The dynamics of digital platform innovation: unfolding the paradox of control and generativity in Apple's iOS

Mobile digital platforms provide an architectural basis for third party innovation of platform complements. Platform owners have property rights, enabling them to establish a boundary of permissible innovation demarcating the permitted from the prohibited. This allows for the curation of complements, which provides a means of controlling for value creation. Consequently, platform innovationthe innovation of platform complements is occasionally refused by platform owners. When this occurs tensions may arise between the two parties over where the boundary of permissible innovation should lie. Tussles may break out, embodied in complex interactions, as each party attempts to get its way. Eventually an outcome is achieved, and a platform innovation is either allowed or prohibited. A body of platform innovation literature is emerging from fields including information systems. Whilst this literature considers many aspects of platform innovation, the dynamics concerning the control of the innovation of platform innovation complements is overlooked. This research attempts to address that gap. Its relevance to information systems concerns the digitalisation of platforms as systemsdigital infrastructures, which affects their capacity for innovation and regulation. This research uses the method of narrative networks to analyse 45 examples of contested platform innovation. This approach, informed by empirical data sourced from over 4500 blog entries, identifies patterned sequences of actions across the examples. These sequences describe how tension builds, how control is asserted, and how control is then resisted. A theory of formal managerial control is used to explain how mechanisms of control are applied by platform owners as well as how developers respond to control. The principle contribution of this research is to theory. It develops and presents a theory to describe and explain the dynamics of contested innovation of complements on curated digital platforms. In doing so, iIt challenges the understanding that the platform owner alone controls platform design rules and concerning which platform complements are allowed, and which are notthe boundary of permissible innovation. Furthermore, tThe study indicates opens up the possibility that the forces of digitalisation provide third parties with the power to affect influence platform architecture, but at the cost of additional means of being controlled

Exploring the impact of real-time communication on media choice in the context of distributed work

This paper presents an exploratory study into the use of real-time communication (RTC) systems to support distributed work. Motivated by the authors’ dissatisfaction with theories assuming individually rational actors, the paper suggests the idea of informated presence to capture phenomena emerging from employees’ increasingly computer-mediated engagement with their work environment. Four case vignettes are presented to illustrate different communicative strategies that develop in response to presence availability updates generated by RTC systems. Drawing from Goffman’s microsociological idea of interaction order and Zuboff’s seminal work on computer-mediated work, the findings indicate the limitations of approaches such as information richness theory in understanding real-time communication in organizational settings. More research is needed to elaborate the implications of informated presence on distributed work and coordination of knowledge workers

On 2-blocks with minimal nonabelian defect groups II

We determine the structure of 2-blocks with minimal nonabelian defect groups, by making use of the classification of finite simple groups.Comment: 7 page

Fragility of Fermi arcs in Dirac semimetals

We use tunable, vacuum ultraviolet laser-based angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic properties of Dirac semimetal candidate cubic PtBi${}_{2}$. In addition to bulk electronic states we also find surface states in PtBi${}_{2}$ which is expected as PtBi${}_{2}$ was theoretical predicated to be a candidate Dirac semimetal. The surface states are also well reproduced from DFT band calculations. Interestingly, the topological surface states form Fermi contours rather than double Fermi arcs that were observed in Na$_3$Bi. The surface bands forming the Fermi contours merge with bulk bands in proximity of the Dirac points projections, as expected. Our data confirms existence of Dirac states in PtBi${}_{2}$ and reveals the fragility of the Fermi arcs in Dirac semimetals. Because the Fermi arcs are not topologically protected in general, they can be deformed into Fermi contours, as proposed by [Kargarian {\it et al.}, PNAS \textbf{113}, 8648 (2016)]. Our results demonstrate validity of this theory in PtBi${}_{2}$.Comment: 6 pages, 4 figure

Associations of depression status and hopelessness with breast cancer.

This study extended the literature by examining whether three profiles of depression predicted breast cancer status. In 1076 women of the Baltimore Epidemiologic Catchment Area study, depression status and hopelessness were measured at baseline and breast cancer status was ascertained 24 years later. Double depression, but not major depression or dysthymia, was associated with breast cancer. Hopelessness predicted fewer new cases of breast cancer. When double depression and hopelessness were simultaneously entered as predictors, the regression weights of both predictors increased. The role of severe and extended duration depression as well as possible explanations for unexpected findings are discussed

A novel multi-scale modelling approach to predict the reduction of transverse strength due to porosity in composite materials

Porosity is a major manufacturing defect which affects the matrix dominate properties of continuous fibre composites, in particular the transverse strength. The simulation of porosity allows for predictions on the reduction of strength to be made, however, there is a trade-off between accuracy and computational efficiency. The multi-scale modelling approach presented here allows for accurate 3-dimensional geometry data of voids to be used. This is accomplished by first evaluating the effect the porosity has on degrading the matrix then subsequently, by using a representative unit cell, ply level strength can be predicted. The model is validated against empirical tensile and compressive testing of unidirectional autoclave cured prepreg with strong correlation. The approach allows for a reduction in overengineered structures by predicting accurate material properties for a given porosity generation

Differences in urinary monochlorobenzene metabolites between rats and humans.

