bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Technology Intangibles and Analysts’ Forecasts
Authors: Barron Orie E. , Byard Donal , Kile Charles , Riedl Edward J.
Published: March 2003

This study examines the association between firms’ intangible assets and properties of the information contained in analysts’ earnings forecasts. We hypothesize that analysts will supplement firms’ financial information by placing greater relative emphasis on their own private (or idiosyncratic) information when deriving their earnings forecasts for firms with significant intangible assets. Our evidence is consistent with this hypothesis. We find that the consensus in analysts’ forecasts, measured as the correlation in analysts’ forecast errors, is negatively associated with a firm’s level of intangible assets. This result is robust to controlling for analyst uncertainty about a firm’s future earnings, which we also find to be higher for firms with high levels of internally generated (and expensed) intangibles. Given that analyst uncertainty increases and analyst consensus decreases with the level of a firm’s intangible assets, we also expect and find that the degree to which the mean forecast aggregates private information and is more accurate than an individual analyst’s forecast increases with a firm’s intangible assets. Finally, additional analysis reveals that lower levels of analyst consensus are associated with high‐technology manufacturing companies, and that this association is explained by the relatively high R&D expenditures made by these firms. Overall, our results are consistent with financial analysts augmenting the financial reporting systems of firms with higher levels of intangible assets (in terms of contributing to more accurate earnings expectations), particularly R&D‐driven high‐tech manufacturers.
Do Non–Audit Service Fees Impair Auditor Independence? Evidence from Going Concern Audit Opinions
Authors: DeFond Mark L. , Raghunandan K. , Subramanyam K.R.
Published: March 2003

We find no significant association between non–audit service fees and impaired auditor independence, where auditor independence is surrogated by auditors’ propensity to issue going concern audit opinions. We also find no association between going concern opinions and either total fees or audit fees. In addition, our findings are robust to controlling for unexpected fees, to controlling for endogeneity among our variables, and to several alternative research design specifications. Our results are consistent with market–based incentives, such as loss of reputation and litigation costs, dominating the expected benefits from compromising auditor independence.
The Intraday Relation between NYSE and CBOE Prices
Authors: Hatch Brian C.
Published: March 2003

I extend the literature regarding price discovery across stock and option markets through an empirical model that allows information to flow through an error‐correction term and volatility. NYSE prices tend to lead CBOE prices by at least thirty minutes over the entire six‐year sample period. In addition, informed trading in the options market is revealed more strongly through persistence in volatility and the spillover of volatility to the stock market than it is through returns.
Skewness and Kurtosis Implied by Option Prices: A Correction
Authors: Brown Christine A. , Robinson David M.
Published: March 2003

Corrado and Su (1996) provide skewness and kurtosis adjustment terms for the Black‐Scholes model, using a Gram‐Charlier expansion of the normal density function. In this note we provide a correction to the expression for the skewness coefficient and illustrate the effect on call option prices of the error found.
Ginkgo biloba: A Cognitive Enhancer?
Authors: Gold Paul E. , Cahill Larry , Wenk Gary L.
Published: March 2003

Ginkgo biloba is an herb often used as an alternative treatment to improve cognitive functions. Like most herbal treatments, the use of ginkgo is poorly regulated by government agencies, on the basis of either its efficacy or its health risks. This article reviews the experimental evidence available regarding efficacy, neurobiological actions, and health risks. Findings obtained in studies of humans often include demonstrations of rather mild cognitive enhancement. Interpretation of these findings is complicated by somewhat inconsistent findings, by experimental designs that do not permit identification of cognitive functions susceptible to the influence of ginkgo, and by the paucity of direct comparisons with other treatments. The number of peer-reviewed reports of studies in nonhuman animals is surprisingly small. In this small set, the findings reveal mild behavioral effects that might be attributable to actions on cognitive functions. However, these experiments in rodents, like those in humans, do not involve the use of designs to assess ginkgo's effects on particular cognitive attributes, and generally do not include direct comparisons with other treatments. Interpretation of the findings is further complicated by evidence, obtained in studies of both humans and rats, showing that a single administration of the treatment enhances performance on cognitive measures.

If ginkgo has effects on cognition, there should be effects evident on biological processes as well. Neurobiological studies have largely examined the effects of chronic ginkgo administration, mirroring the most common design in behavioral studies. However, the addition of findings that single administration of ginkgo may influence behavior directs biological investigations to short-term actions of the treatment. Biological effects of ginkgo include vasodilation, protection of neurons from oxidative stress, and actions mediated by effects via neurotransmitters. Adverse reactions to ginkgo consumption have been observed but are relatively rare.

