bluuebunny/crossref_metadata_2025 huggingface dataset:
The implicit use of business concepts in the UK Research Assessment Exercise
Authors: Ball Derrick F. , Butler Jeff
Published: January 2004

Research assessment exercises covering universities in the United Kingdom were established to produce quality ratings as a basis for allocating much of the research funding from central government. They represent some of the largest research management exercises ever undertaken. Amongst other aspects of university performance, the publications of all ‘research active’ UK academics are evaluated. This paper describes the way in which quality was assessed and funds were allocated as a result of the 1992, 1996 and 2001 exercises. It looks at how the exercises might continue to evolve and the value of a further exercise.

The strategies adopted by universities to maximise their ratings and their income are also considered. Universities have improved their research performance and their reporting methods in response to changes in the criteria and weightings used in the exercise. In parallel the HEFC (Higher Education Funding Council) has changed the ways in which funds have been distributed once the level of research performance has been determined.

The exercises have received much criticism as well as an acceptance that they have changed the culture of academic research. This paper considers the parallel evolution of trends in the management of R&D in business with trends in the management of university research via these exercises. There are underlying assumptions that seem to influence the transfer of policy design principles and management lessons between the two sectors.
Changing Family Policy in Sweden and Finland during the 1990s
Authors: Hiilamo Heikki
Published: January 2004

The aim of the article is to analyse changes in family policy programmes in Sweden and Finland during the turbulent years of the 1990s. The results suggest that in spite of cutbacks some features of the ideal‐typical model of Nordic family policy became more prominent towards the end of the 1990s. For example, the importance of universalism was strengthened by such measures as the discontinuation of several forms of tax benefits for families with children in Sweden, and especially in Finland. The subjective right to day care was extended in both countries to cover all children of preschool age. Because of cutbacks, however, policies aimed at promoting horizontal and vertical distribution suffered. There was hardly any change in pronatalism. Compared with the 1970s and 1980s, the 1990s were indeed a period of retrenchment. However, this did not mean profound structural change. In the case of family policy, the early fears concerning the demise of the Nordic model proved false.
Importing Workfare: Policy Transfer of Social and Labour Market Policies from the USA to Britain under New Labour
Authors: Daguerre Anne
Published: January 2004

Britain's New Labour government has put welfare reform at the top of its political agenda. It has followed a radical “workfare” agenda in relation to labour and social market policies and no longer aims to secure full employment mainly through direct job creation or Keynesian demand management. Instead, it promotes equal opportunity for all based on a contract between benefits claimants and the employment service. The New Deal is at the heart of British activation programmes for the unemployed. American policy paradigms have influenced the design of the New Deal. Policy transfer in activation policies from the USA to Britain is due to institutional similarities in British and American welfare states on the one hand, and to the comparable structure of their labour markets on the other hand. The influence of the European social model on British labour market policies thus remains limited.
Learning, Large Deviations, And Recurrent Currency Crises*
Authors: Kasa Kenneth
Published: January 2004

This article studies a version of Obstfeld's (Journal of International Economics43 (1997), 61–77) “escape clause” model. The model is calibrated to produce three rational expectations equilibria. Two of these equilibria are E‐stable and one is unstable. Dynamics are introduced by assuming that agents must learn about the government's decision rule. It is assumed they do this using a stochastic approximation algorithm. It turns out that as a certain parameter describing the sensitivity of beliefs to new information gets small, the algorithm converges to a small noise diffusion process. The dynamics of exchange rate changes are then characterized using large deviation techniques from Freidlin and Wentzell (Random Perturbations of Dynamical Systems, Second Edition, Berlin: Springer‐Verlag, 1998). These methods describe the sense in which the limiting distribution of exchange rate changes is approximated by a two‐state Markov‐Switching process, where the two states correspond to the two E‐stable equilibria. The model is calibrated to the exchange rate histories of Argentina, Brazil, and Mexico. Currency crises in these countries resemble the predicted “escape routes” of the model. A key feature of these escape routes is that expectations of a devaluation erupt suddenly, without large contemporaneous shocks. This is consistent with evidence showing that crises are often poorly anticipated by financial markets.
A Markov‐Switching Model Of Gnp Growth With Duration Dependence*
Authors: Lam Pok‐sang
Published: January 2004

A Markov‐switching model of postwar quarterly real GNP growth is used to examine the duration dependence of business cycles. It extends the Hamilton model and the duration‐dependent model of Durland and McCurdy, and compares quite favorably to simpler models in out‐of‐sample forecasting. When an expansion begins, the probability of the expansion ending is 0.2, but it gradually decreases as the expansion ages. When a contraction begins, the probability of the contraction terminating is 0.07, but it increases rapidly as the contraction ages. Output growth slows over the course of an expansion. The hypothesis of the 7–10‐year cycle is not supported.
Pattern Bargaining*
Authors: Marshall Robert C. , Merlo Antonio
Published: January 2004

