bluuebunny/crossref_metadata_2025 huggingface dataset:
Micromechanical modeling and characterization of elastic behavior of carbon nanotube‐reinforced polymer nanocomposites: A combined numerical approach and experimental verification
Authors: Kassa Mesfin Kebede , Arumugam Ananda Babu
Published: May 2020

In this study, a combined analytical and finite element‐based micromechanical modeling is performed to characterize the elastic properties of carbon nanotube (CNT) reinforced polymer nanocomposites and validated with experimental work. First, coordinates of armchair and zigzag type CNTs are generated using MATLAB based on the geometric structure of the CNTs and imported to the computational software ANSYS to model and characterize the elastic properties of the individual single‐walled CNT (SWCNT) and multi‐walled CNT by applying various loading and boundary conditions. The present developed finite element method (FEM) model of CNTs is validated with the available literature in terms of elastic properties. Subsequently, the equivalent elastic properties of CNT reinforced epoxy nanocomposites are determined through representative volume element (RVE) model by finite element simulations and Mori‐Tanaka homogenization techniques by replacing CNTs with equivalent fibers as microinclusions. The equivalent elastic properties of nanocomposite obtained by the FEM and analytical model are compared and validated with the experimental results. Further, the detailed parametric study is performed to investigate the influence of tube chirality, volume fraction, and orientation of CNT in terms of the elastic properties of the nanocomposite. It was observed that the armchair type CNT reinforced nanocomposites are stiffer than the zigzag type SWCNT reinforced nanocomposites in terms of elastic moduli. Further, it was noticed that the tube chirality and the number of walls of CNTs have significantly influenced the elastic behavior of nanocomposites. It can be concluded that the presented combined model provides an efficient methodology and comprehensive understanding to analyze the elastic behavior of CNTs and CNT reinforced nanocomposites. So, the presented combined numerical and experimental study could serve as a guideline in micromechanical modeling and characterization of elastic behavior of CNT‐reinforced polymer nanocomposites.
Nano‐silica modification of UV‐curable EVA resin for additive manufacturing
Authors: Xue Hanyu , Ye Yuansong , Li Xinzhong , Xia Jianrong , Lin Qi
Published: May 2020

Due to layer by layer printing, the interlayer adhesion of resin used in extrusion‐based additive manufacturing (AM) is poor, while thermal curing affects the accuracy of the resin. Therefore, methods of photo‐curing and nanomodification were used in this work to improve the adhesion between layers and the overall performance of AM resins. Specifically, ethylene‐vinyl acetate (EVA) copolymer with dual curing agent of benzophenone/triallyl isocyanurate (BP/TAIC) and nano‐silica (NS) were introduced. The results of light transmittance, scanning electron microscopy and gel content test showed that BP/TAIC with NS were proved to be able to improve the curing process of EVA. The filling of a small amount of NS did not act as ultraviolet light barrier, but instead improved the photo‐curing of the resin and reduced the amount of agents. UV curing also improved the adhesion between layers of EVA resin. The tensile strength was 7.1% higher than that of EVA/NS/BT without curing. At the same time, due to good interface bonding and dispersion, the thermal conductivity of resin improved from 0.212 W/m·k to 0.252 W/m·k. A 16.1% raise in tensile strength and a 10.0% increase in the volume resistivity were demonstrated for the 3.0 wt% NS. Furthermore, this resin is potential to be used in AM.
Ignition and Combustion Developments of Granular Explosive (RDX/HMX) in Response to Mild‐Impact Loading
Authors: Wu Yanqing , Duan Hongzheng , Yang Kun , Guo Hongfu , Huang Fenglei
Published: May 2020

The experimental analyses of ignition and burning responses of mild‐impacted granular explosive, namely, cyclotrimethylene trinitramine (RDX) and cyclotetramethylene tetranitramine (HMX), were performed based on an optimized drop‐weight system equipped with a High‐Speed Camera (HSC). It has been found that jetting phenomena observed by HSC is the result of the energy released by gaseous products, which push the pulverized or melted explosives to splash radially. Jetting is the only and the most obvious difference between reactive and inert particles prior to combustion so that it can be regarded as the sign of ignition more accurately than other ways. For RDX sample, the molten phase plays an important role in the hot‐spots formation. After a piece of waxed paper is put on the glass anvil, the jetting of molten‐phase RDX will be limited due to the high‐roughness of waxed paper. Moreover, ignition growth to burning probability of RDX particles is increased compared with the non‐waxed paper case. Radial deformation velocity, jetting velocity, and flame propagation velocity have been estimated via image processing, making it possible to quantify the violence of mechanical deformation and chemical reaction.
Identification and transcriptional response of ATP‐binding cassette transporters to chlorantraniliprole in the rice striped stem borer, Chilo suppressalis
Authors: Meng Xiangkun , Yang Xuemei , Wu Zhaolu , Shen Qinwen , Miao Lijun , Zheng Yang , Qian Kun , Wang Jianjun
Published: May 2020

BACKGROUND

As the largest transporter gene family in metazoans, ATP‐binding cassette (ABC) transporters regulate the efflux of a broad spectrum of substrates from the cytoplasm to the outside of the cell. In arthropods, ABC transporters are involved in phase III of the detoxification process, and play important roles in the metabolism and transport of insecticides.

