bluuebunny/crossref_metadata_2025 huggingface dataset:
Flight patterns in zoo‐housed fruit bats (Pteropus spp.)
Authors: Bell Edward , Price Eluned , Balthes Samantha , Cordon Matthew , Wormell Dominic
Published: March 2019

Maintaining the capacity for sustained flight in captivity is a key goal for the management of threatened fruit bats. We developed quantifiable descriptions of flight complexity and used them to assess the suitability of an enclosure for two species of fruit bat of differing size, the large Livingstone's fruit bat, Pteropus livingstonii, and the smaller Rodrigues fruit bat, Pteropus rodricensis, in a two‐part study. In Phase 1, Rodrigues fruit bats flew more often than Livingstone's fruit bats and although the majority of flights in both species were linear, Rodrigues fruit bats were more likely to display complex flight paths involving turns, while flights by Livingstone's fruit bats were more likely to end in a crash‐landing than Rodrigues fruit bat flights. The enclosure may therefore not have been large enough for Livingstone's fruit bats to display a full range of flight behavior over longer distances. In Phase 2, juvenile Livingstone's fruit bats ( < 3 years old) flew more than twice as often as younger adults (3–10 years old) did. Older adult Livingstone's fruit bats over the age of 10 years were not observed to fly. We could not separate out the effects of age, weight and environment during development as these factors were strongly correlated in our study; future work in this area will be very important in understanding the factors that affect flight in captive bats, and how it can be encouraged by appropriate enclosure design.
Compact G2 holonomy spaces from SU(3) structures
Authors: Andriolo S. , Shiu G. , Triendl H. , Van Riet T. , Venken G. , Zoccarato G.
Published: March 2019

Abstract

We construct novel classes of compact G2 spaces from lifting type IIA flux backgrounds with O6 planes. There exists an extension of IIA Calabi-Yau orientifolds for which some of the D6 branes (required to solve the RR tadpole) are dissolved inF2fluxes. The backreaction of these fluxes deforms the Calabi-Yau manifold into a specific class of SU(3)-structure manifolds. The lift to M-theory again defines compact G2 manifolds, which in case of toroidal orbifolds are a twisted generalisation of the Joyce construction. This observation also allows a clear identification of the moduli space of a warped compactification with fluxes. We provide a few explicit examples, of which some can be constructed from T-dualising known IIB orientifolds with fluxes. Finally we discuss supersymmetry breaking in this context and suggest that the purely geometric picture in M-theory could provide a simpler setting to address some of the consistency issues of moduli stabilisation and de Sitter uplifting.
Emergent geometry from stochastic dynamics, or Hawking evaporation in M(atrix) theory
Authors: Du Haoxing , Sahakian Vatche
Published: March 2019

Abstract

We develop an microscopic model of the M-theory Schwarzschild black hole using the Banks-Fischler-Shenker-Susskind Matrix formulation of quantum gravity. The underlying dynamics is known to be chaotic, which allows us to use methods from Random Matrix Theory and non-equilibrium statistical mechanics to propose a coarse-grained bottom-up picture of the event horizon — and the associated Hawking evaporation phenomenon. The analysis is possible due to a hierarchy between the various timescales at work. Event horizon physics is found to be non-local at the Planck scale, and we demonstrate how non-unitary physics and information loss arise from the process of averaging over the chaotic unitary dynamics. Most interestingly, we correlate the onset of non-unitarity with the emergence of spacetime geometry outside the horizon. We also write a mean field action for the evolution of qubits — represented by polarization states of supergravity modes. This evolution is shown to have similarities to a recent toy model of black hole evaporation proposed by Osuga and Page — a model aimed at developing a plausible no-firewall scenario.
Group theoretic approach to fermion production
Authors: Min Ui , Son Minho , Suh Han Gyeol
Published: March 2019

Abstract

We propose a universal group theoretic description of the fermion production through any type of interaction to scalar or pseudo-scalar. Our group theoretic approach relies on the group SU(2) × U(1), corresponding to the freedom in choosing representations of the gamma matrices in Clifford algebra, under which a part of the Dirac spinor function transforms like a fundamental representation. In terms of a new SO(3) (∼ SU(2)) vector constructed out of spinor functions, we show that fermion production mechanism can be analogous to the classical dynamics of a vector precessing with the angular velocity. In our group theoretic approach, the equation of motion takes a universal form for any system, and choosing a different type of interaction or a different basis amounts to selecting the corresponding angular velocity. The expression of the particle number density is greatly simplified, compared to the traditional approach, and it provides us with a simple geometric interpretation of the fermion production dynamics. For the purpose of the demonstration, we focus on the fermion production through the derivative coupling to the pseudo-scalar.
The Genus Solanum: An Ethnopharmacological, Phytochemical and Biological Properties Review
Authors: Kaunda Joseph Sakah , Zhang Ying-Jun
Published: March 2019

