bluuebunny/crossref_metadata_2025 huggingface dataset:
Borrelia burgdorferi 297 bmpA encode the mRNA that contains ORF for a leader peptide that regulates bmpA gene expression.
Authors: Dubytska Lidiya
Published: February 2019

The Bmp proteins are highly conserved proteins with no well established functions in B. burgdorferi sensu lato and are immunogenic. It was reported that four genes from this cluster bmpD-bmpC-bmpA-bmpB are expressed in vitro as monocistronic and polycistronic messages. Evidence is presented in this report that bmpA mRNA contains two ribosome binding sites (SD) separated by 90 bases pairs. The SD1 precedes a small 32 amino acid ORF - leader peptide (BmpAL). The SD2 is the RBS for 342 amino acids BmpA. The bmpAL and bmpA ORFs in B.burgdorferi 297 overlap by eight base pairs suggesting that two proteins can be co-regulated. First five codons in the leader peptide and -GGG- in SD2 are rarely used in Borrelia, suggesting that they can regulate BmpAL and BmpA expression. Deletion of SD1 in the leader sequence, or introducing a stop codon immediately before SD2 leads to increased BmpA::GFP expression in B.burgdorferi 297 that contains bmpA::gfp translational fusion on the plasmid. In B. garinii G25 and B. afzelii IP3 the leader sequence is in frame with bmpA, and a result, in B. afzelii IP3 BmpA are expressed as the higher molecular weight protein compared to BmpA of B. burgdorferi 297 and B. afzelii DK7.
Auxin export from proximal fruits drives arrest in competent inflorescence meristems
Authors: Ware Alexander , Walker Catriona H. , Šimura Jan , Ljung Karin , Bishopp Anthony , Wilson Zoe , Bennett Tom
Published: February 2019

A well-defined set of regulatory pathways control entry into the reproductive phase in flowering plants [1]. Conversely, little is known about the mechanisms that control the end of the reproductive phase (‘floral arrest’), despite this being a critical process for optimising fruit and seed production. Complete fruit removal or lack of fertile fruit-set in male sterile mutants, for example male sterile1 (ms1), prevents timely floral arrest in the model plant Arabidopsis [2]. These observations formed the basis for Hensel and colleagues’ model in which end-of-flowering was proposed to result from a cumulative fruit/seed-derived signal that caused simultaneous ‘global proliferative arrest’ (GPA) in all inflorescences [2]. Recent studies have suggested that end-of-flowering involves gene expression changes at the floral meristem which are at least in part controlled by the FRUITFULL-APETELA2 pathway [3,4], however there is limited understanding of how this process is controlled and the communication needed at the whole plant level. Here, we provide new information providing a framework for the fruit-to-meristem (F-M) communication implied by the GPA model [5]. We show that floral arrest in Arabidopsis is not ‘global’ and does not occur synchronously between branches, but rather that the arrest of each inflorescence is a local process, driven by auxin export from fruit proximal to the inflorescence meristem (IM). Furthermore, we show that inflorescence meristems are only competent for floral arrest once they reach a certain developmental age. Understanding the regulation of floral arrest is of major importance for the future manipulation of flowering to extend and maximise crop yields.
Developmental time course of SNAP-25 isoform regulation of hippocampal long-term synaptic plasticity and hippocampus-dependent learning
Authors: Gopaul Katisha R. , Irfan Muhammad , Miry Omid , Vose Linnea R. , Moghadam Alexander A. , Hökfelt Tomas , Bark Christina , Stanton Patric K.
Published: February 2019

SNAP-25 is essential in activity-dependent vesicle fusion and neurotransmitter release in the nervous system. During development and adulthood, SNAP-25 appears to have differential influences on long- and short-term synaptic plasticity in the hippocampus. The involvement of SNAP-25 in this process may be altered by two different splice variants expressed in adolescences versus adulthood in hippocampal neurons. This study suggests that the adolescent isoform, SNAP-25a can contribute to developmental regulation of the expression of LTD and LTP. In mice deficient in SNAP-25b, the adult isoform, Schaffer collateral-CA1 synapses showed slower release kinetics, reduced initial release probabilities, decreased LTP and enhanced LTD at 1 month. By 4 months of age, when mice have fully developed in the absence of SNAP-25b, the gene targeted mice appear to have compensated for the lack of the adult SNAP-25b isoform. Moreover, hippocampal-dependent training reversed reductions in LTP, but not LTD, seen at 1 month. In 4 month old adult mice, training prevented the compensatory reversal of LTD that had been observed prior to training. These findings support the hypothesis that immature SNAP-25a plays a strong role in the expression of plasticity at Schaffer collateral-CA1 synapses in adolescent mice, but compensatory mechanisms that reverse alterations in synaptic plasticity once mice reach adulthood.
A proposed microcosm for landscape ecology – beyond the binary to the patch-mosaic model
Authors: Wiersma Yolanda F. , Wigle Rachel D. , McMullin R. Troy
Published: February 2019

