bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficiently activated ε‐poly‐L‐lysine production by multiple antibiotic‐resistance mutations and acidic pH shock optimization in Streptomyces albulus
Authors: Wang Liang , Li Shu , Zhao Junjie , Liu Yongjuan , Chen Xusheng , Tang Lei , Mao Zhonggui 
Published: October 2018

Abstractε‐Poly‐L‐lysine (ε‐PL) is a food additive produced by Streptomyces and is widely used in many countries. Working with Streptomyces albulus FEEL‐1, we established a method to activate ε‐PL synthesis by successive introduction of multiple antibiotic‐resistance mutations. Sextuple mutant R6 was finally developed by screening for resistance to six antibiotics and produced 4.41 g/L of ε‐PL in a shake flask, which is 2.75‐fold higher than the level produced by the parent strain. In a previous study, we constructed a double‐resistance mutant, SG‐31, with high ε‐PL production of 3.83 g/L and 59.50 g/L in a shake flask and 5‐L bioreactor, respectively. However, we found that R6 did not show obvious advantages in fed‐batch fermentation when compared with SG‐31. For further activation of ε‐PL synthesis ability, we optimized the fermentation process by using an effective acidic pH shock strategy, by which R6 synthetized 70.3 g/L of ε‐PL, 2.79‐fold and 1.18‐fold greater than that synthetized by FEEL‐1 and SG‐31, respectively. To the best of our knowledge, this is the highest reported ε‐PL production to date. This ε‐PL overproduction may be due to the result of R99P and Q856H mutations in ribosomal protein S12 and RNA polymerase, respectively, which may be responsible for the increased transcription of the ε‐poly‐lysine synthetase gene (pls) and key enzyme activities in the Lys synthesis metabolic pathway. Consequently, ε‐PL synthetase activity, intracellular ATP, and Lys concentrations were improved and directly contributed to ε‐PL overproduction. This study combined ribosome engineering, high‐throughput screening, and targeted strategy optimization to accelerate ε‐PL production and probe the fermentation characteristics of hyperyield mutants. The information presented here may be useful for other natural products produced by Streptomyces.
Dual‐band bidirectional circularly polarized microstrip antenna for CubeSat system
Authors: Lee Sunghee , Pyo Seongmin , Kim Jae‐Hyun 
Published: October 2018

AbstractThis article proposes a novel dual‐band bidirectional microstrip antenna with an identical right‐handed circularly polarized sense for a CubeSat system application. The asymmetrical arrow‐ended cross slot embedded only on the ground layer is dually utilized as the backward slot antenna at 1.575 GHz and the perturbing element of the microstrip antenna with forward radiations at 2.23 GHz. The implemented antenna successfully demonstrates dual‐band bidirectional right‐handed circular polarizations in good agreement with the simulation results for the global positioning system and the satellite telemetry of a CubeSat system.
Demonstration of an optical wireless communication link with pre‐emphasis circuit for high‐speed application
Authors: Silveira David , Wijekoon Wimansha , Lee Ghang‐Ho 
Published: October 2018

AbstractIn this article, we experimentally demonstrate an optical wireless communication link based on Non‐Return to Zero (NRZ) On‐Off Keying (OOK) modulation with pre‐emphasis circuit for high‐speed application. We propose an economical hardware pre‐emphasis circuit comprise of one operational amplifier and an RC filter stage with a high‐pass frequency response to enhance passband characteristic of optical wireless communication link. The validity of the pre‐emphasis circuit has been demonstrated by using existing fiber optic and optical wireless communication link and components in our laboratory operating at 1550 nm. But the same pre‐emphasis circuit can be used in other wavelength applications including visual light wavelength range via light‐emitting diodes (LED). By using proposed pre‐emphasis circuit, 3 dB bandwidth of optical wireless link can be extended from 225 to 942 MHz (compared to 289 to 469 MHz without pre‐emphasis circuit). We observed the Bit‐Error‐Rate (BER) optical power penalty improvement of 2.5 dB at BER of 2 × 10−3 (forward error correction [FEC] limits) and 3.6 dB improvement at BER of 1 × 10−9, with a data rate of 1.244 Gb/s.
Prospective motion correction improves high‐resolution quantitative susceptibility mapping at 7T
Authors: Mattern Hendrik , Sciarra Alessandro , Lüsebrink Falk , Acosta‐Cabronero Julio , Speck Oliver 
Published: October 2018

