bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of transfusion therapy on transcranial doppler ultrasonography velocities in children with sickle cell disease
Authors: Kwiatkowski Janet L. , Yim Eunsil , Miller Scott , Adams Robert J. ,   for the STOP 2 Study Investigators
Published: December 2010

Background

Children with sickle cell disease (SCD) and abnormal transcranial Doppler (TCD) ultrasonography have a high risk of stroke, but this risk is greatly reduced when chronic transfusion therapy is administered. The change in TCD velocities during chronic transfusion therapy and rate and frequency of normalization of TCD findings have not been studied extensively.

Procedures

Using data from children with SCD enrolled as potential subjects in the Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) trial, we characterized the change in TCD velocities on transfusion therapy and identified predictors of developing a normal TCD.

Results

Among 88 children with serial TCD data after starting transfusions for abnormal TCD 46 (52%) converted to normal TCD after a mean of 4.3 months (median 3.0; range 0.85–14.3 months) of transfusions. TCD studies remained abnormal in 19/88 (21.6%) after a mean of 2.4 years of transfusion. The median TCD velocity was lowered by 38 cm/sec within 3 months of initiating transfusions, followed by a more gradual decline then stabilization of velocities, although with significant individual variation. Factors associated with conversion to normal TCD included lower initial TCD velocity, younger age, and higher pre‐transfusion hemoglobin level during transfusion therapy.

Conclusion

Younger children with higher pre‐transfusion hemoglobin levels and lower abnormal TCD velocities are most likely to have rapid normalization of TCD on transfusions. Long‐term follow‐up of children with persistently abnormal exams or worsening velocities on transfusion is needed to determine if these children are at higher risk of stroke. Pediatr Blood Cancer 2011;56:777–782. © 2010 Wiley‐Liss, Inc.
Impact of serum acetaminophen concentration on changes in serum potassium, creatinine and urea concentrations among patients with acetaminophen overdose
Authors: Zyoud Sa'ed H. , Awang Rahmat , Sulaiman Syed Azhar Syed , Al‐Jabi Samah W.
Published: December 2010

Background

Acetaminophen overdose may be accompanied by electrolyte disturbances. The basis for electrolyte change appears to be due to increased fractional urinary electrolyte excretion.

Purpose

This study investigated the impact of serum acetaminophen concentration on changes in serum potassium, creatinine and urea concentrations in patients with acetaminophen overdose.

Methods

This was a retrospective cohort study which included patients admitted to the emergency department and hospital within 24 h of acetaminophen ingestion. The study was conducted over a period of 5 years from 1 January 2004 to 31 December 2008. Data are presented as mean ± SD and as medians (interquartile range) and groups were compared using independent two‐tailed Student t‐test. Statistical Package for Social Sciences (SPSS) 15 was used for data analysis.

Results

Two hundred and eighty‐three patients were studied (44 males and 239 females), mean age 23 ± 7.5 years. Patients who had a serum acetaminophen concentration above a ‘possible toxicity’ treatment line were associated with an elevation in serum creatinine concentration (p = 0.044) and a reduction in the serum potassium concentration (p < 0.001) but were not associated with a reduction in serum urea concentration (p > 0.99). During the study period, 63.3% (179 patients) had serum potassium concentrations less than the normal concentration (3.5 mmol/l) and 31.4% (89 patients) had serum urea concentrations less than the normal concentration (2.5 mmol/l). The serum creatinine concentration in all patients was within the normal range.

Conclusions

Acetaminophen appears to cause a concentration‐dependent reduction of potassium concentrations and an elevation of creatinine concentrations of short duration (<24 h) after overdose. Copyright © 2010 John Wiley & Sons, Ltd.
Enhanced physician adherence to antibiotic use guidelines through increased availability of guidelines at the time of drug ordering in hospital setting
Authors: Westphal Jean‐Frederic , Jehl Francois , Javelot Herve , Nonnenmacher Cathy
Published: December 2010

Purpose

Some studies have shown that making practice guidelines accessible to physicians when they are making clinical decisions could improve prescribing practices. The aim of the study was to assess the benefit of impact on physician adherence of the intervention that consisted of embedding previously paper‐based antibiotic guidelines in the computerized physician drug order entry system of a teaching hospital in order to make these guidelines available to physician at the time of antibiotic ordering. Before the intervention, these guidelines were available in booklet form in all the wards of the hospital.

Methods

Adherence to guidelines was evaluated in 471 consecutive antibiotic orders for pneumonia, 104 just before and 367 just after the intervention. The evaluation criteria were: the choice of the antibiotic relative to the context of acquisition of pneumonia, the daily dose, the planned duration of treatment. Evaluation of antibiotic orders was performed at the initiation of antibiotic treatment.

Results

The intervention was followed by a significant decrease in the proportion of antibiotic orders containing at least one criterion of non‐conformity to the guidelines, respectively, 33% after vs. 51% (p < 0.001) before the intervention. Proportion of non‐conform orders decreased in the post‐ vs. pre‐intervention period for the daily dosage of antibiotics, respectively, 12.2% vs. 26.9% (p < 0.001), for the planned duration of treatment, respectively, 7.3% vs. 18.3% (p < 0.001), whereas for the choice of antibiotics relative to the context of acquisition of pneumonia, the improvement failed to reach statistical significance, respectively, 18.2% vs. 25% (p = 0.12).

