bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topology optimization of compliant circular path mechanisms based on an aggregated linear system and singular value decomposition
Authors: Takezawa A. , Kitamura M. 
Published: July 2011

SUMMARYThis paper proposes a topology optimization method for the design of compliant circular path mechanisms, or compliant mechanisms having a set of output displacement vectors with a constant norm, which is induced by a given set of input forces. To perform the optimization, a simple linear system composed of an input force vector, an output displacement vector and a matrix connecting them is constructed in the context of a discretized linear elasticity problem using FEM. By adding two constraints: 1, the dimensions of the input and the output vectors are equal; 2, the Euclidean norms of all local input force vectors are constant; from the singular value decomposition of the matrix connecting the input force vector and the output displacement vector, the optimization problem, which specifies and equalizes the norms of all output vectors, is formulated. It is a minimization problem of the weighted summation of the condition number of the matrix and the least square error of the second singular value and the specified value. This methodology is implemented as a topology optimization problem using the solid isotropic material with penalization method, sensitivity analysis and method of moving asymptotes. The numerical examples illustrate mechanically reasonable compliant circular path mechanisms and other mechanisms having multiple outputs with a constant norm. Copyright © 2011 John Wiley & Sons, Ltd.
Raw Material Availability and Technological Choice: Modified Metapodia from an Early Bronze Age Site in Central Israel
Authors: Allentuck A. 
Published: July 2011

ABSTRACTThis paper explores the incongruous relationship between bone raw material availability and technological choice at the Early Bronze Age site of Horvat 'Illin Tahtit (HIT) in central Israel. At HIT, the worked bone assemblage is mostly comprised of minimally modified sheep and goat metapodia whose function(s) are enigmatic. Most specimens have longitudinally oriented scraping abrasions on at least one face, and of these, some have bilaterally symmetrical drilled perforations on the distal–posterior face. Furthermore, the distal epiphyseal plates of almost all worked metapodia are unfused, whereas unfused epiphyses are nearly absent from the general faunal assemblage. Worked goat metacarpals are significantly more common than sheep metacarpals or metatarsals of either species, despite the greater abundance of sheep over goat in the general faunal assemblage. This paper proposes that the desire to express specific visible attributes of the bone raw material was the key motivation in choosing unfused goat metacarpals over similar, more abundant choices. The analysis considers material properties such as bone mineral density and natural morphology and concludes that material properties between various choices were equivocal. This result suggests that social meanings attributed to specific animals and specific skeletal elements structured bone raw material procurement decisions. Copyright © 2011 John Wiley & Sons, Ltd.
High‐risk pregnancy and neonatal complications in the DNA repair and transcription disorder trichothiodystrophy: report of 27 affected pregnancies
Authors: Tamura Deborah , Merideth Melissa , DiGiovanna John J. , Zhou Xiaolong , Tucker Margaret A. , Goldstein Alisa M. , Brooks Brian P. , Khan Sikandar G. , Oh Kyu‐Seon , Ueda Takahiro , Boyle Jennifer , Moslehi Roxana , Kraemer Kenneth H. 
Published: July 2011

AbstractObjectiveTo identify the frequency of pregnancy and neonatal complications in pregnancies carrying fetuses affected with trichothiodystrophy (TTD).MethodsWe identified pregnancy and neonatal complications and serum screening results from mothers of TTD patients in a DNA repair diseases study from 2001 to 2011.ResultsPregnancy reports of 27 TTD patients and their 23 mothers were evaluated and 81% of the pregnancies had complications: 56% had preterm delivery, 30% had preeclampsia, 19% had placental abnormalities, 11% had HELLP syndrome, and 4% had an emergency c‐section for fetal distress, while 44% had two or more complications. Only 19% of the pregnancies delivered at term without complications. Eight of the ten pregnancies tested had abnormal multiple marker results including elevated levels of human chorionic gonadotrophin. Eighty‐five percent of the neonates had complications: 70% were low birth weight (<2500 g), 35% had birth weight < 10 centile for gestational age, 70% had NICU admission, 67% had a collodion membrane, and 31% of the 16 males had cryptorchidism. Cataracts were present in 54% of the TTD patients examined.ConclusionTTD is a multisystem disease that predisposes mothers of affected patients to substantial risks for pregnancy complications and TTD neonates have a high incidence of multiple abnormalities. Published 2011. This article is a U.S. Government work and is in the public domain in the USA
Ultrasonographic findings of placenta lacunae and a lack of a clear zone in cases with placenta previa and normal placenta
Authors: Hamada Shoko , Hasegawa Junichi , Nakamura Masamitsu , Matsuoka Ryu , Ichizuka Kiyotake , Sekizawa Akihiko , Okai Takashi 
Published: July 2011

