bluuebunny/crossref_metadata_2025 huggingface dataset:
Normalisation Control in Deep Inference via Atomic Flows
Authors: Guglielmi Alessio , Gundersen Tom
Published: June 2008

We introduce `atomic flows': they are graphs obtained from derivations by
tracing atom occurrences and forgetting the logical structure. We study simple
manipulations of atomic flows that correspond to complex reductions on
derivations. This allows us to prove, for propositional logic, a new and very
general normalisation theorem, which contains cut elimination as a special
case. We operate in deep inference, which is more general than other syntactic
paradigms, and where normalisation is more difficult to control. We argue that
atomic flows are a significant technical advance for normalisation theory,
because 1) the technique they support is largely independent of syntax; 2)
indeed, it is largely independent of logical inference rules; 3) they
constitute a powerful geometric formalism, which is more intuitive than syntax.
Semi-continuous Sized Types and Termination
Authors: Abel Andreas
Published: June 2008

Some type-based approaches to termination use sized types: an ordinal bound
for the size of a data structure is stored in its type. A recursive function
over a sized type is accepted if it is visible in the type system that
recursive calls occur just at a smaller size. This approach is only sound if
the type of the recursive function is admissible, i.e., depends on the size
index in a certain way. To explore the space of admissible functions in the
presence of higher-kinded data types and impredicative polymorphism, a
semantics is developed where sized types are interpreted as functions from
ordinals into sets of strongly normalizing terms. It is shown that upper
semi-continuity of such functions is a sufficient semantic criterion for
admissibility. To provide a syntactical criterion, a calculus for
semi-continuous functions is developed.
Digital Natives, Digital Immigrants: An Analysis of Age and Ict Competency in Teacher Education
Authors: Guo Ruth Xiaoqing , Dobson Teresa , Petrina Stephen
Published: June 2008

This article examines the intersection of age and ICT (information and communication technology) competency and critiques the “digital natives versus digital immigrants” argument proposed by Prensky (2001a, 2001b). Quantitative analysis was applied to a statistical data set collected in the context of a study with over 2,000 pre-service teachers conducted at the University of British Columbia, Canada, between 2001 and 2004. Findings from this study show that there was not a statistically significant difference with respect to ICT competence among different age groups for either pre-program or post-program surveys. Classroom observations since 2003 in different educational settings in Canada and the United States support this finding. This study implies that the digital divide thought to exist between “native” and “immigrant” users may be misleading, distracting education researchers from more careful consideration of the diversity of ICT users and the nuances of their ICT competencies.
Development and Initial Validation of the Online Learning Value and Self-Efficacy Scale
Authors: Artino Anthony R. , McCoach D. Betsy
Published: June 2008

Recently, several scholars have suggested that academic self-regulation may be particularly important for students participating in online learning. The purpose of the present study was to develop a quantitative self-report measure of perceived task value and self-efficacy for learning within the context of self-paced, online training, and to investigate reliability and validity evidence for the instrument. Investigations of this kind are essential because task value and self-efficacy have been shown to be important predictors of students' self-regulated learning competence and academic achievement in both traditional and online contexts. In Study 1 ( n = 204), 28 survey items were created for the Online Learning Value and Self-Efficacy Scale (OLVSES) and an exploratory factor analysis was conducted. Results suggested two interpretable factors: task value and self-efficacy. In Study 2 ( n = 646), confirmatory factor analysis suggested several survey modifications that resulted in a refined, more parsimonious version of the OLVSES. The resulting 11-item, two-factor scale appears to be psychometrically sound, with reasonable factor structure and good internal reliability. In Study 3 ( n = 481), a third sample was collected, and scores from the OLVSES appeared to demonstrate evidence of adequate criterion-related validity. Instrument applications and suggestions for future research are discussed.
Does Existential Meaning Require Hope, or is Interest Enough?
Authors: Kunzendorf Robert G. , Buker Franz
Published: June 2008

One hundred seventy-one subjects were administered Crumbaugh and Maholick's (1981) Purpose in Life Test as a measure of meaninglessness versus existential meaning; Beck, Weissman, Lester, and Trexler's (1974) Hopelessness Scale as a measure of hopelessness versus hope; and Farmer and Sundberg's (1986) Boredom Proneness Scale as a measure of boredom versus interest. Four findings emerged. First, either hope alone or interest alone was sufficient to elevate existential meaning. Second, interest alone was associated with a level of meaning statistically equivalent to the levels associated with hope alone and with hope and interest combined. Third, loss of hope was associated with suicidal ideation, but loss of interest was not. Fourth, compared to subjects identifying with no religion, those identifying with a religion exhibited significantly greater hopefulness, but not significantly greater interest. The clinical implications of these findings are discussed.
A Culture of (in)Equality?: A Cross-National Study of Gender Parity and Gender Segregation in National School Systems
Authors: Wiseman Alexander W.
Published: June 2008