Collectively, the behavioral literature reviewed cannot be used conclusively to document or to refute the efficacy of ginkgo in improving cognitive functions. At best, the effects seem quite modest. In particular, it is questionable whether effects of ginkgo, if present, are equal to those obtained by administration of acetylcholinesterase inhibitors, hearing an arousing story, or ingesting glucose.
Determinants of No‐Fault Insurance Measures
Authors: Devlin Rose Anne
Published: March 2003

In spite of being touted as the panacea for rising premiums and unfair settlements, no‐fault automobile insurance provisions exist in fewer than one third of U.S. states. Few researchers have examined why such measures exist in some states but not in others. This article focuses directly on this issue by looking at the factors that help explain the type of no‐fault regime in place. The article conducts an empirical analysis using a data set that spans all 50 states over the 19‐year period from 1972 to 1990. Among other things, the analysis finds that the structure of the insurance industry and the type of rate regulation under which it operates are determinants of these decisions.
Relationship Formation on the Internet: What’s the Big Attraction?
Authors: McKenna Katelyn Y. A. , Green Amie S. , Gleason Marci E. J.
Published: March 2003

We hypothesized that people who can better disclose their “true” or inner self to others on the Internet than in face‐to‐face settings will be more likely to form close relationships on‐line and will tend to bring those virtual relationships into their “real” lives. Study 1, a survey of randomly selected Internet newsgroup posters, showed that those who better express their true self over the Internet were more likely than others to have formed close on‐line relationships and moved these friendships to a face‐to‐face basis. Study 2 revealed that the majority of these close Internet relationships were still intact 2 years later. Finally, a laboratory experiment found that undergraduates liked each other more following an Internet compared to a face‐to‐face initial meeting.
Internet Use and Well‐Being in Adolescence
Authors: Gross Elisheva F. , Juvonen Jaana , Gable Shelly L.
Published: March 2003

Previous research suggests that Internet use may be associated with decreases in well‐being among adolescents. However, there has been little investigation of the relationship between well‐being and social aspects of Internet use. In the present study, 130 7th graders from a middle‐class public school in California completed dispositional measures of well‐being, and on three subsequent evenings they responded to questions regarding their Internet use (including detailed logs of instant messages) and daily well‐being. Time spent on‐line was not associated with dispositional or daily well‐being. However, as suggested by intimacy theory, the closeness of instant message communication partners was associated with daily social anxiety and loneliness in school, above and beyond the contribution of dispositional measures.
Hateful Sirens. . .Who Hears Their Song? An Examination of Student Attitudes Toward Hate Groups and Affiliation Potential
Authors: Turpin‐Petrosino Carolyn
Published: March 2003

Sources indicate a rise in hate crimes committed by persons affiliated with hate groups (Bowles, 1993; Levin, 2002). Although the majority of these offenders remain unaffiliated, it is nevertheless important to understand why individuals become attracted to hate groups. This exploratory study examined youth attitudes toward hate groups. Deprivation and interpersonal bonds theories were used to explain hate group attraction among students. Secondary and university students completed the 567 surveys used in the analysis. Results indicated that crime‐related measures and exposure to hate groups by word‐of‐mouth contacts were more often related to supportive attitudes. These effects were further associated with secondary students. Neodeprivation theory is offered for exploring hate group attraction by more educated persons.
Well–Being Among Older Adults on Different Continents
Authors: Antonucci Toni C. , Okorodudu Corann , Akiyama Hiroko
Published: March 2003

Old age represents a new frontier. The number of older people is increasing throughout the world. This changing demography affects individuals, but also families, communities and societies. The focus of this issue is the well–being of older adults on different continents. Scientists from around the world address this issue using a wide array of research designs and methodologies to provide a broad perspective on aging. Five topics are considered: Well–Being Among Older Adults; Social Support; Functional Status, Well–Being and Successful Aging; Cross–Cultural Approaches to the Study of Aging; and Research Perspectives in Aging. This issue clearly demonstrates that scientists have much to contribute to the goal of optimizing the experience of aging and creating a society for all ages.
A Holistic Theoretical Model for Examining Welfare Reform: Quality of Life
Authors: Hollar Danielle
Published: March 2003

Policy makers, public administrators, the media, and others are celebrating the “success” of the latest version of welfare reform, codified into law by the Personal Responsibility and Work Opportunity Reconciliation Act of 1996. Most often, success is defined in terms of declining case loads or some other economic measure—a practice that does not provide a true sense of the impact of policy changes such as welfare reform. Assessing the human impact of policy change requires more than evaluating economic outcomes; it requires knowing the resources of beneficiaries of social services and their conditions of life from various perspectives. Thus, we must strive for greater understanding about the sociocultural aspects of people’s lives that create the whole person—aspects such as health, family and friendship networks, housing situations, public and private support service and program use, conditions of work, and so forth. This is how we come to understand one’s quality of life. The present research creates a conceptual model of quality of life and illustrates the model using data from a follow–up study of former welfare recipients in a county in northern Virginia. Evaluation activities that are premised on a quality–of–life model will help policy actors understand the impact of policies and how public institutions can be managed strategically within their very complex contexts, especially in an era of welfare reform.
Employee Commitment and Firefighters: It’s My Job
Authors: Lee Seok–Hwan , Olshfski Dorothy
Published: March 2003

The events of September 11, 2001, have led us to rethink the importance of public service and public–sector employees’ commitment. In previous research, we argued that employee commitment is a construct comprising three dimensions: commitment to the boss, to the work group, and to the organization. However, this characterization cannot explain the behavior of public employees on September 11. For this article, we argue that employee commitment is a construct that comprises four dimensions: With the help of identity theory, there is reason to include commitment to a job as part of the commitment construct. Based on an analysis of an existing data set, we find that firefighters identified themselves as committed to their job, which they viewed as an honorable profession that performs a valuable service to the community.
Commercial Real Estate Leasing, Asymmetric Information, and Monopolistic Competition
Authors: Mooradian Robert M. , Yang Shiawee X.
Published: March 2003

