bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging of Carpal Instabilities
Authors: Grunz Jan-Peter , Gietzen Carsten Herbert , Grunz Katharina , Bley Thorsten , Schmitt Rainer
Published: September 2020

Background The term “carpal instability” describes different debilitating wrist conditions, in which the carpus is unable to maintain its physiological range of motion and load transfer. Depending on the cause and location of the dysfunction, four groups can be defined: dissociative, non-dissociative, complex, and adaptive carpal instability. As the most common form by far, dissociative carpal instability can further be categorized as dorsal or palmar intercalated segment instability, contingent on the afflicted interosseous ligament.

Method This review article outlines the different entities of carpal instability, their pathophysiology, and their clinical presentation. It further discusses the diagnostic significance of different imaging methods as well as the established treatment options for each form of instability in context with the current literature.

Results and Conclusion Early detection and treatment of carpal instability are essential for preventing carpal osteoarthritis. Traumatic lesions of the scapholunate interosseous ligament are the most frequent cause of instability. They can occur in an isolated fashion or in context with other carpal injuries. While stress imaging and fluoroscopy facilitate the differentiation between dynamic and static forms of carpal instability, only MRI and CT/MR arthrography can directly reveal the extent of ligament discontinuity.

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Five Reasons for the Failure to Diagnose Aldosterone Excess in Hypertension
Authors: Piaditis George P. , Kaltsas Gregory , Markou Athina , Chrousos George P.
Published: September 2020

Primary hyperaldosteronism (PA) is a well-known cause of hypertension although its exact prevalence amongst patients with apparent essential hypertension has been a matter of debate. A number of recent studies have suggested that mild forms of PA may be relatively common taking into consideration factors that were previously either overestimated or ignored when developing diagnostic tests of PA and when applying these tests into normotensive individuals. The performance characteristics and diagnostic accuracy of such tests are substantially increased when the adrenocorticotrophin effect, inappropriate potassium levels and their application in carefully selected normotensive individuals are considered. In the present review, we critically analyze these issues and provide evidence that several, particularly mild, forms of PA can be effectively identified exhibiting potentially important clinical implications.
Cross-insitutional standardization of imaging protocols – A pilot study within the scope of the Comprehensive Cancer Center Lower Saxony
Authors: Römermann Inka , Al-Bourini Omar , Seif Amir Hosseini Ali , Hinrichs Jan B. , Wacker Frank K. , Lotz Joachim , Ringe Kristina I.
Published: September 2020

Purpose Cross-institutional establishment of standardized protocols for CT and MR imaging of primary liver and pancreas tumors in an oncological center.

Materials and Methods This prospective dual-institution study was approved by the local IRBs. Minimum requirements (phases, sequences, slice thickness) for imaging of primary liver and pancreas tumors were defined and implemented at both sites. Between 06/19 and 08/19 in-house examinations were evaluated in terms of compliance with defined protocols and image quality. In addition, extramural examinations that were demonstrated at interdisciplinary tumor board meetings in the same study period were reviewed. Results were analyzed by means of descriptive statistics, and differences between centers, modalities and organs assessed (Fisher-exact Test, p < 0.05 deemed significant).

Results 480 data sets (397 internal, 83 extramural) were included in this study and analyzed. Overall protocol compliance for in-house examinations was 93.5 % (371/397 datasets), without statistical significant difference between the two institutions (p = 0.0615). External studies met minimum requirements in 48.2 % (40/83 datasets). Regarding in-house imaging, significant differences were observed between CT of the liver and the pancreas (p < 0.05) and between CT and MRI of the pancreas (p < 0.05).

Conclusion As demonstrated in this pilot project, cross-institutional establishment of standardized imaging protocols is feasible with a compliance rate of more than 90 %. Standardized imaging protocols may serve as a quality indicator in oncological imaging, and over time, improve cross-institutional patient care.

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Exposure to Mosquito Repellents Causes Profound Development Defects and Induces Oxidative Stress in Zebrafish
Authors: Prabhakara Aprathi , Nanjappa Dechamma Pandyanda , Babu Nishith , Kalladka Krithika , Chakraborty Anirban , Chakraborty Gunimala
Published: September 2020

Objective The study was designed to investigate the effects of commercially available mosquito repellents on embryonic development of zebrafish.

Materials and Methods Transfluthrin is a type I pyrethroid present in all commercial mosquito and insect repellents. Pyrethrins are neurotoxins that target the nervous system of insects. Three popular brands of liquid vaporizer repellents coded as compound A, B, and C that contained transfluthrin, ranging from 0.88 to 1.6% w/w, were used in this study. The effects of these compounds on the embryonic development of zebrafish were investigated. In addition, the ability of transfluthrin to induce oxidative stress was examined by analyzing the generation of reactive oxygen species in exposed embryos.

Results The exposure to mosquito repellents resulted in extensive morphological defects in zebrafish embryos. The severity of the anomalies correlated with the concentration of transfluthrin in the repellents. Exposure to pure transfluthrin generated high levels of reactive oxygen species in zebrafish embryos, suggesting the induction of oxidative stress.