Conclusion

In this study, the increased availability of antibiotic guidelines at the time of drug ordering, combined with a periodical reinforcement educational round, was associated with an enhanced physician adherence to these guidelines. Copyright © 2010 John Wiley & Sons, Ltd.
What I do and What I think they Would Do: Social Axioms and Behaviour
Authors: Kurman Jenny
Published: December 2010

The social axioms system uniquely predicted a large variety of behaviours and preferences. It is suggested that (a) the assistance social axioms provide in predicting the behaviour of others, and (b) the self–characteristics embedded in the axioms account for this unique prediction ability. Three studies, each pertaining to a different axiom, tested the prediction power of the social axiom regarding two types of behaviours: One that is directly impacted by how others are expected to behave, and another that is more self–directed. Results consistently revealed a unique contribution of the social axioms over personal characteristics in prediction of behaviours directed by how others are expected to behave, whereas behaviours that are more self–directed were largely explained by relevant personal characteristics. Copyright © 2010 John Wiley & Sons, Ltd.
General Belief in A Just World and Resilience: Evidence from A Collectivistic Culture
Authors: Wu Michael Shengtao , Yan Xiaodan , Zhou Chan , Chen Yiwen , Li Juan , Zhu Zhuohong , Shen Xiangqin , Han Buxin
Published: December 2010

Previous research showed that in the individualistic culture, adults endorse the personal more than the general belief in a just world (PBJW vs. GBJW). Comparatively little is known about the prevalence character and adaptive functions of GBJW, especially in the collectivistic culture. We conducted three surveys among the Chinese adults and adolescents. We found that (1) Chinese adults and adolescents endorsed more GBJW than PBJW; (2) Adult survivors with high exposure to post–earthquake trauma and adolescents in the poverty–stricken area maintained high GBJW, with relatively lower PBJW. (3) GBJW predicted the psychological resilience in all the three samples independent of PBJW. The results imply that in contrast to populations from the individualistic culture, people from the collectivistic culture endorse a robust GBJW, which allows them to resiliently confront harsh realities. Copyright © 2010 John Wiley & Sons, Ltd.
Knowledge, attitudes and beliefs of Arabic‐Australians concerning cancer
Authors: Saleh Mona , Barlow‐Stewart Kristine , Meiser Bettina , Tucker Kathy , Eisenbruch Maurice , Kirk Judy
Published: December 2010

Objectives: To explore with Arabic‐Australian patients and their communities, the cultural context of cancer, both sporadic and inherited, by examining their beliefs about its causes and the modes of communication about cancer with family, friends and the community.

Method: The design is an ethnographic and qualitative interview study with thematic analysis. Arabic‐Australian participants were recruited in two stages. First, patients who had attended a family cancer clinic in Sydney, Australia, were invited to participate. Second, participants from the general community in Sydney were recruited with the aim of either verifying or challenging the reported findings from the clinic sample.

Results: A total of 38 interviews with 26 females and 12 males provided cultural descriptions of illnesses, including cancer, and its causes. The terminologies around cancer and a cancer diagnosis were believed to have more impact and generate greater fear in people in the Arabic community living in Australia than the terms used to describe a diagnosis of other illnesses. Despite this, those interviewed were aware of screening and community programs and were open to discuss their views about cancer with the research team.

Conclusion: Arabic‐Australians are an important group in the community with unique culture‐specific attributes that can affect communication about cancer in the clinical setting. Barriers to communication such as the negative feelings associated with the word cancer and the stigma it arouses must be acknowledged. Culturally competent clinical practices with this group include the incorporation of these belief systems into the communication process and avoidance of stereotyping. Copyright © 2010 John Wiley & Sons, Ltd.
Role of telehealth/videoconferencing in managing cancer pain in rural American Indian communities
Authors: Haozous Emily , Doorenbos Ardith Z. , Demiris George , Eaton Linda H. , Towle Cara , Kundu Anjana , Buchwald Dedra
Published: December 2010

Objectives: This project is aimed at determining the feasibility and effect of using videoconferencing to deliver cancer‐related pain management education and case consultation to health care providers in rural AI/AN communities.

Methods: The project provided four educational sessions and nine case conferences to health care providers at tribal clinics in Washington State and Alaska using videoconferencing with pain experts at the University of Washington. A cross‐sectional, descriptive study design was used to survey the participating providers. Measures included satisfaction with the telehealth system and self‐perceived competence in pain management.

Results: Fifty‐two providers from 11 sites attended the educational sessions. Ninety‐three providers from 16 sites participated in the case conferences. Case conference participants scored significantly higher on perceived competence in treating pain compared with clinic providers who did not attend. Educational session participants and case conference participants both reported a high level of satisfaction with videoconferencing.