Many unions in the United States have for several years engaged in what is known as pattern bargaining. In this article, we show that pattern bargaining is preferred by a union to both simultaneous industry‐wide negotiations and sequential negotiations without a pattern. Allowing for interfirm productivity differentials within an industry, we show that for small differentials, the union most prefers a pattern in wages, but for a sufficiently wide differential, the union prefers a pattern in labor costs. Finally, we demonstrate that pattern bargaining can be a significant entry deterrent. This provides an explanation for why incumbent firms in an industry may support the use of pattern bargaining in labor negotiations.
Free‐Riding and the Provision of Public Goods in the Family: A Laboratory Experiment*
Authors: Peters H. Elizabeth , Ünür A. Sinan , Clark Jeremy , Schulze William D.
Published: January 2004

We examine the provision of family public goods using experimental economics methods. With sufficient altruism and shared resource arrangements, families can provide the efficient level of family public goods. Becker's Rotten Kid Theorem asserts that transfers from altruistic parents will induce children to maximize family income even if children are not altruistic toward other family members. Consistent with altruism, parents and children contributed more to a public good when in groups with family members than when in groups with strangers. In contrast to the predictions of the Rotten Kid Theorem, however, children's behavior fell short of maximizing family income.
The Yin and Yang of the H-Channel and Its Role in Epilepsy
Authors: Poolos Nicholas P.
Published: January 2004

Voltage-gated ion channels clearly are involved in the pathogenesis of epilepsy, with evidence implicating derangement of Na+, K+, and Ca2+ voltage-gated channels, in both inherited and acquired forms of epilepsy ( 1 ). A newcomer to this list of ion channels involved in epilepsy is the hyperpolarization-activated cation channel or h-channel (otherwise known as Ih or the pacemaker channel). This voltage-gated channel now is known to play a significant role in regulating neuronal excitability and recently has been shown to be modulated by seizures. Unlike other channels implicated in epilepsy whose function in normal neurons can clearly be labeled “excitatory” (Na+ and Ca2+) or “inhibitory” (K+), the unique physiologic behavior of the h-channel allows it to both augment and decrease the excitability of neurons. Thus the role of Ih in epilepsy, at present, is controversial and is a growing area of intense investigation ( 2 , 3 ).
Social‐Information‐Processing Skills of Kindergarten Children with Developmental Learning Disabilities
Authors: Tur‐Kaspa Hana
Published: January 2004

The study examined the social‐information‐processing skills of kindergarten children with developmental learning disabilities (LD) utilizing Crick and Dodge's (1994) model of children's social adjustment as a theoretical framework. Participants consisted of 20 kindergarten children with developmental LD who attended three integrated kindergartens and 20 children without developmental LD from the same kindergartens. Participants were assessed on social‐information‐processing skills, feelings of loneliness, sense of coherence, and teachers' ratings of behavioral problems and positive resources. The results indicated that girls with developmental LD performed significantly lower on two information‐processing steps—the response decision and the enactment steps—than did girls without LD. Such differences were not found for boys. The results also showed that the social‐information‐processing skills of children with developmental LD were correlated with teachers' ratings.
Patterns of Close Relationships and Socioemotional and Academic Adjustment Among School‐Age Children with Learning Disabilities
Authors: Al‐Yagon Michal , Mikulincer Mario
Published: January 2004

This study examined patterns of close relationships among school‐age children with learning disabilities (LD) as manifested in their attachment style, their self‐perceived loneliness, their sense of coherence, and teacher ratings of their academic functioning. In line with resilience theory, this study also aimed to further explore predictors of positive adjustment for children with LD. The sample comprised 98 children with LD from regular classes in four Israeli public elementary schools, and 98 non‐LD children from the same classes. Significant group differences emerged in attachment styles and adjustment. Attachment style significantly correlated with socioemotional adjustment but not with academic functioning. In addition, a subgroup of resilient children emerged among the LD children. Discussion focused on the value of attachment patterns for understanding social and emotional adjustment among school‐age children with LD.
Social and Emotional Functioning of Children with Learning Disabilities: Does Special Education Placement Make a Difference?
Authors: Wiener Judith , Tardif Christine Y.
Published: January 2004

Children with learning disabilities in four types of special education settings were compared in terms of social acceptance, number of friends, quality of relationship with best friends, self‐concept, loneliness, depression, social skills, and problem behaviors. Two of the placements (In‐Class Support and Resource Room) were for children with mild to moderate learning disabilities and involved between 30 and 90 minutes of special education per school day. The other two placements (Inclusion Class and Self‐Contained Special Education Class) were designated for children with severe learning disabilities and involved at least a half‐day of special education. Children in the more inclusive placements had more positive social and emotional functioning. Children receiving In‐Class Support were more accepted by peers, had higher self‐perceptions of mathematics competence, and fewer problem behaviors than children receiving Resource Room Support. Children in Inclusion Classes had more satisfying relationships with their best school friends, were less lonely, and had fewer problem behaviors than children in Self‐Contained Special Education Classes.
Positive and Negative Self‐Perceptions: Is There a Cyclical Relationship Between Teachers' and Students' Perceptions of Effort, Strategy Use, and Academic Performance?
Authors: Meltzer Lynn , Reddy Ranjini , Pollica Laura Sales , Roditi Bethany , Sayer Julie , Theokas Christina
Published: January 2004