We model the choice of lease type, gross lease versus net lease, in an environment in which lessees have private information with respect to their expected intensity of utilization of the leased space, and in which lessors have market power with respect to the pricing of the lease. Unless the lessor can provide operating services at lower cost than the lessee, there exists a lemons problem. We examine a market in which lessors can provide operating services at lower cost. Given asymmetric information with respect to expected lessee utilization and/or damage to the leased space, the lessor offers both a gross and net lease, where the higher expected utilization lessees select the gross lease and the lower expected utilization lessees select a net lease. Lease pricing depends on both the lessor’s beliefs with respect to lessee utilization of the space and the lessor’s market power. In a monopolistic market, relative to a competitive market, a lessor charges higher rent for a gross lease relative to a net lease in order to extract a portion of the gain from shifting operating services to the lessor. Given the higher rent for a gross lease, a smaller proportion of lessees (only very high utilization lessees) selects a gross lease in a monopolistic market. Therefore, the expected cost savings associated with shifting operating services/provision of maintenance to the lessor are smallest in a monopolistic market.
Local Action in a Transitional State: Community Responses to Proposed Development in the Czech Republic, 1992–1996*
Authors: Carmin JoAnn
Published: March 2003

Objective After the fall of the communist regime, the Czech government placed an emphasis on economic growth and development. Although research has been conducted on national‐level change and civil society reactions to new institutions and initiatives, little is known about the transition process at the local level and the ways community sentiments and actions varied in response to development policies. This study examines responses to proposed development in communities in the Czech Republic and investigates the extent that actions were influenced by values, the availability of resources, and the local political context.

Methods To understand factors shaping action, structured interviews were conducted with the mayors of 237 towns in the Czech Republic where landfills, incinerators, highways, and protected‐area development were proposed or first publicly discussed between 1992–1996.

Results Values pertaining to health, employment, property value, nature protection, and connection to place were associated with the adoption of newer modes of behavior, as were resources including national media coverage of an issue, the presence of a local environmental organization, and previous experience. Many aspects of the local political context had no relationship to behavior. Those that did appeared to foster and reinforce more ingrained patterns of action reminiscent of the former regime.

Conclusions In general, while styles of action common during the former regime began to reemerge, they were balanced by new patterns of action signifying confidence and trust in the newly formed democratic institutions.
Forestalling the Business Veto: Investment Confidence and the Rise of Swedish Social Democracy, 1932–1936*
Authors: Anderson Karen M. , Snow Steven G.
Published: March 2003

Objective. We investigate the causes of the stability of Swedish business confidence in the early 1930s. Surprisingly, investors seemed unruffled by the Social Democrats’ heterodox “Crisis Program,” a proto‐Keynesian response to the Great Depression. This research allows a productive modification of the argument that the state is dependent on private capital formation.

Methods. Analysis of stock markets, currency prices, patterns of domestic investment, as well as written primary sources in Swedish and English.

Results. The cross‐class cooperation practiced by the Social Democrats, and the lack of a threat of radicalization, had an important calming effect on investors.

Conclusions. To avoid capital flight and resulting economic dislocation, reformist governments must cooperate with business and conservatives, and turn away from workers and revolutionaries.
The Timing of Adoptions of Land‐Use Plans and Regulations in Pennsylvania Localities*
Authors: Steele Jennifer , Luloff A. E.
Published: March 2003

Objective. This article explores the relationship between the timing of land‐use tool adoptions and local growth.

Methods.

Land cover data, census data, and information about land‐use tools were merged for all Pennsylvania minor civil divisions (MCDs) for the period 1975/1980 to 1990/1992. First, the extent to which growth was absorbed in MCDs without land‐use tools was assessed. Second, the importance of structural changes for distinguishing new adopters and nonadopters was analyzed using a subset of MCDs.

Results.

Both the aggregate‐ and MCD‐level analyses suggested that nonadoptions under growth pressure were not widespread. Growth was not a necessary condition, however, for adoption.

Conclusions.

The findings support an emphasis on outreach aimed at improving the effective use of existing tools, but suggest that the importance of improving the capacity of MCDs without tools is increasing with population decentralization.
Nonlinear Pricing Kernels, Kurtosis Preference, and Evidence from the Cross Section of Equity Returns
Authors: Dittmar Robert F.
Published: March 2003

This paper investigates nonlinear pricing kernels in which the risk factor is endogenously determined and preferences restrict the definition of the pricing kernel. These kernels potentially generate the empirical performance of nonlinear and multifactor models, while maintaining empirical power and avoiding ad hoc specifications of factors or functional form. Our test results indicate that preference‐restricted nonlinear pricing kernels are both admissible for the cross section of returns and are able to significantly improve upon linear single‐ and multifactor kernels. Further, the nonlinearities in the pricing kernel drive out the importance of the factors in the linear multi‐factor model.
Bank Performance around the Introduction of a Section 20 Subsidiary
Authors: Cornett Marcia Millon , Ors Evren , Tehranian Hassan
Published: March 2003

