bluuebunny/crossref_metadata_2025 huggingface dataset:
AFIR: A Dimensionless Potency Metric for Characterizing the Activity of Monoclonal Antibodies
Authors: Stein AM , Ramakrishna R
Published: April 2017

For monoclonal antibody (mAb) drugs, soluble targets may accumulate several thousand fold after binding to the drug. Time course data of mAb and total target is often collected and, although free target is more closely related to clinical effect, it is difficult to measure. Therefore, mathematical models of this data are used to predict target engagement. In this article, a “potency factor” is introduced as an approximation for the model‐predicted target inhibition. This potency factor is defined to be the time‐Averaged Free target concentration to Initial target concentration Ratio (AFIR), and it depends on three key quantities: the average drug concentration at steady state; the binding affinity; and the degree of target accumulation. AFIR provides the intuition for how changes in dosing regimen and binding affinity affect target capture and AFIR can be used to predict the druggability of new targets and the expected benefits of more potent, second‐generation mAbs.
Enabling robust assessment of QTc prolongation in early phase clinical trials
Authors: Mehrotra Devan V. , Fan Li , Liu Fang , Tsai Kuenhi
Published: April 2017

Since the implementation of the International Conference on Harmonization (ICH) E14 guideline in 2005, regulators have required a “thorough QTc” (TQT) study for evaluating the effects of investigational drugs on delayed cardiac repolarization as manifested by a prolonged QTc interval. However, TQT studies have increasingly been viewed unfavorably because of their low cost effectiveness. Several researchers have noted that a robust drug concentration‐QTc (conc‐QTc) modeling assessment in early phase development should, in most cases, obviate the need for a subsequent TQT study. In December 2015, ICH released an “E14 Q&As (R3)” document supporting the use of conc‐QTc modeling for regulatory decisions. In this article, we propose a simple improvement of two popular conc‐QTc assessment methods for typical first‐in‐human crossover‐like single ascending dose clinical pharmacology trials. The improvement is achieved, in part, by leveraging routinely encountered (and expected) intrasubject correlation patterns encountered in such trials. A real example involving a single ascending dose and corresponding TQT trial, along with results from a simulation study, illustrate the strong performance of the proposed method. The improved conc‐QTc assessment will further enable highly reliable go/no‐go decisions in early phase clinical development and deliver results that support subsequent TQT study waivers by regulators.
Estimating model‐error covariances in nonlinear state‐space models using Kalman smoothing and the expectation–maximization algorithm
Authors: Dreano D. , Tandeo P. , Pulido M. , Ait‐El‐Fquih B. , Chonavel T. , Hoteit I.
Published: April 2017

Specification and tuning of errors from dynamical models are important issues in data assimilation. In this work, we propose an iterative expectation–maximization (EM) algorithm to estimate the model‐error covariances using classical extended and ensemble versions of the Kalman smoother. We show that, for additive model errors, the estimate of the error covariance converges. We also investigate other forms of model error, such as parametric or multiplicative errors. We show that additive Gaussian model error is able to compensate for non‐additive sources of error in the algorithms we propose. We also demonstrate the limitations of the extended version of the algorithm and recommend the use of the more robust and flexible ensemble version. This article is a proof of concept of the methodology with the Lorenz‐63 attractor. We developed an open‐source Python library to enable future users to apply the algorithm to their own nonlinear dynamical models.
Surface Engineering of Spherical Metal Nanoparticles with Polymers toward Selective Asymmetric Synthesis of Nanobowls and Janus‐Type Dimers
Authors: Liu Ben , Thanneeru Srinivas , Lopes Aaron , Jin Lei , McCabe Meghan , He Jie
Published: April 2017

New synthetic methods capable of controlling structural and compositional complexities of asymmetric nanoparticles (NPs) are very challenging but highly desired. A simple and general synthetic approach to designing sophisticated asymmetric NPs by anisotropically patterning the surface of isotropic metallic NPs with amphiphilic block copolymers (BCPs) is reported. The selective galvanic replacement and seed‐mediated growth of a second metal can be achieved on the exposed surface of metal NPs, resulting in the formation of nanobowls and Janus‐type metal–metal dimers, respectively. Using Ag and Au NPs tethered with amphiphilic block copolymers of poly(ethylene oxide)‐block‐polystyrene (PEO‐b‐PS), anisotropic surface patterning of metallic NPs (e.g., Ag and Au) is shown to be driven by thermodynamical phase segregation of BCP ligands on isotropic metal NPs. Two proof‐of‐concept experiments are given on, i) synthesis of Au nanobowls by a selective galvanic replacement reaction on Janus‐type patched Ag/polymer NPs; and ii) preparation of Au–Pd heterodimers and Au–Au homodimers by a seed‐mediated growth on Janus‐type patched Au/polymer NPs. The method shows remarkable versatility; and it can be easily handled in aqueous solution. This synthetic strategy stands out as the new methodology to design and synthesis asymmetric metal NPs with sophisticated topologies.
Entwicklung von weichen Türmen für Windenergieanlagen – Softtower
Authors: Lange Holger , Elberg Christian
Published: April 2017

Herrn Univ.‐Prof. em. Dr.‐Ing. Herbert Schmidt zur Vollendung seines 80. Lebensjahres gewidmet