Over the past 30 years, the genusSolanumhas received considerable attention in chemical and biological studies. Solanumis the largest genus in the family Solanaceae, comprising of about 2000 species distributed in the subtropical and tropical regions of Africa, Australia, and parts of Asia, e.g., China, India and Japan. Many of them are economically significant species. Previous phytochemical investigations onSolanumspecies led to the identification of steroidal saponins, steroidal alkaloids, terpenes, flavonoids, lignans, sterols, phenolic comopunds, coumarins, amongst other compounds. Many species belonging to this genus present huge range of pharmacological activities such as cytotoxicity to different tumors as breast cancer (4T1 and EMT), colorectal cancer (HCT116, HT29, and SW480), and prostate cancer (DU145) cell lines. The biological activities have been attributed to a number of steroidal saponins, steroidal alkaloids and phenols. This review features 65 phytochemically studied species ofSolanumbetween 1990 and 2018, fetched from SciFinder, Pubmed, ScienceDirect, Wikipedia and Baidu, using “Solanum” and the species’ names as search terms (“all fields”).
The Shirts of the Donso Hunters: materiality and power between concealment and visual display
Authors: Ferrarini Lorenzo
Published: March 2019

This article looks at the characteristic shirts of thedonso, or initiated Mande hunters. Often described in the literature as visual displays of the wearer’s power, in the context of contemporary Burkina Faso these shirts are instead an example of how hunters deal with representations of power through an aesthetics of concealment (Ferme 2001). An excess of display is conversely connected with the politics of state-recognized hunters’ associations. Issues of ecological change, local conceptions of power, and contemporary struggles with state authority intersect in the practices and discourses on hunters’ shirts.
The Invisible Social Body: Experience and Poro Ritual in Northern Côte d’Ivoire
Authors: Förster Till
Published: March 2019

Secrecy and its performative display have been privileged perspectives in the study ofporoand similar power associations in West Africa. I develop an alternative understanding of the Senufo poro as an institution that fosters and sustains bodily experience, establishing an all-embracing sensory regime for members as well as non-members in their villages. Participation in nighttime funerary rites creates the image of an invisible social body, and shared bodily experience informs collective intentionality towards the social. Serving as a stable nodal point in everyday discourse, this function contributes to the recent revitalization of poro associations in Côte d’Ivoire’s post-conflict society.
Mande hunters and the state: cooperation and contestation in post-conflict Côte d’Ivoire
Authors: Heitz-Tokpa Kathrin
Published: March 2019

This article analyzes the relationship between Mande hunters (dozos) and the Ivorian state in the prefecture of Ouangolodougou in northern Côte d’Ivoire. Having adopted a prominent security role during the violent conflict of 2002–2011, dozos have made continuing efforts to maintain their position in the post-conflict state. To negotiate their position, they draw on a performative repertoire, such as the display of powerful attributes in the context of processions. Although they have had to concede some more strategic and profitable activities to the reestablished state, dozo chiefs effectively govern the rural northern borderlands of Côte d’Ivoire.
Guest Editors’ Introduction to the Power of Performance—the Performance of Power Forum
Authors: Förster Till , Sanogo Aïdas
Published: March 2019

The West African savannah is an area where old and new institutions fill the lacunae that limited statehood has left. Some of them claim a long history, others have emerged recently as a reaction to military and civil crises. The performance of power, its display and presentation, is a theme that all these associations share. They do so on different occasions and by different means, which highlights their diverging ethics and attitudes towards their local communities and the state. This introduction to the guest edited forum outlines central themes of these performances and discusses performativity in West African power associations.
Homology of odometers
Authors: SCARPARO EDUARDO
Published: March 2019

We compute the homology groups of transformation groupoids associated with odometers and show that certain $(\mathbb{Z}\rtimes \mathbb{Z}_{2})$-odometers give rise to counterexamples to the HK conjecture, which relates the homology of an essentially principal, minimal, ample groupoid $G$ with the K-theory of $C_{r}^{\ast }(G)$. We also show that transformation groupoids of odometers satisfy the AH conjecture.
Codimension one compact center foliations are uniformly compact
Authors: DE MARTINO VERÓNICA , MARTINCHICH SANTIAGO
Published: March 2019

Let $f:M\rightarrow M$ be a dynamically coherent partially hyperbolic diffeomorphism whose center foliation has all its leaves compact. We prove that if the unstable bundle of $f$ is one-dimensional, then the volume of center leaves must be bounded in $M$.
Making the implicit quality standards and performance expectations for traditional legal scholarship explicit
Authors: Snel Marnix
Published: March 2019

Scholars in search of quality standards for traditional legal scholarship could well end up disappointed. By answering the question concerning what standards legal academics use for evaluating such works—through reviewing the international literature on evaluative standards and interviews with forty law professors—this Article aims at filling this gap. This Article recommends that traditional legal scholarship is judged by using the following criteria: (1) the conceptual design—a clearly formulated research question that is both original and significant and the adequacy of the methods proposed to answer that question; (2) the composition of a particular line of reasoning—does the researcher adhere to principles of accountability, accuracy, balance, and credibility?; and (3) the overall characteristics of a work of scholarship—the readability and persuasiveness of the whole and the extent to which the researcher managed to identify and clarify the presuppositions that may have potentially affected her inquiry.
A variational principle for three-dimensional interactions between water waves and a floating rigid body with interior fluid motion
Authors: Alemi Ardakani Hamid
Published: March 2019

