bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Yielding Alkyne‐Tetracyanoethylene Addition Reactions: A Powerful Tool for Analyzing Alkyne‐Linked Conjugated Polymer Structures
Authors: Fujita Hiroyuki , Tsuboi Kazuma , Michinobu Tsuyoshi
Published: June 2011

Poly(o‐phenyleneethynylene) and poly(o‐phenylenebutadiynylene) derivatives are synthesized by the Sonogashira polycondensation or oxidative polymerization of an asymmetric monomer, 3,4‐diethynyl‐N,N‐dihexylaniline. Postfunctionalization of the poly(o‐phenyleneethylene) derivatives is unsuccessful due to the occurrence of undesired side reactions. In contrast, the poly(o‐phenylenebutadiynylene) derivative is converted into the donor–acceptor type polymer without side reactions. The resulting polymer features a well‐defined charge‐transfer (CT) band in the Vis–NIR region and redox activity in both the anodic and cathodic directions. The results suggest that the oxidative polymerization mainly proceeds through the pseudo two‐step pathway.

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An epistemic event‐based correlation approach for managing pervasive networks
Authors: Ganapathy Vinayak , Pissinou Niki , Makki S. Kami , Ali Bakhtiar Qutub
Published: June 2011

Existing pervasive applications are based on time series data that possess the form of time‐ordered series of events. Such applications also embody the need to handle large volumes of unexpected events, often modified on‐the‐fly, containing conflicting information, and dealing with rapidly changing contexts while producing results with low latency. Correlating events across contextual dimensions holds the key to expanding the capabilities and improving the performance of these applications. In this paper we analyze complex‐event semantic correlation that examines epistemic uncertainty in computer networks by using Dempster–Shafer theory to support a high‐volume, event‐based, in‐network and non‐deterministic pervasive network management. We consider imprecision and uncertainty when an event is detected and associate a belief parameter with the semantics and the detection of composite events. The approach taps into in‐network processing capabilities of pervasive computer networks and can withstand missing or conflicting information gathered from multiple participating entities. In the end, we establish that a lightweight, distributed, large‐volume, event‐based technique which exploits epistemic uncertainty to correlate events along contextual dimensions provides a successful technique for enabling management of large‐scale and pervasive contemporary and future computer networks. Copyright © 2011 John Wiley & Sons, Ltd.
Low dielectric constant polyimide nanomats by electrospinning
Authors: Chen Fei , Bera Debaditya , Banerjee Susanta , Agarwal Seema
Published: June 2011

The proper combination of material (i.e. fluorinated polyimides) and processing technique (electrospinning) could lead to the formation of polyimides with low dielectric constant, high thermo‐oxidative stability and glass transition temperature, and high hydrophobicity. The polyimides in this work were based on 4, 4‐bis [3′‐trifluoromethyl‐4′ (4′‐amino benzoxy) benzyl] biphenyl (Q) and various fluorinated and non‐fluorinated dianhydrides namely benzene‐1,2,4,5‐tetracarboxylic dianhydride, 3,3′,4,4′‐biphenyltetracarboxylic dianhydride, benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride, and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Processing of the polyimides was carried out in poly(amic acid) stage by two different methods—electrospinning and solution casting for comparison purposes. The processing of polyimides by electrospinning led to enhancement in mechanical properties (dianhydride‐structure dependent) and hydrophobicity without sacrificing thermo‐oxidative stability and glass transition temperatures significantly. Also, low dielectric constants (as low as 1.43) could be attained by suitable combination of dianhydride (6FDA) with 4, 4‐bis [3′‐trifluoromethyl‐4′ (4′‐amino benzoxy) benzyl] biphenyl diamine. Copyright © 2011 John Wiley & Sons, Ltd.
Investigations into the Phenolic Constituents of Dog's Mercury (Mercurialis perennis L.) by LC‐MS/MS and GC‐MS analyses
Authors: Lorenz Peter , Conrad Jürgen , Bertrams Julia , Berger Melanie , Duckstein Sarina , Meyer Ulrich , Stintzing Florian C.
Published: June 2011

Introduction

Dog's mercury (Mercurialis perennis L.) is a traditional European medicinal plant considered as a rich source of bioactive natural products. Yet phytochemical data of the plant are scant.

Objective

This study aimed to identify the hydrophilic phenolic constituents from M. perennis by aqueous and hydroalcoholic extraction.

Methodology

Extracts of herbal parts were investigated in‐depth by HPLC(DAD)‐MS/MS and GC/MS analyses. In addition, a novel compound was isolated and fully characterised by 1‐ and 2D‐NMR experiments.

Results

Several conjugates of caffeic, p‐coumaric and ferulic acids together with glucaric or 2‐hydroxyglutaric acids (depsides) were detected in the aqueous extracts from aerial plant parts by use of LC‐MS/MS techniques as well UV‐spectral data. By implementation of preparative chromatography on polyamide pretreated with formic acid followed by vacuum liquid chromatography on reversed‐phase C18‐silica, one of the predominant depsides was isolated as a pure compound. The NMR spectra (1H and 13C NMR) together with 2D‐hetereonuclear multiple bond correlation NMR experiments (gHMBC and gHSQC) and chiral GC investigation, allowed identification of this compound as (−)‐(E)‐caffeoyl‐2‐(R)‐oxoglutarate. This structure was additionally supported by GC/MS data after silylation and methylation reactions. The hydroalcoholic extract from aerial parts was separated by solvent partition between ethyl acetate and n‐butanol. The latter fraction (n‐butanol) yielded a mixture of mono‐ and oligo‐glycosides of kaempferol and quercetin, all of them being assigned by LC‐MS/MS.

