bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiological and Genetic Drivers Underpinning Canopy Development are Associated with Durum Wheat Yield in Rainfed Environments
Authors: Kang Yichen , Haeften Shanice V. , Bustos-Korts Daniela , Vukasovic Stjepan , Khan Sana Ullah , Dinglasan Eric , Christopher Jack , Chenu Karine , Able Jason A. , Smith Millicent R. , Voss-Fels Kai P. , Potgieter Andries B. , Jordan David R. , Borrell Andrew K. , Alahmad Samir , Hickey Lee T.
Published: August 2021

New durum wheat (Triticum turgidum L. ssp. Durum) cultivars with improved adaptation to variable rainfall environments are required to sustain productivity in the face of climate change. Physiological traits related to canopy development underpin the production of biomass and yield, as they interact with solar radiation and affect the timing of water use throughout the growing season. This study explored the temporal canopy dynamics of durum wheat using a nested-association mapping population evaluated for longitudinal normalized difference vegetation index (NDVI) measurements. Association mapping was performed to identify quantitative trait loci (QTL) for time-point NDVI and spline-smoothed NDVI trajectory traits. Yield effects associated with QTL for canopy development were investigated using data from four rainfed field trials. Four QTL associated with slower canopy closure, improved yield in specific environments, and notably, were not associated with a yield penalty in any environment. This was likely due to optimised timing of water-use and pleiotropic effects on yield component traits, including spike number and spike length. Overall, this study suggests that slower canopy closure is beneficial for durum wheat production in rainfed environments. Selection for traits or loci associated with canopy development may improve yield stability of durum wheat in water limited environments.
Decoding cellular deformation from pseudo-simultaneously observed Rho GTPase activities
Authors: Kunida Katsuyuki , Takagi Nobuhiro , Ikeda Kazushi , Nakamura Takeshi , Sakumura Yuichi
Published: August 2021

The inability to simultaneously observe all of the important Rho GTPases (Cdc42, Rac1, and RhoA) has prevented us from obtaining evidence of their coordinated regulation during cell deformation. Here, we propose Motion-Triggered Average (MTA), an algorithm that converts individually observed GTPases into pseudo-simultaneous observations. Using the time series obtained by MTA and mathematical model, we succeeded for the first time in decoding the cell edge velocity from the three GTPase activities to provide clear numerical evidence for coordinated cell edge regulation by the three GTPases. We found that the characteristics of the obtained activities were consistent with those of previous studies, and that GTPase activities and their derivatives were involved in edge regulation. Our approach provides an effective strategy for using single-molecule observations to elucidate problems hampered by the lack of simultaneous observations.
The origin of universal cell shape variability in a confluent epithelial monolayer
Authors: Sadhukhan Souvik , Nandi Saroj Kumar
Published: August 2021

Cell shape is fundamental in biology. The average cell shape can influence crucial biological functions, such as cell fate and division orientation. But cell-to-cell shape variability is often regarded as noise. In contrast, recent works reveal that shape variability in diverse epithelial monolayers follows a nearly universal distribution. However, the origin and implications of this universality are unclear. Here, assuming contractility and adhesion are crucial for cell shape, characterized via aspect ratio (AR), we develop a mean-field analytical theory for shape variability. We find that a single parameter, α, containing all the system-specific details, describes the probability distribution function (PDF) of AR; this leads to a universal relation between the standard deviation and the average of AR. The PDF for the scaled AR is not strictly but almost universal. The functional form is not related to jamming, contrary to common beliefs, but a consequence of a mathematical property. In addition, we obtain the scaled area distribution, described by the parameter µ. We show that α and µ together can distinguish the effects of changing physical conditions, such as maturation, on different system properties. The theory is verified in simulations of two distinct models of epithelial monolayers and agrees well with existing experiments. We demonstrate that in a confluent monolayer, average shape determines both the shape variability and dynamics. Our results imply the cell shape variability is inevitable, where a single parameter describes both statics and dynamics and provides a framework to analyze and compare diverse epithelial systems.
AlphaFold2 transmembrane protein structure prediction shines
Authors: Hegedűs Tamás , Geisler Markus , Lukács Gergely , Farkas Bianka
Published: August 2021

