bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary health care nursing staff in Crete: an emerging profile
Authors: Markaki A. , Antonakis N. , Philalithis A. , Lionis C.
Published: January 2006

Background:  In 2001, the newly established Regional Health and Welfare System of Crete commissioned the first needs’ assessment study of nursing personnel employed in the public sector of primary health care (PHC).

Aim:  To capture the profile and professional needs of nursing staff working in Health Centers throughout the island of Crete and explore variations in nursing practice by educational preparation.

Methods:  A newly developed, psychometrically tested questionnaire, was administered to all nursing staff in 14 rural Health Centers.

Findings:  Vacancy rates are high, indicating a serious staffing deficit. The type of degree earned (2‐year vs. 3 or 4‐year program) does not differentiate nursing practice, with only two exceptions (obtaining a patient's history and counselling patients). The majority of respondents assess their existing knowledge and skills as ‘adequate’ while indicating a strong desire for continuing education. Job satisfaction is high in terms of interactions with clients and community recognition, while it is rated ‘low’ in terms of daily interactions with colleagues and support from work environment.

Conclusion:  Cretan nursing staff in PHC operate within a restricted and task‐orientated framework. Their educational preparation has little effect in practice role variations and professional needs. The Regional Health and Welfare System of Crete should address daily supervision and support issues, on‐the‐job training, continuing education needs, while taking immediate action to avoid potential turnover of existing staff and to aggressively recruit young, qualified nursing staff who will choose a career in PHC nursing.
Comparison of several shortened versions of the EMBU: Exploratory and confirmatory factor analyses
Authors: ALUJA ANTON , DEL BARRIO VICTORIA , GARCÍA LUIS F.
Published: January 2006

The aim of the present study was to analyze the psychometric properties of different versions of the EMBU (Egna Minnen av Barndoms Uppfostran – My memories of upbringing) in a non‐clinical sample of adolescents. The factor structure of the questionnaire was studied by means of more adequate exploratory and confirmatory factor procedures in order to ascertain which version achieves a better fit to data. The 64‐item version of the EMBU was administered to a non‐clinical sample of 832 adolescents. Exploratory and Confirmatory factor analyses were carried out for successive versions of 64, 37, 24 and 23 items. The theoretical four‐factor structure of the 64‐item version is not replicated in a factor analysis through principal axis extraction with direct oblimin rotation. The “Favoring Subject” factor was not found. 37 items present loadings equal to or larger than 0.30 for the “Rejection”, “Emotional Warmth” and “Overprotection” factors. A re‐analysis of these items shows a clear three‐factor structure. When Arrindell et al.'s (1999) 23‐item version was analysed, the three expected factors were also found. Confirmatory factor analyses allow us to reduce the 36‐item version to a shorter one of 24 items. This last version achieves the best fit to data, including the 23‐item version. The new 24‐item version improves the construct validity of the EMBU and presents similar reliability coefficients.
Testing Constancy for Isotonic Regressions
Authors: COLUBI ANA , SANTOS DOMÍNGUEZ‐MENCHERO J. , GONZÁLEZ‐RODRÍGUEZ GIL
Published: January 2006

Abstract.  In this paper, we propose a bootstrap method for testing the constancy of an isotonic regression. The technique we develop is completely non‐parametric and enlarges the appli‐cability of the classical chi‐bar‐squared tests, which require normality assumptions. We prove that our procedure is asymptotically correct and consistent. Moreover, by means of simulations we show that it behaves suitably in practice, and similarly to the chi‐bar‐squared tests under normality. Finally, we illustrate the method with the study of a real case that is well known in the related literature.
On Optimal Point and Block Prediction in Log‐Gaussian Random Fields
Authors: DE OLIVEIRA VICTOR
Published: January 2006

Abstract.  This work discusses the problems of point and block prediction in log‐Gaussian random fields with unknown mean. New point and block predictors are derived that are optimal in mean squared error sense within certain families of predictors that contain the corresponding lognormal kriging point and block predictors, as well as a block predictor originally motivated under the assumption of ‘preservation of lognormality’, and hence improve upon them. A comparison between the optimal, lognormal kriging and best linear unbiased predictors is provided, as well as between the two new block predictors. Somewhat surprisingly, it is shown that the corresponding optimal and lognormal kriging predictors are almost identical under most scenarios. It is also shown that one of the new block predictors is uniformly better than the other.
Detecting Intraday Periodicities with Application to High Frequency Exchange Rates
Authors: Brooks Chris , Hinich Melvin J.
Published: January 2006