Conclusion Liquid vaporizer repellents are generally used for control of mosquitos and are common in many households. This study demonstrated that its exposure to mosquito repellents causes severe morphological defects and embryonic lethality in zebrafish. The study also showed that transfluthrin, the active insecticide in these repellents, induces oxidative stress in zebrafish.
Our need for associative coherence
Authors: Afiki Yael , Bar Moshe
Published: September 2020

The world around us consists of typical settings manifested as statistical regularities and stored as associations. These associations are beneficial for performance, and we rely on them as a source of stability in our perception of a coherent surrounding. What happens when such associativity is not apparent? We presented pairs of associated images and pairs of non-associated images and compared their corresponding effect on subsequent performance in three different visual perception paradigms: contrast-sensitivity, global vs. local perception, and critical-flicker-fusion. In all three experiments, performance was significantly inferior when preceded by images with no clear associative connection. We propose that these results reflect the need to find coherence in our environment. When such coherence is not easily detected, we seem to persist in seeking for it, which in turn poses a lingering cognitive load that taxes performance even in low-level perception.
ELECTROSTATICS IN MODERN PHYSICS AND TECHNOLOGY
Authors: Morse Robert A.
Published: September 2020

There are a variety of industrial and research applications of electrostatics and continuing research in the fundamental processes of electrostatic charging and discharging. Applications include electrostatic smoke precipitation, electrostatic separation of materials, electrostatic coating, spray painting and flocking, xerographic imaging, ink-jet printing, electrostatic microphones and loudspeakers, electrostatic effects in semiconductor design, high voltage generators, and others. The prevention of damage by lightning is an old concern and the prevention of accidental electrostatic discharge in combustible atmospheres is a major industrial safety concern. Many of these applications are discussed in the books by A.D. Moore (Electrostatics, Doubleday & Co., Garden City, NY, 1968; Electrostatics and its Applications, Wiley, 1973) and J.A. Cross (Electrostatics: Principles, Problems and Applications, Adam Hilger, Bristol, UK, 1987.)
Simultaneous Equations
Authors: Swartz Clifford E.
Published: September 2020

Simultaneous equations is the name given to any set of equations that all have to be satisfied by the same set of values for the variables. This is a very broad definition, but in fact the major type consists of two or more variables in a linear combination: ak1x1 + ak2x2 + ⋯ + akkxk = b. In general, if there are n variables, it takes n and only n linearly independent equations of this form to obtain a unique solution, i.e., obtain only one value for each variable. Linearly independent means none of the equations can be made up by adding or subtracting some of the others to themselves or other equations any number of times.
MECHANICS
Authors: Frier G. D. , Anderson F. J.
Published: September 2020

Copies of the standard meter and standard yard can be placed on the lecture table for examination by the students.
Physics Laboratory Activity #13a Prediction of Landing Position
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

The purpose of this laboratory activity is to predict the landing position of a swinging ball released at the lowest point of its swing.
Physics Laboratory Activity #18a Images Formed by a Thin Converging Lens
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

The goal of this laboratory activity is to determine the properties of the image formed by the light that refracts as it passes through a converging lens. Look through a converging lens. Is the image right side up or upside down? Is the image enlarged or diminished? Move the lens toward and away from an object, and observe how moving the lens affects the image. Does the size and orientation of the image change when you move the lens toward you or away from you? As you can see the answer to the questions about the properties of the image formed by the refraction of light through a converging lens does not have a single answer, rather there are several answers depending upon the position of the object relative to the converging lens.
Physics Laboratory Activity # 20a Single and Double Slit
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

The purpose of this laboratory activity is to determine the wavelength of red and blue light.
Physics Laboratory Activity #98a The “Race Track” Game
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

Note: The purpose of this game is to emphasize two types of acceleration, first the acceleration along a path (i.e., speeding up and slowing down), and second the centripetal acceleration (i.e., changing direction).
Physics Laboratory Activity #99a Fermi Experiments
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

A. What is the volume of a swimming pool. Explain how you determine the volume of the pool. (Include diagrams!) Determine the volume of water required in cubic meters and in gallons to fill the pool. How often is the water in the pool replaced? How many families daily needs can be supplied by the water in the pool.
Student Handbook, Activities, and Demonstrations
Authors: Davids Mark , Rea R. Stephen , Zitzewitz Paul W.
Published: September 2020

This module investigates the development of lightwave communication systems and is organized into three sections. The first section considers simple methods of modulating light for use in transmitting information, the second section describes the role of low-loss glass as a medium for the transmission of light, and the third section explores the relative advantages of using digital signals for transmitting information, as compared with analog methods.
Demonstrations and Displays
Authors: Davids Mark , Rea R. Stephen , Zitzewitz Paul W.
Published: September 2020

The following demonstrations are included in Section 3.
Introduction, Workshop Outline, Materials List, and Bibliography
Authors: Franklin Bill
Published: September 2020

This unit divides color and color vision into four major topics:The eye and color vision; colors from mixing light or pigmentsThe colors of surfaces and light sources; absorption and emission, refraction, scattering, and diffraction and interferenceColors from interference involving diffraction and thin filmsColors from interference involving polarization
Use of Technology
Authors: Franklin Bill
Published: September 2020

