bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggregation of Sampling Units: An Analytical Solution to Predict Variance
Authors: Bellehumeur Claude , Legendre Pierre
Published: September 2010

Geographical variables generally show spatially structured patterns corresponding to intrinsic characteristics of the environment. The size of the sampling unit has a critical effect on our perception of phenomena and is closely related to the variance and correlation structure of the data. Geostatistical theory uses analytical relationships for change of support (change of sampling unit size), allowing prediction of the variance and autocorrelation structure that would be observed if a survey was conducted using different sampling unit sizes.

To check the geostatistical predictions, we use a test case about tree density in the tropical rain forest of the Pasoh Reserve, Malaysia. This data set contains exhaustive information about individual tree locations, so it allows us to simulate and compare various sampling designs. The original data set was reorganized to compute tree densities for 5 times 5‐, 10 times 10‐, and 20 times 20‐meter quadrat sizes. Based upon the 5 times 5‐meter data set, the spatial structure is modeled using a nugget effect (white noise) plus an exponential model. The change of support relationships, using within‐quadrat variances inferred from the variogram model, predict the spatial autocorrelation structure and new variances corresponding to 10 times 10‐meter and 20 times 20‐meter quadrats. The theoretical and empirical results agreed closely, whereas neglecting the autocorrelation structure would have led to largely underestimating the variance. As the quadrat size increases, the range of autocorrelation increases, while the variance and the proportion of noise in the data decrease.
A Minimax Method for Finding the k Best “Differentiated” Paths
Authors: Kuby Michael , Zhongyi Xu , Xiaodong Xie
Published: September 2010

In real‐world applications, the k‐shortest‐paths between a pair of nodes on a network will often be slight variations of one another. This could be a problem for many path‐based models, particularly those on capacitated networks where different routing alternatives are needed that are less likely to encounter the same capacity constraints. This paper develops a method to solve for k differentiated paths that are relatively short and yet relatively different from one another, but not necessarily disjoint. Our method utilizes the sum of a path's distance plus some fraction of its shared distance with each other path. A minimax algorithm is used to select the path whose largest sum of length, plus shared length vis‐à‐vis each previously selected path, is as small as possible. We present computational results for the Chinese railway system, comparing the paths generated by a standard k‐shortest‐path algorithm with those from our new model.
Effect(s) of the “No‐Same‐Color‐Touching” Constraint on the Join‐Count Statistic: A Simulation Study
Authors: Lowell Kim
Published: September 2010

The join‐count statistic is used to measure the tendency of polygons of a given map type to attract or repel polygons of the same or different map types. Yet in certain maps—for example, natural resources maps—it is often impossible for a polygon of a given type to touch another polygon of the same type. (This is the no‐same‐color or “No‐Same‐Type‐Touching” (NSTT) constraint referred to in the title.) This violates an underlying assumption of the join‐count statistic and may render its use to study certain spatial phenomena inappropriate—even for measuring spatial autocorrelation among polygons that are not the same type. This was explored using Monte Carlo simulation. For polygons of different types, it appears that results of the join‐count statistic can be interpreted without any special consideration for the NSTT constraint provided there are a minimum of five to eight colors in the spatial system. For polygons of the same type, results can simply be ignored since it is known that no two polygons of the same type will touch.
Large Projects in Hinterland Regions: A Dynamic Multiregional Input‐Output Model for Assessing the Economic Impacts
Authors: DiFrancesco Richard
Published: September 2010

Interregional spillovers and the expansion of capacity in hinterland sectors represent two types of economic impact associated with large capital projects in hinterland regions. The simultaneous treatment of these within an input‐output (I‐O) framework is the subject of this paper. A dynamic multiregional I‐O (DMRIO) model is derived and applied to a scenario of oil development in Canada's Northwest Territories (NWT). A comparision of output profiles generated by the DMRIO model and a static MRIO model shows that the DMRIO formulation has merit. Specifically, in years where capacity adjustments are called for in the hinterland region, the static MRIO model is unable to capture the intraregional and interregional economic implications of this activity. In a year of particularly large‐capacity shortfalls in several NWT sectors a static MRIO model underestimates the Canada‐wide total impact of the project by more than one billion 1984 dollars.
Multiple Contexts as Cross‐classified Models: The Labor Vote in the British General Election of 1992
Authors: Jones Kelvyn , Gould Myles I. , Watt Robert
Published: September 2010

Voters make their decisions in social and geographical contexts that can be seen as different levels in an overall data structure. Increasingly these structures are being analyzed by multilevel models, but this approach has so far been limited to structures that are strictly hierarchical. This paper outlines the approach of cross‐classified multilevel models in which units at lower levels in the structure can be nested in more than one higher‐level unit simultaneously. An appropriate modeling framework is outlined, models are specified, and particular attention is paid to efficient computation. The approach is illustrated through a cross‐classified logit analysis of Labor versus Conservative support for a nationally representative sample of voting behavior for the 1992 British General Election. The data is structured so that individual voters at level 1 are nested within constituencies at level 2 which are cross‐classified by geographical and functional regionalizations at level 3. A conclusion discusses the general utility of a cross‐classified approach to geographically based contextual research, while two technical appendices provide details on model estimation.
The Hollowing‐Out Process in the Chicago Economy, 1975–2011
Authors: Hewings Geoffrey J. D. , Sonis Michael , Guo Jiemin , Israilevich Philip R. , Schindler Graham R.
Published: September 2010