RESULTS

We identified 54 ABC transporters from the genome and transcriptome of Chilo suppressalis, one of the most damaging pests of rice in China. The identified ABC transporters were classified into eight subfamilies (ABCA to ABCH) based on NCBI BLAST and phylogenetic analysis. Synergism studies showed that treatment with verapamil, a potent inhibitor of ABC transporters, resulted in significantly increased toxicity of chlorantraniliprole against C. suppressalis larvae. Among the 21 tested ABC genes, three ABC transporter genes including CsABCC8, CsABCG1C and CsABCH1 were significantly upregulated after chlorantraniliprole treatment.

CONCLUSION

ABC transporters play important roles in the detoxification and transport of chlorantraniliprole in C. suppressalis. The results from our study provide valuable information on C. suppressalis ABC transporters, and are helpful in understanding the roles of ABC transporters in chlorantraniliprole resistance mechanisms in C. suppressalis and other insect pests. © 2020 Society of Chemical Industry
Local Structures in Disordered Rocksalt‐Type Li3NbO4‐Based Positive Electrode Materials for a Lithium‐Ion Battery
Authors: Kitamura Naoto , Araki Yusuke , Ishida Naoya , Idemoto Yasushi
Published: May 2020

Li‐rich transition‐metal oxides with a disordered rocksalt structure have drawn much attention as promising candidates for a positive electrode material of a lithium‐ion battery. Among the oxides, this study focuses on Li1.3Nb0.3Fe0.4O2 and Li1.3Nb0.43Ni0.27O2, and investigates local distortions around the cations and local cation ordering in the materials by means of a reverse Monte Carlo modeling using neutron and synchrotron X‐ray total scattering data. It is found from the simulated atomic configurations that a local distortion around Nb is larger than those around the other cations in both the materials. The large distortion is supposed to be induced by a smaller ionic radius of Nb than the others and/or a mismatch of electronic state of Nb in the disordered rocksalt structure. Furthermore, a coordination‐number analysis on the materials demonstrates that Li tends to be surrounded by Nb significantly in the disordered rocksalt structure. From these results, it can be considered that Li diffusion is disturbed by a cation with a higher valence in the disordered rocksalt structure.
Fragility of 1D Floppy Materials
Authors: Tanaka Keiji
Published: May 2020

The fragility works as a fundamental concept characterizing glass‐forming liquids, whereas its atomic structural interpretation remains a challenge. Herein, viscosity behaviors in polyethylene (PE), S, Se, and Te are examined, which consist of distorted chain molecules with varied interchain strength, in comparison with that in SiO2, a typical strong material. Among the 1D materials, S and PE appear to be fairly strong. Such results suggest that the viscosity exhibits Arrhenius‐type behaviourif it is governed by single microscopic mechanisms such as SiO bond scission or interchain slippages. In contrast, Se and Te appear fragile with non‐Arrhenius variations, which could be ascribable to mixed inter‐ and intrachain interactions. Among these floppy materials, it is known that Se is the best glass former, the reason being discussed.
Molecular Mechanisms, Characterization Methods, and Utilities of Nanoparticle Biotransformation in Nanosafety Assessments
Authors: Cai Xiaoming , Liu Xi , Jiang Jun , Gao Meng , Wang Weili , Zheng Huizhen , Xu Shujuan , Li Ruibin
Published: May 2020

It is a big challenge to reveal the intrinsic cause of a nanotoxic effect due to diverse branches of signaling pathways induced by engineered nanomaterials (ENMs). Biotransformation of toxic ENMs involving biochemical reactions between nanoparticles (NPs) and biological systems has recently attracted substantial attention as it is regarded as the upstream signal in nanotoxicology pathways, the molecular initiating event (MIE). Considering that different exposure routes of ENMs may lead to different interfaces for the arising of biotransformation, this work summarizes the nano–bio interfaces and dose calculation in inhalation, dermal, ingestion, and injection exposures to humans. Then, five types of biotransformation are shown, including aggregation and agglomeration, corona formation, decomposition, recrystallization, and redox reactions. Besides, the characterization methods for investigation of biotransformation as well as the safe design of ENMs to improve the sustainable development of nanotechnology are also discussed. Finally, future perspectives on the implications of biotransformation in clinical translation of nanomedicine and commercialization of nanoproducts are provided.
The Influence of Nanoparticle Shape on Protein Corona Formation
Authors: Madathiparambil Visalakshan Rahul , González García Laura E. , Benzigar Mercy R. , Ghazaryan Arthur , Simon Johanna , Mierczynska‐Vasilev Agnieszka , Michl Thomas D. , Vinu Ajayan , Mailänder Volker , Morsbach Svenja , Landfester Katharina , Vasilev Krasimir
Published: May 2020