In der Windenergie übernimmt der Turm eine immer wichtigere Rolle, da er mit dem Fundament zusammen für bis zu 45 % der Gesamtkosten verantwortlich ist. Für weitere Ertragssteigerungen werden in Zukunft Türme bis auf 160 m anwachsen. Um dem immer weiter wachsenden Kostendruck in der Windenergie entgegenzuwirken, werden Türme entwickelt, die sehr weich ausgelegt sind und sich gezielt im Resonanzbereich der drehenden Windenergieanlage (WEA) befinden. Hierdurch übernimmt der Turm eine Schlüsselrolle bei der Entwicklung der Anlagensteuerung und der damit einhergehenden Lasten. In diesem Aufsatz wird beschrieben, wie der weiche Turm mit der Windenergieanlage zusammen als eine Einheit die zukünftigen Windenergieanlagen mit bestimmen wird. Es werden die aeroelastischen Einflüsse und die damit verbundenen positiven aerodynamischen Dämpfeffekte in Zusammenhang gebracht und untersucht.
Einblick in das Vorspannverhalten von geschraubten Verbindungen aus nichtrostendem Stahl
Authors: Stranghöner Natalie , Jungbluth Dominik , Afzali Nariman , Lorenz Christoph
Published: April 2017

Herrn Univ.‐Prof. em. Dr.‐Ing. Herbert Schmidt zur Vollendung seines 80. Lebensjahres gewidmet

Vorgespannte geschraubte Verbindungen aus nichtrostendem Stahl sind derzeit normativ nicht zulässig. Dennoch besteht der Wunsch seitens der Bauausführenden, in Spezialfällen diese Art von Verbindungen tragsicherheitsrelevant oder auch nur aus Gebrauchstauglichkeitsgründen auszuführen. Gemeinhin wird den vorgespannten Verbindungen aus nichtrostendem Stahl unterstellt, dass sie sehr hohen Vorspannkraftverlusten infolge Relaxieren und Kriechen der Schrauben und Kriechen des Klemmpaktes unterliegen, weshalb die tatsächlich in der Verbindung verbleibende Vorspannkraft nicht abschätzbar sein soll. Im Rahmen des europäischen RFCS‐Forschungsvorhabens SIROCO laufen derzeit umfangreiche Untersuchungen zum Anzieh‐ und Vorspannverhalten von geschraubten Verbindungen aus nichtrostenden austenitischen und Duplex‐Stählen zum Einsatz in gleitfesten Verbindungen aus ebenfalls nichtrostenden Stählen. Erste Ergebnisse aus diesem Vorhaben zeigen, dass ein gezieltes Anziehen solcher Verbindungen durchaus möglich ist, dass die Vorspannkraftverluste infolge Relaxieren bei Weitem nicht so hoch sind wie vermutet und dass das Fressen der Verbindungen bei geeigneter Werkstoffpaarung und Wahl des Schmiermittels durchaus zu vermeiden ist. Der vorliegende Beitrag soll erste Einblicke in die vorliegenden Ergebnisse des derzeit noch laufenden Vorhabens geben.
Origin and characterization of alpha smooth muscle actin-positive cells during murine lung development
Authors: Moiseenko Alena , Kheirollahi Vahid , Chao Cho-Ming , Ahmadvand Negah , Quantius Jennifer , Wilhelm Jochen , Herold Susanne , Ahlbrecht Katrin , Morty Rory E. , Rizvanov Albert A. , Minoo Parviz , El Agha Elie , Bellusci Saverio
Published: April 2017

ACTA2 expression identifies pulmonary airway and vascular smooth muscle cells (SMCs) as well as alveolar myofibroblasts (MYF). Mesenchymal progenitors expressing fibroblast growth factor 10 (Fgf10), Wilms tumor 1 (Wt1), or glioma-associated oncogene 1 (Gli1) contribute to SMC formation from early stages of lung development. However, their respective contribution and specificity to the SMC and/or alveolar MYF lineages remain controversial. In addition, the contribution of mesenchymal cells undergoing active WNT signaling remains unknown. Using Fgf10CreERT2, Wt1CreERT2, Gli1CreERT2, and Axin2CreERT2 inducible driver lines in combination with a tdTomatoflox reporter line, the respective differentiation of each pool of labeled progenitor cells along the SMC and alveolar MYF lineages was quantified. The results revealed that while FGF10+ and WT1+ cells show a minor contribution to the SMC lineage, GLI1+ and AXIN2+ cells significantly contribute to both the SMC and alveolar MYF lineages, but with limited specificity. Lineage tracing using the Acta2-CreERT2 transgenic line showed that ACTA2+ cells labeled at embryonic day (E)11.5 do not expand significantly to give rise to new SMCs at E18.5. However, ACTA2+ cells labeled at E15.5 give rise to the majority (85%–97%) of the SMCs in the lung at E18.5 as well as alveolar MYF progenitors in the lung parenchyma. Fluorescence-activated cell sorting-based isolation of different subpopulations of ACTA2+ lineage-traced cells followed by gene arrays, identified transcriptomic signatures for alveolar MYF progenitors versus airway and vascular SMCs at E18.5. Our results establish a new transcriptional landscape for further experiments addressing the function of signaling pathways in the formation of different subpopulations of ACTA2+ cells.
Intranuclear Actin Structure Modulates Mesenchymal Stem Cell Differentiation
Authors: Sen Buer , Uzer Gunes , Samsonraj Rebekah M. , Xie Zhihui , McGrath Cody , Styner Maya , Dudakovic Amel , van Wijnen Andre J. , Rubin Janet
Published: April 2017