The metropolitan economy of Chicago has experienced a significant transformation in its economic structure over the past twenty years. Using a method for extraction of input‐output tables that has been described elsewhere, it has been possible to produce an economic photograph of the changes in the Chicago region, annually, for the period 1975–2011. This paper explores the nature of these structural changes through examination of the changes in the composition of the Leontief multipliers and changes in the economic landscapes interpreted through application of the multiplier product matrix. The resulting picture, at the nine‐sector level of detail, reveals a hollowing‐out process, with intrametro‐politan dependence replaced by dependence on sources of supply and demand outside the region. Furthermore, the analysis reveals a complex internal transformation, as dependence on locally sourced manufacturing inputs is replaced by dependence on local service activities.
Recognition and Classification of Urban Shapes
Authors: Medda Francesco , Nijkamp Peter , Rietveld Piet
Published: September 2010

This paper is concerned with a methodology that is able to recognize and classify geometric shapes, in particular urban shapes. The main objective of this study is to develop a shape index that will address Whyte's category of “spatial form” (1968), that is, the external appearance or outward form, in contrast with the “internal form,” which is the structural form. We first review methodologies of shape recognition and classification. Next, we propose a viable formulation for such an endeavor by drawing from the aforementioned methodologies, and we aim to overcome some of their limitations by formulating a new index. We will apply the resulting shape index to an illustrative case in order to recognize urban shapes.
Extensions to the Hub Location Problem: Formulations and Numerical Examples
Authors: Bryan Deborah
Published: September 2010

Although a tremendous amount of analytical research is being conducted on the hub location problem, few models exist that extend the number of characteristics found in actual hub‐and‐spoke networks. Four extensions are presented in this paper: (1) a capacitated network model; (2) a minimum threshold model; (3) a model that endogenously determines the number of open hubs for the network; and (4) a model that incorporates a flow‐dependent cost function for the spokes as well as the interhub links. Both the capacitated and the minimum threshold models drop the assumption of a completely interconnected network commonly found in hub location models. Numerical results show that total network costs are often minimized by closing a few interhub links. The third extension is the first known hub location model to determine the optimal number of hubs based on the needs of the network. In this model, the number of open hubs depends on the distribution of flows in the network and how cost effectively the flows can be moved across the network. Previous models that endogenously determined the number of open hubs utilized a fixed cost for establishing each hub in order to limit the number of hubs in the network. The final extension recognizes the potential of all links to amalgamate flows and includes a separate flow‐dependent cost function for the spokes in addition to the one for the interhub links. Numerical results are shown for all four models.
Measuring Space‐Time Accessibility Benefits within Transportation Networks: Basic Theory and Computational Procedures
Authors: Miller Harvey J.
Published: September 2010

Accessibility is a fundamental but often neglected concept in transportation analysis and planning. Three complementary views of accessibility have evolved in the literature. The first is the constraints‐oriented approach, best implemented by Hägerstrand's space‐time prisms. The second perspective follows a spatial interaction framework and derives “attraction‐accessibility measures” that compare destinations' attractiveness with the travel costs required. A third approach measures the benefit provided to individuals by the transportation land‐use system. This paper reconciles the three complementary approaches by deriving space‐time accessibility and benefit measures that are consistent with the rigorous Weibull axiomatic framework for accessibility measures. This research also develops computational procedures for calculating these measures within network structures. This provides realistic accessibility measures that reflect the locations, distances, and travel velocities allowed by an urban transportation network. Since their computational burdens are reasonable, they can be applied at the urban scale using a GIS.
Scale‐Economy Conditions for Spatial Variation in Farm Size
Authors: Visser Sent
Published: September 2010

Given the usual neoclassical assumptions of economic rationality, perfect competition, long‐term spatial equilibrium, a Thunian context, and perfectly divisible labor and capital, this paper expresses economies of scale in farming in terms of the yield derived from a given level of intensity. If yield increases as farm scale increases, there are economies of scale. If yield decreases, there are diseconomies of scale. The literature on scale economies in agriculture suggests that scale economies accrue from increases in capital inputs, but diseconomies occur as a result of increases in farm area. The models of the spatial structure of agriculture, with farm size included, show the following: 1. Unless there are economies of scale giving way to diseconomies of scale with increases in farm size, no optimal farm area or farm scale can be defined; 2. If the optimal intensity for farming does not vary over space, the optimal farm scale or area should be constant over space; 3. If intensity varies spatially, and if the optimal economies of scale are a function of area only, farm areas should not vary spatially, and sales volume per farm should increase as market access and fertility increase; 4. It is only if intensity varies spatially and optimal scale economies are a function of both area and total quantities of nonland inputs per farm that farm area should increase as distance to market increases or fertility decreases. In this last case, quantities of nonland inputs per farm should also decrease, and usually sales volume per farm should decrease also.
An Evaluation of Domain Decomposition Strategies for Parallel Spatial Interpolation of Surfaces
Authors: Cramer Barton E. , Armstrong Marc P.
Published: September 2010

