bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards a valid, reliable measure of sleep effort
Authors: BROOMFIELD NIALL M. , ESPIE COLIN A.
Published: December 2005

A frequent clinical observation is that patients with insomnia strive to control their sleep. However, sleep is an involuntary physiological process, which cannot be placed under full voluntary control. Therefore, direct, voluntary attempts to control sleep may actually exacerbate and perpetuate insomnia. To date, no reliable scale has been available to test this hypothesis directly. Moreover, while sleep effort is a core International Classification of Sleep Disorders – Revised criterion for psychophysiological insomnia, clinicians lack a reliable measure with which to assess the construct. In this initial scale validation study, we present psychometric data for the Glasgow Sleep Effort Scale based on a relatively small but representative sample of patients with insomnia and good sleepers. The clinical and research value of the new scale is discussed and future research directions are described.
Sleep latency testing as a time course measure of state arousal
Authors: BONNET MICHAEL H. , ARAND DONNA L.
Published: December 2005

The purpose of this study was to determine how long the effects of a brief period of physiological arousal persisted using repeated sleep latency testing and measurement of heart rate. Thirteen normal sleeping young adults spent two non‐consecutive nights and the following days in the laboratory. On each day, subjects had five sleep latency measurements – at 09:00, 09:30, 10:00, 10:30, and 11:00 hours. The 09:00 test was a premanipulation baseline. Following this nap, subjects either walked for 5 min (on one day) or rested in bed for 10 min (on another day) prior to the 09:30 hours sleep latency test. Significant increases in sleep latency were found at 09:30, 10:00, and 11:00 hours following the single 5‐min walk as compared with resting in bed (mean sleep latency after the walk was 11.7 min compared with 7.1 min for the resting condition). Heart rate was significantly higher throughout all of the postmanipulation naps following the walk. The elevated sleep latency is probably secondary to the changes in underlying physiological arousal as measured in this study by heart rate.
Organization of ETRAMPs and EXP‐1 at the parasite–host cell interface of malaria parasites
Authors: Spielmann Tobias , Gardiner Donald L. , Beck Hans‐Peter , Trenholme Katharine R. , Kemp David J.
Published: November 2005

The parasite–host cell interface is a key compartment of vacuolated intracellular pathogens but little is known about its molecular composition and architecture. We used in vivo cross‐linking to analyse the parasite–host cell interface of asexual stages of the most virulent human malaria parasite Plasmodium falciparum. We show that the integral membrane protein members of the early transcribed membrane protein (ETRAMP) family and exported protein 1 (EXP‐1), which are components of the parasite–host cell interface, form complexes of oligomeric arrays in this compartment. The most notable feature is that each ETRAMP member and EXP‐1 define separate arrays, demonstrating that the protein distribution in this membrane is non‐random. Each of three recombinant ETRAMPs readily oligomerized in bacterial membranes, confirming that these arrays can form independently of other Plasmodium proteins. We propose that the malaria parasite–host cell interface contains patches of integral membrane proteins forming a mosaic of different microdomains in this membrane.
SepF, a novel FtsZ‐interacting protein required for a late step in cell division
Authors: Hamoen Leendert W. , Meile Jean‐Christophe , De Jong Wouter , Noirot Philippe , Errington Jeff
Published: November 2005

Cell division in nearly all bacteria is initiated by polymerization of the conserved tubulin‐like protein FtsZ into a ring‐like structure at midcell. This Z‐ring functions as a scaffold for a group of conserved proteins that execute the synthesis of the division septum (the divisome). Here we describe the identification of a new cell division protein in Bacillus subtilis. This protein is conserved in Gram positive bacteria, and because it has a role in septum development, we termed it SepF. sepF mutants are viable but have a cell division defect, in which septa are formed slowly and with a severely abnormal morphology. Yeast two‐hybrid analysis showed that SepF can interact with itself and with FtsZ. Accordingly, fluorescence microscopy showed that SepF accumulates at the site of cell division, and this localization depends on the presence of FtsZ. Combination of mutations in sepF and ezrA, encoding another Z‐ring interacting protein, had a synthetic lethal division effect. We conclude that SepF is a new member of the Gram positive divisome, required for proper execution of septum synthesis.
Factors influencing infection of mechanical wounds by Fusarium circinatum on Monterey pines (Pinus radiata)
Authors: Sakamoto J. M. , Gordon T. R.
Published: November 2005

Pitch canker, caused by the fungus Fusarium circinatum, is a disease affecting many pine tree species. In California, Pinus radiata (Monterey pine) is the principal pine host affected by pitch canker. This investigation into factors affecting infection frequency by F. circinatum of P. radiata examined the influence of: (i) wound size; (ii) relative humidity; (iii) time of inoculation; (iv) inoculum density; and (v) wound age. Wounded branches sustained significantly more infections when large‐diameter (1·6 mm) rather than small‐diameter (0·5 mm) wounds were made. Infection frequencies tended to be higher at 100% RH than at ambient humidity, although these differences were not statistically significant. Infection frequencies were significantly higher on branches inoculated after 17·00 h than on branches inoculated before noon. Infection frequencies were significantly higher for wounded branches spray‐inoculated with 5 × 107 rather than 1 × 107 spores mL−1. Infection frequencies of pruning wounds declined as wounds aged.
On‐farm Conservation Strategy to Ensure Crop Genetic Diversity in Changing Agro‐ecosystems in the Republic of Korea
Authors: Park Y.‐J. , Dixit A. , Ma K.‐H. , Kang J.‐H. , Rao V. R. , Cho E.‐G.
Published: November 2005

