bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabry pedigree analysis: A successful program for targeted genetic approach
Authors: Rozenfeld Paula A. , Masllorens Francisca M. , Roa Norma , Rodriguez Fernanda , Bonnano Mariela , Yvorra Carolina , Ceci Romina
Published: June 2019

Background

Fabry disease (FD) is an X‐linked disorder of glycosphingolipid catabolism caused by a deficiency of the lysosomal enzyme alpha‐galactosidase A (GLA). FD is still an underdiagnosed disorder worldwide. Moreover, there is delay between symptom onset and Fabry diagnosis of at least 10 years. Family screening offers an important benefit for detection of new patients. The aim of this work is to present the approach along with the results of a targeted genetic strategy for pedigree analysis for FD in Argentina.

Methods

By this strategy as soon as a new index Fabry patient is diagnosed, the pedigree group contacts the physician and a meeting is arranged with the physician and the family to build the family tree.

Results

Pedigree analysis was carried out for full in 31 families. In the work period, we have tested 1,462 relatives, and 501 were diagnosed FD. The proportion of positive detection was 33%.

Conclusion

The targeted family screening approach is successful to detect undiagnosed Fabry patients. By this approach, the highest ratio index to pedigree ever reported for FD pedigree analysis of 1:15 was obtained.
Prednisone may rebuild the immunologic homeostasis: Alteration of Th17 and Treg cells in the lymphocytes from rats' spleens after treated with prednisone‐containing serum
Authors: Fu Xiao‐Qian , Cai Jun‐Ying , Li Mu‐Jun
Published: June 2019

Background

This study aimed to investigate alterations of T helper 17 (Th17), regulatory T (Treg) cells and relative cytokines after treating with prednisone‐contained serum. Lymphocytes were isolated from female rats' spleens.

Methods

The splenic lymphocytes were divided into four groups: which were treated with normal rats' serum (control); prednisone‐containing rats' serum (PDN); normal rats' serum and cytokines (CTK); cytokines and prednisone‐containing rats' serum (PDN + CTK). The mRNA expression level of RORC, Foxp3 and interleukin‐17 (IL‐17) was examined by reverse transcription‐polymerase chain reaction. The quantities of Th17 and Treg cells were tested by flow cytometry, and the concentrations of IL‐17 and IL‐10 were detected by enzyme‐linked immunosorbent assay.

Results

Higher mRNA expression level of Foxp3, percentages of Treg/CD4+, and concentrations of IL‐10, lower mRNA expressions of RORC and IL‐17, concentrations of IL‐17 and percentages of Th17/CD4+ in PDN group were detected, compared with control group (all p < 0.01). Similar trend was detected in PDN + CTK group, compared with CTK group (all p < 0.01).

Conclusion

Our results suggest that prednisone may rebuild the immunologic homeostasis and may be used in human diseases with changes in the imbalance immune system such as unexplained recurrent spontaneous abortion (URSA), hepatitis B infection, or other autoimmune diseases.
Medicinal Chemistry Aware Database GDBMedChem
Authors: Awale Mahendra , Sirockin Finton , Stiefl Nikolaus , Reymond Jean‐Louis
Published: June 2019

The generated database GDB17 enumerates 166.4 billion possible molecules up to 17 atoms of C, N, O, S and halogens following simple chemical stability and synthetic feasibility rules, however medicinal chemistry criteria are not taken into account. Here we applied rules inspired by medicinal chemistry to exclude problematic functional groups and complex molecules from GDB17, and sampled the resulting subset uniformly across molecular size, stereochemistry and polarity to form GDBMedChem as a compact collection of 10 million small molecules. This collection has reduced complexity and better synthetic accessibility than the entire GDB17 but retains higher sp3‐carbon fraction and natural product likeness scores compared to known drugs. GDBMedChem molecules are more diverse and very different from known molecules in terms of substructures and represent an unprecedented source of diversity for drug design. GDBMedChem is available for 3D‐visualization, similarity searching and for download at http://gdb.unibe.ch.
Design and validation of a surgical navigation system for brachytherapy based on mixed reality
Authors: Zhou Zeyang , Yang Zhiyong , Jiang Shan , Zhang Fujun , Yan Huzheng
Published: June 2019

Purpose

An accurate position of the needle is vitally important in low‐dose‐rate seed implantation brachytherapy. Our paper aims to implement a mixed reality navigation system to assist with the placement of the I125 seed implantation thoracoabdominal tumor brachytherapy needle and to validate the accuracy and quality of this type of method.

Methods

With the surgical navigation system, based on mixed reality through a novel modified multi‐information fusion method, the fusion of virtual organs and a preoperative plan for a real patient and the tracking of surgical tools in real time were achieved. Personalized image recognition and pose estimation were used to track needle punctures in real time and to perform registration processes. After a one‐time registration with a hexagonal prism tracker that used an iterative closest point algorithm, all information, including medical images and volume renderings of organs, needles, and seeds, was precisely merged with the patient. Doctors were able to observe the tumor target and to visualize the preoperative plan. This system was validated in both phantom and animal experiments. The accuracy of this system was validated by calculating the positional and rotational error of each needle insertion. The accuracy of implantation of each seed was determined in an animal experiment to test the accuracy in low‐dose‐rate brachytherapy. The efficiency of this system was also validated through time consumption assessments.

