bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the Frame Effect
Authors: Cavanagh Patrick , Anstis Stuart , Lisi Matteo , Wexler Mark , Maechler Marvin , ’t Hart Marius , Shams-Ahmar Mohammad , Saleki Sharif 
Published: February 2022

AbstractProbes flashed within a moving frame are dramatically displaced (Özkan et al, 2021; Wong &Mack, 1981). The effect is much larger than that seen on static or moving probes (induced motion, Duncker, 1929; Wallach et al, 1978). These flashed probes are often perceived with the separation they have in frame coordinates — a 100% effect. Here we explore this frame effect on flashed tests with several versions of the standard stimulus. We find that the frame effect holds for smoothly or abruptly displacing frames, even when the frame changed shape or orientation between the endpoints of its travel. The path could be non-linear, even circular. The effect was driven by perceived not physical motion. When there were competing overlapping frames, the effect was determined by which frame was attended. There were a number of constraints that limited the effect. A static anchor near the flashes suppressed the effect but an extended static texture did not. If the probes were continuous rather than flashed, the effect was abolished. The observational reports of 30 online participants suggest that the frame effect is robust to many variations in its shape and path and leads to a perception of flashed tests in their locations relative to the frame as if the frame were stationary. Our results highlight the role of frame continuity and of the grouping of the flashes with the frame in generating the frame effect.
The regulatory protein ChuP connects heme and siderophore-mediated iron acquisition systems required for Chromobacterium violaceum virulence
Authors: de Lima Vinicius M. , Batista Bianca B. , Silva Neto José F. da 
Published: February 2022

ABSTRACTChromobacterium violaceum is an environmental Gram-negative beta-proteobacterium that causes systemic infections in humans. C. violaceum uses siderophore-based iron acquisition systems to overcome the host-imposed iron limitation, but its capacity to use other iron sources is unknown. In this work, we characterized ChuPRSTUV as a heme utilization system employed by C. violaceum to explore an important iron reservoir in mammalian hosts, free heme and hemoproteins. We demonstrate that the chuPRSTUV genes comprise a Fur-repressed operon that is expressed under iron limitation. The chu operon potentially encodes a small regulatory protein (ChuP), an outer membrane TonB-dependent receptor (ChuR), a heme degradation enzyme (ChuS), and an inner membrane ABC transporter (ChuTUV). Our nutrition growth experiments using C. violaceum chu deletion mutants revealed that, with the exception of chuS, all genes of the chu operon are required for heme and hemoglobin utilization in C. violaceum. The mutant strains without chuP displayed increased siderophore halos on CAS plate assays. Significantly, we demonstrate that ChuP connects heme and siderophore utilization by acting as a positive regulator of chuR and vbuA, which encode the TonB-dependent receptors for the uptake of heme (ChuR) and the siderophore viobactin (VbuA). Our data favor a model of ChuP as a heme-binding post-transcriptional regulator. Moreover, our virulence data in a mice model of acute infection demonstrate that C. violaceum uses both heme and siderophore for iron acquisition during infection, with a preference for siderophores over the Chu heme utilization system.
Sexual transmission of Anopheles gambiae densovirus (AgDNV) leads to disseminated infection in mated females
Authors: Werling Kristine L , Johnson Rebecca M. , Metz Hillery C , Rasgon Jason L 
Published: February 2022

AbstractBackgroundAnopheles gambiae densovirus (AgDNV) is an insect-specific, single-stranded DNA virus that infects An. gambiae, the major mosquito species responsible for transmitting malaria parasites throughout Sub-Saharan Africa. AgDNV is a benign virus that is very specific to its mosquito host and therefore has potential to serve as a vector control tool via paratransgenesis (genetic modification of mosquito symbionts) to limit transmission of human pathogens. Prior to being engineered into a control tool, the natural transmission dynamics of AgDNV between An. gambiae mosquitoes needs to be fully understood. Additionally, improved knowledge of AgDNV infection in male mosquitoes is needed. In this study, we examine the tissue tropism of AgDNV in the male reproductive tract and investigate both venereal and vertical transmission dynamics of the virus.MethodsAn. gambiae adult males were infected with AgDNV via micro-injection and reproductive tissues collected and assayed for AgDNV using qPCR. Next, uninfected females were introduced to AgDNV-infected or control males and, after several nights of mating, both the spermatheca and female carcass were assessed for venereally transmitted AgDNV. Finally, F1s from this cross were collected and assayed to quantify vertical transmission of the virus.ResultsAgDNV infected the reproductive tract of male mosquitoes, including the testes and male accessory glands (MAGs), without affecting mating rates. AgDNV-infected males venereally transmitted virus to females, and these venereally-infected females developed disseminated infection throughout the body. However, AgDNV was not vertically transmitted to F1s resulting from this cross.ConclusionsInfected male releases could be an effective strategy to introduce AgDNV-based paratransgenic tools into naïve populations of An. gambiae females.
Long-term antibody response to SARS-CoV-2 in children
Authors: Dunay Gabor A. , Barroso Madalena , Woidy Mathias , Danecka Marta K. , Engels Geraldine , Hermann Katharina , Neumann Friederike S. , Paul Kevin , Beime Jan , Escherich Gabriele , Fehse Kristin , Grinstein Lev , Haniel Franziska , Haupt Luka J. , Hecher Laura , Kehl Torben , Kemen Christoph , Kemper Markus J. , Kobbe Robin , Kohl Aloisa , Klokow Thomas , Nörz Dominik , Olfe Jakob , Schlenker Friderike , Schmiesing Jessica , Schrum Johanna , Sibbertsen Freya , Stock Philippe , Tiede Stephan , Vettorazzi Eik , Zazara Dimitra E. , Zapf Antonia , Lütgehetmann Marc , Oh Jun , Mir Thomas S. , Muntau Ania C. ,   the C19.CHILD Study Group, Gersting Søren W. 
Published: February 2022

