bluuebunny/crossref_metadata_2025 huggingface dataset:
A physicochemical characterization of the waters of the El‐Kabir River and major tributaries in Syria and Lebanon
Authors: Thomas Richard L. , Cadham John C. , Hassan Siba , Kawass Issam , Khawlie Mohamad , Shaban Amin , Walker J.
Published: July 2005

Thirty‐nine sampling sites were selected in the El‐Kabir River watershed, including 18 in Syria and 21 in Lebanon. Three major tributaries, the Nahr al‐Arous and the Nahr Nasrive in Syria, and the Chadra River in Lebanon, were included in the site selection, together with Wadi el‐Aatchane and Wadi Khaled. Instrumental measurements for temperature, specific conductivity (Sp. Cond.), dissolved oxygen (DO) and pH were taken directly in the water at each site visit. Measurements were taken in both countries in May 2001, January, April and August 2002, and there was an additional sampling in Lebanon during September 2001. The interpretation of the data led to some specific conclusions on the conditions in the watershed. The waters of the El‐Kabir River are derived almost exclusively from ground water, with many significant springs functioning throughout the year. The water that flows rapidly through the system is well‐mixed and consistent in its major characteristics. The DO concentration > 5 mg L−1, averaging 8.53 mg L−1 (three DO values < 5 mg L−1 were observed, all at the same spring). Some variability in water character was observed for Sp. Cond.; these differences could be related to the spring‐source waters originating in limestone or basaltic terrain. Furthermore, an increase in Sp. Cond. in the lower reaches of the river might be related to salinization, resulting from surface water and near‐surface ground water withdrawals for anthropogenic use, particularly irrigation.
Watershed characteristics, land use and fabric: The application of remote sensing and geographical information systems
Authors: Khawlie Mohamad , Shaban Amin , Abdallah Chadi , Darwish T. , Kawass Issam
Published: July 2005

Integrated watershed assessment, especially relying on remote sensing (RS), is a newly established procedure in developing countries. It is proving to be a major component in river‐basin environmental management. The recurrence of environmental problems in the Akkar El Kabir River watershed, as well as the lack of proper data on sources and sinks of pollutants, and the extent of human interference, led to the current study. Advanced geoinformation tools, such as RS and geographical information systems (GIS), prove to be a valuable asset in securing data on the fabric of the Akkar watershed in relation to its natural setting and anthropic interference. This is particularly true in the current study as the river constitutes the boundary between Lebanon and Syria. Remote sensing captures the watershed characteristics and land use on both sides without constraints. The natural fabric includes geology, drainage, hydrogeology, forest and soil. The anthropic fabric includes settlements, utilities, roads, agriculture and land use. If it were not for geoinformation techniques, the task of securing such data would be difficult. Also, these techniques show the impact of malpractices from excessive human interference that result in degradation of land and water quality. Changes in the watershed, such as environmental deterioration, are observed as water pollution, soil erosion, forest decline and socioeconomic imbalance. Obviously, this is the outcome of malpractices in a multisectorial system. A major challenge for RS and GIS is to quantify, model and predict, if possible, the extent of these changes. Remote sensing inherently captures the impact of interaction between nature and human beings. Detection of change is a major indicator that RS can contribute to the evaluation of the state of the environment. The application of it on this watershed reveals that significant changes have occurred over the last 10–15 years, most of which are anthropic.
Bacterial indicators of faecal pollution in the waters of the El‐Kabir River and Akkar watershed in Syria and Lebanon
Authors: Hamze Monzer , Hassan Siba , Thomas Richard L. , Khawlie Mohamad , Kawass Issam
Published: July 2005

Water samples for bacterial analyses were taken, when possible, at 41 sites in Lebanon and Syria in the El‐Kabir River watershed. Samples were analysed for total coliform (TC), faecal coliform (FC) and faecal streptococcus. The Lebanese samples also were analysed for the presence of sulphate‐reducing bacteria. The TC and FC concentrations were extremely high throughout the watershed, rendering the water unfit for any human uses. The origin of the bacteria is the untreated sewage waste from the numerous settlements situated throughout the watershed. This primary origin is supported by high ratios of FC/faecal streptococcus, although impacts from animal wastes also were observed. The bacterial levels were higher in summer than in winter, indicating a high winter river flow that dilutes a relatively constant source of human sewage discharged to the system. Spring waters also exhibited elevated levels of bacteria, implicating surface land use and waste disposal practices upstream of the springs. The data clearly shows that human health is at a high risk and that strategies for improving water quality and protecting spring water must be expeditiously implemented.
Geochemistry of the sediments of the El‐Kabir River and Akkar watershed in Syria and Lebanon
Authors: Thomas Richard L. , Shaban Amin , Khawlie Mohamad , Kawass Issam , Nsouli Bilal
Published: July 2005

