bluuebunny/crossref_metadata_2025 huggingface dataset:
Families of loblolly pine that are the most stable for resistance to fusiform rust are the least predictable
Authors: McKeand S E , Amerson H V , Li B , Mullin T J
Published: August 2003

In an extensive series of trials with open-pollinated families of loblolly pine (Pinus taeda L.), resistance to fusiform rust disease (caused by Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme) at individual test sites was relatively unpredictable for the families deemed most resistant. The most resistant families were also the most stable for performance across test sites, with stability defined as the slope of the regression of family means for rust infection versus site means for rust infection. A family's R-50 value (its predicted rust infection level when the site mean infection is 50%) was correlated to its stability parameter or slope (r = 0.78). On average, any one family's level of infection (% galled) was reasonably predictable for any given infection level at a given site; the average coefficient of determination (r2) was 0.78 for the regression of family means for rust infection versus site means for rust infection. However, the six most stable families for resistance had the lowest r2 values (average r2 = 0.58). We speculated that the lower predictability for the most resistant families was due to interactions of specific resistance genes in these families and corresponding avirulence and (or) virulence levels in the pathogen populations that may differ among sites. Although the predictability of the individual resistant families was relatively low, if these families were bulked into a resistant seed lot, they performed in a more predictable manner with r2 = 0.74 for the regression of the bulk mean versus site means. Bulks of four to six highly resistant families appeared to be a good solution to obtain stable and predictable performance across a range of sites.
A comparison of estimation methods for fitting Weibull and Johnson's SB distributions to mixed sprucefir stands in northeastern North America
Authors: Zhang Lianjun , Packard Kevin C , Liu Chuangmin
Published: August 2003

Four commonly used estimation methods were employed to fit the three-parameter Weibull and Johnson's SB distributions to the tree diameter distributions of natural pure and mixed red spruce (Picea rubens Sarg.)  balsam fir (Abies balsamea (L.) Mill.) stands, respectively, in northeastern North America. The results indicated that the Weibull and the Johnson's SB distributions were, in general, equally suitable for modeling the diameter frequency distributions of this forest type, but the relative performance directly depended on the estimation method used. In this study, the linear regression methods for Johnson's SB were found to give the lowest mean Reynolds' error indices. The conditional maximum likelihood for Johnson's SB and the maximum likelihood estimation for Weibull produced comparable results. However, moment- or mode-based methods were not well suited to the observed diameter distributions that were typically positively skewed, reverse-J, and mound shapes.
Distribution of cavity trees in midwestern old-growth and second-growth forests
Authors: Fan Zhaofei , Shifley Stephen R , Spetich Martin A , Thompson III Frank R , Larsen David R
Published: August 2003

We used classification and regression tree analysis to determine the primary variables associated with the occurrence of cavity trees and the hierarchical structure among those variables. We applied that information to develop logistic models predicting cavity tree probability as a function of diameter, species group, and decay class. Inventories of cavity abundance in old-growth hardwood forests in Missouri, Illinois, and Indiana found that 811% of snags had at least one visible cavity (as visually detected from the ground; smallest opening [Formula: see text]2 cm diameter), about twice the percentage for live trees. Five percent of live trees and snags had cavities on mature ([Formula: see text]110 years) second-growth plots on timberland in Missouri. Because snags accounted for typically no more than 10% of standing trees on any of these sites, 8085% of cavity trees are living trees. Within the subset of mature and old-growth forests, the presence of cavities was strongly related to tree diameter. Classification and regression tree models indicated that 30 cm diameter at breast height (DBH) was a threshold size useful in distinguishing cavity trees from noncavity trees in the old-growth sample. There were two diameter thresholds in the mature second-growth sample: 18 and 44 cm DBH. Cavity tree probability differed by species group and increased with increasing decay class.
Do critical load models adequately protect forests? A case study in south-central Ontario
Authors: Watmough Shaun A , Dillon Peter J
Published: August 2003

We calculated critical loads of acidity (S and S + N separately) for seven forested catchments in south-central Ontario, using a critical threshold designed to maintain the Ca/Al molar ratio above 1.0 or the base cation (BC; Ca + Mg + K) to Al molar ratio above 10 in soil solution. Critical loads are ~1050% lower using the BC/Al ratio compared with the Ca/Al ratio, and harvesting greatly increases forest sensitivity to acid deposition. If forests are harvested, critical load calculations indicate that further reductions in S and N bulk deposition are required to maintain the BC/Al ratio in soil solution above 10, but reductions in S deposition are only mandatory for three of the seven catchments. However, S export exceeds inputs in bulk deposition by 40100%. Our study indicates that setting the critical threshold of BC/Al at 10 may not maintain soil base saturation above 20%, and that N export is unpredictable at current deposition levels. We calculate that SO4 leaching (and therefore deposition) must be reduced by between 10 and 74% to maintain healthy, productive forests in catchments that are harvested. More reliable estimates of base cation removals during harvest, minimum Ca leaching losses from soils that can occur without affecting forest productivity, and critical limits for soil base saturation are needed to improve these critical load estimates.
Communities of aquatic insects of old-growth and clearcut coastal headwater streams of varying flow persistence
Authors: Price Karen , Suski Arlene , McGarvie Joanna , Beasley Barbara , Richardson John S
Published: August 2003

