bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of EGFR and HER-2/NEU Expression in Gall Bladder Carcinoma (GBC)
Authors: Das Chhanda , Mukhopadhyay Madhumita , Subba Srijana , Saha Ashis Kumar , Mukhopadhyay Biswanath
Published: May 2021

Background Gall bladder carcinoma (GBC) is the most common malignancy of the biliary tract. Being known for its geographical and racial variations, and compared with the global statistics, its incidence is higher in the Indian subcontinent, mainly in the northern and eastern regions, accounting for 80 to 95% of cases.

Aims and Objectives This study was conducted to evaluate the clinic-pathological spectrum and expression of EGFR and HER-2/NEU in GBCs and to understand their relation to prognosis, paving the way for targeted therapies for better treatment outcomes and patient survival.

Materials and Methods This is a prospective study performed in a tertiary care hospital in 30 resected specimens of GBC cases recorded in our Department of Pathology from November 2017 to November 2019. Clinical history including the radiological reports and demographic parameters were included in the study pro forma. Immunohistochemical (IHC) staining for EGFR and HER-2/NEU was performed on all the selected cases. Clinicopathologic parameters like age, sex, histologic type, perineural, and lymphovascular invasion were compared and correlated with EGFR and HER-2/NEU status.

Results Expression of EGFR was found in 93.33% of cases, which showed a highly significant correlation with histological tumor type (p = 0.000). HER-2/NEU expression was found in 56.66% of cases, which also showed a significant correlation with histological tumour type (p = 0.021). We found most of the cases with strong EGFR immunoreactivity (3+) were poorly differentiated tumors and most of the cases showing weak immunoreactivity for EGFR (1+) were well-differentiated. Conversely, in case of HER-2/NEU immunoreactivity, strong staining (3+) was seen in well-differentiated tumors and weak staining (1+) in poorly differentiated tumors. A significant correlation was also found between EGFR and HER-2/NEU expression (p = 0.000) and between cholelithiasis and EGFR expression (p = 0.033).

Conclusion EGFR is expressed in most cases of GBC. Its expression is more in poorly differentiated carcinomas as compared to the well-differentiated carcinomas, whereas HER-2/NEU expression is more in well-differentiated carcinomas. Therefore, they may serve as independent prognostic factors and also as targets for molecular therapy in GBCs.
A Fatal and Rare Case of Hydatid Cyst in the Pouch of Douglas
Authors: Asnani Ritu , Yeshvanth Sunil Kumar , Lobo Lancelot , Sonkusare Shipra
Published: May 2021

Hydatid cyst is a zoonotic infection and a significant public health problem in low- and middle-income countries. A 79-year-old female patient was presented to the gynecology outpatient department with complaints of pain in the abdomen and difficulty in micturition, with a mass palpable per speculum. The ultrasound was suggestive of an ovarian cystadenocarcinoma, whereas computed tomography of the abdomen favored hydatid cyst with adnexal neoplasm as a differential diagnosis. Considering the contradictory findings, a frozen section was sent to confirm the diagnosis, which showed hooklets of Echinococcus granulosus/hydatid cyst under the microscope. This was a rare case of pelvic hydatid cyst mimicking ovarian malignancy and was associated with a less-preferred mode of investigation (frozen section). This article focuses on how a frozen section, despite its limitations and being expensive, can still be considered for accurate patient management.
A Retrospective Comparative Functional and Aesthetic Outcome Study of Muscle versus Cutaneous Free Flaps for Distal Upper Extremity Reconstruction
Authors: Thomas Benjamin , Warszawski Jan , Falkner Florian , Nagel Sarah S. , Vollbach Felix , Gazyakan Emre , Schmidt Volker J. , Kneser Ulrich , Bigdeli Amir K.
Published: May 2021

Background Function and cosmesis are crucial in upper extremity reconstruction. Yet, there persists a lack of outcome evaluations, particularly regarding differences between free flap types.

Methods In a single-center retrospective analysis, outcomes were compared between patients with cutaneous or muscle free flaps for distal upper extremity reconstruction between 2008 and 2018. The Disabilities of Arm, Shoulder and Hand -Score, Michigan-Hand (MHQ), and Short Form 36 Health Survey (SF-36) Questionnaires were assessed, motor function was quantified, and self-reported measures of cosmesis were compared, including the Vancouver Scar-Scale (VSS), MHQ aesthetics-subscale (MAS), and Moscona's cosmetic validation-score (CVS).

Results One-hundred forty-one cases were identified, with a shift toward cutaneous flaps over the study period. Muscle flaps were used for larger defects (251 vs. 142 cm2, p = 0.008). Losses, thromboses, and donor-site complications were equally distributed. Partial necroses were more frequent in muscle flaps (11 vs. 1%, p = 0.015). Seventy patients with 53 cutaneous versus 17 muscle flaps were reexamined. There was no difference in the timing of flap coverage (after 16 vs. 15 days, p = 0.79), number of preceding (2 vs. 1.7, p = 0.95), or subsequent operations (19/53 vs. 5/17, p = 0.77). Patients with cutaneous flaps showed higher grip strength (25 vs. 17 kg, p = 0.046) and reported better hand function (MHQ: 58 vs. 47, p = 0.044) and general health (SF-36: 70 vs. 61, p = 0.040), as well as more favorable appearance (MAS: 71 vs. 57, p = 0.044, CVS: 77 vs. 72, p = 0.048), and scar burden (VSS: 0 vs. 3, p < 0.001).

