bluuebunny/crossref_metadata_2025 huggingface dataset:
LncRNA Gm2044 promotes 17β‐estradiol synthesis in mpGCs by acting as miR‐138‐5p sponge
Authors: Hu Ke , He Chaofan , Ren Huanhuan , Wang Haiyan , Liu Kuan , Li Leina , Liao Yaping , Liang Meng
Published: June 2019

Long noncoding RNAs (lncRNAs) have been demonstrated to play vital roles in mammalian reproduction. Our previous research revealed that lncRNA Gm2044 is highly expressed in mouse spermatocytes and regulates male germ cell function. The gene annotation database BioGPS shows that Gm2044 is not only highly expressed in testicular tissue but also in ovarian tissue, which suggests that Gm2044 may be involved in female reproductive development. In this study, we confirmed that lncRNA Gm2044 promotes 17β‐estradiol synthesis in mouse pre‐antral follicular granulosa cells (mpGCs). Furthermore, bioinformatics methods, western blot, and the luciferase assay proved that Gm2044 functions as a miR‐138‐5p sponge to inhibit the direct target of miR‐138‐5p, Nr5a1, which enhances 17β‐estradiol synthesis through cyp19a1 activation. Taken together, our results provide an insight into the mechanistic roles of lncRNA Gm2044 for 17β‐estradiol synthesis by acting as competing‐endogenous RNAs to modulate the function of mpGCs. Studying the potential lncRNAs, which regulate estradiol release, will be beneficial for the diagnosis and treatment of steroid hormone‐related disease.
Nursing research: A marriage of theoretical influences
Authors: Jensen Kari Toverud
Published: June 2019

Aim

The aim is to examine PhD theses in nursing science, their purpose or aim and the theoretical approaches and methods employed. The study seeks to examine how such theses may be categorized, what they study, what theoretical approaches they employ and, in particular, to what degree nursing theory is employed as a current theoretical approach.

Design

This study has a descriptive qualitative design.

Method

This study complied with the Standard for Reporting Qualitative Research (SRQR). Data were collected from 61 PhD theses in nursing science published from 1994–2015, at University of Edinburgh.

Results

Twenty of the PhD theses used theoretical approaches with a sociological perspective and 12 used a psychological perspective. Eighteen of the PhD theses were based on theoretical approaches from philosophy, ethics, pedagogy, medicine or biology as a primary perspective. Nursing theories, in their conventional definition, have a limited presence in the theses examined.
Successful treatment of metachronous contralateral intratubular germ cell neoplasia with partial orchiectomy and low‐dose radiation in a patient previously treated for testicular carcinoma
Authors: Schneller Netta , Grimes Amanda , Muscal Jodi , Quintanilla Norma , Mittal Angela , Paulino Arnold , Foster Jennifer
Published: June 2019

Intratubular germ cell neoplasia (ITGCN) of the testis is a precursor to testicular germ cell tumor (TGCT), which can lead to the development of invasive cancer. In patients with a history of previously treated unilateral TGCT, treatment for ITGCN of the contralateral testis needs to be balanced with the risks of subsequent infertility. Here, we present a 17‐ year‐ old patient with ITGCN diagnosed after treatment of contralateral nonseminomatous TGCT who was successfully treated with a partial orchiectomy followed by low‐dose radiation with preservation of his testosterone production.
Impact of lithium chloride on the performance of wood fiber reinforced polyamide 6/high‐density polyethylene blend composites
Authors: Xu Shihua , Fang Yiqun , Chen Zhenyi , Yi Shunmin , Zhai Xianglin , Yi Xin , He Jun , Song Yongming , Wang Qingwen
Published: June 2019

Wood fiber reinforced polyamide 6 (PA6) and high‐density polyethylene (HDPE) blend composites were prepared via hot pressing. The PA6 was modified by lithium chloride (LiCl) for reducing the melting point. Crystallization analysis exhibited the decrease of the melting point (220°C to none) and the processing temperature (240°C to 200°C) of PA6. Thus, undesired discoloration and degradation were improved. LiCl was in favor of the interfacial compatibility among PA6, HDPE, and wood fiber. Also the LiCl could enhance the mechanical properties of the final products. The maximum flexural strength can reach up to 100.4 MPa. Besides, both maleic anhydride grafted high‐density polyethylene and wood fiber had positive effects on the mechanical performance.
Synthesis and self‐healing behavior of thermoreversible epoxy resins modified with nitrile butadiene rubber
Authors: Feng Libang , Zhao Hanwen , He Xia , Zhao Yanhua , Gou Liuxiaohui , Wang Yanping
Published: June 2019

