bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of TVT and TVT‐O in patients with stress urinary incontinence: Short‐term cure rates and factors influencing the outcome. A prospective randomised study
Authors: KARATEKE Ates , HALILOGLU Berna , CAM Cetin , SAKALLI Mustafa
Published: March 2009

Background: Recently, mid‐urethral slings have been commonly used in treatment of patients with stress urinary incontinence (SUI).

Aims: To investigate tension‐free vaginal tape (TVT) and tension‐free obturator tape (TVT‐O) for surgical treatment of SUI for cure rates (primary endpoint), complications and factors influencing cure rate (secondary endpoints).

Methods: One‐hundred and sixty‐four patients were included in the study (n = 81 for TVT, n = 83 for TVT‐O). The cure rates, complications, preoperative and postoperative urodynamic evaluation, Q‐tip test, the Turkish version of Incontinence Impact Questionnaire (IIQ‐7) and Urogenital Distress Inventory (UDI‐6) scores were recorded. At three and 12 months, the patients were evaluated regarding outcome measures.

Results: The cure rates were similar in TVT and TVT‐O groups, 88.9% versus 86.7% respectively. Mean operative time was significantly shorter in TVT‐O group (P = 0.001). The cure rate was significantly higher in both groups in patients with urethral hypermobility when compared with those with no hypermobility (P = 0.001).

Conclusions: The TVT and TVT‐O procedures appear to be equally effective for the treatment of SUI. Also, urethral hypermobility seems to be a factor influencing cure rate of mid‐urethral slings.
Acupuncture as Pain Relief During Delivery: A Randomized Controlled Trial
Authors: Borup Lissa , Wurlitzer Winnie , Hedegaard Morten , Kesmodel Ulrik S. , Hvidman Lone
Published: March 2009

ABSTRACT:  Background:
Many women need some kind of analgesic treatment to relieve pain during childbirth. The objective of our study was to compare the effect of acupuncture with transcutaneous electric nerve stimulation (TENS) and traditional analgesics for pain relief and relaxation during delivery with respect to pain intensity, birth experience, and obstetric outcome.
Methods:
A randomized controlled trial was conducted with 607 healthy women in labor at term who received acupuncture, TENS, or traditional analgesics. Primary outcomes were the need for pharmacological and invasive methods, level of pain assessed by a visual analogue scale, birth experience and satisfaction with delivery, and pain relief evaluated at 2 months postpartum. Secondary obstetric outcomes were duration of labor, use of oxytocin, mode of delivery, postpartum hemorrhage, Apgar score, and umbilical cord pH value. Analysis complied with the intention‐to‐treat principle.
Results:
Use of pharmacological and invasive methods was significantly lower in the acupuncture group (acupuncture vs traditional, p < 0.001; acupuncture vs TENS, p = 0.031). Pain scores were comparable. Acupuncture did not influence the duration of labor or the use of oxytocin. Mean Apgar score at 5 minutes and umbilical cord pH value were significantly higher among infants in the acupuncture group compared with infants in the other groups.Conclusions: Acupuncture reduced the need for pharmacological and invasive methods during delivery. Acupuncture is a good supplement to existing pain relief methods. (BIRTH 36:1 March 2009)
Consumer Involvement in the South Australian State Policy for Planned Home Birth
Authors: Newman Lareen , Hood Jo
Published: March 2009

Abstract:  Two consumer representatives were participants in the development of their state government’s Policy for Planned Birth At Home in South Australia. It was released in November 2007 to guide staff in public hospital and community midwifery programs, and the first hospital‐based home birth service is commencing in February 2009. Consumer experiences of policy development and perceived benefits of consumer involvement for policy and transparency processes are described. Inclusion of consumers widely and actively during development and reform of maternity care is essential if real consumer participation is to occur and contribute to care that is truly woman‐centered. (BIRTH 36:1 March 2009)
Clinical Practice Guideline for the Evaluation of Fever and Infection in Older Adult Residents of Long‐Term Care Facilities: 2008 Update by the Infectious Diseases Society of America
Authors: High Kevin P. , Bradley Suzanne F. , Gravenstein Stefan , Mehr David R. , Quagliarello Vincent J. , Richards Chesley , Yoshikawa Thomas T.
Published: March 2009

Residents of long‐term care facilities (LTCFs) are at great risk for infection. Most residents are older and have multiple comorbidities that complicate recognition of infection; for example, typically defined fever is absent in more than one‐half of LTCF residents with serious infection. Furthermore, LTCFs often do not have the on‐site equipment or personnel to evaluate suspected infection in the fashion typically performed in acute care hospitals. In recognition of the differences between LTCFs and hospitals with regard to hosts and resources present, the Infectious Diseases Society of America first provided guidelines for evaluation of fever and infection in LTCF residents in 2000. The guideline presented here represents the second edition, updated by data generated over the intervening 8 years. It focuses on the typical elderly person institutionalized with multiple chronic comorbidities and functional disabilities (e.g., a nursing home resident). Specific topic reviews and recommendations are provided with regard to what resources are typically available to evaluate suspected infection, what symptoms and signs suggest infection in a resident of an LTCF, who should initially evaluate the resident with suspected infection, what clinical evaluation should be performed, how LTCF staff can effectively communicate about possible infection with clinicians, and what laboratory tests should be ordered. Finally, a general outline of how a suspected outbreak of a specific infectious disease should be investigated in an LTCF is provided.
Driving Issues in Epilepsy: Past, Present, and Future
Authors: Krumholz Allan
Published: March 2009

