Systemic Risk, Information Technology Artifacts, and High Reliability Organizations: A Case of Constructing a Radical Architecture

“The test of a first-class mind is the ability to hold two opposing views...at the same time and still retain the ability to function.” (F. Scott Fitzgerald) In distributed, complex socio-technical systems, risks increasingly originate from multiple sources, affect multiple agents in diverse ways, and thus become systemic. The traditional linear causal model of risk control and an individual decision-maker orientation is no longer adequate to contain such risks. This paper reports a detailed case study of a highly complex architectural project by the architect Frank Gehry and his firm Gehry Partners, L.L.C. Gehry and his partners successfully used the 3D representation software Catia to construct radical architectures with dauntingly complex geometric surfaces in spite of increasing systemic risks. Our findings suggest that, in order to successfully combat such risks, organizations rely upon organizing mechanisms characteristic of high reliability organizations (HROs). Our analysis also indicates that creating and maintaining a collective mindfulness is critical for risk control and mitigation in complex socio-technical systems. IT artifacts such as Catia, in combination with other social/technical elements such as skilled workers, contracts, and communication protocols, can enable the five cognitive processes underlying collective mindfulness: preoccupation with failure, reluctance to simplify interpretations, sensitivity to operations, commitment to resilience, and under-specification of structures

Uncovering Patterns for Adverse Pregnancy Outcomes with Spatial Analysis: Evidence from Philadelphia

We introduce a spatial model for analyzing patient-specific and neighborhood risks of stillbirth and preterm birth in Philadelphia. Using electronic health records and census tract data, we find that both patient-level characteristics (e.g. self-identified race/ethnicity) and neighborhood-level characteristics (e.g. violent crime) are associated with patients' odds of stillbirth or preterm birth. Census tracts with higher rates of women in poverty or on public assistance have greater neighborhood risk for these outcomes, whereas census tracts with higher rates of college-educated women or women in the labor force have lower risk. Our findings could be useful for targeted individual and neighborhood interventions.Comment: 27 pages, 7 figures, 9 table

Can stroke survivors use e-bikes as a form of outdoor physical activity?

This research is adapted from Exploring the factors influencing the use of electrically assisted bikes (e-bikes) by stroke survivors: a mixed methods multiple case study published by Taylor & Francis in Disability and Rehabilitatio

Implementation of neurological group-based telerehabilitation within existing healthcare during the COVID-19 pandemic: a mixed methods evaluation

Background There is a need to evaluate if and how telerehabilitation approaches might co-exist within healthcare in the long-term. Our aim was to implement and evaluate a multidisciplinary group-based telerehabilitation approach for people engaging in neurological rehabilitation. Methods NeuroRehabilitation OnLine (NROL) was adapted and implemented within an existing healthcare system as a programme of repeating six-week blocks. A robust evaluation was undertaken simultaneously using a convergent parallel design underpinned by implementation frameworks. This included service data, and patient and staff interviews. Implementation success was conceptualised using the outcomes of appropriateness, acceptability and sustainability. Results Eight NROL blocks delivered 265 sessions with 1347 patient contacts, and NROL continues as part of standard practice. The approach was appropriate for varied demographics and had positive patient opinions and outcomes for many. Staff perceived NROL provided a compatible means to increase therapy and help meet targets, despite needing to mitigate some challenges when fitting the approach within the existing system. NROL was considered acceptable due to good attendance (68%), low drop-out (12%), and a good safety record (one non-injury fall). It was accepted as a new way of working across rehabilitation disciplines as an ‘extra layer of therapy’. NROL had perceived advantages in terms of patient and staff resource (e.g. saving time, energy and travel). NROL provided staffing efficiencies (ratio 0.6) compared to one-to-one delivery. Technology difficulties and reluctance were surmountable with dedicated technology assistance. Leadership commitment was considered key to enable the efforts needed for implementation and sustained use. Conclusion Pragmatic implementation of group-based telerehabilitation was possible as an adjunct to neurological rehabilitation within an existing healthcare system. The compelling advantages reported of having NROL as part of rehabilitation supports the continued use of this telerehabilitation approach. This project provides an exemplar of how evaluation can be run concurrently with implementation, applying a data driven rather than anecdotal approach to implementation

Topological materials as promising candidates for tuneable helicity-dependent terahertz emitters

Topological materials have rapidly gained interest as contenders for development of coherent, controllable terahertz emitters. Possessing Weyl nodes either at the surface or within the bulk, they host spin-polarised, helicity-dependent currents that offer possibility to control the emitted THz pulse by changing the polarization of the optical pulses generating the radiation. Here, we show that upon near-infrared excitation at oblique incidence, multi-cycle pulses are generated with a narrow bandwidth of ∼0.4 THz for cadmium arsenide bulk crystals and nanowire ensembles. Both the bandwidth and peak emission frequency of the generated THz radiation can be tuned by respectively varying the photon helicity and angle of incidence of the photoexcitation light