A total of 39 sediment samples were collected from the El‐Kabir River and its major tributaries during the low‐flow period of August/September 2001. Of these samples, six were selected for a scan for pesticide residues, polychlorinated biphenyls and polycyclic aromatic hydrocarbons (PAHs). An additional seven samples were analysed for major elements and trace elements. Despite the limited number of samples analysed, it can be concluded that major elements reflect the distribution and chemistry of major rock types in the watershed, the sodium oxide concentrations indicate an early onset of salinization in the coastal plain, dichlorodiphenyltrichloroethane is currently in use in the watershed despite being a banned substance, the PAH contamination is directly linked to an old, disused railway track, and chromium and nickel are the two trace elements showing anthropogenic enrichment, being attributed to leather tanning and metal plating by small‐scale industries in the watershed.
The appetite‐suppressant effect of nicotine is enhanced by caffeine*
Authors: Jessen A. , Buemann B. , Toubro S. , Skovgaard I. M. , Astrup A.
Published: July 2005

Aim:  To test whether the anorectic effect of nicotine may be amplified by caffeine.

Methods:  Chewing gums with nicotine and caffeine were administered to 12 healthy young men of normal weight. Different combinations of 0, 1 or 2 mg of nicotine and 0, 50 or 100 mg of caffeine were applied during a 2‐h period in a randomized, double blind, cross over design. Appetite sensations were measured using visual analogue scales.

Results:  Hunger and prospective food consumption were negatively associated with the increasing doses of nicotine, whereas satiety and fullness were positively associated with the increasing doses of nicotine (p < 0.05). Caffeine appeared to amplify the effects of nicotine on hunger and fullness as a caffeine × nicotine × time interaction was observed in these scores (p < 0.05). The 2‐mg dose of nicotine in combination with the 100‐mg dose of caffeine caused nausea in four of the non‐smokers. However, the effects of nicotine and the caffeine × nicotine × time interaction persisted after the exclusion of these subjects.

Conclusion:  Caffeine added to nicotine chewing gum appears to amplify its attenuating effects on appetite and the combinations of 1‐mg of nicotine with caffeine seem to be well tolerated.
Financial Reporting and the Austrian Theory of Entrepreneurship
Authors: YOUNG S. DAVID
Published: July 2005

The Austrian School of economics, with its emphasis on the market as a process and the role of the entrepreneur as the catalyst of that process, sheds new light on the social role of accounting. This paper examines the implications of the School's teachings to financial reporting, including its insistence on relegating accounting to the role of retrospective economic calculation, and the use of current cash equivalents for asset valuation. The Austrian School's replacement of neo‐classical general equilibrium theory with a dynamic model of the market process offers accounting researchers some relief of having to cope with the real world of error, discovery, and disequilibrium.
The Methodology of Early Accounting Theorists
Authors: GAFFIKIN M. J. R.
Published: July 2005

If, as Watts and Zimmerman (1986) suggest, a unique methodological foundation is the hallmark of a mature discipline, accounting fails to qualify. In this article, methodological arguments of accounting theorists in the first part of this century are examined. ‘Pattern Modeling’ is suggested as a basis for methodological appraisal. The conclusion reached is that the major theoretical works in accounting were methodologically unsophisticated‐particularly in comparison with other disciplines such as economics.
Accounting for Shrinkage in Continuous Flow Industries: An Expository Note
Authors: MENSAH YAW M. , CHHATWAL GURPRIT S.
Published: July 2005

This study explores accounting for shrinkage in continuous flow industries, an area which has received no attention in the literature, but which appears to present some difficulty to cost accountants in some companies studied. The study presents an appropriate approach for process cost accounting where the materials in process undergo some dimensional transformation but remain measurable in the same physical units as the raw materials. Appropriate formulae are presented to help calculate the equivalent units of finished output that the semi‐processed materials in inventory represent. The initial development assumes a uniform loss rate, an assumption later relaxed to illustrate the solution procedure for non‐uniform loss rates.
A New Approach to Depreciation
Authors: GRINYER JOHN R.
Published: July 2005

This paper presents a new ‘matching’ based approach to depreciation that incorporates interest adjustments and generates accounting measurements that are consistent with the ex post Net Terminal Values of fixed assets. The method has been developed from the concept of Earned Economic Income by the application of concepts drawn from the existing literature. The calculations and ledger entries involved are illustrated in the appendices.
Accounting: The Structure of a Growing Profession
Authors: BARLEV BENZION , PELES YORAM C.
Published: July 2005

Complete membership records of the Institute of Certified Public Accountants in Israel are analysed to determine the level of concentration and growth of the accounting profession. This study differs from previous studies in that it concentrates on the supply side of the market. Previously, because of the unique characteristics of auditing services, they were assumed to have no substitute. An analysis of firm switching by CPAs in Israel indicates the existence of substitutes in production. Low levels of overall concentration were found, although large clients are generally audited by large public accounting firms. The profession appears to be competitive as entry is quite easy and switching between firms by CPAs is common.
Boussard's ‘Effectiveness of Inflation Accounting Adjustments’: A Comment
Authors: BELL PHILIP W.
Published: July 2005

