bluuebunny/crossref_metadata_2025 huggingface dataset:
Bottled water in Mexico: The rise of a new access to water paradigm
Authors: Greene Joshua
Published: April 2018

Providing a case of bottled water as the main source of drinking water for a nation, this article looks at the unfolding of this development in Mexico and locates it into the mainstream debate about how to achieve sustainable development goals (SDGs) Target 6.1: universal and equitable access to safe and affordable drinking water for all. This is timely and relevant due to the 2017 amplification of the indicators defining access to improved sources of water to include the use of bottled water, under the broader category of “packaged water.” This signifies that populations that rely on bottled water as a complement to tap water, independent of the frequency and quality of this service, will be considered to have achieved the target. In only two decades, the phenomenon of bottled water has grown from a high‐end, niche consumer good to a global industry valued at $170 billion and climbing. The industry now stands poised to show how the private sector can be involved in achieving global targets, such as SDG 6.1, while earning large profits. In Mexico, 2017 estimates show 73% of the national population relies on bottled water as their unique source of drinking water, up from 61% in 2010. The article will trace the industry's history in Mexico rising out of an earthquake, a cholera epidemic, a financial crisis and the actions of the bottled water corporations. The profitability of this particular model of water delivery has attracted large‐scale investment by multinational food and beverage corporations and banks as well a recent explosion of small‐scale neighborhood water shops selling relatively small quantities of water. Today, this Mexican model is actively being replicated in other regions. Using a literature review and interviews with key informants from CONAGUA, Mexico's national water commission, the article traces four “lines of flight” of the origin and development of the bottled water industry in Mexico. The article reviews the current expansion of market actors and the published strategies of the dominant multinational corporations, to show the various configurations of the bottled water industry that are competing for the future of water delivery. The paper concludes by suggesting that the consequences of this trend deserve renewed examination by the water research community.

This article is categorized under:

Engineering Water > Planning Water

Human Water > Water Governance
Metal‐coordinated Hydroxide as a Nucleophile: a Brief History
Authors: Blackman Allan G. , Gahan Lawrence R.
Published: April 2018

It is well known that a metal‐bound hydroxido ligand is an efficient nucleophile around neutral pH. In a mechanistic sense, the presence and chemical reactivity of the coordinated hydroxido nucleophile are frequently invoked both in biomimetic chemistry and in numerous examples of hydrolytic metalloenzymes. In this review, we explore the background of this chemistry in order to attempt to trace the thinking which led to what is now a fully accepted mechanistic pathway.
Building a Strong Foundation Concerning Whole Number Arithmetic in Primary Grades: Editorial Introduction
Authors: Bartolini Bussi Maria G. , Sun Xu Hua
Published: April 2018

This volume is the outcome of ICMI Study 23 (Primary Mathematics Study on Whole Numbers). This editorial introduction outlines the rationale, the launch, the discussion document, the study conference, the content of the study volume, the main implications of the study, merits and limits of the study, concluding remarks, and acknowledgments.
How to Teach and Assess Whole Number Arithmetic: Some International Perspectives
Authors: Novotná Jarmila , Kaur Berinderjeet , Gervasoni Ann , Askew Mike , Veldhuis Michiel , Pearn Catherine , Sun Xu Hua
Published: April 2018

This chapter focusses on the diverse theoretical and methodical frameworks that capture the complex relationship between whole number arithmetic (WNA) learning, teaching and assessment. Its aim is to bring these diverse perspectives into conversation. It comprises seven sections. The introduction is followed by a narrative of a Macao primary school lesson on addition calculations with two-digit numbers, and this sets the context for the subsequent three sections that focus on the development of students’ mathematical and metacognitive strategies during their learning of WNA. Apart from examining the impact of teachers’ knowledge of pedagogy, learning trajectories, mathematics and students on children’s learning of WNA, learning theories are also drawn on to interpret the lesson in the Macao Primary School. Two interpretations of the variation theory (VT), an indigenous one and a Western perspective, provide much needed lenses for readers to make sense of the lesson. In addition, the theory of didactical situations (TDS) is also applied to the lesson. The chapter also includes a reflection on possible classroom assessment and the role of textbooks, both of which were less apparent in the lesson, for the teaching and learning of WNA.
Professional Development Models for Whole Number Arithmetic in Primary Mathematics Teacher Education: A Cross-Cultural Overview
Authors: Novotná Jarmila , Bartolini Bussi Maria G. , Beckmann Sybilla , Inprasitha Maitree , Kaur Berinderjeet , Sun Xu Hua , Venkat Hamsa , Askew Mike
Published: April 2018

The goal of the chapter is to explore and discuss teacher education in different parts of the world and to emphasize the commonalities and differences not only in the panellists’ countries, but in a broad perspective. By looking at differences in the parts and processes of different educational systems, we can learn from each other and develop a more integrated perspective on teacher education. Most research studies in the field of primary mathematics teacher education at the international level focus on curricula within teacher education and on the knowledge a primary teacher needs for teaching well. WNA provides a context for developing understandings and constructing arguments that adhere to the practices and norms of more advanced mathematics. Two key issues frame the chapter: ways to increasing and deepening teachers’ mathematical understandings and developing tools that support their mathematics teaching. Examples from seven countries are accompanied by brief information about the organization of primary teacher education in each of them.
The Theory of School Arithmetic: Whole Numbers
Authors: Ma Liping , Kessel Cathy
Published: April 2018

In 1999, Knowing and Teaching Elementary Mathematics: Teachers’ Understanding of Fundamental Mathematics in China and the United States presented readers with a puzzle. Four of its six chapters concerned interviews of US and Chinese primary teachers. (Note that the two groups of teachers were not chosen to be representative or similar in status.) The teachers described how they would respond to four classroom situations: teaching subtraction with regrouping; addressing a mistake in multi-digit multiplication; creating a word problem for division by fractions; and addressing an incorrect student conjecture about area and perimeter. The puzzle: Why did the US teachers, all of whom had tertiary degrees and were enrolled in intensive post-graduate programs, show less knowledge of school mathematics than the Chinese teachers, who had so much less education?

An important part of the answer may be that school arithmetic in the two countries was profoundly different. (We write ‘was’ because expectations have changed in both countries. For example, influenced by the 1989 US Curriculum and Evaluation Standards, significant changes in school arithmetic appear in the 2001 Chinese Mathematics Curriculum Standards.) The knowledge displayed by the Chinese teachers was supported by the solid substance of school arithmetic in China. But, such knowledge was not readily available to their US counterparts. In this article, we give an account of this ‘solid substance’ for whole numbers and end with some examples of its connection with the teachers’ responses.
Low Numeracy: From Brain to Education
Authors: Butterworth Brian
Published: April 2018

It is widely agreed that humans inherit a numerical competence, though the exact nature of this competence is disputed. I argue that it is the inherited competence with whole numbers (the ‘number module’) that is foundational for arithmetical development. This is clear from a longitudinal study of learners from kindergarten to year 5. Recent research has identified a brain network that underlies our capacity for numbers and arithmetic, with whole number processing a core region of this network. A twin study shows a strong heritable component in whole number competence, its link to arithmetical development and to the brain region. These findings have implications for improving numeracy skills especially among low-attaining learners.
The What and Why of Whole Number Arithmetic: Foundational Ideas from History, Language and Societal Changes
Authors: Sun Xu Hua , Chambris Christine , Sayers Judy , Siu Man Keung , Cooper Jason , Dorier Jean-Luc , de Lora Sued Sarah Inés González , Thanheiser Eva , Azrou Nadia , McGarvey Lynn , Houdement Catherine , Ejersbo Lisser Rye
Published: April 2018

Increasing globalization encourages assumptions of universalism in teaching and learning, in which cultural and contextual factors are perceived as nonessential. However, our teaching and learning are unavoidably embedded in history, language and culture, from which we draw to organize our educational systems. Such factors can remain hidden but can also provide us with opportunities to gain a deeper understanding of constraints that are taken for granted. This chapter provides a meta-level analysis and synthesis of the what and why of whole number arithmetic (WNA). The summary provides background for the whole volume, which identifies the historical, cultural and linguistic foundations upon which other aspects of learning, teaching and assessment are based. We begin with a historical survey of the development of pre-numeral and numeral systems. We then explore the epistemological and pedagogical insights and highlight the differences between linguistic practices and their links with the universal decimal features of WNA. We investigate inconsistencies between spoken and written numbers and the incompatibility of numeration and calculation and review a number of teaching interventions. Finally, we report the influence of economics and business, academic mathematics, science and technology and public and private stakeholders on WNA to understand how and why curriculum changes are made, with a focus on the fundamental losses and gains.
Metal hyperaccumulating Brassicaceae from the ultramafic area of Yahyalı in Kayseri province, Turkey
Authors: Çelik Jale , Aksoy Ahmet , Leblebici Zeliha
Published: April 2018

Many of the plants found in serpentine areas are endemics and they may accumulate Ni at high concentration. High accumulation of Cr is rare, or in some views, never properly demonstrated. Generally, a very small proportion of any serpentine flora shows high accumulation of Ni, in some serpentine areas Ni accumulators are completely absent. There are approximately 570 hyperaccumulator plant species found on earth, 450 of them are Ni hyperaccumulators. A few of the Ni accumulators have potential for phytoremediation or phytomining. In the present study, 19 different Brassicaceae members growing in serpentine habitats in the district of Yahyalı, Kayseri province, Turkey viz., members of genera Aethionema, Alyssum, Arabis, Heldreichia, Hesperis, Iberis, Isatis, Microthlaspi, Odontarrhena, Pseudosempervivum and Thlaspi were investigated. Nickel concentrations in the soil and underground and aboveground parts of plants were determined by using ICP‐OES. It was observed that Ni concentrations of seven taxa (Odontarrhena muralis, O. oxycarpa, Isatis cappadocica subsp. cappadocica, Microthlaspi perfoliatum, Pseudosempervivum sempervivum, Thlaspi triangulare, Thlaspi rosulare) reach the threshold criterion of 1,000 mg kg−1 for Ni hyperaccumulation. In this study Ni concentrations in aboveground tissues of I. cappadocica subsp. cappadocica are determined as 5,587 mg kg−1 (in dry weight). Accordingly, it is suggested that this taxon be added to the list of Ni hyperaccumulator plants.
Multi-objective colliding bodies optimization algorithm for design of trusses
Authors: Kaveh Ali , Mahdavi Vahid Reza
Published: April 2018

This article presents a new population-based optimization algorithm to solve the multi-objective optimization problems of truss structures. This method is based on the recently developed single-solution algorithm proposed by the present authors, so called colliding bodies optimization (CBO), with each agent solution being considered as an object or body with mass. In the proposed multi-objective colliding bodies optimization (MOCBO) algorithm, the collision theory strategy as the search process is utilized and the Maximin fitness procedure is incorporated to the CBO for sorting the agents. A series of well-known test functions with different characteristics and number of objective functions are studied. In order to measure the accuracy and efficiency of the proposed algorithm, its results are compared to those of the previous methods available in the literature, such as SPEA2, NSGA-II and MOPSO algorithms. Thereafter, two truss structural examples considering bi-objective functions are optimized. The performance of the proposed algorithm is more accurate and requires a lower computational cost than the other considered algorithms. In addition, the present methodology uses simple formulation and does not require internal parameter tuning.

Highlights A new population-based algorithm is presented for multi-objective optimization. The algorithm is based on the recently developed single-solution colliding bodies optimization (CBO). The proposed multi-objective colliding bodies optimization is abbreviated as MOCBO. MOCBO utilizes the maximin fitness procedure for sorting the agents. A series of well-known test functions and number of objective functions are studied. The MOCBO is more accurate and requires lower computational cost. The MOCBO method uses simple formulation and requires no internal parameter tuning.
ASSESSING THE EARLY HOLOCENE ENVIRONMENT OF NORTHWESTERN GUYANA: AN ISOTOPIC ANALYSIS OF HUMAN AND FAUNAL REMAINS
Authors: Daggers Louisa , Plew Mark G. , Edwards Alex , Evans Samantha , Trayler Robin B.
Published: April 2018

This study uses stable carbon δ13C and oxygen δ18O isotope compositions data to assess the extent to which diet breadths of northwestern Guyana changed during the Holocene. We analyzed human bone and enamel remains from seven shell mound sites dating between 7500 and 2600 BP. Our analyses demonstrate some constancy in C3 plant availability during the past several thousand years, though we note increasing reliance on such plants beginning in the Early Holocene. We also document warming intervals during the Early Holocene (Early Archaic) that appear to correlate with dry periods known elsewhere in the central Amazon during this period.
Use of vaccines and factors associated with their uptake variability in dogs, cats and rabbits attending a large sentinel network of veterinary practices across Great Britain
Authors: Sánchez-Vizcaíno F. , Muniesa A. , Singleton D. A. , Jones P. H. , Noble P. J. , Gaskell R. M. , Dawson S. , Radford A. D.
Published: April 2018

Vaccination remains a mainstay of companion animal population health. However, how vaccine use at a population level complies with existing guidelines is unknown. Here we use electronic health records to describe vaccination in dogs, cats and rabbits attending a large sentinel network of UK veterinary practices. In total, 77.9% (95% CI: 77.6–78.1) of animals had recorded vaccinations. The percentage of animals with recorded vaccinations was higher in dogs, neutered animals, in insured dogs and cats and in purebred dogs. Vaccination rates varied in different regions of Great Britain in all species. Dogs and cats belonging to owners living in less deprived areas of England and Scotland were more likely to be recorded as vaccinated. In the vaccinated population, cats received more core vaccines per year of life (0.86) than dogs (0.75), with feline leukaemia vaccines almost as frequent as core vaccines. In dogs, leptospira vaccines were more frequent than core vaccines. This descriptive study suggests a substantial proportion of animals are not benefiting from vaccine protection. For the first time, we identify potential factors associated with variations in recorded vaccination frequency, providing a critical baseline against which to monitor future changes in companion animal vaccination and evidence to inform future targeted health interventions.
Cultured Human Retinal Pigment Epithelial (hRPE) Sheets: A Search for Suitable Storage Conditions
Authors: Khan Ayyad Z. , Utheim Tor P. , Reppe Sjur , Sandvik Leiv , Lyberg Torstein , Roald Borghild B.-H. , Ibrahim Ibrahim B. , Eidet Jon R.
Published: April 2018

The advancement of human retinal pigment epithelial cell (hRPE) replacement therapy is partly dependent on optimization of cell culture, cell preservation, and storage medium. This study was undertaken to search for a suitable storage temperature and storage medium for hRPE. hRPE monolayer sheets were cultured under standard conditions at 37°C and then randomized for storage at six temperatures (4, 16, 20, 24, 28, and 37°C) for 7 days. After revealing a suitable storage temperature, hRPE sheets were subsequently stored with and without the silk protein sericin added to the storage medium. Live/dead assay, light microscopy, pH, and phenotypic expression of various proteins were used to assess cell cultures stored at different temperatures. After 7 days of storage, hRPE morphology was best preserved at 4°C. Addition of sericin to the storage medium maintained the characteristic morphology of the preserved cells, and improved pigmentation and levels of pigmentation-related proteins in the cultured hRPE sheets following a 7-day storage period at 4°C.
Controlling symmetry and localization with an artificial gauge field in a disordered quantum system
Authors: Hainaut Clément , Manai Isam , Clément Jean-François , Garreau Jean Claude , Szriftgiser Pascal , Lemarié Gabriel , Cherroret Nicolas , Delande Dominique , Chicireanu Radu
Published: April 2018

Anderson localization, the absence of diffusion in disordered media, draws its origins from the destructive interference between multiple scattering paths. The localization properties of disordered systems are expected to be dramatically sensitive to their symmetries. So far, this question has been little explored experimentally. Here we investigate the realization of an artificial gauge field in a synthetic (temporal) dimension of a disordered, periodically driven quantum system. Tuning the strength of this gauge field allows us to control the parity–time symmetry properties of the system, which we probe through the experimental observation of three symmetry-sensitive signatures of localization. The first two are the coherent backscattering, marker of weak localization, and the recently predicted coherent forward scattering, genuine interferential signature of Anderson localization. The third is the direct measurement of the β(g) scaling function in two different symmetry classes, allowing to demonstrate its universality and the one-parameter scaling hypothesis.
The ASIC3/P2X3 cognate receptor is a pain-relevant and ligand-gated cationic channel
Authors: Stephan Gabriele , Huang Lumei , Tang Yong , Vilotti Sandra , Fabbretti Elsa , Yu Ye , Nörenberg Wolfgang , Franke Heike , Gölöncsér Flóra , Sperlágh Beáta , Dopychai Anke , Hausmann Ralf , Schmalzing Günther , Rubini Patrizia , Illes Peter
Published: April 2018

Two subclasses of acid-sensing ion channels (ASIC3) and of ATP-sensitive P2X receptors (P2X3Rs) show a partially overlapping expression in sensory neurons. Here we report that both recombinant and native receptors interact with each other in multiple ways. Current measurements with the patch-clamp technique prove that ASIC3 stimulation strongly inhibits the P2X3R current partly by a Ca2+-dependent mechanism. The proton-binding site is critical for this effect and the two receptor channels appear to switch their ionic permeabilities during activation. Co-immunoprecipation proves the close association of the two protein structures. BN-PAGE and SDS-PAGE analysis is also best reconciled with the view that ASIC3 and P2X3Rs form a multiprotein structure. Finally, in vivo measurements in rats reveal the summation of pH and purinergically induced pain. In conclusion, the receptor subunits do not appear to form a heteromeric channel, but tightly associate with each other to form a protein complex, mediating unidirectional inhibition.
Distinct molecular pathways mediate Mycn and Myc-regulated miR-17-92 microRNA action in Feingold syndrome mouse models
Authors: Mirzamohammadi Fatemeh , Kozlova Anastasia , Papaioannou Garyfallia , Paltrinieri Elena , Ayturk Ugur M. , Kobayashi Tatsuya
Published: April 2018

Feingold syndrome is a skeletal dysplasia caused by loss-of-function mutations of either MYCN (type 1) or MIR17HG that encodes miR-17-92 microRNAs (type 2). Since miR-17-92 expression is transcriptionally regulated by MYC transcription factors, it has been postulated that Feingold syndrome type 1 and 2 may be caused by a common molecular mechanism. Here we show that Mir17-92 deficiency upregulates TGF-β signaling, whereas Mycn-deficiency downregulates PI3K signaling in limb mesenchymal cells. Genetic or pharmacological inhibition of TGF-β signaling efficiently rescues the skeletal defects caused by Mir17-92 deficiency, suggesting that upregulation of TGF-β signaling is responsible for the skeletal defect of Feingold syndrome type 2. By contrast, the skeletal phenotype of Mycn-deficiency is partially rescued by Pten heterozygosity, but not by TGF-β inhibition. These results strongly suggest that despite the phenotypical similarity, distinct molecular mechanisms underlie the pathoetiology for Feingold syndrome type 1 and 2.
Pharmacodynamics of mutant-IDH1 inhibitors in glioma patients probed by in vivo 3D MRS imaging of 2-hydroxyglutarate
Authors: Andronesi Ovidiu C. , Arrillaga-Romany Isabel C. , Ly K. Ina , Bogner Wolfgang , Ratai Eva M. , Reitz Kara , Iafrate A. John , Dietrich Jorg , Gerstner Elizabeth R. , Chi Andrew S. , Rosen Bruce R. , Wen Patrick Y. , Cahill Daniel P. , Batchelor Tracy T.
Published: April 2018

Inhibitors of the mutant isocitrate dehydrogenase 1 (IDH1) entered recently in clinical trials for glioma treatment. Mutant IDH1 produces high levels of 2-hydroxyglurate (2HG), thought to initiate oncogenesis through epigenetic modifications of gene expression. In this study, we show the initial evidence of the pharmacodynamics of a new mutant IDH1 inhibitor in glioma patients, using non-invasive 3D MR spectroscopic imaging of 2HG. Our results from a Phase 1 clinical trial indicate a rapid decrease of 2HG levels by 70% (CI 13%, P = 0.019) after 1 week of treatment. Importantly, inhibition of mutant IDH1 may lead to the reprogramming of tumor metabolism, suggested by simultaneous changes in glutathione, glutamine, glutamate, and lactate. An inverse correlation between metabolic changes and diffusion MRI indicates an effect on the tumor-cell density. We demonstrate a feasible radiopharmacodynamics approach to support the rapid clinical translation of rationally designed drugs targeting IDH1/2 mutations for personalized and precision medicine of glioma patients.
A new failure mechanism of electromigration by surface diffusion of Sn on Ni and Cu metallization in microbumps
Authors: Chang Yuan-Wei , Hu Chia-chia , Peng Hsin-Ying , Liang Yu-Chun , Chen Chih , Chang Tao-chih , Zhan Chau-Jie , Juang Jing-Ye
Published: April 2018

