bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of Gaussian process regression for effective regional post‐earthquake building damage inference
Authors: Sheibani Mohamadreza , Ou Ge
Published: October 2020

Post‐earthquake reconnaissance survey of structural damage is an effective way of documenting and understanding the impact of earthquakes on structures. This article aims at providing an efficient data‐based framework that reduces the required time for reconnaissance missions and predicts the damage intensities for every building in the affected region. We hypothesize that a joint selection of necessary structural and earthquake parameters along with sparse damage observations are sufficient to train a supervised learning algorithm and accurately infer the damage for other buildings in the region. Gaussian process regression is employed to prove the hypothesis for probabilistic inference of different damage indices. The algorithm performs efficiently by selecting a set of diverse and representative buildings for damage observations using K‐medoids clustering. To validate the hypothesis and the proposed method, the algorithm framework is implemented on two severe earthquake simulation testbeds. The impacts of different building and ground motion variables on the damage inference performance are discussed. Furthermore, the effectiveness of observation sampling by clustering in the post‐earthquake damage inference is compared with random sampling.
Genome‐wide identification of Streptococcus sanguinis fitness genes in human serum and discovery of potential selective drug targets
Authors: Zhu Bin , Green Shannon P. , Ge Xiuchun , Puccio Tanya , Nadhem Haider , Ge Henry , Bao Liang , Kitten Todd , Xu Ping
Published: October 2020

Streptococcus sanguinis is a primary colonizer of teeth and is associated with oral health. When it enters the bloodstream, however, this bacterium may cause the serious illness infective endocarditis. The genes required for survival and proliferation in blood have not been identified. The products of these genes could provide a rich source of targets for endocarditis‐specific antibiotics possessing greater efficacy for endocarditis, and also little or no activity against those bacteria that remain in the mouth. We previously created a comprehensive library of S. sanguinis mutants lacking every nonessential gene. We have now screened each member of this library for growth in human serum and discovered 178 mutants with significant abundance changes. The main biological functions disrupted in these mutants, including purine metabolism, were highlighted via network analysis. The components of an ECF‐family transporter were required for growth in serum and were shown for the first time in any bacterium to be essential for endocarditis virulence. We also identified two mutants whose growth was reduced in serum but not in saliva. This strategy promises to enable selective targeting of bacteria based on their location in the body, in this instance, treating or preventing endocarditis while leaving the oral microbiome intact.
Chorismate mutase and isochorismatase, two potential effectors of the migratory nematode Hirschmanniella oryzae, increase host susceptibility by manipulating secondary metabolite content of rice
Authors: Bauters Lander , Kyndt Tina , De Meyer Tim , Morreel Kris , Boerjan Wout , Lefevere Hannes , Gheysen Godelieve
Published: October 2020

Hirschmanniella oryzae is one of the most devastating nematodes on rice, leading to substantial yield losses. Effector proteins aid the nematode during the infection process by subduing plant defence responses. In this research we characterized two potential H. oryzae effector proteins, chorismate mutase (HoCM) and isochorismatase (HoICM), and investigated their enzymatic activity and their role in plant immunity. Both HoCM and HoICM proved to be enzymatically active in complementation tests in mutant Escherichia coli strains. Infection success by the migratory nematode H. oryzae was significantly higher in transgenic rice lines constitutively expressing HoCM or HoICM. Expression of HoCM, but not HoICM, increased rice susceptibility against the sedentary nematode Meloidogyne graminicola also. Transcriptome and metabolome analyses indicated reductions in secondary metabolites in the transgenic rice plants expressing the potential nematode effectors. The results presented here demonstrate that both HoCM and HoICM suppress the host immune system and that this may be accomplished by lowering secondary metabolite levels in the plant.
Antifungal susceptibility testing of dermatophytes: Development and evaluation of an optimised broth microdilution method
Authors: Curatolo Riccardo , Juricevic Nada , Leong Cheryl , Bosshard Philipp P.
Published: October 2020

Background

Dermatophytosis is one of the most common infections affecting 3%–17% of the population. Resistance to antifungals so far was not of concern in the therapeutic management. However, recent reports of terbinafine‐resistant strains in several countries are worrisome making antifungal susceptibility testing inevitable.

Objectives

We aimed to develop and evaluate an optimised broth microdilution assay for antifungal drug susceptibility testing of dermatophytes.

Methods

We first studied the effect of different inocula, incubation temperatures and incubation times to establish an optimised assay. Subsequently, we tested 79 clinical strains of 11 dermatophyte species with 13 antifungals.

Results

We found inoculating with 0.5–5 × 104 colony forming units (CFU) and incubating at 29°C ± 1°C for 4 days to be appropriate. Terbinafine was the most active antifungal agent with minimum inhibitory concentration (MIC) values ≤ 0.06 µg/mL, expect for one resistant T mentagrophytes strain, which was isolated from an Indian patient. Also, a majority of MICs of other antifungals that are commonly used to treat dermatophytosis were low, except those of fluconazole. Fluconazole MICs do not correlate with the good efficacy in the clinical management.

