bluuebunny/crossref_metadata_2025 huggingface dataset:
An algebraic algorithm for generation of three-dimensional grain maps based on diffraction with a wide beam of hard X-rays
Authors: Markussen T. , Fu Xiaowei , Margulies L. , Lauridsen E. M. , Nielsen S. F. , Schmidt S. , Poulsen H. F.
Published: January 2004

A reconstruction method is presented for generation of three-dimensional maps of the grain boundaries within powders or polycrystals. The grains are assumed to have a mosaic spread below 1°. They are mapped by diffraction with a wide beam of hard X-rays, using a setup similar to that of parallel-beam absorption contrast tomography. First the diffraction spots are sorted with respect to grain of origin. Next, for each grain the reconstruction is performed by an algebraic algorithm known as three-dimensional ART. From simulations it is found that reconstructions with a spatial accuracy better than the pixel size of the detector can be obtained from as few as five diffraction spots. The results are superior to three-dimensional reconstructions based on the same data using a variant of the filtered back-projection algorithm. In comparison with layer-by-layer type reconstructions based on the two-dimensional ART algorithm, as introduced by Poulsen & Fu [J. Appl. Cryst.(2003),36, 1062–1068], the quality of the maps is found to be similar, provided that five to ten spots are available for analysis, while data acquisition with the three-dimensional method is much faster. The three-dimensional ART methodology is validated on experimental data. With state-of-the-art detectors, the spatial accuracy is estimated to be 5 µm.
Electron diffraction of thin-film pentacene
Authors: Wu J. S. , Spence J. C. H.
Published: January 2004

The structure of pentacene thin films deposited on NaCl substrates have been studied by electron diffraction. The lattice parameters of a `thin film' phase [a= 6.1 (1),b= 7.6 (1),c= 15.3 (3) Å, α = 81.0 (16), β = 85.0 (17), γ = 89.5 (9)°] were determined using a series of diffraction patterns obtained by tilting the crystal in the electron microscope. This phase has a (001)dspacing of 15.1 (3) Å. The packing of molecules in the structure is discussed.
Structural refinement by restrained molecular-dynamics algorithm with small-angle X-ray scattering constraints for a biomolecule
Authors: Kojima Masaki , Timchenko Alexander A. , Higo Junichi , Ito Kazuki , Kihara Hiroshi , Takahashi Kenji
Published: January 2004

A new algorithm to refine protein structures in solution from small-angle X-ray scattering (SAXS) data was developed based on restrained molecular dynamics (MD). In the method, the sum of squared differences between calculated and observed SAXS intensities was used as a constraint energy function, and the calculation was started from given atomic coordinates, such as those of the crystal. In order to reduce the contribution of the hydration effect to the deviation from the experimental (objective) curve during the dynamics, and purely as an estimate of the efficiency of the algorithm, the calculation was first performed assuming the SAXS curve corresponding to the crystal structure as the objective curve. Next, the calculation was carried out with `real' experimental data, which yielded a structure that satisfied the experimental SAXS curve well. The SAXS data for ribonuclease T1, a single-chain globular protein, were used for the calculation, along with its crystal structure. The results showed that the present algorithm was very effective in the refinement and adjustment of the initial structure so that it could satisfy the objective SAXS data.
Reciprocal-space instrumental effects on the real-space neutron atomic pair distribution function
Authors: Qiu Xiangyun , Božin Emil S. , Juhas Pavol , Proffen Thomas , Billinge Simon J. L.
Published: January 2004

An atomic pair distribution function (PDF) neutron powder diffraction round-robin experiment was performed on six diffractometers at three spallation sources. Instrument-specific effects on the real-space PDF were investigated, such as finite measurement range, the instrument resolution and the asymmetric shape of diffraction peaks. Two illustrative samples, a perfectly long-range-ordered element, Pb, and a locally strained alloy ZnSe0.5Te0.5, were measured at low temperatures. Various aspects of the PDF were explored, either qualitatively by direct comparison or quantitativelyviastructural modelling. Future implementation of modelling codes incorporating some of these instrumental effects are also discussed.
Diffraction line broadening due to lattice-parameter variations caused by a spatially varying scalar variable: its orientation dependence caused by locally varying nitrogen content in ∊-FeN0.433
Authors: Leineweber Andreas , Mittemeijer Eric J.
Published: January 2004

The diffraction line broadening due to lattice-parameter variations caused by a position-dependent (spatial) scalar variable (e.g.the composition) was analysed theoretically. It was shown that the anisotropy of the resulting microstrain-like line broadening depends on the symmetry of the crystal system of the phase concerned. This model provides a physical basis for a special case of a previously reported phenomenological description of anisotropic microstrain broadening [Stephens (1999).J. Appl. Cryst.32, 281–289], which is widely used in Rietveld refinement. The model presented was used to analyse thehkldependence of the X-ray diffraction line broadening of a sample of hexagonal ∊-iron nitride, FeNy0with the average N contenty0= 0.433. The observed anisotropy of the line broadening was shown to be compatible with the known composition dependencies of the lattice parametersa(y) andc(y). From the extent of the line broadening, the standard deviation ofy0could be determined very well, as 0.008.
TWINLAWandHKLF5: two programs for the handling of non-merohedral twins
Authors: Bolte Michael
Published: January 2004

