bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosis of atmospheric pressure helium surface micro-discharge by two-dimensional temporal and spatial resolved emission spectroscopy
Authors: Wang Zhiwei , Feng Chunlei , Gao Liang , Ding Hongbin
Published: June 2018

The time dependence of the spectral emission of atmospheric pressure surface micro-discharge (SMD) in helium has been investigated with a two-dimensional spatial resolution. The time-resolved emission spectra from OH (309 nm), N2+ (391.4 nm), He (706.5 nm), and O (777.4 nm) behave differently. The results indicate that direct electron impact excitation dominates the generation of the plasma emission in the middle part of the rim electrode where the discharge event originates during the initial period. However, the fan-shaped diffusion of the discharge patterns head is principally due to Penning ionization and charge transfer reaction in later phases. Furthermore, the dynamic evolution of SMD emission pattern has a bullet-like structure in the negative half cycle while it looks like a glow in the positive half cycle. It implies that the polarity of applied voltage plays an important role in the dynamics of the SMD emission patterns.
Shear Alfvén fluctuation spectrum in divertor tokamak test facility plasmas
Authors: Wang T. , Qiu Z. , Zonca F. , Briguglio S. , Fogaccia G. , Vlad G. , Wang X.
Published: June 2018

The Divertor Tokamak Test (DTT) facility is proposed for studying power exhaust solutions as well as integrated physics and technology aspects for the demonstration power plant. To illuminate the richness of new novel plasma physics that can be explored in this device, linear stability properties and shear Alfvén fluctuation spectra of a typical DTT reference scenario are investigated by self-consistent hybrid magnetohydrodynamic-gyrokinetic simulations. The DTT core plasmas can be divided into two regions, characterized by reverse shear Alfvén eigenmode in the central core and by toroidal Alfvén eigenmode in the outer core region. The non-perturbative effect of energetic particles (EPs) and the wave-EP resonance condition as well as power transfer is analyzed in great detail, demonstrating the peculiar role played by EPs in multi-scale dynamics. The most unstable mode numbers of dominant Alfvénic fluctuations are shown to be of the order of 10, consistent with the typical orbit widths of the EPs normalized to the plasma minor radius and the DTT target design.
Layered nested Markov chain Monte Carlo
Authors: Jackson Nicholas E. , Webb Michael A. , de Pablo Juan J.
Published: June 2018

A configurational sampling algorithm based on nested layerings of Markov chains (Layered Nested Markov Chain Monte Carlo or L-NMCMC) is presented for simulations of systems characterized by rugged free energy landscapes. The layerings are generated using a set of auxiliary potential energy surfaces. The implementation of the method is demonstrated in the context of a rugged, two-dimensional potential energy surface. The versatility of the algorithm is next demonstrated on a simple, many-body system, namely, a canonical Lennard-Jones fluid in the liquid state. In that example, different layering schemes and auxiliary potentials are used, including variable cutoff distances and excluded-volume tempering. In addition to calculating a variety of properties of the system, it is also shown that L-NMCMC, when combined with a free-energy perturbation formalism, provides a straightforward means to construct approximate free-energy surfaces at no additional computational cost using the sampling distributions of each auxiliary Markov chain. The proposed L-NMCMC scheme is general in that it could be complementary to any number of methods that rely on sampling from a target distribution or methods that exploit a hierarchy of time scales and/or length scales through decomposition of the potential energy.
Reaction of the toroidal resistive wall on the magnetic field variations in tokamak-like systems
Authors: Pustovitov V. D.
Published: June 2018

The study is devoted to the problem of the magnetic field diffusion through a toroidal resistive shell (wall with respect to the interior). This is the same task as that considered in Dialetis et al. [J. Appl. Phys. 69, 1813 (1991)], but with a new element: current-carrying plasma inside the vessel. This extends the study on tokamaks with a resistive wall. The shape and position of the magnetically confined plasma must react on the field variations which brings considerable complications in the plasma electromagnetic description as compared to that of the rigid wall and external conductors. The proposed algorithm is devised so that the plasma properties are fully accounted for. It is based on the Green's function technique providing correct asymptotic behavior of the solutions that determine, through Maxwell equations and Ohm's law, the current induced in the wall during transient events. For tokamaks, this gives a closure in the analytical approaches incorporating the plasma-wall electromagnetic interaction with non-ideal wall reaction. This is needed for disruption modeling and, in particular, for evaluation of the disruption forces on the wall in large tokamaks like ITER with expected plasma current quench from 15 MA to zero in 35 ms.
Axial compression of plasma structures in a plasma focus discharge
Authors: Kubes P. , Paduch M. , Sadowski M. J. , Cikhardt J. , Cikhardtova B. , Klir D. , Kravarik J. , Munzar V. , Rezac K. , Zielinska E. , Skladnik-Sadowska E. , Szymaszek A. , Tomaszewski K. , Zaloga D.
Published: June 2018

