bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of a reduction in the number of gap junction channels or in their conductance on ischemia-reperfusion arrhythmias in isolated mouse hearts
Authors: Sánchez Jose A. , Rodríguez-Sinovas Antonio , Fernández-Sanz Celia , Ruiz-Meana Marisol , García-Dorado David
Published: September 2011

A transient reduction of cell coupling during reperfusion limits myocardial necrosis, but little is known about its arrhythmogenic effects during ischemia-reperfusion. Thus, we analyzed the effect of an extreme reduction in the number of gap junction channels or in their unitary conductance on ventricular arrhythmias during myocardial ischemia-reperfusion. Available gap junction uncouplers have electrophysiological effects independent from their uncoupling actions. Thus, isolated hearts from Cx43Cre-ER(T)/fl mice treated with 4-hydroxytamoxifen (4-OHT), from Cx43KI32 mice [in which connexin (Cx)43 was replaced with Cx32], and from control animals were submitted to regional ischemia and reperfusion, and spontaneous and induced ventricular arrhythmias were monitored. In additional hearts, changes in activation time and electrical impedance during global ischemia-reperfusion were assessed. In contrast to treatment with 4-OHT, replacement of Cx43 with Cx32 did not modify baseline activation time or electrical impedance. However, the number of extrasistole and ventricular tachyarrhytmias was higher in isolated hearts from Cx43KI32 and 4-OHT-treated Cx43Cre-ER(T)/fl animals versus wild-type animals during normoxia, ischemia (12.29 ± 3.26 and 52.17 ± 22.51 vs. 3.00 ± 1.46 spontaneous tachyarrhythmias, P < 0.05), and reperfusion. The impairment in conduction during ischemia was steeper in isolated hearts from Cx43KI32 animals, whereas changes in myocardial impedance were attenuated during ischemia in both transgenic models, suggesting altered cell-to-cell coupling at baseline. In conclusion, both reduction of Cx43 with 4-OHT and replacement of Cx43 by less-conductive Cx32 were arrhythmogenic under normoxia and ischemia-reperfusion, despite no major effects on baseline electrical properties. These results suggest that modifications in gap junction communication silent under normal conditions may be arrhythmogenic during ischemia-reperfusion.
Left-ventricular shape determines intramyocardial mechanical heterogeneity
Authors: Choi Hon Fai , Rademakers Frank E. , Claus Piet
Published: September 2011

Left-ventricular remodeling is considered to be an important mechanism of disease progression leading to mechanical dysfunction of the heart. However, the interaction between the physiological changes in the remodeling process and the associated mechanical dysfunction is still poorly understood. Clinically, it has been observed that the left ventricle often undergoes large shape changes, but the importance of left-ventricular shape as a contributing factor to alterations in mechanical function has not been clearly determined. Therefore, the interaction between left-ventricular shape and systolic mechanical function was examined in a computational finite-element study. Hereto, finite-element models were constructed with varying shapes, ranging from an elongated ellipsoid to a sphere. A realistic transmural gradient in fiber orientation was considered. The passive myocardium was described by an incompressible hyperelastic material law with transverse isotropic symmetry. Activation was governed by the eikonal-diffusion equation. Contraction was incorporated using a Hill model. For each shape, simulations were performed in which passive filling was followed by isovolumic contraction and ejection. It was found that the intramyocardial distributions of fiber stress, strain, and stroke work density were shape dependent. Ejection performance was reduced with increasing sphericity, which was regionally related to a reduction in the active fiber stress development, fiber shortening, and stroke work in the midwall and subepicardial region at the midheight level in the left-ventricular wall. Based on these results, we conclude that a significant interaction exists between left-ventricular shape and regional myofiber mechanics, but the importance for left-ventricular remodeling requires further investigation.
Platelet-activating factor stimulates sodium-hydrogen exchange in ventricular myocytes
Authors: Ajiro Yoichi , Saegusa Noriko , Giles Wayne R. , Stafforini Diana M. , Spitzer Kenneth W.
Published: September 2011

Sodium-hydrogen exchanger (NHE), the principal sarcolemmal acid extruder in ventricular myocytes, is stimulated by a variety of autocrine/paracrine factors and contributes to myocardial injury and arrhythmias during ischemia-reperfusion. Platelet-activating factor (PAF; 1- o-alkyl-2-acetyl- sn-glycero-3-phosphocholine) is a potent proinflammatory phospholipid that is released in the heart in response to oxidative stress and promotes myocardial ischemia-reperfusion injury. PAF stimulates NHE in neutrophils and platelets, but its effect on cardiac NHE (NHE1) is unresolved. We utilized quiescent guinea pig ventricular myocytes bathed in bicarbonate-free solutions and epifluorescence to measure intracellular pH (pHi). Methylcarbamyl-PAF (C-PAF; 200 nM), a metabolically stable analog of PAF, significantly increased steady-state pHi. The alkalosis was completely blocked by the NHE inhibitor, cariporide, and by sodium-free bathing solutions, indicating it was mediated by NHE activation. C-PAF also significantly increased the rate of acid extrusion induced by intracellular acidosis. The ability of C-PAF to increase steady-state pHiwas completely blocked by the PAF receptor inhibitor WEB 2086 (10 μM), indicating the PAF receptor is required. A MEK inhibitor (PD98059; 25 μM) also completely blocked the rise in pHiinduced by C-PAF, suggesting participation of the MAP kinase signaling cascade downstream of the PAF receptor. Inhibition of PKC with GF109203X (1 μM) and chelerythrine (2 μM) did not significantly affect the alkalosis induced by C-PAF. In summary, these results provide evidence that PAF stimulates cardiac NHE1, the effect occurs via the PAF receptor, and signal relay requires participation of the MAP kinase cascade.
Phosphodiesterase 4 inhibition attenuates persistent heart and lung injury by neonatal hyperoxia in rats
Authors: de Visser Yvonne P. , Walther Frans J. , Laghmani El Houari , Steendijk Paul , Middeldorp Maaike , van der Laarse Arnoud , Wagenaar Gerry T. M.
Published: September 2011