Transmembrane (TM) proteins are major drug targets, indicated by the high percentage of prescription drugs acting on them. For a rational drug design and an understanding of mutational effects on protein function, structural data at atomic resolution are required. However, hydrophobic TM proteins often resist experimental structure determination and in spite of the increasing number of cryo-EM structures, the available TM folds are still limited in the Protein Data Bank. Recently, the DeepMind’s AlphaFold2 machine learning method greatly expanded the structural coverage of sequences, with high accuracy. Since the employed algorithm did not take specific properties of TM proteins into account, the validity of the generated TM structures should be assessed. Therefore, we investigated the quality of structures at genome scales, at the level of ABC protein superfamily folds, and also in specific individual cases. We tested template-free structure prediction also with a new TM fold, dimer modeling, and stability in molecular dynamics simulations. Our results strongly suggest that AlphaFold2 performs astoundingly well in the case of TM proteins and that its neural network is not overfitted. We conclude that a careful application of its structural models will advance TM protein associated studies at an unexpected level.
A robust ex vivo system to study cellular dynamics underlying mouse peri-implantation development
Authors: Ichikawa Takafumi , Zhang Hui Ting , Panavaite Laura , Erzberger Anna , Fabrèges Dimitri , Snajder Rene , Wolny Adrian , Korotkevich Ekaterina , Tsuchida-Straeten Nobuko , Hufnagel Lars , Kreshuk Anna , Hiiragi Takashi
Published: August 2021

Upon implantation, mammalian embryos undergo major morphogenesis and key developmental processes such as body axis specification and gastrulation. However, limited accessibility obscures study of these crucial processes. Here, we develop an ex vivo Matrigel-collagen-based culture to recapitulate mouse development from E4.5 to 6.0. Our system not only recapitulates embryonic growth, axis initiation, and overall 3D architecture in 49% of cases, its compatibility with light-sheet microscopy enables study of cellular dynamics through automatic cell segmentation. We find that upon implantation, release of the increasing tension in the polar trophectoderm is necessary for its constriction and invagination. The resulting extra-embryonic ectoderm plays a key role in growth, morphogenesis and patterning of the neighboring epiblast, which subsequently gives rise to all embryonic tissues. This 3D-ex vivo system thus offers an unprecedented access to peri-implantation development for in toto monitoring, measurement and spatio-temporally controlled perturbation, revealing a mechano-chemical interplay between extra-embryonic and embryonic tissues.
Population birth outcomes in 2020 and experiences of expectant mothers during the COVID-19 pandemic: a ‘Born in Wales’ mixed methods study using routine data
Authors: Jones Hope , Seaborne Mike , Cowley Laura , Odd David , Paranjothy Shantini , Akbari Ashley , Brophy Sinead
Published: August 2021

Background

Pregnancy can be a stressful time and the COVID-19 pandemic has affected all aspects of life. This study aims to investigate the impact of the pandemic on population birth outcomes in Wales, rates of primary immunisations and examine expectant mothers’ experiences of pregnancy including self-reported levels of stress and anxiety.

Methods

Population-level birth outcomes in Wales: Stillbirths, prematurity, birth weight and Caesarean section births before (2016–2019) and during (2020) the pandemic were compared using national-level routine anonymised data held in the Secure Anonymised Information Linkage (SAIL) Databank. The first three scheduled primary immunisations were compared between 2019 and 2020. Self-reported pregnancy experience: 215 expectant mothers (aged 16+) in Wales completed an online survey about their experiences of pregnancy during the pandemic. The qualitative survey data was analysed using codebook thematic analysis.

Findings

There was no significant difference between annual outcomes including gestation and birth weight, stillbirths, and Caesarean sections for infants born in 2020 compared to 2016-2019. There was an increase in late term births (≥42 weeks gestation) during the first lockdown (OR: 1.28, p=0.019) and a decrease in moderate to late preterm births (32-36 weeks gestation) during the second lockdown (OR: 0.74, p=0.001). Fewer babies were born in 2020 (N=29,031) compared to 2016-2019 (average N=32,582). All babies received their immunisations in 2020, but there were minor delays in the timings of vaccines. Those due at 8-weeks were 8% less likely to be on time (within 28-days) and at 16-weeks, they were 19% less likely to be on time. The pandemic had a negative impact on the mental health of 71% of survey respondents, who reported anxiety, stress and loneliness; this was associated with attending scans without their partner, giving birth alone, and minimal contact with midwives.

Interpretation

The pandemic had a negative impact on mothers’ experiences of pregnancy; however, population-level data suggests that this did not translate to adverse birth outcomes for babies born during the pandemic.
Proposed independent organisational structure for memory institutions in Zimbabwe and South Africa
Authors: Bhebhe Sindiso
Published: August 2021

Purpose

The idea of convergence of cultural institutions, especially the libraries, archives and museums (LAMS) to operate as one, has a long theoretical history which unfortunately has not been translated into practice. This subject has been discussed by a number of scholars but the implementation has just remained theoretical with only a few countries practically adopting such an organisational structure. In Africa, this concept of LAMS is yet to gain traction. Therefore, the purpose of this paper is aimed at proposing such LAMS structures for African nations, especially in Zimbabwe and South Africa considering the emergence of community “archives” which have blurred further the distinction between museology, archiving and librarianship. The motivation in advocating for the adoption of LAMS is also driven by the theory behind participatory archives which thrive on the advanced use of internet including social media platforms that can make it possible to have one-stop virtual archive on the cloud that also incorporates museums and libraries.