(This section is empty, but is included as a place for the user to file appropriate materials.)
COMPUTER APPLICATIONS FOR TEACHING MAGNETISM
Authors: Reiland Robert J.
Published: September 2020

EM Field by David Trowbridge and Bruce Sherwood for Macintosh and MS-DOS computers allows students to get field line maps and field strength vectors around current carrying wires that they “place” on the computer screen. It also has an exploration feature that asks them to find hidden wires by sampling the magnetic field at points of their choosing. It is sold by Physics Academic Software. Contact John Risley, Dept. of Physics, North Carolina State Univ., Raleigh, NC 27695-8202.
TEST QUESTIONS FOR MAGNETISM
Authors: Reiland Robert J.
Published: September 2020

For the two magnets shown below:draw representative field lines.indicate where the magnetic field is greatest and weakest.indicate where an iron filing would experience the greatest net magnetic force.
General practice's early response to the COVID-19 pandemic
Authors: Wright Michael , Versteeg Roald , Hall Jane
Published: September 2020

The COVID-19 pandemic has resulted in multiple changes in the delivery of general practice services. In response to the threat of the pandemic and in order to keep their businesses safe and viable, general practices have rapidly moved to new models of care, embraced Medicare-funded telehealth and responded to uncertain availability of personal protective equipment with innovation. These changes have shown the adaptability of general practice, helped keep patients and practice staff safe, and undoubtedly reduced community transmission and mortality. The pandemic, and the response to it, has emphasised the potential dangers of existing fragmentation within the Australian health system, and is affecting the viability of general practice. These impacts on primary care highlight the need for improved integration of health services, should inform future pandemic planning, and guide the development of Australia’s long-term national health plan.
Fruit setting rewires central metabolism via gibberellin cascades
Authors: Shinozaki Yoshihito , Beauvoit Bertrand P. , Takahara Masaru , Hao Shuhei , Ezura Kentaro , Andrieu Marie-Hélène , Nishida Keiji , Mori Kazuki , Suzuki Yutaka , Kuhara Satoshi , Enomoto Hirofumi , Kusano Miyako , Fukushima Atsushi , Mori Tetsuya , Kojima Mikiko , Kobayashi Makoto , Sakakibara Hitoshi , Saito Kazuki , Ohtani Yuya , Bénard Camille , Prodhomme Duyen , Gibon Yves , Ezura Hiroshi , Ariizumi Tohru
Published: September 2020

Significance

Fruit set, which is triggered by the phytohormone gibberellin (GA), is the developmental transition of ovaries into fruits. Our multiomics approaches revealed that PROCERA
-
dependent GA responses rewired central carbon metabolism, predominantly under transcriptional control. The kinetic analysis approach used in this study enabled us to construct a carbon flux model of the earliest processes that occur during fruit set. The model revealed that fruit set coincided with the temporal changes in sugar compartmentalization due to the coordinated actions of the enzymes and tonoplastic carriers and highlighted that fructokinase likely contributed to early ovary growth by pulling fructose out of the vacuole to feed the downstream pathways for biosynthesis of cell wall components and energy provision.
Impact of Pharmacist Contact via Telephone vs Letter on Rate of Acquisition of Naloxone Rescue Kits by Patients with Opioid use Disorder
Authors: Hoefling Austin D. , Ash Lauren R. , Linneman Travis W.
Published: September 2020

Background

Limited data describes the effectiveness of strategies to optimize naloxone rescue kit distribution. Mental health clinical pharmacy specialists (CPS) at VA St. Louis HCS aimed to increase distribution of naloxone rescue kits to patients with Opioid Use Disorder (OUD). An informational letter detailing the purpose of rescue kits and how to obtain one were sent to patients with OUD who had no active order for a naloxone rescue kit within the previous year. Roughly half of these patients were targeted for follow-up education via telephone.

Methods

A retrospective study was conducted comparing the effectiveness of these contact methods. Study groups included those contacted by letter alone and those contacted by both letter and phone call. The primary outcome was order placement for a rescue kit within 90 days of contact. Post-hoc analysis included a multivariate regression, case-control evaluation of variables potentially associated with kit distribution.

Results

In total, 335 patients were included. Of 185 patients targeted for phone follow-up, 81 were reached (43.8%), and 254 received the letter alone. The primary outcome was achieved by 13 (5.1%) and 52 (64.2%) participants in the letter alone and letter plus phone contact groups, respectively ( p < 0.001). In multivariate analysis, phone contact (OR 38.6; 95% CI 17.5–85.0), nonwhite race (OR 3.4; 95% CI 1.5–7.6), prior participation in the substance abuse rehabilitation treatment program (OR 3.2; 95% CI 1.3–8.0), and current active opioid prescription (OR 3.7; 95% CI 1.3–10.2) were independently associated with an order for a naloxone rescue kit.