Conclusion Cutaneous flaps yielded better motor function, self-perceived cosmesis, patient satisfaction, and quality of life in our cohort of distal upper extremity reconstructions.
Understanding supersonic combustion with numerical simulation
Authors: Patrick Chris
Published: May 2021

A numerical simulation method reveals characteristics of the atomization of a liquid jet in supersonic airflow, a process related to aircraft engines.
Study on aerodynamic performance of a combined vertical axis wind turbine based on blade element momentum theorem
Authors: Zhang Lei , Qu Jianjun
Published: May 2021

The vertical axis wind turbine is mainly divided into lift type and drag type. The lift-type wind turbine has high-power coefficient, but it is difficult to start. The drag-type wind turbine is easy to start, but the power coefficient is low. Combined with the advantages of the two, a combined wind turbine with the lift blade and the drag blade is designed in this paper, which is expected to obtain higher power coefficient and better starting ability. For the combined wind turbine, based on the blade element momentum theorem, the analytical model of multiple-disk-multiple-streamtube is established. By solving the model with the program code, a method of analyzing the aerodynamic characteristics of the combined vertical axis wind turbine is given. The characteristics of attack angle, normal force, tangential force, and power coefficient of the combined wind turbine with different tip speed ratio are obtained by using the analytical model. The Navier–Stokes equation is solved by SST(Shear Stress Transfer) k–w turbulence model (four equations) in fluent 16.0 software. The tangential force coefficient, power coefficient and starting ability of the combined wind turbine are obtained by computational fluid dynamic method. The accuracy of the analytical model in solving the aerodynamic performance of the combined wind turbine is verified by comparing the solution results of the analytical model with the simulation results.
Quantum computing for atomic and molecular resonances
Authors: Bian Teng , Kais Sabre
Published: May 2021

The complex-scaling method can be used to calculate molecular resonances within the Born–Oppenheimer approximation, assuming that the electronic coordinates are dilated independently of the nuclear coordinates. With this method, one will calculate the complex energy of a non-Hermitian Hamiltonian, whose real part is associated with the resonance position and imaginary part is the inverse of the lifetime. In this study, we propose techniques to simulate resonances on a quantum computer. First, we transformed the scaled molecular Hamiltonian to second quantization and then used the Jordan–Wigner transformation to transform the scaled Hamiltonian to the qubit space. To obtain the complex eigenvalues, we introduce the direct measurement method, which is applied to obtain the resonances of a simple one-dimensional model potential that exhibits pre-dissociating resonances analogous to those found in diatomic molecules. Finally, we applied the method to simulate the resonances of the H2− molecule. The numerical results from the IBM Qiskit simulators and IBM quantum computers verify our techniques.
Surface resonator for wireless power transmission systems with stable working frequency and high quality factor
Authors: Dong Lijuan , Zhao Yue , Shi Taixia , Chen Yongqiang , Liu Yanhong , Deng Fusheng , Liu Lixiang , Shi Yunlong
Published: May 2021

A surface resonator is used to improve the efficiency and working-frequency stability of three- and four-coil wireless power transmission (WPT) systems in both simulations and experiments. A surface resonator comprises chip capacitors and a structured printed circuit board. Compared to the simple three-coil WPT system, the transmission coefficient is increased by ∼10% for mid-range transmission in a three-coil WPT system with a surface resonator, and the quality factor is enhanced. For a four-coil WPT system with a surface resonator, the quality factor is improved without drastic reduction in transmittance. Moreover, by introducing a surface resonator, working-frequency splitting is suppressed strongly for short-range transmission in three- and four-coil WPT systems. The present findings will help in designing WPT systems for practical applications.
A novel technique for in situ calibration of the C-2W electromagnetic neutral particle analyzer utilizing machine learning
Authors: Player G. , Clary R. , Dettrick S. , Korepanov S. , Magee R. M. , Tajima T. ,   TAE Team
Published: May 2021

In TAE Technologies’ current experimental device, C-2W, neutral beam injection creates a large fast ion population that sustains a field-reversed configuration (FRC) plasma. Diagnosis of these fast ions is therefore critical for understanding the behavior of the FRC. Neutral Particle Analyzers (NPAs) are used to measure the energy spectrum of fast ions that charge exchange on background or beam neutrals and are lost from the plasma. To ensure correct diagnosis of the fast ion population, a calibration check of the NPAs was performed. A novel, generally applicable method for an in situ relative calibration of diagnostics on an unknown source with a small dataset was developed. The method utilizes a machine learning technique, Generalized Additive Models (GAMs), to reconstruct the diagnostic source distribution, and Stochastic Gradient Descent (SGD) to determine the NPA channel calibration factors. The results on both synthetic and experimental datasets are presented.
On physical optics approximation of stratified shear flows with eddy viscosity
Authors: Karjanto Natanael
Published: May 2021

