bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurons and cardiomyocytes derived from induced pluripotent stem cells as a model for mitochondrial defects in Friedreich's ataxia
Authors: Hick Aurore , Wattenhofer-Donzé Marie , Chintawar Satyan , Tropel Philippe , Simard Jodie P. , Vaucamps Nadège , Gall David , Lambot Laurie , André Cécile , Reutenauer Laurence , Rai Myriam , Teletin Marius , Messaddeq Nadia , Schiffmann Serge N. , Viville Stéphane , Pearson Christopher E. , Pandolfo Massimo , Puccio Hélène
Published: November 2012

Friedreich's ataxia (FRDA) is a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy. FRDA is due to expanded GAA repeats within the first intron of the gene encoding frataxin, a conserved mitochondrial protein involved in iron-sulphur cluster biosynthesis. This mutation leads to partial gene silencing and substantial reduction of the frataxin level. To overcome limitations of current cellular models of FRDA, we derived induced pluripotent stem cells (iPSCs) from two FRDA patients and successfully differentiated them into neurons and cardiomyocytes, two affected cell types in FRDA. All FRDA iPSC lines displayed expanded GAA alleles prone to high instability and decreased levels of frataxin, but no biochemical phenotype was observed. Interestingly, both FRDA iPSC-derived neurons and cardiomyocytes exhibited signs of impaired mitochondrial function, with decreased mitochondrial membrane potential and progressive mitochondrial degeneration, respectively. Our data show for the first time that FRDA iPSCs and their neuronal and cardiac derivatives represent promising models for the study of mitochondrial damage and GAA expansion instability in FRDA.
Impact and workload implications on service provision with establishment of a neonatal complex airway service in Scotland
Authors: Harry C L , Trivers C , Kubba H , Clement Wa , Simpson J H
Published: November 2012

The objective of this study was to assess if any changes have occurred in the utilization of neonatal services with referral for neonatal airway assessment and how this is related to the establishment of a National Complex Airway Service. A retrospective case-note review was performed for neonates referred for airway assessment from 2004-2010 inclusive. Seventy-nine neonates were referred from throughout Scotland; 10 in 2004-2006, 24 in 2007-2008 and 45 in 2009-2010. The mean gestational age was 35 weeks; 39% were preterm. Stridor was the most common reason for referral (46%). The most common diagnosis was airway malacia (38%). Fifty-three procedures were performed on the ward. In total, 64 microlaryngobronchoscopies were performed; 45 diagnostic and 19 interventional. The most common intervention was supraglottoplasty for airway malacia. Thirty-five separate airway procedures were undertaken. Additional investigations were frequently requested and co-morbidities were common. Since the establishment of the Scottish National Complex Airway Service in 2006, referrals for neonatal airway assessment have increased significantly. The reasons for this include a greater awareness of the service, improved treatment options and increased preterm survival. These neonates frequently have associated co-morbidities and require a repertoire of specialist input. This increase has significant implications for further service provision.
Equity and efficiency: striving for a solution for the introduction of new medicines
Authors: Hems S , Black C , Mciver L , Bennie M
Published: November 2012

The aim of this study was to describe the evolution of mechanisms to manage the introduction of new medicines and their impact on the health-care system in Scotland. The study was a review of published and unpublished national audits and surveys on the introduction of new medicines in Scotland. Before the Scottish Medicines Consortium (SMC) was established, Area Drug and Therapeutics Committees (ADTCs) played a key role in advising National Health Service (NHS) Boards in Scotland on the use of new medicines. There was evidence of variation in the medicines evaluated and, in some cases, the evidence used leading to different decisions for the same medicine. After the SMC was established, ADTC decisions had become more consistent and comprehensive. The role of ADTCs evolved from evaluation of medicines to assessment of local implications and implementation of SMC advice. There was increased recognition of the importance of monitoring medicine use. This review demonstrated a clear evolution in the evaluation and implementation of new medicines by ADTCs across NHS Scotland. After the SMC was established, more medicines were considered by ADTCs and there was greater consistency in those considered for local implementation. ADTCs have moved from evaluation of new medicines to other aspects of medicine management, including assessment of local implications and implementation of SMC advice.
Pricing Games and Impact of Private Demand Information in Decentralized Assembly Systems
Authors: Kalkancı Başak , Erhun Feryal
Published: November 2012

This paper analyzes decentralized assembly systems under asymmetric demand information and sequential contracting. We reveal new insights on the value of contract type (price-only versus complex), demand information (complete versus asymmetric), and contract sequence (first mover versus second mover) to different players. Our results for the basic model show the following: (1) Complex contracts increase the suppliers' aggregate profit; however, individual suppliers do not necessarily benefit from a complex contracting equilibrium. We identify the conditions under which each supplier benefits from such an equilibrium. (2) Eliminating information asymmetry is not always beneficial for the suppliers because obtaining information might bring only marginal value and hence might not be realistically justified. Furthermore, a downstream supplier might prefer information asymmetry to complete information, especially when demand variability is moderate. (3) Unless there is a high demand risk, the first-mover advantage is prevalent when the assembler is a price-taker.