Differences in urinary excretion of monochlorobenzene between rats and humans were studied. Monochlorobenzene was administered to rats and humans intraperitoneally, orally or by inhalation. Urinary p-chlorophenylmercapturic acid and 4-chlorocatechol, after hydrolysis of its conjugate, were measured. The excretion of p-chlorophenylmercapturic acid was somewhat more than that of 4-chlorocatechol in rats which were administered monochlorobenzene orally or intraperitoneally. The excretion of p-chlorophenylmercapturic acid was markedly less than that of 4-chlorocatechol in humans who received monochlorobenzene orally or by inhalation. The results indicate that the 4-chlorocatechol conjugate is a suitable index of metabolites in the urine of workers exposed to monochlorobenzene.</p

Analysis of delayed surgical treatment and oncologic outcomes in clinical stage I non-small cell lung cancer

Importance: The association between delayed surgical treatment and oncologic outcomes in patients with non-small cell lung cancer (NSCLC) is poorly understood given that prior studies have used imprecise definitions for the date of cancer diagnosis. Objective: To use a uniform method to quantify surgical treatment delay and to examine its association with several oncologic outcomes. Design, Setting, and Participants: This retrospective cohort study was conducted using a novel data set from the Veterans Health Administration (VHA) system. Included patients had clinical stage I NSCLC and were undergoing resection from 2006 to 2016 within the VHA system. Time to surgical treatment (TTS) was defined as the time between preoperative diagnostic computed tomography imaging and surgical treatment. We evaluated the association between TTS and several delay-associated outcomes using restricted cubic spline functions. Data analyses were performed in November 2021. Exposure: Wait time between cancer diagnosis and surgical treatment (ie, TTS). Main Outcomes and Measures: Several delay-associated oncologic outcomes, including pathologic upstaging, resection with positive margins, and recurrence, were assessed. We also assessed overall survival. Results: Among 9904 patients who underwent surgical treatment for clinical stage I NSCLC, 9539 (96.3%) were men, 4972 individuals (50.5%) were currently smoking, and the mean (SD) age was 67.7 (7.9) years. The mean (SD) TTS was 70.1 (38.6) days. TTS was not associated with increased risk of pathologic upstaging or positive margins. Recurrence was detected in 4158 patients (42.0%) with median (interquartile range) follow-up of 6.15 (2.51-11.51) years. Factors associated with increased risk of recurrence included younger age (hazard ratio [HR] for every 1-year increase in age, 0.992; 95% CI, 0.987-0.997; P = .003), higher Charlson Comorbidity Index score (HR for every 1-unit increase in composite score, 1.055; 95% CI, 1.037-1.073; P \u3c .001), segmentectomy (HR vs lobectomy, 1.352; 95% CI, 1.179-1.551; P \u3c .001) or wedge resection (HR vs lobectomy, 1.282; 95% CI, 1.179-1.394; P \u3c .001), larger tumor size (eg, 31-40 mm vs \u3c10 mm; HR, 1.209; 95% CI, 1.051-1.390; P = .008), higher tumor grade (eg, II vs I; HR, 1.210; 95% CI, 1.085-1.349; P \u3c .001), lower number of lymph nodes examined (eg, ≥10 vs \u3c10; HR, 0.866; 95% CI, 0.803-0.933; P \u3c .001), higher pathologic stage (III vs I; HR, 1.571; 95% CI, 1.351-1.837; P \u3c .001), and longer TTS, with increasing risk after 12 weeks. For each week of surgical delay beyond 12 weeks, the hazard for recurrence increased by 0.4% (HR, 1.004; 95% CI, 1.001-1.006; P = .002). Factors associated with delayed surgical treatment included African American race (odds ratio [OR] vs White race, 1.267; 95% CI, 1.112-1.444; P \u3c .001), higher area deprivation index [ADI] score (OR for every 1 unit increase in ADI score, 1.005; 95% CI, 1.002-1.007; P = .002), lower hospital case load (OR for every 1-unit increase in case load, 0.998; 95% CI, 0.998-0.999; P = .001), and year of diagnosis, with less recent procedures more likely to have delay (OR for each additional year, 0.900; 95% CI, 0.884-0.915; P \u3c .001). Patients with surgical treatment within 12 weeks of diagnosis had significantly better overall survival than those with procedures delayed more than 12 weeks (HR, 1.132; 95% CI, 1.064-1.204; P \u3c .001). Conclusions and Relevance: Using a more precise definition for TTS, this study found that surgical procedures delayed more than 12 weeks were associated with increased risk of recurrence and worse survival. These findings suggest that patients with clinical stage I NSCLC should undergo expeditious treatment within that time frame

Blocks with transitive fusion systems

Suppose that all nontrivial subsections of a $p$-block $B$ are conjugate (where $p$ is a prime). By using the classification of the finite simple groups, we prove that the defect groups of $B$ are either extraspecial of order $p^3$ with $p \in \{3,5\}$ or elementary abelian