The paper describes the behaviour of plasma within a MA plasma-focus with a novel electrode configuration, in which the anode and anti-anode were both equipped with conical tips. This configuration was applied to test the possibility of reducing the pinch axial dimensions during the radial compression of a current sheath. It made it possible to strengthen a dense plasma jet near the anode end, which ejected plasma into a bigger plasmoidal structure formed in the central pinch region. It did not allow forming an opposite anti-anode jet and stopped the axial motion of this structure. In plasma focus discharges with the deuterium filling, the decay of the anode jet and the corresponding plasmoid evolution were accompanied by the fusion-neutron production. Some results obtained with this configuration have also supported the hypothesis of the acceleration of fast electrons and ions at a release of the magnetic energy during magnetic reconnections in the organized dense plasma structures.
Structural and electronic properties of a-edge dislocations along ⟨1-100⟩ in GaN
Authors: Giaremis S. , Komninou Ph. , Belabbas I. , Chen J. , Kioseoglou J.
Published: June 2018

Computational analysis via molecular dynamics and density functional theory simulations elucidated the structural and electronic properties of a-type basal edge dislocations lying in the ⟨1–100⟩ direction in wurtzite GaN. As a particular and predominant type of misfit dislocations, experimentally identified in coherently grown semipolar heterostructures, understanding of their properties at the atomistic level is crucial for exploring the growth conditions of the material and improving its performance in its various applications. A total of six core configurations are revealed for the first time and investigated systematically. The energetic hierarchy of these core configurations and their electronic structures are determined. The two shuffle core configurations 3-1 and 4-2 are found to be energetically favorable with respect to the glide 2-2 core in both polarities. It is demonstrated that all the core configurations of the a-type basal dislocations introduce multiple gap states which leads to a narrowing of the bandgap in comparison to that of the pristine material, with the N-polar configurations having a more pronounced and detrimental impact. The presence of Ga-related dangling bonds in the vicinity of the core is widely observed, leading to a shift of the Fermi level to the related s orbitals.
Effect of radius ratios of two droplets on coalescence-induced self-propelled jumping
Authors: Wang Yuhang , Ming Pingjian
Published: June 2018

The coalescence-induced self-propelled droplet jumping behaviors on superhydrophobic surfaces have attracted extensive interest, due to a huge application potential. The coalescence and jumping of two droplets with different radius ratios are numerically simulated, and the jumping velocity is theoretically analyzed. The jumping type changes from the vertical motion to the upward rotation motion, with the decrease of radius ratio. The droplet is not able to jump when the radius ratio is smaller than 0.4. The jumping velocity reaches several peak values when the radius ratio is smaller than 0.7. The maximum jumping velocities are theoretically predicted, which is based on the law of conservation of energy. The viscous dissipation energy which should not be ignored is the main and direct source of the errors.
Experimental characterization of non-linear interfacial wave interaction in stratified gas-liquid pipe flow
Authors: Ayati A. A.
Published: June 2018

We present a statistical and spectral study of interfacial waves in stratified turbulent gas-liquid flow in a horizontal pipe. The main objective of this paper is to report on experimental findings with respect to the influence of the gas flow rate on statistical and spectral properties of interfacial waves. Emphasis is put on the assessment of non-linear interfacial mode interactions by means of higher-order spectra. Interfacial elevation time series were acquired using conductance probes with sampling frequency Fs = 500 Hz. The probes were placed at the pipe centerline and 270D downstream of the pipe inlet. Local wave parameters such as wavelengths, heights, and phase speeds were extracted by means of a zero-crossing technique. The evolution of their statistical properties is assessed for a range of flow conditions in which the liquid flow rate was kept constant at Usl = 0.1 m/s, whilst the gas flow rate was gradually increased from 1.3 to 4 m/s. The mode wave speed is compared to linear and weakly non-linear theory. Interfacial mode interactions are investigated through an assessment of first and second-order spectra, i.e., power spectral density and bispectrum. The results indicate that weakly non-linear (triadic) interactions in the form of overtone and sub-harmonic interactions play an important role and may partially be responsible for the observed transition to the wave saturation regime reported in our previous studies. Finally, a flow map is presented in terms of a Ursell-vs-Froude number plot, in which observed wave regimes are classified according to underlying linear/non-linear mechanisms.
Superconducting coincidence photon detector with short timing jitter
Authors: Miki S. , Miyajima S. , Yabuno M. , Yamashita T. , Yamamoto T. , Imoto N. , Ikuta R. , Kirkwood R. A. , Hadfield R. H. , Terai H.
Published: June 2018

We demonstrate the operation of a coincidence photon detector with a short timing jitter consisting of two superconducting nanowire single photon detectors (SSPDs) and a single flux quantum (SFQ) circuit. By utilizing the timing discrimination capability of the SFQ coincidence circuit, the full width at half maximum timing jitter of the entire coincidence photon detector was evaluated as 32.3 ps, which is 36 ps less than that of the standard commercial time correlated single photon counting module, and the timing jitter of the SSPD was estimated as ∼15 ps. Owing to the short timing jitter characteristics, our coincidence photon detector could correctly capture the effect of pulse-width broadening by insertion of an optical bandpass filter. We have also demonstrated that our coincidence photon detection clearly shows Hong-Ou-Mandel interference with a weak coherent pulse. These results are a crucial step to realizing high timing resolution coincidence measurements, ushering in a technology for timing measurement based multi-photon quantum interference.
Modelling non-additive genetic effects using ridge regression for an Angus–Nellore crossbred population
Authors: Bertoli C. D. , Neto J. Braccini , McManus C. , Cobuci J. A. , Campos G. S. , Piccoli M. L. , Roso V.
Published: June 2018

