bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impediments to contract enforcement in day labour markets: a perspective from India
Authors: NARAPARAJU KARTHIKEYA 
Published: November 2015

AbstractIn developing countries, lack of formal contract enforcement mechanisms is compensated by informal governance enforced through trust, kinship, reputation, etc. This paper focuses on one such setting in India's urban informal economy: the ‘day labour’ market for casual labour. We survey seven such markets in Navi Mumbai (a city on the outskirts of Mumbai), and find considerable incidence of contract enforcement problems in the form of employers reneging on wage payments to labourers. We find that payments to labourers with access to social networks and a record of work done are less likely to be reneged. Further, consistent with the literature on the limits of informal enforcement, we find that labourers in large markets, with greater linguistic and caste-based diversity, are more likely to be reneged. We argue that interventions aimed at facilitating access to formal mechanisms might help overcome some of the limitations with informal enforcement.
Reputation in the Internet black market: an empirical and theoretical analysis of the Deep Web
Authors: HARDY ROBERT AUGUSTUS , NORGAARD JULIA R. 
Published: November 2015

AbstractThis paper is an analysis of the role reputation plays in the Deep Web using data from the Internet black-market site, The Silk Road. This encrypted online marketplace employed cryptocurrency and functioned over the Tor network. Utilizing a modeling technique, informed by trade auction theory, we investigate the effect of seller reputation. Analysis of the seller's reputation gives us insights into the factors that determine the prices of goods and services in this black marketplace. Data on cannabis listings is parsed from the Silk Road website and covers an 11-month time period, from November 2013 to October 2014. This data demonstrates that reputation acts as a sufficient self-enforcement mechanism to allow transactions. These findings exemplify the robustness of spontaneous order with respect to the Deep Web as an emergent marketplace.
Total synthesis of palau’amine
Authors: Namba Kosuke , Takeuchi Kohei , Kaihara Yukari , Oda Masataka , Nakayama Akira , Nakayama Atsushi , Yoshida Masahiro , Tanino Keiji 
Published: November 2015

AbstractPalau’amine has received a great deal of attention in the past two decades as an attractive synthetic target by virtue of its intriguing molecular architecture and significant immunosuppressive activity. Here we report the total synthesis of palau’amine characterized by the construction of an ABDE tetracyclic ring core including a trans-bicylo[3.3.0]octane skeleton at a middle stage of total synthesis. The ABDE tetracyclic ring core is constructed by a cascade reaction of a cleavage of the N–N bond, including simultaneous formation of imine, the addition of amide anion to the resulting imine (D-ring formation) and the condensation of pyrrole with methyl ester (B-ring formation) in a single step. The synthetic palau’amine is confirmed to exhibit excellent immunosuppressive activity. The present synthetic route has the potential to help elucidate a pharmacophore as well as the mechanistic details of immunosuppressive activity.
Photoinduced spontaneous free-carrier generation in semiconducting single-walled carbon nanotubes
Authors: Park Jaehong , Reid Obadiah G. , Blackburn Jeffrey L. , Rumbles Garry 
Published: November 2015

AbstractStrong quantum confinement and low dielectric screening impart single-walled carbon nanotubes with exciton-binding energies substantially exceeding kBT at room temperature. Despite these large binding energies, reported photoluminescence quantum yields are typically low and some studies suggest that photoexcitation of carbon nanotube excitonic transitions can produce free charge carriers. Here we report the direct measurement of long-lived free-carrier generation in chirality-pure, single-walled carbon nanotubes in a low dielectric solvent. Time-resolved microwave conductivity enables contactless and quantitative measurement of the real and imaginary photoconductance of individually suspended nanotubes. The conditions of the microwave conductivity measurement allow us to avoid the complications of most previous measurements of nanotube free-carrier generation, including tube–tube/tube–electrode contact, dielectric screening by nearby excitons and many-body interactions. Even at low photon fluence (approximately 0.05 excitons per μm length of tubes), we directly observe free carriers on excitation of the first and second carbon nanotube exciton transitions.
Intronic regulation of Aire expression by Jmjd6 for self-tolerance induction in the thymus
Authors: Yanagihara Toyoshi , Sanematsu Fumiyuki , Sato Tetsuya , Uruno Takehito , Duan Xuefeng , Tomino Takahiro , Harada Yosuke , Watanabe Mayuki , Wang Yuqing , Tanaka Yoshihiko , Nakanishi Yoichi , Suyama Mikita , Yoshinori Fukui 
Published: November 2015