Cracks may generate in epoxy resins, which can affect the comprehensive property and shorten service life. The problem is expected to be resolved by endowing epoxy resin with self‐healing performance. Herein, a new kind of self‐healing epoxy resin containing both Diels–Alder (DA) bonds and nitrile butadiene rubber (NBR) has been developed. The self‐healing performance and mechanical properties of as‐prepared epoxy resins are investigated by qualitative observation and quantitative measuring. Results reveal that the as‐prepared epoxy resins exhibit excellent self‐healing performance and multiple repair ability, and the self‐healing behavior is based on dual actions of thermal reversibility of DA reaction and thermal movement of molecular chains. Furthermore, the thermoreversible DA bonds contribute much to the recovery of mechanical property, while the incorporated thermoplastic NBR accelerates the whole healing process. The self‐healing efficiency of epoxy resins can be enhanced markedly by introducing thermoplastic NBR. In addition, the self‐healing epoxy resins also exhibit outstanding reprocessing performance, which makes it possible of recycling waste epoxy resin. POLYM. ENG. SCI., 59:1603–1610 2019. © 2019 Society of Plastics Engineers
Pharmacometrics, Physiologically Based Pharmacokinetics, Quantitative Systems Pharmacology—What's Next?—Joining Mechanistic and Epidemiological Approaches
Authors: Schmidt Stephan , Kim Sarah , Vozmediano Valvanera , Cristofoletti Rodrigo , Winterstein Almut G. , Brown Joshua D.
Published: June 2019

The application of modeling and simulation (M&S) tools to biological, physiological, and clinical data has great potential to enhance drug development and regulatory decision making. The strategic development of multidisciplinary projects aimed at integrating methodologies from different disciplines may bridge between preclinical and clinical drug development as well as between academic curiosity and clinical practice. Herein we review the history and present the state of M&S approaches as well as our vision for future challenges and applications.
Mammalian germ cell migration during development, growth, and homeostasis
Authors: Kanamori Mizuho , Oikawa Kenta , Tanemura Kentaro , Hara Kenshiro
Published: June 2019

Background

Germ cells represent one of the typical cell types that moves over a long period of time and large distance within the animal body. To continue its life cycle, germ cells must migrate to spatially distinct locations for proper development. Defects in such migration processes can result in infertility. Thus, for more than a century, the principles of germ cell migration have been a focus of interest in the field of reproductive biology.

Methods

Based on published reports (mainly from rodents), investigations of germ cell migration before releasing from the body, including primordial germ cells (PGCs), gonocytes, spermatogonia, and immature spermatozoon, were summarized.

Main findings

Germ cells migrate with various patterns, with each migration step regulated by distinct mechanisms. During development, PGCs actively and passively migrate from the extraembryonic region toward genital ridges through the hindgut epithelium. After sex determination, male germline cells migrate heterogeneously in a developmental stage‐dependent manner within the testis.

Conclusion

During migration, there are multiple gates that disallow germ cells from re‐entering the proper developmental pathway after wandering off the original migration path. The presence of gates may ensure the robustness of germ cell development during development, growth, and homeostasis.
Matrix completion from a computational statistics perspective
Authors: Chi Eric C. , Li Tianxi
Published: June 2019

In the matrix completion problem, we seek to estimate the missing entries of a matrix from a small sample of the total number of entries in a matrix. While this task is hopeless in general, structured matrices that are appropriately sampled can be completed with surprising accuracy. In this review, we examine the success behind low‐rank matrix completion, one of the most studied and employed versions of matrix completion. Formulating the matrix completion problem as a low‐rank matrix estimation problem admits several strengths: good empirical performance on real data, statistical guarantees, and practical algorithms with convergence guarantees. We also examine how matrix completion relates to the classical study of missing data analysis (MDA) in statistics. By drawing on the MDA perspective, we see opportunities to weaken the commonly enforced assumption of missing completely at random in matrix completion.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Multivariate Analysis
Subgroup identification for precision medicine: A comparative review of 13 methods
Authors: Loh Wei‐Yin , Cao Luxi , Zhou Peigen
Published: June 2019

Natural heterogeneity in patient populations can make it very hard to develop treatments that benefit all patients. As a result, an important goal of precision medicine is identification of patient subgroups that respond to treatment at a much higher (or lower) rate than the population average. Despite there being many subgroup identification methods, there is no comprehensive comparative study of their statistical properties. We review 13 methods and use real‐world and simulated data to compare the performance of their publicly available software using seven criteria: (a) bias in selection of subgroup variables, (b) probability of false discovery, (c) probability of identifying correct predictive variables, (d) bias in estimates of subgroup treatment effects, (e) expected subgroup size, (f) expected true treatment effect of subgroups, and (g) subgroup stability. The results show that many methods fare poorly on at least one criterion.