Recent international education reports have highlighted some of the progress (as well as remaining disparity) in gendered education enrollment rates. But, the problem of gender segregation is still a very real issue even in some nations where girls are enrolled at levels on par with boys. Separate classes, curricula, and in many countries separate schools for boys and girls persist. This is juxtaposed against the opposite extreme that exists in some other countries' educational systems where girls are sometimes pushed into classes and advanced curricula for which they have not been adequately prepared. Using data from the most recent Trends in International Mathematics and Science Study (TIMSS) and the United Nations Educational, Scientific and Cultural Organization (UNESCO), this article reports on gender parity across approximately 45 nations in access (measured by enrollment rates), performance (mathematics achievement scores), and opportunity (implemented curriculum, teacher characteristics, classroom interaction) among 13-year-old girls and boys. The results of this study suggest that while cross-national gender parity numerically exists in many of these 45 nations in access, performance, and opportunity, the implications for gender equality are less clear. Several theoretical propositions are posited to explain these cross-national trends in gender parity versus equality.
Business School Teaching and Democratic Culture: An International and Comparative Analysis
Authors: Kragh Simon Ulrik , Bislev Sven
Published: June 2008

Egalitarian and participation-oriented teaching emphasizes critical discussion and informal relationships between students and professors. The authors argue that the use of egalitarian and some aspects of participation-oriented teaching at business schools differs systematically across countries according to the strength of democratic culture. Countries with high levels of well-being, strong emancipatory and civic values as well as a stable political democracy also tend to have egalitarian and, to some extent, participation-oriented teaching at their business schools. The article draws on survey data collected at Copenhagen Business School and macro-sociological data from a number of publicly available databases.
Functional Outcomes and Quality of Life After Tumor-Related Hemipelvectomy
Authors: Beck Lisa A , Einertson Marlene J , Winemiller Mark H , DePompolo Robert W , Hoppe Kurtis M , Sim Franklin F
Published: June 2008

Background and Purpose

Hemipelvectomy is a life-changing treatment for pelvic malignancies. This study compared functional outcomes and quality of life of patients following internal or external hemipelvectomies.

Subjects

Ninety-seven patients who underwent tumor-related internal (n=39) or external (n=58) hemipelvectomy surgery between January 1, 1988, and December 31, 2004, participated in the study.

Methods

Using a descriptive retrospective cohort study design, functional status was evaluated with the Barthel Index at 3 time points. Quality-of-life parameters were evaluated at follow-up using the Linear Analog Self-Assessment tool (LASA).

Results

Data were collected on all 97 patients at rehabilitation consultation and hospital discharge. Follow-up data were obtained via survey on 44% of the original group at a median of 5.8 years (interquartile range [IRQ]=1.7–10.4) after surgery. Median total Barthel Index scores were similar between the internal and external hemipelvectomy groups at the initial physical medicine and rehabilitation assessment (10 [IQR=10–15] versus 10 [IQR=3.75–15]), at discharge (40 [IQR=30–65] versus 50 [IQR=35–66.25]), and at follow-up (92.5 [IQR=76.25–100] versus 92.5 [IQR=78.75–96.25]). Participants with external hemipelvectomies were less independent in bladder function and experienced greater pain severity at follow-up compared with those with internal hemipelvectomies. Overall quality-of-life parameters were similar between the groups.

Discussion and Conclusion

Despite significant differences in surgical procedures, immediate and long-term functional outcomes and quality-of-life parameters were similar among participants with internal and external hemipelvectomies.
Brominated Flame Retardants – Endocrine-Disrupting Chemicals in the Swiss Environment
Authors: Gereckea Andreas C. , Schmid Peter , Bogdal Christian , Kohler Martin , Zennegg Markus , Heeb Norbert V.
Published: June 2008

Brominated flame retardants (BFR) are additives used to protect plastic materials and textiles against ignition. As some widely used BFR have chemical structures similar to well known endocrine disruptors such as polychlorinated biphenyls (PCB) or bisphenol A, adverse effects were also
presumed for BFR. When the NRP50 programme started in 2001, the sparse knowledge on environmental behavior and toxicology of BFR did not allow a proper assessment of the risks associated with the widespread use of these chemicals. Therefore, we proposed to address questions such as the exposure
of animals and humans, temporal trends in the environment as well as transformation and transport processes of BFR. Concentrations of BFR in wildlife and humans in Switzerland today pose no serious concerns for negative health effects according to the current knowledge on the toxicity of BFR.
However, negative health effects cannot be ruled out in the future, since some BFR persist in the environment and their concentrations in freshwater lake sediments are increasing rapidly. The development of environmentally safe alternatives to these chemicals will be an important issue for
the future.
Environmental Exposure to Estrogenic and other Myco- and Phytotoxins
Authors: Hartmann Niccolo , Erbs Marianne , Wettstein Felix E. , Hörger Corinne C. , Vogelgsang Susanne , Forrer Hans-Rudolf , Schwarzenbach René P. , Bucheli Thomas D.
Published: June 2008

