bluuebunny/crossref_metadata_2025 huggingface dataset:
A probabilistic model for analysing species co‐occurrence
Authors: Veech Joseph A.
Published: August 2012

Aim

To develop a new probabilistic model that can be used to test for statistically significant pair‐wise patterns of species co‐occurrence. The model gives the probability that two species would co‐occur at a frequency less than (or greater than) the observed frequency if the two species were distributed independently of one another among a set of sites. The model can be used to classify species associations as negative, positive or random.

Innovation

Historically, the analysis of species co‐occurrence has involved the use of data randomization. An observed species presence–absence matrix is compared with randomized matrices to determine if the observed matrix has structure, either an excess or deficit of species positively or negatively associated with each other. The computer algorithms used to randomize matrices can sometimes produce Type I and Type II errors (when the randomization algorithm produces a biased set of all possible matrices) due to the randomization process itself. The probabilistic model does not rely on any data randomization, hence it has a very low Type I error rate and is powerful having a low Type II error rate.

Main conclusions

When applied to 10 different data sets the probabilistic model revealed significant positive and negative species associations in most of the data sets. Compared with previous analyses the model tended to find fewer significant associations; this may indicate a generally low rate of Type I error in the model. The model is easy to implement and requires no special software. The model could potentially transform the way that ecologists test for species co‐occurrence in a wide range of ecological studies.
Specialists leave fewer descendants within a region than generalists
Authors: Ozinga Wim A. , Colles Audrey , Bartish Igor V. , Hennion Françoise , Hennekens Stephan M. , Pavoine Sandrine , Poschlod Peter , Hermant Marie , Schaminée Joop H. J. , Prinzing Andreas
Published: August 2012

Aim

Current conservation biology suggests that across ecological time‐scales specialist species existing in the recent past have left on average fewer descendant populations today than generalist species. Conversely, the speciation literature suggests that on an evolutionary time‐scale specialists leave as many or more descendant lineages as generalists, i.e. they have high rates of global diversification. This begs the question: which of these two processes has more influence on the regional scale, i.e. do specialists leave more or fewer descendants than generalists within a region?

Location

The flora of the Netherlands.

Methods

We quantified niche volume of 707 plant species from coexistence data and ecological indicator values and used sister taxon comparisons to compare specialist and generalist sister taxa for the relative numbers of descendants across three temporal scales: ecological, microevolutionary and macroevolutionary.

Results

We show, first, that specialist species are more likely to be currently declining, i.e. to leave only few descendant populations. Second, specialists are less likely to be currently diversifying into intra‐specific taxa. Finally, most specialist clades left fewer descendant species within a region than their generalist sister clades. These results were consistent across sublineages, unbiased by geographic sampling of lineages and environments, and held after accounting for species life histories. Differences between specialist and generalist sister clades increased with clade age, suggesting that they reflect differences in rates at which specialists left descendants (rather than differences in ecological limits to the numbers of specialists and generalists).

Main conclusions

Specialists left only few descendants within a region (i.e. the Netherlands), both at ecological, microevolutionary and macroevolutionary scales. While specialists may leave numerous evolutionary descendants at a global scale, these might be absent from most regions. Humans, by threatening specialist species, may hence further accelerate biotic homogenization with descendants of generalist lineages proliferating within regions while specialist lineages disappear.
Social Movement Theory, Collective Action Frames and Union Theory: A Critique and Extension
Authors: Gahan Peter , Pekarek Andreas
Published: August 2012

The publication of John Kelly's Rethinking Industrial Relations in 1998 spawned a growing interest among researchers in exploring how social movement (SM) theory can be used to inform union research, particularly in the context of revitalization/renewal debates. Our starting proposition is that this approach can be extended through an engagement with the larger corpus of SM theory. We focus in particular on the ‘collective action frame’ concept. Drawing on examples used by SM scholars, we illustrate how these concepts can be used to extend and enrich union theory and pose new questions concerning the role of unions.
Georelief Transfiguration in Areas Affected by Open‐cast Mining
Authors: Pacina Jan , Novák Kamil , Popelka Jan
Published: August 2012

Open‐cast mining activity causes the largest georelief transfigurations all over the world. Large localities in north‐west Bohemia (the Czech Republic) are affected. In this area, we focus on a very significant case: the royal town Most, which has been turned into a lake. The main aim of this article is the reconstruction of the original georelief in different time periods together with analysis showing the process of landscape devastation. The workflow and analysis is based on precise elevation data obtained from aerial photographs and old maps. The georelief development is reconstructed using the digitized contour lines contained in Derived state‐map 1:5,000 (SMO5) from the years 1953, 1972, and 1980; maps of the 3rd Military Survey (year 1936); and digital surface models (DSM) extracted, using the pixel correlation method, from aerial images (year 1953 and 2008). The most important results of the analysis are digital terrain models showing the evolution of the landscape which may be used for many purposes in landscape development analysis, historical applications, visualization or landscape reclamation.
On Doing Things Intentionally
Authors: COVA FLORIAN , DUPOUX EMMANUEL , JACOB PIERRE
Published: August 2012