We study a mathematical model of a perturbed stratified shear mean flow in the presence of eddy coefficients of turbulent viscosity. We adopt the standard Boussinesq approximation in the natural convection of the buoyancy-driven flow and neglect the influence of the eddy coefficients of turbulent diffusivity. Comprising both the vertical and horizontal viscosity effects, a model for the vertical velocity perturbation corresponds to a fourth-order Taylor–Goldstein (TG) differential equation. Considering only the latter, we obtained a modified TG equation with the same order as the classical, inviscid one. Under an assumption of the slowly varying Brunt–Väisälä frequency and background horizontal velocity, we discuss the corresponding geometrical and physical optics approximations of the modified TG equation using the WKB method. We further investigate the behavior of these asymptotic solutions near singular values of a turning point and critical level.
Stiffness modeling for near field acoustic levitation bearings
Authors: Wang Yaoke , Guo Ping
Published: May 2021

The dynamic characteristics of near field levitation bearings have been investigated in this study. Through theoretical analysis, two different types of system stiffness are defined and derived analytically. The dynamic stiffness relates the excitation amplitude to the dynamic force amplitude, while the effective stiffness governs the time-averaged force–displacement relationship. The results indicate two non-linear and asymmetric spring constants that can effectively predict levitation force and height. The models are verified with a carefully designed experimental setup to eliminate the structural resonance effect. Besides, some unique dynamic behaviors are investigated and predicted based on the proposed stiffness model.
Superconductivity in magnetically doped SrTiO3
Authors: Salmani-Rezaie Salva , Galletti Luca , Schumann Timo , Russell Ryan , Jeong Hanbyeol , Li Yuntian , Harter John W. , Stemmer Susanne
Published: May 2021

Doped SrTiO3 is a superconductor whose pairing mechanism is still not fully understood. The response of a superconductor to impurities has long been used to obtain insights into the nature of the superconducting state. Here, the superconductivity of SrTiO3 films that are doped or alloyed with different rare earth ions, which carry a magnetic moment, is investigated. It is shown that large concentrations (up to a few percent) of rare earth ions with unpaired f-electrons, such as Sm and Eu, do not reduce the superconducting critical temperature and critical fields. The finding is independent of whether the rare earth ion acts as a dopant or is an isovalent impurity. The interactions between the superconducting condensate and the magnetic dopants that could result in the observed insensitivity to magnetic impurities are discussed.
Multimode semiconductor laser gyroscope and factors determining its operation
Authors: Sakharov V.K.
Published: May 2021

We report the results of a study of a multimode semiconductor laser gyroscope (MSLG) with a long fibre-optic ring cavity (RC) and alternating frequency dithering formed by a lithium niobate phase modulator, and discuss the factors that determine the device operation. The fundamental limitations in MSLG operation are phase fluctuations and the multimode nature of radiation. Phase fluctuations caused by spontaneous emission of photons in a semiconductor optical amplifier (SOA) result in a slow drop in the beat amplitude. However, its complete decay does not occur due to the periodic and short-term lock-in phenomenon, which leads to the equalisation of the fluctuation levels in pairs of counterpropagating waves (PCPWs) that form the RC modes, and, thereby, to the restoration of the beat amplitude. The limitations associated with the multimode lasing regime are overcome due to the fact that the emission spectrum consists of a small number of narrow lines, and the positions of the antinodes and nodes of standing waves in the SOA field distribution coincide or are close. Both factors lead to the mode locking in spectral lines and, as a consequence, to synchronisation of PCPW beats at the device output. The mechanism of the formation of these factors is not yet clear.
Implementation of one-qubit quantum gates with individual addressing of two rubidium atoms in two optical dipole traps
Authors: Beterov I.I. , Yakshina E.A. , Tretyakov D.B. , Entin V.M. , Al’yanova N.V. , Mityanin K.Yu. , Faruk A.M. , Ryabtsev I.I.
Published: May 2021

We report the results of experiments on implementing individually addressable one-qubit quantum gates on a microwave transition with two 87Rb atoms in two optical dipole traps. Addressing is carried out using additional focused laser light, which results in a differential light shift of the microwave transition frequency. In the absence of addressing in each of the atoms, Rabi oscillations are obtained on the microwave clock transition 5S1/2 (F = 2, mF
= 0) → 5S1/2(F = 1, mF
= 0) between two working levels of qubits with a frequency of up to 5.1 kHz, a contrast up to 98 %, and a coherence time up to 4 ms. When addressing is turned on, the probability of a microwave transition in the addressed atom is suppressed to an average value of less than 5 %. The Rabi oscillations remaining in the other atom have the same contrast and correspond to the implementation of individually addressable basic one-qubit quantum operations (Hadamard gate and NOT gate) from different initial states of a qubit with an average fidelity of 92% ± 3 %. After renormalising this fidelity to the error in the preparation and measurement of quantum states of qubits, an estimate of 97% ± 3% is obtained for the fidelity of individual qubit rotations.
Plasma-assisted synthesis of size-controlled monodisperse submicron gold particles using inkjet droplets
Authors: Nitta Kaishu , Shimizu Yoshiki , Terashima Kazuo , Ito Tsuyohito
Published: May 2021

In this study, we synthesized gold spheroidized particles with sub-micrometer diameters via atmospheric-pressure plasma-assisted processing with inkjet droplets. Microdroplets of chloroauric acid (HAuCl4) solution were generated by an inkjet device with high reproducibility and exposed to radio frequency plasma. The synthesized sub-micrometer gold particles have a very narrow size distribution (3%–9% standard deviation), and their diameters can be controlled in the 0.3–0.6 μm range by adjusting the concentration of the solution.
Multiple power-law viscoelastic relaxation in time and frequency domains with atomic force microscopy
Authors: de Sousa F B , Babu P K V , Radmacher M , Oliveira C L N , de Sousa J S
Published: May 2021