Conclusions

In patients with OUD, those contacted by phone in addition to receiving a letter were significantly more likely to receive a naloxone kit than those contacted via letter alone. In addition to contact by phone, nonwhite race, prior participation in rehabilitation and active opioid prescription were associated with a higher rate of kit obtainment.
Anti–IFN-γ autoantibodies underlie disseminatedTalaromyces marneffeiinfections
Authors: Guo Jing , Ning Xin-Qiang , Ding Jing-Ya , Zheng Yan-Qing , Shi Na-Na , Wu Feng-Yao , Lin You-Kun , Shih Han-Po , Ting He-Ting , Liang Gang , Lu Xiang-Chan , Kong Jin-Ling , Wang Ke , Lu Yi-Bo , Fu Yu-Jiao , Hu Rong , Li Tian-Min , Pan Kai-Su , Li Xiu-Ying , Huang Chun-Yang , Lo Yu-Fang , Chang Ian Yi-Feng , Yeh Chun-Fu , Tu Kun-Hua , Tsai Yu-Huan , Ku Cheng-Lung , Cao Cun-Wei
Published: September 2020

Talaromyces marneffei causes life-threatening opportunistic infections, mainly in Southeast Asia and South China. T. marneffei mainly infects patients with human immunodeficiency virus (HIV) but also infects individuals without known immunosuppression. Here we investigated the involvement of anti–IFN-γ autoantibodies in severe T. marneffei infections in HIV-negative patients. We enrolled 58 HIV-negative adults with severe T. marneffei infections who were otherwise healthy. We found a high prevalence of neutralizing anti–IFN-γ autoantibodies (94.8%) in this cohort. The presence of anti–IFN-γ autoantibodies was strongly associated with HLA-DRB1*16:02 and -DQB1*05:02 alleles in these patients. We demonstrated that adult-onset acquired immunodeficiency due to autoantibodies against IFN-γ is the major cause of severe T. marneffei infections in HIV-negative patients in regions where this fungus is endemic. The high prevalence of anti–IFN-γ autoantibody–associated HLA class II DRB1*16:02 and DQB1*05:02 alleles may account for severe T. marneffei infections in Southeast Asia. Our findings clarify the pathogenesis of T. marneffei infection and pave the way for developing novel treatments.
A projected Bouligand–Landweber iteration for non-smooth ill-posed problems
Authors: Fu Zhenwu , Chen Yong , Han Bo
Published: September 2020

In this work, we formulate a projected Bouligand–Landweber iteration for non-smooth ill-posed problems. The approach is a combination of Bouligand–Landweber iteration and the projection onto stripes the width of which is controlled by both the noise level and the structure of the operator. Since the forward mapping is not Fréchet differentiable, the convergence analysis will be based on the concept of asymptotic stability and a generalized tangential cone condition. Finally, numerical examples will be presented.
Flow modeling and experimental verification of flow resistors used in microfluidic chips driven by capillary force
Authors: Zhong Hao , Huang Weifeng , Li Yong , Tong Hao , Liu Guodong , Wang Zhiqiang
Published: September 2020

A microfluidic chip driven by capillary force has the advantage of low cost and ease of manufacturing in batches, and its flow behavior is dominated by the geometry and surface characteristics of the microchannel. The design of mirochannel structures is very important for the microfluidic chips. This study presents a semi analytical method for the design of capillary microchannel. In this method, the quasi-steady state approximate solution method of the Young–Laplace equation is used to derive the capillary surface tension, and the parallel flow assumption based on the Reynolds equation is used to derive the resistance of the channel wall. A computational fluid dynamics simulation is used to provide the inlet effect coefficient and channel shape effect coefficient of this model. The availability of the semi analytical model is verified by the experiment. This model realizes the flow analysis of two-dimensional capillary flow channel with a continuous shape of the flow channel wall, providing a fast and accurate method for the structural design of the microfluidic chip driven by capillary force.
Near-infrared nanosecond pulsed laser ablation of silver nanowire in aqueous media for low-power and low-debris laser processing
Authors: Hwang June Sik , Park Jong-Eun , Kim Gun Woo , Lee Huseung , Yang Minyang
Published: September 2020

Silver nanowire (Ag NW) is used as an attractive alternative material to fabricate flexible transparent conductive electrodes (TCE) instead of indium tin oxide, which has brittle characteristics and unstable processing expenses. For practical applications of Ag NW TCE, a proper patterning process is essential because the Ag NW layer is usually formed from the solution process. Laser ablation is one of the promising patterning processes for fabricating Ag NW-based optoelectronic devices. Among the laser processes, the nanosecond near-infrared pulsed laser ablation (NIR PLA) is considered advantageous because it is cheaper than ultrashort or ultraviolet pulsed lasers and causes little damage to the flexible substrate. However, since the Ag NW absorbance in this wavelength is very low, laser processing of Ag NW can deteriorate processing quality due to the remaining debris that resulted from incomplete evaporation of Ag NW. In this study, we report NIR PLA of Ag NW in aqueous media that improved the processing results of Ag NW laser patterning. We found that effective debris removal with a low fluence was a result of advantages such as the reduced heat-affected zone and dispersion of silver nanoparticle debris in the liquid media. Under different processing parameters, the performance of patterned Ag NW improved in liquid media compared to the ambient condition. Significant improvements in the processing quality were also observed in the laser patterning of Ag NW on the flexible substrate without any degradation. Consequently, the patterned flexible Ag NW TCE was successfully fabricated via the proposed process.
Stability threshold of formamidinium lead iodide determined by strain amplitudes
Authors: Karthick S , Rıéos-Ramıérez J J , Velumani S , Martirosyan K S , Castaneda H
Published: September 2020