Headwater streams, varying in flow persistence from ephemeral to intermittent to perennial, provide the tightest coupling between water and land, yet they often receive the least protection during forest management. We described communities of aquatic insects in perennial, intermittent, and ephemeral channels surrounded by old-growth forest and 4- to 8-year-old clearcuts in Clayoquot Sound, British Columbia, to determine whether temporary streams have unique aquatic communities and to examine the short-term impacts of harvesting. We measured flow persistence, stream size, canopy cover, organic detritus, and algal biomass in 19 streams. We sampled aquatic invertebrates with a combination of emergence cages and kicknet samples. Temporary and old-growth streams had more organic detritus and a higher abundance of shredders. Perennial and clearcut streams had a higher abundance of some algal grazers, but not higher algal biomass. Insect richness was similar in intermittent and perennial streams of each seral stage but lower in ephemeral streams. Intermittent streams contained four taxa not found in the other stream classes; perennial and ephemeral streams had none. Communities of aquatic insects differed between streams surrounded by clearcuts and old growth, and varied with continuity of flow.
Collective Intelligence of the Artificial Life Community on Its Own Successes, Failures, and Future
Authors: Rasmussen Steen , Raven Michael J. , Keating Gordon N. , Bedau Mark A.
Published: August 2003

We describe a novel Internet-based method for building consensus and clarifying conflicts in large stakeholder groups facing complex issues, and we use the method to survey and map the scientific and organizational perspectives of the artificial life community during the Seventh International Conference on Artificial Life (summer 2000). The issues addressed in this survey included artificial life's main successes, main failures, main open scientific questions, and main strategies for the future, as well as the benefits and pitfalls of creating a professional society for artificial life. By illuminating the artificial life community's collective perspective on these issues, this survey illustrates the value of such methods of harnessing the collective intelligence of large stakeholder groups.
Between East and West and the Politics of `Cultural Ingénuité`
Authors: Deutscher Penelope
Published: August 2003

This article compares the status of sexual and cultural difference in Luce Irigaray's earliest work and her most recent publication Between East and West (2002), in which Irigaray argues that a culture of sexual difference would facilitate improved structural relations between those of different cultures, races and traditions. Many commentators have argued that Irigaray's recent, more simple formulations on legal reform must be understood in the context of the early, very complex Irigarayan concept of sexual difference. But what about Irigaray's recent formulations concerning cultural difference? Are we to understand these as based on an `aporia' of recognition, as are her formulations on sexual difference? The article argues against such an interpretation, and considers problems arising from the disjunction between Irigaray's treatment of sexual and cultural difference.
Music Performance Research at the Millennium
Authors: Gabrielsson Alf
Published: August 2003

Empirical research on music performance has increased considerably during recent decades. This article updates the review of the research up to 1995 published by the current author in 1999. Covering about 200 papers from 1995 up to 2002, this article confirms the impression that music performance research is in a very active stage. As in the previous review, the majority of papers are on measurement of performance, but there is a rapidly increasing number of contributions concerning models of performance, performance planning and practice. Although fewer in number, there are also many new contributions within each of the remaining areas of performance research analysed in this review.
Five Facets of Musical Expression: A Psychologist's Perspective on Music Performance
Authors: Juslin Patrik N.
Published: August 2003

The aim of this article is to outline a psychological approach to expression in music performance that could help to provide a solid foundation for the teaching of expressive skills in music education. Drawing on previous research, the author suggests that performance expression is best conceptualized as a multi-dimensional phenomenon consisting of five primary components: (a) Generative rules that function to clarify the musical structure; (b) Emotional expression that serves to convey intended emotions to listeners; (c) Random variations that reflect human limitations with regard to internal time-keeper variance and motor delays; (d) Motion principles that prescribe that some aspects of the performance (e.g. timing) should be shaped in accordance with patterns of biological motion; and (e) Stylistic unexpectedness that involves local deviations from performance conventions. An analysis of performance expression in terms of these five components - collectively referred to as the GERMS model - has important implications for research and teaching of music performance.
In Respect of Performance: The View from Musicology
Authors: Rink John
Published: August 2003

This article surveys a range of musicological approaches to musical performance. It first addresses the place of Western art music within the world of performance at large; it then considers the retrospective means by which musicologists have investigated individual performances and the manifold issues related to them. The discussion turns thereafter to the practical application of research to performance. A case study of Chopin's Nocturne in E-flat major Op. 9 No. 2 demonstrates how the gaps between research and practice might be bridged to enhance the moment of truth that each performance represents. Emphasis is placed on the need for both mediation and a contextualized understanding of whatever it is that historical, analytical and other modes of research might offer the performer.
Identities and Insecurities: Selves at Work
Authors: Collinson David L.
Published: August 2003