Boussard's (1984) notion that Current Cost/Constant Dollar Accounting does not provide ‘meaningful rates of return’ when inflationary conditions are compared with non‐inflationary conditions is based on a misleading example.
Children's understanding of the Ulysses conflict
Authors: Choe Katherine S. , Keil Frank C. , Bloom Paul
Published: July 2005

Two studies explored children's understanding of how the presence of conflicting mental states in a single mind can lead people to act so as to subvert their own desires. Study 1 analyzed explanations by children (4–7 years) and adults of behaviors arising from this sort of ‘Ulysses conflict’ and compared them with their understanding of conflicting desires in different minds, as well as with changes of mind within an individual across time. The data revealed that only the adults were able to adequately explain the Ulysses conflict. Study 2 asked children (4–7 years) and adults to choose among three explicitly presented competing explanations for self‐subverting behaviors. The results suggest that an understanding of the influence of conflicting mental states on behaviors does not occur until at least 7 years of age.
Reorientation by geometric and landmark information in environments of different size
Authors: Vallortigara Giorgio , Feruglio Marco , Sovrano Valeria Anna
Published: July 2005

It has been found that disoriented children could use geometric information in combination with landmark information to reorient themselves in large but not in small experimental spaces. We tested domestic chicks in the same task and found that they were able to conjoin geometric and nongeometric (landmark) information to reorient themselves in both the large and the small space used. Moreover, chicks reoriented immediately when displaced from a large to a small experimental space and vice versa, suggesting that they used the relative metrics of the environment. However, when tested with a transformation (affine transformation) that alters the geometric relations between the target and the shape of the environment, chicks tended to make more errors based on geometric information when tested in the small than in the large space. These findings suggest that the reliance of the use of geometric information on the spatial scale of the environment is not restricted to the human species.
Motor processes in children's imagery: the case of mental rotation of hands
Authors: Funk Marion , Brugger Peter , Wilkening Friedrich
Published: July 2005

In a mental rotation task, children 5 and 6 years of age and adults had to decide as quickly as possible if a photograph of a hand showed a left or a right limb. The visually presented hands were left and right hands in palm or in back view, presented in four different angles of rotation. Participants had to give their responses with their own hands either in a regular, palms‐down posture or in an inverted, palms‐up posture. For both children and adults, variation of the posture of their own hand had a significant effect. Reaction times were longer the more awkward it was to bring their own hand into the position shown in the stimulus photograph. These results, together with other converging evidence, strongly suggest that young children's kinetic imagery is guided by motor processes, even more so than adults’.
Toddlers recognize verbs in novel situations and sentences
Authors: Naigles Letitia R. , Bavin Edith L. , Smith Melissa A.
Published: July 2005

Toddlers’ (MA = 22 and 27 months) ability to extend newly taught verbs to new situational and sentential contexts was investigated. Children were interactively taught two novel verbs, presented in only the transitive frame (e.g. You’re lorping the ball), in a playroom setting. They then viewed the verb actions presented on side‐by‐side monitors and were asked to distinguish the verbs in three test frames (transitive, intransitive, neutral (e.g. lorping)). Both groups demonstrated learning of the verbs in the new situation and generalized the verbs to the intransitive sentence frame, but neither generalized reliably to the neutral frame. We conclude that even 22‐month‐olds demonstrate considerable context independence in their verb representations.
11‐month‐olds’ knowledge of how familiar words sound
Authors: Swingley Daniel
Published: July 2005

During the first year of life, infants’ perception of speech becomes tuned to the phonology of the native language, as revealed in laboratory discrimination and categorization tasks using syllable stimuli. However, the implications of these results for the development of the early vocabulary remain controversial, with some results suggesting that infants retain only vague, sketchy phonological representations of words. Five experiments using a preferential listening procedure tested Dutch 11‐month‐olds’ responses to word, nonword and mispronounced‐word stimuli. Infants listened longer to words than nonwords, but did not exhibit this response when words were mispronounced at onset or at offset. In addition, infants preferred correct pronunciations to onset mispronunciations. The results suggest that infants’ encoding of familiar words includes substantial phonological detail.
The genetic relationship between individual differences in social and nonsocial behaviours characteristic of autism
Authors: Ronald Angelica , Happé Francesca , Plomin Robert
Published: July 2005

Two types of behaviours shown in children – those reflecting social impairment and nonsocial obsessive repetitive behaviours – are central to defining and diagnosing autism spectrum disorders (ASDs). Parent and teacher data on social and nonsocial behaviours were obtained from a community sample of >3000 7‐year‐old twin pairs. Social and nonsocial behaviours were only modestly correlated, and it was found that some individuals had extreme scores on either social or nonsocial scales but not both. Genetic model‐fitting showed that social and nonsocial behaviours are both highly heritable, but their genetic overlap is modest, with most of the genetic influence being specific to either social or nonsocial behaviours. Considering these behaviours separately might help clarify gene‐brain‐behaviour pathways in future research.
A Learner-Centered Framework for E-Learning
Authors: Mccombs Barbara L. , Vakili Donna
Published: July 2005

