transform infrared spectroscopy (FT-IR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, correlated with chromatographic separation.
Synthesis and Properties of Poly(Arylene Ether Pyrazole)S
Authors: Srinivasan K R , Bass R G , Smith J G
Published: August 2002

Poly(arylene ether pyrazole)s containing N–H and N-phenyl groups have been prepared by the aromatic nucleophilic displacement reaction of two new bisphenols containing a pyrazole ring with activated aromatic dihalides in N,N-dimethylacetamide at 155 °C in the presence of anhydrous potassium carbonate. The polymers exhibited glass transition temperatures ( Tg) ranging from 190–296 °C and inherent viscosities from 0.44–1.96 dl g−1. Poly(arylene ether-pyrazole)s containing N–H groups exhibited higher Tg and mechanical properties than the corresponding N-phenyl-containing poly(arylene ether pyrazole)s. The chemistry, physical and mechanical properties of these polymers are discussed.
Poly(1, 3, 4-Oxadiazole-Amide)s Containing Pendent Phenoxy Groups
Authors: Hamciuc Corneliu , Hamciuc Elena , Bruma Maria
Published: August 2002

A series of new poly(1, 3, 4-oxadiazole-amide)s have been synthesized by solution polycondensation of aromatic diamines containing preformed 1, 3, 4-oxadiazole rings with phenoxyterephthalic diacid chloride or by the reaction of the same diacid chloride with p-aminobenzhydrazide resulting in a polyhydrazide-amide which was cyclodehydrated to the corresponding oxadiazolic structure. The new polymers were soluble or partially soluble in polar amidic solvents, were stable up to 375–400 °C in air and had a glass transition temperature in the range of 225–272 °C.
Propargylic- and Chromene-Terminated Prepolymers. 4. Influence of the Type of Catalyst on Reaction Mechanisms and Kinetics
Authors: Grenier-Loustalot M F , Sanglar C
Published: August 2002

The addition of catalyst to polymerize the propargylic function causes a decrease in the reaction onset temperature T0. Depending on the nature of the catalyst we demonstrate different reaction mechanisms involving the formation of the chromene group (as in the case of non-catalysed systems), of the Sabourin dimer, or the cyclooctatetraene structure in the molten state. We thus show that the catalytic effect is more determinant towards the propargylic function than towards the chromene group.
Lap Shear Bond Strength of Thermoplastic Polyimides and Copolyimides
Authors: Furukawa Nobuyuki , Yamada Yasuharu , Kimura Yoshiharu
Published: August 2002

Adhesion properties of various thermoplastic polyimides and copolyimides were studied in order to develop suitable heat resistant adhesive film with excellent hot-melt processability under moderate conditions and to discover the effect of polysiloxane units introduced as soft segments on the bond strength. The single-lap shear strength of the steel joints adhered with the polyimides and copolyimides was found to depend on the structure of the aromatic components: linear aromatic polyimides with multi-phenylene linkages and meta linkages, particularly those prepared from 3, 3′ 4, 4′-diphenylethertetracarboxylic dianhydride and 3, 3′ 4, 4′-benzophenonetetracarboxylic dianhydride, showed an increased lap shear strength. The introduction of polysiloxane segments into the polymide backbone increased not only the processability of adhesion, but also the lap shear strength, significantly. However, the shear strength was lowered at high temperature because the cohesive force of the polymer decreased with decreasing glass transition temperature. The adhesion strength was also influenced by such bonding conditions as pressure and temperature.
Polymerizable UV Stabilizers: I
Authors: Parmar Ramsinh J , Parmar Jayant S
Published: August 2002

The UV stabilizers 2-OH-4-allyloxybenzophenone and its oxime were prepared. They were copolymerized with styrene to give copolymers containing 2–8% UV stabilizers. The films were exposed to UV light and tested for any change in the carbonyl index, hydroxyl index, tensile strength, elongation at break and evaporation loss. The stabilization efficiency was evaluated by comparing with similar testing on pure polystyrene.
Electronic and Optical Parameters of the TGM-3 Photopolymer
Authors: Sahraoui B , Kityk I V , Czerwinski M , Kasperczyk J
Published: August 2002