Phosphodiesterase (PDE) 4 inhibitors are potent anti-inflammatory drugs with antihypertensive properties, and their therapeutic role in bronchopulmonary dysplasia (BPD) is still controversial. We studied the role of PDE4 inhibition with piclamilast on normal lung development and its therapeutic value on pulmonary hypertension (PH) and right ventricular hypertrophy (RVH) in neonatal rats with hyperoxia-induced lung injury, a valuable model for premature infants with severe BPD. The cardiopulmonary effects of piclamilast treatment (5 mg·kg−1·day−1) were investigated in two models of experimental BPD: 1) daily treatment during continuous exposure to hyperoxia for 10 days; and 2) late treatment and injury-recovery in which pups were exposed to hyperoxia or room air for 9 days, followed by 9 or 42 days of recovery in room air combined with treatment started on day 6 of oxygen exposure until day 18. Prophylactic piclamilast treatment reduced pulmonary fibrin deposition, septum thickness, arteriolar wall thickness, arteriolar vascular smooth muscle cell proliferation and RVH, and prolonged survival. In the late treatment and injury-recovery model, hyperoxia caused persistent aberrant alveolar and vascular development, PH, and RVH. Treatment with piclamilast in both models reduced arteriolar wall thickness, attenuated RVH, and improved right ventricular function in the injury recovery model, but did not restore alveolarization or angiogenesis. Treatment with piclamilast did not show adverse cardiopulmonary effects in room air controls in both models. In conclusion, PDE4 inhibition attenuated and partially reversed PH and RVH, but did not advance alveolar development in neonatal rats with hyperoxic lung injury or affect normal lung and heart development.
Targeting the restricted α-subunit repertoire of airway smooth muscle GABAA receptors augments airway smooth muscle relaxation
Authors: Gallos George , Yim Peter , Chang Sucie , Zhang Yi , Xu Dingbang , Cook James M. , Gerthoffer William T. , Emala Charles W.
Published: September 2011

The prevalence of asthma has taken on pandemic proportions. Since this disease predisposes patients to severe acute airway constriction, novel mechanisms capable of promoting airway smooth muscle relaxation would be clinically valuable. We have recently demonstrated that activation of endogenous airway smooth muscle GABAA receptors potentiates β-adrenoceptor-mediated relaxation, and molecular analysis of airway smooth muscle reveals that the α-subunit component of these GABAA receptors is limited to the α4- and α5-subunits. We questioned whether ligands with selective affinity for these GABAA receptors could promote relaxation of airway smooth muscle. RT-PCR analysis of GABAA receptor subunits was performed on RNA isolated by laser capture microdissection from human and guinea pig airway smooth muscle. Membrane potential and chloride-mediated current were measured in response to GABAA subunit-selective agonists in cultured human airway smooth muscle cells. Functional relaxation of precontracted guinea pig tracheal rings was assessed in the absence and presence of the α4-subunit-selective GABAA receptor agonists: gaboxadol, taurine, and a novel 8-methoxy imidazobenzodiazepine (CM-D-45). Only messenger RNA encoding the α4- and α5-GABAA receptor subunits was identified in RNA isolated by laser capture dissection from guinea pig and human airway smooth muscle tissues. Activation of airway smooth muscle GABAA receptors with agonists selective for these subunits resulted in appropriate membrane potential changes and chloride currents and promoted relaxation of airway smooth muscle. In conclusion, selective subunit targeting of endogenous airway smooth muscle-specific GABAA receptors may represent a novel therapeutic option for patients in severe bronchospasm.
Association of Imaging Markers of Myocardial Fibrosis With Metabolic and Functional Disturbances in Early Diabetic Cardiomyopathy
Authors: Jellis Christine , Wright Jeremy , Kennedy Dominic , Sacre Julian , Jenkins Carly , Haluska Brian , Martin Jennifer , Fenwick John , Marwick Thomas H.
Published: September 2011

Background—

Metabolic and vascular disturbances contribute to diabetic cardiomyopathy, but the role of interstitial fibrosis in early disease is unproven. We sought to assess the relationship between imaging markers of diffuse fibrosis and myocardial dysfunction and to link this to possible causes of early diabetic cardiomyopathy.