Conclusions

Our assay enables fast and reliable susceptibility testing of dermatophytes with a large panel of different antifungals. This helps to improve the therapeutic management of dermatophytosis by detecting resistant strains.
Suspected COVID‐19‐related reticulated purpura of the soles in an infant
Authors: Andina David , Colmenero Isabel , Santonja Carlos , Muñoz de León Irene , Noguera‐Morel Lucero , Hernández‐Martín Angela , Torrelo Antonio
Published: October 2020

A growing number of skin lesions during the COVID‐19 pandemic are being recognized. Acral ischemic lesions identical to chilblains are most typical in children and young adults. We report an infant girl, aged 1 month and 29 days, with a peculiar reticulated purpuric eruption on her soles, with positive immunohistochemistry for SARS‐CoV‐2 in the endothelia of dermal blood vessels. The patient had an excellent outcome without specific therapy.
Clinical, trichoscopy, and light microscopic findings in hypohidrotic ectodermal dysplasia: Report of 21 patients and a review of the literature
Authors: Peña‐Romero Adriana Guadalupe , Sáez‐de‐Ocariz Marimar , Toussaint‐Caire Sonia , Morán‐Villaseñor Edna , Orozco‐Covarrubias Luz , Durán‐McKinster Carola
Published: October 2020

Introduction

Hypohidrotic ectodermal dysplasia (HED) is a genetic condition typified by alterations in skin structures including sweat glands, hair, nails, and teeth. Hair findings in HED have been poorly characterized in larger series.

Objective

To characterize scalp and hair findings of patients with HED clinically and with trichoscopy and light microscopy.

Methods

A cross‐sectional study in 21 pediatric HED patients was performed using available clinical and scalp dermatoscopic images, as well as pulled‐hair samples for clinical evaluation, trichoscopic, and light microscopic analyses.

Results

Seventeen out of 21 patients (81%) were men. Twenty patients had straight hair. Sixteen patients had decreased hair density, 6 of whom had hair loss mainly in the temporal and occipital regions. Fourteen patients had hair whorls. On trichoscopy, we observed: single‐hair follicular units (n = 19, 90%), scalp hyperpigmentation (n = 13, 62%), variable diameter of the hair shafts (n = 12, 57%), perifollicular scales (n = 8, 38%), scalp erythema (n = 8, 38%), and short curly pigtail hairs (n = 6, 29%). On light microscopy, findings included: hair shafts with irregular diameter (n = 7, 33%), heterogeneous hair color (n = 6, 29%), trichoptilosis (n = 2, 10%), and pili torti (n = 1, 5%).

Conclusions

In this series, hair findings in HED were similar to those described in previous studies. However, we describe two new clinical and two trichoscopic findings: decreased hair density mainly in the temporal and occipital regions, oblique upwards occipital hair follicles orientation, angled hairs, and short curly pigtail hairs. These heterogeneous findings may reflect the multiple factors and signaling pathways that can be affected in these syndromes.
Implementing best‐practice with a local syringe service program: Needs‐based syringe distribution
Authors: Turner‐Bicknell Tasha
Published: October 2020

Objectives

The Centers for Disease Control and Prevention (CDC) cite access to sterile syringes as a key component of a comprehensive strategy aimed at limiting the spread of infectious disease among people who inject drugs (CDC, 2020, America’s drug overdose epidemic: Data to action). In an effort to implement best‐practice, inform stakeholders, and improve the current availability of services, a needs‐based syringe distribution model was piloted at one local syringe service program.

Design

A needs‐based syringe distribution model was piloted at one syringe program location for 5 months. An analysis of pre‐ and post‐implementation program utilization data was conducted.

Sample

Inclusion criteria included current participation in syringe service programs at the identified location. Participants from other locations were excluded.

Measurements

The following program utilization measures were analyzed: volume of syringes distributed, new client enrollment, routine client visits, and utilization of ancillary services such as on‐site testing and naloxone distribution.

Results

Engagement increased across all four program utilization measures during the implementation of needs‐based distribution.

Conclusions

Implementation of a needs‐based syringe distribution model can increase the effectiveness of syringe service programs by increasing individual syringe coverage, which reduces high‐risk injection behavior, such as syringe reuse and sharing.
A global analysis on the systemic effects of antibiotics in cultured fish and their potential human health risk: a review
Authors: Limbu Samwel Mchele , Chen Li‐Qiao , Zhang Mei‐Ling , Du Zhen‐Yu
Published: October 2020

The rearing of fish in intensive systems reduces their immunity leading to eruption of diseases, consequently prompting the use of antibiotics. Antibiotics are currently used in cultured fish globally to treat/prevent diseases. On the one hand, antibiotics used in aquaculture help to improve fish health by killing or inhibiting pathogenic bacteria proliferation. However, on the other hand, they cause multiple side effects. To date, information on systemic effects of antibiotics in cultured fish is scattered and their potential human health risk remains elusive. This review critically analyses and discusses the available information in the literature on the positive and negative effects of antibiotics in cultured fish and their potential human health risk via fish consumption. The review found 44 different antibiotics dominated by oxytetracycline were studied in various fish species worldwide. Antibiotics used in global aquaculture either decrease or increase fish growth and survival rates. They induce oxidative stress, which affect antioxidant and detoxification responses and cause host–microbiota dysbiosis. These changes compromise the fish immunity system, which ultimately lead to cellular damage. The toxicities generated inhibit the fish aerobic glycolysis, suppress lipogenesis and fatty acid β‐oxidation while increase energy demand by initiating gluconeogenesis and anaerobic glycolysis. Consumption of fish treated with antibiotics causes human health risk. Future studies are required on agents to restore dysfunctions induced by antibiotics in cultured fish, while attempts to limit their utilisation in aquaculture production are underway. [Correction added on 21 November 2020, after first online publication: The abstract has been amended to clarify the scope of the review.]
The Effects of Key Influencing Factors on Unsafe Events in Airport Flight Areas According to Time Series Data
Authors: Shao Quan , Liu Haoran , Zhu Pei , Wei Wei , Zhou Hang , Yang Mingming
Published: October 2020