As of 1987, commercial banks in the United States were allowed to establish Section 20 subsidiaries to conduct investment‐banking activities. A concern of regulators was that these activities would result in a decrease in performance of commercial banks relative to the risk being undertaken. This paper examines the performance of commercial banks around the establishment of a Section 20 subsidiary. We find that Section 20 activities undertaken by banks result in increased industry‐adjusted operating cash flow return on assets, due mainly to revenues from noncommercial‐banking activities. Further, risk measures for the sample banks do not change significantly.
Dynamic Asset Allocation with Event Risk
Authors: Liu Jun , Longstaff Francis A. , Pan Jun
Published: March 2003

Major events often trigger abrupt changes in stock prices and volatility. We study the implications of jumps in prices and volatility on investment strategies. Using the event‐risk framework of Duffie, Pan, and Singleton (2000), we provide analytical solutions to the optimal portfolio problem. Event risk dramatically affects the optimal strategy. An investor facing event risk is less willing to take leveraged or short positions. The investor acts as if some portion of his wealth may become illiquid and the optimal strategy blends both dynamic and buy‐and‐hold strategies. Jumps in prices and volatility both have important effects.
Two Steps Forward, One Step Back: The Family and Medical Leave Act as Retrenchment Policy
Authors: WISENSALE STEVEN K.
Published: March 2003

abstract This article discusses recent efforts by states to adopt paid family leave since the original passage of the Family and Medical Leave Act in 1993. In proposing their legislation, 21 of 26 states dropped the family component of the original law and, instead, reduced coverage to baby care or parental leave. I explore the potential policy implications of what appears to be a retrenchment of the FMLA, as it shifts from an emphasis on family (including care of elderly parents) to parental (baby care only). This discussion is particularly important in light of a growing aging population that will demand greater assistance from family caregivers who will most likely be in the workforce and in need of benefits such as family leave.
Physical and colloquial meanings of the term “work”
Authors: Mendelson Kenneth S.
Published: February 2003

Physicists are often apologetic about the difference between the physical and colloquial meanings of the term “work,” particularly in situations in which a lot of effort is involved but nothing is moved so no work is done in the physical sense. I argue that there is no need to be apologetic. Many words in mechanics have different physical and colloquial meanings. In the sense that work applies to output rather than input, its physical meaning is closer to the colloquial meaning than many other terms in mechanics. A review of the history shows that force×distance was used to refer to the output of engines since the early eighteenth century. During the eighteenth and early nineteenth centuries, several terms were used to denote force×distance, but none became widespread and work quickly became the preferred term after it was suggested by G. Coriolis in 1829.
The one-dimensional harmonic oscillator in the presence of a dipole-like interaction
Authors: Palma G. , Raff U.
Published: February 2003

The Schrödinger equation for a one-dimensional harmonic oscillator is solved in the presence of an external dipole field. The solution is obtained in closed form and resembles the solution of the three-dimensional harmonic oscillator in spherical coordinates. Due to the existence of a singularity at the origin and the absence of tunneling, this one-dimensional system has a twofold degeneracy. Therefore, the nondegeneracy of the eigenvalues breaks down as has been observed in other systems.
Field line motion in classical electromagnetism
Authors: Belcher John W. , Olbert Stanislaw
Published: February 2003

We consider the concept of field line motion in classical electromagnetism for crossed electromagnetic fields and suggest definitions for this motion that are physically meaningful but not unique. Our choice has the attractive feature that the local motion of the field lines is in the direction of the Poynting vector. The animation of the field line motion using our approach reinforces Faraday’s insights into the connection between the shape of the electromagnetic field lines and their dynamical effects. We give examples of these animations, which are available on the Web.
α4β1 Integrin Acts as a Cell Receptor for Murine Polyomavirus at the Postattachment Level
Authors: Caruso Maddalena , Belloni Laura , Sthandier Olga , Amati Paolo , Garcia Marie-Isabelle
Published: March 2003

The initial interaction of murine polyomavirus (Py) with host cells occurs through direct binding of the major capsid protein VP1 with cell membrane molecules containing terminal sialic acids; however, these Py receptor molecules have not yet been identified. Analysis of the capsid protein primary sequences of all murine strains revealed the presence of integrin ligand motifs in the DE and EF loops of VP1 (LDV and DLXXL, respectively) and at the N terminus of VP2 (DGE). We show that infectivity of the Py A2 strain in mouse Swiss 3T3 fibroblasts is significantly reduced only in the presence of natural integrin ligands carrying an LDV motif or antibodies directed against the α4 and β1 integrin subunits. Furthermore, we demonstrate that expression of the α4 subunit in the α4-deficient BALB/c 3T3 cells increases viral infectivity. Addition of α4 function-blocking antibodies, prior to or after virus adsorption, blocks this increased infectivity without affecting virus binding to cells. Taken together, these data indicate that expression of α4 integrin enhances permissivity to Py, probably by acting as one of the postattachment receptors.
Characterization of the Complete Genome of the Tupaia (Tree Shrew) Adenovirus
Authors: Schöndorf Eva , Bahr Udo , Handermann Michaela , Darai Gholamreza
Published: March 2003