The age is here of distance learning and new forms of e-learning. The rate at which a variety of institutions are entering the distance learning arena is increasing rapidly. In spite of the increased popularity and presence of online learning opportunities, however, many researchers and practitioners are decrying the lack of a research-validated framework to guide their design. Other researchers and practitioners point out that what works in effective traditional learning environments may or may not work in online environments. These concerns are addressed in this article through a review of relevant research and the presentation of a learner-centered framework. This framework is based on the American Psychological Association's (1997) research-validated Learner-Centered Psychological Principles, developed from over a century of research.
Pupil campimetry in patients with visual field loss
Authors: Schmid R. , Luedtke H. , Wilhelm B. J. , Wilhelm H.
Published: July 2005

Pupil campimetry is an objective test of the visual field. In pupil campimetry, the pupil light response elicited by focal light stimuli at different locations within the visual field is measured. Pupil campimetry was performed in patients with visual field loss because of different pathologies. The match between reduced pupil response and visual field loss was assessed. The pupil field of 23 patients was recorded by infrared video‐pupillography with light stimuli generated on a computer screen. A visual field was obtained on the same day with the Tuebingen Automated Perimeter. Both fields were compared by subjective judgement. Six of nine patients with large, two of five patients with incomplete, and three of six patients with minor field loss showed matching defects in their pupil and their visual fields. In functional loss of visual field sensitivity, no pupil field defect was seen (three patients). In most patients, the loss of visual field sensitivity could be revealed objectively by pupil campimetry.
Edge and Area Effects on the Occurrence of Migrant Forest Songbirds
Authors: PARKER TIMOTHY H. , STANSBERRY BROOKE M. , BECKER C. DUSTIN , GIPSON PHILIP S.
Published: July 2005

Abstract: Concerns about forest fragmentation and its conservation implications have motivated numerous studies that investigate the influence of forest patch area and forest edge on songbird distribution patterns. The generalized effects of forest patch size and forest edge on animal distributions is still debatable because forest patch size and forest edge are often confounded and because of an incomplete synthesis of available data. To fill a portion of this gap, we incorporated all available published data (33 papers) in meta‐analyses of forest edge and area effects on site occupancy patterns for 26 Neotropical migrant forest‐nesting songbirds in eastern North America. All reported area effects are confounded or potentially confounded by edge effects, and we refer to these as “confounded” studies. The converse, however, is not true and most reported edge effects are independent of patch area. When considering only nonconfounded studies of edge effects, only 1 of 17 species showed significant edge avoidance and 3 had significant affinity for edges. In confounded studies, 12 of 22 species showed significant avoidance of small patches and edges, and 1 had an affinity for small patches and edges. Furthermore, average effect sizes averaged across studies or species tended to be higher for confounded studies than for edge studies. We discuss three possible reasons for differences in results between these two groups of studies. First, studies of edge effects tended to be carried out in landscapes with greater forest cover than studies of confounded effects; among confounded effects studies, as forest cover increased, we observed a nonsignificant trend towards decreasing strength of small patch or edge avoidance effects. Thus, the weaker effects in edge studies may be due to the fact that these studies were conducted in forest‐dominated landscapes. Second, we may have detected strong effects only in confounded studies because area effects are much stronger than edge effects on bird occurrence, and area effects drive the results in confounded studies. Third, edge and area effects may interact in such a way that edge effects become more important as forest patch size decreases; thus, both edge and area effects are responsible for results in confounded studies. These three explanations cannot be adequately separated with existing data. Regardless, it is clear that fragmentation of forests into small patches is detrimental to many migrant songbird species.
A Mesofilter Conservation Strategy to Complement Fine and Coarse Filters
Authors: HUNTER MALCOLM L.
Published: July 2005

Abstract:  Setting aside entire ecosystems in reserves is an efficient way to maintain biodiversity because large numbers of species are protected, but ecosystem conservation constitutes a coarse filter that does not address some species. A complementary, fine‐filter approach is also required to provide tailored management for some species (e.g., those subject to direct exploitation). Mesofilter conservation is another complementary approach that focuses on conserving critical elements of ecosystems that are important to many species, especially those likely to be overlooked by fine‐filter approaches, such as invertebrates, fungi, and nonvascular plants. Critical elements include structures such as logs, snags, pools, springs, streams, reefs, and hedgerows, and processes such as fires and floods. Mesofilter conservation is particularly appropriate for seminatural ecosystems that are managed for both biodiversity and commodity production (e.g., forests managed for timber, grasslands managed for livestock forage, and aquatic ecosystems managed for fisheries) and is relevant to managing some agricultural and urban environments for biodiversity.
Demographic Limitations of the Ability of Habitat Restoration to Rescue Declining Populations
Authors: SCHROTT GREGORY R. , WITH KIMBERLY A. , KING ANTHONY W.
Published: July 2005