Nanoscale Near-Field Tomography of Surface States on (Bi(0.5)b(0.5))(2)Te-3

Three-dimensional topological insulators (TIs) have attracted tremendous interest for their possibility to host massless Dirac Fermions in topologically protected surface states (TSSs), which may enable new kinds of high-speed electronics. However, recent reports have outlined the importance of band bending effects within these materials, which results in an additional two-dimensional electron gas (2DEG) with finite mass at the surface. TI surfaces are also known to be highly inhomogeneous on the nanoscale, which is masked in conventional far-field studies. Here, we use near-field microscopy in the mid infrared spectral range to probe the local surface properties of customtailored (Bi0.5Sb0.5)(2)Te-3 structures with nanometer precision in all three spatial dimensions. Applying nanotomography and nanospectroscopy, we reveal a few-nanometer-thick layer of high surface conductivity and retrieve its local dielectric function without assuming any model for the spectral response. This allows us to directly distinguish between different types of surface states. An intersubband transition within the massive 2DEG formed by quantum confinement in the bent conduction band manifests itself as a sharp, surface-bound, Lorentzian-shaped resonance. An additional broadband background in the imaginary part of the dielectric function may be caused by the TSS. Tracing the intersubband resonance with nanometer spatial precision, we observe changes of its frequency, likely originating from local variations of doping or/and the mixing ratio between Bi and Sb. Our results highlight the importance of studying the surfaces of these novel materials on the nanoscale to directly access the local optical and electronic properties via the dielectric function

Activin Signaling in Microsatellite Stable Colon Cancers Is Disrupted by a Combination of Genetic and Epigenetic Mechanisms

Activin receptor 2 (ACVR2) is commonly mutated in microsatellite unstable (MSI) colon cancers, leading to protein loss, signaling disruption, and larger tumors. Here, we examined activin signaling disruption in microsatellite stable (MSS) colon cancers.Fifty-one population-based MSS colon cancers were assessed for ACVR1, ACVR2 and pSMAD2 protein. Consensus mutation-prone portions of ACVR2 were sequenced in primary cancers and all exons in colon cancer cell lines. Loss of heterozygosity (LOH) was evaluated for ACVR2 and ACVR1, and ACVR2 promoter methylation by methylation-specific PCR and bisulfite sequencing and chromosomal instability (CIN) phenotype via fluorescent LOH analysis of 3 duplicate markers. ACVR2 promoter methylation and ACVR2 expression were assessed in colon cancer cell lines via qPCR and IP-Western blots. Re-expression of ACVR2 after demethylation with 5-aza-2'-deoxycytidine (5-Aza) was determined. An additional 26 MSS colon cancers were assessed for ACVR2 loss and its mechanism, and ACVR2 loss in all tested cancers correlated with clinicopathological criteria.Of 51 MSS colon tumors, 7 (14%) lost ACVR2, 2 (4%) ACVR1, and 5 (10%) pSMAD2 expression. No somatic ACVR2 mutations were detected. Loss of ACVR2 expression was associated with LOH at ACVR2 (p<0.001) and ACVR2 promoter hypermethylation (p<0.05). ACVR2 LOH, but not promoter hypermethylation, correlated with CIN status. In colon cancer cell lines with fully methylated ACVR2 promoter, loss of ACVR2 mRNA and protein expression was restored with 5-Aza treatment. Loss of ACVR2 was associated with an increase in primary colon cancer volume (p<0.05).Only a small percentage of MSS colon cancers lose expression of activin signaling members. ACVR2 loss occurs through LOH and ACVR2 promoter hypermethylation, revealing distinct mechanisms for ACVR2 inactivation in both MSI and MSS subtypes of colon cancer

An Ultrafast Switchable Terahertz Polarization Modulator Based on III-V Semiconductor Nanowires

Progress in the terahertz (THz) region of the electromagnetic spectrum is undergoing major advances, with advanced THz sources and detectors being developed at a rapid pace. Yet, ultrafast THz communication is still to be realized, owing to the lack of practical and effective THz modulators. Here, we present a novel ultrafast active THz polarization modulator based on GaAs semiconductor nanowires arranged in a wire-grid configuration. We utilize an optical pump–terahertz probe spectroscopy system and vary the polarization of the optical pump beam to demonstrate ultrafast THz modulation with a switching time of less than 5 ps and a modulation depth of −8 dB. We achieve an extinction of over 13% and a dynamic range of −9 dB, comparable to microsecond-switchable graphene- and metamaterial-based THz modulators, and surpassing the performance of optically switchable carbon nanotube THz polarizers. We show a broad bandwidth for THz modulation between 0.1 and 4 THz. Thus, this work presents the first THz modulator which combines not only a large modulation depth but also a broad bandwidth and picosecond time resolution for THz intensity and phase modulation, making it an ideal candidate for ultrafast THz communicationThe authors thank the EPSRC (U.K.) and Australian Research Council for financial support. H.J.J. thanks the Royal Commission for the Exhibition of 1851 for her research fellowship. The Australian National Fabrication Facility (ACT node) is acknowledged for access to the growth facility used in this work

Characterizing temporary hydrological regimes at a European scale

Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios