bluuebunny/crossref_metadata_2025 huggingface dataset:
Community organizations and sense of community: further development in theory and measurement
Authors: Peterson N. Andrew , Speer Paul W. , Hughey Joseph , Armstead Theresa L. , Schneider John E. , Sheffer Megan A.
Published: July 2008

The Community Organization Sense of Community Scale (COSOC) is a frequently used or cited measure of the construct in community psychology and other disciplines, despite a lack of confirmation of its underlying 4‐factor framework. Two studies were conducted to test the hypothesized structure of the COSOC, the potential effects of method bias on psychometric properties, and whether a revised measure (COSOC‐R) yielded improved model‐to‐data fit. Study 1 included year 2002 data from two samples: (a) randomly selected community residents (n=724) of five cities in the United States, and (b) randomly selected organizational members (n=508) of community‐organizing initiatives in the same five US cities. Study 2 included year 2006 data from organizational members (n=151) of community‐based prevention partnerships located in the midwestern United States. Results from both samples in Study 1 confirmed that method bias from the mixed use of positively and negatively worded items had a detrimental effect on the factor structure of the original COSOC. Results of Study 2 strongly supported the hypothesized 4‐factor structure of the COSOC‐R (i.e., relationship to organization, organization as mediator, influence of the organization, and bond to community). Study 2 results also showed that the overall COSOC‐R and its subscales were reliable and related in expected ways with psychological empowerment, community participation, and organizational involvement. Implications of the study and strategies to further develop the COSOC are discussed. © 2008 Wiley Periodicals, Inc.
Early parenting intervention aimed at maternal sensitivity and discipline: a process evaluation
Authors: Stolk Mirjam N. , Mesman Judi , van Zeijl Jantien , Alink Lenneke R. A. , Bakermans‐Kranenburg Marian J. , van IJzendoorn Marinus H. , Juffer Femmie , Koot Hans M.
Published: July 2008

This study investigated the influence of the intervention process on the effectiveness of a program aimed at promoting positive parenting. The study involved a homogeneous intervention sample (N=120) of mothers and their 1‐, 2‐, or 3‐year‐old children screened for high levels of externalizing problems. The alliance between mother and intervener, mothers' active skills implementation, and father involvement were examined in relation to changes in maternal sensitivity and positive discipline strategies. Results revealed that only alliance predicted change in positive parenting. Implications for future process evaluations and intervention programs are discussed. © 2008 Wiley Periodicals, Inc.
An accurate and nondestructive GC method for determination of cocaine on US paper currency
Authors: Zuo Yuegang , Zhang Kai , Wu Jingping , Rego Christopher , Fritz John
Published: July 2008

The presence of cocaine on US paper currency has been known for a long time. Banknotes become contaminated during the exchange, storage, and abuse of cocaine. The analysis of cocaine on various denominations of US banknotes in the general circulation can provide law enforcement circles and forensic epidemiologists objective and timely information on epidemiology of illicit drug use and on how to differentiate money contaminated in the general circulation from banknotes used in drug transaction. A simple, nondestructive, and accurate capillary gas chromatographic method has been developed for the determination of cocaine on various denominations of US banknotes in this study. The method comprises a fast ultrasonic extraction using water as a solvent followed by a SPE cleanup process with a C18 cartridge and capillary GC separation, identification, and quantification. This nondestructive analytical method has been successfully applied to determine the cocaine contamination in US paper currency of all denominations. Standard calibration curve was linear over the concentration range from the LOQ (2.00 ng/mL) to 100 μg/mL and the RSD less than 2.0%. Cocaine was detected in 67% of the circulated banknotes collected in Southeastern Massachusetts in amounts ranging from ∼︁2 ng to 49.4 μg per note. On average, $5, 10, 20, and 50 denominations contain higher amounts of cocaine than $1 and 100 denominations of US banknotes.
Evaluation of mobile phase, ion pairing, and temperature influence on an HILIC‐MS/MS method for L‐arginine and its dimethylated derivatives detection
Authors: Paglia Giuseppe , D'Apolito Oceania , Tricarico Filomena , Garofalo Daniela , Corso Gaetano
Published: July 2008

Asymmetric NG,–NG‐dimethylarginine (ADMA) increases in diseases such as renal failure, diabetes mellitus, and hypercholesterolemia. The feasibility and utility of a hydrophilic interaction chromatography (HILIC) method for the separation of free L‐arginine (Arg), ADMA, and symmetric NG,–NG′‐dimethylarginine (SDMA) on a typical silica column were explored and the impact of some experimental parameters on the chromatographic behavior of these analytes was investigated. The effect of water and TFA content in mobile phase and of column temperature was investigated during the development of a fast and simple HILIC‐MS/MS method that might be suitable for the quantification of free Arg, ADMA, and SDMA in plasma for routine analysis. Our results show that a good compromise between efficiency and peak shape with acceptable retention and total chromatographic run time is achieved using an ACN/water (90:10) mobile phase with TFA% as additive ranging from 0.015 to 0.025% and column temperature ranging from 25 to 30°C.
A DEA‐based method to enhance intellectual capital management
Authors: Campisi Domenico , Costa Roberta
Published: July 2008

In these days of ever increasing competitiveness and constantly evolving markets, the way a company leverages and measures its Intellectual Capital is crucial to its success and indeed to its survival. For investors, intangible assets represent indicators of the future performance, potentialities and, at the same time, weaknesses of a firm's business model. Although several methods for Intellectual Capital measurement and management exist, most of these methods are not able to identify and quantify the cause–effect link between Intellectual Capital management and business performance improvement. Following this lead, the paper suggests a methodology to overcome the lacks of the existing methods.