This study applied modern econometric models to analyze the factors affecting the number of unsafe events (NUE) in the airport flight area using time series data from 1993 to 2017. Influencing factors considered in this article include gross domestic product (GDP) per capita (GDPPC), household consumption level (HCL), the civil aviation passenger turnover (CAPT), the number of civil aviation transport aircraft (NCATA), the total population of the whole country, and the number of civil aviation employment (NCAE). First, the Johansen cointegration test results demonstrate that HCL, NCATA, and NCAE have long‐term effects on unsafe events—namely, a 1% increase in HCL corresponds to an average 0.262% increase in NUE. In addition, a 1% increase in NCATA correlates to an average 2.339% increase, and a 1% increase in NCAE corresponds to an average 2.202% decrease in NUE with fixed variables. The analysis results based on the vector error correction model suggest that CAPT has short‐term effects on unsafe events and positively correlates to unsafe events. The results of the impulse response function also indicate that the impact of NUE in the previous period on the change of NUE gradually weakens and finally tends to be stable. Finally, NCATA is found to promote the change of NUE significantly. Similarly, the results of variance decomposition also indicate that NCATA has the greatest contribution to the change of NUE, followed by NUE in the previous period. The findings reveal the effects of key factors on the change of unsafe events in airport flight areas, thus providing a valuable theoretical basis for preventing the occurrence of unsafe incidents.
Line‐field confocal optical coherence tomography—Practical applications in dermatology and comparison with established imaging methods
Authors: Ruini Cristel , Schuh Sandra , Sattler Elke , Welzel Julia
Published: October 2020

Background

Non‐invasive diagnostic techniques in dermatology gained increasing popularity in the last decade. Reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) are meanwhile established in research and clinical routine. While OCT is mainly indicated for detecting non‐melanoma skin cancer, RCM has proven its usefulness additionally in distinguishing melanocytic lesions. Line‐field confocal optical coherence tomography (LC‐OCT) is an emerging tool combining the principles of both above‐mentioned methods.

Methods

Healthy skin at different body sites and exemplary skin lesions (basal cell carcinoma, malignant melanoma, actinic keratosis) were examined using dermoscopy, RCM, OCT and LC‐OCT. Standard features for RCM and OCT and comparable features for LC‐OCT were analysed.

Results

LC‐OCT has a lower penetration depth but superior resolution compared to OCT. In comparison with RCM, which provides only horizontal sections, LC‐OCT creates both vertical and horizontal images in real time and has nearly the same cellular resolution.

Discussion

Our preliminary experiences suggest that LC‐OCT combines the advantages of RCM and OCT, with optimal resolution and penetration depth to diagnose all types of skin cancer.

Larger systematic studies are needed to further characterize the field of use of this device and its sensitivity and specificity compared to histology.
The effect of dual‐frequency ultrasound waves on B16F10 melanoma cells: Sonodynamic therapy using nanoliposomes containing methylene blue
Authors: Adelnia Akbar , Mokhtari‐Dizaji Manijhe , Hoseinkhani Saman , Bakhshandeh Mohsen
Published: October 2020

Background

We investigated the effect of dual‐frequency sonication on the viability of B16F10 melanoma cells in the presence of methylene blue (MB) encapsulated in nanoliposomes.

Methods

Treatment protocols were studied: sonication groups (40 kHz, 1 MHz and dual‐frequency), the same sonication groups with nanoliposomes containing MB, MB free and nanoliposomes containing MB groups, and so sham and control groups. The nanoliposomes were prepared by the lipid film hydration method. The cell viability of the different treatment groups was evaluated by the MTT assay.

Results

The dual‐frequency protocols caused higher viability losses compared to the kHz and MHz sonications (P < .05). In presence of the nanoliposomes containing MB, dual frequency led to 6% and 3% viability for 600 and 1200 seconds, respectively, while the corresponding values were 10% and 4% for the 40 kHz protocols and 22% and 9% for the 1 MHz, as compared to the control group (100%). The result of KI dosimetry showed that the cavitation activity of the dual‐frequency protocol was about 1.23, as compared to sonication at 40 kHz and 1 MHz.

Conclusion

Enhancement of inertial cavitation induction by dual‐frequency sonication may be the primary effective mechanism, which causes increased sonochemical processes and drug release from nanocarriers.
Factors associated with registrant availability for unrelated adult donor hematopoietic stem cell donation: Analysis of the stem cell registry at Canadian Blood Services
Authors: Monaghan Madeline , Yi Qi‐Long , Green Meagan , Campbell Todd , Weiss Jason T. , Dibdin Nicholas , Mercer Dena , Elmoazzen Heidi , Allan David S.
Published: October 2020

Background

Greater use of unrelated donors to support hematopoietic cell transplantation can be hampered by unavailability of registrants when identified as potential candidates for donation.

