bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convergence radii of the polarization expansion of intermolecular potentials
Authors: Adams William H. 
Published: August 2009

AbstractA new method is presented to evaluate convergence radii of the polarization expansion of interaction energies for pairs of atoms or molecules. The method is based on an analysis of the variation of the perturbed state vector as a function of the coupling constant λ and does not require a calculation of perturbation corrections to high order. The convergence radii at infinite interatomic/intermolecular distances R, as well as a remarkably accurate representation of the R dependence of the convergence radii are obtained from simple calculations involving only monomer wave functions. For the interaction of the lithium and hydrogen atoms, the obtained convergence radii agree well with those obtained previously from the large‐order calculations of Patkowski et al. (Patkowski et al., J Chem Phys, 2002, 117, 5124), but are expected to be considerably more accurate. Rigorous upper bounds and reasonable approximations to the convergence radii at R = ∞ are obtained for the pairs of lithium, beryllium, boron, neon, and sodium atoms, as well as for the dimer consisting of two LiH molecules. For all the systems studied, the convergence radii are significantly smaller than the unity and rapidly decrease with the increase of the nuclear charge. It is hoped that the results of this investigation will help to analyze and eventually to compute the convergence radii of the symmetry‐adapted perturbation theories which utilize the same partitioning of the Hamiltonian as the polarization expansion. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Mass spectrometry of intact neutral macromolecules using intense non‐resonant femtosecond laser vaporization with electrospray post‐ionization
Authors: Brady John J. , Judge Elizabeth J. , Levis Robert J. 
Published: August 2009

AbstractIntact, nonvolatile, biological macromolecules can be transferred directly from the solid state into the gas phase, in ambient air, for subsequent mass spectral analysis using non‐resonant femtosecond (fs) laser desorption combined with electrospray ionization (ESI). Mass spectral measurements for neat samples, including a dipeptide, protoporphyrin IX and vitamin B12 adsorbed on a glass insulating surface, were obtained using an 800 nm, 70 fs laser with an intensity of 1013 W cm−2. No appreciable signal was detected when atmospheric matrix‐assisted or neat (matrix‐free) fs laser desorption was performed without ESI, indicating neutral desorption. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of nivalenol and deoxynivalenol by liquid chromatography/atmospheric pressure photoionization mass spectrometry
Authors: Tanaka Hiroki , Takino Masahiko , Sugita‐Konishi Yoshiko , Tanaka Toshitsugu , Toriba Akira , Hayakawa Kazuichi 
Published: August 2009

AbstractFusarium species, a plant pathogenic fungus of wheat and other cereals, produces toxic metabolites such as nivalenol (NIV) and deoxynivalenol (DON). Control of contamination by these toxins is very difficult, and a continuous survey of the occurrence is necessary for these toxins. Thus, the accurate and convenient determination of the cereals contaminated with these toxins is important for the supply of safe foods. A selective analytical method based on high‐performance liquid chromatography, combined with atmospheric pressure photoionization (APPI) mass spectrometry, has been developed for simultaneous determination of NIV and DON. The parameters investigated for the optimization of APPI were the ion source parameters fragmentor voltage, capillary voltage, and vaporizer temperature, and also mobile phase composition and flow rate. Furthermore, chemical noise and signal suppression of analyte signals due to sample matrix interference were investigated for APPI. The results indicated that APPI provides lower matrix effect and the correlation coefficient of NIV and DON in the range 0.2–100 ng · mL−1 was above 0.999. Recoveries of NIV and DON in wheat ranged from 86 to 107% and limits of detection of NIV and DON were 0.20 ng · g−1 and 0.39 ng · g−1, respectively. In addition, the proposed method was applied for the analysis of naturally contaminated wheat samples. APPI was found to offer lower matrix effect and was a convenient technique for routine analysis of NIV and DON residues in wheat at trace levels. Copyright © 2009 John Wiley & Sons, Ltd.
Addressing agent loss in vehicle formations and sensor networks
Authors: Summers Tyler H. , Yu Changbin , Anderson Brian D. O. 
Published: August 2009