A linear programming model (Data Envelopment Analysis (DEA)) and the choice of inputs and outputs, properly correlated to components of the Intellectual Capital, allow us to determine the relative efficiency of an enterprise in comparison to other enterprises operating in the same business sector. Moreover, the optimal value of efficiency, that highlights a Best Practice, indicates, in term of percentage, the quantity of productive factors that an enterprise should use to become efficient. This approach offers the advantage of allowing us to make a direct comparison between firms of the same industry in the perspective of improvement through benchmarking.

The paper concludes with the application of the DEA model to the evaluation of the productivity of intangible assets, trying to establish if the investments in Intellectual Capital have indeed achieved an increase in business performance significant enough to justify the sustained financial expenditure. The results show that enterprises that invest more in intangible assets are not automatically the ones that get better business performance, but there is a cause–effect relation only when an enterprise manages its intangible assets optimally. Copyright © 2008 John Wiley & Sons, Ltd.
Electron Beam Crosslinking of Atactic Poly(propylene): Development of a Potential Novel Elastomer
Authors: Schulze Ulrich , Majumder Papiya Sen , Heinrich Gert , Stephan Michael , Gohs Uwe
Published: July 2008

Atactic amorphous poly(propylene) of various molecular weights has been modified with high energy electrons over an irradiation dose range of 0–200 kGy. Tri‐ and tetrafunctional monomers in varied concentrations have been used as crosslinking additives. A correlation between the original molecular weight and crosslinking behavior of the polymer was observed. A higher gel content is obtained with the tetrafunctional acrylate as compared to that with the trifunctional one, under the same treatment conditions. Electron irradiation treatment at elevated temperature gives rise to an increased gel content over that at room temperature. Similarly, the mechanical properties also enhance with gel content. Moreover, the stress‐strain behavior of the electron modified systems indicates a more pronounced elastomeric nature.

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Role of MyoD in denervated, disused, and exercised muscle
Authors: Legerlotz Kirsten , Smith Heather K.
Published: July 2008

The myogenic regulatory factor MyoD plays an important role in embryonic and adult skeletal muscle growth. Even though it is best known as a marker for activated satellite cells, it is also expressed in myonuclei, and its expression can be induced by a variety of different conditions. Several model systems have been used to study the mechanisms behind MyoD regulation, such as exercise, stretch, disuse, and denervation. Since MyoD reacts in a highly muscle‐specific manner, and its expression varies over time and between species, universally valid predictions and explanations for changes in MyoD expression are not possible. This review explores the complex role of MyoD in muscle plasticity by evaluating the induction of MyoD expression in the context of muscle composition and electrical and mechanical stimulation. Muscle Nerve, 2008
Increased level of cell‐free placental mRNA in a subgroup of placenta previa that needs hysterectomy
Authors: Miura Kiyonori , Miura Shoko , Yamasaki Kentaro , Yoshida Atsushi , Yoshiura Koh‐ichiro , Nakayama Daisuke , Niikawa Norio , Masuzaki Hideaki
Published: July 2008

Objective

The purpose of this study was to investigate whether cell‐free placental mRNA levels have the potential to predict a placenta previa resulting in hysterectomy.

Methods

Twenty‐eight singleton pregnant women with placenta previa were classified into the following four groups: 16 women with placenta located at a posterior part of the uterine wall (Group A); 4 each with placenta located at the anterior wall without (Group B) or with (Group C) previous cesarean section; and the other 4 with a history of previous cesarean section and who had the placenta located at an anterior part of uterine wall and underwent a cesarean hysterectomy (Group D). The maternal plasma concentrations of the cell‐free placental lactogen (PL) mRNA measured by real‐time reverse‐transcription polymerase chain reaction (PCR) were converted into multiples of the median (MoM).

Results

The MoM (range) values of cell‐free PL mRNA in the control group and Groups A to D were 1.00 (0.39–2.35), 2.04 (0.91–3.93), 2.58 (1.90–3.90), 3.50 (1.20–4.30), and 6.28 (5.24–7.63), respectively. The concentration of cell‐free PL mRNA was significantly higher in Group D than in Group A, B, or C (Mann–Whitney's U‐test, P < 0.05).

Conclusion

The cell‐free PL mRNA concentration in maternal plasma has the potential to predict a subgroup of placenta accreta resulting in hysterectomy. Copyright © 2008 John Wiley & Sons, Ltd.
Sublethal and Killing Effects of Atmospheric‐Pressure, Nonthermal Plasma on Eukaryotic Microalgae in Aqueous Media
Authors: Tang Ying Zhong , Lu Xin Pei , Laroussi Mounir , Dobbs Fred C.
Published: July 2008

In‐depth studies on the interaction of nonthermal plasmas with microorganisms usually focus on bacteria; only little attention has been given to their effects on more complex eukaryotic cells. We report here nonthermal plasma's effects on cell motility, viability staining, and morphology of eukaryotic microalgae, with three marine dinoflagellates and a marine diatom as major targets. The effects on motility and viability staining depended on the time of exposure to plasma and the species of microalgae. We observed a strong pH decrease in aqueous samples (marine and freshwater algal cultures, their culture media, and deionized water) after exposure to plasma, and hypothesized this decreased pH as the principal mechanism by which plasma exerts its deleterious effects on cells in aqueous media. The hypothesis was supported by results of experiments in which decreasing the pH of algal samples (effected by addition of acid) caused the same morphological damage (as determined with scanning‐electron microscopy) as did exposure to plasma.

