bluuebunny/crossref_metadata_2025 huggingface dataset:
Aromaticity and antiaromaticity: what role do ionic configurations play in delocalization and induction of magnetic properties?
Authors: Shurki Avital , Hiberty Philippe C. , Dijkstra Fokke , Shaik Sason
Published: September 2003

CmHm (m= 4, 6, 8) species are analyzed in Dmh and D(1/2)mh geometries by means of valence bond (VB) calculations. The fundamental factors that distinguish aromatic and antiaromatic modes of electron delocalization are elucidated by analysis of the mixing between the covalent‐state and ionic structures that distribute the electrons in all possible modes available in the cycle. The major difference found is that, by contrast to the aromatic species where all the ionic structures mix into the covalent state, in the antiaromatic species the set of diagonal‐ionic structures is excluded from mixing with the covalent‐state, owing to its fundamental symmetry features. This exclusion of covalent–ionic mixing is expressed at the most fundamental building blocks of the wavefunction; the spin‐alternant state. The spin‐alternant state is a resonance hybrid of the two spin‐alternant determinants. This resonance hybrid will support a collective motion of the pπ‐electrons around the perimeter of the ring only if ionic structures can mix to mediate the electronic flow. It is shown that in aromatic species all the ionic structures mix and sustain a continuous electronic flow around the ring perimeter. By contrast, owing to the exclusion of the diagonal‐ionic structures in antiaromatic compounds, the electronic flow in antiaromatic species is interrupted. Symmetry and angular momentum analyses of the ground state in the presence of an external magnetic field show that the properties of the spin‐alternant state can qualitatively describe the magnetic properties of the two classes. The continuous flow of π‐electrons mediated by the ionic structures of aromatic species is responsible for the enhanced diamagnetism of these species. By contrast, paramagnetic π‐ring current in antiaromatic species becomes possible only in the presence of the magnetic field that allows the mixing of the otherwise excluded ionic structures. Copyright © 2003 John Wiley & Sons, Ltd.
Potential‐controlled coordination of coumarin to an Au(210) electrode surface
Authors: Iannelli Anna , Lipkowski Jacek
Published: September 2003

Adsorption of coumarin on an Au(210) single‐crystal electrode was investigated using chronocoulometry and phase‐sensitive a.c. voltammetry. The adsorption parameters, such as the relative Gibbs surface excess, the Gibbs energies of adsorption and the electrosorption valencies, were calculated. The results suggest that coumarin molecules assume a flat, π‐bonded orientation on the Au(210) surface. The zero coverage Gibbs energy of adsorption at the potential of maximum adsorption is −42 kJ mol−1, which is a value typical of chemisorption. The adsorption of coumarin on the Au(210) surface was compared with adsorption at the (111) and (100) planes of gold. Copyright © 2003 John Wiley & Sons, Ltd.
Role of CH···O hydrogen bonds in the ionic complexes of 1,8‐bis(dimethylamino)naphthalene
Authors: Wozniak Krzysztof , Mallinson Paul R. , Smith Garry T. , Wilson Chick C. , Grech Eugeniusz
Published: September 2003

On the basis of experimental charge density distributions in a series of ionic complexes of 1,8‐bis(dimethylamino)naphthalene (DMAN) with four different acids, 1,2,4,5‐benzenetetracarboxylic acid (pyromellitic acid), 4,5‐dichlorophthalic acid, dicyanoimidazole ando‐benzoic sulfimide dihydrate (saccharin), the role of minor CH···O hydrogen bonds was analysed. We propose a multicentre model of hydrogen bonding in proton sponges {[Me2NH···.NMe2]+··· Xδ−}. It appears that weak interactions of electronegative atoms with the nearest methyl hydrogen atoms can influence the location of the proton in the intramolecular {NH···N}+hydrogen bridge. In the case of CH···O hydrogen bonds, the amount of electron density in the donor CH bonds involved in hydrogen bonding is slightly larger than that in those CH from the same methyl group which are not involved in hydrogen bonding. Numerical values of the Laplacian follow a reverse relation (they are smaller for the donor CH bonds). Both of these critical point parameters (rho and Laplacian) are linearly dependent on the length of interaction line. An increase in the amount of electron density in the H···O hydrogen bonding is associated with an increase in electron density in the donor C(methyl)H donor bond, which confirms the mainly ionic nature of such weak hydrogen bonds. Copyright © 2003 John Wiley & Sons, Ltd.
Influence of solvent polarity on the stereoselectivity of the uncatalyzed [4+2] cycloaddition of cyclopentadiene to an N,N′‐fumaroyl bis‐(six‐membered ring [(2R)‐10a‐homobornane‐10a,2‐sultam])
Authors: Pia̧tek Anna , Chapuis Christian , Jurczak Janusz
Published: September 2003

