bluuebunny/crossref_metadata_2025 huggingface dataset:
Dentate Gyrus and CA3 GABAergic Interneurons Bidirectionally Modulate Signatures of Internal and External Drive to CA1
Authors: Aery Jones Emily A. , Rao Antara , Zilberter Misha , Djukic Biljana , Gillespie Anna K. , Koutsodendris Nicole , Nelson Maxine , Yoon Seo Yeon , Huang Kylie , Yuan Heidi , Gill Theodore M. , Huang Yadong , Frank Loren M.
Published: January 2021

Specific classes of GABAergic neurons are thought to play specific roles in regulating information processing in the brain. In the hippocampus, two major classes – parvalbumin-expressing (PV+) and somatostatin-expressing (SST+) neurons – differentially regulate endogenous firing patterns and target different subcellular compartments of principal cells, but how these classes regulate the flow of information throughout the hippocampus is poorly understood. We hypothesized that PV+and SST+interneurons in the dentate gyrus (DG) and CA3 might differentially modulate CA3 patterns of output, thereby altering the influence of CA3 on CA1. We found that while suppressing either interneuron type increased DG and CA3 output, the effects on CA1 were very different. Suppressing PV+interneurons increased local field potential signatures of coupling from CA3 to CA1 and decreased signatures of coupling from entorhinal cortex to CA1; suppressing SST+interneurons had the opposite effect. Thus, DG and CA3 PV+and SST+interneurons bidirectionally modulate the flow of information through the hippocampal circuit.
Heterologous autoimmunity and prokaryotic immune defense
Authors: Chen Hanrong , Mayer Andreas , Balasubramanian Vijay
Published: January 2021

Some prokaryotes possess CRISPR-Cas systems that provide adaptive immunity to viruses guided by DNA segments called spacers acquired from invading phage. However, the patchy incidence and limited memory breadth of CRISPR-Cas systems suggest that their fitness benefits are offset by costs. Here, we propose that cross-reactive CRISPR targeting can lead to heterologous autoimmunity, whereby foreign spacers guide self-targeting in a spacer-length dependent fashion. Balancing antiviral defense against autoimmunity predicts a scaling relation between spacer length and CRISPR repertoire size. We find evidence for this scaling through comparative analysis of sequenced prokaryotic genomes, and show that this association also holds at the level of CRISPR types. In contrast, the scaling is absent in strains with nonfunctional CRISPR loci. Finally, we demonstrate that stochastic spacer loss can explain variations around the scaling relation, even between strains of the same species. Our results suggest that heterologous autoimmunity is a selective factor shaping the evolution of CRISPR-Cas systems.
Beyond the pandemic: the role of the built environment in supporting people with disabilities work life
Authors: Martel Andrew , Day Kirsten , Jackson Mary Ann , Kaushik Saumya
Published: January 2021

Purpose

The COVID-19 pandemic has engendered changes in previously unimaginable timeframes, leading to new ways of working, which can quickly become the “ordinary” way of working. Many traditional workplace and educational practices and environments, however, are disadvantageous to people with disability and consequently are under-represented in the workforce and higher education.

Design/methodology/approach

Contributing factors include exclusionary societal and employer attitudes and inaccessible built environments including lack of attention to paths of travel, amenities, acoustics, lighting and temperature. Social exclusion resulting from lack of access to meaningful work is also problematic. COVID-19 has accelerated the incidence of working and studying from home, but the home environment of many people with disability may not be suitable in terms of space, privacy, technology access and connection to the wider community.

Findings

However, remote and flexible working arrangements may hold opportunities for enhancing work participation of people with disabilities. Instigating systemic conditions that will empower people with disability to take full advantage of ordinary working trajectories is key. As the current global experiment in modified work and study practices has shown, structural, organisational and design norms need to change. The future of work and study is almost certainly more work and study from home. An expanded understanding of people with disabilities lived experience of the built environment encompassing opportunities for work, study and socialisation from home and the neighbourhood would more closely align with the UNCRPD's emphasis on full citizenship.

Originality/value

This paper examines what is currently missing in the development of a distributed work and study place continuum that includes traditional workplaces and campuses, local neighbourhood hubs and homes.
Specialty coffee in Brazil: transition among consumers' constructs using structural equation modeling
Authors: Santos Patricia Mendes dos , Cirillo Marcelo Ângelo , Guimarães Elisa Reis
Published: January 2021

Purpose

Building on Guimarães et al. (2019) study and using the modeling of structural equations, the objective of this paper was to elaborate constructs whose variables would enable the characterization and distinction of individuals among these different groups of consumers and to provide insights into their transition between them.

Design/methodology/approach

The constructs were validated by the average variance extracted adaptive (AVEADP) index. The transition between consumer groups is explained and encouraged by advances in their conceptual and perceptual knowledge. Thus, regular consumers should be addressed with messages aimed primarily for the social aspect of consumption; enthusiasts, by reinforcing simple to moderate aspects commonly used as product purchase criteria and experts, attracted by the emphasis on complex criteria related to specialty coffee's conceptual and perceptual knowledge, highlighting their influence on the beverage's sensory profile.