The programTWINLAWreads two orientation matrices obtained from a non-merohedrally twinned crystal and evaluates the twin law. In a second step, the programHKLF5 uses this twin law to generate a reflection file for refinement with the HKLF5 option of theSHELXLprogram. The use of both programs is demonstrated by means of the structure determination of Sr(H2PO4)2·H2O.
Formation of rocking curves for quasi-forbidden reflections in short-periodic superlattices GaAs/AlGaAs
Authors: Kladko Vasyl , Datsenko Leonid , Machulin Volodymyr , Domagala Jaroslaw , Lytvyn Petro , Bak-Misiuk Jadwiga , Kuchuk Andrian , Korchovyi Andrii
Published: January 2004

Peculiarities of the diffraction patterns in short-periodic GaAlAs/GaAs superlattices were investigated in the case of quasi-forbidden reflections. The weak influence of GaAs layers on the diffraction pattern intensity, associated with a small value of an atomic form-factor difference as well as the appearance of periodic satellites, has been established. The reasons for the appearance and disappearance of the satellite structure in the diffraction patterns are discussed in relation to the structural perfection of the layers, interfacial strain and roughness of the boundaries, and layer thickness fluctuation.
Impedance modelling on multiple dielectric builds
Authors: Gaudion Martyn , Staniforth J. Alan
Published: January 2004

As printed circuit board (PCB) track geometries shrink, sometimes it becomes necessary to look deeper than the material data sheet when modelling electrical properties of transmission lines; this study looks at how variation in dielectric constant should be handled in multiple and single dielectric PCB builds. This paper describes how even FR4 builds should in some cases be treated as multiple dielectric builds. Approaches for understanding the root cause of effective dielectric constant variation with structure, coupling and scale are considered. An outline of the implementation of the boundary element method is provided for those wishing to look a little deeper into the modelling process. Finally, a brief investigation covers the sources of measurement errors aimed at helping to put the best data back into the modelling process.
End‐of‐life electronics legislation – an industry perspective
Authors: Goosey Martin
Published: January 2004

Increasing awareness of man's impact on the environment and pressure to behave in a more sustainable manner are encouraging both the recycling and reuse of materials and the replacement of hazardous chemicals with more benign ones. The Waste Electrical and Electronic Equipment (WEEE) Directive and the Restriction on the use of certain Hazardous Substances in Electrical and Electronic Equipment (RoHS) Directive, have recently been adopted into law with the specific intention of further encouraging these activities through legislation. In addition to these directives, there is a growing need to adopt sound design principles so that new products are created in a more environmentally acceptable way and that their environmental impact throughout their lifecycles is minimised. This paper gives an overview of this new European legislation and discusses its impact on the electronics industry. The potential benefits of adopting such an approach are outlined.
Re‐assessing 21st century risk: 21st century trends in risk management – board level decisions set the agenda
Authors: Mundy Chris
Published: January 2004

Through the 1990s board level risk was the key area of attention. But, the author argues, the events of 9/11 changed all that. Now the focus has moved, first to hazard risk management, and then widening out to cover all areas which board level risk management decisions must now encompass.
New accounting guidance for variable interest entities: will the new rules reduce the risk?
Authors: Wilson Arlette , Jones Jefferson
Published: January 2004

Special purpose entities, generally known as SPEs, have been the bane of everyone in the risk management and the asset management business. But they can also be extremely useful. Now, post‐Enron, further rules have been put into place to ensure that SPEs are clearly identifiable and their purpose can be transparent. The author examines how these new rules will work and assesses the likelihood of success.
Looking ahead at 2004: a global standard‐setter’s perspective
Authors: Tweedie David
Published: January 2004

2004 is the year when companies around the world need to move their financial reporting to the rules laid down by the International Accounting Standards Board. In this article the chairman of that board, Sir David Tweedie outlines what this change will mean. He also points out that the success of the process is down to way that the regulators behave and whether vested interests are allowed to triumph.
How prospective financial information will transform 2004
Authors: Hodgkinson Robert
Published: January 2004

The author, technical director of the UK’s biggest accounting body, assesses how businesses will cope with new financial reporting rules in 2004 and predicts that an emphasis on reporting on prospective financial information will come to the fore.
Hopes and fears for financial reporting and corporate governance
Authors: Eccles Robert G.
Published: January 2004

The author, one of the leading business thinkers in the USA and a former Harvard Business School professor, puts forward his hopes and fears for the year 2004. He hopes that the worlds of financial reporting and corporate governance will become clearer and more effective but he worries that resistance from company directors and a preference for rules rather than principles will hinder this process. On balance he concludes that he is more hopeful than fearful for the year ahead.
Learning in the age of global information technology: development of a generic architecture for an advanced learning management system
Authors: Watson Jason , Ahmed Pervaiz K.
Published: January 2004