Conclusions

The present investigation constitutes the first comprehensive report on the hydrophilic constituents of the rarely studied plant Mercurialis and thus completes the phytochemical knowledge on M. perennis. Copyright © 2011 John Wiley & Sons, Ltd.
Characterisation of the Degradation of Salvianolic Acid B Using an On‐line Spectroscopic Analysis System and Multivariate Curve Resolution
Authors: Xintian Zheng , Haibin Qu
Published: June 2011

Introduction

Chinese herbal medicines contain complex ingredients that are unstable during the manufacturing process. Current off‐line methods are usually time‐consuming and inaccurate.

Objective

The aim of this study was to develop a continuous‐flow‐based on‐line spectroscopic system for monitoring the degradation of unstable compounds in Chinese herbal medicines.

Methodology

An on‐line spectroscopic analysis system in the evaluation of the degradation of unstable compounds was implemented, using salvianolic acid B from Danshen (Radix Salviae Miltiorrhizae) as a model compound. Resolution of the mixture spectra obtained during the reaction was performed with multivariate curve resolution (MCR), and the pure spectra and kinetic profiles of reactant species were reconstructed.

Results

The degradation process of salvianolic acid B is probably a consecutive two‐step reaction of the form A → B → C, where A is salvianolic acid B, and B and C are the intermediate and final products, respectively. The intermediate and final products were suggested to be a mixture of lithospermic acid and danshensu [3‐(3, 4‐dihydroxyphenyl) lactic acid], and a mixture of danshensu and salvianolic acid A, respectively.

Conclusion

The findings suggested that the combined use of on‐line spectroscopic analysis and MCR might be a cheap, readily available, sensitive tool to monitor the transformation of unstable components of Chinese herbal medicines. Copyright © 2011 John Wiley & Sons, Ltd.
The development of a rapid assay for prenatal testing of common aneuploidies and microdeletion syndromes
Authors: Shaffer Lisa G. , Coppinger Justine , Morton S. Annie , Alliman Sarah , Burleson Jessica , Traylor Ryan , Walker Cathryn , Byerly Steve , Lamb Allen N. , Schultz Roger , Ravnan J. Britt , Kashork Catherine D. , Torchia Beth S. , Sulpizio Scott , Sundin Kyle , Schermer Mack , Adler Karl , Dallaire Stephanie , Ballif Blake C.
Published: June 2011

Objective

To develop a novel, rapid prenatal assay for pregnancies with high likelihood of normal karyotypes, using BACs‐on‐Beads™ technology, a suspension array‐based multiplex assay that employs Luminex® xMAP® technology, for the detection of gains and losses in chromosomal DNA.

Methods

Fifteen relatively common microdeletions were selected that are not detectable, or may be missed, by karyotyping and usually do not present with abnormal ultrasound findings. Chromosomes 13, 18, 21, X, and Y were included. We validated the assay with 430 samples.

Results

All microdeletions and aneuploidies were correctly identified, except for a 69,XXX incorrectly identified as a normal female and a male with ∼20% maternal cell contamination (MCC) that could not be distinguished from 69,XXY. MCC became apparent at 20 to 30%. Mosaicism was identified at 30 to 35% abnormal cells.

Conclusion

We have developed an alternative to fluorescence in situ hybridization (FISH) aneuploidy screening and microarray analysis in otherwise normal pregnancies undergoing invasive testing. We demonstrated that the assay will detect all microdeletions and aneuploidies of regions covered on the assay. We developed analytical software that displays results for well‐characterized syndromes but not abnormalities of unclear clinical significance. This assay is likely to be preferred by women seeking testing beyond routine karyotyping but who desire more information than provided by aneuploidy FISH. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular basis and prenatal diagnosis of β‐thalassemia among Balouch population in Iran
Authors: Miri‐Moghaddam E. , Zadeh‐Vakili A. , Rouhani Z. , Naderi M. , Eshghi P. , Khazaei Feizabad A.
Published: June 2011

Objective

To determine the molecular spectrum of β‐thalassemia mutations among at‐risk Balouch couples in Iran.

Methods

Mutations' detection in DNAs extracted from the blood of partners of at‐risk couples was characterized, and chorion villus sampling by amplification refractory mutation system and DNA sequencing was performed. Fetal diagnosis was also confirmed by linkage analysis.

Results

Out of a total of 1234 at‐risk Balouch couples referred to the center for prenatal diagnosis (PND) from June 2002 to June 2010, a high percentage of ‘67.4%’ were from consanguineous marriages and 37.4% had between one and four affected children. The trend in referring gradually increased from 34 cases in 2002 to 357 cases in 2010. The astonishing finding was that, unlike most previous studies, only IVS 1‐5 with an unusual frequency of 87.20% along with codon 8/9 (+G) with 4% constitutes about 91% of mutations. Altogether, 729 PNDs were made in 583 couples, 25% of whom had over one PND, and surprisingly five PNDs were made in the same woman within just 8 years.