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Multiple spatial‐scale resource selection function models in relation to human disturbance for moose in northeastern China
Authors: Jiang Guangshun , Ma Jianzhang , Zhang Minghai , Stott Philip
Published: July 2008

The moose (Alces alces cameloides) population in northeastern China is on the southernmost edge of its distribution in Asia. A survey was conducted to determine moose resource selection and the effects of human disturbance on moose in a study area of 20,661 ha located on the northwestern slope of the Lesser Khingan Mountains, located in northeastern China. Predictive models of resource selection were developed using logistic and autologistic regression. All models considered resource variable selection at two spatial scales, patch and landscape. At the patch scale, moose preferred larger birch (Betula platyphylla) patches, but avoided larger tamarack (Larix gmelinii) patches. At the landscape scale, moose preferred higher densities of tamarack patches, i.e., heterogeneity of tamarack stands, selected areas with more abundant annual shoots, terrain conducive to better concealment, higher altitudes and areas saturated with soil moisture. Roads and forest harvest intervals were identified as important human disturbance factors. This is the first time that moose have been reported to avoid roads, and the avoidance distance was nearly 3 km. We believe that in this region moose under the influence of roads are behaviorally plastic, compared with the indifference of moose to the presence of roads in other regions. Moose avoided forest areas logged more than 3 years previously and preferred areas logged 1–2 years previously. In addition, it may be necessary to monitor the effect of the dynamic of density of roe deer on the spatial distribution of the moose population.
Cut-off points for anthropometric indices of adiposity: differential classification in a large population of young women
Authors: Duggleby Sarah L. , Jackson Alan A. , Godfrey Keith M. , Robinson Siân M. , Inskip Hazel M. ,   the Southampton Women's Survey Study Group
Published: July 2008

Anthropometric indices of adiposity include BMI, waist circumference and waist:height ratio. In the recruitment phase of a prospective cohort study carried out between 1998 and 2002 we studied a population sample of 11 786 white Caucasian non-pregnant women in Southampton, UK aged 20–34 years, and explored the extent to which proposed cut-off points for the three indices identified the same or different women and how these indices related to adiposity. Height, weight and waist circumference were measured and fat mass was estimated from skinfold thicknesses; fat mass index was calculated as fat mass/height1·65. Of the subjects, 4869 (42 %) women were overweight (BMI ≥ 25 kg/m2) and 1849 (16 %) were obese (BMI ≥ 30 kg/m2). A total of 890 (8 %) subjects were not overweight but had a waist circumference ≥ 80 cm and 748 (6 %) subjects were overweight but had a waist circumference < 80 cm (6 %). Of the women, 50 % had a BMI ≥ 25 kg/m2 or a waist circumference ≥ 80 cm or a waist:height ratio ≥ 0·5. Of the variation in fat mass index, 85 % was explained by BMI, 76 % by waist circumference and 75 % by waist:height ratio. Our findings demonstrate that many women are differentially classified depending on which index of adiposity is used. As each index captures different aspects of size in terms of adiposity, there is the need to determine how the three indices relate to function and how they can be of use in defining risk of ill health in women.
Impression Management 2.0
Authors: Krämer Nicole C. , Winter Stephan
Published: July 2008

Social networking sites like MySpace, Facebook, and StudiVZ are popular means of communicating personality. Recent theoretical and empirical considerations of homepages and Web 2.0 platforms show that impression management is a major motive for actively participating in social networking sites. However, the factors that determine the specific form of self-presentation and the extent of self-disclosure on the Internet have not been analyzed. In an exploratory study, we investigated the relationship between self-reported (offline) personality traits and (online) self-presentation in social networking profiles. A survey among 58 users of the German Web 2.0 site, StudiVZ.net, and a content analysis of the respondents’ profiles showed that self-efficacy with regard to impression management is strongly related to the number of virtual friends, the level of profile detail, and the style of the personal photo. The results also indicate a slight influence of extraversion, whereas there was no significant effect for self-esteem.
Long‐term tilt and acceleration data from the Logatchev Hydrothermal Vent Field, Mid‐Atlantic Ridge, measured by the Bremen Ocean Bottom Tiltmeter
Authors: Fabian Marcus , Villinger Heinrich
Published: July 2008

