bluuebunny/crossref_metadata_2025 huggingface dataset:
Provision of straw and the presence of undocked lambs reduce the behavioural and physiological expressions of pain and stress associated with tail docking in lambs: a preliminary study
Authors: Larrondo Cristian , Orihuela Agustín , Strappini Ana , Acosta-Jamett Gerardo , Mota-Rojas Daniel , Gallo Carmen
Published: November 2020

Aims
The aim of this experiment was to determine if the provision of straw and the presence of undocked twins could be used to mitigate the pain experienced by lambs having their tails docked using rubber rings.

Methods
A total of 54 twin St. Croix 60-days-old weaned lambs were assigned to one of four treatments: (i) the presence of undocked twins and no provision of straw (U); (ii) the provision of straw and no presence of undocked twins (St); (iii) the provision of straw and the presence of undocked twins (StU); and (iv) no provision of straw and no presence of undocked twins (C). Straw was provided as bed material over the concrete floor; whereas the presence of undocked twins was achieved by leaving one twin intact within each pair. From the placement of the rubber rings, the behaviour of tail-docked twins was video recorded continuously for 60 min, and blood samples were taken from these lambs immediately before placing the rubber ring (time 0), and at 0.5, 1, 1.5, 24, 48 and 72 h after, for cortisol and physio-metabolic profiles determination, and at 168 h after, for cortisol determination.

Key results
Lambs in treatment C spent three times longer in abnormal lying postures (P = 0.002) compared with St and StU lambs (6.49 ± 4.73 vs 1.78 ± 1.26 and 1.83 ± 1.94 min respectively). Lambs in all treatments experienced an increase in cortisol levels 1 h after tail docking, except for StU lambs. In addition, 48 and 72 h after tail docking, lambs in treatments St and StU had lower concentrations of cortisol than C lambs.

Conclusion
This study shows that the provision of straw and the presence of undocked twins reduce the behavioural and physiological expressions of pain associated with tail docking in lambs.

Implications
In lambs raised under intensive conditions, the addition of straw as bedding material and the presence of intact tail lambs could be a practical strategy to improve the welfare of tail-docked lambs, whereas for those lambs raised under extensive conditions, leaving intact those lambs that will be sold might serve as social buffering for their tail-docked conspecifics that will remain in the farm.
Effect of environmental temperature change on the neuromechanical function of the quadriceps muscle
Authors: Spillane Pádraig , Bampouras Theodoros M.
Published: November 2020

This study compared neuromechanical characteristics of voluntary (maximum voluntary contraction (MVC) peak torque, rate of torque development (RTD), voluntary activation (VA)) and electrically stimulated contractions (peak torque, RTD) when performed under the same temperature conditions. Twelve physically active males performed two isometric MVCs of the quadriceps muscle group in an isokinetic dynamometer. The MVCs were performed after lower limb submersion for 20 min in hot (40°C) or cold (10°C) water. A control MVC was performed in ambient room temperature (17 ± 0.7°C). Electrical twitches were delivered at rest pre‐MVC (Unpotentiated), during the plateau phase of the MVC (Superimposed) and post‐MVC (Potentiated). Peak torque for MVC, Unpotentiated and Potentiated was recorded. RTD was calculated for the MVC (at 50, 100, 150, 200 ms and peak torque time points), Unpotentiated and Potentiated twitches, while VA (using the central activation ratio method) was calculated. There was no significant change between conditions in MVC peak torque, MVC RTD, VA and (averaged) twitch peak torque (p > 0.05). Twitch RTD for the hot condition (1025.0 ± 163.0 N·m·s−1) was significantly higher (p = 0.003) than control (872.3 ± 142.9 N·m·s−1). In conclusion, environmental temperature changes, in the range examined, do not affect the ability to generate maximum torque or any of the RTD parameters in maximum voluntary isometric contractions. In contrast, increased heat results in higher RTD in electrically stimulated contractions, most likely induced by reduced contraction time. This has practical implications for the use of electromyostimulation for injury prevention.
Value of isokinetic strength testing for hamstring injury risk assessment: Should the ‘strongest’ mates stay ashore?
Authors: Pieters Dries , Witvrouw Erik , Wezenbeek Evi , Schuermans Joke
Published: November 2020

Although isokinetic strength testing is commonly used in hamstring strain injury (HSI) rehabilitation and prevention, research findings concerning its predictive value remain inconclusive. Existing research focuses on peak torque (PT) and angle of PT, not analysing the torque behaviour throughout the testing range of motion (ROM). This study intended to assess the value of isokinetic curve evaluation in association with HSI. A sample of 116 male football players with and without a recent HSI history was submitted to bilateral isokinetic assessment of the knee and hip muscles. Raw isokinetic data were filtered and normalized prior to curve analysis submission in MATLAB. Torque development of each muscle group throughout the entire testing ROM was assessed using HSI history as an independent variable. Curve analysis revealed significant differences in torque behaviour in function of injury history. Players with an HSI history demonstrated significantly stronger concentric knee flexion and extension, eccentric knee extension and concentric hip extension patterns compared to the controls and their uninjured limb. HSI history was also associated with lower concentric hip flexion torques and lower mixed H:Q ratios compared to the control group and their contralateral limb. HSI history was associated with altered knee and hip muscle strength profiles, potentially due to isolated focus on local strength training in rehabilitation or mechanisms of neuromuscular inhibition. Because the differences in torque amplitude were range‐dependent and did not systematically concur with the point of PT achievement, isokinetic strength evaluation should most probably be conducted using curve analysis.
Evaluation of occupational radon exposure and comparison with residential radon exposure in Canada—a population-level assessment
Authors: Chen Jing
Published: November 2020