Conclusion

Regarding the limited types of frequent mutations among Balouch population, it is hopefully believed that the incidence of β‐thalassemia could be controlled by a correct diagnosis in the due time. Copyright © 2011 John Wiley & Sons, Ltd.
Heavy metals in human amniotic fluid: a pilot study
Authors: Caserta D. , Mantovani A. , Ciardo F. , Fazi A. , Baldi M. , Sessa M. T. , la Rocca C. , Ronchi A. , Moscarini M. , Minoia C.
Published: June 2011

Objective

Many heavy metals are essential nutrients for a healthy life. However, significant evidence supports prolonged prenatal exposure as a risk factor for several adverse health effects. The aim of this study is to evaluate the presence of heavy metals in human amniotic fluid (AF) to demonstrate that there is an early fetal in utero exposure.

Methods

The concentrations of a variety of heavy metals, including Be, Ag, Ba, Pb, U, Hg, Sr, Cu, Mn, V, Pd, Sn, Sb, Te, Pt, Sc, Tl, Ni, As, Co, Zn and Se, were measured in 25 AF samples obtained from amniocentesis between 15 and 18 weeks of gestational, after informed consent.

Results

Be, Ag, Ba, Pb, U, Cu, Sr, Mn, V, Sn, Te, Pt, As, Tl, Sb, Co, Se and Zn concentrations were detected in measurable amounts in second trimester AF. Mg levels are elevated in all samples. Pd, Ni, Sc and Hg concentrations are below the detection limits in all samples.

Conclusion

This study demonstrates that heavy metals pass into and accumulate in AF from a very early stage of gestation. Other studies are needed to evaluate the long‐term health effects of this early exposure. Copyright © 2011 John Wiley & Sons, Ltd.
The effect of copper alloy mold tooling on the performance of the injection molding process
Authors: Kelly A.L. , Mulvaney‐Johnson L. , Beechey R. , Coates P.D.
Published: June 2011

The performance of copper alloy mold tool materials in injection molding has been examined with respect to cycle time, part quality and energy consumption using in‐process monitoring techniques. A mold insert manufactured from conventional tool steel was compared to four identical inserts made from beryllium‐free copper alloys with copper contents ranging from 85 to 96%. Injection molding trials using high density polyethylene and polybutyl terepthalate were performed using a highly instrumented injection molding machine. Results showed that copper alloy mold tools exhibited cooling rates up to 29% faster than conventional tool steel and that cooling rate was related to thermal conductivity of the alloy. Lower cycle times were achievable with copper alloy than for tool steel before part quality deterioration occurred. The results suggest that copper alloy tooling has the potential to achieve significant reductions in cycle time without detriment to the process or product quality. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Lipid composition influences the release of Alzheimer's amyloid β‐peptide from membranes
Authors: Lemkul Justin A. , Bevan David R.
Published: June 2011

The behavior of the amyloid β‐peptide (Aβ) within a membrane environment is integral to its toxicity and the progression of Alzheimer's disease. Ganglioside GM1 has been shown to enhance the aggregation of Aβ, but the underlying mechanism is unknown. Using atomistic molecular dynamics simulations, we explored the interactions between the 40‐residue alloform of Aβ (Aβ40) and several model membranes, including pure palmitoyloleoylphosphatidylcholine (POPC) and palmitoyloleoylphosphatidylserine (POPS), an equimolar mixture of POPC and palmitoyloleoylphosphatidylethanolamine (POPE), and lipid rafts, both with and without GM1, to understand the behavior of Aβ40 in various membrane microenvironments. Aβ40 remained inserted in POPC, POPS, POPC/POPE, and raft membranes, but in several instances exited the raft containing GM1. Aβ40 interacted with GM1 largely through hydrogen bonding, producing configurations containing β‐strands with C‐termini that, in some cases, exited the membrane and became exposed to solvent. These observations provide insight into the release of Aβ from the membrane, a previously uncharacterized process of the Aβ aggregation pathway.
Influence of Paperboard Structure and Processing Conditions on Forming of Complex Paperboard Structures
Authors: Östlund Magnus , Borodulina Svetlana , Östlund Sören
Published: June 2011

Experiments were made with a laboratory apparatus for forming paper sheets into double‐curved structures. The purpose was to learn more about the design criteria for forming of paper materials into complex shapes. The influence of forming parameters such as moisture and temperature was studied, and the performance of some common pulps as raw materials for the paper sheets was evaluated. Papers made from short hardwood fibres performed worse than papers from other pulps, and the method of moisture application was more important than the amount of moisture that was applied. Copyright © 2011 John Wiley & Sons, Ltd.
Monitoring the Evolution of Damage in Packaging Systems under Sustained Random Loads
Authors: Lamb M. J. , Rouillard V. , Sek M. A.
Published: June 2011