Conclusions: Telehealth is a feasible and effective way to deliver cancer‐related pain management education and increase competence among rural health care providers. Copyright © 2010 John Wiley & Sons, Ltd.
Flutter valve improves respiratory mechanics and sputum production in patients with bronchiectasis
Authors: Figueiredo Pedro H. S. , Zin Walter A. , Guimarães Fernando S.
Published: December 2010

Background and Purpose. Although the application of airway clearance techniques is considered an important component in the treatment of several obstructive pulmonary diseases, there is no scientific evidence supporting the use of Flutter Valve™ in the management of patients with bronchiectasis. Moreover, the consequences of respiratory physiotherapy techniques on respiratory mechanics have not been fully studied. Therefore, we investigated the acute, short‐term effects of Flutter Valve™ on respiratory mechanics and sputum production in bronchiectatic patients. Methods. Eight patients were evaluated in a randomized, blinded, cross‐over trial. Impedance at 5 Hz (R5), resistance as a function of oscillation frequency (dR/dF), reactance at 5 Hz (X5), resonant frequency (f0) and integral of reactance between 5 Hz and resonant frequency (AX) were recorded. Results. Flutter Valve™ cleared 8.4 mL more secretions than the Sham Flutter intervention (95% confidence interval [95% CI], 3.4–13.4). There was a higher percentage decrease in R5 (−11.2%; 95% CI, −4.4 to −18.2), dR/dF (−20.8%; 95% CI, −32.4 to −9) and AX (−7.8%; 95% CI, −11.9 to −3.7) under Flutter Valve™. X5 and f0 variation did not differ between interventions. Conclusions. Flutter Valve™ increases sputum removal during treatment and diminishes total and peripheral airway resistance in hypersecretive patients with bronchiectasis. Impulse oscillometry is a user‐friendly tool to evaluate the effects of airway clearance techniques on respiratory mechanics. Copyright © 2010 John Wiley & Sons, Ltd.
Hot‐electron drift velocity and hot‐phonon decay in AlInN/AlN/GaN
Authors: Ardaravicˇius L. , Liberis J. , Kiprijanovicˇ O. , Matulionis A. , Wu M. , Morkoç H.
Published: December 2010

A nanosecond‐pulsed current–voltage technique was applied to study hot‐electron transport along the two‐dimensional electron gas channel confined at a nominally undoped AlInN/AlN/GaN heterointerface. Hot‐electron drift velocity was deduced under the assumptions of uniform longitudinal electric field and field‐independent electron sheet density. At a fixed electric field strength, a resonance‐type non‐monotonous dependence of the velocity on the electron density was found in the investigated range from 1 to When the electric field increased from 20 kV/cm to 80 kV/cm, the peak velocity increased from ∼1.1 to cm/s, and the position of the resonance shifted from ∼1.1 to ∼1.2 respectively. The resonance position correlates with that for the fastest decay of hot phonons known from independent experiment. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of the maximum torque of a cap liner using a power‐law friction and finite element analysis
Authors: Lajmi Abdelmajid , Champliaud Henri , Lê Van Ngan
Published: December 2010

In the ‘filled closed’ containers, the cap removal torque and the sealing of the contents are two crucial criteria in the closing quality, and the consumer perceives these two parameters as constituting a guarantee of packaging integrity. This work looks at the experimental study and the finite element analysis of the maximum torque of a metal cap with a liner over a glass bottle. For studying parameters influencing the cap removal torque (twist‐off torque), several experiments and simulations were conducted in order to evaluate the maximum torque of a loose crown cap. A test bench was built to measure the torque required to slide a cap liner on the top of a glass bottle, and the result of the experiment is compared with the predicted torque given by an axisymmetric finite element (FE) analysis. Since the behaviour of the cap liner is hyperelastic, compression and friction tests were conducted to evaluate the elastic properties and the non‐linear static friction behaviour of the elastomer seal. Contact regions, material non‐linear elasticity for the liner and large displacement options are included in the FE model in order to describe the evolution of the contact area and the distribution of contact pressure as a function of the applied force. The predicted maximum torque is then calculated by a numerical integration scheme over the contact surface, using an experimental coefficient of static friction as a function of the normal pressure. The predicted torque shows good agreement with that measured through experiments, thereby making it possible to understand the influence of the liner on the cap removal torque of a glass bottle. Copyright © 2010 John Wiley & Sons, Ltd.
Best management practices for environmental restoration programs
Authors: Gibbs James T. , Santillan Javier , Callier Mozella , Porter Ronald
Published: December 2010

Based on a review of hundreds of environmental restoration program optimization reviews, this article describes management tools found in successful and efficient remediation programs. Projects that consistently struggled to achieve their objectives were observed to be missing certain, or to have inadequately used, these tools. The tools are articulated as best practices because when they are present and actively used, project shortcomings were minimal. Priority objectives for site owners and project managers include improving efficiency and effectiveness through performance management, reducing resource usage and energy consumption, ensuring protectiveness, and reducing uncertainty in management decision making.

Restoring environmental resources damaged by historic waste management practices began in earnest in the late 1960s and early 1970s with the broad recognition of the problems caused by environmental discharges and spills when wastes are not managed appropriately. Under new regulations, soil and groundwater remediation projects could be, and were, conducted within a defined framework.