Radon is a naturally occurring radioactive gas and presents everywhere on the Earth at varying concentration in workplaces and at homes. With Canadian labour statistics, time statistics and more than 7600 long-term radon measurements in workplaces, occupational radon exposure is evaluated for all 20 job categories based on North American Industry Classification System. Results are compared with residential radon exposure based on more than 22 000 long-term radon tests conducted in Canadian homes. The average annual effective dose due to radon exposure in workplaces is 0.21 mSv, which is lower than the average annual effective dose of 1.8 mSv from radon exposure at home by a factor of eight. Due to relatively higher radon concentration in residential homes and longer time spent indoors at home, exposure at home contributes to 90% of workers’ total radon exposure (on average 1692 h in workplaces and 5852 h at homes). The analysis presented here is based on province-wide average radon exposures in various indoor and outdoor environments. Since the risk of developing lung cancer increases proportionally with increasing radon exposure, this evaluation indicates that on average reduction of radon levels in homes is very important and an effective way to reduce radon-induced lung cancers in Canada.
Adversarial domain adaptation with classifier alignment for cross-domain intelligent fault diagnosis of multiple source domains
Authors: Zhang Yongchao , Ren Zhaohui , Zhou Shihua , Yu Tianzhuang
Published: November 2020

Recently, most cross-domain fault diagnosis methods focus on single source domain adaptation. However, it is usually possible to obtain multiple labeled source domains in real industrial scenarios. The question of how to use multiple source domains to extract common domain-invariant features and obtain satisfactory diagnosis results is a difficult one. This paper proposes a novel adversarial domain adaptation with a classifier alignment method (ADACL) to address the issue of multiple source domain adaptation. The main elements of ADACL consist of a universal feature extractor, multiple classifiers and a domain discriminator. The parameters of the main elements are simultaneously updated via a cross-entropy loss, a domain distribution alignment loss and a domain classifier alignment loss. Under the framework of multiple loss cooperative learning, not only is the distribution discrepancy among all domains minimized, but so is the prediction discrepancy of target domain data among all classifiers. Two experimental cases on two source domains and three source domains verify that the ADACL can remarkably enhance the cross-domain diagnostic performance under diverse operating conditions. In addition, the diagnostic performance of different methods is extensively evaluated under noisy environments with a different signal-to-noise ratio.
A novel self-adaptive, multi-peak detection algorithm for blade tip clearance measurement based on a capacitive probe
Authors: Li Jian , Guo Guanghui , Duan Fajie , Niu Guangyue , Shao Xingchen , Zhou Cong , Shi Xiaojiang , Zhong Zhicai
Published: November 2020

Peak height detection is critical for blade tip clearance (BTC) measurement based on capacitive probes. However, the noise interference of the complicated working environments and instabilities of the rotation speed make high-precision peak detection a challenge. To solve this problem, a novel self-adaptive, multi-peak detection algorithm is proposed in this paper. The adaptive dual thresholds are used to identify the single peak and pre-estimate its peak parameters for the segmentation of the peak support region and the selection basis of the wavelet parameters. Then, based on the prior pre-estimation information, the wavelet matching is performed on the segmented single peak adaptively for eight times, and the derived mathematical models of the wavelet matching are fitted using the obtained matching coefficients to get precise peak parameters such as peak height and peak position. The blade tip clearance is calculated from the peak height through the calibration curve. The experiments show that the BTC measurement error of the proposed algorithm is under 15 μm, with the clearance ranging from

1
mm

to

3
mm

, and the proposed algorithm has preferable stability to comparable algorithms with the rotation speed ranging from 1000 rpm to 4000 rpm. This implies that the proposed algorithm has high anti-noise performance and good adaptability to rotation speed change.
Silver nanoparticles functionalized Paclitaxel nanocrystals enhance overall anti-cancer effect on human cancer cells
Authors: Muhammad Nazim , Zhao He , Song Wenjing , Gu Mingyang , Li Qian , Liu Yujia , Li Cheng , Wang Jihui , Zhan Honglei
Published: November 2020

