bluuebunny/crossref_metadata_2025 huggingface dataset:
Profitability, risk and cash flow deficit for beginning cow–calf producers
Authors: Trejo-Pech Carlos J.O. , Bruhin Jared , Boyer Christopher N. , Smith S. Aaron
Published: March 2021

Purpose

The purpose of this study is to estimate the amount of cash flow deficit, if any, needed to maintain the operating costs and service debt of a startup cow–calf enterprise. The study compares long-term profitability and risk between starting small and building a herd to full carrying capacity or by starting at desired herd capacity.

Design/methodology/approach

A dynamic cattle growth model was developed to capture expanding and maintaining the desired herd size. Discounted cash flow (DCF) models over a 15-year period were calculated to estimate net present value (NPV), modified internal rate of return (MIRR) and cash flow deficit to keep the business operating and service debt. Simulation analyses were conducted considering price and production risk.

Findings

Starting at the desired herd size was preferred, according to NPV/MIRR and cash flow deficit, but the differences were not substantial. Assuming the operation is liquidated at book values, there was a 36.3% probability of this enterprise having a zero or positive NPV. If the conservative terminal value assumption is relaxed up to feasible market values, the cow–calf enterprise is economically attractive at an estimated 2.4% opportunity cost of capital. However, the producer would experience a cash flow deficit during the first seven years, which was simulated to be $14,892 and $15,985 annual for both strategies.

Originality/value

Innovative methods used in this study include varying the annual opportunity cost of capital as a function of financing decisions, stochastic prices by cattle type and stochastic weaning weights that are a function of a dynamic cattle model.
The assessment of the attitude of Sicilian consumers towards wild and farmed seafood products – a sample survey
Authors: Allegro Rosalinda , Calagna Antonino , Lo Monaco Daniela , Ciprì Valentina , Bongiorno Carmelo , Cammilleri Gaetano , Battaglia Luisa , Sadok Saloua , Benfante Viviana , Tliba Ines , Di Bella Calogero
Published: March 2021

Purpose

The purpose of the paper was to know and evaluate consumption, preferences and the knowledge of labelling legislation about wild and farmed seafood products.

Design/methodology/approach

A sample survey on Sicilian families was conducted through a direct interviews between October 2015 and October 2016 to study the attitudes of Sicilian consumers towards wild and farmed fish and seafood products. A stratified two-stage sampling design was chosen with variable probability of inclusion of the units of first stage and 1,700 subjects were interviewed.

Findings

The results obtained showed that the 69.4% of respondent ate fresh fish at least once a week and the 86% of respondents consumed aquaculture products at least once a month. Also, the 77.3% of respondents did not know the current legislation on the labelling. Multiple correspondence analysis allowed to identified three profiles of Sicilian families and binary logit model was used to examine the factors that influenced different frequency of fresh fish consumption in general and farmed seafood products in particular.

Research limitations/implications

Extending the research throughout the Italian territory would have allowed further comparisons at the national level.

Practical implications

The research provides useful information on Sicilian consumers that could be used by policymakers and by marketing communications company.

Social implications

This research, on a restricted group of European consumers (Sicilian), characterised by living in an island, reinforce the knowledge regarding seafood consumers.

Originality/value

This study used a probabilistic sampling design and a face-to-face questionnaire which produce results more robust in compare to surveys used more frequently such as non-probabilistic sampling design.
Lean startup for opportunity exploitation: adoption constraints and strategies in technology new ventures
Authors: Silva Diego Souza , Ghezzi Antonio , Aguiar Rafael Barbosa de , Cortimiglia Marcelo Nogueira , ten Caten Carla Schwengber
Published: March 2021

Purpose

Most studies investigating the adoption of lean startup (LS) practices by technology new ventures focus on software startups in mature entrepreneurial ecosystems and disregard their applicability for opportunity exploitation in other technological backgrounds. This study contributes to this research stream by exploring how Brazilian technology new ventures (in different technological fields) tentatively adopt LS to exploit opportunities and whether LS is suitable to their emerging economy context.

Design/methodology/approach

The authors adopt an exploratory multiple-case study based on qualitative data collection and analysis of nine Brazilian biotechnology, engineering and software startups.

Findings

The study shows how technology new ventures tackle the activities of opportunity exploitation – namely, developing a product or service, acquiring human resources, gathering financial resources and setting up the organization – by leveraging LS tools and practices for business model validation; also, it identifies six contextual constraints hindering the systematic adoption of LS and reveals how technology new ventures cope with such constraints in their early stages by integrating LS with complementary strategies and practices. Furthermore, the study reveals that the systematic and comprehensive adoption of LS nurtures the development of an entrepreneurial experimental capability to explore opportunities in a quasi-scientific and hypothesis-driven fashion.