The number and variety of restoration projects that were launched resulted in a slew of projects progressing through the stages of characterization, decision, and cleanup, and more were added to the cleanup process each year. In the 1990s, the Department of Defense noted that many cleanup efforts were projected to incur substantial operational, maintenance, and monitoring costs for decades into the future. This was correctly perceived as an opportunity to optimize those systems and programs, minimize costs, and reduce health and environmental risks. The best practices outlined in this article address management tools that were identified in optimization efforts that led to effective and efficient environmental remediation projects. © 2010 Wiley Periodicals, Inc.
Advanced site diagnostic tool 3D‐CSIA for in situ remediation
Authors: Wang Yi , Smith Gregory J.
Published: December 2010

In situ remediation is inherently considered “green remediation.” The mechanisms of destruction by in situ technologies, however, are often unseen and not well understood. Further, physical effects of amendment application affect concentration data in an identical manner as the desired reactive mechanism. These uncertainties have led to the weight‐of‐evidence approach when proving viability: multiple rounds of data collection, bench studies, pilot studies, and so on. Skipping these steps has resulted in many failed in situ applications. Traditional assessment data are often tangential to the desired information (e.g., “Is contaminant being destroyed or just being pushed around and diluted?” and “What is the mechanism of the destruction and can it be monitored directly?”). An advanced site diagnostic tool, “Three‐Dimensional Compound Specific Stable Isotope Analysis” (3D‐CSIA), can assess the viability of in situ technologies by providing definitive data on contaminant destruction that are not concentration‐related. The 3D‐CSIA tool can also locate source zones and apportion remediation cost by identifying plumes of different isotope signatures and fractionation trends. Further, use of the 3D‐CSIA tool allows remediation professionals to evaluate effectiveness of treatment and make better decisions to expedite site closure and minimize costs. This article outlines the fundamentals of advanced site diagnostic tool 3D‐CSIA in detail, and its benefit is highlighted through a series of case studies at chlorinated solvent–contaminated sites. © 2010 Wiley Periodicals, Inc.
Successful application of monitored natural attenuation in a surficial aquifer
Authors: Crouch Dylan , White Jay D. , Butler‐Veytia Belinda , Medler Robert
Published: December 2010

Groundwater investigations conducted since 1988 at a Tennessee Department of Environment and Conservation (TDEC) Voluntary Oversight and Assistance Program (VOAP) site located in Millington, Tennessee, have defined the lateral and vertical extent of site chemicals of concern (COCs) consisting of tetrachloroethene (PCE), trichloroethene (TCE), and associated degradation products. Results of a groundwater remedial investigation determined that aquifer conditions were favorable for anaerobic degradation of COCs through reductive dechlorination. A subsequent groundwater feasibility study determined that monitored natural attenuation (MNA) coupled with long‐term groundwater monitoring was the most effective and suitable remedial option for the site. A Record of Decision was issued by the TDEC VOAP approving MNA and long‐term groundwater monitoring as the remedial option for the site, a first for such a site in Tennessee involving chlorinated organics. A groundwater fate and transport model (the 1998 model) developed during the RI was used as the basis for the MNA remedy. Analytical data from 1998 to 2008 indicate COCs in former high‐concentration areas continue to degrade at rates consistent with or ahead of the 1998 model predictions. Evidence of reductive dechlorination is also supported by the continued presence of breakdown products—specifically, vinyl chloride and ethene (terminal endpoint of PCE breakdown through reductive dechlorination). The continued detection of breakdown products along the flow‐path wells also confirms the effectiveness of the MNA remedy at the site. Current analytical data indicate that COC plumes beneath the site are not migrating and are actually retracting. © 2010 Wiley Periodicals, Inc.
Sustainable remediation panel—Measuring the social and economic benefits of a sustainable remediation project
Authors: Havranek Timothy J. , Watts Daniel J. , Geckeler Grant , Rowland Marty , Fabersunne Mikos
Published: December 2010

Remediation developed a Sustainable Remediation Panel in the Summer 2009 issue, which featured the Sustainable Remediation Forum White Paper. The panel is composed of leaders in the field of sustainable remediation who have volunteered to provide their opinions on difficult subjects related to the topic of how to integrate sustainability principles into the remediation practice. The panel's opinions are provided in a question‐and‐answer format, whereby selected experts provide an answer to a question. This issue's question is provided below, followed by opinions from five experts in the remediation field.

What are the best methods of measuring the social and economic benefits of a sustainable remediation project? Are there ways to develop quantitative metrics or are qualitative metrics the best alternative for measuring the social and economic benefits of sustainable remediation? © 2010 Wiley Periodicals, Inc.
Semiconducting Two‐Dimensional Graphene Nanoconstriction Arrays
Authors: Safron Nathaniel S. , Brewer Adam S. , Arnold Michael S.
Published: December 2010

The fabrication and characterization of two‐dimensional nanoconstriction arrays consisting of sub‐20‐nm graphene constrictions and interconnecting graphene islands are reported. The arrays are fabricated in a scalable top–down fashion using self‐assembled close‐packed polystyrene nanospheres as lithographic templates and characterized using electron microscopy, Raman spectroscopy, and charge transport measurements. At room temperature, the arrays behave as semiconductors with a field‐effect conductance modulation of up to 450 and charge mobilities of ∼1 cm2 V−1 s−1. The effective bandgap of the arrays scales inversely with the nanoconstriction width, indicating that its magnitude is determined by quantum confinement in the constrictions. At low temperatures, the arrays act as semiconductors, with increasing ON/OFF conductance modulation up to ∼1000, and simultaneously act as 2D arrays of coupled Coulomb islands affected by single‐electron charging events. The high conductance modulation of these nanopatterned graphene materials, combined with the scalability of the patterning approach is expected to impact thin film, flexible, and transparent semiconductor electronics.
A New Shear Test for Sheet Metal Characterization
Authors: Brosius A. , Yin Q. , Güner A. , Tekkaya A.E.
Published: December 2010