Long‐term seafloor deformations in the Logatchev Hydrothermal Vent Field (LHF) at the Mid‐Atlantic Ridge are largely unexplored and unknown, even though the LHF has been the focus of international research for many years. As seafloor tilt and vertical acceleration provide key information about seafloor deformations, the Bremen Ocean Bottom Tiltmeter (OBT) was deployed in May 2005 at position 14°45′11.7″N, 44°58′47.0″W, 3035 m water depth in the LHF. The OBT recorded 384 days and was recovered in January 2007. Strong tilt steps and strong gradual tilt changes over less than a minute to days in the range of some 10 mrad and aligned mostly with the topography possibly indicate nearby mass movements like avalanches of bulk material due to local uplift or subsidence or may show tectonic activity. A vertically aligned high‐resolution microelectromechanical systems (MEMS) accelerometer of type Servo K‐Beam in the sensor package seems to be helpful to distinguish between tilt signals caused by a true rotation and fake tilt related to a transient translational motion of the OBT in a horizontal direction. Hodographs show elliptic motion patterns with about 1 mrad total tilt amplitude and distinct orientations of tilt toward hydrothermal vents. It is up to speculation whether the latter signals are related to hydrothermal fluid circulation. The amplitude spectra of these tilt signals and acceleration show discrete lines mostly between 0.1 and 50 mHz. The spectra show the periodic character of those signals and also proof that tides or bottom currents, which are known to show lower signal frequencies, or tremor, which generally has higher frequencies, are most likely not the reason. Compared with studies onshore and offshore, the LHF is most likely an area of strong and highly variable seafloor deformations.
A study of low‐albedo deposits within Amazonis Planitia craters: Evidence for locally derived ultramafic to mafic materials
Authors: Stockstill‐Cahill Karen R. , Anderson F. Scott , Hamilton Victoria E.
Published: July 2008

We studied low‐albedo deposits in the floors of craters within the Amazonis Planitia region using infrared data from Mars Global Surveyor Thermal Emission Spectrometer (TES) and Mars Odyssey Thermal Emission Imaging System (THEMIS), high‐resolution visible images from the Mars Orbiter Camera and THEMIS, and topographic data from the Mars Orbiter Laser Altimeter. These deposits are found within subdued to sharp‐rimmed craters that impacted into thick basaltic lava flows from Olympus Mons. These lava flows flooded the region and were subsequently eroded by aeolian processes. TES spectral modeling of the low‐albedo deposits reveals a mineralogy that is dominated by mafic minerals (olivine, pyroxene) with a derived bulk chemistry that ranges from ultramafic to mafic (∼40–52 wt % SiO2) in composition. These bulk compositions are comparable to some Martian lithologies but represent some of the lowest silica contents identified on Mars. The compositional range could be produced by either primary igneous processes or subsequent alteration by aeolian processes. The spatial distribution of the compositions reveals weak to absent groupings and does not distinguish between the igneous or aeolian scenarios. In some craters, possible local sources have been identified within the crater walls, floors and interiors; local sources may be present in additional craters but obscured by dust. No regional sources were identified within a reasonable distance in terms of sand transport but may also be obscured by dust. Therefore, the low‐albedo deposits probably resulted from aeolian erosion of local intracrater basaltic materials that were subsequently redistributed within the floors of these craters.
Conservation potential of agricultural water conservation subsidies
Authors: Huffaker Ray
Published: July 2008

A current policy subsidizes farmers to invest in improved on‐farm irrigation efficiency, expecting water to be conserved off farm. Contrary to expectation, water has been increasingly depleted in some regions after such improvements. This paper investigates the policy's failure to conserve water consistently by (1) formulating an economic model of irrigated crop production to determine a profit‐maximizing irrigator's range of responses to a subsidy and (2) embedding these responses into hypothetical streamflow diagrams to ascertain their potential to conserve water under various hydrologic regimes. Testable hypotheses are developed to predict the conservation potential of a subsidy in real‐world application.
The juxtaposition of a promoter with a locus control region transcriptional domain activates gene expression
Authors: Ho Yugong , Tadevosyan Aleksey , Liebhaber Stephen A , Cooke Nancy E
Published: July 2008

Nonlinear chromatin configurations can juxtapose widely separated elements within a genomic locus; however, it remains unclear how these structures are established and contribute to transcriptional control. A 5′‐remote locus control region (LCR) regulates the human growth hormone (hGH‐N) gene. HSI, a pituitary‐specific component of the hGH LCR, establishes a domain of polymerase II (PolII) transcription 5′ to hGH‐N. Repression of this transcriptional domain by HSI deletion or PolII blockade decreases hGH‐N expression. Here, we show that hGH‐N activation is accompanied by positioning of the hGH‐N promoter to this LCR transcriptional domain. Selectively blocking LCR transcription inhibits the formation of this active ‘looped’ conformation. Thus, HSI is crucial for establishing a domain of noncoding PolII transcription, and this domain is intimately linked with chromatin organization of the active hGH‐N locus. This integration of LCR transcription with chromatin reconfiguration constitutes a robust pathway for long‐range gene activation.
Anterior Olfactory Nucleus
Authors:   Allen Institute for Brain Science, Solan Beth , Ng Lydia , Guillozet-Bongaarts Angela
Published: July 2008