A new six‐membered ring (2R)‐bornane‐10a,2‐sultam was tested as chiral auxiliary for the [4+2] cycloaddition of cyclopentadiene to the bis‐fumaroyl derivative (−)‐1f and shows under chelating conditions similar complete selectivity to Oppolzer's sultam. Inversion of the π‐face selectivity is nevertheless observed under uncatalyzed conditions under the influence of solvent polarity, varying from 82% de for the (2R,3R) cycloadduct 2f in trifluoroethanol to 70% de in favour of the (2S,3S) diastereoisomer in hexane as solvent. A predictive linear correlation is observed between the stereoselectivity and the solvent parameters according to the Abboud–Abraham–Kamlet‐Taft model. PM3 calculations allowed a rationalization of these results based on the transition‐state dipole moment. Illustrated by an x‐ray analysis of cycloadduct (2S,3S)‐2f, the main structural differences and influences in terms of steric and stereoelectronic factors are discussed by comparison of the five‐ versus six‐membered ring homologues. Copyright © 2003 John Wiley & Sons, Ltd.
The emergence of a new paradigm in ape language research
Authors: Shanker Stuart G. , King Barbara J.
Published: September 2003

In recent years we have seen a dramatic shift, in several different areas of communication studies, from an information-theoretic to a dynamic systems paradigm. In an information processing system, communication, whether between cells, mammals, apes, or humans, is said to occur when one organism encodes information into a signal that is transmitted to another organism that decodes the signal. In a dynamic system, all of the elements are continuously interacting with and changing in respect to one another, and an aggregate pattern emerges from this mutual co-action. Whereas the information-processing paradigm looks at communication as a linear, binary sequence of events, the dynamic systems paradigm looks at the relation between behaviors and how the whole configuration changes over time.

One of the most dramatic examples of the significance of shifting from an information processing to a dynamic systems paradigm can be found in the debate over the interpretation of recent advances in ape language research (ALR). To some extent, many of the early ALR studies reinforced the stereotype that animal communication is functional and stimulus bound, precisely because they were based on an information-processing paradigm that promoted a static model of communicative development. But Savage-Rumbaugh's recent results with bonobos has introduced an entirely new dimension into this debate. Shifting the terms of the discussion from an information-processing to a dynamic systems paradigm not only highlights the striking differences between Savage-Rumbaugh's research and earlier ALR studies, but further, it sheds illuminating light on the factors that underpin the development of communication skills in great apes and humans, and the relationship between communicative development and the development of language.
The cognitive functions of language
Authors: Carruthers Peter
Published: September 2003

This paper explores a variety of different versions of the thesis that natural language is involved in human thinking. It distinguishes amongst strong and weak forms of this thesis, dismissing some as implausibly strong and others as uninterestingly weak. Strong forms dismissed include the view that language is conceptually necessary for thought (endorsed by many philosophers) and the view that language is de facto the medium of all human conceptual thinking (endorsed by many philosophers and social scientists). Weak forms include the view that language is necessary for the acquisition of many human concepts and the view that language can serve to scaffold human thought processes. The paper also discusses the thesis that language may be the medium of conscious propositional thinking, but argues that this cannot be its most fundamental cognitive role. The idea is then proposed that natural language is the medium for non-domain-specific thinking, serving to integrate the outputs of a variety of domain-specific conceptual faculties (or central-cognitive “quasi-modules”). Recent experimental evidence in support of this idea is reviewed and the implications of the idea are discussed, especially for our conception of the architecture of human cognition. Finally, some further kinds of evidence which might serve to corroborate or refute the hypothesis are mentioned. The overall goal of the paper is to review a wide variety of accounts of the cognitive function of natural language, integrating a number of different kinds of evidence and theoretical consideration in order to propose and elaborate the most plausible candidate.
Ethnography should replace experimentation
Authors: Armstrong David F.
Published: September 2003

This paper points to the need in ape language research to shift from experimentation to ethnography. We cannot determine what goes on inside the head of an ape when it communicates with a human being, but we can learn about the nature and content of the communication that occurs in such face-to-face interaction. This information is fundamental for establishing a baseline for the abilities of an ape-human common ancestor.
The proper study of chimpkind
Authors: Gardner R. Allen
Published: September 2003

The target article issues a stirring call for more appropriate treatment of chimpanzees in experimental laboratories. This commentary heartily endorses that position with examples of methods and results found in sign language studies of cross-fostered chimpanzees.
Language isn't quite that special
Authors: Bryson Joanna J.
Published: September 2003

Language isn't the only way to cross modules, nor is it the only module with access to both input and output. Minds don't generally work across modules because this leads to combinatorial explosion in search and planning. Language is special in being a good vector for mimetics, so it becomes associated with useful cross-module concepts we acquire culturally. Further, language is indexical, so it facilitates computationally expensive operations.
The developmental cognitive neuroscience approach to the study of developmental disorders
Authors: Temple Elise
Published: September 2003

Functional magnetic resonance imaging studies of developmental disorders and normal cognition that include children are becoming increasingly common and represent part of a newly expanding field of developmental cognitive neuroscience. These studies have illustrated the importance of the process of development in understanding brain mechanisms underlying cognition and including children in the study of the etiology of developmental disorders.
Models of atypical development must also be models of normal development
Authors: Westermann Gert , Mareschal Denis
Published: September 2003

Connectionist models aiming to reveal the mechanisms of atypical development must in their undamaged form constitute plausible models of normal development and follow a developmental trajectory that matches empirical data. Constructivist models that adapt their structure to the learning task satisfy this demand. They are therefore more informative in the study of atypical development than the static models employed by Thomas & Karmiloff-Smith (T&K-S).
Bilingual inner speech as the medium of cross-modular retrieval in autobiographical memory
Authors: Schrauf Robert W.
Published: September 2003