Zearalenone (ZON) is known as a very potent, naturally occurring estrogenic mycotoxin. It is one of the most prevalent mycotoxin produced as a secondary metabolite by Fusarium species growing on cereals such as wheat and corn. It has been studied extensively in food and feed
products for decades but only rarely and somewhat by chance in the environment. We therefore elucidated its agro-environmental fate and behavior by conducting a series of field studies and monitoring campaigns. Specifically, ZON was investigated in plants, soils and drainage waters from wheat
and corn fields artificially infected with Fusarium graminearum. In addition, manure, sewage sludge and surface waters were analyzed for ZON. Three main input pathways of ZON onto soil could be identified: i) wash-off from Fusarium-infected plants (in the order of 100 mg/ha),
ii) plant debris remaining on the soil after harvest (up to few g/ha), and iii) manure application (in the order of 100 mg/ha). Our results show that these input sources altogether caused the presence of several g/ha of ZON in topsoil. Compared to this, ZON emission by drainage water from
Fusarium-infected fields was generally low, with maximum concentrations of 35 ng/l and total amounts of a few mg/ha. Due to dilution, ZON concentrations dropped below environmental relevance in larger surface water bodies. However in small catchments dominated by runoff from agricultural
land, ZON might substantially contribute to the estrogenicity of such waters. Apart from ZON, other natural toxins monitored in this study, such as the mycotoxin deoxynivalenol or the estrogenic phytoestrogen formononetin, emitted to and occurred in surface waters at considerably higher amounts.
To date their ecotoxicological effects are largely unknown.
Estrogens in Swiss Rivers and Effluents – Sampling Matters
Authors: Vermeirssen Etiënne L. M. , Eggen Rik I. L. , Escher Beate I. , Suter Marc J.-F.
Published: June 2008

Estrogenic activity of treated sewage effluents and receiving waters surfaced as an issue of general concern some 15 years ago. Since then, a large number of studies investigated the distribution and nature of the estrogenic substances in various aquatic ecosystems. Within NRP50, a
five-year Swiss research programme on endocrine disruptors, four field studies were performed to characterize the presence of environmental estrogens in rivers and effluents. The estrogenic activity was quantified with a biological assay – the yeast estrogen screen. An overview of the
sampling approaches and results of the various studies is presented here. In a first study, using grab sampling, it appeared that estrogenic activity in river water was highly variable. Average estrogenicity values did not correlate with sewage treatment works and/or river characteristics,
e.g. effluent dilution factor. However, variability was not 'random' but clearly associated with river size, and possibly its discharge. A second study specifically addressed this issue of variability of estrogenicity. The study was conducted at a single effluent source and its receiving
river. Variability of estrogenicity in the grab samples was again large but again not 'random'; some of the variability was explained by the time over which the effluent resided in the treatment process. In a third study it was explored if passive sampling would be a better way to assess average
estrogenicity. Indeed, passive samplers identified sources of estrogens, and passive sampling data correlated well with both repeated grab sampling and bioaccumulation data. Subsequently, passive samplers were deployed across Switzerland in a fourth study. It involved 22 effluent discharges
and the associated rivers. Data analysis of the last study is still ongoing, preliminary observations are discussed here. Although a lot could be learned from repeated grab sampling campaigns, it emerged that passive sampling is a very effective and appropriate technique to assess: i) effluent
treatment efficiency, and ii) the chemical load of river water. For these reasons it is a valuable monitoring tool for water quality criteria assessments as well as for studies that aim to link exposure and effect. The passive samplers that are currently available not only target estrogenic
substances, but many other polar organic compounds of concern, such as antibiotics (see NRP49), other pharmaceuticals and biocides.
High Plasma Levels of MCP-1 and Eotaxin Provide Evidence for an Immunological Basis of Fibromyalgia
Authors: Zhang Zhifang , Cherryholmes Gregory , Mao Allen , Marek Claudia , Longmate Jeffrey , Kalos Michael , Amand R. Paul ST. , Shively John E.
Published: June 2008

Fibromyalgia (FMS), a predominantly female (85%) syndrome, affects an estimated 2% of the US population with skeletal muscle ache, fatigue, headache, and sleep disorder. The pathogenesis of FMS is unknown and there is no laboratory test for diagnosis. In this study, plasma levels of 25 cytokines and chemokines in 92 female patients with FMS and 69 family members were measured compared to 77 controls. Trans-endothelial migration of normal leukocytes in response to FMS plasma and the cytokine profile of human myoblasts were analyzed. High levels of MCP-1 ( P < 0.001) and eotaxin ( P < 0.01) were found in patients and family members compared to controls. Patients (56/92) treated with the single agent guaifenesin (>3 months) had higher levels of eotaxin than those not treated ( P < 0.01). Diluted plasma from patients increased the migration of normal eosinophils and monocytes, but not neutrophils, through an endothelial/Matrigel barrier only when mast cells are included in the lower wells ( P < 0.05). Furthermore, myoblasts can secrete MCP-1, eotaxin, and IP-10, while treatment with MCP-1 caused secretion of IL-1β, eotaxin and IP-10. FMS is associated with inflammatory chemokines, that MCP-1 and eotaxin may contribute to the symptoms of FMS, and that similar cytokine profiles found in family members support the idea that FMS has a genetic component. Furthermore, the chemokine profile associated with FMS has direct effects on the migration of eosinophils and monocytes in the presence of mast cells, and skeletal muscle itself may secrete
Dietary Lactoferrin Does Not Prevent Dextran Sulfate Sodium Induced Murine Intestinal Lymphocyte Death
Authors: Spagnuolo Paul A. , Hoffman-Goetz Laurie
Published: June 2008

