bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity analysis of consumption cycles
Authors: Jungeilges Jochen , Ryazanova Tatyana , Mitrofanova Anastasia , Popova Irina
Published: May 2018

We study the special case of a nonlinear stochastic consumption model taking the form of a 2-dimensional, non-invertible map with an additive stochastic component. Applying the concept of the stochastic sensitivity function and the related technique of confidence domains, we establish the conditions under which the system's complex consumption attractor is likely to become observable. It is shown that the level of noise intensities beyond which the complex consumption attractor is likely to be observed depends on the weight given to past consumption in an individual's preference adjustment.
A comment on the position dependent diffusion coefficient representation of structural heterogeneity
Authors: Wolfson Molly , Liepold Emily R. , Lin Binhua , Rice Stuart A.
Published: May 2018

Experimental studies of the variation of the mean square displacement (MSD) of a particle in a confined colloid suspension that exhibits density variations on the scale length of the particle diameter are not in agreement with the prediction that the spatial variation in MSD should mimic the spatial variation in density. The predicted behavior is derived from the expectation that the MSD of a particle depends on the system density and the assumption that the force acting on a particle is a point function of position. The experimental data are obtained from studies of the MSDs of particles in narrow ribbon channels and between narrowly spaced parallel plates and from new data, reported herein, of the radial and azimuthal MSDs of a colloid particle in a dense colloid suspension confined to a small circular cavity. In each of these geometries, a dense colloid suspension exhibits pronounced density oscillations with spacing of a particle diameter. We remove the discrepancy between prediction and experiment using the Fisher-Methfessel interpretation of how local equilibrium in an inhomogeneous system is maintained to argue that the force acting on a particle is delocalized over a volume with radius equal to a particle diameter. Our interpretation has relevance to the relationship between the scale of inhomogeneity and the utility of translation of the particle MSD into a position dependent diffusion coefficient and to the use of a spatially dependent diffusion coefficient to describe mass transport in a heterogeneous system.
Predicting structural properties of fluids by thermodynamic extrapolation
Authors: Mahynski Nathan A. , Jiao Sally , Hatch Harold W. , Blanco Marco A. , Shen Vincent K.
Published: May 2018

We describe a methodology for extrapolating the structural properties of multicomponent fluids from one thermodynamic state to another. These properties generally include features of a system that may be computed from an individual configuration such as radial distribution functions, cluster size distributions, or a polymer’s radius of gyration. This approach is based on the principle of using fluctuations in a system’s extensive thermodynamic variables, such as energy, to construct an appropriate Taylor series expansion for these structural properties in terms of intensive conjugate variables, such as temperature. Thus, one may extrapolate these properties from one state to another when the series is truncated to some finite order. We demonstrate this extrapolation for simple and coarse-grained fluids in both the canonical and grand canonical ensembles, in terms of both temperatures and the chemical potentials of different components. The results show that this method is able to reasonably approximate structural properties of such fluids over a broad range of conditions. Consequently, this methodology may be employed to increase the computational efficiency of molecular simulations used to measure the structural properties of certain fluid systems, especially those used in high-throughput or data-driven investigations.
Spectroscopy and formation of lanthanum-hydrocarbon radicals formed by association and carbon-carbon bond cleavage of isoprene
Authors: Cao Wenjin , Hewage Dilrukshi , Yang Dong-Sheng
Published: May 2018

La atom reaction with isoprene is carried out in a laser-vaporization molecular beam source. The reaction yields an adduct as the major product and C—C cleaved and dehydrogenated species as the minor ones. La(C5H8), La(C2H2), and La(C3H4) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of all three species exhibit a strong origin band and several weak vibronic bands corresponding to La-ligand stretch and ligand-based bend excitations. La(C5H8) is a five-membered metallacycle, whereas La(C2H2) and La(C3H4) are three-membered rings. All three metallacycles prefer a doublet ground state with a La 6s1-based valence electron configuration and a singlet ion. The five-membered metallacycle is formed through La addition and isoprene isomerization, whereas the two three-membered rings are produced by La addition and insertion, hydrogen migration, and carbon-carbon bond cleavage.
Engineering of vascularized 3D cell constructs to model cellular interactions through a vascular network
Authors: Sano Emi , Mori Chihiro , Nashimoto Yuji , Yokokawa Ryuji , Kotera Hidetoshi , Torisawa Yu-suke
Published: May 2018

Current in vitro 3D culture models lack a vascular system to transport oxygen and nutrients, as well as cells, which is essential to maintain cellular viability and functions. Here, we describe a microfluidic method to generate a perfusable vascular network that can form inside 3D multicellular spheroids and functionally connect to microchannels. Multicellular spheroids containing endothelial cells and lung fibroblasts were embedded within a hydrogel inside a microchannel, and then, endothelial cells were seeded into both sides of the hydrogel so that angiogenic sprouts from the cell spheroids and the microchannels were anastomosed to form a 3D vascular network. Solution containing cells and reagents can be perfused inside the cell spheroids through the vascular network by injecting it into a microchannel. This method can be used to study cancer cell migration towards 3D co-culture spheroids through a vascular network. We recapitulated a bone-like microenvironment by culturing multicellular spheroids containing osteo-differentiated mesenchymal stem cells (MSCs), as well as endothelial cells, and fibroblasts in the device. After the formation of vascularized spheroids, breast cancer cells were injected into a microchannel connected to a vascular network and cultured for 7 days on-chip to monitor cellular migration. We demonstrated that migration rates of the breast cancer cells towards multicellular spheroids via blood vessels were significantly higher in the bone-like microenvironment compared with the microenvironment formed by undifferentiated MSCs. These findings demonstrate the potential value of the 3D vascularized spheroids-on-a-chip for modeling in vivo-like cellular microenvironments, drug delivery through blood vessels, and cellular interactions through a vascular network.
Segregation of chlorine in n-type tin monosulfide ceramics: Actual chlorine concentration for carrier-type conversion
Authors: Iguchi Yuki , Sugiyama Taiki , Inoue Kazutoshi , Yanagi Hiroshi
Published: May 2018