Carruthers’ notion that natural language(s) might serve as the medium of non-domain-specific, propositionally based inferential thought is extended to the case of effortful retrieval of autobiographical memory among bilinguals. Specifically, the review suggests that the resources of bilingual inner speech might play a role in the cyclical activation of information from various informational domains during memory retrieval.
Guest Editor's Foreword
Authors: MESYATS GENNADY A.
Published: September 2003

It is my pleasure to present the Special Issue of Laser and Particle Beams devoted to the 25th anniversary of the Institute of High Current Electronics (IHCE) of the Russian Academy of Sciences Siberian Division.
Decimeter-band frequency-tunable sources of high-power microwave
pulses
Authors: KOROVIN SERGEI D. , KURKAN IVAN K. , LOGINOV SERGEY V. , PEGEL IGOR V. , POLEVIN SERGEI D. , VOLKOV SERGEI N. , ZHERLITSYN ANDREY A.
Published: September 2003

This article describes S-band sources of high-power microwave
(HPM) pulses: a resonant backward wave oscillator (BWO) producing
∼5-GW, 100-J pulses, based on the SINUS-7 electron accelerator,
and a double-section vircator with a peak power of ∼1 GW
and a pulse width of 20–50 ns, powered from either the
SINUS-7 accelerator or the MARINA inductive-store pulse driver
with a fuse opening switch.
COMPETENCE SIMILARITIES BETWEEN NATIVE AND NEAR-NATIVE SPEAKERS
Authors: Montrul Silvina , Slabakova Roumyana
Published: September 2003

It has been suggested that tense and aspect distributions are very difficult to learn in a second language (L2), they are prone to fossilize universally, and their interpretive properties are subject to a critical period (Coppieters, 1987). This study focuses on the acquisition of the semantic implications of the preterite-imperfect contrast in Spanish by English-speaking individuals of very advanced proficiency in Spanish who were not living in a Spanish-speaking country. By assuming that aspect is encoded in a functional category where the features [+/-perfective] are checked, depending on the language (Giorgi & Pianesi, 1997), this study asks whether ultimate attainment in the aspectual domain is possible and whether features of functional categories not selected in early childhood are subject to a critical period, as Hawkins and Chan's (1997) Failed Formal Features Hypothesis states. Experimental evidence from two tasks probing the interpretations of perfective and imperfective aspectual forms in Spanish suggests that many learners (almost 30%) in our total subject pool (including advanced to near-native speakers) and 70% of the near-native group performed like native speakers on all sentence types in all tasks. Although aspect is certainly a difficult area to master, particularly because the meanings of the imperfect are acquired quite late, L2 learners are clearly able to overcome the parametric options of their native language. At least for this domain, it is suggested that access to Universal Grammar does not necessarily decay with age in L2 acquisition.
INDIVIDUAL FREEDOM IN LANGUAGE TEACHING: HELPING LEARNERS TO DEVELOP A DIALECT OF THEIR OWN. Christopher Brumfit. Oxford: Oxford University Press, 2001. Pp. xvi + 208. $29.95 paper.
Authors: Bender Linda A.
Published: September 2003

In this volume Brumfit provides a detailed, yet highly readable, analysis of many problems that at least partially arise from viewing language as a static code. He describes language as a dynamic force that interacts with other social forces and practices and as a process that is permeable, variable, and useful. He argues that the best way to teach, research, and plan language policy is to recognize and enhance the users' abilities to use language for their own permeable, variable, and unpredictable purposes.
What Front‐Line CBO Staff Can Tell Us About Culturally Anchored Theories of Behavior Change in HIV Prevention for Asian/Pacific Islanders
Authors: Yoshikawa Hirokazu , Wilson Patrick A. , Hsueh JoAnn , Rosman Elisa A. , Chin John , Kim Jennifer H.
Published: September 2003

Few rigorously tested primary prevention programs have been developed to prevent HIV infection among immigrant communities in the United States. This is in part because of the lack of culturally specific behavioral theories that can inform HIV prevention for immigrant communities in the United States. This article aims to develop such theories for a population—Asian/Pacific Islanders (A/PIs) immigrant communities—who have been overlooked in theory development and program evaluation. Frontline community‐based organization (CBO) peer educators, an underutilized source of expertise regarding cultural factors specific to HIV infection among A/PI communities, are the sample of study Asian/Pacific Islander peer educators working at an urban AIDS service organization devoted to health promotion for this population; (N=35). They were interviewed to examine (1) detailed narratives describing instances of behavior change and (2) culturally anchored theories of behavior change which the narratives imply. Theories of the influence of positive cultural symbols on the taboo of HIV/AIDS, moderators of the effectiveness of social network influences on behavior change, and setting‐ and community‐level processes predicting HIV risk behavior were implicit in the peer educators' narratives. Implications for future research, methodology and prevention practice are discussed.
“Talking About Chance”: The Presentation of Risk Information During Genetic Counseling for Breast and Ovarian Cancer
Authors: Hallowell Nina , Statham Helen , Murton Frances , Green Jo , Richards Martin
Published: September 2003