This report contains a gene expression summary of the anterior olfactory nucleus (AON), derived from the Allen Brain Atlas (ABA) in situ hybridization mouse data set. The structure's location and morphological characteristics in the mouse brain are described using the Nissl data found in the Allen Reference Atlas. Using an established algorithm, the expression values of the AON were compared to the values of the macro/parent-structure, in this case the olfactory areas, for the purpose of extracting regionally selective gene expression data. The genes with the highest ranking selectivity ratios were manually curated and verified. 50 genes were then selected and compiled for expression characterization. The experimental data for each gene may be accessed via the links provided; additional data in the sagittal plane may also be accessed using the ABA. Correlations between gene expression in the AON and the rest of the brain, across all genes in the coronal dataset (~4300 genes), were derived computationally. A gene ontology table (derived from DAVID Bioinformatics Resources 2007) is also included, highlighting possible functions of the 50 genes selected for this report.
The Drosophila p21-activated kinase Mbt modulates DE-cadherin-mediated cell adhesion by phosphorylation of Armadillo
Authors: Menzel Nicolas , Melzer Juliane , Waschke Jens , Lenz Christof , Wecklein Heike , Lochnit Günter , Drenckhahn Detlev , Raabe Thomas
Published: July 2008

Phosphorylation by tyrosine and serine/threonine kinases regulate the interactions between components of the cadherin–catenin cell-adhesion complex and thus can influence the dynamic modulation of cell adhesion under normal and disease conditions. Previous mutational analysis and localization experiments suggested an involvement of single members of the family of PAKs (p21-activated kinases) in the regulation of cadherin-mediated cell adhesion, but the molecular mechanism remained elusive. In the present study, we address this question using the Drosophila PAK protein Mbt, which is most similar to vertebrate PAK4. Previous phenotypic analysis showed that Mbt has a function to maintain adherens junctions during eye development and indicated a requirement of the protein in regulation of the actin cytoskeleton and the cadherin–catenin complex. Here we show that activation of Mbt leads to destabilization of the interaction of the Drosophila β-catenin homologue Armadillo with DE-cadherin resulting in a decrease in DE-cadherin-mediated adhesion. Two conserved phosphorylation sites in Armadillo were identified that mediate this effect. The findings of the present study support the previous observation that activation of the human Mbt homologue PAK4 leads to anchorage-independent growth and provide a functional link between a PAK protein and the cadherin–catenin complex.
The mitochondrial pool of free amino acids reflects the composition of mitochondrial DNA-encoded proteins: indication of a post- translational quality control for protein synthesis
Authors: Ross-Inta Catherine , Tsai Chern-Yi , Giulivi Cecilia
Published: July 2008

Mitochondria can synthesize a limited number of proteins encoded by mtDNA (mitochondrial DNA) by using their own biosynthetic machinery, whereas most of the proteins in mitochondria are imported from the cytosol. It could be hypothesized that the mitochondrial pool of amino acids follows the frequency of amino acids in mtDNA-encoded proteins or, alternatively, that the profile is the result of the participation of amino acids in pathways other than protein synthesis (e.g. haem biosynthesis and aminotransferase reactions). These hypotheses were tested by evaluating the pool of free amino acids and derivatives in highly-coupled purified liver mitochondria obtained from rats fed on a nutritionally adequate diet for growth. Our results indicated that the pool mainly reflects the amino acid composition of mtDNA-encoded proteins, suggesting that there is a post-translational control of protein synthesis. This conclusion was supported by the following findings: (i) correlation between the concentration of free amino acids in the matrix and the frequency of abundance of amino acids in mtDNA-encoded proteins; (ii) the similar ratios of essential-to-non-essential amino acids in mtDNA-encoded proteins and the mitochondrial pool of amino acids; and (iii), lack of a correlation between codon usage or tRNA levels and amino-acid concentrations. Quantitative information on the mammalian mitochondrial content of amino acids, such as that presented in the present study, along with functional studies, will help us to better understand the pathogenesis of mitochondrial diseases or the biochemical implications in mitochondrial metabolism.
Transition layers at the SiO2∕SiC interface
Authors: Zheleva Tsvetanka , Lelis Aivars , Duscher Gerd , Liu Fude , Levin Igor , Das Mrinal
Published: July 2008

The electrical performance of SiC-based microelectronic devices is strongly affected by the densities of interfacial traps introduced by the chemical and structural changes at the SiO2∕SiC interface during processing. We analyzed the structure and chemistry of this interface for the thermally grown SiO2∕4H-SiC heterostructure using high-resolution transmission electron microscopy (TEM), Z-contrast scanning TEM, and spatially resolved electron energy-loss spectroscopy. The analyses revealed the presence of distinct layers, several nanometers thick, on each side of the interface; additionally, partial amorphization of the top SiC surface was observed. These interfacial layers were attributed to the formation of a ternary Si–C–O phase during thermal oxidation.
Tailoring gas sensing properties of carbon nanotubes
Authors: Brahim Sean , Colbern Steve , Gump Robert , Grigorian Leonid
Published: July 2008