Molecular properties of the TGM-3 photopolymer have been investigated using a HYPERCHEM 4.0 computer package. The geometry of this photopolymer was successfully optimized and the TGM-3 structure obtained shows a very complicated non-linear shape. The total charge density of TGM-3 is strongly nonuniform. C=O double chemical bonds are roughly perpendicular to a bent central chain. We have calculated a value of the HOMO–LUMO energy gap which is not in agreement with our experimental data for the fundamental absorption edge. A possible origin of this difference is suggested. One can expect that the TGM-3 properties have a strong influence on its solid many-component mixtures with other photopolymers.
Structures and Gas Separation Properties of Silicone-Containing Polyimides
Authors: Yamada Yasuharu , Furukawa Nobuyuki , Tujita Yoshiharu
Published: August 2002

In order to obtain polymer materials suitable for thermally stable gas separation membranes, silicone-containing polyimides (SPIs) with various chemical structures and silicone contents were prepared, and the relationship between the chemical structures and the gas separation properties was studied. The permeability of gases such as oxygen, nitrogen, carbon dioxide and methane increased with the silicone content, while the permselectivity decreased. Therefore the permeability and the permselectivity were found to be controlled by the silicone content as well as the chemical structure of the SPIs.
Electrical Conductivity of Pyrolysed Polyamides Derived from 1,4-Bis(2-Cyano-2-Carboxyvinyl)Benzene and Various Aromatic Diamines
Authors: Krontiras Christoforos A , Pisanias Michael N , Mikroyannidis John A , Georga Stavroula N
Published: August 2002

The electrical conductivity of three homopolyamides, synthesized from aromatic diamines and identified as PAM, PAP and PAS, was investigated as a function of temperature in the range 100–700 K, following pyrolysis for 24 h in an atmosphere of N2 at temperatures of 550, 700, 800 and 850 °C. X-ray profiles were recorded for the three polymers before and following pyrolysis. The non-heat-treated polymers are amorphous whereas a certain degree of crystallinity is observed following pyrolysis. The observed conductivity covered a range from 10−9 to 10 S cm−1 depending on the polymer and the pyrolysis temperature. The results suggest that the conductivity is thermally activated and is due to two mechanisms, the intra-chain conductivity and the inter-chain conductivity. The activation energy for the intra-chain mechanism varies from 0.36 to 0.01 eV and for the inter-chain mechanism the activation energy varies from 2.76 to 0.08 eV, depending on the pyrolysis temperature for both mechanisms.
Reception and rejection of science knowledge: choice, style and home culture
Authors: Solomon Joan
Published: August 2002

One reason why there is little public understanding of science concepts could be active personal rejection. There are many informal sources of scientific knowledge, but individual style and choice govern how and whether they are used. Other research shows that groups are interested in particular information, but that they reject science principles. Data from a study of students discussing issues from television show how they present themselves through their preferred knowledge sources. Finally I describe a home study of parents doing science investigations with primary-aged children. Interviews with the parents show that how they react to science and to education depends upon the home culture they have constructed. The parents reproduce this culture in the activities of their children, more or less strongly, and this affects their own acceptance or rejection of the scientific knowledge.
Mapping variety in public understanding of science
Authors: Bauer Martin , Schoon Ingrid
Published: August 2002

We analyse around 15 000 responses from 11 countries to the open survey question `please tell me in your own words, what does it mean to study something scientifically' in order to show cultural diversity in public representations of science. In past studies this question has been coded on a five-point rating scale that is used to rank scientific literacy across different countries. We develop, apply and evaluate an alternative coding frame. We show that our coding is more adequate, more reliable and produces less noise than the frame used by others to analyse responses to the same question. Multiple coding on five dimensions allows us to characterize people's understanding of science in terms of methods, institutions, effects, examples and level of differentiation of the response. We use correspondence analysis to characterize distinct response patterns in ten European countries and the USA. The data shows that no simple cultural division such as Protestant versus Catholic, or north-south divide, or Latin versus Anglo-Saxon fits the variance in the data. The paper closes with an agenda for future research in the area of public understanding of science and technology.
EICOS: a European Initiative for Communicators of Science
Authors: Waksman Byron H. , Adelmann-Grill Bernhard C. , Kreutzberg Georg W.
Published: August 2002