Many recent papers have documented periodicities in returns, return volatility, bid–ask spreads and trading volume, in both equity and foreign exchange markets. We propose and employ a new test for detecting subtle periodicities in time series data based on a signal coherence function. The technique is applied to a set of seven half-hourly exchange rate series. Overall, we find the signal coherence to be maximal at the 8-h and 12-h frequencies. Retaining only the most coherent frequencies for each series, we implement a trading rule that is based on these observed periodicities. Our results demonstrate in all cases except one that, in gross terms, the rules can generate returns that are considerably greater than those of a buy-and-hold strategy, although they cannot retain their profitability net of transactions costs. We conjecture that this methodology could constitute an important tool for financial market researchers which will enable them to detect, quantify and rank the various periodic components in financial data better.
A NOTE ON SEMIVARIANCE
Authors: Jin Hanqing , Markowitz Harry , Yu Zhou Xun
Published: January 2006

In a recent paper (Jin, Yan, and Zhou 2005), it is proved that efficient strategies of the continuous‐time mean–semivariance portfolio selection model are in general never achieved save for a trivial case. In this note, we show that the mean–semivariance efficient strategies in a single period are always attained irrespective of the market condition or the security return distribution. Further, for the below‐target semivariance model the attainability is established under the arbitrage‐free condition. Finally, we extend the results to problems with general downside risk measures.
CHARACTERIZATION OF OPTIMAL STOPPING REGIONS OF AMERICAN ASIAN AND LOOKBACK OPTIONS
Authors: Dai Min , Kwok Yue Kuen
Published: January 2006

A general framework is developed to analyze the optimal stopping (exercise) regions of American path‐dependent options with either the Asian feature or lookback feature. We examine the monotonicity properties of the option values and stopping regions with respect to the interest rate, dividend yield, and time. From the ordering properties of the values of American lookback options and American Asian options, we deduce the corresponding nesting relations between the exercise regions of these American options. We illustrate how some properties of the exercise regions of the American Asian options can be inferred from those of the American lookback options.
A BENCHMARK APPROACH TO FINANCE
Authors: Platen Eckhard
Published: January 2006

This paper derives a unified framework for portfolio optimization, derivative pricing, financial modeling, and risk measurement. It is based on the natural assumption that investors prefer more rather than less, in the sense that given two portfolios with the same diffusion coefficient value, the one with the higher drift is preferred. Each such investor is shown to hold an efficient portfolio in the sense of Markowitz with units in the market portfolio and the savings account. The market portfolio of investable wealth is shown to equal a combination of the growth optimal portfolio (GOP) and the savings account. In this setup the capital asset pricing model follows without the use of expected utility functions, Markovianity, or equilibrium assumptions. The expected increase of the discounted value of the GOP is shown to coincide with the expected increase of its discounted underlying value. The discounted GOP has the dynamics of a time transformed squared Bessel process of dimension four. The time transformation is given by the discounted underlying value of the GOP. The squared volatility of the GOP equals the discounted GOP drift, when expressed in units of the discounted GOP. Risk‐neutral derivative pricing and actuarial pricing are generalized by the fair pricing concept, which uses the GOP as numeraire and the real‐world probability measure as pricing measure. An equivalent risk‐neutral martingale measure does not exist under the derived minimal market model.
UTILITY MAXIMIZATION IN AN INSIDER INFLUENCED MARKET
Authors: Kohatsu‐Higa Arturo , Sulem Agnès
Published: January 2006

We study a controlled stochastic system whose state is described by a stochastic differential equation with anticipating coefficients. This setting is used to model markets where insiders have some influence on the dynamics of prices. We give a characterization theorem for the optimal logarithmic portfolio of an investor with a different information flow from that of the insider. We provide explicit results in the partial information case that we extend in order to incorporate the enlargement of filtration techniques for markets with insiders. Finally, we consider a market with an insider who influences the drift of the underlying price asset process. This example gives a situation where it makes a difference for a small agent to acknowledge the existence of an insider in the market.
CLASSICAL AND IMPULSE STOCHASTIC CONTROL FOR THE OPTIMIZATION OF THE DIVIDEND AND RISK POLICIES OF AN INSURANCE FIRM
Authors: Cadenillas Abel , Choulli Tahir , Taksar Michael , Zhang Lei
Published: January 2006

This paper deals with the dividend optimization problem for a financial or an insurance entity which can control its business activities, simultaneously reducing the risk and potential profits. It also controls the timing and the amount of dividends paid out to the shareholders. The objective of the corporation is to maximize the expected total discounted dividends paid out until the time of bankruptcy. Due to the presence of a fixed transaction cost, the resulting mathematical problem becomes a mixed classical‐impulse stochastic control problem. The analytical part of the solution to this problem is reduced to quasivariational inequalities for a second‐order nonlinear differential equation. We solve this problem explicitly and construct the value function together with the optimal policy. We also compute the expected time between dividend payments under the optimal policy.
Integrating Economic Base Theory with Regional Adjustment Models: The Nonmetropolitan Rocky Mountain West
Authors: WAS ALEXANDER C. , MULLIGAN GORDON F.
Published: January 2006