Dextran sulfate sodium (DSS) induced intestinal inflammation is characterized by pronounced mucosal and epithelial cell damage. Bovine lactoferrin (bLf), a common dietary protein, influences inflammatory cytokines and intestinal lymphocyte (IL) apoptosis. The objectives of this study were to determine if 1) DSS induces IL necrotic or apoptotic death, 2) dietary bLf affects DSS induced IL death and 3) bLf alters cytokine profiles during DSS induced inflammation. Female C57BL/6 mice were randomized to 2% or 0% bLf diets for 12 d and within diets to 5% or 0% DSS in the drinking water for 4 d after which intestinal histology, IL number, IL apoptosis/necrosis, IL phenotypes, protein levels of pro-inflammatory cytokine (TNF-α) and transcription factor (NFκB), apoptotic (caspase 3, Bax) proteins, anti-inflammatory cytokine (IL-10) and anti-apoptotic (Bcl-2) protein in IL were evaluated. DSS treatment resulted in shortened intestinal length, decreased body weight and widespread mucosal damage as well as increased IL death as determined by a decreased percentage of viable (PI−/ANN−, P < 0.005) and increased percentage of necrotic/late apoptotic (PI+/ ANN+, P < 0.05) and necrotic (PI+/ANN−, P < 0.05) IL. DSS exposure increased caspase 3 ( P < 0.05) and decreased Bcl-2 ( P < 0.01) protein levels in mouse IL. Dietary bLf did not influence these cell death outcome measures. However, bLf reduced protein levels of the pro-inflammatory transcription factor, NFκB, in IL ( P < 0.05) and was associated with a 34%, albeit non-significant, reduction in TNF-α relative to non-bLf fed mice. DSS treatment increased apoptosis and necrosis of mouse IL and elevated pro-apoptotic and reduced anti-apoptotic protein levels in these cells. Dietary bLf did not influence necrosis or apoptosis of IL but may provide limited protection in the intestine by affecting the pro-inflammatory transcription factor NFκB, and potentially, cytokine expression.
Nonisothermal crystallization kinetics of poly(ethylene terephthalate)/antimony‐doped tin oxide nanocomposites
Authors: Chen Xiaolei , Li Chunzhong , Shao Wei , Liu Tianxi , Wang Lumin
Published: June 2008

Poly(ethylene terephthalate) (PET)/antimony‐doped tin oxide (ATO) nanocomposites were prepared by in situ polymerization. The nonisothermal crystallization behaviors of neat PET and PET/ATO nanocomposites were investigated with differential scanning calorimetry. The nonisothermal crystallization data were analyzed with the Avrami analysis modified by Jeziorny, the Ozawa method, and a method developed by Liu et al. The modified Avrami equation could describe only the primary stage of nonisothermal crystallization of PET and PET/ATO nanocomposites. The Ozawa analysis, when applied to the polymer systems studied here, failed to describe their nonisothermal crystallization behavior. The kinetic method developed by Liu et al. was successful in describing the nonisothermal crystallization of neat PET and PET/ATO nanocomposites. According to the Kissinger equation, the activation energies were determined to be −205.3, −220.0, and −243.7 kJ/mol for neat PET and 99/1 and 95/5 PET/ATO nanocomposites, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
pH‐responsive fibers based on acrylonitrile acrylic acid block copolymers: Effect of spinning conditions and postspinning operations on response and mechanical properties
Authors: Sahoo Anasuya , Jassal Manjeet , Agrawal Ashwini K.
Published: June 2008

pH sensitive poly(acrylonitrile‐co‐acrylic acid) having ∼50 mol % acrylic acid with block type structure (AA50B) was synthesized by controlled dosing method of free radical polymerization. The polymer was converted into fibers by wet solution spinning technique in DMF‐water system. The resulting block type copolymer could generate a domain type morphology with segregated domains of acrylonitrile and acrylic acid on heat‐setting. The drawing ratio and heat‐setting temperature had a significant effect on the formation of these domains and their stability. The domain formation was more pronounced when the fibers could be drawn to higher draw ratios during coagulation or heat‐set at higher temperature. The stability of the fibers, which is influenced by domain formation, was lowest (at few cycles of transitions) when the fibers were heat‐set at 100°C, while it is improved significantly to more than 50 cycles as the heat‐setting temperature was increased to 150°C. The coagulation conditions, drawing and the heat‐setting also greatly influenced the mechanical properties, transition behavior, and retractive stresses of the responsive fibers. The tenacity improved by 6.6 times in swollen state and 1.4 times in deswollen state, while the retractive stresses during deswelling were significantly increased to about 4.7 times. However, the increased heat‐setting temperature was also found to have a negative effect on the equilibrium swelling values as well as the response rate. The effect of heat‐setting on chemical structure of the copolymer was also investigated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of phosphor coated with a polymer by emulsion polymerization and its application in low‐density polyethylene
Authors: Chen Tonghua , Luo Yongyue , Zou Jiangpeng , Jiang Long , Dan Yi , Zhang Li , Zhao Kun
Published: June 2008

