bluuebunny/crossref_metadata_2025 huggingface dataset:
The coordinate transformation method for design of polarizers on HL-2A electron cyclotron resonance heating and current drive systems
Authors: Xia D. H. , Huang M. , Zhou J. , Rao J. , Zhuang G.
Published: October 2013

Polarizers are widely used to change the polarization of millimeter waves on the electron cyclotron resonance heating and current drive (ECRH and CD) systems. A new method based on the coordinate transformation and the Fourier expansion (the so-called C-method) has been developed for design of polarizers on the HL-2A ECRH and CD systems. This method transforms the grating problem to an eigenvalue problem, making it easy and clear to understand and solve. The comparison between the C-method, the integral method, and the low power test results is presented. It indicates that the C-method can be considered as a rigorous numerical method for the design of polarizers. Finally, two polarizers were designed based on the C-method which can be used together to achieve almost arbitrary polarization.
In-situ energy dispersive x-ray diffraction study of the growth of CuO nanowires by annealing method
Authors: Srivastava Himanshu , Ganguli Tapas , Deb S. K. , Sant Tushar , Poswal H. K. , Sharma Surinder M.
Published: October 2013

The in-situ growth of CuO nanowires was studied by Energy Dispersive X-ray Diffraction (EDXRD) to observe the mechanism of growth. The study was carried out for comparison at two temperatures—at 500 °C, the optimum temperature of the nanowires growth, and at 300 °C just below the temperature range of the growth. The in situ observation revealed the successive oxidation of Cu foil to Cu2O layer and finally to CuO layer. Further analysis showed the presence of a compressive stress in CuO layer due to interface at CuO and Cu2O layers. The compressive stress was found to increase with the growth of the nanowires at 500 °C while it relaxed with the growth of CuO layer at 300 °C. The present results do not support the existing model of stress relaxation induced growth of nanowires. Based on the detailed Transmission Electron Microscope, Scanning Electron Microscope, and EDXRD results, a microstructure based growth model has been suggested.
Charge of water droplets in non-polar oils
Authors: Schoeler Andreas M. , Josephides Dimitris N. , Sajjadi Shahriar , Lorenz Christian D. , Mesquida Patrick
Published: October 2013

Recent advances in droplet manipulation methods by electric fields and signals require a deeper understanding of water droplet charge. In this paper, we have investigated the electrophoretic motion of individual water microdroplets injected into non-polar silicone and paraffin oil by video optical microscopy on an individual droplet basis to determine droplet charge. It was found that the initial surface charge density of surfactant free droplets directly after injection from a micropipette is positive and of the order of 10−6 C/m2, regardless of pH and ion concentration in the range from pH 4 to pH 10 and from 0.01 mmol/l to 1.5 mol/l, respectively. The experimental results together with molecular dynamics simulations show that the nature and polarity of the charge can be explained by anisotropic orientation of water molecules at the interface rather than selective adsorption of ions. Furthermore, we showed that slip at the liquid-liquid boundary must be taken into account when interpreting electrophoretic measurements of droplets.
A method for thermal diffusivity measurement in fluids
Authors: Marín E. , Hernández-Rosales E. , Mansanares A. M. , Ivanov R. , Rojas-Trigos J. B. , Calderón A.
Published: October 2013

A technique is proposed for thermal diffusivity measurement in fluids. It is based on the Angstrom method, but with excitation of thermal waves by electromagnetic energy absorption and pyroelectric detection. The good agreement between measured thermal diffusivity of air and some test liquids with literature values shows the validity of the method. It is free of some limitations of conventional photopyroelectric technique with length scanning because it is free of moving parts inside the sample and because it avoids problems associated with the non-parallelism between thermal wave generator surface and sensor. It does not require any data normalization procedure or special sample preparation.
Energy efficiency and waste reuse: A solution for sustainability in poor West African countries? Case study of the shea butter supply chain in Burkina Faso
Authors: Noumi Eric Serges , Dabat Marie-Hélène , Blin Joël
Published: October 2013

In West African countries, the objective of producer insertion in competitive markets is often associated with the need to modernize and mechanize production processes, i.e., replace labour by machines. This excludes traditional producers who can barely comply with the economic criteria but who must remain competitive to generate higher incomes. The challenge is to improve the efficiency of traditional methods in supply chains rather than imposing modern technologies that producers hardly adopt. Moreover, West African populations suffer from not having cheap and available energy sources. They, therefore, have to be imaginative for more efficient energy use in order to improve the productivity and quality of their products and support sustainable rural development and incomes. Building on the case study of the shea butter supply chain in Burkina Faso, this article proposes an original approach consisting of improved energy use for a more competitive and sustainable activity. The traditional butter production process consumes a great deal of energy from firewood and generates a lot of organic waste that could be used as an energy source. We examined the feasibility of using alternative energy techniques that could be taken on board as they are simple and designed from local resources, whilst using by-products from the shea butter production chain as biofuels to partially replace firewood. We showed that using alternative energy techniques, taken one by one or combined, can lead to lower energy use and thereby increase women's incomes, whilst helping to conserve forests.
A microfluidic device for uniform-sized cell spheroids formation, culture, harvesting and flow cytometry analysis
Authors: Patra Bishnubrata , Chen Ying-Hua , Peng Chien-Chung , Lin Shiang-Chi , Lee Chau-Hwang , Tung Yi-Chung
Published: October 2013