Abstract: Habitat restoration is often recommended in conservation without first evaluating whether populations are in fact habitat limited and thus whether declining populations can be stabilized or recovered through habitat restoration. We used a spatially structured demographic model coupled with a dynamic neutral landscape model to evaluate whether habitat restoration could rescue populations of several generic migratory songbirds that differed in their sensitivity to habitat fragmentation (i.e., severity of edge effects on nesting success). Simulating a best‐case scenario, landscapes were instantly restored to 100% habitat before, at, or after habitat loss exceeded the species' vulnerability threshold. The vulnerability threshold is a measure of extinction risk, in which the change in population growth rate (δλ) scaled to the rate of habitat loss (δh) falls below −1% (δλ/δh ≤−0.01). Habitat restoration was most effective for species with low‐to‐moderate edge sensitivities and in landscapes that had not previously experienced extensive fragmentation. To stabilize populations of species that were highly edge sensitive or any species in heavily fragmented landscapes, restoration needed to be initiated long before the vulnerability threshold was reached. In practice, habitat restoration is generally not initiated until a population is at risk of extinction, but our model results demonstrate that some populations cannot be recovered at this point through habitat restoration alone. At this stage, habitat loss and fragmentation have seriously eroded the species' demographic potential such that halting population declines is limited more by demographic factors than the amount of available habitat. Evidence that populations decline in response to habitat loss is thus not sufficient to conclude that habitat restoration will be sufficient to rescue declining populations.
Avian Diversity and Functional Insectivory on North‐Central Florida Farmlands
Authors: JONES GREGORY A. , SIEVING KATHRYN E. , JACOBSON SUSAN K.
Published: July 2005

Abstract: We studied the potential for native birds to control insect pests on farms. We assessed habitat factors correlated with diversity, distribution, and insect‐foraging activity of native birds on farms in north‐central Florida and then characterized common bird species that consumed insect biomass in crops as “functional insectivores” (birds most likely to contribute to pest control). Analyses of point‐count survey data and foraging observations collected over 2 years on paired organic and conventional farm sites indicated that (1) farms supported most (82–96%) land birds known to breed in the region; (2) bird species richness and abundance varied significantly with matrix habitat and field border type (but not with year or farm management type); (3) the highest bird abundances were associated with mixed crop plantings, field borders, and adjacent matrix composed of forest and hedge; and (4) abundances of 10 species identified as functional insectivores were primarily influenced by crop type (mixed crops attracted significantly more insect foragers into fields than monocrops). We documented birds eating pest insects in crops and did not observe substantive crop damage by birds during growing‐season observations. We advocate use of the termfunctional insectivoreto emphasize the potential positive role of avian insectivory on farms during the growing season.
A Novel Insulin Delivery Algorithm in Rats With Type 1 Diabetes: The Fading Memory Proportional‐Derivative Method
Authors: Gopakumaran Bala , Duman Heather M. , Overholser Douglas P. , Federiuk Isaac F. , Quinn Matthew J. , Wood Michael D. , Ward W. Kenneth
Published: July 2005

Abstract:  An algorithm designed to automatically control insulin delivery was tested in rats with Type 1 diabetes. This nonlinear algorithm included a fading memory component of proportional and derivative errors in order to simulate normal insulin secretion. Error‐weighting functions for the proportional and derivative terms were used with a performance index designed for error adaptation. In the first version of the algorithm, the proportional gain was adaptively varied. In the second version, a low rate of basal insulin delivery was adaptively varied. Six 6‐h studies with each version were conducted using frequent blood sampling and intravenous insulin delivery. In Version 2 studies, blood glucose levels during the last two hours were well‐controlled and significantly lower than in Version 1 (118 ± 2.0 vs. 130 ± 2.9 mg/dL). Neither version produced hypoglycemia. Future research using this algorithm needs to focus on automated glucose sensing in combination with insulin delivery.
Predictive Value of Carotid Intima Media Thickness in Hemodialysis Patients
Authors: Ekart Robert , Hojs Radovan , Hojs‐Fabjan Tanja , Balon Breda Pečovnik
Published: July 2005

Abstract:  Atherosclerosis is accelerated in hemodialysis patients. Intima media thickness (IMT) is a strong predictor for cardiovascular events in the general population. Using B‐mode ultrasonography, IMT in the common carotid arteries was measured in 99 nondiabetic hemodialysis patients (44 women and 55 men, mean age 53.1 years and mean dialysis duration 45.8 months). During a follow‐up of 42.4 ± 19.5 months, 33 patients died, 19 (57.6%) of them of cardiovascular causes. In these 19 patients IMT was significantly higher (0.89 vs. 0.69 mm) than in those who survived. Correlation between cardiovascular mortality and IMT was found. Patients were divided in relationship to the tertiles of IMT and the risk for cardiovascular death was progressively higher from the first tertile of IMT onward (P < 0.0006). IMT turned out to be an independent predictor of cardiovascular death (P < 0.025). According to our results IMT may be usefully applied for cardiovascular mortality risk stratification in nondiabetic hemodialysis patients.
The Effects of Graft Geometry on the Patency of a Systemic‐to‐Pulmonary Shunt: A Computational Fluid Dynamics Study
Authors: Waniewski Jacek , Kurowska Weronika , Mizerski Jeremi K. , Trykozko Anna , Nowiński Krzysztof , Brzezińska‐Rajszys Grażyna , Kościesza Andrzej
Published: July 2005