In order to predict plastic material behavior for sheet forming processes by finite element simulation, shear tests are useful to identify material parameters. Since the existing shear test setups have certain disadvantages, a new twin bridge torsion shear test is proposed. Stress and strain calculation is derived from the presented geometrical features. The clamping situation and the shear gauge dimensions are investigated to evaluate the quality of the obtained flow curves. It is shown that this test specimen is suitable to determine anisotropic yield behavior and to characterize prestrained specimen, for instance due to cold rolling, when the yield locus is shifted by a backstress tensor.
An Endothelial Cell Niche Induces Hepatic Specification Through Dual Repression of Wnt and Notch Signaling
Authors: Han Songyan , Dziedzic Noelle , Gadue Paul , Keller Gordon M. , Gouon-Evans Valerie
Published: December 2010

Complex cross-talk between endoderm and the microenvironment is an absolute requirement to orchestrate hepatic specification and expansion. In the mouse, the septum transversum and cardiac mesoderm, through secreted bone morphogenetic proteins (BMP) and fibroblast growth factors (FGF), respectively, instruct the adjacent ventral endoderm to become hepatic endoderm. Consecutively, endothelial cells promote expansion of the specified hepatic endoderm. By using a mouse reporter embryonic stem cell line, in which hCD4 and hCD25 were targeted to the Foxa2 and Foxa3 loci, we reconstituted an in vitro culture system in which committed endoderm cells coexpressing hCD4-Foxa2 and hCD25-Foxa3 were isolated and cocultured with endothelial cells in the presence of BMP4 and bFGF. In this culture setting, we provide mechanistic evidence that endothelial cells function not only to promote hepatic endoderm expansion but are also required at an earlier step for hepatic specification, at least in part through regulation of the Wnt and Notch pathways. Activation of Wnt and Notch by chemical or genetic approaches increases endoderm cell numbers but inhibits hepatic specification, and conversely, chemical inhibition of both pathways enhances hepatic specification and reduces proliferation. By using identical coculture conditions, we defined a similar dependence of endoderm harvested from embryos on endothelial cells to support their growth and hepatic specification. Our findings (1) confirm a conserved role of Wnt repression for mouse hepatic specification, (2) uncover a novel role for Notch repression in the hepatic fate decision, and (3) demonstrate that repression of Wnt and Notch signaling in hepatic endoderm is controlled by the endothelial cell niche.
Locally Applied Vascular Endothelial Growth Factor A Increases the Osteogenic Healing Capacity of Human Adipose-Derived Stem Cells by Promoting Osteogenic and Endothelial Differentiation
Authors: Behr Björn , Tang Chad , Germann Günter , Longaker Michael T. , Quarto Natalina
Published: December 2010

Human adipose-derived stem cells (hASCs) are known for their capability to promote bone healing when applied to bone defects. For bone tissue regeneration, both sufficient angiogenesis and osteogenesis is desirable. Vascular endothelial growth factor A (VEGFA) has the potential to promote differentiation of common progenitor cells to both lineages. To test this hypothesis, the effects of VEGFA on hASCs during osteogenic differentiation were tested in vitro. In addition, hASCs were seeded in murine critical-sized calvarial defects locally treated with VEGFA. Our results suggest that VEGFA improves osteogenic differentiation in vitro as indicated by alkaline phosphatase activity, alizarin red staining, and quantitative real-time polymerase chain reaction analysis. Moreover, local application of VEGFA to hASCs significantly improved healing of critical-sized calvarial defects in vivo. This repair was accompanied by a striking enhancement of angiogenesis. Both paracrine and, to a lesser degree, cell-autonomous effects of VEGFA-treated hASCs were accountable for angiogenesis. These data were confirmed by using CD31−/CD45− mouse ASCsGFP+ cells. In summary, we demonstrated that VEGFA increased osteogenic differentiation of hASCS in vitro and in vivo, which was accompanied by an enhancement of angiogenesis. Additionally, we showed that during bone regeneration, the increase in angiogenesis of hASCs on treatment with VEGFA was attributable to both paracrine and cell-autonomous effects. Thus, locally applied VEGFA might prove to be a valuable growth factor that can mediate both osteogenesis and angiogenesis of multipotent hASCs in the context of bone regeneration.
Side Population is Not Necessary or Sufficient for a Cancer Stem Cell Phenotype in Glioblastoma Multiforme
Authors: Broadley Kate W. R. , Hunn Martin K. , Farrand Kathryn J. , Price Kylie M. , Grasso Carole , Miller Rose J. , Hermans Ian F. , McConnell Melanie J.
Published: December 2010