Findings

Those results enabled a better understanding of these consumers and can guide the marketing strategies of different actors in this market.

Originality/value

Important attempts to understand and characterize Brazilian specialty coffee consumers were conducted by Guimarães et al. (2019) and Ramírez-Correa et al. (2020). However, further studies are needed to differentiate different specialty coffee consumer groups and enhance the market applicability of those studies results. In addition, despite its importance, there is a paucity of public domain studies about the national consumption of specialty coffees, being the results of this work important for the wide dissemination of such information.
Application of robust H-infinity controller in transition flight modeling of autonomous VTOL convertible Quad Tiltrotor UAV
Authors: Hegde Navya Thirumaleshwar , George V. I. , Nayak C. Gurudas , Vaz Aldrin Claytus
Published: January 2021

Purpose

This paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned aerial vehicles (UAVs). The variation in the aerodynamics and model dynamics of these aerial vehicles due to its tilting rotors are the key issues and challenges, which attracts the attention of many researchers. They carry parametric uncertainties (such as non-linear friction force, backlash, etc.), which drives the designed controller based on the nominal model to instability or performance degradation. The controller needs to take these factors into consideration and still give good stability and performance. Hence, a robust H-infinity controller is proposed that can handle these uncertainties.

Design/methodology/approach

A unique VTOL Quad Tiltrotor hybrid UAV, which operates in three flight modes, is mathematically modeled using Newton–Euler equations of motion. The contribution of the model is its ability to combine high-speed level flight, VTOL and transition between these two phases. The transition involves the tilting of the proprotors from 90° to 0° and vice-versa in 15° intervals. A robust H-infinity control strategy is proposed, evaluated and analyzed through simulation to control the flight dynamics for different modes of operation.

Findings

The main contribution of this research is the mathematical modeling of three flight modes (vertical takeoff–forward, transition–cruise-back, transition-vertical landing) of operation by controlling the revolutions per minute and tilt angles, which are independent of each other. An autonomous flight control system using a robust H-infinity controller to stabilize the mode of transition is designed for the Quad Tiltrotor UAV in the presence of uncertainties, noise and disturbances using MATLAB/SIMULINK. This paper focused on improving the disturbance rejection properties of the proposed UAV by designing a robust H-infinity controller for position and orientation trajectory regulation in the presence of uncertainty. The simulation results show that the Tiltrotor achieves transition successfully with disturbances, noise and uncertainties being present.

Originality/value

A novel VTOL Quad Tiltrotor UAV mathematical model is developed with a special tilting rotor mechanism, which combines both aircraft and helicopter flight modes with the transition taking place in between phases using robust H-infinity controller for attitude, altitude and trajectory regulation in the presence of uncertainty.
Can configurations of motivation and extraversion attenuate job demands-job burnout bond?
Authors: Farivar Sadegh , Esmaeelinezhad Osveh
Published: January 2021

Purpose

Recent research highlights the necessity to critically examine the factors that can reduce the relationship between job stressors, such as job demand and burnout, to create healthier workplaces. This study aims to explore how five types of motivations (extrinsic motivation-social, extrinsic motivation- material, introjected, identified and intrinsic motivation), in combination with extraversion trait influence the impact of job demands on job burnout.

Design/methodology/approach

This study adopted a set-theoretic approach named fuzzy-set qualitative comparative analysis to analyze the data collected from 84 employees working in an research and development department of a public organization.

Findings

Findings revealed two distinct configurations. First, the absence of intrinsic and identified motivations lead to job burnout if extraverted participants suffer from high job demands. Second, non-extraverted participants reported high job burnout in the presence of high job demands, although all five types of motivations drove them.

Practical implications

This study suggests managers need to consider personalized preventive actions, depending on the level of extraversion trait when they try to motivate their employees who are dealing with high levels of job demands.

Originality/value

The emerging trend in social science suggests adopting linearity assumptions to study social phenomena is inconsistent with the reality of human behavior. Thus, this study used fuzzy-set qualitative comparative analysis to examine the complex interplay among all five types of motivations, extraversion trait, job demands, which contribute to burnout.
Digital touchpoints and multichannel segmentation approach in the life insurance industry
Authors: Alt Mónika Anetta , Săplăcan Zsuzsa , Benedek Botond , Nagy Bálint Zsolt
Published: January 2021

Purpose

Digital technology is revolutionizing insurance distribution allowing the insurer companies to reach customers via multichannel. The aim of this study is to segment potential customers of life insurance based on their information search, purchasing channels and personal characteristics in the digital environment.

Design/methodology/approach

The study uses cross-sectional research survey. In total, 422 questionnaires were collected through a convenience sample of the Romanian population. The data was segmented based on consumer information touchpoints (online vs offline), purchase channel preference (offline by a professional vs online by a standardized platform) and personal characteristics (age, marital status and children).