Driving restrictions for people with seizure disorders are intended to ensure the public's safety, but driving is of such great importance in the United States that the imposed restrictions also may unduly harm the welfare of these individuals. Because driving restrictions historically have been based more on expert opinion than sound scientific evidence, the appropriateness and application of standards for licensing drivers with seizures continue to raise questions and concerns, as does the role physicians should have in the process. Driving is an important and complex practical concern for physicians who care for people with epilepsy or who may serve as consultants to regulatory authorities, requiring them to be well informed about the relevant issues to properly manage their patients and to protect themselves against lawsuits.
A Pregnant Pause to Consider Teratogenicity of Topiramate
Authors: Fountain Nathan B.
Published: March 2009

Topiramate in Pregnancy: Preliminary Experience from the UK Epilepsy and Pregnancy Register. Hunt S, Russell A, Smithson WH, Parsons L, Robertson I, Waddell R, Irwin B, Morrison PJ, Morrow J, Craig J, UK Epilepsy and Pregnancy Register. Neurology 2008;71(4):272–276.

Objectives

Topiramate (Topamax®) is licensed to be used, either in monotherapy or as adjunctive treatment, for generalized tonic-clonic seizures or partial seizures with or without secondary generalization and for prevention of migraine. The safety of topiramate in human pregnancy is largely unknown. Here we report on our experience of pregnancies exposed to topiramate.

Methods

This study is part of a prospective, observational registration and follow-up study. Suitable cases are women with epilepsy who become pregnant while taking topiramate either singly or along with other antiepileptic drugs (AEDs), and who are referred before outcome of the pregnancy is known. The main outcome measure is the major congenital malformation (MCM) rate. Secondary outcomes include risk of specific MCM, minor malformation rate, birthweight, and gestational age at delivery.

Results

Full outcome data are available on 203 pregnancies. Of these, 178 resulted in live birth; 16 had an MCM (9.0%; 95% CI 5.6–14.1%). Three MCMs were observed in 70 monotherapy exposures (4.8%; 95% CI 1.7–13.3%) and 13 in cases exposed to topiramate as part of a polytherapy regimen (11.2%; 95% CI 6.7–18.2%). Four of the MCMs were oral clefts (2.2%; 95% CI 0.9–5.6%). Four cases of hypospadias were reported (5.1%; 95% CI 0.2–10.1%) among 78 known live male births, of which two were classified as major malformations.

Conclusions

The number of outcomes of human pregnancies exposed to topiramate is low, but the MCM rate for topiramate polytherapy raises some concerns. Overall, the rate of oral clefts observed was 11 times the background rate. Although the present data provide new information, they should be interpreted with caution due to the sample size and wide confidence intervals.
Dietary Therapy for Epilepsy: The Advantage of Rapid Onset of Action
Authors: Abou-Khalil Bassel W.
Published: March 2009

When Do Seizures Usually Improve with the Ketogenic Diet? Kossoff EH, Laux LC, Blackford R, Morrison PF, Pyzik PL, Hamdy RM, Turner Z, Nordli DR Jr. Epilepsia 2008;49:329–333.

Purpose

Parents often expect immediate seizure improvement after starting the ketogenic diet (KD) for their children. The purpose of this study was to determine the typical time to seizure reduction as well as the time after which it was unlikely to be helpful in those children started on the KD.

Methods

Records of all children started on the KD at Johns Hopkins Hospital, Baltimore, ( n = 83) and Children's Memorial Hospital, Chicago, ( n = 35) from November 2003 to December 2006 were examined to determine the first day in which seizures were reportedly improved.

Results

Of the 118 children started on the KD, 99 (84%) had documented seizure reduction. The overall median time to first improvement was 5 days (range: 1–65 days). Seventy-five percent of children improved within 14 days. In those children who were fasted at KD onset, the time to improvement was quicker (median 5 vs 14 days, p < 0.01) with a higher percentage improving within 5 days (60% vs 31%, p = 0.01). No difference was identified between fasting and nonfasting in regards to long-term outcomes, however.

Discussion

The KD works quickly, when effective, typically within the first 1–2 weeks. Starting the KD after a fasting period may lead to a more rapid but equivalent long-term seizure reduction, confirming prior reports. If the KD has not led to seizure reduction after 2 months, it can probably be discontinued.
Is Modulation of Cortical Synapses after Brain Trauma Homeostatic? or, since When is Epilepsy Normal?
Authors: Dudek F. Edward
Published: March 2009