This study was part of a larger research program designed to investigate how effort interacts with strategy use to mediate the academic performance of successful students with learning disabilities (LD) and how teachers' and students' perceptions influence these relationships. The sample consisted of 46 students with LD and 46 matched students without LD and their seven teachers from Grades 6–8. A self‐report survey was used to obtain an index of students' perceptions of their effort, strategy use, academic struggles, and academic competence. Our findings indicated that students with LD with positive academic self‐perceptions were more likely to work hard and to use strategies in their schoolwork than were students with LD who had negative academic self‐perceptions. Teachers viewed students with LD who had positive academic self‐perceptions as working equally hard and attaining similar levels of academic competence as their peers without LD. In marked contrast, students with LD who had negative academic self‐perceptions were judged by their teachers as making limited effort in school and achieving at a below‐average level in comparison with their peers. Findings suggested a cyclical relationship between students' self‐perceptions and their teachers' judgments and supported the notion of a reciprocal strategy‐effort interaction.
Second‐Generation Research on Resilience: Social‐Emotional Aspects of Children with Learning Disabilities
Authors: Margalit Malka
Published: January 2004

The goal of this commentary is to focus attention on the various protective factors examined by the four studies of this special issue, in order to predict resilient functioning. These factors include internal factors (cognitive information processing, affective information processing—the attachment/proximity conceptualization) as well as external factors such as teacher perceptions and classroom ecology. By bringing together major themes from these studies, this commentary aims to explicate core elements of resilience in order to enhance the conceptual clarity of the construct within empowerment models, and to point out major directions for future research. Questions emerging from the results yielded by these studies will also be presented.
Diagnostic Utility of the Bannatyne WISC‐III Pattern
Authors: Smith Courtney B. , Watkins Marley W.
Published: January 2004

Regrouping Wechsler Intelligence Scale for Children‐Third Edition (WISC‐III) subtests into Bannatyne's spatial, conceptual, and sequential patterns has been thought by many to identify children with learning disabilities (LD). This study investigated the prevalence and diagnostic utility of WISC‐III Bannatyne patterns by comparing 1,302 children with LD to 2,158 children in the WISC‐III normative sample. Further analysis was conducted on a subsample of students with specific reading disabilities. Results indicated that the presence of the Bannatyne WISC‐III pattern would not lead to decisions that are useful in differentiating children with LD from children without LD. For example, receiver operating characteristic (ROC) analysis, measured by the area under the curve (AUC), indicated that the Bannatyne WISC‐III pattern exhibited low diagnostic utility (AUC = 0.54–0.55). Due to its inaccuracy, use of the Bannatyne WISC‐III pattern is not recommended.
Extended Test Time and postsecondary Students with Learning Disabilities: A Model for Decision Making
Authors: Ofiesh Nicole S. , Hughes Charles , Scott Sally S.
Published: January 2004

The most frequently requested accommodation among students with learning disabilities (LD) in postsecondary settings is extended test time. The frequency with which this accommodation is requested and granted compels disability service providers to become knowledgeable about the factors that influence the need for, and appropriateness of, the accommodation. Moreover, the synthesis of these factors becomes the basis for determining if the accommodation is reasonable under federal law. The purpose of this article is to present a step‐by‐step model to be used as a decision‐making process when considering the accommodation of extended test time for postsecondary students with LD. The model is designed to assist disability service providers in the analysis and synthesis of information collected from (1) the student's diagnostic evaluation, (2) the course or classroom test to be accommodated, and (3) student interviews. A list of diagnostic tests from the four most frequently administered test batteries used with adults is provided, along with a concise explanation of how characteristics of LD impact reading, writing, and math, and relate to the need for extended time. This information can be used to determine if extended test time is a reasonable accommodation and to estimate how much additional time to provide.
Compensation, Incentives, and the Duality of Risk Aversion and Riskiness
Authors: Ross Stephen A.
Published: January 2004

The common folklore that giving options to agents will make them more willing to take risks is false. In fact, no incentive schedule will make all expected utility maximizers more or less risk averse. This paper finds simple, intuitive, necessary and sufficient conditions under which incentive schedules make agents more or less risk averse. The paper uses these to examine the incentive effects of some common structures such as puts and calls, and it briefly explores the duality between a fee schedule that makes an agent more or less risk averse, and gambles that increase or decrease risk.
Parasympathetic Blockade Promotes Recovery from Atrial Electrical Remodeling Induced by Short‐term Rapid Atrial Pacing
Authors: MIYAUCHI MIZUHO , KOBAYASHI YOSHINORI , MIYAUCHI YASUSHI , ABE JUNKO , MORITA NORISHIGE , IWASAKI YU‐KI , HAYASHI MEISO , TAKANO TERUO
Published: January 2004