Findings

The channel segmentation analysis revealed that information channel preferences are the most important clustering variables, followed by purchase channel preferences, marital status, having children and age. Four distinct segments were identified: young fully offliners (23.7%), mature fully offliners (31.5%), committed online searchers (23.2%) and cross-channel onliners (21.6%).

Practical implications

Insurance companies should adapt their communication and distribution strategy based on multichannel segmentation and should focus on digital touchpoints with costumers.

Originality/value

Firstly, the paper reveals multichannel and hybrid segmentation for life insurance. Secondly, it extends the already studied retail channels with search engines and companies' websites. Thirdly, it extends the behavioural variables for channel segmentation with technology acceptance behaviour, attitude towards life insurance, knowledge about life insurance, attitude towards personal selling and quality appraisal of online information sources.
Optimal pricing and ordering policies with different patience levels of consumers
Authors: Tang Yuewu , Song Yang , Xu Chang , Fan Tijun
Published: January 2021

Purpose

Using information systems via data mining and cluster analysis technologies, consumers' strategic behaviour can be measured, and their patience levels can be accurately described. This paper investigates the retailer's pricing and ordering policies when facing strategic consumers with different levels of patience and discusses the impacts of consumers' patience levels and proportions on retailers' maximum expected profits.

Design/methodology/approach

By cluster analysing transaction data on the number of websites visited, browsing time and purchase decision time, consumers' patience levels can be obtained. The authors formulate a newsvendor model considering customers' different patience levels. Three scenarios are investigated: two segments of consumers with two different levels of patience (Scenario I), multiple segments of consumers with different levels of patience (Scenario II) and a continuum of consumers whose levels of patience follow a continuous distribution (Scenario III). Then, general formulas are deduced for retailers' optimal prices, ordering quantities and profits.

Findings

Under Scenario I, if the proportion of less patient consumers is greater (less) than a threshold, the retailer's optimal price is equal to the less (more) patient consumers' reserve price. Under Scenario II, once the proportion of fully strategic consumers exceeds a certain threshold, the retailers' optimal price is equal to the fully strategic consumers' reserve price regardless of consumers' patience levels and proportions. Under Scenario III, the retailer's pricing and ordering policies depend on the distribution of their patience level.

Originality/value

Few studies have considered consumers' different levels of patience when making retailer pricing and ordering decisions. In this paper, strategic consumer behaviour is measured, and consumers' patience levels and proportions are obtained by cluster analysing consumer transaction data recorded by an information system. Three scenarios in which strategic consumers may be heterogeneous and have different patience levels are investigated. The results can guide retailer decision-making.
Constituting an Islamic social welfare function: an exploration through Islamic moral economy
Authors: Asutay Mehmet , Yilmaz Isa
Published: January 2021

Purpose

This study aims to theoretically explore and examine the possibility of developing an Islamic social welfare function (ISWF) within the Islamic moral economy (IME) frame by going beyond the traditional fiqhī approach. It focuses on issues of preference ordering and utility through the normative dimension of Islamic ontology, as expressed and articulated within the IME.

Design/methodology/approach

Being a theoretical paper, a conceptual and critical discursive approach is used in this paper.

Findings

To establish an ISWF, a narrow juristic approach remains inadequate; there is a need to integrate the substantive morality to complement the juristic approach to achieve the ihsani process as the ultimate individual objective, which makes an ISWF possible. As the scattered debate on the topic concentrates mainly on the juristic approach, the main contribution of this study is to present a model in which juristic and moralist positions endogenized and augmented to constitute ISWF.

Originality/value

As there is a limited amount of research available on the subject matter, this paper will be an important theoretical contribution. In addition, this study develops an IME approach rather than fiqh-based approach used in the available research, which makes it novel.
Sub-grade characteristics of clayey soil incorporating municipal solid waste incineration ash and marble dust
Authors: Singh Preetpal , Boora Amardeep , Gupta Ashok Kumar
Published: January 2021

Purpose

The purpose of this paper is to use the waste materials in soil stabilization and low traffic volume roads so as to minimize the cost of subgrades for road construction along with solving disposal problems of waste materials thus protecting the environment.

Design/methodology/approach

An extensive laboratory study has been carried out on various samples of soil alone and along with waste materials such as municipal solid waste incineration ash and marble dust by adding cement to evaluate their effect on geotechnical characteristics of clayey soils.

Findings

The experimental study revealed that mixture of soil:Municipal solid waste incineration ash (MSWIA):Cement and soil:Marble dust (MD):Cement can be successfully used for the construction of low traffic volume roads. The differential free swell of the clayey soil is nil on adding MSWIA: cement and MD: cement to clayey soil in optimum amounts.

Research limitations/implications

The research needs further experimentation on combining both MSWIA and MD together to stabilize clayey soil.

Practical implications

The research can be successfully used by government agencies in subgrades of low traffic roads.