With the recognition of certain limitations of ex situ methods for conservation of plant genetic resources the Convention on Biological Diversity (CBD) at the ‘Earth Summit’ in 1992 highlighted the importance of traditional knowledge of indigenous and local communities that are relevant for the conservation and sustainable use of biological diversity and gave considerable attention to on‐farm and other forms of in situ conservation. Unlike semi‐static nature of ex situ conservation the in situ or on‐farm conservation (OFC) is a dynamic evolutionary process. In developing countries like Republic of Korea, where there is a continuum between the use of traditional and modern cultivars, integration of OFC with already existing gene‐bank activities in the country will be an effective approach for conservation and sustainable use of the country's crop genetic resources. However, very little efforts have been made so far in developing strategies for OFC, therefore, in this paper we describe the importance of OFC and strategies for its development in Republic of Korea. Surveys over the last 20 years have shown that the landraces of major crops have been almost replaced by newly bred varieties in the country. But some vegetatively propagated or minor crop species are still being maintained in the farmers’ fields. We have identified crop landraces, which can be classified into four different categories from the OFC point of view. These are vegetatively propagated landraces, sexually reproduced landraces, landraces with improved varieties and landraces cultivated for the reasons of personal preference. The related issues on OFC including implementation methods from the point of national cooperative system in designated specific condition are also discussed to ensure the genetic diversity in the fast changing agro‐ecosystem of the country.
An Effect of Various Nitrogen Forms Used as Fertilizer on Lupinus albus L. Yield and Protein, Alkaloid and α‐Galactosides Content
Authors: Ciesiołka D. , Muzquiz M. , Burbano C. , Altares P. , Pedrosa M. M. , Wysocki W. , Folkman W. , Popenda M. , Gulewicz K.
Published: November 2005

The influence of various forms of nitrogen supplied to the ground as N2, NH, NO, [NH + NO], –NH2, and Nd (N‐deficiency) on Lupinus albus L. cvs. Butan (sweet) and Bac (bitter) yield and protein, alkaloid and α‐galactoside biosynthesis in their seeds were studied. The experiments were performed in a greenhouse on perlite using, in all cases, the same dose of P, K, Mg and micronutrients (B, Zn, Mn, Cu, Mo, Fe). The Nd treatment contained only macro‐ and micronutrients without any nitrogen support. We found that different nitrogen forms used as a fertilizer had a significant influence on the development and yield structure of both lupin cultivars. It was found that the plants developed most favourably when nitrogen was supplied as N2 and [NH + NO]. For the other forms, the anomalies like necrosis, chlorosis, leaves with small surface of assimilation were noticed. However, these observations were not always reflected by all parameters of yield structure. The forms of nitrogen had a pivotal influence on yield of generative and vegetative parts of lupin. Moreover, significant differences in protein, alkaloid and α‐galactoside content in seeds were observed.
Emergence of Fluoroquinolone Resistance in Campylobacter jejuni in Chickens Exposed to Enrofloxacin Treatment at the Inherent Dosage Licensed in Japan
Authors: Takahashi T. , Ishihara K. , Kojima A. , Asai T. , Harada K. , Tamura Y.
Published: December 2005

The objective of the present study was to determine whether selection of fluoroquinolone resistance could be easily induced in Campylobacter jejuni‐colonized chickens by treatment with enrofloxacin of representative fluoroquinolones at the inherent dosage licensed in Japan (50 ppm in drinking water for 3 days). In the case of isolates from chickens of study 1, an increase in the population of susceptible isolates appeared after the cessation of treatment and maintained throughout the experiments. On the contrary, our results of study 2 demonstrated that administration of enrofloxacin generated a rapid increase of fluoroquinolone resistance in C. jejuni showing the mutation of Asp‐90‐Asn in the gyrA gene. Present results indicate that the enrofloxacin treatment for broilers at the inherent dosage is able to select fluoroquinolone resistance in C. jejuni. We conclude that whatever enrofloxacin dosage is used, an emergence of fluoroquinolone resistant of C. jejuni occurs.
Virus Spread Pattern within Infected Chicken Farms using Regression Model: the 2003–2004 HPAI Epidemic in the Republic of Korea
Authors: Yoon H. , Park C.‐K. , Nam H.‐M. , Wee S.‐H.
Published: December 2005

During the 2003–2004 epidemic in Korea, the infection time and within‐farm spread pattern of virus were analysed for the highly pathogenic avian influenza (HPAI) outbreak on chicken farms using regression models based on epidemiological data. Mortality observed on a given day had a positive linear association with time after initial infection. HPAI spread more rapidly on farms managed by employees and on farms with larger numbers of chicken houses in use. The disease spread more rapidly among layer chickens than among broilers. Using statistical model, we found that farmers recognize the abnormally high mortality resulting from HPAI approximately 5 days after infection. Without any intervention, entire flocks would die within 12 days of introduction of the HPAI virus to the infected farm.
Identification of an aadA2 Gene Cassette from Salmonella enterica subsp. enterica Serovar Derby
Authors: Michael G. B. , Cardoso M. , Schwarz S.
Published: December 2005