This article explores the growing interest in selves and subjects at work. In particular, it examines the analytical importance of insecurity for understanding the subjective power relations and survival strategies of organization. Insecurity in organizations can take many different, sometimes overlapping forms. Highlighting how these insecurities can intersect in the reproduction of workplace selves and organizational power relations, the article argues that attempts to overcome these insecurities can have contradictory outcomes. It also illustrates how `conformist', `dramaturgical' and `resistant' selves may be reproduced, particularly in surveillance-based organizations. The article concludes that a greater appreciation of subjectivity and its insecurities can enhance our understanding of the ways that organizational power relations are reproduced, rationalized, resisted and sometimes even transformed within the contemporary workplace.
Women Studying Violent Male Institutions:
Authors: Huggins Martha K. , Glebbeek Marie-Louise
Published: August 2003

To promote discussions of methodological issues associated with cross-gender research in criminology, we focus on two women's studies of Latin American police. This uncovered five working propositions about women studying organizations dominated numerically and structurally by men. First, feminist scholarship provides some guidelines for such research, but its applicability is neither direct nor immediate. Second, for example, much cross-gender research requires negotiating and maintaining power differentials between researcher and researched. Third, particularly in cross-gender research on secrecy and danger, inter-gender dynamics can thwart some research objectives and promote others. Fourth, inter-gender dynamics can complicate the ethical dilemmas associated with research on powerful agents and agencies of the state. Finally, the emotional reflexivity associated with such inter-gender research is epistemologically relevant for understanding research outcomes.
Three Theoretical Perspectives on One of Marketing's Most Fundamental Exchanges
Authors: Murgolo-Poore Marie E. , Pitt Leyland F. , Berthon Pierre R.
Published: August 2003

Attempts have been made to develop theory in marketing over the years, both from a broad perspective (`general' theories of marketing) and from more specific viewpoints (theories that address narrower marketing issues). Other researchers have employed theories from marketing's ancestor disciplines, such as economics, psychology and sociology, to explicate marketing problems and issues. However, efforts to allow different theories to compete in terms of explanatory power with regard to a specific marketing problem have been less prevalent in the marketing literature. This article considers a fundamental marketing exchange problem, namely heterosexual partner seeking behaviour or the search for personal relationships, from the perspectives of three competing theories: social exchange theory, evolutionary psychology and feminist theory. Based in these theories, various propositions regarding the exchange of resources in the partner-seeking process are made, and an extensive comparative table of hypotheses constructed. Then, a research agenda is outlined that would permit the testing of these hypotheses and a determination of the relative predictive power of the three theories.
Revisiting Consumption Experience
Authors: Carù Antonella , Cova Bernard
Published: August 2003

The notion of experience entered the field of consumption and marketing with Holbrook and Hirschman's pioneering article of 1982. Twenty years later, this notion has become a key element in understanding consumer behaviour, and, in some views, a foundation for the economy and marketing of the future. In our view, however, this development is not without its risks, as the concept of experience is still illdefined or, worse, defined in ideological terms. To this end, the present paper looks 1) to give an overview of the different meanings ascribed to the word `experience' in various scientific disciplines and to detail the different meanings ascribed to the notion of consumption experience; and 2) to highlight, using a deconstructive approach, that in the field of marketing we must use a typology of consumption experiences which goes beyond an ideological view that tends to consider every experience as extraordinary.
Fracture characterization at Valhall: Application of P‐wave amplitude variation with offset and azimuth (AVOA) analysis to a 3D ocean‐bottom data set
Authors: Hall Stephen A. , Kendall J‐Michael
Published: August 2003