AbstractAlmost two years into the pandemic and with vaccination of children significantly lagging behind adults, long-term pediatric humoral immune responses to SARS-CoV-2 are understudied. The C19.CHILD Hamburg (COVID-19 Child Health Investigation of Latent Disease) Study is a prospective cohort study designed to identify and follow up children and their household contacts infected in the early 2020 first wave of SARS-CoV-2. We screened 6113 children <18 years by nasopharyngeal swab-PCR in a low-incidence setting after general lockdown, from May 11 to June 30, 2020. 4657 participants underwent antibody testing. Positive tests were followed up by repeated PCR and serological testing of all household contacts over 6 months. In total, the study identified 67 seropositive children (1.44 %), the median time after infection at first presentation was 83 days post-symptom onset (PSO). Follow up of household contacts showed incomplete seroconversion in most families, with higher seroconversion rates in families with adult index cases compared to pediatric index cases (OR: 1.79, P=0.047). Most importantly, children showed sustained seroconversion up to nine months PSO, and serum antibody concentrations persistently surpassed adult levels (ratio serum IgG Spike children vs. adults 90 days PSO: 1.75, P<0.001, 180 days: 1.38, P=0.01, 270 days: 1.54, P=0.001).In a low-incidence setting, SARS-CoV-2 infection and humoral immune response present distinct patterns in children including higher antibody levels, and lower seroconversion rates in families with pediatric index cases. Children show long-term SARS-CoV-2 antibody responses. These findings are relevant to novel variants with increased disease burden in children, as well as for the planning of age-appropriate vaccination strategies.
Omission responses in field potentials but not spikes in rat auditory cortex
Authors: Auksztulewicz Ryszard , Rajendran Vani Gurusamy , Peng Fei , Schnupp Jan Wilbert Hendrik , Harper Nicol Spencer 
Published: February 2022

ABSTRACTNon-invasive recordings of gross neural activity in humans often show responses to omitted stimuli in steady trains of identical stimuli. This has been taken as evidence for the neural coding of prediction or prediction error. However, evidence for such omission responses from invasive recordings of cellular-scale responses in animal models is scarce. Here, we sought to characterise omission responses using extracellular recordings in the auditory cortex of anaesthetised rats. We profiled omission responses across local field potentials (LFP), analogue multiunit activity (AMUA), and single/multi-unit spiking activity, using stimuli that were fixed-rate trains of acoustic noise bursts where 5% of bursts were randomly omitted. Significant omission responses were observed in LFP and AMUA signals, but not in spiking activity. These omission responses had a lower amplitude and longer latency than burst-evoked sensory responses, and omission response amplitude increased as a function of the number of preceding bursts. Contrary to theories of neural entrainment, rhythmic stimulus presentation did not increase low-frequency phase-locking of neural activity specific to the stimulus presentation rate. Together, our findings show that omission responses are observed in LFP and AMUA signals, with laminar specificity, but are not observed in spiking activity, and do not show evidence for low-frequency phase locking. This has implications for models of cortical processing that require many neurons to encode prediction error in their spike output, and may have some consistency with representation of error in dendrites electrotonically distant from the soma.
Active vibration reductions of a lift-offset compound helicopter using individual blade pitch control with multiple harmonic inputs
Authors: Kwon Young-Min , Hong Sung-Boo , Park Jae-Sang , Lee Yu-Been 
Published: February 2022

Purpose
The purpose of this study is to use the individual blade pitch control (IBC), reduce actively both the rotor hub vibratory loads and airframe vibration responses for the lift-offset compound helicopter at a high-speed flight condition.