A variational principle is given for the motion of a rigid body dynamically coupled to its interior fluid sloshing in three-dimensional rotating and translating coordinates. The fluid is assumed to be inviscid and incompressible. The Euler–Poincaré reduction framework of rigid body dynamics is adapted to derive the coupled partial differential equations for the angular momentum and linear momentum of the rigid body and for the motion of the interior fluid relative to the body coordinate system attached to the moving rigid body. The variational principle is extended to the problem of interactions between gravity-driven potential flow water waves and a freely floating rigid body dynamically coupled to its interior fluid motion in three dimensions.
The Basset problem with dynamic slip: slip-induced memory effect and slip–stick transition
Authors: Premlata A. R. , Wei Hsien-Hung
Published: March 2019

When there exists slip on the surface of a solid body moving in an unsteady manner, the extent of slip is not fixed but constantly changes with the time-varying Stokes boundary layer thickness$\unicode[STIX]{x1D6FF}$in competition with the slip length$\unicode[STIX]{x1D706}$. Here we revisit the unsteady motion of a slippery spherical particle to elucidate this dynamic slip situation. We find that even if the amount of slip is minuscule, it can dramatically change the characteristics of the history force, markedly different from those due to non-spherical and fluid particles (Lawrence & Weinbaum,J. Fluid Mech., vol. 171, 1986, pp. 209–218; Yang & Leal,Phys. FluidsA, vol. 3, 1991, pp. 1822–1824). For an oscillatory translation of such a particle of radius$a$, two distinctive features are identified in the frequency response of the viscous drag: (i) the high-frequency constant force plateau of$O(a/\unicode[STIX]{x1D706})$much greater than the steady drag due to a constant shear stress caused by$\unicode[STIX]{x1D6FF}$much thinner than$\unicode[STIX]{x1D706}$and (ii) the persistence of the plateau while lowering the frequency until the slip–stick transition point$\unicode[STIX]{x1D6FF}\sim \unicode[STIX]{x1D706}$, beyond which$\unicode[STIX]{x1D6FF}$becomes thicker and the usual Basset decay reappears. Similar features can also be observed in the short-term force response for the particle subject to a sudden movement, as well as in the behaviour of the torque when it undergoes rotary oscillations. In addition, for both translational and rotary oscillations, slip can further introduce a phase jump from the no-slip value to zero in the high-frequency limit. As these features and the associated slip–stick transitions become more evident as$\unicode[STIX]{x1D706}$becomes smaller and are exclusive to the situation where surface slip is present, they might have potential uses for extracting the slip length of a colloidal particle from experiments.
Selecting the Most Reliable 14C Dating Material Inside Mortars: the Origin of the Padua Cathedral
Authors: Addis Anna , Secco Michele , Marzaioli Fabio , Artioli Gilberto , Arnau Alexandra Chavarría , Passariello Isabella , Terrasi Filippo , Brogiolo Gian Pietro
Published: March 2019

In order to radiocarbon (14C) date a building, several components of the mortar could be used, such as the mortar binder, the lime lumps, the charcoal particles and shell fragments eventually present among the aggregates. In particular, the mortar binder requires a purification treatment in order to separate it from other sources of carbon, which could change the 14C signature of the binder invalidating the dating process. Here, we present the application of the Cryo2Sonic method to 14C dating of the ancient building structures unearthed during excavation at the Padua Cathedral complex. The dated samples were pretreated by using Cryo2Sonic method and the improved Cryo2Sonic version 2.0, recently developed by introducing additional steps such as centrifugation of the mortar suspension and gravimetric sedimentation of the binder fractions. The Cryo2Sonic version 2.0 relies heavily on the characterization of the mortar and of the purified binder fractions, allowing the isolation of a reliable 14C datable mortar fraction. Through this new method, the 14C dating of different ancient structures excavated next to the Padua Cathedral allow to identify the first religious complex of the city of Padua (3rd–4th centuries AD).
Soil conservation service on the Tibetan Plateau, 1984–2013
Authors: SUN Jian , LIU Yu , ZHOU Tiancai , LIU Guohua , WANG Jingsheng
Published: March 2019

Soil erosion can pose a serious problem to environmental quality and sustainable development. On the Tibetan Plateau, soil erosion is one of the main challenges to regional ecological security. Our analysis investigates soil erosion and evaluates its economic value in alpine steppe, alpine meadow, alpine desert steppe and forest ecosystems on the Tibetan Plateau. Analysis was carried out from 1984 to 2013. The results show that the annual average potential soil erosion, practical soil erosion and soil conservation calculated by the Revised University Soil Loss Equation model were 2.19×109ta–1, 2.16×109ta–1 and 2.72×107ta–1, respectively. The economic value of retaining soil nutrients, reducing the formation of wasteland and the economic benefit of reducing sediment deposition were 1.98×108RMBa–1, 2.55×1012RMBa–1 and 7.44×104RMBa–1, respectively. From comparing different ecosystems, we found that the forest ecosystem had the greatest soil retention and economic values. We also found that the potential and actual soil erosion values were extremely high on the Tibetan Plateau. The study highlights that state and local policymakers must give greater emphasis to ecological protection in the future.
A new hexactinellid sponge from the Silurian of the Pentland Hills (Scotland) with similarities to extant rossellids
Authors: BOTTING Joseph P. , CANDELA Yves , CARRIÓ Vicen , CRIGHTON William R. B.
Published: March 2019