We extend our basic model to analyze two additional scenarios. First, we study cases where the suppliers may offer contracts of different complexity. Beyond enriching our understanding of contract choice in decentralized assembly systems, such variations enhance the analysis beyond the standard methodology of principal-agent models and utilize solution techniques from optimal control. Second, we analyze the situation where the suppliers may possess different levels of information on demand under complex contracts. We show that an upstream supplier always benefits from a downstream supplier's superior information. However, the additional information might decrease the downstream supplier's profit, especially when the forecast variability is low compared to the total demand variability in the system. Our results for the basic model and its extensions confirm that studying interactions between suppliers, specifically under different contract types and information structures, in assembly systems presents rich opportunities for future research.
Comparative Statics Analysis of Multiproduct Newsvendor Networks Under Responsive Pricing
Authors: Bish Ebru K. , Zeng Xin , Liu Juqi , Bish Douglas R.
Published: November 2012

We propose a novel analytic approach for the comparative statics analysis of multiproduct multiresource newsvendor networks under responsive pricing. Our approach involves exploiting the properties of the primal mathematical programming formulation and of the dual variables and linking those properties to the concept of convex orders and to properties of the underlying demand function. The use of convex orders allows us to establish our main results without restriction to a specific demand distribution. A major strength of our approach is that it is “scalable,” i.e., it applies to newsvendor networks with any number of “nonindependent” (i.e., demand or resource sharing) products and resources, without an exponential increase in effort as problem size increases. This is unlike the current approaches commonly used in the operations management literature, which typically involve a parametric analysis of the recourse problem, followed by the use of Jacobians and the implicit function theorem. Providing a rigorous framework for comparative statics analysis, which can be applied to other problems that are not amenable to traditional parametric analysis, is our main contribution.

We demonstrate this approach on the optimal capacity decision problem in multiproduct newsvendor networks under responsive pricing, formulated as a two-stage stochastic programming problem with recourse: The firm determines the resource capacities ex ante, in the first stage, when demand intercepts are uncertain, and makes the pricing and production decisions ex post, in the second stage, when demand intercepts (e.g., market conditions) are fully observed. This particular problem and its variants are well studied in the operations management literature. A comparative statics analysis is integral to the study of the capacity investment decision, as it allows answers to important questions such as the following: “Does the firm acquire more or less of the different resources available as demand uncertainty increases? Does the firm benefit from an increase in demand uncertainty?” Using our proposed approach, we establish comparative statics results on how the newsvendor's expected profit and optimal capacity decision change with demand risk in multiproduct multiresource newsvendor networks. We also extend our analysis to the study of demand dependence in two-product networks.
Stopping Trials Early for Benefit—Not So Fast!
Authors: Faust Andrew C , Chung Tammy , Feldman Mark
Published: November 2012

On October 25, 2011, Eli Lilly and Company announced the voluntary withdrawal of Xigris (drotrecogin alfa [activated]) following the negative results of its most recent clinical trial, the PROWESS-SHOCK study. The purpose of this commentary is to briefly review the history of drotrecogin alfa, discuss issues surrounding early cessation of clinical trials for benefit, and highlight the scientific and ethical dilemmas faced when deciding whether or not to stop a trial early for benefit. This review should serve as an introduction to the topic of stopping trials early for benefit.
Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Disoproxil Fumarate Single Tablet for HIV-1 Infection Treatment
Authors: Olin Jacqueline L , Spooner Linda M , Klibanov Olga M
Published: November 2012

Objective:

To review the clinical trials, pharmacologic characteristics, safety, and efficacy of the elvitegravir/cobicistat/emtricitabine/tenofovir single tablet formulation (Stribild).

Data Sources:

Literature searches were performed in MEDLINE (1948-September 2012) and PubMed (1966-September 2012) using the search terms GS-9137, elvitegravir, GS 9350, cobicistat, quad pill, Stribild, and integrase inhibitors. Abstracts from HIV/AIDS conferences were reviewed.

Study Selection and Data Extraction:

Phase 3 studies evaluating the safety and efficacy of Stribild were preferentially evaluated, as well as relevant references from the published studies.

Data Synthesis:

Stribild contains complete antiretroviral therapy for HIV-1 infection in a single tablet. It is the first once-daily therapy option available with an integrase inhibitor and a novel pharmacokinetic boosting agent. Stribild has shown non-inferiority in viral load suppression at 48 weeks when compared with dual nucleoside/nucleotide reverse transcriptase inhibitor and either a ritonavir-boosted protease inhibitor or nonnucleoside reverse transcriptase inhibitor regimen. Stribild was well tolerated, but some patients experienced increases in serum creatinine early in treatment that stabilized over time.