Methods and Results—

Hemodynamic and metabolic data were measured in 67 subjects with type 2 diabetes mellitus (age 60±10 years) with no cardiac symptoms. Myocardial function was evaluated with standard echocardiography and myocardial deformation; ischemia was excluded by exercise echocardiography. Calibrated integrated backscatter was calculated from parasternal long-axis views. T1 mapping was performed after contrast with a modified Look-Locker technique using saturation recovery images. Amino-terminal propeptides of procollagens type I and III, as well as the carboxy-terminal propeptide of procollagen type I, were assayed to determine collagen turnover. Subjects with abnormal early diastolic tissue velocity (E
m
) had shorter postcontrast T1 values (
P
=0.042) and higher calibrated integrated backscatter (
P
=0.007). They were heavier (
P
=0.003) and had worse exercise capacity (
P
<0.001), lower insulin sensitivity (
P
=0.003), and blunted systolic tissue velocity (
P
=0.05). Postcontrast T1 was associated with diastolic dysfunction (E
m
r
=0.28,
P
=0.020; E/E
m
r
=−0.24,
P
=0.049), impaired exercise capacity (
r
=0.30,
P
=0.016), central adiposity (
r
=−0.26,
P
=0.046), blood pressure (systolic
r
=−0.30,
P
=0.012; diastolic
r
=−0.49,
P
<0.001), and insulin sensitivity (
r
=0.30,
P
=0.037). The association of T1 with E/E
m
(β=−0.31,
P
=0.017) was independent of blood pressure and metabolic disturbance. Amino-terminal propeptide of procollagens type III was linked to diastolic dysfunction (E
m
r
=−0.32,
P
=0.008) and calibrated integrated backscatter (
r
=0.30,
P
=0.015) but not T1 values.

Conclusions—

The association between myocardial diastolic dysfunction, postcontrast T1 values, and metabolic disturbance supports that diffuse myocardial fibrosis is an underlying contributor to early diabetic cardiomyopathy.
Arid geomorphology
Authors: Tooth Stephen
Published: September 2011

Arid geomorphological research continues apace with publications appearing in a diverse range of outlets. Themes common to several recent (2008–2009) books include greater emphasis on the global diversity of arid environments, the improved temporal framework for research findings, and the growing contribution of arid geomorphology to interdisciplinary research fields. Building on previous progress reports, this article touches on all three themes, but particularly highlights how applications of geochronology (e.g. cosmogenic isotope analysis, luminescence dating, and radiocarbon dating) are challenging or revolutionizing understanding of the timing and rates of arid geomorphological change. Four case studies from ‘iconic’ arid landscapes illustrate changes over different timescales: (1) canyons of the Colorado Plateau region, southwest USA (last ~5–6 Ma); (2) aeolian dunefields in central Australia (last ~1 Ma); (3) palaeolakes in the Kalahari, central southern Africa (last ~300 ka); and (4) alluvial and bedrock-controlled rivers in the southwest USA (last ~12 ka). Other developments across the suite of geochronological techniques are also contributing to improved understanding of arid landscape dynamics and the links with late Cenozoic environmental changes, biological (including hominin) evolution and cultural developments, but many outstanding issues remain. These include: (1) compiling large geochronological data sets to enable rigorous hypothesis testing; (2) establishing guiding conceptual frameworks to aid the selection and interpretation of geochronological data; (3) using multiple chronometers; (4) combining geochronology with other investigative techniques such as computational modelling; and (5) clarifying the causal links between events in different palaeorecords, even when temporal correlation can be established with a high degree of certainty. Despite recent rapid advances, today’s understanding of the antiquity and tempo of landscape development in Earth’s arid environments undoubtedly will be challenged and extended by further research, with particularly valuable perspectives likely to be provided by arid geomorphological research on other planetary bodies.
Cytotoxicity of the venom from the nematocysts of jellyfish Cyanea nozakii Kishinouye
Authors: Cuiping Li , Pengcheng Li , Jinhua Feng , Rongfeng Li , Huahua Yu
Published: September 2011

In this article, the cytotoxicity of the venom from the nematocysts of jellyfish Cyanea nozakii Kishinouye on human hepatoma cells (Bel-7402, SMMC-7721) and human colon cancer cells (H630) was investigated first. Of the three kinds of cells, the venom had the strongest cytotoxicity on H630 cells with the 50% lethal concentration (IC50) of 5.1 μg/ml. However, the IC50 on Bel-7402 and SMMC-7721 was approximate 17.9 and 24.3 μg/ml, respectively. The cytotoxicity of the venom was affected by pH, temperature and storage conditions. At the pH 4.5–8.5, the venom displayed obvious cytotoxicity and the percentage of survival was about 50%. When pre-incubated at temperatures over 60°C for as short as 10 min, the percentage of survival sharply improved from 4.6% up to 80%. The venom was stored in a more stable condition at −80°C and in lyophilized state compared to other storage conditions used in this study. Lactate dehydrogenase release assay performed on H630 cells indicated that exposure to the venom could result in damage to the cell membrane.
Simulation and experimental realization of μ-channels using a μED-milling process
Authors: Karthikeyan G , Sambhav K , Ramkumar J , Dhamodaran S
Published: September 2011