The delineation and characterization of fracturing is important in the successful exploitation of many hydrocarbon reservoirs. Such fracturing often occurs in preferentially aligned sets; if the fractures are of subseismic scale, this may result in seismic anisotropy. Thus, measurements of anisotropy from seismic data may be used to delineate fracture patterns and investigate their properties. Here fracture‐induced anisotropy is investigated in the Valhall field, which lies in the Norwegian sector of the North Sea. This field is a chalk reservoir with good porosity but variable permeability, where fractures may significantly impact production, e.g., during waterflooding. To investigate the nature of fracturing in this reservoir, P‐wave amplitude variation with offset and azimuth (AVOA) is analyzed in a 3D ocean‐bottom cable (OBC) data set. In general, 3D ocean‐bottom seismic (OBS) acquisition leads to patchy coverage in offset and azimuth, and this must be addressed when considering such data. To overcome this challenge and others associated with 3D OBS acquisition, a new method for processing and analysis is presented. For example, a surface fitting approach, which involves analyzing azimuthal variations in AVO gradients, is used to estimate the orientation and magnitude of the fracture‐induced anisotropy. This approach is also more widely applicable to offset‐azimuth analysis of other attributes (e.g., traveltimes) and any data set where there has been true 3D data acquisition, land or marine. Using this new methodology, we derive high‐resolution maps of P‐wave anisotropy from the AVOA analysis for the top‐chalk reflection at Valhall. These anisotropy maps show coherent but laterally varying trends. Synthetic AVOA modeling, using effective medium models, indicates that if this anisotropy is from aligned fracturing, the fractures are likely liquid filled with small aspect ratios and the fracture density must be high. Furthermore, we show that the fracture‐normal direction is parallel to the direction of most positive AVO gradient. In other situations the reverse can be true, i.e., the fracture‐normal direction can be parallel to the direction of the most negative AVO gradient. Effective medium modeling or comparisons with anisotropy estimates from other approaches (e.g., azimuthal variations in velocity) must therefore be used to resolve this ambiguity. The inferred fracture orientations and anisotropy magnitudes show a degree of correlation with the positions and alignments of larger scale faults, which are estimated from 3D coherency analysis. Overall, this work demonstrates that significant insight may be gained into the alignment and character of fracturing and the stress field variations throughout a field using this high‐resolution AVOA method.
Estimating scattering attenuation from vugs or karsts
Authors: Hackert Chris L. , Parra Jorge O.
Published: August 2003

Cavities in carbonate rock, such as vugs or karsts, cause scattering attenuation in passing waves. The degree of such attenuation is often difficult to quantify because the exact scale and structure of the cavities is unknown. Taking the exact vug structure from X‐ray computerized‐tomography scans of two carbonate cores, we use 3D finite‐difference modeling to determine the P‐wave scattering attenuation in these cores at ultrasonic frequencies. The predicted scattering attenuation is quite high, with Q of 15 and 8 near the source frequency of 250 kHz. In spite of the sharp contrast in medium properties between cavity and rock, and the violation of the small perturbation assumption, the computed scattering attenuation is roughly comparable to that predicted by various random medium scattering theories. This suggests that if the volume fraction and typical size of vugs or karsts can be estimated, then a rough estimate of frequency‐dependent scattering attenuation can be made.
Inversion of helicopter electromagnetic data to a magnetic conductive layered earth
Authors: Huang Haoping , Fraser Douglas C.
Published: August 2003

Inversion of airborne electromagnetic (EM) data for a layered earth has been commonly performed under the assumption that the magnetic permeability of the layers is the same as that of free space. The resistivity inverted from helicopter EM data in this way is not reliable in highly magnetic areas because magnetic polarization currents occur in addition to conduction currents, causing the inverted resistivity to be erroneously high.

A new algorithm for inverting for the resistivity, magnetic permeability, and thickness of a layered model has been developed for a magnetic conductive layered earth. It is based on traditional inversion methodologies for solving nonlinear inverse problems and minimizes an objective function subject to fitting the data in a least‐squares sense. Studies using synthetic helicopter EM data indicate that the inversion technique is reasonably dependable and provides fast convergence. When six synthetic in‐phase and quadrature data from three frequencies are used, the model parameters for two‐ and three‐layer models are estimated to within a few percent of their true values after several iterations. The analysis of partial derivatives with respect to the model parameters contributes to a better understanding of the relative importance of the model parameters and the reliability of their determination.

The inversion algorithm is tested on field data obtained with a Dighem helicopter EM system at Mt. Milligan, British Columbia, Canada. The output magnetic susceptibility‐depth section compares favorably with that of Zhang and Oldenburg who inverted for the susceptibility on the assumption that the resistivity distribution was known.
Coherent noise attenuation in the radial trace domain
Authors: Henley David C.
Published: August 2003

Coherent noise is a persistent problem in seismic imaging, and a number of techniques have been developed to attenuate it. The radial trace (RT) transform, a simple seismic data mapping algorithm, can be used as the basis for a particularly flexible and effective method for attenuating coherent noise on both prestack and poststack seismic data. Described here are the principles and some practical application details for attenuating coherent noise in the RT domain. A comparison between frequency–wavenumber (f–k) and RT domain filtering on a synthetic model is presented, and some of the differences and advantages of RT methods are identified. Next, RT coherent noise attenuation is demonstrated using a set of good‐quality field data; it is then applied to a very noisy data set. The results obtained with this last set prove to be as good as, or better than, those produced using f–k filtering.
Optimization of bone growth and remodeling in response to loading in tapered mammalian limbs
Authors: Lieberman Daniel E. , Pearson Osbjorn M. , Polk John D. , Demes Brigitte , Crompton A. W.
Published: August 2003