During a study on Salmonella enterica subsp. enterica serovar Derby from slaughter‐age pigs in Brazil, two epidemiologically unrelated multi‐resistant S. Derby isolates were found to carry a class 1 integron with a single gene cassette. Sequence analysis confirmed that this gene cassette harboured an aadA2 gene. The aadA2 gene codes for an aminoglycoside adenyltransferase, which mediates resistance to the aminoglycoside streptomycin and the aminocyclitol spectinomycin. Although aadA2 gene cassettes are widely distributed among Salmonella, database searches identified an AadA2 protein indistinguishable from that of S. Derby only in single isolates of S. enterica subsp. enterica Enteritidis from France and S. enterica subsp. enterica Typhimurium from Japan. Structural analysis of the 59‐base element revealed at least one base pair difference between the 59‐base element of the aadA2 cassette from S. Derby and any of the 59‐base elements deposited in the databases.
Pseudomembranous and obstructive Aspergillus tracheobronchitis – optimal diagnostic strategy and outcome
Authors: Tasci Selçuk , Glasmacher Axel , Lentini Silvia , Tschubel Klaus , Ewig Santiago , Molitor Ernst , Sauerbruch Tilman , Lüderitz Berndt , Rabe Christian
Published: November 2005

Pseudomembranous and obstructive Aspergillus tracheobronchitis (PMATB/OATB) are still considered to be refractory to therapy and to have a fatal outcome. To evaluate the optimal diagnostic strategy and to describe factors affecting the outcome of PMATB and OATB. Retrospective analysis of four new cases of PMATB and OATB combined with 16 previously reported cases over a 10‐year period (1995–2004). Among the four new cases reported and the 16 published cases, four patients survived their infection. The mortality rate was significantly higher in the group of ventilated patients [94% (15 of 16 patients)] than in the group of non‐ventilated patients [25% (1 of 4 patients), P < 0.05, Fisher's exact test]. In all 20 patients, diagnosis was established by bronchoscopy. Culture examination of mucous plugs was positive in 8 of 10, culture of the tracheobronchial aspirate was positive in 8 of 12, and bronchoalveolar lavage was diagnostic in 7 of 13 patients. All bronchoscopic techniques were complementary in improving the yield of bronchoscopy. However, microscopy of mucous plugs and/or necrotic material was the best diagnostic modality [positive in 94% (17 of 18 patients)]. Prognosis of PMATB and OATB remains poor. Microscopy of respiratory specimens is the most sensitive tool to confirm the diagnosis. The characteristic appearance of the disease makes it possible to start antifungal therapy immediately.
Initial Candida dubliniensis isolate in Candida spp. positive haemocultures in Turkey between 2001 and 2004
Authors: Tekeli Alper , Akan Ozay Arıkan , Koyuncu Esra , Dolapci Istar , Uysal Sevil
Published: November 2005

Candida dubliniensis which was first recognized in 1995 can be easily misidentified because of its phenotypic similarities with Candida albicans. In this study blood samples of patients from various departments of Ankara University Medical Faculty between January 2001–June 2004 were investigated for the distribution of Candida spp. and the presence of C. dubliniensis. Culture positive 67 fungi were included to the study. Phenotypic tests such as chlamydospore formation, colony morphology on Staib agar, growth at 45 °C, carbohydrate assimilation profiles were investigated for identification and differentiation of C. dubliniensis from C. albicans. To confirm the results polymerase chain reaction were used for suspected C. albicans and C. dubliniensis isolates. Among 38 germ tube and chlamydospore forming isolates, 37 of them were found as C. albicans and one as C. dubliniensis. The incidence of C. dubliniensis in our hospital is still low, this is the first C. dubliniensis isolate as an agent of candidaemia reported from Turkey.
Etiology of fungaemia and catheter colonisation in Argentinean paediatric patients
Authors: Giusiano Gustavo , Mangiaterra Magdalena , Saito Viviana García , Rojas Florencia , Gómez Verónica , Díaz María Cristina
Published: November 2005

Yeast strains obtained from blood cultures and catheters from intensive care units (ICU) and hospitalised oncology paediatrics were studied. Yeast were the first cause of catheter colonisation (51/627), and the third cause of bloodstream infection (44/6065). In catheter, the most frequent species were Candida albicans (34%), C. parapsilosis (27.7%) and C. tropicalis (15%). In blood, C. albicans (40.8%), C. parapsilosis (26.6%), C. tropicalis (15%). Malassezia furfur and Malassezia sympodialis were isolated from catheters from ICU patients. All isolates were susceptible to amphotericin B, 88.8% to itraconazole and 91.9% to fluconazole. Candida albicans and C. tropicalis strains resistant to fluconazole and itraconazol were detected. These results reveal a change in the predominant role of C. albicans as cause of candidemia in hospitalised children and the emergence of antifungal resistant species. These variations emphasise the importance of performing a permanent surveillance to observe and assess them.
Sensitivity of executive pay to accounting performance measures in all‐equity firms
Authors: Iyengar Raghavan (Raj) J. , Williams H. James , Zampelli Ernest M.
Published: December 2005

