bluuebunny/crossref_metadata_2025 huggingface dataset:
A Social Network Contagion Theory of Risk Perception
Authors: Scherer Clifford W. , Cho Hichang
Published: December 2004

Risk perceptions have, to a great extent, been studied exclusively as individual cognitive mechanisms in which individuals collect, process, and form perceptions as atomized units unconnected to a social system. These individual‐level theories do not, however, help explain how perception of risk may vary between communities or within a single community. One alternative approach is based on a network theory of contagion. This approach, emerging largely from organizational and community social network studies, suggests that it is the relational aspects of individuals and the resulting networks and self‐organizing systems that influence individual perceptions and build “groups or communities of like‐minded” individuals. These social units, it is argued, behave as attitude, knowledge, or behavioral structures. The study reported in this article tests one aspect of this theoretical perspective. The central hypothesis proposes the existence of risk perception networks—relational groupings of individuals who share, and perhaps create, similar risk perceptions. To test this idea, data were collected from individuals involved in a community environmental conflict over a hazardous waste site cleanup. The statistical analysis used a matrix of relational social linkages to compare with a matrix of individual risk perceptions. The analysis confirmed the hypothesis suggesting that social linkages in communities may play an important role in focusing risk perceptions.
Using Risk Communication to Disclose the Outcome of a Participatory Decision‐Making Process: Effects on the Perceived Acceptability of Risk‐Policy Decisions
Authors: Arvai Joseph L.
Published: December 2004

It has been suggested that public participation during decision making about risks can lead to more widely accepted risk policies. This article discusses an experiment to determine if this is true when people are made aware of the fact that a participatory decision‐making process has taken place only through information disclosed during a subsequent risk communication effort. The results from this experiment showed that, after receiving information during risk communication that cast risk policies about space exploration as the product of a participatory decision process, participants in the study felt more supportive of the resulting decisions than did participants in a control group. This result coincided with the participants in the study group perceiving the risks associated with the decision to be lower and the benefits higher. Responses from these participants also showed that they were more satisfied with the decision‐making process than they were with the outcome of the decision itself. Therefore, it may be premature to view the objective of participatory decision‐making approaches—and the risk communication efforts that discuss them—as a means of making risk policies more widely acceptable to the public at large. Rather, it may be better to view the benefits of these approaches in terms of their ability to help lead to higher quality decisions that are the product of more widely accepted decision processes.
Exploring Technical and Cultural Appeals in Strategic Risk Communication: The Fernald Radium Case
Authors: Hamilton Jennifer Duffield
Published: December 2004

Risk disputes are often characterized by tensions between technical and cultural understandings of risk and by communication practices that reflect those differing perspectives. This study considers how participants in risk debates draw upon and combine aspects of technical and cultural rationality as broad orientations to risk in expressing their views and formulating persuasive appeals during risk debates. Rhetorical theorist Kenneth Burke's (1984) concept offrames of acceptanceis used to analyze a case study involving competing priorities for radium stored at the Fernald site, a former Department of Energy nuclear weapons facility. A rhetorical analysis is conducted using the transcript from a 1995 public meeting during which local residents and a nuclear medicine expert discussed priorities of Fernald site cleanup versus providing radium stored on site for promising cancer research. Two tensions are identified that fostered disagreement among discussants: the first a tension between a local or global context for the controversy and the second a tension between competing definitions of public participation for this issue. This study analyzes the rhetorical strategies by which participants in the Fernald radium debate articulated these tensions and argues that technical and cultural rationality (Plough & Krimsky, 1987) acted as sources of rhetorical invention influencing participants' individualframes of acceptanceand the ways they defined and interpreted the situation and crafted persuasive appeals.
Studying Heuristic‐Systematic Processing of Risk Communication
Authors: Kahlor LeeAnn , Dunwoody Sharon , Griffin Robert J. , Neuwirth Kurt , Giese James
Published: December 2004

Using a model of risk information seeking and processing developed by Griffin, Dunwoody, and Neuwirth (1999), this study looks at predictors of the processing strategies that people apply to health risk information. Specifically, this article focuses on one relationship within the model—the relationship between perceived amount of information needed to deal with a risk and heuristic‐systematic processing. Perceived amount of information needed refers to the gap between one's understanding of a risk and the level of understanding that one needs in order to make a decision about that risk. Building on the work of Chaiken (cf. 1980), the Griffin et al. model predicts—and finds—that the larger the gap, the more likely one will process information systematically. The study employs a novel measure of information processing in a survey setting by sending actual information to participants and then asking them how they attended to it; the researchers evaluate this strategy. Finally, the researchers discuss how these findings might help agencies and practitioners create more effective risk messages.
Enforcement or Ethical Capacity: Considering the Role of State Ethics Commissions at the Millennium
Authors: Smith Robert W.
Published: December 2004