Recent empirical and conceptual research has shown that moral considerations have an influence on the way we use the adverb ‘intentionally’. Here we propose our own account of these phenomena, according to which they arise from the fact that the adverb ‘intentionally’ has three different meanings that are differently selected by contextual factors, including normative expectations. We argue that our hypotheses can account for most available data and present some new results that support this. We end by discussing the implications of our account for folk psychology.
Testing the Political Replacement Effect: A Panel Data Analysis*
Authors: Leonida Leone , Patti Dario Maimone Ansaldo , Navarra Pietro
Published: August 2012

This article tests for the existence of the political replacement effect, as suggested by Acemoglu and Robinson: [American Political Science Review, Vol. 100, pp. 115–131]. They argue that the implementation of market‐oriented reform is crucially driven by the political calculus of incumbent governments: they implement economic policy change if such a choice is not expected to reduce their chances to retain power. This implies a non‐monotonic relationship between the level of political competition and the extent of economic reform. We test this hypothesis using data for 102 countries over the period 1980 to 2005. Our results strongly support the theory.
State‐Dependent Threshold Smooth Transition Autoregressive Models*
Authors: Dueker Michael J. , Psaradakis Zacharias , Sola Martin , Spagnolo Fabio
Published: August 2012

In this article, we consider extensions of smooth transition autoregressive (STAR) models to situations where the threshold is a function of variables that affect the separation of regimes of the time series under consideration. Our specification is motivated by the observation that unusually high/low values for an economic variable may sometimes be best thought of in relative terms. State‐dependent contemporaneous‐threshold STAR and logistic STAR models are introduced and discussed. These models are also used to investigate the dynamics of US short‐term interest rates, where the threshold is allowed to be a function of past output growth and inflation.
Time Demands and Gender Roles: The Case of a Big Four Firm in Mexico
Authors: Ruiz Castro Mayra
Published: August 2012

This article studies time demands in a big four firm in Mexico. It does so by examining the way time demands are (re)created by masculinities and how their interplay with societal gender roles shape employees' professional and personal lives. Qualitative interviews with women and men across different hierarchical levels and departments show that long hours are an indicator of commitment and potential for career progression, thus suggesting that accounting firms' organizational culture and accountants' professional identity predominate in different cultural contexts. However, paternalistic masculinity and ‘the father’ figure appear to characterize management control in the Mexican context, in contrast to most previous studies conducted in developed countries. The article demonstrates how paternalistic relations prevent women from complying with time demands, which has important implications for career advancement. Finally, the article demonstrates how time demands perpetuate work–life conflict for all organizational members, albeit in different ways according to the individual's stage in life.
Monetary Policy Announcements and Short‐Term Interest Rate Futures Volatility: Evidence from the Mexican Market
Authors: Herrerías Renata , Gurrola Pedro
Published: August 2012

The relationship between monetary policy and the behaviour of financial markets is commonly examined to assess the effectiveness of the actions of central banks. Our study explores, for the case of Mexico, the reaction of short‐term interest rate futures to monetary policy announcements, and to what extent the change to the operational targeting of interest rates implemented by the central bank in 2004 led to changes in this reaction. The results show that in a market dominated by institutional investors trading solely for hedging purposes, the actions of the central bank are not fully incorporated into prices in advance. As a result, interest rate futures prices are adjusted on announcement dates. Furthermore, the change to an interest rate operational target modified the trading behaviour so that the changes in the volatility, volume and prices of the futures contracts on the announcement dates are now more evident.
Mentoring as professional development for novice entrepreneurs: maximizing the learning1
Authors: St‐Jean Etienne
Published: August 2012

Mentoring can be seen as relevant if not essential in the continuing professional development of entrepreneurs. In the present study, we seek to understand how to maximize the learning that occurs through the mentoring process. To achieve this, we consider various elements that the literature suggested are associated with successful mentoring and test a comprehensive model with the main parts of the mentoring process. Using a structural equation model on a sample of 360 Canadian‐mentored entrepreneurs, the study demonstrates that mentor's career‐related functions are the most effective factor in the development of learning, followed by psychological functions and the role model function. In order to foster these functions, trust and perceived similarity are needed to build a strong and high‐quality relationship as is mentee self‐disclosure. These results are of interest because they highlight the different elements that influence learning through mentoring and show the mediating role of trust, perceived similarity and mentor's functions between the mentee's self‐disclosure and learning.
Validation of a clinical evaluation score for irritative dermatitis: SCOREPI
Authors: Le Maître M. , Crickx B. , Lacour J.P. , Bagot M. , Chevallier J.‐M. , Cribier B. , Doutre M.‐S. , Giordano‐Labadie F. , Guillot B. , Joly P. , Schmutz J.‐L. , Vabres P. , Bensimon D.
Published: August 2012

Background  Most dermatological conditions can be evaluated using validate clinical scores, no such tool is available for irritant contact dermatitis (ICD).

Objective  To create and validate a grid‐based ICD severity score.