Results

In the phantom experiment, the average error of the needle locations was 0.664 mm and the angle error was 4.74°, average time consumption was 16.1 min with six needles inserted. Based on the results of the animal experiment, the accuracy of the needle insertion was 1.617 mm, while the angle error was 5.574° and the average error of the seed positions was 1.925 mm.

Conclusions

This paper describes the design and experimental validation of a novel surgical navigation system based on mixed reality for I125 seed brachytherapy for thoracoabdominal tumors. This system was validated through a series of experiments, including phantom experiments and animal experiments. Compared with the traditional image‐guided system, the procedure presented here is convenient, displays clinically acceptable accuracy and reduces the number of CT scans, allowing doctors to perform surgery based on a visualized plan. All the experimental results indicated that the procedure is ready to be applied in further clinical studies.
A stable interface‐enriched formulation for immersed domains with strong enforcement of essential boundary conditions
Authors: van den Boom Sanne J. , Zhang Jian , van Keulen Fred , Aragón Alejandro M.
Published: June 2019

Generating matching meshes for finite element analysis is not always a convenient choice, for instance, in cases where the location of the boundary is not known a priori or when the boundary has a complex shape. In such cases, enriched finite element methods can be used to describe the geometric features independently from the mesh. The Discontinuity‐Enriched Finite Element Method (DE‐FEM) was recently proposed for solving problems with both weak and strong discontinuities within the computational domain. In this paper, we extend DE‐FEM to treat fictitious domain problems, where the mesh‐independent boundaries might either describe a discontinuity within the object, or the boundary of the object itself. These boundaries might be given by an explicit expression or an implicit level set. We demonstrate the main assets of DE‐FEM as an immersed method by means of a number of numerical examples; we show that the method is not only stable and optimally convergent but, most importantly, that essential boundary conditions can be prescribed strongly.
Genomic landscape of lymphoepithelioma‐like hepatocellular carcinoma
Authors: Chan Anthony W‐H , Zhang Zhe , Chong Charing C‐N , Tin Edith K‐Y , Chow Chit , Wong Nathalie
Published: June 2019

Lymphoepithelioma‐like hepatocellular carcinoma (LEL‐HCC) is a distinct variant of HCC that is characterized by dense tumor‐infiltrating lymphocytes (TILs). Patients with LEL‐HCC also show better clinical outcomes compared to conventional HCC (c‐HCC), which is commonly presented with low TIL. Emerging evidence has begun to highlight tumor‐intrinsic genetic abnormalities in the tumor–host immune interfaces. However, genome‐wide characterization of LEL‐HCC remains largely unexplored. Here, we defined the genomic landscape of 12 LEL‐HCC using whole‐exome sequencing, and further underpinned those genetic alterations related to an immune active microenvironment by comparing findings to 15 c‐HCC that were sequenced in parallel. Overall, the mutational load between LEL‐HCC and c‐HCC was similar. Interestingly, SNV incidences of specific genes (CTNNB1, AXIN1, NOTCH1, and NOTCH2) were significantly higher in c‐HCC than LEL‐HCC, suggesting a plausible link between activated Wnt/β‐catenin and Notch signaling pathways and immune avoidance. Marked focal amplification of chromosome 11q13.3 was prevalent in LEL‐HCC. Using The Cancer Genome Atlas dataset, we further established oncogenes expressed from chromosome 11q13.3 (CCND1, FGF19, and FGF4) to be strongly associated with the immune checkpoint signature (CD274, PDCD1, BTLA, CTLA4, HAVCR2, IDO1, and LAG3). Our results have illustrated for the first time the somatic landscape of LEL‐HCC, and highlighted molecular alterations that could be exploited in combinatory therapy with checkpoint inhibitors in targeting HCC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Analysis of PGT‐M and PGT‐SR outcomes at a Canadian fertility clinic
Authors: Butler Rachel , Nakhuda Gary , Guimond Colleen , Jing Chen , Lee Nora , Hitkari Jason , Tallon Niamh , Taylor Beth , Yuzpe Albert
Published: June 2019

Objective

Outcomes from in vitro fertilization (IVF)/intrauterine insemination (ICSI) cycles for patients who underwent preimplantation genetic testing for monogenic/single gene (PGT‐M) and structural chromosome rearrangements (PGT‐SR) patients were reviewed. Patients pursuing PGT‐M and PGT‐SR often do not have pre‐existing fertility issues and therefore may have uncertain expectations of successful outcomes. Before pursuing PGT‐M and PGT‐SR, patients require evidence‐based counseling regarding the probability of having a healthy child.

Method

Retrospective review from a single private IVF clinic of 73 PGT patients, from whom a total of 437 blastocysts were biopsied and screened. Embryo results and pregnancy outcomes were analyzed.

Results

Of the 45 PGT‐M patients, 64.4% had at least one euploid unaffected embryo. The cumulative pregnancy rate for patients who had embryo transfers in this group was 89.7%, with an ongoing pregnancy or delivery rate of 48.9%. For the 28 PGT‐SR patients, 60.7% had at least one euploid unaffected embryo. The cumulative pregnancy rate for patients who had embryo transfers in this group was 87.5%, with an ongoing pregnancy or delivery rate of 42.9%.