This paper briefly introduces the trends towards e‐learning and amplifies some examples of state of the art systems, pointing out that all of these are, to date, limited by adaptability and shareability of content and that it is necessary for industry to develop and use an inter‐operability standard. Uses SCORM specifications to specify the skeleton of an architecture to develop an advanced learning management system.
A syntagm of networked educational management: case study – University of Botswana
Authors: Uys Philip
Published: January 2004

Networked educational management has emerged as an effective, distributed management approach for managing educational technologies and e‐learning in educational institutions. This management model has been developed during the writer’s doctorate research and implementation of e‐learning (also referred to as networked education) at Massey University, New Zealand, as well as on consulting assignments over the last six years including a five‐month consulting engagement at Cape Technikon, South Africa. Networked educational management has found its widest syntagmatic expression or manifestation at the University of Botswana where the writer has been leading the university‐wide implementation of modern educational technologies and e‐learning since early 2001. This paper describes this syntagm or practical manifestation of networked educational management and concludes that networked educational management, as a new educational management paradigm, has promising features for addressing the need for client satisfaction within higher education while also ensuring that strategic imperatives of the institution are being fulfilled.
Data mining in the e‐learning domain
Authors: Hanna Margo
Published: January 2004

Higher education (HE) is becoming a big business, with huge investments in IT technology supporting online learning. With the awareness of the knowledge economy has come a growing consciousness that HE constitutes a large industry or economic sector in its own right. In a marketing fashion, we understand that some customers present much greater profit potential than others. But, how will we find those high‐potential customers in a database that contains hundreds of data items for each of millions of customers? Data mining software can help find the “high‐profit” gems buried in mountains of information. However, merely identifying the best prospects is not enough to improve customer value. One must somehow fit the data mining results into the execution of the content management system that enhances the profitability of customer relationships. However, data mining is not yet engaged into e‐learning systems. This paper describes how we can profit from the integration of data mining and the e‐learning technology.
Plate 432. Broussonetia papyrifera
Authors: Barker Christine
Published: January 2004

The taxonomy, distribution, cultural requirements and uses of the eastern Asiatic Broussonetia papyrifera (L.) L’Herit. ex Vent. (Moraceae), are discussed; an illustration is provided, together with a full description.
Plate 433. Edgeworthia chrysantha
Authors: Clennett Chris , Harvey Yvette , Pearman Georgina
Published: January 2004

The shrub Edgeworthia chrysantha Lindl. (Thymelaeaceae) from Japan, China and Korea is illustrated. A full description is provided and its taxonomy, relationships, distribution, economic uses and cultivation requirements are discussed.
Plate 434. Eichhornia crassipes
Authors: Simpson David , Sanderson Helen
Published: January 2004

The taxonomy, distribution, cultural requirements and uses of the WATER HYACINTH, Eichhornia crassipes (Mart.) Solms (Pontederiaceae), are discussed; an illustration and a full description of the species are provided.
Plate 437. Musa basjoo
Authors: Turner Jill , Mathew Brian , Lock Mike
Published: January 2004

The uses, classification, distribution and cultural requirements of the Japanese banana, Musa basjoo Siebold ex Baker (Musaceae) are discussed; an illustration is provided, together with a full description.
Papyrus, Paper and Paper making: A view of Kew's Economic Botany Collections
Authors: Prendergast Hew D.V.
Published: January 2004

The first overview is presented of the paper contents of Kew's Economic Botany Collections (EBC). There are more than 350 specimens of paper representing nearly 50 plant families and more than a hundred genera. The dominant families numerically – and each for different reasons – are the Moraceae, Gramineae, Thymelaeaceae and Cyperaceae, examples from which are highlighted. Some emphasis is given to the historical context and geographical origin of papers, and to the people who collected or donated them. It is suggested that one focus of a future collecting strategy for the EBC should be the sorts of plant products, including papers, that are under threat due to losses of cultural diversity or biological diversity, or both.
Plate 440. Liparis latifolia
Authors: Wood Jeffrey , Bell Sandra
Published: January 2004

The widespread South–east Asian Liparis latifolia (Blume) Lindl. (Orchidaceae) is illustrated. Its taxonomy, relationships, distribution and cultivation requirements are discussed and a full description is provided.
Plate 442. Pinus pungens
Authors: Farjon Aljos , Frankis Michael
Published: January 2004

The distribution, history, taxonomy, ecology, uses and cultivation of Pinus pungens Lamb. (Pinaceae), a native of the eastern United States of America, are discussed, and a full description and illustration are provided.
Bird versus bat pollination in the genus Marcgravia and the description of a new species
Authors: Dressler Stefan , Tschapka Marco
Published: January 2004

A short account on the history of observations into the pollination ecology in Marcgravia (Marcgraviaceae) is given. The different pollination syndromes encountered in the genus are discussed. The circumstances of the discovery of a new species in southern Ecuador are presented. This new species, Marcgravia helverseniana, is described and is illustrated here for the first time.
Unemployment as Illness: An Exploration of Accounts Voiced by the Unemployed in Aotearoa/New Zealand
Authors: Cullen Andrea , Hodgetts Darrin
Published: January 2004