The ability of protective packaging systems to withstand dynamic loads during transportation is an important consideration when it comes to selecting a suitable material. The performance characteristics of packaging systems are best determined by subjecting the systems (such as cushioning materials and containers) to sustained random loads under controlled conditions. It is during these fatigue endurance tests that the loss of structural integrity of a material or an element needs to be quantified. The research presented herein uses two recently developed continuous structural integrity assessment techniques to evaluate variations in the mechanical properties (namely stiffness) of typical packaging elements. The first technique is based on the short‐time Fourier transform, and the other uses an adaptive digital finite impulse response (FIR) filter technique developed by the authors. The effectiveness and the limitations of the techniques were evaluated by undertaking selected controlled experiments during which damage was simulated by varying the length of a single degree‐of‐freedom vibratory system subjected to random base excitation. The materials used for the controlled experiments include steel, aluminium, acrylic and carbon fibre. Results show that, although both methods are capable of identifying the level of damage and the time at which it occurs, the FIR technique is generally more sensitive and better able to detect small changes in stiffness. Finally, the ability of integrity assessment techniques to monitor the progression of damage in real packaging elements, such as biodegradable air cushions and corrugated paperboard containers, was established. The analysis of real protective packaging elements subjected to random loads using both structural integrity assessment techniques yielded positive results. Generally, the adaptive FIR technique was found to be more sensitive in detecting small changes in system characteristics, even when the estimates were obtained with relatively coarse temporal resolution. Overall, the results presented in this study indicate that the adaptive FIR technique can be a practical and effective tool for establishing the ability of materials and structures to withstand sustained random loads. Copyright © 2011 John Wiley & Sons, Ltd.
Rough terrain mapping and classification for foothold selection in a walking robot
Authors: Belter Dominik , Skrzypczyński Piotr
Published: June 2011

Although legged locomotion over a moderately rugged terrain can be accomplished by employing simple reactions to the ground contact information, a more effective approach, which allows predictively avoiding obstacles, requires a model of the environment and a control algorithm that takes this model into account when planning footsteps and leg movements. This article addresses the issues of terrain perception and modeling and foothold selection in a walking robot. An integrated system is presented that allows a legged robot to traverse previously unseen, uneven terrain using only onboard perception, provided that a reasonable general path is known. An efficient method for real‐time building of a local elevation map from sparse two‐dimensional (2D) range measurements of a miniature 2D laser scanner is described. The terrain mapping module supports a foothold selection algorithm, which employs unsupervised learning to create an adaptive decision surface. The robot can learn from realistic simulations; therefore no a priori expert‐given rules or parameters are used. The usefulness of our approach is demonstrated in experiments with the six‐legged robot Messor. We discuss the lessons learned in field tests and the modifications to our system that turned out to be essential for successful operation under real‐world conditions. © 2011 Wiley Periodicals, Inc.
A peak‐capture algorithm used on an autonomous underwater vehicle in the 2010 Gulf of Mexico oil spill response scientific survey
Authors: Zhang Yanwu , McEwen Robert S. , Ryan John P. , Bellingham James G. , Thomas Hans , Thompson Charles H. , Rienecker Erich
Published: June 2011

During the Gulf of Mexico Oil Spill Response Scientific Survey on the National Oceanic and Atmospheric Administration Ship Gordon Gunter Cruise GU‐10‐02 (27 May–4 June 2010), a Monterey Bay Aquarium Research Institute autonomous underwater vehicle (AUV) was deployed to make high‐resolution surveys of the water column in targeted areas. There were 10 2‐liter samplers on the AUV for acquiring water samples. An essential challenge was how to autonomously trigger the samplers when peak hydrocarbon signals were detected. In ship hydrocasts (measurements by lowered instruments) at a site to the southwest of the Deepwater Horizon wellhead, the hydrocarbon signal showed a sharp peak between 1,100‐ and 1,200‐m depths, suggesting the existence of a horizontally oriented subsurface hydrocarbon plume. In response to this finding, we deployed the AUV at this site to make high‐resolution surveys and acquire water samples. To autonomously trigger the samplers at peak hydrocarbon signals, we modified an algorithm that was previously developed for capturing peaks in a biological thin layer. The modified algorithm still uses the AUV's sawtooth (i.e., yo‐yo) trajectory in the vertical dimension and takes advantage of the fact that in one yo‐yo cycle, the vehicle crosses the horizontal plume (i.e., the strong‐signal layer) twice. On the first crossing, the vehicle detects the peak and logs the corresponding depth (after correcting for the detection delay). On the second crossing, a sampling is triggered when the vehicle reaches the depth logged on the first crossing, based on the assumption that the depth of the horizontal oil layer does not vary much between two successive crossings that are no more than several hundred meters apart. In this paper, we present the algorithm and its performance in an AUV mission on 3 June 2010 in the Gulf of Mexico. In addition, we present an improvement to the algorithm and the corresponding results from postprocessing the AUV mission data. © 2011 Wiley Periodicals, Inc.*

This article is a US Government work
and, as such, is in the public domain of the United States of America.
Secondary students' responses to perceptions of the relationship between science and religion: Stances identified from an interview study
Authors: Taber Keith S. , Billingsley Berry , Riga Fran , Newdick Helen
Published: June 2011