Methods

Multivariate analysis was performed to identify donor factors associated with availability for verification of human leukocyte antigen typing (VT) needed before donor activation. All VT requests for registrants on the Canadian Blood Services Stem Cell Registry between 1 January and 31 December 2018 were reviewed (n = 1358).

Results

Potential donors identified by transplant centers were categorized as available at the time of VT but ineligible for medical or other reasons (n = 130 and excluded from further analysis), available (n = 622) or unavailable (n = 566) due to scheduling, loss of interest, and/or inability to contact. With multivariate analysis, registrants who previously donated blood, those recruited online or from blood donation clinics, and a shorter interval between registration and VT request were significantly correlated with increased donor availability. Donor sex and geographic location, however, displayed no correlation.

Conclusion

Online registration and recruitment at whole blood donation centers should be enhanced to increase the availability of registrants at VT. More insight is needed to maintain registrant availability following community in‐person recruitment events, especially if the interval between registration and activation is prolonged. Recruitment of male registrants who are well informed should not negatively impact availability.
Assessing false paternity risk in simulated motherless cases from more than 20 000 real exclusion trios
Authors: Aguiar Vitor R. C. , de Castro Amanda M. , Pinto Laélia M. , Ferreira Alessandro C. S. , dos Santos Eldamária V. W. , Louro Iuri D.
Published: October 2020

Background

When the motherʼs DNA profile is not available for paternity testing, there is a smaller probability that a locus will exclude an alleged father. This study aims to evaluate the risk of potential false paternity inclusions in motherless cases.

Study Design and Methods

More than 20 000 duos were generated by removing the maternal genotypes from exclusion trios. After recalculating paternity in these duos, any found inclusions would be false.

Results

The use of an appropriate number of loci, mutation model, and mutation rates to analyze motherless paternity cases was robust against false inclusions. A single potential false inclusion was observed in a case wherein kinship plays a role. This result highlights the importance of testing the mother when available and of obtaining information on family circumstances for the proper handling of cases involving related individuals.

Conclusion

The guidelines we used here were sufficient to avoid false inclusions in a data set of more than 20 000 motherless cases.
The Existence Of Refugees And Immigrants From Middle East In Southeast Asia
Authors: Sultoni Yahya , Efendi Khoirul
Published: October 2020

Refugees and immigrants are the people who move from a region to another region crossing the countries border for surviving purposes. The reason they migrate to another place moslty because of conflict in their own country, also due to welfare and economic problems. The majority of refugees and immigrant in Indonesia go to Christmas Island, Australia as the final destination seeking the asylum or protection. Automatically they passed the area of the countries in Southeast Asia. It takes a long time for the moving process to the destination country until the status of the determination process for asylum or refugee by UNHCR. Because of the long time, there are fears that the immigrants will impact the stability of national security, economy, social, culture and other aspects. It also considered as demographic problems while increasing population in a country which is traversed by refugees and immigrant. It is important to analyze the influence of the existence of refugees and immigrants, as well as their potential in Southeast Asia Countries. Managing the existence of refugees and immigrant also considered for helping the government and other stakeholders to make the right policy for handling refugees and immigrants.
Photodegradation of Molecular Iodine on SiO2 Particles: Influence of Temperature and Relative Humidity
Authors: Figueiredo A. , Strekowski R. S. , Bosland L. , Durand A. , Wortham H.
Published: October 2020

A molecular derivatization method followed by gas chromatographic separation coupled with mass spectrometric detection was used to study photodegradation of molecular I2 adsorbed on solid SiO2 particles. The heterogeneous photodegradation of I2 was studied as a function of temperature and relative humidity in synthetic air to better understand its environmental fate. Two sets of experiments were carried out. In the first set of experiments, the temperature was T = (298 ± 1) K and relative humidity was varied from ≤ 2% to 75%RH under given experimental conditions. In the second set of experiments, the relative humidity within the Pyrex bulb was 40%RH and the temperature was varied from 283 ± 1 ≤ T (K) ≤ 323 ± 1. The obtained results show a considerably enhanced atmospheric lifetime of molecular iodine adsorbed on solid media that does not depend on relative humidity of the environment. The obtained results show that the rate constant for the photolysis of molecular iodine adsorbed on model SiO2 particles depends on temperature and is reported to be J (T)=(1.24 ± 1.4)×10−2×exp[(1482±345)/T]/s over the measured temperature range. The heterogeneous atmospheric residence time () of I2 adsorbed on solid media is calculated to range from 2 to 4.1 h. The experimentally obtained heterogeneous lifetime of I2 is shown to be considerably longer than its destruction by its principal atmospheric sink, photolysis. The observed enhanced atmospheric lifetime of I2 on heterogeneous media will likely have direct consequences on the atmospheric transport of I2 that influences the toxicity or the oxidative capacity of the atmosphere.
Review of Gas Turbine Internal Cooling Improvement Technology
Authors: Nourin Farah Nazifa , Amano Ryoichi S.
Published: October 2020