EICOS offers European science journalists from the print and broadcast media the opportunity to gain first-hand experience of working in a scientific laboratory. In 1992 EICOS obtained support and funds from major agencies, and in the Spring of 1993 twelve of the 58 applicants were accepted as EICOS Fellows. They worked during April-May 1993 at the Max Planck Institutes (MPI) for Biochemistry and for Psychiatry near Munich, Germany, at first on a one-week programme of laboratory exercises, demonstrations and lectures. Those Fellows staying for a longer period then participated in the daily life of the host laboratories. They also gave lectures to the MPI scientists on the problems of reporting science to the public. First evaluations of the experience by the Fellows and their laboratory hosts were generally positive, and plans for an expansion and reinforcement of the programme are now being considered.
The image of the scientist and its functions
Authors: Petkova Kristina , Boyadjieva Pepka
Published: August 2002

This study is an attempt to reveal the historical roots of the idealized image of the scientist, and its functions for the scientific community. The analysis is based on historical excursions into important periods of the development of science. The evidence reveals the specific ways and means of the idealization of the image of the scientist, the importance of this ideal for the social recognition of science, and the establishment and functioning of the scientific community. The image is also revealed by empirical data, i.e. content analysis of essays written by a sample of Bulgarian high-school students. The students shared representation comprises idealized elements. The historical analysis and the empirical data show that the idealized image of the scientist has become a means for recruitment to the scientific community and for regulating its relations with other social communities.
The use of scientific discourse by creation scientists: some preliminary findings
Authors: Locke Simon
Published: August 2002

A central issue to emerge from recent research into the public understanding of science concerns the methods of study adopted. A distinction is made here between the public understanding of science (meaning knowledge of scientific orthodoxy), and the public understanding of science (meaning what people take `science' to mean). This is used to consider the case of creation science, which is analysed using the method of discourse analysis developed initially by Gilbert and Mulkay. It is shown that creationists appear to employ similar discursive techniques and resources—supplemented by their alternative beliefs—to those used by orthodox scientists. Whilst acknowledging limitations of the creationist case, it is argued that it is sufficient to show the value of methods of study that are sensitive to possible contextual variations in the public understanding of science. It is suggested that more research of this nature is needed to determine the extent to which science is used as a resource of accounting, both alone and in conjunction with alternative discursive resources.
When wildlife make the news: an analysis of rural and urban north-central US newspapers
Authors: Corbett Julia B.
Published: August 2002

This research concerned newspaper coverage of wildlife in the north-central US: what kinds of animals make the news, who speaks on behalf of wildlife, and whether coverage differs in rural and urban newspapers. State wildlife officials dominated news coverage: they were the most frequently attributed news sources, and coverage focused on management actions and management conflicts. Game animals received the bulk of attention (81%), rather than endangered or threatened ones. Although species diversity is an important concept for the public's understanding of science, such an approach was not evident. Almost half of the 592 stories were found on weekly `outdoor' pages, the domain of game management information and little conflict. Rural newspapers differed significantly from urban ones: story themes in rural papers tended to be more `utilitarian' while urban themes were more `stewardship', Rural newspapers also were more likely to print `trophy photos' and less likely to discuss management conflicts.
Knowing your genes
Authors: Love Rosaleen
Published: August 2002

The gene is entering the vernacular in increasingly powerful images. Each day comes the announcement in the print and electronic media of the discovery of a new gene for a disease or an aspect of human behaviour. This article seeks to explore some representations of the gene in public culture in Australia today, in particular notions of death and the gene, jokes about genes, and genetic literacy.
A new approach to surveying public opinion on different areas of scientific research
Authors: Shibata Jiro
Published: August 2002

The public's attitude towards different areas of scientific research is an important element in formulating science and technology policy. This paper proposes a new approach to surveying public opinion on specific areas of scientific research. A preliminary study was conducted using this approach that found a difference of opinion between scientists and the public, demonstrating the significance of this kind of survey. Through conducting a regression analysis of the results of the survey, it is concluded that the most suitable way of grasping public opinion is to ask a question about the respondents' wish for the early realization of a scientific objective.
Scheduled science: TV coverage of science, technology, medicine and social science and programming policies in Britain and Germany
Authors: Göpfert Winfried
Published: August 2002