Looking back on the twentieth century, the American public has witnessed numerous incidents of unethical behavior by a variety of federal, state, and local government officials. Ongoing cases of political and bureaucratic corruption raise questions about what governments are doing to prevent these “ethical lapses.” Most state governments have comprehensive ethics laws and ethics commissions to enforce these laws. Very few studies have examined the role of ethics commissions in state government. This article stems from research conducted during 1997–98 involving more than 60 anonymous interviews with ethics officials and stakeholders in Connecticut, Florida, and New York. This analysis reveals that ethics commissions are instruments and symbols, policemen and consultants, politicians and neutral technicians, and interpreters of and prisoners to the ethics laws. The article concludes with 10 recommendations to improve ethics enforcement and the ethics‐building capacity of state governments as society enters the next millennium.
Workplace Spirituality and Organizational Performance
Authors: Garcia‐Zamor Jean‐Claude
Published: December 2004

This article reviews the literature on workplace spirituality, pointing out emergent theories and examining the links between this phenomenon and organizational dynamics. It also examines workplace spirituality in a historical context and compares it to religious beliefs and to established ethical theories and moral principles. The article also looks at organizations in which an emphasis on spiritual values has had an impact on work productivity. While some corporations have institutionalized spirituality, public agencies are reluctant to follow suit for fear of violating the principle of church‐state separation. Finally, the article suggests ways that managers and administrators in both the public and the private sector can use workplace spirituality to increase performance and develop ethical organizations.
How Should We Wage the War on Drugs? Determinants of Public Preferences for Drug Control Alternatives
Authors: Timberlake Jeffrey M. , Lock Eric D. , Rasinski Kenneth A.
Published: December 2004

When citizens are presented with alternative policy solutions to a given social problem, why do they choose to support one over another? In this article, the authors analyze a survey of residents of the five largest U.S. metropolitan areas to understand determinants of public support for spending on three major components of American drug control policy: law enforcement programs, rehabilitative services for addicts, and school‐based prevention programs. The authors estimate effects of self‐interest, political socialization, and policy attitudes on support for total drug control expenditures and on preferences for each drug control alternative versus the others. Effects of group self‐interest, societal interest, and political socialization change dramatically across dimensions of support. Policy attitudes are strong predictors of both types of support, whereas individual self‐interest measures are not associated with either dimension.
Unilateral Action and Presidential Power: A Theory
Authors: Moe Terry M. , Howell William G.
Published: December 2004

In this article, the authors explore a basis for presidential power that has gone largely unappreciated to this point but that has become so pivotal to presidential leadership that it virtually defines what is distinctively modern about the modern presidency. This is the president's formal capacity to act unilaterally and thus to make law on his own. The purpose of the article is to outline a theory of this aspect of presidential power. The authors argue that the president's powers of unilateral action are a force in American politics precisely because they are not specified in the Constitution. They derive their strength and resilience from the ambiguity of the contract. The authors also argue that presidents have incentives to push this ambiguity relentlessly to expand their own powers—and that, for reasons rooted in the nature of their institutions, neither Congress nor the courts are likely to stop them.
The number and size of seeds in common versus restricted woodland herbaceous species in central Iowa, USA
Authors: Mabry Catherine M.
Published: December 2004

Few plants have widespread distributions and occur wherever there is suitable habitat. Most species are absent from seemingly suitable sites because of limited colonizing ability. At a landscape scale colonization is limited by lack of seeds or suitable microsites, and this limit is likely to be exacerbated by current human alteration of the landscape. To test the hypothesis that species with restricted distributions have a more limited capacity for dispersal compared to common species, I compared seed number in a group of seven common woodland herbaceous species compared to seven species in the same genus or family with more restricted distributions. Restricted species had nearly an order of magnitude fewer seeds compared to closely related common species. They also produced over an order of magnitude larger seeds. These results support dispersal limitation. The ability to detect these differences was reduced when taxonomic information was not included. The data suggest that these species can not maximize both seed size and seed number. The results are interpreted in light of the human disturbance history that has had an overriding influence on the Iowa landscape and has likely favored species with an output advantage of abundant seeds over species with far many fewer seeds.
Novel patch–matrix interactions: patch width influences matrix use by birds
Authors: Tubelis Dárius P. , Lindenmayer David B. , Cowling Ann
Published: December 2004

This study investigated the influence of the width of patches of native eucalypt forest on bird occurrence in stands of exotic radiata pine (Pinus radiata) forests that surrounded such patches. Boundaries between eucalypt and pine forests were surveyed to examine bird occurrence and species richness at different distances in the pine matrix from eucalypt forest edges. Birds were counted by the area search method within 0.5 ha quadrats at 32 study sites (where sites spanned the boundaries of pine and eucalypt forests). Data were examined using generalised linear mixed models. Species richness and occurrence of particular species in quadrats located within pine forests decreased with increasing distance from eucalypt patches. This resulted, in part, from the fact that several species found in native patches also use pine plantations as additional foraging areas. Species richness decreased more quickly with distance from eucalypt patches in younger than in older pine stands. The width of native forest patches also influenced bird occurrence in adjacent pine forest matrix. Bird species richness decreased more rapidly in exotic plantations adjacent to wide rather than narrow patches of native forest. To the best of our knowledge, no studies have previously reported that dimensions of patches can influence the use of surrounding matrix. We introduce the term “halo effect” for the influence of patch attributes on the differential use of matrix adjacent to native patches. These patterns highlight that conservation efforts in patchy environments should protect not only native patches but also adjacent areas of matrix into which animals extend their home ranges.
The biology and ecology of narrow endemic and widespread plants: a comparative study of trait variation in 20 congeneric pairs
Authors: Lavergne Sébastien , Thompson John D. , Garnier Eric , Debussche Max
Published: December 2004