Actin structure contributes to physiologic events within the nucleus to control mesenchymal stromal cell (MSC) differentiation. Continuous cytochalasin D (Cyto D) disruption of the MSC actin cytoskeleton leads to osteogenic or adipogenic differentiation, both requiring mass transfer of actin into the nucleus. Cyto D remains extranuclear, thus intranuclear actin polymerization is potentiated by actin transfer: we asked whether actin structure affects differentiation. We show that secondary actin filament branching via the Arp2/3 complex is required for osteogenesis and that preventing actin branching stimulates adipogenesis, as shown by expression profiling of osteogenic and adipogenic biomarkers and unbiased RNA-seq analysis. Mechanistically, Cyto D activates osteoblast master regulators (e.g., Runx2, Sp7, Dlx5) and novel coregulated genes (e.g., Atoh8, Nr4a3, Slfn5). Formin-induced primary actin filament formation is critical for Arp2/3 complex recruitment: osteogenesis is prevented by silencing of the formin mDia1, but not its paralog mDia2. Furthermore, while inhibition of actin, branching is a potent adipogenic stimulus, silencing of either mDia1 or mDia2 blocks adipogenic gene expression. We propose that mDia1, which localizes in the cytoplasm of multipotential MSCs and traffics into the nucleus after cytoskeletal disruption, joins intranuclear mDia2 to facilitate primary filament formation before mediating subsequent branching via Arp2/3 complex recruitment. The resulting intranuclear branched actin network specifies osteogenic differentiation, while actin polymerization in the absence of Arp2/3 complex-mediated secondary branching causes adipogenic differentiation.
Hypoxia Inducible Factor-1α Potentiates Jagged 1-Mediated Angiogenesis by Mesenchymal Stem Cell-Derived Exosomes
Authors: Gonzalez-King Hernán , García Nahuel A. , Ontoria-Oviedo Imelda , Ciria María , Montero José Anastasio , Sepúlveda Pilar
Published: April 2017

Insufficient vessel growth associated with ischemia remains an unresolved issue in vascular medicine. Mesenchymal stem cells (MSCs) have been shown to promote angiogenesis via a mechanism that is potentiated by hypoxia. Overexpression of hypoxia inducible factor (HIF)-1α in MSCs improves their therapeutic potential by inducing angiogenesis in transplanted tissues. Here, we studied the contribution of exosomes released by HIF-1α-overexpressing donor MSCs (HIF-MSC) to angiogenesis by endothelial cells. Exosome secretion was enhanced in HIF-MSC. Omics analysis of miRNAs and proteins incorporated into exosomes pointed to the Notch pathway as a candidate mediator of exosome communication. Interestingly, we found that Jagged1 was the sole Notch ligand packaged into MSC exosomes and was more abundant in HIF-MSC than in MSC controls. The addition of Jagged1-containing exosomes from MSC and HIF-MSC cultures to endothelial cells triggered transcriptional changes in Notch target genes and induced angiogenesis in an in vitro model of capillary-like tube formation, and both processes were stimulated by HIF-1α. Finally, subcutaneous injection of Jagged 1-containing exosomes from MSC and HIF-MSC cultures in the Matrigel plug assay induced angiogenesis in vivo, which was more robust when they were derived from HIF-MSC cultures. All Jagged1-mediated effects could be blocked by prior incubation of exosomes with an anti-Jagged 1 antibody. All together, the results indicate that exosomes derived from MSCs stably overexpressing HIF-1α have an increased angiogenic capacity in part via an increase in the packaging of Jagged1, which could have potential applications for the treatment of ischemia-related disease.
Adipogenic Differentiation of Mesenchymal Stem Cells Alters Their Immunomodulatory Properties in a Tissue-Specific Manner
Authors: Munir Hafsa , Ward Lewis S. C. , Sheriff Lozan , Kemble Samuel , Nayar Saba , Barone Francesca , Nash Gerard B. , McGettrick Helen M.
Published: April 2017

Chronic inflammation is associated with formation of ectopic fat deposits that might represent damage-induced aberrant mesenchymal stem cell (MSC) differentiation. Such deposits are associated with increased levels of inflammatory infiltrate and poor prognosis. Here we tested the hypothesis that differentiation from MSC to adipocytes in inflamed tissue might contribute to chronicity through loss of immunomodulatory function. We assessed the effects of adipogenic differentiation of MSC isolated from bone marrow or adipose tissue on their capacity to regulate neutrophil recruitment by endothelial cells and compared the differentiated cells to primary adipocytes from adipose tissue. Bone marrow derived MSC were immunosuppressive, inhibiting neutrophil recruitment to TNFα-treated endothelial cells (EC), but MSC-derived adipocytes were no longer able to suppress neutrophil adhesion. Changes in IL-6 and TGFβ1 signalling appeared critical for the loss of the immunosuppressive phenotype. In contrast, native stromal cells, adipocytes derived from them, and mature adipocytes from adipose tissue were all immunoprotective. Thus disruption of normal tissue stroma homeostasis, as occurs in chronic inflammatory diseases, might drive “abnormal” adipogenesis which adversely influences the behavior of MSC and contributes to pathogenic recruitment of leukocytes. Interestingly, stromal cells programmed in native fat tissue retain an immunoprotective phenotype.
The Interactional Construction of Social Authenticity: “Real” Identities and Intergroup Relations in a Transylvania Internet Forum
Authors: Weninger Csilla , Williams J. Patrick
Published: April 2017