Machining of microchannels (µ-channels) on hard conducting materials can be performed effectively using a micro electric discharge milling (µED-milling) process. The method of bulk machining is considered in this work, as it takes less machining time than conventional layer-by-layer machining. However, the tool wear in this method occurs both in the side and bottom of the tool, which causes dimensional inaccuracy. Hence, to achieve the desired µ-channel shape, the technique of multiple-pass machining is introduced, wherein a dressed tool is used in each pass to compensate tool wear. The basic idea behind the work is to compute the number of passes and machining time required in achieving the shape. A computer-aided design-based algorithm is used to simulate the shape of the µ-channel and tool for a single pass and for further multiple passes. At the end of each pass, the volume of material removal and tool wear are estimated quantitatively. The desired channel shape is considered to be achieved when the volume of the material left-out is less than or equal to 5 per cent of the ideal volume to be removed. This paper elaborates on the procedure for single- and multiple-pass simulation to determine the number of passes and machining time. The results are validated with experiments for the desired µ-channel shape.
Six-degree-of-freedom active vibration isolation system with decoupled collocated control
Authors: Pu H , Chen X , Zhou Z , Luo X
Published: September 2011

An ultra-precision vibration isolation system for high-resolution equipment is presented in this paper. The system consists of a passive isolation subsystem using a combination of an air spring and a pendulum mechanism, and an active subsystem using collocated actuator–sensor pairs. The six-degree-of-freedom kinematic model of the passive system is derived and then verified by carrying out a set of frequency response experiments. The controller design is based on a combination of decentralized control and modal control. The former is to improve the characteristics of a single passive isolator; the latter is to shape the main vibration modes actively in the frequency domain. The modal decoupling method based on the kinematic model of the system is used to implement the decoupled collocated control. Because of the sensor dynamics and inherent delay of control system, the stability of the vibration control system is affected. The upper boundary of the control gain is obtained through a root locus analysis. The performances of the hybrid system are investigated in the frequency domain and finally validated by comparison with the passive isolation system.
Hybrid piezo-electrostatic inkjet head for printed electronics
Authors: Choi K H , Muhammad N M , Rehmani M A A , Kim D S
Published: September 2011

Even after the successful demonstration of the electrostatic printing method for the generation of the printed conductive lines, it has not been commercialized until now for printed electronics fabrication. This is mainly because of the application of high voltage for the ejection of the droplet being reported and high throughput. In the study presented in this article, a novel hybrid piezoelectric and electrostatic device is proposed for reducing energy requirements of the electrostatic inkjet head with the help of a pre-developed meniscus through piezoelectric actuation. In the proposed concept, the meniscus is generated at the tip of the electrode and the electrostatic potential applied which has its highest gradient at the electrode apex. Two different arrangements of piezo-actuator installation in the inkjet printing head are analysed. Furthermore, the numerical simulations have been performed to compare the drop size for pre-developed meniscus and electrostatically developed meniscus and cone-jet for the ejection of the drop. It is demonstrated that this approach reduces the size of the droplet considerably and also reduces the electrostatic potential for droplet generation.
Oblique nozzle loaded by the torque moment–stress state in the cylindrical shells on the pressure vessel
Authors: Petrovic A L , Balac M M , Jovovic A , Dedic A
Published: September 2011

Influence of local loads on the stress state of the shell appears as the consequence of pressure, external forces, and moment influence. Loads which act directly upon the shell surface or the parts (nozzles) connected to the shell appear in their proximity, especially in the welded joint influence zones.

The influence of the torque moment affecting the free end of a slanted branch on the pressure vessel cylindrical shell is considered in this article. The stress on the cylindrical shell was analysed on 245 models of different geometrical characteristics. Stress calculated by applying the finite element method was classified by maximum stress criteria. For every considered model, maximum stress envelope has been prepared. The regressive analysis enabled the determination of correlation functions, which allow calculation of stress maximum values on the cylindrical shell according to which the shell dimensions may be determined. Result analysis shows that the percentual error is within limits as follows: from −13.4 per cent to +12.7 per cent.
Design, development, and manufacture of an aluminium honeycomb sandwich panel monocoque chassis for Formula Student competition
Authors: Davies H C , Bryant M , Hope M , Meiller C
Published: September 2011