The mechanical stability of α-phase formamidinium (FA) lead iodide perovskite is investigated using a systematic finite deformation method based on all the possible FA cation orientations, inside an inorganic cage. Two specific strain boundaries of deformation or strain amplitudes were efficiently examined over this optimized pseudo-cubic structure, which needs nine independent elastic constants (EC) to determine the stability. The stable structure was found while applying an initial amplitude limit (0.02), which is attributed to the balanced charge distribution in between the hydrogens (H4, H5 and H2, H3) to the specific iodine (I2) atom. Surprisingly, with increasing amplitude (0.04), the structure was unstable due to their disturbed charge distribution and FA cation tilting as found from electron density difference (EDD) spectrum. From the computational perspective, the obtained EC values, Mulliken charge, and EDD results provide some crucial information’s to understand the reason behind the instability issues based on the FA cation position which is reported so far. Hence, we provide a solid justification regarding the stability threshold of a pseudo-cubic model based on the FA cation position to get an insight into this FA cation-based perovskite material.
Flux flow instability as a probe for quasiparticle energy relaxation time in Fe-chalcogenides
Authors: Leo Antonio , Nigro Angela , Braccini Valeria , Sylva Giulia , Provino Alessia , Galluzzi Armando , Polichetti Massimiliano , Ferdeghini Carlo , Putti Marina , Grimaldi Gaia
Published: September 2020

In this work, we aim to demonstrate the potential of the flux flow instability (FFI) tool as a probe for the evaluation of the quasiparticle energy relaxation time τ
ϵ in iron-based superconductors (IBS). The knowledge of this microscopic parameter, its temperature dependence and the magnetic field influence, turns particularly useful to implement IBS materials in photon detection applications, as well as to get information on the gap symmetry or its anisotropy. Here, we focus on Fe(Se,Te) thin films that both from structural and magnetic properties show the simpler behaviour, thus it can be a reference test for any more complex IBS. By current-voltage characterizations and resistance measurements, we investigate the FFI features in the presence of an external applied magnetic field as a function of the angular dependence between the crystal structure of the film and the orientation of the field. We describe the observed experimental characteristics of FFI within the intrinsic electronic mechanism of Larkin-Ovchinnikov model. In this way, we are able to give a quantitative estimate of τ
ϵ in Fe(Se,Te) that can be compared with evaluation from other techniques such as pump and probe measurements. Thus, the angular measurements of FFI in high magnetic fields are a viable route to the possible mechanisms of quasiparticle relaxation and to the complementary knowledge on its anisotropy.
Expansion of EYM amplitudes in gauge invariant vector space *
Authors: Feng Bo , Li Xiao-Di , Huang Rijun
Published: September 2020

Motivated by the problem of expanding the single-trace tree-level amplitude of Einstein-Yang-Mills theory to the BCJ basis of Yang-Mills amplitudes, we present an alternative expansion formula in gauge invariant vector space. Starting from a generic vector space consisting of polynomials of momenta and polarization vectors, we define a new sub-space as a gauge invariant vector space by imposing constraints on the gauge invariant conditions. To characterize this sub-space, we compute its dimension and construct an explicit gauge invariant basis from it. We propose an expansion formula in this gauge invariant basis with expansion coefficients being linear combinations of the Yang-Mills amplitude, manifesting the gauge invariance of both the expansion basis and coefficients. With the help of quivers, we compute the expansion coefficients via differential operators and demonstrate the general expansion algorithm using several examples.
Optimizing experiment design for chemical measurement
Authors: Toman Blaza , Nelson Michael A , Ma Yong
Published: September 2020

Chemical measurement laboratories that provide a broad range of services rely on efficient and rigorously validated measurement procedures to meet industry demands. The success of these laboratories ultimately hinges upon their ability to produce results that are both fit-for-purpose and affordable. Skillful planning of measurement experiments must therefore provide adequate confidence in results without being overly complex. A statistical procedure is presented that can be used by laboratories to optimize such experiment designs. Inputs to the statistical model are based upon simple criteria such as the number of available samples, expected variabilty of calibration data, and the largest acceptable uncertainty in the result. The outputs of the model guide a measurement scheme that can provide results with as small an uncertainty as possible under specified constraints, such as the desired range of calibration and the number of samples and repeated measurements that should be made. The method and software used to execute this model are demonstrated for planning evaluations of vitamin D in serum that inform clinical medicine diagnostics.
Semi-analytic approximate stability selection for correlated data in generalized linear models
Authors: Takahashi Takashi , Kabashima Yoshiyuki
Published: September 2020