We investigate the relation between chief executive officer compensation and accounting performance measures as a function of the firm's capital structure. We specifically analyse pay–performance relationships for all‐equity firms relative to high‐levered firms. We find a significant positive association between return on equity and the level of compensation for all‐equity firms. Consistent with optimal contracting theory, we cannot discern any such relationship for high‐levered firms. Because of agency costs of debt, managerial compensation in high‐levered firms plays the role of a precommitment mechanism in addition to its conventional role of aligning management incentives with shareholder interest.
Modelling conditional heteroscedasticity and jumps in Australian short‐term interest rates
Authors: Chan Kam Fong
Published: December 2005

The present paper explores a class of jump–diffusion models for the Australian short‐term interest rate. The proposed general model incorporates linear mean‐reverting drift, time‐varying volatility in the form of LEVELS (sensitivity of the volatility to the levels of the short‐rates) and generalized autoregressive conditional heteroscedasticity (GARCH), as well as jumps, to match the salient features of the short‐rate dynamics. Maximum likelihood estimation reveals that pure diffusion models that ignore the jump factor are mis‐specified in the sense that they imply a spuriously high speed of mean‐reversion in the level of short‐rate changes as well as a spuriously high degree of persistence in volatility. Once the jump factor is incorporated, the jump models that can also capture the GARCH‐induced volatility produce reasonable estimates of the speed of mean reversion. The introduction of the jump factor also yields reasonable estimates of the GARCH parameters. Overall, the LEVELS–GARCH–JUMP model fits the data best.
Run length and the predictability of stock price reversals
Authors: Yao Juan , Partington Graham , Stevenson Max
Published: December 2005

Survival analysis is used to estimate time‐varying probabilities of price reversals using daily data for the Australian All Ordinaries Price Index. Lagged price changes lead to persistence (shortening) in a price run if they are of the same (opposite) sign as the run. An increase in the number of runs observed in the previous 30 days also increases the probability of price reversal. The predictive accuracy of the models is assessed using a probability scoring rule. Consistent with market efficiency, the estimated models are less accurate than the random walk model in predicting the length of individual price runs out‐of‐sample.
Incomplete Freund's adjuvant enhances locomotor performance following spinal cord injury
Authors: Azari M. F. , Karnezis T. , Bernard C. C. , Profyris C. , LeGrande M. R. , Zang D. W. , Cheema S. S. , Petratos S.
Published: November 2005

Following spinal cord injury (SCI), the pathological sequelae which ensue through the secondary mechanisms of degeneration produce myelin deposits which are potent inhibitors of endogenous neuroregeneration. We have enhanced the immune‐mediated response following a hemisection lesion by immunizing adult C57Bl/6 female mice against the inhibitor of neurite outgrowth Nogo‐A(623–640) peptide. Moderate anti‐Nogo‐A(623–640) antibody titre levels were obtained by using Montanide as the adjuvant. However, this antibody response was not obtained using incomplete Freund's adjuvant (IFA). Significant benefit in locomotor performance was demonstrated only in animals which were vaccinated with IFA and not with Montanide. No further benefit could be demonstrated with the Nogo‐A(623–640) peptide beyond that seen for adjuvant alone. These data imply that generating antibodies against Nogo‐A(623–640) in vivo alone is not sufficient to enhance locomotor recovery and that subcutaneous injection of IFA prior to SCI can enhance locomotor performance.
Debt as a source of financial stress in Australian households
Authors: Worthington Andrew C.
Published: December 2005

This paper examines the role of demographic, socio‐economic and debt portfolio characteristics as contributors to financial stress in Australian households. The data are drawn from the most recent Household Expenditure Survey and relate to 3268 probability‐weighted households. Financial stress is defined, among other things, in terms of financial reasons for being unable to have a holiday, to have meals with family and friends, to engage in hobbies and other leisure activities, and general money management. Characteristics examined include family structure and composition, source and level of household income, age, gender and marital status, ethnic background, housing value, debt repayment of various types and credit card usage. Binary logit models are used to identify the source and magnitude of factors associated with financial stress. The evidence provided suggests that financial stress is higher in families with more children and those from ethnic minorities, especially when reliant on government pensions and benefits, and lower in families with higher disposable incomes and housing values. There is weak evidence that Australia's historically high levels of household debt cause financial stress.
Interpersonal influence and consumer innovativeness
Authors: Clark Ronald A. , Goldsmith Ronald E.
Published: December 2005

Innovators represent a small and somewhat elusive group of consumers who are often the earliest adopters of new products. As such, marketing researchers and practitioners alike are interested in determining the personality characteristics that influence innovators to purchase a new product early in the product life cycle. This correlational study examined the relationships of three of these characteristics (susceptibility to interpersonal influence, attention to social comparison information, and role‐relaxed consumption) to individual innate innovativeness. Data were collected using self‐report surveys administered to 326 students at a large public university in the south‐east United States. The results supported hypothesized negative relationships between consumer innovativeness and both susceptibility to interpersonal influence and attention to social comparison information, as well as a positive relationship between consumer innovativeness and role‐relaxed consumption.
Consumer attitude toward US versus domestic apparel in Taiwan
Authors: Wang Yun , Heitmeyer Jeanne
Published: December 2005