In Aotearoa/New Zealand unemployment is a continuing social concern that has been linked to a range of negative consequences, including various psychological and physical ailments. Whereas findings linking unemployment to such conse‐quences are highly prevalent, few studies have explored people's experiences of unemployment. This article presents an analysis of 26 semistructured individual interviews with unemployed people in order to explore the social construction of unemployment. It is argued that the meaning of unemployment is in many respects analogous to what previous research on lay health beliefs has found regarding the meaning of illness. Prominent themes from literature on the meaning of illness are used to inform an analysis of the meaning of unemployment. The implications of constructing unemployment as an illness are explored in relation to the assignment of cause and responsibility and to the ways the unemployed are socially positioned. Tactics used by participants to preserve a sense of moral worth in response to the stigma of unemployment provide a key focal point for this article.
Accountability and the Camera Perspective Bias in Videotaped Confessions
Authors: Lassiter G. Daniel , Munhal Patrick J. , Geers Andrew L. , Weiland Paul E. , Handley Ian M.
Published: January 2004

Prior research indicates that altering the perspective from which a videotaped confession is recorded influences assessments of the confession's voluntariness. The present study examined whether increasing decision makers’ sense of accountability attenuates this biasing effect of camera perspective. Participants in a high‐accountability (but not a low‐accountability) condition were told that they would have to justify their judgments concerning the voluntary status of a video‐taped confession to a trial judge. Although supplementary measures indicated that high‐accountability participants processed information contained in the video‐taped confession more carefully and thoroughly, the camera perspective bias persisted. This result adds to a growing body of work indicating that the criminal justice system needs to be seriously concerned with how it acquires and utilizes videotaped confession evidence.
Affirmative Action: Psychological Contributions to Policy
Authors: Crosby Faye J. , Clayton Susan
Published: January 2004

Affirmative action is a controversial policy. Lauded by many, the attempt at social engineering has also been condemned by some as unnecessary and by others as counterproductive to the goal of social equality. As such, affirmative action is ideally situated to benefit from psychological research pertaining to the need for and the effectiveness of the policy. This article discusses both the potential benefits to American society of affirmative action and the potential costs of such a policy. Concluding that affirmative action is useful, we end with a look at ways to make affirmative action programs as effective as possible.
Documenting the Positive Case for Affirmative Action
Authors: Suinn Richard M.
Published: January 2004

Affirmative action is under intense scrunity and attack across the nation. One historical rationale for affirmative action is the need to redress past discriminatory activities that prevented ethnic minorities from equal access. This article presents the new argument that increasing diversity can benefit the nonminority population. Briefly reviewed are findings relating to academic and intellectual outcomes as well as health outcomes.
The Prevention of Homelessness Revisited
Authors: Shinn Marybeth , Baumohl Jim , Hopper Kim
Published: January 2004

Conceptual and methodological problems plague efforts to prevent homelessness. Attempts to identify individuals at risk are inefficient, targeting many people who will not become homeless for each person who will. Such interventions may do useful things for needy people, but evidence that they prevent homelessness is scant. Subsidized housing, with or without supportive services, has ended homelessness for families and played a key role in ending it for people with serious mental illnesses. Other risk factors may be less important once housing is secured. But programs that allocate scarce housing may simply reallocate homelessness, determining who goes to the head of the line for housing, not shortening the line itself. We recommend reorienting homelessness prevention from work with identified at‐risk persons to efforts to increase the supply of affordable housing and sustainable sources of livelihood nationwide or in targeted communities.
Focus Groups as a Tool for Policy Analysis
Authors: Kahan James P.
Published: January 2004

Focus groups were formerly associated with market research but have recently gained some measure of social scientific respectability. In this article, I briefly recapitulate the history of focus groups and then examine their role in 4 (2 Dutch, 2 American) policy research projects. In each case, the focus groups provided an understanding of the interests and values of different stakeholder groups and per‐mitted the analysts to predict the groups’ reactions to policy alternatives. This served to link the focus groups to the underlying policy problem, to set the policy issues in their appropriate context, to take due account of the technical complexities of the situation, and to orient toward integrating the results of the focus groups with the other tools used in the policy analysis. The four cases shared a “spiral” model approach to focus groups, in which the discussion moves from generic to specific toward the object of focus rather than tackling it directly. This permits both a breadth and depth of perspective and helps avoid posturing. I conclude that focus groups provide a value for policy analysis because they enable participant stakeholders to become part of the process, help uncover misunderstandings that conceal underlying agreements among stakeholders, and uncover potential problems of implementation.
Building a Research and Advocacy Agenda on Issues of Economic Justice
Authors: Bullock Heather E. , Lott Bernice
Published: January 2004

In this article we call for a research agenda focused on classism and poverty and for advocacy of social justice. Examples of recent efforts toward such an agenda are discussed, including the American Psychological Association's adoption of its “Resolution on Poverty and Socioeconomic Status.” In response to the resolution's call for more research on classist attitudes and discrimination against the poor, we outline several directions for future research. Recommendations for how psychological research can be used to advocate for economic justice are offered.
The Impact of Exchange Rate Volatility on UK Exports to EU Countries
Authors: De vita Glauco , Abbott Andrew
Published: January 2004