Authenticity has become an increasingly salient topic within various interactional traditions, including conversational and discourse analysis, discursive psychology, interactional sociolinguistics, pragmatics, and symbolic interactionism. However, there has been remarkably little cross‐fertilization of ideas and concepts. In this study, we consider the relevance of the interactional sociolinguistic concept of relationality for symbolic interactionist theories of authenticity. We first disambiguate two forms of authenticity that are commonly studied but not clearly differentiated in symbolic interactionist research—self‐authenticity, which emphasizes selves, and social authenticity, which emphasizes social identities. We then argue that relationality and its three pairs of interactional tactics—verification and denaturalization, adequation and distinction, and authorization and illegitimation—are particularly useful in conceptualizing social authenticity. We draw on data from an interethnic internet forum to show how members of two ethnic groups, Hungarian and Romanian, employ these relational tactics to authenticate their own ethnicity as the rightful inheritors of a place‐based Transylvanian identity, and to limit the other ethnicity's similar identity work. We then clarify the significance of social authenticity for the interactional study of category‐based identities by widening our discussion to other contestations over social identities in everyday life.
Bathrooms, Boundaries, and Emotional Burdens: Cisgendering Interactions Through the Interpretation of Transgender Experience
Authors: Mathers Lain A. B.
Published: April 2017

Building on findings demonstrating that social institutions may cisgender realities by creating and enforcing binary notions of gender rooted in cisgender experience, this study examines the ways cisgender people reinforce cisnormative gender binaries in their ongoing interactions. Utilizing interviews with 99 cisgender people, I show how respondents react to a vignette about a gender nonconforming person seeking to use a public bathroom by “cisgendering interactions,” which I define as the process whereby people reassert binary understandings of gender to make sense of transgender experience while placing an unequal emotional burden on transgender and gender nonconforming people to mend the interactional disruption of the gender panic. Additionally, my analysis extends transgender scholarship by demonstrating some ways cisgender people make sense of transgender people in public spaces. In conclusion, I draw out insights for understanding (1) the ways people cisgender their realities in the face of conflicting stimuli, (2) the ways in which emotions are a mechanism of inequality reproduction, and (3) the consequences these actions have for the perpetuation of gender inequality.
Novel Deposition System Designs for Thin Film Materials Research
Authors: Gaines James Roland
Published: April 2017

Modern thin film deposition systems must be designed for maximum flexibility with respect to their physical footprint as well as the range of processes and materials they can support. Increasingly disciplines that have not traditionally utilized thin film deposition, such as biology and medicine, are demanding that materials never intended for vacuum be applied on a molecular level. Multi‐user nanofabrication facilities are tasked to adapt and accommodate new requirements while also making room for new tools in environments which may already be over crowded. New system designs, mindful of these challenges, are discussed.
Unit root tests
Authors: Herranz Edward
Published: April 2017

Unit roots are nonstationary autoregressive (AR) or autoregressive moving average (ARMA) time series processes which may include an intercept and/or a trend. These processes are used often in economics and finance, but can also be found in other scientific fields. Unit root tests address the null hypothesis of a unit root, and an alternative hypothesis of a stationary (or trend stationary) time series. Critical values for unit root tests are typically derived via simulation of limiting distributions expressed as functionals of Brownian motions. The critical values for the Dickey Fuller unit root test with a constant and linear trend are derived via simulation in the R language. Simulation studies are presented showing that linear regressions with unit root processes often produce spurious results. Additional simulation studies are reviewed providing statistical evidence that near‐unit roots can often result in spurious cointegration relationships. Various unit root tests are presented, including ones that allow for structural breaks in intercept and/or trend. Threshold unit root tests are introduced. Simulation studies are used to compare the unit root tests under various scenarios. The case where the analyzed time series may have stationary and nonstationary segments is also considered. WIREs Comput Stat 2017, 9:e1396. doi: 10.1002/wics.1396

This article is categorized under:

Applications of Computational Statistics > Computational Finance

Statistical and Graphical Methods of Data Analysis > Monte Carlo Methods

Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
Human diseases, immunity and the oral microbiota—Insights gained from metagenomic studies
Authors: Idris Adi , Hasnain Sumaira Z. , Huat Lu Z. , Koh David
Published: April 2017

The immune system consists of a complex but organised myriad of cell types that continually maintain and survey their resident environment. It is this balanced homeostatic relationship between the cells of the immune system and its surrounding environment that shapes the microbial flora. In the oral cavity, the immune system not only has to harmonise with the ecology of commensal bacteria, fungi and viruses but also should be able to defend against pathogenic microbes. In fact, the oral microbiota is altered in situations when the immune system is dysregulated. There are a number of human diseases or conditions that perturb the balance of the host immune system and have an effect on the host oral microbiota. If this balance is disturbed, the symbiotic relationship will shift to allow the colonisation or overgrowth of potentially pathogenic species, inducing a pathogenic process that leads to various disease symptoms. The dynamics balance between the immune status and the oral microbial community of an individual has remained understudied till recently. Advances in metagenomics allow detailed investigations into oral microbial population and the possible diversity. This concise review summarises the current findings using metagenomic approaches for studying oral microbial flora diversity.
ANALYSIS OF FACTORS THAT INFLUENCE THE USE OF IRRIGATION TECHNOLOGIES AND WATER MANAGEMENT PRACTICES IN ARKANSAS
Authors: HUANG QIUQIONG , XU YING , KOVACS KENT , WEST GRANT
Published: April 2017

