bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating intergalactic gas for DESI-like small scale Lymanα forest observations
Authors: Walther Michael , Armengaud Eric , Ravoux Corentin , Palanque-Delabrouille Nathalie , Yèche Christophe , Lukić Zarija
Published: April 2021

Measurements of the Lyα forest based on large numbers of quasar spectra from sky surveys such as SDSS/eBOSS accurately probe the distribution of matter on small scales and thus provide important constraints on several ingredients of the cosmological model. A main summary statistic derived from those measurements is the one-dimensional power spectrum, P1D, of the Lyα absorption. However, model predictions for P1D rely on expensive hydrodynamical simulations of the intergalactic medium, which was the limiting factor in previous analyses. Datasets from upcoming surveys such as DESI will push observational accuracy near the 1%-level and probe even smaller scales. This observational push mandates even more accurate simulations as well as more careful exploration of parameter space. In this work we evaluate the robustness and accuracy of simulations and the statistical framework used to constrain cosmological parameters. We present a comparison between the grid-based simulation code Nyx and SPH-based code Gadget in the context of P1D. In addition, we perform resolution and box-size convergence tests using Nyx code.
We use a Gaussian process emulation scheme to reduce the number of simulations required for exploration of parameter space without sacrificing the model accuracy. We demonstrate the ability to produce unbiased parameter constraints in an end-to-end inference test using mock eBOSS- and DESI-like data, and we advocate for the usage of adaptive sampling schemes as opposed to using a fixed Latin hypercube design.
Numerical analysis of the pump’s spectral linewidth impact on single and multi-wavelength Brillouin fiber lasers
Authors: Silva Luís C B , Castellani Carlos E S
Published: April 2021

Brillouin fiber lasers (BFLs) are a promising optical source technology for industrial and academic purposes that have experienced continuous progress in recent years. Currently, part of this development is focused on delivering laser solutions with low resonator loss, relatively low pump threshold, high efficiency, very small linewidth, and multi-wavelength architecture. In this perspective, this study employs an accurate numerical model based on an analytical solution to investigate the effect of the pump’s spectral linewidth on BFLs working both in single and cascaded multi-wavelength configurations. Output powers, thresholds, and the Stokes lines number simulated are analyzed here using a standard single-mode optical fiber as the Brillouin gain medium. The numerical results obtained not only allow identifying the regions of the pump’s spectral linewidth in which there is greater, moderate, or even no suppression of the stimulated Brillouin scattering inside the laser cavity but also provides a deep understanding of the internal dynamics of the BFLs cavities.
Bounds on edge shear layer persistence while approaching the density limit
Authors: Singh Rameswar , Diamond P.H.
Published: April 2021

This paper details the theory of edge shear layer collapse as the density approaches the Greenwald density limit. It significantly extends earlier work, which was restricted in applicability. The zonal shear flow screening length is calculated for banana, plateau and Pfirsch–Schluter regimes. Poloidal field scaling persists in the plateau regime. Neoclassical screening and drift wave–zonal flow dynamics are combined in a theory, which is then reduced to a predator–prey model. Zonal noise, due to incoherent mode coupling, is retained. The threshold condition for edge shear layer collapse is computed, and linked to a critical value of the dimensionless parameter

ρ

s

/

ρ

s
c

L

n

. Here

ρ
s

is the ion sound radius,

ρ

s
c

is the zonal flow screening length and

L
n

is the equilibrium density scale length. The limiting initial edge density for shear layer collapse is derived and shown to scale favorably with the plasma current. The results are discussed in light of the density limit and Ohmic phenomenology.
Innovative recycling or extended use? Comparing the global warming potential of different ownership and end-of-life scenarios for textiles
Authors: Levänen Jarkko , Uusitalo Ville , Härri Anna , Kareinen Elisa , Linnanen Lassi
Published: April 2021

The implementation of circular economy (CE) thinking to reduce environmental impacts and resource use has led to the development of innovative recycling technologies and business models. The implications of these technologies and models, however, remain largely unclear. In many CE strategies, there is a high risk of rebound, meaning a situation in which activities aimed at environmental benefits are not realized because of external reasons. A similar risk relates to limited understanding about the behavioral changes required by extensive implementation of circular practices. Using life cycle assessment, we compare the global warming potential (GWP) of five ownership and end-of-life scenarios for creating and using a pair of jeans. The scenarios are as follows: (a) BASE, i.e. basic use with waste disposal; (b) REDUCE, i.e. extended use; (c) REUSE, i.e. re-selling; (d) RECYCLE, i.e. industrial processing into new raw materials; and (e) SHARE, i.e. a rental service. Our results show that the lowest global warming impacts are achieved in the REDUCE scenario, and the second lowest are achieved in the REUSE scenario. The RECYCLE scenario leads to relatively high overall emissions because the replaced emissions from cotton production are relatively low. The use of rental services is likely to increase customers’ mobility, and if that happens in a large scale, then the SHARE scenario has the highest GWP. It was found that many new CE innovations come with a high rebound risk, and existing practices carry similar, yet smaller risks.
Particle on the sphere: group-theoretic quantization in the presence of a magnetic monopole
Authors: Andrade e Silva Rodrigo , Jacobson Ted
Published: April 2021