Complex viscoelastic materials exhibit power law (PL) relaxations, as opposed to simple materials described by exponential decays. Other interesting materials, like living cells, hold a universal double PL behavior whose exponents depend on the health and type of the cells. Usually, only dynamic assays are considered capable to study such viscoelastic relaxation mechanisms. In this work, we propose analytical responses with single or multiple power-law relaxation behavior by generalizing classical viscoelastic models in terms of fractional derivatives of arbitrary order α (0

⩽
α
⩽

1). In addition, we demonstrate that simple atomic force microscopy force curves are powerful methods to directly observe the viscoelastic relaxation of such complex materials. In order to validate our findings, we compare the viscoelastic relaxation exponents measured directly from simple force curves (SFCs) with those measured with dynamic techniques in both living cells and polyacrylamide gels. We believe the fractional models unveiled here describe a variety of complex materials and may be used (with SFCs) to explore sophisticated viscoelastic phenomena.
A super-fast optimal attitude matrix in attitude determination
Authors: Gongmin Yan , Ruotong Chen , Jun Weng
Published: May 2021

The fast optimal attitude matrix (FOAM) for minimizing Wahba’s loss function solves the optimal attitude matrix directly and efficiently. This method is more intuitive compared with the method of calculating attitude quaternion. A method named super-FOAM (SFOAM) is proposed with a more precise initial iteration value and a faster iterative algorithm. A condition number estimation method of third-order matrices is presented for cases without exact singular value. When the matrix condition number is not particularly large, the root-seeking formula for the quartic equation is directly used to obtain the maximum characteristic root. Otherwise, under large condition numbers, a high-accuracy estimation algorithm for the maximum eigenvalue is given to achieve a high-accuracy initial value set, which is beneficial to iteration reduction and convergence speed improvement. Finally, some comparative simulations show that the SFOAM method has the same accuracy as the singular value decomposition (Matlab) method even in the case of a very large matrix condition number, while the SFOAM’s computation is only 50%–60% of the traditional FOAM algorithm. This algorithm has good generalization and application values.
Significance of Brownian motion and thermophoresis influence on dynamics of Reiner-Rivlin fluid over a disk with non-Fourier heat flux theory and gyrotactic microorganisms: A Numerical approach
Authors: Ali Bagh , Ali Liaqat , Abdal Sohaib , Asjad Muhammad Imran
Published: May 2021

Bioconvection for rotational flow is conceived to provide stability to improved thermal transportation for Reiner-Rivlin nano fluid over a disk with multi-slips. The nonFourier heat flux, binary chemical reaction, magnetic force, and activation energy are incorporated. A system of nonlinear differential equations in coupled form is acquired through the fundamental relations of Reiner-Rivlin fluids. The Runge-Kutta method of fourth-order is used to solved differential equations in MATLAB environment. The impact of various parameters are discussed and drawn physically with the help of graphs. The Reiner-Rivlin fluid parameter, magnetic parameter, thermophoresis, and Brownian motion parameter escalated the nanofluid temperature field. The electromagnetic parameter and Reiner-Rivlin fluid parameter decelerated the primary flow velocity and activation energy augmented the volume fraction of nanoparticles in the boundary layer region. An excellent accord among the present and previously existing solutions is establishes the validity of the current findings.
The Comparative Analysis of Graphene Nano-based and Copper Nano-based Patched Antenna using HFSS
Authors: Atser A R , Mom J M , Igwue G A
Published: May 2021

Patch material plays a significant role in controlling the performance and resonating frequency of patch based antennas. In this work, we compared graphene and copper nano-based patch antennas in terms of return loss, bandwidth, gain, directivity and voltage standing wave ratio (VSWR). The simulation is carried out using high frequency structure simulator HFSS. The substrate material used is Silicon dioxide. The antenna is designed to operate in the THz frequency band of (1-15THz) with the fundamental frequency of 5.5THz. The result shows that, the classical metallic antennas with copper material resonant at lower frequency of 3THz while graphene resonant at the higher frequency of 7THz, this is due to high electrons mobility in graphene than in copper. Graphene based patch antenna achieves maximum return loss of -24.4555dB with the corresponding VSWR of 1.0413. The maximum gain of 7.1943dB is achieved with a bandwidth of 522.3GHz; this shows better antenna performance than copper except the bandwidth. The contemporary copper antenna attains return loss of -14.7028dB with the corresponding VSWR of 3.2336. The gain of 4.6219dB is achieved with a bandwidth of 1188.5GHz. With this result, it can be seen that graphene is a suitable choice and can replace copper patch material for patch antennas for wireless applications in terahertz frequency band.
Review of Voltage Stability Indices
Authors: Samuel I A , Soyemi A O , Awelewa A A , Olajube A A , Ketande J
Published: May 2021

Voltage stability indices (VSIs) are very vital to voltage stability assessment; they have several areas of application such as distributed generation (DG) placement and sizing, detection of the critical regions, lines, and buses and contingency ranking and planning. These indices can be used to activate countermeasures against voltage instability. This article examines voltage stability indices with particular focus on line VSIs, and it highlights the classification, accuracy of VSIs, and enumerates for some selected line VSIs drawbacks and advantages as seen in literature.
Numerical Modelling Of The Effect Of Temperature And Thickness On The Electrical Properties Of Polycrystalline Semi-Conductor Solar Cells [CdTe and Cu(In,Ga)Se2(CIGS)] Using One Dimensional Device Simulation
Authors: Isa M.M , Mustapha Ibrahim , Yahaya A.A
Published: May 2021