Methods  Three dermatologists developed the SCOre de REparation de l’EPIderme (SCOREPI) grid. Two studies were conducted to validate the SCOREPI. A cross‐sectional study assessed the intra‐ and inter‐observer error associated with using the SCOREPI. Each investigator received 15 min of training on proper use of the SCOREPI. A computer displayed a series of 20 photos of ICD, each of which were repeated three times in a randomized order. The prospective study assessed the correlation between SCOREPI with the severity of clinical symptoms as well as the sensitivity of the score to changes in ICD in response to topical treatment.

Results  The SCOREPI took an average of 35 ± 5 s to be completed and was characterized by an excellent intra‐observer and moderate inter‐observer reproducibility (intra‐class correlation coefficient = 0.93 and 0.74, respectively). Significant divergence was observed between the physicians’ assessment of estimated surface (P = 0.04), the presence of erythema (P < 0.0001) and the number of deep cracks (P = 0.0008). In the prospective analysis of patients, SCOREPI was correlated with tightness (r = 0.45; P < 0.0001), pain (r = 0.45; P < 0.0001), burning (r = 0.42; P < 0.0001), and pruritus (r = 0.28; P = 0.0055). SCOREPI decreased considerably during follow‐up from 10.45 ± 4.61 to 4.82 ± 4.15 (P < 0.0001).

Conclusion  The SCOREPI is easy to use, sensitive to change, and characterized by high intra‐ and moderate inter‐observer reliability.
Macroeconomic Imbalances as Indicators for Debt Crises in Europe*
Authors: KNEDLIK TOBIAS , VON SCHWEINITZ GREGOR
Published: August 2012

European authorities and scholars published proposals on which indicators of macroeconomic imbalances might be used to uncover risks for the sustainability of public debt in the European Union. In this article the ability of four proposed sets of indicators to send early warnings of debt crises is tested using a signals approach for the study of indicators and the construction of composite indicators. It is found that a broad composite indicator has the highest predictive power. This fact still holds true if equal weights are used for the construction of the composite indicator in order to reflect the uncertainty about the origin of future crises.
Polity‐Building in the Constitutional Convention: Transnational Party Groups in European Union Institutional Reform*
Authors: VAN HECKE STEVEN
Published: August 2012

The abundant literature on the European Constitution has largely overlooked the role party politics played in the European Convention. This article fills this gap by analyzing transnational party groups: how they were organized and which purposes they served. It shows that they mattered, but in unexpected ways due to the particular set‐up of the Convention. For instance, they helped to bring MEPs and MNPs closer to each other. Overall, the analysis contributes to a better understanding of how parties operate at the transnational level and helps to explain the way in which polity‐building in the European Union's multi‐level system takes place.
Avoidance of roads by large herbivores and its relation to disturbance intensity
Authors: Leblond M. , Dussault C. , Ouellet J. –P.
Published: August 2012

Avoidance of roads has been demonstrated for many animal species, but little is known about the relationship between anthropogenic disturbance levels and the degree of avoidance by animals. We investigated the hypothesis that the strength of road‐avoidance behaviour increases with the intensity of the disturbance for a large, disturbance‐sensitive herbivore: the forest‐dwelling caribou Rangifer tarandus caribou. We assessed the behaviour of 53 global positioning system‐collared caribou monitored during the gradual modification of a highway over a 7‐year period, while controlling for potentially confounding factors. We studied caribou movements, resource selection and distribution before, during and after road modifications at multiple scales. We expected that the degree of avoidance would be positively related to road width, traffic density and the presence of active construction sites. The proportion of individuals that excluded the highway from their home range increased as highway modifications progressed. A lower proportion of caribou locations was found in a 5000 m road‐effect zone during and after highway modifications compared with before. Within that zone, caribou avoided habitat types that were selected at the home range scale. Caribou displayed higher movement rates in the vicinity of the highway, especially when traffic density was high. Our data support the hypothesis that avoidance of roads by large herbivores is positively related to disturbance intensity. Our results shed light on the behavioural mechanisms determining avoidance of human infrastructure by large herbivores, and suggest that increased human activity may affect behaviour at multiple scales. Conservation efforts in areas where roads are constructed or modified should be directed towards maintaining access to critical habitat resources, while also restoring habitat quantity and quality.
The effect of challenge and threat states on performance: An examination of potential mechanisms
Authors: Moore Lee J. , Vine Samuel J. , Wilson Mark R. , Freeman Paul
Published: August 2012

Challenge and threat states predict future performance; however, no research has examined their immediate effect on motor task performance. The present study examined the effect of challenge and threat states on golf putting performance and several possible mechanisms. One hundred twenty‐seven participants were assigned to a challenge or threat group and performed six putts during which emotions, gaze, putting kinematics, muscle activity, and performance were recorded. Challenge and threat states were successively manipulated via task instructions. The challenge group performed more accurately, reported more favorable emotions, and displayed more effective gaze, putting kinematics, and muscle activity than the threat group. Multiple putting kinematic variables mediated the relationship between group and performance, suggesting that challenge and threat states impact performance at a predominately kinematic level.
Mechanisms of change: Effects of repetitive exposure to feared stimuli on the brain's fear network
Authors: Wendt Julia , Schmidt Luise E. , Lotze Martin , Hamm Alfons O.
Published: August 2012