Conclusions:

Stribild is the first single-tablet regimen for HIV-1 infection treatment containing an integrase inhibitor. It is expected to have a prominent place in the formularies of health plans providing care for individuals with HIV-1 infection.
SOX17 Promoter Methylation in Circulating Tumor Cells and Matched Cell-Free DNA Isolated from Plasma of Patients with Breast Cancer
Authors: Chimonidou Maria , Strati Areti , Malamos Nikos , Georgoulias Vasilis , Lianidou Evi S
Published: November 2012

INTRODUCTION

Detection of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) in the peripheral blood of patients with solid tumors has been widely studied for the early detection of metastatic spread. We evaluated whether there was an association between the origin of cfDNA and CTCs. We investigated whether SRY (sex determining region Y)-box 17 (SOX17) promoter methylation in CTCs was associated with the methylation pattern of this gene in matched cfDNA isolated from plasma of patients with breast cancer.

METHODS

We examined SOX17 methylation in 79 primary breast tumors, in 114 paired samples of DNA isolated from CTCs and cfDNA, and in 60 healthy individuals. Isolated DNA was modified by sodium bisulfite and subjected to methylation specific PCR.

RESULTS

The SOX17 promoter was methylated in 68 (86.0%) of 79 of primary breast tumors. In CTCs, SOX17 was methylated in 19 (34.5%) of 55 patients with early breast cancer, 27 (45.8%) of 59 patients with metastatic cancer, and 1 (4.3%) of 23 healthy individuals, whereas in matched cfDNA SOX17 was methylated in 19 (34.5%) of 55, 24 (40.7%) of 59, and 1 (2.0%) of 49 of these same groups, respectively. There was a significant correlation between SOX17 methylation in cfDNA and CTCs in patients with early breast cancer (P = 0.008), but not in patients with verified metastasis (P = 0.283).

CONCLUSIONS

The SOX17 promoter is highly methylated in primary breast tumors, in CTCs isolated from patients with breast cancer, and in corresponding cfDNA samples. Our findings indicate a direct connection between the presence of CTCs and cfDNA in patients with operable breast cancer, after surgical removal of the primary tumor.
External Quality Assessment of Point-of-Care Methods: Model For Combined Assessment of Method Bias and Single-Participant Performance by the Use of Native Patient Samples and Noncommutable Control Materials
Authors: Stavelin Anne , Petersen Per Hyltoft , Sølvik Una Ø , Sandberg Sverre
Published: November 2012

BACKGROUND

An important objective in external quality assessment (EQA) is to evaluate systematic deviations between methods. However, this is not possible when noncommutable control materials are used. The aim of this study was to develop an EQA model that incorporates a method bias evaluation using native patient samples into EQA schemes in which noncommutable materials are used.

METHODS

The model was applied twice in a point-of-care (POC) international normalized ratio survey among 1341 and 1578 participants. To estimate bias, about 100 native patient samples for each POC method were analyzed by a selected group of “expert” primary healthcare centers and on a designated comparison method. In addition, the expert centers as well as all the other EQA participants analyzed 2 noncommutable control materials, and method-specific target values were established. Both method bias and the deviation of a single-participant result from the method target value were evaluated against analytical quality specifications, making combined assessment possible. The best-case scenario occurred when both results were within the quality specifications.

RESULTS

Two POC methods fulfilled the quality specification for bias, whereas one did not. The best-case scenario was achieved by more than 90% of the participants using the methods with no bias, whereas none of the participants using the method with unacceptable bias achieved this result.

CONCLUSIONS

We propose an EQA model for which the bias of POC methods can be evaluated in situations in which commutable control materials are not available.
When Humanizing Brands Goes Wrong: The Detrimental Effect of Brand Anthropomorphization amid Product Wrongdoings
Authors: Puzakova Marina , Kwak Hyokjin , Rocereto Joseph F.
Published: November 2012

The brand relationship literature shows that the humanizing of brands and products generates more favorable consumer attitudes and thus enhances brand performance. However, the authors propose negative downstream consequences of brand humanization; that is, the anthropomorphization of a brand can negatively affect consumers’ brand evaluations when the brand faces negative publicity caused by product wrongdoings. They find that consumers who believe in personality stability (i.e., entity theorists) view anthropomorphized brands that undergo negative publicity less favorably than nonanthropomorphized brands. In contrast, consumers who advocate personality malleability (i.e., incremental theorists) are less likely to devalue an anthropomorphized brand from a single instance of negative publicity. Finally, the authors explore three firm response strategies (i.e., denial, apology, and compensation) that can affect the evaluations of anthropomorphized brands for consumers with different implicit theory perspectives. They find that entity theorists have more difficulty in combating the adverse effects of brand anthropomorphization than incremental theorists. Furthermore, they demonstrate that compensation (vs. denial or apology) is the only effective response among entity theorists.
A Practical Anti-bubble Prescription
Authors: Andrade Sandro C. , Bian Jiangze , Burch Timothy R.
Published: November 2012