Background

Microcosms such as pitcher plants, or patches of mosses on a rock surface, have been used worldwide to allow for manipulative experiments that test hypotheses for patterns observed at larger extents, such as dispersal or community assemblage. Such microcosms can also be applied to questions in landscape ecology, but are limited by their binary (patch/non-patch structure). Here we examine a more realistic model landscape system that shares the patch-mosaic structure common to kilometres-extent landscapes. This system of lichen thalli on tree trunks has been shown to have consistent spatial patterns across replicate microcosms, but only when sampling within a limited area. To be relevant for experimentation across scales, it is necessary to determine whether previously observed patterns are consistent when sampling across a broader region and when using different tree species. Here, we test for consistent landscape patch pattern in both maco- and micro-lichens across 21 balsam fir (Abies balsamea) and yellow birch (Betula alleghaniensis) trees.

Methods

We measured spatial pattern of lichen thalli along the trunks of two species of trees, at two spatial resolutions; trees within a single stand (∼100 × 50 m) and trees dispersed across a larger region (500 km2). We used a “lichen ladder” comprised of 5 10 × 10 cm sampling blocks to quantify number of species and individuals in a 50 cm section of the tree trunk. We tested for similar patterns along the trunk and between the north and south sides at both sampling intensities using perMANOVA.

Results

We find that lichen patches on tree trunks can function as replicate microscoms for landscape ecology. Patterns of thalli along the trunks of trees and between the north and south aspects of the trunk are statistically significantly consistent, although there is variation between tree species, and groups of lichens included. Our microcosm could be used as a model system for landscape ecology research; but researchers should test for consistent patterns first.
The U125 insertion device beamline at the Metrology Light Source
Authors: Gottwald Alexander , Kaser Hendrik , Kolbe Michael
Published: February 2019

At the Metrology Light Source, an electron storage ring dedicated to metrological applications, the U125 insertion device beamline utilizes undulator radiation for various applications over a broad spectral range. Using a hybrid normal-incidence and grazing-incidence in-vacuum switchable plane-grating monochromator, a spectral region ranging from the near-infrared to soft X-ray is covered. The beamline is dedicated to surface-analytical methods, e.g. ellipsometry, photoelectron spectroscopy or photoemission tomography. The traceability of radiometric quantities, i.e. quantitative determination of the available radiant power (or photon flux), is required for some of these applications to support the metrological aspect of the measurements. In particular, attention is paid to the suppression of unwanted spectral contributions from higher diffraction orders, and to the monitoring of the radiation intensity during the measurements. With the results from the beamline commissioning, an uncertainty budget for all relevant radiometric quantities was established.
Thermoelectric transport properties in magnetically ordered crystals. Corrigendum and addenda
Authors: Grimmer Hans
Published: February 2019

A correction and additions concerning the limiting point groups are made to the article by Grimmer [Acta Cryst. (2017), A73, 333–345].
A side-by-side comparison of the solidification dynamics of quasicrystalline and approximant phases in the Al–Co–Ni system
Authors: Han Insung , Xiao Xianghui , Sun Haiping , Shahani Ashwin J.
Published: February 2019

Quasicrystals and their approximants have triggered widespread interest due to the challenge of solving their complex crystal structures as well as their possibly exceptional properties. The structural motifs of approximants are similar to those of the corresponding quasicrystals, but to what extent are their crystallization pathways the same? Unfortunately, there have been very few in situ experimental investigations to answer this question. Here, by leveraging the high penetrating power of hard X-rays, synchrotron-based X-ray tomography was conducted in order to capture the nucleation and growth of a decagonal quasicrystal and its related approximant. The combination of data-driven computational analysis with new thermodynamic databases allowed the characterization, with high precision, of the constitutional and kinetic driving forces for crystallization. The experimental results prove that the growth of both crystals from a liquid is dominated by first-order kinetics. Nevertheless, and somewhat surprisingly, significant differences were observed in their rates of nucleation and growth. The reasons for such divergent behaviours are discussed in light of contemporary theories of intermetallic crystallization.
High-speed tensor tomography: iterative reconstruction tensor tomography (IRTT) algorithm
Authors: Gao Zirui , Guizar-Sicairos Manuel , Lutz-Bueno Viviane , Schröter Aileen , Liebi Marianne , Rudin Markus , Georgiadis Marios
Published: February 2019