Culture of cells as three-dimensional (3D) aggregates, named spheroids, possesses great potential to improve in vitro cell models for basic biomedical research. However, such cell spheroid models are often complicated, cumbersome, and expensive compared to conventional Petri-dish cell cultures. In this work, we developed a simple microfluidic device for cell spheroid formation, culture, and harvesting. Using this device, cells could form uniformly sized spheroids due to strong cell–cell interactions and the spatial confinement of microfluidic culture chambers. We demonstrated cell spheroid formation and culture in the designed devices using embryonic stem cells, carcinoma cells, and fibroblasts. We further scaled up the device capable of simultaneously forming and culturing 5000 spheroids in a single chip. Finally, we demonstrated harvesting of the cultured spheroids from the device with a simple setup. The harvested spheroids possess great integrity, and the cells can be exploited for further flow cytometry assays due to the ample cell numbers.
Minimal mechanistic model of siRNA-dependent target RNA slicing by recombinant human Argonaute 2 protein
Authors: Deerberg Andrea , Willkomm Sarah , Restle Tobias
Published: October 2013

Significance

Argonaute (Ago) proteins are the key component of the RNA-induced silencing complex (RISC) and mediate RNA interference (RNAi) in association with small RNAs. Although overall the mechanism of RNAi is well understood, many molecular details of this complex process are not. The implementation of pre-steady-state kinetic techniques enabled us to develop a comprehensive minimal mechanistic model for human Ago 2 (hAgo2)-mediated target RNA binding and cleavage, dissecting binary as well as ternary complex formation and target RNA cleavage into individual substeps. The model presented provides in-depth insights into the complicated interplay of hAgo2 with small RNAs and corresponding target molecules, which in combination with available X-ray structures will eventually lead to better understanding of the underlying mechanisms of RNAi.
Expanded therapeutic potential in activity space of next-generation 5-nitroimidazole antimicrobials with broad structural diversity
Authors: Miyamoto Yukiko , Kalisiak Jarosław , Korthals Keith , Lauwaet Tineke , Cheung Dae Young , Lozano Ricardo , Cobo Eduardo R. , Upcroft Peter , Upcroft Jacqueline A. , Berg Douglas E. , Gillin Frances D. , Fokin Valery V. , Sharpless K. Barry , Eckmann Lars
Published: October 2013

Significance

Drugs against disease-causing microbes are among the major achievements of modern medicine, but many microbes show a tenacious ability to develop resistance, so they are no longer killed by available drugs. We show here for an important class of these drugs, represented by the common drug metronidazole, that broad modifications of the basic drug structure can improve drug activities against several clinically important microbes and unexpectedly overcome different forms of resistance. Several of these new drugs cure infections in animal models and are safe in initial toxicity evaluations. These findings provide reasons to develop this class of drugs as human medicines in the ongoing fight against disease-causing microbes.
Universal features in the photoemission spectroscopy of high-temperature superconductors
Authors: Zhao Junjing , Chatterjee Utpal , Ai Dingfei , Hinks David G. , Zheng Hong , Gu G. D. , Castellan John-Paul , Rosenkranz Stephan , Claus Helmut , Norman Michael R. , Randeria Mohit , Campuzano Juan Carlos
Published: October 2013

The energy gap for electronic excitations is one of the most important characteristics of the superconducting state, as it directly reflects the pairing of electrons. In the copper–oxide high-temperature superconductors (HTSCs), a strongly anisotropic energy gap, which vanishes along high-symmetry directions, is a clear manifestation of the
d
-wave symmetry of the pairing. There is, however, a dramatic change in the form of the gap anisotropy with reduced carrier concentration (underdoping). Although the vanishing of the gap along the diagonal to the square Cu–O bond directions is robust, the doping dependence of the large gap along the Cu–O directions suggests that its origin might be different from pairing. It is thus tempting to associate the large gap with a second-order parameter distinct from superconductivity. We use angle-resolved photoemission spectroscopy to show that the two-gap behavior and the destruction of well-defined electronic excitations are
not
universal features of HTSCs, and depend sensitively on
how
the underdoped materials are prepared. Depending on cation substitution, underdoped samples either show two-gap behavior or not. In contrast, many other characteristics of HTSCs, such as the dome-like dependence of

on doping, long-lived excitations along the diagonals to the Cu–O bonds, and an energy gap at the Brillouin zone boundary that decreases monotonically with doping while persisting above

(the pseudogap), are present in all samples, irrespective of whether they exhibit two-gap behavior or not. Our results imply that universal aspects of high-

superconductivity are relatively insensitive to differences in the electronic states along the Cu–O bond directions.
Excitable human dynamics driven by extrinsic events in massive communities
Authors: Mathiesen Joachim , Angheluta Luiza , Ahlgren Peter T. H. , Jensen Mogens H.
Published: October 2013

Significance

Online social networks have over the last decade influenced the way people interact. Data from Twitter allow for a detailed study of the activity in online massive communities. By studying the frequency by which international brands appear on Twitter and the trade of financial securities on financial markets, we find a characteristic bursty behavior of the activity levels of Twitter users and market participants. We explain the bursty behavior by a simple model of the large-scale human behavior and quantify the correlations in the activity levels. The statistical similarity of the two social systems is an indication that the complex process underlying individual decision-making might not be very different for Twitter users and participants in financial markets.
Direct observation of structurally encoded metal discrimination and ether bond formation in a heterodinuclear metalloprotein
Authors: Griese Julia J. , Roos Katarina , Cox Nicholas , Shafaat Hannah S. , Branca Rui M. M. , Lehtiö Janne , Gräslund Astrid , Lubitz Wolfgang , Siegbahn Per E. M. , Högbom Martin
Published: October 2013