Tin monosulfide (SnS) is an attractive material for photovoltaic cells because of its suitable band-gap energy, high absorption coefficient, and non-toxic and abundant constituent elements. The primary drawback of this material is the lack of n-type SnS. We recently demonstrated n-type SnS by doping with Cl. However, the Cl-doped n-type SnS bulk ceramics exhibited an odd behavior in which carrier-type conversion but not electron carrier concentration depended on the Cl concentration. In this study, the electron probe microanalysis (EPMA) elemental mapping of Cl-doped SnS revealed continuous homogeneous regions with a relatively low Cl concentration along with the islands of high Cl concentration in which Sn/S is far from unity. The difference between the Cl concentration in the homogeneous region (determined by EPMA) and the bulk Cl concentration (determined by wavelength-dispersive X-ray fluorescence spectroscopy) increased with the increasing Cl doping amount. The carrier concentration and the Hall coefficient clearly depended on the Cl concentration in the homogeneous region. Carrier-type conversion was observed at the Cl concentration of 0.26 at. % (in the homogeneous region).
Experimental investigation of effective parameters on signal enhancement in spark assisted laser induced breakdown spectroscopy
Authors: Hassanimatin M. M. , Tavassoli S. H.
Published: May 2018

A combination of electrical spark and laser induced breakdown spectroscopy (LIBS), which is called spark assisted LIBS (SA-LIBS), has shown its capability in plasma spectral emission enhancement. The aim of this paper is a detailed study of plasma emission to determine the effect of plasma and experimental parameters on increasing the spectral signal. An enhancement ratio of SA-LIBS spectral lines compared with LIBS is theoretically introduced. The parameters affecting the spectral enhancement ratio including ablated mass, plasma temperature, the lifetime of neutral and ionic spectral lines, plasma volume, and electron density are experimentally investigated and discussed. By substitution of the effective parameters, the theoretical spectral enhancement ratio is calculated and compared with the experimental one. Two samples of granite as a dielectric and aluminum as a metal at different laser pulse energies are studied. There is a good agreement between the calculated and the experimental enhancement ratio.
Collaborating teams compare wind turbine simulation codes
Authors: Patrick Chris
Published: May 2018

Researchers from four institutions find that their four different codes conduct essentially the same wind turbine simulation.
Thermodynamic extrapolations predict fluid structural properties at many conditions
Authors: Fellet Melissae
Published: May 2018

Extrapolation methods can improve the computational efficiency of estimating the structural properties of a fluid, thus enabling the prediction of properties over a wide range of thermodynamic conditions.
Effects of Praseodymium Doping on Conductivity and Oxygen Permeability of Cobalt-Free Perovskite-Type Oxide BaFeO3−δ
Authors: Wei Bang-zheng , Wang Yu , Liu Meng , Xu Chen-xi , Cheng Ji-gui
Published: May 2018

Among the perovskite-type oxides with symmetrical structure applied in oxygen permeable membranes, cubic phase structure is the most favorable for oxygen permeation. In order to stabilize the cubic perovskite structure of BaFeO3−δ material at room temperature, iron was partially substituted by praseodymium. BaFe1−yPryO3−δ powders were synthesized by a solid state reaction method, and sintered samples were prepared from the synthesized BaFe1−yPryO3−δ powders. X-ray diffraction results reveal that the BaFe1−yPryO3−δ samples remain cubic structure at praseodymium substitution amount of y=0.05, 0.075, 0.1. Scanning electron microscope observation indicates that the sintered samples contain only a small amount of enclosed pores and the grain size of BaFe1−yPryO3−δ increase monotonically with the increase of the praseodymium doping amount, praseodymium doping promotes the grain size growth. Tests of electrical conductivity and oxygen permeation flux show that praseodymium doping improves the conduction properties of BaFe1−yPryO3−δ and BaFe0.9Pr0.1O3−δ composition has an electrical conductivity of 6.5 S/cm and an oxygen permeation of 1.112 mL/(cm2·min) at 900 °C, respectively. High temperature XRD investigation shows that the crystal structure of BaFe0.975Pr0.025O3−δ membrane completely transform to cubic phase at 700 °C. The present test results have shown that partially substitution of Fe by praseodymium in BaFeO3 can stabilize the cubic structure and improve the properties.
Highly Sensitive Silver Nanorod Arrays for Rapid Surface Enhanced Raman Scattering Detection of Acetamiprid Pesticides
Authors: Han Cai-qin , Yao Yue , Wang Wen , Tao Liu-qian , Zhang Wen-xin , Ingram Whitney Marvella , Tian Kang-zhen , Liu Ying , Lu Ai-xia , Wu Ying , Yan Chang-chun , Qu Lu-Lu , Li Hai-tao
Published: May 2018