The objective of this paper is to investigate static and dynamic methods for spatially subdividing the work required to interpolate a gridded surface into a set of subtasks that are allocated to separate processors for execution in parallel. A description of the parallel implementation and testing procedures is preceded by a review of the serial version of the particular neighborhood‐based, inverse‐distance‐weighted interpolation (Clarke) algorithm chosen for interpolation. The effects on serial program execution time of data distribution (dispersed or clustered) are documented, and these results are used to inform a partial parallelization process. Next, six problem decomposition and task scheduling strategies are evaluated on a shared memory multiprocessor. The choice of problem decomposition and task scheduling combination is shown to exercise a significant role in determining parallel program performance, with a medium‐grained, dynamically scheduled approach showing the best adaptability to variable spatial workload and uneven processor power.
Measuring Space‐Time Accessibility Benefits within Transportation Networks: Basic Theory and Computational Procedures
Authors: Miller Harvey J.
Published: September 2010

Accessibility is a fundamental but often neglected concept in transportation analysis and planning. Three complementary views of accessibility have evolved in the literature. The first is the constraints‐oriented approach, best implemented by Hägerstrand's space‐time prisms. The second perspective follows a spatial interaction framework and derives “attraction‐accessibility measures” that compare destinations' attractiveness with the travel costs required. A third approach measures the benefit provided to individuals by the transportation/land‐use system. This paper reconciles the three complementary approaches by deriving space‐time accessibility and benefit measures that are consistent with the rigorous Weibull axiomatic framework for accessibility measures. This research also develops computational procedures for calculating these measures within network structures. This provides realistic accessibility measures that reflect the locations, distances, and travel velocities allowed by an urban transportation network. Since their computational burdens are reasonable, they can be applied at the urban scale using a GIS.
Local Forms of Spatial Analysis
Authors: Fotheringham A. Stewart , Brunsdon Chris
Published: September 2010

Local forms of spatial analysis focus on exceptions to the general trends represented by more traditional global forms of spatial analysis. There is currently a rapid expansion in the development of such techniques but their history almost exactly parallels that ofGeographical Analysis,with the first examples of local analysis appearing in the late 1960s. Indeed, Geographical Analysis has published many of the significant contributions in this field. This paper reviews the development of local forms of spatial analysis and assesses the current situation. Following a discussion on the nature and importance of local analysis, examples are given of local forms of point pattern analysis; local graphical approaches; local measures of spatial dependency; the spatial expansion method; adaptive filtering; multilevel modeling; geographically weighted regression; random coefficients models; autoregressive models; and local forms of spatial interaction models.
A Shape Definition for Geographic Applications Based on Edge, Elongation, and Perforation
Authors: Wentz Elizabeth A.
Published: September 2010

An expanded definition for measuring shape in a geographic context is presented. Shape analysis is important in many geographic contexts such as studying the effects of urban development, measuring geographic characteristics of drainage basins, and examining the patterns of geologic formations.

This research implements and tests an approach to expand the current mathematical definition of shape and to measure shape for geographic applications, called the trivariate shape definition. The expanded definition involves identifying three characteristics to define shape: edge, elongation, and perforation. Indices to measure these characteristics were identified and applied to two different data sets. Analysis of results from these data sets suggests that the trivariate index clustered groups of objects based on shape similarity. The trivariate approach provides more flexibility to measure shape by relying on a more specific definition of shape.
On the Application of Inductive Machine Learning Tools to Geographical Analysis
Authors: Gahegan Mark
Published: September 2010

Inductive machine learning tools, such as neural networks and decision trees, offer alternative methods for classification, clustering, and pattern recognition that can, in theory, extend to the complex or “deep” data sets that pervade geography. By contrast, traditional statistical approaches may fail, due to issues of scalability and flexibility. This paper discusses the role of inductive machine learning as it relates to geographical analysis. The discussion presented is not based on comparative results or on mathematical description, but instead focuses on the often subtle ways in which the various inductive learning approaches differ operationally, describing (1) the manner in which the feature space is partitioned or clustered, (2) the search mechanisms employed to identify good solutions, and (3) the different biases that each technique imposes. The consequences arising from these issues, when considering complex geographic feature spaces, are then described in detail. The overall aim is to provide a foundation upon which reliable inductive analysis methods can be constructed, instead of depending on piecemeal or haphazard experimentation with the various operational criteria that inductive learning tools call for. Often, it would appear that these criteria are not well understood by practitioners in the geographic sphere, which can lead to difficulties in configuration and operation, and ultimately to poor performance.
Contiguity Constraints for Single‐Region Site Search Problems
Authors: Cova Thomas J. , Church Richard L.
Published: September 2010

