Problem Specification in Crowdsourcing Contests: A Natural Experiment

Problem specification is a key aspect in crowdsourcing contests through which seekers convey their requirements and taste for the desired submissions. Hence, it is important to understand how problem specification should be framed to achieve better crowdsourcing contest outcomes. In this empirical study, we investigate the effects of a relatively more structured problem specification on contest quantity, solver quantity, and idea quality. We leverage a natural experiment set up on a major crowdsourcing contest platform where the problem specification of logo design contests changed from open-ended to structured. Our results show that the specification change impacts both seekers and solvers. Specifically, the number of contests increases after the change but solver quantity and idea quality in the respective contests tend to be lower. We discuss the theoretical and practical contributions of this research

Confirmation Bias in Adoption of Seeker Exemplars in Crowdsourcing Ideation Contests

This study examineshow solutionexemplarsthat seekers providein crowdsourcing ideation contestsaffect the scanning, shortlisting, and selection of ideas by solvers; thesethreeideation activities are essential layersin the Knowledge Reuse for Radical Innovation model.Specifically, we consider the role of confirmation bias in solvers’ behaviors and their use of seeker exemplarsinthe ideation activities. We posit that solvers’ use of exemplars is affected by the extent to which the exemplars are consistent with solvers’ prior beliefand by different considerations in different ideation activities. The results from a crowdsourcing ideationcontest experiment largely support our theorizing, as we find that problem-related and problem-unrelated seeker exemplars affecteddifferent ideation activitiesdifferently. This research contributes insights into seeker involvements and solver behaviors in crowdsourcing ideation contests and offers practical implications for seekers

Trust Across Borders: Buyer-Supplier Trust in Global Business-to-Business E-Commerce

This study focuses on trust formation and development in global buyer-supplier relationships. Trust affects all business relationships, especially global business-to-business (B2B) transactions due to the distances between buyers and suppliers. We use information signaling theory to examine how information indices and signals affect buyers’ trust in suppliers in global B2B commerce. Specifically, we examine how buyers’ trust is affected by (1) their perceptions of the national integrity and legal structure of suppliers’ country, and (2) third-party verifications of suppliers on B2B exchanges. Because buyer-supplier relationships usually evolve over time, we study how the effects of indices and signals change as the number of transactions between the partners increases. A survey of global organizational buyers finds that perceptions of national integrity, legal structure, and supplier verifications are all positively related to buyers’ trust. However, the number of prior transactions between buyers and suppliers moderates the impact of perceived legal structure on buyers’ trust

The effect of cotton-based collection methods on eosinophil cationic protein (ECP) concentrations detected in saliva

Teck Yee Wong, David Koh, Andrew Wee, Vivian Ng, Yong Tat Koh, Zhenjie Sum, Gerald KohDepartment of Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, SingaporeBackground: Salivary eosinophil cationic protein (ECP) level has the potential to be an assessment tool for asthma. Its measurement is not well-established and needs standardization. We studied how passive drool (PD) and two commercial devices, Salivette® (cotton-based device) and Sorbette® (cellulose–cotton-based-device), may affect ECP levels during collection among healthy subjects.Methods: Study I (n = 10) involved direct sampling of healthy adult subjects with Salivette® and Sorbette®. Study II (n = 33) involved ‘indirect’ sampling of previously collected PD by both devices.Results: In study I, ECP levels were detected in all PD samples but only in three with Sorbette® and none with Salivette® (collection order: PD, Sorbette® and Salivette®). We changed the order of collection (Salivette®, Sorbette®, PD) and the results were similar (ECP levels detected in all PD samples, three with Sorbette® and only one with Salivette®). In study II, ECP levels in saliva collected by PD was 12.8 μg/L (median) and using Sorbette® and Salivette® were < 2.0 μg/L and 3.4 μg/L respectively (p < 0.01). ECP levels in PD correlated with Sorbette® (rs = 0.79, p < 0.01) and Salivette® (rs = 0.62, p 0.01).Conclusion: Compared to PD, saliva collected using cotton or cellulose-based collection devices resulted in lower measurable ECP levels.Keywords: salivary ECP, collection method