It has been argued that learning science may be complicated, and even compromised, when students hold worldviews that may seem at odds with what is presented in science lessons. In particular, in some parts of the world, there has been considerable concern that students from particular religious backgrounds may reject some science teaching if perceived as inconsistent with their faith commitments. In this paper, we report the findings from an interview study that investigated how 12 13–14‐year‐olds from four diverse English schools perceived the relationship between science and religion. In particular, we consider how these students responded to any perceived contradiction and conflict between science and religion. We found a spectrum of stances among this small sample of secondary students. The more extreme positions represented a choice for either science or religion when conflict was perceived. However, other stances were found that sought a synthesis, accommodated inconsistent frameworks, or considered science and religion as noninteracting domains. These alternative stances present a similar range of possibilities to the possible outcomes that have been discussed when students' informal ideas in science are inconsistent with formal science teaching. The implications for further research and for curriculum development and teaching are considered. © 2011 Wiley Periodicals, Inc. Sci Ed 95:1000–1025, 2011
Wrapping Graphene Sheets Around Organic Wires for Making Memory Devices
Authors: Wang Shuai , Manga Kiran Kumar , Zhao Meng , Bao Qiaoliang , Loh Kian Ping
Published: June 2011

Hybrids of organic semiconductors and graphene can generate a whole new class of materials with enhanced properties. A simple solution‐phase route to synthesize a hybrid material made of organic nanowires and graphene oxide (GO) sheets is demonstrated by sonicating tetracene molecules and GO together in diluted fuming nitric acid. The self‐assembled tetracene‐derived organic wires become encapsulated by GO sheets during the reaction to produce an interconnected, one‐dimensional/two‐dimensional lamellar film. Memory devices fabricated using the hybrid film as the sandwiched layer between aluminum electrodes exhibit excellent electrical bistability. The charge retention properties are attributed to charge transfer and a charge‐trapping/detrapping mechanism operational at the interfaces and isolated matrices of the GO–tetracene hybrid.
Quantifying the Nanomachinery of the Nanoparticle–Biomolecule Interface
Authors: de Puig Helena , Federici Stefania , Baxamusa Salmaan H. , Bergese Paolo , Hamad‐Schifferli Kimberly
Published: June 2011

A study is presented of the nanomechanical phenomena experienced by nanoparticle‐conjugated biomolecules. A thermodynamic framework is developed to describe the binding of thrombin‐binding aptamer (TBA) to thrombin when the TBA is conjugated to nanorods. Binding results in nanorod aggregation (viz. directed self‐assembly), which is detectable by absorption spectroscopy. The analysis introduces the energy of aggregation, separating it into TBA–thrombin recognition and surface‐work contributions. Consequently, it is demonstrated that self‐assembly is driven by the interplay of surface work and thrombin‐TBA recognition. It is shown that the work at the surface is about −10 kJ mol−1 and results from the accumulation of in‐plane molecular forces of pN magnitude and with a lifetime of <1 s, which arises from TBA nanoscale rearrangements fuelled by thrombin‐directed nanorod aggregation. The obtained surface work can map aggregation regimes as a function of different nanoparticle surface conditions. Also, the thermodynamic treatment can be used to obtain quantitative information on surface effects impacting biomolecules on nanoparticle surfaces.
Considerations in Using the Discrete Phase Model (DPM)
Authors: Chattopadhyay Kinnor , Isac Mihaiela , Guthrie Roderick I. L
Published: June 2011

Many metallurgical processes involve multiphase flows and liquid metal processing is not an exception. During the secondary refining, and casting of steel, there are many interactions between the liquid phase, and the dispersed phases (spherical gas bubbles, inclusions, liquid slag droplets etc.). To mathematically model these operations, the Discrete Phase Method (DPM) is now being used by significant number of researchers. However, in certain publications, the equations presented are ambiguous but have nonetheless been referenced by many researchers. The present technical note highlights a mistake in the interpretation of the discrete phase equation in a technical paper by Hulstrung et al. 1 and also points out the mis‐leading equation in the ANSYS‐FLUENT 12.0 theory guide 2.
Manufacturing of Austenitic Stainless Steel‐Zirconia Composites by Infiltration
Authors: Weider M. , Eigenfeld K.
Published: June 2011

Within the framework of the CRC 799 “TRIP‐Matrix‐Composites” at the TU Bergakademie Freiberg new composite materials consisting of TRIP steel and zirconium dioxide ceramics are designed in a powder route and a casting route. To manufacture faultless samples basic investigations of the feeding and infiltration behaviour within macro porous ceramics such as filters were needed. The effects of bottom pouring and top pouring were investigated as well as the effects of different preheating temperatures, contents of phosphorous in the steel and flow trough rates. Bottom pouring corrupts the feeding mainly of filters with high ppi (pores per inch). Top pouring improves the feeding, but generates inhomogeneous infiltration qualities, which can affected and enhanced by a increasing preheating temperature, an addition of phosphorous or a defined melt flow trough the filters.
Ceramic Processing for TRIP‐Steel/Mg‐PSZ Composite Materials for Mechanical Applications
Authors: Weigelt C. , Aneziris C. G. , Yanina A. , Guk S.
Published: June 2011

Composite materials are up‐to‐date products in a growing range of applications and markets. Due to the advantageous combination of two or more materials new generations of materials can be generated. Closely linked to expanding variations of material combinations are increasing numbers of manufacturing techniques. The combination of ductile metals with hard and brittle ceramics offers a range of applications in the field of crash‐absorber and structural products with high mechanical load. This paper deals with the challenges of powder metallurgical processing of TRIP‐steel/Mg‐PSZ composite materials. The presented results are a contribution to improvements in plastic processing especially for lightweight honeycomb structures.
Re‐conceptualization of scientific literacy in South Korea for the 21st century
Authors: Choi Kyunghee , Lee Hyunju , Shin Namsoo , Kim Sung‐Won , Krajcik Joseph
Published: June 2011