Using observations, questionnaires, and interviews, this study describes the formats used to present risk information during genetic counseling for breast and ovarian cancer. Counselees' preferences for different types of qualitative and quantitative presentation formats are also discussed. The data indicate that there is considerable variation in the presentation of risk information both within and between consultations. The counselees were positive about the way the counselors had described their risk. Seventy‐three percent of the sample expressed a preference for risk to be described using quantitative formats, and there was little difference in the number who stated a preference for percentages, proportions, or population comparisons. Comparing preferred formats with those used in the consultations indicated that in over 40% of cases, risk information was not presented in the counselees' preferred quantitative format. This descriptive study raises questions about the presentation of risk information which warrant further research.
Knowledge of Breast Cancer Genetics Among Breast Cancer Patients and First‐Degree Relatives of Affected Individuals
Authors: Wonderlick Aimee L. , Fine Beth A.
Published: September 2003

The cloning of BRCA1, a susceptibility gene for inherited breast cancer, has made genetic screening possible for individuals and families whose medical histories are suggestive of an inherited predisposition to breast cancer. To date, few systematic attempts have been made to determine the level of knowledge about breast cancer genetics among women who are likely to seek BRCA1 screening when it becomes widely available. The present study attempted to assess the general knowledge about BRCA1 mutations in two groups: (1) first‐degree relatives (FDRs) of breast cancer patients; and (2) women with a previous diagnosis of breast cancer. A self‐administered, thirty‐item questionnaire was developed through a pilot study. Ten of the items were objective, factual questions about breast cancer genetics. Responses to these questions were used to generate an overall knowledge score for each respondent. The study population was moderately knowledgeable about breast cancer genetics, with an average score of 5.35 out of 10. Counselors should not underestimate the importance of evaluating each counselee's existing knowledge about breast cancer, which can affect the provision and reception of genetic information. In particular, specific areas of knowledge that may be confusing or misunderstood were identified and these topics are discussed in detail.
Family, School, and Community Factors and Relationships to Racial–Ethnic Attitudes and Academic Achievement
Authors: Smith Emilie Phillips , Atkins Jacqueline , Connell Christian M.
Published: September 2003

This study examined family, school, and community factors and the relationships to racial–ethnic attitudes and academic achievement among 98 African American fourth‐grade children. It has been posited that young people who feel better about their racial–ethnic background have better behavioral and academic outcomes, yet there is a need for more empirical tests of this premise. Psychometric information is reported on measures of parent, teacher, and child racial–ethnic attitudes. Path analysis was used to investigate ecological variables potentially related to children's racial–ethnic attitudes and achievement. Parental education and level of racial–ethnic pride were correlated and both were related to children's achievement though in the final path model, only the path from parental education level was statistically significant. Children whose teachers exhibited higher levels of racial–ethnic trust and perceived fewer barriers due to race and ethnicity evidenced more trust and optimism as well. Children living in communities with higher proportions of college‐educated residents also exhibited more positive racial–ethnic attitudes. For children, higher racial–ethnic pride was related to higher achievement measured by grades and standardized test scores, while racial distrust and perception of barriers due to race were related to reduced performance. This study suggests that family, school, and community are all important factors related to children's racial–ethnic attitudes and also to their academic achievement.
Underemployment in America: Measurement and Evidence
Authors: Jensen Leif , Slack Tim
Published: September 2003

An important way in which employment hardship has come to be conceptualized and measured is as underemployment. Underemployment goes beyond mere unemployment (being out of a job and looking for work), to include those who have given up looking for work, part‐time workers whose employer(s) cannot give them full‐time work, and the working poor. To provide needed background for the other articles in this special issue, we trace the history of the concept of underemployment, review existing empirical literature, offer a critique of the measurement of underemployment as conventionally operationalized, and provide up‐to‐date evidence on the trends and correlates of underemployment in the United States.
Economic Antecedents of Foster Care
Authors: Catalano Ralph , Lind Samuel , Rosenblatt Abram , Novaco Raymond
Published: September 2003

Individual and ecological research suggests that rising unemployment may affect the incidence of violence through two countervailing mechanisms suggested by frustration–aggression theory. The first, or provocation effect, assumes increased violence among persons who feel anger because they believe their job loss was arbitrary. The second, or inhibition effect, posits less violence among employed persons who attempt to reduce their chances of job loss by curtailing behavior objectionable to employers. The literature also reports that these mechanisms affect victimization measured as foster care sought by the state for abused children. The foster care finding, although consistent with theory and important for basic as well as applied reasons, arises from methods that cannot rule out several rival hypotheses. We revisit this research and apply improved methods to test the reported association in Los Angeles and San Francisco counties. We find that, as implied by the provocation and inhibition mechanisms, differences in monthly prevalence of foster care placements increase with modest increases in unemployment but decline when unemployment becomes much higher than usual levels.
Spring mesozooplankton communities in the epipelagic Ionian Sea in relation to the Eastern Mediterranean Transient
Authors: Mazzocchi M. G. , Nervegna D. , D'Elia G. , Di Capua I. , Aguzzi L. , Boldrin A.
Published: September 2003