The role of Simmelian friendship ties on retaliation within triads

We examine the effect of friendship in triads on retaliatory responses to unfair outcomes that originate from a group member. Drawing on Simmel’s classic discussion of relationships in social triads versus dyads, we hypothesized that the effect of unfairness on retaliation between friends is stronger when the third party in the triad is a mutual friend, rather than a stranger. We also draw on social categorization theory to hypothesize that the effect of unfairness on retaliation between strangers is stronger when the third party is a friend of that stranger than when the triad consists of all strangers. Hypotheses were tested in an experiment where participants negotiated with one another in a three-person exchange network. The results supported our hypothesis that between friends, the increase in retaliation was stronger following an unfair deal when third parties were mutual friends, rather than strangers. </jats:p

ST-Elevation Myocardial Infarction in Situs Inversus Dextrocardia : A Case Report

ST-elevation myocardial infarction (STEMI) in situs inversus dextrocardia is a rare combination and poses many challenges in terms of diagnosis and management. These include the early detection of dextrocardia as well as the interpretation of the ECG. In addition, percutaneous coronary intervention could be challenging in the setting of dextrocardia because of diffi culty in cannulating the coronary arteries, selection of catheters, catheter manipulation, image acquisition and interpretation

Early cardiovascular MRI post successful reperfusion of acute myocardial infarction : An exploratory study

Post-myocardial infarction (MI) patients has varied outcome despite successful reperfusion. Our study aimed to use cardiac magnetic resonance imaging (CMR) to explore parameters that may influence outcome in successfully reperfused post-MI patients. We used left ventricular (LV) remodelling and major adverse cardiovascular event (MACE) at 6 months as a pooroutcome indicator. Consecutive patients admitted to Sarawak Heart Centre from Dec 2012 to Nov 2014 with acute anterior or inferior ST elevation MI were screened. A total of 101 patients with TIMI-3 flow were recruited. Patients underwent CMR imaging during the index admission, and another between 3 to 6 months later. LV remodelling occurred in 21.8% while microvascular obstruction (MVO) in 38.6% of patients. LV infarct size and MVO were significant in those who developed LV remodelling, while door-to-perfusion time and total-ischaemic time were not significantly different. MACE was significant in patients with larger infarcts but not significant in patients with MVO. LV infarct size was also significant in those who had reverse LV remodelling. These results suggest that early CMR measurement of infarct size and detection of MVO has the potential to predict LV improvement or deterioration at 6 months

COVID-19 Antibody Surveillance Among Healthcare Workers in A Non-COVID designated Cardiology Centre

BACKGROUND: Reports on healthcare worker antibody response to COVID-19 infection are scarce. We aim to determine theCOVID-19 antibody prevalence among healthcare workers in a cardiology centre and the relationship between case definitioncriteria with the COVID-19 antibody result. METHODS: Convenience sampling was applied. Healthcare workers in SarawakHeart Centre (SHC) cardiology, radiology, and emergency unit were recruited. A survey form on clinical symptoms and closecontact history was distributed. HEALGEN COVID-19 IgG/IgM rapid test was performed using serum/ whole blood specimen.Staff with positive COVID-19 antibody results were referred to the infectious disease specialist for assessment. RESULTS: Atotal of 310 staff were screened. 220(71%) were female, and the mean age was 36±7.7 years old. 46(14.8%) staff reported havingclinical symptoms at some stage from the end of January 2020 to the time of this surveillance. Number of staff who had a historyof overseas travel, close contact with confirmed COVID-19 patients, or had visited places with identified COVID-19 clusterswere 4(1.3%), 24(7.7%) and 24(7.7%) respectively. There were 14 staff (4.5%) with positive tests positive, 2 for IgM, and 12for IgG. All those with positive antibody were subsequently tested negative with RT-PCR test. The history of having clinicalsymptoms and exposure to COVID-19 cluster area were independently associated with a positive IgG result. CONCLUSION:The application of COVID-19 antibody serology rapid tests could determine true exposure of staff to the infection and allowus to reassess existing measures of infection control within the hospital

Clinical Outcomes and Predictors of Improved Left Ventricular Ejection Fraction in Heart Failure with Reduced Ejection Fraction due to Non-Ischemic Cardiomyopathy