The objective of this study is to examine whether habitat, herbivory and traits related to resource acquisition, resource conservation, reproduction and dispersal differ between narrow endemic plant species and their widespread congeners. We undertook pairwise contrasts of 25 ecological characteristics and biological traits in 20 congeneric pairs of narrow endemic and widespread plant species in the French Mediterranean region. Within each pair, the two species had the same life‐form, pollination mode and dispersal mode. Endemic species differed significantly from widespread congeners for a number of attributes. Endemic species occur in habitats on steeper slopes, with higher rock cover and in lower and more open vegetation than their widespread congeners. Endemic species are significantly smaller than widespread species, but show no differences in traits related to resource acquisition (specific leaf area, leaf nitrogen content, maximum photosynthetic rate) or resource conservation (leaf dry matter content). After accounting for their smaller stature, endemic species produce fewer and smaller flowers with less stigma‐anther separation and lower pollen/ovule ratios and produce fewer seeds per plant than their widespread congeners. No consistent variation in seed mass and propagule structure was found between congeneric species. Herbivory levels did not differ between congeneric species. Ecological characteristics, notably the occupation of rocky habitats with low aboveground competition, may thus have played an important role in the differentiation of narrow endemic species in the Western Mediterranean. Morphological and ecophysiological traits of narrow endemic species indicate that they are not more stress‐tolerant than their widespread congeners. Lower investment in pollen transfer and seed production suggest that local persistence is a key feature of the population ecology of narrow endemic species.
Grass‐to‐grass protection from grazing in a semi‐arid steppe. Facilitation, competition, and mass effect
Authors: Oesterheld Martín , Oyarzábal Mariano
Published: December 2004

Plants of low palatability often serve as biotic refuges from grazing to palatable plants. Evidence for this facilitation comes from cases where the interacting species have different life form, which may minimize competition. Protected plants act as remnant seed sources that may maintain the palatable populations locally viable through mass effects. Here, we assess (1) the spatial association between a highly palatable Patagonian grass (Bromus pictus) and less preferred tussock grasses, (2) the role played by seed sources in maintaining the population in the face of heavy grazing by sheep, and (3) the facilitative and competitive components of the interaction. We quantified B. pictus density and its distance to nearest tussocks inside and outside a grazing exclosure. We also considered different distances from the exclosure, both leeward and windward, because strong westerly winds may be critical for dispersal. Additionally, we quantified several attributes of protected and unprotected B. pictus plants with and without grazing. Density of B. pictus was about 20 times greater inside the exclosure than outside. However, this difference was less pronounced in the leeward vicinity of the exclosure than in the windward one, which suggests a mass effect. B. pictus was significantly associated to less palatable tussocks, and the association became stronger under grazing and as distance from the exclosure edge increased. Protection under grazing was associated with a significant increase in plant biomass, height, tiller number, and panicle number, whereas protection in the absence of grazing, which could evidence competition, resulted in reductions of tiller number and panicle number, and an increase of height. These results suggest that in areas under grazing pressure on palatable grasses, other less palatable grasses may provide a protection from grazing that outweighs competitive effects. Such protection may generate small‐scale mass effects that maintain the population at relatively high density.
Type 3 functional response of mice to gypsy moth pupae: is it stabilizing?
Authors: Schauber Eric M. , Ostfeld Richard S. , Jones Clive G.
Published: December 2004

We conducted field experiments in 2002 and 2003 to determine whether the functional response of white‐footed mice (Peromyscus leucopus) to gypsy moth (Lymantria dispar) pupae is decelerating (e.g. type 2) or accelerating (e.g. type 3) at low pupal density. In both experiments, live gypsy moth pupae were deployed in June (prior to the appearance of natural pupae) at densities of approximately 1, 8, and 35 pupae per mouse home range in oak‐forest grids in upstate New York and monitored over 10 days for signs of predation. Pupae were deployed 1.5‐m high on tree boles in 2002, whereas in 2003 the three density treatments were crossed with a height treatment: ground level vs 1.5‐m high. The relationship between daily predation rate (proportion of pupae eaten/day) and pupal density was significantly positive in both years, indicating an accelerating functional response. Daily predation rates on ground‐level pupae were substantial in the lowest density treatment, suggesting that dense mouse populations could drive gypsy moths to extinction despite an accelerating functional response. Daily predation rates on elevated pupae increased over several days in the medium and high density treatments, suggesting a lagged shift from ground‐ to tree‐level foraging by mice. Within the high‐density treatments, predation rates on pupae showed no apparent relationship with the number of pupae on a tree. Our results disagree qualitatively with simple models of type 3 functional response, in which predation rate of prey approaches zero as prey approach extinction, and support the contention that an accelerating functional response alone may be insufficient to prevent prey extinction.
Site‐Specific Updating and Aggregation of Bayesian Belief Network Models for Multiple Experts
Authors: Stiber Neil A. , Small Mitchell J. , Pantazidou Marina
Published: December 2004