This study investigates whether or not consumer attitudes toward domestic‐ vs. US‐made apparel differ among consumers in Taiwan. Variables to be examined include (1) apparel attributes; (2) self‐concept; and (3) demographics. The Fishbein attitude model was used to measure consumer attitudes. The mall‐intercept method was used to collect most data in four major cities of Taiwan. A total of 485 Taiwanese consumers completed and returned useable questionnaires. Results indicated that consumer attitudes toward Taiwan vs. US‐made apparel differed significantly among consumers in Taiwan. Consumers had an overall more positive attitude towards US‐made apparel compared with Taiwan‐made apparel with regards to care instruction label, colour, quality, apparel fibre content, fashionableness, attractiveness, brand name, and comfort apparel attributes. For self‐concept variables only modest/vain and thrifty/indulgent had a significant difference between consumers who preferred US‐ over Taiwan‐made apparel. Demographic factors of age, gender, education, residence area, travelled abroad and country‐of‐origin preference had a significant relationship with consumer attitudes toward apparel. This study is aimed at understanding Taiwanese consumers’ attitudes toward foreign‐made apparel. Overall, Taiwanese consumers preferred US‐made apparel; however, the apparel attribute of size range needed improvement to increase customers’ satisfaction.
Testing for Down syndrome in the older woman: a risky business?
Authors: HODGES Ryan J. , WALLACE Euan M.
Published: December 2005

For over 30 years, antenatal diagnosis of Down syndrome has been offered on the basis of advanced maternal age. While this was appropriate in the 1970s, developments in antenatal screening have rendered this a most inefficient strategy that is associated with excessive costs and procedure‐related pregnancy losses. In this article we argue for a review of how we test for Down syndrome in the older woman.
Placenta praevia: maternal morbidity and place of birth
Authors: OLIVE Emily C. , ROBERTS Christine L. , ALGERT Charles S. , MORRIS Jonathan M.
Published: December 2005

Background:  International guidelines recommend that women with placenta praevia should be delivered by an experienced operator at a hospital with an on‐site blood bank.

Aim:  To determine the risk factors, level of care at the birth hospital and incidence of maternal morbidity for women with placenta praevia.

Methods:  Data were obtained from linked hospital separation and perinatal databases for 375 790 women giving birth in a NSW hospital, 1998–2002. We defined clinically significant placenta praevia as those women who were delivered by Caesarean section at or after 26 weeks gestation. Outcomes for women with and without placenta praevia were compared. Among women with placenta praevia, antenatal predictors of maternal morbidity were assessed.

Results:  A total of 1612 (4.3/1000) women had significant placenta praevia. Women with placenta praevia were more likely to be older, have a prior Caesarean section, require general anaesthetic for delivery and deliver preterm. Among women with placenta praevia, 61% delivered in hospitals with 24‐h on site blood banks, 33% in hospitals with on‐call blood bank services after hours and 6% in hospitals with no blood bank. Two hundred and twenty three (14%) women with placenta praevia suffered a major morbidity (OR = 15.0, 95%CI 12.9–17.4). The proportion of this morbidity that occurred among women delivered electively at term was 40% in hospitals with 24 h blood banks and 55% in other hospitals (P = 0.06).

Conclusions:  For women with placenta praevia, the risk of major morbidity is high, yet 39% deliver in hospitals without immediate access to a 24‐h blood bank. Australian guidelines on the appropriate level of care for women with placenta praevia are needed.
Transcortical Cooling Inhibits Hippocampal‐kindled Seizures in the Rat
Authors: Burton Justin M. , Peebles Gregory A. , Binder Devin K. , Rothman Steven M. , Smyth Matthew D.
Published: November 2005

Summary:  Purpose: When epileptogenic regions encroach on eloquent brain, surgery may incur unacceptable deficits. Reversible cooling may control seizures while preserving function. We describe the effects of cooling kindled seizures in awake, freely moving rats.

Methods: We kindled rats after placement of a bipolar electrode and a copper cooling coil in dorsal hippocampus. Fully kindled animals (three consecutive grade 5 seizures) were cooled to one of two target temperatures (24° or 27°C) for 3 min preceding a kindling stimulation and 2 minutes after. We compared seizure score (0–5) and afterdischarge duration (ADD) with and without cooling. Target temperatures were confirmed in identical animals by using a needle thermocouple advanced to the kindling target while circulating coolant.

Results: Circulation of 16°C and 8°C coolant reliably achieved transcortical cooling of the hippocampal target to 27.0 ± 1.2°C and 23.8 ± 2.0°C, respectively, by 180 s. Cooling with 16°C coolant (n = 5) significantly reduced seizure scores from 5 to 2.57 ± 1.56, and ADD from 142 ± 94.5 s to 45.7 ± 20.5 s. Cooling with 8°C coolant (n = 5) reduced seizure scores from 5 to 2.0 ± 0.42, and ADD from 132.3 ± 29.6 s to 55.5 ± 25.9 s. In 33.3% of all cooled stimulations, grade 0 seizures resulted; grade 5 seizures recurred during subsequent stimulations when cooling was withheld.

Conclusions: Fully kindled, tonic–clonic seizures can be suppressed or aborted with periictal cooling of the kindling target. Anticonvulsant activity occurred at temperatures well above those known to result in tissue injury or inhibition of normal neurologic function. These findings have important implications for the potential use of implantable cooling devices in humans with refractory epilepsies in or near eloquent cortex or dominant hippocampal formations.
Platelet ADP response deteriorates in synthetic storage media
Authors: Keuren Jeffrey F.W. , Cauwenberghs Sandra , Heeremans Judith , De Kort Wim , Heemskerk Johan W.M. , Curvers Joyce
Published: December 2005

BACKGROUND:  During storage under blood bank conditions, platelets (PLTs) are known to secrete ADP. PLT stimulation by ADP results in refractoriness to restimulation, making this response one of the most unstable PLT reactions. The goal of this study was to evaluate the ADP‐induced responses of PLTs stored in full plasma or in plasma and additive solution (AS).