The present work on mesozooplankton of the Ionian Sea is part of a study aimed at assessing if the epipelagic communities had been affected by the changes in circulation (named EMT, Eastern Mediterranean Transient) observed in the eastern Mediterranean starting from 1988 as a transient effect of climate forcing. A temporal comparison was performed on data obtained in the springs of 1999 and 1992, periods characterized by opposite patterns in the upper circulation that in 1998 reversed from an anticyclonic to a cyclonic flow. A spatial comparison was performed on the data collected in 1999 from areas that previous oceanographic surveys had shown to be diversely affected by the EMT. Interannual differences were observed in the distribution of mesozooplankton abundance in the upper layer that might be related to the EMT dynamics and the effects of the reversed circulation. In 1999, abundance and composition of epipelagic mesozooplankton differed between the northwestern and eastern areas of the Ionian Sea. The distribution of species, trophic groups and copepod gut pigments suggested that different pelagic food webs took place at the opposite sides of the basin. A “classic” type food web prevailed in the northwestern, more productive area, whereas the microbial links prevailed in the eastern, more oligotrophic area. The characteristics of the northwestern area may in large part be due to the enrichment effects of the cyclonic circulation enhanced by the nutricline uprise due to the EMT, and to the interaction between the cyclonic circulation and the continental slope.
Asymmetric deformation in the backarc region of the Kuril arc, northwest Pacific: New insights from analogue modeling
Authors: Schellart W. P. , Jessell M. W. , Lister G. S.
Published: September 2003

The Eocene to middle/late Miocene tectonic evolution of the Kuril arc and backarc region has been simulated with analogue experiments. The experiments simulate asymmetric deformation in the overriding plate due to anticlockwise rollback of the subducting Pacific plate. The results show the formation of a N‐S to NE‐SW‐oriented dextral shear zone near the far edge of the retreating boundary analogous to the Sakhalin‐Hokkaido dextral shear zone. Contemporaneously, normal faults and grabens form, striking parallel to the retreating boundary near the far edge but striking more oblique near the hinge point and away from the retreating boundary. This is similar to extensional structures observed in the Kuril Basin and the Sea of Okhotsk. Furthermore, the model shows that the amount of extension progressively decreases away from the retreating boundary. This appears to have also happened in the Kuril‐Okhotsk region, as evidenced by crustal thickness variation in the region. Finally, the model results show that extension is increasingly accommodated by the region close to the retreating boundary with progressive deformation. This can account for the Eocene‐early Miocene extension in the Sea of Okhotsk followed by Miocene spreading in the Kuril Basin.
Analysis of pore‐scale nonaqueous phase liquid dissolution in etched silicon pore networks
Authors: Chomsurin Cheema , Werth Charles J.
Published: September 2003

Predicting the dissolution rate of nonaqueous phase liquids (NAPLs) in groundwater is difficult, as the effects of variable pore and NAPL blob geometry are poorly understood. To elucidate these effects, fluorescence microscopy and digital image analysis were used to quantify the size and location of variably distributed NAPL blobs during dissolution in homogeneous and heterogeneous pore networks etched into silicon wafers. Results show that the dissolution rate constant (expressed as the Sherwood number, Sh) is relatively constant regardless of pore and NAPL blob geometry when the average mass transfer length scale remains constant during dissolution. Results also show that Sh increases with Peclet (Pe) between 2 and 26 and then levels off. The limiting value of Sh reached depends on the average diffusion length scale; this length scale was directly calculated and found to vary depending on the pore and NAPL blob geometry. For example, the average diffusion length scale decreases (and Sh increases) as the pore throat width to grain diameter increases. Last, results show that the volumetric NAPL content (θn) is linearly related to the specific NAPL‐water interfacial area (ait) over much of the dissolution process. However, this relationship depends on the pore and blob size distribution. For example, when multipore blobs control dissolution, the relationship between these parameters will change as smaller blobs dominate dissolution at low θn. These results are important because existing mass transfer correlations do not account for limiting values of Sh that can be obtained at high Pe for the effect of blob or pore geometry on the average diffusion length scale (and therefore on Sh) or for the effect of pore geometry and transient blob size distribution on the relationship between ait and θn.
Stability analysis of gravity‐driven infiltrating flow
Authors: Egorov Andrey G. , Dautov Rafail Z. , Nieber John L. , Sheshukov Aleksey Y.
Published: September 2003

Stability analysis of gravity‐driven unsaturated flow is examined for the general case of Darcian flow with a generalized nonequilibrium capillary pressure‐saturation relation. With this nonequilibrium relation the governing equation is referred to as the nonequilibrium Richards equation (NERE). For the special case where the nonequilibrium vanishes, the NERE reduces to the Richards equation (RE), the conventional governing equation for describing unsaturated flow. A generalized linear stability analysis of the RE shows that this equation is unconditionally stable and therefore not able to produce gravity‐driven unstable flows for infinitesimal perturbations to the flow field. A much stronger result of unconditional stability for the RE is derived using a nonlinear stability analysis applicable to the general case of heterogeneous porous media. For the general case of the NERE model, results of a linear stability analysis show that the NERE model is conditionally stable, with lower‐frequency perturbations being unstable. A result of this analysis is that the nonmonotonicity of the pressure and saturation profile is a requisite condition for flow instability.
Low energy charged particles in the high latitude heliosphere: Comparing solar maximum and solar minimum
Authors: Maclennan C. G. , Lanzerotti L. J. , Gold R. E.
Published: September 2003