A method for combining multiple expert opinions that are encoded in a Bayesian Belief Network (BBN) model is presented and applied to a problem involving the cleanup of hazardous chemicals at a site with contaminated groundwater. The method uses Bayes Rule to update each expert model with the observed evidence, then uses it again to compute posterior probability weights for each model. The weights reflect the consistency of each model with the observed evidence, allowing the aggregate model to be tailored to the particular conditions observed in the site‐specific application of the risk model. The Bayesian update is easy to implement, since the likelihood for the set of evidence (observations for selected nodes of the BBN model) is readily computed by sequential execution of the BBN model. The method is demonstrated using a simple pedagogical example and subsequently applied to a groundwater contamination problem using an expert‐knowledge BBN model. The BBN model in this application predicts the probability that reductive dechlorination of the contaminant trichlorethene (TCE) is occurring at a site—a critical step in the demonstration of the feasibility of monitored natural attenuation for site cleanup—given information on 14 measurable antecedent and descendant conditions. The predictions for the BBN models for 21 experts are weighted and aggregated using examples of hypothetical and actual site data. The method allows more weight for those expert models that are more reflective of the site conditions, and is shown to yield an aggregate prediction that differs from that of simple model averaging in a potentially significant manner.
Tiered Chemical Testing: A Value of Information Approach
Authors: Yokota Fumie , Gray George , Hammitt James K. , Thompson Kimberly M.
Published: December 2004

In December 2000 the EPA initiated the Voluntary Children's Chemical Evaluation Program (VCCEP) by asking manufacturers to voluntarily sponsor toxicological testing in a tiered process for 23 chemicals selected for the pilot phase. The tiered nature of the VCCEP pilot program creates the need for clearly defined criteria for determining when information is sufficient to assess the potential risks to children. This raises questions about how to determine the “adequacy” of the existing information and assess the need to undertake efforts to reduce uncertainty (through further testing). This article applies a value of information analysis approach to determine adequacy by modeling how toxicological and exposure data collected through the VCCEP may be used to inform risk management decisions. The analysis demonstrates the importance of information about the exposure level and control costs in making decisions regarding further toxicological testing. This article accounts for the cost of delaying control action and identifies the optimal testing strategy for a constrained decisionmaker who, absent applicable human data, cannot regulate without bioassay data on a specific chemical. It also quantifies the differences in optimal testing strategy for three decision criteria: maximizing societal net benefits, ensuring maximum exposure control while net benefits are positive (i.e., benefits outweigh costs), and controlling to the maximum extent technologically feasible while the lifetime risk of cancer exceeds a specific level of risk. Finally, this article shows the large differences that exist in net benefits between the three criteria for the range of exposure levels where the optimal actions differ.
MORM—A Petri Net Based Model for Assessing OH&S Risks in Industrial Processes: Modeling Qualitative Aspects
Authors: Vernez David , Buchs Didier R. , Pierrehumbert Guillaume E. , Besrour Adel
Published: December 2004

Because of the increase in workplace automation and the diversification of industrial processes, workplaces have become more and more complex. The classical approaches used to address workplace hazard concerns, such as checklists or sequence models, are, therefore, of limited use in such complex systems. Moreover, because of the multifaceted nature of workplaces, the use of single‐oriented methods, such as AEA (man oriented), FMEA (system oriented), or HAZOP (process oriented), is not satisfactory. The use of a dynamic modeling approach in order to allow multiple‐oriented analyses may constitute an alternative to overcome this limitation. The qualitative modeling aspects of the MORM (man‐machine occupational risk modeling) model are discussed in this article. The model, realized on an object‐oriented Petri net tool (CO‐OPN), has been developed to simulate and analyze industrial processes in an OH&S perspective. The industrial process is modeled as a set of interconnected subnets (state spaces), which describe its constitutive machines. Process‐related factors are introduced, in an explicit way, through machine interconnections and flow properties. While man‐machine interactions are modeled as triggering events for the state spaces of the machines, the CREAM cognitive behavior model is used in order to establish the relevant triggering events. In the CO‐OPN formalism, the model is expressed as a set of interconnected CO‐OPN objects defined over data types expressing the measure attached to the flow of entities transiting through the machines. Constraints on the measures assigned to these entities are used to determine the state changes in each machine. Interconnecting machines implies the composition of such flow and consequently the interconnection of the measure constraints. This is reflected by the construction of constraint enrichment hierarchies, which can be used for simulation and analysis optimization in a clear mathematical framework. The use of Petri nets to perform multiple‐oriented analysis opens perspectives in the field of industrial risk management. It may significantly reduce the duration of the assessment process. But, most of all, it opens perspectives in the field of risk comparisons and integrated risk management. Moreover, because of the generic nature of the model and tool used, the same concepts and patterns may be used to model a wide range of systems and application fields.
The Use of Risk Assessment to Decide the Control Strategy for Bluetongue in Italian Ruminant Populations
Authors: Giovannini Armando , MacDiarmid Stuart , Calistri Paolo , Conte Annamaria , Savini Lara , Nannini Donatella , Weber Steve
Published: December 2004