Synaptic Strength Modulation after Cortical Trauma: A Role in Epileptogenesis. Avramescu S, Timofeev I. J Neurosci. 2008;28(27):6760–6772. Traumatic brain injuries are often followed by abnormal hyperexcitability, leading to acute seizures and epilepsy. Previous studies documented the rewiring capacity of neocortical neurons in response to various cortical and subcortical lesions. However, little information is available on the functional consequences of these anatomical changes after cortical trauma and the adaptation of synaptic connectivity to a decreased input produced by chronic deafferentation. In this study, we recorded intracellular (IC) activities of cortical neurons simultaneously with extracellular (EC) unit activities and field potentials of neighboring cells in cat cortex, after a large transection of the white matter underneath the suprasylvian gyrus, in acute and chronic conditions (at 2, 4, and 6 weeks) in ketamine–xylazine-anesthetized cats. Using EC spikes to compute the spike-triggered averages of IC membrane potential, we found an increased connection probability and efficacy between cortical neurons weeks after cortical trauma. Inhibitory interactions showed no significant changes in the traumatized cortex compared with control. The increased synaptic efficacy was accompanied by enhanced input resistance and intrinsic excitability of cortical neurons, as well as by increased duration of silent network periods. Our electrophysiological data revealed functional consequences of previously reported anatomical changes in the injured cortex. We suggest that homeostatic synaptic plasticity compensating the decreased activity in the undercut cortex leads to an uncontrollable cortical hyperexcitability and seizure generation.
Fast Ripples: What Do New Data about Gap Junctions and Disrupted Spike Firing Reveal about Underlying Mechanisms?
Authors: Ben-Ari Yehezkel
Published: March 2009

Gap Junctions on Hippocampal Mossy Fiber Axons Demonstrated by Thin-Section Electron Microscopy and Freeze Fracture Replica Immunogold Labeling. Hamzei-Sichani F, Kamasawa N, Janssen WG, Yasumura T, Davidson KG, Hof PR, Wearne SL, Stewart MG, Young SR, Whittington MA, Rash JE, Traub RD. Proc Natl Acad Sci USA 2007;104(30):12548–12553. Gap junctions have been postulated to exist between the axons of excitatory cortical neurons based on electrophysiological, modeling, and dye-coupling data. Here, we provide ultrastructural evidence for axoaxonic gap junctions in dentate granule cells. Using combined confocal laser scanning microscopy, thin-section transmission electron microscopy, and grid-mapped freeze–fracture replica immunogold labeling, 10 close appositions revealing axoaxonic gap junctions (30–70 nm in diameter) were found between pairs of mossy fiber axons (100–200 nm in diameter) in the stratum lucidum of the CA3b field of the rat ventral hippocampus, and one axonal gap junction (100 connexons) was found on a mossy fiber axon in the CA3c field of the rat dorsal hippocampus. Immunogold labeling with two sizes of gold beads revealed that connexin 36 was present in that axonal gap junction. These ultrastructural data support computer modeling and in vitro electrophysiological data suggesting that axoaxonic gap junctions play an important role in the generation of very fast (>70 Hz) network oscillations and in the hypersynchronous electrical activity of epilepsy.

Reduced Spike-Timing Reliability Correlates with the Emergence of Fast Ripples in the Rat Epileptic Hippocampus. Foffani G, Uzcategui YG, Gal B, Menendez de la Prida L. Neuron 2007;55(6):930–941. Ripples are sharp-wave-associated field oscillations (100–300 Hz) recorded in the hippocampus during behavioral immobility and slow-wave sleep. In epileptic rats and humans, a different and faster oscillation (200–600 Hz), termed fast ripples, has been described. However, the basic mechanisms are unknown. Here, we propose that fast ripples emerge from a disorganized ripple pattern caused by unreliable firing in the epileptic hippocampus. Enhanced synaptic activity is responsible for the irregular bursting of CA3 pyramidal cells due to large membrane potential fluctuations. Lower field interactions and a reduced spike-timing reliability concur with decreased spatial synchronization and the emergence of fast ripples. Reducing synaptically driven membrane potential fluctuations improves both spike-timing reliability and spatial synchronization and restores ripples in the epileptic hippocampus. Conversely, a lower spike-timing reliability, with reduced potassium currents, is associated with ripple shuffling in normal hippocampus. Therefore, fast ripples may reflect a pathological desynchronization of the normal ripple pattern.
Thalamic Reticular Neurons Are Unexcited by New Stargazer Seizure Mechanism
Authors: Chetkovich Dane
Published: March 2009

Loss of Inhibitory Neuron AMPA Receptors Contributes to Ataxia and Epilepsy in Stargazer Mice. Menuz K, Nicoll RA. J Neurosci. 2008;28(42):10599–10603. Stargazer mice are characterized by ataxia and seizures, which resemble the human disorder absence epilepsy. Stargazin, the protein mutated in stargazer mice, promotes the expression and function of neuronal AMPA receptors (AMPARs). However, it is unclear how decreased expression of excitatory AMPARs generates stargazer seizures, given that seizures often result from increased neuronal excitability. Additionally, although stargazer ataxia has been attributed to loss of AMPARs from cerebellar granule cells, other cerebellar neurons have not been examined. To examine the role of AMPAR dysfunction in these behavioral phenotypes, electrophysiological recordings were used to probe AMPAR regulation in relevant brain regions. We found that both cerebellar Purkinje cells and inhibitory thalamic reticular nucleus neurons have strongly reduced synaptic AMPAR function in stargazer mice. Together, our data suggest that impaired AMPAR regulation in multiple neuron populations may contribute to the behavioral phenotypes of absence seizures and ataxia seen in stargazer mice and imply that an understanding of human genetic disorders will require knowledge of both the genes that are mutated as well as their precise cellular expression pattern.
Policy Learning for Flood Mitigation: A Longitudinal Assessment of the Community Rating System in Florida
Authors: Brody Samuel D. , Zahran Sammy , Highfield Wesley E. , Bernhardt Sarah P. , Vedlitz Arnold
Published: March 2009