Low energy charged particles in the global (3‐D) heliosphere within ∼2.3 AU of the Sun are compared during the two fast latitude scans by the Ulysses spacecraft at solar minimum and maximum. This comparison of data taken by the HISCALE instrument illustrates quantitatively the differences in the population of the heliosphere during the only two solar cycles for which 3‐dimensional information are available. At solar minimum the largest intensities of particles are found in and near the heliospheric current sheet, whereas at solar maximum the entire 3‐D volume is filled. An example is presented of solar‐produced charged particles (electrons and heavy ions measured when Ulysses was at its highest heliolatitude) that provide evidence of a heliosphere ‘reservoir’ with a volume as much as 50 AU3; this reservoir subsequently decays with an e‐folding time of the order of 3 days. Anomalous He, O, and Ne ions are clearly measured at high heliolatitudes at solar minimum, whereas during solar maximum their fluxes, if present, are completely swamped at these energies by the higher intensities of solar particles.
Determination of low latitude plasma drift speeds from FUV images
Authors: Immel Thomas J. , Mende Stephen B. , Frey Harald U. , Peticolas Laura M. , Sagawa Eiichi
Published: September 2003

Thousands of images of the nighttime equatorial airglow arcs have been obtained by the Far‐Ultraviolet Imager (FUV) on‐board the NASA IMAGE satellite. Imaging periods lasting several hours around the time of satellite apogee allow for the determination of the velocity of drifting plasma density depletions occurring within the airglow arcs. These velocities reflect the E × B drift of low‐latitude plasma under the influence of a vertical electric field. A survey of several weeks of data produces information regarding the variation of drift speeds with solar 10.7‐cm radio flux. Comparisons to previous measurements by the Jicamarca radar show that the FUV‐determined plasma drift speeds are 10–35% greater, particularly before 2100 local time. This difference is attributed mainly to the different magnetic latitudes of the observations.
On the source and acceleration of energetic He+: A long‐term observation with ACE/SEPICA
Authors: Kucharek H. , Möbius E. , Li W. , Farrugia C. J. , Popecki M. A. , Galvin A. B. , Klecker B. , Hilchenbach M. , Bochsler P. A.
Published: September 2003

We report on a systematic study of the He+/He2+ abundance ratio in the energetic population during the years 1998–2000. For the investigation we have used data in the energy range 0.25–0.8 MeV/n from SEPICA on board ACE and from CELIAS STOF on SOHO in the energy range 0.085–0.28 MeV/q. The ratio is quite variable, with values up to 1. Over the entire time period the integral abundance ratio of the energetic population is 0.06, which exceeds the abundance of He+ in the solar wind and corona by several orders of magnitude and even surpasses substantially the average relative contribution of He+ pickup ions. This requires preferential injection and acceleration of He+ over He2+. In a case study of a CME with plasma rich in He+, which drives a shock and is being overtaken by another shock, the largest enhancement is found near the driven shock way ahead of the ejecta. In addition, CMEs which are He+ rich are very rare. This implies that the source of the energetic He+ is primarily interstellar pickup ions and not ejecta material. However, signatures of large‐scale structures in the interstellar source, such as the gravitational focusing cone, have not been identified in this survey. Enhanced He+/He2+ ratios are associated with interplanetary structures in the solar wind, such as stream‐stream interfaces and interplanetary traveling shocks. In fact, more than 90% of all shocks and stream interfaces show ratios that exceed our lower limit of 0.04. This association points to local acceleration of interplanetary He+, whose injection and acceleration efficiency may vary substantially from event to event, thus probably washing out large‐scale structures of the source strength. While the enhancements tend to be very localized at interplanetary traveling shocks, they are much more prolonged in the case of CIRs.
Compositional variation of density and seismic velocities in natural peridotites at STP conditions: Implications for seismic imaging of compositional heterogeneities in the upper mantle
Authors: Lee Cin‐Ty Aeolus
Published: September 2003

Densities and elastic properties of solid natural spinel‐ and garnet‐peridotite samples (n = 133) at standard temperature (T) and pressure (P) (STP) conditions were calculated for compositions ranging from Mg# (100 × Mg/(Mg + Fe)) of 86–94. The physical properties were used to investigate how natural compositional variations control density and seismic velocity. A corresponding set of compositional derivatives (d/dMg#) of density and seismic velocity is provided. Because the P and T derivatives of elastic moduli are very similar for different compositional end‐members of peridotitic minerals, the variation of elastic moduli with Mg# at STP conditions holds at elevated P and T. Increased Mg# leads to a significant increase in VS because of the sensitivity of mineral shear moduli to this parameter (dVS/dMg# = 0.0143 ± 0.0009 km s−1). In contrast, the compressional wave velocity (VP) is insensitive to Mg# and, instead, correlates weakly with increasing olivine abundance at STP conditions. The ratio VP/VS therefore exhibits a significant negative correlation with Mg# (d(VP/VS)/dMg# = −0.00407 ± 0.00038). Because the temperature dependency of VP/VS is small (<∼0.04%/100°C) compared to the compositional dependency (1.7%/Mg# unit), the variation in VP/VS is a fairly robust measure of compositional variation even when temperature varies. Finally, a new density versus Mg# parameterization is derived. Combined with a compilation of bulk‐rock Mg#s of peridotite xenoliths from cratonic lithospheric mantle, it is shown that the intrinsic density of cratonic mantle balances to within error its negative thermal buoyancy imposed by its cooler thermal state relative to upwelling asthenospheric mantle.
Paleomagnetic tracking of mountain building in the Peruvian Andes since 10 Ma
Authors: Rousse Sonia , Gilder Stuart , Farber Daniel , McNulty Brendan , Patriat Philippe , Torres Victor , Sempere Thierry
Published: September 2003

