bluuebunny/crossref_metadata_2025 huggingface dataset:
The heme precursor delta‐aminolevulinate blocks peripheral myelin formation
Authors: Felitsyn Natalia , McLeod Colin , Shroads Albert L. , Stacpoole Peter W. , Notterpek Lucia
Published: July 2008

Delta‐aminolevulinic acid (δ‐ALA) is a heme precursor implicated in neurological complications associated with porphyria and tyrosinemia type I. Delta‐ALA is also elevated in the urine of animals and patients treated with the investigational drug dichloroacetate (DCA). We postulated that δ‐ALA may be responsible, in part, for the peripheral neuropathy observed in subjects receiving DCA. To test this hypothesis, myelinating cocultures of Schwann cells and sensory neurons were exposed to δ‐ALA (0.1–1 mM) and analyzed for the expression of neural proteins and lipids and markers of oxidative stress. Exposure of myelinating samples to δ‐ALA is associated with a pronounced reduction in the levels of myelin‐associated lipids and proteins, including myelin protein zero and peripheral myelin protein 22. We also observed an increase in protein carbonylation and the formation of hydroxynonenal and malondialdehyde after treatment with δ‐ALA. Studies of isolated Schwann cells and neurons indicate that glial cells are more vulnerable to this pro‐oxidant than neurons, based on a selective decrease in the expression of mitochondrial respiratory chain proteins in glial, but not in neuronal, cells. These results suggest that the neuropathic effects of δ‐ALA are attributable, at least in part, to its pro‐oxidant properties which damage myelinating Schwann cells.
Anticipating Tax Changes: Evidence from the Finnish Corporate Income Tax Reform of 2005*
Authors: Kari Seppo , Karikallio Hanna , Pirttilä Jukka
Published: July 2008

Using register‐based panel data covering all Finnish firms from 1999 to 2004, we examine how corporations anticipated the 2005 dividend tax increase via changes in their dividend and investment policies. The Finnish capital and corporate income tax reform of 2005 creates a useful opportunity to measure this behaviour, since it involves exogenous variation in the tax treatment of different types of firms. The estimation results reveal that those firms that anticipated a dividend tax hike increased their dividend payouts in a statistically significant way. This increase was not accompanied by a reduction in investment activities, but rather was associated with increased indebtedness in non‐listed firms. The results also suggest that the timing of dividend distributions probably offsets much of the potential for increased dividend tax revenue following the reform.
How Did the Elimination of the US Earnings Test above the Normal Retirement Age Affect Labour Supply Expectations?*
Authors: Michaud Pierre‐Carl , Van Soest Arthur
Published: July 2008

We look at the effect of the 2000 repeal of the earnings test above the normal retirement age (NRA) on the self‐reported probabilities of working full‐time after ages 65 and 62 of male workers in the US Health and Retirement Study (HRS). Using administrative records on social security benefit entitlements linked to the HRS survey data, we can distinguish groups of respondents according to the predicted effect of the earnings test before its repeal on their marginal wage rate after the NRA. We use panel data models with fixed and random effects to investigate the effect of the repeal. We find that male workers whose predicted marginal wage rate increased because the earnings test was repealed had the largest increase in the subjective probability of working full‐time after age 65. We find no significant effects of the repeal on the subjective probability of working full‐time past age 62.
The Anticipated Capitalisation Effect of a New Metro Line on Housing Prices*
Authors: Agostini Claudio A. , Palmucci Gastón A.
Published: July 2008

Housing units with closer access to public transportation enjoy a higher market value than those with similar characteristics but poorer access. This difference can be explained by the lower cost of transport to the main workplaces and shopping areas in town. For this reason, investments in public transport infrastructure, such as building a new metro line, are capitalised totally or partially into land and housing prices.

This work empirically analyses the degree of capitalisation into housing prices of the benefits of the new Line 4 of the Santiago metro system, which began operating in December 2005. We focus on anticipated capitalisation into housing prices at the moment construction of Line 4 was announced and at the moment information on the basic engineering project was unveiled, identifying the location of the future stations.

We use a unique database containing all home buying and selling transactions in the Greater Santiago area between December 2000 and March 2004. The results show that the average apartment price rose by between 4.2 per cent and 7.9 per cent after construction was announced and by between 3.1 per cent and 5.5 per cent after the location of the stations was identified. These increases were not distributed evenly, but depended on the distance from the apartment to the nearest station.