Originality/value

The study investigates how Brazilian engineering, biotechnology and software startups exploit opportunities and overcome constraints to business model validation through the combined adoption of LS and complementary strategies and practices and provides a set of propositions to guide future research.
Characterizing third-party logistics setups in the context of construction
Authors: Fredriksson Anna , Janné Mats , Rudberg Martin
Published: March 2021

Purpose

The use of third-party logistics (TPL) setups in construction has increased but is still a new phenomenon. The purpose was to increase understanding of how structural and management dimensions are related in CLSs by describing how CTPL setups are used.

Design/methodology/approach

Ten dimensions to describe and structure CLSs were identified from the literature and used to structure a cross-case analysis of 13 Swedish CLSs.

Findings

The main findings are: (1) there are three typical initiators of CLSs: municipalities, developers and contractors; (2) CLSs are drivers for service differentiation and modularization among TPL providers as construction specific services are required; (3) CLSs play a new role in construction by coordinating logistics activities between the construction project and the vicinity of the site.

Research limitations/implications

The study is based on 13 cases in the Swedish construction context. Additional studies of CLSs in other countries are needed.

Practical implications

The ten dimensions can be used as a guide in designing a CLS and in determining the order of design decisions. The identification and structuring of CTPL services also exemplify the variety of service offerings.

Originality/value

This is one of the first cross-case analyses of CLSs enabling the characterization of CTPL setups. This study identifies how different services included in the setup relate to the roles of SCM and logistics in construction.
A bibliometric review of advances in building information modeling (BIM) research
Authors: Babalola Ayotunde , Musa Shamsudeen , Akinlolu Mariam Temisola , Haupt Theo C.
Published: March 2021

Purpose

This paper aims to provide a bibliometric analysis of advances in building information modeling (BIM) research globally. It provides a recent state-of-the-art assessment on trends as it relates to the architecture, engineering and construction (AEC) industry. Being a vastly emerging research area, there is a need for the appraisal of research trends.

Design/methodology/approach

A comprehensive bibliometric analysis was conducted using a dual step filtering system on an initial volume of 2347 documents in the first stage between 2010 and 2020, and of 311 publications in the final stage of the analyses which emphasized more on 2015–2020 from the WoS database. Frequency analyses on the sources, affiliations, authors and country/ region of publication were assessed in the first stage of the analyses. Co-authorship and evidence of author collaboration were also examined. The second stage included a co-occurrence keyword network analysis. Further, text mining/mapping of the abstract of the documents was performed.

Findings

Emerging trends in the field of BIM research include but are not limited to historical building information modeling (h-BIM) applications, the use of blockchain technology, digital twin, Construction Operations Building information exchange (COBiE), Industry Foundation Classes (IFC), dynamo-bim, energy plus software and BIM laser scanning innovations. The possibility of these innovations solving some current BIM challenges were also discussed.

Originality/value

The study provides an insight into the BIM research trends globally while identifying existing challenges. The study uses text mining of unstructured abstracts, which has not been reported in BIM research.
Critical success factors for implementing design-build: analysing Malaysian public projects
Authors: Lee Zheng Ping , Rahman Rahimi A. , Doh Shu Ing
Published: March 2021

Purpose

The success rate of design-build (D-B) implementation in Malaysia’s private construction projects is low compared to the nation’s public projects. Thus, the purpose of this paper is to investigate the critical success factors (CSFs) for D-B implementation in Malaysian public construction projects.

Design/methodology/approach

To achieve the research objectives, 111 questionnaire survey responses from construction-related professionals were collected and analysed using multivariate analysis, including t-test, analysis of variance (ANOVA) and factor analysis.

Findings

The results indicate that while the client’s briefing effectiveness remained the top CSF among many nations, the other top CSFs in Malaysia D-B construction projects vastly differed compared to those countries. Moreover, the underlying components for successful D-B projects in Malaysia include the project management team, leader competency and “stakeholder” management.

Originality/value

This is one of the first studies that identify the CSFs for D-B implementation in the Malaysian construction industry. The outcomes provide a valuable reference and resource for academic scholars and construction practitioners to increase D-B implementation in the Malaysian private sector.
Teachers’ perceptions of their schools changing toward professional learning communities
Authors: de Jong Loes , Wilderjans Tom , Meirink Jacobiene , Schenke Wouter , Sligte Henk , Admiraal Wilfried
Published: March 2021

Purpose

In professional learning communities (PLCs), teachers collaborate and learn with the aim of improving students' learning. The aim of this study is to gain insight into teachers' perceptions of their schools' changing toward PLCs and conditions which support or hamper this change.

Design/methodology/approach

Questionnaires were completed by a total of 2.111 teachers from 15 Dutch secondary schools for three years. With the use of multilevel regression analyses, the research questions were answered.

Findings

Although the development of a school toward a PLC seems to be a slow process, the findings demonstrate the influence of school conditions on this development. Human resource management (HRM) stands out, as this school condition has a direct and longitudinal effect on the change.