We consider the variable selection problem of generalized linear models (GLMs). Stability selection (SS) is a promising method proposed for solving this problem. Although SS provides practical variable selection criteria, it is computationally demanding because it needs to fit GLMs to many re-sampled datasets. We propose a novel approximate inference algorithm that can conduct SS without the repeated fitting. The algorithm is based on the replica method of statistical mechanics and vector approximate message passing of information theory. For datasets characterized by rotation-invariant matrix ensembles, we derive state evolution equations that macroscopically describe the dynamics of the proposed algorithm. We also show that their fixed points are consistent with the replica symmetric solution obtained by the replica method. Numerical experiments indicate that the algorithm exhibits fast convergence and high approximation accuracy for both synthetic and real-world data.
Design and calibration model of a bioinspired attitude and heading reference system based on compound eye polarization compass
Authors: Liu Xin , Yang Jian , Guo Lei , Yu Xiang , Wang Shanpeng
Published: September 2020

Insects such as honeybees are capable of fusing the information sensed by multiple sensory organs for attitude and heading determination. In this paper, inspired by the sensory fusion mechanism of insects’ polarization compass and haltere, a bioinspired polarization-based attitude and heading reference system (PAHRS) is presented. The PAHRS consists of compound eye polarization compass and inertial measurement unit (IMU). By simulating multi-view structure of the dorsal rim area in insects’ compound eyes, a non-coplanar ‘polarization-opponent (POL)-type’ architecture is adopted for the compound eye polarization compass. The polarization compass has multi-directional observation channels, which is capable of adaptively selecting the angle of polarization and obtaining the polarization vectors. Therefore, the environmental adaptability of the polarization compass can be enhanced. In addition, the integration strategy between the compound eye polarization compass and IMU is proposed. Moreover, the sources of system errors are analyzed to improve the heading angle accuracy, based on which a new calibration model is established to compensate the installation errors of the PAHRS. Finally, experiments are carried out under both clear sky and cloudy conditions. The test results show that the error root mean square of heading angle is 0.14° in clear sky, and 0.42° in partly cloudy conditions.
Burst-and-coast swimming is not always energetically beneficial in fish (Hemigrammus bleheri)
Authors: Ashraf Intesaaf , Van Wassenbergh Sam , Verma Siddhartha
Published: September 2020

Burst-and-coast swimming is an intermittent mode of locomotion used by various fish species. The intermittent gait has been associated with certain advantages such as stabilizing the visual field, improved sensing ability, and reduced energy expenditure. We investigate burst-coast swimming in rummy nose tetra fish (Hemigrammus bleheri) using a combination of experimental data and numerical simulations. The experiments were performed in a shallow water channel where the tetra fish swam against an imposed inflow. High speed video recordings of the fish were digitized to extract the undulatory kinematics at various swimming speeds. The kinematics data were then used in Navier–Stokes simulations to prescribe the undulatory motion for three-dimensional geometrical models of the fish. The resulting steady-state speeds of the simulated self-propelled swimmers agree well with the speeds observed experimentally. We examine the power requirements for various realistic swimming modes, which indicate that it is possible to use continuous swimming gaits that require considerably less mechanical energy than intermittent burst-coast modes at comparable speeds. The higher energetic cost of burst-coast swimming suggests that the primary purpose of intermittent swimming may not be to conserve energy, but it may instead be related to a combination of other functional aspects such as improved sensing and the likely existence of a minimum tail-beat frequency. Importantly, using sinusoidal traveling waves to generate intermittent and continuous kinematics, instead of using experiment-based kinematics, results in comparable power requirements for the two swimming modes.
Sodium alginate-based composites as a collagen substitute for skin bioengineering
Authors: Solovieva Elena V , Teterina Anastasiya Yu , Klein Olga I , Komlev Vladimir S , Alekseev Andrey A , Panteleyev Andrey A
Published: September 2020

The skin is a combination of two different types of tissue—epithelial and connective (mesenchymal). The outer protective layer of the skin, the epidermis, consists of multiple layers of keratinocytes residing on the basement membrane that separates them from the underlying dermis, which consists of a well-vascularized fibrous extracellular matrix seeded mainly by fibroblasts and mesenchymal stromal cells. These skin features suggest that the development of a fibroblast-friendly porous scaffold covered with a flat dense sheath mimicking the basement membrane, and sufficient to support keratinocyte attachment, would be a reasonable approach in the generation of clinically-relevant skin substitutes useful for reconstructive dermatology and burn treatment. Therefore, we developed a procedure to obtain biocompatible composite bilayer scaffolds comprising a spongy dermis-like body (supporting vascularization and appropriate fibroblast and multipotent stromal cell activity) fused with a film-like cover (supporting keratinocyte attachment, growth and differentiation). The sodium alginate (SA), an algae-derived biopolymer, has been used as a base component for these scaffolds while collagen (CL) and fibrinogen (FG) were used as minor additives in variable concentrations. The slow rates of composite SA-based scaffold biodegradation were achieved by using Ba2+ as cross-linking cations. By manipulating the SA/CL/FG ratio we managed to obtain sponge scaffolds with highly interconnected porous structures, with an average pore size ranging from 60 to 300 μm, and sufficient tensile strength (3.12–5.26 MPa). The scaffolds biocompatibility with the major human skin cell types was confirmed by seeding the scaffold sponge compartment with primary skin fibroblasts and subcutaneous adipose-derived stromal cells while the film side biocompatibility was tested using primary human keratinocytes. The obtained results have shown that bilayer alginate-based scaffolds have biological and mechanical properties comparable with CL scaffolds but surpass them in cost efficiency and vascularization ability in the subcutaneous implantation model in laboratory mice.
Ecological redline policy may significantly alter urban expansion and affect surface runoff in the Beijing-Tianjin-Hebei megaregion of China
Authors: Ju Xinhui , Li Weifeng , He Liang , Li Junran , Han Lijian , Mao Jingqiao
Published: September 2020