An indirect effect of this kind of capitalization is that property tax collections will increase if property is reappraised following the price rise. This effect is not negligible in magnitude and could represent 11 to 17 per cent of investment in the new metro line. This raises and interesting discussion on how the metro network extension is financed.
Horizontal Inequity and Vertical Redistribution with Indirect Taxes: The Greek Case*
Authors: Kaplanoglou Georgia , Newbery David M.
Published: July 2008

Non‐uniform indirect taxes treat equals and those unequal differently (horizontal inequity and vertical redistribution). Horizontal inequity is caused by taste differences among similar households, but some excises are designed to reflect social, not revealed, preferences. We apply two methodologies for decomposing the overall redistributive effect of the present and three alternative indirect tax structures into vertical and horizontal effects for Greece, using the 1998–99 Household Expenditure Survey micro‐database. In all cases, the taste component is considerable, even when we allow for social preferences, while improvements in vertical redistribution can be achieved, albeit at the cost of increased horizontal inequity.
The Effect of Financial Incentives on Labour Supply: Evidence for Lone Parents from Microsimulation and Quasi‐Experimental Evaluation*
Authors: Cai Lixin , Kalb Guyonne , Tseng Yi‐Ping , Vu Ha
Published: July 2008

The aim of this paper is to analyse the work incentive effects of a change in the Australian tax and transfer system on lone parents in July 2000. To evaluate the effect of the total change only, microsimulation can be used; but for a subgroup of lone parents, a few components of this policy change can be analysed through two alternative approaches — microsimulation and quasi‐experimental evaluation. Both approaches examine the effects on the probability of employment and on average working hours. The results from microsimulation show that the combined changes introduced in July 2000 — involving reduced withdrawl rates, changed family payments and lower income tax rates — have increased labour supply for lone parents to a moderate extent. The estimated effect on average working hours when using microsimulation is very close to the effect estimated in a quasi‐experimental approach using matching techniques to control for alternative influences.
Long‐term Follow up of Helicobacter pylori IgG Serology After Eradication and Reinfection Rate of H. pylori in South Korea
Authors: Lee Jung Hoon , Kim Nayoung , Chung Jae Il , Kang Kyung Phil , Lee Sang Hyup , Park Young Soo , Hwang Jin‐Hyeok , Kim Jin‐Wook , Jeong Sook‐Hyang , Lee Dong Ho , Jung Hyun Chae , Song In Sung
Published: July 2008

Background: Serology is widely used for epidemiologic research of Helicobacter pylori. However, there is limited information on the long‐term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long‐term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea.

Methods: Among 247 patients, who were enrolled during 2003–07, 185 patients with invasive H. pylori test positive received proton pump inhibitor‐based triple therapy, and follow‐up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication.

Results: The initial H. pylori IgG optical density (OD450nm), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests.

Conclusion: The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori, in Korea, was found to be very low, 2.94% per year.
In utero exposure to vigabatrin: No indication of visual field loss
Authors: Lawthom Charlotte , Smith Philip E. M. , Wild John M.
Published: July 2008

The purpose of the study was to determine whether in utero exposure to vigabatrin caused visual field loss.

 Three mothers with four children who had been exposed to vigabatrin in utero and who were subsequently formula fed were identified. All seven individuals underwent perimetry and imaging of the retinal nerve fiber layer (RNFL).

 All individuals yielded reliable outcomes to perimetry and RNFL images of acceptable quality. Two of the three mothers exhibited vigabatrin‐attributed visual field loss and an abnormally attenuated RNFL. The third exhibited an upper left quadrantanopia, consistent with previous temporal lobe surgery, and a normal RNFL. All four children yielded normal visual fields and RNFL thicknesses.

 The presence of the normal findings for the children is reassuring and, if representative, suggests a lack of vigabatrin visual toxicity and therefore obviates the need for ophthalmological examination of those exposed to vigabatrin prenatally.
Electroclinical features of epilepsy in patients with juvenile type dentatorubral‐pallidoluysian atrophy
Authors: Egawa Kiyoshi , Takahashi Yukitoshi , Kubota Yuko , Kubota Hideki , Inoue Yushi , Fujiwara Takeki , Onodera Osamu
Published: July 2008

Purpose: To clarify the electroclinical characteristics of epileptic seizures in patients with juvenile type dentatorubral‐pallidoluysian atrophy (DRPLA).

Methods: Seventeen patients with juvenile type DRPLA confirmed by genetic analysis were studied retrospectively. The clinical records of all 17  patients and the ictal video electroencephalography (EEG) recordings from 12 of the 17 patients were reviewed.

Results: Electroclinical studies in 12 patients identified 11 habitual seizures in 6 patients as partial seizures on ictal video EEG recordings. Clinical manifestations composed mainly of versions of the head and loss of consciousness. These partial seizures were persistently recorded throughout the clinical course. Brief generalized seizures (atypical absence and myoclonic seizure) were observed in 6 of 12 patients at the early stage. In contrast, generalized tonic–clonic seizures (GTCS) were recorded in four advanced stage patients who were almost bedridden. Semiological studies in 17 patients showed that the prevalence of partial seizures was significantly higher in patients with younger epilepsy onset (below 10 years of age; χ2test, p < 0.05) and that the age of epilepsy onset was significantly lower in patients with partial seizures than in those without partial seizures (Mann‐Whitney U test, p = 0.02). However, the number of CAG repeats and age at clinical onset were not significantly different between two groups.