The Pentland Hills sponge fauna (Llandovery, Telychian) consists of an unusual, aberrant assemblage, but of low diversity. A new specimen of a unique sponge,Eoghanospongia carlinslowpensisgen. et sp. nov., is described from the classic locality of R82. The mushroom-shaped, probably stalked body (peduncle attachment to body not exposed) resembles that of some living rossellids, especiallyCaulophacus. The sponge also shows prominent projecting pentactins and monaxon derivatives – a spicule type diagnostic of the Rossellidae among living taxa, albeit in a robust form not described from extant sponges, includingCaulophacusor other pedunculate lyssacinosidans. Certain attribution to the Rossellidae is not possible from the single specimen, largely because of weak preservation of the primary spicule skeleton, but no other fossil or modern sponges show any significant similarity to it. Although similarly early relatives of the Rossellidae have recently been described from elsewhere, the new sponge is even more unexpected in being from a shallow-water environment, making the absence of rossellids through the rest of the Palaeozoic much more problematic.
Impulsively Reflected Ions: A Plausible Mechanism for Ion Acoustic Wave Growth in Collisionless Shocks
Authors: Goodrich Katherine A. , Ergun Robert , Schwartz Steven J. , Wilson Lynn B. , Johlander Andreas , Newman David , Wilder Frederick D. , Holmes Justin , Burch James , Torbert Roy , Khotyaintsev Yuri , Lindqvist Per‐Arne , Strangeway Robert , Gershman Daniel , Giles Barbara
Published: March 2019

We present recent high time resolution observations from an oblique (43°) shock crossing from the Magnetospheric Multiscale mission. Short‐duration bursts between 10 and 100 ms of ion acoustic waves are observed in this event alongside a persistent reflected ion population. High time resolution (150 ms) particle measurements show strongly varying ion distributions between successive measurements, implying that they are bursty and impulsive by nature. Such signatures are consistent with ion bursts that are impulsively reflected at various points within the shock. We find that, after instability analysis using a Fried‐Conte dispersion solver, the insertion of dispersive ion bursts into an already stable ion distribution can lead to wave growth in the ion acoustic mode for short durations of time. We find that impulsively reflected ions are a plausible mechanism for ion acoustic wave growth in the terrestrial bow shock and, furthermore, suggest that wave growth can lead to a small but measurable momentum exchange between the solar wind ions and the reflected population.
Characterization of Intraseasonal Kelvin Waves in the Equatorial Pacific Ocean
Authors: Rydbeck A. V. , Jensen T. G. , Flatau M.
Published: March 2019

Kelvin waves in the equatorial Pacific Ocean are an important subseasonal modulator of upper‐ocean thermal and kinetic energies. This study develops a methodology for the objective identification of the waves, including their phase and amplitude, that is based on satellite‐derived sea surface height anomalies. Composite analysis of intraseasonal Kelvin waves based on the newly developed index reveals important patterns of wave evolution across the Pacific Ocean. The waves maintain an average phase speed of 2.55 m/s, with maximum of 2.73 m/s when the downwelling portion of the wave is near 150°W and minimum of 2.35 m/s near 175°W. Kelvin waves attain their maximum amplitude at 150°W, the region where intraseasonal surface wind forcing strongly relaxes, and the waves transition from a forced to a freely propagating mode. The dominant processes controlling the mixed‐layer temperature also shift near 150°W. Intraseasonal SST anomalies associated with the waves have maximum amplitude of +/−0.25 °C at 140°W, with much stronger anomalies, +/−1.4 °C, along the thermocline at 155°W. Waves strengthen the eastward equatorial undercurrent by 76% while shifting its maximum 3,500 km to the east. The El Niño Southern Oscillation exerts considerable control over the vigor of Kelvin waves, with statistically significant increases of kinetic energy during El Niño versus La Niña periods. For the benefit of the ocean forecasting community, a counterpart intraseasonal Kelvin wave index is developed that avoids the use of forward time filtering such that wave information is available in real time.
Wind in Jezero Crater, Mars
Authors: Day Mackenzie , Dorn Taylor
Published: March 2019

Wind generates erosional and depositional morphologies across Mars, including in Jezero crater, the planned landing site for the Mars 2020 rover. Known for subaqueously formed sedimentary features, Jezero crater also hosts wind‐formed features that provide insights about the local wind regime. We combine interpretations from dunes, wind streaks, transverse aeolian ridges, and yardangs to holistically understand the recent history of wind in Jezero crater. Together, these features describe modern easterly winds trending toward 263° ± 8° and older southwesterly winds that formed small yardangs. Previous research has suggested that aeolian processes eroded the delta deposit in Jezero crater. We propose early southwesterly winds removed the majority of material, exposing the more lithified units seen today. Modern easterly winds continue to cause erosion, but lithologic heterogeneities remain the dominant control on delta deposit evolution. Aeolian erosion has accentuated existing sedimentary structures, leaving the striking delta remnant seen today.
Integrating the role of antifungal bacteria into skin symbiotic communities of three Neotropical frog species
Authors: Rebollar Eria A , Bridges Tiffany , Hughey Myra C , Medina Daniel , Belden Lisa K , Harris Reid N
Published: March 2019