PurposeRecent literature has shown the potential of high‐resolution quantitative susceptibility mapping (QSM) with ultra‐high field MRI for imaging the anatomy, the vasculature, and investigating their magnetostatic properties. Higher spatial resolutions, however, translate to longer scans resulting, therefore, in higher vulnerability to, and likelihood of, subject movement. We propose a gradient‐recalled echo sequence with prospective motion correction (PMC) to address such limitation.MethodsData from 4 subjects were acquired at 7T. The effect of small and large motion on QSM with and without PMC was assessed qualitatively and quantitatively. Full brain QSM and QSM‐based venograms with up to 0.33 mm isotropic voxel size were reconstructed.ResultsWith PMC, motion artifacts in QSM and QSM‐based venograms were largely eliminated, enabling—in both large‐ and small‐amplitude motion regimes—accurate depiction of the cortex, vasculature, and other small anatomical structures that are often blurred as a result of head movement or indiscernible at lower image resolutions. Quantitative analyses demonstrated that uncorrected motion could bias regional susceptibility distributions, a trend that was greatly reduced with PMC.ConclusionQualitatively, PMC prevented image degradation because of motion artifacts, providing highly detailed QSM images and venograms. Quantitatively, PMC increased the reproducibility of susceptibility measures.
Nitroxide mediated polymerization of sustainably sourced isobornyl methacrylate and tridecyl methacrylate with acrylonitrile co‐monomer
Authors: Hajiali Faezeh , Métafiot Adrien , Benitez‐Ek Laura , Alloune Lea , Marić Milan 
Published: October 2018

ABSTRACTNitroxide‐mediated polymerization (NMP) of isobornyl methacrylate (IBOMA) and tridecyl methacrylate (TDMA), derived from sustainable feedstocks, with a low fraction of acrylonitrile (AN) co‐monomer were conducted with unimolecular initiator BlocBuilder‐MA™ (BB) and the succinimidyl ester‐functionalized form, NHS‐BB. IBOMA and TDMA‐rich compositions were both polymerized at 100 °C in a controlled manner (i.e., linear increase in number average molecular weight [Mn] with conversion up to ∼40% and low dispersity, Đ < 1.5). SG1‐terminated poly(IBOMA‐stat‐AN) macroinitiator was then cleanly chain‐extended with poly(TDMA‐stat‐AN) and the diblock copolymers exhibited two distinct glass transition temperatures (Tgs), indicative of microphase separation. IBOMA/TDMA/AN terpolymers with different IBOMA/TDMA molar ratios were also synthesized where terpolymers with higher IBOMA content had higher apparent rate constants and higher Tgs. Moreover, chain growth was linear up to conversions of ∼60% and all Đs were 1.51 to 1.64. Finally, 2‐hydroxyethyl methacrylate (HEMA) was incorporated into the IBOMA/TDMA/AN system, resulting in statistical quadripolymers. The quadripolymer Tg decreased with increasing TDMA content and Mn ranged from 12 to 15.4 kg mol−1 and the Đ were 1.39 to 1.54, suggesting the successful incorporation of sustainably sourced monomers into quadripolymers with a broad range of tunable Tgs via NMP with additional functionalities from HEMA. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2422–2436
Heteroatom‐Doped Carbon Materials: Synthesis, Mechanism, and Application for Sodium‐Ion Batteries
Authors: Chen Weimin , Wan Min , Liu Qing , Xiong Xiaoqin , Yu Faquan , Huang Yunhui 
Published: October 2018

AbstractSodium‐ion batteries (SIBs) show promising application in large‐scale energy storage as future alternatives to lithium‐ion batteries. Carbonaceous materials are attractive anode candidates for SIBs due to low cost, abundance, and high safety. In general, doping heteroatoms such as N, B, O, S, and P in carbon‐based materials gives rise to high electronic mobility, good sodium mobility, and enhanced capacity, showing a great potential in sodium storage. This review summarizes the recent progress in the design, synthesis, and electrochemical properties of heteroatom‐doped carbon anodes, including one‐element doped carbons and several‐elements codoped carbons, aiming to help the readers comprehensively learn how to fabricate heteroatom‐doped carbons and use them in SIBs. Additionally, the advantages, mechanism, critical issues, and possible solutions of heteroatom‐doped carbons are discussed and the future research trends are proposed. This will provide a deep insight into the development of SIBs anode materials.
Pollen Development
Authors: Halbritter Heidemarie , Ulrich Silvia , Grímsson Friðgeir , Weber Martina , Zetter Reinhard , Hesse Michael , Buchner Ralf , Svojtka Matthias , Frosch-Radivo Andrea 
Published: October 2018

AbstractPollen is source and transport unit for the male gametes (or their progenitor cell). The unicellular pollen grain represents the microspore of seed plants, the multicellular pollen grain the male gametophytic generation. The development of a pollen grain includes microsporogenesis and microgametogenesis (Figs. 1 and 2, Gomez et al. 2015; Keijzer and Willemse 1988). Microsporogenesis starts with the differentiation of microspore mother cells (MMC) respectively pollen mother cells (PMC). These diploid cells become enclosed by a thick callose wall and undergo meiosis, forming a tetrad of four haploid microspores, each encased in another callose wall insulating them from each other and from the surrounding diploid tapetal cells (Figs. 1 C-E, and 2). Cytokinesis following meiotic nuclear divisions is accompanied by the formation of cleavage planes determined by the configuration and orientation of the meiotic spindle axes. In the case of successive cytokinesis, planes are formed after the first and second meiotic divisions leading to the formation of various microspore tetrad types (see “Pollen Morphology and Ultrastructure”). During simultaneous cytokinesis the cleavage planes are formed simultaneously after the second meiotic division and microspores become arranged in a tetrahedral tetrad (Furness and Rudall 1999, 2001).
Fixed effects in rare events data: a penalized maximum likelihood solution
Authors: Cook Scott J. , Hays Jude C. , Franzese Robert J. 
Published: October 2018

AbstractMost agree that models of binary time-series-cross-sectional data in political science often possess unobserved unit-level heterogeneity. Despite this, there is no clear consensus on how best to account for these potential unit effects, with many of the issues confronted seemingly misunderstood. For example, one oft-discussed concern with rare events data is the elimination of no-event units from the sample when estimating fixed effects models. Many argue that this is a reason to eschew fixed effects in favor of pooled or random effects models. We revisit this issue and clarify that the main concern with fixed effects models of rare events data is not inaccurate or inefficient coefficient estimation, but instead biased marginal effects. In short, only evaluating event-experiencing units gives an inaccurate estimate of the baseline risk, yielding inaccurate (often inflated) estimates of predictor effects. As a solution, we propose a penalized maximum likelihood fixed effects (PML-FE) estimator, which retains the complete sample by providing finite estimates of the fixed effects for each unit. We explore the small sample performance of PML-FE versus common alternatives via Monte Carlo simulations, evaluating the accuracy of both parameter and effects estimates. Finally, we illustrate our method with a model of civil war onset.
14C leaching and speciation studies on Irradiated graphite from vandellós I Nuclear Power Plant
Authors: Magro Enrique , Márquez Eva María , Piña Gabriel , Rodríguez Marina , Gascón José Luís , Lara Esperanza , Sevilla Lucía 
Published: October 2018

ABSTRACTThe understanding of the 14C behavior in waste packages could lead, in the Spanish context, to a revision of the management strategies for radioactive waste and a revaluation of the near surface repository devoted to the disposal of waste containing this radionuclide in high concentrations. To achieve this objective, and in the context of the EU project Carbon-14 Source Term (CAST), the authors of the work presented in this paper have performed leaching experiments with irradiated graphite considering two different scenarios. One, in which the leaching solution simulates some of the expected conditions in a repository where a granite/bentonite mixture has been used as backfill material, and the other, using deionized water as a high efficiency chemical removal agent and for comparison purposes. The analytical approach to measure the release rate and speciation of 14C from irradiated graphite samples in the aqueous and gaseous phase is also described. The main results obtained shows that, after 359 days of leaching, no 14C activity was detected above the detection limits, and only leaching rates regarding beta-gamma emitters were observed: 2×10–6 cm/day for 137Cs and 1×10–5 cm/day for 60Co in granite/bentonite water media and 4×10–6 cm/day for 137Cs in pure water.
MODERN MOUNTAINS FROM THE ENLIGHTENMENT TO THE ANTHROPOCENE
Authors: SIMPSON THOMAS 
Published: October 2018