Microbumps in three-dimensional integrated circuit now becomes essential technology to reach higher packaging density. However, the small volume of microbumps dramatically changes the characteristics from the flip-chip (FC) solder joints. For a 20 µm diameter microbump, the cross-section area and the volume are only 1/25 and 1/125 of a 100 µm diameter FC joint. The small area significantly enlarges the current density although the current crowding effect was reduced at the same time. The small volume of solder can be fully transformed into the intermetallic compounds (IMCs) very easily, and the IMCs are usually stronger under electromigration (EM). These result in the thoroughly change of the EM failure mechanism in microbumps. In this study, microbumps with two different diameter and flip-chip joints were EM tested. A new failure mechanism was found obviously in microbumps, which is the surface diffusion of Sn. Under EM testing, Sn atoms tend to migrate along the surface to the circumference of Ni and Cu metallization to form Ni3Sn4and Cu3Sn IMCs respectively. When the Sn diffuses away, necking or serious void formation occurs in the solder, which weakens the electrical and mechanical properties of the microbumps. Theoretic calculation indicates that this failure mode will become even significantly for the microbumps with smaller dimensions than the 18 µm microbumps.
Metabolomics and pathway analyses to characterize metabolic alterations in pregnant dairy cows on D 17 and D 45 after AI
Authors: Guo Y. S. , Tao J. Z.
Published: April 2018

Nutrient flow to the embryo and placenta is crucial for proper development and growth during pregnancy. In this study, a metabonomic analysis was undertaken to better understand global changes in pregnant dairy cows on D 17 and D 45 after timed artificial insemination (AI). Metabolic changes in the blood plasma of pregnant dairy cows were investigated using HPLC-MS and a multivariate statistical analysis. Changes in metabolic networks were established using the MetPA method. Alterations in six metabolic pathways were found on D 17 and D 45, including variations in the level of alpha-linolenic acid metabolism, glycerophospholipid metabolism, pentose and glucuronate interconversions, glycerolipid metabolism, folate biosynthesis, and tyrosine metabolism. In addition to these pathways, 9 metabolic pathways were markedly altered on D 45. These pathways included changes in the one-carbon pool caused by folate; phenylalanine, tyrosine and tryptophan biosynthesis; thiamine metabolism; pantothenate and CoA biosynthesis; purine metabolism; inositol phosphate metabolism; amino sugar and nucleotide sugar metabolism; pentose phosphate; and the TCA pathway. The combination of metabonomics and network methods used in this study generated rich biochemical insight into possible biological modules related to early pregnancy in dairy cows.
Beyond dose: Pulsed antibiotic treatment schedules can maintain individual benefit while reducing resistance
Authors: Baker Christopher M. , Ferrari Matthew J. , Shea Katriona
Published: April 2018

The emergence of treatment-resistant microbes is a key challenge for disease treatment and a leading threat to human health and wellbeing. New drugs are always in development, but microbes regularly and rapidly acquire resistance. We must consider if altering how we administer drugs at the individual level could slow development of resistance. Here we use mathematical models to show that exposing microbes to drug pulses could greatly reduce resistance without increasing individual pathogen load. Our results stem from two key factors: the presence of antibiotics creates a selection pressure for antibiotic resistant microbes, and large populations of bacteria are more likely to harbor drug resistance than small populations. Drug pulsing targets these factors simultaneously. Short duration pulses minimize the time during which there is selection for resistance, and high drug concentrations minimize pathogen abundance. Our work provides a theoretical basis for the design of in vitro and in vivo experiments to test how drug pulsing might reduce the impact of drug resistant infections.
Highly Interactive Brain–Computer Interface Based on Flicker-Free Steady-State Motion Visual Evoked Potential
Authors: Han Chengcheng , Xu Guanghua , Xie Jun , Chen Chaoyang , Zhang Sicong
Published: April 2018

Visual evoked potential-based brain–computer interfaces (BCIs) have been widely investigated because of their easy system configuration and high information transfer rate (ITR). However, the uncomfortable flicker or brightness modulation of existing methods restricts the practical interactivity of BCI applications. In our study, a flicker-free steady-state motion visual evoked potential (FF-SSMVEP)-based BCI was proposed. Ring-shaped motion checkerboard patterns with oscillating expansion and contraction motions were presented by a high-refresh-rate display for visual stimuli, and the brightness of the stimuli was kept constant. Compared with SSVEPs, few harmonic responses were elicited by FF-SSMVEPs, and the frequency energy of SSMVEPs was concentrative. These FF-SSMVEPs evoked “single fundamental peak” responses after signal processing without harmonic and subharmonic peaks. More stimulation frequencies could thus be selected to elicit more responding fundamental peaks without overlap with harmonic peaks. A 40-target online SSMVEP-based BCI system was achieved that provided an ITR up to 1.52 bits per second (91.2 bits/min), and user training was not required to use this system. This study also demonstrated that the FF-SSMVEP-based BCI system has low contrast and low visual fatigue, offering a better alternative to conventional SSVEP-based BCIs.
Toxicity of enrofloxacin, copper and their interactions on soil microbial populations and ammonia-oxidizing archaea and bacteria
Authors: Wei Ziyan , Wang Jinhua , Zhu Lusheng , Wang Jun , Zhu Guodong
Published: April 2018