Social implications

The utilization of waste materials in the study solved the disposal problem of both waste materials, thus protecting the environment and giving quality living standards to people.

Originality/value

The use of MSWIA along with cement and use of MD along with cement for evaluating geotechnical properties has not been studied in the past. The present study is focussed on the use of both these materials along with cement in soil stabilization.
Could China meet its emission reduction goal by CO2-EOR
Authors: Shannak Sa’d , Malov Artem
Published: January 2021

Purpose

This paper aims to discuss opportunities for pairing the carbon dioxide (CO2) points of supply from stationary sources such as power plants, steel and cement production, coal to liquid plants and refineries, with potential oil reservoirs in China.

Design/methodology/approach

This study builds a linear optimization model to analyze the tradeoffs in developing CO2-enhance oil recovery (EOR) projects in China for a range of policy options to match points of supply with the points of demand (oil fields). The model works on optimizing CO2 application costs by meeting four principal components; CO2 storage, CO2 capture, transport costs and additional oil recovery.

Findings

This study reveals new opportunities and economic sources to feed CO2-EOR applications and offers reasonable options to supply CO2 for potential points of demand. Furthermore, power plants and coal to liquid industries had the most significant and economic contributions to potential CO2-EOR projects in China. Total annual emission reduction is expected to be 10% (based on 10 Gton annual emissions). The emission reductions and potential CO2 storage from the different industries as follow; 94% from power plants, 4% from biofuel and 2% from coal to liquid plants.

Social implications

Carbon capture and storage (CCS) is one practice aiming to reduce the amounts of anthropogenic emissions of carbon dioxide emitted into the atmosphere and reduce the related social costs. However, given the relatively high cost associated with this practice, coupling it with EOR could offer a significant financial incentive to facilitate the development of CCS projects and meet climate change objectives.

Originality/value

The model used in this study can be straightforwardly adapted to any geographic location where industry and policymakers are looking to simultaneously reduce CO2 emissions while increasing hydrocarbon recovery. The model is highly adaptable to local values in the parameters considered and to include additional local considerations such as geographic variation in capture costs, taxes and premiums to be placed on CO2 capture in so-called “non-attainment zones” where pollution capture make could make a project politically and economically viable. Regardless of how and where this model is applied, it is apparent that CO2 from industrial sources has substantial potential value as a coproduct that offsets its sequestration costs using existing, commercially available CO2-EOR technology, once sources and sinks are optimally paired.
Exploring how the intangible side of an organization impacts its business model
Authors: Sanchez-Segura Maria-Isabel , Dugarte-Peña German-Lenin , Amescua-Seco Antonio , Medina-Dominguez Fuensanta
Published: January 2021

Purpose

Information technology/software (IT/SW) professionals use the business model canvas (BMC) to identify innovative digital solutions that improve their client’s business values. This paper aims to address the issue of considering, for a client company, the status of its intangible assets (IAs) in decision-making on the most innovative digital solution.

Design/methodology/approach

This paper provides a method (BMCIA-method) and a simulation tool (BMCIA-NetSim) to help IT/SW professionals identify and assess an organization’s IAs and their impact on the BMC of digital business.

Findings

IT/SW professionals used this approach, at 14 small and medium-sized enterprises (SMEs), to identify innovative solutions and add digital value to their businesses. They used the BMCIA to provide their clients (SME’s chief executive officer or chief operating officer) with a view of the BMC enhanced with the status of IAs. These expressed interest in the use of the BMCIA and underscore its importance for making better decisions while aligning IT and the business. A survey reveals how well the BMCIA-method performed during its use to discover the best solution to be developed at each SME.

Research limitations/implications

IAs affect the achievement of the business goal targeted using the BMC. If these are not identified, valued and properly aligned with the BMC blocks, critical information is hidden from the eyes of IT/SW professionals and their clients, preventing optimal decision-making on which is the best IT/SW solution to be implemented to add digital value to the client company.

Originality/value

This proposal is unique insofar as it outlines a simulation-based methodological and technical solution using software agents to simulate the impact of the intangible side of an organization on its business model.
Psychological And Physiological Benefits Of Plants In The Indoor Environment: A Mini And In-Depth Review
Authors: Yeo Lee Bak
Published: January 2021