The long‐afterglow phosphor SrAl2O4 : Eu2+, Dy3+ is liable to hydrolyze in water with deterioration of its luminescent properties. In this study, in situ emulsion polymerization was first used to prepare phosphor coated with poly(methyl methacrylate‐co‐butyl acrylate) [P(MMA‐co‐BA)] to improve water resistance. Fourier transform infrared spectra suggested that the polymer attached to the phosphor by chemical bonding. Observation by scanning electron microscopy (SEM) showed that a polymer layer formed on the surface of the phosphor. The resistance to water of the phosphor coated with the polymer layer was much better than that of the uncoated phosphor because the transparent polymer layer could suppress its hydrolysis process. Low‐density polyethylene (LDPE) plastics, doped with long‐afterglow phosphors, were manufactured with an extrusion technique. Through coating with P(MMA‐co‐BA), the compatibility of phosphor with the LDPE matrix was improved, as determined by SEM. The luminous LDPE plastics blended with the phosphor coated with polymer showed long and strong phosphorescence with little loss of persistence phosphorescence compared to the uncoated phosphor. The LDPE plastics still retained their mechanical properties through doping with 3% (mass fraction) of the phosphors. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
High‐speed microchip electrophoresis method for the separation of (R,S)‐naproxen
Authors: Guihen Elizabeth , Hogan Anna‐Marie , Glennon Jeremy D.
Published: June 2008

In this research, a capillary electrophoretic method for the fast enantiomeric resolution of (R,S)‐naproxen was investigated. Method development involved variation of applied potential, buffer concentration, buffer pH, and cyclodextrin concentration. The optimum electrophoretic separation conditions were 110 mM sodium acetate run buffer (pH 6.0), 30 mM methyl‐β‐cyclodextrin, 20% (v/v) acetonitrile, 25°C. The total length of capillary was 48 cm, (50 μm I.D.) with ultra violet (UV) detection at 232 nm. Using these conditions, the number of theoretical plates was close to one million (896,000/m). The possibility of achieving a fast chiral separation of (R,S)‐naproxen on a microchip of 2.5 cm in length was investigated. Complete enantiomeric resolution of naproxen was achieved in less than 1 min, on this microchip platform, with linear imaging UV detection. This system had the advantage of real‐time separation monitoring, so that enantiomeric resolution could be visually observed, and high‐speed chiral analysis was realized. The microchip electrophoresis (MCE) separation was compared with the capillary electrophoresis (CE) separation with regards to speed, efficiency, separation platform, and precision. This work highlights the potential of CE and MCE in future chiral separations. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
PERMIS: a modular authorization infrastructure
Authors: Chadwick David , Zhao Gansen , Otenko Sassa , Laborde Romain , Su Linying , Nguyen Tuan Anh
Published: June 2008

Authorization infrastructures manage privileges and render access control decisions, allowing applications to adjust their behavior according to the privileges allocated to users. This paper describes the PERMIS role‐based authorization infrastructure along with its conceptual authorization, access control, and trust models. PERMIS has the novel concept of a credential validation service, which verifies a user's credentials prior to access control decision‐making and enables the distributed management of credentials. PERMIS also supports delegation of authority; thus, credentials can be delegated between users, further decentralizing credential management. Finally, PERMIS supports history‐based decision‐making, which can be used to enforce such aspects as separation of duties and cumulative use of resources. Details of the design and the implementation of PERMIS are presented along with details of its integration with Globus Toolkit, Shibboleth, and GridShib. A comparison of PERMIS with other authorization and access control implementations is given, along with suggestions where future research and development are still needed. Copyright © 2008 John Wiley & Sons, Ltd.
Crystalline bismuth oxide nanorods fabricated on Pt‐coated substrates using a trimethylbismuth and oxygen mixture
Authors: Kim Hyoun Woo , Lee Jong Woo , Shim Seung Hyun , Kebede Mesfin A. , Lee Chongmu
Published: June 2008

The current work reports the fabrication of crystalline Bi2O3 nanorods on Pt‐coated Si substrates using trimethylbismuth and O2 as the bismuth and the oxygen sources, respectively, in the metalorganic chemical vapor deposition process. Their microstructures were characterized by scanning electron microscopy, X‐ray diffraction, and transmission electron microscopy. The obtained nanorods were crystalline, with their diameters in the range of 20–200 nm. The absence of tip‐nanoparticle and the presence of predeposited Bi2O3 layer indicated that the growth was dominated by a vapor‐solid process. The photoluminescence measurements of the Bi2O3 nanorods at room temperature exhibited an emission band peaked at around 422 nm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Power transformation models and volatility forecasting
Authors: Sadorsky Perry , McKenzie Michael D.
Published: June 2008

This paper considers the forecast accuracy of a wide range of volatility models, with particular emphasis on the use of power transformations. Where one‐period‐ahead forecasts are considered, the power autoregressive models are ranked first by a range of error metrics. Over longer forecast horizons, however, generalized autoregressive conditional heteroscedasticity models are preferred. A value‐at‐risk‐based forecast assessment indicates that, while the forecast errors are independent, they are not independent and identically distributed, although this latter result is sensitive to the choice of forecast horizon. Our results are robust across a number of different asset markets. Copyright © 2008 John Wiley & Sons, Ltd.
Age‐related changes in the cerebral substrates of cognitive procedural learning
Authors: Hubert Valérie , Beaunieux Hélène , Chételat Gaël , Platel Hervé , Landeau Brigitte , Viader Fausto , Desgranges Béatrice , Eustache Francis
Published: June 2008