The determination of pesticide residue on agricultural products is increasingly important. Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia. In this work, we developed a rapid and sensitive method to detect acetamiprid pesticide residue based on surface-enhanced Raman scattering. Silver nanorod (AgNR) arrays were fabricated by oblique angle deposition technology and were used as SERS substrates. Prior to detection, the AgNR arrays were cleaned with nitric acid solution or a mixture of methanol and acetone. Compared to the unwashed AgNR arrays, the AgNR arrays washed with methanol and acetone shows a signal enhancement 1000 times greater than the unwashed AgNR array due to the effective removal of the impurities on its surface. The limit of detection of acetamiprid was determined to be 0.05 mg/L. In addition, the molecular structure of acetamiprid was simulated and the corresponding vibration modes of the characteristic bands of acetamiprid were calculated by density function theory. To demonstrate its practical application, the AgNRs array substrates were applied successfully to the rapid identification of acetamiprid residue on a cucumber's surface. These results confirmed possibility of utilizing the AgNRs SERS substrates as a new method for highly sensitive pesticide residue detection.
Activity-dependent aberrations in gene expression and alternative splicing in a mouse model of Rett syndrome
Authors: Osenberg Sivan , Karten Ariel , Sun Jialin , Li Jin , Charkowick Shaun , Felice Christy A. , Kritzer Mary , Nguyen Minh Vu Chuong , Yu Peng , Ballas Nurit
Published: May 2018

Significance

Rett syndrome (RTT) is a severe neurological disease affecting girls in their early childhood. The underlying cause of most RTT cases is mutations in the gene methyl-CpG-binding protein 2 (
MECP2
). How the loss of MeCP2 function in the brain due to these mutations causes such severe neurological symptoms remains a mystery. Here, we show widespread aberrations in gene expression and anomalous patterns of alternative splicing, specifically when neurons of RTT mice are stimulated. Furthermore, these aberrations occur in conjunction with higher seizure susceptibility in response to neuronal stimulation in these RTT mice. Our findings suggest that MeCP2 is required for adjusting the robust changes in gene transcription and for proper regulation of alternative splicing during neuronal stimulation.
Targeting tumor cell plasticity by combined inhibition of NOTCH and MAPK signaling in colon cancer
Authors: Schmidt Eva Marina , Lamprecht Sebastian , Blaj Cristina , Schaaf Christian , Krebs Stefan , Blum Helmut , Hermeking Heiko , Jung Andreas , Kirchner Thomas , Horst David
Published: May 2018

In colorectal cancer, signaling pathways driving tumor progression are promising targets for systemic therapy. Besides WNT and MAPK signaling, activation of NOTCH signaling is found in most tumors. Here, we demonstrate that high NOTCH activity marks a distinct colon cancer cell subpopulation with low levels of WNT and MAPK activity and with a pronounced epithelial phenotype. Therapeutic targeting of MAPK signaling had limited effects on tumor growth and caused expansion of tumor cells with high NOTCH activity, whereas upon targeting NOTCH signaling, tumor cells with high MAPK activity prevailed. Lineage-tracing experiments indicated high plasticity between both tumor cell subpopulations as a mechanism for treatment resistance. Combined targeting of NOTCH and MAPK had superior therapeutic effects on colon cancer growth in vivo. These data demonstrate that tumor cells may evade systemic therapy through tumor cell plasticity and provide a new rationale for simultaneous targeting of different colon cancer cell subpopulations.
Strength design of Zr(x)Ti(x)Hf(x)Nb(x)Mo(x) alloys based on empirical electron theory of solids and molecules
Authors: Li Y K , Chen Y W , Cheng X W , Wu C , Cheng B
Published: May 2018

In this paper, the valence electron structure parameters of Zr(x)Ti(x)Hf(x)Nb(x)Mo(x) alloys were calculated based on the empirical electron theory of solids and molecules (EET), and their performance through these parameters were predicted. Subsequently, the alloys with special valence electron structure parameters were prepared byarc melting. The hardness and high-temperature mechanical properties were analyzed to verify the prediction. Research shows that the influence of shared electron number nA
on the strongest bond determines the strength of these alloys and the experiments are consistent with the theoretical prediction.
Densities of hyperbolic cusp invariants of knots and links
Authors: Adams Colin , Kaplan-Kelly Rose , Moore Michael , Shapiro Brandon , Sridhar Shruthi , Wakefield Joshua
Published: May 2018

We find that cusp densities of hyperbolic knots in

S
3

S^3

include a dense subset of

[
0
,
0.6826
…
]

[0,0.6826\dots ]

and those of links are a dense subset of

[
0
,
0.853
…
]

[0,0.853\dots ]

. We define a new invariant associated with cusp volume, the cusp crossing density, as the ratio between the cusp volume and the crossing number of a link, and show that cusp crossing density for links is bounded above by

3.1263
…

3.1263\dots

. Moreover, there is a sequence of links with cusp crossing density approaching 3. For two-component hyperbolic links, cusp crossing density is shown to include a dense subset of the interval

[
0
,
1.6923
…
]