Cardiff University students have used the freedom of the Formula Student rules to create an innovative chassis that combines a high performance with an efficient manufacturing process. All aluminium sandwich panels were pre-cut using computer numerical control routing, which is a rapid low-cost operation that produced highly accurate results. Assembling the monocoque consisted of folding and bonding panels along pre-routed lines and reinforcing the relevant joints. This required no specialist tools or equipment and was a rapid non-labour-intensive operation. The key design features, the manufacturing techniques, and the results of experimental and computational performance testing are presented here. This chassis construction technique is the result of research and development for seven years over six generations of Formula Student race cars.
The Impact of Environmental Experiences on Symptoms of Anxiety and Depression Across the Life Span
Authors: Kendler Kenneth S. , Eaves Lindon J. , Loken Erik K. , Pedersen Nancy L. , Middeldorp Christel M. , Reynolds Chandra , Boomsma Dorret , Lichtenstein Paul , Silberg Judy , Gardner Charles O.
Published: September 2011

Symptoms of anxiety and depression are relatively stable over time. Can this stability be explained by genetic influences, or is it caused by the long-lasting effects of accumulating environmental experiences? To address this question, we analyzed longitudinally assessed symptoms of anxiety and depression in eight samples of monozygotic twins of widely varying ages. These samples were drawn from American and European population-based registries. Using hierarchical linear modeling, we examined individual differences and individual changes in the level of symptoms over time. This method enabled us to decompose the variance into the predictable variance shared by both members of each pair of twins, the differences between individuals within pairs, and the residual variance. We then modeled how these components of individual variation changed over time. Within pairs, the twins’ predicted levels of symptoms increasingly diverged from childhood until late adulthood, at which point the divergence ceased. By middle adulthood, environmental experiences contributed substantially to stable and predictable interindividual differences in levels of anxiety and depression.
A Rough Set-based gas turbine fault classification approach using enhanced fault signatures
Authors: Wang L , Li Y G , Abdul Ghafir M F , Swingler A
Published: September 2011

Gas turbine engine health management has become more and more important because of its ability to optimize the total gas turbine operation. Gas path fault classification is one of the most important techniques in gas turbine engine health management. In this article, a Rough Set-based gas turbine fault classification approach is introduced to enhance gas turbine engine health management by taking its advantages in selecting appropriate measurements for fault classification and dealing with uncertainties caused by measurement noise. In the approach, a Rough Set-based knowledge discovery tool is used to find the knowledge hidden in fault samples, and transfer the knowledge into rules representing the logical relationship between the faults and the fault signatures. Such rules can then be used by the Rough Set diagnostic approach to classify faults. Enhanced fault signatures, represented by the measurement deviations and their ranking pattern in terms of their magnitude, are used to make the diagnostic approach more effective. The Rough Set-based diagnostic approach was applied to a model two-spool turbofan gas turbine engine for the classification of single- and dual-component faults. The results show that such Rough Set-based diagnostic approach is able to classify complex-component faults accurately in the presence of measurement noise.
Direct design of a U-model-based generalized predictive controller for a class of non-linear (polynomial) dynamic plants
Authors: Du W , Wu X , Zhu Q
Published: September 2011

Facing the big challenge of directly designing a generalized predictive controller (GPC) for a class of smooth non-linear dynamic plants described with polynomial models, this study reformulates the classical GPC into a U-model-based implementation. Mathematically, the final solution of the controller output is converted into resolving a polynomial equation in terms of current controller output u( k), which dramatically reduces the difficulties and complexity encountered in non-linear control system synthesis, algorithm development, and online implementation. It is believed that the integrated procedure provides a straightforward methodology to apply linear control system design techniques to design non-linear control systems without any enforced linearization of plant models. For a demonstration of the feasibility and effectiveness of the designed procedure, a continuously stirred tank reactor, and the other simulated example to represent chemical kinetics, are selected for the initial bench tests. The key contribution of the study is to derive and demonstrate feasibility and effectiveness of the U-model approach to GPC of non-linear systems. This is further evidence to support the author’s insight on the U-model approach that was previously used to design pole placement controller (PPC).
Did the mid-Holocene environmental changes cause the boom and bust of hunter-gatherer population size in eastern Fennoscandia?
Authors: Tallavaara Miikka , Seppä Heikki
Published: September 2011

Prehistoric hunter-gatherer population size is often assumed to follow climatic and other environmental forcings that affect environmental productivity and the availability of food for human foragers. We tested this assumption by studying the co-variation of archaeological and palaeoenvironmental records during the Holocene in eastern Fennoscandia. The reconstruction of population history is based on the summed probability distribution of archaeological radiocarbon dates, and environmental changes are tracked with locally available, high-resolution biological and physical proxies that are relevant in terms of hunter-gatherer food availability and population dynamics. The results show major population growth during the period of high summer temperature and high productivity of the terrestrial, lacustrine and marine ecosystems that occurred during 7500–5700 cal. yr BP. The growth was followed by an abrupt decline during 5500–4000 cal. yr BP correlating with the onset of late-Holocene cooling and a major forest ecosystem change brought about by the expansion of Norway spruce and the associated change from species-rich mixed forests to a conifer-dominated boreal ecosystem. Forest ecosystem changes likely enforced the negative effects of decreasing productivity on hunter-gatherer food availability. The link between population and environmental proxies breaks down along with the intensification of agriculture after 3500 cal. yr BP, which indicates that agriculture weakened the environmental forcing on long-term human population dynamics.
Professional Suitability for Social Work Practice
Authors: Tam Dora M. Y. , Coleman Heather , Boey Kam-Wing
Published: September 2011