The recent advent of tensor tomography techniques has enabled tomographic investigations of the 3D nanostructure organization of biological and material science samples. These techniques extended the concept of conventional X-ray tomography by reconstructing not only a scalar value such as the attenuation coefficient per voxel, but also a set of parameters that capture the local anisotropy of nanostructures within every voxel of the sample. Tensor tomography data sets are intrinsically large as each pixel of a conventional X-ray projection is substituted by a scattering pattern, and projections have to be recorded at different sample angular orientations with several tilts of the rotation axis with respect to the X-ray propagation direction. Currently available reconstruction approaches for such large data sets are computationally expensive. Here, a novel, fast reconstruction algorithm, named iterative reconstruction tensor tomography (IRTT), is presented to simplify and accelerate tensor tomography reconstructions. IRTT is based on a second-rank tensor model to describe the anisotropy of the nanostructure in every voxel and on an iterative error backpropagation reconstruction algorithm to achieve high convergence speed. The feasibility and accuracy of IRTT are demonstrated by reconstructing the nanostructure anisotropy of three samples: a carbon fiber knot, a human bone trabecula specimen and a fixed mouse brain. Results and reconstruction speed were compared with those obtained by the small-angle scattering tensor tomography (SASTT) reconstruction method introduced by Liebiet al.[Nature(2015),527, 349–352]. The principal orientation of the nanostructure within each voxel revealed a high level of agreement between the two methods. Yet, for identical data sets and computer hardware used, IRTT was shown to be more than an order of magnitude faster. IRTT was found to yield robust results, it does not require prior knowledge of the sample for initializing parameters, and can be used in cases where simple anisotropy metrics are sufficient,i.e.the tensor approximation adequately captures the level of anisotropy and the dominant orientation within a voxel. In addition, by greatly accelerating the reconstruction, IRTT is particularly suitable for handling large tomographic data sets of samples with internal structure or as a real-time analysis tool during the experiment for online feedback during data acquisition. Alternatively, the IRTT results might be used as an initial guess for models capturing a higher complexity of structural anisotropy such as spherical harmonics based SASTT in Liebiet al.(2015), improving both overall convergence speed and robustness of the reconstruction.
CO2 adsorption in Y zeolite: a structural and dynamic view by a novel principal-component-analysis-assisted in situ single-crystal X-ray diffraction experiment
Authors: Conterosito Eleonora , Palin Luca , Caliandro Rocco , van Beek Wouter , Chernyshov Dmitry , Milanesio Marco
Published: February 2019

The increasing efficiency of detectors and brightness of X-rays in both laboratory and large-scale facilities allow the collection of full single-crystal X-ray data sets within minutes. The analysis of these `crystallographic big data' requires new tools and approaches. To answer these needs, the use of principal component analysis (PCA) is proposed to improve the efficiency and speed of the analysis. Potentialities and limitations of PCA were investigated using single-crystal X-ray diffraction (XRD) data collected in situ on Y zeolite, in which CO2, acting as an active species, is thermally adsorbed while cooling from 300 to 200 K. For the first time, thanks to the high sensitivity of single-crystal XRD, it was possible to determine the sites where CO2 is adsorbed, the increase in their occupancy while the temperature is decreased, and the correlated motion of active species, i.e. CO2, H2O and Na+. PCA allowed identification and elimination of problematic data sets, and better understanding of the trends of the occupancies of CO2, Na+ and water. The quality of the data allowed for the first time calculation of the enthalpy (ΔH) and entropy (ΔS) of the CO2 adsorption by applying the van 't Hoff equation to in situ single-crystal data. The calculation of thermodynamic values was carried out by both traditional and PCA-based approaches, producing comparable results. The obtained ΔH value is significant and involves systems (CO2 and Y zeolite) with no toxicity, superb stability and chemical inertness. Such features, coupled with the absence of carbonate formation and framework inertness upon adsorption, were demonstrated for the bulk crystal by the single-crystal experiment, and suggest that the phenomenon can be easily reversed for a large number of cycles, with CO2 released on demand. The main advantages of PCA-assisted analysis reside in its speed and in the possibility of it being applied directly to raw data, possibly as an `online' data-quality test during data collection, without any a priori knowledge of the crystal structure.
Challenge data set for macromolecular multi-microcrystallography
Authors: Holton James M.
Published: February 2019

A synthetic data set demonstrating a particularly challenging case of indexing ambiguity in the context of radiation damage was generated. This set shall serve as a standard benchmark and reference point for the ongoing development of new methods and new approaches to robust structure solution when single-crystal methods are insufficient. Of the 100 short wedges of data, only the first 36 are currently necessary to solve the structure by `cheating', or using the correct reference structure as a guide. The total wall-clock time and number of crystals required to solve the structure without cheating is proposed as a metric for the efficacy and efficiency of a given multi-crystal automation pipeline.
Red capital in Hong Kong
Authors: Wang-Kaeding Heidi , Kaeding Malte Philipp
Published: February 2019

Purpose

The purpose of this paper is threefold: first, to recount the scale, composition and agents of red capital in Hong Kong; second, to conceptualise the peculiarity of red capital; and third, to explore the impact of red capital on the political and economic institutional setup in Hong Kong.