Data from 294045 records from a crossbred Angus × Nellore population were used to estimate fixed genetic effects (both additive and non-additive) and to test different non-additive models using ridge regression. The traits studied included weaning gain (WG), postweaning gain (PG), phenotypic scores for weaning (WC) and postweaning (PC) conformation, weaning (WP) and postweaning (PP) precocity, weaning (WM) and postweaning (PM) muscling and scrotal circumference (SC). All models were compared using the likelihood-ratio test. The model including all fixed genetic effects (breed additive and complementarity, heterosis and epistatic loss non-additive effects, both direct and maternal) was the best option to analyse this crossbred population. For the complete model, all effects were statistically significant (P < 0.01) for weaning traits, except the direct breed additive effects for WP and WM; direct complementarity effect for WP, WM, PP and PM and maternal epistatic loss for PG. Direct breed additive effect was positive for weaning traits and negative for postweaning. Maternal breed additive effect was negative for SC and WP. Direct complementarity and heterosis were positive for all traits and maternal complementarity and heterosis were also positive for all traits, except for PG. Direct and maternal epistatic loss effects were negative for all traits. We conclude that the fixed genetic effects are mostly significant. Thus, it is important to include them in the model when evaluating crossbred animals, and the model that included breed additive effects, complementarity, heterosis and epistatic loss differed significantly from all reduced models, allowing to infer that it was the best model. The model with only breed additive and heterosis was parsimonious and could be used when the structure or amount of data does not allow the use of complete model.
Germination biologies and seedbank dynamics of Acacia shrubs in the Western Desert: implications for fire season impacts on recruitment
Authors: Wright Boyd R. , Clarke Peter J.
Published: June 2018

In arid Australia, fires in different seasons often result in markedly different recruitment rates of woody plants, and this can have important and long-lasting impacts on post-fire community structure and composition. The current study investigated ecological mechanisms behind this effect in four widespread arid Acacia species: Acacia aptaneura, Maslin & J.E.Reid Acacia kempeana F.Muell., Acacia maitlandii F.Muell. and Acacia melleodora Pedley. Specifically, the study examined whether increased recruitment after summer compared with winter burning relates to (1) higher soil temperatures during summer fires having increased capacity to overcome dormancy of seeds with heat-stimulated germination; (2) warmer soil temperature conditions after summer fires providing more favourable incubation temperatures for germination; and/or (3) summer fires coinciding with seasonal fluxes in seedbank densities, which may occur in response to granivory and/or rapid rates of seed deterioration after dispersal. Results supported hypotheses (1) and (2), as germination of all species responded positively to heat shock and warmer incubation temperatures. Some support was also demonstrated for hypothesis (3), as seedbank densities were shown to fluctuate seasonally, most likely in response to strong granivory. This multi-species study provides insights into mechanisms behind enhanced shrub recruitment after arid zone summer fires; and reinforces the notion that season of burn can be a strong determinant of regeneration trajectories of woody plants after fire.
Intraspecific competition in oat varieties selected for grain yield and milling
Authors: Sadras Victor O. , Mahadevan M. , Zwer Pamela K.
Published: June 2018

Oats likely emerged as part of the weedy grass assemblage in early wheat and barley crops. Some Avena species, such as A. fatua and A. sterilis, evolved into aggressive weeds, and the high interspecific competitive ability of cultivated oats (A. sativa) is valued agronomically to facilitate weed control in rotations. We tested the hypothesis, verified in many crops, that high yield of oats is related to low intraspecific competitive ability. Ten contemporary oat varieties, selected for grain yield and milling attributes, where grown in three environments. Response to competition was calculated as 100 × (Yb – Yc)/Yc, where Y is yield measured in border (b) and centre (c) rows. The same definition was used to calculate response to competition of yield components (biomass, harvest index, grain number, grain weight) and the components of grain number (panicle number and grains per panicle). Yield response to competition was affected by all three sources of variation, i.e. environment, variety and variety × environment interaction. The interaction demonstrates the plasticity of yield response to intraspecific competition; for example, the response to competition of variety Mortlock varied from 9% to 71% among environments. This plasticity in yield response to competition was partially related to variety-dependent responses to competition for biomass and harvest index, number of panicles and number of grains per panicle. We did not find the expected negative association between yield and variety-dependent response to competition. We discuss how this lack of correlation could relate to sampling issues, i.e. a limitation in the range of environments and varieties explored in this study, or reflect a legitimate feature of oat crops arising from early and contemporary selective pressures.
In-situ sampling of available calcium using diffusive gradients in thin-films technique based on benzo-crown ether-functionalised silica as the binding agent
Authors: Yao Hui , You Nan , Cao Hong-Guang , Kang Li-Xia , Wu Jin-Bao , Zhao Yu-Jie , Fan Hong-Tao , Yi Yan-Li
Published: June 2018