This paper proposes an explicit set of constraints as a general approach to the contiguity problem in site search modeling. Site search models address the challenging problem of identifying the best area in a study region for a particular land use, given that there are no candidate sites. Criteria that commonly arise in a search include a site's area, suitability, cost, shape, and proximity to surrounding geographic features. An unsolved problem in this modeling arena is the identification of a general set of mathematical programming constraints that can guarantee a contiguous solution (site) for any 0–1 integer‐programming site search formulation. The constraints proposed herein address this problem, and we evaluate their efficacy and efficiency in the context of a regular and irregular tessellation of geographic space. An especially efficient constraint form is derived from a more general form and similarly evaluated. The results demonstrate that the proposed constraints represent a viable, general approach to the contiguity problem.
Using Decision Tree Induction Systems for Modeling Space‐Time Behavior
Authors: Arentze T. A. , Hofman F. , van Mourik H. , Timmermans H.J.P. , Wets G.
Published: September 2010

Discrete choice models are commonly used to predict individuals' activity and travel choices either separately or simultaneously in activity‐scheduling models. This paper investigates the possibilities of decision tree induction systems as an alternative approach. The ability of decision trees to represent heuristic decision rules is evaluated and a method of capturing interactions across decisions in a sequential decision model is outlined. Decision tree induction algorithms, such as C4.5, CART, and CHAID, are suited to derive the decision rules from empirical data. A case study to illustrate the approach considers decisions of individuals when they are faced with the choice to combine different out‐of‐home activities into a multipurpose, multistop trip or make a trip for each activity separately. Data from a large‐scale activity diary survey are used to induce the decision rules. Possible directions of future research are identified.
On the Spatial Decomposition of Forecasts
Authors: Jackson Randall W. , Sonis Michael
Published: September 2010

This paper uses historical socioeconomic data to evaluate the elasticities of a Dendrinos‐Sonis one‐population/two‐locations nonlinear dynamic comparative advantage model for determining subregional shares of aggregate regional forecasts. The fractal dimension properties of the discrepancies between the actual and simulated data are used to enhance the forecasting framework. The analysis focuses in the first phase on total population, total personal income, and earnings by sector for the Columbus, Ohio Metropolitan Statistical Area, and Delaware County, one of its component counties. For the second phase of the analysis, these data for nondurable goods and for services are used, along with monthly data for total employment in Columbus, Cincinnati, and Cleveland, Ohio. Annual data for the analysis are drawn from the U. S. Bureau of Economic Analysis, Regional Economic Information System, while the monthly data come from the Ohio Bureau of Employment Securities. The nonlinear dynamic model is shown to outperform conventional approaches for the majority of socioeconomic stocks.
Absent and Accounted For: Absenteeism and Cooperative Learning*
Authors: Koppenhaver G. D.
Published: September 2010

In a small section collaborative learning environment where student work teams promote mutual learning about investments, students limit the opportunity to learn from other students if they are absent from class. Absenteeism not only denies the student the opportunity to learn from others but also denies other members of the student's work team the opportunity to learn from the absent student. Other team members' absenteeism should be costly for individual performance if collaborative learning fosters learning and retention. The research finds that while absenteeism is detrimental to the student's own performance, absenteeism of other team members from team activities has a significant negative effect on both individual exam and homework scores. The conclusions validate the benefits of active learning and of encouraging attendance in collaborative learning environments in all disciplines.
Examining Drivers of Course Performance: An Exploratory Examination of an Introductory CIS Applications Course
Authors: Syler Rhonda A. , Cegielski Casey G. , Oswald Sharon L. , Rainer R. Kelly
Published: September 2010

The accelerating diffusion of broadband Internet access provides many opportunities for the development of pedagogically robust Web‐based instruction (WBI). While the supporting technology infrastructure of broadband disseminates, the attention of academic researchers focuses upon issues such as the drivers of student usage of WBI. Specifically, the research presented herein examined the impact of WBI on a student's aggregate course performance. We hypothesized that learning independence (LI) is a determinate factor in a student's use of WBI. In this study, we employed structural equation modeling techniques to examine the data and assess the direct and indirect effects of LI on WBI usage. The subjects, students in an introductory Computer Information Systems applications course, used a Web‐based tutorial program for skills instruction. The findings of this study suggest that WBI usage has a significant impact on a student's course performance. Despite its plausibility, the effect of LI on WBI usage was not significant. However, we did conclude that two of the second order factors of the LI construct have a direct effect on a student's performance in the course.
Seeing Is Believing: The Transitory Influence of Reputation Information on E‐Commerce Trust and Decision Making
Authors: Fuller Mark A. , Serva Mark A. , Benamati John “Skip”
Published: September 2010