This article is categorized under:

Technologies > Machine Learning

Algorithmic Development > Hierarchies and Trees

Algorithmic Development > Statistics

Application Areas > Health Care
Characterization of a triple‐GEM position sensitive detector for X‐ray fluorescence imaging
Authors: de Souza Geovane G. A. , da Luz Hugo Natal
Published: June 2019

In this work, we characterized an X‐ray position sensitive gaseous detector based in a triple stack of gas electron multipliers. The readout circuit is divided in 256 strips for each dimension and using a resistive chain interconnecting the strips, we are able to reconstruct the radiation interaction points by resistive charge division. The detector achieved gains above 104, energy resolution of 15.28% (full width at half maximum) for 5.9 keV X‐rays, and position resolution of 1.2 mm, while operating in Ar/CO2(90/10) at atmospheric pressure.
State dependent spread of entanglement in relatively local Hamiltonians
Authors: Lee Sung-Sik
Published: June 2019

Abstract

Relatively local Hamiltonians are a class of background independent non-local Hamiltonians from which local theories emerge within a set of short-range entangled states. The dimension, topology and geometry of the emergent local theory is determined by the initial state to which the Hamiltonian is applied. In this paper, we study dynamical properties of a simple relatively local Hamiltonian for N scalar fields in the large N limit. It is shown that the coordinate speeds at which entanglement spreads and local disturbance propagates in space strongly depend on state in the relatively local Hamiltonian.
Extension of positivity bounds to non-local theories: IR obstructions to Lorentz invariant UV completions
Authors: Tokuda Junsei
Published: June 2019

Abstract

We derive positivity bounds on low energy effective field theories which admit gapped, analytic, unitary, Lorentz invariant, and possiblynon-localUV completions, by considering 2 to 2 scatterings of Jaffe fields whose Lehmann-Källén spectral density can grow exponentially. Several properties of S-matrix, such as analyticity properties, are assumed in our derivation. Interestingly, we find that some of the positivity bounds obtained in the literature, such as sub-leading order forward-limit bounds, must be satisfied even when UV completions fall into non-localizable theories in Jaffe’s language, unless momentum space Wightman functions grow too rapidly at high energy. Under this restriction on the growth rate, such bounds may provide IR obstructions to analytic, unitary, and Lorentz invariant UV completions.
3d field theory, plane partitions and triple Macdonald polynomials
Authors: Zenkevich Yegor
Published: June 2019

Abstract

We argue that MacMahon representation of Ding-Iohara-Miki (DIM) algebra spanned by plane partitions is closely related to the Hilbert space of a 3d field theory. Using affine matrix model we propose a generalization of Bethe equations associated to DIM algebra with solutions also labelled by plane partitions. In a certain limit we identify the eigenstates of the Bethe system as new triple Macdonald polynomials depending on an infinite number of families of time variables. We interpret these results as first hints of the existence of an integrable 3d field theory, in which DIM algebra plays the same role as affine algebras in 2d WZNW models.
Freezing in response to social threat: a replication
Authors: Noordewier Marret K. , Scheepers Daan T. , Hilbert Leon P.
Published: June 2019

Freezing is an adaptive defensive response to a stressful event. Recent research suggests that freezing not only occurs in response to physical threats but also in response to social threats (e.g., angry faces; Roelofs et al. in Psychol Sci 21:1575–1581, 2010). Given the practical and theoretical importance of this finding, the current study aimed to replicate and extend it. Following the original study, we measured heart rate while participants viewed emotional faces (angry, happy, neutral). Extending the original study, we included a baseline measure and performed additional, more fine-grained analyses. Our results support the hypothesis that participants show physiological signs of freezing when looking at angry faces. Importantly, we also find this effect when comparing heart rate in the angry block to baseline levels. Interestingly, the heart rate effects are explained by deceleration in the first 30 s of the 1-min angry block, but not in the second 30 s. Like Roelofs et al., we find evidence that the effects are modulated by state anxiety, but our effects are only marginal and we do not replicate the negative correlation between heart rate and state anxiety in the angry block. In general, we thus find evidence for physiological signs of freezing in response to social threat. We discuss implications and venues for future research.
Optimal Item Calibration for Computerized Achievement Tests
Authors: Ul Hassan Mahmood , Miller Frank
Published: June 2019

Item calibration is a technique to estimate characteristics of questions (called items) for achievement tests. In computerized tests, item calibration is an important tool for maintaining, updating and developing new items for an item bank. To efficiently sample examinees with specific ability levels for this calibration, we use optimal design theory assuming that the probability to answer correctly follows an item response model. Locally optimal unrestricted designs have usually a few design points for ability. In practice, it is hard to sample examinees from a population with these specific ability levels due to unavailability or limited availability of examinees. To counter this problem, we use the concept of optimal restricted designs and show that this concept naturally fits to item calibration. We prove an equivalence theorem needed to verify optimality of a design. Locally optimal restricted designs provide intervals of ability levels for optimal calibration of an item. When assuming a two-parameter logistic model, several scenarios with D-optimal restricted designs are presented for calibration of a single item and simultaneous calibration of several items. These scenarios show that the naive way to sample examinees around unrestricted design points is not optimal.
An exploratory scenario analysis of strategic pathways towards a sustainable electricity system of the drought-stricken São Francisco River Basin
Authors: Souza Júnior Clécio Barbosa , Koch Hagen , Siegmund-Schultze Marianna , Köppel Johann
Published: June 2019