Abstract:  The modified Blalock–Taussig shunt is a palliative operation for some congenital heart diseases. An artificial conduit with antithrombotic surface placed between the subclavian (or innominate) and the pulmonary artery supplies blood to the lungs in defects with decreased pulmonary flow. Clotting of the graft is the main cause of its failure. Stenosis of the arteries is also observed. The objective of the present study was to investigate the flow pattern in the graft to investigate the possibility that clotting is initiated by the stimulation of platelets by high shear stress, and the possible effect of the pathological wall shear stress on the stenosis formation. The model included the left subclavian artery (LSA), the left pulmonary artery (LPA), and the graft. The three‐dimensional relative position and size of the arteries was obtained from a CT scan of real anatomy. Four different types of the graft with two different diameters (3 and 4 mm) and two different shapes (straight and curved) of the pipe, and one variable diameter pipe were inserted in the model. A pulsatile flow of 0.81 L/min on average was assumed at the inlet to LSA, and 80% of the flow was directed through the graft. Computer simulations demonstrated a complex flow pattern with eddies and low velocity regions in the arteries at the anastomoses with the graft in all five models. An eddy was also found inside the straight 4 mm graft. A high pathological shear rate was present within the graft, with higher values in the 3 mm grafts. The fractional volume with a high (>2500 L/s) shear rate was between 2.5% and 4.5%, and that with a very high (>7500 L/s) shear rate between 0 and 1.5% of the model volume, and depended on the graft geometry and the phase of the cardiac cycle. Pathologically high (>3.5 Pa) and pathologically low (<1.0 Pa) wall shear stress, which may induce neointimal growth, was found in LSA and LPA. We conclude that the activation of platelets by high shear rate is possible within the graft, followed by their subsequent aggregation in the eddies with a low flow rate. Flow‐induced changes of the vessel wall thickness (stenosis) can also appear, especially in the pulmonary artery.
Games Hospitals Play: Entry Deterrence in Hospital Procedure Markets
Authors: Dafny Leemore S.
Published: July 2005

Strategic investment models, though popular in the theoretical literature, have rarely been tested empirically. This paper develops a model of strategic investment in inpatient procedure markets, which are well‐suited to empirical tests of this behavior. Potential entrants are easy to identify in such markets, enabling the researcher to accurately estimate the entry threat faced by different incumbents. I derive straightforward empirical tests of entry deterrence from a model of patient demand, procedure quality, and differentiated product competition. Using hospital data on electrophysiological studies, an invasive cardiac procedure, I find evidence of entry‐deterring investment. These findings suggest that competitive motivations play a role in treatment decisions.
An Alternative Perspective On Information Asymmetry; Implications For Consumer Authority In Physician Services Markets
Authors: Smith Richard B.
Published: July 2005

This paper looks at the impact of patient knowledge on utilization and quality in physician services markets, developing a theoretical framework based on an alternative to the “market failure” perspective first proposed by Arrow (1963). Specifically, this paper looks at how outcomes in physician services markets are determined by whether patient and physician knowledge are substitutes or complements in health production. Empirical testing of the theoretical predictions indicates patient and physician knowledge have changed from substitutes to complements in recent years, and that this change may be hindering a more consumer‐driven market from ensuring high quality outcomes.
Differing Patterns of Antiresorptive Pharmacotherapy in Nursing Facility Residents and Community Dwellers
Authors: Jachna Carolyn M. , Shireman Theresa I. , Whittle Jeff , Ellerbeck Edward F. , Rigler Sally K.
Published: July 2005

Objectives:Little is known about differences between current patterns of antiresorptive therapy (ART) use in nursing facility (NF) residents and by community‐dwelling older adults (CDs). ART use was compared in older NF residents and CDs.

Design:Cross‐sectional analysis.

Setting:Kansas Medicaid files from May 2000 through April 2001.

Participants:Women aged 65 and older having at least 9 months of data as a CD or NF resident.

Measurements:Pharmacy claims were used to identify any ART prescription, including hormone replacement therapy (HRT), a bisphosphonate, raloxifene, or calcitonin. Demographic and clinical variables were identified from the claims files. Factors associated with ART use in bivariate analyses were entered into logistic regression models. Similar analyses were performed for bisphosphonate use among non‐estrogen replacement therapy (non‐ERT) ARTs (excluding HRT).

Results:The final study sample (N=2,289) included 898 NF (mean age 85.2) residents and 1,391 CDs (mean age 76.6). CDs were more likely to receive any ART (24.5%) than NF residents (19.6%). After adjustment for potential confounders, NF residents aged 65 to 84 were less likely (odds ratio (OR)=0.61, 95% confidence interval (CI)=0.44–0.85) to receive ART than CDs of the same age. Conversely, of those aged 85 and older, NF residents were more likely than CDs to receive ART (OR=1.96, 95% CI=1.18–3.25). Calcitonin was the most common non‐ERT ART prescribed for NF residents, whereas bisphosphonates were more often prescribed for CDs.