AbstractIn this paper, we address the problem of agent loss in vehicle formations and sensor networks via two separate approaches: (1) perform a ‘self‐repair’ operation in the event of agent loss to recover desirable information architecture properties or (2) introduce robustness into the information architecturea priorisuch that agent loss does not destroy desirable properties. We model the information architecture as a graphG(V, E), whereVis a set of vertices representing the agents andEis a set of edges representing information flow amongst the agents. We focus on two properties of the graph called rigidity and global rigidity, which are required for formation shape maintenance and sensor network self‐localization, respectively. For the self‐repair approach, we show that while previous results permit local repair involving only neighbours of the lost agent, the repair cannot always be implemented using only local information. We present new results that can be applied to make the local repair using only local information. We describe implementation and illustrate with algorithms and examples. For the robustness approach, we investigate the structure of graphs with the property that rigidity or global rigidity is preserved after removing any single vertex (we call the property as2‐vertex‐rigidityor2‐vertex‐global‐rigidity, respectively). Information architectures with such properties would allow formation shape maintenance or self‐localization to be performed even in the event of agent failure. We review a characterization of a class of2‐vertex‐rigidityand develop a separate class, making significant strides towards a complete characterization. We also present a characterization of a class of2‐vertex‐global‐rigidity. Copyright © 2008 John Wiley & Sons, Ltd.
The development of capabilities in new firms
Authors: Arikan Asli M. , McGahan Anita M. 
Published: August 2009

AbstractThis research explores evidence of corporate capabilities for conducting acquisition and alliance deals in young firms. We hypothesize that investors conjecture about the future based on information about a firm's capabilities. Each successive deal carries intrinsic value, creates experience, generates feedback, and yields information about the firm's underlying capabilities. We evaluate whether stock prices impute expectations that firms will capably pursue particular programs of acquisitions and alliances. The analysis covers how investor responses change across successive deals on the theory that firms with a concentrated program of deals may develop capabilities more intensively than those with programs that involve both acquisitions and alliances. The dataset covers the population of firms that went through an initial public offering (IPO) in the United States between 1988 and 1999. It contains information on all of their post‐IPO acquisitions and alliances, and on how their stock prices changed in response to the announcement of each deal. The results suggest that within the first year after IPO, investors expect firms to execute particular streams of alliances and acquisitions that reflect their unique histories of demonstrated capabilities. We also find evidence that investors cannot fully anticipate deal programs. The findings support a capabilities‐based view of the firm and also show that accurate inference using event‐study methods may require digging deep into the early histories of firms. Copyright © 2009 John Wiley & Sons, Ltd.
Alignment of Semiconductor Nanowires Using Ion Beams
Authors: Borschel Christian , Niepelt Raphael , Geburt Sebastian , Gutsche Christoph , Regolin Ingo , Prost Werner , Tegude Franz‐Josef , Stichtenoth Daniel , Schwen Daniel , Ronning Carsten 
Published: August 2009

AbstractGallium arsenide nanowires are grown on 〈100〉 GaAs substrates, adopting the epitaxial relation and thus growing with an angle around 35° off the substrate surface. These straight nanowires are irradiated with different kinds of energetic ions. Depending on the ion species and energy, downwards or upwards bending of the nanowires is observed to increase with ion fluence. In the case of upwards bending, the nanowires can be aligned towards the ion beam direction at high fluences. Defect formation (vacancies and interstitials) within the implantation cascade is identified as the key mechanism for bending. Monte Carlo simulations of the implantation are presented to substantiate the results.
Bioluminescent Imaging Demonstrates That Transplanted Human Embryonic Stem Cell-Derived CD34+ Cells Preferentially Develop into Endothelial Cells
Authors: Tian Xinghui , Hexum Melinda K. , Penchev Vesselin R. , Taylor Russell J. , Shultz Leonard D. , Kaufman Dan S. 
Published: August 2009