How bones respond dynamically to mechanical loading through changes in shape and structure is poorly understood, particularly with respect to variations between bones. Structurally, cortical bones adapt in vivoto their mechanical environments primarily by modulating two processes,modeling and Haversian remodeling. Modeling, defined here as the addition of new bone, may occur in response to mechanical stimuli by altering bone shape or size through growth. Haversian remodeling is thought to be an adaptation to repair microcracks or prevent microcrack propagation. Here, we examine whether cortical bone in sheep limbs modulates periosteal modeling and Haversian remodeling to optimize strength relative to mass in hind-limb midshafts in response to moderate levels of exercise at different growth stages. Histomorphometry was used to compare rates of periosteal growth and Haversian remodeling in exercised and sedentary treatment groups of juvenile, subadult and young adult sheep. In vivo strain data were also collected for the tibia and metatarsal midshafts of juvenile sheep. The results suggest that limb bones initially optimize responses to loading according to the varying power requirements associated with adding mass at different locations. In juveniles, exercise induces higher rates of periosteal modeling in proximal midshafts and higher rates of Haversian remodeling in distal midshafts. Consequently, distal element midshafts experience higher strains and,presumably, have lower safety factors. As animals age, periosteal modeling rates decline and Haversian remodeling rates increase, but moderate levels of mechanical loading stimulate neither process significantly.
Metabolite comparisons and the identity of nutrients translocated from symbiotic algae to an animal host
Authors: Whitehead L. F. , Douglas A. E.
Published: August 2003

Dinoflagellate algae of the genus Symbiodinium in symbiosis with marine animals release much of their photosynthetic carbon to the animal host. The compounds translocated to the host (`mobile compounds') were investigated by metabolite comparison as follows: a substrate was identified as a candidate mobile compound when comparable profiles of metabolites were generated from host metabolism of this substrate (supplied exogenously) and the endogenous mobile compounds. When the sea anemone Anemonia viridis was incubated with NaH14CO2 under photosynthesizing conditions, most of the radioactivity in the animal tissue was recovered from the low-molecular-mass fraction and distributed in the ratio 1:2:1 between the neutral, acidic and basic sub-fractions. Prominent 14C-labelled compounds included glucose, malate and glucose-6-phosphate. When the symbiosis was incubated with 14C-labelled glucose plus succinate or fumarate(but none of eight other substrate combinations tested), the 14C-labelled metabolites closely matched those obtained with NaH14CO2. These data suggest that glucose and succinate/fumarate (or metabolically allied compounds) may be important photosynthetic compounds transferred from the Symbiodinium cells to the tissues of A. viridis. Metabolite comparisons can be applied to study nutritional interactions in symbioses involving photosynthetic algae and, with appropriate modification, other associations between microorganisms and plants or animals.
Retinoid X receptor and retinoic acid response in the marine sponge Suberites domuncula
Authors: Wiens Matthias , Batel Renato , Korzhev Michael , Müller Werner E. G.
Published: August 2003

To date no nuclear receptors have been identified or cloned from the phylogenetically oldest metazoan phylum, the Porifera (sponges). We show that retinoic acid causes tissue regression in intact individuals of the demosponge Suberites domuncula and in primmorphs, special three-dimensional cell aggregates. Primmorphs were cultivated on a galectin/poly-L-lysine matrix in order to induce canal formation. In the presence of 1 or 50 μmol l–1 retinoic acid these canals undergo regression, a process that is reversible. We also cloned the cDNA from S. domunculaencoding the retinoid X receptor (RXR), which displays the two motifs of nuclear hormone receptors, the ligand-binding and the DNA-binding domains, and performed phylogenetic analyses of this receptor. RXR expression undergoes strong upregulation in response to treatment with retinoic acid, whereas the expression of the sponge caspase is not increased. The gene encoding the LIM homeodomain protein was found to be strongly upregulated in response to retinoic acid treatment. These data indicate that the RXR and its ligand retinoic acid play a role in the control of morphogenetic events in sponges.
The effect of temperature on swimming performance and oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch)salmon stocks
Authors: Lee C. G. , Farrell A. P. , Lotto A. , MacNutt M. J. , Hinch S. G. , Healey M. C.
Published: August 2003

Our knowledge of the swimming capabilities and metabolic rates of adult salmon, and particularly the influence of temperature on them, is extremely limited, and yet this information is critical to understanding the remarkable upstream migrations that these fish can make. To remedy this situation, we examined the effects of temperature on swimming performance and metabolic rates of 107 adult fish taken from three stocks of sockeye salmon Oncorhynchus nerka and one stock of coho salmon O. kisutchat various field and laboratory locations, using large, portable, swim tunnels. The salmon stocks were selected because of differences in their ambient water temperature (ranging from 5°C to 20°C) and the total distance of their in-river migrations (ranging from ∼100 km for coastal stocks to ∼1100 km for interior stocks). As anticipated, differences in routine metabolic rate observed among salmon stocks were largely explained by an exponential dependence on ambient water temperature. However, the relationship between water temperature and maximum oxygen consumption(ṀO2max), i.e. the ṀO2 measured at the critical swimming speed (Ucrit), revealed temperature optima for ṀO2max that were stock-specific. These temperature optima were very similar to the average ambient water temperatures for the natal stream of a given stock. Furthermore,at a comparable water temperature, the salmon stocks that experienced a long and energetically costly in-river migration were characterized by a higher ṀO2max, a higher scope for activity, a higher Ucrit and, in some cases, a higher cost of transport, relative to the coastal salmon stocks that experience a short in-river migration. We conclude that high-caliber respirometry can be performed in a field setting and that stock-specific differences in swimming performance of adult salmon may be important for understanding upstream migration energetics and abilities.
Steroids for free? No metabolic costs of elevated maternal androgen levels in the black-headed gull
Authors: Eising Corine M. , Visser G. Henk , Müller Wendt , Groothuis Ton G. G.
Published: August 2003