STUDY DESIGN AND METHODS:  Surface expression of P‐selectin, ADP‐induced aggregation, and reconstituted whole‐blood thrombus formation were determined on collagen surfaces in a perfusion model with PLTs that were stored for 4 days either in plasma or in the presence of plasma with PAS‐II or Composol.

RESULTS:  After 4 days of storage in PAS‐II but not in Composol, the percentage of PLTs that had secreted granule contents (P‐selectin) was increased, when compared to PLTs stored in full plasma. Maximal aggregation in response to ADP was reduced for PLTs stored in PAS‐II or Composol. Resuspension of these PLTs in plasma at 37°C for 1 hour caused partial recovery of the aggregation response. Addition of apyrase to PLTs in AS preserved the responsiveness toward ADP. Titration experiments indicated that this response gradually decreased with decreasing plasma concentration. The functional significance of these findings was demonstrated by perfusion experiments. Thrombus formation on collagen was significantly higher for PLTs stored in full plasma than for PLTs stored in PAS‐II or Composol.

CONCLUSIONS:  Storage of PLTs in the presence of AS under blood bank conditions induces deterioration of the PLT responsiveness to ADP compared to PLT concentrates in 100 percent plasma. Higher plasma‐to‐AS ratios result in better preserved responses.
Release of platelet‐derived growth factors and proliferation of fibroblasts in the releasates from platelets stored in the liquid state at 22°C after stimulation with agonists
Authors: Valeri C. Robert , Saleem Batool , Ragno Gina
Published: December 2005

BACKGROUND:  Fresh platelet (PLT)‐rich plasma (PRP) treated with thrombin plus calcium chloride (CaCl2) is used to prepare a PLT gel to promote hemostasis and wound healing in a variety of surgical procedures. The effects of various agonists on stimulating the release of growth factors from liquid‐preserved PLTs and the effects of the PLT releasate on the growth of fibroblasts in tissue culture were investigated.

STUDY DESIGN AND METHODS:  Plateletpheresis PLTs stored at 22°C as high‐yield PLTs for 3 to 6 days or outdated PLTs for 9 days were treated with agonists to assess release of platelet‐derived growth factor (PDGF) AA, PDGF AB, PDGF BB, transforming growth factor‐β1 (TGF‐β1), and osteocalcin and the proliferation of fibroblasts treated with the PLT releasates in tissue culture.

RESULTS:  All treatments except for CaCl2 alone and zeolite‐CaCl2 produced significant increases in PDGF AA compared to PRP. Thrombin‐CaCl2 produced significant increases in PDGF BB. Treatment by all the agonists produced similar increases in PDGF AB. TGF‐β1 and osteocalcin levels after treatment were similar to those in PRP. PRP releasate before and after stimulation with different agonists increased proliferation of fibroblasts in tissue culture.

CONCLUSION:  High‐yield and outdated liquid‐preserved PLTs released PDGF AA, AB, and BB but not TGF‐β1 or osteocalcin. The releasate from untreated PRP stimulated the proliferation of fibroblasts in tissue culture similar to the releasates from PRP treated with the different agonists. Further studies are needed to assess whether or not high‐yield and outdated PLTs may be useful in wound healing.
Controlled‐rate versus uncontrolled‐rate freezing as predictors for platelet cryopreservation efficacy
Authors: Balint Bela , Paunovic Dragica , Vucetic Dusan , Vojvodic Danilo , Petakov Marijana , Trkuljic Miroljub , Stojanovic Nevenka
Published: December 2005

BACKGROUND:  Cryobiologic variables responsible for cell injuries and freezing techniques applicable in medical cryopractice should be revised and/or reengineered for minimizing cryoinjuries and maximizing cell recovery. In this study, the efficacy of different cryopreservation protocols based on platelet (PLT) recovery was evaluated.

STUDY DESIGN AND METHODS:  PLTs (n = 33) were prepared from whole‐blood units. Cell count and viability, PLT morphologic score (PMS), and hypotonic shock response were determined. PLT surface antigens were measured by flow cytometry. Controlled‐rate (with compensated fusion heat) and uncontrolled‐rate freezing methods combined with 6 percent dimethyl sulfoxide were used.

RESULTS:  PLT recovery was superior in the controlled‐rate setting (91.0 ± 5.5 vs. 86.0 ± 6.5; p < 0.05). PMS was significantly better in controlled‐rate freezing (p < 0.01). GPIb/CD42b expression was reduced in both freezing groups versus control. GP140/CD62p expression was significantly (p < 0.05) lower in the controlled‐rate group and in both frozen groups was significantly higher than in the control groups.