The São Francisco River Basin in Brazil’s Northeast region suffered from a serious multi-year drought, which started in 2012. This drought was characterized by long periods of water stress, variability and unpredictability of levels and flows of rivers and reservoirs, decreases in hydropower generation, and rising of conflicts between agricultural and electrical sectors. Besides, the electricity sector faced a crisis due to its dependency on hydroelectricity generation. Applying a Multi-Criteria Decision Analysis (MCDA) can contribute to resolve such conflicts. Particular challenges are establishing transparent rules for water level management at the dams and securing electricity supply. Ultimately, identifying options to invest in sustainable power sources may positively impact the regional electricity matrix. We used Soft Systems Methodology to structure the decision-making context and set the main objectives to be considered in the MCDA. Different scenarios of reservoir management were simulated using the Soil and Water Integrated Model and Incomplete Pairwise Comparison, while bibliographic research and expert interviews led to the selection of indicators for structuring the MCDA. We present projections for hydropower generation and meeting of water demands of further users, based on two climate change projections. The driest scenario shows a reduction in hydropower generation, indicating the necessity to reconfigure the composition of electricity sources, considering economic, technical and social-environmental constraints. These elements of the structuring phase are prerequisites for the evaluation phase of the MCDA.
Immigrants in Their Parental Homeland: Half a Million U.S.-born Minors Settle Throughout Mexico
Authors: Masferrer Claudia , Hamilton Erin R. , Denier Nicole
Published: June 2019

In the past 10 years, a historical change occurred in migration flows within North America: specifically, Mexico–U.S. migration reached zero net migration. Alongside Mexican adults returning to their homeland was an unprecedented number of U.S.-born minors. Little is known about this massive migration of U.S. citizen children. We analyze Mexican census data from 2000 to 2015 to estimate the size and characteristics of the population of U.S.-born minors residing in Mexico. Between 2000 and 2010, the population of U.S.-born minors doubled to more than half a million. The population stabilized, aged, and became longer-term Mexican residents thereafter. The large majority of U.S.-born minors are primary school–aged. Although concentrated in the northern border and traditional migrant-sending regions, U.S.-born minors are distributed throughout Mexico. The majority of U.S.-born minors live in Mexico with two Mexican-born parents, but one-third are separated from one or both parents, and most of those separated from parents reside with grandparents. We interpret these trends in reference to the determinants of Mexico–U.S. migration, transnational and mixed-status families, and the future spatial and social mobility of U.S.-born minors living in Mexico.
Reconsidering the Chronology: Carbonized Food Residue, Accelerator Mass Spectrometry Dates, and Compositional Analysis of a Curated Collection from the Upper Great Lakes
Authors: Kooiman Susan M. , Walder Heather
Published: June 2019

Recent reexamination of pottery, copper objects, and glass trade beads using modern analytic methods has amended the occupational history of the Cloudman site (20CH6), once interpreted as an early “Contact” period site in Michigan. The original chronology of the site, located on northern Michigan's Drummond Island in Lake Huron, was based on an apparent association of Iroquoian pottery with European-made trade goods relatively dated to circa AD 1630. Current advances in archaeological dating methods have revealed new insights into the poorly understood settlement patterns and social interactions of various Upper Great Lakes groups between AD 1300 and 1700. Accelerator mass spectrometry dating of carbonized food residue collected from late Late Woodland and Ontario Iroquoian pottery vessels suggests some contemporaneous use of both styles and the culmination of occupation by pottery-making groups by AD 1500. Elemental analysis of glass beads indicates that the recovered trade items were likely manufactured post–AD 1650. Likewise, compositional analysis of copper-base metal artifacts clarifies how such objects were made and used over time at the site. The results demonstrate how the application of modern analytic methods to curated collections can lead to significant reinterpretation, ultimately enhancing understandings of regional chronologies, social relationships, and population movements.
Hyperacute Infarct on Intraoperative Diffusion Imaging of Pediatric Brain Tumor Surgery
Authors: Saint-Martin Christine , Apuzzo Sergio , Salman Ayat , Farmer Jean-Pierre
Published: June 2019

Background:

Brain neoplasms are the second-most prevalent cancer of childhood for which surgical resection remains the main treatment. Intraoperative MRI is a useful tool to optimize brain tumor resection. It is, however, not known whether intraoperative MRI can detect complications such as hyperacute ischemic infarcts.

Methods:

A retrospective analysis of pre- and intraoperative MRIs including DWI sequence and correlation with early and 3-month postoperative MRIs was conducted to evaluate the incidence of hyperacute arterial infarct during pediatric brain tumor resection. Patient demographics, pathological type, tumor location, resection type as well as preoperative tumoral vessel encasement, evolution of the area of restricted diffusion were collected and analyzed comparatively between the group with acute infarct and the control group. Extent of the hyperacute infarct was compared to both early postsurgical and 3-month follow-up MRIs.