Conclusion

This information can supplement the existing data in the literature to counsel new patients in terms of realistic expectations of success following PGT‐M and PGT‐SR.
Fetal pleural effusion: Contemporary methods of genetic evaluation
Authors: Weissbach Tal , Kushnir Anya , Rasslan Rana , Rosenblatt Orgad , Yinon Yoav , Berkenstadt Michal , Weisz Boaz , Mazaki Tovi Shali , Kassif Eran
Published: June 2019

Objective

To determine the contribution of chromosomal microarray (CMA) and other advanced genetic tests to the genetic evaluation of fetal pleural effusion (FPE) and to identify parameters that might assist in predicting genetic abnormality.

Methods

A retrospective study of FPE cases referred between 2013 and 2018 was conducted. Cases that underwent genetic evaluation were divided into two groups, chromosomally normal and genetically abnormal. The types and prevalence of genetic abnormalities were reported. Clinical and sonographic parameters were compared. Univariate and multivariate analyses were performed to determine an association between different parameters and genetic abnormality.

Results

Sixty‐two cases were included in the study. Forty‐eight cases were genetically assessed (karyotype, CMA, whole exome sequencing, Noonan panel, or a combination). A clinically significant genetic abnormality was detected in 29.17% (14/48) of cases. Aneuploidy and single gene disorders were found in 78.6% (11/14) and 21.4% (3/14) of abnormal cases. Four additional cases had microdeletion/duplications detected, yet none were of clinical significance. Multivariate analysis indicated that the presence of anomalies was statistically associated with genetic abnormality (95% CI, 1.144‐168.2; 0.039).

Conclusion

In our cohort, CMA did not demonstrate an additional clinical yield over karyotyping. The presence of anomalies was independently associated with underlying genetic abnormality.
Sacroiliac Joint Fusion: Approaches and Recent Outcomes
Authors: Yson Sharon C. , Sembrano Jonathan N. , Polly David W.
Published: June 2019

The sacroiliac joint may be a primary source of pain in patients complaining of low back and/or buttock pain. Nonsurgical treatment of sacroiliac joint pain typically includes structured core and pelvic muscle flexibility and strengthening; pharmaceutical management through oral and injectable medication; and ablation procedures. For patients who do not improve with comprehensive, nonoperative treatment, surgical fusion of the sacroiliac joint is an option with overall good reported outcomes and high patient satisfaction. Minimally invasive surgery (MIS) approaches have been shown to have lower morbidity and earlier recovery than traditional open approaches. To date, the majority of published clinical studies on MIS sacroiliac joint fusion are industry‐sponsored and predominantly using one system (ingrowth triangular titanium rods). These include two level 1 randomized controlled trials comparing MIS sacroiliac joint fusion to nonoperative management, with results favoring surgery.
Characterization of Interfacial Micro‐Structures of Explosive‐Binder Composites by Gas Permeation
Authors: Li Shichun , Xu Jinjiang , Liu Yu
Published: June 2019

The interface between explosive and binder in plastic‐bonded explosives (PBXs) plays an important role in their properties such as thermal and mechanical stability, and also their performance in detonation processes. However, characterization of their interfacial micro‐structures remains challenging, due to the sensitive nature of the explosive material, and the extremely thin nature of the interface. This work demonstrates a concept of characterizing interfacial structures between explosives and binders by gas permeation. The N2 permeability data of composite films of cyclotetramethylene‐tetranitramine (HMX) particles dispersed in fluororubber binder (copolymers of vinylidene fluoride and chlorotrifluoro‐ethylene, F2311) were tested and fitted by using gas transport mechanism theory, e. g. the Hashemifard‐Ismail‐Matsuura (HIM) model, and the Knudsen diffusion equation. The results indicate the presence of voids of thickness 2.2 nm between HMX and F2311, consistent with the results of neutron reflection and thermal conductivity measurements. These interfacial voids are considered to be related to the surface roughness of HMX particles. This work provides an alternative characterization technique for, as well as a new insight into, the interface between HMX and F2311.
A new Bayesian multivariate exponentially weighted moving average control chart for phase II monitoring of multivariate multiple linear profiles
Authors: Ahmadi Yazdi Ahmad , Zeinal Hamadani Ali , Amiri Amirhossein , Grzegorczyk Marco
Published: June 2019

Recently, statistical profile monitoring methods have become efficient tools for monitoring the quality of a product (or a production process) using control charts. The key idea is to describe the relationship between a response variable and a set of explanatory variables in the form of a statistical regression model, which called profile. Traditionally, those control charts are constructed with standard “frequentistic” regression models. Recently, it has been proposed to apply Bayesian regression models instead, and it has been empirically demonstrated that Bayesian regression models have the potential to perform significantly better. In this paper, we introduce a novel Bayesian multivariate exponentially weighted moving average control chart for monitoring multivariate multiple linear profiles in phase II. The key idea is to use the data from historical data sets to generate informative prior distributions for the regression models in phase II. The results of our empirical simulation studies show that the Bayesian multivariate multiple linear regression model is superior to its classical “frequentistic” counterpart in terms of the average run length. Our empirical findings are in agreement with findings reported in recently published articles. To shed more light onto the merit of the proposed Bayesian method, we carry out a sensitivity analysis, in which we investigate how the amount of phase I data influences the results. We also demonstrate the applicability and superiority of the proposed Bayesian method by a real‐world application.
Far‐Red to Near‐Infrared Carbon Dots: Preparation and Applications in Biotechnology
Authors: Shi Xinxin , Meng Hongmin , Sun Yuanqiang , Qu Lingbo , Lin Yuehe , Li Zhaohui , Du Dan
Published: June 2019