The purpose of the present study was to assess the influence of autonomic blockade on shortening of effective refractory period (ERP) induced by short‐term rapid atrial pacing (RAP) and its recovery process. Fifteen patients (8 men, 7 women, age 52 ± 16 years) without structural heart disease and without a history of atrial fibrillation were included in this study. All patients underwent RAP at a cycle length of 300 ms for 5 minutes, after which the ERP was measured in all patients at 1, 3, 5, 7.5, and 10 minutes following cessation of RAP. In ten patients, these RAP and measurements of ERPs were repeated after administration of propranolol (P) and subsequent administration of atropine (P + A), respectively. In the remaining five patients atropine (A) was given first and then the administration of propranolol followed (P + A). Relative to the baseline value, the ERP immediately after RAP did not differ significantly from the Control(C), P, A, or P + A (C, 79%± 8%; P, 82%± 9%; A, 80%± 6%; P + A, 82%± 13%). However, the ERP 3 minutes after cessation of RAP was significantly (P < 0.05) longer in A (93%± 4%) and P + A (97%± 5%) than that in C (86%± 5%) and P (86%± 5%). The recovery time for ERP to return to pre‐RAP value was significantly shorter during A and P + A than during either C or P (C, 536 ± 161 s; P, 503 ± 172 s; A, 282 ± 111 s; P + A, 291 ± 147 s; P < 0.05). Parasympathetic blockade may promote recovery from ERP shortening induced by short‐term RAP. (PACE 2004; 27:33–37)
Implantable Cardioverter Defibrillators in Adults with Congenital Heart Disease:
Authors: Dore Annie , Santagata Patrizia , Dubuc Marc , Mercier Lise‐Andrée
Published: January 2004

Sudden death is the most frequent cause of late mortality in adults with congenital heart disease. This study reviews the experience of an Adult Congenital Heart Center with the use of implantable cardioverter defibrillators (ICDs). The charts of adults with congenital heart disease who had an ICD implantation were reviewed for diagnosis, residual lesions, reoperations, reason for implantation, complications, and recurrence of arrhythmias. Since 1995, 13 patients (mean age 43 years) had an ICD implantation for aborted sudden death (4), and spontaneous (6), or induced (3) ventricular tachycardia. Diagnosis were repaired (6) or palliated (1) tetralogy of Fallot, operated pulmonary stenosis (2), palliated complex pulmonary atresia (1), congenitally corrected transposition (1), operated ventricular (1), and atrial (1) septal defects. Significant residual lesions included severe pulmonary regurgitation (2), systemic ventricular dysfunction (2), and severe pulmonary hypertension (1). Five patients had a QRS > 180 ms, four had a QRS < 180 ms, four had a paced rhythm. Overall, four (31%) patients had no ventricular dysfunction, no residual lesion, and QRS < 180 ms. During a mean follow‐up of 29 months, seven patients had recurrent ventricular tachycardia, three with normal ventricular function, no residual lesion, and QRS < 180 ms. ICD implantation is an important adjunct in the management of adults with congenital heart disease. As malignant arrhythmias occur even in patients with no residual lesion, no QRS prolongation and no ventricular dysfunction, the recognition of those who would benefit from an ICD remains a clinical challenge. (PACE 2004; 27:47–51)
Risk for injury when playing in a national football team
Authors: Ekstrand Jan , Waldén Markus , Hägglund Martin
Published: January 2004

The Swedish male senior national football team was followed prospectively between 1991 and 1997. During these 6 years, the team played 73 official matches and had three training camps. The senior author (J. E.) attended 57 of these matches and the three training camps and these matches and training camps, are included in the present study. Exposure to football was recorded individually for each player. The team physician examined all injuries. Total exposure was 7245 h (6235 training and 1010 match hours) and there were 71 injuries (40 training and 31 match injuries). Five (16%) of the match injuries were major, with more than 4 weeks of absence from football. The injury incidence during training was 6.5/1000 h and the injury risk during matchplay was 30.3/1000 h. A significantly higher injury incidence was found for matches lost compared to matches won or drawn (52.5 vs. 22.7/1000 h, P=0.026). No statistically significant difference for injury was found between competitive matches and friendly matches. No difference was found between home and away matches or matches on neutral ground. The risk for injury when playing in a national team compares with previously reported figures for professional football at a high level.
Contralateral tendon rupture risk is increased in individuals with a previous Achilles tendon rupture
Authors: Årøen A. , Helgø D. , Granlund O. G. , Bahr R.
Published: January 2004

The purpose of this study was to examine the outcome after surgery for an acute Achilles tendon rupture. In particular, we wanted to study whether persons who have suffered an Achilles tendon rupture are at greater risk of a contralateral tendon rupture. From September 1990 to April 1997, 168 acute Achilles tendon ruptures in 26 women and 142 men were treated operatively. In August 1998 (median: 4.2 years post injury), 154 of these patients (92%) responded to a follow‐up questionnaire. Local symptoms (pain, decreased strength and/or reduced range of motion) were reported pre injury by 25% of the patients; at follow‐up this had increased to 52%. Ten patients (6%) experienced a rupture on the contralateral side during the follow‐up period (OR: 176 [70–282] vs. the expected rate based on the general population risk of this injury, P<0.001). Thus, this study suggests that patients with an Achilles tendon rupture are at significantly increased risk of a contralateral tendon rupture, as well. Also, as many as half of the patients suffered from post‐injury problems at long‐term follow‐up.
Attitudes to and perceptions of oral health and oral care among community‐dwelling elderly residents of Stockholm, Sweden: an interview study*
Authors: Andersson Kerstin , Nordenram Gunilla
Published: January 2004