Discussion: Partial seizure is one of the common epileptic features in juvenile type DRPLA, especially in patients with younger epilepsy onset. Seizure types may be affected in an age‐dependent manner and change evolutionally during progression of the clinical stage.
Idiopathic epilepsy with generalized tonic–clonic seizures only versus idiopathic epilepsy with phantom absences and generalized tonic–clonic seizures: One or two syndromes?
Authors: Koutroumanidis Michael , Aggelakis Konstantinos , Panayiotopoulos Chrysostomos P.
Published: July 2008

Purpose: To define the relationship between two syndromes of idiopathic generalized epilepsy (IGE) with apparently similar phenotypes: The form with generalized tonic–clonic seizures only (IGE‐GTCS) and that with phantom absences (IGE‐PA).

Methods: We compared the electroclinical features of 33 consecutive patients with GTCS and generalized spike wave (GSW); 18 had only GTCS and were diagnosed as IGE‐GTCS, and 15 had hitherto unnoticed mild absences on the electroencephalography (EEG) and were diagnosed as IGE‐PA. All patients were subjected to the same diagnostic workout, including video EEG during hyperventilation with breath counting (HBC). Patients with a clinical history of absences or myoclonic seizures were excluded.

Results: PA were easily identified with the first or second EEG in 14 of 15 patients with IGE‐PA and always with sleep‐deprived EEGs; conversely, PA did not occur in the IGE‐GTCS patients despite using more EEGs. GTCS were twice as frequent in the IGE‐GTCS group and tended to occur on awakening, whereas episodes of absence status affected twice as many patients with IGE‐PA. The hereditary risk was 30% in the IGE‐GTCS and 6.7% in IGE‐PA. GSW had a strong polyspike component in IGE‐PA and were briefer in IGE‐GTCS. There is no evidence for a maturational influence on the duration of GSW in either syndrome.

Conclusion: Our findings clearly indicate that IGE‐GTCS and IGE‐PA are two distinct IGE syndromes and emphasize the role of PA for patients' diagnosis and management and for syndromic classification. They also appear to validate HBC as a simple, sensitive, and pragmatic method for the clinical identification of typical absences.
Case‐control analysis of ambulance, emergency room, or inpatient hospital events for epilepsy and antiepileptic drug formulation changes
Authors: Zachry, III Woodie M. , Doan Quynhchau D. , Clewell Jerry D. , Smith Brien J.
Published: July 2008

Purpose:  Although antiepileptic drugs (AEDs) with multisource generic alternatives are becoming more prevalent, no case‐control studies have been published examining multisource medication use and epilepsy‐related outcomes. This study evaluated the association between inpatient/emergency epilepsy care and the occurrence of a recent switch in AED formulation.

Methods:  A case‐control analysis was conducted utilizing the Ingenix LabRx Database. Eligible patients were 12–64 years of age, received ≥145 days of AEDs in the preindex period, had continuous eligibility for 6 months preindex, and no prior inpatient/emergency care. Cases received care between 7/1/2006 and 12/31/2006 in an ambulance, emergency room, or inpatient hospital with a primary epilepsy diagnosis. Controls had a primary epilepsy diagnosis in a physician's office during the same period. The index date was the earliest occurrence of care in each respective setting. Cases and controls were matched 1:3 by epilepsy diagnosis and age. Odds of a switch between “A‐rated” AEDs within 6 months prior to index were calculated.

Results:  Cases (n = 416) had 81% greater odds of having had an A‐rated AED formulation switch [odds ratio (OR) = 1.81; 95% confidence interval (CI) = 1.25 to 2.63] relative to controls (n = 1248). There were no significant differences between groups regarding demographics or diagnosis. Significant differences were found with regard to medical coverage type (case Medicaid = 4.6%, control Medicaid = 1.8%, p = 0.002). Post hoc analysis results excluding Medicaid recipients remained significant and concordant with the original analysis.

Discussion:  This analysis found an association between patients receiving epilepsy care in an emergency or inpatient setting and the recent occurrence of AED formulation switching involving A‐rated generics.
Prolonged infusion of inhibitors of calcineurin or L‐type calcium channels does not block mossy fiber sprouting in a model of temporal lobe epilepsy
Authors: Ingram Elizabeth A. , Toyoda Izumi , Wen Xiling , Buckmaster Paul S.
Published: July 2008

Purpose: It would be useful to selectively block granule cell axon (mossy fiber) sprouting to test its functional role in temporal lobe epileptogenesis. Targeting axonal growth cones may be an effective strategy to block mossy fiber sprouting. L‐type calcium channels and calcineurin, a calcium‐activated phosphatase, are critical for normal growth cone function. Previous studies have provided encouraging evidence that blocking L‐type calcium channels or inhibiting calcineurin during epileptogenic treatments suppresses mossy fiber sprouting.

Methods: Rats were treated systemically with pilocarpine to induce status epilepticus, which lasted at least 2 h. Then, osmotic pumps and cannulae were implanted to infuse calcineurin inhibitors (FK506 or cyclosporin A) or an L‐type calcium channel blocker (nicardipine) into the dorsal dentate gyrus. After 28 days of continuous infusion, extent of mossy fiber sprouting was evaluated with Timm staining and stereological methods.

Results: Percentages of volumes of the granule cell layer plus molecular layer that were Timm‐positive were similar in infused and noninfused hippocampi.