The affiliation. assessment and management of risks is a traditional part of veterinary medicine. In the past, veterinary services involved in this type of activity usually assessed risks qualitatively. However, since the 1990s, quantitative methods have become increasingly important. The establishment of the World Trade Organization in 1994, and the promulgation of its Agreement on the Application of Sanitary and Phytosanitary Measures (the “SPS Agreement”) led to an increased application of import risk analysis and to significant improvements in the methodology of risk analysis as applied to international trade policy for animals and animal products. However, there was very little development of risk analysis in veterinary fields other than international trade and management of health risks to consumers of animal products and little has been published on its use in the choice and definition of control or prophylaxis strategies for animal diseases. This article describes a quantitative risk assessment, which was undertaken in Italy to help choose an appropriate national response strategy following an incursion of bluetongue, an infectious disease of sheep and goats. The results obtained in this study support the use of risk analysis as a tool to assist in choosing an appropriate animal disease management strategy. The use of risk analysis in the evaluation of disease management strategies also offers advantages in international trade. It makes easier the comparison of different strategies applied in the various countries, and thus facilitates the assessment of equivalence of the guarantees provided by different strategies.
Role of the Standard Deviation in the Estimation of Benchmark Doses with Continuous Data
Authors: Gaylor David W. , Slikker William
Published: December 2004

For continuous data, risk is defined here as the proportion of animals with values above a large percentile, e.g., the 99th percentile or below the 1st percentile, for the distribution of values among control animals. It is known that reducing the standard deviation of measurements through improved experimental techniques will result in less stringent (higher) doses for the lower confidence limit on the benchmark dose that is estimated to produce a specified risk of animals with abnormal levels for a biological effect. Thus, a somewhat larger (less stringent) lower confidence limit is obtained that may be used as a point of departure for low‐dose risk assessment. It is shown in this article that it is important for the benchmark dose to be based primarily on the standard deviation among animals, sa, apart from the standard deviation of measurement errors, sm, within animals. If the benchmark dose is incorrectly based on the overall standard deviation among average values for animals, which includes measurement error variation, the benchmark dose will be overestimated and the risk will be underestimated. The bias increases as sm increases relative to sa. The bias is relatively small if sm is less than one‐third of sa, a condition achieved in most experimental designs.
The Diagnostic Criteria of Gianotti‐Crosti Syndrome: Are They Applicable to Children in India?
Authors: Chuh Antonio , Lee Albert , Zawar Vijay
Published: December 2004

Abstract:  In order to evaluate the applicability of the diagnostic criteria to children with Gianotti‐Crosti syndrome (GCS) in India we retrieved all clinical records of children with a definite diagnosis of this syndrome seen over 30 months in a private dermatology practice. The controls were children for whom Gianotti‐Crosti had been suspected but the final diagnosis was not this syndrome, and children in whom it was not suspected but who were diagnosed with any of the differential diagnoses of the syndrome. We documented the presence or absence of the positive and negative clinical features for all patients and controls. The clinical records of 23 children with GCS and 74 controls were retrieved. The three positive clinical features – 1) papules or papulovesicles 1–10 mm in diameter on at least three of the following four sites: cheeks, buttocks, extensor surfaces of the forearms, extensor surfaces of legs; 2) being symmetrical; 3) lasting for at least 10 days – were sensitive and positively correlated with GCS. Both negative clinical features – extensive truncal lesions and scaly lesions – are negatively correlated with this syndrome. All 23 children with GCS and none of the controls fulfilled the set of diagnostic criteria. We concluded that the Gianotti‐Crosti diagnostic criteria are applicable to affected children in India.
Infantile Acute Hemorrhagic Edema and Rotavirus Infection
Authors: Di Lernia Vito , Lombardi Mara , Lo Scocco Giovanni
Published: December 2004