ABSTRACT
Interest in the use of adjustment models has recently increased as analysts have come to see the value of these models in the study of regional growth processes. Adjustment models are especially useful in clarifying the nature and direction of population‐employment interactions. However, other models of regional growth suggest that employment should not be treated as a single homogeneous variable, as is the usual assumption in regional adjustment models. This paper looks at the issue of employment disaggregation, and suggests that adjustment models can be alternatively specified by making use of economic base theory to separate employment into at least two broad sectors. Alternative economic base specifications are tested using data for the nonmetropolitan counties (n=254) of the US. Rocky Mountain West during a recent time period. The results show that an economic base version of the adjustment model provides insights to regional change that are not available from the traditional version of the model.
Extending Carlino‐Mills Models to Examine Urban Size and Growth Impacts on Proximate Rural Areas
Authors: HENRY MARK S. , SCHMITT BERTRAND , KRISTENSEN KNUD , BARKLEY DAVID L. , BAO SHUMING
Published: January 2006

ABSTRACT
A modification of the Boamet model of local economic change is developed that links the growth of urban nodes in functional economic regions to employment and population change in the rural hinterlands of these regions. The two‐equation model uses labor market and residential zone observations that are consistent with commuter fields around each rural community in the regions studied. The model parameters are estimated for 204 Danish rural municipalities, for 3515 rural communes in six regions of Eastern France, and for 268 rural census tracts in South Carolina. Results indicate that urban nodal spread effects are often significant and tend to dominate urban backwash impacts on rural communities. Accordingly, rural communities need to be concerned with the economic fortunes of their urban nodes and with policies that affect the pattern of urban growth between urban center and the urban fringe.
‘The Suggested Basis for a Russian Federal Republic’: Britain, Anti‐Bolshevik Russia and the Border States at the Paris Peace Conference, 1919
Authors: ALSTON CHARLOTTE
Published: January 2006

Allied policy towards Russia at the Paris Peace Conference was confused and uncoordinated. Throughout 1919 civil war continued to rage in Russia and its former borderlands. While piecemeal assistance was being given to the anti‐Bolshevik forces led by Kolchak and Denikin, the Allies also made promises to support the independence of the newly established states on the borders of Russia. At the height of Kolchak's military success in May 1919, they were seriously considering recognition of his Omsk government. This article shows that the British government investigated the possibility of a reconstructed Russian federation based around the Kolchak government. James Simpson, a member of the Foreign Office's Political Intelligence Department, was sent to Paris to negotiate with the parties involved. While his efforts were a short and abortive episode in the history of the Peace Conference, his discussions and the reports he received shed interesting light on the attitudes and actions of the many unrecognized delegations from former parts of Russia at the conference and on their relations with Russia, the Allies, and each other.
Pay Policies of Firms and Collective Wage Contracts—An Uneasy Partnership?
Authors: GERLACH KNUT , STEPHAN GESINE
Published: January 2006

Theoretical considerations suggest that firms establish consistent internal wage structures and pay wage premiums of similar size across occupational groups. Strong evidence for the existence of coherent employer pay policies across occupations is found using a German employer–employee data set. However, firm‐specific elements of wage policies are less prevalent in firms applying industry‐level collective contracts than in firms with individual‐level wage contracts.
PREFERENTIAL TRADE AGREEMENTS AND MULTILATERAL TARIFF COOPERATION*
Authors: Saggi Kamal
Published: January 2006

Are preferential trade agreements (PTAs) building or stumbling blocks for multilateral trade liberalization? I address this question in an infinitely repeated tariff game between three countries engaged in intraindustry trade under oligopoly. The central result is that when countries are symmetric, a free trade agreement (FTA) undermines multilateral tariff cooperation by adversely affecting the cooperation incentive of the nonmember whereas a customs union (CU) does so via its effect on the cooperation incentives of members. However, when countries are asymmetric with respect to either market size or cost, there exist circumstances where PTAs facilitate multilateral tariff cooperation.
SEARCH, LIMITED PARTICIPATION, AND MONETARY POLICY*
Authors: Williamson Stephen D.
Published: January 2006

A model is developed that employs recent developments in the literature on search models of money to capture the distributional effects of monetary policy in a tractable way. Deterministic and stochastic versions of the model are studied. Money is not neutral, and these nonneutralities persist, whether or not the change in the money supply is anticipated or unanticipated. At the optimum, monetary policy is geared to correcting distortions in the search sector of the economy, while correcting for the persistent effects of past monetary policy actions.
DEMAND REDUCTION IN MULTI‐UNIT AUCTIONS WITH VARYING NUMBERS OF BIDDERS: THEORY AND EVIDENCE FROM A FIELD EXPERIMENT*
Authors: Engelbrecht‐Wiggans Richard , List John A. , Reiley David H.
Published: January 2006

Recent auction theory and experimental results document strategic demand reduction by bidders in uniform‐price auctions. The present article extends this area of research to consider the effects of varying the number of bidders. Our theoretical model predicts that demand reduction should decrease with an increase in the number of bidders. Considerable demand reduction remains even in the asymptotic limit, although truthful bidding yields profits very close to those of equilibrium play. We experimentally confirm several of our predictions by examining bidding behavior of subjects in an actual marketplace, auctioning dozens of sportscards using both uniform‐price and Vickrey auction formats.
INFORMATIONAL CASCADES ELICIT PRIVATE INFORMATION*
Authors: Gossner Olivier , Melissas Nicolas
Published: January 2006