An approach to tune the chemical properties (electronic density of states, chemical potential) of carbon nanotubes (CNTs) for gas/vapor sensing is presented. The technique involves infiltrating CNTs with transition metal as opposed to decorating the outer sidewalls. NO2 was chosen as a model gas to demonstrate the variable/tunable sensing behavior of the metal-CNT hybrids. By varying the nature of the transition metal infiltrated into the CNT, we observe dramatically different responses among the hybrid sensors upon exposure to ppm levels of the target analyte. These responses are manifested as simultaneous resistive and capacitive components of the CNT impedance. While some hybrid materials demonstrated superior sensitivity (approximately two-fold increase) to detection of NO2 at room temperature compared to the pristine SWCNT sensor, other hybrid sensors showed suppressed sensitivity (approximately 20-fold decrease) to NO2 relative to the single wall CNT sensor. These differential impedimetric responses created from a library of metal-CNT hybrid materials may function as a practical approach for offering enhanced sensitivity and selectivity for gas sensing.
Dielectric, ferroelectric properties, and grain growth of CaxBa1−xNb2O6 ceramics with tungsten-bronzes structure
Authors: Ke Shanming , Fan Huiqing , Huang Haitao , Chan H. L. W. , Yu Shuhui
Published: July 2008

Dielectric properties, microstructures, and phase transition behaviors of α and β phases of CaxBa1−xNb2O6 (x=0.22, 0.30, and 0.38) ceramics were investigated. All the three compositions had partially filled tungsten-bronze structure (TTB) and relatively high Curie temperatures (up to 345°C) compared with Sr1−xBaxNb2O6. The α phase exhibits unambiguously a diffused phase transition, while the β phase is associated with an incommensurate phase and needs to be further studied. The dielectric and ferroelectric properties of CaxBa1−xNb2O6 ceramics were strongly processing-dependent. A mechanism was proposed to explain the grain growth behavior of TTB ceramic niobates.
Psychology Textbooks: Examining Their Accuracy
Authors: Steuer Faye B. , Ham K. Whitfield
Published: July 2008

Sales figures and recollections of psychologists indicate textbooks play a central role in psychology students' education, yet instructors typically must select texts under time pressure and with incomplete information. Although selection aids are available, none adequately address the accuracy of texts. We describe a technique for sampling textbooks' content and evaluating accuracy. Preliminary studies indicated multiple errors in texts we examined. We present a proposed taxonomy of such errors. We speculate that errors are more likely when textbook authors use “deductive” rather than “inductive referencing,” but acknowledge that authors frequently are under pressure to use the former. Discipline-wide efforts to assess textbooks' scholarly quality could facilitate improvements in accuracy, providing fundamental benefits to the discipline.
The Roles of CPG Phase Modulation and Reflexive Muscular Patterns in Balance Recovery During Walking—A Simulation Study
Authors: Ikemoto Yu , Yu Wenwei
Published: July 2008

Most walking assist systems reported are not available for real world environments where frequent perturbations are caused by slips, uneven terrain, slopes and obstacles. It is evident that humans are able to cope with such perturbations with reflexes that cause unconscious, relatively fixed muscular response patterns to perturbations within a short period of time. In our previous study, we showed that artificial reflexes could improve the perturbation resistance for simulated walkers, though the roles of different reflexive mechanisms were not quantitatively clarified. In this study, we focused on the different roles of reflexive muscle responses and the CPG phase modulation mechanism. By proposing and evaluating two stability criteria through a series of simulation experiments, we revealed different roles for two mechanisms in the simulated walkers. These will not only further increase the possibility of realising artificial reflexes for paralysed individuals, but also bring new insights into the field of motor control.
PLZT‐Modified Relaxor Piezoelectric Ceramic System for Medical Diagnostic Applications
Authors: Ramam Koduri , Lopez Marta
Published: July 2008

The piezoelectric ceramic system [Pb0.978–yLa0.012Ba0.01Sry][(Zr0.534Ti0.466)0.987Nb0.008]O3 (PLBSZNT) has been fabricated for use in medical diagnostics applications. The fundamental pre‐requisites are high‐density, high dielectric constant and high piezoelectric properties that serve as compatible ceramic materials for medical diagnostic applications. It is essential for sensitive transducers that the piezoelectric ceramics must efficiently convert between electrical and mechanical energy, and so the electromechanical coupling coefficients should be high, as the fabrication process of tiny elements for medical arrays must be carried out without damaging the material and its properties. In our study, Sr‐modified PLBZNT had shown single ferroelectric tetragonal phase. An analysis of different Sr doping concentration is reported, and the high dielectric permittivity, low dielectric loss along with high electromechanical properties indicate that PLBSZNT is suitable for medical diagnostic applications as well as sensors and actuators.
Context-induced relapse to drug seeking: a review
Authors: Crombag Hans S , Bossert Jennifer M , Koya Eisuke , Shaham Yavin
Published: July 2008

In humans, exposure to environmental contexts previously associated with drug intake often provokes relapse to drug use, but the mechanisms mediating this relapse are unknown. Based on early studies by Bouton & Bolles on context-induced ‘renewal’ of learned behaviours, we developed a procedure to study context-induced relapse to drug seeking. In this procedure, rats are first trained to self-administer drug in one context. Next, drug-reinforced lever responding is extinguished in a different (non-drug) context. Subsequently, context-induced reinstatement of drug seeking is assessed by re-exposing rats to the drug-associated context. Using variations of this procedure, we and others reported reliable context-induced reinstatement in rats with a history of heroin, cocaine, heroin–cocaine combination, alcohol and nicotine self-administration. Here, we first discuss potential psychological mechanisms of context-induced reinstatement, including excitatory and inhibitory Pavlovian conditioning, and occasion setting. We then summarize results from pharmacological and neuroanatomical studies on the role of several neurotransmitter systems (dopamine, glutamate, serotonin and opioids) and brain areas (ventral tegmental area, accumbens shell, dorsal striatum, basolateral amygdala, prefrontal cortex, dorsal hippocampus and lateral hypothalamus) in context-induced reinstatement. We conclude by discussing the clinical implications of rat studies on context-induced reinstatement of drug seeking.
Acute effects of cocaine on the neurobiology of cognitive control
Authors: Garavan Hugh , Kaufman Jacqueline N , Hester Robert
Published: July 2008