Enrofloxacin (EFX) is one of the most frequently used broad-spectrum veterinary drugs, and copper (Cu) is a heavy metal that could easily bind to certain antibiotic molecules. Hence EFX and Cu were chosen as representatives of antibiotics and heavy metals to explore the abundance and variation of soil microbial populations with a plate-counting technique, as well as the copy numbers of amoA gene in ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) by quantitative PCR methods in Argosols samples. Treatments of applied EFX (0.05, 0.20, 0.80 mmol/kg), Cu (1.60 mmol/kg) and combined EFX and Cu (at molar ratios of 1:32,1:8,1:2) exhibited various effects on different soil microorganisms. The toxicity of combined EFX and Cu was more strongly expressed on both soil microbial populations and amoA gene (AOA and AOB) compared to the EFX treatment alone, in most cases, time and dose effects were observed. With respect to the amoA gene, the AOA-amoA gene was more abundant than the AOB-amoA gene, and the ratio ranged from ~8 to ~11. Moreover, the interaction types of EFX and Cu were more likely to be antagonistic (64.29%) than synergistic (35.71%) on soil abundance and function, which may be related to the incubation time and the ratio of EFX to Cu in the soil.
A Multi-Parameter Analysis of Cellular Coordination of Major Transcriptome Regulation Mechanisms
Authors: Jiang Wen , Guo Zhanyong , Lages Nuno , Zheng W. Jim , Feliers Denis , Zhang Fangyuan , Wang Degeng
Published: April 2018

To understand cellular coordination of multiple transcriptome regulation mechanisms, we simultaneously measured transcription rate (TR), mRNA abundance (RA) and translation activity (TA). This revealed multiple insights. First, the three parameters displayed systematic statistical differences. Sequentially more genes exhibited extreme (low or high) expression values from TR to RA, and then to TA; that is, cellular coordination of multiple transcriptome regulatory mechanisms leads to sequentially enhanced gene expression selectivity as the genetic information flow from the genome to the proteome. Second, contribution of the stabilization-by-translation regulatory mechanism to the cellular coordination process was assessed. The data enabled an estimation of mRNA stability, revealing a moderate but significant positive correlation between mRNA stability and translation activity. Third, the proportion of mRNA occupied by un-translated regions (UTR) exhibited a negative relationship with the level of this correlation, and was thus a major determinant of the mode of regulation of the mRNA. High-UTR-proportion mRNAs tend to defy the stabilization-by-translation regulatory mechanism, staying out of the polysome but remaining stable; mRNAs with little UTRs largely followed this regulation. In summary, we quantitatively delineated the relationship among multiple transcriptome regulation parameters, i.e., cellular coordination of corresponding regulatory mechanisms.
Antagonistic PCP Signaling Pathways in the developing Drosophila eye
Authors: Katanaev Vladimir L. , Egger-Adam Diane , Tomlinson Andrew
Published: April 2018

In Planar cell polarity (PCP), cells coordinately polarize their cytoskeletons within the plane of the epithelium in which they lie. In most insect epithelia this is indicated by the coordinated projections of the hairs secreted by the ectodermal cells. PCP of this form has been effectively studied in Drosophila, but it has proven difficult to achieve an integrated description of the roles played by the various proteins. In the insect eye, PCP is not evident as the polarization of individual cells, but as the asymmetric arrangements of the cells of the ommatidia. This different form of PCP allows different studies to be performed, and using this system we have detected the action of two antagonistic signaling pathways. Even though antagonistic, the two pathways synergize and cooperate to ensure that the correct arrangement of the cells is achieved. The cooperative use of antagonistic signaling pathways occurs in the polarization of chemotacting cells, and we discuss the possibility that a similar molecular principle may underlie PCP.
Inhibition of homoserine dehydrogenase by formation of a cysteine-NAD covalent complex
Authors: Ogata Kohei , Yajima Yui , Nakamura Sanenori , Kaneko Ryosuke , Goto Masaru , Ohshima Toshihisa , Yoshimune Kazuaki
Published: April 2018

Homoserine dehydrogenase (EC 1.1.1.3, HSD) is an important regulatory enzyme in the aspartate pathway, which mediates synthesis of methionine, threonine and isoleucine from aspartate. Here, HSD from the hyperthermophilic archaeon Sulfolobus tokodaii (StHSD) was found to be inhibited by cysteine, which acted as a competitive inhibitor of homoserine with a Ki of 11 μM and uncompetitive an inhibitor of NAD and NADP with Ki’s of 0.55 and 1.2 mM, respectively. Initial velocity and product (NADH) inhibition analyses of homoserine oxidation indicated that StHSD first binds NAD and then homoserine through a sequentially ordered mechanism. This suggests that feedback inhibition of StHSD by cysteine occurs through the formation of an enzyme-NAD-cysteine complex. Structural analysis of StHSD complexed with cysteine and NAD revealed that cysteine situates within the homoserine binding site. The distance between the sulfur atom of cysteine and the C4 atom of the nicotinamide ring was approximately 1.9 Å, close enough to form a covalent bond. The UV absorption-difference spectrum of StHSD with and without cysteine in the presence of NAD, exhibited a peak at 325 nm, which also suggests formation of a covalent bond between cysteine and the nicotinamide ring.
Author Correction: The Incipient Motion Features of Sediment from Yangtze Estuary: Annular Flume Experiments
Authors: Wei Huang , Ya-kun Liu , Hua-lin Wu , Yuan-yang Wan
Published: April 2018