Environmental contextLow availability of calcium (Ca2+) in soils is one of the major factors in Ca2+ deficiency of plants and physiological plant disorders. A device based on functionalised silica was developed for in-situ measurement of the available Ca2+ in soils. Application of the proposed device to measure available Ca2+ may help to develop and improve agricultural practices.
AbstractCalcium is an ion of particular interest due to its importance in plant nutrition and soil structure. A novel device of diffusion gradients in thin-films (DGT) based on the benzo-crown ether-functionalised silica (BCES) as the binding agent and the polyethersulfone (PES) membrane as diffusive layer (BCES-DGT) was developed for in-situ sampling of available calcium (Ca2+) in freshwater and soil samples. The performance characteristics of the BCES-DGT device were assessed. The BCES was prepared using the sol-gel process and characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis and N2 adsorption–desorption. Results evinced that BCES was obtained successfully with a rough wrinkled surface and good specific surface area of 111.3 m2 g−1. The diffusion coefficient of Ca2+ ions in PES membrane was found to be 1.23 × 10−6 cm2 s−1 at 25 °C and was independent of pH in the range of 3–10 and ionic strength (as pNaCl) from 1 to 3. The high binding capacity of BCES binding gel for Ca2+ ions was determined to be 9822.4 ± 452.9 μg Ca2+/disk and was conducive to the deployment of long-term or high concentration. The BCES-DGT device can accurately measure the concentrations of Ca2+ over wide ranges of ionic strengths (1–3 as pNaCl) and pH (5–10). There was no significant interference on the uptake of Ca2+ by the BCES-DGT device at the tolerance limits up to 500 for Mg2+, Li+, HCO3−, H2PO4−, NO3− and SO42−, 250 for Sr2+, 2000 for K+ and 50 for fulvic acid. The results from BCES-DGT device were in excellent agreement with those measured directly using ion selective electrode in several water and soil samples. Field application in river water indicated that a good agreement was obtained between BCES-DGT value and mean grab sample measurements of Ca2+ and that the relative standard deviation of BCES-DGT measurement (4.7 %) was superior to that of grab sample measurements (13.5 %), suggesting that BCES-DGT was reliable for in-situ sampling and measurement of available Ca2+ with good accuracy and precision.
Whole-genome data reveal the complex history of a diverse ecological community
Authors: Bunnefeld Lynsey , Hearn Jack , Stone Graham N. , Lohse Konrad
Published: June 2018

Significance

Widespread biological communities are common, but little is known about how they assemble. A key question is how sets of trophically linked species (predators and their prey, hosts and parasites) spread to occupy current distributions. Do they disperse together, preserving ecological interactions, or separately, such that interactions are interrupted? This is central to assessing the potential for coevolution in a system and requires inference of species associations both over space and through time. Here, we use de novo genomic data and likelihood-based approaches to infer the assembly history of a multispecies community of Western Palearctic insect herbivores and parasitoid natural enemies—the two trophic groups that together comprise 50% of all animal species.
Learning atoms for materials discovery
Authors: Zhou Quan , Tang Peizhe , Liu Shenxiu , Pan Jinbo , Yan Qimin , Zhang Shou-Cheng
Published: June 2018

Significance

Motivated by the recent achievements of artificial intelligence (AI) in linguistics, we design AI to learn properties of atoms from materials data on its own. Our work realizes knowledge representation of atoms via computers and could serve as a foundational step toward materials discovery and design fully based on machine learning.
Arthropods in modern resins reveal if amber accurately recorded forest arthropod communities
Authors: Solórzano Kraemer Mónica M. , Delclòs Xavier , Clapham Matthew E. , Arillo Antonio , Peris David , Jäger Peter , Stebner Frauke , Peñalver Enrique
Published: June 2018

Significance

It is not known whether the fossil content of amber accurately represents the arthropod biodiversity of past forests, and if and how those fossils can be compared with recent fauna for studies and predictions of biodiversity change through time. Our study of arthropods (mainly insects and spiders) living around the resinous angiosperm treeHymenaea verrucosaGaertner, 1791 in the lowland coastal forest of Madagascar, and arthropods trapped by the resin produced by this tree species, demonstrates that amber does not record the true past biodiversity of the entire forest. However, our results reveal how taphonomic processes, arthropod behaviors, and ecological relationships can influence arthropod death assemblages in resins and play a crucial role in controlling their taxonomic compositions.
Kinetically guided radical-based synthesis of C(sp
3
)−C(sp
3
) linkages on DNA
Authors: Wang Jie , Lundberg Helena , Asai Shota , Martín-Acosta Pedro , Chen Jason S. , Brown Stephen , Farrell William , Dushin Russell G. , O’Donnell Christopher J. , Ratnayake Anokha S. , Richardson Paul , Liu Zhiqing , Qin Tian , Blackmond Donna G. , Baran Phil S.
Published: June 2018

Significance

Combinatorial synthesis via DNA encoded library (DEL) has evolved as a technology of great importance in drug discovery. However, the idiosyncratic aqueous, dilute, DNA-sensitive parameters and infinitesimal scale of this system present new challenges for traditional organic reactions. A detailed protocol aiding the transition from organic reactions to reactions with DNA-bound molecules was developed using a tactical combination of kinetic analysis and reaction screening. As an example, the venerable Giese addition was applied to forge high-value C−C bonds, including all-carbon quaternary centers, on DNA, representing the first radical-based synthesis in DEL that expands the traditional toolbox beyond pericyclic, carbonyl-based, and two-electron cross-couplings.
Microstructure and mechanical properties’ modification of friction stir welded Invar 36 alloy joint
Authors: Xu Nan , Song Qining , Bao Yefeng
Published: June 2018