Cognitive procedural learning occurs in three qualitatively different phases (cognitive, associative, and autonomous). At the beginning of this process, numerous cognitive functions are involved, subtended by distinct brain structures such as the prefrontal and parietal cortex and the cerebellum. As the learning progresses, these cognitive components are gradually replaced by psychomotor abilities, reflected by the increasing involvement of the cerebellum, thalamus, and occipital regions. In elderly subjects, although cognitive studies have revealed a learning effect, performance levels differ during the acquisition of a procedure. The effects of age on the learning of a cognitive procedure have not yet been examined using functional imaging. The aim of this study was therefore to characterize the cerebral substrates involved in the learning of a cognitive procedure, comparing a group of older subjects with young controls. For this purpose, we performed a positron emission tomography activation study using the Tower of Toronto task. A direct comparison of the two groups revealed the involvement of a similar network of brain regions at the beginning of learning (cognitive phase). However, the engagement of frontal and cingulate regions persisted in the older group as learning continued, whereas it ceased in the younger controls. We assume that this additional activation in the older group during the associative and autonomous phases reflected compensatory processes and the fact that some older subjects failed to fully automate the procedure. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Effects of warm‐supplementing kidney yang (WSKY) capsule added on risperidone on cognition in chronic schizophrenic patients: a randomized, double‐blind, placebo‐controlled, multi‐center clinical trial
Authors: Chen Zhen‐hua , Wang Gao‐hua , Wang Xiao‐ping , Chen Ren‐yun , Wang Hui‐lin , Yang Ming‐hua , Huo Yun‐xiang , Mei Hong‐bing
Published: June 2008

Objective

To evaluate the effects of warm‐supplementing kidney yang (WSKY) capsule added on risperidone on cognition in chronic schizophrenic patients.

Methods

A randomized, double‐blind, placebo‐controlled, multi‐center clinical trial was conducted. All 200 patients who met the DSM‐IV diagnostic criteria for schizophrenia were randomly assigned to double‐blind treatment with WSKY capsule (n = 100) or placebo (n = 100) added on risperidone for 8 weeks. The primary outcome measure was the cognitive function assessment assessed by the classic form of the Wisconsin Card Sorting Test (WCST) at baseline and week 8. The secondary outcome measures were assessed including the positive and negative symptoms scale (PANSS), the social disability screening schedule (SDSS), and the Hamilton rating scale for depression (HAM‐D‐17) at baseline, week 2, week 4, and week 8. The extrapyramidal side effects were assessed each week using the abnormal involuntary movement scale (AIMS) and rating scale for extrapyramidal side effects (RSESE), while adverse events were assessed using treatment emergent symptoms scale (TESS) as additional indicators of tolerability throughout the trial.

Results

The response rates of the WSKY group for the number of completed categories (CC), errors responses number (ER), perseveringly errors responses number (PER), and conceptual level (CL) of WCST assessment were significantly higher than those of placebo. The reduction in the SDSS score from baseline to endpoint was significantly greater in the WSKY group than those in the placebo. There were no significant differences in the response rates for the correct responses number, perseveringly responses number (PR) of WCST between the treatment groups. The improvements in the WCST indexes, PANSS score, HAM‐D‐17 score were no significant differences from baseline to endpoint between the two groups at week 8.There were no significant differences in AIMS, RSESE, and TESS compared patients treated with WSKY capsule with those in placebo during treatment.

Conclusion

WSKY capsule added on risperidone may improve cognitive function, social function of the chronic schizophrenic patients, and the WSKY safely during treatment. Copyright © 2008 John Wiley & Sons, Ltd.
A simple and rapid automated radiosynthesis of [18F]fluoroacetate
Authors: Tang Ganghua , Tang Xiaolan , Wang Mingfang , Li Baoyuan , Liang Mingquan , Wang Quanshi
Published: June 2008

Two fully automated synthetic procedures of [18F]fluoroacetate ([18F]FAC) have been developed using a modified commercial TRACERlab FXFN synthesizer. One was a two‐step one‐pot procedure, consisting of nucleophilic [18F]fluorination of benzyl‐2‐bromoacetate as a precursor with no‐carrier‐added [18F]fluoride, hydrolysis within the same [18F]fluorination reaction vessel, and purification with/without high‐performance liquid chromatography (HPLC). The second procedure consisted of nucleophilic [18F]fluorination, hydrolysis on the column, and purification with SEP‐PAK cartridges instead of HPLC. The radiochemical purity of [18F]FAC was >95% by the two procedures. The second procedure was a simple, rapid, and fully automated synthesis of [18F]FAC with a high and reproducible radiochemical yield exceeding 60% (decay uncorrected) within the total synthesis time less than 20 min. The new, simple, and rapid on‐column hydrolysis procedure should be adaptable to the fully automated synthesis of [18F]FAC at a commercial fluoro‐deoxyglucose synthesis module. Copyright © 2008 John Wiley & Sons, Ltd.
An efficient synthesis of [13C6]‐3,5‐dichloroaniline
Authors: Latli Bachir , Hrapchak Matt , Krishnamurthy Dhileepkumar , Senanayake Chris H.
Published: June 2008

