bluuebunny/crossref_metadata_2025 huggingface dataset:
Crossmodal links in spatial attention are mediated by supramodal control processes: Evidence from event‐related potentials
Authors: Eimer Martin , van Velzen José
Published: December 2004

Crossmodal links in spatial attention were studied in an experiment where participants had to detect peripheral tactile or visual targets on the attended side, while ignoring all stimuli on the unattended side and in the currently irrelevant modality. Both relevant locations and relevant modalities were specified on a trial‐by‐trial basis by auditory precues. Spatial orienting in the cue–target interval was reflected in anterior negativities and occipital positivities contralateral to the cued side, either when vision or touch was cued as relevant. These effects resembled previously reported ERP modulations during shifts of visual attention, implicating supramodal mechanisms in the control of spatial attention and demonstrating their independence of cue modality. Early effects of spatial attention on somatosensory and visual ERPs were of equivalent size for currently relevant and irrelevant modalities. Results support the idea that crossmodal links in spatial attention are mediated by supramodal control mechanisms.
Visual categorization during childhood: An ERP study
Authors: Batty M. , Taylor M.J.
Published: December 2004

Categorization is a basic means of organizing the world around us and offers a simple way to process the mass of stimuli one perceives every day. The ability to categorize appears early in infancy, and has important ramifications for the acquisition of other cognitive capacities, but little is known of its development during childhood. We studied 48 children (7–15 years of age) and 14 adults using an animal/nonanimal visual categorization task while event‐related potentials (ERPs) were recorded. Three components were measured: P1, N2, and P3. Behaviorally, the children performed the task very similarly to adults, although the children took longer to make categorization responses. Decreases in latencies (N2, P3) and amplitudes (P1, N2, P3) with age indicated that categorization processes continue to develop through childhood. P1 latency did not differ between the age groups. N2 latency, which is associated with stimulus categorization, reached adult levels at 9 years and P3 latency at 11 years of age. Age‐related amplitude decreases started after the maturational changes in latencies were finished.
Shifting hemodynamics of blood pressure control during prolonged mental stress
Authors: Ring Christopher , Burns Victoria E. , Carroll Douglas
Published: December 2004

The present study examined the hemodynamics underlying blood pressure elevations for evidence of a shift in the control of blood pressure during prolonged mental stress. Mean arterial pressure (MAP), cardiac output (CO), and total peripheral resistance (TPR) were measured at rest, during a 28‐min mental arithmetic stress task, and during recovery, in 30 young healthy men and women. The stress task elicited a sustained increase in MAP: CO rose during the first half of the task but returned to baseline levels during the last quarter of the task, whereas TPR increased as the task progressed. When participants' hemodynamic reactions were classified as cardiac, vascular, or neither, there were more cardiac reactors early relative to late in the task, whereas there were more vascular reactors late relative to early. Thus, the sustained pressor response was initially supported mainly by cardiac mechanisms but subsequently by predominantly vascular mechanisms.
Error rate on the antisaccade task: Heritability and developmental change in performance among preadolescent and late‐adolescent female twin youth
Authors: Malone Stephen M. , Iacono William G.
Published: December 2004

We examined heritability of error rate on the antisaccade task among female twin youths. This task appears to be sensitive to prefrontal functioning, providing a measure of individual differences in inhibitory control associated with genetic risk for schizophrenia. The sample consisted of 674 11‐year‐olds and 616 17‐year‐olds, comprising the two cohorts of female twins from the Minnesota Twin Family Study, a population‐based investigation of substance abuse and related psychopathology. We used biometric model‐fitting methods to determine the relative magnitude of genetic and environmental influences on performance. In both age cohorts, the best fitting model contained additive genes and nonshared environment. Despite substantial age‐related differences in mean performance levels (effect size = .81), additive genes accounted for greater than half the variance in performance in both age cohorts. These results are consistent with the hypothesis that antisaccade error rate might serve as an endophenotype for behavior disorders reflecting frontal lobe dysfunction or problems with inhibitory control.
Influence of a monetary incentive upon attentional modification of short‐lead prepulse inhibition and long‐lead prepulse facilitation of acoustic startle
Authors: Hawk Larry W. , Redford Joshua S. , Baschnagel Joseph S.
Published: December 2004

Short‐lead prepulse inhibition and long‐lead prepulse facilitation of startle are greater during attended than ignored prestimuli. The present work examined whether this attentional modification is influenced by monetary incentive. Participants (43 college students) were randomly assigned to receive a small performance‐based monetary incentive or were instructed to try their best. The task was to judge the duration of tones of one of two pitches during a series of 48 tones. Prepulse inhibition of startle eyeblink EMG was assessed at 60, 120, and 240 ms, and prepulse facilitation was assessed at 4,500 ms following tone onset. Short‐lead percent prepulse inhibition was greater during attended than ignored prestimuli only at 120 ms among paid participants. Long‐lead prepulse facilitation was greater for attended than ignored tones, but this effect did not vary with incentive condition. This study demonstrates that attentional modification of short‐lead prepulse inhibition is sensitive to a monetary incentive and provides a basis for further examination of motivational effects on early attentional processing.
Intermodal spatial attention differs between vision and audition: An event‐related potential analysis
Authors: Talsma Durk , Kok Albert
Published: December 2004