A novel approach named large-load and low-speed friction stir welding was developed to joining Invar36 alloy. The stir zone was characterised by a mean grain size of 0.7 μm and high angle boundaries of 90.7%. Abundant twin boundaries were produced in the grains as well. The grain refinement mechanism is attributed to the combination of discontinuous dynamic recrystallisation and microshear-bands-assisted dynamic recrystallisation. A good combination of strength and ductility was achieved. This work provides a new insight for joining face-centred cubic metals or alloys with higher melmelting points, such as austenite stainless steel and Ni-base alloys.
Can international elite sport success trickle down to mass sport participation? Evidence from Danish team handball
Authors: Storm Rasmus K. , Nielsen Christian Gjersing , Jakobsen Tor Georg
Published: June 2018

Many scholars do not find evidence of a trickle‐down effect from elite sport success to mass sport participation. Contrary to what is assumed by the trickle‐down effect “theorem”, successful elite sportspeople do not seem to inspire amateurs to take up sport themselves. However, recent studies present evidence that elite sport can have an influence. In this article, we apply regression models on time series data from one of the most successful Danish sports, team handball. Our findings are mixed, but lean towards supporting scholars who argue that trickle‐down effects are not necessarily an inherent part of international sporting success. Further studies should examine more sports to identify where trickle‐down effects occur and why.
Actin polymerization controls cilia-mediated signaling
Authors: Drummond Michael L. , Li Mischa , Tarapore Eric , Nguyen Tuyen T.L. , Barouni Baina J. , Cruz Shaun , Tan Kevin C. , Oro Anthony E. , Atwood Scott X.
Published: June 2018

Primary cilia are polarized organelles that allow detection of extracellular signals such as Hedgehog (Hh). How the cytoskeleton supporting the cilium generates and maintains a structure that finely tunes cellular response remains unclear. Here, we find that regulation of actin polymerization controls primary cilia and Hh signaling. Disrupting actin polymerization, or knockdown of N-WASp/Arp3, increases ciliation frequency, axoneme length, and Hh signaling. Cdc42, a potent actin regulator, recruits both atypical protein pinase C iota/lambda (aPKC) and Missing-in-Metastasis (MIM) to the basal body to maintain actin polymerization and restrict axoneme length. Transcriptome analysis implicates the Src pathway as a major aPKC effector. aPKC promotes whereas MIM antagonizes Src activity to maintain proper levels of primary cilia, actin polymerization, and Hh signaling. Hh pathway activation requires Smoothened-, Gli-, and Gli1-specific activation by aPKC. Surprisingly, longer axonemes can amplify Hh signaling, except when aPKC is disrupted, reinforcing the importance of the Cdc42–aPKC–Gli axis in actin-dependent regulation of primary cilia signaling.
Ca2+–mitochondria axis drives cell division in hematopoietic stem cells
Authors: Umemoto Terumasa , Hashimoto Michihiro , Matsumura Takayoshi , Nakamura-Ishizu Ayako , Suda Toshio
Published: June 2018

Most of the hematopoietic stem cells (HSCs) within the bone marrow (BM) show quiescent state with a low mitochondrial membrane potential (ΔΨm). In contrast, upon stress hematopoiesis, HSCs actively start to divide. However, the underlying mechanism for the initiation of HSC division still remains unclear. To elucidate the mechanism underlying the transition of cell cycle state in HSCs, we analyzed the change of mitochondria in HSCs after BM suppression induced by 5-fluoruracil (5-FU). We found that HSCs initiate cell division after exhibiting enhanced ΔΨm as a result of increased intracellular Ca2+ level. Although further activation of Ca2+–mitochondria pathway led to loss of HSCs after cell division, the appropriate suppression of intracellular Ca2+ level by exogenous adenosine or Nifedipine, a Ca2+ channel blocker, prolonged cell division interval in HSCs, and simultaneously achieved both cell division and HSC maintenance. Collectively, our results indicate that the Ca2+–mitochondria pathway induces HSC division critically to determine HSC cell fate.
TRIMming TGF-β signals in Th17 cells
Authors: Rapaport Aaron S. , Ouyang Wenjun
Published: June 2018

The precise downstream mediators of TGF-β signaling in Th17 and T reg cells remain unclear. In this issue of JEM, Tanaka et al. report that Trim33 transduces TGF-β signals in Th17 cells to generate an optimal proinflammatory cytokine profile.
Weighted Beckmann problem with boundary costs
Authors: Dweik Samer
Published: June 2018