We introduce cheap talk in a dynamic investment model with information externalities. We first show how social learning adversely affects the credibility of cheap talk messages. Next, we show how an informational cascade makes truth‐telling incentive compatible. A separating equilibrium only exists for high‐surplus projects. Both an investment subsidy and an investment tax can increase welfare. The more precise the sender's information, the higher her incentives to truthfully reveal her private information.
Precipitation of lead–zinc ores in the Mississippi Valley‐type deposit at Trèves, Cévennes region of southern France
Authors: LEACH D. , MACQUAR J.‐C. , LAGNEAU V. , LEVENTHAL J. , EMSBO P. , PREMO W.
Published: January 2006

The Trèves zinc–lead deposit is one of several Mississippi Valley‐type (MVT) deposits in the Cévennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150°C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of δ34S values determined for the minerals in the deposit (12.2–19.2‰ for barite, 3.8–13.8‰ for sphalerite and galena, and 8.7 to −21.2‰ for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur‐rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced sulfur concentration on the Zn and Pb transport capacity of the ore fluid and the volumes of fluid required to form the deposit. The studies of the Trèves ores provide insights into the ore‐forming processes of a typical MVT deposit in the Cévennes region. However, the extent to which these processes can be extrapolated to other MVT deposits in the Cévennes region is problematic. Nevertheless, the evidence for the extensive migration of fluids in the basement and sedimentary cover rocks in the Cévennes region suggests that the ore forming processes for the Trèves deposit must be considered equally viable possibilities for the numerous fault‐controlled and mineralogically similar MVT deposits in the Cévennes region.
Hydrochemical characterization of a coal mine plume detected by an airborne geophysical survey
Authors: BEAMISH D. , KLINCK B.
Published: January 2006

A trial airborne electromagnetic (AEM) geophysical survey was carried out across a 13 × 9 km area of the northern Nottinghamshire (UK) coalfield. One of the objectives was to examine the influence of coal mines (collieries) and associated spoil heaps situated above the Triassic Sherwood Sandstone aquifer. The conductivity models obtained from the AEM survey revealed extensive zones of enhanced subsurface conductivity in the vicinity of all the collieries in the survey area. The present study provides information regarding subsequent investigations (ground geophysics and borehole) to confirm the AEM results and to investigate the geochemical nature of the conductive zone identified in the vicinity of one of the collieries.Following ground geophysical confirmation of the airborne results, three boreholes were drilled into one of the conductive zones to the east of a working colliery. Geophysical logs and analysis of pore fluid geochemistry demonstrate that there is a very strong correlation between the borehole induction logs (formation conductivity), total dissolved solids (TDS) and chloride in the pore waters. The three cored boreholes have confirmed that there is a groundwater plume with high concentrations of TDS, compared with background, moving east from the Thoresby Colliery on a hydraulic gradient of 0.023. Porewater geochemistry obtained from core has been compared with that of local aquifer waters and with samples obtained from the colliery. The results indicate that the plume chemistry could result from the mixing of a typical Sherwood Sandstone composition with colliery spoil leachate. The AEM conductivity models have been successfully correlated with ground geophysical models, borehole induction logs, TDS and chloride in the pore waters. By implication, the geophysical results obtained over a larger area indicate the wider extent of such impacts in relation to both former and current mining activities.
Structure of grain boundaries in wet, synthetic polycrystalline, statically recrystallizing halite – evidence from cryo‐SEM observations
Authors: SCHENK O. , URAI J. L. , PIAZOLO S.
Published: January 2006

It is well known from nature and experiments that the presence of brine strongly affects the microstructural evolution and the mechanical and transport properties of halite. Existing interpretations of the grain boundary structure in deformed, wet, salt samples annealed statically at room temperature are based on indirect evidence from reflected light microscopy and conventional scanning electron microscopy. This paper presents direct observations of fluid‐filled grain boundaries using the cryogenic‐scanning electron microscope (cryo‐SEM) in which the grain boundary fluids were frozen before breaking the samples. The rapid cooling transforms the brine into two phases, i.e. ice and hydrohalite, which are easily recognized from characteristic segregation patterns. We studied samples of wet, synthetic, polycrystalline halite annealed under static conditions at room temperature. In coarse‐grained samples, fine‐scale segregation patterns were observed at the boundaries of the primary recrystallizing grains. These points indicate the existence of fluid films with a thickness in the range of 30 nm, but the finer scale structure of the fluid remains unknown. In fine‐grained samples, the distribution and reorganization of fluids with annealing time is recorded by the combination of contact healing and successive accumulation of fluids in triple junction tubes. The contact healing is attributed to the small initial grain size, such that the fluid film necks down by accumulating the fluids into previously existing triple junctions via neck growth. Electron backscatter diffraction measurements of both primary and secondary recrystallized grains indicate that they are euhedral, i.e. the grain growth morphology is controlled by the anisotropy of the grain boundary energy of the growing grain, which results in planar growth faces.
Endocrine targets for pharmacological intervention in aging inCaenorhabditis elegans
Authors: Gill Matthew S.
Published: January 2006