[0,1.6923\dots ]

and for all hyperbolic links, cusp crossing density is shown to include a dense subset of

[
0
,
2.120
…
]

[0, 2.120\dots ]

.
Integral relations associated with the semi-infinite Hilbert transform and applications to singular integral equations
Authors: Antipov Y. , Mkhitaryan S.
Published: May 2018

Integral relations with the Cauchy kernel on a semi-axis for the Laguerre polynomials, the confluent hypergeometric function, and the cylindrical functions are derived. A part of these formulas is obtained by exploiting some properties of the Hermite polynomials, including their Hilbert and Fourier transforms and connections to the Laguerre polynomials. The relations discovered give rise to complete systems of new orthogonal functions. Free of singular integrals, exact and approximate solutions to the characteristic and complete singular integral equations in a semi-infinite interval are proposed. Another set of the Hilbert transforms in a semi-axis are deduced from integral relations with the Cauchy kernel in a finite segment for the Jacobi polynomials and the Jacobi functions of the second kind by letting some parameters involved go to infinity. These formulas lead to integral relations for the Bessel functions. Their application to a model problem of contact mechanics is given. A new quadrature formula for the Cauchy integral in a semi-axis based on an integral relation for the Laguerre polynomials and the confluent hypergeometric function is derived and tested numerically. Bounds for the remainder are found.
Checking Behavior, Fear of Recurrence, and Daily Triggers in Breast Cancer Survivors
Authors: Soriano Emily C , Valera Rosmeiry , Pasipanodya Elizabeth C , Otto Amy K , Siegel Scott D , Laurenceau Jean-Philippe
Published: May 2018

Background

Fear of cancer recurrence (FCR) is a top ongoing concern of breast cancer (BC) survivors and thus the focus of recent intervention development. The Self-Regulation Model of FCR (Lee-Jones C, Humphris G, Dixon R, Hatcher MB. Fear of cancer recurrence–a literature review and proposed cognitive formulation to explain exacerbation of recurrence fears. Psychooncology. 1997;6:95–105.) states that everyday cancer-related events trigger FCR, which, in turn, leads to specific behavioral responses, including checking the body for signs or symptoms of cancer. Links between triggering events, FCR, and checking behavior have not yet been studied in the context of daily life or at the within-person level.

Purpose

The goal of this study was to examine whether FCR has a within-person link with daily checking behavior and whether FCR mediates the link between triggering events and checking behavior.

Methods

Seventy-two early-stage BC survivors completed daily diaries over a 21-day period approximately 5 months after BC surgery. FCR, checking behavior, and triggering events were assessed each evening.

Results

Multilevel modeling results indicated that FCR predicted greater odds of same-day, but not next-day, checking behavior. We found that daily FCR significantly mediated the same-day effect of triggering events on checking behavior. These average within-person effects varied substantially between patients and were not explained by momentary negative affect.

Conclusions

Findings support the within-person relationship between triggering events, FCR, and checking behavior posited by guiding theory, and can inform FCR intervention development.
The Role of Angiogenesis Inhibitors in Hypertension: Following “Ariadne’s Thread”
Authors: Sanidas Elias , Papadopoulos Dimitris P , Velliou Maria , Tsioufis Kostas , Mantzourani Marina , Iliopoulos Dimitris , Perrea Despoina , Barbetseas John , Papademetriou Vasilios
Published: May 2018

Arterial hypertension (HT) is one of the most frequently recorded comorbidities among patients under antiangiogenic therapy. Inhibitors of vascular endothelial growth factor and vascular endothelial growth factor receptors are most commonly involved in new onset or exacerbation of pre-existing controlled HT. From the pathophysiology point of view, data support that reduced nitric oxide release and sodium and fluid retention, microvascular rarefaction, elevated vasoconstrictor levels, and globular injury might contribute to HT. The purpose of this review was to present recent evidence regarding the incidence of HT induced by antiangiogenic agents, to analyze the pathophysiological mechanisms, and to summarize current recommendations for the management of elevated blood pressure in this field.
Qualitative Research in the Chinese Social Work Academy: Optimism and Invisible Disadvantages
Authors: Xu Yanfeng , Shdaimah Corey , Zhao Fang , Gioia Deborah
Published: May 2018

There has been much discussion about the contributions of qualitative research to social work knowledge, but the experiences of social work faculty engaged in qualitative research are rarely discussed. Social work is at the early developmental stage in China, which makes the country a useful laboratory to examine this question. The current study aimed to understand experiences of Chinese qualitative social work faculty and how their methodological orientation affected their career trajectories. Nine semi-structured, in-depth interviews were conducted and analysed. Thematic data analysis revealed three major themes: suitability, methodological challenges and structural barriers. Findings indicate that qualitative social work research has an optimistic future in China, but methodological challenges and structural barriers create invisible disadvantages. This study highlights the need for rigorous qualitative research training, including apprenticeship; translation of more qualitative learning materials into Chinese; and support for the purchase, training and use of qualitative software packages. The results also point to the need for institutional review boards or other ethical oversight mechanisms. More importantly, there must be greater consensus regarding what constitutes scientific rigour, which projects should be funded, what are evaluative criteria for publication, and whom to hire and promote.
Comparison of the Cumulative Efficacy and Safety of Chloroquine, Artesunate, and Chloroquine-Primaquine in Plasmodium vivax Malaria
Authors: Chu Cindy S , Phyo Aung Pyae , Lwin Khin Maung , Win Htun Htun , San Thida , Aung Aye Aye , Raksapraidee Rattanaporn , Carrara Verena I , Bancone Germana , Watson James , Moore Kerryn A , Wiladphaingern Jacher , Proux Stéphane , Sriprawat Kanlaya , Winterberg Markus , Cheah Phaik Yeong , Chue Amy L , Tarning Joel , Imwong Mallika , Nosten François , White Nicholas J
Published: May 2018

