Seeing the invisible: from imagined to virtual urban landscapes

Urban ecosystems consist of infrastructure features working together to provide services for inhabitants. Infrastructure functions akin to an ecosystem, having dynamic relationships and interdependencies. However, with age, urban infrastructure can deteriorate and stop functioning. Additional pressures on infrastructure include urbanizing populations and a changing climate that exposes vulnerabilities. To manage the urban infrastructure ecosystem in a modernizing world, urban planners need to integrate a coordinated management plan for these co-located and dependent infrastructure features. To implement such a management practice, an improved method for communicating how these infrastructure features interact is needed. This study aims to define urban infrastructure as a system, identify the systematic barriers preventing implementation of a more coordinated management model, and develop a virtual reality tool to provide visualization of the spatial system dynamics of urban infrastructure. Data was collected from a stakeholder workshop that highlighted a lack of appreciation for the system dynamics of urban infrastructure. An urban ecology VR model was created to highlight the interconnectedness of infrastructure features. VR proved to be useful for communicating spatial information to urban stakeholders about the complexities of infrastructure ecology and the interactions between infrastructure features.https://doi.org/10.1016/j.cities.2019.102559Published versio

Patient-Specific Fetal Dose Determination for Multi-Target Gamma Knife Radiosurgery: Computational Model and Case Report.

A 42-year-old woman at 29 weeks gestation via in vitro fertilization who presented with eight metastatic brain lesions received Gamma Knife stereotactic radiosurgery (GKSRS) at our institution. In this study, we report our clinical experience and a general procedure of determining the fetal dose from patient-specific treatment plans and we describe quality assurance measurements to guide the safe practice of multi-target GKSRS of pregnant patients. To estimate fetal dose pre-treatment, peripheral dose-to-focal dose ratios (PFRs) were measured in a phantom at the distance approximating the fundus of uterus. Post-treatment, fetal dose was calculated from the actual patient treatment plan. Quality assurance measurements were carried out via the extrapolation dosimetry method in a head phantom at increasing distances along the longitudinal axis. The measurements were then empirically fitted and the fetal dose was extracted from the curve. The computed and measured fetal dose values were compared with each other and associated radiation risk was estimated. Based on low estimated fetal dose from preliminary phantom measurements, the patient was accepted for GKSRS. Eight brain metastases were treated with prescription doses of 15-19 Gy over 143 min involving all collimator sizes as well as composite sector mixed shots. Direct fetal dose computation based on the actual patient's treatment plan estimated a maximum fetal dose of 0.253 cGy, which was in agreement with surface dose measurements at the level of the patient's uterine fundus during the actual treatment. Later phantom measurements also estimated fetal dose to be in the range of 0.21-0.28 cGy (dose extrapolation curve R2 = 0.998). Using the National Council on Radiation Protection and Measurements (NCRP) population-based model, we estimate the fetal risk of secondary malignancy, which is the primary toxicity after 25 weeks gestation, to be less than 0.01%. Of note, the patient delivered the baby via scheduled cesarean section at 36 weeks without complications attributable to the GKSRS procedure. GKSRS of multiple brain metastases was demonstrated to be safe and feasible during pregnancy. The applicability of a general patient-specific fetal dose determination method was also demonstrated for the first time for such a treatment

Microscopic Aspects of Stretched Exponential Relaxation (SER) in Homogeneous Molecular and Network Glasses and Polymers

Because the theory of SER is still a work in progress, the phenomenon itself can be said to be the oldest unsolved problem in science, as it started with Kohlrausch in 1847. Many electrical and optical phenomena exhibit SER with probe relaxation I(t) ~ exp[-(t/{\tau}){\beta}], with 0 < {\beta} < 1. Here {\tau} is a material-sensitive parameter, useful for discussing chemical trends. The "shape" parameter {\beta} is dimensionless and plays the role of a non-equilibrium scaling exponent; its value, especially in glasses, is both practically useful and theoretically significant. The mathematical complexity of SER is such that rigorous derivations of this peculiar function were not achieved until the 1970's. The focus of much of the 1970's pioneering work was spatial relaxation of electronic charge, but SER is a universal phenomenon, and today atomic and molecular relaxation of glasses and deeply supercooled liquids provide the most reliable data. As the data base grew, the need for a quantitative theory increased; this need was finally met by the diffusion-to-traps topological model, which yields a remarkably simple expression for the shape parameter {\beta}, given by d*/(d* + 2). At first sight this expression appears to be identical to d/(d + 2), where d is the actual spatial dimensionality, as originally derived. The original model, however, failed to explain much of the data base. Here the theme of earlier reviews, based on the observation that in the presence of short-range forces only d* = d = 3 is the actual spatial dimensionality, while for mixed short- and long-range forces, d* = fd = d/2, is applied to four new spectacular examples, where it turns out that SER is useful not only for purposes of quality control, but also for defining what is meant by a glass in novel contexts. (Please see full abstract in main text