People tend to spend approximately 87% of their time in the indoor environment. There is a possibility that they are exposed to volatile organic compound (VOC) and particle pollution, and to experience stress related disorder. This has potential threaten the well-being of indoor occupants if left untreated. Hence, plants were introduced to alleviate these negative impacts. This paper reviews past literature from 1990 to 2010s, to examine the relationship of plants with indoor environment and identifies how they influence people, psychologically and physiologically, and how they promote indoor environment quality. Most studies suggest that the presence of plants is associated with positive feelings and able to enhance productivity. In addition, they also may help to promote general health such as reducing blood pressure, perceived stress, sick building syndrome, and increase pain tolerance of the patient. Moreover, plants also help in improving the indoor environment quality (IEQ), for instance, they can reduce carbon dioxide (CO2), indoor ozone (O3) level, VOC, and particulate matter accumulation through bioremediation process. Despite all the benefits that the plants could offer, several studies pointed out that factors such as gender, perceived attractiveness of the space, physical characteristics of plants, and methods of interaction with plants may lead to non-identical results. Hence, the selection of the right species of plant in an indoor environment becomes mandatory in order to improve the indoor environment quality; to provide restorative effect; to invoke positive feelings and comfort of the people. In conclusion, this review may provide notable insights to landscape architects, gardeners and even interior designers to choose the right species of plant in an indoor environment, to maximize their psychological and physiological benefits, at the same time, improving indoor environment quality.
Towards Promoting Efficient Management Of Mass-Housing Reconstruction Schemes
Authors: Sodangi Mahmoud , Kazmi Zaheer Abbas , Salman Alaa , Bakri Muhammad Hassan , Anwar Fahad
Published: January 2021

To ensure quick socio-economic recovery of the communities affected by insurgents’ attacks in the north-eastern Nigeria, the first phase of the mass-housing reconstruction scheme has been completed but with many issues overshadowing the achievement like unsatisfactory involvement of local beneficiary communities; poor cooperation among key stakeholders; and communication gaps between donors, construction companies and local beneficiaries, which results in low quality housing products. Therefore, it became necessary to ensure that only contractors who satisfactorily passed the efficiency test are allowed to participate in the subsequent phases of the reconstruction scheme. Thus, this paper provides quantitative technique for evaluating the efficiency of contractors in managing the housing reconstruction. It is expected that the technique will seek to guide informed decisions on the efficiency of managing the reconstruction scheme, which is in different phases and locations. Although the evidences on which the results of this study emanate from reconstruction of building structures experiences in some parts of Nigeria, the technique developed could be adopted in other areas faced with similar issues. This paper updated existing knowledge on the management of mass-housing reconstruction works and offers support to decision-makers and practitioners involved in managing reconstruction of building structures affected by insurgency.
New Three-Term Conjugate Gradient Method with Exact Line Search
Authors: Fadhilah Nurul Hafawati , Rivaie Mohd , Ishak Fuziyah , Idalisa Nur
Published: January 2021

Conjugate Gradient (CG) methods have an important role in solving largescale unconstrained optimization problems. Nowadays, the Three-Term CG method hasbecome a research trend of the CG methods. However, the existing Three-Term CGmethods could only be used with the inexact line search. When the exact line searchis applied, this Three-Term CG method will be reduced to the standard CG method.Hence in this paper, a new Three-Term CG method that could be used with the exactline search is proposed. This new Three-Term CG method satisfies the descent conditionusing the exact line search. Performance profile based on numerical results show thatthis proposed method outperforms the well-known classical CG method and some relatedhybrid methods. In addition, the proposed method is also robust in term of number ofiterations and CPU time.
Nanofabrication of silicon surfaces for reduced virus adhesion
Authors: Guo Ao , Shieh Y. Carol , Divan Ralu , Wang Rong R.
Published: January 2021

Nanofabrication is a remarkably effective technique to create desirable nanoscale patterns. In this work, the effect of surface nanofabrication on altering virus adhesion to the substrates was examined. Arrays of nanoholes, 50 nm in diameter, 22 nm deep, and 100 nm in pitch distance, were created on silicon (Si) wafers by electron-beam lithography and reactive ion etching. MS2 coliphage, which is 26 ± 2 nm in diameter and is frequently used as a surrogate for human viruses, was applied to investigate the interaction between the virions and smooth or nanostructured Si surfaces. Scanning electron microscopy and atomic force microscopy along with surface wettability analyses revealed that the nanofabrication had the effect of reducing not only the number of viruses attached but also the strength of virus adhesion. These effects were ascribed to the presence of nanoholes, which were inaccessible to the virions due to the unique surface topographical parameters and the surface chemistry, resulting in the decrease of the overall solid contact area for MS2 attachment. The periodic spacing of the nanoholes also limited the unit landing area for MS2 particles, restricting the formation of MS2 aggregates and leading to the reduced amount of MS2 attachment. We anticipate that smart design of a surface’s chemical composition and nanostructure will offer a feasible solution to improve mitigations for controlling viral adhesion and transmission to and from food contact surfaces.
Acoustic detection range and population density of Cuvier's beaked whales estimated from near-surface hydrophones
Authors: Barlow Jay , Fregosi Selene , Thomas Len , Harris Danielle , Griffiths Emily T.
Published: January 2021