We argue that coordinated mass dissemination of information about asset fundamentals should make asset markets less prone to bubbles. The key idea is to establish a centralized and popular information source to make key information common knowledge across as many market participants as possible. This realistic, micro-level anti-bubble policy faces fewer challenges than monetary policy and macro-prudential tools.
Contributions of peroxisome proliferator-activated receptor β/δ to skin health and disease
Authors: Montagner Alexandra , Wahli Walter
Published: November 2012

Among the three peroxisome proliferator-activated receptor (PPAR) transcription factors, PPARβ/δ is the isotype with the broadest expression pattern. In fact, the expression of PPARβ/δ is ubiquitous, albeit at levels that are tightly regulated. Herein, we reviewed its multiple functions in skin health and disease. PPARβ/δ has pro-differentiating effects in keratinocytes, regulates sebocyte differentiation, and promotes hair follicle growth in healthy skin. Furthermore, we reviewed novel insights into the roles of PPARβ/δ in skin wound healing, especially in inhibiting apoptosis and in modulating keratinocyte proliferation and migration. Therefore, PPARβ/δ represents a research target for the understanding and treatment of inflammatory skin diseases, such as psoriasis and acne vulgaris. In addition, PPARβ/δ is a tumor growth modifier. Epidemiological studies have established that tumor progression may be exacerbated by chronic low-grade inflammation, a condition promoting the production of the lipids that act as modulators of PPARβ/δ activity. The action of PPARβ/δ in skin cancer is ambivalent, which might be explained by this receptor’s putative highly context-specific behavior, which depends on a combination of factors ranging from receptor expression levels to co-regulator distribution, diversity and activity of the ligands produced, and other tissue-specific conditions. Given its diverse and crucial roles in many tissues and organs, PPARβ/δ will remain a major focus of future research.
Bioanalytical methods for quantitation of levamisole, a widespread cocaine adulterant
Authors: Shea Jennifer L.
Published: November 2012

Levamisole is an anthelminthic that was first used as a de-worming agent in humans and animals. It has also been used to treat inflammatory conditions as well as certain types of cancer. Levamisole was discontinued for human use in the early 21st century due to toxic side effects including agranulocytosis and vasculitis. Recently, levamisole was discovered as a cocaine adulterant after reports emerged of drug users with the above disorders. As the prevalence of cocaine usage has grown in the last 15 years, measurement of levamisole in human samples has become increasingly important. This review focuses on the various bioanalytical methods available for the determination of levamisole in human plasma and urine. Earlier methods employed gas chromatography coupled with nitrogen-selective thermionic specific detection and nitrogen-phosphorus detection, as well as high performance liquid chromatography coupled with ultraviolet detection. In addition, gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) have also been described. Currently, GC-MS appears to be the method of choice however recent developments in the area of LC-MS/MS make this technology an attractive alternative. The merits of both GC-MS and LC-MS/MS for the determination of levamisole are evaluated on the basis of sample preparation, chromatographic separation conditions, run time, and analytical performance. In addition, emerging methods in this area are also reviewed.
Temperature Dependence of the Spontaneous Polarization Near the Ferroelectric-Paraelectric Transition in NaNO2
Authors: Kuşoğlu Sarıkaya C. , Yurtseven H.
Published: November 2012

The paraelectric-ferroelectric transition in NaNO2 is studied using the Levanyuk-Sannikov and the mean field models which we have developed here. From both models, the temperature dependence of the spontaneous polarization is derived and is fitted to the experimental data from the literature.

Our results show that both mean field models are adequate to describe the observed behaviour of the spontaneous polarization close to the paraelectric-ferroelectric transition in NaNO2. The two models are compared in regard to the transition mechanism in this crystal.
Improving Aboriginal and Torres Strait Islander Australians’ well-being using participatory community singing approach
Authors: Sun Jing , Buys Nicholas Jan
Published: November 2012

There is increasing international interest in the idea that well-being and health are related to resilience. Participative community singing is beneficial for well-being not only in people who are free from health problems, but especially for those whose physical and mental health is compromised. This study examined the development of five Aboriginal and Torres Strait Islander singing groups and the benefits relating to promoting resilience and ultimately preventing chronic disease in this population. Mixed methods, including both quantitative and qualitative approaches, were used. Questionnaires were administered to collect data on chronic life stresses, resilience, social support and social connectedness. Focus group interviews were conducted to obtain data on the participants’ and stakeholders’ perceptions of the impact of the singing groups. Multivariate analysis of variance was used to test the effectiveness of the intervention program on improving resilience at both the individual and the community levels. Structural equation modelling was used to analyse the pathways from the benefits gained from the singing program to the prevention of chronic disease. The results suggested that the singing groups served multiple functions, which are underpinned by social ecological resilience mechanisms to promote self-esteem, learning and education and confidence at the individual level, as well as community connectedness, reduction of loneliness and promoting social support from family, community and the social context such as support from community-controlled health services, and ultimately preventing chronic disease.
On a Conjecture Regarding Balancing with Powers of Fibonacci Numbers
Authors: Alvarado Saúl Díaz , Dujella Andrej , Luca Florian
Published: November 2012