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Testing the impact of effective population size on speciation rates – a negative correlation or lack thereof in lichenized fungi
Authors: Huang Jen-Pan , Leavitt Steven D. , Lumbsch H. Thorsten
Published: April 2018

The effect of microevolutionary processes on macroevolutionary patterns, and vice versa, is an important but under-investigated question. Here we present an integrative population genetic and phylogenetic study using molecular sequence data from three lichen-forming fungal lineages to empirically test the potential correlation between effective population size – approximated by the parameter θ – and estimated speciation rates using a phylogenetic tree (λ). A negative association between θ and λ was supported in one lineage of lichen-forming fungi, Melanelixia (Parmeliaceae), while no significant relationships was found for two other genera within the same family, Melanohalea and Xanthoparmelia. We discuss the significance of our results and the importance of considering microevolutionary processes when studying macroevolutionary patterns.
Effects of muscle relaxants on ischaemia damage in skeletal muscle
Authors: Ledowski Thomas , Nißler Simone , Wenk Manuel , Pogatzki-Zahn Esther M. , Segelcke Daniel
Published: April 2018

Muscle ischaemia is frequently induced intraoperatively by i.e. a surgical tourniquet or during the re-grafting phase of a free muscle transplant. The resulting muscle cell damage may impact on postoperative recovery. Neuromuscular paralysis may mitigate the effects of ischaemia. After ethics approval, 25 male Sprague-Dawley rats were anaesthetized and randomly assigned to 1 of 4 groups: Sham operation, treatment with normal saline, treatment with rocuronium (muscle relaxant) 0.6 or 1 mg kg−1, respectively. In the non-sham groups, ischaemia of one hind leg was achieved by ligation of the femoral vessels. Muscle biopsies were taken at 30 and 90 min, respectively. Cell damage was assessed in the biopsies via the expression of dystrophin, free calcium, as well as the assessment of cell viability. Pre-ischaemia muscle relaxation led to a reduction in ischaemia-induced muscle cell damage when measured by the expression of dystrophin, cell viability and the expression of free calcium even after 90 min of ischaemia (i.e. ratio control/ischaemic site for dystrophin expression after saline 0.58 ± 0.12 vs. after 1 mg/kg rocuronium 1.08 ± 0.29; P < 0.05). Muscle relaxation decreased the degree of ischaemia-induced muscle cell damage. The results may have significant clinical implications.
Quantization of geometric phase with integer and fractional topological characterization in a quantum Ising chain with long-range interaction
Authors: Sarkar Sujit
Published: April 2018

An attempt is made to study and understand the behavior of quantization of geometric phase of a quantum Ising chain with long range interaction. We show the existence of integer and fractional topological characterization for this model Hamiltonian with different quantization condition and also the different quantized value of geometric phase. The quantum critical lines behave differently from the perspective of topological characterization. The results of duality and its relation to the topological quantization is presented here. The symmetry study for this model Hamiltonian is also presented. Our results indicate that the Zak phase is not the proper physical parameter to describe the topological characterization of system with long range interaction. We also present quite a few exact solutions with physical explanation. Finally we present the relation between duality, symmetry and topological characterization. Our work provides a new perspective on topological quantization.
Increasing salinity drastically reduces hatching success of crustaceans from depression wetlands of the semi-arid Eastern Cape Karoo region, South Africa
Authors: Mabidi Annah , Bird Matthew S. , Perissinotto Renzo
Published: April 2018

Salinity is an important factor affecting freshwater aquatic species distribution and diversity. The semi-arid Eastern Cape Karoo region of South Africa has been earmarked for shale gas development through hydraulic fracturing. The process uses large amounts of water and produces briny wastewater. When not managed properly, these wastewaters may lead to salinisation of surface freshwater bodies in the region. Therefore, the effect of salinity on the hatching success of crustacean resting eggs was examined using sediments from four depression wetlands found in the region. The sediments were exposed for 28 days to salinity levels of 0.5 g L−1, 2.5 g L−1, 5 g L−1 and 10 g L−1. Control aquaria in which no salt was added were also set up. There was a significant decrease in the emerged taxa richness and abundances at salinities of 2.5 g L−1 and above. Anostraca, Notostraca and Spinicaudata hatchlings were abundant at salinities of 0.5 g L−1 and below, while Copepoda, Daphniidae (Cladocera) and Ostracoda were observed in the highest salinity, but their densities were still lower with increased salinities. Given the importance of large branchiopods in the trophic balance of depression wetlands, their loss may alter the ecological balance and function of these ecosystems.
Activation of the DnaK-ClpB Complex is Regulated by the Properties of the Bound Substrate
Authors: Fernández-Higuero Jose Angel , Aguado Alejandra , Perales-Calvo Judit , Moro Fernando , Muga Arturo
Published: April 2018