This research examines the transitory influence of reputation information on consumer decision making regarding an e‐vendor. Using social judgment theory to explain how reputation information's effect on perceptions may be fleeting, we specifically examined how user trusting beliefs related to an e‐vendor change after a simple exposure to the Web site. A total of 369 college students participated in an experiment that found that reputation information was initially strongly related to trusting beliefs regarding the e‐vendor, but a brief nonpurchase‐related exposure to the e‐vendor's Web site—that is, direct experience—reduced reputation's effects significantly. This research provides insights into why reputation information may be more important in certain circumstances than in others and enhances our understanding of how consumer decision making is affected by different purchasing contexts. This research also has implications on the design and use of trust‐building technologies.
Environmental Shocks and SME Alliance Formation Intentions in an Emerging Economy: Evidence from the Asian Financial Crisis in Indonesia
Authors: Marino Louis D. , Lohrke Franz T. , Hill John S. , Weaver K. Mark , Tambunan Tulus
Published: September 2010

Environmental shocks can occur when emerging country governments open their markets to outside influences. We extend research conducted primarily in mature economies on how managers react to environmental shocks by evaluating how environmental shock type, a firm's strategic orientation, and its slack resources affected strategic alliance formation intentions during and immediately following the Asian Financial Crisis. Results from two Indonesian small– and medium–sized enterprises (SME) samples show that these factors influenced alliance intentions, although not always in ways that were consistent with previous research findings in more mature markets. Overall, our results provide critical insights into emerging market firms’ strategic actions, particularly related to key managerial motivations for SME alliance formation.
Institutional Environments for Entrepreneurship: Evidence from Emerging Economies in Eastern Europe
Authors: Manolova Tatiana S. , Eunni Rangamohan V. , Gyoshev Bojidar S.
Published: September 2010

In this article, we sought to empirically validate an instrument for measuring country institutional profiles for the promotion of entrepreneurship in a sample of 254 business students from three emerging economies: Bulgaria, Hungary, and Latvia. Results from the confirmatory factor analysis suggest high reliability, internal consistency, and construct validity of the instrument. Further, we find important differences in the three dimensions (regulatory, cognitive, and normative) of the institutional profiles across the three emerging economies, reflecting their idiosyncratic cultural norms and values, traditions, and institutional heritage in promoting entrepreneurship. Implications for future research, managerial practice, and public policy are discussed.
Exploring an Inverted U–Shape Relationship between Entrepreneurial Orientation and Performance in Chinese Ventures
Authors: Tang Jintong , Tang Zhi , Marino Louis D. , Zhang Yuli , Li Qianwen
Published: September 2010

The critical role of entrepreneurial orientation (EO) in firm performance has been widely studied in the U.S. context. However, the examination of this key construct in emerging regions such as China has been very limited. In this article, we hypothesize that the relationship between EO and firm performance is best represented as curvilinear, as opposed to linear, in China. We use a two–study approach to test the link between EO and performance, as expressed in both perceptual and objective performance. Findings of both studies demonstrate an inverted U–shape relationship. Implications for future research on EO are discussed.
The Role of Family Influence in Firms’ Strategic Responses to Threat of Imitation
Authors: Sirmon David G. , Arregle Jean–Luc , Hitt Michael A. , Webb Justin W.
Published: September 2010

We integrate theory on the resource–based view and threat rigidity with family business research to explain the role family influence plays in responding to threats of imitation. As opposed to family control, we find that family influence affects resource management actions taken in response to threats of imitation. Specifically, results show that R&D investment and internationalization actions mediate the relationship between imitability and performance. However, we find that family–influenced firms are less rigid in their responses to such threats, reducing R&D and internationalization significantly less than firms without family influence.
Affiliate Directors and Perceived Risk Bearing in Publicly Traded, Family–Controlled Firms: The Case of Diversification
Authors: Jones Carla D. , Makri Marianna , Gomez–Mejia Luis R.
Published: September 2010

The present study examines the influence exerted by affiliate directors in the diversification decisions of family–controlled, publicly traded firms. Using a relational view based on the development of social capital, we argue that affiliate directors play a different role in boards of family firms vis–à–vis nonfamily firms. Specifically, we develop a set of hypotheses proposing that affiliate directors stimulate family firms to pursue diversification strategies by sharing their knowledge and experience with family executives, and hence reducing the perceived risk that may be associated with growth strategies. Affiliates can play this advisory role without reducing the control of family owners, and this facilitates the firm's willingness to adopt growth–oriented strategies. Namely, affiliates who are business experts or support specialists would tend to encourage diversification. These effects are supported empirically.
Commentary: The Servant, the Parasite, and the Enigma: A Tale of Three Ownership Structures and Their Affiliate Directors
Authors: Combs James G.
Published: September 2010