Vivax malaria relapses frequently even in low-transmission settings. Chloroquine delays but does not prevent recurrences. Adding primaquine to a slowly eliminated schizonticide significantly reduces recurrences and improves hematocrit, but this advantage is offset by hemolysis in G6PD-deficient females.
Trading for peace*
Authors: Jha Saumitra
Published: May 2018

I examine the conditions under which trade can support peaceful coexistence and prosperity when particular social and ethnic groups are cheap targets of violence. A simple theoretical framework reveals that for a broad set of cases, while inter-group competition generates incentives for violence, the presence of non-replicable, non-expropriable inter-group complementarities becomes necessary to sustain peaceful coexistence over long time horizons. In addition to complementarity, two further conditions are important for deterring violence over time. When relatively mobile groups (e.g. immigrants) are vulnerable, a credible threat to leave can deter violence. When less mobile (indigenous) groups are vulnerable, high-monitoring costs that allow them to withhold production can improve their gains from trade. I describe the implications for indigenous entrepreneurship and cultural assimilation, the development of local institutions supporting inter-ethnic trust and immigration policies and policies aimed at mitigating conflict through financial innovations. I illustrate these implications using contemporary evidence and historical cases of organizations and institutions created to engender trade and support peace drawn from Africa, Asia, Europe and Latin America.
Unpacking policy formulation and industry influence: the case of the draft control of marketing of alcoholic beverages bill in South Africa
Authors: Bertscher Adam , London Leslie , Orgill Marsha
Published: May 2018

Alcohol is a major contributor to the Non-Communicable Disease burden in South Africa. In 2000, 7.1% of all deaths and 7% of total disability-adjusted life years were ascribed to alcohol-related harm in the country. Regulations proposed to restrict alcohol advertising in South Africa present an evidence-based upstream intervention. Research on policy formulation in low- and middle-income countries is limited. This study aims to describe and explore the policy formulation process of the 2013 draft Control of Marketing of Alcoholic Beverages Bill in South Africa between March 2011 and May 2017. Recognising the centrality of affected actors in policy-making processes, the study focused on the alcohol industry as a central actor affected by the policy, to understand how they—together with other actors—may influence the policy formulation process. A qualitative case study approach was used, involving a stakeholder mapping, 10 in-depth interviews, and review of approximately 240 documents. A policy formulation conceptual framework was successfully applied as a lens to describe a complex policy formulation process. Key factors shaping policy formulation included: (1) competing and shared values—different stakeholders promote conflicting ideals for policymaking; (2) inter-department jostling—different government departments seek to protect their own functions, hindering policy development; (3) stakeholder consultation in democratic policymaking—policy formulation requires consultations even with those opposed to regulation and (4) battle for evidence—evidence is used strategically by all parties to shape perceptions and leverage positions. This research (1) contributes to building an integrated body of knowledge on policy formulation in low- and middle-income countries; (2) shows that achieving policy coherence across government departments poses a major challenge to achieving effective health policy formulation and (3) shows that networks of actors with commercial and financial interests use diverse strategies to influence policy formulation processes to avoid regulation.
The Limit Point of the Pentagram Map
Authors: Glick Max
Published: May 2018

The pentagram map is a discrete dynamical system defined on the space of polygons in the plane. In the 1st paper on the subject, Schwartz proved that the pentagram map produces from each convex polygon a sequence of successively smaller polygons that converges exponentially to a point. We investigate the limit point itself, giving an explicit description of its Cartesian coordinates as roots of certain degree three polynomials.
Vertical Distribution Relations for Special Cycles on Unitary Shimura Varieties
Authors: Boumasmoud Réda , Brooks Ernest Hunter , Jetchev Dimitar P
Published: May 2018

We consider cycles on three-dimensional Shimura varieties attached to unitary groups, defined over extensions of a complex multiplication (CM) field $E$, which appear in the context of the conjectures of Gan et al. [6]. We establish a vertical distribution relation for these cycles over an anticyclotomic extension of $E$, complementing the horizontal distribution relation of [8], and use this to define a family of norm-compatible cycles over these fields, thus obtaining a universal norm construction similar to the Heegner $\Lambda $-module constructed from Heegner points.
Collections of Hypersurfaces Containing a Curve
Authors: Tseng Dennis
Published: May 2018

We consider the closed locus parameterizing $k$-tuples of hypersurfaces that have positive dimensional intersection and fail to intersect properly, and show in a large range of degrees that its unique irreducible component of maximal dimension consists of tuples of hypersurfaces whose intersection contains a line. We then apply our methods in conjunction with a known reduction to positive characteristic argument to find the unique component of maximal dimension of the locus of hypersurfaces with positive dimensional singular loci. We will also find the components of maximal dimension of the locus of smooth hypersurfaces with a higher dimensional family of lines through a point than expected.
Multidimensional Assessment of Social Desirability Bias: An Application of Multiscale Item Randomized Response Theory to Measure Academic Misconduct
Authors: Wlömert Nils , Pellenwessel David , Fox Jean-Paul , Clement Michel
Published: May 2018