A numerical simulation program SCAPS 1D (solar cell and capacitance simulator) was used in the simulation of CdTe and CIGS solar cells. We concentrated on the effect of temperature and thickness on the electrical properties of CdTe and CIGS solar cells and the agreement between the simulations and measurements was shown and discussed using SCAPS 3.3.00. The influences of temperature and thickness on CdTe and CIGS solar cells were investigated by I-V measurements. The simulated efficiencies for CdTe and CIGS solar cells at 300K were observed to be 16.03% and 16.54% which compare very well with the measured efficiencies 10.72% for CdTe and 15.96% for CIGS solar cell at same temperature. It was found out that as temperature and thickness increases from (200 – 400)K and (2 – 6μm, efficiencies decrease from 18% to 10% for CdTe and 20% to 8% for CIGS from (250 – 400)K and (1 – 5μm respectively.
Improving Biogas Yield Using Organic Fraction of Plant and Animal Wastes by Co-Digestion
Authors: Ezekoye Veronica A , Geraldine I Okoro , Anthony Ofomatah , David Ezekoye , Ada Agdaogu
Published: May 2021

This study presented the effects of co-digestion and catalysts on the performance of biogas production. Poultry dropping and walnut waste were used as feedstock materials while clay, KOH and NaOH were used as catalysts. The experiment was divided into five setups. The retention time was 45days. The digester temperature floated around 20-44°C while the PH varies from 5.7-8.7. Gas composition, physicochemical properties, calorific value as well as elemental composition of the organic waste were analyzed. The result revealed that the gas produced has high methane content ranging from 66.52 – 73.44% with low CO2 concentration ranging from 9.97 -16.92%. The total volume of gas was noted to be 135.2l, 115.2l, 82.2l, 162.4l and 115.7l for each sample. The physicochemical properties revealed that the TS varies from 3.04% – 4.15%, while VS varies from 3.27% – 4.49%. The TOC ranges from 3.13% – 3.84% while the nitrogen content ranges within 0.112% – 0.392%, while Crude fibre ranges from 0.70 – 1.79%. Ash content ranges within 1.16 – 2.67% and moisture content varies between 87.77 – 92.34%. The COD and BOD were also obtained. The calorific values of the samples obtained ranges from 15,882 – 22,036KJ/kg. The phosphorus content was between 0.33% and 0.43% while potassium was between 0.29and 0.42% on average.
Design of a STS Electrical Energy Meter with Two-Way Communications Capability over GSM Network
Authors: Diegbegha Tonbra A. , Benjamin Ayibapreye K.
Published: May 2021

A STS (System Transfer Specification) energy meter with an embedded solution for two-way communications over Global System for Mobile Communications (GSM), was designed and simulated with Proteus. This meter should be able to report any tampering attempt on the customer’s meter, by sending an SMS (Short Message Service) via Global System for Mobile Communications (GSM) as regards energy theft from the point of theft to an automated meter management station. Every meter is part of an automated metering management network, which is a scaled down version of a conventional Advanced Metering Infrastructure (AMI). This research provides an additional capability to STS energy Meters. The additional two-way communications capability of the Energy Meter is implemented with the addition of a GSM module to a conventional STS meter. The additional functionality to the STS meter real-time reporting was achieved by adding a GSM module to its design.
Global Oil Price Changes, Drivers and Key Indicators With Reference To Africa Energy Security–Outlook for 2025 and Beyond
Authors: Amadi C S , Onuoha K M , Onwuka J O
Published: May 2021

Recent collapse in oil prices around the world from 2014–2016 and 2019/2020 has been reported as the most significant downward trend in the history of oil price glut. The COVID 19 pandemic caused additional fall to crude oil price expectedly, given the dynamics of demand and supply. Following world economic shut down, crude oil prices dipped to all time low. Global economies were heavily impacted by the crude oil price drop and Africa, which is known to be at the top of receiving end of fluctuating oil prices historically, once more suffered negative consequences. Africa energy security and sustainability becomes paramount following the continued negative impact of global oil prices change on the continent. Issues with crude oil transportation, storage and accessibility in Africa remains significant. Nigeria, whose economy is predominantly dependent on revenue from crude oil, witnessed another round of devaluation of the naira and with inflation in the negative direction due to the collapse in oil price. This paper focused on global energy security and sustainability in Africa. It explored the windows of opportunities in areas of transportation, storage and distribution of refined petroleum products and in advanced world and how Africa can adopt such methods. It looked at how Africa can take advantage of the advanced technology deployed in conventional petroleum development globally and in unconventional areas like nuclear, solar and wind energy. The results considered how Nigeria can be preserved from negative oil prices and the technologies available to boost her petroleum industry, particularly developments of unconventional resources beyond 2025 and sustainability of energy security within the polity. Suitable alternative and the sustainability of refined petroleum transportation and distribution is critical with reference to energy security in Africa.
ℎ𝑝-version discontinuous Galerkin methods on essentially arbitrarily-shaped elements
Authors: Cangiani Andrea , Dong Zhaonan , Georgoulis Emmanuil
Published: May 2021