For chemotherapeutic drugs, precise tumor-targeting and high anti-cancer efficiency is equally important in order to enhance chemotherapy and reverse drug resistance. The combination of multifunctional agents to achieve synergy should be a promising strategy. In our study, we have successfully developed novel multifunctionalized drug nanocrystals to realize co-delivery of the organic drug Paclitaxel (PTX), inorganic silver nanoparticles (AgNPs) and a tumor targeting agent. To be specific, PTX nanocrystals were first prepared as a template, then coated with polydopamine (PDA). The PDA layer was utilized as the connection bridge to produce and deposit AgNPs in situ, and provide sites for tumor-targeting peptide NR1 (RGDARF) grafting. As a result, these NR1/AgNP-decorated drug nanocrystals exhibited dramatically improved cellular uptake efficiency, in vitro anti-cancer activity and an anti-migratory effect against a variety of cancer cells, which was attributable to the synergistic, or at least additive, effect of the AgNPs and PTX, enhanced cellular uptake efficiency through NR1-receptor interaction, pH-responsive drug release and the nanoscaled nature. In particular, high anti-cancer activity and low side effects from these NR1/AgNP-decorated PTX nanocrystals were well balanced in terms of good selectivity and biocompatibility. Moreover, these novel drug nanocrystals displayed strong apoptotic-inducing potency, resulting in cell membrane lysis, nuclear damage, mitochondria dysfunction, excessive ROS release and double-stranded DNA breakage. The potential acting mechanism and molecular basis of these novel drug nanocrystals is relevant to the regulation of mitochondria-mediated apoptosis with a greater Bax-to-Bcl-2 ratio and the activation of pro-apoptotic P53 and caspase 3.
Probabilistic definition of the clinical target volume—implications for tumor control probability modeling and optimization
Authors: Bortfeld Thomas , Shusharina Nadya , Craft David
Published: November 2020

Evidence has been presented that moving beyond the binary definition of clinical target volume (CTV) towards a probabilistic CTV can result in better treatment plans. The probabilistic CTV takes the likelihood of disease spread outside of the gross tumor into account. An open question is: how to optimize tumor control probability (TCP) based on the probabilistic CTV. We derive expressions for TCP under the assumptions of voxel independence and dependence. For the dependent case, we make the assumption that tumors grow outward from the gross tumor volume. We maximize the (non-convex) TCP under convex dose constraints for all models. For small numbers of voxels, and when a dose-influence matrix is not used, we use exhaustive search or Lagrange multiplier theory to compute optimal dose distributions. For larger cases we present (1) a multi-start strategy using linear programming with a random cost vector to provide random feasible starting solutions, followed by a local search, and (2) a heuristic strategy that greedily selects which subvolumes to dose, and then for each subvolume assignment runs a convex approximation of the optimization problem. The optimal dose distributions are in general different for the independent and dependent models even though the probabilities of each voxel being tumorous are set to the same in both cases. We observe phase transitions, where a subvolume is either dosed to a high level, or it gets ‘sacrificed’ by not dosing it at all. The greedy strategy often yields solutions indistinguishable from the multi-start solutions, but for the 2D case involving organs-at-risk and the dependent TCP model, discrepancies of around 5% (absolute) for TCP are observed. For realistic geometries, although correlated voxels is a more reasonable assumption, the correlation function is in general unknown. We demonstrate a tractable heuristic that works very well for the independent models and reasonably well for the dependent models. All data are provided.
On the possibility of limit-cycle-state of peeling mode near stability boundary in the quiescent H-mode
Authors: Itoh Kimitaka , Kamiya Kensaku , Aiba Nobuyuki , Itoh Sanae-I
Published: November 2020

A model is proposed for the edge harmonic oscillation, in which the stationary coherent mode is sustained in the almost linear phase as has been observed in JT-60U. We study the coupled dynamics of the peeling mode amplitude and edge pressure gradient. The limit cycle oscillation is predicted. The peeling mode (which is almost in the linear phase) is in a dynamical stationary state with amplitude modulation. In this model, the time scales for the change of parameters that specify magnetic structures (such as magnetic shear and edge plasma current) are assumed to be much slower, so that are decoupled from the limit cycle dynamics. The condition that the limit cycle state appears is shown. The oscillation frequency of the modulation is given by the hybrid mean of the typical growth rate of the peeling mode and the additional loss rate of pressure gradient by the peeling mode.
Kirigami auxetic structure for high efficiency power harvesting in self-powered and wireless structural health monitoring systems
Authors: Farhangdoust Saman , Georgeson Gary , Ihn Jeong-Beom , Chang Fu-Kuo
Published: November 2020

Kirigami and auxetic topologies are combined to design an innovative metamaterial-based substrate (MetaSub) for piezoelectric energy harvesters. The proposed MetaSub piezoelectric energy harvester (MPEH) contains both advantageous metamaterial properties of negative Poisson’s ratio capability and enhanced planar stretchability. A computational parametric analysis is conducted to develop the optimum design for the MPEH to trap the maximum elastic energy. A finite element analysis (FEA) is employed to analytically and numerically validate the simulation model of the MPEH. Accordingly, two experimental results of conventional and auxetic strain energy harvesters are used to evaluate the power enhancement of the MPEH. The FEA results demonstrate the average power gained by the MPEH at a low level of frequency and strain excitation (10 Hz and 150

μ
ε

peak-to-peak) is 165

μ

W which easily satisfies the minimum electric power amount required as a sensor node for self-powered wireless sensor networks. The harvested power output of the MPEH is 19.2 times more than power output produced by an equivalent conventional harvester with a plain substrate (8.6