I present an analysis of the content, audience share and scheduling of TV coverage of science, technology, medicine and social science in Britain and Germany. The sample consists of all science-related programmes broadcast from October to December 1992 during broadly defined peak hours. Four British TV channels were compared with 16 German channels. Nine different content categories were defined, which exhibited some interesting differences. There were some differences in the programme makers' approach to different subjects such as medicine, environment and social sciences; and there were many differences in scheduling practices. The more competitive market in Germany leads to an even sharper separation between the public and the commercial sector, but a second distinction seems to be more important: the public sector, at least, tends to separate a more popular from a more specialist strand. Strategies for science broadcasting are discussed with comments from prominent science producers and editors in both Britain and Germany.
Teaching biotechnology: identity in the context of ignorance and knowledgeability
Authors: Michael Mike , Grinyer Anne , Turner Jill
Published: August 2002

This paper considers the sorts of identities constructed by biotechnology teachers for themselves, biotechnology and their students. Drawing upon insights from critical studies of the public understanding of science, we analyse teachers' views on biotechnology and the teaching of it. These views were partly derived from questionnaires and participant observation, though our main source of data were focus group discussions. Our analysis shows that the teachers held ambivalent views about their role and biotechnology. For example, on the one hand, science and biotechnology are `impure' in the sense of being part of the messy world of politics and ethics. Within this controversial domain, the teachers saw their role as one of assuring `balance' in which the students are exposed to both pro and con dimensions of biotechnology. On the other hand, science and biotechnology are `pure', part of an idealized realm in which useful scientific knowledge is produced. Biotechnology thus was `intellectually interesting in its own right'. We suggest that such ambivalence is not necessarily a problem, reflecting broader social trends.
Aversion preceding rejection: results of the Eurobarometer Survey 39.1 on biotechnology and genetic engineering in Austria
Authors: Torgersen Helge , Seifert Franz
Published: August 2002

In late 1994, we performed a representative survey on attitudes to biotechnology and genetic engineering in Austria using the questionnaire applied in the Eurobarometer survey 39.1 of 1993. The results showed that support for genetic engineering in Austria was low compared to support in the rest of Europe. However, risks were perceived as being comparatively low, and the demand for government control was below average. Together with the very low level of knowledge and the reluctant optimism towards new technologies, the data suggested that, in Austria, the low level of acceptance might have been influenced by a conservative attitude to new technology rather than by any developed perception of the associated risk. However, when in 1996 the first releases of genetically modified organisms in Austria triggered widespread rejection, this was accompanied by a growing awareness of risk. Thus a more or less unreflected aversion to biotechnology seemed to precede risk perception in Austria.
Language constraints in producing prefiguration posters for a scientific exhibition
Authors: Simonneaux Laurence , Jacobi Daniel
Published: August 2002

The museographic transposition of scientific knowledge leads notably to the preparation of exhibition posters. This is a delicate operation, on account of the constraints imposed by space, language, concepts and the text. These difficulties are even greater in the case of bovine reproduction biotechnologies, such as cloning, where knowledge is not yet stable. This paper deals with the choices made during the phase of museographic transposition. First of all, based on an epistemological approach, a historical analysis of knowledge-building underpins the choice of information to be presented. Language is then selected according to the linguistic analysis of a series of articles which popularize science. Finally, the posters are assessed by samples of potential visitors.
African-American responses to the Human Genome Project
Authors: Jackson Fatimah
Published: August 2002

Data generated by the Human Genome Project are expected to have a powerful impact on how we view human biodiversity. Given the history of past biomedical and quasi-genetic abuse inflicted upon Americans of African descent, it is significant that African-Americans have been at the forefront of calls for a variation-inclusive Human Genome Project database and for full participation in all aspects of the project. As articulated in the 1994 Manifesto on Genomic Studies among African-Americans, historically and demographically representative genomic sampling is directly linked to the potential for social justice and equal access to the project's anticipated value. Now, as the Human Genome Project turns its attention to the collection and evaluation of human sequence variation, it is important to concurrently develop research strategies that foster inclusion and collaboration and produce benefits that are accessible to all who have paid for the project's success.
Genetic privacy, discrimination, and the U.S. Congress
Authors: Frankel Mark S.
Published: August 2002

Advances in genetics research have fueled public debate over the use of genetic information about individuals and families by health insurers. Fears of discrimination based on one's genetic inheritance have prompted various private and public sector groups to press for restrictions on access to and use of genetic information in health insurance decisions. As a result, the U.S. Congress has considered several pieces of legislation that would impose such restrictions. This paper discusses the merging of several factors that are responsible for placing and maintaining this issue on the congressional policy agenda.
Public understanding of the environmental impact of road transport
Authors: Lane Ben
Published: August 2002