This paper investigates the impact of exchange rate volatility on UK exports to European Union (EU) countries by means of a newly developed ARDL bounds testing procedure to cointegration. Using monthly data disaggregated by market of destination and sectors for the period 1993ml to 2001m6, our results indicate that UK exports to the EU14, at both aggregate and sectoral level, are generally income elastic, relative price inelastic and largely unaffected by short‐term exchange rate volatility. Re‐estimation of the model using a long‐term measure of volatility, however, provides evidence supporting the hypothesis that exchange rate uncertainty has a negative and significant influence on UK exports to EU countries.
Ricardian Consumers With Non‐Keynesian (And Possibly Ricardian) Propensities
Authors: Pemberton James
Published: January 2004

Barsky, Mankiw and Zeldes (1986) have argued that uncertainty about future income can generate strong ‘Keynesian’ responses to tax changes by consumers who have far‐sighted ‘Ricardian’ preferences. The paper argues that this conclusion relies on an inappropriate treatment of future tax policies. Using a more appropriate framework generates behaviour which may instead be approximately Ricardian, and which, if it deviates from the Ricardian benchmark, usually does so in an anti‐Keynesian direction. If Keynesian behaviour is observed, therefore, it requires a different explanation.
Productive Efficiency and Salary Distribution: The Case of US Major League Baseball
Authors: Todd jewell R. , Molina David J.
Published: January 2004

Recent theoretical research suggests that a firm's salary structure can affect the firm's productivity. We investigate the relationship between payroll inequality and production using US Major League Baseball data. Employing panel data methods, this study finds that salary inequality has a significantly negative effect on team success. A general result is that team success in term of wins does not seem to be correlated with efficiency; specifically, some of the least successful teams are also some of the most efficient. In addition, salary inequality does not appear to be correlated with efficiency. Furthermore, revenues generated by teams are not necessarily correlated with team efficiency.
Reconstruction of the maxillary midline papilla following a combined orthodontic–periodontic treatment in adult periodontal patients
Authors: Cardaropoli Daniele , Re Stefania , Corrente Giuseppe , Abundo Roberto
Published: January 2004

Objective: The aim of the present study was to evaluate the role of a combined orthodontic–periodontic treatment in determining the reconstruction of midline papilla lost following periodontitis.

Material and Methods: Twenty‐eight patients, with infrabony defect and extrusion of one maxillary central incisor, were treated. At baseline, all patients presented opening of the interdental diastema and loss of the papilla. At 7–10 days after open‐flap surgery, the intrusive movement started. For each patient, probing pocket depth (PPD), clinical attachment level (CAL) and papilla presence index (PI) were assessed at baseline, end of treatment and after 1 year. PI was also evaluated independently in patients with narrow or wide periodontal biotype (NPB–WPB).

Results: All parameters showed statistical improvement between the initial and final measurements, and showed no changes at follow‐up time. The mean residual PPD was 2.50 mm, with a decrease of 4.29 mm, while the mean CAL gain was 5.93 mm. Twenty‐three out of 28 patients improved the PI score at the end of therapy. No statistical difference was recorded in PI values between groups NPB and WPB.

Conclusion: The presented clinical protocol resulted in the improvement of all parameters examined. At the end of orthodontic treatment, a predictable reconstruction of the interdental papilla was reported, both in patients with thin or wide gingiva.
Impact of mouthrinses on morning bad breath in healthy subjects
Authors: Carvalho M. D. , Tabchoury C. M. , Cury J. A. , Toledo S. , Nogueira‐Filho G. R.
Published: January 2004

Background: During sleep, a proliferation of oral bacteria is responsible for the release of offending gases in morning breath even in healthy people. Thus, the aim of this study was to evaluate the bad breath‐inhibiting effect of four commercially available mouthrinses (0.03% triclosan, 0.12% chlorhexidine gluconate, 0.05% cetylpyridinium chloride and essential oils) on morning breath when compared with a positive and a negative control.

Method: A six‐step double‐blind, crossover, randomised study was conducted in 12 dental students with healthy periodontium, who refrained from mechanical plaque control during a 4‐day period. The subjects were instructed to rinse twice daily with the assigned product during each period. Fifteen‐day washout intervals were used. Before professional plaque and tongue coating removal (baseline), the morning breath was scored through volatile sulphur compounds (VSCs) level measured by a sulphide monitor. After 4 days, VSCs and plaque index (PI) were recorded.

Results: Even in the absence of mechanical plaque control, there was a decrease in VSC level with the use of all mouthrinses, with the exception of an increase with the use of the negative control. The VSC formation was inhibited in descending order, by positive control (0.2% chlorhexidine), 0.12% chlorhexidine, triclosan and essential oils and cetylpyridinium chloride. Plaque formation was inhibited by chlorhexidine mouthrinses and essential oils.