Repetitive exposure to feared stimuli is considered as the essential element in therapy with phobic patients. However, the mechanisms mediating symptom reduction and their underlying neurobiological processes are poorly understood. Therefore, we presented the same fear‐relevant and neutral stimuli repeatedly to individuals with high and low fear of animals during fMRI scanning. High‐, but not low‐fearful individuals showed an initial fear‐stimulus‐related potentiation of amygdala and insula activity. Potentiation of the amygdala in the high‐fearful group habituated quickly, but insula activity was still potentiated during later repetition trials. Both groups showed an initial potentiation of the dorsomedial prefrontal cortex (dmPFC) that continuously decreased in low‐, but not in high‐fearful participants. Thus, within‐session habituation may occur on an automatic processing level (amygdala), but does not cause lasting neural changes on a higher order cortical level (dmPFC).
Young adults’ attitudes towards credit
Authors: Lachance Marie J.
Published: August 2012

This research project was undertaken to study young adults’ attitudes towards credit in general. A sample of 980 young Canadian adults, ages 18–29, participated in a telephone survey. Results reveal that they recognize both the advantages and the risks associated with credit. Regression analysis shows that attitudes towards credit is positively related to education, the number of credit cards held and knowledge of credit, but negatively related to the number of children. The young adults who reported that their parents and friends are heavy credit users are more likely to have positive attitudes towards credit. No link was found with the participants’ level of debt.
The effects of financial literacy on the borrowing behaviour of Turkish financial consumers
Authors: Sevim Nurdan , Temizel Fatih , Sayılır Özlem
Published: August 2012

Our research attempts to measure the effects of financial literacy of Turkish financial consumers on the borrowing behaviour. A questionnaire is administered to a sample of 550 people in the city of Eskisehir. In‐depth interviews are undertaken with 10 financial consumers to support the findings. Findings of the study indicate differences in the borrowing behaviour of consumers with different levels of financial literacy. Considering the relationship between financial literacy and borrowing behaviour, we suggest that attempts to increase financial literacy of financial consumers may have important implications in the prevention of excessive borrowing.
Monitoring agricultural diffuse pollution through a dense monitoring network in the River Eden Demonstration Test Catchment, Cumbria, UK
Authors: Owen G J , Perks M T , Benskin C McW H , Wilkinson M E , Jonczyk J , Quinn P F
Published: August 2012

The water quality of our rivers and lakes is a reflection of the landscape over and through which it travels. The UK government, along with all European Union member states, are obliged under the Water Framework Directive (WFD) to aim for good ecological status of fresh water bodies by 2015. In order to evaluate the effectiveness of potential mitigation measures in reducing diffuse water pollution from agriculture at the catchment scale, the Demonstration Test Catchment (DTC) project was developed. The project is jointly funded by Defra, the Environment Agency (EA) and the Welsh Assembly Government (WAG). There are three DTCs across the country: the Eden catchment, Cumbria; the Wensum catchment, Norfolk and the Hampshire Avon catchment. The Eden DTC has established three ∼10 km2 focus catchments, chosen to reflect different farming practices, geologies, elevations and hydrological characteristics. Within each focus catchment, two sub‐catchments have been selected, one control and one mitigated, in which numerous existing and novel mitigation measures will be tested. It is hoped that the mitigation features will be multi‐purpose, having positive effects on pollutant retention, flooding, carbon sequestration, habitat creation and biodiversity. The effectiveness of these measures is assessed through networks of hydro‐meteorological and water‐quality instrumentation, most of which will provide data in near real time, with sub‐hourly time steps.
Aβ oligomer toxicity inhibitor protects memory in models of synaptic toxicity
Authors: Scopes DIC , O'Hare E , Jeggo R , Whyment AD , Spanswick D , Kim E‐M , Gannon J , Amijee H , Treherne JM
Published: August 2012

BACKGROUND AND PURPOSE

Amyloid‐β (Aβ) aggregation into synaptotoxic, prefibrillar oligomers is a major pathogenic event underlying the neuropathology of Alzheimer's disease (AD). The pharmacological and neuroprotective properties of a novel Aβ aggregation inhibitor, SEN1269, were investigated on aggregation and cell viability and in test systems relevant to synaptic function and memory, using both synthetic Aβ1‐42 and cell‐derived Aβ oligomers.

EXPERIMENTAL APPROACH

Surface plasmon resonance studies measured binding of SEN1269 to Aβ1–42. Thioflavin‐T fluorescence and MTT assays were used to measure its ability to block Aβ1–42–induced aggregation and reduction in cell viability. In vitro and in vivo long‐term potentiation (LTP) experiments measured the effect of SEN1269 on deficits induced by synthetic Aβ1–42 and cell‐derived Aβ oligomers. Following i.c.v. administration of the latter, a complex (alternating‐lever cyclic ratio) schedule of operant responding measured effects on memory in freely moving rats.