Abstract: The aim of this study was to document perceptions of oral health of community‐dwelling elderly people and how it had been affected through life. Twelve individuals (mean age 78.2 years) were gradually recruited to an interview study. The interviews were conducted as conversations, and the topics in a guide model were introduced only if they did not arise spontaneously. The interviews lasted 60–90 min and were tape‐recorded and transcribed verbatim and analysed by the phenomenological–hermeneutic method. The interviews dealt with perceptions of growing old, life style, general health, former dental experiences, dental care in adult life, current oral health, general medical care, dental care, oral hygiene, dental hygienist care and the level of participation in treatment decisions. The interviewees were generally satisfied with their present oral health and often referred to their parents' oral problems as deterrents. Dental experiences from childhood, in association with the welfare state and personal financial security, were factors which influenced attitudes and perceptions of oral health and oral care. Although dental care was regarded as very expensive, it had been given priority over other expenses in adult life. The results confirm that the dental hygienist must take into account the importance of oral health to well being in old age and be aware that in elderly people, perception of personal oral health is multifactorial, influenced by life‐long experience.
Ingredients in dentifrices and their effect on plaque, gingivitis and mutans streptococci
Authors: Jannesson L , Birkhed D , Renvert S
Published: January 2004

The main objectives of this thesis were to study: (i) the effect of an enzyme‐containing dentifrice (Zendium Dentine®), with addition of xylitol on mutans streptococci (MS) in saliva and dental plaque (Paper I) (ii) the effect of a combination of triclosan and xylitol in a dentifrice (Colgate Total®) on MS in saliva and dental plaque (Paper II), and (iii) the effect of oxybenzone on prostaglandin E2 (PGE2)‐production in cell culture and the effect of an oxybenzone‐containing dentifrice on plaque, gingivitis and MS (Paper III). In Paper I, the subjects were divided into two test groups: one using a 10% xylitol and the other using a 5% xylitol dentifrice for 3 months. The addition of 10% xylitol to Zendium Dentine® had an inhibitory effect on MS in both saliva and dental plaque, and the effect of xylitol seemed to be dose dependent. In Paper II, three groups were using one of the following dentifrices: (i) Colgate Total® with addition of 10% xylitol; (ii) Colgate Total®; and (iii) Colgate Total® without triclosan and without xylitol. The results showed that the addition of 10% xylitol to Colgate Total® reduced the number of MS in saliva and plaque. This effect was more pronounced at 6 months than at 2 months. In Paper III, the effect of oxybenzone was studied in vitro and in vivo. Human Embryo Palatal Mesenchyme (HEPM) cells were used to test the inhibition of IL‐1β‐stimulated PGE2 production by different concentrations of oxybenzone. The results revealed that there was no decrease of cell viability up to 50 µm. A dose‐dependent inhibition of stimulated PGE2 production was found: 50% inhibition (IC50) was found at 0.6 µm. Paper III also included a double‐blind clinical trial testing two fluoride dentifrices: one with the addition of 0.5% oxybenzone and one without. Plaque index was reduced in both groups. There was no difference between the groups. A 25% reduction in gingival index was observed in the oxybenzone group after 6 weeks, compared to 2% in the placebo group, indicating an anti‐inflammatory effect of oxybenzone.
Research utilisation among Swedish dental hygienists
Authors: Öhrn K , Olsson C
Published: January 2004

Dental hygienists have to practise evidence‐based decision making in the future, which means that actively seeking and utilising research findings will become more important. Objective: The objective of this study was to explore barriers to and facilitators of research utilisation in clinical practice among Swedish dental hygienists. Methods: The study was a descriptive, comparative cross‐sectional survey including a random sample of 491 dental hygienists in Sweden. The response rate was 62%. A validated questionnaire covering different aspects of participation in research, support for and availability of research, and research utilisation was employed. Results: The most common research‐related activities were: reading research projects in professional journals, 83%; participating in clinical audit, 67%; and sharing research findings with their own professional colleagues, 65%. The most commonly reported available research‐related resources were computer services to access the internet, which was true for 84%. A total of 31% reported exploring how research findings can be used in clinical settings as the best help to make research more useful. The most reported item that discouraged dental hygienists the most from using research in clinical practice was time limitation (42%). Dental hygienists with continuing education university courses reported a higher activity in seeking new research and more support and available research‐related activities than those without a university course. Dental hygienists with a 2‐year education reported a more positive attitude towards research and rated their own research utilisation in clinical practice higher than those with a 1‐year education. Dental hygienists educated at universities without a dental school reported a more positive attitude towards research and rated their own research utilisation in clinical practice higher than those who were educated in connection with a dental school. Dental hygienists working in public dental care reported higher activity in seeking new research and rated their own research utilisation in clinical practice higher than those working in private dental offices. Conclusions: There is a need for continuing education in evidence‐based dental hygiene. The length of the education is important, and a more comprehensive education support research utilisation.
Slow group velocity propagation of sound via defect coupling in a one-dimensional acoustic band gap array
Authors: Robertson W. M. , Baker C. , Bennett C. Brad
Published: January 2004