Compromised ability to exert control over drug urges and drug-seeking behaviour is a characteristic of addiction. One specific cognitive control function, impulse control, has been shown to be a risk factor for the development of substance problems and has been linked in animal models to increased drug administration and relapse. We present evidence of a direct effect of cocaine on the neurobiology underlying impulse control. In a laboratory test of motor response inhibition, an intravenous cocaine administration improved task performance in 13 cocaine users. This improvement was accompanied by increased activation in right dorsolateral and inferior frontal cortex, regions considered critical for this cognitive function. Similarly, for both inhibitory control and action monitoring processes, cocaine normalized activation levels in lateral and medial prefrontal regions previously reported to be hypoactive in users relative to drug-naive controls. The acute amelioration of neurocognitive dysfunction may reflect a chronic dysregulation of those brain regions and the cognitive processes they subserve. Furthermore, the effects of cocaine on midline function suggest a dopaminergically mediated intersection between cocaine's acute reinforcing effects and its effects on cognitive control.
Effectiveness of vocabulary learning via mobile phone
Authors: Lu M.
Published: July 2008

Whereas the penetration of mobile phones in Asian countries keeps climbing, little research has explored the application of the short message service (SMS) in second language learning. This study aims to examine the effectiveness of SMS vocabulary lessons of limited lexical information on the small screens of mobile phones. Thirty high school students were randomly distributed into two groups and given two sets of English words either on paper or through SMS messages during two weeks. Students recognized more vocabulary during the post‐test after reading the regular and brief SMS lessons than they did after reading the relatively more detailed print material. Qualitative data from interviews offer information about the learning process as well as the benefits and limitations of m‐learning. Results of the questionnaires show that students in general hold positive attitudes towards learning vocabulary via mobile phone. On the other hand, technological limitations, unfamiliar presentations and learning activities may prevent students from reading SMS lessons.
The impact of combination therapy with peginterferon alfa‐2a and ribavirin on the energy intake and body weight of adult hepatitis C patients
Authors: Hamer C.
Published: July 2008

Background It is recognized that interferon therapy has an adverse effect on the appetite and nutritional status of children with hepatitis B and C. No similar studies have been undertaken in adults. The aim of the present study was to determine if and how combination therapy with peginterferon alfa‐2a and ribavirin affects energy intake and body weight in adult hepatitis C patients. A secondary aim was to investigate whether any changes are related to the presence of perceived side effects of treatment.

Methods The energy intake of 15 adult hepatitis C patients was measured using a 3‐day food diary. A visual analogue scale (VAS) was used to investigate patients’ perception of fatigue, appetite and nausea. These measurements and body weight were taken before the start of treatment and at weeks 1, 3, 11, 24 and 28 in order to assess changes at intervals throughout interferon therapy.

Results Fourteen patients (93%) lost weight during therapy. The greatest rate of mean [95% confidence interval (CI)] weight loss occurred at week 1 [1.64% (0.95–2.33)]. Weight loss continued until week 24. The greatest decrease in mean (95% CI) energy intake occurred at week 1 [9.74% (0.78–18.70)]. Mean VAS scores for fatigue, loss of appetite and nausea increased at week 1 and remained above pretreatment levels throughout the study period.

Conclusion Adult hepatitis C patients treated with a combination of peginterferon alfa‐2a and ribavirin are likely to experience decreased energy intake and weight loss during treatment. This may be related to the impact of side effects of treatment and may require dietetic intervention.
Rationalizing blood transfusion in cardiac surgery: the impact of a red cell volume‐based guideline on blood usage and clinical outcome
Authors: Slight R. D. , O'Donohoe P. , Fung A. K. Y. , Alonzi C. , McClelland D. B. L. , Mankad P. S.
Published: July 2008

Background and Objectives  Cardiac surgery is currently considered one of the heaviest users of red blood cells. An explanation may be found, in part, in considering the effect of the heavy clear fluid load associated with cardiopulmonary bypass. This may result in the artificial depression of haemoglobin concentration, overestimating the requirement for red cell transfusion if this is the sole parameter considered. To address this issue, we examined the impact of a red cell volume‐based transfusion guideline on transfusion requirement.

Materials and Methods  This was a single‐centre, randomized controlled trial. The cohort of 86 patients was allocated to receive red cells as per the red cell volume guideline (group RCV) or standard haemoglobin concentration‐based departmental policy (group C). Outcome measures were red cell transfusion and clinical outcome.

Results  All preoperative data were comparable between the two groups. A significantly fewer percentage of patients in group RCV were transfused red cells (RCV = 32·6% vs. C = 53·5%, P = 0·05). No significant difference was found between any of the outcome measures with the exception of median hospital stay (RCV = 5·9 days vs. C = 6·8 days, P = 0·02).