Policy makers are hoping that the public will assist in the move toward a sustainable transport system by purchasing alternatively fueled vehicles (AFVs), many of which are now available in the UK. But if the public's knowledge-base of transport issues is low, it seems unlikely that consumer behavior will change sufficiently enough to solve the problems associated with high levels of traffic pollution. To assess the extent of popular understanding, an open-ended questionnaire has been used to investigate the perceptions of the British public on issues relating to transport. Topics include the environmental impact of vehicle emissions and the level of awareness of other alternative transport technologies such as natural gas, fuel-cell, and hybrid vehicles. The focus is to identify the most common misconceptions, with a view to improving educational programs designed to encourage the uptake of AFVs.
Public Science Day and the public understanding of science in America
Authors: Daley Shane M.
Published: August 2002

Many countries around the world have instituted day-long or week-long events celebrating science and technology. This article describes the “Public Science Day” sponsored by the American Association for the Advancement of science, focusing especially on organizational context, goals, and activities.
The contribution of museums to scientific literacy: views from audience and museum professionals
Authors: Henriksen Ellen K. , Frøyland Merethe
Published: August 2002

The new goals outlined for museums in recent reports are in line with the efforts to improve the public's civic and practical scientific literacy. We have made a preliminary exploration of the potential of museums to provide information and experiences that the audience finds relevant in the context of science-related issues they encounter in their private or civic lives. We found that for a group of parents faced with the issue of radon in their children's school, two museums in Oslo were not seen as having such a function; neither did the parents expect museums to have such a role. Professionals from the two museums expressed similar attitudes. If this skepticism toward the new goals is widespread, museums face a great challenge concerning how to relate to the new goals. Based on our findings, we suggest some pertinent issues for future research.
Preparation of Electro-codeposited Film Consisting of Phthalocyanine and Perylene Derivatives
Authors: KUDO TERUHISA , KIMURA MUTSUMI , HANABUSA KENJI , SHIRAI HIROFUSA
Published: August 2002

A novel electro-codeposited film was homogeneously obtained on an indium tin oxide (ITO)-coated glass electrode by cathodic polarization of a solution of 2,9,16,23-tetracarboxyphthalocyaninatomagnesium(II) ( Mg II taPc ), N,N′-4-hydroxyphenyl-3,4,9,10-perylenetetra-carboxylic-diimide (4-hph-PTC) and ZnCl 2 as supporting electrolyte in N,N-dimethylformamide (DMF). The cyclic voltammogram for the codeposited film showed a reduction at −0.8 V vs SCE which was assigned to the reduction of Mg II taPc and one at −1.5 V vs SCE which was assigned to the reduction of 4-hph-PTC. A device based on the codeposited film was prepared by the formation of an aluminum electrode on the codeposited film. The device exhibited rectification and photoconduction. The results suggest that the codeposited film forms a number of p-n junction interfaces which are distributed on the ITO electrode.
Molecular Orientation of Perfluoro-vanadyl-phthalocyanine Examined by Electron Energy Loss Spectroscopy
Authors: HASHIMOTO SHUGO , ISODA SEIJI , KURATA HIROKI , LIESER GÜNTER , KOBAYASHI TAKASHI
Published: August 2002

A polymorph of perfluoro-vanadyl-phthalocyanine was found to be formed epitaxially on a potassium iodide monocrystalline surface by vacuum deposition. The molecular orientation and molecular packing of the polymorph were analysed by a combination of several electron microscopic methods, namely electron diffraction, high-resolution imaging and electron energy loss spectroscopy. The polymorph is different from the tetragonal polymorph previously obtained on potassium chloride and potassium bromide single crystals. The molecular packing of the new polymorph on potassium iodide was found to be orthorhombic with a = 1.48 nm , b = 0.37 nm and c = 27 nm , the ab-plane being parallel to the substrate surface.
Impacts of six genetic modifications of corn on feed cost and consumption of traditional feed ingredients
Authors: Yu Tun‐Hsiang , Baumel C. Phillip , Hardy Connie L. , McVey Marty J. , Johnson Lawrence A. , Sell Jerry L.
Published: August 2002