μ

W). The performance of the MPEH is investigated at different combinations of both low and high excitation frequencies. The creative design of the MetaSub can significantly improve the productivity of strain-induced devices whose efficiency is dependent on their deformation performance such as vibration energy harvesters, wearable sensors, flexible actuators, and micro electromechanical applications.
Surface acoustic wave pressure sensor on ScAlN/3C-SiC/Si layer structure incorporating biomimetic microcantilever: modelling and performance enhancement
Authors: Zhang Qiaozhen , Zhao Xiangyong , Wang Feifei , Luo Yang , Mao Hongwei , Han Tao
Published: November 2020

This paper presents a bio-inspired cantilever-type SAW pressure sensor based on Scandium-doped AlN (ScAlN)/3CSiC/Si layer structure. The proposed biomimetic microcantilever is configured with stress concentration region (SCR) comprising of a series of narrow slits. For a given depth, by properly setting the number and the width of those slits for a given depth, homogeneous stress/strain distribution in vicinity of SCR are achieved. Furthermore, multi-physics finite element modeling for evaluating the pressure coefficient of frequency (PCF) of a one-port SAW resonant sensor is performed and validated. Then the PCF for the proposed SAW pressure sensor with the optimized biomimetic microcantilever is analyzed. The dependence of ScAlN thin film thickness h
ScAlN and scandium-doped concentration r of Sc
r
Al1-r
N thin film on PCF for different SAW modes including Rayleigh mode and Sezawa mode are calculated. The investigation results show that the maximum PCF of −111 ppm bar−1 can be achieved for Rayleigh mode, which is 2.4 times larger than that of the previously reported ZnO/Si structure. In addition, its PCF has weak dependence on h
ScAlN, which are quite favorable for manufacturing pressure sensors with good reproducibility. The conceived bio-inspired cantilever-type SAW devices based on ScAlN/3 CSiC/Si structure will open the door to develop pressure sensors with a stable and reliable performance and enhanced sensitivity.
A proposal for a lightweight, large current superconducting cable for aviation
Authors: Yamaguchi Sataro , Kanda Masae
Published: November 2020

More Electric Aircraft (MEA) is one of the most important subjects for designing the next generation of aircraft. Since we cannot ground the electric power systems of a flying aircraft and the air insulation voltage is lower at high altitude, a low voltage, direct current (DC) aircraft electrical system is preferable for a MEA. Since the current must be high to supply high power, we consider high temperature superconducting (HTS) technology because it handles large currents well. We propose a new HTS cable in this paper. The cable uses a stacked conductor, with oppositely directed current in each HTS tape, a structure that has already been shown to be feasible for low voltage cables. It enhances the critical current compared to a single tape conductor, especially for Bi2223 tape. In order to avoid a current imbalance in the stacked conductor, we use the current lead resistance rather than a Roebel conductor design. Then the critical current remains high, and this is confirmed by measurements. The cryogenic pipe will be made of magnesium-lithium alloy, one of the lightest metals available at the present time. We estimate the weight-to-current ratio per unit length to be less than 0.5 kg/A/km at the liquid nitrogen operational temperature of 77 K, lighter than conventional copper cable. If instead we use liquid hydrogen at 20 K, we expect a value less than 0.1 kg/A/km, which is one of the lowest presently achievable values and satisfies the requirements for MEA.
Quantum chaos approach in exciton energy transfer in a photosynthetic system
Authors: Hosseinnezhad P , Behnia S , Fathizadeh S
Published: November 2020

Photosynthesis is the most important photon-induced process to fuel the activities of the organism. In the current work, we have investigated the exciton energy transfer in a photosynthetic complex connected to a thermal bath using the quantum chaos approach. The statistical distribution of the energy levels of the system investigates a quasi-degeneracy level distribution and, therefore, a stable system. The system is sensitive to the environmental effects, and the Hamiltonian parameters. Among the practical factors, we have studied the effect of temperature and solvent on the chlorosome system. At low temperatures, the Izrailev distribution is quasi-Poisson and the general behavior of the system approaches to a nearly localized state. Gradually, with increasing temperature, it corresponds to the Poisson state and shows an improvement in exciton transmission. In the presence of a solvent, at low solvent frequency, via the increasing the temperature, the system changes its behavior from the localized state to the transition state. But, by increasing the frequency, the system presents the opposite behavior: with increasing the temperature, the system becomes more localized. Accordingly, the most appropriate conditions for exciton energy transfer in the chlorosome system are low-frequency solvent and high-temperature. To compare the temperature effect on different parts of the photosynthetic system, we have studied the temperature effect on the FMO complex conductivity, which shows the increase in conductivity and exciton energy transfer with increasing the temperature. Modulation of transport properties in the system provides the potential application in the nanoscale biomaterial devices.
Degree-ordered-percolation on uncorrelated networks
Authors: Caligiuri Annalisa , Castellano Claudio
Published: November 2020