Urban expansion leads to surface changes that disrupt hydrological processes and increases flooding risks in cities. This increase may be severe in urban megaregions where clusters of cites have agglomerated. The China Ecological Redline Policy (ERP) is a national policy that protects priority areas with high-value ecosystem services. However, it is not clear how the ERP alters megaregion expansion and what this means for surface runoff across entire regions. By integrating specified models, we developed future urban expansion scenarios for 2030 with and without the ERP in the Chinese Beijing-Tianjin-Hebei (BTH) megaregion. The annual surface runoff volume under the ERP scenario decreased by 78 million m3 compared to the non-ERP involved scenario, but the ERP effectiveness at surface runoff regulation was different between the ecological redline areas (ERAs) and the non-ERAs. This suggested that multi-solutions should be incorporated into megaregions, such as regional ERPs and local, nature-based solutions, which could efficiently reduce the risk of urban flooding across whole regions.
Periglacial vegetation dynamics in Arctic Russia: decadal analysis of tundra regeneration on landslides with time series satellite imagery
Authors: Verdonen Mariana , Berner Logan T , Forbes Bruce C , Kumpula Timo
Published: September 2020

Changes in vegetation productivity based on normalized difference vegetation index (NDVI) have been reported from Arctic regions. Most studies use very coarse spatial resolution remote sensing data that cannot isolate landscape level factors. For example, on Yamal Peninsula in West Siberia enhanced willow growth has been linked to widespread landslide activity, but the effect of landslides on regional NDVI dynamics is unknown. Here we apply a novel satellite-based NDVI analysis to investigate the vegetation regeneration patterns of active-layer detachments following a major landslide event in 1989. We analyzed time series data of Landsat and very high-resolution (VHR) imagery from QuickBird-2 and WorldView-2 and 3 characterizing a study area of ca. 35 km2. Landsat revealed that natural regeneration of low Arctic tundra progressed rapidly during the first two decades after the landslide event. However, during the past decade, the difference between landslide shear surfaces and surrounding areas remained relatively unchanged despite the advance of vegetation succession. Time series also revealed that NDVI generally declined since 2013 within the study area. The VHR imagery allowed detection of NDVI change ‘hot-spots’ that included temporary degradation of vegetation cover, as well as new and expanding thaw slumps, which were too small to be detected from Landsat satellite data. Our study demonstrates that landslides can have pronounced and long-lasting impacts on tundra vegetation. Thermokarst landslides and associated impacts on vegetation will likely become increasingly common in NW Siberia and other Arctic regions with continued warming.
A two-stage clustering approach to investigate lifestyle carbon footprints in two Australian cities
Authors: Froemelt Andreas , Wiedmann Thomas
Published: September 2020

Given the key role of households in driving global emissions and resource use, a change in their consumption behaviours towards more sustainable levels is essential to reduce worldwide adverse environmental impacts. Thereby, focusing on cities is especially important because of today’s large share of the global population living in cities and because local authorities are close to the needs of their residents. However, devising targeted and effective policy measures implies a thorough understanding of prevailing consumption patterns and associated environmental consequences. The goal of this article is to investigate and compare household behaviours and lifestyle-induced carbon footprints in Sydney and Melbourne in order to enhance today’s understanding of household consumption in cities of a high-income, high-emission country. For this purpose, we employed a two-stage clustering approach with a Self-Organising Map and a subsequent Ward-clustering. This allowed for including expenditure data along with socio-economic attributes and thus for recognising lifestyle-archetypes. These emerging archetypes represent households with similar characteristics and comparable consumption patterns. Analysing the archetypes in detail and performing a city-comparison based on multi-dimensional scaling revealed similarities and dissimilarities between the two metropoles. ‘Older’ archetypes seem to behave more alike across cities but show different carbon footprints emphasising the importance of regionalised environmental assessments and of city-specific supply chains. Distinct patterns especially emerged in the high- and low-income segments highlighting the different importance of different lifestyles in each city. Socio-economically similar family-archetypes were found in both cities, but some of them showed diverging consumption behaviours. This article showed that studying household-induced environmental impacts in cities should not rely on macro-trends but should rather be based on city-specific analyses that capture local peculiarities and consider socio-economic characteristics and consumption data simultaneously.
The moving-eigenvalue method: hitting time for Itô processes and moving boundaries
Authors: Nilsson Martin N P
Published: September 2020