There is strong evidence for the existence of cancer stem cells (CSCs) in the aggressive brain tumor glioblastoma multiforme (GBM). These cells have stem-like self-renewal activity and increased tumor initiation capacity and are believed to be responsible for recurrence due to their resistance to therapy. Several techniques have been used to enrich for CSC, including growth in serum-free defined media to induce sphere formation, and isolation of a stem-like cell using exclusion of the fluorescent dye Hoechst 33342, the side population (SP). We show that sphere formation in GBM cell lines and primary GBM cells enriches for a CSC-like phenotype of increased self-renewal gene expression in vitro and increased tumor initiation in vivo. However, the SP was absent from all sphere cultures. Direct isolation of the SP from the GBM lines did not enrich for stem-like activity in vitro, and tumor-initiating activity was lower in sorted SP compared with non-SP and parental cells. Transient exposure to doxorubicin enhanced both CSC and SP frequency. However, doxorubicin treatment altered the cytometric profile and obscured the SP demonstrating the difficulty of identifying SP in cells under stress. Doxorubicin-exposed cells showed a transient increase in SP, but the doxorubicin-SP cells were still not enriched for a stem-like self-renewal phenotype. These data demonstrate that the GBM SP does not necessarily contribute to self-renewal or tumor initiation, key properties of a CSC, and we advise against using SP to enumerate or isolate CSC.
Pramel7 Mediates LIF/STAT3-Dependent Self-Renewal in embryoniC Stem Cells
Authors: Casanova Elisa A. , Shakhova Olga , Patel Sameera S. , Asner Igor N. , Pelczar Pawel , Weber Fabienne A. , Graf Urs , Sommer Lukas , Bürki Kurt , Cinelli Paolo
Published: December 2010

A unique and complex signaling network allows ESCs to undergo extended proliferation in vitro, while maintaining their capacity for multilineage differentiation. Genuine ESC identity can only be maintained when both self-renewal and suppression of differentiation are active and balanced. Here, we identify Pramel7 (preferentially expressed antigen in melanoma-like 7) as a novel factor crucial for maintenance of pluripotency and leukemia inhibitory factor (LIF)-mediated self-renewal in ESCs. In vivo, Pramel7 expression was exclusively found in the pluripotent pools of cells, namely, the central part of the morula and the inner cell mass of the blastocyst. Ablation of Pramel7 induced ESC differentiation, whereas its overexpression was sufficient to support long-term self-renewal in the absence of exogenous LIF. Furthermore, Pramel7 overexpression suppressed differentiation in ESCs in vitro and in vivo. This process was reversible, as on transgene excision cells reverted to a LIF-dependent state and regained their capacity to participate in the formation of chimeric mice. Molecularly, LIF directly controls Pramel7 expression, involving both STAT3-dependent transcriptional regulation and PI3K-dependent phosphorylation of glycogen synthase kinase 3β. Pramel7 expression in turn confers constitutive self-renewal and prevents differentiation through inactivation of extracellular signal-regulated kinase phosphorylation. Accordingly, knockdown of Pramel7 promotes ESC differentiation in presence of LIF and even on forced STAT3-activation. Thus, Pramel7 represents a central and essential factor in the signaling network regulating pluripotency and self-renewal in ESCs.
Performance of tall buildings in Concepción during the 27 February 2010 moment magnitude 8.8 offshore Maule, Chile earthquake
Authors: Rojas Fabian , Naeim Farzad , Lew Marshall , Carpenter Lauren D. , Youssef Nabih F. , Saragoni G. Rodolfo , Adaros Macarena Schachter
Published: December 2010

Concepción, near the southern end of the fault rupture zone of the offshore Maule, Chile earthquake, suffered significant damage to all types of structures. Tall reinforced concrete buildings in the region were also affected, some severely. Spectacular collapse and partial collapse were experienced in two buildings, and many buildings had failure of thin shear walls that lacked sufficient boundary element confinement. Concrete spalling and crushing occurred and reinforcing steel buckled and were sometimes fractured. Copyright © 2010 John Wiley & Sons, Ltd.
US climate change politics and policymaking
Authors: Selin Henrik , VanDeveer Stacy D.
Published: December 2010

The United States is often identified as a global laggard on climate change policymaking and implementation. Although this reputation may be deserved by the US federal government, a look across all levels of the US federal political system and a multitude of political actors demonstrates the existence of a significant number of climate change and energy‐related activities. This brief review of US climate change politics covers climate change policy support and opposition across different governance levels, involving legal and political activities and interactions of a large number of public, private, and civil society sector actors. It examines US federal climate change legislation and politics, and how activities in Washington, DC are connected to both international politics and domestic conditions and debates. This discussion is linked to state and municipal level climate change action, followed by a discussion of how activities of firms and advocacy groups and aspects of US public opinion shape US climate change politics. The review ends with a few concluding remarks about the future of US climate change policymaking and implementation. WIREs Clim Change 2011 2 121–127 DOI: 10.1002/wcc.94

This article is categorized under:

Policy and Governance > National Climate Change Policy
Event perception
Authors: Radvansky Gabriel A. , Zacks Jeffrey M.
Published: December 2010

Events are central elements of human experience. Formally, they can be individuated in terms of the entities that compose them, the features of those entities, and the relations amongst entities. Psychologically, representations of events capture their spatiotemporal location, the people and objects involved, and the relations between these elements. Here, we present an account of the nature of psychological representations of events and how they are constructed and updated. Event representations are like images in that they are isomorphic to the situations they represent. However, they are like models or language in that they are constructed of components rather than being holistic. Also, they are partial representations that leave out some elements and abstract others. Representations of individual events are informed by schematic knowledge about general classes of events. Event representations are constructed in a process that segments continuous activity into discrete events. The construction of a series of event representations forms a basis for predicting the future, planning for that future, and imagining alternatives. WIREs Cogni Sci 2011 2 608–620 DOI: 10.1002/wcs.133