Results:

Of the 115 cases, 13 (11%) developed a hyperacute arterial ischemic infarct during brain tumor resection. Tumoral encasement of vessels was more frequent in the infarct group (69%) compared to 25.5% in the control group. Four cases showed additional vessel irregularities on intraoperative MRI. On early follow-up, the infarcted brain area had further progressed in six cases and was stable in seven cases. No further progression was noted after the first week post-surgery.

Conclusions:

Hyperacute infarcts are not rare events to complicate pediatric brain tumor resection. Tumoral encasement of the circle of Willis vessels appears to be the main risk factor. Intraoperative DWI underestimates the final extent of infarcted tissue compared to early postsurgical MRI.
Quotidian Routines: The Cooperative Practices of a Business Elite
Authors: WRIGHT CLAIRE , VILLE SIMON , MERRETT DAVID
Published: June 2019

Cooperative corporate behavior has often been explained through the social anatomy of business leaders and structural ties among firms. Our alternative approach investigates how quotidian interactions built trust and routines among a group of major firms in the Australian wool trade—a sector that required regular interaction to be effective. Deploying extensive archives of their meetings, we use social network analysis to examine interactions among the key group of firms and individuals. Through content analysis we infer the behavior and atmosphere of meetings. Finally, an evaluation of meeting agendas and outcomes demonstrates cooperation and a shared commitment to improving the operation of the wool trade in the 1920s.
Healing of thermocapillary film rupture by viscous heating
Authors: Kirkinis E. , Andreev A. V.
Published: June 2019

Thin liquid films sitting on a heated solid substrate and surrounded by a colder ambient gas phase are strongly affected by surface-shear stresses induced by surface tension and temperature gradients, as well as by viscous and capillary forces. The temperature dependence of surface tension may lead to thinning of liquid-film depressions promoting instability which takes place when a critical temperature difference $\unicode[STIX]{x0394}\unicode[STIX]{x1D717}_{cr}$ between the substrate and the ambient gas phase is exceeded. In this article we show theoretically that viscous heating, previously neglected in related literature, may delay or suppress the thermocapillary instability and leads to film healing. The viscous heating effect, by inhibiting heat transfer, prevents the system from reaching the critical value $\unicode[STIX]{x0394}\unicode[STIX]{x1D717}_{cr}$ required to bring about instability. As a consequence, the system remains within the stability region, suppressing film rupture. The presence of the viscous heating effect leads to a persistent circulating motion of two counter-rotating vortices lying diametrically opposite to a depression of the liquid–gas interface reducing the wavelength of disturbances to one half of its initial value. This effect has yet to be observed in experiment.
Modelling fluid deformable surfaces with an emphasis on biological interfaces
Authors: Torres-Sánchez Alejandro , Millán Daniel , Arroyo Marino
Published: June 2019

Fluid deformable surfaces are ubiquitous in cell and tissue biology, including lipid bilayers, the actomyosin cortex or epithelial cell sheets. These interfaces exhibit a complex interplay between elasticity, low Reynolds number interfacial hydrodynamics, chemistry and geometry, and govern important biological processes such as cellular traffic, division, migration or tissue morphogenesis. To address the modelling challenges posed by this class of problems, in which interfacial phenomena tightly interact with the shape and dynamics of the surface, we develop a general continuum mechanics and computational framework for fluid deformable surfaces. The dual solid–fluid nature of fluid deformable surfaces challenges classical Lagrangian or Eulerian descriptions of deforming bodies. Here, we extend the notion of arbitrarily Lagrangian–Eulerian (ALE) formulations, well-established for bulk media, to deforming surfaces. To systematically develop models for fluid deformable surfaces, which consistently treat all couplings between fields and geometry, we follow a nonlinear Onsager formalism according to which the dynamics minimizes a Rayleighian functional where dissipation, power input and energy release rate compete. Finally, we propose new computational methods, which build on Onsager’s formalism and our ALE formulation, to deal with the resulting stiff system of higher-order partial differential equations. We apply our theoretical and computational methodology to classical models for lipid bilayers and the cell cortex. The methods developed here allow us to formulate/simulate these models in their full three-dimensional generality, accounting for finite curvatures and finite shape changes.
Velocity and spatial distribution of inertial particles in a turbulent channel flow
Authors: Fong Kee Onn , Amili Omid , Coletti Filippo
Published: June 2019