We analyze the properties of degree-ordered percolation (DOP), a model in which the nodes of a network are occupied in degree-descending order. This rule is the opposite of the much studied degree-ascending protocol, used to investigate resilience of networks under intentional attack, and has received limited attention so far. The interest in DOP is also motivated by its connection with the susceptible-infected-susceptible (SIS) model for epidemic spreading, since a variation of DOP is related to the vanishing of the SIS transition for random power-law degree-distributed networks P(k) ∼ k
−γ
. By using the generating function formalism, we investigate the behavior of the DOP model on networks with generic value of γ and we validate the analytical results by means of numerical simulations. We find that the percolation threshold vanishes in the limit of large networks for γ ⩽ 3, while it is finite for γ > 3, although its value for γ between 3 and 4 is exceedingly small and preasymptotic effects are huge. We also derive the critical properties of the DOP transition, in particular how the exponents depend on the heterogeneity of the network, determining that DOP does not belong to the universality class of random percolation for γ ⩽ 3.
A novel vertical aligned mesoporous silica coated nanohydroxyapatite particle as efficient dexamethasone carrier for potential application in osteogenesis
Authors: Jia Sen , Liu Yan , Ma Zhiwei , Liu Changkui , Chai Juan , Li Zixia , Song Wen , Hu Kaijin
Published: November 2020

Bone defect is a common problem and inducing osteoblasts differentiation is the key process for the regenerative repair. Recently, the mesoporous silica (MS) coated nanohydroxyapatite (nHA) particles (nHA-MS) has shown enhanced intrinsic potency for bone regeneration, whereas whether the osteogenesis potency can be further enhanced after drug delivery has not been investigated. In this study, the nHA-MS was fabricated by a novel biphase stratification growth way. The cytotoxicity in MC3T3-E1 was validated by MTT assay, apoptosis analysis and cell cycle examination. The cell uptake was observed by confocal laser scanning microscope and transmission electron microscope respectively. After adsorption with dexamethasone (DEX), the osteogenic differentiation was determined both in vitro and in vivo. The synthesized nHA-MS showed a core–shell structure that the nanorod-like nHA was coated by a porous MS shell (∼5 nm pores diameter, ∼50 nm thickness). A dose-dependent cytotoxicity was observed and below 10 µg ml−1 was a safe concentration. The nHA-MS also showed efficient cell uptake efficiency and more efficient in DEX loading and release. After DEX adsorption, the nanoparticles exhibited enhanced osteogenic induction in MC3T3-E1 and rat calvarial bone defect regeneration. In conclusion, the nHA-MS is a favorable platform for drug delivery to obtain more enhanced osteogenesis capabilities.
Fourth Painlevé and Ermakov equations: quantum invariants and new exactly-solvable time-dependent Hamiltonians
Authors: Zelaya K , Marquette I , Hussin V
Published: November 2020

In this work, we introduce a new realization of exactly-solvable time-dependent Hamiltonians based on the solutions of the fourth Painlevé and the Ermakov equations. The latter is achieved by introducing a shape-invariant condition between an unknown quantum invariant and a set of third-order intertwining operators with time-dependent coefficients. New quantum invariants are constructed after adding a deformation term to the well-known quantum invariant of the parametric oscillator. Such a deformation depends explicitly on time through solutions of the Ermakov equation, a property that simultaneously ensures the regularity of the new time-dependent potentials at each time. The fourth Painlevé equation appears after introducing an appropriate reparametrization of the spatial coordinate and the time parameter, where the parameters of the fourth Painlevé equation dictate the spectral information of the quantum invariant. In this form, the eigenfunctions of the third-order ladder operators lead to several sequences of solutions to the Schrödinger equation, which are determined in terms of the solutions of the Riccati equation, Okamoto polynomials, and nonlinear bound states of the derivative nonlinear Schrödinger equation. Remarkably, it is noticed that the solutions in terms of the nonlinear bound states lead to a quantum invariant with equidistant eigenvalues, which contains both an finite-dimensional and an infinite-dimensional sequences of eigenfunctions. The resulting family of time-dependent Hamiltonians is such that, to the authors’ knowledge, have been unnoticed in the literature of stationary and nonstationary systems.
InGaN quantum dots with short exciton lifetimes grown on polar c-plane by metal-organic chemical vapor deposition
Authors: Zhao Chunyu , Tang Chak Wah , Cheng Guanghui , Wang Jiannong , Lau Kei May
Published: November 2020

An investigation of self-assembled polar InGaN quantum dots (QDs) on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) is reported. The radiative exciton lifetime is measured by time-resolved photoluminescence at a low temperature of 18 K, where the non-radiative recombination can be negligible. A mono-exponential exciton decay with a radiative exciton lifetime of 480 ps for uncapped QDs is revealed. With an optimized GaN capping layer grown by a two-step method, a radiative exciton lifetime of 707 ps for the capped QDs is preserved. The short radiative exciton lifetime is much shorter than that for previously studied polar QDs and is even comparable with those grown along non-polar QDs, which is strong evidence of the reduction of built-in fields in these polar InGaN QDs.
Dense positrons and γ-rays generation by lasers interacting with convex target
Authors: YASEN Nureli , XIE Baisong , LIU Weiyuan
Published: November 2020