The population density of Cuvier's beaked whales is estimated acoustically with drifting near-surface hydrophone recorders in the Catalina Basin. Three empirical approaches (trial-based, distance-sampling, and spatially explicit capture-recapture) are used to estimate the probability of detecting the echolocation pulses as a function of range. These detection functions are used with two point-transect methods (snapshot and dive-cue) to estimate density. Measurement errors result in a small range of density estimates (3.9–5.4 whales per 1000 km2). Use of multiple approaches and methods allows comparison of the required information and assumptions of each. The distance-sampling approach with snapshot-based density estimates has the most stringent assumptions but would be the easiest to implement for large scale surveys of beaked whale density. Alternative approaches to estimating detection functions help validate this approach. The dive cue method of density estimation has promise, but additional work is needed to understand the potential bias caused by animal movement during a dive. Empirical methods are a viable alternative to the theoretical acoustic modeling approaches that have been used previously to estimate beaked whale density.
Modeling of wave fields generated by ultrasonic transducers using a quasi-Monte Carlo method
Authors: Zhang Shuzeng , Huang Yunatian , Li Xiongbing , Jeong Hyunjo
Published: January 2021

The sound fields generated by ultrasonic transducers are modeled using the quasi-Monte Carlo (QMC) method, which is found to overcome the conflict between accuracy and efficiency that occurs in existing wave field calculation methods. The RI equation, which is frequently used as a model equation in ultrasonic field calculation, is used here as an exact method and for comparison purposes. In the QMC method, the judgment sampling method and Halton sequence are used for pseudo-random sampling from the sound source, and then the sound field distributions are found by solving the integral solution using the sample mean. Numerical examples and results are presented when modeling unfocused, focused, and steered and focused beam fields. The accuracy and efficiency of the QMC method are discussed by comparing the results obtained using different modeling methods. The results show that the proposed method has a high level of efficiency due to the nature of the QMC algorithm and a high level of accuracy because no approximation is required. In addition, wave fields can be modeled with the QMC method as long as sound sources can be effectively pseudo-randomly sampled, allowing the proposed method to be applied to various types of transducers.
Resolution dependence of rough surface scattering using a power law roughness spectrum
Authors: Olson Derek R. , Lyons Anthony P.
Published: January 2021

Contemporary high-resolution sonar systems use broadband pulses and long arrays to achieve high resolution. It is important to understand effects that high-resolution sonar systems might have on quantitative measures of the scattered field due to the seafloor. A quantity called the broadband scattering cross section is defined, appropriate for high-resolution measurements. The dependence of the broadband scattering cross section, σbb, and the scintillation index, SI, on resolution was investigated for one-dimensional rough surfaces with power-law spectra and backscattering geometries. Using integral equations and Fourier synthesis, no resolution dependence of σbb was found. The incoherently averaged frequency-domain scattering cross section has negligible bandwidth dependence. SI increases as resolution increases, grazing angle decreases, and spectral strength increases. This trend is confirmed for center frequencies of 100 and 10 kHz, as well as for power-law spectral exponents of 1.5, 2, and 2.5. The hypothesis that local tilting at the scale of the acoustic resolution is responsible for intensity fluctuations was examined using a representative model for the effect of slopes (inspired by the composite roughness approximation). It was found that slopes are responsible in part for the fluctuations, but other effects, such as multiple scattering and shadowing may also play a role.
Additivity of segregation cues in simulated cocktail-party listening
Authors: Rodriguez Briana , Lee Jungmee , Lutfi Robert
Published: January 2021

An approach is borrowed from Measurement Theory [Krantz et al. (1971). Foundations of Measurement (Academic, New York), Vol. 1] to evaluate the interaction of voice fundamental frequency and spatial cues in the segregation of talkers in simulated cocktail-party listening. The goal is to find a mathematical expression whereby the combined effect of cues can be simply related to their individual effects. On each trial, the listener judged whether an interleaved sequence of four vowel triplets (heard over headphones) were spoken by the same (MMM) or different (FMF) talkers. The talkers had nominally different fundamental frequencies and spoke from nominally different locations (simulated using head-related transfer functions). Natural variation in these cues was simulated by adding a small, random perturbation to the nominal values independently for each vowel on each trial. Psychometric functions (PFs) relating d′ performance to the difference in nominal values were obtained for the cues presented individually and in combination. The results revealed a synergistic interaction of cues wherein the PFs for cues presented in combination exceeded the simple vector sum of the PFs for the cues presented individually. The results are discussed in terms of their implications for possible emergent properties of cues affecting performance in simulated cocktail-party listening.
Genomic Insights into Methicillin-Resistant Staphylococcus aureus
spa
Type t899 Isolates Belonging to Different Sequence Types
Authors: Tegegne Henok Ayalew , Koláčková Ivana , Florianová Martina , Wattiau Pierre , Gelbíčová Tereza , Boland Cécile , Madec Jean-Yves , Haenni Marisa , Karpíšková Renáta
Published: January 2021