The members of the family
Adenoviridae
are widely spread among vertebrate host species and normally cause acute but innocuous infections. Special attention is focused on adenoviruses because of their ability to transform host cells, their possible application in vector technology, and their phylogeny. The primary structure of the genome of Tupaia adenovirus (TAV), which infects
Tupaia
spp. (tree shrew) was determined. Tree shrews are taxonomically assumed to be at the base of the phylogenetic tree of mammals and are frequently used as laboratory animals in neurological and behavior research. The TAV genome is 33,501 bp in length with a G+C content of 49.96% and has 166-bp inverted terminal repeats. Analysis of the complete nucleotide sequence resulted in the identification of 109 open reading frames (ORFs) with a coding capacity of at least 40 amino acid residues. Thirty-eight of them are predicted to encode viral proteins based on the presence of transcription and translation signals and sequence and positional conservation. Thirty viral ORFs were found to show significant similarities to known adenoviral genes, arranged into discrete early and late genome regions as they are known from mastadenoviruses. Analysis of the nucleotide content of the TAV genome revealed a significant CG dinucleotide depletion at the genome ends that suggests methylation of these genomic regions during the viral life cycle. Phylogenetic analysis of the viral gene products, including penton and hexon proteins, viral protease, terminal protein, protein VIII, DNA polymerase, protein IVa2, and 100,000-molecular-weight protein, revealed that the evolutionary lineage of TAV forms a separate branch within the phylogenetic tree of the
Mastadenovirus
genus.
A DYNAMIC ANATOMICAL STUDY OF ULNAR NERVE MOTION AFTER ANTERIOR TRANSPOSITION FOR CUBITAL TUNNEL SYNDROME
Authors: Nikitins M. D. , Griffin P. A. , Ch'ng S. , Rice N. J.
Published: February 2003

Cubital tunnel syndrome is the second most commonly encountered compression neuropathy of the upper limb. Multiple techniques for surgical management have been proposed but no universally accepted algorithm for management exists. Six cadaveric upper limbs underwent ulnar nerve decompression and anterior transposition into subcutaneous and then submuscular positions. After marking nerves with tungsten, radiological examination of nerve motion was performed and nerve angulations were measured in the region of the flexor carpi ulnaris (FCU) origin. Comparison of ulnar nerves in each position revealed statistically significant greater angulation after subcutaneous transposition than after submuscular transposition with the elbow held in full flexion. This point of angulation may act as a secondary point of compression or as a focus for neuritis and scar formation. This finding can contribute to the understanding of why differing outcomes may be observed after different forms of anterior transposition.
A CADAVERIC MODEL FOR BIOMECHANICAL STUDY OF FIXATION METHODS FOR AO TYPE C2 FRACTURES OF DISTAL RADIUS: DESIGN AND TESTING WITH DORSAL PLATING FIXATION
Authors: Zhu Lijun , Ho Henry , Lu William , Leung Frankie , Chow S. P.
Published: February 2003

Fracture of the distal radius is a common injury. Functional recovery correlates well with restoration of anatomy and early motion. Various fixation methods have been proposed to achieve this. To evaluate the stability of different treatment options, a cadaveric model for biomechanical study of fixation methods for AO type C2 fracture of distal radius was designed and its efficacy assessed in the present experiment.
SPLINTING PROGRAMMES FOR TENDON INJURIES
Authors: Chu Mary M. L.
Published: February 2003

It is beyond doubt that splinting programmes have often been an integral and important part of the rehabilitation process in tendon injuries. Over the past three decades, hand splints for tendon injuries of various designs and different mobilisation programmes have been developed in the hope of pursuing better clinical and functional outcome for patients. In this paper, the development of different splinting programmes in flexor and extensor tendon injuries and the current practice in some acute hospitals in Hong Kong were discussed.
SPLINTING PROGRAMME FOR PATIENTS WITH BURNT HAND
Authors: Kwan Mike W. W. , Ha Kennis W. Y.
Published: February 2003

Splintage is commonly used in conjunction with pressure therapy to tackle the contracted scars, make it supple and thus minimise dysfunction. A static or dynamic splint can provide valuable therapy that goes beyond any treatment session. The patient's active participation in the splint programme can facilitate early recovery. A good splinting design and wearing regime often depends on the therapist's understanding and integration of visco-elastic properties in soft tissues, maturation process of hypertrophic scars and mechanical principles in splinting. Different types of splints serve different functions at different stages of rehabilitation. A suitable and efficient application of splints can minimise most of the corrective surgical intervention and alleviate psychological trauma. This article attempts to highlight the clinical rationale and special considerations when applying different splintage on burns patients with upper limbs involvement.
A NONOSCILLATION THEOREM FOR SUBLINEAR EMDEN-FOWLER EQUATIONS
Authors: WONG JAMES S. W.
Published: March 2003

Consider the Emden-Fowler equation (E) : y″ + a(x)|y|γ-1y = 0, where γ > 0 and a(x) is a positive continuous function on (0, ∞). I. T. Kiguradze showed in 1962 that if x(γ+3)/2+δa(x) is nonincreasing for any δ > 0, then equation (E) is nonoscillatory when γ > 1. We prove in this paper that the same theorem remains valid in the sublinear case, i.e., equation (E) when 0 < γ < 1.
Summarizing Scientific Articles: Experiments with Relevance and Rhetorical Status
Authors: Teufel Simone , Moens Marc
Published: February 2003

In this article we propose a strategy for the summarization of scientific articles that concentrates on the rhetorical status of statements in an article: Material for summaries is selected in such a way that summaries can highlight the new contribution of the source article and situate it with respect to earlier work.