We present simple solutions of first-passage and first-exit time problems for general moving boundaries and general Itô processes in one dimension, including diffusion processes with convection. The approach uses eigenfunction expansion, despite the boundary time-variability that, until now, has been an obstacle for spectral methods. The eigenfunction expansion enables the analytical reduction of the problem to a set of equivalent ordinary differential equations, which can be input directly to readily available solvers. The method is thus suitable as a basis for efficient numerical computation. We illustrate the technique by application to Wiener and Ornstein–Uhlenbeck processes for a variety of moving boundaries, including cases for which exact results are known.
Yang–Baxter deformations and generalized supergravity—a short summary
Authors: Orlando Domenico , Reffert Susanne , Sakamoto Jun-ichi , Sekiguchi Yuta , Yoshida Kentaroh
Published: September 2020

Integrable deformations of type IIB superstring theory on AdS5 × S5 have played an important role over the last years. The Yang–Baxter deformation is a systematic way of generating such integrable deformations. Since its introduction, this topic has seen important conceptual progress and has among others led to the intriguing discovery generalized supergravity, a new low-energy effective theory. This review endeavors to not only introduce the historical development of the Yang–Baxter deformation, but also its relation to generalized supergravity, non-geometric backgrounds, non-abelian T-duality and preserved Killing spinors. We supplement the general treatment with a wealth of explicit examples.
Joint separable numerical range and bipartite ultrafine entanglement witnessing
Authors: Wu Pan , Tang Runhua
Published: September 2020

The entanglement witness is an important tool to detect entanglement. In 2017 an idea considering a pair of Hermitian operators in product form was published, which is called ultrafine entanglement witnessing. In 2018 some rigorous results were given. Here we improve their work. First we point this idea can be directly derived from an earlier concept named joint separable numerical range and explain how it works as a series of witnesses. Second by a simple method we present a sufficient condition for an effective pair. Finally we prove this condition is necessary for optimization. [M Gachechiladze et al 2018 J. Phys. A: Math. Theor. 51 36].
Physico chemical and phase separation characterization of high molecular PLLA blended with low molecular PCL obtained from solvent cast processes
Authors: Arbeiter Daniela , Eickner Thomas , Oschatz Stefan , Reske Thomas , Specht Olaf , Teske Michael , Senz Volkmar , Schmitz Klaus-Peter , Grabow Niels
Published: September 2020

Blends of PLLA and PCL yielded by solvent casting usually exhibit phase separation and crystallization behavior which have a strong impact on their suitability for certain biomedical applications such as degradable coatings or drug carriers. Therefore, it is important to understand the underlying mechanisms. In this study, high-molecular biodegradable semi-crystalline poly(L-lactide) (PLLA) (Mw = 320 kDa) was blended with low-molecular biodegradable semi-crystalline poly(ε-caprolactone) (PCL) (Mw = 40 kDa) in various combinations (10, 50 and 90 wt.% PCL) by solvent casting. The yielded blends were subjected to annealing at 40 °C, 80 °C and 200 °C and cooled down slowly to maintain thermodynamic equilibrium. Scanning electron microscopy, atomic force microscopy, Raman images and differential scanning calorimetry were used to investigate the structure, morphology and thermal properties of the solvent cast PLLA/PCL blends. It was shown that the physico-chemical properties of PLLA/PCL blends prepared by solvent casting differ substantially compared to those accessed by melt manufacturing processes. In summary, the blends showed a complex phase separation behavior, which is completely dependent on the method of preparation and the adjusted temperature during production process.
Graphene oxide—Polymethyl methacrylate coatings for Corrosion protection of aerospace aluminium alloy 7075—T651 surfaces
Authors: Aravindh S , Karthikeyan B
Published: September 2020

We report a corrosion study on Al 7075—T651 surface. The purpose of the study is to use Graphene oxide—Polymethyl methacrylate (GO—PMMA) coating as corrosion resistant layer on Al 7075—T651, an alloy of aluminium mainly used in aerospace industries. The study is done with and without GO—PMMA coating on Al 7075—T651 respectively, by varying the exposure time of material (24, 48 and 72 h) with HCl in atmospheric condition. The formation of corrosion is resisted by the GO—PMMA coated samples. The effect is studied by material characterization and non-destructive evaluation (NDE) techniques. The formation of aluminium hydroxide in uncoated samples is confirmed by Raman spectroscopy and x-ray diffraction (XRD). Corrosion formation, GO—PMMA coating on plain and coated samples are clearly visible in Scanning Electron Microscope (SEM) study. Shift in current is observed in I–V Characteristics study, due to pitting in plain samples. Material loss is observed, to be low in GO—PMMA coated samples, using pulsed thermography. The work proves that the GO—PMMA coating is very effective in corrosion resistance.
COGENT: evaluating the consistency of gene co-expression networks
Authors: Bozhilova Lyuba V. , Pardo-Diaz Javier , Reinert Gesine , Deane Charlotte M.
Published: September 2020

Gene co-expression networks can be constructed in multiple different ways, both in the use of different measures of co-expression, and in the thresholds applied to the calculated co-expression values, from any given dataset. It is often not clear which co-expression network construction method should be preferred. COGENT provides a set of tools designed to aid the choice of network construction method without the need for any external validation data.

Availability and implementation

https://github.com/lbozhilova/COGENT.

Supplementary information

Supplementary information is available at Bioinformatics online.