Conclusions: These findings suggest that mouthrinses can reduce morning bad breath, and that such a reduction is not attributable only to the reduction of supragingival plaque formation.
Radiographic parameters as prognostic indicators for healing of class II furcation defects
Authors: Horwitz Jacob , Machtei Eli E. , Reitmeir Peter , Holle Rolf , Kim Ti‐Sun , Eickholz Peter
Published: January 2004

Objective: To evaluate radiographic measurements for use as prognostic indicators for healing of class II furcation defects following regenerative therapy.

Material and Methods: In 17 patients (eight females), 33 class II furcation defects (mandibular buccal (n=10) and lingual (n=12), and maxillary buccal (n=11)) were treated using the barrier membrane technique. Twenty‐six furcations were treated using a bioabsorbable membrane, while a nonresorbable membrane was used to treat the remaining seven furcation defects. Clinical parameters and standardized radiographs were obtained before as well as 6 and 24 months after therapy. All radiographs were digitized and evaluated by an examiner blinded to the clinical data. The following distances were measured: cemento‐enamel junction line (CEJ‐line) to alveolar crest (AC) at the furcation site (AC‐CEJ line), CEJ‐line to the furcation fornix (Fx‐CEJ line), width of the furcation at the level of the AC (FW) as well as the distance from Fx to a straight line between the AC mesial and distal of the tooth (Fx‐AC line).

Results: Statistically significant (p<0.001) horizontal attachment gains could be observed 6 and 24 months after therapy (6 months: 1.49±0.85 mm; 24 months: 1.14±0.91 mm). However, a small but statistically significant (p=0.031) attachment loss of 0.35 mm was observed between the 6 and 24 months examination. Multilevel regression analyses identified baseline probing depth (p=0.0017) and 3 of the radiographic distances as prognostic factors: Fx‐CEJ line (p=0.014), FW (p=0.0535), Fx‐AC line (p=0.0827).

Conclusion: The analysis of presurgical radiographs may yield information on the success of the regenerative therapy of buccal and lingual class II furcation defects. A long root trunk, a wide furcation entrance and an Fx coronal to the AC have negative influences on the success of therapy. Further, a deep probing depth at the furcation site at baseline increases the likelihood for more favourable horizontal attachment gain in furcations.
Validity and reliability of partial examination to assess severe periodontitis
Authors: Aída Borges‐Yáñez S. , Maupomé Gerardo , Jiménez‐García Gustavo
Published: January 2004

Objectives: To compare the extent and severity index (ESI) with a gold standard represented by actual readings of loss of attachment on six sites around all teeth present (excluding third molars).

Methods: Five standardized dentists (κ=0.6) examined 712 subjects 20 years of age at a dental school (1993–1995). Sensitivity, specificity, positive and negative predictive values, and true and apparent prevalence were established.

Results: True severe periodontitis prevalence was 95.8%. ESI underestimated the severity (0.1 mm), extent (4%), and prevalence (16%) of periodontitis. The severity, as established by ESI, coincided 23.4% with the gold standard. ESI failed to identify 16.7% of subjects with severe periodontal disease, but specificity and positive predictive value were very high.

Conclusions: The underestimation of severe periodontitis through ESI may lead to inadequate recommendations for further treatment. Accurately identifying subjects with severe periodontitis requires a full‐mouth examination. Because the ESI relies on measurements taken on only 28 periodontal sites to estimate the periodontitis status of the entire mouth, the validity and reliability of ESI may be modified by the prevalence of severe periodontal disease and the distribution of disease according to age and operational definitions.
Prevalence of gingival overgrowth in transplant patients immunosuppressed with tacrolimus
Authors: Ellis J. S. , Seymour R. A. , Taylor J. J. , Thomason J. M.
Published: January 2004

Aims: The study aims to determine the prevalence and severity of gingival overgrowth in a group of adult organ transplant recipients immunosuppressed with tacrolimus in comparison with ciclosporin, and to examine various risk factors for the development of gingival overgrowth.

Methods: Forty patients taking tacrolimus were compared with 197 ciclosporin patients. Demographic, pharmacological and periodontal data were recorded for all patients. Comparison between the groups was made using independent sample t‐tests, χ2 statistic or Mann–Whitney test. The effects of risk variables on overgrowth severity were examined using forward and backward stepwise regression analysis.

Results: Those taking tacrolimus had a significantly lower mean gingival overgrowth score (14.1%) compared with ciclosporin (22.4%). Fifteen percent of the tacrolimus group had clinically significant gingival overgrowth compared with 30% in the ciclosporin group (p=0.053).

Conclusions: The prevalence and severity of gingival overgrowth is less in adult transplant patients taking tacrolimus compared with ciclosporin. Concomitant use of calcium channel blockers and previous medication with ciclosporin are significant risk factors for the presence and severity of gingival overgrowth. Patients who have alteration of their immunosuppressant from ciclosporin to tacrolimus may persist in demonstrating gingival overgrowth attributable to their ongoing therapy with calcium channel blockers.
Quadrant root planing versus same‐day full‐mouth root planing
Authors: Apatzidou D. A. , Riggio M. P. , Kinane D. F.
Published: January 2004

Objectives: The aim of this study was to test the hypothesis that over a period of 6 months, same‐day full‐mouth scaling and root planing (FM‐SRP) resulted in greater reductions in the detection frequency of five putative periodontal pathogens compared with quadrant scaling and root planing (Q‐SRP) in chronic periodontitis patients.