Abstract:  Infantile acute hemorrhagic edema (AHE) is a benign condition characterized by a dramatic onset of inflammatory edema and ecchymotic purpura in a target or cockade pattern. It is considered an uncommon form of cutaneous vasculitis occurring in children younger than 2 years of age. The outbreak is frequently preceded by an immunization or various infections. We describe an 11‐month‐old girl with rosette‐shaped purpuric plaques on the face and limbs, clinically consistent with a diagnosis of AHE of the skin, associated with fever and diarrhea. Laboratory investigations showed a rotavirus infection, which has not previously been reported in association with AHE of the skin. The disease had a benign course without relapses. Appropriate microbiologic investigations are advisable to confirm the possible etiologic role of rotavirus.
Dermatitis Herpetiformis Presenting as Chronic Urticaria
Authors: Powell Gavin R. , Bruckner Anna L. , Weston William L.
Published: December 2004

Abstract:  Childhood dermatitis herpetiformis (DH) is an immunobullous disease associated with gluten‐sensitive enteropathy. This disease is rare in children and is typically characterized by intensely pruritic vesicles on the extensor surfaces. Definitive diagnosis of DH depends on the direct immunofluorescence finding of granular or fibrillar IgA deposits along the basement membrane zone of biopsied perilesional skin. We report an 11‐year‐old boy with an unusual presentation of DH characterized by a 7‐month history of chronic urticaria‐like skin lesions. He had evanescent, largely asymptomatic, urticarial wheals on his trunk, face, and extremities that were unresponsive to conventional therapy for urticaria. Skin biopsy specimen findings were consistent with DH and direct immunofluorescence of perilesional skin was diagnostic. The patient had no symptoms of gluten‐sensitive enteropathy at the time of diagnosis, and his skin lesions rapidly cleared with dapsone therapy. This patient serves to highlight an unusual presentation of childhood DH and the need to consider this diagnosis when evaluating chronic urticarial lesions in children.
Extensive Fixed Drug Eruption Secondary to Vancomycin
Authors: Gilmore Elaine S. , Friedman Jared S. , Morrell Dean S.
Published: December 2004

Abstract:  Fixed drug eruption is an infrequent but well‐known adverse event most commonly associated with antibiotics and nonsteroidal anti‐inflammatory medications. We herein describe a second reported instance of vancomycin‐induced fixed drug eruption involving an extensive area of the body surface.
Within‐canopy variation in the rate of development of photosynthetic capacity is proportional to integrated quantum flux density in temperate deciduous trees
Authors: NIINEMETS Ü. , KULL O. , TENHUNEN J. D.
Published: December 2004

The present study was undertaken to test for the hypothesis that the rate of development in the capacity for photosynthetic electron transport per unit area (Jmax;A), and maximum carboxylase activity of Rubisco (Vcmax;A) is proportional to average integrated daily quantum flux density (Qint) in a mixed deciduous forest dominated by the shade‐intolerant species Populus tremula L., and the shade‐tolerant species Tilia cordata Mill. We distinguished between the age‐dependent changes in net assimilation rates due to modifications in leaf dry mass per unit area (MA), foliar nitrogen content per unit dry mass (NM), and fractional partitioning of foliar nitrogen in the proteins of photosynthetic electron transport (FB), Rubisco (FR) and in light‐harvesting chlorophyll‐protein complexes (Vcmax;A ∝ MANMFR; Jmax;A ∝ MANMFB). In both species, increases in Jmax;A and Vcmax;A during leaf development were primarily determined by nitrogen allocation to growing leaves, increases in leaf nitrogen partitioning in photosynthetic machinery, and increases in MA. Canopy differences in the rate of development of leaf photosynthetic capacity were mainly controlled by the rate of change in MA. There was only small within‐canopy variation in the initial rate of biomass accumulation per unit Qint (slope of MA versus leaf age relationship per unit Qint), suggesting that canopy differences in the rate of development of Jmax;A and Vcmax;A are directly proportional to Qint. Nevertheless, MA, nitrogen, Jmax;A and Vcmax;A of mature leaves were not proportional to Qint because of a finite MA in leaves immediately after bud‐burst (light‐independent component of MA). MA, leaf chlorophyll contents and chlorophyll : N ratio of mature leaves were best correlated with the integrated average quantum flux density during leaf development, suggesting that foliar photosynthetic apparatus, once developed, is not affected by day‐to‐day fluctuations in Qint. However, for the upper canopy leaves of P. tremula and for the entire canopy of T. cordata, there was a continuous decline in N contents per unit dry mass in mature non‐senescent leaves on the order of 15–20% for a change of leaf age from 40 to 120 d, possibly manifesting nitrogen reallocation to bud formation. The decline in N contents led to similar decreases in leaf photosynthetic capacity and foliar chlorophyll contents. These data demonstrate that light‐dependent variation in the rate of developmental changes in MA determines canopy differences in photosynthetic capacity, whereas foliar photosynthetic apparatus is essentially constant in fully developed leaves.
Hydraulic limitations imposed by crown placement determine final size and shape of Quercus rubra L. leaves
Authors: ZWIENIECKI M. A. , BOYCE C. K. , HOLBROOK N. M.
Published: December 2004