We show that a solution to a variant of the Beckmann problem can be obtained by studying the limit of some weighted

p
−

p-

Laplacian problems. More precisely, we find a solution to the following minimization problem:
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="min left-brace integral Underscript normal upper Omega Endscripts k normal d StartAbsoluteValue w EndAbsoluteValue plus integral Underscript partial-differential normal upper Omega Endscripts g Superscript minus Baseline normal d nu Superscript minus Baseline minus integral Underscript partial-differential normal upper Omega Endscripts g Superscript plus Baseline normal d nu Superscript plus Baseline colon w element-of script upper M Superscript d Baseline left-parenthesis normal upper Omega right-parenthesis comma nu element-of script upper M left-parenthesis partial-differential normal upper Omega right-parenthesis comma minus nabla dot w equals f plus nu right-brace comma">

min

{

∫
Ω

k

d

|

w

|

+

∫

∂
Ω

g
−

d

ν
−

−

∫

∂
Ω

g
+

d

ν
+

:

w
∈

M

d

(
Ω
)
,

ν
∈

M

(
∂
Ω
)
,

−
∇
⋅
w
=
f
+
ν

}

,

\begin{equation*} \min \bigg \{\int _\Omega k \,\mathrm {d}|w| + \int _{\partial \Omega } g^-\,\mathrm {d}\nu ^- - \int _{\partial \Omega } g^+\,\mathrm {d}\nu ^+\,:\,w \in \mathcal {M}^d(\Omega ),\,\nu \in \mathcal {M}(\partial \Omega ),\,-\nabla \cdot w =f + \nu \bigg \}, \end{equation*}

where

f
,

k

f,\,k

, and

g
±

g^\pm

are given. In addition, we connect this problem to a formulation with Kantorovich potentials with Dirichlet boundary conditions.
Examining the School-to-Prison Pipeline Metaphor
Authors: Crawley Kayla , Hirschfield Paul
Published: June 2018

The school-to-prison pipeline (STPP) is a commonly used metaphor that was developed to describe the many ways in which schools have become a conduit to the juvenile and criminal justice systems. The STPP metaphor encompasses various disciplinary policies and practices that label students as troublemakers, exclude students from school, and increase their likelihood of involvement in delinquency, juvenile justice, and subsequent incarceration. Many external forces promote these policies and practices, including high-stakes testing, harsh justice system practices and penal policies, and federal laws that promote the referral of certain school offenses to law enforcement. Empirical research confirms some of the pathways posited by STPP. For example, research has shown that out-of-school suspensions predict school dropout, justice system involvement and adult incarceration. However, research on some of the posited links, such as the impact of school-based arrests and referrals to court on school dropout, is lacking.

Despite gaps in the empirical literature and some theoretical shortcomings, the term has gained widespread acceptance in both academic and political circles. A conference held at Northeastern University in 2003 yielded the first published use of the phrase. Soon, it attained widespread prominence, as various media outlets as well as civil rights and education organizations (e.g., ACLU, the Advancement Project (they also use “schoolhouse-to-jailhouse track”), the National Education Association (NEA), and the American Federation of Teachers) referenced the term in their initiatives. More recently, the Obama administration used the phrase in their federal school disciplinary reform efforts. Despite its widespread use, the utility of STPP as a social scientific concept and model is open for debate.

Whereas some social scientists and activists have employed STPP to highlight how even non-criminal justice institutions can contribute to over-incarceration, other scholars are critical of the concept. Some scholars feel that the pipeline metaphor is too narrow and posits an overly purposeful or mechanistic link between schools and prisons; in fact, there is a much more complicated relationship that includes multiple stakeholders that fail our nation’s youth. Rather than viewing school policies and practices in isolation, critical scholars have argued that school processes of criminalization and exclusion are inextricably linked to poverty, unemployment, and the weaknesses of the child welfare and mental health systems. In short, the metaphor does not properly capture the web of institutional forces and missed opportunities that can push youth toward harmful choices and circumstances, often resulting in incarceration. Many reforms across the nation seek to dismantle STPP, including non-exclusionary discipline alternatives such as restorative justice and limiting the role of school police officers. Rigorous research on their effectiveness is needed.
courts, Roman
Authors: Bablitz Leanne
Published: June 2018

Because the modern legal system used in most western countries derives from ancient Rome, it is easy to assume that Roman courts (and the activities that took place before them) were the same as their modern descendants. However, differences exist—great enough in number and importance that all scholars of the ancient world must take care when drawing conclusions without solid evidence to support them. The history of Roman courts, in both the republican and imperial periods, shows the profound differences between Roman and modern courts in both their cultural and physical aspects.
mysteries, Bacchic
Authors: Graf Fritz
Published: June 2018

Mystery cults of Dionysos are attested to in Greece from the late Archaic epoch and expanded to Rome in Hellenistic times. They appear in two forms, the group (thíasos) of ecstatic women (mainádes) who celebrate their rituals in the wilderness outside the city and in opposition to the restrictive female city life; and the thíasos of both men and women that constitutes itself as a cultic association and celebrates inside the cities but preserves the ideology of a performance outside the city. The main goal in both types of cult groups was the extraordinary experience of loss of self through drinking wine and dancing; the mixed-gender groups often added eschatological hopes. The purely female thiasoi were led by a priestess of Dionysos, whereas the mixed-gender groups were often led by a male professional initiator. The most conspicuous trace of these initiations are the so-called Orphic gold tablets that attest to the expectations for a better afterlife.
lex (P)Laetoria
Authors: Candy Peter
Published: June 2018