This study evaluates the impact of six genetically modified corns on swine and poultry feed costs and on the use of traditional feed ingredients. A Brill linear programming model was used to calculate least‐cost feed rations for broilers, layers, tom turkeys, 8–13 pound pigs and finisher hogs. This analysis indicates that likely price reductions in traditional feed ingredients will drive most of the current genetic modifications of corn out of the feed markets. Alternative methods of making genetically modified corns more competitive in the marketplace include stacking modifications to increase the gross value per bushel and lowering the costs of modified corn by reducing yield drag and seed costs. [EconLit Classification: Q17] © 2002 Wiley Periodicals, Inc.
Borrowing constraints and the agricultural investment decision process
Authors: Gutierrez Luciano
Published: August 2002

This paper develops a dynamic intertemporal model under the hypothesis of asymmetric information for the analysis of the rate of investment in the agricultural sector. The model stresses the importance of borrowing constraints for the investment decision of firms. Using the model we derive, following Abel and Blanchard's (1986) approach, an estimate for marginal Tobin's Q. We find that this series is positively and strongly related to the agricultural rate of investment in Italy during the period of 1960–1996. [Econ‐Lit Citations: Q14, E62, E22] © 2002 Wiley Periodicals, Inc.
Progressive multifocal leukoencephalopathy after fludarabine therapy for low‐grade lymphoproliferative disease
Authors: Vidarsson Brynjar , Mosher Deane F. , Salamat M. Shahriar , Isaksson Helgi J. , Onundarson Pall T.
Published: August 2002

Fludarabine is becoming the initial therapy for low‐grade lymphoproliferative malignancies, such as CLL and follicular lymphoma. Fludarabine is highly immunosuppressive in addition to being myelosuppressive and has been associated with neurotoxicity. Progressive multifocal leukoencephalopathy (PML) is an infection with JC virus of the white matter of the central nervous system seen mostly in immunosuppressed patients. We describe two patients treated with fludarabine who developed PML. Immunolabeling was positive for JCV in both patients, but PCR was repeatedly negative in one of them. We suggest that fludarabine may increase the risk of PML in patients with lymphoproliferative diseases. Am. J. Hematol. 70:51–54, 2002. © 2002 Wiley‐Liss, Inc.
Hematologic masquerade of rhabdomyosarcoma
Authors: Sandberg Avery A. , Stone John F. , Czarnecki Lawrence , Cohen Jesse D.
Published: August 2002

We present the case of a 12‐year‐old boy admitted with the diagnosis of acute leukemia, but found to have an infiltration of the marrow by an alveolar rhabdomyosarcoma (RMS) as determined by the cytogenetic demonstration of a t(2;13)(q25;q14). A primary tumor could not be found. With this case as a basis, we have tabulated features of all similar cases in the literature and discuss the possible optimal approaches to establishing the correct diagnosis in such patients. Am. J. Hematol. 68:51–57, 2001. © 2001 Wiley‐Liss, Inc.
Association of polymorphisms of the estrogen receptor gene with anxiety‐related traits in children and adolescents: A longitudinal study
Authors: Prichard Zoë , Jorm Anthony F. , Prior Margot , Sanson Ann , Smart Diana , Zhang Yafei , Huttley Gavin , Easteal Simon
Published: August 2002

Anxiety problems and associated temperamental traits are multifactorial, determined by the interaction of genetic and environmental factors. Genetic effects may involve both neurotransmitters and hormones. A good candidate gene for association with anxiety‐related traits is the estrogen receptor (ESRα). Estrogen exerts an effect on mood and behavior in humans through gene regulation on binding to estrogen receptor protein. Association between ESRα polymorphism and anxiety‐related traits was investigated in a cohort of 680 Australian adolescents studied from 4–8 months to 15–16 years of age. Genotype frequencies were estimated for polymorphic PvuII and XbaI restriction sites in intron 1 and a microsatellite [(TA)n] locus 5′ of ESRα. There was strong linkage disequilibrium between the three loci and a significant sex difference was observed in allele (for (TA)n, PvuII) and genotype (for XbaI) frequencies. There were no significant allelic or genotypic differences in anxiety‐related traits for the three loci tested. However, some significant associations were found for PvuII/(TA)n and XbaI/(TA)n two‐locus genotypes and anxiety, accounting for between 1.6% and 2.8% of the total variance for anxiety in this population. The discordance in Hardy‐Weinberg proportions at the XbaI locus between the sexes is an important finding, perhaps indicating a sex‐specific role for ESRα in fetal survival. © 2001 Wiley‐Liss, Inc.
Ring chromosome 6 in three fetuses: Case reports, literature review, and implications for prenatal diagnosis
Authors: Urban Maik , Bommer Christiane , Tennstedt Cornelia , Lehmann Katarina , Thiel Gundula , Wegner Rolf‐Dieter , Bollmann Rainer , Becker Rolf , Schulzke Ines , Körner Hannelore
Published: August 2002