AbstractRecent scholarship across a range of historical sub-disciplines shows that uplands are where many forms of modernity are both crafted and overwhelmed. Maintaining multiple tensions – between assimilation and distinction, between projections of power and material and human resistance, and between knowledge and elusiveness – is essential to the modernities crafted in mountain spaces. This review highlights a number of common threads running through recent writings on modern mountains. These include heightened attention to the importance of mountains as arenas for the performance of gendered, racial, national, and class-based subjectivities, and the persistence of earlier attitudes and activities in avowedly disenchanted modern visions of uplands. For all of the successes of recent scholarship, more work remains in order to consider mountains in global contexts and to come to terms with our continued entanglement in modern ways of understanding and acting in high places. Looking ahead, it is vital that historians think with and about mountains in order to contribute positively and persuasively to discussions on the human and environmental impacts of global change.
SIR JOHN ELIOT'STHE MONARCHIE OF MANAND EARLY STUART POLITICAL THOUGHT
Authors: WHITE WILLIAM 
Published: October 2018

AbstractThis article seeks to revise existing interpretations of the political writings composed by the early Stuart MP, Sir John Eliot (1592–1632), while imprisoned in the Tower of London between 1629 and 1632. In particular, it challenges the common understanding of Eliot as an absolutist writer. This characterization is shown to be based on a misreading of his principal treatise,The monarchie of man, and the problematic assumption thatDe jure– a translation he undertook of the continental absolutist, Arnisaeus – should be taken to epitomize Eliot's own views. The article also refutes the notion thatThe monarchie of manis an uncontroversial text that ignores contemporary political context. It is argued that the treatise can, in fact, only be read in relation to the constitutional crisis of the late 1620s: Eliot's work is presented as a subversive attack on Charles I's tyrannical pretensions, which supplies a remedy in the form of a Ciceronian insistence on active virtue. These findings in turn have implications for how we understand the political thought and culture of early Stuart England more generally.
EXPERIENCING SYNDEMIC: DISENTANGLING THE BIOSOCIAL COMPLEXITY OF TUBERCULOSIS THROUGH QUALITATIVE RESEARCH
Authors: Zvonareva Olga , van Bergen Willemien , Kabanets Nadezhda , Alliluyev Aleksander , Filinyuk Olga 
Published: October 2018

AbstractTuberculosis (TB) remains a major global public health problem that has become a crisis fuelled by HIV and the increasing occurrence of antimicrobial resistance. What has been termed the biosocial nature of TB challenges effective control of the disease. Yet, biosocial interactions involved in the persistence of TB in diverse settings are difficult to systematically account for. The recently developed framework of syndemics provides a way to capture how complex health problems result from the interactions between diseases such as HIV and TB, and harmful social conditions such as unemployment, malnutrition and substance abuse. This article advances the syndemics scholarship by examining health conditions that cluster together with TB in the Russian Federation, by eliciting a set of social processes that precipitate this clustering and exacerbate health outcomes, and by analysing interactions between these health conditions and social processes. To provide an account of this complexity, the article takes a qualitative approach and draws on the perspectives and experiences of people with TB. The results demonstrate emergence of a syndemic of stress, substance abuse, TB and HIV that is sustained by poverty, occupational insecurity, marginalization and isolation. Frictions between the narrow focus of the health care system on TB and the wider syndemic processes in which the lives of many persons with TB are embedded, contribute to poorer health outcomes and increase the risks of developing drug resistance. Finally, the article argues that the large-scale and impersonal forces become embodied as individual pathology through the crucial interface of the ways in which persons experience and make sense of these forces and pathologies. Qualitative research is needed for the adequate analysis of this biosocial complexity in order to provide a solid basis for responses to TB-centred syndemics in various settings.
Efficient Phrase Table pruning for Hindi to English machine translation through syntactic and marker-based filtering and hybrid similarity measurement
Authors: CHATTERJEE NILADRI , GUPTA SUSMITA 
Published: October 2018