We report paleomagnetic data from 73 sites (628 samples) of upper Oligocene to Pliocene rocks from central and northern Peru. The data indicate that the Subandean Zone has not experienced vertical axis rotation since the upper Oligocene, whereas the coast and the Western Cordillera record a coherent pattern of counterclockwise rotations emplaced in the last 10 Ma. This pattern can best be explained by two competing hypotheses: (1) a propagation in rotations from the Bolivian Orocline toward the north or (2) a more punctual and widespread event linked to subduction of the Nazca Ridge that caused the rotations. On the basis of the time‐space relationship of paleomagnetic rotations, deformation, magmatism and Nazca‐South America plate convergence, the latter appears more likely. Moreover, because the rotations north of the Abancay deflection (∼15.5°S) are synchronous with deformation and exhumation, they indicate that major mountain building in the Peruvian Andes has occurred since 10 Ma. Finally, we suggest that a succession of aseismic ridge subduction events played an important role in shaping the modern topography of the Andean chain.
Periodontal ultrasonography
Authors: Tsiolis Fotis I. , Needleman Ian G. , Griffiths Gareth S.
Published: September 2003

Objectives: The aim of this study was to investigate high‐frequency ultrasound imaging for periodontal assessment.

Material and methods: A newly developed ultrasonic scanner with a frequency of 20 MHz was used. Pig jaws were selected as the experimental model. Three teeth per jaw were imaged with the scanner and duplicate measurements were made of the distance from a fixed landmark on the teeth to the alveolar bone crest. These measurements were compared to transgingival and direct measurements of the same teeth following reflection of the soft tissues. One further jaw was used for histological comparison with the ultrasound image.

Results: Using ultrasonography, it was possible to image the main periodontal structures. The ultrasound measurements showed better repeatability than either of the other two methods (repeatability coefficient: 0.44 mm for ultrasound, 0.93 mm for transgingival probing and 0.6 mm for direct measurements). Also, ultrasound was in better agreement with direct, open probing measurements (0.004±0.58 mm) than transgingival probing with direct measurements (0±0.7 mm).

Conclusions: Ultrasonography provides a highly accurate and repeatable technique for periodontal assessment in this model.
Psychotherapies and Older Adults
Authors: Garner Jane
Published: September 2003

Objective: To confirm clinical experience which suggests that older people are offered psychotherapies significantly less often than younger ones. For those who are able to access psychotherapeutic help the outcome is comparable, sometimes better, than for younger patients.

Method: Contemporary and older seminal literature was reviewed for psychodynamic, cognitive–behavioural, reminiscence and systemic family therapies treating older patients.

Results: The main findings supported the experience of staff in old age psychiatry that if the reluctance of referrers and sometimes of older patients themselves can be overcome this type of work is valuable and effective.

Conclusions: Each patient is unique. Generalizations are not always appropriate, however, with advancing years some common themes emerge in therapeutic work. It may be necessary to make modifications to the therapeutic technique to accommodate the difficulties experienced by people in later life but also to use their strengths.

Staff working in this field need to have the capacity to be aware of and to understand their own feelings and prejudices about the second half of life. For patients not offered formal therapy a psychotherapeutic approach will nevertheless enhance their psychiatric care.

Although the body of research is growing, more work needs to be done in evaluating all of the psychotherapies offered to older people.
Borderline Personality Disorder and the Search for Meaning: An Attachment Perspective
Authors: Holmes Jeremy
Published: September 2003

Objective: To explore the links between the attachment theory-derived concept of disorganized attachment, and the psychiatric diagnosis of borderline personality disorder (BPD).

Method: Literature search for characteristics of disorganized attachment. Clinical case material from psychotherapeutic work with patients suffering from BPD.

Results: Disorganized attachment can be understood in terms of an approach-avoidance dilemma for infants for whom stressed or traumatized/traumatizing caregivers are simultaneously a source of threat and a secure base. Interpersonal relationships in BPD including those with caregivers is similarly seen in terms of an approach-avoidance dilemma, which manifests itself in disturbed transference/countertransference interactions between therapists and BPD sufferers. Borderline personality disorder sufferers lack meaning in their lives because they are unable to play ‘language games’ with their potential intimates, resorting to actions rather than words to express feelings.