Conclusions: These findings suggest inhibiting calcineurin or L‐type calcium channels does not block mossy fiber sprouting in the pilocarpine‐treated rat model of temporal lobe epilepsy.
Focal generation of paroxysmal fast runs during electrographic seizures
Authors: Boucetta Sofiane , Chauvette Sylvain , Bazhenov Maxim , Timofeev Igor
Published: July 2008

Purpose:  A cortically generated Lennox‐Gastaut type seizure is associated with spike‐wave/poly‐spike‐wave discharges at 1.0–2.5 Hz and fast runs at 7–16 Hz. Here we studied the patterns of synchronization during runs of paroxysmal fast spikes.

Methods:  Electrographic activities were recorded using multisite intracellular and field potential recordings in vivo from cats anesthetized with ketamine‐xylazine. In different experiments, the recording electrodes were located either at short distances (<1 mm) or at longer distances (up to 12 mm). The main experimental findings were tested in computational models.

Results:  In the majority of cases, the onset and the offset of fast runs occurred almost simultaneously in different recording sites. The amplitude and duration of fast runs could vary by orders of magnitude. Within the fast runs, the patterns of synchronization recorded in different electrodes were as following: (1) synchronous, in phase, (2) synchronous, with phase shift, (3) patchy, repeated in phase/phase shift transitions, and (4) nonsynchronous, slightly different frequencies in different recording sites or absence of oscillatory activity in one of the recording sites; the synchronous patterns (in phase or with phase shifts) were most common. All these patterns could be recorded in the same pair of electrodes during different seizures, and they were reproduced in a computational network model. Intrinsically bursting (IB) neurons fired more spikes per cycle than any other neurons suggesting their leading role in the fast run generation.

Conclusions:  Once started, the fast runs are generated locally with variable correlations between neighboring cortical foci.
Factors influencing clinical features of absence seizures
Authors: Sadleir Lynette G. , Scheffer Ingrid E. , Smith Sherry , Carstensen Bendix , Carlin John , Connolly Mary B. , Farrell Kevin
Published: July 2008

Purpose:  The clinical features of absence seizures in idiopathic generalized epilepsy have been held to be syndrome‐specific. This hypothesis is central to many aspects of epilepsy research yet has not been critically assessed. We examined whether specific factors such as epilepsy syndrome, age, and state determine the features of absence seizures.

Methods:  Children with newly presenting absence seizures were studied using video electroencephalography (EEG) recording. We analyzed whether a child's epilepsy syndrome, age, state of arousal, and provocation influenced specific clinical features of their absence seizures: duration, eyelid movements, eye opening, and level of awareness during the seizure.

Results:  Seizures (509) were evaluated in 70 children with the following syndromes: Childhood absence epilepsy (CAE), 37; CAE plus photoparoxysmal response (PPR), 10; juvenile absence epilepsy (JAE), 8; juvenile myoclonic epilepsy (JME), 6; unclassified, 9. Seizure duration was associated with epilepsy syndrome as children with JME had shorter seizures than in other syndromes, independent of age. Age independently influences level of awareness and eye opening. Arousal or provocation affected all features except level of awareness. Specific factors unique to the child independently influenced all features; the nature of these factors has not been identified.

Discussion:  The view that the clinical features of absence seizures have syndrome‐specific patterns is not supported by critical analysis. We show that confounding variables profoundly affect clinical features and that syndromes also show marked variation. Variation in clinical features of absence seizures results from a complex interaction of many factors that are likely to be genetically and environmentally determined.
Electroencephalographic evolution of hypsarrhythmia: Toward an early treatment option
Authors: Philippi Heike , Wohlrab Gabriele , Bettendorf Uli , Borusiak Peter , Kluger Gerhard , Strobl Karl , Bast Thomas
Published: July 2008

Purpose:  A retrospective study for a classification of prehypsarrhythmic elecroencephalographies (EEGs) was carried out to enable an early treatment option for West syndrome.

Methods:  Out of 39 infants with symptomatic West syndrome, 18 infants (age 3–14 months) with 61 serial non‐REM sleep EEG records of the prehypsarrhythmic phase were identified. The prehypsarrhythmic phase encompassed 2 to 13 months (mean 4.5 months) after an initial insult. A classification system of three EEG types corresponding to the clinical states prior to West syndrome occurrence was developed. In addition, follow‐up of all patients presenting with type 2 EEGs (n = 22) was evaluated.

Results:  Three clinical states and corresponding EEG types were classified. Clinical state 1 (weeks to months, silent phase) presented with (multi‐)focal epileptic discharges <50% of the non‐REM EEG recording time (type 1 EEG). Clinical state 2 (several weeks, beginning mental deterioration) was accompanied by type 2 EEG with bihemispheric epileptic discharges >50% of the non‐REM EEG recording time within abnormal background activity (imminent hypsarrhythmia). Clinical state 3 (mental deterioration) was characterized by hypsarryhthmia. Interrater reliability of seven blinded raters was good (median weighted κ 0.67). Out of 22 patients presenting with type 2 EEGs, two were lost for follow‐up, and 16 developed West syndrome, whereas four were treated early with anti‐epileptic drugs and remained stable.