Significance

Metallocofactors enable enzymes to catalyze difficult reactions that would otherwise not be possible, such as the reduction of oxygen. Nature utilizes a number of different metals, and it is crucial that proteins bind the correct metals to execute their function. Nonetheless, the principles that govern metal specificity in proteins remain poorly understood. Here we use an enzyme that forms a heterodinuclear Mn/Fe cofactor with the same protein ligands in both metal-coordinating positions to study how proteins can differentiate between two such similar metals. We show that the protein is intrinsically capable of site-specific metal discrimination. Surprisingly, specificity is achieved in a stepwise process involving not only fundamental affinity differences, but also chemical maturation upon reaction with molecular oxygen.
Milk oligosaccharide sialyl(α2,3)lactose activates intestinal CD11c
+
cells through TLR4
Authors: Kurakevich Ekaterina , Hennet Thierry , Hausmann Martin , Rogler Gerhard , Borsig Lubor
Published: October 2013

Significance

Breast milk provides all nutrients required for the growth and development of the newborn child. In addition to energy source, milk contains other biomolecules, such as oligosaccharides, which contribute to the intestinal colonization through microbiota and development of mucosal immunity. This study shows that specific milk oligosaccharides stimulate intestinal immune responses through binding and activation of dendritic cells. We demonstrate that the milk oligosaccharide sialyl(α2,3)lactose is directly recognized by dendritic cells, resulting in a proinflammatory stimulation. This finding provides evidence that oligosaccharides from dietary sources indeed modulate mucosal immunity.
Structures of the flax-rust effector AvrM reveal insights into the molecular basis of plant-cell entry and effector-triggered immunity
Authors: Ve Thomas , Williams Simon J. , Catanzariti Ann-Maree , Rafiqi Maryam , Rahman Motiur , Ellis Jeffrey G. , Hardham Adrienne R. , Jones David A. , Anderson Peter A. , Dodds Peter N. , Kobe Bostjan
Published: October 2013

Significance

Fungal and oomycete pathogens cause devastating diseases in crop plants and facilitate infection by delivering effector molecules into the plant cell. The secreted effector protein AvrM from flax rust, a fungal pathogen that infects flax plants, internalizes into host cells in the absence of the pathogen, binds to phosphoinositides, and is recognized directly by the resistance protein M in flax to initiate effector-triggered immunity. We describe the crystal structure of AvrM and identify functionally important surface regions in the protein, which advances our understanding of the molecular mechanisms underlying how effectors enter host cells and how they are detected by the plant immune system.
Evidence for supernova injection into the solar nebula and the decoupling of
r
-process nucleosynthesis
Authors: Brennecka Gregory A. , Borg Lars E. , Wadhwa Meenakshi
Published: October 2013

Significance

We present isotopic evidence that supports the injection of supernova material into the early Solar System within a small window of time around the formation of the first solids in the protoplanetary disk. This injected material was not incorporated into the first solids, but subsequently changed the elemental and isotopic composition of the nascent Solar System. The isotopic differences between the first solids and subsequently formed matter in the Solar System require the existence of multiple sources for
r
-process nucleosynthesis.
Nonfunctional Na
V
1.1 familial hemiplegic migraine mutant transformed into gain of function by partial rescue of folding defects
Authors: Cestèle Sandrine , Schiavon Emanuele , Rusconi Raffaella , Franceschetti Silvana , Mantegazza Massimo
Published: October 2013

Significance

Mutations of
SCN1A
, a gene encoding the Na
v
1.1 Na
+
channel, can cause familial hemiplegic migraine (FHM-3) or epilepsy. Epileptogenic mutations induce reduction of its function, leading to decreased excitability of GABAergic neurons, but studies of FHM-3 mutations have generated confusing results. We have reported gain-of-function effects, but complete loss of function has been reported for the mutant L1649Q, a paradoxical result. Here we show that L1649Q function can be rescued in conditions that more closely model real conditions in neurons. When partially rescued, L1649Q shows gain of function and can induce neuronal hyperexcitability, consistently with hyperexcitability of GABAergic neurons as the cause of FHM-3.
Regulation of p53 is critical for vertebrate limb regeneration
Authors: Yun Maximina H. , Gates Phillip B. , Brockes Jeremy P.
Published: October 2013

Significance

Our work establishes that endogenous regulation of the activity of the tumor-suppressor p53 is a critical component in vertebrate limb regeneration and is required for the process to occur. We show that down-regulation of p53 is required for cell cycle reentry of postmitotic differentiated cells, the critical step in the formation of the progenitors for the process of regeneration. We propose that the absence of tumor-suppressors that stabilize p53 and the presence of dominant-negative isoforms, permit regeneration by negative regulation of p53. This research sheds light onto previously unknown molecular mechanisms critical for limb regeneration and offers a new perspective on the functions of the tumour suppressor p53.
CDC5, a DNA binding protein, positively regulates posttranscriptional processing and/or transcription of primary microRNA transcripts
Authors: Zhang Shuxin , Xie Meng , Ren Guodong , Yu Bin
Published: October 2013