Materials and Methods: Forty patients were recruited into this study. Subjects were randomised into two groups. The FM‐SRP group received full‐mouth scaling and root planing completed within the same day, while the Q‐SRP group received quadrant root planing at 2‐weekly intervals over four consecutive sessions. Selected‐site analyses were performed on the deepest site in each quadrant before and after therapy, at approximately 3 and 6 months from baseline (R1 and R2) and clinical indices were recorded with an electronic pressure‐sensitive probe. In addition, subgingival plaque samples were collected from these sites at baseline (BAS), at reassessment 1 (R1), approximately 6 weeks after the completion of therapy and at reassessment 2 (R2), 6 months from baseline. Polymerase chain reaction (PCR) was used to determine the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Treponema denticola and Bacteroides forsythus in plaque.

Results: Both therapies resulted in significant improvements in all clinical indices both at R1 and R2. A marked reduction in the presence of all candidate periodontal pathogens was noted after both treatment modalities, reaching statistical significance for the majority of the test organisms. These improvements were maintained over a period of 6 months. When the two treatment groups were compared, a significantly higher percentage of Q‐SRP patients was positive for P. intermedia at R1 compared with FM‐SRP patients (p<0.05). In addition, a greater reduction in the patient prevalence for T. denticola was found for the FM‐SRP group than the Q‐SRP group at R1 and R2 from baseline (p<0.005), but the significance of this is questionable given the skewed detection frequency of this organism at baseline between the two treatments (p<0.01).

Conclusion: This study failed to confirm that same‐day FM‐SRP resulted in greater microbiological improvements compared with Q‐SRP at 2‐weekly intervals over a 6‐month period, as determined by PCR.
Does cavitation occur around powered toothbrushes?
Authors: Lea S. C. , Price G. J. , Walmsley A. D.
Published: January 2004

Aims/objectives: The aim of this investigation was to determine if cavitational activity occurred around powered toothbrushes using a chemical dosimeter system based on terephthalic acid (TA).

Material and Methods: Five powered toothbrushes were used in this investigation: Braun Plaque Remover D8, Braun Oral‐B 3D, Philips Jordan Sensiflex HX2520, Sonicare PS‐1 and Sonicare Elite HX 7351/02. Each brush head was inserted into a conical flask containing 50 cm3 of aqueous TA solution. Brushes were operated for 10 and 20 min and a cuvette of the solution was placed in a fluorescence spectrometer (Perkin Elmer 3000). The fluorescence emitted at wavelength 425 nm, which is proportional to •OH radical concentration, was monitored.

Results: Any cavitational activity that may have been produced by the powered toothbrushes was below the limit of detection of the system (<10−8 M) for the timescales investigated.

Conclusions: This work has demonstrated that cavitational activity does not occur around powered toothbrushes. Operating the toothbrushes for periods up to 20 min resulted in no cavitational activity being detected.
The ability of rufous hummingbirds Selasphorus rufus to dilute and concentrate urine
Authors: Lotz Chris N. , Martínez del Rio Carlos
Published: January 2004

Most terrestrial animals face the challenge of having to conserve water in a desiccating environment. Not surprisingly, the ability to produce concentrated urine has been relatively well studied in birds. Nectar‐feeding birds are unusual among terrestrial animals in that they often ingest and excrete prodigious water volumes to obtain adequate energy. Thus, they confront the unusual challenge of having to conserve electrolytes. The diluting abilities of birds and the renal mechanisms that may correlate with them have been relatively neglected. To elucidate diluting and concentrating abilities in nectar‐feeding birds, we fed rufous hummingbirds Selasphorus rufus an electrolyte‐free nectar and a nectar containing a range of NaCl concentrations. Hummingbirds had a spectacular (and possibly unique) diluting ability: when fed on electrolyte‐free food they produced excreta containing less than 0.5 mM l−1 each of sodium and potassium. Hummingbirds also had a poor concentrating ability, retaining sodium and chloride when their food (0.632 M l−1 sucrose) contained more than 35 mM l−1 of NaCl. The kidneys of hummingbirds do not appear to be suited for concentrating urine, and possibly contain structural features that give them a unique diluting ability compared with those of birds that do not feed on nectar.
Excretory organ growth and implications for salt tolerance in hatchling American avocets Recurvirostra americana
Authors: Rubega Margaret A. , Oring Lewis W.
Published: January 2004

The role of salt glands in avian osmoregulation has been widely studied. Acclimation to saline habitats in aquatic birds involves increases in the relative size and complexity of the salt glands, and it is generally agreed that salt gland size varies as a function of salt loading, and is broadly correlated with habitat salinity. We report here salt gland sizes in three age classes of American avocet Recurvirostra americana chicks. Mean relative (mg/g body mass) salt gland masses for newly hatched (<24 h old) avocet chicks collected at a wetland supplied with pumped fresh water was 0.48 mg salt gland/g body mass. This value is comparable to the low end of published values for some strictly marine birds and similar to values for adult American avocets collected at saline lakes. These results suggest that American avocets, which are frequently raised in saline environments, hatch with salt glands that are large enough to cope with the osmoregulatory demands of saline environments.
Fat soluble antioxidants in brood‐rearing great tits Parus major: relations to health and appearance
Authors: Hõrak Peeter , Surai Peter F. , Ots Indrek , Møller Anders P.
Published: January 2004