CONCLUSION:  The use of strictly equalized (1°C/min) controlled‐rate freezing, combined with an intensified cooling rate (2°C/min) during the liquid–to–solid‐phase transition period, allows advanced quantitative and qualitative PLT recovery, even though the minor intergroup differences for some variables were observed.
Improving Removal‐Based Estimates of Abundance by Sampling a Population of Spatially Distinct Subpopulations
Authors: Dorazio Robert M. , Jelks Howard L. , Jordan Frank
Published: December 2005

Summary A statistical modeling framework is described for estimating the abundances of spatially distinct subpopulations of animals surveyed using removal sampling. To illustrate this framework, hierarchical models are developed using the Poisson and negative‐binomial distributions to model variation in abundance among subpopulations and using the beta distribution to model variation in capture probabilities. These models are fitted to the removal counts observed in a survey of a federally endangered fish species. The resulting estimates of abundance have similar or better precision than those computed using the conventional approach of analyzing the removal counts of each subpopulation separately. Extension of the hierarchical models to include spatial covariates of abundance is straightforward and may be used to identify important features of an animal's habitat or to predict the abundance of animals at unsampled locations.
MLE and Bayesian Inference of Age‐Dependent Sensitivity and Transition Probability in Periodic Screening
Authors: Wu Dongfeng , Rosner Gary L. , Broemeling Lyle
Published: December 2005

Summary This article extends previous probability models for periodic breast cancer screening examinations. The specific aim is to provide statistical inference for age dependence of sensitivity and the transition probability from the disease free to the preclinical state. The setting is a periodic screening program in which a cohort of initially asymptomatic women undergo a sequence of breast cancer screening exams. We use age as a covariate in the estimation of screening sensitivity and the transition probability simultaneously, both from a frequentist point of view and within a Bayesian framework. We apply our method to the Health Insurance Plan of Greater New York study of female breast cancer and give age‐dependent sensitivity and transition probability density estimates. The inferential methodology we develop is also applicable when analyzing studies of modalities for early detection of other types of progressive chronic diseases.
Generalization of the Mantel–Haenszel Estimating Function for Sparse Clustered Binary Data
Authors: Wang Molin , Williamson John M.
Published: December 2005

Summary We extend the Mantel–Haenszel estimating function to estimate both the intra‐cluster pairwise correlation and the main effects for sparse clustered binary data. We propose both a composite likelihood approach and an estimating function approach for the analysis of such data. The proposed estimators are consistent and asymptotically normally distributed. Simulation results demonstrate that the two approaches are comparable in terms of bias and efficiency; however, the estimating equation approach is computationally simpler. Analysis of the Georgia High Blood Pressure survey is used for illustration.
A Case‐Cohort Design for Assessing Covariate Effects in Longitudinal Studies
Authors: Pfeiffer Ruth M. , Ryan Louise , Litonjua Augusto , Pee David
Published: December 2005

Summary The case‐cohort design for longitudinal data consists of a subcohort sampled at the beginning of the study that is followed repeatedly over time, and a case sample that is ascertained through the course of the study. Although some members in the subcohort may experience events over the study period, we refer to it as the “control‐cohort.” The case sample is a random sample of subjects not in the control‐cohort, who have experienced at least one event during the study period. Different correlations among repeated observations on the same individual are accommodated by a two‐level random‐effects model. This design allows consistent estimation of all parameters estimable in a cohort design and is a cost‐effective way to study the effects of covariates on repeated observations of relatively rare binary outcomes when exposure assessment is expensive. It is an extension of the case‐cohort design (Prentice, 1986, Biometrika73, 1–11) and the bidirectional case‐crossover design (Navidi, 1998, Biometrics54, 596–605). A simulation study compares the efficiency of the longitudinal case‐cohort design to a full cohort analysis, and we find that in certain situations up to 90% efficiency can be obtained with half the sample size required for a full cohort analysis. A bootstrap method is presented that permits testing for intra‐subject homogeneity in the presence of unidentifiable nuisance parameters in the two‐level random‐effects model. As an illustration we apply the design to data from an ongoing study of childhood asthma.
Individual and Population Penalized Regression Splines for Accelerated Longitudinal Designs
Authors: Harezlak Jaroslaw , Ryan Louise M. , Giedd Jay N. , Lange Nicholas
Published: December 2005

Summary In an accelerated longitudinal design (ALD), individuals enter the study at different points of their growth trajectory and are observed over a short time span relative to the entire time span of interest. ALD data are combined across independent units to provide an estimate of an overall population curve and predictions of individual patterns of change. As a modest extension of the work of Ruppert et al. (2003, Semiparametric Regression, Cambridge University Press), we develop a computationally efficient procedure for the application of longitudinal semiparametric methods under ALD sampling schemes. We compare balanced and complete longitudinal designs to ALDs using the Berkeley Growth Study data and apply our method to longitudinal magnetic resonance imaging (MRI) brain structure size (volume) measurements from an ongoing developmental study. Potential applications extend beyond growth studies to many other fields in which cost and feasibility constraints impose restrictions on sample size and on the numbers and timings of repeated measurements across subjects.
Doubly Robust Estimation in Missing Data and Causal Inference Models
Authors: Bang Heejung , Robins James M.
Published: December 2005

Summary The goal of this article is to construct doubly robust (DR) estimators in ignorable missing data and causal inference models. In a missing data model, an estimator is DR if it remains consistent when either (but not necessarily both) a model for the missingness mechanism or a model for the distribution of the complete data is correctly specified. Because with observational data one can never be sure that either a missingness model or a complete data model is correct, perhaps the best that can be hoped for is to find a DR estimator. DR estimators, in contrast to standard likelihood‐based or (nonaugmented) inverse probability‐weighted estimators, give the analyst two chances, instead of only one, to make a valid inference. In a causal inference model, an estimator is DR if it remains consistent when either a model for the treatment assignment mechanism or a model for the distribution of the counterfactual data is correctly specified. Because with observational data one can never be sure that a model for the treatment assignment mechanism or a model for the counterfactual data is correct, inference based on DR estimators should improve upon previous approaches. Indeed, we present the results of simulation studies which demonstrate that the finite sample performance of DR estimators is as impressive as theory would predict. The proposed method is applied to a cardiovascular clinical trial.
Time‐Varying Functional Regression for Predicting Remaining Lifetime Distributions from Longitudinal Trajectories
Authors: Müller Hans‐Georg , Zhang Ying
Published: December 2005