The higher firing temperature reflects the higher efficiency of the gas turbine. However, using higher temperatures is limited as it may cause a rupture, bending, or failure of the turbine blades. Hence, the development of an effective internal cooling system of the gas turbine blade is essential. At the same time, it is necessary to ensure the lowest possible penalty on the thermodynamics performance cycle. Researchers are working over the years to find out the efficient cooling channel design with high transfer while the lowest pressure drop. They ran several cases both numerically and experimentally. This paper reviews the published research in the various methods of gas turbine internal cooling, such as using rib turbulators, dimples, jet impingement, pin fins, and guide vane, of the gas turbine blade.
Experimental Investigation of a Hydrostatic Bearing Between Barrels and Port Plates in Floating Cup Axial Piston Pumps
Authors: Achten Peter , Mommers Robin , Potma Jeroen , Achten Jasper
Published: October 2020

Hydrostatic machines often have multiple hydrodynamic bearing interfaces, which also serve as a sealing interface. In axial piston machines, the bearing and sealing interface between the barrel and the port plate is a well known example. At reasonably high operating speeds, hydrodynamic effects create an oil film between the barrel and the port plate. This oil film will then, to a certain extend, lift the barrel from the port plate, thereby avoiding metal-to-metal contact.

The disadvantage of hydrodynamic bearings is, that they need a relatively high velocity of the sliding components, in order to reduce the friction. Below a certain speed, mixed lubrication and finally solid friction will occur. This results in strongly increased friction losses and wear.

Low speed operation has always been of interest for hydrostatic motors, which are often operated at close to zero speed or at low rotational speeds. But low and near zero speed operation has also become of importance for pumps when being operated in electro-hydraulic actuators (EHAs). Many of the existing pump principles are not allowed to be operated below a certain minimum speed, due to excessive wear which results from coulomb friction conditions. Furthermore, the stick-slip-behaviour creates additional nonlinear behaviour of the EHA-operation, and makes it difficult to control EHAs.

In order to overcome the disadvantages of hydrodynamic bearings, a new hydrostatic bearing has been developed [1]. In the new bearing, the sealing land of the barrel is divided into three concentric rings. In the middle ring, so called pockets are created. Each pocket has a direct connection with the corresponding port by means of a small groove. The new bearing not only lifts the barrel to a certain height, but also helps to counteract the tilting torque of the barrel.

The size of the pocket grooves determines the height of the oil film, and therefore also the leakage and viscous friction of the bearing and sealing interface. In a recent research project, INNAS has performed a number of experiments to measure the influence of the groove size on the overall efficiency, as well as on the leakage and torque loss. Measurements have been performed on a 24 cc floating cup pump in a speed range between 500 and 4000 rpm and a pressure range between 100 and 400 bar. At the end of the project, the range has been extended to a speed range between 0.23 and 4400 rpm, and a pressure range between 50 and 450 bar.

This paper describes some of the results of these experiments. The measured width of the pocket grooves is taken as a characteristic parameter for the size of the flow area and resistance of the pocket grooves.
On Secondary Control Principles in Pump Controlled Electro-Hydraulic Linear Actuators
Authors: Schmidt Lasse , Ketelsen Søren , Grønkær Nikolaj , Hansen Kenneth Vorbøl
Published: October 2020

Developments in the field of electro-hydraulic linear actuators controlled by variable-speed pump drives have been increasing over the past decade. The majority of these benefits from the speed control loops realized in the associated electric drives, hence these variable-speed pump drives have been operated as flow control units. For this reason, control methodologies commonly used in valve operated linear drives can be adopted. Such approaches may be characterized as primary control strategies, meaning that there is a flow coupling between the variable-speed pump drive and the linear actuator, with a pressure reaction. Alternatively, other technologies like hydraulic transformers benefit from secondary control abilities, meaning that there is a pressure/force coupling between the actuating device and the linear actuator, with a flow reaction. This paper presents a study considering the application of secondary control principles in electro-hydraulic linear actuators, where the usage of only the electric motor current control loops allow for this to be realized. It is found that by feeding back the hydraulic force measurement in addition to the current loops, allow for a high force control bandwidth by virtue of state feedback controls. The high bandwidth of the force control enables alternative approaches to motion control of electro-hydraulic linear actuators.
The Challenge of Feedback in Fluid Power Tribotronic Control Systems
Authors: Johansen Per , Grønkær Nikolaj , Langbak Andreas , Krempin Simon , Schmidt Lasse
Published: October 2020

The hunt for increased efficiency and reliability of fluid power components have entailed a great deal of research on loss and wear mechanisms by means of computational tribology simulation in the last decades. The vast amount of theoretical work within tribology necessitates validation of the simulation models. The aim to validate such models has in recent years increased interest in sophisticated tribological measurement technology. A next level, for tribology in fluid power, is the integration of modelling, analysis and measurement technology with control to achieve active tribology, namely fluid power tribotronics. In this paper the challenge of feedback for tribotronic control loops in fluid power are addressed. Fundamental questions are in this regard to what extend do we need information? Is it necessary to measure fluid film thickness absolutely or dynamically, or do we even need in-situ information on the tribological joints? These questions are analysed in this paper by use of a dynamic lubricated journal-bearing model. From this analysis a conclusion on the oil whirl limit is found, which reveal an interesting perspective and potential risk in the application of feedforward in tribotronic control of lubricated journal-bearings. Finally, a discussion is concluded with the submission of relevant open research directions for fluid power tribotronic control systems.
Design and Performance of a Curvilinear Circular-Arc Tooth Gear for Gear Pump Applications
Authors: Williams Logan T.
Published: October 2020