AbstractThe thymus has spatially distinct microenvironments, the cortex and the medulla, where the developing T-cells are selected to mature or die through the interaction with thymic stromal cells. To establish the immunological self in the thymus, medullary thymic epithelial cells (mTECs) express diverse sets of tissue-specific self-antigens (TSAs). This ectopic expression of TSAs largely depends on the transcriptional regulator Aire, yet the mechanism controlling Aire expression itself remains unknown. Here, we show that Jmjd6, a dioxygenase that catalyses lysyl hydroxylation of splicing regulatory proteins, is critical for Aire expression. Although Jmjd6 deficiency does not affect abundance of Aire transcript, the intron 2 of Aire gene is not effectively spliced out in the absence of Jmjd6, resulting in marked reduction of mature Aire protein in mTECs and spontaneous development of multi-organ autoimmunity in mice. These results highlight the importance of intronic regulation in controlling Aire protein expression.
Identification of Reliable Components in Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS): a Data-Driven Approach across Metabolic Processes
Authors: Motegi Hiromi , Tsuboi Yuuri , Saga Ayako , Kagami Tomoko , Inoue Maki , Toki Hideaki , Minowa Osamu , Noda Tetsuo , Kikuchi Jun 
Published: November 2015

AbstractThere is an increasing need to use multivariate statistical methods for understanding biological functions, identifying the mechanisms of diseases and exploring biomarkers. In addition to classical analyses such as hierarchical cluster analysis, principal component analysis and partial least squares discriminant analysis, various multivariate strategies, including independent component analysis, non-negative matrix factorization and multivariate curve resolution, have recently been proposed. However, determining the number of components is problematic. Despite the proposal of several different methods, no satisfactory approach has yet been reported. To resolve this problem, we implemented a new idea: classifying a component as “reliable” or “unreliable” based on the reproducibility of its appearance, regardless of the number of components in the calculation. Using the clustering method for classification, we applied this idea to multivariate curve resolution-alternating least squares (MCR-ALS). Comparisons between conventional and modified methods applied to proton nuclear magnetic resonance (1H-NMR) spectral datasets derived from known standard mixtures and biological mixtures (urine and feces of mice) revealed that more plausible results are obtained by the modified method. In particular, clusters containing little information were detected with reliability. This strategy, named “cluster-aided MCR-ALS,” will facilitate the attainment of more reliable results in the metabolomics datasets.
High specific selectivity and Membrane-Active Mechanism of the synthetic centrosymmetric α-helical peptides with Gly-Gly pairs
Authors: Wang Jiajun , Chou Shuli , Xu Lin , Zhu Xin , Dong Na , Shan Anshan , Chen Zhihui 
Published: November 2015

AbstractWe used a template-assisted approach to develop synthetic antimicrobial peptides, which differ from naturally occurring antimicrobial peptides that can compromise host natural defenses. Previous researches have demonstrated that symmetrical distribution patterns of amino acids contribute to the antimicrobial activity of natural peptides. However, there is little research describing such design ideas for synthetic α-helical peptides. Therefore, here, we established a centrosymmetric α-helical sequence template (y + hhh + y)n (h, hydrophobic amino acid; +, cationic amino acid; y, Gly or hydrophobic amino acid), which contributed to amphipathicity and a series of centrosymmetric peptides was designed with pairs of small amino acids (Ala and Gly), which were utilized to modulate the biological activity. The centrosymmetric peptides with 3 repeat units exhibited strong antimicrobial activity; in particular, the Gly-rich centrosymmetric peptide GG3 showed stronger selectivity for gram-negative bacteria without hemolysis. Furthermore, beyond our expectation, fluorescence spectroscopy and electron microscopy analyses indicated that the GG3, which possessed poor α-helix conformation, dramatically exhibited marked membrane destruction via inducing bacterial membrane permeabilization, pore formation and disruption, even bound DNA to further exert antimicrobial activity. Collectively, the Gly-rich centrosymmetric peptide GG3 was an ideal candidate for commercialization as a clinical therapeutic to treat gram-negative bacterial infections.
Biometamaterials: Black Ultrathin Gold Film Fabricated on Lotus Leaf
Authors: Ebihara Yuusuke , Ota Ryoichi , Noriki Takahiro , Shimojo Masayuki , Kajikawa Kotaro 
Published: November 2015