Subjects were required to attend to a combination of stimulus modality (vision or audition) and location (left or right). Intermodal attention was measured by comparing event‐related potentials (ERPs) to visual and auditory stimuli when the modality was relevant or irrelevant, while intramodal (spatial) attention was measured by comparing ERPs to visual and auditory stimuli presented at relevant and irrelevant spatial locations. Intramodal spatial attention was expressed differently in visual and auditory ERPs. When vision was relevant, spatial attention showed a contralateral enhancement of posterior N1 and P2 components and enhancement of parietal P3. When audition was relevant, spatial attention showed a biphasic fronto‐central negativity, starting after around 100 ms. The same effects were also present in ERPs to stimuli that were presented in the irrelevant modality. Thus, spatial attention was not completely modality specific. Intermodal attention effects were also expressed differently in vision and audition. Taken together, the obtained ERP patterns of the present study show that stimulus attributes such as modality and location are processed differently in vision and audition.
Reliability analysis of event‐related brain potentials to olfactory stimuli
Authors: Thesen Thomas , Murphy Claire
Published: December 2004

Olfactory event‐related potentials (OERP) have been used to investigate olfactory processing in health and disease. However, the reliability of the OERP has yet to be established statistically. The present study examined test–retest reliability of the OERP over a 4‐week interval. EEG was recorded from Fz, Cz, and Pz, using a single‐stimulus paradigm with amyl acetate. Reliabilities for ERP component latencies and interpeak amplitudes were assessed as intraclass and Pearson product‐moment correlation coefficients. Reliabilities were higher for latency than for amplitude. Highest correlation coefficients were observed for P2 latency, specifically at Cz and Pz P3 amplitude and latency exhibited high reliability at Cz and Pz. Fz demonstrated weakest correlation coefficients. The data suggest that OERP reliability is comparable to that of auditory and visual ERPs, supporting the use of OERPs in both basic research and clinical assessment.
Competitiveness and hemodynamic reactions to competition
Authors: Veldhuijzen Van Zanten Jet J.C.S. , de Boer Dolf , Harrison Lesley K. , Ring Christopher , Carroll Douglas , Willemsen Gonneke , de Geus Eco J.C.
Published: December 2004

This study examines the effects of competition and competitiveness on hemodynamics. Cardiovascular activity was measured in 27 men at resting baseline and during a car racing game, which comprised a solo race against time and three races against an experimenter. To assess hematocrit, blood was collected at rest and after the final race. Trait competitiveness was assessed by questionnaire. Competition elicited increases in hematocrit, blood pressure, heart rate, and total peripheral resistance, as well as decreases in preejection period and heart rate variability. The final race was rated as more competitive than the solo race. Compared to intrapersonal solo racing, the final interpersonal race was associated with shorter preejection periods and faster heart rates, markers of beta‐adrenergic activation. Although trait competitiveness was not associated with beta‐adrenergic activation, variations in state competitiveness were.
Neural synchronization mediates on‐line sentence processing: EEG coherence evidence from filler‐gap constructions
Authors: Haarmann Henk J. , Cameron Katherine A. , Ruchkin Daniel S.
Published: December 2004

This study investigated cognitive and neural processes involved in gap filling during on‐line sentence comprehension. Electroencephalogram (EEG) coherences were used to demonstrate that increases in the synchronization of neural activity in different cortical regions occur during gap filling when load in semantic working memory is high due to semantically unrelated words in the filler‐gap interval. Sentences could either require gap filling at a verb or not, and the nouns preceding the verb could be either semantically related or unrelated. In the unrelated but not related condition, coherences in the beta band were larger during verb processing for sentences requiring gap filling compared to sentences not requiring gap filling. The coherence changes involved linkages between frontal and posterior temporal‐parietal sites in both hemispheres. These results further indicate that semantic working memory is involved in the process of gap filling.
The relationship of adult attachment dimensions to depression and agoraphobia
Authors: Strodl Esben , Noller Patricia
Published: December 2004

We examined the unique relations between the five dimensions of the Attachment Style Questionnaire (ASQ; Feeney, Noller, & Hanrahan, 1994) and depression and agoraphobic behavior (i.e., avoidance of situations where high anxiety is experienced). In addition, we examined mediation models in an attempt to clarify the link between adult attachment and these two dimensions of psychopathology. In testing these models, we administered the ASQ, General Self‐Efficacy Scale, Agoraphobic Catastrophic Cognitions Questionnaire, Beck Depression Inventory, and the Mobility Inventory for Agoraphobia (a measure of the degree to which situations are avoided that are typically anxiety provoking for people with agoraphobia) to 122 participants (44 with agoraphobia, 25 with a current major depressive disorder, and 53 with no current psychopathology). The results showed that the insecure attachment dimensions of need for approval, preoccupation with relationships, and relationships as secondary were uniquely associated with depression and that general self‐efficacy partly mediated the relationship between need for approval and depression. In contrast, only preoccupation with relationships was uniquely associated with agoraphobic behavior, and catastrophic cognitions about bodily sensations partly mediated this association.
‘Historia praestat omnibus disciplinis’: Juan Luis Vives on history and historical study
Authors: Bejczy István
Published: December 2004