Design/methodology/approach

The paper consults the comparative capitalism literature to conceptualise the phenomenon of red capital. The paper gathers data from Hong Kong Stock Exchange and indices to provide an overview of red capital. Furthermore, the case study of 2016 Legislative Election is deployed to investigate the mechanisms of red capital’s influence. The paper concludes with a summary of how red capital may challenge the validity of the “One Country, Two Systems” framework.

Findings

This paper argues that red capital replicates China’s state–capital nexus in Hong Kong and morphs the game of competition in favour of Chinese nationally controlled companies. In tandem with the emerging visibility of the party–state in Hong Kong’s economic sphere, the authors observe attempts of Chinese economic actors to compromise democratic institutions, deemed obstacles to state control.

Originality/value

This paper is the first attempt to systematically embed the discussion of red capital into comparative capitalism literature. This study provides conceptual tools to examine why red capital could pose a threat to liberal societies such as Hong Kong. Through this paper, we introduce a novel research agenda to scrutinise capital from authoritarian states and investigate how the capital is changing the political infrastructure shaped by liberal principles and values.
Volunteer educational initiative for undocumented immigrants’ children
Authors: Murthy Venkatesh
Published: February 2019

Learning outcomes

The learning outcomes are as follows: to gain insights into an immigrant community with an emphasis on positioning stakeholders using power, legitimacy and urgency constructs; to help participants dwell on a decision-making process under challenging circumstances; and to help learners understand the level of commitment and efforts needed in initiating and sustaining a volunteer initiative. At the micro level, the case helps learners understand the nature of an interaction between two distinct social groups (ragpickers and volunteers). At the macro level, the case helps the learners understand the way marginalised migratory communities think and behave in the larger scheme of politics, religion and ever-increasing migration at the global level.

Case overview/synopsis

This case is about an informal educational activity initiated by a group of volunteers who intend to eradicate illiteracy amongst ragpickers’ children in Rohtak, a small city in Haryana, India. This town has a population of <0.4 million and houses several immigrant families who come from different regions of India. Most immigrant families are into construction and rag picking. The localites mostly perceive ragpickers as undocumented immigrants from Bangladesh. Usually, most ragpickers’ children engage in garbage collection and do not attend school. In this backdrop, a group led by Mohan set up an evening class in an open ground, which in turn attracted several children from both the ragpicker and local communities alike. However, after a few days, the harsh weather made the volunteer team to shift the classes to a closed room. The shifting from the open ground to the closed room infuriated the parents and resulted in the parents not allowing their children to go to school. In this context, the volunteer team has to decide whether to continue the voluntary school or shut it down.

Complexity academic level

Executive, Under-Graduation and Post Graduation

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 7: Management Science
Impact of vertical line extensions on brand attitudes and new extensions
Authors: Palmeira Mauricio , Lei Jing , Valenzuela Ana
Published: February 2019

Purpose

Companies often extend brands to higher or lower quality tiers to access different market segments. However, the impact of such extensions on the brand and its subsequent offerings is not yet conclusive. While some studies found an “averaging” pattern (all models contribute equally to the overall perception of the brand: a symmetric effect), others found a “best-of-brand” pattern (the positive impact of an upstream extension is much greater than the negative impact of a downstream extension: an asymmetric effect). This paper aims to reconcile these seemingly conflicting findings by assessing the conditions under which each pattern is likely to emerge.

Design/methodology/approach

Three experimental studies are presented to test the conditions under which a symmetric or asymmetric pattern of brand evaluation would merge. Study 1 examined the impact of judgment focus (quality vs expertise) on the pattern of brand evaluations. Study 2 tested the impact of having a comparative set on the assessment of specific brand dimensions. Study 3 examined the impact of the informativeness of price positioning on product quality expectations.

Findings

Brand evaluations and attitudes are determined by the presence of a comparative brand and judgment focus. When brands are evaluated without a comparison, a symmetric pattern emerges, as a low-tier extension hurts a brand as much as a high-tier extension helps it. In contrast, when brands are evaluated with a comparison, focusing the assessment on quality leads to a symmetric pattern, while focusing it on expertise leads to an asymmetric one.

Research limitations/implications

The present research specifies conditions under which a low-tier model may hurt brand perceptions. We used hypothetical brands to avoid the impact of preexisting attitudes. While we expect our results to generalize to real brands, this may be considered a limitation of the present research.

Practical implications

The current research delineates the circumstances under which vertical line extensions have positive, neutral or negative impact on brand perceptions and future product expectations. We introduce the presence of a comparison set as a key variable and show how it interacts with assessment focus to affect brand evaluations. When thinking about the impact of extensions on brand perceptions, marketers need to consider which assessment focus is likely to be triggered by environmental cues and whether comparisons are salient.

Originality/value

Brand extension is an important area of investigation as evidenced by the vast literature dedicated to the subject. The present paper advances knowledge in this area by identifying key factors affecting the impact of vertical extensions on brand perceptions.
Engaging customers through online and offline referral reward programs
Authors: Wirtz Jochen , Orsingher Chiara , Cho Hichang
Published: February 2019

Purpose

This paper aims to examine the psychological consequences of a customer engagement initiative through referral reward programs (RRPs) in online versus offline environments.