Conclusions: Possible ways of handling these phenomena are suggested, based on Main's (1995) notion of ‘meta-cognitive monitoring’, in the hope of re-instating meaning and more stable self-structures, in these patients’ lives.
Community Study of Dementia in the Older Korean Rural Population
Authors: Je Cho Maeng , Kyu Kim Jang , Suh Guk-Hee
Published: September 2003

Objective: This study aims to estimate the prevalence of all dementias, including Alzheimer's disease (AD) and vascular dementia (VaD) in a population of Korean elderly and to identify possible risk factors which correlated with specific types of dementia.

Method: A two-phase survey, based on a door-to-door survey, was conducted. Initially, the Korean version of the Psychogeriatric Assessment Scale (PAS-K) was administered to all 1037 participants aged 65 years and older. Three hundred and seventy people sampled from the case groups (n = 320) of PAS-K subscales and the non-case group (n = 50) entered the second phase for clinical evaluation. Dementia was defined using the DSM-III-R, NINCDSADRDA and NINDS-AIREN criteria.

Results: Among 1037 elderly people aged 65–94 years who completed the interview, 74 cases of dementia were detected, giving an overall age-standardized prevalence (95% CI) of 6.8% (6.1–7.5) (male 6.3%[5.3–7.4]; female 7.1% [6.1–8.0]). The prevalence (95% CI) of AD was 4.2% (3.6–4.7) (male 2.4% [2.0–2.8]; female 5.3% [4.5–6.1]), and it increased with age. The prevalence (95% CI) of VaD was 2.4% (2.0–2.8) (male 3.5% [2.7–4.3]; female 1.6% [1.2–2.1]). Smoking for longer than 30 pack-years significantly increased the risk of VaD (OR = 11.5 [2.8–44,6]).

Conclusion: Long-term smoking, much more prevalent in men, may be closely related to higher risk of cerebrovascular disease that leads to vascular dementia.
A Classification Tree for Predicting Recurrent Falling in Community‐Dwelling Older Persons
Authors: Stel Vianda S. , Pluijm Saskia M. F. , Deeg Dorly J. H. , Smit Johannes H. , Bouter Lex M. , Lips Paul
Published: September 2003

Objectives: To develop a classification tree for predicting the risk of recurrent falling in community‐dwelling older persons using tree‐structured survival analysis (TSSA).

Design: A prospective cohort study.

Setting: A community in the Netherlands.

Participants: One thousand three hundred sixty‐five community‐dwelling older persons (≥65) from the Longitudinal Aging Study Amsterdam (LASA).

Measurements: In 1995, physical, cognitive, emotional, and social aspects of functioning were assessed. Subsequently, a prospective fall follow‐up, specifically on recurrent falls (two falls within 6 months) was conducted for 3 years.

Results: The classification tree included 11 end groups differing in risk of recurrent falling based on a minimum of two and a maximum of six predictors. The first split in the tree involved two or more falls versus fewer than two falls in the year preceding the interview. Respondents with two or more falls in the year preceding the interview (n=193) and with at least two functional limitations (n=98) had a 75% risk of becoming a recurrent faller, whereas respondents with fewer than two functional limitations were further divided into a group with regular dizziness (n=11, risk of 68%) and a group with no regular dizziness (n=84, risk of 30%). In respondents with fewer than two falls in the year preceding the interview (n=1,172), the risk of becoming a recurrent faller varied between 9% and 70%. Predictors in this branch of the tree were low performance, low handgrip strength, alcohol use, pain, high level of education, and high level of physical activity.

Conclusion: This classification tree included 11 end groups differing in the risk of recurrent falling based on specific combinations of a maximum of six easily measurable predictors. The classification tree can identify subjects who are eligible for preventive measures in public health strategies.
Cross‐Linked Fibrin Degradation Products (D‐Dimer), Plasma Cytokines, and Cognitive Decline in Community‐Dwelling Elderly Persons
Authors: Wilson Craig J. , Cohen Harvey Jay , Pieper Carl F.
Published: September 2003

Objectives:To investigate the effect of coagulation and inflammatory pathway activation on future cognitive decline in older persons.

Design:Prospective cohort study.

Setting:Rural and urban communities in North Carolina.

Participants:Community‐dwelling older people enrolled in the Duke Established Populations for Epidemiologic Studies of the Elderly in 1986.

Measurements:In 1992, blood was drawn for assay of D‐dimer (1,723 subjects), Interleukin‐6 (1,726 subjects), and other cytokines (1,551 subjects). Cognitive and functional assessments were performed in 1986, 1989, 1992, and 1996. Cognition was measured using the Short Portable Mental Status Questionnaire.

Results:Cognitive decline over a 4‐year period was significantly correlated (P<.001) with D‐dimer, age, race, and physical performance status as measured using the Rosow‐Breslau and Nagi instruments. After controlling for demographics, functional status, and comorbidities, D‐dimer remained predictive of cognitive decline. Proinflammatory cytokines were not associated with current cognitive status in cross‐sectional analyses or with incident cognitive decline in prospective analyses.

Conclusion:In a large sample of community‐dwelling elders, higher levels of D‐dimer were predictive of cognitive decline over a 4‐year period. No clinically significant associations were found between age‐related peripheral cytokine dysregulation and cognition.