As novel fluorescent nanomaterials, carbon dots (CDs) exhibit excellent photostability, good biocompatibility, and high quantum yield (QY). Their superior properties make them promising candidates for biomedical assays and therapy. Among them, the red‐emission (>600 nm) CDs have attracted increasing attention in the past years due to their little damage to the biological matrix, deep tissue penetration, and minimum autofluorescence background of biosamples. This Review, summarizes the recent progress of far‐red to near‐infrared (NIR) CDs from the preparation and their biological applications. The challenges in designing far‐red and NIR CDs and their further applications in biomedical fields are also discussed.
Additive Manufacturing of Nanostructures That Are Delicate, Complex, and Smaller than Ever
Authors: Gross Andrew J. , Bertoldi Katia
Published: June 2019

Additive manufacturing with two‐photon polymerization (TPP) has opened new opportunities for the rapid fabrication of 3D structures with sub‐micrometer resolution, but there are still many fabrication constraints associated with this technique. This study details a postprocessing method utilizing oxygen‐plasma etching to increase the capabilities of TPP. Underutilized precision in the typical fabrication process allows this subtractive technique to dramatically reduce the minimum achievable feature size. Moreover, since the postprocessing occurs in a dry environment, high aspect ratio features that cannot survive the typical fabrication route can also be achieved. Finally, it is shown that the technique also provides a pathway to realize structures that otherwise are too delicate to be fabricated with TPP, as it enables to introduce temporary support material that can be removed with the plasma. As such, the proposed approach grants access to a massively expanded design domain, providing new capabilities that are long sought in many fields, including optics, biology, robotics, and solid mechanics.
The effect of operator experience on scanning time in ultrasound assessment of the shoulder
Authors: McLoughlin Emer , Murphy Jennifer , Iqbal Aamer , McGarry Sharon , James Steven L. , Botchu Rajesh
Published: June 2019

Introduction

There has been a significant increase in ultrasound imaging over the past three decades that has resulted in a strain on imaging departments including in musculoskeletal subspeciality where resources are already stretched to meet targets in United Kingdom (UK) National Health Service (NHS). We performed a retrospective study to assess the effect of operator experience on scanning duration in ultrasound assessment of the shoulder.

Method

Four different operators (one sonographer and three consultant musculoskeletal radiologists) with experience ranging from 1 to 10 years were included in the study. A total of 100 consecutive shoulder ultrasound examinations were reviewed, with each operator having performed 25 of these scans.

Results

The scanning duration decreased with increasing experience in operators 1 to 3; however, operator 4, who had the most scanning experience, was found to have a statistically significant longer scanning duration when compared with operator 3, and this reflected the presence of a radiology trainee in operator 4's ultrasound session.

Conclusion

There is decrease in scanning duration with experience, and this would help for workforce planning and accurate scheduling of ultrasound lists.
ISUOG Practice Guidelines: ultrasound assessment of fetal biometry and growth
Authors: Salomon L.J. , Alfirevic Z. , Da Silva Costa F. , Deter R.L. , Figueras F. , Ghi T. , Glanc P. , Khalil A. , Lee W. , Napolitano R. , Papageorghiou A. , Sotiriadis A. , Stirnemann J. , Toi A. , Yeo G.
Published: June 2019

INTRODUCTION

These Guidelines aim to describe appropriate assessment of fetal biometry and diagnosis of fetal growth disorders. These disorders consist mainly of fetal growth restriction (FGR), also referred to as intrauterine growth restriction (IUGR) and often associated with small‐for‐gestational age (SGA), and large‐for‐gestational age (LGA), which may lead to fetal macrosomia; both have been associated with a variety of adverse maternal and perinatal outcomes. Screening for, and adequate management of, fetal growth abnormalities are essential components of antenatal care, and fetal ultrasound plays a key role in assessment of these conditions.

The fetal biometric parameters measured most commonly are biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FL). These biometric measurements can be used to estimate fetal weight (EFW) using various different formulae1. It is important to differentiate between the concept of fetal size at a given timepoint and fetal growth, the latter being a dynamic process, the assessment of which requires at least two ultrasound scans separated in time. Maternal history and symptoms, amniotic fluid assessment and Doppler velocimetry can provide additional information that may be used to identify fetuses at risk of adverse pregnancy outcome.

Accurate estimation of gestational age is a prerequisite for determining whether fetal size is appropriate‐for‐gestational age (AGA). Except for pregnancies arising from assisted reproductive technology, the date of conception cannot be determined precisely. Clinically, most pregnancies are dated by the last menstrual period, though this may sometimes be uncertain or unreliable. Therefore, dating pregnancies by early ultrasound examination at 8–14 weeks, based on measurement of the fetal crown–rump length (CRL), appears to be the most reliable method to establish gestational age. Once the CRL exceeds 84 mm, HC should be used for pregnancy dating2–4. HC, with or without FL, can be used for estimation of gestational age from the mid‐trimester if a first‐trimester scan is not available and the menstrual history is unreliable. When the expected delivery date has been established by an accurate early scan, subsequent scans should not be used to recalculate the gestational age1. Serial scans can be used to determine if interval growth has been normal.