A simple experimental system is presented in which the group velocity of acoustic wave packets traveling in an air-filled waveguide can be slowed to values much smaller than the speed of sound in air. The experiment is an acoustic analog of the much-studied optical phenomenon of slow light propagation. Slow (or even stopped) light propagation has been observed in atomic vapors in the vicinity of strong dispersion, typically associated with electromagnetically induced transparency. In the acoustic experiment described here, strong dispersion is produced by the introduction of a defect in an otherwise perfectly periodic one-dimensional acoustic band gap array. The defect produces a narrow transmission band within the forbidden acoustic band gap region resulting in strong dispersion. By tuning the carrier frequency of the acoustic wave packet to the peak transmission of the defect, the group velocity can be slowed to 0.24vs, where vs is the speed of sound in air. These results are shown to be consistent with theoretical calculations.
Single light scattering: Bubbles versus droplets
Authors: Kokhanovsky Alexander A.
Published: January 2004

The intensity and polarization characteristics of scattered light beams are studied for bubbles in water and compared to the case of water droplets in air. The size distributions of the scatters in both systems are assumed to be the same. It is shown that spherical polydispersions of water droplets give generally larger depolarization effects than bubbles, leading to larger entropy production by droplets than bubbles.
Specific Inhibition of Human Cytomegalovirus Glycoprotein B-Mediated Fusion by a Novel Thiourea Small Molecule
Authors: Jones Thomas R. , Lee Shi-Wu , Johann Stephen V. , Razinkov Vladimir , Visalli Robert J. , Feld Boris , Bloom Jonathan D. , O'Connell John
Published: January 2004

A novel small molecule inhibitor of human cytomegalovirus (HCMV) was identified as the result of screening a chemical library by using a whole-virus infected-cell assay. Synthetic chemistry efforts yielded the analog designated CFI02, a compound whose potency had been increased about 100-fold over an initial inhibitor. The inhibitory concentration of CFI02 in various assays is in the low nanomolar range. CFI02 is a selective and potent inhibitor of HCMV; it has no activity against other CMVs, alphaherpesviruses, or unrelated viruses. Mechanism-of-action studies indicate that CFI02 acts very early in the replication cycle, inhibiting virion envelope fusion with the cell plasma membrane. Mutants resistant to CFI02 have mutations in the abundant virion envelope glycoprotein B that are sufficient to confer resistance. Taken together, the data suggest that CFI02 inhibits glycoprotein B-mediated HCMV virion fusion. Furthermore, CFI02 inhibits the cell-cell spread of HCMV. This is the first study of a potent and selective small molecule inhibitor of CMV fusion and cell-cell spread.
The Mature Avian Leukosis Virus Subgroup A Envelope Glycoprotein Is Metastable, and Refolding Induced by the Synergistic Effects of Receptor Binding and Low pH Is Coupled to Infection
Authors: Smith Jason G. , Mothes Walther , Blacklow Stephen C. , Cunningham James M.
Published: January 2004

The spring-loaded model stipulates that influenza virus infection is coupled to the transition of the virus hemagglutinin (HA) from a metastable conformation to a highly stable conformation at low pH. The properties of retrovirus envelope glycoproteins indicate that infection is coupled to an analogous conformational change. As a test of this hypothesis, the requirements for avian leukosis virus A (ALV-A) infection were examined. These studies indicate that, like HA, the conformation of the mature ALV-A envelope glycoprotein is metastable and that infection is linked to refolding at low pH. However, unlike HA, low-pH activation is only observed after priming by receptor. Therefore, ALV-A infection is dependent on the synergistic effects of receptor binding and low pH, suggesting that receptor binding superimposes an additional constraint on activation of ALV-A fusion that proceeds by a mechanism comparable to that of influenza virus.
VARIATIONAL PRINCIPLE FOR NON-EQUILIBRIUM STEADY STATES OF THE XX MODEL
Authors: MATSUI TAKU , OGATA YOSHIKO
Published: January 2004

We show that non-equilibrium steady states of the one-dimensional exactly-solved XX model can be characterized by the variational principle of free energy of a long range interaction and that they cannot be a KMS state for any C*-dynamical system of the UHF algebra.
SOME REMARKS ON THE GRAVITATIONAL AHARONOV–BOHM EFFECT
Authors: MARQUES GEUSA DE A. , BEZERRA VALDIR B.
Published: January 2004

A massless spinor particle is considered in the background spacetimes generated by a moving mass current and by a spinning cosmic string. In the weak field approximation it is shown that the solution of the Weyl equations depends on the velocity of the source, which does not affect the curvature in this approximation in the case of a moving mass current. In the case of a spinning cosmic string, the solution of the Weyl equations depends on the deficit angle and on the angular momentum of the string. These effects may be viewed as examples of the gravitational analogues of the Aharonov–Bohm effect in electrodynamics.
LOOP VARIABLES WITH CHAN–PATON FACTORS
Authors: SATHIAPALAN B.
Published: January 2004