We use quantum electrodynamics particle-in-cell simulation to study the generation of dense electron–positron plasma and strong γ-ray bursts in counter-propagating laser beam interactions with two different solid targets, i.e. planar (type I) and convex (type II). We find that type II limits fast electron flow most effectively. while the photon density is increased by about an order of magnitude and energy by approx. 10%–20% compared with those in type I target. γ-photon source with an ultrahigh peak brilliance of 2 × 1025 photons/s/mm2/mrad2/0.1% BW is generated by nonlinear Compton scattering process. Furthermore, use of type II target increases the positron density and energy by 3 times and 32% respectively, compared with those in type I target. In addition, the conversion efficiencies of total laser energy to γ-rays and positrons of type II are improved by 13.2% and 9.86% compared with type I. Such improvements in conversion efficiency and positron density are envisaged to have practical applications in experimental field.
Improving the reliability of conductive atomic force microscopy-based electrical contact resistance measurements
Authors: Sumaiya Saima A , Martini Ashlie , Baykara Mehmet Z
Published: November 2020

Electrical contact resistance (ECR) measurements performed via conductive atomic force microscopy (C-AFM) suffer from poor reliability and reproducibility. These issues are due to a number of factors, including sample roughness, contamination via adsorbates, changes in environmental conditions such as humidity and temperature, as well as deformation of the tip apex caused by contact pressures and/or Joule heating. Consequently, ECR may vary dramatically from measurement to measurement even on a single sample tested with the same instrument. Here we present an approach aimed at improving the reliability of such measurements by addressing multiple sources of variability. In particular, we perform current-voltage spectroscopy on atomically flat terraces of highly oriented pyrolytic graphite (HOPG) under an inert nitrogen atmosphere and at controlled temperatures. The sample is annealed before the measurements to desorb adsorbates, and conductive diamond tips are used to limit tip apex deformation. These precautions lead to measured ECR values that follow a Gaussian distribution with significantly smaller standard deviation than those obtained under conventional measurement conditions. The key factor leading to this improvement is identified as the switch from ambient conditions to a dry nitrogen atmosphere. Despite these improvements, spontaneous changes in ECR are observed during measurements performed over several minutes. However, it is shown that such variations can be suppressed by applying a higher normal load.
Interplay between finite topological rank minimal Cantor systems, 𝒮-adic subshifts and their complexity
Authors: Donoso Sebastián , Durand Fabien , Maass Alejandro , Petite Samuel
Published: November 2020

Minimal Cantor systems of finite topological rank (that can be represented by a Bratteli-Vershik diagram with a uniformly bounded number of vertices per level) are known to have dynamical rigidity properties. We establish that such systems, when they are expansive, define the same class of systems, up to topological conjugacy, as primitive and recognizable

S

{\mathcal S}

-adic subshifts. This is done by establishing necessary and sufficient conditions for a minimal subshift to be of finite topological rank. As an application, we show that minimal subshifts with non-superlinear complexity (like many classical zero-entropy examples) have finite topological rank. Conversely, we analyze the complexity of

S

{\mathcal S}

-adic subshifts and provide sufficient conditions for a finite topological rank subshift to have a non-superlinear complexity. This includes minimal Cantor systems given by Bratteli-Vershik representations whose tower levels have proportional heights and the so-called left to right

S

{\mathcal S}

-adic subshifts. We also show that finite topological rank does not imply non-superlinear complexity. In the particular case of topological rank two subshifts, we prove their complexity is always subquadratic along a subsequence and their automorphism group is trivial.
Effect of the COVID-19 lockdown on disease recognition and utilisation of healthcare services in the older population in Germany: a cross-sectional study
Authors: Michalowsky Bernhard , Hoffmann Wolfgang , Bohlken Jens , Kostev Karel
Published: November 2020

Background

There is little evidence about the utilisation of healthcare services and disease recognition in the older population, which was urged to self-isolate during the COVID-19 lockdown.

Objectives

We aimed to describe the utilisation of physician consultations, specialist referrals, hospital admissions and the recognition of incident diseases in Germany for this age group during the COVID-19 lockdown.

Design

Cross-sectional observational study.

Setting

1,095 general practitioners (GPs) and 960 specialist practices in Germany.

Subjects

2.45 million older patients aged 65 or older.

Methods

The number of documented physician consultations, specialist referrals, hospital admissions and incident diagnoses during the imposed lockdown in 2020 was descriptively analysed and compared to 2019.

Results

Physician consultations decrease slightly in February (−2%), increase before the imposed lockdown in March (+9%) and decline in April (−18%) and May (−14%) 2020 compared to the same periods in 2019. Volumes of hospital admissions decrease earlier and more intensely than physician consultations (−39 versus −6%, respectively). Overall, 15, 16 and 18% fewer incident diagnoses were documented by GPs, neurologists and diabetologists, respectively, in 2020. Diabetes, dementia, depression, cancer and stroke were diagnosed less frequently during the lockdown (−17 to −26%), meaning that the decrease in the recognition of diseases was greater than the decrease in physician consultations.