The problem of quantizing a particle on a two-sphere has been treated by numerous approaches, including Isham’s global method based on unitary representations of a symplectic symmetry group that acts transitively on the phase space. Here we reconsider this simple model using Isham’s scheme, enriched by a magnetic flux through the sphere via a modification of the symplectic form. To maintain complete generality we construct the Hilbert space directly from the symmetry algebra, which is manifestly gauge-invariant, using ladder operators. In this way, we recover algebraically the complete classification of quantizations, and the corresponding energy spectra for the particle. The famous Dirac quantization condition for the monopole charge follows from the requirement that the classical and quantum Casimir invariants match. In an appendix we explain the relation between this approach and the more common one that assumes from the outset a Hilbert space of wave functions that are sections of a nontrivial line bundle over the sphere, and show how the Casimir invariants of the algebra determine the bundle topology.
Spark plasma sintering of W-10Ti alloys: microstructure, properties and grain growth kinetics
Authors: Xu Wenfei , Huang Lei , Peng Tianshuai , Pan Yafei , Zhang Jiuxing , Zhang Shuyan
Published: April 2021

The microstructure, properties and grain growth kinetics of W-10 wt.% Ti alloys prepared by spark plasma sintering (SPS) method at the temperatures from 1400 to 1700 °C, with the dwelling time from 0 to 30 min and a constant axial pressure of 30 MPa were investigated. The sintered W-10Ti alloys only contained a dominant β-W(Ti) phase and a fractional β-Ti(W) phase. The content of Ti-rich phase declined with the rise of sintering temperatures. In addition, the higher the sintering temperature, the higher the alloy density. When the sintering temperature was constant, the alloy density first increased and then decreased with the increasing dwelling time, and reached the maximum at 15 min. With the increase of the sintering temperature and dwelling time, the thermal conductivity first decreased, then flattened or slightly increased. At low temperatures (1400 °C–1500 °C), the grain growth was not obvious, but at high temperatures (1600 °C–1700 °C), the grain grew rapidly. The grain growth exponent of W-10Ti alloys was found to be n = 2, suggesting grain boundary diffusion controlled grain growth in the alloys. Activation energy for grain growth was calculated as 49.21–61.46 kJ mol−1.
Polarization dependent structural colors from tilted metalo-dielectric nanopillars
Authors: Vennberg Felix , Ravishankar Ajith P , Anand Srinivasan
Published: April 2021

The structural color from self-assembled metalo-dielectric (In/InP) nanopillars is shown to be polarization sensitive when the axial symmetry is broken. The characteristic dip in the reflection spectra due to resonant absorption is shifted by 90 nm as the polarization of incident light is altered from TE to TM at an incidence angle of 40°. We also show wafer-scale, mask-less fabrication of pillars that are tilted with respect to the substrate, a fast and cost effective method of creating the asymmetrical structures required for polarization sensitivity at normal incidence. A dip shift of 100 nm is observed for 40° tilted nanopillars of average height 380 nm, resulting in a smooth range of colors with changing polarization. FDTD simulations confirm the polarization dependent dip-shift in the resonant absorption wavelength. Furthermore, the field and intensity profiles obtained from the simulations indicate that the resonant absorption dips are due to HE1m-like modal excitations and their shift with respect to the incident angle and polarization leads to the change in perceived color from the tilted nanopillar system.
High-performance FeaTibOx catalyst loaded on ceramic filter for NOx reduction
Authors: Wu Ruian , Jin Jiang , Li Kun , Zhao Lei , Zhang Hua
Published: April 2021

The FeaTibOx catalyst was loaded into the pores of porous ceramic using impregnation method for removing nitrogen oxides with selective catalytic reduction (SCR) technology. The catalytic performance over FeaTibOx catalyst was studied in detail. The Fe6Ti1Ox catalyst displayed more than 95% NOx conversion within the range of 280 °C–400 °C, and still maintained 97% NOx conversion when 300 ppm SO2 and 10 vol.% water vapor were introduced at the testing temperature of 300 °C. The influence factors (including filtration velocity, NH3/NO mole ratio and oxygen concentration) for NOx conversion over Fe6Ti1Ox catalyst were also studied. The suitable NH3/NO mole ratio and oxygen concentration was 0.9 and 6%, respectively. The XRD, N2-BET, H2-TPR, NH3-TPD and XPS were employed to investigate physicochemical property of the FeaTibOx catalyst. The results illustrated that Fe6Ti1Ox catalyst has hematite Fe2O3 and TiO2 structure, better redox properties and stronger surface acid.
A detailed electrochemical analysis of sensitized AISI 410 martensitic stainless steel
Authors: Morshed-Behbahani Khashayar , Najafisayar Pooria , Zakerin Nika , Pakshir Mahmoud
Published: April 2021