Studies in the nematodeCaenorhabditis eleganshave been instrumental in defining genetic pathways that are involved in modulating lifespan. Multiple processes such as endocrine signaling, nutritional sensing and mitochondrial function play a role in determining lifespan in the worm and these mechanisms appear to be conserved across species. These discoveries have identified a range of novel targets for pharmacological manipulation of lifespan and it is likely that the nematode model will now prove useful in the discovery of compounds that slow aging. This review will focus on the endocrine targets for intervention in aging and the use ofC. elegansas a system for high throughput screens of compounds for their effects on aging.
Inhibition of Amazon Deforestation and Fire by Parks and Indigenous Lands
Authors: NEPSTAD D. , SCHWARTZMAN S. , BAMBERGER B. , SANTILLI M. , RAY D. , SCHLESINGER P. , LEFEBVRE P. , ALENCAR A. , PRINZ E. , FISKE GREG , ROLLA ALICIA
Published: January 2006

Abstract:  Conservation scientists generally agree that many types of protected areas will be needed to protect tropical forests. But little is known of the comparative performance of inhabited and uninhabited reserves in slowing the most extreme form of forest disturbance: conversion to agriculture. We used satellite‐based maps of land cover and fire occurrence in the Brazilian Amazon to compare the performance of large (>10,000 ha) uninhabited (parks) and inhabited (indigenous lands, extractive reserves, and national forests) reserves. Reserves significantly reduced both deforestation and fire. Deforestation was 1.7 (extractive reserves) to 20 (parks) times higher along the outside versus the inside of the reserve perimeters and fire occurrence was 4 (indigenous lands) to 9 (national forests) times higher. No strong difference in the inhibition of deforestation (p= 0.11) or fire (p= 0.34) was found between parks and indigenous lands. However, uninhabited reserves tended to be located away from areas of high deforestation and burning rates. In contrast, indigenous lands were often created in response to frontier expansion, and many prevented deforestation completely despite high rates of deforestation along their boundaries. The inhibitory effect of indigenous lands on deforestation was strong after centuries of contact with the national society and was not correlated with indigenous population density. Indigenous lands occupy one‐fifth of the Brazilian Amazon—five times the area under protection in parks—and are currently the most important barrier to Amazon deforestation. As the protected‐area network expands from 36% to 41% of the Brazilian Amazon over the coming years, the greatest challenge will be successful reserve implementation in high‐risk areas of frontier expansion as indigenous lands are strengthened. This success will depend on a broad base of political support.
An Evaluation of Threatened Species Categorization Systems Used on the American Continent
Authors: De GRAMMONT PALOMA C. , CUARÓN ALFREDO D.
Published: January 2006

Abstract:  Endangered species lists are important tools in conservation. It is essential that these lists be prepared using categorization systems that objectively assess species extinction risk. To determine which threatened species categorization system is the most appropriate and the virtues and limitations of systems used on the American continent, we evaluated 25 categorization systems from 20 countries. These systems included examples of international lists, most national systems used on the American continent, and some systems independently proposed by academics. We based our assessment on 15 characteristics that categorization systems should have, in terms of categories, criteria, and other relevant issues, in order to evaluate species conservation status objectively. Of all evaluated systems, the current World Conservation Union system is the most suitable for assessing species extinction risk. Most categorization systems, but particularly national systems, have serious deficiencies and need to be improved substantially. We recommend governments use three types of lists: (1) threatened species lists constructed following a sound categorization system, (2) lists of species of conservation priority, and (3) lists that serve as normative tools (e.g., Convention on International Trade in Endangered Species of Wild Fauna and Flora). Additionally, the information used to categorize species should be explicit and available to the public. To make the most of threatened species lists in conservation, it is imperative that all countries use the same categorization system.
A Graduate Education Framework for Tropical Conservation and Development
Authors: KAINER KAREN A. , SCHMINK MARIANNE , COVERT HANNAH , STEPP JOHN RICHARD , BRUNA EMILIO M. , DAIN JONATHAN L. , ESPINOSA SANTIAGO , HUMPHRIES SHOANA
Published: January 2006