AbstractWe report on a black metamaterial of gold fabricated on a lotus leaf that was used as a template. In spite of the extremely thin gold coating (10-nm thick) on the lotus leaf, the surface shows reflectivity below 0.01 over the entire visible spectral range. Finite-difference time-domain (FDTD) calculations suggest that the low reflectivity stems from the secondary structures on the lotus leaf, where randomly oriented nanorods are distributed.
Coevolutionary dynamics between tribe Cercopithecini tetherins and their lentiviruses
Authors: Takeuchi Junko S. , Ren Fengrong , Yoshikawa Rokusuke , Yamada Eri , Nakano Yusuke , Kobayashi Tomoko , Matsuda Kenta , Izumi Taisuke , Misawa Naoko , Shintaku Yuta , Wetzel Katherine S. , Collman Ronald G. , Tanaka Hiroshi , Hirsch Vanessa M. , Koyanagi Yoshio , Sato Kei 
Published: November 2015

AbstractHuman immunodeficiency virus, a primate lentivirus (PLV), causes AIDS in humans, whereas most PLVs are less or not pathogenic in monkeys. These notions suggest that the co-evolutionary process of PLVs and their hosts associates with viral pathogenicity and therefore, that elucidating the history of virus-host co-evolution is one of the most intriguing topics in the field of virology. To address this, recent studies have focused on the interplay between intrinsic anti-viral proteins, such as tetherin and viral antagonists. Through an experimental-phylogenetic approach, here we investigate the co-evolutionary interplay between tribeCercopithecinitetherin and viral antagonists, Nef and Vpu. We reveal that tribeCercopithecinitetherins are positively selected, possibly triggered by ancient Nef-like factor(s). We reconstruct the ancestral sequence of tribeCercopithecinitetherin and demonstrate that all Nef proteins are capable of antagonizing ancestralCercopithecinitetherin. Further, we consider the significance of evolutionary arms race between tribeCercopitheciniand their PLVs.
Systems biology-guided identification of synthetic lethal gene pairs and its potential use to discover antibiotic combinations
Authors: Aziz Ramy K. , Monk Jonathan M. , Lewis Robert M. , In Loh Suh , Mishra Arti , Abhay Nagle Amrita , Satyanarayana Chitkala , Dhakshinamoorthy Saravanakumar , Luche Michele , Kitchen Douglas B. , Andrews Kathleen A. , Fong Nicole L. , Li Howard J. , Palsson Bernhard O. , Charusanti Pep 
Published: November 2015

AbstractMathematical models of metabolism from bacterial systems biology have proven their utility across multiple fields, for example metabolic engineering, growth phenotype simulation and biological discovery. The usefulness of the models stems from their ability to compute a link between genotype and phenotype, but their ability to accurately simulate gene-gene interactions has not been investigated extensively. Here we assess how accurately a metabolic model forEscherichia colicomputes one particular type of gene-gene interaction, synthetic lethality and find that the accuracy rate is between 25% and 43%. The most common failure modes were incorrect computation of single gene essentiality and biological information that was missing from the model. Moreover, we performed virtual and biological screening against several synthetic lethal pairs to explore whether two-compound formulations could be found that inhibit the growth of Gram-negative bacteria. One set of molecules was identified that, depending on the concentrations, inhibitsE. coliandS. entericaserovar Typhimurium in an additive or antagonistic manner. These findings pinpoint specific ways in which to improve the predictive ability of metabolic models and highlight one potential application of systems biology to drug discovery and translational medicine.
Identification and functional analysis of novel FZD4 mutations in Han Chinese with familial exudative vitreoretinopathy
Authors: Fei Ping , Zhu Xiong , Jiang Zhilin , Ma Shi , Li Jing , Zhang Qi , Zhou Yu , Xu Yu , Tai Zhengfu , Zhang Lin , Huang Lulin , Yang Zhenglin , Zhao Peiquan , Zhu Xianjun 
Published: November 2015