In the present work, the effect of sensitization heat treatment on the intergranular corrosion (IGC) behavior of AISI 410 martensitic stainless steel was investigated using potentiodynamic electrochemical impedance spectroscopy (PDEIS) in conjunction with conventional methods including acid etching test, anodic potentiodynamic polarization, double-loop electrochemical potentiodynamic reactivation (DLEPR) and electrochemical noise (EN). Microstructural studies by scanning electron microscopy revealed that increasing tempering time up to 2h would be followed by more severe localized attack, but desensitization state attributed to specimens undergone prolonged tempering cannot be interpreted based on the standard test method. Susceptibility to IGC via DLEPR experiments indicates differences in the degree of sensitization (DOS) of specimens with varying tempering time, revealing a healing effect arising from prolonged tempering. The EN results elucidated the alloy tendency for active dissolution, but no obvious correlation can be established between the EN results and IGC behavior. The PDEIS data clarified that the charge transfer resistance values related to the AC responses in the middle of transpassive potential region can be utilized to investigate and compare the IGC susceptibility of the alloy. Moreover, the surface morphology of corroded samples under such experimental conditions can be used to qualitatively compare the severity of intergranular attack.
Ag2S/CdS/Ni ternary nanostructures: long-range electric field to enhanced photocatalytic hydrogen production activity
Authors: Yan Fengpo , Yang Fugui , Zhang Hao , Luo Peihui
Published: April 2021

Silver sulfide, cadmium sulfide and nickel (Ag2S/CdS/Ni) ternary nanostructures were fabricated by a two step process and characterized by x-ray powder diffraction, transmission electron microscopy, and UV–vis diffuse reflection spectroscopy. The photocatalytic hydrogen production activity of ternary nanostructures and reference samples were evaluated using triethanolamine (TEOA) as sacrificial reagent in water under visible-light illumination (λ ≥ 420 nm). The result shows Ag2S/CdS/Ni nanostructures exhibited a high visible light photocatalytic H2 evolution rate of 1.54 mmolh−1 g−1, which was 4.6 times and 1.4 times higher than that of 1.2% mol Ag2S/CdS and Ni/CdS. The degree of photocorrosion of CdS were employed to study the photogenerated carriers transfer route by measuring and comparing the concentration of Cd2+ in the solution of the photocorrosion experiments in a nonsacrificial system. A long-range electric field, which is similar to the p-i-n electric field structure, was proposed to be constructed by Ni nanoparticles and Ag2S nanoparticles in CdS. Most of the photogenerated electrons and holes in CdS drift to the electron donor and electron acceptor respectively under the action of long-range electric field, which greatly improves the separation efficiency of photogenerated carriers and the photocatalytic H2 production activity.
Room-temperature tunnel magnetoresistance across biomolecular tunnel junctions based on ferritin
Authors: Karuppannan Senthil Kumar , Pasula Rupali Reddy , Herng Tun Seng , Ding Jun , Chi Xiao , Barco Enrique Del , Roche Stephan , Yu Xiaojiang , Yakovlev Nikolai , Lim Sierin , Nijhuis Christian A
Published: April 2021

We report exceptionally large tunnel magnetoresistance (TMR) for biomolecular tunnel junctions based on ferritins immobilized between Ni and EGaIn electrodes. Ferritin stores iron in the form of ferrihydrite nanoparticles (NPs) and fulfills the following roles: (a) it dictates the tunnel barrier, (b) it magnetically decouples the NPs from the ferromagnetic (FM) electrode, (c) it stabilizes the NPs, and (d) it acts as a spin filter reducing the complexity of the tunnel junctions since only one FM electrode is required. The mechanism of charge transport is long-range tunneling which results in TMR of 60 ± 10% at 200 K and 25 ± 5% at room temperature. We propose a magnon-assisted transmission to explain the substantially larger TMR switching fields (up to 1 Tesla) than the characteristic coercive fields (a few Gauss) of ferritin ferrihydrite particles at T < 20 K. These results highlight the genuine potential of biomolecular tunnel junctions in designing functional nanoscale spintronic devices.
Define and measure the dimensional accuracy of two-photon laser lithography based on its instrument transfer function
Authors: Dai Gaoliang , Hu Xiukun , Hering Julian , Eifler Matthias , Seewig Jörg , von Freymann Georg
Published: April 2021

Two-photon polymerization (TPP) is a powerful technique for direct three-dimensional (3D) micro- and nanomanufacturing owing to its unique ability of writing almost arbitrary structures of various materials. In this paper, a novel method is proposed to quantitatively define and measure the dimensional accuracy of TPP tools based on the concept of instrument transfer function (ITF). A circular linear-chirp pattern is designed for characterizing the ITF. Such a pattern is arranged in a linear chirp function with respect to its radial distance

r

from the pattern centre, thus, well representing a signal with a quasi-flat amplitude over a given spectral bandwidth. In addition, the pattern is rotational symmetric, therefore, it is well suited for characterizing the ITF in different angular directions to detect angular-dependent asymmetries. The feasibility of the proposed method is demonstrated on a commercial TPP tool. The manufactured pattern is calibrated by a metrological large range atomic force microscope (AFM) using a super sharp AFM tip, thus the dimensional accuracy and angular-dependent anisotropy of the TPP tool have been well characterized quantitatively. The proposed method is easy to use and reveals the dimensional accuracy of TPP tools under real manufacturing conditions, which concerns not only the optical focus spot size of the exposing laser but also influencing factors such as material shrinkage, light–matter interaction and process parameters.
A novel membrane emulsification technique for microencapsulation in self-healing concrete: development and proof of concept
Authors: Litina Chrysoula , Palmer David , Al-Tabbaa Abir
Published: April 2021