Juan Luis Vives (1492–1540) is justly celebrated as a philosopher of education, language, and psychology. Unfortunately, posterity has largely overlooked Vives's historical thought. Notably in De disciplinis (1531), the most comprehensive of his writings, Vives unfolds a remarkable view of the meaning of the past which runs through his work like a continuous thread, giving a historical dimension to his ideas on culture and education. This article aims to demonstrate the importance of Vives as a historical theorist, examining his discussion of the nature of history in De disciplinis, his idea of progress, and his views on the study of history. In particular two diverging accounts of the origins of learning emerge, which have philosophical implications, as well as a number of important restrictions on the study of history. Comparison of his views with those of contemporary humanists, notably Erasmus, brings out clearly Vives's originality in this field. (pp. 69–83)
Paduan culture in Venetian care: the patronage of Bishop Pietro Donato (Padua 1428–47)
Authors: Holgate Ian
Published: December 2004

The paper discusses the cultural patronage of the Venetian Pietro Donato, bishop of Padua, concentrating particularly upon his work at Padua's duomo and Studium. Donato presents a useful example of a prolific patron of the arts in a period which currently lacks documented case studies; his artistic commissions bridge the gap between the fall of the Carrara dynasty in 1405 and the flourishing Paduan art market which emerged in the late 1440s. The Council of Basel is identified as having played a key role in the formation of Paduan culture from the early 1430s. Throughout his Paduan office, the bishop's cultural patronage took account of his roles as both father of the Paduan Church and representative of the Venetian authorities. The paper argues that, in both guises, his actions were consistently and strategically defined in relation to the patronage of the previous Carrara rulers in order to address the vacuum left by their sudden fall from power and to nullify their political significance.
Evaluating Citizen Advisory Boards: The Importance of Theory and Participant‐Based Criteria and Practical Implications
Authors: Santos Susan L. , Chess Caron
Published: December 2004

The role of risk communication and public participation in environmental and public policy decision making has significantly increased over the last 15 years and remains an important social policy issue. In spite of this emphasis, government officials and participants in the process continue to struggle with what makes for “good” public participation. This study used two frameworks—one theoretical and one participant‐based—to evaluate two U.S. Army Restoration Advisory Boards (RABs). The theoretical framework explores the extent to which the RABs facilitate Habermas's idealized conditions of speech as related to fairness. Not surprisingly, we found that the two RABs do not consistently foster the idealized aspects of fairness suggested by Habermas. The participant‐based criteria were elicited through interviews with participants from the various stakeholder groups represented on the RAB, direct observation of RAB meetings, and a review of RAB‐related documents. We found that participants' value outcomes (the results of participatory processes) and not just the process itself, which is the focus of the theoretical framework. We also found that participants in the various stakeholder groups had different perceptions of the goals of the participatory process, which were closely related to their notions of success. Our results illustrate both the complexity and importance of using multiple frameworks for evaluating participatory efforts and the need for more systematic evaluation.
The Function of Credibility in Information Processing for Risk Perception
Authors: Trumbo Craig W. , McComas Katherine A.
Published: December 2004

This study examines how credibility affects the way people process information and how they subsequently perceive risk. Three conceptual areas are brought together in this analysis: the psychometric model of risk perception, Eagly and Chaiken's heuristic‐systematic information processing model, and Meyer's credibility index. Data come from a study of risk communication in the circumstance of state health department investigations of suspected cancer clusters (five cases, N= 696). Credibility is assessed for three information sources: state health departments, citizen groups, and industries involved in each case. Higher credibility for industry and the state directly predicts lower risk perception, whereas high credibility for citizen groups predicts greater risk perception. A path model shows that perceiving high credibility for industry and state—and perceiving low credibility for citizen groups—promotes heuristic processing, which in turn is a strong predictor of lower risk perception. Alternately, perceiving industry and the state to have low credibility also promotes greater systematic processing, which consistently leads to perception of greater risk. Between a one‐fifth and one‐third of the effect of credibility on risk perception is shown to be indirectly transmitted through information processing.
Perceptions of Recreational Fishing Boat Captains: Knowledge and Effects of Fish Consumption Advisories
Authors: Burger J. , Johnson B. B. , Shukla S. , Gochfeld M.
Published: December 2004