The canopies of large broad‐leaf trees exhibit significant heterogeneity in both micro‐environmental conditions and leaf morphology. Whether the visible differences in the size and shape of leaves from the top and bottom of the crown are determined prior to bud break or result from different patterns of leaf expansion is not known. Analysis of ontogenetic changes of both the degree of lobing and vein density in Quercus rubra demonstrates that leaves throughout the crown are identical in size and shape at the time of bud break. Morphological adaptation to the local micro‐environment takes place during the expansion phase and starts after the determination of the vascular architecture has been completed. Leaves from the bottom of the crown undergo greater expansion in the tissue close to the main veins than occurs either in the more peripheral tissue of the same leaf or anywhere in leaves from the top of the crown. This results in a water transport system that is well suited to the low evaporative rates near the bottom of the crown, but inadequate for the conditions found at the top of the tree. Acclimation of leaf form and function based upon differential expansion may be entirely driven by the local hydraulic demand during the expansion phase, resulting in leaf size and vein density being determined during development by the same hydraulic properties which will constrain the size of leaf that can be functionally supported at maturity.
Complementation of notabilis, an abscisic acid‐deficient mutant of tomato: importance of sequence context and utility of partial complementation
Authors: THOMPSON A. J. , THORNE E. T. , BURBIDGE A. , JACKSON A. C. , SHARP R. E. , TAYLOR I. B.
Published: December 2004

The abscisic acid (ABA)‐deficient tomato mutant notabilis (not) is believed to be a null mutation in the gene LeNCED1, encoding a 9‐cis‐epoxycarotenoid dioxygenase involved in ABA biosynthesis. We have sequenced and analysed a 19 kb genomic clone containing LeNCED1 and 5.4 kb of its promoter. This clone was transferred to not homozygotes and several non‐wilty transformed plants were obtained. The basal ABA content, water relations, shoot and root growth, adventitious rooting, ethylene evolution and ability to accumulate ABA under water stress are described for two of these lines, notcomp.13 and notcomp.1. Partial complementation was observed for most parameters measured for notcomp.1. Full complementation was observed in notcomp.13 for all parameters measured in whole plants under well‐watered and water‐stressed conditions. These data provide further evidence that LeNCED1 is the wild‐type allele of the not mutant gene. However, notcomp.13 was unable to accumulate the wild‐type levels of ABA in rapidly dehydrated leaves, indicating that it too was only partially complemented. Since LeNCED1 is an environmentally regulated gene encoding a rate‐limiting enzyme, precise levels and patterns of gene expression may be needed to fully recreate wild‐type phenotype. The utility of partially complemented lines to study the role of ABA in plant responses to stress conditions, and in promoter analysis, is discussed.
Role of an endogenous nitric oxide burst in the resistance of wheat to stripe rust
Authors: GUO P. , CAO Y. , LI Z. , ZHAO B.
Published: December 2004

The stripe rust (or yellow rust) disease caused by Puccinia striiformis Westend is a serious disease of wheat in many areas of the world. The role of NO, which is an important redox‐active signalling molecule in plants, was investigated in the wheat‐stripe rust system. The phenotypes from interactions of the same wheat variety, Lovrin10, with two different clones of stripe rust strains (P. striiformis Westend), namely China yellow rust (CY)22‐2 and CY29‐1, which are immune and susceptible reaction types, respectively. The time course of host endogenous NO detected by electron spin resonance indicated that recognition of an avirulent strain was associated with two peaks of NO production. The first peak of NO accumulated in the early infection stage whereas the second peak accumulated in the latent period; however, only a single peak of NO was observed in the latent period for the virulent strain. Furthermore, the activity of pathogen‐related protein‐phenylalanine ammonia‐lyase was higher in the resistant system than in the susceptible system, which suggested that the first NO production was associated with resistance. Exogenous NO improved the activity of phenylalanine ammonia‐lyase and induced a resistant response of Lovrin10 to the virulent strain CY29‐1, thereby providing further evidence that the first peak of NO production was associated with resistance. These results indicate that the first NO burst in the immune system plays an important role in the resistant reaction of wheat to strip rust.
Pseudomonas syringae pv. maculicola in Australia: pathogenic, phenotypic and genetic diversity
Authors: Peters B. J. , Ash G. J. , Cother E. J. , Hailstones D. L. , Noble D. H. , Urwin N. A. R.
Published: December 2004

Pseudomonas syringae pv. maculicola causes bacterial leaf spot on cruciferous plants in Australia. This is the first record confirming the identity of seven isolates currently stored as P. syringae pv. maculicola in the herbarium of the Department of Agriculture, Orange, Australia (Herb. DAR). The isolates were identified using pathogenicity testing on cauliflower and fatty acid methyl ester analysis. They clustered together using repetitive sequence‐based polymerase chain reaction (rep‐PCR) and PCR‐restriction fragment‐length polymorphism (RFLP) of the 16S−23S internal transcribed spacer region (ITS) using seven restriction enzymes. Identification was confirmed by comparison of these isolates with known overseas isolates of P. syringae pv. maculicola, but there was significant variation in their pathogenicity and genetic structure.
Interval Estimation for Log-Linear Models with One Variable Subject to Non-Ignorable Non-Response
Authors: Clarke Paul S. , Smith Peter W. F.
Published: December 2004