Within- and between-clutch variation in yolk titres of hormones of maternal origin has been found in many avian species. So far, experiments have revealed mainly beneficial effects of maternal androgens. This would also apply to black-headed gulls (Larus ridibundus). Previous experiments have shown that chicks benefit from these higher levels since their competitive abilities are improved and growth and survival probabilities thus enhanced. However, not all females show the same increase in yolk hormones from first to last egg or invest equally high amounts of androgens in their clutches. Possibly, there is a trade-off between the beneficial effects of high androgen levels and potential costs, such as increased metabolic rates. We studied possible metabolic costs of experimentally elevated yolk androgen levels for chicks of several age classes, starting three days prior to hatching until fledging at an age of approximately 30 days. Daily energy expenditure in the field, measured using the doubly labelled water technique, did not differ between treatments or between sexes. Oxygen consumption measured in birds at rest in the lab (RMR) did not vary between chicks hatched from androgen-injected (T) or oil-injected (Oil) control eggs at any age in thermo-neutral or below thermo-neutral conditions. Males showed a lower RMR than females towards the fledging age. We conclude that it is unlikely that the costs of high maternal androgen levels can be found in higher energy expenditure in the chick.
Two-year evaluation of telepathology
Authors: Hutarew Georg , Dandachi Nadia , Strasser Felix , Prokop Eva , Dietze Otto
Published: August 2003

We evaluated a dynamic telepathology system in routine use after a two-year developmental phase. In two three-month studies, two years apart, all intraoperative frozen sections were examined by one pathologist via the telepathology system. Laboratory technicians sampled tissues at gross examination and were connected with the pathologist by videoconference. Specimens were immediately reviewed after the telepathology diagnosis by the same diagnostician. In the second study there were 342 cases. The mean time required to diagnose small specimens such as biopsies was 8 min (range 4–14); for specimens with extensive gross examination it was 22 min (range 10–45). The telepathology and traditional frozen-section diagnoses agreed in 99.4% of cases, but telepathology took two to four times longer for gross and histological examinations, and up to 10 times longer for histological examination only. There were five false diagnoses (1.5%), two of which originated from telepathology (0.6%) and were recognized in the subsequent light microscopy review. Telepathology is not a replacement for light microscopy, but should be regarded as a complementary technique.
Realtime teleconsultations versus face-to-face consultations in dermatology: immediate and six-month outcome
Authors: Granlund Håkan , Thoden Carl-Johan , Carlson Christer , Harno Kari
Published: August 2003

We evaluated the outcome of both realtime teleconsultations and face-to-face consultations in dermatology. Forty-six patients were enrolled in an open controlled study. Twenty-nine patients (60%) answered the questionnaire sent to them after six months. Over the six-month follow-up, similar proportions of the two patient groups had visited a general practitioner or a specialist in the consulting hospital. At follow-up, overall patient satisfaction with the consultation, measured on a linear analogue scale (0–10), had fallen only slightly and to the same extent after both types of consultation, that is by 1.2 (SD 3.7) after realtime teleconsultations and by 1.4 (SD 4.5) after face-to-face consultations. The proportions of patients who would prefer the same mode of consultation for their next appointment had decreased from 83% to 50% in the realtime teleconsultation group and from 83% to 62% in the face-to-face consultation group. However, in neither group was the change significant. The study suggests that patient satisfaction with teleconsultation is well preserved after six months.
Family members' narrated experiences of communicating via video-phone with patients with dementia staying at a nursing home
Authors: Sävenstedt Stefan , Brulin Christine , Sandman P-O
Published: August 2003

We studied the experience of family members who communicated via video-phones with elderly demented patients who were either staying at a home for temporary respite care or living in a nursing home. The study was based on qualitative data from seven interviews. The interviewees each had three or more months' experience with a video-phone. The open interviews were transcribed. Content analysis showed that video-phone conversations made the relatives of patients at nursing homes more involved in the caring process and that conversation via the video-phone was a different way of communicating. Video-phone conversations with demented patients were in some cases more focused and of better quality than face-to-face conversations. In most cases the video-phone conversations required the assistance of staff at the home in order to be meaningful. Video-phones have the potential to become useful tools for family members caring for elderly relatives.
Seizure Potential of Concomitant Medications and Radiographic Contrast Media Agents
Authors: Fedutes Bethany A , Ansani Nicole T
Published: August 2003

Objective

To review seizure risk of concomitant medication administration and nonionic, water-soluble radiographic contrast media agents for myelography.