Membrane emulsification is a promising new technique that can be deployed as a scalable modular conduit for the consistent and continuous production of single and complex emulsions. This work reports on the development of a manufacturing platform based on membrane emulsification for the first time for microcapsule-based self-healing cementitious materials. The feasibility of single and double emulsion production with wall formation as a secondary step through UV radical polymerisation was explored using a discrete membrane emulsification dispersion cell. The operational parameters (pressure, dispersed phase flux, temperature, shear rate) were established for the specific phase characteristics (viscosity, density, interfacial tension) to achieve control of emulsion droplets and maintain a high encapsulation of core content (high payload). Microcapsules with sodium silicate core and an average diameter of ∼130 μm were produced. Microcapsules were shown to achieve high payload (∼89%). Moreover their thermal stability was characterised and their release performance in the cementitious matrix established. The results demonstrated the capability of membrane emulsification to produce microcapsules with an aqueous core for use in self-healing of cementitious materials.
Warriors in an age of peace
Authors: Wert Michael
Published: April 2021

This chapter covers the Tokugawa period, a time of relative peace, when historians know more about the rank-and-file samurai. It begins by describing how Tokugawa Ieyasu and his descendants created the strongest and longest lasting warrior regime, the Tokugawa Shogunate. After describing the political authority at the top, the chapter details the life of daimyo lords, their interaction with samurai, and the curtailing of daimyo interaction with Western countries. Then the chapter covers the average samurai life cycle from childhood, education, and marriage, to concerns about job and free time, and retirement.
Temporal Trends in Hypertension Death Rate in Mississippi, 2000–2018
Authors: Mendy Vincent L , Rowell-Cunsolo Tawandra , Bellerose Meghan , Vargas Rodolfo , Zhang Lei , Enkhmaa Byambaa
Published: April 2021

BACKGROUND

In Mississippi, hypertension as a leading cause of death moved from 15th in 2000 to 11th in 2018, but research on temporal trends is limited. We examined temporal trends in hypertension-related mortality among Mississippi adults by age, sex, and race.

METHODS

We extracted data on the number of deaths due to hypertension among adults aged 45 or older annually from 2000 to 2018 from Mississippi Vital Statistics. We used underlying cause-of-death codes from the International Classification of Diseases, Tenth Revision to identify hypertension deaths. We calculated the annual percentage change (trend segment) and average annual percentage change (AAPC) in age-adjusted hypertension death rates from 2000 to 2018 and examined differences in the AAPC by age, sex, and race.

RESULTS

From 2000 through 2018, the age-adjusted hypertension death rate increased annually by 3.0% (AAPC 3.0%, 95% confidence interval, 1.9%–4.0%) with 3 distinct time periods. There was an average annual increase in age-adjusted hypertension death rates for all subgroups, i.e., men, women, Blacks, Whites, White females, Black males, and White males. The highest magnitude of increase was among those aged 45–64 years (AAPC 6.0%), men (AAPC 4.5%), Whites (AAPC 3.5%), and White men (AAPC 6.2%) compared with other age groups, women, Blacks, and Black men, respectively.

CONCLUSIONS

For nearly 2 decades, there was an increase in age-adjusted hypertension death rates among Mississippi adults aged 45 years or older. Blood pressure lowering interventions that target hypertensive adults are needed.
The Relationship Between Brain Metabolites Alterations and Neuropsychological Deficits in Patients with Methamphetamine Use Disorder: A Proton Magnetic Resonance Spectroscopy Study
Authors: Bakhshinezhad Hamideh , Darharaj Mohammad , Feyzi Yasha Fayaz , Babaei Shirzad , Ahadi Reza , Jamei Behnammaddin , Pourhamzeh Mahsa , Daneshi Abdolhadi , Arezoomandan Reza
Published: April 2021

Introduction

Chronic use of methamphetamine induces neuropsychological deficits and neurochemical changes in frontostriatal regions. This study aimed to examine the relationship between brain metabolites alterations in frontostriatal regions and neuropsychological deficits in patients with methamphetamine use disorder.

Method

A total of 30 methamphetamine users and 20 control participants were selected and a battery of standardized executive function, attention, and memory tasks, including the Wisconsin Card Sorting Test, Stroop Test, and Wechsler Memory Scale, was administered to them. Proton-Magnetic resonance spectroscopy (H-MRS) of N-Acetylaspartate/Creatine (NAA/Cr), Choline/Creatine (Cho/Cr), and glutamate + glutamine/creatine (Glx/Cr) in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and basal ganglia (BG) were also undertaken.

Results

Current findings indicated that there were significant differences between two groups in metabolite ratios including NAA/Cr, Cho/Cr, and Glx/Cr in three areas, except for Glx/Cr in BG. Moreover, compared to healthy controls, methamphetamine users showed poorer performance in all neuropsychological tests. Finally, a significant relationship was found between regional metabolites alterations, particularly in the ACC, and neuropsychological deficits in methamphetamine users.

Conclusions

In addition to neurochemical changes and neuropsychological deficits in patients with methamphetamine use disorder, current results highlighted the relationship between these changes in DLPFC, ACC, and BG with cognitive deficits in methamphetamine users.
COBRAC: a fast implementation of convex biclustering with compression
Authors: Yi Haidong , Huang Le , Mishne Gal , Chi Eric C
Published: April 2021

Biclustering is a generalization of clustering used to identify simultaneous grouping patterns in observations (rows) and features (columns) of a data matrix. Recently, the biclustering task has been formulated as a convex optimization problem. While this convex recasting of the problem has attractive properties, existing algorithms do not scale well. To address this problem and make convex biclustering a practical tool for analyzing larger data, we propose an implementation of fast convex biclustering called COBRAC to reduce the computing time by iteratively compressing problem size along with the solution path. We apply COBRAC to several gene expression datasets to demonstrate its effectiveness and efficiency. Besides the standalone version for COBRAC, we also developed a related online web server for online calculation and visualization of the downloadable interactive results.