We present experimental observations of the velocity and spatial distribution of inertial particles dispersed in turbulent downward flow through a vertical channel at friction Reynolds numbers $\mathit{Re}_{\unicode[STIX]{x1D70F}}=235$ and 335. The working fluid is air laden with size-selected glass microspheres, having Stokes numbers $St=\mathit{O}(10)$ and $\mathit{O}(100)$ when based on the Kolmogorov and viscous time scales, respectively. Cases at solid volume fractions $\unicode[STIX]{x1D719}_{v}=3\times 10^{-6}$ and $5\times 10^{-5}$ are considered. In the more dilute regime, the particle concentration profile shows near-wall and centreline maxima compatible with a turbophoretic drift down the gradient of turbulence intensity; the particles travel at speed similar to that of the unladen flow except in the near-wall region; and their velocity fluctuations generally follow the unladen flow level over the channel core, exceeding it in the near-wall region. The denser regime presents substantial differences in all measured statistics: the near-wall concentration peak is much more pronounced, while the centreline maximum is absent; the mean particle velocity decreases over the logarithmic and buffer layers; and particle velocity fluctuations and deposition velocities are enhanced. An analysis of the spatial distributions of particle positions and velocities reveals different behaviours in the core and near-wall regions. In the channel core, dense clusters form which are somewhat elongated, tend to be preferentially aligned with the vertical/streamwise direction and travel faster than the less concentrated particles. In the near-wall region, the particles arrange in highly elongated streaks associated with negative streamwise velocity fluctuations, several channel heights in length and spaced by $\mathit{O}(100)$ wall units, supporting the view that these are coupled to fluid low-speed streaks typical of wall turbulence. The particle velocity fields contain a significant component of random uncorrelated motion, more prominent for higher $St$ and in the near-wall region.
Superconvergence of a fully conservative finite difference method on non-uniform staggered grids for simulating wormhole propagation with the Darcy–Brinkman–Forchheimer framework
Authors: Li Xiaoli , Rui Hongxing
Published: June 2019

In this paper, a finite difference scheme on non-uniform staggered grids is proposed for wormhole propagation with the Darcy–Brinkman–Forchheimer framework in porous media by introducing an auxiliary flux variable to guarantee full mass conservation. Error estimates for the pressure, velocity, porosity, concentration and auxiliary flux with second-order superconvergence in different discrete norms are established rigorously and carefully on non-uniform grids. We also obtain second-order superconvergence for some terms of the $H^{1}$ norm of the velocity on non-uniform grids. Finally, some numerical experiments are presented to verify the theoretical analysis and effectiveness of the proposed scheme.
Three-dimensional effects on the transfer function of a rectangular-section body in turbulent flow
Authors: Yang Yang , Li Mingshui , Liao Haili
Published: June 2019

This paper investigates the influence of three-dimensional effects on the transfer function of a rectangular-section body in turbulent flow. The dimensionless factor$\unicode[STIX]{x1D713}$, as derived by Liet al.(J. Fluid Mech., vol. 847, 2018, pp. 768–785), is adapted to evaluate this influence. The calculation of$\unicode[STIX]{x1D713}$requires the spanwise influence term. For this purpose, an adapted form of the lift coherence function is derived, enabling the use of the measured lift coherence for the estimation of the spanwise influence term. Three rectangular models with different cross-sections (chord-to-depth ratios of 3, 5 and 10) are chosen for testing, and a NACA 0015 airfoil model is tested for comparison. Using the measured spanwise influence terms, the dimensionless factors of these models are then numerically calculated under different ratios of the turbulent integral scale to the chord$\unicode[STIX]{x1D6FE}$and aspect ratios$\unicode[STIX]{x1D703}$. It is shown that the dimensionless factors of the rectangular models increase as$\unicode[STIX]{x1D6FE}$and$\unicode[STIX]{x1D703}$increase, which are similar to the dimensionless factor of the airfoil model. If$\unicode[STIX]{x1D6FE}$and$\unicode[STIX]{x1D703}$have suitable values, the strip theory could be applicable to the rectangular-section body. It is also found that the dimensionless factors of all the rectangular models are larger than the dimensionless factor of the airfoil model under the same parameters. The smaller the chord-to-depth ratio is, the larger the dimensionless factor is. Using the strip theory to calculate the lift response of the rectangular-section body may provide more accurate estimation. Additionally, the one-wavenumber transfer functions of these models are determined under the consideration of the three-dimensional effects. The results show that the experimental transfer functions of the rectangular models cannot be captured by the Sears function. They are larger than the Sears function at lower frequencies, while falling at a faster rate as the frequency increases. For bluff bodies with separated flow, the modified transfer function presented here appears to be an appropriate approach.
Spatial Distribution and Problems in the Interpretation of Radiocarbon Dates of the Sungir Site, Russia
Authors: Soldatova Taisiya
Published: June 2019

The Upper Paleolithic open-air site Sungir is located in the central Russian Plain. The blank production of the lithic industry is characterized by parallel reduction with flakes being the main blank type. The tool assemblage has two components: archaic types (Mousterian-like) on the one hand and Upper Paleolithic types on the other. The available data does not allow for a confident determination of the chronological position of the Sungir site, nor does it enable researchers to distinguish different stages of human occupation. The horizontal distribution of the dated samples demonstrates the almost complete absence of radiocarbon (14C) dates for household features identified at the site (fireplaces, fire and ritual pits, large accumulations of bones, etc.). In addition, the vertical distribution of 14C dates in the rather thick cultural layer points to the exposure of the site to solifluction.
On Extra Risks in relation to Double Endowment Assurances
Authors: Levine A.
Published: June 2019