It is challenging for survey researchers to investigate sensitive topics due to concerns about socially desirable responding (SDR). The susceptibility to social desirability bias may vary not only between individuals (e.g., different perceptions about social norms) but also within individuals (e.g., perceived sensitivity of different items). Thus, controlling for SDR is particularly challenging when analyzing multidimensional constructs that are measured via multiple groups of items with varying degrees of sensitivity. In this research, we address this challenge using a combination of a randomized response (RR) approach for data collection and a multiscale item response theory (IRT) model for data analysis. While the RR approach protects the anonymity of respondents at the item level, the multiscale IRT approach accounts for the multidimensional nature of the construct and explicitly models the item-level differences in the measurement of its dimensions. We empirically demonstrate the benefits of the model using a multidimensional self-report instrument for the assessment of academic misconduct of university students. Based on an experiment with random assignment, our results uncover considerable differences in the perceived sensitivity, both between the construct dimensions and between their measurement items. These findings support the view that individuals engage in SDR to varying degrees depending on the perceived sensitivity of the specific items and groups of items. In contrast, a social desirability scale that treats SDR as a stable personality trait is not found to capture meaningful differences in response style. Finally, we show how structural models can be incorporated into the framework to link the latent construct’s dimensions to individual-level explanatory variables.
Research network emergence: Societal issues in nanotechnology and the center for nanotechnology in society
Authors: Youtie Jan , Shapira Philip , Reinsborough Michael , Fisher Erik
Published: May 2018

This article looks at the creation of a network of researchers of social issues in nanotechnology and the role of the Center for Nanotechnology in Society at Arizona State University (CNS-ASU) in the creation of this network. The extent to which CNS-ASU is associated with the development of a research network around the study of social issues in nanotechnology is examined through geographic mapping of co-authors and citations of center publications, network analysis of co-authors of papers on social issues in nanotechnology, and a disciplinary analysis of these papers. The results indicate that there is an extensive network of co-authorships among researchers studying social issues in nanotechnology with CNS-ASU at the center of this network. In addition, papers written by center members and affiliates integrate a diverse range of disciplines. Qualitative data are used to interpret some of the ways that citation occurs.
The feasibility and acceptability of mass drug administration for malaria in Cambodia: a mixed-methods study
Authors: Peto Thomas J , Tripura Rupam , Sanann Nou , Adhikari Bipin , Callery James , Droogleever Mark , Heng Chhouen , Cheah Phaik Yeong , Davoeung Chan , Nguon Chea , von Seidlein Lorenz , Dondorp Arjen M , Pell Christopher
Published: May 2018

Background

Mass drug administrations (MDAs) are part of the World Health Organization’s Plasmodium falciparum elimination strategy for the Greater Mekong Subregion (GMS). In Cambodia, a 2015–2017 clinical trial evaluated the effectiveness of MDA. This article explores factors that influence the feasibility and acceptability of MDA, including seasonal timing, financial incentives and the delivery model.

Methods

Quantitative data were collected through structured questionnaires from the heads of 163 households. Qualitative data were collected through 25 semi-structured interviews and 5 focus group discussions with villagers and local health staff. Calendars of village activities were created and meteorological and malaria treatment records were collected.

Results

MDA delivered house-to-house or at a central point, with or without compensation, were equally acceptable and did not affect coverage. People who knew about the rationale for the MDA, asymptomatic infections and transmission were more likely to participate. In western Cambodia, MDA delivered house-to-house by volunteers at the end of the dry season may be most practicable but requires the subsequent treatment of in-migrants to prevent reintroduction of infections.

Conclusions

For MDA targeted at individual villages or village clusters it is important to understand local preferences for community mobilisation, delivery and timing, as several models of MDA are feasible.
A Confounding Effect of Bacterial Titer in a Type III Delivery–Based Assay of Eukaryotic Effector Function
Authors: Carter Morgan E. , Bogdanove Adam J. , Innes Roger W. , Wise Roger P.
Published: May 2018

This letter describes a newly discovered confounding effect of bacterial titer in a previously published type III delivery-based assay of the fungal effector BEC1019. The original publication (Whigham et al. 2015) has been retracted as a consequence of this discovery. Here, we tabulate the affected and unaffected figures and conclusions in the original publication and briefly reflect on potential pitfalls to bear in mind when designing experiments that use bacterial type III secretion to characterize eukaryotic effectors.
Plant Selenium Hyperaccumulation Affects Rhizosphere: Enhanced Species Richness and Altered Species Composition
Authors: Cochran Alyssa T. , Bauer Jemma , Metcalf Jessica L. , Lovecka Petra , Sura de Jong Martina , Warris Sven , Mooijman Paul J. W. , van der Meer Ingrid , Knight Rob , Pilon-Smits Elizabeth A. H.
Published: May 2018