Data Sources

Clinical literature was identified through MEDLINE (1966–May 2003). Key search terms included metrizamide, iohexol, myelogram, myelography, seizure, and contraindications.

Data Synthesis

Administration of myelography contrast media can produce rare serious adverse events, including meningeal irritation, seizures, or psychological disturbances. An evaluation of case reports and clinical trials concerning seizure risks of nonionic, water-soluble radiographic myelography contrast media and concomitant medications with potential to lower the seizure threshold was performed.

Conclusions

Available data supporting the incidence of increased seizure risk with nonionic, water-soluble contrast media agents and concomitant medication administration that lowers the seizure threshold are anecdotal. However, because of product labeling and additive potential to decrease the seizure threshold, discontinuation of such medications should be considered to avoid the presumed increased risk of seizures.
Smart neural control of uncertain non‐linear systems
Authors: Wang Cong , Chen Guanrong , Ge Shuzhi S.
Published: August 2003

In this paper, we present a ‘smart’ neural control scheme for uncertain non‐linear systems using the localized radical basis function (RBF) networks. This scheme is designed such that the current control action can utilize the knowledge that the NN learned from the past control process. Compared with most existing adaptive neural controllers, which are in general very‐high‐order dynamic controllers due to the simultaneous adaptation of a large number of neural weights, the smart RBF neural controller is a static and low‐order one, and thus is more computationally feasible in practical design and implementation. To improve the generalization ability of the RBF networks, which plays an important role in the smart neural control scheme, chaotic reference signals are employed in the training phase of the scheme, where the complex chaotic signals offer richer information for NN learning due to the ergodicity of chaos. The proposed neural control scheme can act ‘smartly’ in the operational phase after the RBF networks have been well‐trained in the training phase, in a way similar to the process that humans accomplish some complicated control tasks easily after the ‘neuro‐controllers’ in their brains have been well‐trained previously. The smart neural control scheme also provides a strong motivation for the current research on chaos generation. Simulation studies are included to demonstrate the effectiveness of the new control scheme. Copyright © 2003 John Wiley & Sons, Ltd.
Sliding mode neural network control of an induction motor drive
Authors: Parma Gustavo G. , Menezes Benjamim R. , Braga Antônio P. , Costa Marcelo A.
Published: August 2003

A new approach for induction motor drive control is presented in this paper. The new scheme is based on the direct application of an artificial neural network, trained with sliding mode control, into the feedback control system. Neural network learning is implemented with an on‐line adaptation algorithm that inherits robustness and high speed of learning from Sliding Mode Control. The results showed that proportional and integral or proportional, integral and differential controllers used in classical motor drives can be replaced with a neural network with on‐line learning. Copyright © 2003 John Wiley & Sons, Ltd.
Stable neural control of uncertain multivariable systems
Authors: Mears Mark J. , Polycarpou Marios M.
Published: August 2003

Tracking control of a class of non‐linear, uncertain, multi‐input, multiple‐output systems is addressed in this paper. The control system architecture uses neural networks for function approximation, certainty equivalent control inputs to cancel plant dynamics and smoothed sliding mode control to insure that the trajectories remain bounded. Lyapunov analysis is used to derive equations for the sliding mode control, neural network training, and to show uniform ultimate boundedness of the closed‐loop system. Stability analysis results are shown for single‐input single‐output and two‐input two‐output systems. Results are then extended to the more general multiple‐input multiple‐output case where the number of inputs is equal to the number of outputs. Simple simulation examples are used to illustrate control system performance. Copyright © 2003 John Wiley & Sons, Ltd.
Ionic Liquids, 3. Synthesis and Utilisation of Protic Imidazolium Salts in Homogeneous Catalysis
Authors: Picquet Michel , Tkatchenko Igor , Tommasi Immacolata , Wasserscheid Peter , Zimmermann Jörg
Published: August 2003

Protonation of 1‐alkylimidazoles provides halogen‐free salts which act as ionic liquids and proton reservoir in proton‐ and metal‐assisted catalytic processes like dimerisation of methyl acrylate and ring closing metathesis, and lead to significant improvements both in activity and selectivity.
Endo‐ and Exotemplating to Create High‐Surface‐Area Inorganic Materials
Authors: Schüth Ferdi
Published: August 2003

Porous and high‐surface‐area materials are of interest to many scientific communities. Templating pathways can be used to synthesize such materials with a high degree of control over their structural and textural properties. As templates molecular or supramolecular units are added to the synthesis mixture. They are occluded in the growing solid and leave a pore system after their removal. For such templates the term “endotemplate” is introduced. Alternatively, the templates can be materials with structural pores in which another solid is created, thus providing a scaffold for the synthesis. After removal of the scaffold, a porous or finely divided solid remains, depending on the connectivity of the template. Such a template is termed an “exotemplate”. By judicious choice of the templating procedure, unprecedented control of the structure and texture on length scales between nanometers and micrometers has been achieved over the last few years.
Study of the exfoliation process of epoxy–clay nanocomposites by different curing agents
Authors: Wang Qi , Song Chunfang , Lin Weiwei
Published: August 2003