AbstractObjectivesTo evaluate whether the frequencies of placenta lacunae and lack of a clear zone are higher in cases of placenta previa compared with those without it.MethodsUltrasonographic findings just before delivery, including placenta lacunae and lack of a clear zone were prospectively evaluated in consecutive subjects. After collection, a case‐control study with 1:5 matched pairs was conducted. The frequencies of ultrasonographic findings were analyzed in cases with placenta previa and normal placenta.ResultsSeventy cases with placenta previa and 350 cases with normal placentas were observed. Five and zero cases with abnormal placental adherence were observed in cases with placenta previa and normal placenta, respectively. Lack of a clear zone was observed in 60 and 1.5% of cases with and without the placental adherence (p = 0.001). Placenta lacunae and lack of a clear zone were observed in 31.4 and 9.7% of cases with and without placenta previa [odds ratio (OR) 4.2]. Lack of a clear zone was observed in 5.7 and 0.9% of cases with and without placenta previa (OR 7.0).ConclusionsPlacenta lacunae and lack of a clear zone are frequently observed in placenta previa even when there is no adherence of the placenta. Copyright © 2011 John Wiley & Sons, Ltd.
Measuring balance and model selection in propensity score methods
Authors: Belitser Svetlana V. , Martens Edwin P. , Pestman Wiebe R. , Groenwold Rolf H.H. , de Boer Anthonius , Klungel Olaf H. 
Published: July 2011

ABSTRACTPurposePropensity score (PS) methods focus on balancing confounders between groups to estimate an unbiased treatment or exposure effect. However, there is lack of attention in actually measuring, reporting and using the information on balance, for instance for model selection. We propose to use a measure for balance in PS methods and describe several of such measures: the overlapping coefficient, the Kolmogorov‐Smirnov distance, and the Lévy distance.MethodsWe performed simulation studies to estimate the association between these three and several mean based measures for balance and bias (i.e., discrepancy between the true and the estimated treatment effect).ResultsFor large sample sizes (n = 2000) the average Pearson's correlation coefficients between bias and Kolmogorov‐Smirnov distance (r = 0.89), the Lévy distance (r = 0.89) and the absolute standardized mean difference (r = 0.90) were similar, whereas this was lower for the overlapping coefficient (r = −0.42). When sample size decreased to 400, mean based measures of balance had stronger correlations with bias. Models including all confounding variables, their squares and interaction terms resulted in smaller bias than models that included only main terms for confounding variables.ConclusionsWe conclude that measures for balance are useful for reporting the amount of balance reached in propensity score analysis and can be helpful in selecting the final PS model. Copyright © 2011 John Wiley & Sons, Ltd.
Soluble alkyl substituted poly(3,4‐propylenedioxyselenophene)s: A new platform for optoelectronic materials
Authors: Atak Samed , İçli‐Özkut Merve , Önal Ahmet M. , Cihaner Atilla 
Published: July 2011

AbstractOptical and electrochemical properties of regiosymmetric and soluble alkylenedioxyselenophene‐based electrochromic polymers, namely poly(3,3‐dibutyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C4), poly(3,3‐dihexyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C6), and poly(3,3‐didecyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C10), are highlighted. It is noted that these unique polymers have low bandgaps (1.57–1.65 eV), and they are exceptionally stable under ambient atmospheric conditions. Polymer films retained 82–97% of their electroactivity after 5000 cycles. The percent transmittance of PProDOS‐Cn (n = 4, 6, 10) films found to be between 55 and 59%. Furthermore, these novel soluble PProDOS‐Cn polymers showed electrochromic behavior: a color change form pure blue to highly transparent state in a low switching time (1.0 s) during oxidation with high coloration efficiencies (328–864 cm2 C−1) when compared to their thiophene analogues. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Influence of branching architecture on polymer properties
Authors: Zhu Xinyuan , Zhou Yongfeng , Yan Deyue 
Published: July 2011