Here, we show that

where
On Odd Perfect Numbers and Even 3-Perfect Numbers
Authors: Cohen Graeme L. , Sorli Ronald M.
Published: November 2012

An idea used in the characterization of even perfect numbers is used, first, to derive new necessary conditions for the existence of an odd perfect number and, second, to show that there are no even 3-perfect numbers of the form
Sierpiński Numbers in Imaginary Quadratic Fields
Authors: Jones Lenny , White Daniel
Published: November 2012

In 1960, Sierpiński proved that there exist infinitely many odd positive rational integers

In this article, we investigate the analogous problem in the ring of integers
Age-gender feeding differences in dwarf blue sheep, Pseudois schaeferi (Cetartiodactyla, Bovidae) magnified by the expansion of an invasive plant species
Authors: De-Pin Li , Scott Matthew B. , Lin Xiao , Wen Xiao
Published: November 2012

Understanding feeding habits and responses to habitat changes can be a critical step toward the conservation of threatened species. Pressured by hunting, habitat loss, and competition from livestock, the dwarf blue sheep (
Nanoplasmonics: a frontier of photovoltaic solar cells
Authors: Gu Min , Ouyang Zi , Jia Baohua , Stokes Nicholas , Chen Xi , Fahim Narges , Li Xiangping , Ventura Michael James , Shi Zhengrong
Published: November 2012

Nanoplasmonics recently has emerged as a new frontier of photovoltaic research. Noble metal nanostructures that can concentrate and guide light have demonstrated great capability for dramatically improving the energy conversion efficiency of both laboratory and industrial solar cells, providing an innovative pathway potentially transforming the solar industry. However, to make the nanoplasmonic technology fully appreciated by the solar industry, key challenges need to be addressed; including the detrimental absorption of metals, broadband light trapping mechanisms, cost of plasmonic nanomaterials, simple and inexpensive fabrication and integration methods of the plasmonic nanostructures, which are scalable for full size manufacture. This article reviews the recent progress of plasmonic solar cells including the fundamental mechanisms, material fabrication, theoretical modelling and emerging directions with a distinct emphasis on solutions tackling the above-mentioned challenges for industrial relevant applications.
Biomedical applications of organosilica nanoparticles toward theranostics
Authors: Nakamura Michihiro
Published: November 2012

Nanoparticles for biomedical applications have several advantages as multifunctional agents. Among various types of nanoparticles for biomedical applications, silica nanoparticles have characteristic positioning due to their inherent property. The recent development of silica nanoparticles is creating a new trend in nanomedicine. A novel type of silica nanoparticle, organosilica nanoparticle, is both structurally and functionally different from the common (inorgano)silica nanoparticle. The organosilica nanoparticles are inherent organic-inorganic hybrid nanomaterials. The interior and exterior functionalities of organosilica nanoparticles are useful for their multifunctionalization. Biomedical applications of organosilica nanoparticles are leading to a wide range of nanomedical fields such as basic biomedical investigations and clinical applications. Multifunctionalizations peculiar to organosilica nanoparticles enable the creation of novel imaging systems and therapeutic applications. In this review, I will introduce differences between (inorgano)silica nanoparticles and organosilica nanoparticles, and then focus on biomedical applications of organosilica nanoparticles toward theranostics.
PROGRESS TOWARDS MELANIN INTEGRATION IN BIO-INSPIRED DEVICES
Authors: Ambrico M. , Ambrico P. F. , Cardone A. , Ligonzo T. , Cicco S. R. , Lavizzera A. , Augelli V. , Farinola G. M.
Published: November 2012

The integration of biopolymers into hybrid electronics is one of the up to date issues in view of the achievement of fully bio-compatible devices. Among ‘hot topics’ in bio-polymer research, synthetic melanin or, briefly, “melanin”, has been recently recognized as a quite intriguing macromolecule thanks to its multifunctional optoelectronic properties. To date, melanin transport properties have been mainly enlightened on pellets, while optical absorption and conductivity properties have been investigated on melanin layers deposited on quartz and indium tin oxide/glass. The unavailability of suitable procedures to improve or promote adequate self assembling of melanin layer deposition onto substrate of interest in organic and solid state electronics (hybrid) like silicon substrates, prevent interesting studies on such structures. The reason stems basically on the difference between the hydrophilic nature of the melanin and the hydrophobic one of the supports (mostly of silicon). However, our group solved this issue and was able to tailor a melanin based metal/insulator/metal and metal/insulator/silicon structures, where synthetic melanin was embedded as the insulating part. This allowed to disclose interesting features related to data storage capabilities of melanin layers deposited on indium tin oxide/glass and silicon never investigated so far. In this work we show an overview on our recent mentioned results, and particular attention is paid on structures on silicon substrates. The use of pSi and nSi substrates and measurements under different environment conditions has enabled to gain insight into ambipolar electrical transport mechanisms, still unexplored. These results constitute a first important basic insight into melanin-based bio inspired structures and represent a significant step towards their integration in several kinds of hybrid organic polymer-based devices.
Dependence of 4H-SiC Epitaxial Layer Quality on Growth Conditions with Wafer Size Corresponding to 150 mm
Authors: Kudou Chiaki , Tamura Kentaro , Aigo Takashi , Ito Wataru , Nishio Johji , Kojima Kazutoishi , Ohno Toshiyuki
Published: November 2012