KEY RESULTS

SEN1269 demonstrated direct binding to monomeric Aβ1–42, produced a concentration‐related blockade of Aβ1–42 aggregation and protected neuronal cell lines exposed to Aβ1–42. In vitro, SEN1269 alleviated deficits in hippocampal LTP induced by Aβ1–42 and cell‐derived Aβ oligomers. In vivo, SEN1269 reduced the deficits in LTP and memory induced by i.c.v. administration of cell‐derived Aβ oligomers.

CONCLUSIONS AND IMPLICATIONS

SEN1269 protected cells exposed to Aβ1–42, displayed central activity with respect to reducing Aβ‐induced neurotoxicity and was neuroprotective in electrophysiological and behavioural models of memory relevant to Aβ‐induced neurodegeneration. It represents a promising lead for designing inhibitors of Aβ‐mediated synaptic toxicity as potential neuroprotective agents for treating AD.
Levofloxacin‐containing Triple and Sequential Therapy or Standard Sequential Therapy as the First Line Treatment for Helicobacter pylori Eradication in China
Authors: Qian Juan , Ye Feng , Zhang Jun , Yang Yan‐Mei , Tu Hui‐Ming , Jiang Qi , Shang Li , Pan Xiao‐Lin , Shi Rui‐Hua , Zhang Guo‐Xin
Published: August 2012

Aims

To compare the efficacy and the adverse effects of levofloxacin‐containing triple therapy, standard sequential therapy, and levofloxacin‐containing sequential therapy as first‐line treatment for Helicobacter pylori eradication.

Methods

Three hundred and forty‐five naive H. pylori‐positive patients were randomized to receive levofloxacin‐containing 7‐day triple therapy (Levo triple, i.e., esomeprazole, 20 mg, twice daily, amoxicillin, 1 g, twice daily, and levofloxacin, 500 mg, once daily for 7 days, n = 114), standard sequential therapy (SST‐10, 5‐day esomeprazole, 20 mg, twice daily and amoxicillin, 1 g, twice daily followed by 5‐day esomeprazole, 20 mg, twice daily, clarithromycin, 500 mg, twice daily and tinidazole, 500 mg, twice daily for 5 days, n = 115) or levofloxacin‐containing sequential therapy (Levo‐ST‐10, 5‐day esomeprazole, 20 mg, twice daily and amoxicillin, 1 g, twice daily for 5 days followed by 5‐day esomeprazole, 20 mg, twice daily, levofloxacin, 500 mg, once daily and tinidazole, 500 mg, twice daily, n = 116). Eradication was confirmed by a 13C‐urea breath test 4 weeks after completion of treatment.

Results

Intention to treat (ITT) eradication rates were 78.1% (95% CI: 69.4, 85.3%), 78.3% (95% CI: 69.6, 85.4%), and 82.8% (95% CI: 74.6, 89.1%) for Levo triple, SST‐10, Levo‐ST‐10, respectively (p = .599). Per protocol (PP) eradication rates were 80.9% (95% CI: 72.3, 87.8%), 82.6% (95% CI: 74.1, 89.2%), and 86.5% (95% CI: 78.7, 92.2%), respectively, for the three therapies (p = .513). Overall, 3.8% experienced mild to moderate adverse events; the rates were 1.75, 4.35, and 5.17%, respectively, in the three groups (p = .325).

Conclusions

Standard sequential therapy and 7‐day levofloxacin triple therapy produced unacceptably therapeutic efficacy in China. Only levofloxacin‐containing sequential therapy achieved borderline acceptable result. None of the regimens tested reliably achieved 90% or greater therapeutic efficacy in China.
Effect of Sex and Estrogens on Neuronal Activation in an Animal Model of Migraine
Authors: Greco Rosaria , Tassorelli Cristina , Mangione A. Stefania , Smeraldi Antonella , Allena Marta , Sandrini Giorgio , Nappi Giuseppe , Nappi Rossella E.
Published: August 2012

Objective.— In this study, we evaluated the influence of sex and estrogen treatment on nitroglycerin (NTG)‐induced neuronal activation in the rat brain.

Background.— Systemic NTG activates cerebral nuclei of rat involved in nociceptive transmission, as well as in neuroendocrine and autonomic functions. These changes are considered relevant for migraine, since NTG consistently induces spontaneous‐like attacks in migraineurs.

Methods.— Intact and castrated male and female rats, and castrated female rats treated with estradiol benzoate (or placebo) were injected with NTG and sacrificed after 4 hours. Rats were perfused, and their brains were processed for Fos protein, a marker of neuronal activation.