This study investigates which factors may influence producers’ use of irrigation technologies and/or water management practices (WMPs). One major finding is that Arkansas producers are more likely to rely on WMPs instead of sprinkler irrigation as a response to changes in depth to water and drought occurrences. This finding highlights the importance of expanding the existing literature that focuses mostly on more efficient irrigation technologies, especially in areas where WMPs are more prevalent. Climate factors also play a role. Sprinkler systems are more prevalent in regions with lower average temperature. WMPs are used to mitigate the impact of more frequent droughts.
ISOTOPIC ANALYSES REVEAL GEOGRAPHICAL AND SOCIOECONOMIC PATTERNS IN HISTORICAL DOMESTIC ANIMAL TRADE BETWEEN PREDOMINANTLY WHEAT- AND MAIZE-GROWING AGRICULTURAL REGIONS IN EASTERN NORTH AMERICA
Authors: Guiry Eric , Szpak Paul , Richards Michael P.
Published: April 2017

Historical zooarchaeologists have made significant contributions to key questions about the social, economic, and nutritional dimensions of domestic animal use in North American colonial contexts; however, techniques commonly employed in faunal analyses do not offer a means of assessing many important aspects of how animals were husbanded and traded. We apply isotopic analyses to faunal remains from archaeological sites to assess the social and economic importance of meat trade and consumption of local and foreign animal products in northeastern North America. Stable carbon and nitrogen isotope analyses of 310 cattle and pigs from 18 rural and urban archaeological sites in Upper Canada (present-day southern Ontario, Canada; ca. A.D. 1790–1890) are compared with livestock from contemporary American sources to quantify the importance of meat from different origins at rural and higher- and lower-status urban contexts. Results show significant differences between urban and rural households in the consumption of local animals and meat products acquired through long-distance trade. A striking pattern in urban contexts provides new evidence for the social significance of meat origins in historical Upper Canada and highlights the potential for isotopic approaches to reveal otherwise-hidden evidence for social and economic roles of animals in North American archaeology.
Nonlinear regimes of spanwise modulated waves in plane Poiseuille flow
Authors: Silva Homero G. , Medeiros M. A. F.
Published: April 2017

Wave modulation is an unavoidable ingredient of natural transition and wavepackets composed of a continuous range of frequencies and wavenumbers are considered as a good model for it. Conclusions regarding wavepacket nonlinear regimes are essentially based on comparison of the dominant mode in the modulated signal nonlinear bands with predictions of the most unstable mode in the corresponding unmodulated cases. The modulated signal bands are very broad and establishing the dominant mode is difficult. If the Reynolds number changes along the packet evolution, the bands also change to adapt to local conditions, which further hinders data interpretation and weakens the conclusions. In view of this, a study at a constant Reynolds number is proposed, the Poiseuille plane flow being chosen as the base flow. The flow choice also allowed an investigation of the phenomenon at different positions in the stability loop, an aspect that has never been addressed before. The work was numerical. Only spanwise modulation was considered and two different regimes were observed. Close to the first branch of the instability loop the packet splits into two patches. Oblique transition was the dominant nonlinear mechanism, which required spanwise interaction of packets. Elsewhere the dominant mechanism was fundamental instability (or$K$-type), which was fed by a previous nonlinear phenomenon and led to a subsequent one. The analysis involved comparison of growth rates, threshold amplitudes and amplitude scalings among other aspects, for modulated and corresponding unmodulated cases. Perfect agreement was found if appropriate variables were used, which enabled firm conclusions to be drawn about the phenomena investigated. This level of agreement was only possible because of the constant Reynolds number character of the flow, but the main conclusions are applicable to other wall shear flows.
Influence of turbulent fluctuations on detonation propagation
Authors: Maxwell Brian McN. , Bhattacharjee R. R. , Lau-Chapdelaine S. S. M. , Falle S. A. E. G. , Sharpe G. J. , Radulescu M. I.
Published: April 2017

The present study addresses the reaction zone structure and burning mechanism of unstable detonations. Experiments investigated mainly two-dimensional methane–oxygen cellular detonations in a thin channel geometry. The sufficiently high temporal resolution permitted the determination of the probability density function of the shock distribution, a power law with an exponent of$-3$, and the burning rate of unreacted pockets from their edges – through surface turbulent flames with a speed approximately 3–7 times larger than the laminar one at the local conditions. Numerical simulations were performed using a novel large-eddy simulation method where the reactions due to both autoignition and turbulent transport were treated exactly at the subgrid scale in a reaction–diffusion formulation. The model is an extension of Kerstein and Menon’s linear eddy model for large-eddy simulation to treat flows with shock waves and rapid gas-dynamic transients. The two-dimensional simulations recovered well the amplification of the laminar flame speed due to the turbulence generated mainly by the shear layers originating from the triple points and subsequent Richtmyer–Meshkov instability associated with the internal pressure waves. The simulations clarified how the level of turbulence generated controlled the burning rate of the pockets, the hydrodynamic thickness of the wave, the cellular structure and its distribution. Three-dimensional simulations were found to be in general good agreement with the two-dimensional ones, in that the subgrid-scale model captured the ensuing turbulent burning once the scales associated with the cellular dynamics, where turbulent kinetic energy is injected, are well resolved.
Response of subtropical submarine-cave ecosystem to Holocene cave development and Asian monsoon variability
Authors: Chiu Wing-Tung Ruby , Yasuhara Moriaki , Iwatani Hokuto , Kitamura Akihisa , Fujita Kazuhiko
Published: April 2017