The chaperone ClpB in bacteria is responsible for the reactivation of aggregated proteins in collaboration with the DnaK system. Association of these chaperones at the aggregate surface stimulates ATP hydrolysis, which mediates substrate remodeling. However, a question that remains unanswered is whether the bichaperone complex can be selectively activated by substrates that require remodeling. We find that large aggregates or bulky, native-like substrates activates the complex, whereas a smaller, permanently unfolded protein or extended, short peptides fail to stimulate it. Our data also indicate that ClpB interacts differently with DnaK in the presence of aggregates or small peptides, displaying a higher affinity for aggregate-bound DnaK, and that DnaK-ClpB collaboration requires the coupled ATPase-dependent remodeling activities of both chaperones. Complex stimulation is mediated by residues at the β subdomain of DnaK substrate binding domain, which become accessible to the disaggregase when the lid is allosterically detached from the β subdomain. Complex activation also requires an active NBD2 and the integrity of the M domain-ring of ClpB. Disruption of the M-domain ring allows the unproductive stimulation of the DnaK-ClpB complex in solution. The ability of the DnaK-ClpB complex to discrimínate different substrate proteins might allow its activation when client proteins require remodeling.
Satellite DNA in Vicia faba is characterized by remarkable diversity in its sequence composition, association with centromeres, and replication timing
Authors: Ávila Robledillo Laura , Koblížková Andrea , Novák Petr , Böttinger Katharina , Vrbová Iva , Neumann Pavel , Schubert Ingo , Macas Jiří
Published: April 2018

Satellite DNA, a class of repetitive sequences forming long arrays of tandemly repeated units, represents substantial portions of many plant genomes yet remains poorly characterized due to various methodological obstacles. Here we show that the genome of the field bean (Vicia faba, 2n = 12), a long-established model for cytogenetic studies in plants, contains a diverse set of satellite repeats, most of which remained concealed until their present investigation. Using next-generation sequencing combined with novel bioinformatics tools, we reconstructed consensus sequences of 23 novel satellite repeats representing 0.008–2.700% of the genome and mapped their distribution on chromosomes. We found that in addition to typical satellites with monomers hundreds of nucleotides long, V. faba contains a large number of satellite repeats with unusually long monomers (687–2033 bp), which are predominantly localized in pericentromeric regions. Using chromatin immunoprecipitation with CenH3 antibody, we revealed an extraordinary diversity of centromeric satellites, consisting of seven repeats with chromosome-specific distribution. We also found that in spite of their different nucleotide sequences, all centromeric repeats are replicated during mid-S phase, while most other satellites are replicated in the first part of late S phase, followed by a single family of FokI repeats representing the latest replicating chromatin.
De novo assembly and analysis of the Artemisia argyi transcriptome and identification of genes involved in terpenoid biosynthesis
Authors: Liu Miaomiao , Zhu Jinhang , Wu Shengbing , Wang Chenkai , Guo Xingyi , Wu Jiawen , Zhou Meiqi
Published: April 2018

Artemisia argyi Lev. et Vant. (A. argyi) is widely utilized for moxibustion in Chinese medicine, and the mechanism underlying terpenoid biosynthesis in its leaves is suggested to play an important role in its medicinal use. However, the A. argyi transcriptome has not been sequenced. Herein, we performed RNA sequencing for A. argyi leaf, root and stem tissues to identify as many as possible of the transcribed genes. In total, 99,807 unigenes were assembled by analysing the expression profiles generated from the three tissue types, and 67,446 of those unigenes were annotated in public databases. We further performed differential gene expression analysis to compare leaf tissue with the other two tissue types and identified numerous genes that were specifically expressed or up-regulated in leaf tissue. Specifically, we identified multiple genes encoding significant enzymes or transcription factors related to terpenoid synthesis. This study serves as a valuable resource for transcriptome information, as many transcribed genes related to terpenoid biosynthesis were identified in the A. argyi transcriptome, providing a functional genomic basis for additional studies on molecular mechanisms underlying the medicinal use of A. argyi.
Etidronate prevents dystrophic cardiac calcification by inhibiting macrophage aggregation
Authors: Bauer Carolin , le Saux Olivier , Pomozi Viola , Aherrahrou Redouane , Kriesen Rene , Stölting Stephanie , Liebers Annett , Kessler Thorsten , Schunkert Heribert , Erdmann Jeanette , Aherrahrou Zouhair
Published: April 2018

Cardiovascular calcification is associated with high risk of vascular disease. This involves macrophage infiltration of injured vascular tissue and osteoclast-related processes. Splenic monocytes from mice, that are predisposed (C3H) or resistant (B6) to calcification, were isolated and differentiated in vitro with M-CSF to generate macrophages, which aggregate to form multinucleated (MN) cells in the presence of RANKL. MN cell formation was significantly decreased in monocytes from resistant compared with calcifying mice. Conditioned media from C3H macrophages strongly induced calcification in vitro. However, medium from B6 macrophages inhibited calcification. An increase in ICAM-1 was detected in conditioned media from C3H macrophages compared with B6, suggesting a key role for this molecule in calcification processes. Due to natural genetic loss of Abcc6, the causal gene for cardiac calcification, C3H mice have reduced plasma levels of inorganic pyrophosphate (PPi), a potential calcification inhibitor. Supplementation of C3H mice with PPi or Etidronate prevented but did not completely reverse cardiac calcification. Our data provide strong evidence of the pathogenesis of macrophages and MNs during tissue calcification and suggest PPi or its analogue Etidronate as a potential inhibitor of MN formation and calcification. Furthermore, the adhesion molecule ICAM-1 was shown to play a key role in calcification.