AbstractHyperbranched polymers (HBPs), invented at the end of 1980s, are one important subclass of the fourth generation macromolecular architectures following the linear, branched, and crosslinking polymers. Due to their unique topological structure and interesting physical/chemical properties, HBPs have attracted wide attention from both academia and industry. HBPs are composed of linear units, dendritic units, and terminal units. The degree of branching (DB), a term to describe the composition of these three structure units and thus the branching architecture of polymers, is one of the most important intrinsic parameters for HBPs. This review has summarized the effect of the DB on the physical and chemical properties of HBPs, including the rheological property, crystallization and melting behaviors, glass transition, thermal and hydrolytic degradations, phase characteristics, lower critical solution temperature phase transition, optoelectronic properties, encapsulation capability, self‐assembly behavior, biomedical applications, and so on. Such a structure and property relationship will build a bridge between the syntheses and applications of HBPs, especially in the application areas of functional materials, biomedical materials, and nanotechnology. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1277–1286, 2011
A human sterile alpha motif domain polymerizome
Authors: Knight Mary Jane , Leettola Catherine , Gingery Mari , Li Hao , Bowie James U. 
Published: July 2011

AbstractThe sterile alpha motif (SAM) domain is one of the most common protein modules found in eukaryotic genomes. Many SAM domains have been shown to form helical polymer structures suggesting that SAM modules can be used to create large protein complexes in the cell. Because many polymeric SAM domains form heterogenous and insoluble aggregates that are experimentally intractable when isolated, it is likely that many polymeric SAM domains have gone uncharacterized. We, therefore, developed a method to maintain polymeric SAM domains in a soluble form that allowed rapid screening for potential SAM polymers. SAM domains were expressed as fusions to a super‐negatively charged green fluorescent protein (negGFP). The negGFP imparts three useful properties to the SAM domains: (1) the charge helps to maintain solubility; (2) the charge leads to reliable migration toward the cathode on native gels; and (3) the fluorescence emission allows visualization in crude extracts. Using the negGFP‐SAM fusions, we screened a large library of human SAM domains for polymerization using a native gel screen. A selected set of hSAM domains were then purified and examined for true polymer formation by electron microscopy. In this manner, we identified a set of new potential SAM polymers: ANKS3, Atherin, BicaudalC1, Caskin1, Caskin2, Kazrin, L3MBTL3, L3MBTL4, LBP, LiprinB1, LiprinB2, SAMD8, SAMD9, and STIM2. While further characterization will be necessary to verify that the SAM domains identified here truly form polymers, our results provide a much stronger working hypothesis for a large number of proteins that was possible from sequence analysis alone.
Crystal structure of the read‐through domain from bacteriophage Qβ A1 protein
Authors: Rumnieks Janis , Tars Kaspars 
Published: July 2011

AbstractBacteriophage Qβ is a small RNA virus that infects Escherichia coli. The virus particle contains a few copies of the minor coat protein A1, a C‐terminally prolonged version of the coat protein, which is formed when ribosomes occasionally read‐through the leaky stop codon of the coat protein. The crystal structure of the read‐through domain from bacteriophage Qβ A1 protein was determined at a resolution of 1.8 Å. The domain consists of a heavily deformed five‐stranded β‐barrel on one side of the protein and a β‐hairpin and a three‐stranded β‐sheet on the other. Several short helices and well‐ordered loops are also present throughout the protein. The N‐terminal part of the read‐through domain contains a prominent polyproline type II helix. The overall fold of the domain is not similar to any published structure in the Protein Data Bank.
Propensity for C‐terminal domain swapping correlates with increased regional flexibility in the C‐terminus of RNase A
Authors: Miller Katherine H. , Marqusee Susan 
Published: July 2011