There appears to be a very general belief that every life may be accepted under the Double Endowment Assurance Table at the same rate, provided the term is fixed. One office, at least, grants such assurances without medical examination; another has accepted publicans under this table without the usual trade extra; and medical officers have been known to recommend acceptance at tabular rates for a Double Endowment after having declined the life out-right for an ordinary Endowment Assurance. It may be useful, perhaps, to ascertain how far this practice is justified by theory; and it is hoped, therefore, that a short note on the subject may not be without interest.
On the Requirements of the Life Assurance Companies Act, 1870, in regard to Valuation Returns, with some Notes on the Classification and Valuation of Special Policies
Authors: Todhunter Ralph
Published: June 2019

The objects which I have set before myself in writing this paper are (1) to advocate a more elastic interpretation than has hitherto been usual, of the requirements of the Act of 1870 in regard to Valuation Returns; (2) to discuss some points that arise in the classification and valuation of Special Policies. The connection between these two objects consists in the fact that the necessity, or the supposed necessity, of conforming to the stereotyped schedules in which valuation returns under the Act are usually made, and the labour entailed by the individual valuation of special policies, constitute, jointly and severally, a serious obstacle to the rapid conduct of a life-office valuation. This may not be a matter of very great importance if or so long as a valuation is looked upon as a quinquennial or septennial event, for which special and extensive preparations must be made, and upon which months of overtime are to be spent, but it becomes a very different matter if a valuation is to be regarded—as it should, I think, be regarded, and as it undoubtedly is regarded in an increasing number of offices—as little more than an incident in the actuarial routine.
“On the Alleged Increase of Cancer”
Authors: King George , Newsholme Arthur
Published: June 2019

During the last few years the minds of medical men and of the general public have been exercised over the rapid and striking increase in the mortality from cancer, as shown by the statistics contained in the Registrar-General's Annual Reports. The following table, taken from these reports, shows how great this increase in registered mortality has been. The registered death-rate of males from this disease was 2·7 times, for females 2·0 times, and for both sexes together 2·2 times, as high in 1891 as in the average for the decade 1851-60.
The Actuarial Aspects of Recent Legislation, in the United Kingdom and other Countries, on the subject of Compensation to Workmen for Accidents
Authors: Nicoll John
Published: June 2019

The liability of the employer to compensate his employees, as well as other persons, for injuries sustained through his fault, may be traced from an early period in the world's history in the Common Law of various countries.

For example, by the Jewish Law, said to have been promulgated about the year 1500 B.C., if a master were the means of causing the loss, either intentionally or unintentionally, of the eye or of the tooth of his slave, he was bound to let him go free for his eye or his tooth's sake. Again, according to the same law, if an employer allowed his ox to gore either his servant or a stranger, he was required to pay various compensations to the injured if he survived, or to his relatives in the event of the injury being followed by death.
A Few Notes upon Certain Methods of allotting Surplus
Authors: Young Thomas Emley
Published: June 2019

With a view to preparing the way, in some humble degree, to a generally satisfactory method of distribution hereafter, I beg leave to submit a few brief observations upon the merits and demerits of certain plans already in operation. Unhappily, I cannot at present, in the existing state of our enquiries, present any constructive notions capable of being fused into a symmetric system.
On the valuation of staff pension funds. Part 2—widows' and children's pensions
Authors: Manly Henry William , Foot Herbert
Published: June 2019

I Have been asked to explain how the benefits of a pension to widows and an allowance to children can be valued when they are included in a pension scheme; and as I have had no experience whatever of a fund providing such benefits, I am, of course, eminently qualified to lecture on the subject. At least, I approach the subject with an unprejudiced mind, and am not affected by anything I may have said or done.
On The Graduation of the Rates of Sickness and Mortality Presented by the Experience of the Manchester Unity of Oddfellows during the period 1893–97
Authors: Spencer John
Published: June 2019

In considering the various methods of graduation open to us, we were impressed, having regard to the large number of series to be dealt with, by the great facility and rapidity with which formulæ of summation can be applied with the certainty that the results obtained will conform closely to the unadjusted facts. For the Sickness Tables the summation method is especially suitable, since the average number of weeks (or rate) of sickness at any age is necessarily separable for practical purposes into “periods of attack”, e.g., in the case of the Manchester Unity Experience, 1893–97, “First 3 Months”, “Second 3 Months”, “Second 6 Months”, “Second 12 Months,” and “After 2 years”, the successive values of each of which must form a regular series, whilst the sum of any two sections forming a “period of attack” in general use (e.g., First 6 Months = First 3 Months + Second 3 Months) must be equally regular in progression. It is obvious that if a summation method be adopted, and the same formula be used throughout, a combination of any two or more of the graduated series will be itself a graduated series, and will, indeed, be identical with the result of an independent graduation of the combined unadjusted rates.
Some Illustrations of the Employment of Summation Formulas in the Graduation of Mortality Tables
Authors: Spencer John
Published: June 2019