We extend the applicability of the popular interior penalty discontinuous Galerkin method discretizing advection-diffusion-reaction problems to meshes comprising extremely general, essentially arbitrarily-shaped element shapes. In particular, our analysis allows for curved element shapes, without the use of non-linear elemental maps. The feasibility of the method relies on the definition of a suitable choice of the discontinuity penalization, which turns out to be explicitly dependent on the particular element shape, but essentially independent on small shape variations. This is achieved upon proving extensions of classical trace and Markov-type inverse estimates to arbitrary element shapes. A further new

H
1

−

L
2

H^1-L_2

-type inverse estimate on essentially arbitrary element shapes enables the proof of inf-sup stability of the method in a streamline-diffusion-like norm. These inverse estimates may be of independent interest. A priori error bounds for the resulting method are given under very mild structural assumptions restricting the magnitude of the local curvature of element boundaries. Numerical experiments are also presented, indicating the practicality of the proposed approach.
Disruption of a ∼23–24 nucleotide small RNA pathway elevates DNA damage responses inTetrahymena thermophila
Authors: Lee Suzanne R. , Pollard Daniel A. , Galati Domenico F. , Kelly Megan L. , Miller Brian , Mong Christina , Morris Megan N. , Roberts-Nygren Kerry , Kapler Geoffrey M. , Zinkgraf Matthew , Dang Hung Q. , Branham Erica , Sasser Jason , Tessier Erin , Yoshiyama Courtney , Matsumoto Maya , Turman Gaea
Published: May 2021

We found that Tetrahymena thermophila RNAi mutants exhibit features of elevated DNA damage, including enlarged extranuclear DNA bodies, DNA repair gene expression, and DNA damage foci. This broadens the range of eukaryotes with recently identified RNAi roles in maintaining genome integrity, here through transposon- and centromere-independent mechanisms.
The frequency and impact of undiagnosed benign paroxysmal positional vertigo in outpatients with high falls risk
Authors: Hawke Lyndon J , Barr Christopher J , McLoughlin James V
Published: May 2021

Background

The frequency and impact of undiagnosed benign paroxysmal positional vertigo (BPPV) in people identified with high falls risk has not been investigated.

Objective

To determine the frequency and impact on key psychosocial measures of undiagnosed BPPV in adult community rehabilitation outpatients identified with a high falls risk.

Design

A frequency study with cross-sectional design.

Setting

A Community Rehabilitation Program in Melbourne, Australia.

Subjects

Adult community rehabilitation outpatients with a Falls Risk for Older People in the Community Screen score of four or higher.

Methods

BPPV was assessed in 34 consecutive high falls risk rehabilitation outpatients using the Dix–Hallpike test and supine roll test. Participants were assessed for anxiety, depression, fear of falls, social isolation and loneliness using the Hospital Anxiety and Depression Scale, Falls Efficacy Scale-International and De Jong Gierveld 6-Item Loneliness Scale.

Results

A total of 18 (53%; 95% confidence interval: 36, 70) participants tested positive for BPPV. There was no significant difference between those who tested positive for BPPV and those who did not for Falls Risk for Older People in the Community Screen scores (P = 0.555), Hospital Anxiety and Depression Scale (Anxiety) scores (P = 0.627), Hospital Anxiety and Depression Scale (Depression) scores (P = 0.368) or Falls Efficacy Scale-International scores (P = 0.481). Higher scores for the De Jong Gierveld 6-Item Loneliness Scale in participants with BPPV did not reach significance (P = 0.056).

Conclusions

Undiagnosed BPPV is very common and associated with a trend towards increased loneliness in adult rehabilitation outpatients identified as having a high falls risk.
Comparison of Anti–SARS-CoV-2 S1 Receptor-Binding Domain Antibody Immunoassays in Health Care Workers Before and After the BNT162b2 mRNA Vaccine
Authors: Carta Mariarosa , Marinello Irene , Cappelletti Anna , Rodolfi Alessandra , Cerrito Erica , Bernasconi Camilla , Gottardo Marlene , Dal Lago Francesca , Rizzetto Daniele , Barzon Elena , Giavarina Davide
Published: May 2021

Objectives

The Pfizer-BioNTech BNT162b2 vaccine against SARS-CoV-2 infection is now available. This vaccine induces antibody production against the receptor-binding domain (RBD) of the spike glycoprotein S1 (S1-RBD). This study evaluated the performance of new immunoassays to measure this type of antibody.

Methods

Blood samples were collected at t0 (prime dose), after 21 days (t1, booster dose), and then after another 15 days (t2) from 70 health care professionals who had tested negative for previous SARS-CoV-2 infection and underwent vaccination with BNT162b2.

Results

Antibodies against S1-RBD were measured using 4 commercial assays. At t0, t1, and t2, the median antibody concentrations (interquartile range) were, respectively, 0.2 (0.1-0.4), 49.5 (19.1-95.7), and 888.0 (603.6-1,345.8) U/mL by Maglumi SARS-CoV-2 S-RBD immunoglobulin G (IgG) (Shenzen New Industries Biomedical Engineering, Snibe Diagnostics); 0.0 (0.0-0.0), 7.9 (4.2-15.6), and 112.3 (76.4-205.6) U/mL by Atellica IM SARS-CoV-2 IgG assay (Siemens Healthineers); 0.0 (0.0-0.0), 59.9 (18.3-122.0), and 2,646.0 (1,351.2-4,124.0) U/mL by Elecsys Anti–SARS-CoV-2 S assay (Roche Diagnostics); and 1.8 (1.8-1.8), 184 (94-294), and 1,841.0 (1,080.0-2,900.0) AU/mL by LIAISON SARS-CoV-2 TrimericS IgG assay (DiaSorin). The differences between medians at t0, t1, and t2 were all statistically significant (P < .001).