Significance

CDC5, a DNA binding protein, regulates the growth and immunity of
Arabidopsis
, however, its functional mechanism remains to be identified. This research reveals that CDC5 acts as a positive transcription factor and a component of the DICER–LIKE1 complex to regulate microRNA (miRNA) accumulation. By identifying a unique regulator and its activities in miRNA biogenesis, this study provides insight on the regulation of miRNA levels. Because CDC5 homologs are present in other organisms, including animals, this study may have a broad effect on the miRNA biogenesis field.
Sperm competition drives the evolution of suicidal reproduction in mammals
Authors: Fisher Diana O. , Dickman Christopher R. , Jones Menna E. , Blomberg Simon P.
Published: October 2013

Significance

In some marsupial genera but in no other mammals, escalating stress hormones during the breeding season cause immune system collapse and synchronized death after mating in all males (suicidal reproduction). In this paper, we resolve the environmental drivers and adaptive mechanism of sexual selection responsible for the repeated evolution of this surprising and extreme life history strategy in mammals. The strategy of synchronized suicidal reproduction in mammals resulting in male death before offspring are born has often been attributed to altruistic or kin-selected paternal suicide to avoid food depletion. We show that rather than altruism or kin-selection, individual sexual selection leads to apparent self-sacrifice in these genera.
Conformational transitions during FtsK translocase activation of individual XerCD–
dif
recombination complexes
Authors: Zawadzki Pawel , May Peter F. J. , Baker Rachel A. , Pinkney Justin N. M. , Kapanidis Achillefs N. , Sherratt David J. , Arciszewska Lidia K.
Published: October 2013

Significance

Insight into the mechanisms that underlie the process of faithful chromosome segregation is of importance for understanding the place of humans in the living world. Bacteria are the most abundant free-living organisms and have important roles in human health and disease. Nevertheless, molecular understanding of bacterial chromosome segregation is in its infancy. In this paper, the action of one conserved molecular machine that acts to coordinate the late steps of chromosome segregation with cell division is analyzed molecule by molecule in real time, using three complementary single-molecule techniques simultaneously. By using normal and mutated proteins, the complete reaction pathway is revealed from assembly of the initial nucleoprotein complex, to its activation by a DNA motor, and to the subsequent steps that lead to chromosome unlinking.
Fast and accurate nonenzymatic copying of an RNA-like synthetic genetic polymer
Authors: Zhang Shenglong , Blain J. Craig , Zielinska Daria , Gryaznov Sergei M. , Szostak Jack W.
Published: October 2013

Significance

The first cells to have emerged on the early Earth lacked enzymes, and therefore probably relied on spontaneous reactions to copy their genetic material, commonly thought to have been RNA. Here we study a close chemical relative of RNA, known as 3′-phosphoramidate-DNA, in an effort to learn general lessons about nonenzymatic replication. We show that short regions of this polymer can be copied, but that the error rate is unacceptably high. We then show that a single atom change in one of the four nucleotides can restore good copying accuracy. These advances may help to achieve chemical copying of RNA, and also suggest that 3′-phosphoramidate-DNA may be a suitable genetic polymer for use in the construction of simple artificial cells.
Structural analysis for glycolipid recognition by the C-type lectins Mincle and MCL
Authors: Furukawa Atsushi , Kamishikiryo Jun , Mori Daiki , Toyonaga Kenji , Okabe Yuki , Toji Aya , Kanda Ryo , Miyake Yasunobu , Ose Toyoyuki , Yamasaki Sho , Maenaka Katsumi
Published: October 2013

Significance

Here we report the crystal structures of human C-type lectin receptors Mincle (macrophage inducible C-type “calcium-dependent” lectin; CLEC4E) and MCL (macrophage C-type lectin; CLEC4D), both of which are receptors for mycobacterial glycolipid adjuvant cord factor (also called trehalose-6,6′-dimycolate; TDM). Our structural and functional studies clearly reveal the simultaneous recognition of sugar and lipid moieties by Mincle and MCL, distinct from other C-type lectin receptors. Because better adjuvants are desired for enhancing vaccination effects of medical treatments for infectious diseases, cancer, and so forth, these structures provide a framework for the rational design of more effective adjuvants than TDM.
Deficits in microRNA-mediated Cxcr4/Cxcl12 signaling in neurodevelopmental deficits in a 22q11 deletion syndrome mouse model
Authors: Toritsuka Michihiro , Kimoto Sohei , Muraki Kazue , Landek-Salgado Melissa A. , Yoshida Atsuhiro , Yamamoto Norio , Horiuchi Yasue , Hiyama Hideki , Tajinda Katsunori , Keni Ni , Illingworth Elizabeth , Iwamoto Takashi , Kishimoto Toshifumi , Sawa Akira , Tanigaki Kenji
Published: October 2013