Little is known about the microbiomes associated with plants with unusual properties, including plants that hyperaccumulate toxic elements such as selenium (Se). Se hyperaccumulators contain up to 1.5% of their dry weight in Se, concentrations shown to affect ecological interactions with herbivores, fungal pathogens and neighboring plants. Hyperaccumulators also enrich their surrounding soil with Se, which may alter the rhizobiome. To investigate whether plant Se affects rhizobacterial diversity and composition, we used a combination of culture-independent and culture-based approaches. Sequencing of 16S rRNA gene amplicons using the Illumina platform revealed that the rhizosphere microbiomes of Se hyperaccumulators were significantly different from nonaccumulators from the same site, with a higher average relative abundance of Pedobacter and Deviosa. Additionally, hyperaccumulators harbored a higher rhizobacterial species richness when compared with nonaccumulators from the same family on the same site. Independent from Se present at the site or in the host plant, the bacterial isolates were extremely resistant to selenate and selenite (up to 200 mM) and could reduce selenite to elemental Se. In conclusion, Se hyperaccumulation does not appear to negatively affect rhizobacterial diversity, and may select for certain taxa in the rhizosphere microbiome. Additionally, Se resistance in hyperaccumulator-associated bacteria and archaea may be widespread and not under selection by the host plant.
Spruce Decline andDiaporthe: Incidence, Taxonomy, Virulence, and Tree Susceptibility in Michigan
Authors: McTavish C. K. , Catal M. , Fulbright D. W. , Jarosz A. M.
Published: May 2018

In the early 2000s, spruce trees in Michigan began displaying basal needle drop and branch death that slowly progressed upward, symptoms of what we call spruce decline. A survey in 2013 revealed that spruce decline was common throughout Michigan’s Lower Peninsula, and Diaporthe was the most likely pathogen causing the cankers associated with these symptoms. Greenhouse inoculation studies completed Koch’s postulates, confirming that Diaporthe could cause cankers that cause needle loss and branch death. The five different Diaporthe haplotypes isolated from symptomatic branches during the survey differed in virulence. Haplotypes 2, 4, and 5 were more virulent, and differed from each other by only one or two base pairs using the internal transcribed spacer (ITS) region and did not differ using the β-tubulin (TUB) gene. These haplotypes were unresolved phylogenetically. Haplotypes 1 and 3 were weakly virulent to avirulent on multiple spruce taxa, and fell into a resolved Diaporthe eres clade. Spruce taxa varied in susceptibility, with Colorado blue spruce (Picea pungens) the most susceptible, followed by Norway (P. abies), then white spruce (P. glauca). Spruce taxa that were much less susceptible were Black Hills (P. glauca var. densata), Serbian (P. omorika), and Meyer spruce (P. meyeri). We demonstrate that one or more Diaporthe species is causing cankers on declining spruce in Michigan, and these cankers elicit symptoms similar to the branch death expressed by declining spruce in the landscape. Future work will focus on further characterizing Diaporthe to species, and determining biotic and abiotic stressors that may predispose spruce trees to express decline symptoms.
Mating System in the Brown Rot Pathogens Monilinia fructicola, M. laxa, and M. fructigena
Authors: Abate Domenico , De Miccolis Angelini Rita M. , Rotolo Caterina , Pollastro Stefania , Faretra Francesco
Published: May 2018

Monilinia fructicola, M. laxa, and M. fructigena are the most important pathogens responsible for brown rot disease of stone and pome fruits. Information on their mating system and sexual behavior is scant. A mating-type-specific PCR-based assay was developed and applied to 155 Monilinia isolates from 10 countries and 10 different host plants. We showed that single isolates carry only one of two opposite idiomorphs at the MAT1 locus consistent with a heterothallic mating system for all three species. MAT1-1 and MAT1-2 mating types were detected in similar proportions in samples of isolates of each species and hence there do not appear to be genetic obstacles to the occurrence of sexual reproduction in their populations. Inter simple sequence repeat markers suggested that asexual reproduction is prevalent, but that sexual recombination occurs in M. fructicola populations in Italy. The genetic architectures of the MAT1 loci of the three pathogens were analyzed. MAT1-1 and MAT1-2 idiomorphs are flanked upstream and downstream by the APN2 and SLA2 genes and resemble those of Botrytis cinerea and other heterothallic fungi in the family Sclerotiniaceae. Each idiomorph contains a specific couple of genes, MAT1-1-1 (with alpha-box domain) and MAT1-1-5 in MAT1-1, and MAT1-2-1 (with HMG-box domain) and MAT1-2-10 in MAT1-2. Small gene fragments (dMAT1-1-1 and dMAT1-2-1) from the opposite idiomorph were detected close to their flanking regions. Constitutive expression of the four MAT1 genes during vegetative growth was ascertained by transcriptomic analysis (RNA-Seq). Antisense transcription of the MAT1-1-1 and MAT1-2-1 genes and intergenic transcribed regions of the MAT1 locus were detected. These results represent new insights into the mating systems of these three economically-important pathogens which could contribute to improve the knowledge on their population biology.
HEART Failure? Episodes of Missed Major Cardiac Events When Applying the HEART Pathway to an Observation Unit Population
Authors: Tesson Alan , Abdo Rami , Kamath Aparna , Sutter Joanne , Cline Rachel , Hale Sarah L. , Bae Jonathan , Verma Lalit
Published: May 2018

Objective:

The HEART Pathway risk prediction tool (HEART score plus serial troponin measures at 0 and 3 hours post-presentation) is used to identify low-risk patients with chest pain who may qualify for safe, early discharge. We calculated the percentage of patients in our observation unit that qualified as low risk using HEART Pathway, as well as their associated outcomes.