Conclusions

Antibodies against nucleocapsid proteins (N) were also measured using Maglumi 2019-nCoV IgG assay, which showed all negative results. All the considered anti-RBD methods detected response to the vaccine, while the method directed against anti-N failed to show response.
Effect of the local wind reduction zone on seed dispersal from a single shrub element on sparsely vegetated land
Authors: Fu Lin-Tao
Published: May 2021

Accurate predictions of seed dispersal kernels are crucial for understanding both vegetation communities and landscape dynamics. The influences of many factors, including the physical properties of seeds, the time-averaged wind speed and the wind turbulence, on seed dispersal have been studied. However, the influence of local wind speed reduction around a single shrub element (e.g. a small patch of scrub) on seed dispersal is still not well understood. Here, the spatial distribution of the wind intensity (represented by the wind friction speed u*) around a single shrub element is described, with an emphasis on the variation in the streamwise direction, and assuming that the time-averaged lateral and vertical speeds are equal to zero. The trajectories of the seeds were numerically simulated using a Lagrangian stochastic model that includes the effects of wind turbulence and particle inertia. The patterns of seed deposition with and without the effect of local wind reduction were compared. The variation in seed deposition with changing wind intensity, release height and shrub porosity were also simulated. The simulation results revealed that the local wind reduction increased seed deposition in nearby regions and therefore decreased seed deposition in the regions farther away. Local wind reduction had a greater impact on short-distance dispersal than on long-distance dispersal. Moreover, the dispersal in the circumferential direction decreased once the motion of a seed moving in the streamwise direction was reduced due to the local wind reduction. As the wind intensity and release height increased, the effect of local wind reduction on seed dispersal weakened. Seed dispersal was both wider and farther as the shrub porosity increased. These results may help explain the disagreement between the mechanistic models and the fitting curves in real cases. In addition, the results of this study may improve the currently used mechanistic models by either increasing their flexibility in case studies or by helping explain the variations in the observed distributions.
Cryopreservation of clonal and polyclonal populations of Chlamydomonas reinhardtii
Authors: Boswell Jacob , Lindsey Charles Ross , Cook Emily , Rosenzweig Frank , Herron Matthew
Published: May 2021

Long-term preservation of laboratory strains of Chlamydomonas reinhardtii has historically involved either liquid nitrogen cryopreservation, which is expensive and labor intensive, or storage on agar plates, which requires frequent transfer to new plates, and which may leave samples susceptible to contamination as well as genetic drift and/or selection. The emergence of C. reinhardtii as a model organism for genetic analysis and experimental evolution has produced an increasing demand for an efficient method to cryopreserve C. reinhardtii populations. The GeneArt™ Cryopreservation Kit for Algae provides the first method for algal storage at −80°C; however, little is known about how this method affects recovery of different clones, much less polyclonal populations. Here, we compare postfreeze viability of clonal and genetically mixed samples frozen at −80°C using GeneArt™ or cryopreserved using liquid nitrogen. We find that the GeneArt™ protocol yields similar percent recoveries for some but not all clonal cultures, when compared to archiving via liquid N2. We also find that relative frequency of different strains recovered from genetically mixed populations can be significantly altered by cryopreservation. Thus, while cryopreservation using GeneArt™ is an effective means for archiving certain clonal populations, it is not universally so. Strain-specific differences in freeze–thaw tolerance complicate the storage of different clones, and may also bias the recovery of different genotypes from polyclonal populations.
Top bunk, bottom bunk: cellsharing in prisons
Authors: Schliehe Anna , Crewe Ben
Published: May 2021

The politics involved in cell-sharing reach into the most personal parts of prisoners’ lives and are highly determinate of their experiences of imprisonment. While there is a small amount of research on the impact of cell-sharing on personal wellbeing and prison quality, much less has been written about the daily dynamics and significance of negotiating shared space under conditions of coercion. In this paper, based on in-depth research undertaken in England & Wales, we explore the experience of cell-sharing and how dynamics in the cell matter both intimately and socially. Essentially, we locate the cell as one of the primary sites of ‘where the action is’ in prisons, and where matters of safety, dignity and abjection are of particular relevance.
Barriers and Facilitators of Mental Health Service Utilisation among Bhutanese Refugees in the USA: Findings from a Mixed-Methods Study
Authors: Soukenik Eliza , Haran Hanna , Kirsch Jaclyn , Pyakurel Sudarshan , Maleku Arati
Published: May 2021