Mr. George King's recent investigation of the magnitude of the error introduced into certain functions of a mortality table following Makeham's law when these are re-graduated by summation formulas (J.I.A., xli, 54), has again attracted attention to the subject of the graduation of mortality tables, and has recalled the lively controversy which took place some years ago between Dr. Sprague and the late Mr. Woolhouse over the merits and demerits of the methods championed by those distinguished authorities. Not the least interesting contribution to the discussion which followed the reading of Mr. King's paper was furnished by Dr. Sprague himself, who wrote in defence of certain criticisms expressed by him with regard to methods of summation generally and Mr. Woolhouse's formula in particular. Dr. Sprague remarked that he had “objected to Mr. Woolhouse's “formula of graduation,on two grounds, which it has in common “with all other summation formulas; that is to say, (1) because “it does not remove the irregularities of the original series of “facts, but only reduces them, and (2) because it distorts the “law of the facts to a greater or less extent.” He went on to say that the results of his re-graduation of the HM (Text-Book) Table by Woolhouse's formula had led him to the conclusion that the second objection might be disregarded in practice, but that there still remained objection (1), which he considered by far the more important.
Osculatory Interpolation by Central Differences; with an application to Life Table Construction
Authors: Buchanan James
Published: June 2019

The new method described in Mr. King's recent paper, “On the Construction of Mortality Tables from Census Returns and Records of Deaths”, marks such a great advance on that employed in the construction of the official English Life Table, that it occurred to me that it might be worth examining whether the numerical application could not be further simplified by the use of central differences. Everett's formula (J.I.A., xxxv, 452) lends itself admirably to the construction of tables by subdivision of intervals. It involves only even central differences of each of the two middle terms of the series between which the interpolation has to be made, and, as was pointed out by the author in communicating his formula to the Journal, “each sum of three terms does double duty, serving both for “the preceding and the succeeding interval. In an extended “computation, the number of ‘sums of three terms’ to be “calculated is accordingly practically identical with the number “of intervals, and the labour of calculation is only about half “what it appears to be on the face of the formula.”

The problem before us is that of fitting between consecutive pairs of a series of points a series of partial interpolation curves, which shall have the same slope and curvature at their points of junction. In what follows, the central difference notation is that introduced by Dr. W. F. Sheppard in his paper on “Central Difference Formulæ” (Proceedings of the London Mathematical Society, xxxi, 449).
The Assurance Companies Act, 1909. Some Explanatory Notes on Such Portions of the Act as Relate to the Business of Life Assurance
Authors: Barrand Arthur Rhys
Published: June 2019

There will, I venture to think, be no difference of opinion among the members of this Institute as to the advisability of an early and adequate discussion of the many points of difficulty presented by the new Assurance Companies Act. Neither will there be any doubt as to this Institute being the proper place for such a discussion, consisting as it does of an unrivalled body of experts on the subject of life assurance. In these circumstances I have ventured to undertake the task of bringing the matter before the Institute, confident in the fact that however inadequate my treatment of the subject may be, those before whom the paper is to be read are fully competent to make good any shortcomings on my part, and will be both able and willing to correct any errors into which I may have fallen.
Whole Life Non-Profit Assurances
Authors: Cameron Finlay James
Published: June 2019

The subject of this Paper is Whole Life Non-Profit Assurances with uniform Premiums payable throughout life.

In choosing this subject for investigation, I have been influenced mainly by the following reasons :

(1) This type of policy represents life assurance in one of its simplest and earliest forms. The premium and the sum assured are both fixed throughout life, save for the very slight chance of insolvency of the office causing the contract to be reduced. Also nowadays it is not uncommon to find that the surrender values and equivalent paid-up policies are guaranteed from the outset.

(2) Other tables such as Whole Life by Limited Premiums, Half Premiums for first “n” years, &c., are as a rule founded on the basis of the simple whole life ordinary rates.

(3) A considerable body of data derived directly from the experience of British Offices under ordinary whole life non-profit policies is available as a result of the British Offices Mortality Investigation, 1863-93.

(4) In spite of the apparent simplicity of the contract, there are marked divergencies in the rates of premium charged by first-class offices and in the surrender values and equivalent paid-up policies offered by them.
The New National Life Tables
Authors: King George
Published: June 2019

The Council invited me to open at a Sessional Meeting a discussion on the new National Life Tables, and I was glad of the opportunity thus given to set forth in a little more detail than heretofore the objects which had to be kept in view in preparing the tables, and the bearing of these objects on selecting a method of construction. At first I had intended to open the discussion by an unwritten speech, but on looking at the subject from this point of view it was found that a mere speech would hardly meet the necessities of the case, and that it would be better to write an informal paper. This I have now the honour to submit.