Availability and implementation

The source code and test data are available at https://github.com/haidyi/cvxbiclustr or https://zenodo.org/record/4620218. The web server is available at https://cvxbiclustr.ericchi.com.

Supplementary information

Supplementary data are available at Bioinformatics online.
Biodiesel from fish waste oil: synthesis via supercritical methanol and thermodynamic optimization
Authors: Espootin Simin , Sameti Mohammad , Zaker Sahar
Published: April 2021

This study evaluates the potential of local fish waste oil as a feedstock for biodiesel via supercritical methanol transesterification (SCMT). Hexane was used as a cosolvent and the transesterification reaction was carried out in a continuous reactor under supercritical conditions. The response surface methodology (RSM) method was applied to analyse the effect of four independent variables, including the weight ratio of methanol to fish-waste oil (W), the reaction temperature (T), the pressure (P) and the feed flow rate (F), on the yield of the biodiesel production in supercritical methanol. According to the calculated optimal operating condition for the RSM, the values of W (22.3 weight ratio of methanol to fish waste oil), T (270°C), P (112.7 bar) and F (2.0 mL min–1) were achieved. Under the optimum conditions, the highest yield was estimated to be 94.6% (g/g). The obtained yield was found to be close to the theoretical yield (95.2%). This value suggests that the proposed strategy has a promising potential in the production of biodiesel fuel.
Aberrant Cerebello-Cortical Connectivity in Pianists With Focal Task-Specific Dystonia
Authors: Kita Kahori , Furuya Shinichi , Osu Rieko , Sakamoto Takashi , Hanakawa Takashi
Published: April 2021

Musician’s dystonia is a type of focal task-specific dystonia (FTSD) characterized by abnormal muscle hypercontraction and loss of fine motor control specifically during instrument playing. Although the neuropathophysiology of musician’s dystonia remains unclear, it has been suggested that maladaptive functional abnormalities in subcortical and cortical regions may be involved. Here, we hypothesized that aberrant effective connectivity between the cerebellum (subcortical) and motor/somatosensory cortex may underlie the neuropathophysiology of musician’s dystonia. Using functional magnetic resonance imaging, we measured the brain activity of 30 pianists with or without FTSD as they played a magnetic resonance imaging-compatible piano-like keyboard, which elicited dystonic symptoms in many but not all pianists with FTSD. Pianists with FTSD showed greater activation of the right cerebellum during the task than healthy pianists. Furthermore, patients who reported dystonic symptoms during the task demonstrated greater cerebellar activation than those who did not, establishing a link between cerebellar activity and overt dystonic symptoms. Using multivoxel pattern analysis, moreover, we found that dystonic and healthy pianists differed in the task-related effective connectivity between the right cerebellum and left premotor/somatosensory cortex. The present study indicates that abnormal cerebellar activity and cerebello-cortical connectivity may underlie the pathophysiology of FTSD in musicians.
Contributions of the Monkey Inferior Temporal Areas TE and TEO to Visual Categorization
Authors: Setogawa Tsuyoshi , Eldridge Mark A G , Fomani Grace P , Saunders Richard C , Richmond Barry J
Published: April 2021

The ability to categorize images is thought to depend on neural processing within the ventral visual stream. Recently, we reported that after removal of architectonic area TE, the terminal region of the ventral stream, monkeys were still able to categorize images as cats or dogs moderately well. Here, we investigate the contribution of TEO, the architectonically defined region located one step earlier than area TE in the ventral stream. Bilateral removal of TEO caused only a mild impairment in categorization. However, combined TE + TEO removal was followed by a severe, long-lasting impairment in categorization. All of the monkeys tested, including those with combined TE + TEO removals, had normal low-level visual functions, such as visual acuity. These results support the conclusion that categorization based on visual similarity is processed in parallel in TE and TEO.
Supporting Drug Development for Neglected Tropical Diseases Using Mathematical Modeling
Authors: Walker Martin , Hamley Jonathan I D , Milton Philip , Monnot Frédéric , Kinrade Sally , Specht Sabine , Pedrique Bélen , Basáñez Maria-Gloria
Published: April 2021

Drug-based interventions are at the heart of global efforts to reach elimination as a public health problem (trachoma, soil-transmitted helminthiases, schistosomiasis, lymphatic filariasis) or elimination of transmission (onchocerciasis) for 5 of the most prevalent neglected tropical diseases tackled via the World Health Organization preventive chemotherapy strategy. While for some of these diseases there is optimism that currently available drugs will be sufficient to achieve the proposed elimination goals, for others—particularly onchocerciasis—there is a growing consensus that novel therapeutic options will be needed. Since in this area no high return of investment is possible, minimizing wasted money and resources is essential. Here, we use illustrative results to show how mathematical modeling can guide the drug development pathway, yielding resource-saving and efficiency payoffs, from the refinement of target product profiles and intended context of use to the design of clinical trials.
Progress in aorta and peripheral cardiovascular disease research
Authors: Mazzolai Lucia , Alatri Adriano , Rivière Alessandra Bura , De Carlo Marco , Heiss Christian , Espinola-Klein Christine , Schlager Oliver , Sillesen Henrik , Staub Daniel , Rodriguez-Palomares José F , Verstraeten Aline , Aboyans Victor ,   the WG on aorta and peripheral vascular diseases
Published: April 2021