As the context of human life expands from personal to global, a new vision of scientific literacy is needed. Based on a synthesis of the literature and the findings of an online survey of South Korean and US secondary science teachers, we developed a framework for scientific literacy for South Korea that includes five dimensions: content knowledge, habits of mind, character and values, science as a human endeavor, and metacognition, and self‐direction. The framework was validated by international science educators. Although the names of these dimensions sound familiar, the framework puts a new perspective on scientific literacy by expanding and refining each dimension, stressing integrated understanding of big idea and the importance of character and values, adding metacognition, and emphasizing global citizenship. Twenty‐first century citizens need integrated understanding of the big ideas of science and habits of mind such as systematic thinking and communications. They also need to realize that science is a human endeavor that changes, as new evidence is uncovered. However, these aspects of scientific literacy provide only a partial picture. Scientific literacy should also emphasize character and values that can lead learners to make appropriate choices and decisions to ensure a sustainable planet and provide all people with basic human rights. Individuals will also need to develop metacognitive skills in order interpret new complex scientific information and know when they need additional information. Although this framework was developed primarily for South Korea, a new vision of scientific literacy that is applicable for K‐12 has the potential to spur the development of new standards, curriculum materials, instructional practices, professional development and assessments, and dialog across nations. © 2011 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 670–697, 2011
Understanding and facilitating self‐regulated help seeking
Authors: Karabenick Stuart A. , Dembo Myron H.
Published: June 2011

Many students are reluctant to seek needed help. In this chapter, we review research on help seeking as a self‐regulated learning strategy and describe a set of interventions designed to promote effective use of help seeking.
The role of Web 2.0 technologies in self‐regulated learning
Authors: Kitsantas Anastasia , Dabbagh Nada
Published: June 2011

This chapter describes how Web 2.0 technologies, especially social software, can be used to support student self‐regulated learning in higher education contexts. Selected examples that demonstrate how instructors can integrate social software into course design to facilitate student self‐regulation are provided.
Self‐regulation of learning with computer‐based learning environments
Authors: Greene Jeffrey A. , Moos Daniel C. , Azevedo Roger
Published: June 2011

This chapter explores the role of self‐regulation in learning with computer‐based learning environments, and how it can be assessed and fostered.
New directions for self‐regulation of learning in postsecondary education
Authors: Bembenutty Héfer
Published: June 2011

This chapter highlights the major contributions of this volume on self‐regulation of learning and provides new directions for cutting‐edge theoretical and empirical work that could serve to facilitate self‐regulation of learning in postsecondary education.
Awareness and Preferences Regarding BRCA1/2 Genetic Counseling and Testing Among Latinas and Non‐Latina White Women at Increased Risk for Hereditary Breast and Ovarian Cancer
Authors: Gammon Amanda Dawn , Rothwell Erin , Simmons Rebecca , Lowery Jan T. , Ballinger Lori , Hill Deirdre A. , Boucher Kenneth M. , Kinney Anita Yeomans
Published: June 2011

This study was an investigation of awareness, cognitions, and psychosocial and educational needs related to genetic counseling and testing among Latinas and non‐Latina whites at increased risk for having a BRCA1/2 mutation. Sixty‐three Latina and eighty‐four non‐Latina white women completed telephone surveys employing a mixture of quantitative and qualitative questions assessing awareness, benefits, risks, barriers, and genetic counseling communication preferences regarding BRCA1/2 testing. Among participants who had not previously had genetic counseling/testing, 56.9% of Latinas (29/51) and 34.8% of non‐Latina white participants (24/69) were unaware of the availability of BRCA1/2 testing. In multivariate logistic regression analysis, Latina ethnicity was the only statistically significant independent factor associated with lack of awareness (OR = 0.42; 95% CI = 0.19–0.35). No appreciable differences were noted between ethnic groups regarding perceived benefits of BRCA1/2 testing or desired genetic counseling topics. These findings underscore the importance of increasing awareness of cancer genetic counseling and genetic testing among both Latina and non‐Latina white populations.
How High is Hispanic/Mexican Fertility in the United States? Immigration and Tempo Considerations
Authors: Parrado Emilio A.
Published: June 2011

In this article, I demonstrate that the apparently much higher fertility of Hispanic/Mexican women in the United States is almost exclusively the product of period estimates obtained for immigrant women and that period measures of immigrant fertility suffer from three serious sources of bias that together significantly overstate fertility levels: difficulties in estimating the size of immigrant groups; the tendency for migration to occur at a particular stage in life; and, most importantly, the tendency for women to have a birth soon after migration. When these sources of bias are taken into consideration, the fertility of native Hispanic/Mexican women is very close to replacement level. In addition, the completed fertility of immigrant women in the United States is dramatically lower than the level obtained from period calculations. Findings are consistent with classical theories of immigrant assimilation but are a striking departure from the patterns found in previous studies and published statistics. The main implication is that without a significant change in immigration levels, current projections based on the premise of high Hispanic fertility are likely to considerably exaggerate Hispanic population growth, its impact on the ethno-racial profile of the country, and its potential to counteract population aging.
Divorced Fathers’ Proximity and Children’s Long-Run Outcomes: Evidence From Norwegian Registry Data
Authors: Kalil Ariel , Mogstad Magne , Rege Mari , Votruba Mark
Published: June 2011