A submarine cave is a unique environment that is dark, food limited, semi-isolated from the outside, and sheltered from wave action. However, our knowledge of the long-term change in submarine-cave ecosystems remains limited. We document here the community-scale responses toward long-term change in a submarine cave, Daidokutsu in Okinawa in southern Japan. Using both metazoans (ostracods and bivalves) and protozoans (larger benthic foraminiferans) in two sediment cores obtained from the cave, we reconstruct the faunal and diversity changes of the past 7 Kyr. All taxonomic groups showed long-term, gradual linear change of faunal composition from predominantly open-water taxa to predominantly cave taxa, and ostracods showed short-term variability of species diversity. The long-term faunal trend probably reflects gradual isolation of the cave ecosystem due to coral reef development (i.e., development of the cave ceiling) during periods of the Holocene transgression and subsequent sea-level highstand. The short-term diversity changes show substantial similarity to centennial- to millennial-scale Holocene Asian monsoon variability. Ostracod species diversity peaks tend to correspond with periods of strong East Asian winter monsoons. The results indicate that limestone submarine-cave ecosystems, an important cryptic habitat, developed gradually during the Holocene and may be sensitive to rapid climate changes.
Haemosporidian infections affect antioxidant defences in great tits Parus major but are not related to exposure to aerial pollutants
Authors: DE ANGELI DUTRA DANIELA , SILVEIRA PATRÍCIA , RAMOS JAIME ALBINO , SOUSA JOSÉ PAULO , BRAGA ÉRIKA MARTINS , NORTE ANA CLÁUDIA
Published: April 2017

Haemosporidian parasites are widespread in avian species and modulate their ecology, behaviour, life-history and fitness. The prevalence of these vector-transmitted parasites varies with host intrinsic and extrinsic factors, such as host resistance and behaviour, and habitat-related characteristics. In this study, we evaluated the prevalence of avian haemosporidians in great tit Parus major populations inhabiting two areas with different degrees of exposure to aerial emissions from pulp mills, to assess if this type of pollution impacted parasite prevalence. We also compared the physiological condition of infected and uninfected individuals. Haemosporidian infection prevalence was high (58%), varied seasonally, but was not associated with air pollution exposure. Fledged birds presented higher infection rates than nestlings and infected fledged birds had higher levels of blood glutathione peroxidase activity. These results allow us to infer that infection by blood parasites may activate antioxidant defences, possibly to protect the organism from the negative oxidative stress side-effects of immune activation against parasites. Because oxidative stress is one of the mechanisms responsible for ageing and senescence and may affect fitness, the relationship between parasitism and oxidative stress markers should be further investigated through studies that include experimental manipulation of infection in model organisms.
The Influence of Forming Companions on the Spectral Energy Distributions of Stars with Circumstellar Discs
Authors: Zakhozhay Olga V.
Published: April 2017

We study a possibility to detect signatures of brown dwarf companions in a circumstellar disc based on spectral energy distributions. We present the results of spectral energy distribution simulations for a system with a 0.8 M⊙ central object and a companion with a mass of 30 MJ embedded in a typical protoplanetary disc. We use a solution to the one-dimensional radiative transfer equation to calculate the protoplanetary disc flux density and assume, that the companion moves along a circular orbit and clears a gap. The width of the gap is assumed to be the diameter of the brown dwarf Hill sphere. Our modelling shows that the presence of such a gap can initiate an additional minimum in the spectral energy distribution profile of a protoplanetary disc at λ = 10–100 μm. We found that it is possible to detect signatures of the companion when it is located within 10 AU, even when it is as small as 3 MJ. The spectral energy distribution of a protostellar disc with a massive fragment (of relatively cold temperature ~400 K) might have a similar double peaked profile to the spectral energy distribution of a more evolved disc that contains a gap.
Geochemical composition of Tanzanian shelf sediments indicates Holocene climatic and sea-level changes
Authors: Liu Xiting , Rendle-Bühring Rebecca , Henrich Rüdiger
Published: April 2017

We present a high-resolution geochemical and grain-size record from a Holocene sediment core off the Pangani River mouth, Tanzania. Elemental ratios between biogenic elements and Al (i.e., Ca/Al, Mg/Al, and Sr/Al) are mainly influenced by terrigenous dilution on carbonate concentration and/or limitation of carbonate production as a result of variations in the supply of fine-grained terrigenous sediments of the Pangani River. Such elemental ratios increased significantly at the end of the mid-Holocene between 5 and 3.5 ka, demonstrating a gradual transition from the humid early and mid-Holocene to the arid late Holocene in East Africa. Among the elemental ratios between terrigenous elements and Al, Si/Al and K/Al ratios correlate to grain-size variation, indicating a change in sedimentation regime. Fe/Al and Ti/Al ratios show that the sediment source area has shifted from the terrestrial volcanic region of Tanzania (Fe, Ti rich) to the coastal and inner-shelf regions (Fe, Ti poor) around 7.5 ka, in response to arid climate and high sea level. Our geochemical results correspond with a sea-surface temperature record derived from the same sediment core, indicating that the end of the East African Humid Period could have been gradual and related to the cooling water in the western Indian Ocean.
Association between lutein intake and lung function in adults: the Rotterdam Study
Authors: Melo van Lent Debora , Leermakers Elisabeth T. M. , Hofman Albert , Stricker Bruno H. , Brusselle Guy G. , Franco Oscar H. , Lahousse Lies , Kiefte-de Jong Jessica C.
Published: April 2017