This study showed the genetic diversity and population structure of
S. aureus
presenting the same
spa
type, t899, but belonging to different STs. Our findings revealed that these isolates vary deeply in their core and accessory genomes, contrary to what is regularly inferred from studies using
spa
typing only.
Listeria
spp. Isolated from Tonsils of Wild Deer and Boars: Genomic Characterization
Authors: Palacios-Gorba Carla , Moura Alexandra , Leclercq Alexandre , Gómez-Martín Ángel , Gomis Jesús , Jiménez-Trigos Estrella , Mocé María L. , Lecuit Marc , Quereda Juan J.
Published: January 2021

Listeria monocytogenes
is a foodborne bacterial pathogen responsible for listeriosis. Whole-genome sequencing has been extensively used in public health and food industries to characterize circulating
Listeria
isolates, but genomic data on isolates occurring in natural environments and wild animals are still scarce.
Dichloroacetate and Pyruvate Metabolism: Pyruvate Dehydrogenase Kinases as Targets Worth Investigating for Effective Therapy of Toxoplasmosis
Authors: Ferrarini Mariana Galvão , Nisimura Lindice Mitie , Girard Richard Marcel Bruno Moreira , Alencar Mayke Bezerra , Fragoso Mariana Sayuri Ishikawa , Araújo-Silva Carlla Assis , Veiga Alan de Almeida , Abud Ana Paula Ressetti , Nardelli Sheila Cristina , Vommaro Rossiane C. , Silber Ariel Mariano , France-Sagot Marie , Ávila Andréa Rodrigues
Published: January 2021

Currently, the drugs used for toxoplasmosis have severe toxicity to human cells, and the treatment still lacks effective and safer alternatives. The search for novel drug targets is timely.
Telephone-guided self-help for mental health difficulties in neurological conditions: a randomised pilot trial
Authors: Bennett Sophie D , Heyman Isobel , Coughtrey Anna E , Varadkar Sophia , Stephenson Terence ,   Epilepsy and Mental Health Programme Development Grant Research Group, Shafran Roz
Published: January 2021

Objective

This study aimed to conduct a randomised pilot trial to assess the feasibility of a randomised controlled trial (RCT) to investigate the effect of telephone-guided self-help for the treatment of mental health difficulties in children with neurological conditions.

Design

Preliminary RCT. The primary outcome measure was the Strengths and Difficulties Questionnaire.

Setting

Neurology clinics in a national tertiary paediatric hospital.

Patients

Young people attending neurology clinics who met criteria for mental health difficulties according to the Development and Wellbeing Assessment.

Interventions

12 weeks of telephone-guided self-help based on a modular approach to psychological therapy for children delivered to children and/or their parents (n=17; eight males; mean age 12.04 years, SD=3.34) or a waiting list for telephone-guided self-help with no additional intervention over 12 weeks (n=17; nine males; mean age 10.53 years, SD=3.14).

Results

124 participants completed the DAWBA, and 34 children and young people were entered into the trial. 65% of those randomised to the intervention arm completed the full intervention, and the intervention was acceptable to those completing it. However, there were significant problems related to lack of data completion (38% data loss for primary outcome measure), choice of control comparator and outcome measures. Due to significant loss of data at follow-up, the effect size findings are considered unreliable.

Conclusions

Further feasibility work should be conducted to improve data completeness before progression to a definitive trial of guided self-help for mental health problems in children with neurological conditions can be recommended.

Trial registration number

ISRCTN21184717.
Determinants of physician networks: an ethnographic study examining the processes that inform patterns of collaboration and referral decision-making among physicians
Authors: Kierkegaard Patrick , Owen-Smith Jason
Published: January 2021

Objective

Most scholarly attention to studying collaborative ties in physician networks has been devoted to quantitatively analysing large, complex datasets. While valuable, such studies can reduce the dynamic and contextual complexities of physician collaborations to numerical values. Qualitative research strategies can contribute to our understanding by addressing the gaps left by more quantitative approaches. This study seeks to contribute to the literature that applies network science approaches to the context of healthcare delivery. We use qualitative, observational and interview, methods to pursue an in-depth, micro-level approach to the deeply social and discursive processes that influence patterns of collaboration and referral decision-making in physician networks.

Design

Qualitative methodologies that paired ethnographic field observations, semistructured interviews and document analysis were used. An inductive thematic analysis approach was used to analyse, identify and describe patterns in those data.

Setting

This study took place in a high-volume cardiovascular department at a major academic medical centre (AMC) located in the Midwest region of the USA.

Participants

Purposive and snowballing sampling were used to recruit study participants for both the observational and face-to-face in-depth interview portions of the study. In total, 25 clinicians and 43 patients participated in this study.

Results

Two primary thematic categories were identified: (1) circumstances for external engagement; and (2) clinical conditions for engagement. Thematic subcategories included community engagement, scientific engagement, reputational value, experiential information, professional identity, self-awareness of competence, multidisciplinary programmes and situational factors.