3,5‐Dichloroaniline is commonly found in many compounds with pharmacological and other biological activities. [13C6]‐Aniline or its hydrochloride salt was converted in three steps to [13C6]‐3,5‐dichloroaniline, which can be incorporated in compounds of interest and used as internal standards in drug metabolism and pharmacokinetics (DMPK) studies. Copyright © 2008 John Wiley & Sons, Ltd.
Cluster emission and chemical reactions in oxygen and nitrogen ices induced by fast heavy‐ion impact
Authors: Ponciano C. R. , Martinez R. , Farenzena L. S. , Iza P. , Homem M. G. P. , Naves de Brito A. , Wien K. , da Silveira E. F.
Published: June 2008

Two ices, O2 and a mixture of O2 and N2, are bombarded by 252Cf fission fragments (FF) (∼65 MeV at target surface); the emitted positive and negative secondary ions are analyzed by time‐of‐flight mass spectrometry (TOF–SIMS). These studies shall enlighten sputtering from planetary and interstellar ices. Three temperature regions in the 28–42‐K range are analyzed: (1) before N2 sublimation, in which hybrid chemical species are formed, (2) before O2 sublimation, in which the TOF mass spectrum is dominated by low‐mass (O2)p cluster ions and (3) after O2 sublimation, in which (N2)p or (O2)p cluster ions are practically inexistent. In the first region, four hybrid ion series are observed: NOn−1+, N2On−2±, and N4On−4−. In the second region, two positive and negative ion series are identified: (O2)pO± and (O2)pO2±. Their yield distributions are fitted by the sum of two decreasing exponentials, whose decay constants are the same for all series. It is observed that the cluster ion desorption from solid oxygen is very similar to that of other frozen gases, but its yield distribution oscillates with a three‐ or six‐atom periodicity, suggesting O3 or 3O2 units in the cluster structure, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Theoretical and vibrational spectroscopic studies on binary mixture of o‐chlorobenzaldehyde
Authors: Anis Fathima A. , Ramakrishnan V.
Published: June 2008

In this work, a combined theoretical and spectroscopic study of binary mixture of liquid o‐chlorobenzaldehyde (OCBZ) is reported using ab initio calculations, Raman and infrared (IR) spectroscopies. The purpose of this study was twofold: firstly, to describe the interaction of OCBZ in terms of bonding energies and preferred geometries; secondly, to characterize the spectroscopic effects on the vibrational modes of OCBZ in the binary mixture of different polar and nonpolar solvents. Ab initio calculations have proven to be a valuable tool for predicting relevant molecular structure and molecular parameters in the intermolecular interactions. Copyright © 2008 John Wiley & Sons, Ltd.
Occult malignancy rate associated with thoracodorsal vessel dissection for free flap breast reconstruction
Authors: Loiselle Frederick , Schrag Christiaan , Magi Enzio , Harrop A. Robert , Temple Walley , de Haas Vim , Lindsay Robert
Published: June 2008

Background

The rate of breast reconstruction following mastectomy is increasing, and currently sits at about 15%. Free flap reconstruction techniques using the thoracodorsal vessels as recipients provide an opportunity for a “second look” at the axillary nodal basin post‐mastectomy. The purpose of this study was to determine the occult malignancy rate associated with free flap breast reconstruction.

Methods

A retrospective chart review was performed to ascertain the occult malignancy rate of women who received a delayed free flap reconstruction at our institution between 1990 and 2001. Any additional therapy as a result of a positive result was also recorded.

Results

Free flap breast reconstructions between 1990 and 2001 totalled 322, and of those 136 reconstructions were delayed and met our inclusion criteria. An occult malignancy rate of 3.6% (five patients) was identified for these patients. Four patients received additional therapy as a result of this finding.

Conclusion

This study serves to alert reconstructive surgeons to the potential for finding occult tumour during free flap breast reconstruction. J. Surg. Oncol. 2008;98:94–96. © 2008 Wiley‐Liss, Inc.
A phase field model for stem cell differentiation
Authors: Witterstein Gabriele
Published: June 2008

Our aim is to develop a two‐dimensional model describing the dynamics of stem cell differentiation. Here we regard the differentiation process as a phase change in the biological material. The resulting phase field model is coupled with the description of liquid flows representing the motility of the cytoplasm. We show that in the process of phase change an additional stress force acts on the liquid particle. On assuming this additional force we can demonstrate that for the process of chemical‐induced differentiation the second law of thermodynamics is fulfilled. The entropy inequality ensures that the proposed model is consistent with thermodynamics. Copyright © 2008 John Wiley & Sons, Ltd.
Weak solutions to a stationary heat equation with nonlocal radiation boundary condition and right‐hand side in Lp (p⩾1)
Authors: Druet Pierre‐Étienne
Published: June 2008