Design/methodology/approach
The Sikorsky X2 technology demonstrator (X2TD) is used as the lift-offset compound helicopter. The X2TD lift-offset rotor is modelled and its rotor hub vibratory loads at a flight speed of 250 knots are predicted using a rotorcraft comprehensive analysis code, CAMRAD II, and the airframe structural dynamics is represented with a finite element analysis code, MSC.NASTRAN. When the propulsive trim methodology is applied for rotor trim, the best input condition for IBC using multiple harmonic inputs is searched to reduce the rotor vibration, while the rotor aerodynamic performance (the rotor effective lift-to-drag ratio) is improved or maintained at least. Finally, the reduction in airframe vibration responses is investigated when the best input condition for IBC with multiple harmonics is applied to the lift-offset rotor.

Findings
When the IBC with the single harmonic input using the 2/rev actuation frequency, amplitude of 2° and control phase angle of 120° (2P/2°/120°) is considered for X2TD rotor, the rotor vibration is reduced by about 26.37% only and the rotor effective lift-to-drag ratio increases slightly by 0.98%. When X2TD rotor uses the IBC with multiple harmonic inputs (2P/2°/45° + 5P/1°/90°), the rotor hub vibratory loads and airframe vibration responses are reduced by 44.69% and from 0.48 to 79.10%, respectively, while rotor effective lift-to-drag ratio is improved by 0.77%, as compared to the baseline without IBC.

Originality/value
This study is the first study to use the 2/rev actuation for IBC to the four-bladed lift-offset coaxial rotor and to investigate to obtain simultaneously the rotor vibration reduction, rotor performance improvement and airframe vibration reduction, using IBC with multiple harmonic inputs.
Impact of mobilization costs on schedule performance of highway projects
Authors: Maharjan Shristy , Shrestha Pramen P. , Srirangam Deekshitha 
Published: February 2022

PurposeThe purpose of this study is to determine whether there is a correlation between mobilization costs and project schedule performance of highway projects. In addition to this, the study will also determine if the mobilization costs are helping small or large highway projects in terms of improving the schedule performance.Design/methodology/approachThe data of 206 highway projects were collected from the Department of Transportation of two states with the help of questionnaire survey. The cost, schedule and mobilization costs data were collected. The performance metrics related to construction schedule growth and construction intensity were developed in order to test the research hypotheses: mobilization costs will increase the schedule performance of highway projects. The data were also divided into two groups based on project cost and analyzed to check whether the mobilization costs impact the schedule performance of these highway projects. Spearman's correlation test was conducted to determine the correlation between dependent and independent variables. In addition, a Mann–Whitney test was conducted to determine the difference in medians of construction schedule growth and the construction intensity of these two groups of projects.FindingsOne major study finding was that there was no strong linear correlation between the mobilization cost percentage and the construction schedule growth and construction intensity of highway projects. However, the study found the projects that have 9% or more mobilization costs had significantly better schedule growth compared to the projects that have less than 9% mobilization costs. When data were analyzed based on the project size, it was found that this pattern was seen only in large projects costing equal to or more than $5 million.Practical implicationsThis study's findings have very crucial practical implications to state DOTs contract engineers. This study shows that the highway contract engineers need to provide the right amount of mobilization costs to complete their projects on and before schedule. If the correct amount of mobilization costs is not provided to the contractors, the impact of these mobilization costs on reducing the schedule growth will be negligible. The findings of this study will assist public agency decision makers to complete their projects on or before time by including the mobilization costs provision in the contract. The state DOTs can improve their schedule performance by providing enough financial help to the contractors so that they can improve their cash flows and complete projects successfully within the given timeframe.Originality/valueThis paper contributes to the existing body of knowledge by validating the impact of mobilization costs on the schedule performance of highway projects. There has been no empirical study conducted prior to this to identify the role of mobilization costs on reducing the schedule growth of highway projects.
Ellerine holdings and African bank: a toxic acquisition recipe?
Authors: Kodongo Odongo , Beswick Claire , van den Berg Helen 
Published: February 2022

Learning outcomes
After working through and discussing this case, learners should be able to:1. evaluate the financial condition of Ellerine Holdings Limited (EHL) at the time of the merger proposal and use it to make inferences about the company’s ability, at that time, to function effectively as a going concern;2. identify the conditions within EHL and in the operating environment that may have made it necessary for EHL to seek to change its business strategy;3. determine whether the acquisition price offered to EHL by African Bank Investments Limited (ABIL) was fair; and4. compute the value accretion/loss expected to be realised by the existing shareholders of ABIL and EHL under the merger proposal.

Case overview/synopsis
This case situates the directors of Ellerine Holdings, a furniture retail company that merged with African Bank Limited in 2007, reflecting on the events that led up to both entities being placed into business rescue in 2014 and asking whether the merger was the cause of the demise. If they had chosen an alternative partner, would the results have been different?