Abstract: Conventional graduate training related to tropical conservation and development has typically separated the two fields, with students focusing on either conservation from the perspective of the biophysical sciences or development as an extension of the social sciences. On entering the workforce, however, graduates find they are required to work beyond disciplinary boundaries to address the complex interconnectivity between biological conservation and human well‐being. We devised a framework for graduate education that broadens students' skill sets to learn outside their immediate disciplines and think in terms of linked socioecological systems, work in teams, communicate in nonacademic formats, and reflect critically on their own perspectives and actions. The University of Florida's Tropical Conservation and Development program has adopted a learning and action platform that blends theory, skills, and praxis to create an intellectual, social, and professionally safe space where students, faculty, and other participants can creatively address the complex challenges of tropical conservation and development. This platform operates within a nondegree‐granting program and includes core courses that are taught by a team of biophysical and social scientists. It incorporates a range of alternative learning spaces such as student‐led workshops, retreats, visiting professionals, practitioner experiences, and a weekly student‐led seminar that collectively encourage students and faculty to enhance their skills and systematically and thoroughly reflect on program activities. Challenges to the described approach include increased service demands on faculty, a redefinition of research excellence to include effective and equitable collaboration with host‐country partners, and the trade‐offs and uncertainties inherent in more collaborative, interdisciplinary research. Despite these challenges, growing interdisciplinary programs, coupled with adaptive educational approaches that emphasize learning and action networks of students, faculty, and field partners, provide the best hope for responding to the emerging challenges of tropical conservation and development.
An In Vitro Investigation of a Comparison of Bond Strengths of Composite to Etched and Air‐Abraded Human Enamel Surfaces
Authors: Gray G.B. , Carey G.P.D. , Jagger D.C.
Published: January 2006

Purpose:
The purposes of the study were to measure the tensile bond strength of composite resin to human enamel specimens that had been either etched or air‐abraded, and to compare the quality of the marginal seal, through the assessment of microleakage, of composite resin to human enamel specimens that had been either etched or air‐abraded.

Materials and Methods:
Thirty mandibular molar teeth were decoronated and sectioned mesio‐distally to produce six groups, each containing ten specimens that were embedded in acrylic resin using a jig. In each of the four treatment groups, the specimen surfaces were treated by either abrasion with 27 or 50 μm alumina at 4 mm or 20 mm distance, and a composite resin was bonded to the treated surfaces in a standardized manner. In the two control groups the specimens were treated with 15 seconds exposure to 36% phosphoric acid gel and then similarly treated before being stored in sterile water for 1 week. All specimens were then subjected to tensile bond strength testing at either 1 or 5 mm/min crosshead speed. For the microleakage study, the degree of dye penetration was measured 32 times for each treatment group, using a neutral methylene blue dye at the interface between composite and either 27 or 50 μm air‐abraded tooth structure or etched enamel surfaces.

Results:
The mean bond strength values recorded for Group 1 (phosphoric acid etch, 5 mm/min crosshead speed) was 25.4 MPa; Group 2 (phosphoric acid etch, 1 mm/min), 22.2 MPa; Group 3 (27 μm alumina at 4 mm distance), 16.8 MPa; Group 4 (50 μm alumina at 4 mm distance), 16.9 MPa; Group 5 (27 μm alumina at 20 mm distance), 4.2 MPa; and for Group 6 (50 μm alumina at 20 mm distance) 3.4 MPa. An analysis of variance (ANOVA) demonstrated significant differences among the groups, and a multiple comparison test (Tukey) demonstrated that conventionally etched specimens had a greater bond strength than air‐abraded specimen groups. No significant difference in dye penetration could be demonstrated among the groups (p= 0.58).

Conclusions:
Composite resin applied to enamel surfaces prepared using an acid etch procedure exhibited higher bond strengths than those prepared with air abrasion technology. The abrasion particle size did not affect the bond strength produced, but the latter was adversely affected by the distance of the air abrasion nozzle from the enamel surface. The crosshead speed of the bond testing apparatus had no effect on the bond strengths recorded. The marginal seal of composite to prepared enamel was unaffected by the method of enamel preparation.
Factors Associated with Masticatory Performance in Unilateral Distal Extension Removable Partial Denture Patients
Authors: Tumrasvin Wacharasak , Fueki Kenji , Ohyama Takashi
Published: January 2006

Purpose:
Masticatory performance of denture patients is an outcome of the intricate inter‐relationship between patient characteristics and denture construction. This study aimed to identify both patient‐ and denture‐related factors associated with masticatory performance in unilateral distal extension removable partial denture patients (RPDs).

Materials and Methods:
Seventy‐two patients (25 male and 47 female, mean age 63.4 ± 6.7 years) with unilateral distal extension RPDs were included in the study. The Mixing Ability Index (MAI) obtained from a chewing test using standard two‐colored wax cubes, determined masticatory performance. The effect of each evaluated factor on masticatory performance was first determined by an independent t‐test or one‐way analysis of variance. The statistically significant factors were entered in a model of multivariate linear regression analysis to estimate the independent effect on MAI.

Results:
The MAI ranged from −3.06 to 0.80 (Mean −0.71 ± 0.86). Univariate analyses identified male gender, high maximum bite force, more functional tooth units, and natural dentition opposing RPDs as patient factors increasing the MAI. Multivariate analysis (adjusted R2= 0.346) revealed that gender (p < 0.001), maximum bite force (p= 0.02), and number of functional tooth units (p= 0.03) were independent predictors for masticatory performance. None of the denture‐related factors had a significant influence on MAI.