Conclusions:  Infants with West syndrome could be reliably identified several weeks before the occurrence of hypsarrhythmia by a typical EEG pattern (type 2), thereby opening the way for early intervention studies.
Risk Perceptions, Optimism, and Natural Hazards
Authors: Smith V. Kerry
Published: July 2008

This article uses the panel survey developed for the Health and Retirement Study to evaluate whether Hurricane Andrew in 1992 altered longevity expectations of respondents who lived in Dade County, Florida, the location experiencing the majority of about 20 billion dollars of damage. Longevity expectations have been used as a proxy measure for both individual subjective risk assessments and dispositional optimism. The panel structure allows comparison of those respondents' longevity assessments when the timing of their survey responses bracket Andrew with those of individuals where it does not. After controlling for health effects, the results indicate a significant reduction in longevity expectations due to the information respondents appear to have associated with the storm.
Explosion Probability of Unexploded Ordnance: Expert Beliefs
Authors: MacDonald Jacqueline Anne , Small Mitchell J. , Morgan M. G.
Published: July 2008

This article reports on a study to quantify expert beliefs about the explosion probability of unexploded ordnance (UXO). Some 1,976 sites at closed military bases in the United States are contaminated with UXO and are slated for cleanup, at an estimated cost of $15–140 billion. Because no available technology can guarantee 100% removal of UXO, information about explosion probability is needed to assess the residual risks of civilian reuse of closed military bases and to make decisions about how much to invest in cleanup. This study elicited probability distributions for the chance of UXO explosion from 25 experts in explosive ordnance disposal, all of whom have had field experience in UXO identification and deactivation. The study considered six different scenarios: three different types of UXO handled in two different ways (one involving children and the other involving construction workers). We also asked the experts to rank by sensitivity to explosion 20 different kinds of UXO found at a case study site at Fort Ord, California. We found that the experts do not agree about the probability of UXO explosion, with significant differences among experts in their mean estimates of explosion probabilities and in the amount of uncertainty that they express in their estimates. In three of the six scenarios, the divergence was so great that the average of all the expert probability distributions was statistically indistinguishable from a uniform (0, 1) distribution—suggesting that the sum of expert opinion provides no information at all about the explosion risk. The experts' opinions on the relative sensitivity to explosion of the 20 UXO items also diverged. The average correlation between rankings of any pair of experts was 0.41, which, statistically, is barely significant (p= 0.049) at the 95% confidence level. Thus, one expert's rankings provide little predictive information about another's rankings. The lack of consensus among experts suggests that empirical studies are needed to better understand the explosion risks of UXO.
An Exploratory Risk Perception Study of Attitudes Toward Homeland Security Systems
Authors: Sanquist Thomas F. , Mahy Heidi , Morris Frederic
Published: July 2008

Understanding the issues surrounding public acceptance of homeland security systems is important for balancing security needs and potential civil liberties infringements. A psychometric survey was used in an exploratory study of attitudes regarding homeland security systems. Psychometric rating data were obtained from 182 respondents on psychological attributes associated with 12 distinct types of homeland security systems. An inverse relationship was observed for the overall rating attributes of acceptability and risk of civil liberties infringement. Principal components analysis (PCA) yielded a two‐factor solution with the rating scale loading pattern suggesting factors of perceived effectiveness and perceived intrusiveness. These factors also showed an inverse relationship. The 12 different homeland security systems showed significantly different scores on the rating scales and PCA factors. Of the 12 systems studied, airport screening, canine detectors, and radiation monitoring at borders were found to be the most acceptable, while email monitoring, data mining, and global positioning satellite (GPS) tracking were found to be least acceptable. Students rated several systems as more effective than professionals, but the overall pattern of results for both types of subjects was similar. The data suggest that risk perception research and the psychometric paradigm are useful approaches for quantifying attitudes regarding homeland security systems and policies and can be used to anticipate potentially significant public acceptance issues.
Upstream Oversight Assessment for Agrifood Nanotechnology: A Case Studies Approach
Authors: Kuzma Jennifer , Romanchek James , Kokotovich Adam
Published: July 2008

Although nanotechnology is broadly receiving attention in public and academic circles, oversight issues associated with applications for agriculture and food remain largely unexplored. Agrifood nanotechnology is at a critical stage in which informed analysis can help shape funding priorities, risk assessment, and oversight activities. This analysis is designed to help society and policymakers anticipate and prepare for challenges posed by complicated, convergent applications of agrifood nanotechnology. The goal is to identify data, risk assessment, regulatory policy, and engagement needs for overseeing these products so they can be addressed prior to market entry. Our approach, termed upstream oversight assessment (UOA), has potential as a key element of anticipatory governance. It relies on distinct case studies of proposed applications of agrifood nanotechnology to highlight areas that need study and attention. As a tool for preparation, UOA anticipates the types and features of emerging applications; their endpoints of use in society; the extent to which users, workers, ecosystems, or consumers will be exposed; the nature of the material and its safety; whether and where the technologies might fit into current regulatory system(s); the strengths and weaknesses of the system(s) in light of these novel applications; and the possible social concerns related to oversight for them.
A Sensitivity Analysis of the Social Vulnerability Index
Authors: Schmidtlein Mathew C. , Deutsch Roland C. , Piegorsch Walter W. , Cutter Susan L.
Published: July 2008