In private family firms, affiliate directors are largely resource–providing servants of the family. In nonfamily public firms with dispersed ownership, affiliates are, figuratively speaking, symbiotic parasites loyally supporting their professional management hosts while extracting revenues for their home firms. The public family firm stands somewhere between and the affiliate directors in such firms are consequently an enigma. Jones, Makri, and Gomez–Mejia compare affiliate directors in public family firms with those in public nonfamily firms and find that they positively influence diversification strategy only in public family firms. They interpret this outcome as evidence that affiliate directors in public family firms act like the servants found in private family firms. I offer an alternative interpretation by suggesting that affiliate directors in public family firms are more successful versions of their parasitic cousins in public nonfamily firms. I draw attention to the Janus–headed nature of these directors to underscore why it is useful to study public family firms as a distinct ownership structure.
Unleashing the Relationship Power of Family Firms: Identity Confirmation as a Catalyst for Performance
Authors: Milton Laurie P.
Published: September 2010

This paper adopts a broad perspective on identity and identity relations and argues that family businesses can develop identity confirmation as a unique, hard to imitate competitive resource that unleashes and leverages the relational capabilities that differentiate them from nonfamily businesses. A person's identities are “confirmed” in a business, to the extent they are supported therein. Identity and identity confirmation research is marshaled to consider the impact of identity confirmation on succession. Implications for other relational challenges family businesses face are explored. The potential for family business research to contribute to a general theory of the firm is illustrated.
False Diagnosis of Aortic Stenosis Due to Doppler Recording of Mitral Regurgitation from the Suprasternal Notch
Authors: RIFKIN ROBERT D. , RAJU PADMA K. , SKOWRONSKI MARJORIE
Published: September 2010

The suprasternal notch provides an important window for estimating aortic valve gradient with a nonimaging continuous‐wave transducer. Since the Doppler beam is highly angulated with respect to mitral flow, it is generally assumed that mitral regurgitation cannot simulate significant aortic stenosis in this window. We report on an 88‐year‐old patient with clinically suspected aortic stenosis and heavy valve calcification, in whom suprasternal notch Doppler with a nonimaging probe showed a high‐velocity flow that appeared to confirm the diagnosis of aortic stenosis. Cardiac catheterization demonstrated moderate mitral regurgitation due to flail leaflet and no aortic gradient. Awareness of the potential to image mitral regurgitation from the suprasternal notch is stressed to avoid misdiagnosis. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Tissue Characterization by Ultrasound: What is Possible Now? What Will be Possible?
Authors: MCPHERSON DAVID D.
Published: September 2010

The purpose of this review is to discuss the principles of ultrasound tissue characterization. We describe gray scale analysis, backscatter techniques, real‐time backscatter imaging, enhancement of abnormal tissue properties with contrast agents or liposomes, and use of acoustic microscopy. Ultrasound tissue characterization offers the promise of direct identification of abnormalities of the myocardium without relying on indirect manifestations such as abnormalities in cardiac function. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Pharmacological Methods Instead of Exercise for the Assessment of Coronary Artery Disease
Authors: DISTANTE ALESSANDRO , MOSCARELLI ELENA , MORALES MARIA AURORA , LATTANZI FABIO , REISENHOFER BARBARA , LOMBARDI MASSIMO , PICANO EUGENIO , ROVAI DANIELE , L'ABBATE ANTONIO
Published: September 2010

Due to new knowledge of pathophysiology, diagnosis, and treatment, the clinical approach to the patient with suspected coronary artery disease has deeply changed over the last few years. The central role of functional factors‐independent from or in association with organic stenosis‐are important in the genesis of myocardial ischemia. On the diagnostic side, the widespread use of new methodologies permits detection of ischemia by means of perfusion, mechanical, and metabolic markers. Drugs such as beta blockers, nitrates, and calcium antagonists, and procedures such as coronary angioplasty, have fostered a new era in which it is crucial not only to document ischemia, but also to understand the underlying mechanism. The present article deals with the most important pharmacological tests that can fit into a modern approach to noninvasive ultrasonic diagnosis of coronary artery disease. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Aortic Pulse Wave Velocity in Subjects with Aortic Valve Sclerosis
Authors: Çelik Şükrü , Durmuş İsmet , Korkmaz Levent , Gedikli Ömer , Kaplan Şahin , Örem Cihan , Baykan Merih
Published: September 2010