Nanoparticles have become an important utility in many areas of medical treatment such as targeted drug and treatment delivery as well as imaging and diagnostics. These advances require a complete understanding of nanoparticles' fate once placed in the body. Upon exposure to blood, proteins adsorb onto the nanoparticles surface and form a protein corona, which determines the particles' biological fate. This study reports on the protein corona formation from blood serum and plasma on spherical and rod‐shaped nanoparticles. These two types of mesoporous silica nanoparticles have identical chemistry, porosity, surface potential, and size in the y‐dimension, one being a sphere and the other a rod shape. The results show a significantly larger amount of protein attaching from both plasma and serum on the rod‐like particles compared to the spheres. Interrogation of the protein corona by liquid chromatography–mass spectrometry reveals shape‐dependent differences in the adsorption of immunoglobulins and albumin proteins from both plasma and serum. This study points to the need for taking nanoparticle shape into consideration because it can have a significant impact on the fate and therapeutic potential of nanoparticles when placed in the body.
Nanometal Oxides with Special Surface Physicochemical Properties to Promote Electrochemical Detection of Heavy Metal Ions
Authors: Yang Meng , Li Pei‐Hua , Chen Shi‐Hua , Xiao Xiang‐Yu , Tang Xiang‐Hu , Lin Chu‐Hong , Huang Xing‐Jiu , Liu Wen‐Qing
Published: May 2020

Heavy metal ions (HMIs) are one of the major environmental pollution problems currently faced. To monitor and control HMIs, rapid and reliable detection is required. Electrochemical analysis is one of the promising methods for on‐site detection and monitoring due to high sensitivity, short response time, etc. Recently, nanometal oxides with special surface physicochemical properties have been widely used as electrode modifiers to enhance sensitivity and selectivity for HMIs detection. In this work, recent advances in the electrochemical detection of HMIs using nanometal oxides, which are attributed to specific crystal facets and phases, surficial defects and vacancies, and oxidation state cycle, are comprehensively summarized and discussed in aspects of synthesis, characterization, electroanalysis application, and mechanism. Moreover, the challenges and opportunities for the development and application of nanometal oxides with functional surface physicochemical properties in electrochemical determination of HMIs are presented.
Microstructure and Mechanical Properties of Inertia‐Friction‐Welded Fe–Cr–Ni–Mo High‐Strength Steel
Authors: Zai Le , You Guoqiang , Tong Xin , Ding Yuhan , Xu Xuanxi , Liu Qing
Published: May 2020

Inertia friction welding (IFW) is a solid‐state welding technology that avoids defects associated with molten weld processes; however, this process has rarely been used to weld ultrahigh‐strength steel (UHSS). Herein, 32CrMnSi2Ni6MoV UHSS is joined successfully via IFW. The mechanical properties after welding at different rotational speeds and the microstructure at 2800 rpm are studied in detail. The temperature distributions in the peripheral and central areas are modeled according to the temperature at the weld zone. The microstructural transformation is analyzed for different temperature intervals, and the microstructural characteristics of each interval correspond to the actual microstructure of the welded joint according to the temperature distribution model. High‐strength martensite forms at the weld zone, and the thermomechanical‐affected zone (TMAZ) in the peripheral region is divided into phase transformation zone, partial recrystallization zone, and plastic deformation zone, whereas the TMAZ in the central region includes only the partial recrystallization and pure plastic deformation zones. This difference is due to the higher frictional heat caused by the higher peripheral linear velocity during rotation. A tensile test shows that fracture occurs in the base metal (BM) region, and the yield strength, tensile strength, and elongation are 805 MPa, 1064 MPa, and 13.88%, respectively.
Section XII: Surrender
Authors: Dinstein Yoram , Dahl Arne Willy
Published: May 2020

Enemy military personnel and civilians who have been directly participating in hostilities who manifest the intent to surrender and who comply with the additional requirements of Rules 103 and 104 arehors de combatand may not be denied quarter.
The Role of Smallholder Farms in a Changing World
Authors: Fan Shenggen , Rue Christopher
Published: May 2020

Despite progress, multiple burdens of malnutrition persist worldwide: 795 million people are hungry more than 2 billion people suffer from micronutrient deficiencies and over 2 billion are overweight or obese. At the same time, various challenges continue to threaten global food security and nutrition. Smallholder farmers are a key to ending hunger and undernutrition worldwide, but they are increasingly facing barriers to profitability. Yet smallholders should not all receive the same kind of support; they are not a homogenous group. While some smallholders should be supported to move up to commercially oriented and profitable farming systems, some should be supported to move out to seek non-farm employment opportunities. Strategies to promote smallholder agriculture as a business can help to overcome these obstacles and move smallholders with profit potential towards greater prosperity, while also contributing to the achievement of multiple Sustainable Development Goals (SDGs).
Rural Development Strategies and Africa’s Small Farms
Authors: Larson Donald F. , Muraoka Rie , Otsuka Keijiro
Published: May 2020

Improving the productivity of smallholder farms in sub-Saharan Africa (SSA) offers the best chance of reducing poverty among this generation of rural poor, by building on the few resources farming households already own. It is also the best and shortest path to meet rising food needs. Using examples from farmers’ maize and rice fields, comparisons with Asia, and an extensive literature review, we explain why the set of technologies promoted to date have produced localised successes rather than transformational change. We also examine the limitations of alternative policies that are not centred on small farms. We give indicative examples of how resource management technologies can supplement seed-fertiliser technologies to speed an African Green Revolution.
Inorganic Fertiliser Use Among Smallholder Farmers in Sub-Saharan Africa: Implications for Input Subsidy Policies
Authors: Ricker-Gilbert Jacob
Published: May 2020