Floods continue to inflict the most damage upon human communities among all natural hazards in the United States. Because localized flooding tends to be spatially repetitive over time, local decisionmakers often have an opportunity to learn from previous events and make proactive policy adjustments to reduce the adverse effects of a subsequent storm. Despite the importance of understanding the degree to which local jurisdictions learn from flood risks and under what circumstances, little if any empirical, longitudinal research has been conducted along these lines. This article addresses the research gap by examining the change in local flood mitigation policies in Florida from 1999 to 2005. We track 18 different mitigation activities organized into four series of activities under the Federal Emergency Management Agency's (FEMA) Community Rating System (CRS) for every local jurisdiction in Florida participating in the FEMA program on a yearly time step. We then identify the major factors contributing to policy changes based on CRS scores over the seven‐year study period. Using multivariate statistical models to analyze both natural and social science data, we isolate the effects of several variables categorized into the following groups: hydrologic conditions, flood disaster history, socioeconomic and human capital controls. Results indicate that local jurisdictions do in fact learn from histories of flood risk and this process is expedited under specific conditions.
The Risk Management of Third Parties During Construction in Multifunctional Urban Locations
Authors: Suddle Shahid
Published: March 2009

Buildings above roads, railways, and existing buildings themselves are examples of multifunctional urban locations. The construction stage of those buildings is in general extremely complicated. Safety is one of the critical issues during the construction stage. Because the traffic on the infrastructure must continue during the construction of the building above the infrastructure, falling objects due to construction activities form a major hazard for third parties, i.e., people present on the infrastructure or beneath it, such as car drivers and passengers. This article outlines a systematic approach to conduct quantitative risk assessment (QRA) and risk management of falling elements for third parties during the construction stage of the building above the infrastructure in multifunctional urban locations. In order to set up a QRA model, quantifiable aspects influencing the risk for third parties were determined. Subsequently, the conditional probabilities of these aspects were estimated by historical data or engineering judgment. This was followed by integrating those conditional probabilities, now used as input parameters for the QRA, into a Bayesian network representing the relation and the conditional dependence between the quantified aspects. The outcome of the Bayesian network—the calculation of both the human and financial risk in quantitative terms—is compared with the risk acceptance criteria as far as possible. Furthermore, the effect of some safety measures were analyzed and optimized in relation with decision making. Finally, the possibility of integration of safety measures in the functional and structural building design above the infrastructure are explored.
The Impact of Revenue‐Maximizing Priority Pricing on Customer Delay Costs
Authors: Gilland Wendell G. , Warsing Donald P.
Published: March 2009

Speed is an increasingly important determinant of which suppliers will be given customers' business and is defined as the time between when an order is placed by the customer and when the product is delivered, or as the amount of time customers must wait before they receive their desired service. In either case, the speed a customer experiences can be enhanced by giving priority to that particular customer. Such a prioritization scheme will necessarily reduce the speed experienced by lower‐priority customers, but this can lead to a better outcome when different customers place different values on speed. We model a single resource (e.g., a manufacturer) that processes jobs from customers who have heterogeneous waiting costs. We analyze the price that maximizes priority revenue for the resource owner (i.e., supplier, manufacturer) under different assumptions regarding customer behavior. We discover that a revenue‐maximizing supplier facing self‐interested customers (i.e., those that independently minimize their own expected costs) charges a price that also minimizes the expected total delay costs across all customers and that this outcome does not result when customers coordinate to submit priority orders at a level that seeks to minimize their aggregate costs of priority fees and delays. Thus, the customers are better off collectively (as is the supplier) when the supplier and customers act independently in their own best interests. Finally, as the number of priority classes increases, both the priority revenues and the overall customer delay costs improve, but at a decreasing rate.
Electronic Data Interchange: Research Review and Future Directions*
Authors: Narayanan Sriram , Marucheck Ann S. , Handfield Robert B.
Published: March 2009

For nearly two decades, electronic data interchange (EDI) has been widely viewed as a technology pivotal to supply chain management that has also provided benefits to firms on multiple levels. Despite a substantial body of literature, there are a number of conflicting and inconclusive research results in this field. In this study, we synthesize the diverse body of research in EDI by organizing the literature into an initial theoretical framework. Based on a meta‐analysis of results from the empirical literature, we seek to clarify conflicting results from the literature in order to develop a more unified theoretical framework of contextual variables associated with EDI adoption factors and outcomes. From a managerial standpoint, our literature‐based framework offers a set of guidelines for making successful EDI adoption and implementation decisions.
Using Buyer–Supplier Performance Frontiers to Manage Relationship Performance*
Authors: Ross Anthony D. , Buffa Frank P. , Droge Cornelia , Carrington Donald
Published: March 2009