Significance

22q11 deletion syndrome (22q11DS) is a chromosome disorder that frequently accompanies psychiatric conditions such as schizophrenia. However, it remains elusive how the chromosomal microdeletion causes the mental manifestation. Here we show that a 22q11DS mouse model has deficits in the development of interneurons and hippocampal dentate gyrus and that
DiGeorge syndrome critical region gene 8 (Dgcr8)
, a microprocessor of microRNA and one of the genes in 22q11, underlies these neurodevelopmental abnormalities. Dgcr8 regulates Chemokine receptor 4/Chemokine ligand 12 (Cxcr4/Cxcl12; Sdf1) signaling, which is indispensable for interneuron and dentate gyrus development. Finally, we observe decreased expression of CXCL12 in olfactory neurons from sporadic schizophrenia. Given the increased risk of 22q11DS in schizophrenia, the overall study suggests that CXCR4/CXCL12 signaling may represent a common downstream mediator in the pathophysiology of schizophrenia.
Cellular organization of cortical barrel columns is whisker-specific
Authors: Meyer Hanno S. , Egger Robert , Guest Jason M. , Foerster Rita , Reissl Stefan , Oberlaender Marcel
Published: October 2013

Significance

Cortical columns are thought to be the elementary functional building blocks of sensory cortices. Here we show that the cellular architecture of cortical “barrel” columns in rodent somatosensory cortex is not stereotypic, but specific for each whisker on the animals’ snout. Our findings challenge the concepts underlying contemporary simulation efforts that build up large-scale network models of repeatedly occurring identical cortical circuits.
Disruption of the expression of the proprotein convertase PC7 reduces BDNF production and affects learning and memory in mice
Authors: Wetsel William C. , Rodriguiz Ramona M. , Guillemot Johann , Rousselet Estelle , Essalmani Rachid , Kim Il Hwan , Bryant Jesse C. , Marcinkiewicz Jadwiga , Desjardins Roxane , Day Robert , Constam Daniel B. , Prat Annik , Seidah Nabil G.
Published: October 2013

Significance

The 7-membered proprotein convertase (PC) family of basic amino acid-specific proteases is implicated in the cleavage-activation of secretory precursor proteins. Although the in vivo functions of most members have been well studied, those of the seventh member PC7 are largely unknown. Herein, we find that PC7 participates in the generation of mature BDNF both in cells and in specific brain areas such as hippocampus and amygdala. Indeed, PC7 exerts a critical role in the brain: The results of various behavioral tests in normal mice compared with those lacking PC7 expression support an in vivo role for PC7 in the regulation of certain types of cognitive performance, such as emotional memories, in part via BDNF activation.
Structural basis for Spt5-mediated recruitment of the Paf1 complex to chromatin
Authors: Wier Adam D. , Mayekar Manasi K. , Héroux Annie , Arndt Karen M. , VanDemark Andrew P.
Published: October 2013

Significance

The polymerase associated factor 1 complex (Paf1C) is an RNA polymerase (pol) II accessory factor that broadly influences gene expression by regulating chromatin structure and the recruitment of RNA-processing factors during transcription. This study shows how phosphorylation of a repeated motif within an additional factor, Spt5, is recognized and used by the Plus3 domain within the Paf1C subunit Rtf1 (restores TBP function 1) to promote recruitment of Paf1C to the transcription machinery. Deletions of both the Rtf1 Plus3 domain and the C domain of Cdc73 (Cell Division Cycle 73) are required to abolish Paf1C-mediated histone modifications and chromatin occupancy suggesting that dual attachment points facilitate the association of Paf1C with RNA pol II.
Intrinsic-mediated caspase activation is essential for cardiomyocyte hypertrophy
Authors: Putinski Charis , Abdul-Ghani Mohammad , Stiles Rebecca , Brunette Steve , Dick Sarah A. , Fernando Pasan , Megeney Lynn A.
Published: October 2013

Significance

Cardiac hypertrophy is a pathologic enlargement of the heart, an alteration that leads to contractile dysfunction and eventual organ failure. The hypertrophy phenotype originates from concentric growth of heart muscle cells and shares many biochemical features with programmed cell death, implying a common molecular origin. Here, we show cell-autonomous activation of a mitochondrial cell death pathway during initial stages of muscle cell hypertrophy, a signal that is essential and sufficient to promote hypertrophy. Targeting individual cell death proteins may offer an effective means to limit the initial stage of cardiac disease, and forgo the transition to heart failure.
Optogenetic-mediated increases in in vivo spontaneous activity disrupt pool-specific but not dorsal-ventral motoneuron pathfinding
Authors: Kastanenka Ksenia V. , Landmesser Lynn T.
Published: October 2013

Significance

The developing nervous systems of birds and mammals exhibit rhythmic waves of electrical activity, but their importance in early circuit formation events, such as initial axon pathfinding, has been unclear. By using flashes of light to activate exogeneously expressed light-sensitive ion channels in intact chick embryos, we show that the two major motoneuron pathfinding decisions (dorsal-ventral and muscle-specific) were differentially sensitive to the precise frequency of waves, with accurate pathfinding requiring the normal control frequency. Thus, many drugs that are known to alter wave frequency in this circuit have the potential to disrupt normal motor circuit formation.
MicroRNA-23a promotes myelination in the central nervous system
Authors: Lin Shu-Ting , Huang Yong , Zhang Luoying , Heng Mary Y. , Ptáček Louis J. , Fu Ying-Hui
Published: October 2013