Practical implications

The main recommendation is to embed PLC elements in HRM policies such as facilitating teachers to collaboratively work and learn and aligning teachers' professional development with schools' vision and ambitions.

Originality/value

PLCs have been studied occasionally in longitudinal in-depth case studies or in large-scale, cross-sectional research. This large-scale longitudinal study provides insights into the sustainability of schools as PLCs and the school conditions that are associated with sustainability.
Digitalizing procurement: the impact of data analytics on supply chain performance
Authors: Hallikas Jukka , Immonen Mika , Brax Saara
Published: March 2021

Purpose

This study aims to investigate digitalization as a performance driver in supply chains, especially the role of data analytics in the digitalization of procurement. The study investigates how digital procurement capabilities are linked to data analytics capabilities and supply chain operational performance and how this links to business success.

Design/methodology/approach

Using operational and dynamic capabilities as foundations for data analytics capabilities, this paper studied the digital procurement capabilities and proposed the conceptual model and hypotheses for empirical testing. The collected industry survey data and structural equation method are then applied to test the hypotheses.

Findings

The study confirms positive and significant relationships among digital procurement capabilities, data analytics capabilities and supply chain performance. Digital procurement capabilities mediate the positive relationship between external data analytics capabilities and supply chain performance.

Research limitations/implications

This study has some limitations that should be addressed. The empirical study was based on survey data from a questionnaire that was probably challenging for some respondent companies with low levels of digital procurement and data analytics. Also, it is necessary to adopt secondary data to measure business performance in future studies which reduces the effect of subjective bias.

Practical implications

From the managerial point of view, the findings highlight the importance of gaining knowledge from gathered data and digitalized processes. Managers must focus on data utilization capabilities to improve the operational performance expected from the digitalization of supply chain activities. In addition, managers need to consider exploiting of data through new creative approaches as part of standardized operations.

Originality/value

The present study contributes to existing knowledge by investigating the mediating role of data analytics capabilities between the digitalization of procurement and supply chain performance. The findings support a positive relationship between the data analytics capabilities and supply chain performance in digital upstream supply chain procurement processes. The present study also clarifies the impact and role of data analytics capabilities in digital supply chain development and success.
Does contract farming improve rice farmers' food security? Empirical evidence from Ghana
Authors: Jagri Binpori Reuben , Awunyo-Vitor Dadson , Wongnaa Camillus Abawiera
Published: March 2021

Purpose

In order to improve access to resources for smallholder farmers, efforts are being made to promote contract farming in Ghana. This is seen as a strategy to increase agricultural productivity of farmers, give better market access and guarantee adequate supply of raw materials to agro-based industries. However, the challenge is whether contract farming leads to improvement in food security status of farmers. The study therefore seeks to explore to what extent farmers' food security status is influenced by their participation in contract farming activities.

Design/methodology/approach

Using Cragg's double-hurdle model to analyse participation in contract farming, the authors control for selection bias using propensity score matching applied to a data set of 336 observations to examine the impact of contract farming on the food security levels of rice farmers in Ghana.

Findings

The results of this study show that yield of paddy and the wealth of the farmer are the main factors that influence the quantity of paddy rice to be contracted in contract farming arrangements. This study also finds that participation in contract farming will increase food security by 109%. In conclusion, contract farming has a significant positive impact on the farmers' food security status.

Originality/value

Agricultural policies and rural development initiatives supporting the promotion and expansion of contract farming should be pursued to persuade more farmers to produce under contract farming agreements.
Investigation of the acousto‐optical properties of Ge–As–Te–(Se) chalcogenide glasses at 10.6 μm wavelength
Authors: Cao Zhenfei , Dai Shixun , Liu Zijun , Liu Chengcheng , Ding Shengjie , Lin Changgui
Published: March 2021

The acousto‐optic parameters of Ge10As90−xTex (x = 30, 40, 50, 60, 70 mol%) and Ge10As20Te70−ySey (y = 20, 30, 40, 50 mol%) glasses, were studied systematically to compare the pros and cons of Te‐based and Se‐based chalcogenide glasses in acousto‐optic performance, as well as the thermomechanical properties. In the Ge10As90−xTex system, the acousto‐optic figure of merit (M2) increased with increased Te content, and the maximum M2 of 2279 × 10−18 s3/g, which is 13 times that of commercial single‐crystal Ge, obtained in Ge10As20Te70 at 10.6 μm. However, its thermal properties and elastic modulus decreased and the acoustic attenuation (α) at different ultrasonic frequencies increased accordingly. In the Ge10As20Te70−ySey system, the thermomechanical performance of the glasses improved with the introduction of Se element, the overall α was lower than that of Te‐based chalcogenide glasses, and the minimum α was 5.29 dB/cm at 30 MHz ultrasonic frequency, although its M2 was inferior to that of Te‐based chalcogenide glasses. Additionally, the difference in the α of these glasses was smaller at low ultrasonic frequencies than at high ultrasonic frequencies. This work will promote the practical application of chalcogenide glasses as promising materials with outstanding acousto‐optic properties in low ultrasonic frequency acousto‐optic devices.
Review of oral minoxidil as treatment of hair disorders: in search of the perfect dose
Authors: Villani A. , Fabbrocini G. , Ocampo‐Candiani J. , Ruggiero A. , Ocampo‐Garza S.S.
Published: March 2021

