How big data alters value creation: through the lens of big data competency

PurposeAs various different and even contradictory concepts are proposed to depict a firm's capabilities related to big data, and extant relevant research is fragmented and scattered in several disciplines, there is currently a lack of holistic and comprehensive understanding of how big data alters value creation by facilitating firm capabilities. To narrow this gap, this study aims to synthesize current knowledge on the firm capabilities and transformation of value creation facilitated by big data.Design/methodology/approachThe authors adopt an inductive and rigorous approach to conduct a systematic review of 185 works, following the “Grounded Theory Literature-Review Method”.FindingsThe authors introduce and develop the concept of big data competency, present an inductive framework to open the black box of big data competency following the logic of virtual value chain, provide a structure of big data competency that consists of two dimensions, namely, big data capitalization and big data exploitation, and further explain the evolution of value creation structure from value chain to value network by connecting the attributes of big data competency (i.e. connectivity and complementarity) with the transformation of value creation (i.e. optimizing and pioneering).Originality/valueThe big data competency, an inclusive concept of firm capabilities to deal with big data, is proposed. Based on this concept, the authors highlight the significant contributions that extant research has made toward our understanding of how big data alters value creation by facilitating firm capabilities. Besides, the authors provide a future research agenda that academics can rely on to study the strategic management of big data.

SensorHub: Multimodal Sensing in Real-Life Enables Home-Based Studies

Observational studies are an important tool for determining whether the findings from controlled experiments can be transferred into scenarios that are closer to subjects’ real-life circumstances. A rigorous approach to observational studies involves collecting data from different sensors to comprehensively capture the situation of the subject. However, this leads to technical difficulties especially if the sensors are from different manufacturers, as multiple data collection tools have to run simultaneously. We present SensorHub, a system that can collect data from various wearable devices from different manufacturers, such as inertial measurement units, portable electrocardiographs, portable electroencephalographs, portable photoplethysmographs, and sensors for electrodermal activity. Additionally, our tool offers the possibility to include ecological momentary assessments (EMAs) in studies. Hence, SensorHub enables multimodal sensor data collection under real-world conditions and allows direct user feedback to be collected through questionnaires, enabling studies at home. In a first study with 11 participants, we successfully used SensorHub to record multiple signals with different devices and collected additional information with the help of EMAs. In addition, we evaluated SensorHub’s technical capabilities in several trials with up to 21 participants recording simultaneously using multiple sensors with sampling frequencies as high as 1000 Hz. We could show that although there is a theoretical limitation to the transmissible data rate, in practice this limitation is not an issue and data loss is rare. We conclude that with modern communication protocols and with the increasingly powerful smartphones and wearables, a system like our SensorHub establishes an interoperability framework to adequately combine consumer-grade sensing hardware which enables observational studies in real life.

Persistence, Magnitude and Patterns of Post-acute Symptoms and Quality of Life Following Onset of SARS-CoV-2 Infection: Cohort Description and Approaches for Measurement

BACKGROUND There is mounting evidence for the presence of post-acute sequelae of SARS-CoV-2 infection (PASC), but there is limited information on the spectrum, magnitude, duration, and patterns of these sequelae as well as their influence on quality of life. METHODS We assembled a cohort of adults with documented history of SARS-CoV-2 RNA-positivity who were ≥ 2 weeks past onset of COVID-19 symptoms or, if asymptomatic, first positive test. At 4-month intervals, we queried physical and mental health symptoms and quality of life. RESULTS Of the first 179 participants enrolled, 10 were asymptomatic during the acute phase of SARS-CoV-2 infection, 125 symptomatic but not hospitalized, and 44 symptomatic and hospitalized. During the post-acute phase, fatigue, shortness of breath, concentration problems, headaches, trouble sleeping and anosmia/dysgeusia were most common through 8 months of observation. Symptoms were typically at least somewhat bothersome and sometimes exhibited a waxing-and-waning course. Some participants experienced symptoms of depression, anxiety, and post-traumatic stress, as well as difficulties with performance of usual activities. The median visual analogue scale rating of general health was lower at 4 and 8 months compared to pre-COVID-19. Two clusters of symptom domains were identified. CONCLUSION Many participants report bothersome symptoms following onset of COVID-19 with variable patterns of persistence and impact on quality of life. The substantial variability suggests the existence of multiple sub-phenotypes of PASC. A rigorous approach to the prospective measurement of symptoms and functional manifestations sets the stage for the next phase of research focusing on the pathophysiologic causes of the various sub-groups of PASC.