Homoepitaxial growth on 4H-SiC Si-face substrates with sizes corresponding to 150 mm was carried out. The influence of growth conditions for uniformity and epitaxial defect density was investigated. A 150 mm size was realized by using two 76.2 mm wafers lined up in a radial direction. C/Si ratio is found to be a major parameter for controlling triangular defect density and the generation of step bunching. As a result, the surface morphology without bunched step structure and the triangular defect density with 0.5 cm−2 were obtained by decreasing C/Si ratio to 1.0 on the size corresponding to 150 mm. Under this condition, good carrier concentration and thickness uniformity of σ/mean =15.2 % and 1.7 % could be obtained.
Improvement of shear strength of loose sandy soils by grouting
Authors: Kumar Santhosh , Abraham Benny Mathews , Sridharan Asuri , Jose Babu T.
Published: November 2012

The soil profile in many coastal areas often consists of very loose sandy soil extending to a depth of 3 to 4 m from ground level underlain by clayey soils of medium consistency. The very low shearing resistance of the foundation bed causes local as well as punching shear failure of soil. Structures built on these soils, may also suffer from excessive settlements. This paper discusses grouting as one of the possible solutions to the foundation problems by improving the properties of loose sandy soil at shallow depths.
Preparation of ultra-high-strength self-compacting concrete and its high-drop casting construction in a pier structure
Authors: Yongjia He , Linnu Lu , Jie Ma , Qingjun Ding , Tingmin Mu , Shuguang Hu
Published: November 2012

Ultra-high-strength grade self-compacting concrete used for steel-tube confined concrete bridge pier structure was designed and prepared. To enhance the performance of the hardened concrete and the cohesiveness of the fresh concrete, fly ash and silica fume combined with polycarboxylic super-plasticiser were used. The mechanical properties and workability of the concrete were investigated in experiments. With the selected mixture from the experimental mixture series, the ultra-high-strength grade concrete was produced at industrial scale and used in bridge pier structures. Self-compacting concrete was cast into the steel tube by the high-drop method. The experiment results and the practical application show that ultra-high-strength self-compacting concrete with excellent performance can be produced with common raw materials.
Mix proportioning of self-compacting high- and ultra-high-performance concretes with and without steel fibres
Authors: Karihaloo Bhushan Lal , Ghanbari Akbar
Published: November 2012

A method is proposed for proportioning self-compacting high- and ultra-high-performance concrete mixes without steel fibres (SCHPC/SCUHPC) and with steel fibres (SCHPFRC/SCUHPFRC) which meet the standard flow and passing ability criteria without segregation. This method is based on an extensive investigation of the flow characteristics of self-compacting concrete (SCC) mixes using computational simulations. It provides an alternative tool to the heuristic mix design of SCC, thus avoiding expensive and time-consuming tests in laboratories or on site.
Blinding struts underlong-term loading
Authors: Abela Jeanette M. , Vollum Robert L. , Izzuddin Bassam A. , Potts David M.
Published: November 2012

The term ‘blinding' is used to describe the thin layer of unreinforced over-site concrete used to protect the base of excavations during construction. Blinding is not generally considered a structural element even though it clearly provides some temporary lateral support to the retaining walls of excavations. The authors have previously shown that enhanced blinding can be used to prop retaining walls in cut-and-cover excavations during construction prior to the completion of the base slab. This paper describes a series of laboratory tests carried out to investigate the effect of concrete creep on the axial resistance of blinding struts. The tests show that blinding can creep to failure if the sustained load exceeds a critical value that depends on the imperfection amplitude and profile as well as the strut thickness. The test results are used to validate a numerical model which is then used to carry out a series of parametric studies on full-scale blinding struts.
Shear design of concrete beams reinforced with grid reinforcement
Authors: Xu Dong , Zhao Yu , Liu Chao , Turmo Jose
Published: November 2012

A new method for designing orthogonal steel grids as shear reinforcement in concrete members is proposed, considering sectional stress distribution and failure criteria of concrete. The concept and formulations of this method have been applied to the analysis and design of reinforced concrete beams subjected to combined shear and bending. An accurate formula for calculation of shear reinforcement ratio is deduced, leading to innovative results. Shear strength of reinforced concrete beams is assumed as the sum of contributions from orthogonal grid reinforcements in the cracked zone and from concrete in the shear compression zone. Eleven reinforced concrete beams with grid reinforcement were tested under bending and shear to validate the accuracy of the proposed method. It was found that the proposed model predicts the experimental behaviour accurately and that grid reinforcement can enhance the shear behaviour of concrete beams.
A laboratory study for full cement replacement by fly ash and silica fume
Authors: Sadique Monower , Al-Nageim Hassan , Atherton William , Seton Linda , Dempster Nicola
Published: November 2012