Design/methodology/approach

The authors conducted a qualitative study followed by a scenario-based experimental study.

Findings

The authors show that recommenders’ concern about how they are viewed by recommendation recipients (i.e. their metaperception) mediates the effects of incentives on referral likelihood in both offline and online environments. However, metaperception has a stronger effect offline where recommenders show higher impression management concerns compared to online. Furthermore, tie-strength and communication environment moderate the effect of incentives on metaperception. When referrals are made to weak-ties, incentives decrease metaperception favorability offline more than online. For strong-ties, this effect is lower, and it is similar in offline and online environments.

Research limitations/implications

The study focused on an online versus offline dyadic communication and did not consider the differences among social media. Furthermore, the authors did not consider how other forms of positive metaperception, like being seen as helpful or knowledgeable, could be increased in an online incentivized referral context. It is possible that a recommender thinks others see him as more helpful or knowledgeable online because a lot more useful information and other resources could be offered here compared to offline communications.

Practical implications

The authors recommend managers to design both online and offline RRPs that minimize metaperception concerns; target strong ties in any communication environment as metaperception concerns are low; and target weak ties online where metaperception concerns are muted.

Originality/value

This work is the first to examine how recommenders’ psychological responses differ offline and online.
Stabilizing periodic orbits of Chua’s system using adaptive fuzzy sliding mode controller
Authors: Medhaffar Hanène , Feki Moez , Derbel Nabil
Published: February 2019

Purpose

The purpose of this paper is to investigate the stabilization of unstable periodic orbits of Chua’s system using adaptive fuzzy sliding mode controllers with moving surface.

Design/methodology/approach

For this aim, the sliding mode controller and fuzzy systems are combined to achieve the stabilization. Then, the authors propose a moving sliding surface to improve robustness against uncertainties during the reaching phase, parameter variations and extraneous disturbances.

Findings

Afterward, the authors design a sliding observer to estimate the unmeasurable states which are used in the previously designed controller.

Originality/value

Numerical results are provided to show the effectiveness and robustness of the proposed method.
The effects of supervisor support and self-efficacy on call center employees’ work engagement and quitting intentions
Authors: Hidayah Ibrahim Siti Nur , Suan Choo Ling , Karatepe Osman M.
Published: February 2019

Purpose

The purpose of this paper is to investigate work engagement as a mediator of the impacts of supervisor support and self-efficacy on quitting intentions, and examine self-efficacy as a mediator between supervisor support and work engagement.

Design/methodology/approach

Data were collected from 177 call center employees in Malaysia. The aforesaid linkages were tested through structural equation modeling.

Findings

As hypothesized, self-efficacy mediates the relationship between supervisor support and work engagement, while work engagement mediates the impacts of supervisor support and self-efficacy on quitting intentions.

Originality/value

Though work engagement is on the decline and employee turnover is on the rise, no attention has been given to investigating the impacts of supervisor support and self-efficacy simultaneously on call center employees’ work engagement and quitting intentions so far. Therefore, the study aims to fill in this void.
Behavioral study and availability optimization of a multi-state repairable system with hot redundancy
Authors: Kumar Amit , Kumar Vinod , Modgil Vikas
Published: February 2019

Purpose

The purpose of this paper is to identify the criticality of various sub-systems through the behavioral study of a multi-state repairable system with hot redundancy. The availability of the system is optimized to evaluate the optimum combinations of failure and repair rate parameters for various sub-systems.

Design/methodology/approach

The behavioral study of the system is conducted through the stochastic model under probabilistic approach, i.e., Markov process. The first-order differential equations associated with the stochastic model are derived with the use of mnemonic rule assuming that the failure and repair rate parameters of all the sub-systems are constant and exponentially distributed. These differential equations are further solved recursively using the normalizing condition to obtain the long-run availability of the system. A particle swarm optimization (PSO) algorithm for evaluating the optimum availability of the system and supporting computational results are presented.

Findings

The maintenance priorities for various sub-systems can easily be set up, as it is clearly identified in the behavioral analysis that the sub-system (A) is the most critical component which highly influences the system availability as compared to other sub-systems. The PSO technique modifies input failure and repair rate parameters for each sub-system and evaluates the optimum availability of the system.

Originality/value

A bottom case manufacturing system is under the evaluation, which is the main component of front shock absorber in two-wheelers. The input failure and repair rate parameters were parameterized from the information provided by the plant personnel. The finding of the paper provides the various availability measures and shows the grate congruence with the system behavior.
Trajectory planning method based on transitional segment optimization of spray painting robot on complex-free surface
Authors: Guan Liwen , Chen Lu
Published: February 2019

Purpose

This paper aims to present a new trajectory optimization approach targeting spray painting applications that satisfies the paint thickness requirements of complex-free surfaces.