Background: Left ventricular ejection fraction (LVEF) improvement is the cornerstone of LV reverse remodelling. It prognosticates heart failure with reduced ejection fraction (HFrEF). There is limited data on the clinical factors that predict LVEF improvement among non-ischemic cardiomyopathy (NICM) patients in Malaysia. Objective: To determine the 3-year outcomes and predictors of LVEF improvement in patients with (NICM) and HFrEF. Materials &amp; Methods: We recruited patients with NICM and HFrEF (LVEF &lt;40%) between 2016 and 2018. NICM was defined as HF with 1) normal coronary arteries or 2) any coronary artery stenosis not involving the proximal left anterior descending artery (LAD) and without transmural fibrosis in the LAD territory from cardiac magnetic resonance (CMR) imaging to account for the impaired LVEF. Clinical and imaging parameters were assessed using logistic regression statistics to determine the predictors of LVEF improvement. LVEF improvement is defined as a recovery of EF to &gt; 40% with at least a 10-point increment from baseline. The clinical outcomes at three year were 1) change in NYHA class and 2) composite of all-cause mortality, unscheduled clinic or emergency department visits, readmission and/or ventricular arrhythmia. Results: 43 patients were recruited. The mean duration of follow-up and echocardiographic assessment interval were 46 and 23 months, respectively. The cohort had a mean age of 46±13 years, and were mostly male (72%). More patients had NYHA 1 at the end of the study (37% vs 86%). 11 patients (25%) recorded composite outcomes. 62.8% had LVEF improvement. Patients with LVEF improvement had a lower incidence of late gadolinium enhancement (51.7% vs 85.7%, odds 5.6 ,p=0.045) and midwall fibrosis on CMR (18.5% vs 62.5%, odds 7.3, p=0.003). LVEF improvement did not affect the functional NYHA recovery (92% vs 81%, p=0.28). Patients with less LVEF improvement had higher incidence of composite outcome (18.5% vs 37.5%, p=0.168). Other characteristics were not significantly different between the groups. Conclusion: Patients with NICM and LVEF improvement had lower composite outcome. Absence of late gadolinium enhancement, particularly midwall fibrosis was an independant predictor of LVEF improvement. This underscores the importance of CMR tissue characterisation to refine the prognostication of NICM patients

Smartphone electrocardiogram for detecting atrial fibrillation after a cerebral ischaemic event: a multicentre randomized controlled trial

Aims: Atrial fibrillation (AF) is a preventable cause of ischaemic stroke but it is often undiagnosed and undertreated. The utility of smartphone electrocardiogram (ECG) for the detection of AF after ischaemic stroke is unknown. The aim of this study is to determine the diagnostic yield of 30-day smartphone ECG recording compared with 24-h Holter monitoring for detecting AF ≥30 s. Methods and results: In this multicentre, open-label study, we randomly assigned 203 participants to undergo one additional 24-h Holter monitoring (control group, n = 98) vs. 30-day smartphone ECG monitoring (intervention group, n = 105) using KardiaMobile (AliveCor®, Mountain View, CA, USA). Major inclusion criteria included age ≥55 years old, without known AF, and ischaemic stroke or transient ischaemic attack (TIA) within the preceding 12 months. Baseline characteristics were similar between the two groups. The index event was ischaemic stroke in 88.5% in the intervention group and 88.8% in the control group (P = 0.852). AF lasting ≥30 s was detected in 10 of 105 patients in the intervention group and 2 of 98 patients in the control group (9.5% vs. 2.0%; absolute difference 7.5%; P = 0.024). The number needed to screen to detect one AF was 13. After the 30-day smartphone monitoring, there was a significantly higher proportion of patients on oral anticoagulation therapy at 3 months compared with baseline in the intervention group (9.5% vs. 0%, P = 0.002). Conclusions: Among patients ≥55 years of age with a recent cryptogenic stroke or TIA, 30-day smartphone ECG recording significantly improved the detection of AF when compared with the standard repeat 24-h Holter monitoring. Keywords: Anticoagulation; Atrial fibrillation; Cryptogenic stroke; Digital health; Smartphone electrocardiogram.