The loop variable method that has been developed for the U(1) bosonic open string is generalized to include non-Abelian gauge invariance by incorporating "Chan–Paton" gauge group indices. The scale transformation symmetry k(s)→λ(s)k(s) that was responsible for gauge invariance in the U(1) case continues to be a symmetry. In addition there is a non-Abelian "rotation" symmetry. Both symmetries crucially involve the massive modes. However, it is plausible that only a linear combination, which is the usual Yang–Mills transformation on massless fields, has a smooth (worldsheet) continuum limit. We also illustrate how an infinite number of terms in the equation of motion in the cutoff theory add up to give a term that has a smooth continuum limit, and thus contributes to the low energy Yang–Mills equation of motion.
THE RADION AND THE PERTURBATIVE METRIC IN RS1
Authors: TOHARIA MANUEL
Published: January 2004

We calculate the linearized metric perturbations in the five-dimensional two-brane model of Randall and Sundrum. In a carefully chosen gauge, we write down and decouple Einstein equations for the perturbations and get the final and simple perturbative metric ansatz. This ansatz turns out to be equal to the linear expansion of the metric solution of Charmousis et al.1 We show that this ansatz, the metric ansatz of Boos et al.2 and the one of Das and Mitov3 are not incompatible, as it appears on the surface, but completely equivalent by an allowed gauge transformation that we give.
GENERALIZED p-FORMS ELECTRODYNAMICS IN CLIFFORD SPACES
Authors: CASTRO C.
Published: January 2004

Using Clifford algebraic methods we describe how to generalize Maxwell theory of Electrodynamics associated with ordinary point-charges to a generalized Maxwell theory in Clifford spaces involving extended charges and p-forms of arbitrary rank. Clifford algebras contain the appropriate algebraic-geometric features to implement the principle of polydimensional transformations (branes of different dimensionality are rotated into each other) that could possibly lead to a proper formulation of string and M theory.
PHANTOM AND QUANTUM MATTER IN AN ANTI DE SITTER UNIVERSE
Authors: ElIZALDE EMILIO , QUIROGA HURTADO JOHN
Published: January 2004

We consider an anti de Sitter universe filled by quantum CFT with classical phantom matter and perfect fluid. The model represents the combination of a trace-anomaly annihilated and a phantom driven anti de Sitter universes. The influence exerted by the quantum effects and phantom matter on the AdS space is discussed. Different energy conditions in this type of universe are investigated and compared with those for the corresponding model in a de Sitter universe.
DEFORMED DENSITY MATRIX AND GENERALIZED UNCERTAINTY RELATION IN THERMODYNAMICS
Authors: SHALYT-MARGOLIN A. E. , TREGUBOVICH A. YA.
Published: January 2004

A generalization of the thermodynamic uncertainty relations is proposed. It is done by introducing an additional term proportional to the interior energy into the standard thermodynamic uncertainty relation that leads to existence of the lower limit of inverse temperature. In our opinion the approach proposed may lead to the proofs of these relations. To this end, the statistical mechanics deformation at Planck scale. The statistical mechanics deformation is constructed by analogy to the earlier quantum mechanical results. As previously, the primary object is a density matrix, but now the statistical one. The obtained deformed object is referred to as a statistical density pro-matrix. This object is explicitly described, and it is demonstrated that there is a complete analogy in the construction and properties of quantum mechanics and statistical density matrices at Planck scale (i.e. density pro-matrices). It is shown that an ordinary statistical density matrix occurs in the low-temperature limit at temperatures much lower than the Planck's. The associated deformation of a canonical Gibbs distribution is given explicitly.
kt-FACTORIZATION AND CCFM: THE SOLUTION FOR DESCRIBING THE HADRONIC FINAL STATES EVERYWHERE?
Authors: JUNG HANNES
Published: January 2004

The basic ideas of kt-factorization and CCFM parton evolution is discussed. The unintegrated gluon densities, obtained from CCFM fits to the proton structure function data at HERA are used to predict hadronic final state cross-sections like jet production at HERA, but also comparisons with recent measurements of heavy quark production at the Tevatron are presented. Finally, the kt-factorization approach is applied to Higgs production at high energy hadron–hadron colliders and the transverse momentum spectrum of Higgs production at the LHC is calculated.
COLLISION DETECTION OPTIMIZATION IN A MULTI-PARTICLE SYSTEM
Authors: GAVRILOVA MARINA L. , ROKNE JON
Published: January 2004

Collision detection optimization in an event-driven simulation of a multi-particle system is one of the crucial tasks, determining the efficiency of the simulation. We present the event-driven simulation algorithm that employs dynamic computational geometry data structures as a tool for collision detection optimization (CDO). The first successful application of the dynamic generalized Voronoi diagram method for collision detection optimization in a system of moving particles is discussed. A comprehensive comparision of four kinetic data structures in d-dimensional space, performed in a framework of an event-driven simulation of a granular-type materials system, is supported by the experimental results.
BALANCED PARTITION OF MINIMUM SPANNING TREES
Authors: ANDERSSON MATTIAS , GUDMUNDSSON JOACHIM , LEVCOPOULOS CHRISTOS , NARASIMHAN GIRI
Published: January 2004

To better handle situations where additional resources are available to carry out a task, many problems from the manufacturing industry involve dividing a task into a number of smaller tasks, while optimizing a specific objective function. In this paper we consider the problem of partitioning a given set [Formula: see text] of n points in the plane into k subsets, [Formula: see text], such that [Formula: see text] is minimized. Variants of this problem arise in applications from the shipbuilding industry.