Conclusion:Underusage of ART is common in NF and CD cohorts. NF residents are less likely to receive bisphosphonates and more likely to receive calcitonin, for which efficacy is less clear. Further research is needed to identify factors influencing ART prescribing and selection of specific ARTs in different settings.
The Class Effect: Is It Relevant to Geriatrics?
Authors: Beers Mark H. , Stefanacci Richard G.
Published: July 2005

The formulary of medications available today provides a remarkable range of choices to all prescribers and their patients. In some ways, choices have become easier to make, whereas in other ways, choosing has become a nightmare of dueling considerations. One approach to simplification has relied on class effect. The hypothesis is that drugs within a pharmacological class all work similarly, have similar advantages and disadvantages, and are—to a large extent—interchangeable. If one develops familiarity with one or two agents in a class, that is all one needs to know, because there is little difference between agents within a drug class. The question is whether this approach based on class effect is relevant to geriatrics.
The Effect of an Individualized Fall Prevention Program on Fall Risk and Falls in Older People: A Randomized, Controlled Trial
Authors: Lord Stephen R. , Tiedemann Anne , Chapman Kirsten , Munro Bridget , Murray Susan M. , Gerontology M , Ther Gymnast Recreat , Sherrington Catherine
Published: July 2005

Objectives: To determine whether an individualized falls prevention program comprising exercise, visual, and counseling interventions can reduce physiological falls risk and falls in older people.

Design: Randomized, controlled trial of 12 months' duration.

Setting: Falls Clinic, Royal North Shore Hospital, Sydney, Australia.

Participants: Six hundred twenty people aged 75 and older recruited from a health insurance company membership database.

Interventions: Participants in the extensive intervention group (EIG) received individualized interventions comprising exercise and strategies for maximizing vision and sensation; the minimal intervention group (MIG) received brief advice; and the control group (CG) received no intervention.

Measurements: Accidental falls, vision, postural sway, coordinated stability, reaction time, lower limb muscle strength, sit‐to‐stand performance, and physiological profile assessment (PPA) falls risk scores.

Results: At the 6‐month follow‐up, PPA falls risk scores were significantly lower in the EIG than in the CG. EIG subjects assigned to the extensive exercise intervention group showed significant improvements in tests of knee flexion strength and sit‐to‐stand times but no improvements in balance. EIG subjects assigned to the extensive visual intervention group showed significant improvements in tests of visual acuity and contrast sensitivity. The rate of falls and injurious falls within the trial period were similar in the three groups.

Conclusion: The individualized intervention program reduced some falls risk factors but did not prevent falls. The lack of an effect on falls may reflect insufficient targeting of the intervention to an at‐risk group.
Microbubble‐induced detachment of coadhering oral bacteria from salivary pellicles
Authors: Sharma Prashant K. , Gibcus Marjon J. , Van Der Mei Henny C. , Busscher Henk J.
Published: July 2005

The presence and maturity of the salivary pellicle influences microbial adhesion and its tenacity in the oral cavity, posing a challenge to different plaque‐control systems. Some plaque‐control systems rely on surface‐tension forces arising from passing microbubbles sprayed over the pellicle. Passage of such bubbles is accompanied by a high fluid flow, but systematic studies are lacking on the contribution of fluid flow vs. microbubbles towards plaque removal. Therefore, the aim of this study was to determine the detachment efficacy of laminar fluid flow (wall shear rates 11,000–16,000 s−1), with and without microbubbles, towards the detachment of Actinomyces naeslundii T14V‐J1 and Streptococcus oralis J22, and their coadhering aggregates, from salivary pellicles formed over 2 h or 16 h from reconstituted human whole saliva. Microbubbles in a fluid flow were more efficient at inducing single bacterial detachment, resulting in almost complete (97%) removal for S. oralis J22 and a 15‐fold increase in A. naeslundii T14V‐J1 removal as compared to the detachment caused by fluid flow alone. A. naeslundii was more difficult to remove and apparently formed the strongest bonds with high‐molecular‐weight proteins in 16‐h pellicles. The detachment of coaggregates after 2 min left a substantial amount of adhered bacterial mass, including more than 60% of singly attached A. naeslundii on the pellicle surface, providing nucleation sites for the de novo adhesion of coadhering streptococci.
Bone morphogenetic protein 3 expression pattern in rat condylar cartilage, femoral cartilage and mandibular fracture callus
Authors: Zheng Li , Yamashiro Takashi , Fukunaga Tomohiro , Balam Tarek A. , Takano‐Yamamoto Teruko
Published: July 2005