The impacts of fish consumption advisories on recreational and subsistence fishing, particularly in fresh waters, have been examined extensively. By contrast, little attention has focused on organized recreational fishing, such as from party and charter boats, and particularly for salt water fish. We interviewed 93 New Jersey boat captains to determine their knowledge about fish consumption advisories, and whether, in their opinion, clients knew of fish consumption advisories, and whether they thought advisories had an effect on recreational fishing and their businesses. Advisories were ranked by captains as a moderate influence on the success of their business, less so than number of fish caught, strength of the economy, overfishing by commercial boats, and management regulations. Only one boat captain had not heard warnings about eating fish, but what captains said they had heard was mixed in its accuracy and completeness. Clients expect captains to know about fish, and about half of boat captains said clients had asked about the safety of eating fish. Captains who felt advisories were affecting their businesses tended to fish for species without high levels of mercury (except for bluefish) or PCBs, the primary contaminants of concern for state advisories and federal advice. However, these captains worked closer to areas (e.g., Raritan Bay complex and New York Harbor) subject to advisories than did other captains, and were more prone to say that management regulations (e.g., fish size, creel limits, seasons) and marketing and advertising by the industry or state were strong influences on the success of their seasons. Comparing captains who thought advisories had some or great effect (60%) versus those reporting “no effect” (40%), there was no difference in the mean percentage of trips targeting high mercury species such as swordfish and shark. Many captains said they would or might post advisories, but 42% of the boat captains said they would not post consumption warnings if the state provided them. The significant portion (at least 15%) of saltwater fishing supported by these businesses suggests that these captains are an important conduit for future risk communication.
The True Cost of Precautionary Chemicals Regulation
Authors: Durodié Bill
Published: December 2004

This article explores the possible social costs of introducing an overly precautionary regulatory regime for chemicals. It begins by examining research by the UK Medical Research Council Institute for Environment and Health (MRC‐IEH), which suggests that the resource implications of the proposals contained in the European Commission White Paper “Strategy for a Future Chemicals Policy”(1) are unrealistic and even unrealizable. The article then focuses on contemporary debates pertaining to endocrine disrupting chemicals (EDCs) and goes on to question whether a “right to know” is always necessarily a good thing, or whether in certain instances it can lead to a society that feels more sorry than safe.(2) Finally, problems relating to the representation and inclusion of public values in decision‐making processes are raised prior to concluding with a call for an ambitious orientation toward social change rather than a self‐limiting obsession with safety.
Reappraising Institutional Contributions to the Efficiency of Environmental Policy
Authors: Welch Eric W.
Published: December 2004

Books reviewed in this article:

Lawrence S. Rothenberg, Environmental Choices: Policy Responses to Green Demands

David M. Driesen, The Economic Dynamics of Environmental Law
Constructing the Electorate during Presidential Campaigns
Authors: Hart Roderick P. , Johnson Mary C.
Published: December 2004

This study examines how the American electorate has been described by political campaigners between 1948 and 1996. Using a database of some five hundred speeches given on the stump or during national political broadcasts, the authors isolated 898 uses of the phrase “the American people.” By examining these phrases for descriptions of the roles, actions, qualities, and circumstances of the people, and by noting their time orientation and the forces aligned against the electorate, the authors present a picture of the people as described. Generally speaking, the people live in the moment, focus on cognitive and axiological matters, serve as agents of the state, and have an equal number of moral, intellectual, and psychological strengths. The texts also show that the people are bedeviled by government itself, but a number of factors—party, era, incumbency, campaign cycle, and so forth—affect the tenor of those characterizations.
Reciprocating dispersal by habitat‐selecting white‐footed mice
Authors: Morris Douglas W. , Diffendorfer James E.
Published: December 2004

Theories of dispersal driven by density‐dependent habitat selection demonstrate that putative examples of source–sink dynamics and balanced dispersal may also be explained by a more general pattern of bi‐directional, reciprocating dispersal. Analyses of 19 years of data on dispersal by white‐footed mice confirm the theory. Fitness of territorial white‐footed mice living in an agricultural mosaic is higher in forest habitat than it is in either edge or fencerows. Density‐dependent habitat selection theory predicts that if net emigration by mice flows from the forest to forest‐edge during periods of population growth, animals should subsequently move from the edge to forest during population decline. The pattern of mouse dispersal varies between seasons as populations wax and wane in abundance. Mice tend, as predicted, to move from high‐density forest habitat into low‐density edge during periods of population increase, and from the low‐density edge into high‐density forest during periods of population decline. Over all years combined, dispersal by white‐footed mice was balanced. Each habitat tended to gain as many dispersing individuals as it lost. The results support a conditional dispersal strategy linked to density‐dependent habitat selection, but also suggest the possibility of multiple coexisting strategies.
Dwarf palms and cyclanths strongly reduce Neotropical seedling recruitment
Authors: (Ophelia) Wang Yung‐Ho , Augspurger Carol
Published: December 2004