Although coronavirus disease 2019 seems to be the leading topic in research number of outstanding studies have been published in the field of aorta and peripheral vascular diseases likely affecting our clinical practice in the near future. This review article highlights key research on vascular diseases published in 2020. Some studies have shed light in the pathophysiology of aortic aneurysm and dissection suggesting a potential role for kinase inhibitors as new therapeutic options. A first proteogenomic study on fibromuscular dysplasia (FMD) revealed a promising novel disease gene and provided proof-of-concept for a protein/lipid-based FMD blood test. The role of NADPH oxidases in vascular physiology, and particularly endothelial cell differentiation, is highlighted with potential for cell therapy development. Imaging of vulnerable plaque has been an intense field of research. Features of plaque vulnerability on magnetic resonance imaging as an under-recognized cause of stroke are discussed. Major clinical trials on lower extremity peripheral artery disease have shown added benefit of dual antithrombotic (aspirin plus rivaroxaban) treatment.
A proposal for uniformity in classification of lymph node stations in esophageal cancer
Authors: Schuring N , Matsuda S , Hagens E R C , Sano J , Mayanagi S , Kawakubo H , van Berge Henegouwen M I , Kitagawa Y , Gisbertz S S
Published: April 2021

The 11th edition of the “Japanese Classification of Esophageal Cancer” by the Japan Esophageal Society (JES) and the 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) “Cancer Staging Manual” are two separate classification systems both widely used for the clinical and pathological staging of esophageal cancer. Furthermore, the lymph node stations from these classification systems are combined for research purposes in the multinational TIGER study, which investigates the distribution pattern of lymph node metastases. The existing classification systems greatly differ with regard to number, location and anatomical boundaries of locoregional lymph node stations. The differences in these classifications cause significant heterogeneity in studies on lymph node metastases in esophageal cancer. This makes data interpretation difficult and comparison of studies challenging. In this article, we propose a match for these two commonly used classification systems and additionally for the TIGER study classification, in order to be able to compare results of studies and exchange knowledge and to make steps towards one global uniform classification system for all patients with esophageal cancer.
A case report of cardiogenic shock from takotsubo cardiomyopathy with left ventricular outflow tract obstruction: fundamental lessons in cardiac pathophysiology
Authors: Bui Quan M , Ang Lawrence , Phreaner Nicholas
Published: April 2021

Background

A subset of patients with takotsubo cardiomyopathy will develop significant dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. However, traditional therapies for cardiogenic shock that focus on increased inotropy and afterload reduction can be detrimental in this situation.

Case summary

We describe a 71-year-old woman who presented to the emergency department with typical, substernal chest pain found to be hypotensive with ST-elevations in the lateral leads. Coronary angiography showed no significant coronary artery disease, but a left ventriculogram demonstrated takotsubo cardiomyopathy. Right heart catheterization revealed cardiogenic shock and elevated filling pressures. Haemodynamics and symptoms worsened with the initiation of dopamine and placement of intra-aortic balloon pump but improved with the initiation of phenylephrine. Follow-up echocardiogram demonstrated dynamic LVOT obstruction with concomitant severe mitral regurgitation (MR). The patient recovered in the intensive care unit for 5 days after successful weaning of phenylephrine and initiation of low-dose beta-blocker. Repeat echocardiogram 3 weeks later showed complete resolution of apical akinesis, LVOT obstruction, and MR.

Discussion

Elucidating whether dynamic LVOT obstruction is contributing to cardiogenic shock physiology is paramount since the management radically differs depending on the presence or absence of obstruction. Corrective therapy focuses on reducing the LVOT gradient and includes fluid administration to improve preload, beta-blocker therapy to increase diastolic filling time, and vasopressors to raise afterload.
Nation-Building and Education
Authors: Alesina Alberto , Giuliano Paola , Reich Bryony
Published: April 2021

Democracies and dictatorships have different incentives when it comes to choosing how much and by what means to homogenise the population, i.e., ‘to build a nation’. We study and compare nation-building policies under the transition from dictatorship to democracy in a model where the type of government and borders of the country are endogenous. We find that the threat of democratisation provides the strongest incentive to homogenise. We focus upon a specific nation-building policy: mass primary education. We offer historical discussions of nation-building across time and space, and provide correlations for a large sample of countries over the 1925–2014 period.
Emergency department management of patients with adult congenital heart disease: a consensus paper from the ESC Working Group on Adult Congenital Heart Disease, the European Society for Emergency Medicine (EUSEM), the European Association for Cardio-Thoracic Surgery (EACTS), and the Association for Acute Cardiovascular Care (ACVC)
Authors: Chessa Massimo , Brida Margarita , Gatzoulis Michael A , Diller Gerhard-Paul , Roos-Hesselink Jolien W , Dimopoulos Konstantinos , Behringer Wilhelm , Möckel Martin , Giamberti Alessandro , Galletti Lorenzo , Price Susana , Baumgartner Helmut , Gallego Pastora , Tutarel Oktay
Published: April 2021

Adult congenital heart disease (ACHD) patients represent a growing population with increasing use of acute emergency department (ED) care. Providing comprehensive ED care necessitates an understanding of the most common clinical scenarios to improve morbidity and mortality in this population. The aim of this position document is to provide a consensus regarding the management of the most common clinical scenarios of ACHD patients presenting to the ED.
Gender equity in medical publications: nurses have smashed the glass ceiling
Authors: Feral-Pierssens Anne-Laure , Avondo Aurélie , Stefano Carla De , Deltour Sandrine , Lapostolle Frédéric
Published: April 2021

Introduction 

Gender equity has become a major concern in many professional fields. The rate of women as authors has to be interpreted according to the rate of women in the related professions. In this perspective, studying nurses’ population should be of particular interest since, worldwide, nurses are mostly women. Then, our aim was to study gender disparity in nurses’ publications.