In these Guidelines, we assume that the gestational age is known and has been determined as described above, the pregnancy is singleton and the fetal anatomy is normal. Details of the grades of recommendation used in these Guidelines are given in Appendix 1. Reporting of levels of evidence is not applicable to these Guidelines.
Theoretical fluorescence yields and widths of the K shell and the L subshells, for the Ne, Ar, and Kr isoelectronic sequences
Authors: Marques José P. , Sampaio Jorge M. , Santos José Paulo , Indelicato Paul , Parente Fernando
Published: June 2019

In this work, we present fluorescence yield and width values of Ne‐, Ar‐, and Kr‐like ion levels for selected values of Z, using a state‐of‐the‐art multiconfiguration Dirac–Fock approach. The results may be useful for the interpretation of spectra from plasmas, in both laboratory and astrophysics, as well as from ion collision experiments.
K‐K electron capture from adenine and CO2 molecule by fast carbon ions using KLL‐Auger electron technique
Authors: Bagdia Chandan , Bhattacharjee Shamik , Roychowdhury Madhusree , Mandal Anuvab , Lapicki Gregory , Tribedi Lokesh C.
Published: June 2019

The experimental measurement of total electron transfer cross section in Bragg peak energy region is important to understand energy loss in the biomolecular system. In this study, we have measured state selective, K‐K electron capture and K‐ionization cross sections for adenine (C 5H 5N 5) in collisions with fast (2.5–5 MeV/u) C ions. These are compared with the data for smaller gas molecule, CO 2. These are derived from a study of the KLL‐Auger electron emission yields as a function projectile charge state. The K‐ionization cross‐section (σKI) data are compared with the ECUSAR (united and separated atom [USA] approximation with energy loss [E], Coulomb deflection [C], and relativistic [R] corrections) model calculation. The measured σKI data and the calculations are in good agreement. The K‐K transfer cross‐section (σK−K) data are compared with the CPSSR (perturbed stationary state [PSS] with Coulomb deflection [C] and relativistic corrections [R]) calculation that underestimates the measured data for such symmetric collision system. The energy dependence of σK−K for adenine is found to be flat in contrast to a sharp variation predicted by the model. The K‐transfer cross section is found to be substantial fraction of the K‐ionization.
Dynamic perfect plasticity and damage in viscoelastic solids
Authors: Davoli Elisa , Roubíček Tomáš , Stefanelli Ulisse
Published: June 2019

In this paper we analyze an isothermal and isotropic model for viscoelastic media combining linearized perfect plasticity (allowing for concentration of plastic strain and development of shear bands) and damage effects in a dynamic setting. The interplay between the viscoelastic rheology with inertia, elasto‐plasticity, and unidirectional rate‐dependent incomplete damage affecting both the elastic and viscous response, as well as the plastic yield stress, is rigorously characterized by showing existence of weak solutions to the constitutive and balance equations of the model. The analysis relies on the notions of plastic‐strain measures and bounded‐deformation displacements, on sophisticated time‐regularity estimates to establish a duality between acceleration and velocity of the elastic displacement, on the theory of rate‐independent processes for the energy conservation in the dynamical‐plastic part, and on the proof of the strong convergence of the elastic strains. Existence of suitably defined weak solutions (even conserving energy) is proved rather constructively by using a staggered two‐step time discretization scheme.
Does an Asset Owner’s Institutional Setting Influence Its Decision to Sign the Principles for Responsible Investment?
Authors: Hoepner Andreas G. F. , Majoch Arleta A. A. , Zhou Xiao Y.
Published: June 2019

From a simple idea to unite asset owners in their quest for responsible investment (RI) at its launch in April 2006, the United Nations supported Principles for Responsible Investment (PRI) have grown in just one decade into an initiative with more than 1500 fee-paying signatories. Jointly, the PRI’s signatories hold assets worth more than $80 trillion, making it one of the more prevalent not-for-profit organizations worldwide. Furthermore, the PRI’s ambitious mission to transform the financial system at large into a more sustainable one makes it a worthwhile subject of inquiry from an institutional perspective. We undertake an empirical investigation of the adoption of the PRI by asset owners during five crucial years of the association’s emergence: 2007–2011. Following a tripartite view of institutional theory proposed by Scott (Institutions and organizations. Foundations for organizational science, A Sage Publication Series, London, 1995), we explore if regulative, normative, and cultural–cognitive factors influence an asset owner’s decision to subscribe to the PRI. Applying both parametric and non-parametric survival analysis, we find that asset owners are indeed significantly affected by normative, cultural–cognitive, and regulative aspects. In particular, (i) public service employee and labor union pension funds (ii) from social backgrounds more culturally aligned with values represented by the RI movement (iii) with historically more voluntary legislation on environmental, social, and governance (ESG) issues are most likely to sign the PRI. In contrast, institutional environments with a higher number of pre-existing mandatory ESG regulation decrease the likelihood of signing the PRI. Our results indicate that normative and cultural–cognitive factors were crucial contributors to the PRI’s growth. With respect to the regulative environments, our results imply that some asset owners may use the PRI as a collective industry initiative to substitute for mandatory legislation. Conversely, a high level of historical mandatory legislation may constrain organizational resources that could otherwise be dedicated to voluntary initiatives such as PRI. Our findings are robust to relevant controls and econometric concerns.
The Role of Academic Partnership in Disaster Risk Management: A Systematic Review
Authors: Seifi Bahar , Seyedin Hesam , Ghanizadeh Ghader
Published: June 2019

Objective:

The aim of this systematic review is to investigate the community-based academic partnership roles in disaster risk management.