The Social Vulnerability Index (SoVI), created by Cutter et al. (2003), examined the spatial patterns of social vulnerability to natural hazards at the county level in the United States in order to describe and understand the social burdens of risk. The purpose of this article is to examine the sensitivity of quantitative features underlying the SoVI approach to changes in its construction, the scale at which it is applied, the set of variables used, and to various geographic contexts. First, the SoVI was calculated for multiple aggregation levels in the State of South Carolina and with a subset of the original variables to determine the impact of scalar and variable changes on index construction. Second, to test the sensitivity of the algorithm to changes in construction, and to determine if that sensitivity was constant in various geographic contexts, census data were collected at a submetropolitan level for three study sites: Charleston, SC; Los Angeles, CA; and New Orleans, LA. Fifty‐four unique variations of the SoVI were calculated for each study area and evaluated using factorial analysis. These results were then compared across study areas to evaluate the impact of changing geographic context. While decreases in the scale of aggregation were found to result in decreases in the variance explained by principal components analysis (PCA), and in increases in the variance of the resulting index values, the subjective interpretations yielded from the SoVI remained fairly stable. The algorithm's sensitivity to certain changes in index construction differed somewhat among the study areas. Understanding the impacts of changes in index construction and scale are crucial in increasing user confidence in metrics designed to represent the extremely complex phenomenon of social vulnerability.
The Lost Value of Groundwater and its Influence on Environmental Decision Making
Authors: Paleologos Evan K.
Published: July 2008

A critical aspect in establishing environmental policies lies in the proper assessment of the value of the resource being affected. Standard risk assessment analyses calculate the cost of pollution as consisting, solely, of the cost to remediate a site. This traditional definition is extended here to include the lost value of groundwater. These concepts and their impact on decision‐making analyses are illustrated through the case of municipal waste landfills. Based on data from existing polluting sites, a simple cost‐benefit probabilistic analysis is conducted first, which equates, as is the practice, the cost of pollution to that of remediation. This leads rationally to selection of the lowest‐protection technology. Using plausible arguments the reduction in value of groundwater from potable high‐quality water to irrigation water, which is what is returned after remediation, is argued. The arguments consist of: (a) the ratio of the subsidized prices of drinking to irrigation water reflects the relative value of the use of water; (b) the amount paid for remediation, in each case, represents, at a minimum, the value of the water recovered; and (c) the lost value of groundwater equals the value of drinking water minus the value of irrigation water. Incorporation of this lost value of groundwater is sufficient to drastically alter the conclusions of the decision‐making analysis and make the highest level technology the most rational and profitable alternative. The broader point of this article lies in that proper accounting of environmental costs is necessary in order to alter environmental policies and practices.
Analysis of Local Acceptance of a Radioactive Waste Disposal Facility
Authors: Chung Ji Bum , Kim Hong‐Kew , Rho Sam Kew
Published: July 2008

Like many other countries in the world, Korea has struggled to site a facility for radioactive waste for almost 30 years because of the strong opposition from local residents. Finally, in 2005, Gyeongju was established as the first Korean site for a radioactive waste facility. The objectives of this research are to verify Gyeongju citizens' average level of risk perception of a radioactive waste disposal facility as compared to other risks, and to explore the best model for predicting respondents' acceptance level using variables related to cost‐benefit, risk perception, and political process. For this purpose, a survey is conducted among Gyeongju residents, the results of which are as follows. First, the local residents' risk perception of an accident in a radioactive waste disposal facility is ranked seventh among a total of 13 risks, which implies that nuclear‐related risk is not perceived very highly by Gyeongju residents; however, its characteristics are still somewhat negative. Second, the comparative regression analyses show that the cost‐benefit and political process models are more suitable for explaining the respondents' level of acceptance than the risk perception model. This may be the result of the current economic depression in Gyeongju, residents' familiarity with the nuclear industry, or cultural characteristics of risk tolerance.
Communicating Risks and Benefits from Fish Consumption: Impact on Belgian Consumers' Perception and Intention to Eat Fish
Authors: Verbeke Wim , Vanhonacker Filiep , Frewer Lynn J. , Sioen Isabelle , De Henauw Stefaan , Van Camp John
Published: July 2008