Chytridiomycosis, caused by the pathogen Batrachochytrium dendrobatidis (Bd), has led to population declines and extinctions of frog species around the world. While it is known that symbiotic skin bacteria can play a protective role against pathogens, it is not known how these defensive bacteria are integrated into the bacterial community on amphibian skin. In this study, we used 16S rRNA gene amplicon sequencing, culturing and Bd inhibition bioassays to characterize the communities of skin bacteria on three Neotropical frog species that persist in a Bd-infected area in Panama and determined the abundance and integration of anti-Bd bacteria into the community. We found that the two treefrog species had a similar bacterial community structure, which differed from the more diverse community found on the terrestrial frog. Co-occurrence networks also revealed differences between frog species such that the treefrogs had a significantly higher number of culturable Bd-inhibitory OTUs with high centrality scores compared with the terrestrial frog. We found that culture-dependent OTUs captured between 21 and 39% of the total relative abundance revealed in culture-independent communities. Our results suggest different ecological strategies occurring within skin antifungal communities on host species that have not succumbed to Bd infections in the wild.
Fast spin exchange across a multielectron mediator
Authors: Malinowski Filip K. , Martins Frederico , Smith Thomas B. , Bartlett Stephen D. , Doherty Andrew C. , Nissen Peter D. , Fallahi Saeed , Gardner Geoffrey C. , Manfra Michael J. , Marcus Charles M. , Kuemmeth Ferdinand
Published: March 2019

Scalable quantum processors require tunable two-qubit gates that are fast, coherent and long-range. The Heisenberg exchange interaction offers fast and coherent couplings for spin qubits, but is intrinsically short-ranged. Here, we demonstrate that its range can be increased by employing a multielectron quantum dot as a mediator, while preserving speed and coherence of the resulting spin-spin coupling. We do this by placing a large quantum dot with 50–100 electrons between a pair of two-electron double quantum dots that can be operated and measured simultaneously. Two-spin correlations identify coherent spin-exchange processes across the multielectron quantum dot. We further show that different physical regimes of the mediated exchange interaction allow a reduced susceptibility to charge noise at sweet spots, as well as positive and negative coupling strengths up to several gigahertz. These properties make multielectron dots attractive as scalable, voltage-controlled coherent coupling elements.
Crossword: A data-driven simulation language for the design of genetic-mapping experiments and breeding strategies
Authors: Korani Walid , Vaughn Justin N.
Published: March 2019

Quantitative genetic simulations can save time and resources by optimizing the logistics of an experiment. Current tools are difficult to use by those unfamiliar with programming, and these tools rarely address the actual genetic structure of the population under study. Here, we introduce crossword, which utilizes the widely available re-sequencing and genomics data to create more realistic simulations and to reduce user burden. The software was written in R, to simplify installation and implementation. Because crossword is a domain-specific language, it allows complex and unique simulations to be performed, but the language is supported by a graphical interface that guides users through functions and options. We first show crossword’s utility in QTL-seq design, where its output accurately reflects empirical data. By introducing the concept of levels to reflect family relatedness, crossword can simulate a broad range of breeding programs and crops. Using levels, we further illustrate crossword’s capabilities by examining the effect of family size and number of selfing generations on phenotyping accuracy and genomic selection. Additionally, we explore the ramifications of large phenotypic difference between parents in a QTL mapping cross, a scenario that is common in crop genetics but often difficult to simulate.
A core-scale reconstructing method for shale
Authors: Ji Lili , Lin Mian , Cao Gaohui , Jiang Wenbin
Published: March 2019

Characterization of shale cores with low and anisotropic permeability is complicated, due to the presence of multiscale pore structure and thin layers, and defies conventional methods. To accurately reproduce the morphology of multiscale pore structure of the shale core, a novel core-scale reconstructing method is proposed to reconstruct 3D digital-experimental models by means of the combination of SEM, EDS images, nitrogen adsorption and pressure pulse decay experiment result. In this method, the multiscale and multicomponent reconstructing algorithm is introduced to build the representative multiscale model for each layer, which can describe the complex 3D structures of nano organic pores, micro-nano inorganic pores, micro slits and several typical minerals. Especially, to reproduce the realistic morphology for shale, the optimization algorithm based on simulated annealing algorithm uses the experimental data as constrain conditions to adjust and optimize the model for each layer. To describe the bedding characteristics of the shale core, bedding fractures are constructed by analysis of the mineral distribution in the interface of two layers, and then the representative models for different layers are integrated together to obtain the final core-scale digital-experimental model. Finally, the model is validated by computing its morphological and flow properties and comparing them with those of the actual 3D shale sample. This method provide a way for systematically and continuously describe the multiscale and anisotropic pore structure (from nm-cm) of the shale core, and will be helpful for understanding the quality of the shale reservoir.
DNA damage signalling from the placenta to foetal blood as a potential mechanism for childhood leukaemia initiation
Authors: Mansell Els , Zareian Nahid , Malouf Camille , Kapeni Chrysa , Brown Natalie , Badie Christophe , Baird Duncan , Lane Jon , Ottersbach Katrin , Blair Allison , Case C. Patrick
Published: March 2019