Topical minoxidil has been used for many years as treatment for different hair disorders. Even though it is an effective therapy, many patients show poor compliance due to the cosmesis, cost and side‐effects. During the last few years, low‐dose oral minoxidil has proven to be an alternative for patients with alopecia. We performed a literature search including all the articles that used oral minoxidil as a primary treatment in various hair diseases in order to evaluate the efficacy and safety of low‐dose oral minoxidil as an alternative to topical minoxidil. Androgenetic alopecia was the most common studied condition, but others included telogen effluvium, tractional alopecia, postchemotherapy‐induced alopecia, monilethrix, loose anagen hair syndrome, alopecia areata and scarring alopecias (frontal fibrosing alopecia and lichen planopilaris). Larger randomized comparative studies including standardized objective measurements should be done in order to clarify the best treatment protocol, including dosage and treatment duration. Oral minoxidil has proven to be a successful and well‐tolerated alternative for patients with hair loss, including those with poor adherence to other therapies. Different dosing regimens have been utilized in scarring and non‐scarring alopecia, varying from 0.25 to 5 mg daily. Higher doses have not been studied in men or women. Available literature suggests women require lower doses, from 0.25 to 2.5 mg daily, while men require higher doses for maximal efficacy, from 1.25 to 5 mg a day.
Homocysteine – from disease biomarker to disease prevention
Authors: Smith A. D. , Refsum H.
Published: March 2021

We have reviewed the literature and have identified more than 100 diseases or conditions that are associated with raised concentrations of plasma total homocysteine. The commonest associations are with cardiovascular diseases and diseases of the central nervous system, but a large number of developmental and age‐related conditions are also associated. Few other disease biomarkers have so many associations. The clinical importance of these associations becomes especially relevant if lowering plasma total homocysteine by B vitamin treatment can prevent disease and so improve health. Five diseases can at least in part be prevented by lowering total homocysteine: neural tube defects, impaired childhood cognition, macular degeneration, primary stroke, and cognitive impairment in the elderly. We conclude from our review that total homocysteine values in adults of 10 μmol/L or below are probably safe, but that values of 11 μmol/L or above may justify intervention. Homocysteine is more than a disease biomarker: it is a guide for the prevention of disease.
On the comparative biology of mammalian telomeres: Telomere length co‐evolves with body mass, lifespan and cancer risk
Authors: Pepke Michael Le , Eisenberg Dan T. A.
Published: March 2021

Telomeres, the short repetitive DNA sequences that cap the ends of linear chromosomes, shorten during cell division and are implicated in senescence in most species. Telomerase can rebuild telomeres but is repressed in many mammals that exhibit replicative senescence, presumably as a tumour suppression mechanism. It is therefore important to understand the co‐evolution of telomere biology and life‐history traits that has shaped the diversity of senescence patterns across species. Gomes et al. previously produced a large data set on telomere length (TL), telomerase activity, body mass and lifespan among 57 mammal species. We re‐analysed their data using the same phylogenetic multiple regressions and with several additional analyses to test the robustness of the findings. We found substantial inconsistencies in our results compared to Gomes et al.'s. Consistent with Gomes et al. we found an inverse association between TL and lifespan. Contrary to the analyses in Gomes et al., we found a generally robust inverse association between TL and mass, and only weak nonrobust evidence for an association between telomerase activity and mass. These results suggest that shorter TL may have been selected for in larger and longer lived species, probably as a mechanism to suppress cancer. We support this hypothesis by showing that longer telomeres predict higher cancer risk across 22 species. Furthermore, we find that domesticated species have longer telomeres. Our results call into question past interpretations of the co‐evolution of telomere biology and life‐history traits and stress the need for careful attention to model construction.
Enabling sustainable agriculture through understanding and enhancement of microbiomes
Authors: Trivedi Pankaj , Mattupalli Chakradhar , Eversole Kellye , Leach Jan E.
Published: March 2021