Significance

Understanding molecular mechanisms that underlie the processes for myelin synthesis and maintenance has been an intensely investigated topic. Concurrently, recent advances in noncoding RNAs (ncRNAs) have uncovered unique insights into many biological processes, and ncRNAs have become recognized as major players for epigenetic regulation. We generated a murine model overexpressing microRNA-23a (
miR-23a
) to investigate its role in myelin regulation. In addition, we used this mouse model to identify two targets of
miR-23a
: one is a protein-coding gene phosphatase and tensin homologue and the other is a long ncRNA (lncRNA)
2700046G09Rik
. Our study demonstrated a complex network comprising a protein-encoding gene, a miRNA, and a lncRNA that is central to the fine tuning and maintenance of healthy myelin.
Der Einfluss sprachspezifischer morpho-syntaktischer Eigenschaften auf den Erwerb von Verb-Argumentstrukturen im Deutschen
Authors: Leischner Franziska N.
Published: October 2013

Die Studie untersucht den Einfluss sprachspezifischer morpho-syntaktischer Eigenschaften (z.B. flexible Wortstellung, Kasus) auf den Erwerb von Verb-Argumentstrukturen im Deutschen. Zu diesem Zweck wurden 65 drei- bis neunjährige Deutsch lernende Kinder aufgefordert, kanonische (Das Schaf läuft) und nicht-kanonische Sätze (*Das Schaf läuft das Pferd) nachzuspielen. Vorangegangene Arbeiten (Naigles, Fowler & Helm, 1992) haben gezeigt, dass Englisch lernende Kinder, die mit solchen nicht-kanonischen Sätzen konfrontiert wurden, die gebräuchliche Verbbedeutung entsprechend der nicht-kanonischen Argumentstruktur veränderten (Frame Compliance). Erwachsene, vor dieselbe Aufgabe gestellt, änderten dagegen die Argumentstruktur des Satzes entsprechend der Bedeutung des Verbs (Verb Compliance). Das Alter, ab dem Kinder bei der Interpretation nicht-kanonischer Sätze von Frame zu Verb Compliance umschwenkten, hing dabei stark von der Struktur des vorgegebenen Satzes ab. Unsere Ergebnisse bestätigen diese Abhängigkeit. Jedoch zeigen sie im Vergleich zum Englischen auch eine wesentlich ausgeprägtere Verb Compliance in allen Altersstufen, die durch die angenommenen sprachspezifischen Faktoren verursacht worden sein könnte.
The Czechs and their View of History
Authors: Šubrt Jiří , Vinopal Jiří , Vávra Martin
Published: October 2013

This article aims to provide the first complete overview of the nature and content of the historical consciousness of the Czech population to be based on knowledge gained through tools from quantitative sociological methodology. First there is a snapshot of the population's interest in the history of the Czech Republic as such; then the focus is on general aspects of historical consciousness, particularly people's ideas about the importance of the forces that influence the course of history, and their assessment of the general importance of history. Interpretation of the analysis concludes with evaluations of Czech national history and its various stages and major events. In the final discussion there is a comprehensive interpretation of the empirical knowledge gained, in the context of existing theoretical concepts.
Recruitment of the autophagic machinery to endosomes during infection is mediated by ubiquitin
Authors: Fujita Naonobu , Morita Eiji , Itoh Takashi , Tanaka Atsushi , Nakaoka Megumi , Osada Yuki , Umemoto Tetsuo , Saitoh Tatsuya , Nakatogawa Hitoshi , Kobayashi Shouhei , Haraguchi Tokuko , Guan Jun-Lin , Iwai Kazuhiro , Tokunaga Fuminori , Saito Kazunobu , Ishibashi Koutaro , Akira Shizuo , Fukuda Mitsunori , Noda Takeshi , Yoshimori Tamotsu
Published: October 2013

Although ubiquitin is thought to be important for the autophagic sequestration of invading bacteria (also called xenophagy), its precise role remains largely enigmatic. Here we determined how ubiquitin is involved in this process. After invasion, ubiquitin is conjugated to host cellular proteins in endosomes that contain Salmonella or transfection reagent–coated latex (polystyrene) beads, which mimic invading bacteria. Ubiquitin is recognized by the autophagic machinery independently of the LC3–ubiquitin interaction through adaptor proteins, including a direct interaction between ubiquitin and Atg16L1. To ensure that invading pathogens are captured and degraded, Atg16L1 targeting is secured by two backup systems that anchor Atg16L1 to ubiquitin-decorated endosomes. Thus, we reveal that ubiquitin is a pivotal molecule that connects bacteria-containing endosomes with the autophagic machinery upstream of LC3.
BET bromodomain inhibition suppresses TH17-mediated pathology
Authors: Mele Deanna A. , Salmeron Andres , Ghosh Srimoyee , Huang Hon-Ren , Bryant Barbara M. , Lora Jose M.
Published: October 2013

Interleukin (IL) 17–producing T helper (TH17) cells have been selected through evolution for their ability to control fungal and bacterial infections. It is also firmly established that their aberrant generation and activation results in autoimmune conditions. Using a characterized potent and selective small molecule inhibitor, we show that the bromodomain and extra-terminal domain (BET) family of chromatin adaptors plays fundamental and selective roles in human and murine TH17 differentiation from naive CD4+ T cells, as well as in the activation of previously differentiated TH17 cells. We provide evidence that BET controls TH17 differentiation in a bromodomain-dependent manner through a mechanism that includes the direct regulation of multiple effector TH17-associated cytokines, including IL17, IL21, and GMCSF. We also demonstrate that BET family members Brd2 and Brd4 associate with the Il17 locus in TH17 cells, and that this association requires bromodomains. We recapitulate the critical role of BET bromodomains in TH17 differentiation in vivo and show that therapeutic dosing of the BET inhibitor is efficacious in mouse models of autoimmunity. Our results identify the BET family of proteins as a fundamental link between chromatin signaling and TH17 biology, and support the notion of BET inhibition as a point of therapeutic intervention in autoimmune conditions.
Orientation of cosmic web filaments with respect to the underlying velocity field
Authors: Tempel E. , Libeskind N. I. , Hoffman Y. , Liivamägi L. J. , Tamm A.
Published: October 2013