For many diseases with a foetal origin, the cause for the disease initiation remains unknown. Common childhood acute leukaemia is thought to be caused by two hits, the firstin uteroand the second in childhood in response to infection. The mechanism for the initial DNA damaging event are unknown. Here we have usedin vitro,ex vivoandin vivomodels to show that a placental barrier will respond to agents that are suspected of initiating childhood leukaemia by releasing factors that cause DNA damage in cord blood and bone marrow cells, including stem cells. We show that DNA damage caused byin uteroexposure can reappear postnatally after an immune challenge. Furthermore, both foetal and postnatal DNA damage are prevented by prenatal exposure of the placenta to a mitochondrially-targeted antioxidant. We conclude that the placenta might contribute to the first hit towards leukaemia initiation by bystander-like signalling to foetal haematopoietic cells.
Field transcriptome revealed a novel relationship between nitrate transport and flowering in Japanese beech
Authors: Satake Akiko , Kawatsu Kazutaka , Teshima Kosuke , Kabeya Daisuke , Han Qingmin
Published: March 2019

Recent advances in molecular and genetic studies about flowering time control have been increasingly available to elucidate the physiological mechanism underlying masting, the intermittent and synchronized production of a large amount of flowers and seeds in plant populations. To identify unexplored developmental and physiological processes associated with masting, genome-wide transcriptome analysis is a promising tool, but such analyses have yet to be performed. We established a field transcriptome using a typical masting species, Japanese beech (Fagus crenata Blume), over two years, and analyzed the data using a nonlinear time-series analysis called convergent cross mapping. Our field transcriptome was found to undergo numerous changes depending on the status of floral induction and season. An integrated approach of high-throughput transcriptomics and causal inference was successful at detecting novel causal regulatory relationships between nitrate transport and florigen synthesis/transport in a forest tree species. The synergistic activation of nitrate transport and floral transition could be adaptive to simultaneously satisfy floral transition at the appropriate timing and the nitrogen demand needed for flower formation.
Anxiety sensitivity, its stability and longitudinal association with severity of anxiety symptoms
Authors: Hovenkamp-Hermelink Johanna H. M. , van der Veen Date C. , Oude Voshaar Richard C. , Batelaan Neeltje M. , Penninx Brenda W.J.H. , Jeronimus Bertus F. , Schoevers Robert A. , Riese Harriëtte
Published: March 2019

Anxiety sensitivity is associated with the onset of panic attacks, anxiety, and other common mental disorders. Anxiety sensitivity is usually seen as a relative stable trait. However, previous studies were inconclusive regarding the longitudinal stability of anxiety sensitivity and differed in study designs and outcomes. The current study examines the stability of anxiety sensitivity over time and its longitudinal associations with severity of anxiety symptoms. Participants from the Netherlands Study of Depression and Anxiety with and without an anxiety, depressive, or comorbid anxiety-depressive disorder diagnosis were included (N = 2052). Stability in anxiety sensitivity over two year follow-up and the longitudinal association between the change in anxiety sensitivity and change in severity of anxiety symptoms were tested. Results indicated that two-year stability of anxiety sensitivity was high (r = 0.72), yet this test-retest estimate leaves room for changes in anxiety sensitivity in some individuals as well. Change in anxiety sensitivity was positively associated with change in severity of anxiety symptoms (B = 0.64 in univariable analysis and B = 0.52 in multivariable analysis). The longitudinal association of anxiety sensitivity with severity of anxiety symptoms indicates that targeting anxiety sensitivity may be of additional benefit in clinical practice.
Growth in syphilis-exposed and -unexposed uninfected children from birth to 18 months of age in China: a longitudinal study
Authors: Luo Huanyuan , Qiu Liqian , Wu Yanqiao , Zhang Xiaohui
Published: March 2019

Early infant growth and development has attracted worldwide attention. Although numerous studies have demonstrated that maternal syphilis increases the risk of adverse pregnancy outcomes and congenital syphilis, the subsequent growth pattern and morbidity of syphilis-exposed uninfected infants are less understood. We conducted a longitudinal study to compare the growth pattern and disease distribution of syphilis-exposed and syphilis-unexposed uninfected children, and World Health Organization (WHO) reference standards from birth to 18 months of age. We obtained data from a prospective cohort study in three representative regions of Zhejiang Province in China. A total of 333 syphilis-uninfected children born to women with syphilis were recruited at birth and matched with 333 syphilis-uninfected children born to women without syphilis during pregnancy. Children were followed-up by medical staff every 3 months until 18 months of age. The mixed-effects model was used to compare changes in growth patterns and influencing factors between the two groups. Mean weight, length, and head circumference of children, as well as disease prevalence, were similar between the groups. Multilevel analysis indicated that, after controlling confounders, growth velocities were comparable in both weight and length measures from birth to 18 months old between the two groups; however, low birth weight had a negative impact on weight gain in both groups. There was no significant negative association between syphilis exposure and early growth and health in children, under 18 months in a setting with universal coverage of therapeutic interventions for maternal syphilis. These findings may contribute to improving prevention efforts for mother-to-child transmission of syphilis, such as early screening for syphilis in pregnant women, universal coverage of treatment, and interventions for exposed children. Children with low birth weight should be given priority as this is a risk factor for weight gain.
Crystal structures of thiamine monophosphate kinase from Acinetobacter baumannii in complex with substrates and products
Authors: Sullivan Amy H. , Dranow David M. , Horanyi Peter S. , Lorimer Donald D. , Edwards Thomas E. , Abendroth Jan
Published: March 2019