Harnessing plant‐associated microbiomes offers an invaluable strategy to help agricultural production become more sustainable while also meeting growing demands for food, feed and fiber. A plethora of interconnected interactions among the host, environment and microbes, occurring both above and below ground, drive recognition, recruitment and colonization of plant‐associated microbes, resulting in activation of downstream host responses and functionality. Dissecting these complex interactions by integrating multiomic approaches, high‐throughput culturing, and computational and synthetic biology advances is providing deeper understanding of the structure and function of native microbial communities. Such insights are paving the way towards development of microbial products as well as microbiomes engineered with synthetic microbial communities capable of delivering agronomic solutions. While there is a growing market for microbial‐based solutions to improve crop productivity, challenges with commercialization of these products remain. The continued translation of plant‐associated microbiome knowledge into real‐world scenarios will require concerted transdisciplinary research, cross‐training of a next generation of scientists, and targeted educational efforts to prime growers and the general public for successful adoption of these innovative technologies.
Advanced domestication: harnessing the precision of gene editing in crop breeding
Authors: Lyzenga Wendy J. , Pozniak Curtis J. , Kagale Sateesh
Published: March 2021

Human population growth has increased the demand for food crops, animal feed, biofuel and biomaterials, all the while climate change is impacting environmental growth conditions. There is an urgent need to develop crop varieties which tolerate adverse growth conditions while requiring fewer inputs. Plant breeding is critical to global food security and, while it has benefited from modern technologies, it remains constrained by a lack of valuable genetic diversity, linkage drag, and an effective way to combine multiple favourable alleles for complex traits. CRISPR/Cas technology has transformed genome editing across biological systems and promises to transform agriculture with its high precision, ease of design, multiplexing ability and low cost. We discuss the integration of CRISPR/Cas‐based gene editing into crop breeding to advance domestication and refine inbred crop varieties for various applications and growth environments. We highlight the use of CRISPR/Cas‐based gene editing to fix desirable allelic variants, generate novel alleles, break deleterious genetic linkages, support pre‐breeding and for introgression of favourable loci into elite lines.
The Motivations for the Adoption of Management Innovation by Local Governments and its Performance Effects
Authors: Andrews Rhys , Bellò Benedetta , Downe James , Martin Steve , Walker Richard M.
Published: March 2021

This article analyses the economic, political, and institutional antecedents and performance effects of the adoption of shared Senior Management Teams (SMTs)—a management innovation (MI) that occurs when a team of senior managers oversees two or more public organizations. Findings from statistical analysis of 201 English local governments and interviews with organizational leaders reveal that shared SMTs are adopted to develop organizational capacity in resource‐challenged, politically risk‐averse governments, and in response to coercive and mimetic institutional pressures. Importantly, sharing SMTs may reduce rather than enhance efficiency and effectiveness due to redundancy costs and the political transaction costs associated with diverting resources away from a high‐performing partner to support their lower‐performing counterpart.
Dementia, infrastructural failure, and new relations of transnational care in Thailand
Authors: Pratt Geraldine , Johnston Caleb
Published: March 2021

We draw on our ethnography of European‐owned care facilities in Thailand, designed for persons from the global north living with dementia, to address the current crisis in dementia care in the global north. Neither cultural approaches (that celebrate a Thai propensity to care for aging people) nor economic critique (focused on the exploitative relations between global north and south) fully or accurately represent the practices of care in these facilities. We outline the skilled nature of the dementia care on offer there, as well as non‐kin‐based relations of care that develop over time, to excite our imaginations of what is possible within long‐term care institutions in the global north. Focusing on skill addresses the chronic devaluation of elder care, and a close appraisal of the personal relations that develop in Thai transnational facilities displaces the family as the most appropriate locus of care. We frame this exploration within a notion of relational comparison, with the goal of cultivating a non‐innocent politics of hope under conditions of infrastructural failure.
Quality Deviation Control for Aircraft Using Digital Twin
Authors: Cai Hongxia , Zhu Jiamin , Zhang Wei
Published: March 2021

During the manufacturing process of aircraft, quality deviation problems inevitably occur due to the high complexity of aircraft design, manufacturing errors, tooling mistakes, human factors, environmental influences, design defects, and other factors. The current quality deviation control system of civil aircraft suffers from two problems: (1) quality deviation control data are scattered in more than 100 management systems, and it is difficult to extract quality data-related information from the whole life cycle of the aircraft involving the main manufacturer and each supplier and (2) there is a lack of quality data analysis and a closed-loop information-physics fusion system for quality deviation control. Thus, it is difficult to locate the quality deviation problems and it takes a long time to deal with these problems as well. In this paper, a digital twin-based quality deviation control model is proposed. Through the digital twin modeling based on asset management shell technology, the multi-source and heterogeneous quality deviation data can be extracted and integrated. Furthermore, to deal with the second problem, a quality deviation system has been built based on digital twin. In this system, the aircraft quality deviation data can be analyzed by the FP-growth association rule algorithm and the results are provided through the system to guide the assembly site, improving the efficiency and accuracy of quality problem-solving in the physical world. In addition, a case study is stated, where the proposed approach is applied to deal with the aircraft quality deviation problems.
Physics-Based Compressive Sensing to Enable Digital Twins of Additive Manufacturing Processes
Authors: Lu Yanglong , Shevtshenko Eduard , Wang Yan
Published: March 2021