Objective: The purpose of this study was to identify the underlying dimensions of professional suitability. Method: Data were collected from a province-wide mail-out questionnaire surveying 341 participants from a random sample of registered social workers. Results: The use of an exploratory factor analysis identified a 5-factor solution on professional suitability: social consciousness suitability, ethical suitability, practice suitability, and personal suitability, and distractors. This factor solution accounted for 47.4% of variance and achieved strong internal consistency with an overall Cronbach’s α value of .89, and subscales values ranged between .89 and .72. Conclusion: The identified underlying dimensions of professional suitability provide groundwork for the development of a psychometrically sound instrument for assessing performance of social work students and/or practicing social workers.
Good Short-Term but not Long-Term Reproducibility of the Antiplatelet Efficacy Laboratory Assessment
Authors: Sevcikova Hana , Vojacek Jan , Bis Josef , Sevcik Robert , Maly Jaroslav , Pecka Miroslav , Fatorova Ilona
Published: September 2011

Background: The antiplatelet effect of acetylsalicylic acid (ASA) varies among individual patients. We assessed the short-term reproducibility (STR) and long-term reproducibility (LTR) of light transmission aggregometry (LTA). Methods: Residual platelet reactivity was measured twice using LTA in a group of 207 consecutive patients (56 females, mean age 67 ± 9 years) on ASA therapy in 10 ± 6 months interval. The STR was assessed in 15 patients (6 females, mean age 61 ± 7 years) with 10 measurements on 2 consecutive days. Results: There was no correlation between both measurements in the long-term part of the study, and also Bland-Altman plot showed a diverging pattern. However, LTA STR was good with a correlation coefficient of .800 ( P < .05) confirmed by Bland-Altman plot. Conclusions: Although short-term intraindividual reproducibility of LTA assessment of platelet reactivity is very good, in the long-term perspective the antiplatelet ASA effectivity may be influenced by additional variables and repeated measurements are warranted.
Verification of surface contamination of Japanese cyclophosphamide vials and an example of exposure by handling
Authors: Hama Koji , Fukushima Koichi , Hirabatake Masaki , Hashida Tohru , Kataoka Kazusaburo
Published: September 2011

Purpose: Cyclophosphamide (CP) contamination has been detected in Japanese hospitals. In other countries, the surface contamination of CP vials has been reported; however, the manufacturing process of Japanese CP vials is unknown, so the conditions are not necessarily the same as in other countries. This study aimed to establish whether vial surface contamination also occurs in Japan.

Method: Contamination of vial surfaces was examined with a wipe test. Urine samples were taken from a pharmacist, engaged solely in dispensing work, for 29 h. It was also investigated whether CP vials were dispensed during the urine sampling period. In addition, vial surfaces, purposely coated with CP and then washed, were examined using wipe tests.

Result: CP was detected at 30–60% in vials, which was 11–62 ng (0.10–0.54 ng/cm2). One of the urine samples was contaminated (CP 13.5 ng); this was taken on Day 2 (11:35 AM). CP was not detected among the washed vials.

Discussion: This study shows that the surface of Japanese CP vials was contaminated and that it was probable that healthcare workers were exposed to CP. CP absorption by the pharmacist was probably due to dermal uptake while dispensing. Washing the vial is considered effective to avoid CP exposure. Manufacturers should be more proactive to prevent contamination and healthcare workers should comply with exposure prevention rules. Cytotoxic drugs should be included in institution monitoring lists.
Fostering Innovation in Cultural Contexts
Authors: Camarero Carmen , Garrido Ma José
Published: September 2011

Many museums are committed to market orientation as the underlying philosophy for their strategies. This orientation has to be coordinated with a service orientation focused on quality and custody in order to fulfill the museum’s mission. In the current work, the authors analyze the different impact of market orientation and service orientation on organizational and technological innovations implemented by museums. The hypotheses posited are examined for a sample of 491 British, French, Italian, and Spanish museums. Findings suggest that visitor and donor orientation are two key market orientation dimensions for technological and organizational innovation in museums, whereas interfunctional coordination and collaboration with competitors do not act directly, although they do boost the effect of visitor orientation. Further, quality orientation is also central to innovation. The present work thus concludes the existence of two interrelated routes that lead to technological and organizational innovation in museums, a business approach based on market orientation and a cultural approach based on service orientation.
The effects of dimensional manufacturing tolerances on stability of a symmetric hydrodynamic journal bearing rotor system – an experimental investigation
Authors: Ogrodnik P J , Xu W , Goodwin M J , Bancroft G A
Published: September 2011