This study examines the link between divorced nonresident fathers’ proximity and children’s long-run outcomes, using high-quality data from Norwegian population registers. We follow (from birth to young adulthood) each of 15,992 children born into married households in Norway in the years 1975–1979 whose parents divorced during his or her childhood. We observe the proximity of the child to his or her father in each year following the divorce and link proximity to educational and economic outcomes for the child in young adulthood, controlling for a wide range of observable characteristics of the parents and the child. Our results show that closer proximity to the father following a divorce has, on average, a modest negative association with offspring’s outcomes in young adulthood. The negative associations are stronger among children of highly educated fathers. Complementary Norwegian survey data show that highly educated fathers report more post-divorce conflict with their ex-wives as well as more contact with their children (measured in terms of the number of nights that the child spends at the father’s house). Consequently, the father’s relocation to a more distant location following the divorce may shelter the child from disruptions in the structure of the child’s life as they split time between households and/or from post-divorce interparental conflict.
On the K-theory of boundaryC*-algebras of Ã2groups
Authors: King Oliver , Robertson Guyan
Published: June 2011

Let Γ be an Ã2subgroup of PGL3(), whereis a local field with residue field of orderq. The module of coinvariantsC(,ℤ)Γis shown to be finite, whereis the projective plane over. If the group Γ is of Tits type and ifq≢ 1 (mod 3) then the exact value of the order of the class [1]K0in the K-theory of the (full) crossed productC*-algebraC(Ω) ⋊ Γ is determined, where Ω is the Furstenberg boundary of PGL3(). For groups of Tits type, this verifies a conjecture of G. Robertson and T. Steger.
Quasi-static magnetohydrodynamic turbulence at high Reynolds number
Authors: FAVIER B. , GODEFERD F. S. , CAMBON C. , DELACHE A. , BOS W. J. T.
Published: June 2011

We analyse the anisotropy of homogeneous turbulence in an electrically conducting fluid submitted to a uniform magnetic field, for low magnetic Reynolds number, in the quasi-static approximation. We interpret contradictory earlier predictions between linearized theory and simulations: in the linear limit, the kinetic energy of transverse velocity components, normal to the magnetic field, decays faster than the kinetic energy of the axial component, along the magnetic field (Moffatt, J. Fluid Mech., vol. 28, 1967, p. 571); whereas many numerical studies predict a final state characterized by dominant energy of transverse velocity components. We investigate the corresponding nonlinear phenomenon using direct numerical simulation (DNS) of freely decaying turbulence, and a two-point statistical spectral closure based on the eddy-damped quasi-normal Markovian (EDQNM) model. The transition from the three-dimensional turbulent flow to a ‘two-and-a-half-dimensional’ flow (Montgomery & Turner, Phys. Fluids, vol. 25, 1982, p. 345) is a result of the combined effects of short-time linear Joule dissipation and longer time nonlinear creation of polarization anisotropy. It is this combination of linear and nonlinear effects which explains the disagreement between predictions from linearized theory and results from numerical simulations. The transition is characterized by the elongation of turbulent structures along the applied magnetic field, and by the strong anisotropy of directional two-point correlation spectra, in agreement with experimental evidence. Inertial equatorial transfers in both DNS and the model are presented to describe in detail the most important equilibrium dynamics. Spectral scalings are maintained in high-Reynolds-number turbulence attainable only with the EDQNM model, which also provides simplified modelling of the asymptotic state of quasi-static magnetohydrodynamic (MHD) turbulence.
Effect of fast dietary proteins on muscle protein synthesis rate and muscle strength in ad libitum-fed and energy-restricted old rats
Authors: Walrand Stéphane , Zangarelli Aude , Guillet Christelle , Salles Jérôme , Soulier Karine , Giraudet Christophe , Patrac Véronique , Boirie Yves
Published: June 2011

Sarcopenia is defined as age-related loss of muscle mass and strength. Energy restriction (ER) delays fibre loss by limiting the accumulated deleterious effects of reactive oxygen species on muscle. However, insufficient protein intake during ER might affect muscle mass and function. We hypothesised that ingestion of fast-digested proteins such as whey protein (WP) improves muscle protein synthesis and muscle strength in aged ER rats. The effect of WP or casein (CAS, slow protein) on muscle mass, protein synthesis and strength was evaluated in 21-month-old rats fed for 5 months either ad libitum (AL) or a 40 % protein and energy-restricted (PER) or 40 % AL-isonitrogenous ER diet. The nitrogen balance was reduced in PER-CAS rats only ( − 48 % v. AL-CAS). WP stimulated muscle protein synthesis rates compared with CAS in all groups (+21,+37 and +34 % in AL, PER and ER conditions, respectively). Muscle strength was higher in ER rats than in AL rats (+23 and +12 % for WP or CAS, respectively). Muscle performance tended to be greater in ER rats fed WP than in ER-CAS rats (P < 0·09). In conclusion, we observed that long-term ER combined with maintained protein intake had a beneficial impact on muscle protein synthesis rate and function during ageing.
Effect of reduced heifer nutrition duringin uteroand post-weaning development on glucose and acetate kinetics
Authors: Waterman Richard C. , Roberts Andrew J. , Geary Thomas W. , Grings Elaine E. , Alexander Leeson J. , MacNeil Michael D.
Published: June 2011