Conclusion

The data suggest that organisational changes were adopted quickly by practice management but also raise concerns about the maintenance of routine care. Prospective studies should evaluate the long-term effects of lockdowns on patient-related outcomes.
Lorna Finlayson on Political Philosophy and Immigration: A Reply
Authors: Miller David
Published: November 2020

Replying to Finlayson (2020), I defend analytic political philosophy from the charge that, by ignoring their historical context, it fails to grasp what is really at stake in the case of issues such as immigration. I also defend my own work on that topic from the charge that it is implicitly racist by virtue of using arguments capable of being appropriated by racists.
miqoGraph: fitting admixture graphs using mixed-integer quadratic optimization
Authors: Yan Julia , Patterson Nick , Narasimhan Vagheesh M
Published: November 2020

Admixture graphs represent the genetic relationship between a set of populations through splits, drift and admixture. In this article, we present the Julia package miqoGraph, which uses mixed-integer quadratic optimization to fit topology, drift lengths and admixture proportions simultaneously. Through applications of miqoGraph to both simulated and real data, we show that integer optimization can greatly speed up and automate what is usually an arduous manual process.

Availability and implementation

https://github.com/juliayyan/PhylogeneticTrees.jl.

Supplementary information

Supplementary data are available at Bioinformatics online.
A framework for modeling epistatic interaction
Authors: Blumenthal David B , Baumbach Jan , Hoffmann Markus , Kacprowski Tim , List Markus
Published: November 2020

Motivation

Recently, various tools for detecting single nucleotide polymorphisms (SNPs) involved in epistasis have been developed. However, no studies evaluate the employed statistical epistasis models such as the χ2-test or quadratic regression independently of the tools that use them. Such an independent evaluation is crucial for developing improved epistasis detection tools, for it allows to decide if a tool’s performance should be attributed to the epistasis model or to the optimization strategy run on top of it.

Results

We present a protocol for evaluating epistasis models independently of the tools they are used in and generalize existing models designed for dichotomous phenotypes to the categorical and quantitative case. In addition, we propose a new model which scores candidate SNP sets by computing maximum likelihood distributions for the observed phenotypes in the cells of their penetrance tables. Extensive experiments show that the proposed maximum likelihood model outperforms three widely used epistasis models in most cases. The experiments also provide valuable insights into the properties of existing models, for instance, that quadratic regression perform particularly well on instances with quantitative phenotypes.

Availability and implementation

The evaluation protocol and all compared models are implemented in C++ and are supported under Linux and macOS. They are available at https://github.com/baumbachlab/genepiseeker/, along with test datasets and scripts to reproduce the experiments.

Supplementary information

Supplementary data are available at Bioinformatics online.
Cerebellar contributions to cognition in corticobasal syndrome and progressive supranuclear palsy
Authors: Tse Nga Yan , Chen Yu , Irish Muireann , Cordato Nicholas J , Landin-Romero Ramon , Hodges John R , Piguet Olivier , Ahmed Rebekah M
Published: November 2020

Mounting evidence suggests an association between cerebellar atrophy and cognitive impairment in the main frontotemporal dementia syndromes. In contrast, whether cerebellar atrophy is present in the motor syndromes associated with frontotemporal lobar degeneration (corticobasal syndrome and progressive supranuclear palsy) and the extent of its contribution to their cognitive profile remain poorly understood. The current study aimed to comprehensively chart profiles of cognitive impairment in relation to cerebellar atrophy in 49 dementia patients (corticobasal syndrome = 33; progressive supranuclear palsy = 16) compared to 33 age-, sex- and education-matched healthy controls. Relative to controls, corticobasal syndrome and progressive supranuclear palsy patients demonstrated characteristic cognitive impairment, spanning the majority of cognitive domains including attention and processing speed, language, working memory, and executive function with relative preservation of verbal and nonverbal memory. Voxel-based morphometry analysis revealed largely overlapping patterns of cerebellar atrophy in corticobasal syndrome and progressive supranuclear palsy relative to controls, primarily involving bilateral Crus II extending into adjacent lobules VIIb and VIIIa. After controlling for overall cerebral atrophy and disease duration, exploratory voxel-wise general linear model analysis revealed distinct cerebellar subregions differentially implicated across cognitive domains in each patient group. In corticobasal syndrome, reduction in grey matter intensity in the left Crus I was significantly correlated with executive dysfunction. In progressive supranuclear palsy, integrity of the vermis and adjacent right lobules I–IV was significantly associated with language performance. These results are consistent with the well-established role of Crus I in executive functions and provide further supporting evidence for vermal involvement in cognitive processing. The current study presents the first detailed exploration of the role of cerebellar atrophy in cognitive deficits in corticobasal syndrome and progressive supranuclear palsy, offering insights into the cerebellum’s contribution to cognitive processing even in neurodegenerative syndromes characterized by motor impairment.
Naive B cells in neuromyelitis optica spectrum disorders: impact of steroid use and relapses
Authors: Janssen Malou , Bruijstens Arlette L , van Langelaar Jamie , Wong YuYi , Wierenga-Wolf Annet F , Melief Marie-José , Rijvers Liza , van Pelt E Daniëlle , Smolders Joost , Wokke Beatrijs H , van Luijn Marvin M
Published: November 2020