AbstractDomain swapping is a type of oligomerization in which monomeric proteins exchange a structural element, resulting in oligomers whose subunits recapitulate the native, monomeric fold. It has been implicated as a potential mechanism for protein aggregation, which provides a strong impetus to understand the structural determinants and folding mechanisms that trigger domain swapping. Bovine pancreatic ribonuclease A (RNase A) is a well‐studied protein known to domain swap under extreme conditions, such as lyophilization from acetic acid. The major domain‐swapped dimer form of RNase A exchanges a β‐strand at its C‐terminus to form a C‐terminal domain‐swapped dimer. To study the mechanism by which C‐terminal swapping occurs, we used a variant of RNase A containing a P114G mutation that readily domain swaps under physiological conditions. Using NMR and hydrogen–deuterium exchange, we find that the P114G variant has decreased protection from hydrogen exchange compared to the wild‐type protein near the C‐terminal hinge region. Our results suggest that domain swapping occurs via a local high‐energy fluctuation at the C‐terminus.
Collaborative service evaluation with the TwoHop trust framework
Authors: Glynos Dimitris , Argyroudis Patroklos , Douligeris Christos 
Published: July 2011

ABSTRACTThe TwoHop trust framework is a collaborative system for computing trust towards service providers in a peer‐to‐peer network. TwoHop participants share their trust information so that peers without prior interaction may establish indirect trust relationships. TwoHop imposes a limit of two hops on trust delegation chains, which allows for increased efficiency in the trust calculation process. In addition, it provides multiple edges between nodes in the trust graph, allowing for the existence of both service evaluations and recommendations for service evaluators. In this paper, we present an improved version of the TwoHop trust calculation algorithm along with a formal description of its model of trust. We evaluate its key characteristics against those of other trust frameworks and compare it with the EigenTrust algorithm and to an improved version of the PeerTrust algorithm in terms of performance. Our simulation results indicate the robustness of our design against dishonest participants and its ability to scale to accommodate the needs of large peer‐to‐peer networks. Copyright © 2011 John Wiley & Sons, Ltd.
The influence of prior industry affiliation on framing in nascent industries: the evolution of digital cameras
Authors: Benner Mary J. , Tripsas Mary 
Published: July 2011

AbstractNew industries sparked by technological change are characterized by high uncertainty. In this paper, we explore how a firm's conceptualization of products in this context, as reflected by product feature choices, is influenced by prior industry affiliation. We study digital cameras introduced from 1991–2006 by firms from three prior industries. We hypothesize and find that: (1) prior industry experience shapes a set of shared beliefs that results in similar and concurrent firm behavior; (2) firms notice and imitate the behaviors of firms from the same prior industry; and, (3) as firms gain experience with particular features, the influence of prior industry decreases. This study extends previous research on firm entry into new domains by examining heterogeneity in firms' framing and feature‐level entry choices. Copyright © 2011 John Wiley & Sons, Ltd.
Transcriptome Analysis of Neural Progenitor Cells by a Genetic Dual Reporter Strategy
Authors: Wang Jun , Zhang Heying , Young Amanda G. , Qiu Runxiang , Argalian Siranush , Li Xuejun , Wu Xiwei , Lemke Greg , Lu Qiang 
Published: July 2011

Abstract
Global analysis of stem/progenitor cells promises new insight into mechanisms that govern self-renewal and cellular potential, an unresolved question of stem/progenitor cell biology. Despite rapid advance of genome-wide profiling methods, the difficulty in cell purification remains a major challenge for global analysis of somatic stem/progenitor cells. Genetic tagging with a reporter provides a powerful tool for identification and isolation of a specific mature cell type; however, for stem/progenitor cells, reporter retention by progeny may be a concern for impurity. Here, we describe a genetic system combining a progenitor cell specific label with a second tag for marking differentiation. We present evidence that differential labeling of neural progenitor cells and their progeny enables prospective purification of these two cell types, whereas isolation based on a single marker compromises the purity of the intended progenitor population. Comparative expression profiling between the purified progenitors and progeny documents a neural progenitor cell transcriptome and uncovers an important role of Tyro3/Axl/Mer receptor tyrosine kinases in the maintenance of neural progenitor cells. This study establishes a general strategy for isolation of somatic stem/progenitor cells and provides a transcriptome database of neural progenitor cells useful for identification of causal factors of neural progenitor cell state, global dissection of epigenetic control of cellular potential, as well as for developing biomarkers or targets of brain cancer stem/initiating cells for therapeutic interventions.
How can urban centers adapt to climate change with ineffective or unrepresentative local governments?
Authors: Satterthwaite David 
Published: July 2011