This article presents a consensus‐building methodology to implement dyadic performance measurement. It focuses on transmuting supplier performance and buyer performance metrics on several important attributes into actionable relationship management plans using Clark's (1996) theory of performance frontiers. Access to the supplier performance management program of a Fortune 100 corporation was granted to the research team. Direct observation of practice and in‐depth discussions with several managers provided a roadmap for investigating both the literature on quantitative evaluation methods and the empirically derived theory on buyer–supplier relationships from several perspectives. This study describes a multiphase, iterative framework that uses current methods and theory on dyadic buyer–supplier evaluation to consider: (i) evaluation criteria and their importance; (ii) whether the improvement focus should be on strengths, weaknesses, or both; and (iii) whether the referent role supplier should be the ideal supplier, best supplier, or best‐in‐strategic‐group supplier in the focal supply base. We illustrate a unifying approach by reporting results from a large buyer and 35 of its key suppliers. This research makes the case for managing supplier relationships through the dyadic performance lens. The outputs from this framework provide individual supplier improvement paths which are actionable prescriptions for each buyer–supplier dyad, as well as recommendations for strategic group formation.
An Empirical Examination of the Structural Dimensions of the Service Recovery System*
Authors: Smith Jeffery S. , Karwan Kirk R. , Markland Robert E.
Published: March 2009

This study identifies the structural dimensions that constitute a service recovery system. We employ a structured scale development process to introduce, define, and operationalize seven distinct first‐order constructs (i.e., structural dimensions) of service recovery. Potential constructs and their items are identified from the literature, experts and practitioners are employed to refine scales, and psychometric properties are tested using data from a sample of 158 service providers. Constructs such as those developed here should prove to be useful as researchers strive to incorporate operational notions into service recovery studies and to move toward systematic recovery prescriptions for service providers. Accordingly, the results presented herein can provide a springboard for future research on service recovery while also providing practicing managers with a diagnostic tool against which to benchmark existing recovery systems.
Bayesian Wombling for Spatial Point Processes
Authors: Liang Shengde , Banerjee Sudipto , Carlin Bradley P.
Published: March 2009

SummaryIn many applications involving geographically indexed data, interest focuses on identifying regions of rapid change in the spatial surface, or the related problem of the construction or testing of boundaries separating regions with markedly different observed values of the spatial variable. This process is often referred to in the literature as boundary analysis or wombling. Recent developments in hierarchical models for point‐referenced (geostatistical) and areal (lattice) data have led to corresponding statistical wombling methods, but there does not appear to be any literature on the subject in the point‐process case, where the locations themselves are assumed to be random and likelihood evaluation is notoriously difficult. We extend existing point‐level and areal wombling tools to this case, obtaining full posterior inference for multivariate spatial random effects that, when mapped, can help suggest spatial covariates still missing from the model. In the areal case we can also construct wombled maps showing significant boundaries in the fitted intensity surface, while the point‐referenced formulation permits testing the significance of a postulated boundary. In the computationally demanding point‐referenced case, our algorithm combines Monte Carlo approximants to the likelihood with a predictive process step to reduce the dimension of the problem to a manageable size. We apply these techniques to an analysis of colorectal and prostate cancer data from the northern half of Minnesota, where a key substantive concern is possible similarities in their spatial patterns, and whether they are affected by each patient's distance to facilities likely to offer helpful cancer screening options.
Modeling Age and Nest‐Specific Survival Using a Hierarchical Bayesian Approach
Authors: Cao Jing , He Chong Z. , Suedkamp Wells Kimberly M. , Millspaugh Joshua J. , Ryan Mark R.
Published: March 2009

Summary:  Recent studies have shown that grassland birds are declining more rapidly than any other group of terrestrial birds. Current methods of estimating avian age‐specific nest survival rates require knowing the ages of nests, assuming homogeneous nests in terms of nest survival rates, or treating the hazard function as a piecewise step function. In this article, we propose a Bayesian hierarchical model with nest‐specific covariates to estimate age‐specific daily survival probabilities without the above requirements. The model provides a smooth estimate of the nest survival curve and identifies the factors that are related to the nest survival. The model can handle irregular visiting schedules and it has the least restrictive assumptions compared to existing methods. Without assuming proportional hazards, we use a multinomial semiparametric logit model to specify a direct relation between age‐specific nest failure probability and nest‐specific covariates. An intrinsic autoregressive prior is employed for the nest age effect. This nonparametric prior provides a more flexible alternative to the parametric assumptions. The Bayesian computation is efficient because the full conditional posterior distributions either have closed forms or are log concave. We use the method to analyze a Missouri dickcissel dataset and find that (1) nest survival is not homogeneous during the nesting period, and it reaches its lowest at the transition from incubation to nestling; and (2) nest survival is related to grass cover and vegetation height in the study area.
Nonparametric Modeling of Longitudinal Covariance Structure in Functional Mapping of Quantitative Trait Loci
Authors: Yap John Stephen , Fan Jianqing , Wu Rongling
Published: March 2009

SummaryEstimation of the covariance structure of longitudinal processes is a fundamental prerequisite for the practical deployment of functional mapping designed to study the genetic regulation and network of quantitative variation in dynamic complex traits. We present a nonparametric approach for estimating the covariance structure of a quantitative trait measured repeatedly at a series of time points. Specifically, we adoptHuang et al.'s(2006, Biometrika 93, 85–98) approach of invoking the modified Cholesky decomposition and converting the problem into modeling a sequence of regressions of responses. A regularized covariance estimator is obtained using a normal penalized likelihood with an L2penalty. This approach, embedded within a mixture likelihood framework, leads to enhanced accuracy, precision, and flexibility of functional mapping while preserving its biological relevance. Simulation studies are performed to reveal the statistical properties and advantages of the proposed method. A real example from a mouse genome project is analyzed to illustrate the utilization of the methodology. The new method will provide a useful tool for genome‐wide scanning for the existence and distribution of quantitative trait loci underlying a dynamic trait important to agriculture, biology, and health sciences.
Modeling Data with Excess Zeros and Measurement Error: Application to Evaluating Relationships between Episodically Consumed Foods and Health Outcomes
Authors: Kipnis Victor , Midthune Douglas , Buckman Dennis W. , Dodd Kevin W. , Guenther Patricia M. , Krebs‐Smith Susan M. , Subar Amy F. , Tooze Janet A. , Carroll Raymond J. , Freedman Laurence S.
Published: March 2009