Prenatal and postnatal findings in three fetuses with a ring chromosome 6 are presented, and the literature of this rare cytogenetic disorder is reviewed. The described fetuses illustrate the broad spectrum of the clinical manifestation of ring chromosome 6. In one fetus, the disorder was diagnosed incidentally by a routine amniocentesis due to advanced maternal age. The other two fetuses were hydrocephalic and had other congenital anomalies. Remarkably, the ring chromosome 6 tends to disappear in cultured amniotic fluid cells; karyotyping revealed complete or nearly complete monosomy 6. In contrast, the ring was preserved in high proportions of fetal leukocytes. Postnatal growth retardation is the only consistent finding of this chromosomal disorder. Maternal age is not significantly above average. An additional review of 20 literature cases revealed a striking tendency to hydrocephalus, either due to deficient brain growth or secondary to an aqueductal stenosis. Children with hydrocephalus and ring chromosme 6 tend to display facial dysmorphism and may have additional malformations, growth failure, eye anomalies, and seizures. In contrast, there are two reports on children with a ring chromosome 6 who had short stature, normal appearance, and a normal or almost‐normal psychomotor development. In such patients at the mild end of the clinical spectrum, the phenotype is basically restricted to what Kosztolányi. [1987: Hum Genet 75:174–179] delineated as “ring syndrome,” comprising “severe growth failure without major malformations, without a specific deletion syndrome, with only a few or no minor anomalies, and mild to moderate mental retardation.” This “ring syndrome” is considered to occur independently of the autosome involved in the ring formation. The overall impression from our cases and from the literature review of cases with ring chromosome 6 is that the karyotype‐genotype correlation is poor. This makes prognostic counseling of parents difficult and unsatisfactory. Serial targeted ultrasound examinations, especially of the brain, are decisive factors in elucidating the prognosis. © 2002 Wiley‐Liss, Inc.
High risk of malignancy in mosaic variegated aneuploidy syndrome
Authors: Jacquemont Sébastien , Bocéno Michelle , Rival Jean Marie , Méchinaud Françoise , David Albert
Published: August 2002

Fourteen cases of mosaic variegated aneuploidy (MVA) syndrome have been reported in the last 10 years. The phenotype of this rare condition has been quite consistent: severe microcephaly, growth deficiency, mild physical anomalies, and mental retardation. We describe here a young boy in whom MVA syndrome is associated to myelodysplasia with a monosomy 7 bone marrow clone. At the age of 3 years, myelodysplasia progressed to an acute lymphoblastic leukemia, and the patient died soon after. Several syndromes with short stature and severe microcephaly, such as the Seckel and Nijmegen syndromes, comprise hematological findings and chromosome instability. However, chromosome instability was not comfirmed in our patient. MVA with hematological findings has not been reported before, but 3 patients of 14 (21%) have developed a malignancy (rhabdomyosarcoma, acute lymphoblastic leukemia, and nephroblastoma). Therefore, we propose that MVA is a condition predisposing to neoplasia. © 2002 Wiley‐Liss, Inc.
Association study of MAO‐A, COMT, 5‐HT2A, DRD2, and DRD4 polymorphisms with illness time course in mood disorders
Authors: Cusin Cristina , Serretti Alessandro , Lattuada Enrico , Lilli Roberta , Lorenzi Cristina , Smeraldi Enrico
Published: August 2002