The lex Laetoria (or Plaetoria) was a law of the late 3rd or early 2nd century bce that gave special protection to minors. The law gave an action against persons who were alleged to have fraudulently induced a minor to enter into a transaction. The praetor built on this protection by allowing a defence to be raised on the basis of the law. By the late Republic, the praetor had also stated in his Edict that he would grant a remedy known as in integrum restitutio to minors who had been taken advantage of. The practice of minors using curators to reassure potential creditors that they were entering into transactions on sound advice was formalised by the emperor Marcus Aurelius. By the post-classical period, the rules concerning the protection of minors (cura minorum) became closely assimilated to those concerning guardianship (tutela).
Oncology Social Work Research
Authors: Oktay Julianne S. , Zebrack Bradley
Published: June 2018

Oncology social work researchers have made (and continue to make) important contributions to the knowledge base that supports the profession. This article discusses the profession of oncology social work, its roots in medical social work in the United States, the development of cancer treatment, and the body of research that informs its art and practice. Oncology social work research is placed in the broader contexts of the social work profession, the field of oncology, and the specific field of oncology social work.

Through the decades, the profession of oncology social work has grown, gained stability and legitimacy. Oncology social work itself, along with oncology social work research, have made rapid strides in the 21st century and accelerating in impact and relevance. Oncology social work research is stronger now than ever. Recent developments, such as the addition of a research institute at the annual AOSW conference and initiatives to establish a “practice-based research network” are expanding capacity in the field.

Oncology social work researchers bring a unique perspective to their research. Social work’s patient-centered perspective is reflected in research that explores the cancer experience of patients and family members and leads to new interventions based on that experience. Social work’s focus on human development over the life course results in research that reflects a developmental framework or focuses on specific age groups, such as children, adolescents, young adults, or the elderly. Social work’s conceptual model of “Person-in-Environment” is reflected in research on cancer patients in the context of their interpersonal relationships. The values of social justice and cultural competence are reflected in research on health disparities, minority populations, and multicultural perspectives. Finally, the field of oncology social work itself has been the focus of recent research on distress screening and its implementation.

In the 21st century, oncology social work research stands in a pivotal position. Although this type of research is now widely recognized as important, it is still a challenge to access the level of support from major funders of cancer research required to establish and reinforce a strong and vibrant knowledge base for the profession.
Pitavastatin Upregulates Nitric Oxide Synthases in the Kidney of Spontaneously Hypertensive Rats and Wistar–Kyoto Rats
Authors: Hu Gaizun , Ito Osamu , Rong Rong , Sakuyama Akihiro , Miura Takahiro , Ito Daisuke , Ogawa Yoshiko , Kohzuki Masahiro
Published: June 2018

BACKGROUND

Clinical trials show potent renoprotective effects of pitavastatin (PTV), although the precise mechanism for these renoprotective effects is not fully clarified. The aim of this study was to examine the antihypertensive and renoprotective effects of PTV, focusing on the nitric oxide (NO) system.

METHODS

Male, 6-week-old, spontaneously hypertensive rats (SHR) and Wistar–Kyoto rats (WKY) were randomized to receive vehicle or PTV (2 mg/kg bodyweight) for 8 weeks. Blood pressure and urinary albumin excretion were measured every 2 weeks. After 8 weeks, plasma biochemical parameters and renal histology were examined. NO synthase isoform (neuronal, nNOS; inducible, iNOS; and endothelial, eNOS) expression and eNOS phosphorylation were examined by western blotting.

RESULTS

PTV attenuated hypertension and albuminuria development in SHR. PTV decreased glomerular desmin expression and medullary interstitial fibrosis in SHR. PTV tended to increase plasma NO in both strains but significantly increased urinary NO excretion only in WKY. PTV significantly increased nNOS and eNOS expression, enhanced eNOS phosphorylation at serine1177, and inhibited eNOS phosphorylation at threonine495 in the kidney of both strains.

CONCLUSIONS

PTV treatment led to increased renal NOS expression and upregulated eNOS activity in both SHR and WKY. The antihypertensive and renoprotective effects of PTV may be related to upregulation of the NO system.
LncFinder: an integrated platform for long non-coding RNA identification utilizing sequence intrinsic composition, structural information and physicochemical property
Authors: Han Siyu , Liang Yanchun , Ma Qin , Xu Yangyi , Zhang Yu , Du Wei , Wang Cankun , Li Ying
Published: June 2018