We provide a gold standard for summaries of this kind consisting of a substantial corpus of conference articles in computational linguistics annotated with human judgments of the rhetorical status and relevance of each sentence in the articles. We present several experiments measuring our judges' agreement on these annotations.

We also present an algorithm that, on the basis of the annotated training material, selects content from unseen articles and classifies it into a fixed set of seven rhetorical categories. The output of this extraction and classification system can be viewed as a single-document summary in its own right; alternatively, it provides starting material for the generation of task-oriented and user-tailored summaries designed to give users an overview of a scientific field.
SOCIAL STATUS AND INVESTIGATORY BEHAVIOUR IN THE ANGELFISH (PTEROPHYLLUM SCALARE)
Authors: Gómez-Laplaza Luis
Published: February 2003

The response of juvenile angelfish (Pterophyllum scalare) with different dominance ranks towards a potential predator and a nonthreatening novel stimulus was studied when in a group, to assess the influence of the social status on investigatory behaviour. Dominant fish showed a cautious predator inspection behaviour, often approaching the predator model from a relatively safe distance. In contrast, middle ranking fish inspected the predator model closely and the number and duration of the inspection visits to the area closest to the predator were greater than those of the other group members. Subordinate fish tended to avoid the potential predator, but showed the greatest interest in the novel harmless stimulus, investigating it more readily and for more time from the shortest distance than their companions. Dominant fish displayed a rather weak response towards the nonthreatening stimulus, exhibiting the shortest duration of investigation and the longest latency of approach. The response of intermediate ranking fish was more variable, existing little differences with that showed by any of the other fish categories in the parameters considered. The results indicate that dominance relationships within a group may affect behavioural decisions during investigatory behaviour, and suggest that individuals with different social status use different behavioural strategies dependent on the focal stimulus, possibly reflecting adaptive changes and physiological condition.
Influence of Dendronization on Spectral Diffusion and Aggregation in Conjugated Polymers
Authors: Lupton J.M. , Schouwink P. , Keivanidis P.E. , Grimsdale A.C. , Müllen K.
Published: February 2003

Dendronization has previously been suggested as a means of controlling the level of intermolecular interactions in macromolecular and polymeric compounds. We therefore studied the spectral relaxation dynamics of dendronized and non‐dendronized polyfluorenes at different temperatures. Dendronization strongly affects inhomogeneous spectral broadening, resulting in a blue‐shift and broadening of the otherwise narrow vibronic progression of polyfluorene at low temperature. Using gated spectroscopy we are able to identify emissive keto defects on isolated chains of both dendronized and non‐dendronized polymers, along with a strong aggregation band in the solid state. Surprisingly, the emission from chemical and structural defects is found to be stronger in the case of the dendronized material. The observation of aggregate emission in dendronized polyfluorenes suggests that aggregation in these materials does not occur through linear π‐stacking, but rather through electronic interactions at point contacts between chains introduced by structural kinks along the backbone.
Template Synthesis and Optical Properties of Chameleonic Poly(N‐isopropylacrylamide) Gels Using Closest‐Packed Self‐Assembled Colloidal Silica Crystals
Authors: Takeoka Y. , Watanabe M.
Published: February 2003

Smart macroporous hydrogels with a range of optical behavior have been prepared using colloidal crystals as templates. The structural color imprinted in the gel (see Figure and cover) varies with a change in the volume of the gel. It is now possible to build a soft material that displays the various structural colors available to living things.
Anisotropic Bending and Unbending Behavior of Azobenzene Liquid‐Crystalline Gels by Light Exposure
Authors: Ikeda T. , Nakano M. , Yu Y. , Tsutsumi O. , Kanazawa A.
Published: February 2003

Freestanding azobenzene‐containing liquid‐crystalline gel films that undergo a significant and anisotropic bending toward the irradiation direction when exposed to UV light have been prepared. When the bent films are exposed to visible light they unbend immediately, and the initial flat films are restored (see Figure and Inside front cover).
Improved Crystal‐Growth and Emission Gain‐Narrowing of Thiophene/Phenylene Co‐Oligomers
Authors: Ichikawa M. , Hibino R. , Inoue M. , Haritani T. , Hotta S. , Koyama T. , Taniguchi Y.
Published: February 2003