A new cementitious material was developed through a laboratory study using waste fly ashes and silica fume. The applied mechano-chemical activation by gypsum-aided grinding was found to modify the physical and rheological properties of fly ashes. The ternary blending of fly ashes and silica fume was found to achieve a synergistic oxide component and the intra constituent sensitivity within the blend was also revealed. The progressive formation of hydration products within the blend was identified and their microstructural characteristics were analysed.
Decline of an endangered amphibian during an extreme climatic event
Authors: Scheele B. C. , Driscoll D. A. , Fischer J. , Hunter D. A.
Published: November 2012

Climate change is a poorly understood, emerging threat to many amphibian species. One of the ways climate change is likely to affect amphibians is through increased recruitment failure associated with more frequent climatic extremes. To understand the risk posed by this threat, we combined 13 years of annual monitoring and multi‐scaled habitat modelling at the site (n = 60), pool (n = 105) and nest (n = 170) levels to investigate the decline of the endangered northern corroboree frog (Pseudophryne pengilleyi), during the most severe drought on record in southern Australia. We documented the local extinction of 42% of P. pengilleyi breeding sites during the climatic extreme. Using logistic regression we investigated habitat variables associated with extinction sites. We found that locally extinct sites now resemble historically absent sites, with fewer pools, less water, and drying‐related tree invasion. Extended periods of limited water availability at extinction sites is likely to have restricted breeding, contributing to localised extinctions. Habitat variables recorded at the pool and nest level did not significantly influence P. pengilleyi presence/absence, indicating that site level wetness had an overriding effect. We anticipate that increasing climate variability is likely to disproportionately threaten seasonal pool‐breeding amphibian species, exacerbating the global amphibian biodiversity crisis. However, our work with P. pengilleyi suggests there are a range of simple habitat manipulations that could help to ameliorate the impacts.
Strategies for Reducing the Risk of Respiratory Syncytial Virus Infection in Infants and Young Children: A Canadian Nurses’ Perspective
Authors: Bracht Marianne , Basevitz Debbie , Cranis Marilyn , Paulley Rose , Paes Bosco
Published: November 2012

Respiratory syncytial virus (RSV) infections are prevalent globally and can cause substantial morbidity in infants and young children. The virus is easily transmitted by direct hand-to-hand contact and can lead to serious respiratory disease and hospitalization, particularly in premature infants and children with certain medical conditions. Educating families with young children, especially those in remote rural regions, regarding the potential adverse health outcomes of RSV infection and measures to reduce the risk of transmitting or acquiring RSV has been a key focus of the health care system in Canada. Geographic, cultural, and socioeconomic factors present formidable challenges to the execution of this endeavor. Therefore, it is critical to develop and systematically implement effective educational programs for both families and health care providers. In Canada, nurses play a critical role in education and counseling. In this review, we share our perspectives and suggest empirical practices that may be applicable worldwide.
Identifying and Ensuring Optimal Care for All Children at Risk of Developing Serious Respiratory Syncytial Virus Disease: A Canadian Nurses’ Perspective
Authors: Bracht Marianne , Basevitz Debbie , Cranis Marilyn , Paulley Rose , Paes Bosco
Published: November 2012

Globally, respiratory syncytial virus (RSV) infection causes substantial morbidity in infants and young children, particularly those with specific risk factors (e.g., prematurity, chronic lung and congenital heart disease). Supportive measures are the mainstay of care for RSV-related disease. In the absence of medical treatments, RSV prophylaxis (RSVP) with palivizumab is recommended for high-risk patients to help reduce the risk of developing serious disease. Geographic distances, language and cultural barriers, and other factors can impede effective education of caregivers regarding the potential impact of RSV disease and benefits of RSVP compliance. We present our experiences developing successful Canadian RSVP programs, organized through a dedicated coordinator or small group of health care staff. These programs focus on identifying all infants and young children eligible for RSVP, effectively educating health care staff and family caregivers, developing educational tools that consider language and cultural factors, and interdisciplinary collaboration and networking throughout the health care system.
Analysis of potential impacts of climate change on intensity–duration–frequency (IDF) relationships for six regions in the United States
Authors: Zhu Jianting , Stone Mark C. , Forsee William
Published: November 2012