The most common gear architecture used in external gear pumps is the spur gear with an involute tooth profile. The involute spur gear has many benefits, such as a constant line of action, tolerance to parallel misalignment, and ease of fabrication. However, the involute spur gear has two major drawbacks in pump applications: the tooth profile results in trapped pockets of fluid that contribute to pressure spikes and noise generation, and the straight axial profile further increases noise due to intermittent tooth shock during meshing. Current state-of-the-art pumps utilize helical gears to enable a gradual mesh to reduce noise and pressure pulsation, which results in an axial load induced on the gears during meshing. A novel gear design has been developed that eliminates axial gear loading while preserving a gradual mesh. A hybrid tooth profile eliminates the trapped fluid pocket while maintaining the benefits of an involute profile. Initial testing demonstrates an increase in volumetric efficiency by 10% and a reduction of sound level by 7 dB compared to a spur gear of the same size.
A Gasless Reservoir Solution for Electro-Hydraulic Compact Drives With Two Prime Movers
Authors: Ketelsen Søren , Padovani Damiano , Kjeld Ebbesen Morten , Andersen Torben Ole , Schmidt Lasse
Published: October 2020

Due to an increased focus on improving the energy efficiency and compactness of hydraulic linear actuators, the electro-hydraulic compact drive (ECD) has received increased attention lately. In this study the ECD consists of variable-speed electric motors and fixed-displacement pumps, which are directly connected to the cylinder, thus controlling the linear motion in a throttleless manner. Furthermore, ECDs are self-contained systems, i.e. based on a fully enclosed oil circuit, in order to avoid external contamination and air to enter the system and to increase system compactness. Conventionally a low-pressure gas-loaded accumulator is used as an oil reservoir to compensate for the flow imbalance occurring whenever utilizing single-rod cylinders in closed systems. The accumulator pressure is to be kept relatively low to stay within the required limits governed by the permitted pump housing’s pressure. Generally, this pressure is not allowed to exceed 1–3 bar. To avoid violating this limitation, the gas volume must be significantly larger than the actual oil volume, which needs to be stored in the accumulator. This requirement decreases the obtainable compactness of the ECD, especially for systems with a large cylinder stroke. Furthermore, the accumulator represents a potential of gas leakage, which ultimately could result in the ECD being non-functional. This paper presents a gasless reservoir solution, improving the system compactness and avoiding the risk of gas leakage. The proposed solution is based on a bootstrap reservoir which is charged by the lowest cylinder chamber pressure. This strategy is feasible for the class of ECDs that is capable of controlling the lowest cylinder chamber pressure alongside the cylinder motion. An ECD consisting of two electric prime movers is considered as a case study. It is shown how the gasless reservoir may be integrated into the system, and an analysis of how this affects the operating range and the dynamic couplings of the system is presented. This leads to the derivation of a control strategy for the Multi-Input-Multi-Output (MIMO) system based on state decoupling, by defining virtual inputs to control virtual outputs. A numerical study suggests that the reservoir volume may be reduced by approximately 50% for the given system dimensions. The proposed control strategy shows good position tracking performance while also being able to control the reservoir pressure within the pre-defined limits of 1 to 3 bar.
Short-Term Energy Storage System for Hydraulic Hybrid Wind Turbine Transmission
Authors: Mohr Eric , Mohanty Biswaranjan , Stelson Kim A.
Published: October 2020

A Hydrostatic Transmission (HST) offers a variable ratio transmission for wind turbines that has a higher power to weight ratio than traditional gearboxes, and requires less maintenance. In a conventional turbine, when the wind speed increases above the rated speed, the blade pitch is controlled to dissipate excess energy and regulate the turbine at rated power. An energy storage system allows the turbine to temporarily operate above rated power, and capture the traditionally dissipated energy in an accumulator. When the wind speed drops below the rated speed, the energy in the accumulator is released, increasing the delivered power This paper presents a high-fidelity mathematical model of the hydraulic hybrid wind turbine transmission. Simulation results for a series of step changes and for turbulent wind speed are investigated for a 60 kW turbine. Using a realistic turbulent wind data sample, energy production increased by 4% with a 52 liter accumulator with significantly smoother output power to the grid.
Fast Meshless Solution With Lumped Friction for Water Hammer
Authors: Xu Yuanzhi , Jiao Zongxia , Zhao Longfei
Published: October 2020

The water hammer in pipelines, with the absence of fluid friction, could be solved by a time-domain exact solution, using a simple recursive process. No computational grid was needed, but the calculation time cost was extremely high. Its improved method, named as the fast meshless solution (FMS), was developed to speed the computation by introducing the time-line interpolation. For the purpose of practical applications, the attempt to consider fluid friction in the FMS is presented here. As there is no mesh grid in the distance-time plane, the distributed friction model can not be employed upon the presented method directly. The fluid friction lumped at the pipe end is proposed, and both steady and unsteady friction are studied. A benchmark problem of the water hammer in a reservoir-pipe-valve (RPV) system is employed for the validation and comparison. The water hammer considering lumped friction can be calculated fast by the FMS, and the accuracy is acceptable. The method discussed here may be of interest in a quick assessment of the piping water hammer.
Hydraulic Ankle Foot Orthosis Emulator for Children With Cerebral Palsy
Authors: Durfee William , Hashemi Saeed , Ries Andrew
Published: October 2020