Lutein, a fat-soluble carotenoid with antioxidant properties, may have an effect on respiratory health. However, the evidence is inconsistent. We aimed to cross-sectionally investigate the association between lutein intake and lung function by measuring forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC% in adults (aged 45–79 years). We included 4402 participants from the Rotterdam Study, a prospective cohort study in The Netherlands. Lutein intake was assessed using a validated FFQ. Lung function was assessed using spirometry around the same time point as the dietary assessment. No independent association was found between lutein intake and FEV1 (−12·17 (95 % CI −34·21, 9·87) ml per sd increase in lutein) after adjustment for age, sex, height, cohort effect, ethnicity, education, weight, total daily energy intake, smoking status, physical activity, and intakes of fatty acids, dietary fibre, alcohol, β-carotene, β-crypotoxanthin, lycopene and zeaxanthin. There was also no association between lutein and FVC or FEV1/FVC%. However, after stratification by smoking status, lutein intake was significantly associated with lower FEV1/FVC% in current smokers (−1·69 (95 % CI −2·93, −0·45) % per sd increase of lutein) independent of other carotenoids. The present study does not support an independent association between lutein intake and lung function in adults. However, future studies should focus on the potential inverse association between high lutein intake and lung function in specific risk groups such as smokers.
The effect of diet, temperature and intermittent low oxygen on the metabolism of rainbow trout
Authors: Stiller Kevin T. , Vanselow Klaus H. , Moran Damian , Riesen Guido , Koppe Wolfgang , Dietz Carsten , Schulz Carsten
Published: April 2017

An automated respirometer system was used to measure VO2, protein catabolism as ammonia quotient and the energy budget to evaluate whether the crude protein content of a standard protein (SP) diet (42·5 %) or a high-protein (HP) diet (49·5 %) influences metabolism in rainbow trout under challenging intermittent, low dissolved oxygen concentrations. In total, three temperature phases (12, 16, 20°C) were tested sequentially, each of which were split into two oxygen periods with 5 d of unmanipulated oxygen levels (50–70 %), followed by a 5d manipulated oxygen period (16.00–08.00 hours) with low oxygen (40–50 %) levels. For both diets, catabolic protein usage was lowest at 16°C and was not altered under challenging oxygen conditions. Low night-time oxygen elevated mean daily VO2by 3–14 % compared with the unmanipulated oxygen period for both diets at all temperatures. The relative change in VO2and retained energy during the intermittent low oxygen period was smaller for the HP diet compared with the SP diet. However, in absolute terms, the SP diet was superior to the HP diet as the former demonstrated 30–40 % lower protein fuel use rates, higher retained energy (1–4 % digestible energy) and slightly lowered VO2(0–8 %) over the range of conditions tested. The decrease in retained energy under low oxygen conditions suggests that there is scope to improve the performance of SP diets under challenging conditions; however, this study suggests that simply increasing the dietary protein content is not a remedy, and other strategies need to be explored.
A Hausdorff measure version of the Jarník–Schmidt theorem in Diophantine approximation
Authors: SIMMONS DAVID
Published: April 2017

We solve the problem of giving sharp asymptotic bounds on the Hausdorff dimensions of certain sets of badly approximable matrices, thus improving results of Broderick and Kleinbock (preprint 2013) as well as Weil (preprint 2013), and generalising to higher dimensions those of Kurzweil ('51) and Hensley ('92). In addition we use our technique to compute the Hausdorfff-measure of the set of matrices which are not ψ-approximable, given a dimension functionfand a function ψ : (0, ∞) → (0, ∞). This complements earlier work by Dickinson and Velani ('97) who found the Hausdorfff-measure of the set of matrices which are ψ-approximable.
Liquid authority in global governance
Authors: Krisch Nico
Published: April 2017

Authority is a key concept in politics and law, and it has found greater attention in the global context in recent years. Most accounts, however, employ a model of ‘solid’ authority borrowed from the domestic realm and focus primarily on commands issued by single institutions. This framing paper argues that such approaches tend to underestimate the extent of authority in global governance and misunderstand its nature, leading to skewed accounts of the emergence of authority and the challenges it poses. Building on an alternative conception – the deference model – the paper calls for including in analyses of global authority also liquid forms, characterized by a higher level of dynamism and typically driven by informality and institutional multiplicity. Such a broader account can help us to redirect empirical inquiries and reframe central questions about authority, relating in particular to the way in which it is produced, the mechanisms through which it might be made accountable and legitimate, and its relation to law.
Glyphosate-Resistant Russian-thistle (Salsola tragus) Identified in Montana and Washington
Authors: Kumar Vipan , Spring John F. , Jha Prashant , Lyon Drew J. , Burke Ian C.
Published: April 2017