This article is categorized under:

Psychology > Memory
Distributed versus focused attention (count vs estimate)
Authors: Chong Sang C. , Evans Karla K.
Published: December 2010

Quantity or numerosity is one of the basic properties of our environment. Humans and animals both have the neural representation of quantity or ‘number sense’. The ability to extract and to manipulate numbers is closely related to our various cognitive functions such as the capacity of working memory, mathematical achievement, and texture perception. Evidence shows that the sense of number is not a unitary mechanism but rather a composition of two distinct processes; enumeration and estimation. The review examines how numerosity is represented in the visual domain and its relation to different modes of attention. Enumeration or counting permits an exact representation of a distinct number of objects, with an awareness of each object achieved through focal deployment of attention to each object serially. On the other hand, estimation involves an approximation of the number of different items or a sense of ensemble statistics, achieved through fast deployment of distributed attention over a set of objects as a whole. In this overview we suggest that a focused attention mode is more suitable for enumeration, whereas a distributed attention mode is better for estimation. WIREs Cogni Sci 2011 2 634–638 DOI: 10.1002/wcs.136

This article is categorized under:

Psychology > Attention
Self‐Assembly of a Novel VIV–CuII Hybrid: Hydrogen Bonds Interlinked [VO(2,3‐DHN)2]2– and [Cu(1,3‐PDA)2]2+ Blocks
Authors: Chi Zixiang , Zhu Linli , Chen Yuyou , Yu Chong , Shi Xudong , Bi Yangang , Lu Xiaoming
Published: December 2010

A novel VIV‐CuII hybrid complex assembled from an O,O‐chelating vanadium block [VO(2,3‐DHN)2]2– and a N,N‐chelating copper block [Cu(1,3‐PDA)2]2+, namely, [VO(2,3‐DHN)2][Cu(1,3‐PDA)2]·0.5CH3CN (1) (2,3‐DHN = 2,3‐dihydroxynaphthalene, 1,3‐PDA = 1,3‐propanediamine), was synthesized at 8 °C (low room temperature) and characterized by IR spectroscopy and single‐crystal X‐ray diffraction. The vanadium and copper blocks are both independent complexes and are interlinked through N–H···O hydrogen bonds donated by [Cu(1,3‐PDA)2]2+ moiety, exhibiting 1D chain, 2D layer, and open 3D channel supramolecular array. This work was originally sparked by the tunicate chemistry and the [VO(2, 3‐DHN)2]2– ion can be seen a sequel of vanadium‐catechol models.
Mixed‐Addenda Lindqvist‐Type Polyoxoanion [V2W4O19]4–‐Supported Copper Complexes
Authors: Wang Chunling , Weng Linhong , Ren Yuanhang , Du Chengbo , Yue Bin , Gu Min , He Heyong
Published: December 2010

Three mixed‐addenda Lindqvist‐type polyoxoanion‐supported copper 1,10‐phenanthroline (phen) or 2,2′‐bipyridine (bpy) complexes, [Cu(phen)(H2O)3]2[V2W4O19] (1), [Cu(bpy)2]‐ [H2V2W4O19]·6H2O (2), and [Cu(bpy)(H2O)]2[V2W4O19]·4H2O (3) were synthesized in aqueous solution and characterized by elemental analysis, IR and 51V NMR spectroscopy, TG as well as X‐ray powder and single‐crystal X‐ray diffraction. The structure of compound 1 is constructed from copper(II)‐tri(aqua)‐phen complexes and [V2W4O19]4– clusters. It exhibits a three‐dimensional (3D) supramolecular framework due to the abundance of hydrogen bonding interaction between the copper‐phen cation and the polyoxoanion. In compound 2 the [V2W4O19]4– cluster as bidentate ligand coordinates two [Cu(bpy)2] units, which leads to a single twist‐armed chain. In both 1 and 2, the crystallographical positions of the two vanadium atoms are totally disordered in the whole Lindqvist [V2W4O19]4– cluster. In compound 3 the [V2W4O19]4– cluster as a quadridentate ligand connects four [Cu(bpy)] units to form double armed chains, where two vanadium atoms are mainly disordered over four positions around the equatorial belt of the [V2W4O19]4– cluster. Compounds 2 and 3 are the first examples of the extended structure based on mixed‐addenda [V2W4O19]4– and metal coordination ions. Furthermore, the extensive hydrogen bonding and π–π packing interactions between the chains play important roles in the construction of the 3D framework of 1–3.
Treatment of boundary layers with anisotropic finite elements
Authors: Apel Th.
Published: December 2010

The aim is to construct a finite element method which resolves layers appearing in singularly perturbed problems, here the easiest case of a reaction diffusion problem. For this, a special anisotropic mesh of Shishkin type is investigated. Estimates of the finite element error in the energy norm are derived which are uniformly valid with respect to the (small) diffusion parameter. A key ingredient for the error analysis is a refined estimate for derivatives of the interpolation error.
Singularities in differential‐algebraic systems with unilateral constraints
Authors: Arnold M.
Published: December 2010