Results.— Data showed a reduced expression of NTG‐induced Fos protein in the paraventricular nucleus (PVH), supraoptic nucleus (SON), and nucleus trigeminalis caudalis (SPVC) of male rats in comparison with female rats. Furthermore, in castrated female rats, NTG‐induced neuronal activation was reduced in PVH, SON, central nucleus of the amygdala (AMI), nucleus tractus solitarius (NTS), area postrema (AP), and SPVC, while in castrated male rats Fos expression was reduced uniquely in the SPVC. Chronic administration of estrogens restored Fos protein expression in PVH, SON, AMI, NTS, AP, and SPVC in castrated female rats.

Conclusion.— These data provide a support for the existence of a sexual dimorphism in NTG‐induced neuronal activation, and they prompt a specific model for evaluating and modulating the influence of estrogens upon the cerebral structures implicated in the pathophysiology of migraine.
Oral Rehabilitation Considerations for Partially Edentulous Periodontal Patients
Authors: Dhingra Kunaal
Published: August 2012

Traditional tooth‐supported and implant‐supported fixed/removable restorations are currently used to replace teeth lost due to periodontal disease. This article reviews the existing literature for oral rehabilitation of partially edentulous periodontal patients with various designs of removable dental prosthesis (RDP), fixed dental prosthesis (FDP) and implant‐supported single crown (SC), by addressing their (a) general features, (b) survival and complication rates, along with considerations for treatment planning in periodontal patients, and (c) preference by patients. To answer these issues, relevant articles were searched and critically analyzed, and their data were extracted. Data reviewed indicated that despite many advantages, implant‐supported restorations have higher complication rates than tooth‐supported restorations. Systematic reviews on conventional RDPs are lacking, but existing literature reviews provide limited evidence suggesting the use of RDPs with design modifications along with strict periodontal care in periodontal patients. Numerous systematic reviews on conventional FDPs and implant‐supported restorations provide a moderate level of evidence favoring their survival in periodontal patients; however, for long‐term success of these restorations, the patient's periodontal condition needs to be stabilized. In terms of patient preference, no restoration is superior, as they all are governed by their cost, advantages, and disadvantages. Thus, in the wake of existing weak evidence for prosthodontic rehabilitation of periodontal patients by these restorations (especially, conventional RDPs and for FDPs and SCs in implant‐supported restorations), longitudinal studies with standardized treatment protocol and methodology are needed to evaluate and compare tooth‐supported and implant‐supported restorations in periodontal patients with regard to survival rates, cost, maintenance, and patient‐centered outcomes.
Our Approach to Maximizing the Durability of Pulmonary Vein Isolation During a Paroxysmal Atrial Fibrillation Ablation Procedure
Authors: REICHLIN TOBIAS , MICHAUD GREGORY F.
Published: August 2012

Maximizing Lesion Durability in PVI. Recurrence of atrial fibrillation (AF) after a single ablation procedure has been reported in the range of 15–60% depending on patient selection. A major factor leading to AF recurrence after catheter ablation therapy is electrical reconnection of one or more pulmonary veins (PVs) due to recovery of excitability of atrial tissue within ablation lesions. Maximizing the durability of pulmonary vein isolation (PVI) is critical to reduce recurrence rates and improve outcome after catheter treatment for AF. Strategies to increase the durability of the lesions include optimization of catheter contact by use of steerable sheaths, direct visualization by intracardiac ultrasound, and observation of the decrease in impedance at the beginning of ablation. Furthermore, currently achievable endpoints in addition to electrical PVI may reduce AF recurrence, such as identification of dormant conduction with adenosine administration and rendering the ablation line unexcitable to pacing. Integration of all these strategies into routine catheter ablation procedures for AF has reduced our AF recurrence rates and can easily be incorporated into practice without additional technological advances. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1272–1276, November 2012)
Dielectric, Ferroelectric, and Piezoelectric Properties of Bi(Ni1/2Ti1/2)O3‐Modified BiFeO3–BaTiO3 Ceramics with High Curie Temperature
Authors: Zhou Qin , Zhou Changrong , Yang Huabin , Chen Guohua , Li Weizhou , Wang Hua
Published: August 2012

New piezoelectric ceramics, 0.71BiFe1−x(Ni1/2Ti1/2)x O3−0.29BaTiO3+0.6 wt% MnO2 [BFNTx–BT] (x = 0–0.09), were fabricated using conventional mixed‐oxide method. It was found that the introduction of BNT into BF‐BT system caused insignificant change in crystal structure, which is a single‐phase perovskite structure. However, an obvious variation in microstructure took place. The ceramics with composition of x = 0.03 showed enhanced piezoelectric, electromechanical, and ferroelectric properties with piezoelectric constant d33 = 156 pC/N, planar electromechanical coupling factors kp = 0.308, remnant polarization Pr = 22.5 μC/cm2, and coercive field Ec = 28.2 kV/cm, with a high Curie temperature Tc = 431°C, respectively. The combination of good piezoelectric properties and high Tc makes these ceramics suitable for elevated temperature piezoelectric devices.
Formation of TiO2 Nanocrystallites in the TiO2–ZnO–B2O3–Al2O3 Glass‐Ceramics
Authors: Masai Hirokazu , Hirakawa Keisuke , Yoshida Kazuki , Miyazaki Takamichi , Takahashi Yoshihiro , Ihara Rie , Fujiwara Takumi
Published: August 2012