Complexity academic level
Masters Level students – MBA or Masters in Finance.

Supplementary materials
For instructors.The following material has been provided with the teaching note for instructors:- Teaching Note.- Johannesburg Stock Exchange News System (SENS) extract of related original filing.For students.The following supplementary material has been provided to accompany the case:- Financial information on the two companies (Excel spreadsheet).- Johannesburg SENS extract of related original filing.

Subject code
CSS 1: Accounting and Finance.
Alibaba: the battle against counterfeits
Authors: Jyani Nancy , Bansal Harbhajan 
Published: February 2022

Learning outcomes
The case will help to understand the concept of online marketplaces and the working of their business model through third party selling. The case highlights how third party selling opens door to online counterfeiting. The case well presents the need of integrity and ethics in business. It showcases how Alibaba took responsibility, designed various initiatives to curb the problem and emerged as a global face for anti-counterfeiting actions.

Case overview/synopsis
Manufacturing and selling of counterfeits have become easier than ever with the wide and easy reach of technology. Internet has smoothened the sale of such fake replicas around the globe. Alibaba Group faced serious problem of counterfeit selling across its various websites. The various challenges were degrading global image, rising number of fake products and numerous lawsuits filed against the company. The case study will help readers to understand the critical aspects of counterfeiting and decisions involved to run such models where the platform is not a direct seller but just an online marketplace. It emphasises how technology and brand collaboration can be used as a means to identify and remove fake product listings from such platforms, thereby preserving the integrity of business. The case also stresses the need to preserve intellectual property rights and exclusivity of original brands.

Complexity academic level
Senior Undergraduate, MBA and Executive MBA.

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 8: Marketing.
The Spinach King’s social enterprise scaling strategy during and post Covid-19 pandemic
Authors: Mamabolo Anastacia 
Published: February 2022

Learning outcomes
Analyse a social business model; explain the scaling motives in a social enterprise; identify and defend scaling strategies in a social enterprise; and use the social enterprise scaling barrier model to evaluate factors that contribute to scaling failure and suggest ways to address the identified barriers.

Case overview/synopsis
Lufefe Nomjana, a Cape Town-based social entrepreneur, decided in 2011 to launch a social enterprise that promotes an affordable but healthy lifestyle by baking and selling spinach bread at a low cost. Nomjana combined a for-profit business venture with the social aspect of providing healthy products at a cost people can afford. When the lockdown was implemented in South Africa in March 2020, he still grew his business despite the strict restrictions. Inspired by the growth of the enterprise, in August 2020, and at the height of the national lockdown necessitated by the Covid-19 pandemic, Nomjana decided to open a company-owned outlet in Johannesburg miles away from the Cape. However, the launch of this company-owned outlet was not successful. The failure of the Johannesburg outlet left him with a dilemma, as he had planned to scale up his enterprise into other cities in South Africa. Launching his business in Cape Town had not been a challenge, but he struggled to launch outlets of his social enterprise outside of the Western Cape Province.

Complexity academic level
Social Entrepreneurship, Commercial Entrepreneurship and Business Management at the Postgraduate Diploma and Masters level.

Supplementary materials
Teaching notes are available for educators only.

Subject code
CCS 3: Entrepreneurship.
Factors that influence service innovation: a systematic approach and a categorization proposal
Authors: Peixoto Marcus Rodrigues , Paula Fabio de Oliveira , da Silva Jorge Ferreira 
Published: February 2022

PurposeService innovation (SI) is crucial for social and economic development. However, most of the studies about innovation relate to product/manufacturing. Aimed at enhancing the academic debate about SI, this paper intends to (1) assess the factors applied in empirical studies about SI from 2006 to 2020, (2) evaluate if researchers differentiate innovation in services from innovation in manufacturing, (3) evaluate if researchers differentiate innovation among distinct service segments within the heterogeneous service industry and (4) propose a categorization model for the factors that influence SI.Design/methodology/approachOur study employs a five-step approach for a systematic literature review of 99 relevant empirical papers from 2006 to 2020.FindingsOur findings demonstrate a persistent lack of conceptual consolidation in the area, adding value to the ongoing dispute between opposite views on current SI's maturity level. Our results also evidence the non-observance of differentiation of innovation factors between service and manufacturing empirical papers. In addition, our paper shows an even higher lack of differentiation in the use of innovation factors among different service segments.Originality/valueThis paper provides the first more systematic verification of the lack of service differentiation within the empirical innovation study field. In addition, despite the abundance of factors that influence SI, the proposed categorization model offers the possibility to promote an area's conceptual consolidation. Our findings and categorization also support the debate about pathways for the field's development and help researchers in their future study designs and analyses.