Design/methodology/approach

In this paper, a new trajectory generation approach is developed to optimize the transitional segments at the junction of adjacent patches for straight line, convex arc and concave arc combinations based on different angles between normal vectors of patches. In addition, the paint parameters including the paint gun velocity, spray height and the distance between adjacent trajectories have been determined in the generation approach. Then a thickness distribution model is established to simulate the effectiveness of trajectory planning.

Findings

The developed approach was applied to a complex-free surface of various curvatures, and the analysis results of the trajectory optimization show that adopting different transitional segment according to the angle between normal vectors can obtain the optimal trajectory. Based on the simulation and experimental validation results, the proposed approach is effective at improving paint thickness uniformity, and the obtained results are consistent with the simulation results, meaning that the simulation model can be used to predict the actual paint performance.

Originality/value

This paper discusses a new trajectory generation approach to decrease the thickness error values to satisfy spray paint requirements. According to the successfully performed simulation and experimental results, the approach is useful and practical in overcoming the challenge of improving the paint thickness quality on complex-free surface.
Comparison of students in an undergraduate university degree offered both in presence and online
Authors: Scarabottolo Nello
Published: February 2019

Purpose

This paper aims to compare the students enrolled to a three-year undergraduate, bachelor degree on Security of Computer Systems and Networks, offered in traditional, classroom fashion as well as online at the University of Milan (Italy). Its main purposes are to estimate the main characteristics of the two different student populations addressed (i.e. online vs classroom students) to understand if an online version of an already existing traditional university degree allows to extend the enrollment of students; and to evaluate the effectiveness of the e-learning approach adopted, comparing performance of the two student populations. The study aims to supply a significant case study, based on a real experience more than 10 years long.

Design/methodology/approach

The paper is based on the statistical interpretation of a huge amount of data, collected during the overall life of Sicurezza dei Sistemi e delle Reti Informatiche (SSRI) online, regarding student age, income, grades obtained in exams and after final dissertation and graduation time.

Findings

The paper allows to conclude that the online student population has very limited overlap with the classroom one, which means that the online version of an already existing degree can definitely enlarge the student enrollment and reach older students; and a carefully designed e-learning environment allows committed online students to obtain results comparable when not better than the ones of classroom students.

Research limitations/implications

The study refers to a single, specific degree in computer science and technology; thus, it may lack generalizability. Similar experiences in other areas could be useful.

Originality/value

This paper fulfills an identified need to study how e-learning can be successfully applied to already existing traditional university degrees.
Multiple choice questions: answering correctly and knowing the answer
Authors: McKenna Peter
Published: February 2019

Purpose

This paper aims to examine whether multiple choice questions (MCQs) can be answered correctly without knowing the answer and whether constructed response questions (CRQs) offer more reliable assessment.

Design/methodology/approach

The paper presents a critical review of existing research on MCQs, then reports on an experimental study where two objective tests (using MCQs and CRQs) were set for an introductory undergraduate course. To maximise completion, tests were kept short; consequently, differences between individuals’ scores across both tests are examined rather than overall averages and pass rates.

Findings

Most students who excelled in the MCQ test did not do so in the CRQ test. Students could do well without necessarily understanding the principles being tested.

Research limitations/implications

Conclusions are limited by the small number of questions in each test and by delivery of the tests at different times. This meant that statistical average data would be too coarse to use, and that some students took one test but not the other. Conclusions concerning CRQs are limited to disciplines where numerical answers or short and constrained text answers are appropriate.

Practical implications

MCQs, while useful in formative assessment, are best avoided for summative assessments. Where appropriate, CRQs should be used instead.

Social implications

MCQs are commonplace as summative assessments in education and training. Increasing the use of CRQs in place of MCQs should increase the reliability of tests, including those administered in safety-critical areas.

Originality/value

While others have recommended that MCQs should not be used (Hinchliffe 2014, Srivastavaet al., 2004) because they are vulnerable to guessing, this paper presents an experimental study designed to demonstrate whether this hypothesis is correct.
Return and volatility spillover across equity markets between China and Southeast Asian countries
Authors: Hung Ngo Thai
Published: February 2019

Purpose

This paper aims to study the daily returns and volatility spillover effects in common stock prices between China and four countries in Southeast Asia (Vietnam, Thailand, Singapore and Malaysia).

Design/methodology/approach

The analysis uses a vector autoregression with a bivariate GARCH-BEKK model to capture return linkage and volatility transmission spanning the period including the pre- and post-2008 Global Financial Crisis.

Findings

The main empirical result is that the volatility of the Chinese market has had a significant impact on the other markets in the data sample. For the stock return, linkage between China and other markets seems to be remarkable during and after the Global Financial Crisis. Notably, the findings also indicate that the stock markets are more substantially integrated into the crisis.