Log-linear models for multiway contingency tables where one variable is subject to non-ignorable non-response will often yield boundary solutions, with the probability of non-respondents being classified in some cells of the table estimated as 0. The paper considers the effect of this non-standard behaviour on two methods of interval estimation based on the distribution of the maximum likelihood estimator. The first method relies on the estimator being approximately normally distributed with variance equal to the inverse of the information matrix. It is shown that the information matrix is singular for boundary solutions, but intervals can be calculated after a simple transformation. For the second method, based on the bootstrap, asymptotic results suggest that the coverage properties may be poor for boundary solutions. Both methods are compared with profile likelihood intervals in a simulation study based on data from the British General Election Panel Study. The results of this study indicate that all three methods perform poorly for a parameter of the non-response model, whereas they all perform well for a parameter of the margin model, irrespective of whether or not there is a boundary solution.
Estimating Functions in Indirect Inference
Authors: Heggland Knut , Frigessi Arnoldo
Published: December 2004

There are models for which the evaluation of the likelihood is infeasible in practice. For these models the Metropolis–Hastings acceptance probability cannot be easily computed. This is the case, for instance, when only departure times from a G/G/1 queue are observed and inference on the arrival and service distributions are required. Indirect inference is a method to estimate a parameter θ in models whose likelihood function does not have an analytical closed form, but from which random samples can be drawn for fixed values of θ. First an auxiliary model is chosen whose parameter β can be directly estimated. Next, the parameters in the auxiliary model are estimated for the original data, leading to an estimate β^. The parameter β is also estimated by using several sampled data sets, simulated from the original model for different values of the original parameter θ. Finally, the parameter θ which leads to the best match to β^ is chosen as the indirect inference estimate. We analyse which properties an auxiliary model should have to give satisfactory indirect inference. We look at the situation where the data are summarized in a vector statistic T, and the auxiliary model is chosen so that inference on β is drawn from T only. Under appropriate assumptions the asymptotic covariance matrix of the indirect estimators is proportional to the asymptotic covariance matrix of T and componentwise inversely proportional to the square of the derivative, with respect to θ, of the expected value of T. We discuss how these results can be used in selecting good estimating functions. We apply our findings to the queuing problem.
Bayesian Inference for Non-Gaussian Ornstein–Uhlenbeck Stochastic Volatility Processes
Authors: Roberts Gareth O. , Papaspiliopoulos Omiros , Dellaportas Petros
Published: December 2004

We develop Markov chain Monte Carlo methodology for Bayesian inference for non-Gaussian Ornstein–Uhlenbeck stochastic volatility processes. The approach introduced involves expressing the unobserved stochastic volatility process in terms of a suitable marked Poisson process. We introduce two specific classes of Metropolis–Hastings algorithms which correspond to different ways of jointly parameterizing the marked point process and the model parameters. The performance of the methods is investigated for different types of simulated data. The approach is extended to consider the case where the volatility process is expressed as a superposition of Ornstein–Uhlenbeck processes. We apply our methodology to the US dollar–Deutschmark exchange rate.
Identification of Non-Linear Additive Autoregressive Models
Authors: Huang Jianhua Z. , Yang Lijian
Published: December 2004

We propose a lag selection method for non-linear additive autoregressive models that is based on spline estimation and the Bayes information criterion. The additive structure of the autoregression function is used to overcome the ‘curse of dimensionality’, whereas the spline estimators effectively take into account such a structure in estimation. A stepwise procedure is suggested to implement the method proposed. A comprehensive Monte Carlo study demonstrates good performance of the method proposed and a substantial computational advantage over existing local-polynomial-based methods. Consistency of the lag selection method based on the Bayes information criterion is established under the assumption that the observations are from a stochastic process that is strictly stationary and strongly mixing, which provides the first theoretical result of this kind for spline smoothing of weakly dependent data.
Asymptomatic small bowel intussusception associated with post‐transplant lymphoproliferative disease
Authors: Barshes Neal R. , Lee Timothy C. , Karpen Saul J. , Bristow Lisa J. , Quiros‐Tejeira Rubin E. , Goss John A.
Published: December 2004

Abstract:  A 2‐yr‐old boy who had undergone orthotopic liver transplantation for biliary atresia 6 months prior presented with generalized lymphadenopathy. Physical exam revealed lymphadenopathy only; the patient had no gastrointestinal signs or symptoms. CT was used to evaluate the patient's lymphadenopathy. The findings were consistent with PTLD, and an incidental intussusception causing small bowel obstruction was found. The intussusception was successfully managed expectantly, and the patient's PTLD responded to administration of rituximab. The etiology, diagnosis and management of intussusception is discussed.