Sensors play an important role in monitoring manufacturing processes and update their digital twins. However, the data transmission bandwidth and sensor placement limitations in the physical systems may not allow us to collect the amount or the type of data that we wish. Recently, a physics-based compressive sensing (PBCS) approach was proposed to monitor manufacturing processes and obtain high-fidelity information with the reduced number of sensors by incorporating physical models of processes in compressed sensing. It can recover and reconstruct complete three-dimensional temperature distributions based on some limited measurements. In this paper, a constrained orthogonal matching pursuit algorithm is developed for PBCS, where coherence exists between the measurement matrix and the basis matrix. The efficiency of recovery is improved by introducing a boundary-domain reduction approach, which reduces the size of PBCS model matrices during the inverse operations. The improved PBCS method is demonstrated with the measurement of temperature distributions in the cooling and real-time printing processes of fused filament fabrication.
Digital Twin-Driven Controller Tuning Method for Dynamics
Authors: He Bin , Li Tengyu , Xiao Jinglong
Published: March 2021

The control performance of the control system directly affects the running performance of the product. In order to solve the problem that the dynamics characteristics of mechanical systems are affected by the performance degradation of the controller, a digital twin-driven proportion integration differentiation (PID) controller tuning method for dynamics is proposed. In this paper, first, the structure and operation mechanism of the digital twin model for PID controller tuning are described. Using the advantages of virtual real mapping and data fusion of the digital twin model, combined with the online identification of the controlled object model, the problems of real-time feedback of an actual control effect of the controller and the unreal virtual model of the control system caused by time-varying working conditions are effectively solved, and the closed-loop self-tuning of PID controller is realized. At the same time, intelligent optimization algorithm is integrated to improve the efficiency and accuracy of PID controller parameter tuning. Second, the modeling method of the digital twin model is described from three aspects of physical prototyping, twin service system, and virtual prototyping. Finally, the controller tuning for gear transmission stability is taken as an example to verify the practicability of the proposed method.
CAD-Model Based Inspection of Sculptured Surfaces
Authors: Huang X. , Gu P.
Published: March 2021

Increasing demands on high precision manufacturing of parts with complex surfaces have been observed in the last several years. Although significant progress has been made in precision machining of complex surfaces, precision inspection of such surfaces remains a difficult problem. A critical issue in surface inspection is localization of design coordinate system (DCS) on a measurement machine. As localization has to rely on manufactured surface features that contain imperfections, a matching method is essential in order to achieve an accurate location. This paper presents a CAD-model based inspection approach to precision inspection of sculptured surfaces. The link between an inspection module and a CAD system was established through neutral files in Pro/Engineer. Surfaces are represented in bicubic parametric spline models. An effective pseudoinverse algorithm was developed and implemented for localization. It consists of two iterative operations: 1), constructing a pseudo transformation matrix, and 2), point matching. Since this approach does not involve solving nonlinear equations for the parameters of positions and orientations, it is fast and robust. The algorithm was implemented and tested with several examples. It is effective and can be used in industry for sculptured surface inspection.
Locating Error Analysis for Computer-Aided Fixture Design and Verification
Authors: Rong Y. , Li W. , Bai Y.
Published: March 2021

In this paper, locating error effects are analyzed on geometric errors produced in machining processes, such as the parallelism, perpendicularity, and angularity of machining plane or hole surfaces. Inaccurate placement of locator positions in a fixture design may cause a change of workpiece position and orientation, and in turn, contribute to the geometric error of the products. This effect could be complex even if only the variation of one locator’s position is considered because relative slip motions between the workpiece and locators are usually allowed in fixture design. In this research, locating reference planes are established according to the positions of locators. When the locators’ positions change, the variation of these planes can be estimated. The coordinates of an arbitrary point on a machining surface of the workpiece can be determined relative to these reference planes. The coordinate variations of the points on the machining surface can be identified based on the change of locators’ positions, which is used for estimating the geometric errors produced in a machining process due to the inaccuracy of locators’ positions. This information is utilized in computer-aided fixture design and verification.
High Power CPU Cooling Experiment
Authors: Nadworny Elizabeth B. , Yip T. Gary , Farag Nader
Published: March 2021

This experimental study focuses on the enhancement of the heat removal process by modifying the geometry of pin fin heat sinks, while maintaining the same effective heat transfer area. The pins are cut at an angle to reduce the blockage of air flow across the surface.

To perform this study, a small scale wind tunnel facility has been designed specifically for testing high power dissipation processors and other ULSI components. The facility is fully automated and controlled by an HP3852A Data Acquisition System interfaced with a 486 based PC computer.