Objective: Ankle foot orthoses (AFOs) are used by nearly 50% of children with cerebral palsy (CP) to ameliorate gait impairments. The methods used to prescribe and tune the mechanical properties of an AFO, including its angular stiffness about the ankle, are based on the intuition and experience of the practitioner. The long-term goal of this research is to develop and deploy a technology-based solution to prescribing passive AFOs that uses an AFO emulator to be used in the clinic that can, under computer control, vary its stiffness in real-time to determine the best stiffness for walking. The objective of this project was to design and bench-test a first-generation wearable hydraulic ankle exoskeleton, and to conduct a small clinical trial to determine whether walking in a conventional plastic AFO was the same as walking in the hydraulic exoskeleton whose stiffness was programmed to match that of the conventional AFO. Methods: The hydraulic ankle exoskeleton was comprised of a wearable ankle exoskeleton tethered by small-diameter hydraulic hose to a push-behind cart that contained the hydraulic power supply and control components. The ankle component contained a novel double-ended cylinder with a cable anchored to the piston. The system was controlled to emulate a rotary spring. Bench top tests were performed to validate the performance of the system. In addition, an early feasibility clinical trial was conducted with five children with cerebral palsy who walked in three conventional AFOs (flexible, medium and stiff) and the hydraulic AFO controlled to match each stiffness. Kinematics and dynamics of gait were measured with a 12-camera motion capture system and a force plate. Results: The weight of the wearable exoskeleton plus shoe was 1.5 kg, 60% over the design goal. The system, running at a rail pressure of 141 bar (2,050 psi), could produce 62 Nm of torque and could emulate springs from 1 to 4.6 Nm/deg, the stiffness range of most conventional AFOs. Once calibrated, the torque-displacement properties were similar to the matched conventional AFO. Walking metrics were the same for hydraulic and conventional AFOs. Interpretation: Small-scale hydraulics are effective for a wearable exoskeleton that is designed to mimic a passive AFO and hydraulics can be used to emulate a rotary stiffness. While heavier than the design target, the added weight of the hydraulic system did not seem to impact walking in a significant way. The metrics used to evaluate walking were not sensitive enough to detect any subtle differences between walking with the hydraulic system and walking in a normal AFO.
A simpler graphical solution and an approximate formula for energy eigenvalues in finite square quantum wells
Authors: Lima F. M. S.
Published: October 2020

The computation of allowed energy levels for a particle bounded to a finite square well potential is ubiquitous in modern physics and introductory quantum mechanics textbooks. For stationary bound states, the matching conditions for the wave functions lead to a pair of transcendental equations whose roots correspond to the energy eigenvalues. However, the graphical solutions available do not make clear the dependence of the energies on the well potential parameters. In this note, I present a simpler graphical solution involving only one dimensionless parameter that determines a straight-line crossing identical sinusoidal curves. I then reduce this solution to a single cosine curve, and from a three-point interpolation, I derive an approximate formula for all energy levels valid for any square quantum well and that demands only a pocket calculator.
Landau levels, edge states, and gauge choice in 2D quantum dots
Authors: Bhuiyan Asadullah , Marsiglio Frank
Published: October 2020

We examine the behavior of a charged particle in a two dimensional quantum dot in the presence of a magnetic field. Emphasis is placed on the high magnetic field regime. Compared to free space geometry, confinement in a dot geometry provides a more realistic system where edge effects arise naturally. It also serves to remove the otherwise infinite degeneracy due to the magnetic field; nonetheless, as described in this paper, additional ingredients are required to produce sensible results. We treat both circular and square geometries, and in the latter, we explicitly demonstrate the gauge invariance of the energy levels and wave function amplitudes. The characteristics of bulk states closely resemble those of free space states. For edge states, with sufficiently high quantum numbers, we achieve significant differences in the square and circular geometries. Both circular and square geometries are shown to exhibit level crossing phenomena, similar to parabolic dots, where the confining potential is a parabolic trap. Confinement effects on the probability current are also analyzed; it is the edge states that contribute non-zero current to the system. The results are achieved using straightforward matrix mechanics, in a manner that is accessible to novices in the field. On a more pedagogical note, we also provide a thorough review of the theory of single electron Landau levels in free space and illustrate how the introduction of surfaces naturally leads to a more physically transparent description of a charged particle in a magnetic field.
Natural polymorphism of Ym1 regulates pneumonitis through alternative activation of macrophages
Authors: Zhu Wenhua , Lönnblom Erik , Förster Michael , Johannesson Martina , Tao Pei , Meng Liesu , Lu Shemin , Holmdahl Rikard
Published: October 2020

Ym1 polymorphism regulates alternative activation of macrophages leading to variable susceptibility to inflammatory diseases.
Nonadjacent dependency processing in monkeys, apes, and humans
Authors: Watson Stuart K. , Burkart Judith M. , Schapiro Steven J. , Lambeth Susan P. , Mueller Jutta L. , Townsend Simon W.
Published: October 2020