Methods:

The assessment of the documents was conducted by reviewing abstracts and full papers of the available studies, which provided considerable background and promoted knowledge in academic interventional roles in disaster risk management. The articles were searched with a wide range of key words related to the research topic. The studies included the research available between 2000 and September 2017 in the English language. The selection of articles was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist.

Results:

Of 997 articles, we selected 12 full-text articles that met the criteria for the final review based on the study objective. The results show that, although universities can play multidirectional roles in disaster risk management phases, the development of the academic partnership potential and collaboration for disaster risk management and disaster risk reduction for stakeholders is necessary.

Conclusion:

The universities’ potential in providing sufficient disaster health literacy is not currently considered important enough in communities.Therefore, the proper context-bound models of development based on a community’s skills and universities’ potential should receive more attention.
Dynamics and flow coupling in two-layer turbulent thermal convection
Authors: Xie Yi-Chao , Xia Ke-Qing
Published: June 2019

We present an experimental investigation of the dynamics and flow coupling of convective turbulent flows in a cylindrical Rayleigh–Bénard convection (RBC) cell with two immiscible fluids, water and Fluorinert FC-77 electronic liquid (FC77). With the lighter water above FC77, the latter is under the condition of constant heat flux at its top and bottom boundaries. It is found that one large-scale circulation (LSC) roll exists in each of the fluid layers, and that their circulation planes have two preferred azimuthal orientations separated by ${\sim }\mathrm{\pi} $. A surprising finding of the study is that cessations/reversals of the LSC in FC77 of the two-layer system occur much more frequently than they do in single-layer turbulent RBC, and that a cessation is most likely to result in a flow reversal of the LSC, which is in sharp contrast with the uniform distribution of the orientational angular change of the LSC before and after cessations in single-layer turbulent RBC. This implies that the dynamics governing cessations and reversals in the two systems are very different. Two coupling modes, thermal coupling (the flow directions of the two LSCs are opposite to each other at the fluid–fluid interface) and viscous coupling (the flow directions of the two LSCs are the same at the fluid–fluid interface), are identified, with the former as the predominant mode. That most cessations (in the FC77 layer) end up as reversals can be understood as a symmetry breaking imposed by the orientation of the LSC in the water layer, which remains unchanged most of the time. Furthermore, the frequently occurring cessations and reversals are caused by the system switching between its two metastable states, i.e. thermal and viscous coupling modes. It is also observed that the strength of the LSC in water becomes weaker when the LSC in FC77 rotates faster azimuthally and that the flow strength in FC77 becomes stronger when the LSC in water rotates faster azimuthally, i.e. the influence of the LSC in one fluid layer on the other is not symmetric.
New points that belong to the nine-point circle
Authors: Fraivert David
Published: June 2019

In the present paper, we show that the point of intersection of the bimedians of a cyclic quadrilateral belongs to the nine-point circle (Euler’s circle) of the triangle with one vertex at the point of intersection of the quadrilateral’s diagonals and the other vertices at the points of intersection of the extensions of its pairs of opposite sides.
Pascal-points quadrilaterals inscribed in a cyclic quadrilateral
Authors: Fraivert David
Published: June 2019

This paper presents some new theorems about the Pascal points of a quadrilateral. We shall begin by explaining what these are.

Let ABCD be a convex quadrilateral, with AC and BD intersecting at E and DA and CB intersecting at F. Let ω be a circle through E and F which meets CB internally at M and DA internally at N. Let CA meet ω again at L and let DB meet ω again at K. By using Pascal’s theorem for the crossed hexagons EKNFML and EKMFNL and which are circumscribed by ω, the following results can be proved [1]:–

(a)

NK, ML and AB are concurrent (at a point P internal to AB)

(b)

NL, KM and CD are concurrent (at a point Q internal to CD)
The need for closure
Authors: Hollings Christopher D.
Published: June 2019

When defining a group, do we need to include closure? This is a detail that is often touched upon when the notion of a group is introduced to undergraduates. Should closure be listed as an axiom in its own right, or should it be regarded as an inherent property of the binary operation? There is no clear answer to this question, although there are firm opinions on both sides. Indeed, a very brief survey of group theory textbooks found in [1, pp. 458-459] suggests that there is a rough 50 : 50 split between authors who include closure explicitly and those who do not. In this Article, we go back to the beginning of the twentieth century to provide some historical perspective on this problem.
Linear differential equations with constant coefficients
Authors: Fralick Bethany , Koo Reginald
Published: June 2019