The Processivity of Telomerase: Insights from Kinetic Simulations and Analyses

Telomerases are moderately processive reverse transcriptases that use an integral RNA template to extend the 3′ end of linear chromosomes. Processivity values, defined as the probability of extension rather than dissociation, range from about 0.7 to 0.99 at each step. Consequently, an average of tens to hundreds of nucleotides are incorporated before the single-stranded sDNA product dissociates. The RNA template includes a six nucleotide repeat, which must be reset in the active site via a series of translocation steps. Nucleotide addition associated with a translocation event shows a lower processivity (repeat addition processivity, RAP) than that at other positions (nucleotide addition processivity, NAP), giving rise to a characteristic strong band every 6th position when the product DNA is analyzed by gel electrophoresis. Here, we simulate basic reaction mechanisms and analyze the product concentrations using several standard procedures to show how the latter can give rise to systematic errors in the processivity estimate. Complete kinetic analysis of the time course of DNA product concentrations following a chase with excess unlabeled DNA primer (i.e., a pulse-chase experiment) provides the most rigorous approach. This analysis reveals that the higher product concentrations associated with RAP arise from a stalling of nucleotide incorporation reaction during translocation rather than an increased rate constant for the dissociation of DNA from the telomerase.

Analysing Mindset Theory and Strategies Supporting the Implementation of Real PE to Develop a Growth Mindset Culture

Growth mindset continues to be a popular topic of conversation in the field of education and Physical Education (PE). However, despite the existence of various schemes for delivering curriculum PE, there are limited studies analysing how they seek to directly develop children’s mindsets. This study analyses the process taken for one of these frameworks, Real PE, to be implemented within a school to develop their growth mindset culture, drawing upon the theories of key educational thinkers. The study is based upon the authors’ experiences as PE Subject Leader and member of the school Senior Leadership Team (SLT) within a single-form entry primary school in Leicestershire, United Kingdom; testimonials from other schools who utilise Real PE and existing literature on the effectiveness of growth mindset. Implementing a growth mindset culture is not straightforward; although important, it is not solely about intelligence and praising effort, nor a battle of fixed versus growth mindsets as within PE, mixed mindsets exist, and, the fixed mindset should be legitimised. Therefore, a long-term, rigorous approach to change considering policies, individual beliefs, training needs, strategies and feedback methods needs to be developed. This study adds to the growing conversation about growth mindset and seeks to support other school settings considering embedding mindset culture within their school setting and PE provision.

Contribution to the systemic modeling of a photovoltaic devices

The modelling of systems using systemic tools has been for a few years, a subject which has attracted the attention of scientists and especially researchers to allow designers to acquire a rigorous approach to problem solving using the capabilities of already existing methods and tools. This document presents a contribution in the field of modelling, where a methodology based on two methods has been proposed. The first concerns the functional analysis to extract the use functions and the constraint parameters from the system. In this methodology, the static functional study is carried out using the SADT method. On the other hand, the dynamic behavioral analysis is carried out by the SA-RT method. Then, we used a behavioral and parametric analysis, the Bond Graph method, to observe the evolution of representative quantities of a photovoltaic system.

A refinement-based development of a distributed signalling system

The decentralised railway signalling systems have a potential to increase capacity, availability and reduce maintenance costs of railway networks. However, given the safety-critical nature of railway signalling and the complexity of novel distributed signalling solutions, their safety should be guaranteed by using thorough system validation methods. To achieve such a high-level of safety assurance of these complex signalling systems, scenario-based testing methods are far from being sufficient despite that they are still widely used in the industry. Formal verification is an alternative approach which provides a rigorous approach to verifying complex systems and has been successfully used in the railway domain. Despite the successes, little work has been done in applying formal methods for distributed railway systems. In our research we are working towards a multifaceted formal development methodology of complex railway signalling systems. The methodology is based on the Event-B modelling language which provides an expressive modelling language, a stepwise development and a proof-based model verification. In this paper, we present the application of the methodology for the development and verification of a distributed protocol for reservation of railway sections. The main challenge of this work is developing a distributed protocol which ensures safety and liveness of the distributed railway system when message delays are allowed in the model.

Wavelets Based Feature Extraction With PCA For Predicting Autism In Neonates Using Navïe Bayes Classifier

Background: Current studies show early interventions of autism increase significant long-term positive effects, symptoms and, later skills. Currently, These interventions are based on the use of an early diagnostic test. Existing methods for diagnosing Autism Spectrum Disorders (ASDs) such as cognitive tests, Intelligence Quotient, and standardized tests like the Autism Diagnostic Observation Schedule (ADOS) are functionally limited since they rely on child development for diagnoses. The standard is that a child must be at least three(3) years to undergo these tests. Accurate diagnosis is only possible after this period, and this may contribute to delayed diagnosis with an overall effect on the health system. In this era of increasing genetic data, it is possible to infer the genetic patterns of the disorder. This study introduces a novel and rigorous approach for predicting ASDs in neonates and their subsequent severity by identifying significant genes that contribute to the disorder. Methods: We used a wavelet transform and t-test to identify the significant genes that contribute to the disease. We subsequently employed the Naive Bayes classifier in the prediction of the autistic status of the neonate. Additionally, Principal Component Analysis (PCA) was employed to remove all the dependencies among the genes to enhance classification. Finally, we used the K-means clustering method to predict the severity level of the disease in the neonate. Results: Up to 200 differentially expressed genes were identified and used for predicting the ASD status of the child with a classification accuracy of 95.91%. Also, the results of the K-means demonstrated that the higher the mean of the cluster, the more severe the disease would be among that corresponding group. Optimizing and implementing these models in clinical settings may significantly reduce the health burden of ASDs.