Two putative glyphosate-resistant (GR) Russian-thistle accessions were collected from fallow fields (wheat-fallow rotation): one from Choteau County, MT (MT-R), and a second from Columbia County, WA (WA-R) in summer/fall of 2015. Greenhouse and outdoor/field whole-plant dose-response studies were conducted to confirm and characterize the levels of glyphosate resistance in these GR accessions relative to known glyphosate-susceptible accessions (MT-S and WA-S from MT and WA, respectively). Based on GR50values of the progeny plants, the MT-R accession exhibited 4.5-fold and 5.9-fold resistance to glyphosate relative to the MT-S accession under greenhouse and outdoor conditions, respectively. The WA-R accession showed 3.0- to 5.0-fold resistance relative to the WA-S accession in greenhouse experiments, and 1.9- to 7.5-fold resistance in multi-site field experiments. In a separate greenhouse study on alternative POST herbicides to control GR Russian-thistle, bicyclopyrone plus bromoxynil, bromoxynil plus fluroxypyr, bromoxynil plus pyrasulfotole, bromoxynil plus MCPA, paraquat alone, paraquat plus metribuzin, saflufenacil alone, saflufenacil plus 2,4-D, and 2,4-D plus bromoxynil plus fluroxypyr provided effective control (≥95%) and shoot dry weight reduction (up to 98%) of GR accessions. This research confirms the first global case of field-evolved GR Russian-thistle. Best management practices (BMPs); including alternative, effective herbicide programs (based on multiple mechanisms of action highlighted in this study) need immediate implementation to prevent further spread of GR or evolution of multiple HR Russian-thistle populations in this region.
Looking Up: Taking Photos May Improve Climate Models
Authors: Underwood Emily
Published: April 2017

Snapshots of clouds taken from the ground reveal orders of magnitude more detail than satellites.
Knockdown of Broad-Complex Gene Expression of Bombyx mori by Oligopyrrole Carboxamides Enhances Silk Production
Authors: Ali Asfa , Bovilla Venugopal Reddy , Mysarla Danti Kumari , Siripurapu Prasanthi , Pathak Rashmi U. , Basu Bhakti , Mamillapalli Anitha , Bhattacharya Santanu
Published: April 2017

Bombyx mori (B. mori) is important due to its major role in the silk production. Though DNA binding ligands often influence gene expression, no attempt has been made to exploit their use in sericulture. The telomeric heterochromatin of B. mori is enriched with 5′-TTAGG-3′ sequences. These sequences were also found to be present in several genes in the euchromatic regions. We examined three synthetic oligopyrrole carboxamides that target 5′-TTAGG-3′ sequences in controlling the gene expression in B. mori. The ligands did not show any defect or feeding difference in the larval stage, crucial for silk production. The ligands caused silencing of various isoforms of the broad-complex transcription factor and cuticle proteins which resulted in late pupal developmental defects. Furthermore, treatment with such drugs resulted in statistically enhanced cocoon weight, shell weight, and silk yield. This study shows for the first time use of oligopyrrole carboxamide drugs in controlling gene expression in B. mori and their long term use in enhancing silk production.
The effect of social connections on the discovery of multiple hidden food patches in a bird species
Authors: Tóth Zoltán , Tuliozi Beniamino , Baldan Davide , Hoi Herbert , Griggio Matteo
Published: April 2017

Social foraging is thought to provide the possibility of information transmission between individuals, but this advantage has been proved only in a handful of species and contexts. We investigated how social connections in captive flocks of house sparrows (Passer domesticus) affected the discovery of (i.e. feeding for the first time from) two hidden food patches in the presence of informed flock-mates. At the first-discovered and most-exploited food patch social connections between birds affected the order of discovery and presumably contributed to a greater exploitation of this patch. However, social connections did not affect discovery at the second food patch despite its close spatial proximity. Males discovered the food sources sooner than females, while feeding activity was negatively related to patch discovery. Age had no effect on the order of discovery. Birds that first discovered and fed at the food patches were characterized by higher level of social indifference, i.e. followed others less frequently than other birds in an independent context. Our findings provide experimental evidence for the importance of variable social connections during social foraging in house sparrow flocks, and suggest that social attraction can contribute differently to the exploitation of different patches when multiple food sources are present.
Association between schizophrenia and violence among Chinese female offenders
Authors: Wang Jun , Li Chun , Zhu Xiao-min , Zhang Si-mei , Zhou Jian-song , Li Qi-guang , Wang Qun , Zhong Shao-ling , Ng Chee H. , Ungvari Gabor S. , Xiang Yu-tao , Wang Xiao-ping
Published: April 2017

Little is known about the association between schizophrenia and violence in women in China. This study aimed to examine the association between schizophrenia and violence in Chinese female offenders. Fifty-two schizophrenia patients were identified from the female offenders who received forensic psychiatric assessments in 2011 in Hunan province, China. Using a propensity score matching method, 104 matched controls without psychiatric disorders were selected from female criminals in Hunan province. Violent offences and homicides were verified and recorded. The percentages of violent offences and homicides were significantly higher in female offenders with schizophrenia than in controls (78.8% vs. 30.8%, P < 0.001; 44.2% vs. 18.3%, P = 0.001, respectively). Multivariate logistic regression analyses revealed that diagnosis of schizophrenia, younger age at first offence, living in rural area and a lower education level were independently and positively associated with violent offences, while having a diagnosis of schizophrenia and lower education level were associated with homicides. There appears to be an independent and positive association between schizophrenia and violent offence in Chinese female offenders. Effective preventive approaches on violence in female schizophrenia patients are warranted.