Methods:

We retrospectively reviewed charts on 966 consecutive patients admitted to our observation unit for chest pain (January 2015 to February 2016); HEART Pathway scores were retrospectively calculated and serial cardiac troponin values logged. The primary outcome was 42-day major adverse cardiac events (MACE), including acute myocardial infarction, urgent revascularization, and all-cause death.

Results:

The patients’ mean age was 59, 42% were male, 46% white, and 68 (7.7%) had MACE. HEART Pathway defined 384 patients as low risk (39.8%) and eligible for early discharge. Applying HEART Pathway would have missed 1.2% of patients with MACE; however, all adverse cardiac events occurred in patients with a HEART Pathway score of 3 (4 of 193, 2.1%) and none in those with a HEART Pathway score ≤2 (0 of 134).

Conclusions:

While the HEART Pathway identifies a pooled population at low risk for MACE, risk is not homogenous within this population. Patients with a score of 3 may have higher risk of 42-day MACE that may be unacceptable to some providers, while scores ≤2 saw no events. Caution is advised for those with HEART Pathway score of 3 until more data is available to accurately estimate risk.
Contrast-Enhanced Stress Echocardiography and Myocardial Perfusion Imaging in Patients Hospitalized With Chest Pain: A Randomized Study
Authors: Salame Gerald , Juselius Whitney E. , Burden Marisha , Long Carlin S. , Bendelow Tiffany , Beaty Brenda , Masoudi Frederick A. , Krantz Mori J.
Published: May 2018

Ultrasound contrast-enhanced stress echocardiography improves endocardial visualization, but diagnostic test rates versus stress myocardial perfusion imaging (MPI) have not been studied. A prospective randomized trial was performed between April 2012 and October 2014 at a single-center, safety net hospital. Hospitalized patients referred for noninvasive stress imaging were randomized 1:1 to stress echocardiography or stress MPI. The primary outcome was diagnostic test rate defined as interpretable images and achievement of >85% of age-predicted maximal heart rate (for dobutamine and exercise). Rates were assessed among those completing testing and then based solely on image interpretability. Charges and length of stay were secondary outcomes. A total of 240 patients were randomized, and 229 completed testing. Diagnostic test rates were similar for stress echocardiography versus MPI {89.4% [95% confidence interval (CI), 82.2–94.4] vs. 94.8% [95% CI, 89.1–98.1], P = 0.13} and did not differ with multivariable adjustment. Modalities requiring a diagnostic heart rate criteria were more frequently ordered with stress echocardiography (100% vs. 26%; P < 0.001). Therefore, an imaging-based analysis without the 12 individuals who failed to achieve target heart rate (n = 217) was evaluated with diagnostic test rates of 100% versus 94.8% (95% CI, 89.1%–98.1%; P = 0.03) for stress echocardiography and MPI, respectively. Median length of stay did not differ. Median (interquartile range) test-related charges were lower with stress echocardiography: $2,424 ($2400–$2508) versus $3619 ($3584–$3728), P < 0.0001. Overall, tests were positive for ischemia in 8% of patients. In conclusion, contrast-enhanced stress echocardiography provides comparable diagnostic test rates to MPI with lower associated charges.
Angiographic Characteristics of ST-Elevation Myocardial Infarction Patients With Infarct-related Coronary Artery Ectasia Undergoing Primary Percutaneous Coronary Intervention
Authors: Geraiely Babak , Salarifar Mojtaba , Alidoosti Mohammad , Mortazavi Seyedeh Hamideh
Published: May 2018

Coronary ectasia accounts for 0.3%–4.9% of patients undergoing coronary angiography. We conducted the present study to evaluate the angiographic characteristics of ST-elevation myocardial infarction (STEMI) patients with infarct-related coronary artery ectasia (IRAE) undergoing primary percutaneous coronary intervention. We evaluated 667 STEMI patients who were divided into 2 groups of IRAE (n = 81) and non-IRAE (n = 568). Preprocedural thrombolysis in myocardial infarction (TIMI) flow grade, postprocedural TIMI flow grade, thrombus burden grade, and TIMI frame count were then evaluated. In adjusted analysis, fewer patients with IRAE had open (TIMI flow grade II or III) infarct-related arteries before the primary percutaneous coronary intervention (7.4% vs. 27.5%; odds ratio: 4.522; 95% confidence interval, 1.924–10.628; P = 0.001). Meanwhile, postprocedural TIMI flow grade 3 was less common in these patients (49.4% vs. 68.4%; odds ratio: 2.239; 95% confidence interval, 1.392–3.599; P = 0.001). High thrombus burden was more frequent in the patients with IRAE, with an odds ratio of 1.938 in the adjusted analysis. The corrected TIMI frame count was also significantly higher in the IRAE patients than in those without. Our STEMI patients with IRAE had impaired perfusion. Moreover, this group of patients more frequently had high thrombus burden. These patients might be at increased risk of unsuccessful revascularization probably due to distal embolization and no-reflow phenomenon, which could impact their short- and long-term outcomes. Because coronary ectasia is a known risk factor for acute coronary syndrome, it is beneficial that these patients be deemed high risk and kept under close monitoring.