We have examined the structure and the crystallization behavior of the 13TiO2–xZnO–17Al2O3–(70−x)B2O3 (TZAB) glass. Coordination number of B2O3 and Al2O3 is changed by substitution of B2O3–ZnO, whereas coordination states of TiO2 and ZnO are not affected by the substitution. With increasing amount of ZnO, network forming AlO4 increases instead of network modifying AlO5 and AlO6. In the case of B2O3, BO4 unit is preferentially formed with increasing amount of ZnO. The glass‐ceramics show selective crystallization of TiO2, and the precipitated phase of TiO2 depends on the amount of ZnO. Dendritic‐like aggregates of anatase crystallites were precipitated in the glass‐ceramic containing lower amount of ZnO, whereas isolated granules of rutile crystallites were precipitated in the glass‐ceramic containing higher amount of ZnO. We have demonstrated that the transparency of the glass‐ceramic strongly depends on the crystallinity of precipitated crystallites. The crystallization behavior indicates that both main network and the interstitial components were affected by the substitution.
Enhanced Broadband 2.0 μm Emission and Energy Transfer Mechanism in Ho–Bi Co‐Doped Borophosphate Glass
Authors: Sheng Qiuchun , Wang Xiaolin , Chen Danping
Published: August 2012

A novel borophosphate glass doped with Ho2O3 and Bi2O3 has been investigated. The efficient energy transfer process between Ho3+ and bismuth ions is observed and the energy transfer efficiency is 47.8%. The enhanced broadband 2.0 μm emission with a full width at half maximum of 180 nm of Ho3+:5I7→5I8 is obtained by codoping Bi2O3 excited by a 445 nm laser diode. The emission properties and energy transfer mechanism of Ho3+ sensitized by bismuth ions are discussed. The results indicate that this glass is a promising candidate for 2.0 μm laser material.
Need for Performance Protocols in TEE and TCD for Detection of Right to Left Shunts
Authors: Chang Jason , Darbonne Carol , Drumm Denise A. , Teleb Mohamed S. , Frey James L.
Published: August 2012

BACKGROUND AND PURPOSE

Although transesophageal echocardiography (TEE) is the gold standard for right to left shunt detection, we observed that transcranial Doppler (TCD) was more sensitive and sought an explanation.

METHODS

We retrospectively evaluated results of TCD and TEE in 118 patients with cryptogenic stroke and transient ischemic attacks. TCDs were done as per modification of a published performance protocol and interpreted by a neurologist and radiologist. TEEs were performed and interpreted by five cardiologists without standardized protocol. Statistical methodology included χ2 tests, Fisher exact tests, and ANOVA.

RESULTS

Overall agreement between TCD and TEE was found for 76 of 118 patients. Sensitivities of TCD and TEE were 93.8% and 53.1%. Sensitivities for TCD interpreters were 61.1% and 64.1%. Sensitivities for TEE operators varied from 46.7% to 75.7%. We were unable to find a performance protocol for TEE microbubble studies in either published literature or certification organizations.

CONCLUSIONS

TEEs and TCDs are operator dependent and thus subject to false negatives. The lower yield and interoperator variability in TEE results appear to reflect the lack of performance protocols and engender concern about false negatives in community use. Consensus performance protocols and certification criteria for both modalities should have an impact on accuracy of shunt detection.
A case–control study of the association between tooth‐development gene polymorphisms and non‐syndromic hypodontia in the Chinese Han population
Authors: Liu Haochen , Zhang Jin , Song Shujuan , Zhao Hongshan , Han Dong , Feng Hailan
Published: August 2012

Hypodontia is one of the most common anomalies of human dentition. Recent genetic studies provide information on a number of genes related to both syndromic and non‐syndromic forms of hypodontia. Fifty putative single nucleotide polymorphisms (SNPs) in 20 genes that play important roles in tooth development were selected, and a case–control study was conducted in 273 subjects with hypodontia (cases) and 200 subjects without hypodontia (controls). DNA was obtained from samples of whole blood or saliva. Genotyping was performed by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS). A significant difference was observed, between subjects with non‐syndromic hypodontia and controls, in the allele and genotype frequencies of two markers [rs929387 of GLI family zinc finger 3 (GLI3) and rs11001553 of Dickkopf‐related protein 1 (DKK1)]. Similar results were observed in a subgroup analysis of test subjects (stratified by gender or missing tooth position). However, this analysis showed no significant difference in the haplotype distribution between the controls and the affected subjects. These data demonstrate an association between some SNPs in tooth development‐associated genes and sporadic non‐syndromic hypodontia in Chinese Han individuals. This information may provide further understanding of the molecular mechanisms of tooth agenesis. Furthermore, these genes can be regarded as candidates for mutation detection in individuals with tooth agenesis.
The global burden of periodontal disease: towards integration with chronic disease prevention and control
Authors: Petersen Poul E. , Ogawa Hiroshi
Published: August 2012