Methods 

We selected the three main journals dedicated to nurse publications: International Journal of Nursing Studies, Journal of Nursing Scholarship, and European Journal of Cardiovascular Nursing. We included 20 recent consecutive papers from each journal. For each paper, the number of authors, their gender, and rank were recorded. Primary endpoint: overall rate of women as authors. Secondary endpoints: rate of women as first, last, second, and third authors.

Results 

Sixty papers including 322 authors were analysed. Overall rate of women authors: 74%. Overall rate of women as first author: 82%. Overall rate of women as last author: 72%. Overall rate of women as second and third authors: respectively, 80% and 70%.

Conclusion 

Almost three-quarters of the authors in these main scientific journals of nursing studies were female. This rate is lower than the gender rate in the nursing profession.
Effective termination of atrial fibrillation by SK channel inhibition is associated with a sudden organization of fibrillatory conduction
Authors: Gatta Giulia , Sobota Vladimir , Citerni Carlotta , Diness Jonas Goldin , Sørensen Ulrik S , Jespersen Thomas , Bentzen Bo Hjorth , Zeemering Stef , Kuiper Marion , Verheule Sander , Schotten Ulrich , van Hunnik Arne
Published: April 2021

Aims

Pharmacological termination of atrial fibrillation (AF) remains a challenge due to limited efficacy and potential ventricular proarrhythmic effects of antiarrhythmic drugs. SK channels are proposed as atrial-specific targets in the treatment of AF. Here, we investigated the effects of the new SK channel inhibitor AP14145.

Methods and results

Eight goats were implanted with pericardial electrodes for induction of AF (30 days). In an open-chest study, the atrial conduction velocity (CV) and effective refractory period (ERP) were measured during pacing. High-density mapping of both atrial free-walls was performed during AF and conduction properties were assessed. All measurements were performed at baseline and during AP14145 infusion [10 mg/kg/h (n = 1) or 20 mg/kg/h (n = 6)]. At an infusion rate of 20 mg/kg/h, AF terminated in five of six goats. AP14145 profoundly increased ERP and reduced CV during pacing. AP14145 increased spatiotemporal instability of conduction at short pacing cycle lengths. Atrial fibrillation cycle length and pathlength (AF cycle length × CV) underwent a strong dose-dependent prolongation. Conduction velocity during AF remained unchanged and conduction patterns remained complex until the last seconds before AF termination, during which a sudden and profound organization of fibrillatory conduction occurred.

Conclusion

AP14145 provided a successful therapy for termination of persistent AF in goats. During AF, AP14145 caused an ERP and AF cycle length prolongation. AP14145 slowed CV during fast pacing but did not lead to a further decrease during AF. Termination of AF was preceded by an abrupt organization of AF with a decline in the number of fibrillation waves.
Infections associated with cardiac electronic implantable devices: economic perspectives and impact of the TYRX™ antibacterial envelope
Authors: Boriani Giuseppe , Vitolo Marco , Wright David Justin , Biffi Mauro , Brown Benedict , Tarakji Khaldoun G , Wilkoff Bruce L
Published: April 2021

The occurrence of cardiac implantable electronic devices (CIED) infections and related adverse outcomes have an important financial impact on the healthcare system, with hospitalization length of stay (2–3 weeks on average) being the largest cost driver, including the cost of device system extraction and device replacement accounting for more than half of total costs. In the recent literature, the economic profile of the TYRX™ absorbable antibacterial envelope was analysed taking into account both randomized and non-randomized trial data. Economic analysis found that the envelope is associated with cost-effectiveness ratios below USA and European benchmarks in selected patients at increased risk of infection. Therefore, the TYRX™ envelope, by effectively reducing CIED infections, provides value according to the criteria of affordability currently adopted by USA and European healthcare systems.
ESTIMATION OF GENETIC VARIABILITY IN NATURAL POPULATIONS OF DROSOPHILA SIMULANS BY TWO-DIMENSIONAL AND STARCH GEL ELECTROPHORESIS
Authors: Ohnishi Seido , Brown Andrew J Leigh , Voelker Robert A , Langley Charles H
Published: April 2021