In recent years, use of inorganic fertiliser among smallholder farm households in Sub-Saharan Africa (SSA) has increased, in large part due to the scale-up of input subsidy programmes (ISPs). However, fertiliser use efficiency for maize remains low, so the benefits of ISPs are often less than their costs. In order to make ISPs more cost-effective, sustainable and beneficial to smallholders, governments who implement ISPs should move towards implementing self-targeting mechanisms where more productive farmers opt into participation and relatively less productive farmers opt out. Such mechanisms include (i) increasing the amount of money that beneficiaries are required to contribute to acquire subsidised inputs and (ii) making receipt of subsidised inputs conditional on a household’s willingness to implement soil fertility management practices that can increase the amount of maize produced per kilogram of fertiliser in future. Limited resource farmers who cannot provide complementary inputs to subsidised fertiliser would likely be better served by a cash transfer programme rather than an input subsidy.
Global Change and Investments in Smallholder Irrigation for Food and Nutrition Security in Sub-Saharan Africa
Authors: Hanjra Munir A. , Williams Timothy O.
Published: May 2020

Investments in irrigation contribute to poverty reduction and enhance food security. This paper considers irrigation investments more broadly in the context of rural–urban linkages and thus examines rural irrigation schemes and peri-urban and urban agriculture using freshwater, groundwater and wastewater. We present case studies from East, West and Southern Africa, while focusing on the imperative of smallholders and of food security and nutrition. Evidence from Big Data and telecoupling show that, amid global change and sustainability issues, irrigation development strengthens connections between humans and nature with notable benefits to food security. Transforming investments to feed the future generation require priority investments in irrigation, solar energy for groundwater pumping, groundwater development policy, and integration of peri-urban and urban agriculture into food systems. Equally important will be no-regret interventions in wastewater reuse, water storage and groundwater buffer, micro-irrigation, and wholesale reconfiguration of farming systems, through anticipatory investments, to safeguard food security and sustainability into the distant future.
Transforming Smallholder Agriculture to Achieve the SDGs
Authors: Abraham Mathew , Pingali Prabhu
Published: May 2020

There is overwhelming historical evidence from the developed world and from the newly emerging economies of the developing world that indicates that agricultural growth has been the primary engine of overall economic growth. The transformation of economies around the world, from predominantly agricultural to industrial, was kick-started by rapid agricultural productivity growth. Does the growth in agricultural productivity have to necessarily come from the small farm sector? Rapid improvement in small farm productivity is one of the primary mechanisms by which dramatic rural poverty reductions can be achieved as shown by the Green Revolution experience in Asia and more recently in sub-Saharan Africa. Economic growth policies that are inclusive of smallholder farmers directly contribute to the SDG 2 that is focused on ending hunger, achieving food security and promoting sustainable agriculture. Past efforts at small farm productivity improvement were focused on staple grains, looking ahead one needs to take a food systems perspective and encourage diversification into nutrition-rich legumes, pulses, horticulture crops and livestock. Investment in rural market infrastructure allows smallholders to commercialise and enhance the supply of perishable products. Linking small farms to urban food value chains is also a promising new avenue for rural poverty reduction.
Axion periodicity and coupling quantization in the presence of mixing
Authors: Fraser Katherine , Reece Matthew
Published: May 2020

Abstract

Mixing of axion fields is widely used to generate EFTs with phenomenologically advantageous features, such as hierarchies between axion couplings to different gauge fields and/or large effective field ranges. While these features are strongly constrained by periodicity for models with only a single axion, mixing has been used in the literature (sometimes incorrectly) to try to evade some of these constraints. In this paper, we ask whether it is possible to use axion mixing to generate an EFT of axions that evades these constraints by flowing to a theory of a non-compact scalar in the IR. We conclude that as long as the light axion is exactly massless, it will inherit the periodicity and associated constraints of the UV theory. However, by giving the light axion a mass, we can relax these constraints with effects proportional to the axion mass squared, including non-quantized couplings and the realignment of monodromy to a light axion with a larger field range. To show this, we consider various examples of axions mixing with other axions or with non-compact scalar fields, and work in a basis where coupling quantization is manifest. This basis makes it clear that in the case where an axion is eaten through the Higgs or Stückelberg mechanism, the light axion does not have a large effective field range, in contrast to some recent claims in the literature. Additionally, we relate our results about axion EFTs to a well-known fact about gauge theory: that QFTs with compact gauge groups in the UV flow to QFTs with compact gauge groups in the IR, and make this correspondence precise in the 2+1 dimensional case.
Electric dipole moments in a leptoquark scenario for the B-physics anomalies
Authors: Altmannshofer Wolfgang , Gori Stefania , Patel Hiren H. , Profumo Stefano , Tuckler Douglas
Published: May 2020

Abstract

Vector leptoquarks can address the lepton flavor universality anomalies in decays associated with the b → cℓν and b → sℓℓ transitions, as observed in recent years. While not required to explain the anomalies, these leptoquarks generically yield new sources of CP violation. In this paper, we explore constraints and discovery potential for electric dipole moments (EDMs) in leptonic and hadronic systems. We provide the most generic expressions for dipole moments induced by vector leptoquarks at one loop. We find that O(1) CP-violating phases in tau and muon couplings can lead to corresponding EDMs within reach of next-generation EDM experiments, and that existing bounds on the electron EDM already put stringent constraints on CP-violating electron couplings.
Digitale Daten für eine effizientere Prävention: Ethische und rechtliche Überlegungen zu Potenzialen und Risiken
Authors: Friele Minou , Bröckerhoff Peter , Fröhlich Wiebke , Spiecker genannt Döhmann Indra , Woopen Christiane
Published: May 2020