Thiamine monophosphate kinase (ThiL) catalyzes the last step of thiamine pyrophosphate (TPP) synthesis, the ATP-dependent phosphorylation of thiamine monophosphate (TMP) to thiamine pyrophosphate. We solved the structure of ThiL from the human pathogen A. baumanii in complex with a pair of substrates TMP and a non-hydrolyzable adenosine triphosphate analog, and in complex with a pair of products TPP and adenosine diphosphate. High resolution of the data and anomalous diffraction allows for a detailed description of the binding mode of substrates and products, and their metal environment. The structures further support a previously proposed in-line attack reaction mechanism and show a distinct variability of metal content of the active site.
Ectopic expression of a bacterial mercury transporter MerC in root epidermis for efficient mercury accumulation in shoots of Arabidopsis plants
Authors: Uraguchi Shimpei , Sone Yuka , Kamezawa Minami , Tanabe Michi , Hirakawa Momoko , Nakamura Ryosuke , Takanezawa Yasukazu , Kiyono Masako
Published: March 2019

For mercury phytoextraction, we previously demonstrated in Arabidopsis thaliana that a constitutive and ubiquitous promoter-driven expression of a bacterial mercury transporter MerC fused with SYP121, a plant SNARE for plasma membrane protein trafficking increases plant mercury accumulation. To advance regulation of ectopic expression of the bacterial transporter in the plant system, the present study examined whether merC-SYP121 expression driven by a root epidermis specific promoter (pEpi) is sufficient to enhance mercury accumulation in plant tissues. We generated five independent transgenic Arabidopsis plant lines (hereafter pEpi lines) expressing a transgene encoding MerC-SYP121 N-terminally tagged with a fluorescent protein mTRQ2 under the control of pEpi, a root epidermal promoter. Confocal microscopy analysis of the pEpi lines showed that mTRQ2-MerC-SYP121 was preferentially expressed in lateral root cap in the root meristematic zone and epidermal cells in the elongation zone of the roots. Mercury accumulation in shoots of the pEpi lines exposed to inorganic mercury was overall higher than the wild-type and comparable to the over-expressing line. The results suggest that cell-type specific expression of the bacterial transporter MerC in plant roots sufficiently enhances mercury accumulation in shoots, which could be a useful phenotype for improving efficiency of mercury phytoremediation.
Performance comparison of III–V//Si and III–V//InGaAs multi-junction solar cells fabricated by the combination of mechanical stacking and wire bonding
Authors: Kao Yu-Cheng , Chou Hao-Ming , Hsu Shun-Chieh , Lin Albert , Lin Chien-Chung , Shih Zun-Hao , Chang Chun-Ling , Hong Hwen-Fen , Horng Ray-Hua
Published: March 2019

The integration of III–V and Si multi-junction solar cells as photovoltaic devices has been studied in order to achieve high photovoltaic conversion efficiency. However, large differences in the coefficients of thermal expansion and the lattice parameters of GaAs, Si, and InGaAs have made it difficult to obtain high-efficiency solar cells grown as epilayers on Si and InP substrates. In this paper, two types of devices, including GaInP/GaAs stacked on Si (GaInP/GaAs//Si) and GaInP/GaAs stacked on InGaAs (GaInP/GaAs//InGaAs), are fabricated via mechanical stacking and wire bonding technologies. Mechanically stacked GaInP/GaAs//Si and GaInP/GaAs//InGaAs triple-junction solar cells are prepared via glue bonding. Current-voltage measurements of the two samples are made at room temperature. The short-circuit current densities of the GaInP/GaAs//Si and GaInP/GaAs//InGaAs solar cells are 13.37 and 13.66 mA/cm2, while the open-circuit voltages of these two samples are measured to be 2.71 and 2.52 V, respectively. After bonding the GaInP/GaAs dual-junction with the Si and InGaAs solar cells, the conversion efficiency is relatively improved by 32.6% and 30.9%, respectively, compared to the efficiency of the GaInP/GaAs dual-junction solar cell alone. This study demonstrates the high potential of combining mechanical stacked with wire bonding and ITO films to achieve high conversion efficiency in solar cells with three or more junctions.
A study of the relationship between the level of anxiety declared by MRI patients in the STAI questionnaire and their respiratory rate acquired by a fibre-optic sensor system
Authors: Dziuda Łukasz , Zieliński Piotr , Baran Paulina , Krej Mariusz , Kopka Lech
Published: March 2019

Magnetic resonance imaging (MRI) patients often experience anxiety-related respiratory disorders, including hyperventilation, but their respiratory indicators are not routinely monitored during scanning. Free from metal parts and immune to electromagnetic radiation, fibre-optic sensors have the potential to better control the patient’s condition by providing continuous non-invasive monitoring of the respiratory rate (RR). The study was purposed to assess the relationship between anxiety in MRI patients and their RR acquired by a fibre-optic sensor system. Forty-four subjects were involved in the study. The mean RR values recorded for 2 minutes immediately after the beginning and immediately before the end of the scanning were assessed relative to the State-Trait Anxiety Inventory (STAI) X-1 scores obtained immediately before and immediately after the scanning, respectively. A growth mixture model analysis was performed to statistically differentiate two groups of subjects according to the trends in repeated measures of RR. A significant lowering of the anxiety state was observed in the group characterised by a decrease in RR, whereas essentially no change in anxiety level was observed in the group with a stable RR. The t-test showed significant differences in changes in anxiety between these groups (t(39) = −2.349, p = 0.012, Cohen’s d = 2.13).
Featherweight long read alignment using partitioned reference indexes
Authors: Gamaarachchi Hasindu , Parameswaran Sri , Smith Martin A.
Published: March 2019