Epoxy–clay nanocomposites were synthesized using two organoclays cured with different chemicals at different temperatures. Interlayer distance of the clay layers and curing process were investigated by X‐ray diffraction and infrared spectra. The clay treated with facilitated curing agent, 2,4,6‐tris[(dimethylamino)methyl]phenol, can exfoliate at all curing conditions, but for the other clay treated with low‐speed curing agent, p,p′‐diaminodiphenylmethane, exfoliation of the clay layers does not occur. It was found that the relative curing speed between the interlayer and extralayer was the most important factor determining clay exfoliation. Exfoliated epoxy–clay nanocomposites can be prepared if the curing speed of the interlayer is higher than that of the extralayer, irrespective of the curing agent and temperature used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 511–517, 2003
Growth and aging of facial soft tissues: A computerized three‐dimensional mesh diagram analysis
Authors: Ferrario Virgilio F. , Sforza Chiarella , Serrao Graziano , Ciusa Veronica , Dellavia Claudia
Published: August 2003

The normal growth, development, and aging of facial soft tissues was studied by three‐dimensional (3D) computerized mesh diagram analysis. The 3D coordinates of 50 soft‐tissue landmarks were collected from 591 healthy white northern Italians (351 males, 240 females) 6–40 years of age. For each gender and age class, mean values were computed, and a standardized mesh of equidistant horizontal, vertical, and anterior‐posterior lines was constructed. Within each age group, male meshes were superimposed on female meshes. For each gender, the 6‐year‐old reference mesh was superimposed on the reference mesh of each age group. The global (size plus shape) difference was evaluated by calculating the relevant displacement vectors for each landmark. Consequently, a size normalization was carried out and the shape difference was evaluated by calculating new relevant displacement vectors for each landmark. Growth and development were different along the three spatial planes: the largest increment was observed in the vertical dimension, with major modifications in the soft‐tissue profile. The vertical dimension in males increased even after 30 years of age: ear dimensions increased, trichion moved superiorly and posteriorly, and pogonion, menton, and gonion moved anteriorly and inferiorly. In all age groups, size‐standardized shape differences were found in the forehead, lower‐third facial profile, eyes, cheeks, and ears. In each age class, male dimensions were larger than female dimensions. During childhood, gender differences in size were limited; shape differences were even less manifest. Overall, the profile was more anterior and inferior, the gonia were more inferior and more lateral, the forehead was more anterior, and the ears were larger in males than in females of corresponding age. Clin. Anat. 16:420–433, 2003. © 2003 Wiley‐Liss, Inc.
Clinical importance of ligamentous and osseous structures in the cervical uncovertebral foraminal region
Authors: Yilmazlar Selcuk , Kocaeli Hasan , Uz Aysun , Tekdemir Ibrahim
Published: August 2003

The vertebral artery, cervical spinal nerves, spinal nerve roots, and the bony and ligamentous tissue related to the cervical vertebrae are structures whose anatomy determines the path of a surgical approach. Defining the anatomy and, in particular, determining the precise location of vulnerable structures at the intervertebral foramen and the uncovertebral foraminal region (UVFR), a region defined by the uncinate process anteriorly, the facet joint posteriorly and the foramen transversarium laterally, has critical significance when selecting the safest surgical approach. We studied the anatomy of the vertebral artery, cervical spinal nerves, and spinal nerve roots within the UVFR in six cadaver specimens. We also obtained measurements of bony structures in 35 dry cervical vertebral columns, from C3–C7. The uncinate process (UP) projects superiorly from the posterolateral aspect of each cervical vertebral body, except for the first and second vertebrae. Because the posterior part of the UP lies adjacent to the vertebral artery, spinal nerve, and spinal nerve roots, its resection creates sufficient space to decompress these structures directly. The posterolateral surface of the UP is covered by ligamentous tissue that originates from the posterior longitudinal ligament and protects the neural and vascular structures during their decompression in the UVFR. Clin. Anat. 16:404–410, 2003. © 2003 Wiley‐Liss, Inc.
Anatomical sciences in the allopathic medical school curriculum in the United States between 1967–2001
Authors: Gartner Leslie P.
Published: August 2003

The present article surveys the changes in the time allocated for the four disciplines in the anatomical sciences in the medical curricula of allopathic medical schools in the United States from 1967–2001. The results indicate that there was a great reduction in the laboratory portions, but not in the lecture portions of Gross Anatomy, Histology, Neuroanatomy, and Embryology. The greatest time reduction overall for the disciplines occurred between 1967–1973 (502 to 387 hr), followed by the time reduction between 1982–1995 (380 to 329 hr). Clin. Anat. 16:434–439, 2003. © 2003 Wiley‐Liss, Inc.