Conclusion  In elective cardiac surgery patients, considering haemoglobin concentration alone may overestimate the requirement for red cell transfusion. More research is required to determine the impact of restrictive transfusion policies on clinical outcome following cardiac surgery.
Reconstructing the demise of Tethyan plants: climate‐driven range dynamics of Laurus since the Pliocene
Authors: Rodríguez‐Sánchez Francisco , Arroyo Juan
Published: July 2008

Aim  Climate changes are thought to be responsible for the retreat and eventual extinction of subtropical lauroid species that covered much of Europe and North Africa during the Palaeogene and early Neogene; little is known, however, of the spatial and temporal patterns of this demise. Herein we calibrate ecological niche models to assess the climatic requirements of Laurus L. (Lauraceae), an emblematic relic from the Tethyan subtropical flora, subsequently using these models to infer how the range dynamics of Laurus were affected by Plio‐Pleistocene climate changes. We also provide predictions of likely range changes resulting from future climatic scenarios.

Location  The Mediterranean Basin and Macaronesian islands (Canaries, Madeira, Azores).

Methods  We used a maximum‐entropy algorithm (Maxent) to model the relationship between climate and Laurus distribution over time. The models were fitted both to the present and to the middle Pliocene, based on fossil records. We employed climatic reconstructions for the mid‐Pliocene (3 Ma), the Last Glacial Maximum (21 ka) and a CO2‐doubling future scenario to project putative species distribution in each period. We validated the model projections with Laurus fossil and present occurrences.

Results  Laurus preferentially occupied warm and moist areas with low seasonality, showing a marked stasis of its climatic niche. Models fitted to Pliocene conditions successfully predicted the current species distribution. Large suitable areas existed during the Pliocene, which were strongly reduced during the Pleistocene, but humid refugia within the Mediterranean Basin and Macaronesian islands enabled long‐term persistence. Future climate conditions are likely to re‐open areas suitable for colonization north of the current range.

Main conclusions  The climatic requirements of Laurus remained virtually unchanged over the last 3 Myr. This marked niche conservatism imposed largely deterministic range dynamics driven by climate conditions. This species's relatively high drought tolerance might account for the survival of Laurus in continental Europe throughout the Quaternary whilst other Lauraceae became extinct. Climatic scenarios for the end of this century would favour an expansion of the species's range towards northern latitudes, while severely limiting southern populations due to increased water stress.
Self‐esteem and cognitive development in the era of the childhood obesity epidemic
Authors: Wang F. , Veugelers P. J.
Published: July 2008

Consequences of obesity for mental health and cognitive development are not established to the same degree as those for chronic diseases. This study aims to document the interrelationships between body weight, self‐esteem and school performance in childhood. Height and weight measurements and self‐report of self‐esteem, diet quality and physical activity of 4945 grade 5 students were linked with standardized literacy test results. Structural equation models were applied to confirm hypothesized relationships between body weight, self‐esteem and school performance, and revealed that body weight affected self‐esteem negatively and that school performance affected self‐esteem positively. Body weight did not affect school performance, and self‐esteem did affect neither body weight nor school performance. Subsequent multi‐level logistic regression showed that obese students, relative to normal weight students, were more likely (1.44; 95% CI: 1.12–1.84), and students with good school performance, relative to those performing poor, were less likely (0.39; 95% CI: 0.26–0.58), to have low self‐esteem. Diet quality and active living had positive effects on both school performance and self‐esteem. The study findings further establish obesity as a risk factor for low self‐esteem and add to the rationale to promote healthy eating and active living among children and youth as this will prevent chronic diseases and improve mental health and cognitive development.
CHANGES IN THE RELATIVE EARNINGS GAP BETWEEN NATIVES AND IMMIGRANTS ALONG THE U.S.‐MEXICO BORDER*
Authors: Dávila Alberto , Mora Marie T.
Published: July 2008

ABSTRACT Using 1990 and 2000 U.S. census data, this study investigates changes in immigrant/native earnings disparities for workers in U.S. cities along the international border with Mexico vis‐à‐vis the U.S. interior during the 1990s. Our findings—based on estimating earnings functions and employing the Juhn‐Murphy‐Pierce (1993, JPE) wage decomposition technique—indicate that the average earnings of Mexican immigrants along the U.S.‐Mexico border improved relative to those accrued by their counterparts in the U.S. interior and by otherwise similar U.S.‐born Mexican Americans between 1990 and 2000. However, when comparing Mexican‐born workers to U.S.‐born non‐Hispanic whites, the immigrant border‐earnings penalty remained statistically unchanged.
Cessation of Hemiplegic Migraine Auras With Greater Occipital Nerve Blockade
Authors: Rozen Todd
Published: July 2008

Prolonged migraine auras can be disabling and potentially can cause permanent neurologic deficits. Several medicinal agents have shown some efficacy in aborting prolonged auras, but results are inconsistent. Greater occipital nerve blockade can alleviate the pain of migraine and in 1 case report the migraine aura. Hemiplegic migraine attacks are marked by motor weakness that can last for minutes to days. Two case patients with a history of hemiplegic migraine with prolonged auras are presented, who both had complete alleviation of their aura symptoms with GON blockade. A hypothesis on how GON blockade may inhibit cortical spreading depression is also presented.