Design/methodology/approach

This is a concept paper which reviewed the literature on national and community archives in Zimbabwe and South Africa which were purposively selected because of their long history in archiving. This was done to come up with a proposed “independent” national heritage organisational structure. “Independent” structure because this paper was based on the assumption that the independence of decision-making in national archival structures in Zimbabwe and South Africa is compromised and biased towards the ethos of political parties’ ruling governments.

Findings

Proposed integrated framework for community archives into the sustainable national archival system which also incorporates the role that can be played by universities. The framework is likely to be feasible and of benefit in the countries that are struggling to have national mainstream independent archives which are just not paying allegiance to those who are in power.

Originality/value

This study is unique in the sense that it mixes LAMS and the concept of independent archival structure in a regional comparative nature that involves Zimbabwe and South Africa.
RML based ontology development approach in internet of things for healthcare domain
Authors: Ahamed Jameel , Mir Roohie Naaz , Chishti Mohammad Ahsan
Published: August 2021

Purpose

A huge amount of diverse data is generated in the Internet of Things (IoT) because of heterogeneous devices like sensors, actuators, gateways and many more. Due to assorted nature of devices, interoperability remains a major challenge for IoT system developers. The purpose of this study is to use mapping techniques for converting relational database (RDB) to resource directory framework (RDF) for the development of ontology. Ontology helps in achieving semantic interoperability in application areas of IoT which results in shared/common understanding of the heterogeneous data generated by the diverse devices used in health-care domain.

Design/methodology/approach

To overcome the issue of semantic interoperability in healthcare domain, the authors developed an ontology for patients having cardio vascular diseases. Patients located at any place around the world can be diagnosed by Heart Experts located at another place by using this approach. This mechanism deals with the mapping of heterogeneous data into the RDF format in an integrated and interoperable manner. This approach is used to integrate the diverse data of heart patients needed for diagnosis with respect to cardio vascular diseases. This approach is also applicable in other fields where IoT is mostly used.

Findings

Experimental results showed that the RDF works better than the relational database for semantic interoperability in the IoT. This concept-based approach is better than key-based approach and reduces the computation time and storage of the data.

Originality/value

The proposed approach helps in overcoming the demerits of relational database like standardization, expressivity, provenance and supports SPARQL. Therefore, it helps to overcome the heterogeneity, thereby enabling the semantic interoperability in IoT.
A novel design layout of three disjoint paths multistage interconnection network & its reliability analysis
Authors: Sharma Vipin , Ansari Abdul Q. , Mishra Rajesh
Published: August 2021

Purpose

The purpose of this paper is to design a efficient layout of Multistage interconnection network which has cost effective solution with high reliability and fault-tolerence capability. For parallel computation, various multistage interconnection networks (MINs) have been discussed hitherto in the literature, however, these networks always required further improvement in reliability and fault-tolerance capability. The fault-tolerance capability of the network can be achieved by increasing the number of disjoint paths as a result the reliability of the interconnection networks is also improved.

Design/methodology/approach

This proposed design is a modification of gamma interconnection network (GIN) and three disjoint path gamma interconnection network (3-DGIN). It has a total seven number of paths for all tag values which is uniform out of these seven paths, three paths are disjoint paths which increase the fault tolerance capability by two faults. Due to the presence of more paths than the GIN and 3-DGIN, this proposed design is more reliable.

Findings

In this study, a new design layout of a MIN has been proposed which provides three disjoint paths and uniformity in terms of an equal number of paths for all source-destination (S-D) pairs. The new layout contains fewer nodes as compared to GIN and 3-DGIN. This design provides a symmetrical structure, low cost, better terminal reliability and provides an equal number of paths for all tag values (|S-D|) when compared with existing MINs of this class.

Originality/value

A new design layout of MINs has been purposed and its two terminal reliability is calculated with the help of the reliability block diagram technique.
A novel OTP based tripartite authentication scheme
Authors: Lone Sajaad Ahmed , Mir Ajaz Hussain
Published: August 2021

Purpose

Because of the continued use of mobile, cloud and the internet of things, the possibility of data breaches is on the increase. A secure authentication and authorization strategy is a must for many of today’s applications. Authentication schemes based on knowledge and tokens, although widely used, lead to most security breaches. While providing various advantages, biometrics are also subject to security threats. Using multiple factors together for authentication provides more certainty about a user’s identity; thus, leading to a more reliable, effective and more difficult for an adversary to intrude. This study aims to propose a novel, secure and highly stable multi-factor one-time password (OTP) authentication solution for mobile environments, which uses all three authentication factors for user authentication.

Design/methodology/approach

The proposed authentication scheme is implemented as a challenge-response authentication where three factors (username, device number and fingerprint) are used as a secret key between the client and the server. The current scheme adopts application-based authentication and guarantees data confidentiality and improved security because of the integration of biometrics with other factors and each time new challenge value by the server to client for OTP generation.