SummaryDietary assessment of episodically consumed foods gives rise to nonnegative data that have excess zeros and measurement error.Tooze et al.(2006, Journal of the American Dietetic Association 106, 1575–1587) describe a general statistical approach (National Cancer Institute method) for modeling such food intakes reported on two or more 24‐hour recalls (24HRs) and demonstrate its use to estimate the distribution of the food's usual intake in the general population. In this article, we propose an extension of this method to predict individual usual intake of such foods and to evaluate the relationships of usual intakes with health outcomes. Following the regression calibration approach for measurement error correction, individual usual intake is generally predicted as the conditional mean intake given 24HR‐reported intake and other covariates in the health model. One feature of the proposed method is that additional covariates potentially related to usual intake may be used to increase the precision of estimates of usual intake and of diet‐health outcome associations. Applying the method to data from the Eating at America's Table Study, we quantify the increased precision obtained from including reported frequency of intake on a food frequency questionnaire (FFQ) as a covariate in the calibration model. We then demonstrate the method in evaluating the linear relationship between log blood mercury levels and fish intake in women by using data from the National Health and Nutrition Examination Survey, and show increased precision when including the FFQ information. Finally, we present simulation results evaluating the performance of the proposed method in this context.
Morphological, Molecular, and Phylogenetic Characterization of Nosema ceranae, a Microsporidian Parasite Isolated from the European Honey Bee, Apis mellifera1
Authors: CHEN YANPING P. , EVANS JAY D. , MURPHY CHARLES , GUTELL ROBIN , ZUKER MICHAEL , GUNDENSEN‐RINDAL DAWN , PETTIS JEFF S.
Published: March 2009

ABSTRACT. Nosema ceranae, a microsporidian parasite originally described from Apis cerana, has been found to infect Apis melllifera and is highly pathogenic to its new host. In the present study, data on the ultrastructure of N. ceranae, presence of N. ceranae‐specific nucleic acid in host tissues, and phylogenetic relationships with other microsporidia species are described. The ultrastructural features indicate that N. ceranae possesses all of the characteristics of the genus Nosema. Spores of N. ceranae measured approximately 4.4 × 2.2 μm on fresh smears. The number of coils of the polar filament inside spores was 18–21. Polymerase chain reaction (PCR) signals specific for N. ceranae were detected not only in the primary infection site, the midgut, but also in the tissues of hypopharyngeal glands, salivary glands, Malpighian tubules, and fat body. The detection rate and intensity of PCR signals in the fat body were relatively low compared with other examined tissues. Maximum parsimony analysis of the small subunit rRNA gene sequences showed that N. ceranae appeared to be more closely related to the wasp parasite, Nosema vespula, than to N. apis, a parasite infecting the same host.
SWP25, A Novel Protein Associated with the Nosema bombycis Endospore1
Authors: WU ZHENGLI , LI YANHONG , PAN GUOQING , ZHOU ZEYANG , XIANG ZHONGHUAI
Published: March 2009

ABSTRACT. Microsporidia are eukaryotic, obligate intracellular, spore‐forming parasites. The resistant spores, which harbor a rigid cell wall, are critical for their host‐to‐host transmission and persistence in the environment. The spore wall comprises two major layers: the exospore and the endospore. In Nosema bombycis, two spore wall proteins have been characterized—an endosporal protein, SWP30, and an exosporal protein, SWP32. Here, we report the identification of the third spore wall protein of N. bombycis, SWP25, the gene of which has no known homologue. SWP25 is predicted to posses a signal peptide and a heparin‐binding motif. Immunoelectron microscopy analysis showed that this protein is localized to the endospore. This characterization of a new spore wall protein of N. bombycis may facilitate our investigation of the relationship between N. bombycis and its host, Bombyx mori.
Green Fluorescent Protein (GFP) as a Reporter Gene for the Plant Pathogenic Oomycete Phytophthora ramorum
Authors: RIEDEL MARKO , CALMIN GAUTIER , BELBAHRI LASSAAD , LEFORT FRANCOIS , GÖTZ MONIKA , WAGNER STEFAN , WERRES SABINE
Published: March 2009