Die Digitalisierung bietet erhebliche Potenziale für eine Stärkung der Prävention im Gesundheitswesen. Daten aus verschiedenen klinischen und außerklinischen Quellen können strukturiert erfasst und mithilfe von Algorithmen systematisch verarbeitet werden. Präventionsbedarfe lassen sich schneller und präziser ermitteln, Interventionen zielgruppenspezifisch planen, implementieren und evaluieren. Zugleich ist es jedoch erforderlich, dass die Datenverarbeitung nicht nur hohen technischen, sondern auch ethischen Standards und den gesetzlichen Datenschutzbestimmungen entspricht, um Risiken zu vermeiden oder zu minimieren.

Der vorliegende Diskussionsbeitrag beleuchtet in ethischer und rechtlicher Hinsicht die Potenziale und Risiken der digitalen Prävention zum einen aus einer „Datenperspektive“, bei der es um die Nutzung von gesundheitsrelevanten Daten geht, und zum anderen aus einer „Algorithmenperspektive“, bei der der Einsatz algorithmischer Systeme, einschließlich künstlicher Intelligenz, zur Bedarfserhebung und Evaluation präventiver Maßnahmen im Mittelpunkt steht. Abschließend werden Empfehlungen für Rahmenbedingungen formuliert, die geschaffen werden sollten, um die Weiterentwicklung der Prävention im Gesundheitswesen zu stärken.
LATE: Nicht jede Demenz ist Alzheimer – Diskussion einer neuen Krankheitsentität am Fallbeispiel
Authors: Görß Doreen , Kilimann Ingo , Dyrba Martin , Nitsch Sascha , Krause Bernd , Teipel Stefan
Published: May 2020

Die limbisch prädominante altersassoziierte TDP-43(Transactivation response(TAR)-DNA-binding protein 43 kDa)-Enzephalopathie (LATE) wurde kürzlich als eigene neuropathologische Entität im Demenzspektrum charakterisiert. Neuropathologische Veränderungen im Sinne von LATE wurden zuvor bereits als Komorbidität der Alzheimer-Krankheit (AD) beschrieben und spätestens seit 2008 auch als ein von der AD unabhängiger autoptischer Befund. Die Konzeptualisierung von LATE rückt nun die pathogenetische Bedeutung von limbischem TDP-43 als alternative oder komorbide Ursache einer der klinischen AD ähnlichen amnestischen Demenz in das Bewusstsein. LATE könnte divergierende klinische und Biomarkerbefunde erklären, bei denen eine ausgeprägte mnestische Störung ohne Amyloid- und Tau-Veränderungen im Sinne einer AD-Pathologie nachweisbar ist. Ob LATE eine eigenständige neuropathologische Entität darstellt oder eine regionale Ausprägung innerhalb des Spektrums der bekannten TDP-43-assoziierten neurodegenerativen Erkrankungen ist aktuell Gegenstand kontroverser Diskussionen. Die weitere, gezielte Erforschung von TDP-43-Proteinopathien ist davon unabhängig ein vielversprechender Forschungsansatz, um Wissenslücken in der Alzheimer- und Demenzforschung zu schließen. So könnte ganz praktisch die Anreicherung eines amnestischen Phänotyps in klinischen Studien zu amyloidzentrierten Therapien durch das erhöhte Risiko limbischer TDP-43-Komorbidität den Nachweis der klinischen Wirksamkeit erschweren. Dieser Artikel stellt den aktuellen Stand der Diskussion zu LATE vor und illustriert das Konzept und daraus abgeleitete klinische Überlegungen an einem Fallbeispiel.
Lack of M4 muscarinic receptors in the striatum, thalamus and intergeniculate leaflet alters the biological rhythm of locomotor activity in mice
Authors: Riljak Vladimir , Janisova Katerina , Myslivecek Jaromir
Published: May 2020

The deletion of M4 muscarinic receptors (MRs) changes biological rhythm parameters in females. Here, we searched for the mechanisms responsible for these changes. We performed biological rhythm analysis in two experiments: in experiment 1, the mice [C57Bl/6NTac (WT) and M4 MR −/− mice (KO)] were first exposed to a standard LD regime (12/12-h light/dark cycle) for 8 days and then subsequently exposed to constant darkness (for 24 h/day, DD regime) for another 16 days. In experiment 2, the mice (after the standard LD regime) were exposed to the DD regime and to one light pulse (zeitgeber time 14) on day 9. We also detected M1 MRs in brain areas implicated in locomotor biological rhythm regulation. In experiment 1, the biological rhythm activity curves differed: the period (τ, duration of diurnal cycle) was shorter in the DD regime. Moreover, the day mean, mesor (midline value), night mean and their difference were higher in KO animals. The time in which the maximal slope occurred was lower in the DD regime than in the LD regime in both WT and KO but was lower in KO than in WT mice. In experiment 2, there were no differences in biological rhythm parameters between WT and KO mice. The densities of M1 MRs in the majority of areas implicated in locomotor biological rhythm were low. A significant amount of M1 MR was found in the striatum. These results suggest that although core clock output is changed by M4 MR deletion, the structures involved in biological rhythm regulation in WT and KO animals are likely the same, and the most important areas are the striatum, thalamus and intergeniculate leaflet.
Single breath-hold saturation recovery 3D cardiac T1 mapping via compressed SENSE at 3T
Authors: Ferreira da Silva Tiago , Galan-Arriola Carlos , Montesinos Paula , López-Martín Gonzalo Javier , Desco Manuel , Fuster Valentín , Ibáñez Borja , Sanchez-Gonzalez Javier
Published: May 2020