AbstractFor a given training corpus of parallel sentences, the quality of the output produced by a translation system relies heavily on the underlying similarity measurement criteria. A phrase-based machine translation system derives its output through a generative process using a Phrase Table comprising source and target language phrases. As a consequence, the more effective the Phrase Table is, in terms of its size and the output that may be derived out of it, the better is the expected outcome of the underlying translation system. However, finding the most similar phrase(s) from a given training corpus that can help generate a good quality translation poses a serious challenge. In practice, often there are many parallel phrase entries in a Phrase Table that are either redundant, or do not contribute to the translation results effectively. Identifying these candidate entries and removing them from the Phrase Table will not only reduce the size of the Phrase Table, but should also help in improving the processing speed for generating the translations. The present paper develops a scheme based on syntactic structure and the marker hypothesis (Green 1979, The necessity of syntax markers: two experiments with artificial languages, Journal of Verbal Learning and Behavior) for reducing the size of a Phrase Table, without compromising much on the translation quality of the output, by retaining the non-redundant and meaningful parallel phrases only. The proposed scheme is complemented with an appropriate similarity measurement scheme to achieve maximum efficiency in terms of BLEU scores. Although designed for Hindi to English machine translation, the overall approach is quite general, and is expected to be easily adaptable for other language pairs as well.
Prevalence thresholds for wasting, overweight and stunting in children under 5 years
Authors: de Onis Mercedes , Borghi Elaine , Arimond Mary , Webb Patrick , Croft Trevor , Saha Kuntal , De-Regil Luz Maria , Thuita Faith , Heidkamp Rebecca , Krasevec Julia , Hayashi Chika , Flores-Ayala Rafael 
Published: October 2018

AbstractObjectivePrevalence ranges to classify levels of wasting and stunting have been used since the 1990s for global monitoring of malnutrition. Recent developments prompted a re-examination of existing ranges and development of new ones for childhood overweight. The present paper reports from the WHO–UNICEF Technical Expert Advisory Group on Nutrition Monitoring.DesignThresholds were developed in relation tosdof the normative WHO Child Growth Standards. The international definition of ‘normal’ (2sdbelow/above the WHO standards median) defines the first threshold, which includes 2·3 % of the area under the normalized distribution. Multipliers of this ‘very low’ level (rounded to 2·5 %) set the basis to establish subsequent thresholds. Country groupings using the thresholds were produced using the most recent set of national surveys.SettingOne hundred and thirty-four countries.SubjectsChildren under 5 years.ResultsFor wasting and overweight, thresholds are: ‘very low’ (<2·5 %), ‘low’ (≈1–2 times 2·5 %), ‘medium’ (≈2–4 times 2·5 %), ‘high’ (≈4–6 times 2·5 %) and ‘very high’ (>≈6 times 2·5 %). For stunting, thresholds are: ‘very low’ (<2·5 %), ‘low’ (≈1–4 times 2·5 %), ‘medium’ (≈4–8 times 2·5 %), ‘high’ (≈8–12 times 2·5 %) and ‘very high’ (>≈12 times 2·5 %).ConclusionsThe proposed thresholds minimize changes and keep coherence across anthropometric indicators. They can be used for descriptive purposes to map countries according to severity levels; by donors and global actors to identify priority countries for action; and by governments to trigger action and target programmes aimed at achieving ‘low’ or ‘very low’ levels. Harmonized terminology will help avoid confusion and promote appropriate interventions.
Regaining In-Group Continuity in Times of Anxiety About the	Group’s Future
Authors: Smeekes Anouk , Jetten Jolanda , Verkuyten Maykel , Wohl Michael J.A. , Jasinskaja-Lahti Inga , Ariyanto Amarina , Autin Frédérique , Ayub Nadia , Badea Constantina , Besta Tomasz , Butera Fabrizio , Costa-Lopes Rui , Cui Lijuan , Fantini Carole , Finchilescu Gillian , Gaertner Lowell , Gollwitzer Mario , Gómez Ángel , González Roberto , Hong Ying Yi , Jensen Dorthe Høj , Karasawa Minoru , Kessler Thomas , Klein Olivier , Lima Marcus , Renvik Tuuli A. , Megevand Laura , Morton Thomas , Paladino Paola , Polya Tibor , Ruza Aleksejs , Shahrazad Wan , Sharma Sushama , Teymoori Ali , Torres Ana R. , van der Bles Anne M. 
Published: October 2018

Abstract. Collective nostalgia for the good old days of the country thrives across the world. However, little is known about the social psychological dynamics of this collective emotion across cultures. We predicted that collective nostalgia is triggered by collective angst as it helps people to restore a sense of in-group continuity via stronger in-group belonging and out-group rejection (in the form of opposition to immigrants). Based on a sample (N = 5,956) of individuals across 27 countries, the general pattern of results revealed that collective angst predicts collective nostalgia, which subsequently relates to stronger feelings of in-group continuity via in-group belonging (but not via out-group rejection). Collective nostalgia generally predicted opposition to immigrants, but this was subsequently not related to in-group continuity.