Abstract
Human embryonic stem cells (hESCs) provide an important resource for novel regenerative medicine therapies and have been used to derive diverse cell populations, including hematopoietic and endothelial cells. However, it remains a challenge to achieve significant engraftment of hESC-derived blood cells when transplanted into animal models. To better understand mechanisms that enhance or limit the in vivo developmental potential of hESC-derived cells, we utilized hESCs that express firefly luciferase (luc) to allow noninvasive, real-time bioluminescent imaging of hESC-derived CD34+ cells transplanted into the liver of neonatal immunodeficient mice. Serial imaging demonstrated stable engraftment and expansion of the luc+ hESC-derived cells in vivo over several months. While we found that these hESC-derived CD34+ cells have bipotential ability to generate both hematopoietic and endothelial lineages in vitro, these studies demonstrate preferential differentiation into endothelial cells in vivo, with only low levels of hematopoietic cell engraftment. Therefore, these studies reveal key differences in the developmental potential of hESC-derived cells using in vitro and in vivo analyses. Although transplanted hESC-derived CD34+ cells are well-suited for revascularization therapies, additional measures are needed to provide higher levels of long-term hematopoietic engraftment.
Disclosure of potential conflicts of interest is found at the end of this article.
Intramuscular Transplantation of G-CSF-Mobilized CD34+ Cells in Patients With Critical Limb Ischemia: A Phase I/IIa, Multicenter, Single-Blinded, Dose-Escalation Clinical Trial
Authors: Kawamoto Atsuhiko , Katayama Minako , Handa Nobuhiro , Kinoshita Makoto , Takano Haruna , Horii Miki , Sadamoto Kazuyo , Yokoyama Ayumi , Yamanaka Takeharu , Onodera Rie , Kuroda Akiko , Baba Rie , Kaneko Yuichiro , Tsukie Tomio , Kurimoto Yasuo , Okada Yukikatsu , Kihara Yasuki , Morioka Shigefumi , Fukushima Masanori , Asahara Takayuki 
Published: August 2009

Abstract
A number of preclinical studies have indicated the therapeutic potential of endothelial progenitor cells for vascular regeneration in ischemic diseases. A phase I/IIa clinical trial of transplantation of autologous CD34+ cells, the endothelial and hematopoietic progenitor-enriched fraction, was performed in no-option patients with atherosclerotic peripheral artery disease or Buerger's disease with critical limb ischemia (CLI). CD34+ cells were isolated from the G-CSF-mobilized apheresis product using a magnetic cell sorting system. CD34+ cells (105/kg, n = 6; 5 × 105/kg, n = 8; or 106/kg, n = 3) were injected i.m. into the leg with more severe ischemia. The Efficacy Score, representing changes in the toe brachial pressure index (TBPI), Wong-Baker FACES pain rating scale, and total walking distance 12 weeks after cell transplantation, the primary endpoint, was positive, indicating improvement in limb ischemia in all patients, although no significant dose-response relationship was observed. During the 12-week observation after cell therapy, the Wong-Baker FACES pain rating scale, TBPI, transcutaneous partial oxygen pressure, total or pain-free walking distance, and ulcer size serially improved in all patients. No death or major amputation occurred, and severe adverse events were rare, although mild to moderate events relating to G-CSF and leukapheresis were frequent during the 12-week follow-up. In conclusion, the outcomes of this prospective clinical study indicate the safety and feasibility of CD34+ cell therapy in patients with CLI. Favorable trends in efficacy parameters encourage a randomized and controlled trial in the future.
Disclosure of potential conflicts of interest is found at the end of this article.
Small-Molecule Induction of Neural Crest-like Cells Derived from Human Neural Progenitors
Authors: Hotta Ryo , Pepdjonovic Lana , Anderson Richard B. , Zhang Dongcheng , Bergner Annette J. , Leung Jessie , Pébay Alice , Young Heather M. , Newgreen Donald F. , Dottori Mirella 
Published: August 2009