Objectives

To propose and validate a novel imaging sequence that uses a single breath-hold whole-heart 3D T1 saturation recovery compressed SENSE rapid acquisition (SACORA) at 3T.

Methods

The proposed sequence combines flexible saturation time sampling, compressed SENSE, and sharing of saturation pulses between two readouts acquired at different RR intervals. The sequence was compared with a 3D saturation recovery single-shot acquisition (SASHA) implementation with phantom and in vivo experiments (pre and post contrast; 7 pigs) and was validated against the reference inversion recovery spin echo (IR-SE) sequence in phantom experiments.

Results

Phantom experiments showed that the T1 maps acquired by 3D SACORA and 3D SASHA agree well with IR-SE. In vivo experiments showed that the pre-contrast and post-contrast T1 maps acquired by 3D SACORA are comparable to the corresponding 3D SASHA maps, despite the shorter acquisition time (15s vs. 188s, for a heart rate of 60 bpm). Mean septal pre-contrast T1 was 1453 ± 44 ms with 3D SACORA and 1460 ± 60 ms with 3D SASHA. Mean septal post-contrast T1 was 824 ± 66 ms and 824 ± 60 ms.

Conclusion

3D SACORA acquires 3D T1 maps in 15 heart beats (heart rate, 60 bpm) at 3T. In addition to its short acquisition time, the sequence achieves good T1 estimation precision and accuracy.
Passive Trunk Exoskeleton Acceptability and Effects on Self-efficacy in Employees with Low-Back Pain: A Mixed Method Approach
Authors: Baltrusch S. J. , Houdijk H. , van Dieën J. H. , Kruif J. Th. C. M. de
Published: May 2020

Purpose Determinants of successfully introducing passive exoskeletons in the working environment to decrease mechanical loading on the back, are acceptability of the device to management and employees, including self-efficacy of employees when using the device. Therefore, the aim of this study was to assess self-efficacy of employees with low-back pain when using an exoskeleton and the acceptability of such a device to these employees and their managers. Methods We used a mixed method approach. We quantitatively assessed the change in self-efficacy of 17 employees with low-back pain when performing daily activity tasks with the exoskeleton, using the modified spinal function sort (M-SFS). Qualitatively, we conducted a focus group with employees and a double interview with two managers to add more insight and understandings into changes in self-efficacy and to discuss challenges of implementing an exoskeleton in the working environment. Results Self-efficacy significantly increased by 7% when using the exoskeleton. Employees acknowledged the flexibility of the exoskeleton being advantageous to current static external lifting devices, which confirmed the increase of self-efficacy in both static and dynamic tasks. Individual data showed that the increase in self-efficacy was largest for participants, being greatly restricted by their low-back pain. In the focus group, employees confirmed that they are mostly open to wearing the exoskeleton if they suffer from low-back pain. Conclusion If potential challenges, e.g. visibility and potential refusal of wearing an exoskeleton are considered in the implementation strategy, acceptability of and self-efficacy in using the passive trunk exoskeleton would be further improved, potentially contributing to reduced risk of low-back pain.
What are the determinants of the willingness to share rides in pooled on-demand services?
Authors: Alonso-González María J. , Cats Oded , van Oort Niels , Hoogendoorn-Lanser Sascha , Hoogendoorn Serge
Published: May 2020

Simulation studies suggest that pooled on-demand services (also referred to as Demand Responsive Transport, ridesharing, shared ride-hailing or shared ridesourcing services) have the potential to bring large benefits to urban areas while inducing limited time losses for their users. However, in reality, the large majority of users request individual rides (and not pooled rides) in existing on-demand services, leading to increases in motorised vehicle miles travelled. In this study, we investigate to what extent fare discounts, additional travel time, and the (un)willingness to share the ride with (different numbers of) other passengers play a role in the decision of individuals to share rides. To this end, we design a stated preference study targeting Dutch urban individuals. In our research, we (1) disentangle the sharing aspect from related time–cost trade-offs (e.g. detours), (2) investigate preference heterogeneity regarding the studied attributes and identify distinct market segments, and (3) simulate scenarios to understand the impact of the obtained parameters in the breakdown between individual and pooled services. We find that less than one third of respondents have strong preferences against sharing their rides. Also, we find that different market segments vary not only in their values of the willingness to share, but also in how they perceive this willingness to share (per-ride or proportional to the in-vehicle time). Further, the scenario analysis demonstrates that the share of individuals who are willing to share rides depends primarily on the time–cost trade-offs, rather than on the disutility stemming from pooling rides per se.
Information load in escalation situations: combustive agent or counteractive measure?
Authors: Roetzel Peter Gordon , Pedell Burkhard , Groninger Daniel
Published: May 2020