Conclusion:
Gender, maximum bite force, and number of functional tooth units were the main factors influencing masticatory performance of unilateral distal extension RPD patients.
An Alveolar Bone Augmentation Technique to Improve Esthetics in Anterior Ceramic FPDs: A Clinical Report
Authors: Taskonak Burak , Ozkan Yasar
Published: January 2006

This clinical report describes guided bone augmentation for treatment of a facial maxillary alveolar bone defect to enhance the esthetic result for an all‐ceramic fixed partial denture (FPD). A combination of decalcified freeze dried bone allograft and resorbable human pericardium, in conjunction with cortical channel expansion, was used for the augmentation process to eliminate a secondary surgical procedure. Post‐operative examinations showed improvement in the alveolar bone contour. The regeneration of the missing osseous structure was accomplished to support the future esthetic soft tissue contours. This osseous regenerative technique significantly increased the functional and esthetic outcome of the final FPD by restoring the alveolar ridge defect to its original dimension.
Prosthodontics as a Specialty Private Practice: Net Income of Private Practitioners
Authors: Nash Kent D. , Pfeifer David L.
Published: January 2006

Purpose: The aim of this study was to use data from a survey of prosthodontists in the US to examine average net earnings of prosthodontists in private practice.

Materials and Methods: A survey of 2500 prosthodontists in the US was used to estimate the net earnings of practicing prosthodontists. The national average net earnings of prosthodontists in private practice was estimated along with average earnings for subgroups of prosthodontists. Estimates for private practitioners by age, gender, size of practice, full‐time/part‐time status, practice ownership, and by type of treatment procedures rendered by the practitioner were also included.

Results: Average earnings for prosthodontists in private practice on a primary or secondary basis were estimated to be $215,300 and for prosthodontists who own or share in the ownership of a private practice, $233,920. Reported earnings estimates ranged from $96,160 for nonowners of a private practice and $103,350 for part‐time private practitioners to $233,920 for practice owners and $275,170 for prosthodontists in practice with two prosthodontists. The average earnings of prosthodontists who are practice owners were estimated to be 35% higher than the corresponding general practitioners.

Conclusion: Average net earnings are often used to examine the current economic health of a profession. The average net earnings of prosthodontists in private practice exceed the average net income reported by the American Dental Association for all dentists and all general practitioners and they are competitive with earnings among all specialty groups. This evaluation of the net earnings of prosthodontists shows that prosthodontics offers a competitive career opportunity for the general dentist with a personal desire to pursue advanced dental education in a specialty as a profession.
Use of Stereolithographic Templates for Surgical and Prosthodontic Implant Planning and Placement. Part I. The Concept
Authors: Lal Kunal , White George S. , Morea Dennis N. , Wright Robert F.
Published: January 2006

Surgical and prosthodontic implant complications are often an inadvertent sequelae of improper diagnosis, planning, and placement. These complications pose a significant challenge in implant dentistry. Presented in this article is a technique using a highly advanced software program along with a rapid prototyping technology called stereolithography. It permits graphic and complex 3D implant simulation and the fabrication of computer‐generated surgical templates. These templates seat directly on the bone and are preprogrammed with the individual depth, angulation, and mesio‐distal and bucco‐lingual positioning of individual implants as planned during the 3D computer simulation.
Proteomics as a tool for assessment of therapeutics in transfusion medicine: evaluation of prothrombin complex concentrates
Authors: Brigulla Matthias , Thiele Thomas , Scharf Christian , Breitner‐Ruddock Susanne , Venz Simone , Völker Uwe , Greinacher Andreas
Published: January 2006

BACKGROUND:  Proteomic technologies are evolving tools to analyze complex protein patterns that to date have been rarely applied to transfusion medicine. The analysis of prothrombin complex concentrates (PCCs) was used as a model to evaluate to what extent these technologies can detect differences in blood‐derived therapeutics beyond that of standard quality control.

STUDY DESIGN AND METHODS:  Three PCCs (two batches each) were individually analyzed for differences in protein content by functional assays, two‐dimensional gel electrophoresis, and mass spectrometry. The results were compared to a pool of 72 normal plasma samples.

RESULTS:  A highly complex protein pattern was found that varied considerably among the three PCCs: 192 spots comprising 40 different proteins were identified. Factor (F) IX activities of the three PCCs were comparable, but their F IX protein contents differed considerably. Many proteins were present in multiple spots (e.g. FII, FX, protein C, vitronectin), indicating a high degree of posttranslational modifications. In comparison with untreated pooled plasma, PCCs displayed several low‐molecular‐weight variants of proteins that likely constitute potential degradation products.