We consider the second order homogeneous linear differential equation
(H)$${ ay'' + by' + cy = 0 }$$
with real coefficients a, b, c, and a ≠ 0. The function y = emx is a solution if, and only if, m satisfies the auxiliary equation am2 + bm + c = 0. When the roots of this are the complex conjugates m = p ± iq, then y = e(p ± iq)x are complex solutions of (H). Nevertheless, real solutions are given by y = c1epx cos qx + c2epx sin qx.
On the Case for Magnetic Field Line Sweep-Back in Pulsars 0950+08 and 1133+16
Authors: Hankins T. H. , Izvekova V. A. , Malofeev V. M. , Rankin J. M. , Shitov Yu. P. , Stinebring D. R.
Published: June 2019

Coordinated profile observations between 25 MHz and 5 GHz have been carried out at the Arecibo and Pushchino observatories, and aligned according to dispersion measure (DM) values determined by cross-correlating microstructure features at adjacent frequencies. The average profiles of the nearly aligned rotator PSR 0950+08 align satisfactorily using the DM value of 2.9701 pc cm–3. For PSR 1133+16 excess delay at low frequencies is observed when alignment is made using the value of DM = 4.8413 pc cm–3 determined from microstructure cross-correlations
The Evolution of the Magnetic Fields of Neutron Stars
Authors: Bhattacharya Dipankar
Published: June 2019

The evolution of the magnetic field strength plays a major role in the life history of a neutron star. In this article the observational evidence of field evolution, in particular that of field decay and magnetic alignment, are critically examined. It is concluded that the observed decay of the spindown torque on radio pulsars cannot be caused by a secular evolution of the “obliqueness” of the neutron star, as suggested by some authors. Recent observations provide a strong indication that the decay of the magnetic field strength of a neutron star may be closely related to its evolution in a binary system. Theoretical models for such an evolution are discussed.
Statistical Search for Magnetic Field Decay
Authors: Michel F. Curtis
Published: June 2019

The claims made in many statistical analyses for magnetic field decay follow from the assumption that radio luminosity declines slower than spin-down luminosity which is suggested by least-squares fits to the data. However, such fits are very sensitive to the behaviors of the fastest and slowest pulsars. If pulsar luminosities are plotted in distance-selected groups, the (radio inefficient) Crab and Vela pulsars are clearly exceptional members and the remaining pulsars are consistent with a mean fixed conversion efficiency of 10–5. Numerical simulations (and theoretical analysis) strongly suggest that the pulsar period distribution peak is caused by luminosity selection and searches limited in distance by dispersion measure, and not by some mechanism that removes old pulsars. We cannot exclude magnetic field decay with some large time constant, ≥107 years say, but only because it would make such a small difference to the expected pulsar statistics, not because it is required by the data.
Self-Consistent Numerical Modelling of Pulsar Magnetospheres
Authors: Herold H. , Ertl T. , Finkbeiner B. , Ruder H.
Published: June 2019

The magnetosphere of a rapidly rotating, strongly magnetized neutron star with aligned magnetic and rotational axes (parallel rotator) is modelled numerically. Including the radiation of the particles accelerated to relativistic energies as an efficient damping mechanism, we obtain a quasi-stationary self-consistent solution to this classical problem. The numerical simulation,which was started from the well-known vacuum solution, yields a global magnetospheric structure that can be characterized by two regions of oppositely charged particles, which eventually produce a relativistic pulsar wind, separated by a vacuum gap of considerable extent.
Equilibrium of the Return-Current Sheet and Structure of the Pulsar Magnetosphere
Authors: Lyubarskii Yu. E.
Published: June 2019

Pulsars are generally identified with rotating, magnetized neutron stars. According to Goldreich and Julian (1969), an induced electric field creates the electric current which flows out of the magnetic poles and fills the magnetosphere with plasma. The current flows along the open magnetic field lines and returns along the boundary between the closed and open parts of the magnetosphere (Scharlemann and Wagoner 1973). The boundary shape is determined by the equilibrium condition for the current sheet.
Radius-to-Frequency Mapping in the Radio Pulsar Emission Mechanism
Authors: Thorsett S. E.
Published: June 2019

A general feature of many models of the pulsar emission mechanism is that radiation of different frequencies is produced at different altitudes above the polar cap. The broadening of pulse components and increasing separation between components at low frequency is in general agreement with these theories. We review the available average profile and pulsar timing observations and discuss the implications for theories of radius-to-frequency mapping.
Observations of PSR 0823+26 And PSR 0943+10 in the Decameter Band
Authors: Bruck Yu. M. , Ulyanov O. M.
Published: June 2019

From December 1987 to February 1988 using the UTR-2 radiotelescope, we recorded the emissions of PSR 0823+26 and PSR 0943+10 at 25 and 16.7 MHz. Both pulsars are of considerable interest; PSR 0943+10 is one of several pulsars having two emission modes (Suleymanova and Izvekova 1984), and PSR 0823+26 has interpulse emission (Backer, Boriakoff, and Manchester 1973, Downs 1979) and dispersion measure, 19.466 pc cm–3. It is known that using the Arecibo telescope at 25 MHz one could succeed in recording only PSR 0919+06 with DM = 27.25 pc cm–3 (Phillips and Wolszczan 1989, 1990). In these papers, the presence of the two modes of PSR 0943+10 emission was confirmed.
Investigation of the Longitudinal Structure of the Interpulse Emission of PSR 1133+16 At 25 MHz Range
Authors: Bruck Yu. M.
Published: June 2019