AbstractFamilial exudative vitreoretinopathy (FEVR) is a hereditary eye disease characterized by defects in the development of retinal vessels. However, known genetic mutations can only explain approximately 50% of FEVR patients. To assess the mutation frequency of Frizzled 4 (FZD4) in Chinese patients, we analysed patients with FEVR from 61 families from China to identify mutations in FZD4 and to study the effects of identified mutations on FZD4 function. All coding exons and adjacent intronic regions of FZD4 were amplified by polymerase chain reaction and subjected to Sanger sequencing analysis. Three mutations in the FZD4 gene were identified in these families. Of these, two were novel mutations: p.E134* and p.T503fs. Both mutations involve highly conserved residues and were not present in 800 normal individuals. Each of these two novel FZD4 mutations was introduced into wild-type FZD4 cDNA by site-directed mutagenesis. Wild-type and mutant FZD4 DNAs were introduced into HEK293 cells to analyse the function of FZD4 in Norrin-dependent activation of the Norrin/β-catenin pathway using luciferase reporter assays. Both the p.E134* and p.T503fs mutants failed to induce luciferase reporter activity in response to Norrin. Our study identified two novel FZD4 mutations in Chinese patients with FEVR.
Effects and possible mechanisms of action of acacetin on the behavior and eye morphology of Drosophila models of Alzheimer’s disease
Authors: Wang Xue , Perumalsamy Haribalan , Kwon Hyung Wook , Na Young-Eun , Ahn Young-Joon 
Published: November 2015

AbstractThe human β-amyloid (Aβ) cleaving enzyme (BACE-1) is a target for Alzheimer’s disease (AD) treatments. This study was conducted to determine if acacetin extracted from the whole Agastache rugosa plant had anti-BACE-1 and behavioral activities in Drosophila melanogaster AD models and to determine acacetin’s mechanism of action. Acacetin (100, 300 and 500 μM) rescued amyloid precursor protein (APP)/BACE1-expressing flies and kept them from developing both eye morphology (dark deposits, ommatidial collapse and fusion and the absence of ommatidial bristles) and behavioral (motor abnormalities) defects. The reverse transcription polymerase chain reaction analysis revealed that acacetin reduced both the human APP and BACE-1 mRNA levels in the transgenic flies, suggesting that it plays an important role in the transcriptional regulation of human BACE-1 and APP. Western blot analysis revealed that acacetin reduced Aβ production by interfering with BACE-1 activity and APP synthesis, resulting in a decrease in the levels of the APP carboxy-terminal fragments and the APP intracellular domain. Therefore, the protective effect of acacetin on Aβ production is mediated by transcriptional regulation of BACE-1 and APP, resulting in decreased APP protein expression and BACE-1 activity. Acacetin also inhibited APP synthesis, resulting in a decrease in the number of amyloid plaques.
Human cooperation in groups: variation begets variation
Authors: Berg Pieter van den , Molleman Lucas , Junikka Jaakko , Puurtinen Mikael , Weissing Franz J. 
Published: November 2015

AbstractMany experiments on human cooperation have revealed that individuals differ systematically in their tendency to cooperate with others. It has also been shown that individuals condition their behaviour on the overall cooperation level of their peers. Yet, little is known about how individuals respond to heterogeneity in cooperativeness in their neighbourhood. Here, we present an experimental study investigating whether and how people respond to heterogeneous behaviour in a public goods game. We find that a large majority of subjects does respond to heterogeneity in their group, but they respond in quite different ways. Most subjects contribute less to the public good when the contributions of their peers are more heterogeneous, but a substantial fraction of individuals consistently contributes more in this case. In addition, we find that individuals that respond positively to heterogeneity have a higher general cooperation tendency. The finding that social responsiveness occurs in different forms and is correlated with cooperativeness may have important implications for the outcome of cooperative interactions.
Disadvantageous associations: Reversible spatial cueing effects in a discrimination task
Authors: Nico Daniele , Daprati Elena 
Published: November 2015