Background: Aortic stiffness is an independent risk factor for cardiovascular events and mortality. The measurement of pulse‐wave velocity (PWV) is the most simple, noninvasive, and robust method to determine aortic stiffness. Whether aortic stiffness contributes to aortic valve sclerosis (AVS) remains unknown. The aim of the present study was to examine the relationship between PWV and AVS in subjects free of clinically evident atherosclerotic disease. Methods: We enrolled 62 patients (48 men; age 65 ± 8 years) diagnosed with AVS and an additional 62 age‐, hypertension‐, diabetes mellitus‐, and history of smoking‐matched subjects without AVS. Applanation tonometry was applied to assess the augmentation index and aortic PWV. The subjects with symptomatic vascular disease were excluded from the study. AVS was defined by echocardiography as thickening and calcification of the normal trileaflet aortic valve without obstruction to the left ventricular outflow. Results: There was no significant difference between the two groups regarding the aortic PWV and augmentation index (11.7±3.3 vs 11.8±3.7, P=0.85; 28.0±9.4 vs 25.0±8.6, P=0. 17, respectively). The presence of AVS was significantly correlated with ejection fraction (r=0.211, P=0.011), male gender (r=0.362, P=0.0001), and age (r=0.200, P=0.026). Conclusions: The lack of an association between the aortic PWV and AVS suggests that AVS is a complex phenomenon consisting of several distinct processes, related to both atherosclerotic and nonatherosclerotic processes.
Left Ventricular Mechanical Dyssynchrony as Assessed by Phase Analysis of ECG‐Gated SPECT Myocardial Perfusion Imaging
Authors: Chen Ji , Garcia Ernest V. , Lerakis Stamatios , Henneman Maureen M. , Bax Jeroen J. , Trimble Mark A. , Borges‐Neto Salvador , Velazquez Eric J. , Iskandrian Ami E.
Published: September 2010

Cardiac resynchronization therapy (CRT) has shown benefits in patients with severe heart failure. The traditional criteria to select patients for CRT (NYHA class III or IV, depressed left ventricular (LV) ejection fraction, and prolonged QRS duration) result in at least 30% of the selected patients with no response to CRT. Recent studies with tissue Doppler imaging (TDI) have shown that the presence of LV dyssynchrony is an important predictor for response to CRT. Phase analysis has been developed to assess LV dyssynchrony from electrocardiography‐gated single photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI). This technique uses Fourier harmonic functions to approximate regional wall thickening over the cardiac cycle and to calculate phases of regional onset of mechanical contraction (OMC). These OMC phases are obtained three‐dimensionally over the left ventricle to generate an OMC phase distribution. Quantitative indices are calculated from the phase distribution to assess degree of LV dyssynchrony. This technique has been compared to other methods of measuring LV dyssynchrony and shown promising results in clinical evaluations. In this review, the phase analysis methodology is described and its up‐to‐date validations are summarized.
Role of MRI in Patient Selection for CRT
Authors: Delfino Jana G. , Fornwalt Brandon K. , Oshinski John N. , Lerakis Stamatios
Published: September 2010

Magnetic resonance imaging has great potential for aiding in the selection of patients who will respond to CRT. MRI is the only imaging tool that can simultaneously assess mechanical dyssynchrony, determine the amount and location of myocardial scar tissue, and map the location of cardiac venous anatomy—three important factors in predicting a patient's response to CRT. The goal of this manuscript is to review the MRI methods that can be used in the selection of patients for CRT.
Effect of seed moisture content and d‐limonene on oviposition decisions of the seed beetle Callosobruchus maculatus
Authors: Hudaib Taghread , Hayes William , Brown Sarah , Eady Paul E.
Published: September 2010

Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae) is a cosmopolitan pest of stored pulses and legumes. Under legume storage conditions neither adults nor larvae drink, with larvae obtaining their hydration from metabolic water. However, lack of water limits female fecundity and longevity, thus females might be expected to preferentially oviposit on seeds with high moisture content so as to minimize water stress on their offspring. This was tested by offering females a choice of seeds that differed in relation to their level of water content. After controlling for differences in seed size, females were found to preferentially oviposit on the driest seeds. Offspring size and larval survival were equivalent on seeds that differed in moisture content, which in combination with the preference to lay on the driest seeds would indicate that the egg laying decisions of C. maculatus females do not function to minimize larval water stress. Analysis of the chemical volatiles released by seeds that differed in their moisture content revealed a greater level of d‐limonene in the environment surrounding high moisture seeds. d‐limonene has known anti‐herbivory properties, thus we suggest the observed female preference for dry seeds may be related to the observed difference in the level of d‐limonene in the immediate vicinity of beans that differ with respect to their moisture content.
The prevalence of BV in the population on the Åland Islands during a 15‐year period
Authors: ERIKSSON KATARINA , ADOLFSSON ANNSOFIE , FORSUM URBAN , LARSSON PER‐GÖRAN
Published: September 2010

Eriksson K, Adolfsson A, Forsum U, Larsson P‐G. The prevalence of BV in the population on the Åland Islands during a 15‐year period. APMIS 2010; 118: 903–8.