The advent of Nanopore sequencing has realised portable genomic research and applications. However, state of the art long read aligners and large reference genomes are not compatible with most mobile computing devices due to their high memory requirements. We show how memory requirements can be reduced through parameter optimisation and reference genome partitioning, but highlight the associated limitations and caveats of these approaches. We then demonstrate how these issues can be overcome through an appropriate merging technique. We incorporated multi-index merging into the Minimap2 aligner and demonstrate that long read alignment to the human genome can be performed on a system with 2 GB RAM with negligible impact on accuracy.
Dynamic flood modeling essential to assess the coastal impacts of climate change
Authors: Barnard Patrick L. , Erikson Li H. , Foxgrover Amy C. , Hart Juliette A. Finzi , Limber Patrick , O’Neill Andrea C. , van Ormondt Maarten , Vitousek Sean , Wood Nathan , Hayden Maya K. , Jones Jeanne M.
Published: March 2019

Coastal inundation due to sea level rise (SLR) is projected to displace hundreds of millions of people worldwide over the next century, creating significant economic, humanitarian, and national-security challenges. However, the majority of previous efforts to characterize potential coastal impacts of climate change have focused primarily on long-term SLR with a static tide level, and have not comprehensively accounted for dynamic physical drivers such as tidal non-linearity, storms, short-term climate variability, erosion response and consequent flooding responses. Here we present a dynamic modeling approach that estimates climate-driven changes in flood-hazard exposure by integrating the effects of SLR, tides, waves, storms, and coastal change (i.e. beach erosion and cliff retreat). We show that for California, USA, the world’s 5th largest economy, over $150 billion of property equating to more than 6% of the state’s GDP and 600,000 people could be impacted by dynamic flooding by 2100; a three-fold increase in exposed population than if only SLR and a static coastline are considered. The potential for underestimating societal exposure to coastal flooding is greater for smaller SLR scenarios, up to a seven-fold increase in exposed population and economic interests when considering storm conditions in addition to SLR. These results highlight the importance of including climate-change driven dynamic coastal processes and impacts in both short-term hazard mitigation and long-term adaptation planning.
Meta-analysis suggests evidence of novel stress-related pathway components in Orsay virus - Caenorhabditis elegans viral model
Authors: Mishra Priyanka , Ngo Jessica , Ashkani Jahanshah , Pio Frederic
Published: March 2019

The genetic model organism,Caenorhabditis elegans(C.elegans), shares many genes with humans and is the best-annotated of the eukaryotic genome. Therefore, the identification of new genes and pathways is unlikely. Nevertheless, host-pathogen interaction studies from viruses, recently discovered in the environment, has created new opportunity to discover these pathways. For example, the exogenous RNAi response inC.elegansby the Orsay virus as seen in plants and other eukaryotes is not systemic and transgenerational, suggesting different RNAi pathways between these organisms. Using a bioinformatics meta-analysis approach, we show that the top 17 genes differentially-expressed duringC. elegansinfection by Orsay virus are functionally uncharacterized genes. Furthermore, functional annotation using similarity search and comparative modeling, was able to predict folds correctly, but could not assign easily function to the majority. However, we could identify gene expression studies that showed a similar pattern of gene expression related to toxicity, stress and immune response. Those results were strengthened using protein-protein interaction network analysis. This study shows that novel molecular pathway components, of viral innate immune response, can be identified and provides models that can be further used as a framework for experimental studies. Whether these features are reminiscent of an ancient mechanism evolutionarily conserved, or part of a novel pathway, remain to be established. These results reaffirm the tremendous value of this approach to broaden our understanding of viral immunity inC.elegans.
Blue carbon potential of coastal wetland restoration varies with inundation and rainfall
Authors: Negandhi Karita , Edwards Grant , Kelleway Jeffrey J. , Howard Dean , Safari David , Saintilan Neil
Published: March 2019

There is a growing interest in how the management of ‘blue carbon’ sequestered by coastal wetlands can influence global greenhouse gas (GHG) budgets. A promising intervention is through restoring tidal exchange to impounded coastal wetlands for reduced methane (CH4) emissions. We monitored an impounded wetland’s GHG flux (CO2and CH4) prior to and following tidal reinstatement. We found that biogeochemical responses varied across an elevation gradient. The low elevation zone experienced a greater increase in water level and an associated greater marine transition in the sediment microbial community (16 S rRNA) than the high elevation zone. The low elevation zone’s GHG emissions had a reduced sustained global warming potential of 264 g m−2yr−1CO2-e over 100 years, and it increased to 351 g m−2yr−1with the removal of extreme rain events. However, emission benefits were achieved through a reduction in CO2emissions, not CH4emissions. Overall, the wetland shifted from a prior CH4sink (−0.07 to −1.74 g C m−2yr−1) to a variable sink or source depending on the elevation site and rainfall. This highlights the need to consider a wetland’s initial GHG emissions, elevation and future rainfall trends when assessing the efficacy of tidal reinstatement for GHG emission control.