This experimental study analyzes how a key factor, information load, influences decision making in escalation situations, i.e., in situations in which decision makers reinvest further resources in a losing course of action, even when accounting information indicates that the project is performing poorly and should be discontinued. This study synthesizes prior escalation research with information overload and investigates how different levels of information load influence the escalation of commitment. Our findings reveal a U-shaped effect of information load: When decision makers face negative feedback, a higher information load mitigates the escalation tendency up to a certain point. However, beyond this point, more information reinforces the escalation tendency. Moreover, we find that the type of feedback affects self-justification, and we find a negative and significant interaction between information load and self-justification in negative-feedback cases. Thus, studies investigating escalation of commitment should control for self-justification and information load when utilizing high levels of information load. Finally, in the positive-feedback condition, higher information load encourages decision makers to continue promising courses of action, i.e., increases decision-making performance.
Optimization of the Epitaxial Growth of Undoped GaN Waveguides in GaN-Based Laser Diodes Evaluated by Photoluminescence
Authors: Netzel C. , Hoffmann V. , Einfeldt S. , Weyers M.
Published: May 2020

Non-intentionally doped c-plane GaN layers are generally employed as p-side waveguide layers in violet/blue-emitting laser diodes. The recombination and diffusion of charge carriers in the p-side GaN waveguide influence the injection efficiency of holes into the InGaN quantum wells of these devices. In this study, the non-radiative recombination and the diffusivity in the [000-1] direction for charge carriers in such GaN layers are investigated by the photoluminescence of buried InGaN quantum wells, in addition to the GaN photoluminescence. The vertical charge carrier diffusion length and the diffusion constant in GaN were determined by evaluating the intensity from InGaN quantum wells in different depths below a top GaN layer. Additionally, the intensity from the buried InGaN quantum wells was found to be more sensitive to variations in the non-radiative recombination rate in the GaN layer than the intensity from the GaN itself. The study enables conclusions to be drawn on how the growth of a p-side GaN waveguide layer has to be optimized: (1) The charge carrier diffusivity in the [000-1] direction at device operation temperature is limited by phonon scattering and can be only slightly improved by material quality. (2) The use of TMGa (trimethylgallium) instead of TEGa (triethylgallium) as a precursor for the growth of GaN lowers the background silicon doping level and is advantageous for a large hole diffusion length. (3) Small growth rates below 0.5 μm/h when using TMGa or below 0.12 μm/h when using TEGa enhance non-radiative recombination. (4) A V/III gas ratio of 2200 or more is needed for low non-radiative recombination rates in GaN.
Struktur—Biomarker zur Früherkennung von Morbus Alzheimer
Authors: Stockmann Julia , Gerwert Klaus
Published: May 2020

Alzheimer’s disease cannot be cured today. In addition to a drug, a predictive blood biomarker is urgently needed to identify high-risk subjects in early cognitively less impaired stages. Here, a biomarker is presented that uses the secondary structure distribution of Aβ-peptides in blood measured by the immuno-infrared sensor. Using this structure-based biomarker clinical conversion of symptomless subjects at baseline were predicted in a follow-up study 14 years before manifestation.
Modeling groundwater total dissolved solid from derived electromagnetic data using multiple linear regression analysis: a case study of groundwater contamination
Authors: Aduojo Ameloko Anthony , Adebowole Ayolabi Elijah , Uchegbulam Okezie
Published: May 2020

The high concentration of total dissolved solids (TDS) and other physicochemical parameters in groundwater around dumpsites have been used to implicate contamination from decomposed waste materials. A simple multiple linear regression (MLR) TDS model that integrates the TDS data derived from boreholes and hand-dug wells to the geophysical parameters obtained from the frequency-domain electromagnetic (EM) data was developed in this research. This is with a view to efficiently monitor groundwater resources and exploration around the Olusosun dumpsite and its communities. With the aid of the MLR equation, the observed TDS concentration of water samples collected from boreholes and hand-dug wells, and the corresponding estimated ground conductivity data in the vertical dipole mode (VD 40) and horizontal dipole modes (HD 40 and HD 20), obtained from geophysical surveys were regressed in Microsoft Excel software to generate a MLR TDS model. The integrity of the derived TDS model was appraised to examine the possibility of deploying it to investigate the TDS content of groundwater around the study area. The EM data and the resistivity models obtained around the study area confirmed contamination going on around the dumpsite. The developed TDS model can be put to use with high confidence, for groundwater TDS prediction around the study area where there are only terrain conductivity data but with no boreholes parameters. Also, terrain conductivity data alone can be applied to the model to predict the concentration of TDS in groundwater where there are no boreholes and hand-dug wells, therefore reducing the cost and time of determining and monitoring both parameters independently. With the aid of the ArcGIS software, the TDS model was used to generate TDS estimate map for the area. The knowledge of the TDS variability in such a map could give a clue about the integrity of the underground water around the site.
Re-thinking humanism as a guiding philosophy for education: a critical reflection on Ethiopian higher educat0ion institutions
Authors: Tamrat Sisay
Published: May 2020