AbstractThis article considers the prospects for urban areas in the Global South to adapt to climate change. It describes how most of the needed adaptations in the next few decades can be integrated into existing government functions, investments, regulations, and agencies. It also considers why most such measures are unlikely to be implemented—because of either the lack of capacity within urban governments or their unwillingness to address the infrastructure and service needs of their low‐income populations. Most urban centers in the Global South also have very large deficits in the basic infrastructure and services that are needed for resilience to climate change impacts. The article also considers how the policies and practices of higher levels of government and international agencies need to change if the much needed adaptive capacity is to be built in urban areas.WIREs Clim Change2011 2 767–776 DOI: 10.1002/wcc.136This article is categorized under:Vulnerability and Adaptation to Climate Change > Institutions for AdaptationClimate and Development > Urbanization, Development, and Climate ChangePolicy and Governance > Governing Climate Change in Communities, Cities, and Regions
Evidence for the presence of a FAD pyrophosphatase and a FMN phosphohydrolase in yeast mitochondria: a possible role in flavin homeostasis
Authors: Pallotta Maria Luigia 
Published: July 2011

AbstractDespite the crucial roles of flavin cofactors in metabolism, we know little about the enzymes responsible for the turnover of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) and their subcellular localization. The mechanism by which mitochondria obtain their own flavin cofactors is an interesting point of investigation, because FMN and FAD are mainly located in mitochondria, where they act as redox cofactors of a number of dehydrogenases and oxidases that play a crucial function in both bioenergetics and cellular regulation. In this context, the capability of yeast mitochondria to metabolize externally added and endogenous FAD and FMN was investigated and use was made of purified and bioenergetically active mitochondria prepared starting from the Saccharomyces cerevisiae cell. To determine whether flavin metabolism can occur, the amounts of flavins in aliquots of neutralized perchloric extracts of both spheroplasts and mitochondria were measured by HPLC, and the competence of S. cerevisiae mitochondria to metabolize FAD and FMN was investigated both spectroscopically and via HPLC. FAD deadenylation and FMN dephosphorylation were studied with respect to dependence on substrate concentration, pH profile and inhibitor sensitivity. The existence of two novel mitochondrial FAD pyrophosphatase (diphosphatase) (EC 3.6.1.18) and FMN phosphohydrolase (EC 3.1.3.2) activities, which catalyse the reactions FAD + H2O → FMN + AMP and FMN + H2O → riboflavin + Pi respectively, is here shown by fractionation studies. Considering cytosolic riboflavin, FMN and FAD concentrations, as calculated by measuring both spheroplast and mitochondrial contents via HPLC, probably mitochondria play a major role in regulating the flavin pool in yeast and in relation to flavin homeostasis. Copyright © 2011 John Wiley & Sons, Ltd.
Construction of diploid zygotes by interallelic complementation of ade6 in Schizosaccharomyces japonicus
Authors: Furuya Kanji , Niki Hironori 
Published: July 2011

AbstractThe construction of diploid cells eases genetic analysis in haploid genetic systems because diploid cells allow for the characterization of essential genes. Here, we report the construction of diploid cells using ade6 point mutants that suppress each other via interallelic complementation in the fission yeast Schizosaccharomyces japonicus var japonicus (Sz. japonicus). We constructed an ade6‐domK mutant in addition to the previously described ade6‐domE. Phenotypes of both mutants exhibited adenine auxotrophy and red colonies. The mutations complemented the phenotypes in a mutually dependent manner. Diploid zygotes, in which the two mutations were introduced simultaneously into the same cells, were isolated by selecting for adenine independence. Such diploid cells are apparently larger in size than haploid cells, yet have a similar nuclear/cytoplasmic ratio, and thus the nuclear size control that has been reported in Sz. pombe is also present in Sz. japonicus. Copyright © 2011 John Wiley & Sons, Ltd.