The aim of our study was to investigate a possible influence of monoamine oxydase A (MAO‐A), catechol‐O‐methyltransferase (COMT), serotonin receptor 2A (5‐HT2A), dopamine receptor D2 (DRD2), and dopamine receptor D4 (DRD4) gene variants on timing of recurrence in mood disorders. Gene variants were determined using PCR‐based techniques in 550 inpatients affected by recurrent mood disorders (major depressives: n = 212; bipolars: n = 338), rapid cycling mood disorder (n = 81), and 663 controls. We investigated possible genetic influences by comparing illness time course of subjects subdivided according to genotype using multivariate analysis of variance (MANOVA). We could not observe a significantly different time course. No demographic and clinical variables such as sex, age or polarity of onset, presence of psychotic features, genetic loading, or education level influenced the observed results. Our results suggest that MAO‐A, COMT, 5‐HT2A, DRD2, and DRD4 gene variants are not involved in susceptibility toward different time courses in mood disorders. © 2002 Wiley‐Liss, Inc.
Arsenic pollution of groundwater in Bangladesh
Authors: Tanabe Kimiko , Yokota Hiroshi , Hironaka Hiromi , Tsushima Sachie , Kubota Yoshihiro
Published: August 2002

Arsenic concentrations in groundwater around the village of Samta, Jessore District, Bangladesh were measured. Distribution patterns of arsenic in groundwater were determined. Arsenic concentrations in drinking water tubewells mostly exceeded WHO guidelines. Copyright © 2001 John Wiley & Sons, Ltd.
Crystallization and crosslinking of polyamide‐1010 under elevated pressure
Authors: Yang Jun , Dong Wenfei , Luan Yucheng , Liu Jingjiang , Liu Shue , Guo Xingyuan , Zhao Xudong , Su Wenhui
Published: August 2002

The structure and thermal properties of polyamide‐1010 (PA1010), treated at 250°C for 30 min under pressures of 0.7–2.5 GPa, were studied with wide‐angle X‐ray diffraction (WAXD), infrared (IR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Crystals were formed when the pressures were less than 1.0 GPa or greater than 1.2 GPa. With increasing pressure, the intensity of the diffraction peak at approximately 24° was enhanced, whereas the peak at approximately 20° was depressed. The triclinic crystal structure of PA1010 was preserved. The highest melting temperature of the crystals obtained in this work was 208°C for PA1010 treated at 1.5 GPa. Crosslinking occurred under pressures of 1.0–1.2 GPa. Only a broad diffraction peak centered at approximately 20° was observed on WAXD patterns, and no melting and crystallization peaks were found on DSC curves. IR spectra of crosslinked PA1010 showed a remarkable absorption band at 1370 cm−1. The NH stretching vibration band at 3305 cm−1 was weakened. Crystallized PA1010 had a higher thermal stability than crosslinked PA1010, as indicated on TGA curves by a higher onset temperature of decomposition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2522–2527, 2002
Porous properties of poly(glycidyl methacrylate‐co‐trimethylolpropane trimethacrylate) resins synthesized by suspension polymerization
Authors: Qi Tao , Sonoda Akinari , Makita Yoji , Kanoh Hirofumi , Ooi Kenta , Hirotsu Takahiro
Published: August 2002

Porous copolymer beads of 2,3‐epoxypropyl methacrylate (glycidyl methacrylate, GMA) crosslinked with 2‐ethyl‐2‐(hydroxymethyl)‐propan‐1,3‐diol trimethacrylate (trimethylolpropane trimethacrylate, TRIM) were prepared with toluene and octan‐2‐one as porogens by suspension polymerization. With an increase in the ratio of porogen to monomer, the total pore volume of poly(GMA‐co‐TRIM) increases significantly, whereas the surface area hardly changes. The total pore volume also depends on the nature of the porogen, exhibiting a maximum at the larger GMA contents in the monomer mixture of 50% v/v with octan‐2‐one and of 60% v/v with toluene, compared to that at the GMA content of 25% v/v with a 9/1 v/v mixture of cyclohexanol and dodecan‐1‐ol [Verweij, P. D.; Sherrington, D. C. J Mater Chem 1991, 1 (3), 371]. The surface area decreases significantly with an increase in the ratio of GMA to TRIM, almost regardless of the nature of the porogen. The porous properties of poly(GMA‐co‐TRIM) was well explained on the basis of phase separation, particularly taking into account not only the solubility parameters of the resulting polymer network and porogen but also the rigidity of TRIM. The porous poly(GMA‐co‐TRIM) may be a promising polymer matrix of novel materials for separation of boron isotopes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2374–2381, 2002