AbstractNeural crest (NC) cells are stem cells that are specified within the embryonic neuroectodermal epithelium and migrate to stereotyped peripheral sites for differentiation into many cell types. Several neurocristopathies involve a deficit of NC-derived cells, raising the possibility of stem cell therapy. In Hirschsprung's disease the distal bowel lacks an enteric nervous system caused by a failure of colonization by NC-derived cells. We have developed a robust method of producing migrating NC-like cells from human embryonic stem cell–derived neural progenitors using a coculture system of mouse embryonic fibroblasts. Significantly, subsequent exposure to Y27632, a small-molecule inhibitor of the Rho effectors ROCKI/II, dramatically increased the efficiency of differentiation into NC-like cells, identified by marker expression in vitro. NC-like cells derived by this method were able to migrate along NC pathways in avian embryos in ovo and within explants of murine bowel, and to differentiate into cells with neuronal and glial markers. This is the first study to report the use of a small molecule to induce cells with NC characteristics from embryonic stem cells that can migrate and generate neurons and support cells in complex tissue. Furthermore, this study demonstrates that small-molecule regulators of ROCKI/II signaling may be valuable tools for stem cell research aimed at treatment of neurocristopathies.Disclosure of potential conflicts of interest is found at the end of this article.
System development planning using readiness levels in a cost of development minimization model
Authors: Magnaye Romulo B. , Sauser Brian J. , Ramirez‐Marquez Jose E. 
Published: August 2009

AbstractThe purpose of this paper is to describe a methodology that enables systems engineers or program managers to formulate a system‐wide optimal development plan in order to facilitate monitoring and evaluation of the development process in terms of the actual readiness of the system. It proposes the use of the System Readiness Level (SRL) scale to measure the maturity of a system composed of technological elements, which are being developed based on cost‐driven strategies (as opposed to time‐to‐market‐driven strategies). A constrained optimization model is used to identify which critical technology elements and integration links can be matured to which levels at a particular time such that the development costs are minimized while a targeted SRL value is attained on schedule. While the algorithm does not necessarily reduce the total cost of development, it is able to find the minimal amount of expenditures which will achieve the desired maturity level during the earlier part of the development process. Essentially, it shifts the rest of the expenditures towards the latter part of the development during which model‐based integration and testing procedures which have been suggested by others can be applied to reduce costs and time further. This can be a useful option to have when there is substantial uncertainty with the system due to its high novelty and technological content. As a value added approach, the model gives the systems engineer the information needed to understand what a delay may mean to development, so a more informed decision can be made. The paper concludes by discussing the possible use of the optimal development plan to monitor and control the progress of systems under development. © 2009 Wiley Periodicals, Inc. Syst Eng
PISA 2006: An assessment of scientific literacy
Authors: Bybee Rodger , McCrae Barry , Laurie Robert 
Published: August 2009

AbstractThis article introduces the essential features of the science component of 2006 Program for International Student Assessment (PISA). Administered every 3 years, PISA alternates emphasis on Reading, Mathematics, and Science Literacy. In 2006, PISA emphasized science. This article discusses PISA's definition of scientific literacy, the three competencies that constitute scientific literacy, the contexts used for assessment units and items, the role of scientific knowledge, and the importance placed on attitude toward science. PISA 2006 included a student test, a student questionnaire, and a questionnaire for school administrators. The student test employed a balanced incomplete block design involving thirteen 30‐minute clusters of items, including nine science clusters. The 13 clusters were arranged into thirteen 2‐hour booklets and each sampled student was assigned one booklet at random. Mean literacy scores are presented for all participating countries, and the percentages of OECD students at the six levels of proficiency are given for the combined scale and for the competency scales. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 865–883, 2009
Quantitative descriptions of resource choice in ecological models
Authors: Abrams Peter A. 
Published: August 2009