The average surface temperature, Reynolds number, Nusselt number and other relevant heat transfer parameters were reduced from the data collected. Results from the study show that a heat sink with an angled trailing edge produces the greatest enhancement of heat removal. The mechanism for the improved heat transfer is the larger temperature gradient across the surface, which is obtained by lowering the minimum temperature on the surface.
A Model Driven Methodology for Business Process Engineering
Authors: Chadha Bipin
Published: March 2021

Having competitive processes has become as important (if not more) as having competitive products. Simply designing good products is not enough to gain competitive edge. Business processes have grown complex and fragmented in an ad-hoc manner. They span several departments and are very inefficient. Often the work being performed conflicts with the organizations’ goals and strategic objectives. Traditional practices and policies tend to encourage this, resulting in being part of the problem instead of being part of the solution.

This paper presents a model driven methodology for Business Process Engineering (BPE) to support an organization’s migration to effective, agile and efficient processes. The essential elements of the methodology are process modeling, process analysis, and process execution by utilizing an array of information technologies. The methodology steps depend on process models for understanding, analyzing, simulating, improving, innovating, and implementing the business processes. The methodology starts by defining the goals and objectives of the BPE project. Candidate business processes are identified. The selected strategic “As-Is” business processes are analyzed to find where problems exist. Several techniques are employed to engineer the “To-Be” process. The new process may be a radical departure from the old process. The alternatives are evaluated using cost/benefit analysis. The selected processes are then implemented using a phased approach that relies on information technology solutions alongwith the implementation of recommended organizational and cultural changes. A continuous improvement program is put into place to ensure long term success.
Test–Retest Reliability of the Total Motion Release® Scale
Authors: Miley Emilie N. , Reeves Ashley J. , Casanova Madeline P. , Martonick Nickolai J.P. , Baker Jayme , Baker Russell T.
Published: March 2021

Context: Total Motion Release® (TMR®) is a novel treatment paradigm used to restore asymmetries in the body (eg, pain, tightness, limited range of motion). Six primary movements, known as the Fab 6, are performed by the patient and scored using a 0 to 100 scale. Clinicians currently utilize the TMR® scale to modify treatment, assess patient progress, and measure treatment effectiveness; however, the reliability of the TMR® scale has not been determined. It is imperative to assess scale reliability and establish minimal detectable change (MDC) values to guide clinical practice. Objective: To assess the reliability of the TMR® scale and establish MDC values for each motion in healthy individuals in a group setting. Design: Retrospective analysis of group TMR® assessments. Setting: University classroom. Participants: A convenience sample of 61 students (23 males and 38 females; 25.48 [5.73] y), with (n = 31) and without (n = 30) previous exposure to TMR®. Intervention: The TMR® Fab 6 movements were tested at 2 time points, 2 hours apart. A clinician with previous training in TMR® led participant groups through both sessions while participants recorded individual motion scores using the 0 to 100 TMR® scale. Test–retest reliability was calculated using an intraclass correlation coefficient (2,1) for inexperienced, experienced, and combined student groups. Standard error of measurement and MDC values were also assessed for each intraclass correlation coefficient. Outcome Measure: Self-reported scores on the TMR® scale. Results: Test–retest reliability ranged from 0.57 to 0.95 across the Fab 6 movements, standard error of measurement values ranged from 4.85 to 11.77, and MDC values ranged from 13.45 to 32.62. Conclusion: The results indicate moderate to excellent reliability across the Fab 6 movements and a range of MDC values. Although this study is the first step in assessing the reliability of the TMR® scale for clinical practice, caution is warranted until further research is completed to establish reliability and MDC values of the TMR® scale in various settings to better guide patient care.
Segment-Specific Kinetics of mRNA, cRNA, and vRNA Accumulation during Influenza Virus Infection
Authors: Phan Thu , Fay Elizabeth J. , Lee Zion , Aron Stephanie , Hu Wei-Shou , Langlois Ryan A.
Published: March 2021

Influenza A virus (IAV) is a respiratory pathogen that has caused significant mortality throughout history and remains a global threat to human health. Although much is known about IAV replication, the regulation of IAV replication dynamics is not completely understood.
Calcium isotope composition ofMorozovellaover the late Paleocene–early Eocene
Authors: Kitch Gabriella D. , Jacobson Andrew D. , Harper Dustin T. , Hurtgen Matthew T. , Sageman Bradley B. , Zachos James C.
Published: March 2021