Potential changes in climate are expected to lead to future changes in the characteristics of precipitation events, including extreme rainfall intensity in most regions. In order for government agencies and design engineers to incorporate these trends and future changes into assessment and design processes, tools for planning and design should be capable of considering nonstationary climate conditions. In this work, potential changes are investigated in intensity–duration–frequency (IDF) curves, which are often used for assessment of extreme rainfall events, using historic data and future climate projections. An approach is proposed for calculating IDF curves that incorporates projected changes in rainfall intensity at a range of locations in the United States. The results elucidate strong regional patterns in projected changes in rainfall intensity, which are influenced by the rainfall characteristics of the region. Therefore, impacts of climate change on extreme hydrologic events will be highly regional and thus such assessments should be performed for specific project locations.
Effective Reading Programs for Spanish-Dominant English Language Learners (ELLs) in the Elementary Grades
Authors: Cheung Alan C. K. , Slavin Robert E.
Published: November 2012

This review synthesizes research on English reading outcomes of all types of programs for Spanish-dominant English language learners (ELLs) in elementary schools. It is divided into two major sections. One focuses on studies of language of instruction and one on reading approaches for ELLs holding constant language of instruction. A total of 13 qualifying studies met the inclusion criteria for language of instruction. Though the overall findings indicate a positive effect (effect size = .21) in favor of bilingual education, the largest and longest term evaluations, including the only multiyear randomized evaluation of transitional bilingual education, did not find any differences in outcomes by the end of elementary school for children who were either taught in Spanish and transitioned to English or taught only in English. The review also identified whole-school and whole-class interventions with good evidence of effectiveness for ELLs, including Success for All, cooperative learning, Direct Instruction, and ELLA. Programs that use phonetic small group or one-to-one tutoring have also shown positive effects for struggling ELL readers. What is in common across the most promising interventions is their use of extensive professional development, coaching, and cooperative learning. The findings support a conclusion increasingly being made by researchers and policymakers concerned with optimal outcomes for ELLs and other language minority students: Quality of instruction is more important than language of instruction.
Teaching Students What They Already Know? The (Mis)Alignment Between Mathematics Instructional Content and Student Knowledge in Kindergarten
Authors: Engel Mimi , Claessens Amy , Finch Maida A.
Published: November 2012

Kindergarten mathematics skills are important for subsequent achievement, yet mathematics is underemphasized in kindergarten classrooms. Using nationally representative data, this study explored the relationship between students’ school-entry math skills, classroom content coverage, and end-of-kindergarten math achievement. Although the vast majority of children entered kindergarten having mastered basic counting and able to recognize simple geometric shapes, their teachers reported spending the most mathematics time—typically about 13 days per month—on this content. On average, exposure to this basic mathematics content was negatively associated with math achievement across kindergarten. Importantly, children with the lowest levels of math skills benefited from exposure to this basic mathematics content whereas other children benefited from exposure to more advanced content.
A Life-cycle Approach to Improve the Sustainability of Rural Water Systems in Resource-Limited Countries
Authors: Jones Sharon A. , Anya Abseen , Stacey Nicholas , Weir Lindsay
Published: November 2012

A WHO and UNICEF joint report states that in 2008, 884 million people lacked access to potable drinking water. A life-cycle approach to develop potable water systems may improve the sustainability for such systems, however, a review of the literature shows that such an approach has primarily been used for urban systems located in resourced countries. Although urbanization is increasing globally, over 40 percent of the world’s population is currently rural with many considered poor. In this paper, we present a first step towards using life-cycle assessment to develop sustainable rural water systems in resource-limited countries while pointing out the needs. For example, while there are few differences in costs and environmental impacts for many improved rural water system options, a system that uses groundwater with community standpipes is substantially lower in cost that other alternatives with a somewhat lower environmental inventory. However, a LCA approach shows that from institutional as well as community and managerial perspectives, sustainability includes many other factors besides cost and environment that are a function of the interdependent decision process used across the life cycle of a water system by aid organizations, water user committees, and household users. These factors often present the biggest challenge to designing sustainable rural water systems for resource-limited countries.
Use of a Deuterated Internal Standard with Pyrolysis-GC/MS Dimeric Marker Analysis to Quantify Tire Tread Particles in the Environment
Authors: Unice Kenneth M. , Kreider Marisa L. , Panko Julie M.
Published: November 2012

Pyrolysis(pyr)-GC/MS analysis of characteristic thermal decomposition fragments has been previously used for qualitative fingerprinting of organic sources in environmental samples. A quantitative pyr-GC/MS method based on characteristic tire polymer pyrolysis products was developed for tread particle quantification in environmental matrices including soil, sediment, and air. The feasibility of quantitative pyr-GC/MS analysis of tread was confirmed in a method evaluation study using artificial soil spiked with known amounts of cryogenically generated tread. Tread concentration determined by blinded analyses was highly correlated (r2 ³ 0.88) with the known tread spike concentration. Two critical refinements to the initial pyrolysis protocol were identified including use of an internal standard and quantification by the dimeric markers vinylcyclohexene and dipentene, which have good specificity for rubber polymer with no other appreciable environmental sources. A novel use of deuterated internal standards of similar polymeric structure was developed to correct the variable analyte recovery caused by sample size, matrix effects, and ion source variability. The resultant quantitative pyr-GC/MS protocol is reliable and transferable between laboratories.