Observations of PSR 1133+16 at frequencies of 20 and 25 MHz were conducted for the first time nearly 20 years ago (Bruck and Ustimenko 1973), and during the course of this work, its interpulse emission (IPE) was discovered. Systematic investigations of this pulsar at frequencies of 17, 20 and 25 MHz have been conducted using the UTR-2 radio telescope over the interval between 1972 and 1988, and occasional additional studies at 30 and 40 MHz were carried out since 1981 using DKR-1000 radio telescope. The form of the main pulse was studied and IPE searched for and investigated. The sporadic IPE components were identified on the basis of their intensity, their dispersion measure, and their time and frequency repeatability, and in some cases were confirmed by observations at different observatories.
Very High Energy γ-Ray Generation Near The Light Cylinder of an Axisymmetric Rotator: Cos-B Like γ-Ray Sources
Authors: Bogovalov S. V. , Kotov YU. D.
Published: June 2019

Super-hard γ-ray radiation spectra have been calculated. This radiation is generated near the velocity-of-light cylinder through the process of inverse-Compton scattering of relativistic electrons by thermal photons radiated by a neutron star. These calculations have been compared with observations of the Crab and Vela pulsars at 1000-GeV γ-ray energies. A correlation between γ-ray flares and those in soft (Ex ≃ lkeV) X-rays are predicted.
The Locations of the Core and Conal Emission Regions in an Inverse-Compton Scattering Model
Authors: Qiao G. J. , Li C. G. , Li M.
Published: June 2019

The physical conditions and locations of the emission regions for core and hollow cone emissions are very important in understanding the mechanism of radio pulsars. We present two related methods in an Inverse-Compton Scattering (ICS) model in this paper, which give a clear scenario for determining the location of the emission regions and are consistent with the results given by Cordes et al. (1984) and Rankin (1990).
Is the pulsar emission produced by superluminally moving charged patterns?
Authors: Ardavan Housang
Published: June 2019

There are no physical principles disallowing the existence of extended sources of the electromagnetic field which move faster than light in empty space (Bolotovskii and Ginzburg 1972). Charge-current distributions whose patterns rotate around a fixed axis rigidly, and so have a phase speed that is greater than the speed of light in vacuo outside the light cylinder, emit radiation—different from both Cherenkov and synchrotron radiation—which has the following characteristics:

1.

It arises almost exclusively from the vicinity of those points within the source which, at the emission time, approach the observer with the speed of light and with zero acceleration.

2.

It consists of the superposition of a (continuous) set of narrow radiation beams whose flux densities fall off with the radial distance R from the source like R–1 (rather than R–2), and so it is intrinsically coherent.

3.

It has a power-law spectrum with no exponential cut-off, at high harmonics of the rotation frequency, whose index lies between –1 and –3 if the longitudinal distribution of the source density is pulse-like.

4.

It consists of two concurrent elliptically polarized signals whose position angles are predominantly orthogonal and simultaneously vary in direction in the course of each rotation.

I suggest that this radiation, here referred to as Schott radiation (cf. Schott 1912), may in fact be that received from pulsars.
Observational Evidence for Persistent Microstructure Periodicities
Authors: Friedman Jeffrey Foster , Boriakoff Valentín
Published: June 2019

By using Cross Spectral Density processing between high time resolution radio intensity observations of pulsars made simultaneously at two different receiver frequencies, several high frequency periodicities that are persistent over many pulses were discovered. A possible interpretation in terms of neutron star vibration models is discussed.
A Mechanism for Circular Polarization in Pulsar Radiation
Authors: Kazbegi A. Z. , Machabeli G. Z. , Melikidze G. I.
Published: June 2019

Observational data show that many pulsars exhibit a moderate amount of circular polarization (CP) as well as linearly polarized emission. Generally, the degree of CP is of the order of several percent, but some of pulsars have higher CP—about 20% (Manchester and Taylor 1977, Taylor and Stinebring 1986) and PSR 1702-19 has 60% (Biggs et al. 1988). No satisfactory explanation for the existence of this CP is now known, and we propose in this paper to outline a possible mechanism for the generation of this CP consistent with our theory of pulsar radio-wave excitation. In Kazbegi et al. (1992; hereafter Paper I) we mentioned that the distribution functions of electrons F− and positrons F+ are shifted with respect to each other due to the presence of the primary electron beam and the quasi-neutrality of the plasma as a whole.
Modeling of Pulsar Polarization Properties
Authors: Shier L. M. , Michel F. C.
Published: June 2019

In the popularly accepted empirical model for pulsar emission, bunches of charged particles traveling along open field lines near the magnetic pole emit curvature radiation. Such radiation is linearly polarized. Most of the radiation is assumed to be emitted from a ring shaped region centered on the pole (the hollow cone model). We have calculated the expected average polarization using this model and find them to be in disagreement with observations. The addition of a second ring inside the first with orthogonal polarization solves this problem. This new model explains other observed features of pulsar emission including discontinuities in position-angle profiles and multicomponent profiles. Plasma interactions might account for a second ring.