We show that this problem is NP-hard, and we also present an approximation algorithm for the problem, in the case when k is a fixed constant. The approximation algorithm runs in time O(n log n) and produces a partition that is within a factor (4/3+ε) of the optimal if k=2, and a factor (2+ε) otherwise.
THE LARGEST EMPTY ANNULUS PROBLEM
Authors: DÍAZ-BÁÑEZ J. M. , HURTADO F. , MEIJER H. , RAPPAPORT D. , SELLARÈS J. A.
Published: January 2004

Given a set of n points S in the Euclidean plane, we address the problem of computing an annulus A, (open region between two concentric circles) of largest width, that partitions S into a subset of points inside and a subset of points outside the circles, such that no point p∈S lies in the interior of A. This problem can be considered as a maximin facility location problem for n points such that the facility is a circumference. We give a characterization of the centres of annuli which are locally optimal and we show that the problem can be solved in O(n3 log n) time and O (n) space. We also consider the case in which the number of points in the inner circle is a fixed value k. When k∈O(n) our algorithm runs in O(n3 log n) time and O(n) space, furthermore, we can simultaneously optimize for all values of k within the same time bound. When k is small, that is a fixed constant, we can solve the problem in O(n log n) time and O(n) space.
SYMMETRY OF FLOW DIAGRAMS DERIVED FROM WEIGHTED POINTS IN THE PLANE
Authors: GIESEN JOACHIM , JOHN MATTHIAS , STÖCKLIN MICHEL
Published: January 2004

We introduce a condition that establishes a symmetry for diagrams associated with a class of dynamical systems (flows) which are induced by weighted points in the plane. This symmetry is known from weighted Delaunay- and power diagrams where it always holds. Under this condition the combinatorial and worst case algorithmic complexities of the flow diagrams are lower than in the general case. The condition is natural in the sense that it is automatically fulfilled for sets of unweighted points.
EXTRACTING MEANINGFUL SLOPES FROM TERRAIN CONTOURS
Authors: DAKOWICZ MACIEJ , GOLD CHRISTOPHER
Published: January 2004

Good quality terrain models are becoming more and more important, as applications such as runoff modelling are being developed that demand better surface orientation information than is available from traditional interpolation techniques. A consequence is that poor-quality elevation grids must be massaged before they provide useable runoff models. Rather than using direct data acquisition, this project concentrated on using available contour data because, despite modern techniques, contour maps are still the most available form of elevation information. Recent work on the automatic reconstruction of curves from point samples, and the generation of medial axis transforms (skeletons) has greatly helped in expressing the spatial relationships between topographic sets of contours. With these techniques the insertion of skeleton points into a TIN model guarantees the elimination of all "flat triangles" where all three vertices have the same elevation. Additional assumptions about the local uniformity of slopes give us enough information to assign elevation values to these skeleton points. In addition, various interpolation techniques were compared using the enriched contour data. Examination of the quality and consistency of the resulting maps indicates the required properties of the interpolation method in order to produce terrain models with valid slopes. The result provides us with a surprisingly realistic model of the surface - that is, one that conforms well to our subjective interpretation of what a real landscape should look like.
NURBS APPROXIMATION OF A-SPLINES AND A-PATCHES
Authors: BAJAJ CHANDRAJIT L. , XU GUOLIANG , HOLT ROBERT J. , NETRAVALI ARUN N.
Published: January 2004

Given A-spline curves and A-patch surfaces that are implicitly defined on triangles and tetrahedra, we determine their NURBS representations. We provide a trimmed NURBS form for A-spline curves and a parametric tensor-product NURBS form for A-patch surfaces. We concentrate on cubic A-patches, providing a C1-continuous surface that interpolates a given triangulation together with surface normals at the vertices. In many cases we can generate cubic trimming curves that are rationally parametrizable on the triangular faces of the tetrahedra; for the remaining faces we resort to using quadratic curves, which are always rationally parametrizable, to approximate the cubic trimming curves.
MINIMAL SET OF CONSTRAINTS FOR 2D CONSTRAINED DELAUNAY RECONSTRUCTION
Authors: DEVILLERS OLIVIER , ESTKOWSKI REGINA , GANDOIN PIERRE-MARIE , HURTADO FERRAN , RAMOS PEDRO , SACRISTÁN VERA
Published: January 2004

Given a triangulation T of n points in the plane, we are interested in the minimal set of edges in T such that T can be reconstructed from this set (and the vertices of T) using constrained Delaunay triangulation. We show that this minimal set is precisely the set of non locally Delaunay edges, and that its cardinality is less than or equal to n+i/2 (if i is the number of interior points in T), which is a tight bound.