ABSTRACT. Transgenic Phytophthora ramorum strains that produce green fluorescent protein (GFP) constitutively were obtained after stable DNA integration using a polyethylene glycol and CaCl2‐based transformation protocol. Green fluorescent protein production was studied in developing colonies and in different propagules of the pathogen to evaluate its use in molecular and physiological studies. About 12% of the GFP transformants produced GFP to a level detectable by a confocal laser scanning microscope. Green fluorescent protein could be visualized in structures with vital protoplasm, such as hyphal tips and germinating cysts. In infection studies with Rhododendron, one of the GFP expressing strains showed aggressiveness equal to that of the corresponding non‐labelled isolate. Thus, GFP could be used as a reporter gene in P. ramorum. Limitations of the technology are discussed.
“Candidatus Cryptoprodotis polytropus,” A Novel Rickettsia‐Like Organism in the Ciliated Protist Pseudomicrothorax dubius (Ciliophora, Nassophorea)
Authors: FERRANTINI FILIPPO , FOKIN SERGEI I. , MODEO LETIZIA , ANDREOLI ILARIA , DINI FERNANDO , GÖRTZ HANS‐DIETER , VERNI FRANCO , PETRONI GIULIO
Published: March 2009

ABSTRACT. Rickettsia‐like organisms (RLO) are obligate, often highly fastidious, intracellular bacterial parasites associated with a variety of vertebrate and invertebrate hosts. Despite their importance as causative agents of severe mortality outbreaks in farmed aquatic species, little is known about their life cycle and their host range. The present work reports the characterization of “Candidatus Cryptoprodotis polytropus,” a novel Rickettsia‐like bacterium associated with the common ciliate species Pseudomicrothorax dubius by means of the “Full‐Cycle rRNA Approach” and ultrastructural observations. The morphological description by in vivo and scanning electron microscopy and the 18S rRNA gene sequence of the host species is provided as well. Phylogenetic analysis based on the 16S rRNA gene supports the inclusion of “Candidatus Cryptoprodotis polytropus” within the family Rickettsiaceae (cl. Alphaproteobacteria) together with the genera Rickettsia and Orientia. Observations on natural ciliate populations account for the occasional nature of this likely parasitic association. The presence of a previously unknown RLO in ciliates sheds a new light on the possible role of protists as transient hosts, vectors or natural reservoir for some economically important pathogens.
Enterocytozoon bieneusi Genotype Nomenclature Based on the Internal Transcribed Spacer Sequence: A Consensus
Authors: SANTÍN MÓNICA , FAYER RONALD
Published: March 2009

ABSTRACT. The standard method for determining the genotypes of Enterocytozoon bieneusi is based on the DNA sequence of the internal transcribed spacer (ITS) region of the rRNA gene. There are 81 genotypes with 111 genotype names: 26 genotypes have been identified exclusively in humans, eight have been identified in humans and in other hosts, 27 have been identified exclusively in cattle and pigs, six have been identified exclusively in cats and dogs, and 14 have been identified in miscellaneous hosts. Because none of these genotypes has taxonomic status and therefore do not adhere to the International Code of Zoological Nomenclature regarding naming, some genotypes have received multiple names, each different and in separate publications by different authors. Because of the proliferation of genotypes with overlapping names and multiple hosts the scientific literature has become confusing and difficult to efficiently utilize. To reduce confusion and provide guidance for future publications we tabulated all names, GenBank accession numbers, and author citations and propose that the first published name has precedence and should become the primary name used in all subsequent publications in which genotyping is based on ITS sequencing. In those publications the names and GenBank numbers that were submitted at later dates should also be provided by the authors as synonyms to aid readers and reviewers.
Past President's Address: Protistan Biogeography: Why All The Fuss?1
Authors: CARON DAVID A.
Published: March 2009

ABSTRACT.Conflicting hypotheses regarding the distribution of protistan species on our planet have led to rather impassioned arguments in the recent literature, and heated discussions at scientific meetings. Both sides of this debate have mounted seemingly credible arguments for endemism on the one hand, or ubiquitous dispersal of protists on the other. At present, the controversy appears unending, perhaps because it is fueled by a convergence of unresolvable issues involving the enormous phylogenetic breadth of species presently encompassed by the term “protist,” the application of multiple species concepts to these taxa, the inability of extant techniques and technology to plumb the depths of microbial diversity in natural ecosystems, and a lack of knowledge regarding the relationship between dispersal rates and rates of evolution of protists. These issues have made it difficult to erect and test hypotheses concerning the distribution of protists. In the absence of definitive experimental or observational information, preconceived attitudes regarding protistan distributions have dominated the interpretation of the available data. On the positive side, the debate has led to the development and application of new approaches to the study of protistan diversity, and stimulated discussions involving how (and why) we define protistan species.
Temperature Dependence of the Conductivity in Ceramic Materials Containing Nickel Nanoparticles
Authors: Abdurakhmanov Umarbek , Rakhimova Yayra , Mukhamedov Gafurjan , Balberg Isaac
Published: March 2009

We have measured and analyzed the temperature dependence of the conductivity of composites in which nickel nanoparticles are embedded in an insulating matrix. Observing a transition from a variable‐range hopping to a near‐neighbor hopping, with increasing temperature, is suggested to correspond to the microscopically observed transition from a homogeneous‐like to a percolation‐like electrical network.
Nanocrystalline Mullite Synthesis at a Low Temperature: Effect of Copper Ions
Authors: Bagchi Biswajoy , Das Sukhen , Bhattacharya Alakananda , Basu Ruma , Nandy Papiya
Published: March 2009