Conclusion

This study adds new contextual knowledge about the mechanisms that characterise referral decision-making processes and how these impact the meaning of physician relationships, organisation of healthcare delivery and the knowledge and beliefs that physicians have about their colleagues. This study highlights the nuances that influence how new collaborative networks are formed and maintained by detailing how relationships among physicians develop and evolve over time.
Counting ribs and thoracic levels under ultrasound: a systematized technical protocol for both posterior and anterior approaches
Authors: Hurdle Mark Friedrich B , Ferreira-Dos-Santos Guilherme , Rosario-Concepcion Raul , Gil Laura V , Eldrige Jason S , Clendenen Steven R
Published: January 2021

Over the last two decades, the clinical applications of diagnostic and interventional ultrasound have expanded rapidly. When analyzing the chest wall and thoracic region, ultrasound has previously been shown to reliably identify chest wall pathologies like rib fracture and slipping rib syndrome, as well as having fundamentally changed perioperative management and patient outcomes after the emergence of point-of-care ultrasound. In addition, ultrasound guidance has recently become more popular for multiple blocks in the field of regional anesthesia and pain medicine. In this technical report, we systematize an ultrasound-guided protocol for counting ribs and thoracic levels for both posterior and anterior approaches, which does not require level confirmation by fluoroscopy. With this protocol, we hope to create an effective educational resource to support physicians from any specialty background as they engage in point-of-care ultrasound applications in the thoracic region.
Self-protection strategies and health behaviour in patients with inflammatory rheumatic diseases during the COVID-19 pandemic: results and predictors in more than 12 000 patients with inflammatory rheumatic diseases followed in the Danish DANBIO registry
Authors: Glintborg Bente , Jensen Dorte Vendelbo , Engel Sara , Terslev Lene , Pfeiffer Jensen Mogens , Hendricks Oliver , Østergaard Mikkel , Horskjær Rasmussen Simon , Adelsten Thomas , Colic Ada , Danebod Kamilla , Kildemand Malene , Loft Anne Gitte , Munk Heidi Lausten , Pedersen Jens Kristian , Østgård René Drage , Møller Sørensen Christian , Krogh Niels Steen , Agerbo Jette , Ziegler Connie , Hetland Merete Lund
Published: January 2021

Aims

In Danish patients with inflammatory rheumatic diseases to explore self-protection strategies and health behaviour including adherence to disease-modifying antirheumatic treatment (DMARD) during the initial phase of the COVID-19 pandemic and again after the reopening of the society started. Furthermore, to identify characteristics of patients with high levels of anxiety and self-isolation.

Methods

Patients in routine care followed prospectively in the nationwide DANBIO registry were invited to answer an online questionnaire regarding disease activity and COVID-19 infection, behaviour in March and June 2020. Responses were linked to patient data in DANBIO. Characteristics potentially associated with anxiety, self-isolation and medication adherence (gender/age/diagnosis/education/work status/comorbidity/DMARD/smoking/EQ-5D/disease activity) were explored with multivariable logistic regression analyses.

Results

We included 12 789 patients (8168 rheumatoid arthritis/2068 psoriatic arthritis/1758 axial spondyloarthritis/795 other) of whom 65% were women and 36% treated with biological DMARD. Self-reported COVID-19 prevalence was 0.3%. Patients reported that they were worried to get COVID-19 infection (March/June: 70%/45%) and self-isolated more than others of the same age (48%/38%). The fraction of patients who changed medication due to fear of COVID-19 were 4.1%/0.6%. Female gender, comorbidities, not working, lower education, biological treatment and poor European Quality of life, 5 dimensions were associated with both anxiety and self-isolation.

Conclusion

In >12 000 patients with inflammatory arthritis, we found widespread anxiety and self-isolation, but high medication adherence, in the initial phase of the COVID-19 pandemic. This persisted during the gradual opening of society during the following months. Attention to patients’ anxiety and self-isolation is important during this and potential future epidemics.
Selection of standard penetration test number for geotechnical investigation of a vertical cross section considering spatial variability and correlation in soil properties
Authors: Guan Zheng , Wang Yu
Published: January 2021

The standard penetration test (SPT) is a widely used in situ test for characterizing variation of subsurface soil properties, and results of site investigation are usually simplified as a two-dimensional (2D) vertical cross section for subsequent geotechnical design and construction. Current geotechnical design codes and guidelines only provide general recommendations for selection of an appropriate number of in situ tests (e.g., SPT) (e.g., the greater variability of subsurface conditions, the larger number of SPTs required to obtain sufficient underground information). No quantitative or rational method is available for selecting the appropriate number of SPTs considering spatial variability and correlation in subsurface conditions. A comprehensive parametric study is carried out in this study to investigate the influence of spatial variability in subsurface conditions on the minimum SPT number needed for satisfying an accuracy requirement of site investigation. Random field is adopted to model spatial variation and correlation in soil properties in typical site conditions, and 2D Bayesian compressive sampling is used to interpolate sparse SPT data. Based on the parametric study results, a statistical chart is developed for geotechnical engineers to conveniently select an appropriate number of SPTs in a vertical cross section. Real SPT data from New Zealand are used to illustrate and validate the proposed method.