Chronic diseases are accelerating globally, advancing across all regions and pervading all socioeconomic classes. Unhealthy diet and poor nutrition, physical inactivity, tobacco use, excessive use of alcohol and psychosocial stress are the most important risk factors. Periodontal disease is a component of the global burden of chronic disease, and chronic disease and periodontal disease have the same essential risk factors. In addition, severe periodontal disease is related to poor oral hygiene and to poor general health (e.g. the presence of diabetes mellitus and other systemic diseases). The present report highlights the global burden of periodontal disease: the ultimate burden of periodontal disease (tooth loss), as well as signs of periodontal disease, are described from World Health Organization (WHO) epidemiological data. High prevalence rates of complete tooth loss are found in upper middle‐income countries, whereas the tooth‐loss rates, at the time of writing, are modest for low‐income countries. In high‐income countries somewhat lower rates for edentulism are found when compared with upper middle‐income countries. Around the world, social inequality in tooth loss is profound within countries. The Community Periodontal Index was introduced by the WHO in 1987 for countries to produce periodontal health profiles and to assist countries in the planning and evaluation of intervention programs. Globally, gingival bleeding is the most prevalent sign of disease, whereas the presence of deep periodontal pockets (≥6 mm) varies from 10% to 15% in adult populations. Intercountry and intracountry variations are found in the prevalence of periodontal disease, and these variations relate to socio‐environmental conditions, behavioral risk factors, general health status of people (e.g. diabetes and HIV status) and oral health systems. National public health initiatives for the control and prevention of periodontal disease should include oral health promotion and integrated disease‐prevention strategies based on common risk‐factor approaches. Capacity building of oral health systems must consider the establishment of a financially fair service in periodontal care. Health systems research is needed for the evaluation of population‐oriented oral health programs.
Periodontal health through public health – the case for oral health promotion
Authors: Watt Richard G. , Petersen Poul E.
Published: August 2012

Periodontal diseases are highly prevalent, particularly amongst socially disadvantaged populations, impact on quality of life and are costly to treat. Clinical treatments and chairside preventive approaches alone will never adequately address this problem. Indeed in many parts of the developing world clinical care and chairside prevention are both unaffordable and inappropriate for the control of periodontal diseases. A paradigm shift away from the individualized treatment approach to a population public health model is needed to promote periodontal health and, in particular to address social inequalities in periodontal status. Public health measures need to focus on the underlying determinants of periodontal diseases. Poor hygiene, tobacco use, psychosocial factors and related systemic diseases are the main risk factors for periodontal diseases. Public health interventions need to tackle these factors but also must recognize and act upon the distal underlying influences that determine and pattern these identified risks. Recognition also needs to be placed on the interlinking and common risk factors shared by periodontal diseases and other chronic conditions. A complementary range of public health policies acting at local, regional, national and international levels need to be implemented to achieve sustainable improvements in oral health. To be effective these policies need to link across the broader public health agenda and require public engagement and support. Clinicians, public health practitioners, commercial organizations and professional groups all have an important role to play in promoting periodontal health.
Oral health care systems in developing and developed countries
Authors: Kandelman Daniel , Arpin Sophie , Baez Ramon J. , Baehni Pierre C. , Petersen Poul E.
Published: August 2012

Health care systems are essential for promoting, improving and maintaining health of the population. Through an efficient health service, patients can be advised of disease that may be present and so facilitate treatment; risks factors whose modification could reduce the incidence of disease and illness in the future can be identified, and further, how controlling such factors can contribute to maintain a good quality of life. In developed countries, clinics or hospitals may be supported by health professionals from various specialties that allow their cooperation to benefit the patient; these institutions or clinics may be equipped with the latest technical facilities. In developing countries, health services are mostly directed to provide emergency care only or interventions towards certain age group population. The most common diseases are dental caries and periodontal disease and frequently intervention procedures aim, at treating existing problems and restore teeth and related structure to normal function. It is unfortunate that the low priority given to oral health hinders acquisition of data and establishment of effective periodontal care programmes in developing countries but also in some developed countries where the periodontal profile is also less than satisfactory. Despite the fact that in several developed countries there are advanced programmes oriented to periodontal disease treatments, the concern is related to the lack of preventive oriented treatments. According to data available on periodontal status of populations from developed countries, despite the number of dentists and trained specialists, dental health professionals do not presently meet adequately the need for prevention, focusing mainly on curative care. The need for strengthening disease prevention and health promotion programmes in order to improve oral health conditions and particularly periodontal status in the majority of countries around the world is evident. Unfortunately, in many countries, the human, financial and material resources are still insufficient to meet the need for oral health care services and to provide universal access, especially in disadvantaged communities, in both developing and developed countries. Moreover, even though the most widespread illnesses are avoidable, not all population groups are well informed about or able to take advantage of the proper measures for oral health promotion. In addition, in many countries, oral health care needs to be fully integrated into national or community health programmes. Improving oral health is a very challenging objective in developing countries, but also in developed countries, especially with the accelerated aging of the population now underway and intensifying over the coming years.