This paper aims to articulate and clarify the very essence of humanism and then contextualize it to the Ethiopian context. In this case, I believe that a humanistic philosophy for education is the best approach that helps students become holistic beings – citizens who are both morally/intellectually and economically capable, autonomous, critical and responsible. Students of Ethiopian Higher Education Institutions (EHEIs), however, are characterized by a dearth of humanistic elements for education. They are marred with intellectual and moral decadence. The methodology is qualitative for it largely depends on reviewing literatures and policy documents on the issue. The upshot of this paper is that the ideals of humanism in education is not an extra – icing on the cake- it is an essential tool that would clean the academic environment from the entrenched overall moral and intellectual decay permeating EHEIs.
Preparing construction supply chains for blockchain technology: An investigation of its potential and future directions
Authors: Tezel Algan , Papadonikolaki Eleni , Yitmen Ibrahim , Hilletofth Per
Published: May 2020

Blockchain, a peer-to-peer, controlled, distributed database structure, has the potential to profoundly affect current business transactions in the construction industry through smart contracts, cryptocurrencies, and reliable asset tracking. The construction industry is often criticized for being slow in embracing emerging technologies and not effectively diffusing them through its supply chains. Often, the extensive fragmentation, traditional procurement structures, destructive competition, lack of collaboration and transparency, low-profit margins, and human resources are shown as the main culprits for this. As blockchain technology makes its presence felt strongly in many other industries like finance and banking, this study investigates the preparation of construction supply chains for blockchain technology through an explorative analysis. Empirical data for the study were collected through semi-structured interviews with 17 subject experts. Alongside presenting a strengths, weaknesses, opportunities, and threats analysis (SWOT), the study exhibits the requirements for and steps toward a construction supply structure facilitated by blockchain technology.
Prehistoric Irrigation in Central Utah: Chronology, Agricultural Economics, and Implications
Authors: Simms Steven R. , Rittenour Tammy M. , Kuehn Chimalis , Cannon Molly Boeka
Published: May 2020

In 1928, Noel Morss was shown “irrigation ditches” along Pleasant Creek on the Dixie National Forest near Capitol Reef National Park, Utah, by a local guide who contended they were ancient. We relocated the site and mapped the route of an unusual mountain irrigation canal. We conducted excavations and employed OSL and AMS14C showing historic irrigation, and an earlier event between AD 1460 and 1636. Geomorphic evidence indicates that the canal existed prior to this time, but we cannot date its original construction. The canal is 7.2 km long, originating at 2,450 m asl and terminating at 2,170 m asl. Less than half of the system was hand constructed. We cannot ascribe the prehistoric use-event to an archaeological culture, language, or ethnic group, but the 100+ sites nearby are largely Fremont in cultural affiliation. We also report the results of experimental modeling of the capital and maintenance costs of the system, which holds implications for irrigation north of the Colorado River and farming during the Little Ice Age. The age of the prehistoric canal is consistent with a fragmentary abandonment of farming and continuity between ancient and modern tribes in Utah.
Coincidence Avoidance and Formulating the Access Problem
Authors: Berry Sharon E.
Published: May 2020

In this article, I discuss a trivialization worry for Hartry Field’s official formulation of the access problem for mathematical realists, which was pointed out by Øystein Linnebo (and has recently been made much of by Justin Clarke-Doane). I argue that various attempted reformulations of the Benacerraf problem fail to block trivialization, but that access worriers can better defend themselves by sticking closer to Hartry Field’s initial informal characterization of the access problem in terms of (something like) general epistemic norms of coincidence avoidance.
COVID-19 pandemic: challenges and opportunities for the Greek health care system
Authors: Giannopoulou Ioanna , Tsobanoglou George O.
Published: May 2020

After coming out of the state debt crisis, Greece is facing yet another crisis – that of the COVID-19 pandemic. The key challenges facing the organizational structure and function of the Greek public health system in order to meet the populations’ health needs are discussed. Social distancing, through imposed national lockdown very early in the pandemic, has been a key emergency public health measure that has saved lives. However, the system needs to enhance its capacity, through strengthening primary health and social support care, to be able to meet existing unmet health needs, the impact of the pandemic on mental health, as well as to tackle future new waves of outbreak. The related changes in health service provisions in response to the COVID-19 pandemic call for developing new models and novel approaches for delivering effective mental health services.
Let us unite against COVID-19 – a New Zealand perspective
Authors: Bandyopadhyay G. , Meltzer A.
Published: May 2020

Novel coronavirus 2019 (COVID-19) has shaken the existence of mankind worldwide, including that of New Zealand. In comparison to other countries, New Zealand has had a very low number of confirmed and probable cases as well as COVID-19-related deaths. New Zealand closed its borders and rapidly declared a stringent lockdown to eliminate COVID-19. The country’s ‘go hard, go early’ policy serves as an exemplar for the rest of the world to date. The mysterious nature of COVID-19 has caused tremendous stress and uncertainty leading to universal conflict between public health and state economy. Mental health services and non-government organisations have been proactive in the fight against COVID-19. Though there has been no significant rise in referrals to secondary mental health services to date (4 May 2020), a rapid surge in mental health presentations is widely anticipated. Telehealth may prove to be an efficient and cost-effective tool for the provision of future health services.