Findings

The proposed authentication scheme is implemented on real android-based mobile devices, tested on real users; experimental results show that the proposed authentication scheme attains improved performance. Furthermore, usability evaluation proves that proposed authentication is effective, efficient and convenient for users in mobile environments.

Originality/value

The proposed authentication scheme can be adapted as an effective authentication scheme to accessing critical information using android smartphones.
Personal cultural orientation and green purchase intention: a case of electric two-wheelers in India
Authors: Ray Sujit Kumar , Sahney Sangeeta
Published: August 2021

Purpose

This study aims to obtain an understanding of the impact of personal cultural orientation on potential consumers’ intention toward the purchase of high-involvement green products, specifically, electric two-wheelers in India, which is one of the largest emerging markets of the world.

Design/methodology/approach

A self-administered questionnaire comprising a total of 30 items was administered over a sample of 582 respondents. The structural equation modeling using partial least square was used to analyze the relative impact of different cultural dimensions on consumers’ green purchase intention. Geert Hofstede’s typology of culture was used to represent personal cultural orientation and four of the five dimensions, namely, collectivism, long-term orientation (LTO), masculinity and uncertainty avoidance were studied.

Findings

Findings of the study revealed that collectivism, LTO and masculinity appear to be significant cultural dimensions that influence Indian consumers’ intention to purchase electric two-wheelers. Collectivism is the most influential dimension, followed by LTO and masculinity.

Research limitations/implications

This study helps in expanding literature in the area of green purchase by providing insight on how consumers’ individual cultural orientation influences their purchase of eco-friendly products such as electric two-wheelers.

Practical implications

The findings of the study offer insights, which can be useful for marketers in developing various promotional strategies, as consumers’ cultural values have significant implications for decisions with respect to the advertisement content.

Originality/value

This study illustrates the relative impact of different dimensions of national culture (measured at consumers’ personal level) on consumers’ green purchase intention. Such a study appears to be important in extending current knowledge on green purchase behavior in one of the largest emerging markets such as India.
Classifying changes. A taxonomy of contemporary coworking spaces
Authors: Orel Marko , Bennis Will Martin
Published: August 2021

Purpose

During the past decade, the coworking concept has expanded and evolved along with the industry associated with it, so that references to coworking often refer to notions quite distinct from the original conception. The purpose of this paper is to establish a classification of contemporary coworking environments and clarify the scholarly, as well as the industry usage of a coworking model.

Design/methodology/approach

The paper reviews popular and scientific literature and the authors’ field experience in the industry to derive three defining features of coworking and distinct categories that help clarify the concept and can be used to identify and evaluate coworking spaces.

Findings

The main finding behind the following paper is the taxonomy of contemporary coworking spaces that takes into account the broad spectrum of shared workspaces that commonly receive the coworking label, specifies the features required to warrant that label and provides a framework for understanding the defining factors of a coworking model. The taxonomy showcases four unalike types of coworking spaces and the three types of non-coworking shared offices that are repeatedly and somewhat mistakenly labeled as coworking environments.

Originality/value

Understanding the core differentiation between unalike models would enable scholars to guide and structure the study to evolve in coworking research. The taxonomy can be seen as a base for further research in the field of coworking that helps ensure scholars are sufficiently specific and distinctive in the shared subject of their research, suggests a roadmap for future coworking research and provides a tool to evaluate real-world examples of work environments concerning the degree they fit the coworking concept.
Does the good lives model work? A systematic review of the recidivism evidence
Authors: Zeccola Jenna , Kelty Sally Fiona , Boer Douglas
Published: August 2021

Purpose

The purpose of this paper is to evaluate the efficacy of good lives model (GLM) interventions on the recidivism outcomes of convicted offenders.

Design/methodology/approach

The review adhered to preferred reporting items for systematic reviews and meta-analysis and Cochrane guidelines. Digital databases were searched and articles reporting outcomes of the GLM amongst convicted offenders and outcomes including recidivism data and pre-post measures of dynamic risk were included in a narrative synthesis.

Findings

Of 1,791 articles screened, only six studies met the criteria for review. Key findings were: in half the reviewed studies, GLM did not increase recidivism risk; in half the reviewed studies, only when the correct treatment dosage was applied that some evidence of risk reduction was found; there was limited support for GLM increasing or sustaining motivation for resistance from reoffending. Research for the review was limited and support for the GLM in reducing recidivism rates was not established.

Practical implications

In this 2021 review, the authors examined the efficacy of the GLM in reducing recidivism. This addresses a gap in the literature. The authors found that there is insufficient evidence to suggest that the GLM can reduce recidivism. This has implications for practitioners who wish to deliver evidence-based practices in prison/community settings. There is currently not enough peer-reviewed evidence to unequivocally confirm the efficacy of the GLM. The authors recommended additional quality programme outcome research be carried out.