AbstractThis article reviews the subject of resource choice by consumers. It is concerned with how such choice has been and should be represented in quantitative ecological models. This requires consideration of the dynamics of behavioral change and the fitness consequences of different resource intake rates. The topic is important because of the impact of choice on the functional response of the consumer to each of the resources it consumes. A variety of open questions related to choice are addressed. These include: the relationship between optimal diet choice and switching; the relationship between adaptive choice of two or resources and type‐3 functional responses to a single resource; whether switching behavior requires choice and whether choice always results in switching behavior; why partial preferences are observed; whether choice between habitats is fundamentally different from choice within habitats; how between‐individual variation in parameters related to resource use alters functional responses measured at the population level. The impacts of choice on stability are discussed briefly. The costs of increased resource use and the type of nutritional interactions between resources are particularly important determinants of adaptive resource choice, and are considered in some detail.
Choline transporter gene variation is associated with attention-deficit hyperactivity disorder
Authors: English Brett A. , Hahn Maureen K. , Gizer Ian R. , Mazei-Robison Michelle , Steele Angela , Kurnik Daniel M. , Stein Mark A. , Waldman Irwin D. , Blakely Randy D. 
Published: August 2009

Abstract
The neurotransmitter acetylcholine (ACh) plays a critical role in brain circuits mediating motor control, attention, learning and memory. Cholinergic dysfunction is associated with multiple brain disorders including Alzheimer’s Disease, addiction, schizophrenia and Attention-Deficit Hyperactivity Disorder (ADHD). The presynaptic choline transporter (CHT, SLC5A7) is the major, rate-limiting determinant of ACh production in the brain and periphery and is consequently upregulated during tasks that require sustained attention. Given the contribution of central cholinergic circuits to the control of movement and attention, we hypothesized that functional CHT gene variants might impact risk for ADHD. We performed a case-control study, followed by family-based association tests on a separate cohort, of two purportedly functional CHT polymorphisms (coding variant Ile89Val (rs1013940) and a genomic SNP 3’ of the CHT gene (rs333229), affording both a replication sample and opportunities to reduce potential population stratification biases. Initial genotyping of pediatric ADHD subjects for two purportedly functional CHT alleles revealed a 2–3 fold elevation of the Val89 allele (n = 100; P = 0.02) relative to healthy controls, as well as a significant decrease of the 3’SNP minor allele in Caucasian male subjects (n = 60; P = 0.004). In family based association tests, we found significant overtransmission of the Val89 variant to children with a Combined subtype diagnosis (OR = 3.16; P = 0.01), with an increased Odds Ratio for a haplotype comprising both minor alleles. These studies show evidence of cholinergic deficits in ADHD, particularly for subjects with the Combined subtype, and, if replicated, may encourage further consideration of cholinergic agonist therapy in the disorder.
Measuring musculoskeletal pain by questionnaires: The manikin versus written questions
Authors: van den Hoven Linda H.J. , Gorter Kees J. , Picavet H. Susan J. 
Published: August 2009

AbstractA picture of a human figure (manikin) on which pain can be indicated can be used to measure musculoskeletal pain in self administered or web‐based questionnaires. In this paper we present an analysis of the agreement between pain reported on a manikin and pain reported using written questions as assessed in the follow‐up questionnaire of the Dutch population‐based Musculoskeletal Conditions and Consequences Cohort (DMC3‐study). Both a manikin and extensive questions on pain were included and the agreement between the two measures was studied for nine pain locations. For a similar pain definition – pain lasting at least a week – the manikin gave slightly higher prevalences than the written questions. Around three quarter of those who reported pain on the written questionnaire also indicated pain on the manikin on the same anatomical location. There were no differences in the percentage of agreement by sex, age group or level of education, except for a lower percentage of agreement of the manikin among the elderly for pain in the lower extremities, neck and shoulder and among the lower level of education group for neck pain. Almost 6% of the participants reported pain according to the questions only and more than 10% (especially men) reported pain on the manikin only. We concluded that a manikin gives similar findings on prevalence of pain as written questions and could therefore be a good alternative for written questions only.