CONCLUSION:  Proteomic technologies allow the identification of potentially modified proteins in clotting factor concentrates, indicating that they could become a useful tool for transfusion medicine to assess the impact of processing on the integrity of blood‐derived therapeutics.
Prospective flow cytometric evaluation of nucleated red blood cells in cord blood units and relationship with nucleated and CD34+ cell quantification
Authors: Larghero Jerome , Rea Delphine , Brossard Yves , Van Nifterik Jacqueline , Delasse Veronique , Robert Isabelle , Biscay Nicole , Chantre Elisabeth , Raffoux Emmanuel , Socié Gerard , Gluckman Eliane , Benbunan Marc , Marolleau Jean‐Pierre
Published: January 2006

BACKGROUND:  Cord blood (CB) represents an alternate source of stem cells in transplantation. Nucleated red blood cells (NRBCs) are a physiological subset of CB population. Although it is important to have an accurate estimate of CD34+ cell number, NRBCs could compromise white blood cell count and interfere with CD34+ cell quantification.

STUDY DESIGN AND METHODS:  A total of 826 CB units were analyzed for total nucleated cells (TNCs), NRBCs, and CD34+ cells by flow cytometry. NRBCs were also counted conventionally by manual microscopy. Percentages of CD34+ cells corrected by NRBC count (CD34+c) were determined as follows: %CD34+c = CD34+/CD45+ (×106)/(TNCs (×108) – NRBCs (×108)).

RESULTS:  The mean percentages of CD34+ cells and NRBCs were 0.27 percent (range, 0.01%‐1.25%) and 7.64 percent (range, 0.13%‐84%), respectively. Comparison between flow cytometric and microscopic NRBC count showed a regression of y = 0.685 + 0.719x and a coefficient of determination of r2 = 0.721. When corrected with NRBC count, the mean percentage of CD34+ c cells was 0.295 percent (p = 0.0008 compared with CD34+%) and mean TNCc count was 14.8 × 108 (p < 10−4 compared to TNC count).

CONCLUSION:  The determination of NRBCs with a flow cytometric method might represent a new strategy for providing satisfactory quality assurance controls of CB products.
Speaking the Truth in Maritime Risk Assessment
Authors: Merrick Jason R. W. , Van Dorp Rene
Published: January 2006

Several major risk studies have been performed in recent years in the maritime transportation domain. These studies have had significant impact on management practices in the industry. The first, the Prince William Sound risk assessment, was reviewed by the National Research Council and found to be promising but incomplete, as the uncertainty in its results was not assessed. The difficulty in assessing this uncertainty is the different techniques that need to be used to model risk in this dynamic and data‐scarce application area. In previous articles, we have developed the two pieces of methodology necessary to assess uncertainty in maritime risk assessment, a Bayesian simulation of the occurrence of situations with accident potential and a Bayesian multivariate regression analysis of the relationship between factors describing these situations and expert judgments of accident risk. In this article, we combine the methods to perform a full‐scale assessment of risk and uncertainty for two case studies. The first is an assessment of the effects of proposed ferry service expansions in San Francisco Bay. The second is an assessment of risk for the Washington State Ferries, the largest ferry system in the United States.
Trust Formation in Collaborative New Product Development*
Authors: Bstieler Ludwig
Published: January 2006

This research examines antecedents of trust formation in new product development partnerships and the effect of trust on performance. Trust is modeled as an outcome of communication behavior, shared problem‐solving, perceived fairness, the existence of conflicts during the development project, and partner egoism. The hypotheses are tested with data on 44 product development partnerships representing the perspective of the manufacturer. The findings suggest that communication behavior and fairness are positive contributors to trust. In contrast, conflicts during product development and perceived egoism of the partner appear to have a detrimental effect. High levels of trust were found to create the conditions for successful outcomes. A higher level of trust clearly differentiates between high‐ and low‐performing collaborative relationships in new product development. Trust also was found to be a powerful mediator, particularly as it relates to mitigating conflicts during such partnerships.
Using Transthoracic Two‐Dimensional Echocardiography to Guide the Placement of Coronary Sinus Catheters: A Randomized Study
Authors: Zhong Jing‐Quan , Dorian Paul , Zhang Wei , Li Li , Zhang Yun
Published: January 2006

Objective: To assess the value of transthoracic echocardiography (TTE) as an image guide in placing a coronary sinus catheter into the coronary sinus. Methods: Sixty consecutive patients undergoing electrophysiologic study were randomized to TTE (30 patients, “TTE group”) or x‐ray fluoroscopy (30 patients, “x‐ray group”) as an image guide to assist in the placement of a coronary sinus catheter. Results: The success rate of placing the coronary sinus catheter was 96.7% in TTE group and 100% in x‐ray group (P > 0.05). The procedure duration was 5.8 ± 5.7 minutes in TTE group and 5.9 ± 3.3 minutes in x‐ray group (P > 0.05), The x‐ray exposure time was 0.15 ± 0 minute in TTE group and 4.2 ± 2.8 minutes in x‐ray group (P < 0.0001). Conclusion: Using TTE as an image guide, coronary sinus cannulation is feasible and as rapid as standard x‐ray fluoroscopy, without the radiation risk.