Originality/value

To the best of the authors’ knowledge, this study is the first to assess quantitative and qualitative studies on the efficacy of the GLM and provides foundations for future research.
Factors influencing corporate sustainability disclosure practices: empirical evidence from Indian National Stock Exchange
Authors: Kumar Kishore , Kumari Ranjita , Poonia Archana , Kumar Rakesh
Published: August 2021

Purpose

This study aims to evaluate the nature and extent of sustainability disclosure practices of publicly listed companies in India. Further, it investigates the impact of potential determinants on the sustainability disclosure of companies.

Design/methodology/approach

The study analyzes data of 75 top listed nonbanking companies operating in India included in NIFTY100 Index for the years 2014-2015 to 2018-2019. In the present study, environment, social and governance disclosure dimensions were considered to evaluate the sustainability reporting performance of companies using content analysis. Panel data analysis was conducted to investigate the impact of various factors on the extent of sustainability information disclosure.

Findings

Results indicate that environmentally polluting industries disclose significantly higher sustainability information than non-polluting industries in India. The empirical findings suggest that determinants such as company size, age, free cash flow capacity, government ownership and global reporting initiative (GRI) usage positively related to the extent of corporate sustainability disclosure. Contrary to the expectations, financial leverage and profitability were found to be negatively related to the sustainability disclosure of companies in India.

Practical implications

This study provides empirical evidence for regulators, practitioners and corporate strategists to assess the progress in the sustainability reporting landscape in India. The finding implies that large and established companies can reduce legitimacy costs through higher sustainability information disclosure. Interestingly, this premise did not hold in the case of high leveraged and profitable companies. Overall findings can also help policymakers to incorporate necessary reforms to improve sustainability reporting in India.

Originality/value

This study is one of the first studies to investigate the nature, extent and potential determinants of corporate sustainability disclosure in India. The paper adds to the existing literature on sustainability reporting by providing empirical evidence on the relationship between sustainability reporting and potential determinants such as government ownership, size, leverage, profitability, age, free cash flow capacity, industry and GRI usage.
Placemaking and pastoral park planning in Japan: the Showa case
Authors: Davidson Ronald A.
Published: August 2021

Purpose

The purpose of this study is to critically assess how a National Government Park in Tokyo aims to commemorate the first 50 years of the Showa era (1926–1976), a time of drastic upheaval and societal change, with a naturalistic landscape.

Design/methodology/approach

The author investigated the park by conducting a literature review, making observations in the park on multiple occasions, conducting a survey of and interviews with park users and compiling photographs.

Findings

The author found that the park nostalgically highlights the early 1950s as the essence of Showa Japan. These few years represent a lull between the two Showa-era upheavals of war and rapid development and urbanization, and symbolize a last flowering of Japan’s 2,000-year-old agrarian way of life. The nostalgic presentation of Japan’s rural essence presents, the author argues, a different nationalist narrative than the military-glorifying variant that has gained traction since the end of the Cold War.

Social implications

According to critical theorists, society and space are dialectically related and mutually constitutive. The nationalist vision of a landscape, then – including the park’s landscape – has potential to inform and help shape social beliefs and values.

Originality/value

While Japanese nationalism is a major topic among Western academics, the literature on nationalist landscapes in Japan – with the exception of “obviously” symbolic sites, such as Yasukuni Shrine – is extremely limited. This paper helps fill the gap.
The role of market orientation and innovation capability in export performance of small- and medium-sized enterprises: a Latin American perspective
Authors: Kolbe Diana , Frasquet Marta , Calderon Haydee
Published: August 2021

Purpose

This study aims to extend the existing base of knowledge of proactive and reactive market orientation and innovation capability by testing their impact on the export performance of emerging-market small- and medium-sized enterprises (SMEs) in a Latin American context.

Design/methodology/approach

This paper is a replication study, and its data were collected through a survey answered by general, marketing, sales or export managers at 155 Mexican SMEs. The research model was tested using partial least squares.

Findings

The study results indicate that innovation capability and reactive market orientation are drivers of export performance in Latin American SMEs. Moreover, proactive market orientation has been found to have an indirect effect on export results.

Practical implications

This study highlights to managers of Latin American SMEs the importance of capability development and deployment to improve export performance.

Social implications

SMEs enabled by strategic and technological innovation based on current and latent customer needs can advantageously perform in foreign markets and can drive economic growth and social and human development in Latin America.