Recruitment limitation, which occurs when species either fail to reach regeneration sites or the number of suitable regeneration sites is limited, has been proposed as an important factor that controls population dynamics and species coexistence in tropical moist forests. Dwarf palms in some Neotropical forests dominate the understory strata, and their umbrella‐like architecture may intensify understory shade and make the site less suitable for seedling regeneration. In this study we surveyed seedlings under dwarf palms in four habitats at La Selva Biological Station, Costa Rica. We compared seedling recruitment in both 2001 and 2002 at non‐palm microsites vs microsites under 1) tall dwarf palms, 2) short dwarf palms, and 3) short palms surrounded by dwarf palms. Light environments at non‐palm and under‐palm sites were quantified with hemispherical photos. Seedling growth, survivorship, density, and species richness all differed significantly among microsites, and were all greatest at non‐palm sites and lowest at dense palm sites. Overall, seedling growth, survivorship, density, and species richness were 30%, 50%, 50%, and 40%, respectively, less at under‐palm than at non‐palm sites. The main restriction by dwarf palms occurred on post‐cotyledonous and woody seedlings. Percent canopy openness differed among microsites, and was greatest at non‐palm sites and lowest at dense palm sites. However, seedling responses were only weakly correlated with percent canopy openness. These results revealed significant reduction in seedling recruitment under individual dwarf palms, with greatest negative effects where a palm was surrounded by palms. Dwarf palms occur at high density (2611 individuals/ha) and cover 21% of the understory in the four habitats (alluvium, residual flat area, residual slope area, swamp) of the primary forest. Therefore, this negative impact by individual dwarf palms is significant at the landscape scale as well, based on the great dwarf palm density and coverage in the four habitats.
Acceptance Sampling Based on Truncated Life Tests in the Birnbaum Saunders Model
Authors: Baklizi Ayman , El Masri Abed El Qader
Published: December 2004

We develop acceptance sampling plans assuming that the life test is truncated at a preassigned time. The lifetimes of the test units are assumed to follow the Birnbaum Saunders distribution. The minimum sample size necessary to ensure the specified average life is obtained and the operating characteristic values of the sampling plans and producer's risk are presented. An illustrative example is given.
Trust, the Asymmetry Principle, and the Role of Prior Beliefs
Authors: Poortinga Wouter , Pidgeon Nick F.
Published: December 2004

Within the risk literature there is an ongoing debate on whether trust is vulnerable or enduring. Previous research on nuclear energy by Slovic in 1993 has shown that negative events have much greater impact on self‐reported trust than do positive events. Slovic attributes this to the asymmetry principle: specifically, that trust is much easier to destroy than to create. In a questionnaire survey concerning genetically modified (GM) food in Britain (n= 396) we similarly find that negative events have a greater impact on trust than positive events. Because public opinion in Britain is skewed in the direction of opposition toward GM food, the pattern of results could either be caused by the fact that negative information is more informative than positive information (a negativity bias) or reflect the influence of people's prior attitudes toward the issue (a confirmatory bias). The results were largely in line with the confirmatory bias hypothesis: participants with clear positive or negative beliefs interpreted events in line with their existing attitude position. However, for participants with intermediate attitudes, negative items still had greater impact than the positive. This latter finding suggests that, congruent with the negativity bias hypothesis, negative information may still be more informative than positive information for undecided people. The study also identified the labeling of GM products, consulting the public, making biotechnology companies liable for any damage, and making a test available to detect GM produce as being particularly important preconditions for maintaining trust in the regulation of agricultural biotechnology.
Characterizing Environmental Harm: Developments in an Approach to Strategic Risk Assessment and Risk Management
Authors: Pollard Simon J. T. , Kemp Ray V. , Crawford Mark , Duarte‐Davidson Raquel , Irwin James G. , Yearsley Roger
Published: December 2004

Environmental policymakers and regulators are often in the position of having to prioritize their actions across a diverse range of environmental pressures to secure environmental protection and improvements. Information on environmental issues to inform this type of strategic analysis can be disparate; it may be too voluminous or even absent. Data on a range of issues are rarely presented in a common format that allows easy analysis and comparison. Nevertheless, judgments are required on the significance of various environmental pressures and on the inherent uncertainties to inform strategic assessments such as “state of the environment” reports. How can decisionmakers go about this type of strategic and comparative risk analysis? In an attempt to provide practical tools for the analysis of environmental risks at a strategic level, the Environment Agency of England and Wales has conducted a program of developmental research on strategic risk assessment since 1996. The tools developed under this program use the concept of “environmental harm” as a common metric, viewed from technical, social, and economic perspectives, to analyze impacts from a range of environmental pressures. Critical to an informed debate on the relative importance of these perspectives is an understanding and analysis of the various characteristics of harm (spatial and temporal extent, reversibility, latency, etc.) and of the social response to actual or potential environmental harm from a range of hazards. Recent developments in our approach, described herein, allow a presentation of the analysis in a structured fashion so as to better inform risk‐management decisions.
Examining Localized Patterns of Air Quality Perception in Texas: A Spatial and Statistical Analysis
Authors: Brody Samuel D. , Peck B. Mitchell , Highfield Wesley E.
Published: December 2004