The importance of gross dimensions on the design and operation of hydrodynamic journal bearing system are widely understood, however, the effects of manufacturing tolerances have only been macroscopically analysed. Building on previous theoretical analyses, an experimental investigation on the effect of dimensional manufacturing tolerances is presented. Importantly, the study looks at individual effects and combined effects. The experimental data suggested that the error created by manufacturing tolerances in estimating the onset of oil film instability can be as much as ±20 per cent, depending on the steady state operating position. This finding shows that in order to minimize the effect of manufacturing tolerances on system stability, the hydrodynamic journal bearing system should be designed to operate at a modified Sommerfeld number greater than 0.1, where the effects of manufacturing tolerances on system stability are negligible.
Low torque loss gears: austempered ductile iron versus carburized steel
Authors: Magalhaes L , Martins R , Seabra J , Gonçalves R
Published: September 2011

Low-loss power transmission gears operate at lower temperature than conventional ones because their teeth geometry is optimized to reduce friction. The main objective of this work is to compare the operating stabilization temperature and efficiency of low-loss austempered ductile iron (ADI) and carburized steel gears. Three different low-loss tooth geometries were adopted (types 311, 411 and 611, all produced using standard 20° pressure angle tools) and corresponding steel and ADI gears were tested in a FZG machine.

The results obtained showed that low-loss geometries had a significant influence on power loss, gears 611 generating lower power loss than gears 311. At low speeds (500 and 1000 rpm) and high torque ADI gears generated lower power loss than steel gears. However, at high speed and high torque (high input power and high stabilization temperature) steel gears had better efficiency.
Recognition of Human Home Activities via Depth Silhouettes and ℜ Transformation for Smart Homes
Authors: Jalal Ahmad , Uddin Md. Zia , Kim Jeong Tai , Kim Tae-Seong
Published: September 2011

This paper presents a novel human home activity recognition (HAR) system designed for smart homes that utilize depth silhouettes and ℜ transformation to continuously recognize the daily activities of the elderly and disabled in an indoor environment for better lifecare and e-healthcare services. Previously, ℜ transformation has been applied only on binary silhouettes that provide only the shape information of human activities. In this work, ℜ transformation was utilized on depth silhouettes such that the depth information of human body parts could be used in HAR in addition to the shape information. In ℜ transformation, 2D directional projection maps are computed via Radon transform, and then 1D feature profiles, which are translation and scaling invariants. Then, by applying the principle component analysis and linear discriminant analysis, the prominent activity features would be extracted. Finally, Hidden Markov Models would be used to train and recognize daily home activities. The results showed a mean recognition rate of 96.55% over ten typical home activities, whereas the same system utilizing binary silhouettes could achieve only 85.75%. The proposed methodology should be useful in designing and developing a compact HAR system that can be practically used in a smart environment including smart home for the care of the elderly, infirmed or disabled people.
Association of angiotensin converting enzyme insertion/deletion gene polymorphism with idiopathic nephrotic syndrome susceptibility in children: a meta-analysis
Authors: Zhou Tian-Biao , Ou Chao , Qin Yuan-Han , Su Li-Na , Lei Feng-Ying , Huang Wei-Fang , Zhao Yan-Jun , Pang Yu-Sheng , Yang Kun-Peng
Published: September 2011

Background and objective: Angiotensin converting enzyme (ACE) gene contains either an insertion (I) allele or a deletion (D) allele forming three potential genotypes: II, ID and DD. The D allele or DD genotype has been reported to be associated with higher plasma ACE level. An assessment of the association between ACE I/D gene polymorphism and idiopathic nephrotic syndrome (INS) susceptibility in children is still controversial. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and the onset of INS.

Method: A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic databases, and eligible investigations were synthesized using the meta-analysis method.

Results: Nine investigations were identified for the analysis of association between ACE I/D gene polymorphism and INS risk in children, including six in Asians, one study for Caucasians and two for Africans. There was positive association between D allele or DD genotype and INS susceptibility in Asians (OR = 1.75, p = 0.01; OR = 2.01, p = 0.02), but not for Caucasian children and Africans (for Caucasians, D: OR=1.35, p = 0.27, DD: OR = 0.95, p = 0.91; for Africans, D: OR = 1.70, p = 0.56, DD: OR = 1.60, p = 0.73). Furthermore, II homozygous seemed to play a positive role against INS onset for Asians (OR = 0.59, p = 0.02), but the link between II genotype and INS risk was not observed in Caucasian children and Africans (Caucasians: OR = 0.31, p = 0.06; Africans: OR = 0.50, p = 0.59).

Conclusions: D allele and DD homozygous might become significant genetic molecular markers for INS susceptibility in Asian children, but the association was not observed in Caucasians or Africans. However, the conclusion from our study cannot be sustained and more investigations on larger sample in different populations are required to further clarify the role of D allele or DD homozygous in the onset of INS in difference races.
A meta-analysis of the association between angiotensin-converting enzyme insertion/deletion gene polymorphism and steroid-sensitive nephrotic syndrome in children
Authors: Zhou Tian-Biao , Qin Yuan-Han , Ou Chao , Su Li-Na , Lei Feng-Ying , Huang Wei-Fang , Zhao Yan-Jun , Pang Yu-Sheng
Published: September 2011

Background and objective: Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism correlates with circulating and cellular ACE concentration. Association between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) risk in children is still controversial. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and SSNS susceptibility in children.