SummaryA recurring objective in longitudinal studies on aging and longevity has been the investigation of the relationship between age‐at‐death and current values of a longitudinal covariate trajectory that quantifies reproductive or other behavioral activity. We propose a novel technique for predicting age‐at‐death distributions for situations where an entire covariate history is included in the predictor. The predictor trajectories up to current time are represented by time‐varying functional principal component scores, which are continuously updated as time progresses and are considered to be time‐varying predictor variables that are entered into a class of time‐varying functional regression models that we propose. We demonstrate for biodemographic data how these methods can be applied to obtain predictions for age‐at‐death and estimates of remaining lifetime distributions, including estimates of quantiles and of prediction intervals for remaining lifetime. Estimates and predictions are obtained for individual subjects, based on their observed behavioral trajectories, and include a dimension‐reduction step that is implemented by projecting on a single index. The proposed techniques are illustrated with data on longitudinal daily egg‐laying for female medflies, predicting remaining lifetime and age‐at‐death distributions from individual event histories observed up to current time.
Processing of Microcellular Mullite
Authors: Kim Young‐Wook , Kim Hai‐Doo , Park Chul B.
Published: December 2005

A new processing route for manufacturing partially interconnected open‐cell, microcellular mullite ceramics has been developed. The strategy adopted for making microcellular mullite ceramics entailed the following steps: (i) fabricating a formed body from combining polysiloxane, Al2O3 (a reactive filler), polymer microbeads (used as sacrificial templates), and Y2O3 (a sintering additive); (ii) cross‐linking the polysiloxane in the formed body; (iii) transforming the polysiloxane by pyrolysis into SiO2; and (iv) synthesizing mullite by reacting SiO2 and Al2O3. By controlling the sintering temperature and the microbead and additive contents, it was possible to adjust the porosity so that it ranged from 38% to 85%.

The compressive strengths of the microcellular ceramics with ∼40% and ∼70% porosities were ∼90 and ∼10 MPa, respectively. The superior compressive strengths were attributed to the homogeneous distribution of small (≤20 μm), spherical cells with dense struts in the microcellular ceramics.
Comparison of the Magnetic, Conduction, and Magnetotransport Behaviors of Ba2+‐ and Al3+‐Doped La0.67Ca0.33MnO3
Authors: Fang Tsang‐Tse , Lu E. , Ho Hei‐Fong
Published: December 2005

A modified Pechini method was used to prepare undoped and doped La0.67Ca0.33MnO3 (LCMO) with homogeneous compositions and uniform fine powders. The variations of the lattice parameters and cell volumes of doped LCMO are attributed to the effect of ionic size and the creation of the oxygen vacancy. The effect of Ba2+ on the magnetic and conduction properties of LCMO is mainly related to the enhancement of the Mn3+–O–Mn4+ bond angle. The occupation of Al ions in Mn sites and the creation of the oxygen vacancies lead to an increase of the resistivity and a decrease of Tc and Ms. The variable‐range hopping model with p=1/4 and ρ0 independent of temperature was found to be the best fit for undoped and doped LCMO, shown in Fig. 4. It is suggested that T0 is mainly the measure of the extent of the disorder. For Al3+‐doped LCMO, the small‐polaron mechanism was found to be dominant in the temperature range from 300 to 350 K, and the evaluated values of the activation energy are about 0.22 eV and independent of the Al concentration. Low‐field magnetoresistance (LFMR) was found to be enhanced by Ba doping but diminished by Al doping. The segregation of Al ions to the grain‐boundary region may play a significant role in the intent to form a one‐slope field‐dependent MR response. The mechanisms of MR response of doped LCMO were suggested.

 Resistivity as a function of temperature showing that the best fit was the variable‐range hopping model with p=1/4 and ρ0 independent of temperature for (a) La0.67(Ca1−xBax)0.33MnO3 in the temperature range from 300 to 430 K, (b) La0.67Ca0.33(Mn1−yAly)O3 in the temperature range from 260 K to Tc, and the small‐polaron mechanism (ρ=CT exp (Ea/kT) for (c) La0.67Ca0.33(Mn1−yAly)O3, in the temperature range from 300 to 350 K.

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Facile Fabrication of Porous Titania Microtube Arrays by Replication of Human Hair
Authors: Liu Shuxia , He Junhui
Published: December 2005

Titania microtube arrays were fabricated by replication of human hair. The microtube is nanoporous in its wall and has nanoporous platelets on its outer surface, which were derived from cuticle cells on hair surface. The wall thickness of titania microtubes could be controlled by adjusting the number of sol–gel cycles applied. The nanopores acted as an effective nanoreactor where Au nanoparticles were in situ synthesized. The microchannels, nanopores, and noble metal nanoparticles may provide a unique combination that would be attractive in such applications as catalysis, adsorption, and separation.