The aim of the study was to describe the prevalence and age distribution of bacterial vaginosis (BV) during an observation period of 15 years in a population study with cross‐sectional samples of adult women living on the Åland Islands. The Åland Islands form an archipelago in the Baltic Sea and are a province of Finland. Every fifth year, specific age groups in the adult female population are invited to participate in a screening program for early diagnosis of cervical cancer using a papanicolaou (PAP)‐stained vaginal smear. Women in the age groups of 20, 25, 30, 35, 40, 45, 50, 55, and 60 years are called each year. BV diagnosis of the PAP‐stained smears uses the classification according to Nugent. The PAP‐stained smears from the screening program of cervical cancer 1993, 1998, 2003, and 2008 were used in this study. A total of 3456 slides were investigated and 271 women could be followed for the 15‐year observation period. The prevalence of BV declined from 15.6% in 1993 to 8.6% in 2008. The highest prevalence occurred among the age groups of 35 and 50 years. Among the 271 women who could be followed for the 15‐year observation period, two‐third showed normal/intermediate flora and one‐third were infected with BV at least once. As this is a cross‐sectional population study spanning 15 years, the prevalence of BV in the female adult population of the Åland Islands can be estimated. The prevalence has declined between 1993 and 2008 from 15.6% to 8.6%.
Methodological issues in longitudinal epidemiologic studies of dental caries
Authors: Slade Gary D. , Caplan Daniel J.
Published: September 2010

Abstract– As longitudinal epidemiologic studies of dental caries address increasingly complex research questions, approaches to analysis of data from those studies have become more sophisticated. This review examines methods available for analyzing and reporting data from such studies. Traditional analytic methods utilize the DMFS increment as the outcome measure in longitudinal studies of caries. However, two other outcome measures may be needed to address some research issues: cumulative incidence, which quantifies caries risk; and incidence density, which quantifies caries rate. Four major analytic decisions have to be addressed when computing DMFS increment: examiner misclassification (“reversals”), teeth lost due to caries, findings from more than two examinations, and multiple events such as caries initiation and progression. We present a uniform approach for enumerating caries events that permits the same analytic decisions made in calculating DMFS increment to be applied to cumulative incidence and incidence density calculations. In view of the variety of analytic decisions that must be made when enumerating events in longitudinal studies of caries, authors should specify how all potential changes in caries status were handled. Further‐more, if a study uses more than one outcome measure, the same decisions for enumerating events should be used when computing those measures.
Permanent make‐up colorants may cause severe skin reactions
Authors: Wenzel Sabrina M. , Welzel Julia , Hafner Christian , Landthaler Michael , Bäumler Wolfgang
Published: September 2010

Background: In recent years, cosmetic tattoos [permanent make‐up (PMU)] on eyelids, eyebrows and lips have become increasingly popular. However, most colorants are manufactured for non‐medical purposes, without any established history of safe use in humans.

Objectives: To investigate severe adverse reactions, such as swelling, burning, and the development of papules, of the lips and the surrounding area in 4 patients who had had at least two PMU procedures on their lips.

Patients, Materials and Methods: Adverse skin reactions were examined with patch and prick testing of the colorants. In addition, skin biopsies were taken in the centre of the prick test for histology. One patient declined prick testing.

Results: Beauticians tended to use various PMU products, but all contained Pigment Red 181 (CI 73360). All patients tested showed a clear delayed reaction to Pigment Red 181 or the tattoo ink, or both, after prick testing. Histology indicated an allergic reaction. Each lip lesion slowly abated after several months of topical or systemic therapy with steroids in combination with tacrolimus, but none has yet completely resolved.

Conclusions: In light of the severe and often therapy‐resistant skin reactions, we strongly recommend the regulation and control of the substances used in PMU colorants.
Survival probability of zirconia‐based fixed dental prostheses up to 5 yr: a systematic review of the literature
Authors: Schley Jaana‐Sophia , Heussen Nicole , Reich Sven , Fischer Jan , Haselhuhn Klaus , Wolfart Stefan
Published: September 2010

Schley J‐S, Heussen N, Reich S, Fischer J, Haselhuhn K, Wolfart S. Survival probability of zirconia‐based fixed dental prostheses up to 5 yr: a systematic review of the literature. Eur J Oral Sci 2010; 118: 443–450. © 2010 Eur J Oral Sci

The purpose of this systematic review was to calculate the 5‐yr survival rates of all‐ceramic zirconia‐based fixed dental prostheses (FDPs) and to analyze technical and biological complications. An electronic literature search of MEDLINE (PubMed) was conducted independently by three reviewers to identify clinical studies from 1999 to 2009 and was completed by a manual search. Keywords and inclusion and exclusion criteria were well‐defined. The search revealed 399 titles and led to the final analysis of 18 full‐text articles. Nine studies met the inclusion criteria. Extracted data were statistically calculated into 5‐yr survival rates and 5‐yr complication‐free rates by using Poisson regression analysis. In total, 310, 3‐ to 4‐unit FDPs and 20 FDPs with more than 4 units were included. The estimated 5‐yr survival rate for all FDPs was 94.29% (95% CI: 58.98–99.32); 19 FDPs were lost as a result of catastrophic failures. The 5‐yr complication‐free rate regarding technical complications was 76.41% (95% CI: 42.42–91.60) with chipping being the most frequent complication. Regarding biological complications, the 5‐yr complication‐free rate was 91.72% (95% CI: 59.19–98.53). The survival rates of zirconia‐based short‐unit FDPs are promising. However, an important improvement of the veneering systems is required, and for FDPs with more units in function, further randomized, controlled clinical trials are necessary.