Methods: The relevant investigations were screened from the search engines of PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) as of 1 March 2011, and eligible studies were synthesized using meta-analysis methods.

Results: Ten studies were identified for the analysis of association between ACE I/D gene polymorphism and SSNS risk in children, including seven in Asians, one for Caucasians and two in Africans. There was no markedly positive association between D allele or DD genotype and SSNS susceptibility in Asians, Caucasians and Africans (D: Asians OR = 1.24, p = 0.28; Caucasians OR = 1.61, p = 0.15; Africans OR = 1.61, p = 0.53; DD: Asians OR = 1.72, p = 0.15; Caucasians OR = 1.39, p = 0.48; Africans OR = 1.80, p = 0.56). Furthermore, II homozygous seemed not to play a protective role against SSNS onset for Asians, Caucasians and Africans (Asians OR = 0.95, p = 0.85; Caucasians OR = 0.30, p = 0.11; Africans OR = 0.60, p = 0.65).

Conclusions: There was no association between ACE I/D gene polymorphism and SSNS susceptibility in Asians, Caucasians and Africans. However, the conclusions for Caucasians and Africans were less powerful.
Rethinking sociability in long-term care: An embodied dimension of selfhood
Authors: Kontos Pia C.
Published: September 2011

Sociability, interaction through which solitariness becomes togetherness or a union with others, has largely been explored without reference to the importance of bodily sources of agency. Encapsulated in the theoretical notion of embodied selfhood is the pre-reflective nature of selfhood deriving from the body's pre-reflective capacity for engaging with the world and the socio-cultural significance of the body. This paper argues for an expansion of the discourse on sociability in dementia to include embodied selfhood as a source of interactive practices. An 8-month ethnographic study of selfhood in dementia was conducted in a Canadian long-term care facility. The findings suggest that social and cultural habits, movements and other physical cues serve important communicative functions in the course of social interaction. This underscores how sociability is an embodied dimension of selfhood, which not only broadens the discourse on sociability in dementia but also offers important insights to inform person-centred dementia care.
Modeling and integration of situational awareness and soldier target search
Authors: Evangelista Paul F , Darken Christian J , Jungkunz Patrick
Published: September 2011

Representation of search and target acquisition (STA) in military models and simulations arguably abstracts the most critical aspects of combat. This research focuses on the search aspect of STA for the unaided human eye. It is intuitive that an individual’s environmental characteristics and interpretation of the environment in the context of all comprehended information, commonly summarized as their situational awareness (SA), influences attention and search. Current simulation models use a primitive sweeping search method that devotes an unbiased amount of time to every area in an entity’s field of regard and neglects the effects of SA. The goal of this research is to provide empirical results and recommend modeling approaches that improve the representation of unaided search in military models and simulations. The major contributions towards this goal include novel empirical results from two incremental eye-tracking experiments, analysis and modeling of the eye-tracking data to illustrate the effect of the environment and SA on search, and a recommended model for unaided search for high-fidelity combat simulation models. The results of this work support soldier search models driven by metrics that summarize the threat based on environmental characteristics and contextual information.
Mobilisation and remobilisation of a large archetypal pathogenicity island of uropathogenic Escherichia coli in vitrosupport the role of conjugation for horizontal transfer of genomic islands
Authors: Schneider György , Dobrindt Ulrich , Middendorf Barbara , Hochhut Bianca , Szijártó Valéria , Emődy Levente , Hacker Jörg
Published: September 2011

Background

A substantial amount of data has been accumulated supporting the important role of genomic islands (GEIs) - including pathogenicity islands (PAIs) - in bacterial genome plasticity and the evolution of bacterial pathogens. Their instability and the high level sequence similarity of different (partial) islands suggest an exchange of PAIs between strains of the same or even different bacterial species by horizontal gene transfer (HGT). Transfer events of archetypal large genomic islands of enterobacteria which often lack genes required for mobilisation or transfer have been rarely investigated so far.

Results

To study mobilisation of such large genomic regions in prototypic uropathogenic E. coli (UPEC) strain 536, PAI II536 was supplemented with the mob
RP4 region, an origin of replication (oriV

R6K
), an origin of transfer (oriT

RP4
) and a chloramphenicol resistance selection marker. In the presence of helper plasmid RP4, conjugative transfer of the 107-kb PAI II536 construct occured from strain 536 into an E. coli K-12 recipient. In transconjugants, PAI II536 existed either as a cytoplasmic circular intermediate (CI) or integrated site-specifically into the recipient's chromosome at the leuX tRNA gene. This locus is the chromosomal integration site of PAI II536 in UPEC strain 536. From the E. coli K-12 recipient, the chromosomal PAI II536 construct as well as the CIs could be successfully remobilised and inserted into leuX in a PAI II536 deletion mutant of E. coli 536.

Conclusions

Our results corroborate that mobilisation and conjugal transfer may contribute to evolution of bacterial pathogens through horizontal transfer of large chromosomal regions such as PAIs. Stabilisation of these mobile genetic elements in the bacterial chromosome result from selective loss of mobilisation and transfer functions of genomic islands.