Communicating about the health effects of fish and seafood may potentially result in a conflict situation: increasing intake is desirable because of health and nutritional benefits, but higher consumption may also lead to an increased intake of potentially harmful environmental contaminants. In order to anticipate the communication challenge this conflict may pose, the research presented here aimed to assess the impact of risk/benefit communication on Belgian consumers' fish consumption behavior and fish attribute perception. Data were collected in June 2005 from a sample of 381 women, aged between 20 and 50 years. An experimental design consisting of four message conditions (benefit‐only; risk‐only; benefit‐risk; and risk‐benefit) combined with three information sources (fish and food industry; consumer organization; government) was used. Exposure to the benefit‐only message resulted in an increase from a self‐reported fish consumption frequency of 4.2 times per month to an intended fish consumption frequency of 5.1 times per month (+21%), while fish attribute perceptions only marginally improved. The risk‐only message resulted in a strong negative perceptual change in the range of two points on a seven‐point scale. This translated into an 8% decrease of behavioral intention (from eating fish 4.5 times per month to an intention of eating fish 4.1 times per month). Balanced messages referring to both risks and benefits yielded no significant change in behavioral intention, despite a significant worsening of fish attribute perception. The presentation order of benefits and risks in the balanced message showed a tendency to affect both behavioral intention and attribute perception, with the first message component being most influential. Information source did not yield any significant impact either on behavioral intention or on attribute perceptions, independent of the message content. The results from this study provide valuable insights for future risk/benefit and balanced communication about seafood.
Trust in the Safety of Tourist Destinations: Hard to Gain, Easy to Lose? New Insights on the Asymmetry Principle
Authors: Eitzinger Claudia , Wiedemann Peter M.
Published: July 2008

According to the asymmetry principle of trust, negative events decrease trust to a much higher extent than positive events increase trust. The study at hand intended to verify whether this notion of asymmetry holds true with respect to trust in the safety of tourist destinations. Thus, in contrast to previous research that analyzed trust asymmetry in the context of involuntary technological risks, the present study evaluates the validity of the asymmetry principle of trust in the context of voluntary tourism risks. The hypothesis that negative or risky information on destination safety (absence of proper safety measures and conditions) has a higher impact on distrust than, conversely, positive or nonrisk information on destination safety (provision of proper safety measures and conditions) has on trust was tested in an online survey (N= 640). In contrast to the asymmetry pattern found by Slovic (1993), results of the current work suggest symmetry rather than asymmetry of trust. The presence of proper safety measures and conditions (positive or nonrisk information) was found to have at least the same—and in some cases an even higher—impact on trust than the absence of such measures and conditions (negative or risky information) had on distrust. Findings provide empirical evidence for the thesis that the prevalence of trust asymmetry is dependent on the risk source and demonstrate that trust is symmetric rather than asymmetric in the context of voluntary tourism risks. Furthermore, results imply an influence of positive versus negative expectations as well as of prior trusting relationships on the occurrence of the asymmetry principle.
Uncertainty and Sensitivity Analyses of a Decision Analytic Model for Posteradication Polio Risk Management
Authors: Duintjer Tebbens Radboud J. , Pallansch Mark A. , Kew Olen M. , Sutter Roland W. , Bruce Aylward R. , Watkins Margaret , Gary Howard , Alexander James , Jafari Hamid , Cochi Stephen L. , Thompson Kimberly M.
Published: July 2008

Decision analytic modeling of polio risk management policies after eradication may help inform decisionmakers about the quantitative tradeoffs implied by various options. Given the significant dynamic complexity and uncertainty involving posteradication decisions, this article aims to clarify the structure of a decision analytic model developed to help characterize the risks, costs, and benefits of various options for polio risk management after eradication of wild polioviruses and analyze the implications of different sources of uncertainty. We provide an influence diagram of the model with a description of each component, explore the impact of different assumptions about model inputs, and present probability distributions of model outputs. The results show that choices made about surveillance, response, and containment for different income groups and immunization policies play a major role in the expected final costs and polio cases. While the overall policy implications of the model remain robust to the variations of assumptions and input uncertainty we considered, the analyses suggest the need for policymakers to carefully consider tradeoffs and for further studies to address the most important knowledge gaps.
Fabrication of Millimeter Wave Components Via Ceramic Stereo‐ and Microstereolithography Processes
Authors: Chartier Thierry , Duterte Charles , Delhote Nicolas , Baillargeat Dominique , Verdeyme Serge , Delage Cyril , Chaput Christophe
Published: July 2008

Complex ceramic parts, designed by 3D electromagnetic simulations for microwave devices of high performances, are difficult, even impossible, to elaborate by classical ceramic processing routes. This paper demonstrates the direct fabrication of useful complex microwave devices in millimeter and submillimeter wavelength domains, with a high dimensional resolution, by the numerical techniques of stereolithography and microstereolithography. Alumina and zirconia formulations have been developed with a powder loading >50 vol%, a suitable rheology to spread thin (25–50 μm) and homogeneous layers, and with a sufficient reactivity to UV for polymerization. Devices built with a satisfying manufacturing accuracy have presented excellent experimental electrical behaviors in good agreement with the theoretical ones.
Applicability of Optical Scattering Model to β‐Quartz Solid Solution Glass–Ceramics with Nanoscale Crystalline Phase
Authors: Sakamoto Akihiko , Himei Yusuke , Seto Tadashi
Published: July 2008