Accurate modelling of heat transfer in high‐temperature situations requires accounting for the effect of heat radiation. In complex industrial applications involving dissipative heating, we hardly can expect from the mathematical theory that the heat sources will be in a better space than L1. In this paper, we focus on a stationary heat equation with nonlocal boundary conditions and Lp right‐hand side, with p⩾1 being arbitrary. Thanks to new coercivity results, we are able to produce energy estimates that involve only the Lp norm of the heat sources and to prove the existence of weak solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Estrogen‐induced uterine abnormalities in TIMP‐1 deficient mice are associated with elevated plasmin activity and reduced expression of the novel uterine plasmin protease inhibitor serpinb7
Authors: Zhang Xuan , Hoang Etter , Nothnick Warren B.
Published: June 2008

Tissue inhibitor of metalloproteinase‐1 (TIMP‐1) is a multifunctional protein capable of regulating a variety of biological processes in a wide array of tissue and cell types. We have previously demonstrated that TIMP‐1 deficient mice exhibit alterations in normal uterine morphology and physiology. Most notably, absence of TIMP‐1 is associated with an altered uterine phenotype characterized by profound branching of the uterine lumen and altered adenogenesis. To begin to assess the mechanism by which TIMP‐1 may control these uterine events, we utilized steroid‐treated ovariectomized wild‐type and TIMP‐1 null mice exposed to estrogen for 72 hr. Administration of estrogen to TIMP‐1 deficient mice resulted in development of an abnormal uterine histo‐architecture characterized by increased endometrial gland density, luminal epithelial cell height, and abnormal lumen structure. To determine the mediators which may contribute to the abnormal uterine morphology in the TIMP‐1 deficient mice, cDNA microarray analysis was performed. Analysis revealed that expression of two plasmin inhibitors (serpbinb2 and serbinb7) was significantly reduced in the TIMP‐1 null mice. Associated with the reduction in expression of these inhibitors was a significant increase in plasmin activity. Localization of the novel uterine serpinb7 revealed that expression was confined to the luminal and glandular epithelial cells. Further, expression of uterine serpinb7 was decreased by estrogen and showed an inverse relationship with plasmin activity. We conclude from these studies that in addition to controlling MMP activity, TIMP‐1 may also control activity of serine proteases through modulation of serine protease inhibitors such as serpinb7. Mol. Reprod. Dev. 76: 160–172, 2009. © 2008 Wiley‐Liss, Inc.
Regulation of the Nanog gene by both positive and negative cis‐regulatory elements in embryonal carcinoma cells and embryonic stem cells
Authors: Boer Brian , Cox Jesse L. , Claassen David , Mallanna Sunil Kumar , Desler Michelle , Rizzino Angie
Published: June 2008

The transcription factor Nanog is essential for mammalian embryogenesis, as well as the pluripotency of embryonic stem (ES) cells. Work with ES cells and embryonal carcinoma (EC) cells previously identified positive and negative cis‐regulatory elements that influence the activity of the Nanog promoter, including adjacent cis‐regulatory elements that bind Sox2 and Oct‐3/4. Given the importance of Nanog during mammalian development, we examined the cis‐regulatory elements required for Nanog promoter activity more closely. In this study, we demonstrate that two positive cis‐regulatory elements previously shown to be active in F9 EC cells are also active in ES cells. We also identify a novel negative regulatory region that is located in close proximity to two other positive Nanog cis‐regulatory elements. Although this negative regulatory region is active in F9 EC cells and ES cells, it is inactive in P19 EC cells. Furthermore, we demonstrate that one of the positive cis‐regulatory elements active in F9 EC cells and ES cells is inactive in P19 EC cells. Together, these and other studies suggest that Nanog transcription is regulated by the interplay of positive and negative cis‐regulatory elements. Given that P19 appears to be more closely related to a later developmental stage of mammalian development than F9 and ES cells, differential utilization of cis‐regulatory elements may reflect mechanisms used during development to achieve the correct level of Nanog expression as embryogenesis unfolds. Mol. Reprod. Dev. 76: 173–182, 2009. © 2008 Wiley‐Liss, Inc.
Selective cauda equina hypertrophy with idiopathic inflammation
Authors: Hayashi Yuichi , Sakurai Takeo , Kimura Akio , Ikeda Takahide , Matsuyama Zenjiro , Suzuki Yoshihiro , Tanaka Yuji , Hozumi Isao , Hosoe Hideo , Takahashi Hitoshi , Inuzuka Takashi
Published: June 2008

A 20‐year‐old woman with selective cauda equina hypertrophy presented with muscle weakness and severe pain in the lower extremities. Serial immunotherapy was not effective. We performed biopsy of the cauda equina, and laminectomy and duraplasty of the thoracolumbar region. Biopsy revealed marked infiltration of small lymphocytes and foamy macrophages in the endoneurium. Three years after decompression surgery, her symptoms have improved slightly without progression or relapse. This is the first case of selective cauda equina hypertrophy with idiopathic inflammation. We propose that this is a new disease entity. Muscle Nerve, 2008
QoS experiences in native IPv6 networks
Authors: Liakopoulos Athanassios , Kalogeras Dimitrios , Maglaris Vasilis , Primpas Dimitris , Bouras Christos
Published: June 2008

Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit‐speed Greek Research and Education Network (GRNET) and the IPv6‐only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common to IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class, while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state‐of‐the‐art router cards at gigabit speeds. Copyright © 2008 John Wiley & Sons, Ltd.