Mandibular condylar cartilage differs from primary cartilage in morphological organization of the chondrocytes and in responses to biomechanical stress and humoral factors. For the first time, we describe the expression of Bmp3 mRNA in relation to types I, II and X collagen mRNA (as determined by in situ hybridization) in chondrocytes of the rat mandibular condylar cartilage, femoral articular cartilage, femoral growth plate cartilage, and temporal cartilage, which transiently appeared in the reparative response stage of mandibular ramus fracture healing. In all cartilages evaluated, Bmp3 was expressed in proliferating chondrocytes that expressed type I collagen in condylar cartilage, articular cartilage, and temporal cartilage appearing during fracture healing. Bmp3 was also found in hypertrophic chondrocytes that expressed type X collagen mRNA in all cartilages evaluated. Furthermore, in remodeling bone, Bmp3 mRNA was strongly expressed in active osteoblast cells in periosteal reaction layers formed after fracture. These findings suggest that Bmp3 expression in a special layer of typical articular cartilage may be regulated by mechanical stress stimulation. We also found that Bmp3 was expressed in the periosteal layers of the bone segments near the fracture site during fracture healing.
The problem of analysing the relationship between change and initial value in oral health research
Authors: Tu Yu‐Kang , Bælum Vibeke , Gilthorpe Mark S.
Published: July 2005

The relationship between initial disease status and subsequent change following treatment has attracted great interest in dental research. However, medical statisticians have repeatedly warned against correlating/regressing change with baseline because of two methodological concerns known as mathematical coupling and regression to the mean. In general, mathematical coupling occurs when one variable directly or indirectly contains the whole or part of another, and the two variables are then analyzed by using correlation or regression. Consequently, the statistical procedure of testing the null hypothesis – that the coefficient of correlation or the slope of regression is zero – may become inappropriate. Regression to the mean occurs with any variable that fluctuates within an individual or a population, either owing to measurement error and/or to physiological variation. The aim of this article was to clarify the conceptual confusion around mathematical coupling and regression to the mean within the statistical literature, and to correct a popular misconception about the correct analysis of the relationship between change and initial value. As examples that use inappropriate methods to analyze the relationship between change and baseline are still found in leading dental journals, this article seeks to help oral health researchers understand these problems and explain how to overcome them.
The relationship between baseline value and its change: problems in categorization and the proposal of a new method
Authors: Tu Yu‐Kang , Bælum Vibeke , Gilthorpe Mark S.
Published: July 2005

Oral health researchers have shown great interest in the relationship between the initial status of diseases and subsequent changes following treatment. Two main approaches have been adopted to provide evidence of a positive association between baseline values and their changes following treatment. One approach is to use correlation or regression to test the relationship between baseline measurements and subsequent change (correlation/regression approach). The second approach is to categorize the lesions into subgroups, according to threshold values, and subsequently compare the treatment effects across the two (or more) subgroups (categorization approach). However, the correlation/regression approach suffers a methodological weakness known as mathematical coupling. Consequently, the statistical procedure of testing the null hypothesis becomes inappropriate. Categorization seems to avoid the problem of mathematical coupling, although it still suffers regression to the mean. We show, first, how the appropriate null hypothesis may be established to analyze the relationship between baseline values and change in the correlation approach and, second, we use computer simulations to investigate the impact of regression to the mean on the significance testing of the differences in the average treatment effects (or average baseline values) in the categorization approach. Data available from previous literature are reanalyzed by testing the appropriate null hypotheses and the results are compared to those from testing the usual (incorrect) null hypothesis. The results indicate that both the correlation and categorization approaches can give rise to misleading conclusions and that more appropriate methods, such as Oldham's method and our new approach of deriving the correct null hypothesis, should be adopted.
PREDICTING INTERSTIMULUS INTERVALS BETWEEN SAMPLES FOR CAPSAICIN‐CONTAINING SALSA WITH A RANGE OF HEAT LEVELS
Authors: DOWELL KAREN J. , CHAMBERS EDGAR , MILLIKEN GEORGE A. , CHAMBERS DELORES H.
Published: July 2005

A model was developed to predict an optimal interstimulus interval during testing for samples of products (such as salsa) that contain capsaicin. Oral “heat burn” intensity for four levels of salsa (mild, 25,000 Scoville Heat Units [SHU]; medium, 70,000 SHU; hot, 130,000 SHU; and extra hot, 250,000 SHU) was evaluated over time using a trained, experienced five‐member descriptive sensory analysis panel. As capsaicin concentrations increased, the time it took for heat perception in the mouth to return to a negligible sensory value increased – a result of the higher amount of heat burn that must dissipate and a slower rate of decay after samples with more intense heat burn. Although a slight sensitization trend may occur with mild and medium salsas, and a slight trend toward desensitization may occur for the hot sample, the maximum intensity ratings after repeated tastings were not significantly different, and real perceptual differences may not exist. Two models were developed that can be used to predict the time required between samples – one based on SHU values and the other based on initial sensory heat score. This information can be used by sensory researchers to approximate the necessary interstimulus interval between salsa samples during sensory testing by trained panels to avoid carryover effects from one sample to another.