The large-scale structure of the Universe is characterized by a web-like structure made of voids, sheets, filaments and knots. The structure of this so-called cosmic web is dictated by the local velocity shear tensor. In particular, the local direction of a filament should be strongly aligned with $\hat{e}_3$, the eigenvector associated with the smallest eigenvalue of the tensor. That conjecture is tested here on the basis of a cosmological simulation. The cosmic web delineated by the halo distribution is probed by a marked point process with interactions (the Bisous model), detecting filaments directly from the halo distribution (P-web). The detected P-web filaments are found to be strongly aligned with the local $\hat{e}_3$: the alignment is within 30° for ∼80 per cent of the elements. This indicates that large-scale filaments defined purely from the distribution of haloes carry more than just morphological information, although the Bisous model does not make any prior assumption on the underlying shear tensor. The P-web filaments are also compared to the structure revealed from the velocity shear tensor itself (V-web). In the densest regions, the P- and V-web filaments overlap well (90 per cent), whereas in lower density regions, the P-web filaments preferentially mark sheets in the V-web.
Impact of Risk Assessments on Prophylactic Antiemetic Prescription and the Incidence of Postoperative Nausea and Vomiting
Authors: Kappen Teus H. , Moons Karel G.M. , van Wolfswinkel Leo , Kalkman Cornelis J. , Vergouwe Yvonne , van Klei Wilton A.
Published: October 2013

Background:

Clinical prediction models have been shown to have moderate sensitivity and specificity, yet their use will depend on implementation in clinical practice. The authors hypothesized that implementation of a prediction model for postoperative nausea and vomiting (PONV) would lower the PONV incidence by stimulating anesthesiologists to administer more “risk-tailored” prophylaxis to patients.

Methods:

A single-center, cluster-randomized trial was performed in 12,032 elective surgical patients receiving anesthesia from 79 anesthesiologists. Anesthesiologists were randomized to either exposure or nonexposure to automated risk calculations for PONV (without patient-specific recommendations on prophylactic antiemetics). Anesthesiologists who treated less than 50 enrolled patients were excluded during the analysis to avoid too small clusters, yielding 11,613 patients and 57 anesthesiologists (intervention group: 5,471 and 31; care-as-usual group: 6,142 and 26). The 24-h incidence of PONV (primary outcome) and the number of prophylactic antiemetics administered per patient were studied for risk-dependent differences between allocation groups.

Results:

There were no differences in PONV incidence between allocation groups (crude incidence intervention group 41%, care-as-usual group 43%; odds ratio, 0.97; 95% CI, 0.87–1.1; risk-dependent odds ratio, 0.92; 95% CI, 0.80–1.1). Nevertheless, intervention-group anesthesiologists administered more prophylactic antiemetics (rate ratio, 2.0; 95% CI, 1.6–2.4) and more risk-tailored than care-as-usual–group anesthesiologists (risk-dependent rate ratio, 1.6; 95% CI, 1.3–2.0).

Conclusions:

Implementation of a PONV prediction model did not reduce the PONV incidence despite increased antiemetic prescription in high-risk patients by anesthesiologists. Before implementing prediction models into clinical practice, implementation studies that include patient outcomes as an endpoint are needed.
Ecological and social correlates of chimpanzee tool use
Authors: Sanz Crickette M. , Morgan David B.
Published: October 2013

The emergence of technology has been suggested to coincide with scarcity of staple resources that led to innovations in the form of tool-assisted strategies to diversify or augment typical diets. We examined seasonal patterns of several types of tool use exhibited by a chimpanzee (Pan troglodytes) population residing in central Africa, to determine whether their technical skills provided access to fallback resources when preferred food items were scarce. Chimpanzees in the Goualougo Triangle exhibit a diverse repertoire of tool behaviours, many of which are exhibited throughout the year. Further, they have developed specific tool sets to overcome the issues of accessibility to particular food items. Our conclusion is that these chimpanzees use a sophisticated tool technology to cope with seasonal changes in relative food abundance and gain access to high-quality foods. Subgroup sizes were smaller in tool using contexts than other foraging contexts, suggesting that the size of the social group may not be as important in promoting complex tool traditions as the frequency and type of social interactions. Further, reports from other populations and species showed that tool use may occur more often in response to ecological opportunities and relative profitability of foraging techniques than scarcity of resources.
Did tool-use evolve with enhanced physical cognitive abilities?
Authors: Teschke I. , Wascher C. A. F. , Scriba M. F. , von Bayern A. M. P. , Huml V. , Siemers B. , Tebbich S.
Published: October 2013