Artificial grammar experiments show that marmosets and chimpanzees can process nonadjacent decencies, a key feature of human language.
Urbanization and market integration have strong, nonlinear effects on cardiometabolic health in the Turkana
Authors: Lea Amanda J. , Martins Dino , Kamau Joseph , Gurven Michael , Ayroles Julien F.
Published: October 2020

Turkana pastoralists who move to cities exhibit poor cardiometabolic health, consistent with evolutionary mismatch.
The
FAM171A2
gene is a key regulator of progranulin expression and modifies the risk of multiple neurodegenerative diseases
Authors: Xu Wei , Han Si-Da , Zhang Can , Li Jie-Qiong , Wang Yan-Jiang , Tan Chen-Chen , Li Hong-Qi , Dong Qiang , Mei Cui , Tan Lan , Yu Jin-Tai
Published: October 2020

The
FAM171A2
gene is a key regulator of progranulin expression and modifies the risk of multiple neurodegenerative diseases.
Targeted sequence design within the coarse-grained polymer genome
Authors: Webb Michael A. , Jackson Nicholas E. , Gil Phwey S. , de Pablo Juan J.
Published: October 2020

Coarse-grained modeling, machine learning, and optimization enable efficient design of polymers with target properties.
Mass screening weighed for type 1 diabetes risk
Authors: Couzin-Frankel Jennifer
Published: October 2020

Studies find benefit to testing thousands of children for antibodies that precede symptoms.
Cultivating fungal research
Authors: Kong Heidi H. , Segre Julia A.
Published: October 2020

Growing interest in host-fungal interactions has implications for human health and disease
Dissolved oxygen and pH criteria leave fisheries at risk
Authors: Tomasetti Stephen J. , Gobler Christopher J.
Published: October 2020

Regulations have not kept pace with scientific understanding of coastal hypoxia and acidification
Ultrafast vector imaging of plasmonic skyrmion dynamics with deep subwavelength resolution
Authors: Davis Timothy J. , Janoschka David , Dreher Pascal , Frank Bettina , Meyer zu Heringdorf Frank-J. , Giessen Harald
Published: October 2020

Watching plasmonic skyrmions

Skyrmions are stable topological textures that arise from solutions of the electromagnetic field. Because these “hedgehog”-like textures are robust, can be manipulated, and can interact, there is an interest in pursuing them for memory and logic applications. Skyrmions can also be generated in thin metal layers under optical excitation, but detailed information about the vectorial dynamics of these surface plasmon polariton skyrmions is so far lacking. Davis
et al.
used a time-resolved photoelectron vector microscope to image their spatiotemporal dynamics, piecing together movies as the skyrmions propagated across the surface of a perfect gold crystal. Access to dynamics with such high spatial and temporal resolution could help in controlling other nanophotonic systems.

Science
, this issue p.
eaba6415
Super-rotating the venusian atmosphere
Authors: Lebonnois Sebastien
Published: October 2020

Analysis of spacecraft observations deciphers the source of fast atmospheric rotation
Calcium as a biased cofactor
Authors: Chaturvedi Madhu , Shukla Arun K.
Published: October 2020

Crystal structure of an anti-obesity drug target reveals an important calcium-binding site
A history of the metaphorical brain
The Idea of the Brain: The Past and Future of Neuroscience
Matthew Cobb
Basic Books, 2020. 496 pp.
Authors: Gomez-Marin Alex
Published: October 2020

Analogies abound and inform our quest to understand the nervous system
Analog-digital computing let robots go through the motions
Authors: Kassanos Panagiotis
Published: October 2020

A hybrid analog-digital computing platform using memristors enables faster, more energy-efficient, and adaptive real-time robot control.
ANXA11
mutations in ALS cause dysregulation of calcium homeostasis and stress granule dynamics
Authors: Nahm Minyeop , Lim Su Min , Kim Young-Eun , Park Jinseok , Noh Min-Young , Lee Sanggon , Roh Ju Eun , Hwang Sung-Min , Park Chul-Kyu , Kim Yong Ho , Lim GyuTae , Lee Jinhyuk , Oh Ki-Wook , Ki Chang-Seok , Kim Seung Hyun
Published: October 2020

ANXA11 dysfunction induces alteration of intracellular Ca
2+
homeostasis and stress granule disassembly in ALS.
Aryl hydrocarbon receptor ligand production by the gut microbiota is decreased in celiac disease leading to intestinal inflammation
Authors: Lamas Bruno , Hernandez-Galan Leticia , Galipeau Heather J. , Constante Marco , Clarizio Alexandra , Jury Jennifer , Breyner Natalia M. , Caminero Alberto , Rueda Gaston , Hayes Christina L. , McCarville Justin L. , Bermudez Brito Miriam , Planchais Julien , Rolhion Nathalie , Murray Joseph A. , Langella Philippe , Loonen Linda M. P. , Wells Jerry M. , Bercik Premysl , Sokol Harry , Verdu Elena F.
Published: October 2020

Impaired AhR ligand production by the gut microbiota decreases AhR pathway activation, promoting inflammation in celiac disease.
Antibiotics make a double play
Authors: Kommagani Ramakrishna
Published: October 2020

In addition to antibacterial activity, tetracycline antibiotics induce disease tolerance by altering host mitochondrial function.