Energetic efficiency was evaluated in composite bred heifers born from dams receiving 1·8 or 1·2 kg/d winter supplementation for approximately 80 d before parturition. Heifers were then developed post-weaning and randomly assigned to heifer development treatments of either control (100 %;ad libitum;n8/year) or restricted (80 %; fed 80 % of supplementation fed to controls adjusted to a common body weight:n8/year) in a 2-year study. A glucose tolerance test (GTT) and acetate irreversible loss test (AILT) were administered to heifers at the termination of a 140 d development period when the heifers were approximately 403 d of age and consumed a silage-based diet, and again at 940 d of age when pregnant with their second calf and grazing dormant forage. No differences were measured (P>0·08) for dam winter nutrition or heifer development treatment for baseline serum metabolites or measures in either the GTT or the AILT. However, changes in baseline serum concentrations (P>0·05) were different between metabolic challenges, which occurred at different stages of development. No difference in acetate disappearance (P = 0·18) and half-life (P = 0·66) was measured between the two metabolic challenges. A trend for glucose half-life to be shorter in heifers born from dams receivingin uterowinter treatments that supplied 1·2 kg/d of winter supplementation was observed (P = 0·083). Heifers developed with lower total DM intake during a 140 d development period had similar glucose and acetate incorporation rates asad libitum-fed heifers when evaluated at two different production stages.
Grassland use in mountain bovine systems according to a hierarchy of geographical determinants
Authors: GARCIA-LAUNAY F. , SIBRA C. , MOLÉNAT H. , AGABRIEL C. , BRUNSCHWIG G.
Published: June 2011

Knowledge of the spatio-temporal management of forage production and grazing in grass-based livestock systems is needed to simulate their functioning and then to propose new cutting and grazing practices that will achieve both environmental and economic benefits. The objectives of the present work were to characterize the types of grassland use in mountain bovine systems and relate them to field geographical characteristics to produce a conceptual model of grassland use. This model can be incorporated into a whole beef and/or dairy farm simulator of the impact of practice changes on environmental and productive performances. For this purpose, a survey of 72 farms was conducted in the traditional Salers system in the Massif Central (France). Information was gathered on geographical characteristics and cutting and/or grazing practices on three general groups of fields: cut only, cut and grazed, and grazed only fields. Principal component and hierarchical cluster analyses constructed 15 field use classes that account for the complexity of forage production and grazing management. Geographical determinants of grassland use follow a certain hierarchy: slope and carrying capacity influence the occurrence of cutting, and field area determines the possibility of allocating a cut field to grazing animals and of allocating a field to milked cows. The distance to the cowshed is involved in the allocation to milked or suckler cows and also influences the order of the cutting and grazing sequence. For the same combination of geographical characteristics, two types of grassland use may be observed, highlighting the flexibility of mountain systems. A conceptual model of grassland use is proposed as the basis for field use allocation in a whole farm model. Further investigation will consider the influence of field pattern characteristics on these relationships.
Variation of digestibility and intake by sheep of lucerne (Medicago sativa L.) hays cut at sunrise or sunset
Authors: ANDUEZA D. , DELGADO I. , MUÑOZ F.
Published: June 2011

An experiment was carried out in 2006 in the Ebro Valley of Spain to test the differences in chemical composition, ruminal degradation, in vivo digestibility and intake between lucerne hays cut at sunrise (AM) or at sunset (PM). Measurements were carried out at 0·50 flowering during spring, summer and autumn growth cycles. PM hays showed higher contents of soluble carbohydrates, starch and total non-structural carbohydrates than AM hays. No significant differences between times of cutting were found for crude protein, neutral detergent fibre, acid detergent fibre or acid detergent lignin. Effective degradability of dry matter (DM) was higher in autumn PM hay (0·57±0·008) than AM hay (0·47±0·008). No differences between times of cutting were found for hays cut in spring or summer. Effective degradability of nitrogen was significantly higher in summer and autumn PM hays than in AM hays. However, degradability did not differ significantly between times of cutting for the hays cut in spring. Differences in organic matter digestibility averaged 0·02±0·008 in spring and 0·05±0·008 in autumn, but no differences were found between cutting times for lucerne hays in summer. For DM intake, differences between PM and AM hays were significant in spring (57±2·0 v. 46±2·0 g/kg BW0·75, respectively) and summer (60±2·0 v. 52±2·0 g/kg BW0·75, respectively), but not significant in autumn (55±2·0 v. 51±2·0 g/kg BW0·75, respectively). Finally, digestible organic matter intake in sheep was higher for PM (34±1·3, 36±1·3 and 32±1·3 g/kg BW0·75) than for AM hays (27±1·3, 30±1·3 and 27±1·3 g/kg BW0·75) in spring, summer and autumn, respectively. In conclusion, cutting lucerne at sunset could be a simple management strategy for improving the feed value of hays.