Neuromyelitis optica spectrum disorders are a group of rare, but severe autoimmune diseases characterized by inflammation of the optic nerve(s) and/or spinal cord. Although naive B cells are considered key players by escaping central tolerance checkpoints, it remains unclear how their composition and outgrowth differ in patients with neuromyelitis optica spectrum disorders. Under complete treatment-naive circumstances, we found that naive mature/transitional B-cell ratios were reduced in the blood of 10 patients with aquaporin-4 immunoglobulin G-positive disease (neuromyelitis optica spectrum disorders) as compared to 11 both age- and gender-matched healthy controls, eight patients with myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disorders and 10 patients with multiple sclerosis. This was the result of increased proportions of transitional B cells, which were the highest in patients with neuromyelitis optica spectrum disorders with relapses and strongly diminished in a separate group of nine patients with neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disorders who received corticosteroid treatment. These findings need to be confirmed in longitudinal studies. For purified naive mature B cells of seven patients with neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disorders with relapses, Toll-like receptor 9 ligand synergized with interferon-γ to enhance plasmablast formation during germinal centre-like cultures. This was not seen for 11 patients without relapses and nine healthy controls. In the neuromyelitis optica spectrum disorders group, in vitro plasmablast formation corresponded to total and anti-aquaporin-4 immunoglobulin G secretion, of which the latter was found only for relapsing cases. These data indicate that naive B-cell homoeostasis is different and selectively targeted by corticosteroids in patients with neuromyelitis optica spectrum disorders. This also supports further exploration of naive B cells for their use in Toll-like receptor 9-dependent in vitro platforms in order to predict the activity of neuromyelitis optica spectrum disorders.
Association Between Statin Use and Inflammatory Bowel Diseases: Results from a Swedish, Nationwide, Population-based Case-control Study
Authors: Lochhead Paul , Khalili Hamed , Sachs Michael C , Chan Andrew T , Olén Ola , Ludvigsson Jonas F
Published: November 2020

Background

In addition to their potent lipid-lowering action, statins may modulate inflammation. However, data on statin use and the risk of inflammatory bowel diseases [IBD] have been inconsistent.

Methods

We searched the Nationwide Swedish Patient Register [inpatient and non-primary outpatient care] to identify adults diagnosed with Crohn’s disease [CD, n = 7637] or ulcerative colitis [UC, n = 15 652] from 2006 to 2014. Each case was matched to 10 general population controls [n = 232 890]. Data on dispensed statin prescriptions were extracted from the Prescribed Drug Register. Conditional logistic regression models estimated odds ratios [ORs] for risk of IBD according to statin exposure while controlling for potential confounders, including indications for statin therapy.

Results

In multivariable adjusted models, compared with no statin use, any statin use was associated with a lower risk of CD (OR = 0.71; 95% confidence interval [CI], 0.63–0.79), but not UC [OR = 1.03; 95% CI, 0.96–1.11]. The lowest OR for CD was seen for current statin use [OR = 0.67; 95% CI, 0.60–0.75]. For CD, the lowest category of cumulative statin dose [31–325 defined daily dose, DDD] was associated with an OR of 0.73 [95% CI, 0.61–0.88] and the highest category [>1500 DDD] with an OR of 0.66 [95% CI, 0.55–0.80], ptrend = 0.10. For UC, the lowest and highest dose categories yielded ORs of 1.12 [95% CI, 1.00–1.25] and 0.99 [95% CI, 0.88–1.13], respectively, ptrend = 0.13.

Conclusions

Statin use was associated with a lower risk of CD, but not of UC. The association with CD risk appeared strongest for current statin use. Our findings suggest that statin use may influence the development of CD.
The Impact of Youth Engagement on Life Satisfaction: A Quasi-Experimental Field Study of a UK National Youth Engagement Scheme
Authors: Laurence James
Published: November 2020

There is growing interest in the role of organized social participation in clubs, associations and activities in shaping subjective well-being (SWB). However, the field remains contested. This study addresses key questions regarding the participation–SWB link: concerns regarding endogeneity; debate surrounding the mechanisms at work; and the role participation can play in closing inequalities in SWB. Each question is addressed through a quasi-experimental field study into the impact of a large-scale, nationally-implemented youth engagement scheme (UK National Citizen Service) on life satisfaction. Using pre-test/post-test data on a sample of participants and (propensity score matched) controls, results suggest discrete periods of youth engagement can lead to significant improvements in life satisfaction, observable at least 4–6 months after involvement ended. Participation can also help close social inequalities in SWB via a significantly stronger impact on life satisfaction among young people from more economically disadvantaged communities. Although youth from disadvantaged communities join the scheme with lower SWB, post-participation, they have entirely closed the gap in SWB with their less-disadvantaged peers. Improvements in SWB emerge from positive impacts of participation on both social- and psychological-resource pathways. However, stronger participation-effects on psychological-resources become increasingly important for explaining the additional SWB-gains of more disadvantaged young people.