Ocean acidification (OA) during the Paleocene-Eocene thermal maximum (PETM) likely caused a biocalcification crisis. The calcium isotope composition (δ44/40Ca) of primary carbonate producers may be sensitive to OA. To test this hypothesis, we constructed the first high-resolution, high-precision planktic foraminiferal δ44/40Ca records before and across the PETM. The records employ specimens of Morozovella spp. collected from Ocean Drilling Program Sites 1209 (Shatsky Rise, Pacific Ocean) and 1263 (Walvis Ridge, Atlantic Ocean). At Site 1209, δ44/40Ca values start at −1.33‰ during the Upper Paleocene and increase to a peak of −1.15‰ immediately before the negative carbon isotope excursion (CIE) that marks the PETM onset. Values remain elevated through the PETM interval and decrease into the earliest Eocene. A shorter-term record for Site 1263 shows a similar trend, although δ44/40Ca values are on average 0.22‰ lower and decrease shortly after the CIE onset. The trends support neither diagenetic overprinting, authigenic carbonate additions, nor changes in the δ44/40Ca value of seawater. Rather, they are consistent with a kinetic isotope effect, whereby calcite δ44/40Ca values inversely correlate with precipitation rate. Geologically rapid Ca isotope shifts appear to reflect the response of Morozovella to globally forced changes in the local carbonate geochemistry of seawater. All data combined suggest that the PETM-OA event occurred near the peak of a gradual reduction in seawater carbonate ion concentrations during a time of elevated atmospheric pCO2, potentially driven by North Atlantic igneous province emplacement.
Clustering error messages produced by distributed computing infrastructure during the processing of high energy physics data
Authors: Grigorieva Maria , Grin Dmitry
Published: March 2021

Large-scale distributed computing infrastructures ensure the operation and maintenance of scientific experiments at the LHC: more than 160 computing centers all over the world execute tens of millions of computing jobs per day. ATLAS — the largest experiment at the LHC — creates an enormous flow of data which has to be recorded and analyzed by a complex heterogeneous and distributed computing environment. Statistically, about 10–12% of computing jobs end with a failure: network faults, service failures, authorization failures, and other error conditions trigger error messages which provide detailed information about the issue, which can be used for diagnosis and proactive fault handling. However, this analysis is complicated by the sheer scale of textual log data, and often exacerbated by the lack of a well-defined structure: human experts have to interpret the detected messages and create parsing rules manually, which is time-consuming and does not allow identifying previously unknown error conditions without further human intervention. This paper is dedicated to the description of a pipeline of methods for the unsupervised clustering of multi-source error messages. The pipeline is data-driven, based on machine learning algorithms, and executed fully automatically, allowing categorizing error messages according to textual patterns and meaning.
Tectonic significance of a supra-ophiolitic sedimentary cover succession, Unst, Shetland, Scottish Caledonides: insights from the U–Pb–Hf detrital zircon record
Authors: Papapavlou Konstantinos , Strachan Rob A , Storey Craig D , Bullen Dean
Published: March 2021

The tectonic significance of the Muness Phyllite, which overlies the Unst–Fetlar ophiolite in Shetland, Scottish Caledonides, is poorly understood. U–Pb analyses of detrital zircons show that it was deposited after
c
. 469 Ma. Early Paleozoic grains have

ε

Hf values of −0.3 to +12.3 and were probably derived from the extension of the Midland Valley arc. Psammite clasts and the matrix of the Muness Phyllite contain Proterozoic and Archean detrital zircons with age peaks of
c
. 1, 1.4–1.5, 1.6–1.7, 1.8–1.9 and 2.7 Ga. These are consistent with ultimate derivation from NE Laurentia sources and were probably recycled from the Neoproterozoic East Mainland Succession that underlies the Mesozoic East Shetland Basin. The Muness Phyllite is interpreted to have been deposited soon after the Grampian I orogeny in a successor basin that overstepped and received detritus from the Midland Valley arc, the East Mainland Succession and the Unst–Fetlar ophiolite. It was then deformed and metamorphosed, probably at
c.
450 Ma during the Grampian II orogenic event. The Muness Phyllite therefore provides a record of middle to late Ordovician tectonic events along the Scottish sector of the Laurentian margin following ophiolite obduction.

Supplementary material:
Analytical details and instrumentation parameters and U–Pb and Lu–Hf isotopic data are available at
https://doi.org/10.6084/m9.figshare.c.5324986
Humanized Mouse Models to Evaluate Cancer Immunotherapeutics
Authors: Guil-Luna Silvia , Sedlik Christine , Piaggio Eliane
Published: March 2021

Immunotherapy is at the forefront of cancer treatment. The advent of numerous novel approaches to cancer immunotherapy, including immune checkpoint antibodies, adoptive transfer of CAR (chimeric antigen receptor) T cells and TCR (T cell receptor) T cells, NK (natural killer) cells, T cell engagers, oncolytic viruses, and vaccines, is revolutionizing the treatment for different tumor types. Some are already in the clinic, and many others are underway. However, not all patients respond, resistance develops, and as available therapies multiply there is a need to further understand how they work, how to prioritize their clinical evaluation, and how to combine them. For this, animal models have been highly instrumental, and humanized mice models (i.e., immunodeficient mice engrafted with human immune and cancer cells) represent a step forward, although they have several limitations. Here, we review the different humanized models available today, the approaches to overcome their flaws, their use for the evaluation of cancer immunotherapies, and their anticipated evolution as tools to help personalized clinical decision-making.