Nanocrystalline mullite with grain sizes in the range of 13–30 nm has been prepared by the sol–gel route at a temperature as low as 600°C with the incorporation of copper ions as copper sulfate. Characterization of the copper‐doped mullite was performed by DTA–TG, X‐ray diffraction (XRD), FESEM, and FTIR spectroscopy.
Enhanced Ferroelectric Properties of Potassium Sodium Niobate Ceramics Modified by Small Amount of K3Li2Nb5O15
Authors: Zeng Jiangtao , Zhang Yanghong , Zheng Liaoying , Li Gurong , Yin Qingrui
Published: March 2009

(1−x)K0.5Na0.5NbO3–xK3Li2Nb5O15 (KNN–100xKLN) ceramics were prepared by the solid‐state reaction method. The results showed that small amount of KLN (x≤0.02) incorporated into the lattice and formed a single phase perovskite structure. The KLN modification lowered the phase transition temperature of orthorhombic–tetragonal (TO−T) and increased the Curie temperature (Tc), but the transition temperatures remained almost unchanged in the range of x from 0.02 to 0.03. Small amount of KLN decreased the amount of defects, thus the remnant polarization increased and the coercive field decreased markedly, and the piezoelectric properties of KNN ceramics modified by small amount of KLN also enhanced markedly.
The Effect of Surface Oxides During Hot Pressing of TiB2
Authors: Jensen Morten Sundheim , Einarsrud Mari‐Ann , Grande Tor
Published: March 2009

Hot pressing of TiB2 has been investigated with particular emphasis on the evolution of secondary phases originating from the initial surface oxide layer on the TiB2 powders. Carbothermal reduction of the surface oxides during sintering was also investigated by adding carbon to the TiB2 powder. TiO1−xCx was shown to be the main secondary phase in hot‐pressed TiB2, and carbon was shown to strongly influence on sintering process and the amount, composition and distribution of the secondary phase TiO1−xCx. The formation of TiO1−xCx is discussed in relation to volatile boron oxide, which reacts with the graphite die to produce CO gas, which further may cause transport of carbon into TiB2 during sintering before pore closure. Finally it was demonstrated that the density could be controlled by addition of carbon to the TiB2 powder.
Delayed Failure of Hi‐Nicalon and Hi‐Nicalon S Multifilament Tows and Single Filaments at Intermediate Temperatures (500°–800°C)
Authors: Gauthier W. , Lamon J.
Published: March 2009

Previous results have shown that tows of SiC Nicalon fibers are sensitive to the phenomenon of delayed failure, at temperatures below 700°C. The present paper examines the static fatigue of Hi‐Nicalon and Hi‐Nicalon S when subjected to constant load, at temperatures between 500° and 800°C in air. Multifilament tows and single filaments were tested. Experimental data show that the rupture times of tows depend on the applied stress according to the conventional power law tσn=A. In contrast, the stress‐rupture time data obtained on single filaments exhibit significant scatter. A model based on slow crack growth in single filaments shows that the stress‐rupture of fiber tows follows the conventional time power law. The dependence on temperature was introduced. The model allowed sound calculations of tow lifetimes and characteristics of the slow crack growth phenomenon to be extracted from the tow stress‐rupture time data.
Piezoelectric Properties of (1−x)(Na0.5K0.5)NbO3–xAgSbO3 Lead‐Free Ceramics
Authors: Wang Yuanyu , Liu Qibin , Wu Jiagang , Xiao Dingquan , Zhu Jianguo
Published: March 2009

(1−x)(Na0.5K0.5)NbO3–xAgSbO3 lead‐free piezoelectric ceramics were prepared by normal sintering. The effects of the AgSbO3 on the phase structure and piezoelectric properties of the ceramics were systematically studied. These results show that the AgSbO3‐modified (K0.50Na0.50)NbO3 lead‐free piezoelectric ceramics form stable solution with orthorhombic structure, and the Curie temperature and the polymorphic phase transition of the ceramics decreased with increasing AgSbO3. The result shows that the piezoelectric properties of the ceramics strongly depend on the AgSbO3. The ceramics with x=0.05 possess optimum properties (d33=192 pC/N, kp=43%, Tc=348°C, To−t=145°C, ɛr∼632, and tan δ∼3.5%). These results indicate that the ceramic is a promising candidate material for lead‐free piezoelectric ceramics.
Low‐Temperature Atomic Layer‐Deposited TiO2 Films with Low Photoactivity
Authors: Liang Xinhua , King David M. , Li Peng , Weimer Alan W.
Published: March 2009

Atomic layer deposition (ALD) has been successfully utilized for the conformal and uniform deposition of ultrathin titanium dioxide (TiO2) films on high‐density polyethylene (HDPE) particles. The deposition was carried out by alternating reactions of titanium tetraisopropoxide and H2O2 (50 wt% in H2O) at 77°C in a fluidized bed reactor. X‐ray photoelectron spectroscopy confirmed the deposition of TiO2 and scanning transmission electron microscopy showed the conformal TiO2 films deposited on polymer particle surfaces. The TiO2 ALD process yielded a growth rate of 0.15 nm/cycle at 77°C. The results of inductively coupled plasma atomic emission spectroscopy suggested that there was a nucleation period, which showed the reaction mechanism of TiO2 ALD on HDPE particles without chemical functional groups. TiO2 ALD films deposited at such a low temperature had an amorphous structure and showed a much weaker photoactivity intensity than common pigment‐grade anatase TiO2 particles.