Originality/value

Recent studies have focused on emerging-market enterprises and the necessity of developing dynamic capabilities to achieve internationalisation. This study extends previous research by assessing the robustness and generalizability of drivers in export performance for manufacturing SMEs in Latin America. In particular, it provides empirical insights on the capabilities to develop by Latin American SMEs to achieve better export performance.
The value of system dynamics' diagrams for business model innovation
Authors: Ammirato Salvatore , Linzalone Roberto , Felicetti Alberto Michele
Published: August 2021

Purpose

System dynamics (SD) is emerging as a powerful approach to understand, analyse, simulate and predict complex and dynamic business processes. In particular, it is true in the process of business model innovation (BMI) and not only as a computational approach. Due to the visual and diagrammatic tools employed by SD, innovation managers overcome humans' mental limitations and improve knowledge management in the BMI. This paper discloses the value of SD's visual tools, i.e. causal loop diagrams and stock and flow diagrams, to contribute to the “Knowldege Visualization” research line, and promote the application of SD as a powerful approach to support decisions in BMI.

Design/methodology/approach

Given the explorative nature and the “how” question driving the research, the methodology involved is a single, holistic case study. In particular, the case is about a business model (BM) diversification, in which an information and communication technology service provider has added to its existing business model a new BM based on a digital multi-sided platform, for passengers transportation.

Findings

The diagrammatic tools of SD, that is causal loop diagrams and stock and flow diagrams, allowed entrepreneurs to overcome the complexity of the business parameters concurring in the design of the BM.

Originality/value

The value of this research is in the exploratory approach and in the originality of the perspective by which SD is analysed: the visual knowledge perspective.
A review of previous studies on dam leakage based on distributed optical fiber thermal monitoring technology
Authors: Fang Xiao , Zeng Yajie , Xiong Feng , Chen Jiang , Cheng Fei
Published: August 2021

Purpose

Seepage of the dam is an important safety problem, which may cause internal erosion of the structure. In the field of seepage monitoring in civil engineering, the distributed optical fiber sensing technology based on the temperature tracing method has been paid more attention due to its unique advantages of high sensitivity, good stability and high resolution. The purpose of this paper is to make a review of the existing related research, so as to facilitate the later scholars to understand and further study more systematically.

Design/methodology/approach

In this paper, three kinds of commonly used distributed fiber temperature measurement technologies are introduced. Based on the working principle, monitoring system, theoretical analysis, experimental research and engineering application of the fiber seepage monitoring technology, the present situation of dam seepage monitoring based on distributed fiber is reviewed in detail and their advantages and disadvantages are compared.

Findings

The thermal monitoring technology of seepage measurement depends on the accuracy of optical fiber temperature measurement (including the accuracy of the system and the rationality of the discrimination method), the correct installation of optical fiber and the quantitative analysis of temperature data. The accuracy of the current monitoring system can basically meet the existing measurement requirements, but the correct installation of optical fiber and the calibration of temperature data need to be further studied for different discrimination methods, and this field has great research value.

Originality/value

At present, there are many applications and research studies of optical fiber sensing in the field of structural health monitoring, and there are also reviews of related aspects. However, there is little or no review only in the field of seepage monitoring. This paper summarizes the research and application of optical fiber sensing in the field of seepage monitoring. The possibility of the gradient method to find its new prospect with the development of monitoring systems and the improvement of temperature resolution is discussed. The idea of extending the seepage monitoring method based on distributed optical fiber thermal monitoring technology to other monitoring fields is also given in the paper.
Wetting characteristics of Sn-5Sb-CuNiAg lead-free solders on the copper substrate
Authors: Wang Xiuqi , Sun Fenglian , Han Bangyao , Cao Yilun , Du Jinyang , Shao Long , Liu Guohuai
Published: August 2021

Purpose

The purpose of this paper is to investigate the wetting behaviors of Sn-5Sb-CuNiAg solders on copper substrates in different soldering processes and the effects of alloying elements on the wettability.

Design/methodology/approach

Sn-5Sb-CuNiAg solder balls (750 µm in diameter) were spread and wetted on 40 × 40 × 1 mm copper plates, in different fluxes, soldering temperatures and time. The contact angles were obtained by a home-made measuring instrument. The samples were polished and deep etched before analyzed by scanning electron microscopy. Energy dispersive X-ray spectroscopy was used to identify the composition of the joints.

Findings

The effects of different soldering processes and alloying elements on the wetting behaviors of Sn-5Sb-CuNiAg solders on copper substrates were calculated and expounded. The rosin-based flux could effectively remove oxidation layers and improve the wettability of Sn-5Sb-CuNiAg solders. Then with the increase of soldering temperature and time, the contact angles decreased gradually. The soldering processes suited for Sn-5Sb-CuNiAg solders were RMA218, 280°C and 30 s. Considered the effects of alloying elements, the wettability of Sn-5Sb-0.5Cu-0.1Ni-0.5Ag was relatively favorable on copper substrates. Besides, Ni could accumulate at the solder/Cu interface and form a jagged (Cu,Ni)6Sn5 IMC.