The applicability of Rayleigh‐Gans and quasi‐continuum scattering models to β‐quartz solid solution (s.s.) glass–ceramics was studied. We evaluated the validity of these models using two specimens with different microstructures. The refractive indices of the crystalline and glass phases of the specimens were calculated by a method utilizing the transmittance change of the specimens due to structural relaxation. It was found that the quasi‐continuum model is applicable to the glass–ceramics for estimating scattering intensity and its microstructure dependence. We demonstrated that the optical transmittance of the glass–ceramics can be simulated as a function of the microstructure on the basis of this model. The result of this study provides a quantitative approach for controlling the optical transmittance of β‐quartz s.s. glass–ceramics.
Single‐Phase MnFe2O4 Powders Obtained by the Polymerized Complex Method
Authors: Popa Monica , Bruna Pere , Crespo Daniel , Calderon Moreno Jose M.
Published: July 2008

The present investigation reports on a simple technique for the preparation of single‐phase MnFe2O4 nanocrystalline powders using the polymerized complex method, starting from manganese carbonate and iron nitrate. A mixed aqueous solution with citric acid, ethylene glycol, Fe, and Mn ions was polymerized. The phases formation, the homogeneity, and the structure of the obtained powders have been investigated by thermogravimetry, X‐ray diffraction (XRD), scanning and transmission electron microscopy, and Mössbauer spectroscopy measurements. The magnetic hysteresis loop behavior was measured at 5 K in a vibrating sample magnetometer. XRD results demonstrated that thermally induced crystallization of cubic MnFe2O4 from the Mn–Fe polymeric precursor occurred at temperatures as low as 400°C. Pure single‐phase MnFe2O4 nanocrystallites without any impurity or amorphous phases were obtained when the precursor was treated at 600°C for 1 h.
Particle Shape and Size Effects on Anisotropic Shrinkage in Tape‐Cast Ceramic Layers
Authors: Besendörfer Georg , Roosen Andreas
Published: July 2008

The particle shape of a commercial low‐temperature cofired ceramic (LTCC) composite powder was determined quantitatively in the as‐received and milled state using a new particle image analyzer. All grades of the milled powder with average particle sizes of 3.0, 2.4, and 1.8 μm, respectively, exhibit a considerable stretched particle shape, because 40% of their particles have circularity values below 0.95. On the basis of the fast particle image analyzer, the influence of the raw materials on particle alignment during tape casting was investigated using “design of experiments” (DOE). In the cast LTCC green tapes, the degree of particle orientation was measured and correlated with the information from the particle shape analyses and with other material and process factors from the DOE. The results showed that the degree of particle alignment correlates significantly with the measured particle shape and size; more than 80% of the particles were oriented in the casting direction if their shape factor was below 0.5. The particle orientation causes shrinkage anisotropy. The use of a coarser LTCC powder with an average particle size d50 of 3.0 μm instead of 1.8 μm increased the sintering anisotropy factor of LTCC tapes and laminates significantly from 1.0% to 1.85% and from 3.6% to 7.6%, respectively. The use of more binder or less solvent led to higher shrinkage anisotropies too. The casting velocity showed only a minor effect on the degree of particle orientation and sintering anisotropy, which is due to the shorter shearing period in which particle rotation can take place.
Effect of Heating Rates during Sintering on the Electrical Properties of Ultra‐Thin Ni–BaTiO3 Multilayer Ceramic Capacitors
Authors: Polotai Anton V. , Fujii Ichiro , Shay Dennis P. , Yang Gai‐Ying , Dickey Elizabeth C. , Randall Clive A.
Published: July 2008

Microstructural control in thin‐layer multilayer ceramic capacitors (MLCCs) is one of the present day challenges for increasing capacitive volumetric efficiency and high voltage dielectric properties. The present paper continues a series of investigations aimed at engineering the stability of ultra‐thin Ni layers in base‐metal electrode MLCCs. A kinetic approach based on the control of sintering profiles is found to not only prevent Ni electrode discontinuities, but also to significantly improve the interfacial electrical properties. Increasing sintering heating rates from 200 to 3000°C/h leads to a decrease in its temperature dependence of capacitance. Faster heating rates also reduce the BaTiO3 grain size, which is beneficial to the reliability of multilayer capacitors. A direct correlation between heating rates, the thickness of an interfacial (Ni, Ba, and Ti) alloy reaction layer and the interfacial contact resistance has been observed. The decrease in the alloy layer thickness at high heating rates leads to an increased effective Schottky barrier height between the dielectric and electrode toward its theoretical value of 1.25 eV for pure Ni–BaTiO3 interfaces.
A New Low‐Loss Microwave Dielectric Ceramic Sr4LaTiNb3O15
Authors: Fang Liang , Su Heping , Yu Qian , Zhang Hui , Wu Bolin
Published: July 2008

A high dielectric constant and low‐loss ceramic with composition Sr4LaTiNb3O15 has been prepared by the conventional solid‐state ceramic route. This compound adopts an A5B4O15 cation‐deficient hexagonal perovskite structure and crystallizes in the trigonal system with unit cell parameters a=5.6307(2), c=11.3692(3) Å, V=312.16(2) Å3, and Z=1. The dielectric properties of dense ceramics sintered in air at 1460°C have been characterized at microwave frequencies. The results show that the material affords a relatively high dielectric constant ɛr∼43, a high quality factor Q×f∼44 718 GHz, and a low temperature coefficient of resonant frequency TCf∼13 ppm/°C.