Mechanisms in Surface Enhanced Raman Scattering

<p>This thesis focusses on a number of topics in surface enhanced Raman scattering (SERS). The aim of the undertaken research was to deepen the general understanding of the SERS effect and, thereby, to clarify some of the disputed issues, among them: What is the origin of the enhancement? What is the physical or chemical effect of 'salt activation' in SERS systems? Can we observe single-molecules using SERS? Can we determine the absorbate's orientation on the surface? In part one (chapters 1-3), as a general introduction, I start with a short overview of the Raman effect and its relation to other molecular spectroscopic effects (such as fluorescence, Rayleigh scattering, etc... ). Following these basic remarks, the surface enhancementmechanisms underlying SERS are explained (as a largely electromagnetic field enhancement) and are investigated theoretically on the canonicalmodel of a nanoscopic dimer of silver spheres. The second part (chapter 4) reports on the experimental investigation (electron microscopy, in-situ Raman measurements) of a typical real SERS system: Lee & Meisel silver colloids. An emphasis is put on the self-limiting aggregation kinetics which is observed in such systems after salt addition. This is also investigated and rationalised by means of Monte-Carlo simulations which are footed on empiric theoretical considerations for the interaction potential. Part three (chapter 5) contains a discussion of the early attempts on singlemolecule SERS and points out the shortcomings of the previously used ultra-lowconcentration approach. In response, an improved andmore rigorous approach is presented: Bi-Analyte SERS. Examplary applications of the technique are discussed. Within these experiments the capability of the technique to prove/disprove (with statistical soundness) single-molecule sensitivity in any SERS system is demonstrated, and single-molecule enhancement factors are derived. The last part (chapter 6) presents computational studies based on densityfunctional theory and its use in the context of Raman spectroscopy and SERS. Of particular interest here were the Raman tensors, their visual representation appropriate in the SERS case, their relation to the relative intensities of Raman peaks, and their modification when the photon energy approaches the electronic resonance of the molecule. Last, but not least, a conclusion chapter is presented, where I highlight what has contributed by the thesis to the general understanding of the SERS effect.</p>

Mechanisms in Surface Enhanced Raman Scattering

<p>This thesis focusses on a number of topics in surface enhanced Raman scattering (SERS). The aim of the undertaken research was to deepen the general understanding of the SERS effect and, thereby, to clarify some of the disputed issues, among them: What is the origin of the enhancement? What is the physical or chemical effect of 'salt activation' in SERS systems? Can we observe single-molecules using SERS? Can we determine the absorbate's orientation on the surface? In part one (chapters 1-3), as a general introduction, I start with a short overview of the Raman effect and its relation to other molecular spectroscopic effects (such as fluorescence, Rayleigh scattering, etc... ). Following these basic remarks, the surface enhancementmechanisms underlying SERS are explained (as a largely electromagnetic field enhancement) and are investigated theoretically on the canonicalmodel of a nanoscopic dimer of silver spheres. The second part (chapter 4) reports on the experimental investigation (electron microscopy, in-situ Raman measurements) of a typical real SERS system: Lee & Meisel silver colloids. An emphasis is put on the self-limiting aggregation kinetics which is observed in such systems after salt addition. This is also investigated and rationalised by means of Monte-Carlo simulations which are footed on empiric theoretical considerations for the interaction potential. Part three (chapter 5) contains a discussion of the early attempts on singlemolecule SERS and points out the shortcomings of the previously used ultra-lowconcentration approach. In response, an improved andmore rigorous approach is presented: Bi-Analyte SERS. Examplary applications of the technique are discussed. Within these experiments the capability of the technique to prove/disprove (with statistical soundness) single-molecule sensitivity in any SERS system is demonstrated, and single-molecule enhancement factors are derived. The last part (chapter 6) presents computational studies based on densityfunctional theory and its use in the context of Raman spectroscopy and SERS. Of particular interest here were the Raman tensors, their visual representation appropriate in the SERS case, their relation to the relative intensities of Raman peaks, and their modification when the photon energy approaches the electronic resonance of the molecule. Last, but not least, a conclusion chapter is presented, where I highlight what has contributed by the thesis to the general understanding of the SERS effect.</p>