Large plate‐like single crystals of several millimeters to ∼ 1 cm in size of organic semiconducting materials are prepared via an improved crystal‐growth technique. The crystals (see Figure) exhibit self‐waveguided amplified spontaneous emission with a relatively small threshold resulting from the excellent optical properties of the crystals, such as high transparency and low light scattering.
Titania/Polypyrrole Hybrid Nanocomposites Built from In‐Situ Generated Organically Functionalized Nanoanatase Building Blocks
Authors: Roux S. , de A.A. Soler‐Illia G.J. , Demoustier‐Champagne S. , Audebert P. , Sanchez C.
Published: February 2003

A bifunctional capping ligand is used to obtain pyrrol‐functionalized monodispersed nanocrystalline TiO2 (anatase) particles in a single step. The pyrrole functionalities in the shell are then (electro)chemically polymerized to create a polypyrrole (PPy)/TiO2 hybrid nanocomposite film (see Figure). Further electronic modification of the conducting polymer is possible, leading to a great variety of potential applications.
GaN Nanorods Doped by Hydride Vapor‐Phase Epitaxy: Optical and Electrical Properties
Authors: Kim H.‐M. , Cho Y.‐H. , Kang T.W.
Published: February 2003

Exciting opportunities in nanoscale technology could be made available thanks to this first report of doping GaN nanorods to create p‐ and n‐type materials. Controlled doping of the nanorods is achieved by hydride vapor‐phase epitaxy, and they are characterized optically and electrically. The Figure shows a scanning electron microscopy image of a nanorod field‐effect transistor (scale bar is 10 μm)
Electrically Switchable, One‐Dimensional Polymeric Resonators from Holographic Photopolymerization: A New Approach for Active Photonic Bandgap Materials
Authors: Jakubiak R. , Bunning T.J. , Vaia R.A. , Natarajan L.V. , Tondiglia V.P.
Published: February 2003

Stimulated emission is demonstrated by optically pumping chromophores within the liquid‐crystal domains of 1D bandgap structures that are derived from holographic polymer‐dispersed liquid‐crystal (H‐PDLC) gratings (see Figure). Electrically switchable laser resonance is also possible using the H‐PDLC, since applying an electric field across the grating aligns the directors of the liquid crystal, diminishing the refractive index profile and, consequently, the lasing action.
Impact of cysteine proteinase inhibition in midgut fluid and oral secretion on fecundity and pollen consumption of western corn rootworm (Diabrotica virgifera virgifera)
Authors: Kim Jae Hak , Mullin Christopher A.
Published: February 2003

Cysteine proteinases predominate in the midgut fluid (MF) and oral secretion (OS) of adult western corn rootworm (WCR) based on their mild acidic pH optima (pH 6.0), enhanced activities after treatment with thiol reducing agents, and inhibition by selective cysteine proteinase inhibitors (PIs). Four cysteine PIs including E‐64, calpeptin, calpain inhibitor II, and leupeptin (also a serine PI) strongly inhibited azocaseinolytic activity in a dose‐dependent manner in both the MF and OS. The most significant effect on adult female WCR of cysteine PI consumption with corn pollen was the reduction in fecundity, but female survival was not apparently affected. Mean fresh weights for all PI‐fed females were also lower than control groups. All PI‐fed groups [E‐64, calpain inhibitor I (Cal I) and leupeptin] had a significantly lower daily egg production than respective corn pollen‐fed controls. E‐64 was more potent than leupeptin and Cal I on inhibiting fecundity, which correlates with their relative anti‐proteinase potency in vitro. E‐64, Cal I, and leupeptin at 1.5–2 nmol/beetle/day reduced fecundity down to 25–45% of control values. Reduced egg production by PI‐fed beetles results from a combination of the direct inhibition of protein digestion and a post‐ingestive negative feedback mechanism, which reduces food intake. The supplement of ten essential amino acids into the E‐64‐treated pollen enhanced up to 3.7‐fold the number of eggs laid compared to the E‐64‐fed group without these amino acids, suggesting that egg production is dependent on the supply of essential amino acids from corn pollen proteolysis. Arch. Insect Biochem. Physiol. 52:139–154, 2003. © 2003 Wiley‐Liss, Inc.
What can be learnt from extragalactic X‐ray surveys?
Authors: Fabian A.C.
Published: February 2003

Extragalactic X‐ray surveys reveal many Active Galactic Nuclei (AGN) as well as clusters and groups of galaxies. Many of the AGN are obscured, leading to the hard spectrum of the X‐ray Background. Constraints from the absorptioncorrected X‐ray Background spectrum and the local mass density of black holes on the radiative efficiency and growth of accreting black holes are discussed. The use of clusters for the determination of cosmological parameters, and the energy and metallicity loss by galaxies and AGN, is noted.
The weak outnumbering the mighty: normal galaxies in deep Chandra surveys
Authors: Hornschemeier A. E. , Bauer F. E. , Alexander D. M. , Brandt W. N. , Sargent W. L. W. , Vignali C. , Garmire G. P. , Schneider D. P.
Published: February 2003