Environmental and human health issues associated with outdoor air pollution, such as ozone, sulfur dioxide, and other pollutants in metropolitan regions, are an area of growing concern for both policy officials and the general public. Increasing attention from the news media, new health data, and public debate over the effectiveness of clean air regulations have raised the importance of air quality in the public consciousness. While public perceptions of air quality have been studied thoroughly dating back to the 1960s, little empirical research has been conducted to explain the spatial aspects of these perceptions, particularly at the local level. Although recent studies suggest characteristics of local setting are important in shaping perceptions of air quality, the roles of proximity, neighborhood characteristics, and location have not been clarified. This study seeks to improve understanding of the major factors shaping public perceptions of air quality by examining the spatial pattern of local risk perception, the role of socioeconomic characteristics in forming these perceptions, and the relationship between perceived and scientifically measured air pollution. First, we map the spatial pattern of local air quality perceptions using Geographic Information Systems (GIS) across the Dallas and Houston metropolitan areas. Next, we explain these perceptions through local contextual factors using both bivariate correlations and multivariate regression analysis. Results indicate that perceptions of air quality in the study areas are not significantly correlated with air quality based on readings of air monitoring stations. Instead, perceptions appear to be influenced by setting (urban vs. rural), state identification, access to information, and socioeconomic characteristics such as age, race, and political identification. We discuss the implications of the findings and provide direction on how further research can provide a deeper understanding of the local contextual factors influencing public perceptions.
Framework for Evaluation of Physiologically‐Based Pharmacokinetic Models for Use in Safety or Risk Assessment
Authors: Clark Leona H. , Woodrow Setzer R. , Barton Hugh A.
Published: December 2004

Proposed applications of increasingly sophisticated biologically‐based computational models, such as physiologically‐based pharmacokinetic models, raise the issue of how to evaluate whether the models are adequate for proposed uses, including safety or risk assessment. A six‐step process for model evaluation is described. It relies on multidisciplinary expertise to address the biological, toxicological, mathematical, statistical, and risk assessment aspects of the modeling and its application. The first step is to have a clear definition of the purpose(s) of the model in the particular assessment; this provides critical perspectives on all subsequent steps. The second step is to evaluate the biological characterization described by the model structure based on the intended uses of the model and available information on the compound being modeled or related compounds. The next two steps review the mathematical equations used to describe the biology and their implementation in an appropriate computer program. At this point, the values selected for the model parameters (i.e., model calibration) must be evaluated. Thus, the fifth step is a combination of evaluating the model parameterization and calibration against data and evaluating the uncertainty in the model outputs. The final step is to evaluate specialized analyses that were done using the model, such as modeling of population distributions of parameters leading to population estimates for model outcomes or inclusion of early pharmacodynamic events. The process also helps to define the kinds of documentation that would be needed for a model to facilitate its evaluation and implementation.
Transient Myeloproliferative Disorder Causing a Vesiculopustular Eruption in a Phenotypically Normal Neonate
Authors: Solky Benjamin A. , Yang F. Clarissa , Xu Xiaowei , Levins Paul
Published: December 2004

Abstract:  We report an unusual congenital vesiculopustular eruption arising in a neonate as the result of the transient myeloproliferative disorder (TMD) associated with trisomy 21. In this instance, the neonate was phenotypically normal, making the diagnosis more elusive. Initially the lesions were clinically suspicious for herpetic infection. The clinical scenario quickly became highly suggestive of leukemia cutis, given the infant's extremely high white blood cell count. Further examination revealed trisomy 21 in the leukemic cells and disomy 21 in the buccal keratinocytes, and a diagnosis of self‐resolving TMD was made. Biopsy specimens of the lesions showed a sparse, perivascular, atypical, mononuclear infiltrate. We suggest that examination for a TMD be undertaken in neonates with a vesiculopustular eruption and leukemic white blood cell counts.
Mutation in the ED1 Gene, Ala349Thr, in a Korean Patient with X‐Linked Hypohidrotic Ectodermal Dysplasia Developing de novo
Authors: Na Gun Yoen , Kim Do Won , Lee Seok Jong , Chung Sang Lip , Park Dong Jae , Kim Jung Chul , Kim Moon Kyu
Published: December 2004

Abstract:  Hypohidrotic ectodermal dysplasia (HED) is a very rare disease characterized by the virtual absence of eccrine glands, dry skin, scanty hair, and dental abnormalities. It is transmitted by an X‐linked recessive gene or rarely an autosomal recessive gene. Therefore it is only males who fully express the condition. It is caused by mutations within the ED1 gene, which encodes a protein, ectodysplasin‐A (EDA). Typically there is frontal bossing, saddle nose, pointed chin, a prominent supraorbital ridge with periorbital hyperpigmentation, and absence of teeth. Those affected show great intolerance to heat. In the current absence of effective treatment for many hereditary skin diseases, comprehensive, accurate prenatal or postnatal genetic counseling can provide information to parents at risk of having affected children. We report HED in a 6‐year‐old boy with an Ala349Thr (GCA → ACA) missense mutation developed de novo. Both parents and a 16‐week gestational age fetus were healthy. We thought direct sequencing analysis for the ED1 gene using peripheral blood or amniotic fluid was preferable for an accurate diagnosis of this disease, although there was some risk of not detecting the mutation. After the results of this study were communicated to the parents, the mother was freed of her guilty feelings of the past 6 years and has now delivered a healthy male infant.
The Harlequin Color Change and Association with Prostaglandin E1
Authors: Rao Jaggi , Campbell Morag E. , Krol Alfons
Published: December 2004