Discovering new long non-coding RNAs (lncRNAs) has been a fundamental step in lncRNA-related research. Nowadays, many machine learning-based tools have been developed for lncRNA identification. However, many methods predict lncRNAs using sequence-derived features alone, which tend to display unstable performances on different species. Moreover, the majority of tools cannot be re-trained or tailored by users and neither can the features be customized or integrated to meet researchers’ requirements. In this study, features extracted from sequence-intrinsic composition, secondary structure and physicochemical property are comprehensively reviewed and evaluated. An integrated platform named LncFinder is also developed to enhance the performance and promote the research of lncRNA identification. LncFinder includes a novel lncRNA predictor using the heterologous features we designed. Experimental results show that our method outperforms several state-of-the-art tools on multiple species with more robust and satisfactory results. Researchers can additionally employ LncFinder to extract various classic features, build classifier with numerous machine learning algorithms and evaluate classifier performance effectively and efficiently. LncFinder can reveal the properties of lncRNA and mRNA from various perspectives and further inspire lncRNA–protein interaction prediction and lncRNA evolution analysis. It is anticipated that LncFinder can significantly facilitate lncRNA-related research, especially for the poorly explored species. LncFinder is released as R package (https://CRAN.R-project.org/package=LncFinder). A web server (http://bmbl.sdstate.edu/lncfinder/) is also developed to maximize its availability.
The choice of sequence homologs included in multiple sequence alignments has a dramatic impact on evolutionary conservation analysis
Authors: Gil Nelson , Fiser Andras
Published: June 2018

Motivation

The analysis of sequence conservation patterns has been widely utilized to identify functionally important (catalytic and ligand-binding) protein residues for over a half-century. Despite decades of development, on average state-of-the-art non-template-based functional residue prediction methods must predict ∼25% of a protein’s total residues to correctly identify half of the protein’s functional site residues. The overwhelming proportion of false positives results in reported ‘F-Scores’ of ∼0.3. We investigated the limits of current approaches, focusing on the so-far neglected impact of the specific choice of homologs included in multiple sequence alignments (MSAs).

Results

The limits of conservation-based functional residue prediction were explored by surveying the binding sites of 1023 proteins. A straightforward conservation analysis of MSAs composed of randomly selected homologs sampled from a PSI-BLAST search achieves average F-Scores of ∼0.3, a performance matching that reported by state-of-the-art methods, which often consider additional features for the prediction in a machine learning setting. Interestingly, we found that a simple combinatorial MSA sampling algorithm will in almost every case produce an MSA with an optimal set of homologs whose conservation analysis reaches average F-Scores of ∼0.6, doubling state-of-the-art performance. We also show that this is nearly at the theoretical limit of possible performance given the agreement between different binding site definitions. Additionally, we showcase the progress in this direction made by Selection of Alignment by Maximal Mutual Information (SAMMI), an information-theory-based approach to identifying biologically informative MSAs. This work highlights the importance and the unused potential of optimally composed MSAs for conservation analysis.

Supplementary information

Supplementary data are available at Bioinformatics online.
Wealth and the health of older Black women in the United States
Authors: Sharma Andy
Published: June 2018

Public health scholars and policy-makers are concerned that the United States continues to experience unmanageable health care costs while struggling with issues surrounding access and equity. To addresses these and other key issues, the National Academy of Medicine held a public symposium, Vital Directions for Health and Health Care: A National Conversation during September 2016, with the goal of identifying clear priorities for high-value health care and improved well-being. One important area was addressing social determinants of health. This article contributes to this objective by investigating the impact of wealth on older Black women’s health. Employing the 2008/2010 waves of the RAND Health and Retirement Study on a sample of 906 older Black women, this panel study examined self-assessed health ratings of very good/good/fair/poor within a relaxed random effects framework, thereby controlling for both (i) observed and (ii) unobserved individual-level heterogeneity. This analysis did not find a statistically significant association with wealth despite a difference of approximately $75 000 in its valuation from very good to poor health. This also occurred after wealth was (i) readjusted for outliers and (ii) reformulated as negative, no change or positive change from 2008. This finding suggests that wealth may not play as integral a role. However, the outcome was significant for earnings and education, particularly higher levels of education. Scholars should further this inquiry to better understand how earnings/education/wealth operate as social determinants of health for minority populations.
A transcultural health education programme led by immigrant adolescents in Southern Spain
Authors: Soriano-Ayala Encarnación , Cala Verónica C
Published: June 2018

Immigration to western countries is a relevant phenomenon that has been linked to health inequalities. One form of inequality is ethnocentrism in health programmes. Therefore, social innovations and a new transcultural approach have been developed to culturally adapt health education interventions. This study aimed to evaluate the effects of a double transcultural health intervention, the Leader Adolescents in Transcultural Health Education (LATES) Project, which is led by high school immigrant adolescents over elementary students of multicultural contexts in southeastern Spain. This double quasi-experimental study had experimental and control groups composed of secondary students (12 health cultural brokers with 36 controls) and elementary students (26 participant students and 26 controls). The LATES Project was delivered to two high schools and two elementary schools in Almeria (Spain). A mixed evaluation method was used. Six attitudinal scales were used pre- and post-intervention to collect the data. The quantitative evaluation was completed using qualitative techniques through in-depth interviews and focal groups. Four sociocultural gradients were identified pre-intervention: a positive rural gradient, a negative gender gradient except in traditional ‘female’ dimensions, a negative age gradient and a dual migrant gradient that combined the health migrant effect in some behaviours and westernization in others. Specifically, the Moroccan population demonstrated better attitudes towards eating and physical activity behaviours. After the intervention, the experimental groups showed more improvement than the controls. However, the attitudinal scale increment is modest compared with the knowledge and motivation improvements. This intervention, which used a transcultural approach, has benefited young Spaniards to a greater extent than immigrants, probably due to the worse initial health conditions of the Spanish.