Practical implications

The results have considerable implications for portfolio managers and institutional investors in the evaluation of investment and asset allocation decisions. The market participants should pay more attention to assess the worth of across linkages among the markets and their volatility transmissions. Additionally, international portfolio managers and hedgers may be better able to understand how the volatility linkage between stock markets interrelated overtime; this situation might provide them benefit in forecasting the behavior of this market by capturing the other market information.

Originality/value

This paper would complement the emerging body of existing literature by examining how China stock market impacts on their neighboring countries including Vietnam, Thailand, Singapore and Malaysia. Furthermore, this is the first investigation capturing return linkage and volatility spill over between China market and the four Southeast Asian markets by using bivariate VAR-GARCH-BEKK model. The authors believe that the results of this research’s empirical analysis would amplify the systematic understanding of spillover activities between China stock market and other stock markets.
Social climate and aggression in IDD services
Authors: Robinson Joanne Emma , Craig Leam
Published: February 2019

Purpose

The purpose of this paper is to adapt a social climate measure for use within a forensic intellectual and developmental disabilities (IDD) service and examine perceptions of social climate and the links with patient aggression across three levels of security.

Design/methodology/approach

Four staff participated in a focus group to discuss how the Essen Climate Evaluation Schema (EssenCES) could be adapted for IDD patients. Subsequently, a pilot study with three patients highlighted some difficulties in administering the adapted measure. Alterations in the administration of the measure were implemented with a further ten patients residing across three levels of security. The EssenCES was adapted to include more visual prompts to assist in the patients’ completion of the measure. The frequency of aggressive incidents in each of the three settings was also collated.

Findings

Statistical analysis revealed a non-significant trend where positive social climate ratings increased as the security level decreased. There was a significant difference in the frequency of aggressive incidents across the three levels of security; however, there were no significant relationships found between the questionnaire ratings and the frequency of incidents.

Research limitations/implications

The results lacked statistical power due to the low number of participants. Further studies with adapted social climate measures need to be conducted to assess the implications of social climate on individuals with IDD in secure forensic services.

Originality/value

The study adapted and piloted a social climate measure for individuals in a forensic IDD service.
Looking good and doing good: family to work spillover through impression management
Authors: Carlson Dawn S. , Kacmar K. Michele , Thompson Merideth J. , Andrews Martha C.
Published: February 2019

Purpose

The purpose of this paper is to examine the role of four impression management (IM) tactics as mediators to help job incumbents manage the impressions others have regarding the spillover of the incumbent’s family domain onto the work domain.

Design/methodology/approach

The authors examined the data from 296 matched job incumbents and coworkers. The authors tested a structural equation model and alternative models to find the best fit and subsequently tested both direct and indirect effects.

Findings

The authors found that family-to-work conflict related to job-focused and supervisor-focused IM behaviors, and family-to-work enrichment related to self-focused, coworker-focused and supervisor-focused IM behaviors. Supervisor-focused IM served as a mediator to the job incumbent’s attitude (job satisfaction) while job-focused, self-focused and coworker-focused IM served as mediators to the job incumbent’s behavior (job performance).

Practical implications

The research is important in that just as employees do not “leave work at the office,” they also do not “leave family at home.” Instead, experiences in the two domains affect one another in ways that are beneficial and harmful. Understanding the role that IM plays in this process adds insight into the spillover of family onto work.

Originality/value

The authors extend both the work-family and IM literatures by looking at potential family domain antecedents to engaging in IM behaviors and their impact on work life.
Dynamic prioritization of equipment and critical failure modes
Authors: Mahmoudi Mohamadreza , Amoozad Mahdiraji Hannan , Jafarnejad Ahmad , Safari Hossein
Published: February 2019

Purpose

The purpose of this paper is to identify critical equipment by dynamically ranking them in interval-valued intuitionistic fuzzy (IVIF) circumstances. Accordingly, the main drawbacks of the conventional failure mode and effects analysis (FMEA) are eliminated. To this end, the authors have presented the interval-valued intuitionistic fuzzy condition-based dynamic weighing method (IVIF-CBDW).

Design/methodology/approach

To realize the objective, the authors used the IVIF power weight Heronian aggregation operator to integrate the data extracted from the experts’ opinions. Moreover, the multi-attributive border approximation area comparison (MABAC) method is applied to rank the choices and the IVIF-CBDW method to create dynamic weights appropriate to the conditions of each equipment/failure mode. The authors proposed a robust FMEA model where the main drawbacks of the conventional risk prioritization number were eliminated.

Findings

To prove its applicability, this model was used in a case study to rank the equipment of a HL5000 crane barge. Finally, the results are compared with the traditional FMEA methods. It is indicated that the proposed model is much more flexible and provides more rational results.