Inequality (unilateral) constraints may introduce various types of singularities in differential‐algebraic systems ([5]). In the present paper we consider contact conditions that are formulated as unilateral constraints for position and velocity coordinates in a mechanical multibody system. If the surfaces of the bodies being in contact are worn then the contact conditions result often in constraints that are only piecewise differentiable. We discuss a regularization that considers qualitatively the elastic deformation of the bodies.
Macroscopic modelling of kinetic gas flows in thin layers
Authors: Babovsky Hans , Mader Alexander
Published: December 2010

This paper presents an approach for the modelling of gas flows in thin gaps within two parallel plates. Starting from the derivation of a diffusion limit for a linear kinetic equation, we propose a first step of how to model nonlinear situations with the help of parameter lists obtained from numerical results.
An algebraic approach to the HBMG method for unstructured grids
Authors: Bank Randolph E. , Gutsch Sabine
Published: December 2010

We will cast some of the previously introduced interpolation coefficients for the construction of hierarchical basis functions into an algebraic formulation of the HBMG method. Furthermore we construct a new set of coefficients that fulfills a consistency condition which results in a better approximation of smooth functions. We provide numerical examples for the convection dominated convection‐diffusion equation on uniformly as well as adaptively refined grids.
Non‐classically damped random vibration of shear building with damages
Authors: Bryja D. , Mironowicz W.
Published: December 2010

A shear building with damages in its columns, dynamically loaded with machines viscoelastically supported on floors, is considered in the paper. Two kinds of damages are taken into account: the first one is most often caused by the corrosion process, that reduces the bending stiffness of columns ‐ usually at the place where piles touch the floors; the second one is caused by exceeding the shearing strength and occurs in the form of horizontal or slant cracks. It is assumed that both the parameters of damages and dynamic excitation are random. The solution is formulated in the correlation theory sphere, by using the influence function of the MDOF system, which is similar to the well known impulse response function related to the SDOF system. Some results of numerical analysis are presented.
An a posteriori estimate for nonconforming finite element methods
Authors: Carstensen Carsten , Jansche Stefan
Published: December 2010

A computable error estimate is established for the model case of the Poisson‐problem. This enables an efficient method in applying the nonconforming Crouzeix‐Raviart Elements for adaptive refinement techniques. We study reliability and efficiency of the proposed algorithm both theoretically and numerically.
Obstacle problems in elasticity
Authors: Schuricht F.
Published: December 2010

Obstacle problems in elasticity are usually described by variational inequalities where the set of admissible deformations is convex in some function space. This is, however, too restrictive for applications on the basis of realistic models. Furthermore it is unsatisfactorily that variational inequalities do not have enough structure to provide a detailed description of the forces exerted by the obstacle. An other point is that in obstacle problems concentrated contact forces actually arise while in standard continuum mechanics body forces and surface tractions with integrable densities are considered only.

It seems that finer nonsmooth methods than variational inequalities and a more general approach to forces are necessary to handle these difficulties. On the basis of the very general Cosserat theory describing planar deformations of shearable nonlinearly elastic rods we demonstrate how this can be done. Using Clarke's calculus of generalized gradients we derive the Euler‐Lagrange equations for very general obstacle problems and we obtain a very natural representation of the contact reactions, including concentrated forces. This finally serves as basis for further regularity results.
Molekulardynamische Simulation ionenstrahlgestützter Verfahren (IBAD) zur Herstellung neuer Schichtmaterialien
Authors: Schweitzer D.
Published: December 2010

Gegenwärtig wird weltweit sehr intensiv an der Synthese von phasenreinen, texturierten Nitridschichten (z. B. BN, TiN, AlN, SiN) geforscht, die wegen ihrer besonderen Eigenschaften ein hohes Anwendungspotential für die Elektronik, Optoelektronik und als verschleißfeste Hartstoffschichten erwarten lassen. Dabei haben sich ionenstrahlgestützte Verfahren, sog. IBAD‐ Verfahren (“Ion Beam Assisted Deposition”), als besonders erfolgversprechend erwiesen. Bei der numerischen Integration der Bewegungsgleichungen eines diesen Prozeß modellierenden Vielteilchensystems erfordert das gleichzeitige Auftreten schneller Ionen mit Energien im keV‐Bereich und langsamer Atome mit thermischen Energien eine adaptive Schrittweitensteuerung mit lokal unterschiedlichen Zeitschritten.
On Infinite‐Dimensional Dynamic Systems Generated by Non‐linear Hyperbolic Equations
Authors: Shirikyan A. , Volevich L.
Published: December 2010

We consider high‐order non‐linear hyperbolic equations that are small perturbations of an equation with constant coefficients. It is assumed that the unperturbed equation has a characteristic polynomial whose roots with respect to the variable dual to time are outside an open strip containing the imaginary axis. We establish the property of exponential dichotomy for the equation in question. Under the additional condition that the roots of the characteristic polynomial belong to the left half‐plane we prove that the zero solution is asymptotically stable as t → + ∞.
Stochastischer Zins in der Ruintheorie
Authors: Siegl T. , Tichy R. F.
Published: December 2010

In den klassischen Modellen der kollektiven Ruintheorie wird keine Verzinsung des verfügbaren Kapitals angenommen. Neuere Entwicklungen auf diesem Gebiet, und die allgemeine Tendenz, finanzmathematische Methoden in der Risikotheorie anzuwenden, führen zur Anwendung stochastischer Zinssätze in der Ruintheorie. Außerdem diskutieren wir die Simulation des Problems mit hybrid Monte Carlo Verfahren.