Although discussions regarding the need to develop culturally responsive mental health services for resettled refugee populations in the USA have been burgeoning, efforts to comprehensively understand the unique barriers and facilitators of mental health services across refugee subpopulations remain fragmented. Our study explored the barriers and facilitators of mental health services experienced by the resettled Bhutanese refugee population in a Midwestern city in the USA using a two-phased sequential explanatory mixed-methods study (N = 46). Study findings draw much needed attention to culturally grounded solutions generated by the community to reduce barriers and increase facilitators of mental health engagement. Building on community-generated solutions and expanding the capacity of local community-based ethnic organisations will be the first step in providing services that are truly responsive to the cultural needs of the Bhutanese refugee population. Recognition of refugee communities’ unique collective strengths will be much needed to holistically collaborate with these new members of the society to promote mental well-being and foster a sense of inclusion and belonging, especially in the post-coronavirus pandemic context. Our study also contributes to emerging knowledge on methodological rigor in research amongst understudied, hard-to-reach populations.
Awkward Encounters with Sarah Waters: Shame, Reading, and Queer Subjectivity
Authors: Zhang Muren
Published: May 2021

Focusing on Sarah Waters’s Tipping the Velvet (1998) and Affinity (1999), this article examines how the reader-pleasure afforded by contemporary reimaginings of Victorian lesbianism accommodates the complicated emotional response of shame. Through an investigation of how both texts relate queer experience to shame and what narrative strategies facilitate or induce shame in the reader during their reading experience, this article argues that Waters’s work invites a more sophisticated analysis of shame: one that relates to, and arguably reproduces, the empathetic engagement between the text and the reader. In so doing, this article demonstrates the importance of affect and narrative studies in unpacking the complicated reading pleasure afforded by Waters’s writings and its political potentials.
Political economy and the pursuit of universal health coverage in Ghana: a case study of the National Health Insurance Scheme
Authors: Novignon Jacob , Lanko Charles , Arthur Eric
Published: May 2021

The road to universal health coverage depends on resources committed to the health sector. In many cases, the political structure and strength of advocacy play an important role in setting budgets for health. However, this has, until recently, not been of interest to health system researchers and policymakers. In this study, we document the political path to the establishment of the Ghana National Health Insurance Scheme (NHIS) as well as continuous political interest in the scheme. To achieve our objectives, we used qualitative data from interviews with key stakeholders. These include stakeholders instrumental in the design and establishment of the NHIS. We also reviewed party manifestoes from the two main political parties in the country. Promises relating to the NHIS were extracted from the various manifestos and analysed. Other documents that account for the design and implementation of the scheme were reviewed. We found that the establishment of the NHIS was down to political commitment and effective engagement with relevant stakeholders. It was considered a solution to the political promise to remove user fees and make healthcare accessible to all. A review of the manifestos shows that in almost every election year after the NHIS was established, there has been some promise related to improving the scheme. There were several policy propositions repeated in different election years. The findings imply that advocacy to get health financing on the political agenda is crucial. This should start from the development of party manifestos. It is important to also ensure that proposed party policies are consistent with national priorities in the medium to long term.
Policy processes leading to the adoption of ‘Jamie’s Ministry of Food’ programme in Victoria, Australia
Authors: Clarke Brydie , Kwon Janelle , Swinburn Boyd , Sacks Gary
Published: May 2021

This study investigated the policy processes related to the 2012 adoption of the Jamie’s Ministry of Food programme by the Victorian Government in Australia. The aim was to provide insight into obesity prevention policy change processes to help strengthen future health promotion action. State-level government policy processes were examined through key informant interviews and a review of relevant documentation. Data were analysed using the Multiple Streams Theory and the Advocacy Coalition Framework in order to understand influences on relevant policy processes and strategies used by policy advocates to facilitate policy adoption. We found that policy adoption was facilitated by dedicated national funding for preventive health at that time, the relatively small number of stakeholders involved in the policy development process and the anticipated support for the programme by the general public due to the association with celebrity chef, Jamie Oliver. We identified that policy brokers aligned the policy with decision-maker ideologies and broader government objectives, and proactively managed potential criticisms. Evidence of intervention effectiveness was not a major driver of policy adoption. We conclude that, iven the complexity of policy processes for obesity prevention, multiple, reinforcing strategies are likely to be needed to facilitate policy change. Support for the adoption of obesity prevention policies is likely to increase when framing of policy options aligns with decision-maker values and has broad public appeal.
Combining acoustic tracking and hydrodynamic modelling to study migratory behaviour of Atlantic salmon (Salmo salar) smolts on entry into high-energy coastal waters
Authors: Mcilvenny J , Youngson A , Williamson B J , Gauld N R , Goddijn- Murphy L , Del Villar-Guerra D
Published: May 2021

Migration from fresh water to the marine environment is a crucial, transitional stage in the development of Atlantic salmon (Salmo salar). This study used a combination of acoustic tracking, instrument data, and hydrodynamic modelling to examine behaviour of juvenile salmon (smolts) during their transition from fresh water to the marine environment. The study focuses on a high-energy coastal environment in northern Scotland, which is currently being developed for renewable energy extraction and where there is potential for negative impacts on salmon with energy extraction devices and structures. Thirty-four smolts were captured in the River Wick in Caithness and tagged with acoustic tags transmitting at 69 kHz. The Telemac–Mascaret modelling suite was utilized to construct a three-dimensional model of the study area and surrounding waters to estimate smolt-current interactions during detection times. Timing of migration was linked to low-light conditions, with smolts mainly exiting the river at night and when the moon was below the horizon. The movement of most of the tags conformed with modelled tidal currents and the tracks matched modelled marine tidal patterns. Smolts were detected only on a single tide suggesting that they rapidly cleared the vicinity of the receiver array.