AbstractCurrent theories describe learning in terms of cognitive or associative mechanisms. To assess whether cognitive mechanisms interact with automaticity of associative processes we devised a shape-discrimination task in which participants received both explicit instructions and implicit information. Instructions further allowed for the inference that a first event would precede the target. Albeit irrelevant to respond, this event acted as response prime and implicit spatial cue (i.e. it predicted target location). To modulate cognitive involvement, in three experiments we manipulated modality and salience of the spatial cue. Results always showed evidence for a priming effect, confirming that the first stimulus was never ignored. More importantly, although participants failed to consciously recognize the association, responses to spatially cued trials became either slower or faster depending on salience of the first event. These findings provide an empirical demonstration that cognitive and associative learning mechanisms functionally co-exist and interact to regulate behaviour.
Strain assisted electrocaloric effect in PbZr0.95Ti0.05O3 films on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate
Authors: Zuo Zhenghu , Chen Bin , Wang Baomin , Yang Huali , Zhan Qingfeng , Liu Yiwei , Wang Junling , Li Run-Wei 
Published: November 2015

AbstractSolid state cooling technologies based on electrocaloric, magnetocaloric and mechanocaloric effects have received much attention during the past decade. To further improve the cooling efficiency and reduce the driving field, it is desirable to combine multiple effects in a single system. Here, we report on the caloric effects induced by both electric field and strain in PbZr0.95Ti0.05O3 films deposited on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate. The isothermal entropy change (ΔS) induced by the antiferroelectric-ferroelectric phase transition of PbZr0.95Ti0.05O3 films is calculated to be 6.78 J K−1 kg−1. Furthermore, the strain from 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate can reduce the electric field where ΔS reaches the maximum by as much as 50 kV/cm. The electrocaloric efficiency is also increased from 0.366 to 0.378 by the strain effect. The electrocaloric effect in an antiferroelectric material assisted by strain may lead to more efficient solid state cooling technology.
Dnmts and Tet target memory-associated genes after appetitive olfactory training in honey bees
Authors: Biergans Stephanie D. , Giovanni Galizia C. , Reinhard Judith , Claudianos Charles 
Published: November 2015

AbstractDNA methylation and demethylation are epigenetic mechanisms involved in memory formation. In honey bees DNA methyltransferase (Dnmt) function is necessary for long-term memory to be stimulus specific (i.e. to reduce generalization). So far, however, it remains elusive which genes are targeted and what the time-course of DNA methylation is during memory formation. Here, we analyse how DNA methylation affects memory retention, gene expression and differential methylation in stimulus-specific olfactory long-term memory formation. Out of 30 memory-associated genes investigated here, 9 were upregulated following Dnmt inhibition in trained bees. These included Dnmt3 suggesting a negative feedback loop for DNA methylation. Within these genes also the DNA methylation pattern changed during the first 24 hours after training. Interestingly, this was accompanied by sequential activation of the DNA methylation machinery (i.e. Dnmts and Tet). In sum, memory formation involves a temporally complex epigenetic regulation of memory-associated genes that facilitates stimulus specific long-term memory in the honey bee.
Analysis of the TCP genes expressed in the inflorescence of the orchid Orchis italica
Authors: De Paolo Sofia , Gaudio Luciano , Aceto Serena 
Published: November 2015

AbstractTCP proteins are plant-specific transcription factors involved in many different processes. Because of their involvement in a large number of developmental pathways, their roles have been investigated in various plant species. However, there are almost no studies of this transcription factor family in orchids. Based on the available transcriptome of the inflorescence of the orchid Orchis italica, in the present study we identified 12 transcripts encoding TCP proteins. The phylogenetic analysis showed that they belong to different TCP classes (I and II) and groups (PCF, CIN and CYC/TB1) and that they display a number of conserved motifs when compared with the TCPs of Arabidopsis and Oryza. The presence of a specific cleavage site for the microRNA miRNA319, an important post-transcriptional regulator of several TCP genes in other species, was demonstrated for one transcript of O. italica and the analysis of the expression pattern of the TCP transcripts in different inflorescence organs and in leaf tissue suggests that some TCP transcripts of O. italica exert their role only in specific tissues, while others may play multiple roles in different tissues. In addition, the evolutionary analysis showed a general purifying selection acting on the coding region of these transcripts.