The concept of parasite‐mediated sexual selection assumes that females may improve offspring fitness by selecting mates on the basis of sexual ornaments that honestly reveal the health state of a partner. Expression of such signals may be particularly sensitive to oxidative damage caused by excess production of oxidative metabolites and free radicals. To control and neutralise free radicals, animals rely heavily on dietary fat‐soluble antioxidants such as vitamin E and A, and carotenoids. However, the organism's need for free radical scavenging may interfere with the opposite need to generate oxidative stress for fighting parasitic infections. We investigated plasma concentrations of carotenoids and vitamin A and E in brood‐rearing great tits Parus major in relation to carotenoid‐based plumage coloration, sex, habitat, leukocyte hemoconcentrations and infection status with Haemoproteus blood parasites. Rural great tits differed from urban ones and males from females with respect to the hue of the yellow ventral feathers. However, plasma antioxidant concentrations were not related to sex, habitat or plumage coloration. Plasma carotenoid concentration correlated positively with indices of immune system activation as measured by blood counts of lymphocytes and eosinophils. Birds with gametocytes of Haemoproteus in their blood had higher plasma concentrations of carotenoids and vitamin E than unparasitized individuals. These results are consistent with the idea that maintenance of high blood antioxidant levels might conflict with individual needs to rely on oxidative stress for fighting infections.
The effect of water availability on fuel deposition of two staging Sylvia warblers
Authors: Sapir Nir , Tsurim Ido , Gal Bruria , Abramsky Zvika
Published: January 2004

In order to succeed in crossing extensive ecological barriers, migratory birds usually deposit fuel en route. High rates of fuel deposition may enable birds to shorten their total migration time and are therefore advantageous for time‐minimizing migrants. Several studies have suggested that water provision may increase food utilization in non‐migratory birds. The goal of this study was to test the influence of water availability on the fuel deposition of en route migratory passerines. We studied fuel deposition of blackcaps Sylvia atricapilla and lesser whitethroats S. curruca staging in a plantation of Mount Atlas gum‐tree Pistacia atlantica in the northern Negev desert, Israel, during the autumns of 2000 and 2002. We manipulated water availability at the site and measured the effect of water supplementation on fuel deposition of birds of both species. We found that when water was available, blackcaps had higher fuel loads and higher fuel deposition rates than during control trials. However, water availability had no effect on fuel deposition of lesser whitethroats. Species‐specific differences in adaptations to arid conditions, reflected in the species’ winter habitat preferences, may be responsible for the between‐species dissimilarity in responding to water provision. We suggest that water availability may have strong ecological and evolutionary consequences for birds migrating through arid environments, by its possible effect on bird behavior and physiology.
Fine‐tuned distribution of feather mites (Astigmata) on the wing of birds: the case of blackcaps Sylvia atricapilla
Authors: Jovani Roger , Serrano David
Published: January 2004

The distribution of feather mites (Astigmata) along the wing of passerine birds could change dramatically within minutes because of the rapid movement of mites between feathers. However, no rigorous study has answered how fine‐tuned is the pattern of distribution of feather mites at a given time. Here we present a multiscale study of the distribution of feather mites on the wing of non‐moulting blackcaps Sylvia atricapilla in a short time period and at a single locality. We found that the number and distribution of mites differed among birds, but it was extremely similar between the wings of each bird. Moreover, mites consistently avoided the first secondary feather, despite that it is placed at the centre of the feathers most used by them. Thus, our results suggest that feather mites do precise, feather‐level decisions on where to live, contradicting the current view that mites perform “mass”, or “blind” movements across wing feathers. Moreover, our findings indicate that “rare” distributions are not spurious data or sampling errors, but each distribution of mites on the wing of each bird is the outcome of the particular conditions operating on each ambient‐bird‐feather mite system at a given time. This study indicates that we need to focus on the distribution of feather mites at the level of the individual bird and at the feather level to improve our understanding of the spatial ecology of mites on the wings of birds.
Fronto, the bishops, and the crowd: Episcopal justice and communal violence in fifth‐century Tarraconensis
Authors: Kulikowski Michael
Published: January 2004

Augustine’s Epistula 11* was addressed to the bishop of Hippo by an aristocratic laymen called Consentius. The letter recounts, ostensibly verbatim, the tribulations of the Spanish monk Fronto in his efforts to prosecute what he regards as a heretical conspiracy amongst the clergy ofHispania Tarraconensis.Fronto's narrative is a rare first‐person account of the late antique judicial process, in all its complexity of overlapping imperial and ecclesiastical jurisdictions. The present article examines the letter's evidence for judicial strategies and rhetoric, as well as the role of status, power and violence in influencing legal outcomes.