Originality/value

This work was carried out with our handmade experiment equipment and the production of the quinary lead-free solder alloy used in wetting tests belongs to us. The investigated Sn-5Sb-CuNiAg alloys exhibited higher melting point and preferable wettability, that was one of the candidates for high-temperature lead-free solders to replace high-Pb solders, and applied extremely to high temperature and frequency working environments of the third-generation semiconductors components, with a greater potential research and development value.
Mechanical and tribological studies of sintered nickel-based ternary alloys
Authors: Babalola Bukola Joseph , Akinribide Ojo Jeremiah , Akinwamide Olukayode Samuel , Olubambi Peter Apata
Published: August 2021

Purpose

During the operation of nickel-based alloys as blades and discs in turbines, the sliding activity between metallic surfaces is subjected to structural and compositional changes. In as much as friction and wear are influenced by interacting surfaces, it is necessary to investigate these effects. This study aims to understand better the mechanical and tribological characteristics of Ni-17Cr-10X (X = Mo, W, Ta) ternary alloy systems developed via spark plasma sintering (SPS) technique.

Design/methodology/approach

Nickel-based ternary alloys were fabricated via SPS technique at 50 MPa, 1100 °C, 100 °C/min and a dwell time of 10 mins. Scanning electron microscopy, X-Ray diffraction, energy dispersive X-ray spectroscopy, nanoindentation techniques and tribometer were used to assess the microstructure, phase composition, elemental dispersion, mechanical and tribological characteristics of the sintered nickel-based alloys.

Findings

The outcome of the investigation showed that the Ni-17Cr10Mo alloy exhibited the highest indentation hardness value of 8045 MPa, elastic modulus value of 386 GPa and wear resistance. At the same time, Ni-17Cr10W possessed the least mechanical and wear properties.

Originality/value

It can be shown that the SPS technique is efficient in the development of nickel-based alloys with good elemental distribution and without defects such as segregation of alloying elements, non-metallic inclusions. This is evident from the scanning electron microscopy micrographs.
NSGA-II algorithm for hub location-allocation problem considering hub disruption and backup hub allocation
Authors: Soleimani Mehnoosh , Khalilzadeh Mohammad , Bahari Arman , Heidary Ali
Published: August 2021

Purpose

One of the practical issues in the area of location and allocation is the location of the hub. In recent years, exchange rates have fluctuated sharply for a number of reasons such as sanctions against the country. Natural disasters that have occurred in recent years caused delays in hub servicing. The purpose of this study is to develop a mathematical programming model to minimize costs, maximize social responsibility and minimize fuel consumption so that in the event of a disruption in the main hub, the flow of materials can be directed to its backup hub to prevent delays in flow between nodes and disruptions in hubs.

Design/methodology/approach

A multi-objective mathematical programming model is developed considering uncertainty in some parameters, especially cost as fuzzy numbers. In addition, backup hubs are selected for each primary hub to deal with disruption and natural disasters and prevent delays. Then, a robust possibilistic method is proposed to deal with uncertainty. As the hub location-allocation problem is considered as NP-Hard problems so that exact methods cannot solve them in large sizes, two metaheuristic algorithms including a non-dominated sorting genetic algorithm non-dominated sorting genetic algorithm (NSGA-II) and multi-objective particle swarm optimization (MOPSO) are applied to tackle the problem.

Findings

Numerical results show the proposed model is valid. Also, they demonstrate that the NSGA-II algorithm outperforms the MOPSO algorithm.

Practical implications

The proposed model was implemented in one of the largest food companies in Iran, which has numerous products manufactured in different cities, to seek the hub locations. Also, due to several reasons such as road traffic and route type the difference in the rate of fuel consumption between nodes, this model helps managers and decision-makers to choose the best locations to have the least fuel consumption. Moreover, as the hub set up increases the employment rate in that city and has social benefits as it requires hiring some staff.

Originality/value

This paper investigates the hub location problem considering backup hubs with multiple objective functions to deal with disruption and uncertainty. Also, this study examines how non-hub nodes are assigned to hub nodes.
Pollination services in a macadamia cultivar depend on across‐orchard transport of cross pollen
Authors: Kämper Wiebke , Trueman Stephen J. , Ogbourne Steven M. , Wallace Helen M.
Published: August 2021

Pollination services are critical in entomophilous crops. Relationships between pollinator visits and fruit set and mass are complex and optimal strategies to improve pollination are poorly defined. We often do not understand what proportions of the crop result from self‐ or cross‐pollination, how cross‐pollination affects crop quality and how far cross‐pollen is transported.

We quantified proportions of self‐ and cross‐paternity in nuts of the partially self‐incompatible macadamia cultivar 816 at increasing distances from cross‐pollen sources. We estimated the distance of effective pollen movement, evaluated how pollination by different parents affected nut size and nutritional quality, and assessed whether distance from a cross‐pollen source determined proportions of cross‐pollinated nuts, nut size and number of nuts harvested.