The use and manufacture of tools have been considered to be cognitively demanding and thus a possible driving factor in the evolution of intelligence. In this study, we tested the hypothesis that enhanced physical cognitive abilities evolved in conjunction with the use of tools, by comparing the performance of naturally tool-using and non-tool-using species in a suite of physical and general learning tasks. We predicted that the habitually tool-using species, New Caledonian crows and Galápagos woodpecker finches, should outperform their non-tool-using relatives, the small tree finches and the carrion crows in a physical problem but not in general learning tasks. We only found a divergence in the predicted direction for corvids. That only one of our comparisons supports the predictions under this hypothesis might be attributable to different complexities of tool-use in the two tool-using species. A critical evaluation is offered of the conceptual and methodological problems inherent in comparative studies on tool-related cognitive abilities.
Is primate tool use special? Chimpanzee and New Caledonian crow compared
Authors: McGrew W. C.
Published: October 2013

The chimpanzee (Pan troglodytes) is well-known in both nature and captivity as an impressive maker and user of tools, but recently the New Caledonian crow (Corvus moneduloides) has been championed as being equivalent or superior to the ape in elementary technology. I systematically compare the two taxa, going beyond simple presence/absence scoring of tool-using and -making types, on four more precise aspects of material culture: (i) types of associative technology (tools used in combination); (ii) modes of tool making; (iii) modes of tool use; and (iv) functions of tool use. I emphasize tool use in nature, when performance is habitual or customary, rather than in anecdotal or idiosyncratic. On all four measures, the ape shows more variety than does the corvid, especially in modes and functions that go beyond extractive foraging. However, more sustained field research is required on the crows before this contrast is conclusive.
Tool use by aquatic animals
Authors: Mann Janet , Patterson Eric M.
Published: October 2013

Tool-use research has focused primarily on land-based animals, with less consideration given to aquatic animals and the environmental challenges and conditions they face. Here, we review aquatic tool use and examine the contributing ecological, physiological, cognitive and social factors. Tool use among aquatic animals is rare but taxonomically diverse, occurring in fish, cephalopods, mammals, crabs, urchins and possibly gastropods. While additional research is required, the scarcity of tool use can likely be attributable to the characteristics of aquatic habitats, which are generally not conducive to tool use. Nonetheless, studying tool use by aquatic animals provides insights into the conditions that promote and inhibit tool-use behaviour across biomes. Like land-based tool users, aquatic animals tend to find tools on the substrate and use tools during foraging. However, unlike on land, tool users in water often use other animals (and their products) and water itself as a tool. Among sea otters and dolphins, the two aquatic tool users studied in greatest detail, some individuals specialize in tool use, which is vertically socially transmitted possibly because of their long dependency periods. In all, the contrasts between aquatic- and land-based tool users enlighten our understanding of the adaptive value of tool-use behaviour.
Maize centromeres expand and adopt a uniform size in the genetic background of oat
Authors: Wang Kai , Wu Yufeng , Zhang Wenli , Dawe R. Kelly , Jiang Jiming
Published: October 2013

Most existing centromeres may have originated as neocentromeres that activated de novo from noncentromeric regions. However, the evolutionary path from a neocentromere to a mature centromere has been elusive. Here we analyzed the centromeres of nine chromosomes that were transferred from maize into oat as the result of an inter-species cross. Centromere size and location were assayed by chromatin immunoprecipitation for the histone variant CENH3, which is a defining feature of functional centromeres. Two isolates of maize chromosome 3 proved to contain neocentromeres in the sense that they had moved from the original site, whereas the remaining seven centromeres (1, 2, 5, 6, 8, 9, and 10) were retained in the same area in both species. In all cases, the CENH3-binding domains were dramatically expanded to encompass a larger area in the oat background (∼3.6 Mb) than the average centromere size in maize (∼1.8 Mb). The expansion of maize centromeres appeared to be restricted by the transcription of genes located in regions flanking the original centromeres. These results provide evidence that (1) centromere size is regulated; (2) centromere sizes tend to be uniform within a species regardless of chromosome size or origin of the centromere; and (3) neocentromeres emerge and expand preferentially in gene-poor regions. Our results suggest that centromere size expansion may be a key factor in the survival of neocentric chromosomes in natural populations.
Equity tension and new public management policy development and implementation in the water industry
Authors: John Hunt Christopher , Staunton John , Dunstan Keitha
Published: October 2013

Purpose

– Within the new public management (NPM) context, this paper aims to examine the inclusion of equity issues in pricing policy development and implementation in the water industry in Australia.

Design/methodology/approach

– A review of literature relevant to the pricing of water shows equity issues have four dimensions which tend to be, at best, only implicitly considered. An empirical illustration employing a transaction cost framework is provided of a case in which change in pricing mechanisms was strongly suggested.

Findings

– An equity paradox emerges as an explanation of why 63.7 per cent of Queensland urban water entities chose not to adopt the user-pays pricing mechanism for water. This suggests that the balance between “equity” and “efficiency” continues to be required in policy development for water pricing. Equity of access and that of distribution continue to be significant factors. As well, equity of interest and of return must be considered, especially under a user-pays pricing mechanism.

Practical implications

– In respect of NPM considerations, it is argued that consideration of the four dimensions of equity in the implementation of a water pricing policy will resolve contradictions with, and paradoxes met in dealing with efficiency.

Originality/value

– The argument used in the paper is interdisciplinary. References and terms used include those which are social, economic, and environmental from an accounting and management perspective.