Abstract:  The harlequin color change is an unusual cutaneous phenomenon observed in newborn infants as transient, benign episodes of a sharply demarcated erythema on half of the infant, with simultaneous contralateral blanching. In this report, two newborns with congenital heart anomalies demonstrated the harlequin color change, one whose skin findings showed a course related to the dose of systemic prostaglandin E1, suggesting a possible association. The benign, self‐limited nature of the color change mandates that prostaglandin E1 not be discontinued for this reason. The entity is likely more common than the paucity of reports in the world literature suggests, and all physicians should recognize its graphic appearance to avoid unnecessary exposure to agents in an effort to treat it.
Reversible Neurotoxicity after an Overdose of Topical Lindane in an Infant
Authors: Bhalla Mala , Thami Gurvinder P.
Published: December 2004

Abstract:  Lindane (gamma benzene hexachloride) is a widely prescribed topical scabicide because of its efficacy and cost‐effectiveness. Although toxicity from a single proper application of lindane is generally not observed, the hazards of repeated applications, industrial exposure, and accidental ingestion have been well documented. We herein describe an infant with reversible neurotoxicity following repeated applications of 1% lindane for the treatment of scabies. The role of factors predisposing to increased absorption and the recommendations to minimize potential neurotoxicity are emphasized.
Photosynthetic pathway alters xylem structure and hydraulic function in herbaceous plants
Authors: KOCACINAR F. , SAGE R. F.
Published: December 2004

Plants using the C4 photosynthetic pathway have greater water use efficiency (WUE) than C3 plants of similar ecological function. Consequently, for equivalent rates of photosynthesis in identical climates, C4 plants do not need to acquire and transport as much water as C3 species. Because the structure of xylem tissue reflects hydraulic demand by the leaf canopy, a reduction in water transport requirements due to C4 photosynthesis should affect the evolution of xylem characteristics in C4 plants. In a comparison of stem hydraulic conductivity and vascular anatomy between eight C3 and eight C4 herbaceous species, C4 plants had lower hydraulic conductivity per unit leaf area (KL) than C3 species of similar life form. When averages from all the species were pooled together, the mean KL for the C4 species was 1.60 × 10−4 kg m−1 s−1 MPa−1, which was only one‐third of the mean KL of 4.65 × 10−4 kg m−1 s−1 MPa−1 determined for the C3 species. The differences in KL between C3 and C4 species corresponded to the two‐ to three‐fold differences in WUE observed between C3 and C4 plants. In the C4 species from arid regions, the difference in KL was associated with a lower hydraulic conductivity per xylem area, smaller and shorter vessels, and less vulnerable xylem to cavitation, indicating the C4 species had evolved safer xylem than the C3 species. In the plants from resource‐rich areas, such as the C4 weed Amaranthus retroflexus, hydraulic conductivity per xylem area and xylem anatomy were similar to that of the C3 species, but the C4 plants had greater leaf area per xylem area. The results indicate the WUE advantage of C4 photosynthesis allows for greater flexibility in hydraulic design and potential fitness. In resource‐rich environments in which competition is high, an existing hydraulic design can support greater leaf area, allowing for higher carbon gain, growth and competitive potential. In arid regions, C4 plants evolved safer xylem, which can increase survival and performance during drought events.
Chemosensory behavioural response of freshwater phytoplanktonic flagellates
Authors: CLEGG M. R. , MABERLY S. C. , JONES R. I.
Published: December 2004

Unlike behavioural responses to physical gradients, active responses to chemical gradients, and their physiological and ecological implications, have rarely been studied in freshwater phytoplanktonic flagellates. This study used microscale preference chambers to investigate the population and individual cell responses of five species exposed to four chemical gradients which commonly develop with depth in lakes: phosphate, oxygen, carbon dioxide and pH. Upon exposure of nutrient‐replete and ‐depleted cells to a phosphate gradient, only nutrient‐depleted cells of the autotrophic Chlamydomonas moewusii responded, accumulating at high concentrations. In contrast, all species responded to an oxygen gradient with Ceratium furcoides, Chlamydomonas moewusii, Dinobryon sertularia and Plagioselmis nannoplanctica preferring high concentrations whereas Euglena gracilis preferred low concentrations. In addition, all species displayed a strong affinity for carbon dioxide which was not mediated by detecting pH. Analysis of the swimming trajectories of individual cells showed that directed chemotaxes, rather than speed‐dependent chemokineses, were responsible for the observed preferences. These complex and diverse species‐dependent chemosensory responses may optimize photosynthesis, facilitate nutrient retrieval during migration, increase growth rate and may influence spatial and temporal distribution, contributing to the delineation of niche separation in phytoplanktonic flagellates.
Scaling phloem transport: information transmission
Authors: THOMPSON M. V. , HOLBROOK N. M.
Published: December 2004