Almost all nuts resulted from cross‐pollination, even at 184 m (23 rows) from a cross‐pollen source. The cross‐pollen cultivars in closest proximity were usually the pollen parents. Cross‐pollination increased nut size and altered kernel nutritional quality. The number of harvested nuts decreased with increasing distance from a cross‐pollen source in one orchard. Nut size was generally not affected by distance from a cross‐pollen source.

Synthesis and applications. Macadamia nut production resulted almost entirely from cross‐pollination. Crop production was dependent on across‐orchard transport of cross pollen, sometimes over at least 184 m. This shows the importance of pollen genotype, not just pollen quantity, in ensuring an effective pollination service. The number of harvested nuts decreased at 24 m from a cross‐pollen source, suggesting that different cultivars should be inter‐planted more closely in macadamia orchards. We need to better understand pollinator behaviour, including what genotype of pollen the different flower visitors carry, and how far and in what direction they transport pollen across orchards, to optimise crop yield and quality.
Experience Teaches Slowly: Non‐linear Effects of Top Management Teams’ International Experience on Post‐acquisition Performance
Authors: Piaskowska Dorota , Trojanowski Grzegorz , Tharyan Rajesh , Ray Suparna
Published: August 2021

Executives’ international experience is commonly considered a critical asset for multinational companies. The underlying presumption is that individuals learn from international experience. We revisit this presumption and propose a conceptualization of learning from international experience that accounts for the process and challenges of such learning. We use this conceptualization to examine how the international experience of top management team (TMT) members affects firm performance following cross‐border acquisition decisions of these TMTs. Empirical analyses addressing potential endogeneity concerns show that high, but not low, levels of TMT international experience have a positive impact, and that these effects are moderated by TMT nationality diversity.
More than Cleaning and Caring: The Profession of Dental Hygiene in Canada, 1951–2010
Authors: Carstairs Catherine
Published: August 2021

Dental hygiene has been a female‐dominated profession that worked primarily for dentists who, until very recently, were usually male. This article explores the early history of dental hygiene in Canada during the 1950s and 1960s; its explosive growth in the 1970s; the influence of feminism on the profession; and the battles dental hygienists fought to improve the status of their profession including better educational opportunities; professional self‐regulation and the right to practice independently of dentists. It argues that dental hygienists have made important gains, and yet the culture of ‘caring’ continues to complicate their professional status.
A prospective, multicenter evaluation of point‐of‐care ultrasound for appendicitis in the emergency department
Authors: Becker Brent A. , Kaminstein Daniel , Secko Michael , Collin Mark , Kehrl Thompson , Reardon Lindsay , Stahlman Barbara A.
Published: August 2021

Objective

The main objective of this study was to evaluate the accuracy of point‐of‐care ultrasound (POCUS) for the diagnosis of appendicitis in a general emergency department (ED) population as performed by emergency physicians with variable ultrasound experience.

Methods

We performed a prospective, multicenter, observational study examining a convenience sample of adult patients with potential appendicitis presenting to the ED between July 2014 and February 2020. Each emergency physician–performed POCUS was interpreted at the bedside and retrospectively by an expert reviewer. Test characteristics were calculated for POCUS and blinded expert interpretation compared to surgical pathology in patients undergoing appendectomy and advanced imaging in patients managed nonoperatively.

Results

A total of 256 subjects were included in the primary analysis with an overall appendicitis prevalence of 28.1%. For the diagnosis of appendicitis, POCUS demonstrated an overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 0.85 (95% confidence interval [CI] = 0.74 to 0.92), 0.63 (95% CI = 0.56 to 0.70), 2.29 (95% CI = 1.85 to 2.84), and 0.24 (95% CI = 0.14 to 0.42), respectively. Expert review yielded a lower sensitivity (0.74 [95% CI = 0.62 to 0.83]) with a similar specificity (0.63 [95% CI = 0.56 to 0.70]).

Conclusion

POCUS is moderately accurate for acute appendicitis as performed by emergency physicians with a wide range of ultrasound expertise, but lacks adequate sensitivity and specificity to function as a definitive test in an undifferentiated ED population. Further study is warranted to elucidate the optimal role of integrated POCUS in the general approach to suspected appendicitis.
Cognitive functioning, financial literacy, and judgment in older age
Authors: Gerrans Paul , Asher Anthony , Earl Joanne Kaa
Published: August 2021

We investigate the relationships between financial literacy, financial judgment, and cognitive ability at older ages. We find people who actively manage their own retirement savings portfolios display greater levels of financial literacy and judgment than those who do not. We identify the different cognitive processes underlying financial judgment and decision‐making tasks versus those underlying learned concepts such as basic financial literacy. Although these decline at different rates the latter may potentially compensate for, and mask declines, in the former. We find an overall low propensity to seek financial advice which has no significant relationship with cognitive functioning. Our findings underscore the importance of monitoring cognitive ability in older ages.