Genic variation in natural populations of Drosophila simulans was surveyed using allozymic and two-dimensional electrophoretic techniques. Consistent with some previous reports, allozymic heterozygosity appeared lower than in the sibling species D. melanogaster (0.07 vs. 0.16). No variation was detected by two-dimensional electrophoresis of 19 lines scored for 70 abundant proteins. This is consistent with reported reductions in estimates of genic heterozygosity by two-dimensional electrophoresis in D. melanogaster, Mus musculus, and man. Although the amount of intraspecific variation detected in abundant proteins was lower than that detected for allozymes in D. simulans and D. melanogaster, the genetic distances between the sibling species calculated from the two data sets are not significantly different (0.35 and 0.20). The allozyme and two-dimensional electrophoresis data confirmed the impression from other measures of genetic variation (mitochondrial DNA restriction maps and inversion polymorphisms) that D. simulans is substantially less variable than D. melanogaster.
INTRACHROMOSOMAL GENE CONVERSION AND THE MAINTENANCE OF SEQUENCE HOMOGENEITY AMONG REPEATED GENES
Authors: Nagylaki Thomas , Petes Thomas D
Published: April 2021

Intrachromosomal gene conversion is the non-reciprocal transfer of information between a pair of repeated genes on a single chromosome. This process produces eventual sequence homogeneity within a family of repeated genes. An evolutionary model for a single chromosome lineage was formulated and analyzed. Expressions were derived for the fixation probability, mean time to fixation or loss, and mean conditional fixation time for a variant repeat with an arbitrary initial frequency. It was shown that a small conversional advantage or disadvantage for the variant repeat (higher or lower probability of producing two variant genes by conversion than two wild-type genes) can have a dramatic effect on the probability of fixation. The results imply that intrachromosomal gene conversion can act sufficiently rapidly to be an important mechanism for maintaining sequence homogeneity among repeated genes.
POLYTENIZATION OF THE RIBOSOMAL GENES ON THE X AND Y CHROMOSOMES OF DROSOPHILA MELANOGASTER
Authors: Endow Sharyn A
Published: April 2021

It has previously been shown (Endow and Glover 1979), that polytenization of the ribosomal genes in D. melanogaster Ore-R X/Y cells and in hybrid X/X cells (Endow 1980) involves replication of genes predominantly from one of the cell's two nucleolus organizers. This analysis takes advantage of strain-specific differences in X and Y chromosome rDNA hybridization patterns detected using the Southern blotting technique. In this report, I extend the previous observations by examining polytene rDNA patterns in wild-type and hybrid X/Y cells. A dominance hierarchy for the X and Y chromosomes from three strains of D. melanogaster is presented and possible mechanisms of replicative dominance are discussed.
THE MATHEMATICS OF MOSAIC ANALYSIS II. FORMULAE FOR INTERACTING FOCI
Authors: Wyman Robert J , Salkoff Lawrence
Published: April 2021

Mosaic fate mapping requires first a measurement of the frequency of separation (by genotype) of two structures and then a conversion of this frequency of separation to distance (Wyman and Thomas 1982). If the genotype of two structures is visible, the frequency of separation (sturt distance) may be directly obtained. If the genotype is not visible (e.g., for behavioral foci) then the frequency of separation (sturt distance) itself must be calculated. The formulae introduced by Hotta and Benzer (1972) for calculating frequency of separation are appropriate only for a set of mosaics in which each fly has half normal and half mutant tissue. Using these formulae for a set of mosaics with a different fraction of mutant tissue can give enormously incorrect results.—In this paper we use intuitive lines of reasoning to obtain simple formulae for frequencies of separation that are algebraically equal to the more elaborate Hotta and Benzer (1972) formulae.—We show that when calculating sturt distances, data from a collection of mosaics with a range of malenesses, even if the average maleness is ½, cannot be lumped together. We prove that applying any formula appropriate for m = ½ to a set of mosaics all of maleness m, and then to a set of maleness 1—m, and then averaging the two results, does give the correct value for sturt distances. In this way all the mapping distances may be obtained.—Another method for locating foci is called "contour mapping". We show that the currently available contour formulae are inaccurate. We suggest that contour maps be drawn using the accurate sturt distances.
On the components of segregation distortion in Drosophila melanogaster. IV. Construction and analysis of free duplications for the Responder locus.
Authors: Brittnacher J G , Ganetzky B
Published: April 2021

Male Drosophila heterozygous for an SD-bearing second chromosome and a normal homolog preferentially transmit the SD chromosome to their offspring. The distorted transmission involves the induced dysfunction of the sperm that receive the SD+ chromosome. The loci on the SD chromosome responsible for causing distortion are the Sd locus the the E(SD) locus. Their target of action on the SD+ chromosome is the Rsps locus. Previous studies of Rsps indicated that deletion of this locus rendered a chromosome insensitive to the action of SD and mapped Rsps physically within the centric heterochromatin of 2R. In this study we have constructed a collection of marked free duplications for the centromeric region of a second chromosome that carried Rsps. The heterochromatic extent of each duplication as well as its sensitivity to distortion was determined. We found that Rsps is the most proximal known locus within the 2R heterochromatin. Furthermore, our results demonstrate that the presence of Rsps is not only necessary but sufficient to confer sensitivity to distortion irrespective of its association with an intact second chromosome or one that pairs meiotically with an SD chromosome. By use of these duplications we increased the usual dosage of Rsps relative to SD to determine whether there was any competition for limited amounts of SD [and/or E(SD)] product. When two Rsps-bearing chromosomes are present within the same spermatocyte nucleus an SD chromosome is capable of causing efficient distortion of both. However, at least in some cases the degree of distortion against a given Rsps was reduced by the presence of an extra dose of Rsps indicating that there was some competition between them. The bearing of these results on present models of segregation distortion are discussed.