Sieve tubes are primarily responsible for the movement of solutes over long distances, but they also conduct information about the osmotic state of the system. Using a previously developed dimensionless model of phloem transport, the mechanism behind the sieve tube's capacity to rapidly transmit pressure/concentration waves in response to local changes in either membrane solute exchange or the magnitude and axial gradient of apoplastic water potential is demonstrated. These wave fronts can move several orders of magnitude faster than the solution itself when the sieve tube's axial pressure drop is relatively small. Unlike the axial concentration drop, the axial pressure drop at steady state is independent of the apoplastic water potential gradient. As such, the regulation of whole‐sieve tube turgor could play a vital role in controlling membrane solute exchange throughout the translocation pathway, making turgor a reliable source of information for communicating change in system state.
Impact of rising CO2 on emissions of volatile organic compounds: isoprene emission from Phragmites australis growing at elevated CO2 in a natural carbon dioxide spring†
Authors: SCHOLEFIELD P. A. , DOICK K. J. , HERBERT B. M. J. , HEWITT C. N. S , SCHNITZLER J.‐P. , PINELLI P. , LORETO F.
Published: December 2004

Isoprene basal emission (the emission of isoprene from leaves exposed to a light intensity of 1000 µmol m−2 s−1 and maintained at a temperature of 30 °C) was measured in Phragmites australis plants growing under elevated CO2 in the Bossoleto CO2 spring at Rapolano Terme, Italy, and under ambient CO2 at a nearby control site. Gas exchange and biochemical measurements were concurrently taken. Isoprene emission was lower in the plants growing at elevated CO2 than in those growing at ambient CO2. Isoprene emission and isoprene synthase activity (IsoS) were very low in plants growing at the bottom of the spring under very rich CO2 and increased at increasing distance from the spring (and decreasing CO2 concentration). Distance from the spring did not significantly affect photosynthesis making it therefore unlikely that there is carbon limitation to isoprene formation. The isoprene emission rate was very quickly reduced after rapid switches from elevated to ambient CO2 in the gas‐exchange cuvette, whereas it increased when switching from ambient to elevated CO2. The rapidity of the response may be consistent with post‐translational modifications of enzymes in the biosynthetic pathway of isoprene formation. Reduction of IsoS activity is interpreted as a long‐term response. Basal emission of isoprene was not constant over the day but showed a diurnal course opposite to photosynthesis, with a peak during the hottest hours of the day, independent of stomatal conductance and probably dependent on external air temperature or temporary reduction of CO2 concentration. The present experiments show that basal emission rate of isoprene is likely to be reduced under future elevated CO2 levels and allow improvement in the modelling of future isoprene emission rates.
Profiles of isoprene emission and photosynthetic parameters in hybrid poplars exposed to free‐air CO2 enrichment†
Authors: CENTRITTO M. , NASCETTI P. , PETRILLI L. , RASCHI A. , LORETO F.
Published: December 2004

Poplar (Populus × euroamericana) saplings were grown in the field to study the changes of photosynthesis and isoprene emission with leaf ontogeny in response to free air carbon dioxide enrichment (FACE) and soil nutrient availability. Plants growing in elevated [CO2] produced more leaves than those in ambient [CO2]. The rate of leaf expansion was measured by comparing leaves along the plant profile. Leaf expansion and nitrogen concentration per unit of leaf area was similar between nutrient treatment, and this led to similar source–sink functional balance. Consequently, soil nutrient availability did not cause downward acclimation of photosynthetic capacity in elevated [CO2] and did not affect isoprene synthesis. Photosynthesis assessed in growth [CO2] was higher in plants growing in elevated than in ambient [CO2]. After normalizing for the different number of leaves over the profile, maximal photosynthesis was reached and started to decline earlier in elevated than in ambient [CO2]. This may indicate a [CO2]‐driven acceleration of leaf maturity and senescence. Isoprene emission was adversely affected by elevated [CO2]. When measured on the different leaves of the profile, isoprene peak emission was higher and was reached earlier in ambient than in elevated [CO2]. However, a larger number of leaves was emitting isoprene in plant growing in elevated [CO2]. When integrating over the plant profile, emissions in the two [CO2] levels were not different. Normalization as for photosynthesis showed that profiles of isoprene emission were remarkably similar in the two [CO2] levels, with peak emissions at the centre of the profile. Only the rate of increase of the emission of young leaves may have been faster in elevated than in ambient [CO2]. Our results indicate that elevated [CO2] may overall have a limited effect on isoprene emission from young seedlings and that plants generally regulate the emission to reach the maximum at the centre of the leaf profile, irrespective of the total leaf number. In comparison with leaf expansion and photosynthesis, isoprene showed marked and repeatable differences among leaves of the profile and may therefore be a useful trait to accurately monitor changes of leaf ontogeny as a consequence of elevated [CO2].