Originality/value

In this paper, the authors have improved and used the IVIF power weight Heronian aggregation operator to integrate information. Furthermore, to dynamically weigh each equipment (failure mode), they presented the IVIF-CBDW method to determine the weight of each equipment (failure mode) based on its equipment conditions in the O, S and D criteria and provide the basis for the calculation. IVIF-CBDW method is presented in this study for the first time. Moreover, the MABAC method has been performed, to rank the equipment and failure mode. To analyze the information, the authors encoded the model presented in the robust MATLAB software and used it in a real sample of the HL5000 crane barge. Finally, to evaluate the reliability of the model presented in the risk ranking and its rationality, this model was compared with the conventional FMEA, fuzzy TOPSIS method, the method of Liu and the modified method of Liu.
An evaluation of primers for detecting denitrifiers via their functional genes
Authors: Ma Yanjun , Zilles Julie L. , Kent Angela D.
Published: February 2019

Microbial populations provide nitrogen cycling ecosystem services at the nexus of agriculture, environmental quality and climate change. Denitrification, in particular, impacts socio‐environmental systems in both positive and negative ways, through reduction of aquatic and atmospheric nitrogen pollution, but also reduction of soil fertility and production of greenhouse gases. However, denitrification rates are quite variable in time and space, and therefore difficult to model. Microbial ecology is working to improve the predictive ecology of denitrifiers by quantifying and describing the diversity of microbial functional groups. However, metagenomic sequencing has revealed previously undescribed diversity within these functional groups, and highlighted a need to reevaluate coverage of existing DNA primers for denitrification functional genes. We provide here a comprehensive in silico evaluation of primer sets that target diagnostic genes in the denitrification pathway. This analysis makes use of current DNA sequence data available for each functional gene. It contributes a comparative analysis of the strengths and limitations of each primer set for describing denitrifier functional groups. This analysis identifies genes for which development of new tools is needed, and aids in interpretation of existing datasets, both of which will facilitate application of molecular methods to further develop the predictive ecology of denitrifiers.
Hospitals and substance use disorder services in the time of the opioid epidemic
Authors: Cronin Cory E. , Franz Berkeley , Skinner Daniel , Haile Zelalem T.
Published: February 2019

Objective

To test whether the opioid epidemic increased hospitals’ offerings of substance use services.

Data Sources/Study Setting

This study employs data from the 2010 and 2015 American Hospital Association Annual Survey.

Study Design

A multilevel, cross‐sectional design was utilized to examine associations between county‐level overdose rates and hospital substance use services.

Data Collection/Extraction Methods

The analytic sample consisted of 3365 acute care hospitals that answered pertinent survey questions.

Principal Findings

In 2010, 334 hospitals offered inpatient opioid services and 588 hospitals offered outpatient services, compared to 327 and 577, respectively, in 2015, indicating that more hospitals dropped services than added them as overdose rates increased. Factors other than growing need weigh more heavily in hospitals’ determination to offer substance use services, including resources, mission, and the presence of psychiatric facilities within their communities. Importantly, hospitals that employ medical home models had greater odds of offering outpatient substance abuse services in 2015 OR, 95 percent CI (1.54; 1.23‐1.93; P < 0.0001).

Conclusions

Hospitals are either not willing or equipped to increase substance use services in response to growing need.
Quality Parameters of Masa and Tortillas Produced from Blue Maize (Zea mays sp. mays) Landraces
Authors: Chimimba Justin , Pratt Richard , Cuellar Maria , Delgado Efren
Published: February 2019

There is increasing interest in the production of landrace blue maize varieties for the production of traditional foods and for specialty (noncommodity) products. Most varieties have soft (floury) endosperm and their suitability for thermo‐alkaline processing is not known. We examined the physical and functional properties of eight floury varieties with those of three dent and one flint variety for masa and tortilla production. Results revealed high variability in physical properties of kernels. Significant differences (P < 0.05) were observed in kernel, flour, masa, and tortilla color. The softer kernels of blue maize varieties had lower (P < 0.05) cooking times during nixtamalization than those of denser kernels. The results showed variation among varieties (P < 0.05) in the kernel, masa, tortilla hardness, as well as in extensibility of the tortillas. Nixtamalization affected (P < 0.05) masa color, resulting in reduced yellow and reddish tones. The gelatinization temperature was the same (P > 0.05) in all studied landraces for the flour and the masa. The enthalpy was affected (P < 0.05) by the landrace analyzed for starch gelatinization (P > 0.05). The landraces studied showed similar (P > 0.05) starch gelatinization and denaturation temperatures. The storage modulus (G′), loss modulus (G′′), and the temperature (TG′) of flour and masa‐dough were different (P < 0.05) among different varieties. Southwestern floury varieties can be cooked during nixtamalization for shorter periods than flint and dent varieties to obtain comparable tortilla quality.

Practical Application

Southwestern blue floury maize varieties are suitable for nixtamalized tortilla production. Variation between varieties was observed for quality parameters. Floury varieties require shorter cooking time but it is recommended that nixtamalization parameters be optimized.