Chandra is detecting a significant population of normal and starburst galaxies in extremely deep X‐ray exposures. For example, approximately 15% of the sources arising in the 2 Ms Chandra Deep Field‐North survey are fairly normal galaxies, where “normal” means “Milky Way‐type” X‐ray emission rather than simply exhibiting an “optically normal” spectrum. Many of these galaxies are being detected at large look‐back times (z ≈ 0.1–0.5), allowing the study of the evolution of X‐ray binary populations over significant cosmological timescales. We are also detecting individual off‐nuclear ultraluminous X‐ray sources (e.g., X‐ray binaries), providing the first direct constraints on the prevalence of lower‐mass black holes at significantly earlier times. The X‐ray emission from such “normal” galaxies may also be a useful star‐formation rate indicator, based on radio/X‐ray cross‐identifications. We describe the contribution of normal galaxies to the populations which make up the X‐ray background and present their directly measured X‐ray number counts. We find that normal and starburst galaxies should dominate the 0.5–2 keV number counts at X‐ray fluxes fainter than ≈ 7 × 10–18 erg cm–2 s–1 (thus they will outnumber the “mighty” AGN). Finally, we look to the future, suggesting that it is important that the population of X‐ray faint normal and starburst galaxies be well constrained in order to design the next generation of X‐ray observatories.
The XMM‐Newton Survey Science Centre Medium Sensitivity Survey
Authors: Barcons X. , Carrera F.J. , Ceballos M.T. , Mateos S. , Page M.J. , Pérez‐Fournon I. , Watson M.G. , The XMM‐Newton Survey Science Centre
Published: February 2003

We present preliminary results on the XMM‐Newton Survey Science Centre medium sensitivity survey, with 0.5‐4.5 keV flux limit 2 × 10–14 erg cm–2s–1. At present, 19 fields have been examined with a total of 239 X‐ray sources. Identifications for about 2/3 of these reveal that type 1 AGN dominate, but type 2 AGN, absorption‐line galaxies and clusters as well as stars are also present. We also discuss on a few X‐ray selected Broad‐Absorption‐Line QSOs found in this survey
X‐ray spectra of XMM‐Newton AXIS serendipitous sources
Authors: Mateos S. , Barcons X. , Carrera F.J. , Ceballos M.T. , the XMM‐Newton Survey Science Centre
Published: February 2003

We have carried out a broad‐band spectral analysis of X‐ray sources detected serendipitously with the EPIC‐pn instrument onboard XMM‐Newton in AXIS fields. Our total catalogue contains 1837 X‐ray sources detected in the energy band 0.5‐4.5 keV down to a flux of ∼ 3 × 10–15erg cm–2s–1. Optical identifications are available for 190 sources: 119 broad‐line AGN (BLAGN), 23 narrow‐line emitting galaxies (NELG), 12 normal galaxies, 34 stars, 1 cluster and 1 BL Lac. We have first fitted individual broad‐band spectra with a single power law model plus Galactic absorption. An analysis of these fits as a whole reveals that this model is not appropriate for the overall population, nor is it for the BLAGNs. We have then refitted the spectra with an absorbed power law model. In this case there is a significant improvement in the spectral fits as a whole. However, detection of absorption in individual sources has not been possible with the current approach and will have to await for a more refined analysis.
HI – the window to the early universe in X‐rays
Authors: Kerp J.
Published: February 2003

A detailed understanding of the soft X‐ray background (SXRB) is of high importance for the next generation of X‐ray telescopes, which will focus on early universe objects. Because of their high redshift the characteristic X‐ray emission of the early universe objects will be observable in the soft X‐ray energy domain below E = 1 keV. In this energy regime the photoelectric absorption of the galactic interstellar medium attenuates the X‐ray emission most strongly. The confusion with the spatially highly variable galactic soft X‐ray emission might be an additional severe problem to disentangle the emission of the early universe object and the SXRB. We present the cross correlation of the Leiden/Dwingeloo HI 21‐cm line survey with the ROSAT all‐sky survey. The analyses disclose the existence of a single temperature plasma within the Milky Way halo. The strength of the photoelectric absorption is quantitatively traced by the distribution of the HI emission across the whole sky. Both findings in combination open the window to the highly redshift early universe objects.
XMM‐Newton observation of the galactic centre – evidence against the X‐ray reflection nebulae model?
Authors: Predehl P. , Costantini E. , Hasinger G. , Tanaka Y.
Published: February 2003

We present preliminary results of a 50 ksec XMM‐Newton observation of the Galactic Centre. Due to the excellent spectral resolution of XMM‐Newton combined with its high throughput at energies even beyond 7 keV, the iron line complex could be resolved into individual components (neutral, ionized, both in Kα and Kβ) in the spectra of a number of sources. In the spectrum of Sgr A East, we find an overabundance of iron, although less than reported in a recent analysis of Chandra data. No flare from Sgr A*was detected. The large scale diffuse emission seen already by Einstein, ROSAT, and ASCA extending into the north‐east direction is most probably of thermal origin. This region extends from Sgra A East also towards both directions perpendicular to the Galactic Plane (“outflow”) and contains some blobs of plasma with a higher temperature. Particularly interesting is the map of the 6.4 keV fluorescence line of neutral iron which shows a very peculiar filamentary structure. Spectral modelling of these filaments is obviously not in agreement with the X‐ray reflection nebulae (XRN) model commonly discussed for the origin of the fluorescence line, primarily because we do not see a significant iron absorption edge at 7.1 keV.