Transforming the patient experience: Bringing to life a patient- and family-centred interprofessional collaborative practice model of care at Kingston General Hospital

The Kingston General Hospital strategic plan includes transforming the patient experience and bringing to life new models of interprofessional care and education. The implementation of the Interprofessional Collaborative Practice Model has been the foundation of this transformational change. Areas identified for improvement included communication, discharge planning, and purposeful engagement of patients and families in the care process. Through a system-wide approach to change, it was expected that the organization would be better prepared to deliver safer, higher quality care and enriched experiences for patients, families and practitioners. From March to October 2009, 54 representatives from various disciplines and services gathered to design a new approach to care delivery. The resulting model was conceptualized as a system of interacting levers: People, Technology, Information, and Process. Between November 2009 and April 2012, the model was implemented on 18 inpatient units and 33 ambulatory care areas. Interprofessional collaboration and patient engagement has been vital in optimizing care through this new care delivery model. We quickly came to realize that in order to create and sustain a patient and family-centred approach to care, we needed patients and families to advise us along the way. A Patient and Family Advisory Council was formed in February 2010 and continues to provide direction. Post-implementation results on four units are encouraging, showing improvements in quality of patient care and quality of work life. Continuous monitoring of the changes and using evaluation results to advance the positive changes are the next steps in this transformation of the healthcare experience

Controlling electron emission from the photoactive yellow protein chromophore by substitution at the coumaric acid group

Understanding how the interactions between a chromophore and its surrounding protein control the function of a photoactive protein remains a challenge. Here, we present the results of photoelectron spectroscopy measurements and quantum chemistry calculations aimed at investigating how substitution at the coumaryl tail of the photoactive yellow protein chromophore controls competing relaxation pathways following photoexcitation of isolated chromophores in the gas phase with ultraviolet light in the range 350-315 nm. The photoelectron spectra are dominated by electrons resulting from direct detachment and fast detachment from the 2(1)ππ* state but also have a low electron kinetic energy component arising from autodetachment from lower lying electronically excited states or thermionic emission from the electronic ground state. We find that substituting the hydrogen atom of the carboxylic acid group with a methyl group lowers the threshold for electron detachment but has very little effect on the competition between the different relaxation pathways, whereas substituting with a thioester group raises the threshold for electron detachment and appears to 'turn off' the competing electron emission processes from lower lying electronically excited states. This has potential implications in terms of tuning the light-induced electron donor properties of photoactive yellow protein

Picosecond time-resolved resonance Raman observation of the iso-CH2Cl-I and iso-CH2I-Cl photoproducts from the "photoisomerization" reactions of CH 2ICl in the solution phase

A preliminary pecosecond Stokes time-resolved resonance Raman investigation was made of the initial formation and subsequent decay of the photoproduct produced following 267 nm excitaiton of CH 2ClI in acetonitrile solution. A coparision was made between density-functional theroy computations for portable photoproduct species and the results from a femtosecond transient absorption study to Raman spectra. This comparision indicated that the iso-CH 2ClI was aminly produced and associated with the 460 nm transient absorption band.published_or_final_versio

A light-in-flight single-pixel camera for use in the visible and short-wave infrared

This is the final version. Available on open access from the Optical Society of America via the DOI in this recordSingle-pixel cameras reconstruct images from a stream of spatial projection measurements recorded with a single-element detector, which itself has no spatial resolution. This enables the creation of imaging systems that can take advantage of the ultra-fast response times of single-element detectors. Here we present a single-pixel camera with a temporal resolution of 200 ps in the visible and short-wave infrared wavelengths, used here to study the transit time of distinct spatial modes transmitted through few-mode and orbital angular momentum mode conserving optical fiber. Our technique represents a way to study the spatial and temporal characteristics of light propagation in multimode optical fibers, which may find use in optical fiber design and communications.Engineering and Physical Sciences Research Council (EPSRC)European Union Horizon 2020Office of Naval Research (ONR)National Science Foundation (NSF

Prevalence and incidence of cancer related lymphedema in low and middle-income countries: a systematic review and meta-analysis.

BACKGROUND:Little is known about the prevalence and incidence in low and middle-income countries (LMICs) of secondary lymphedema due to cancer. The purpose of the study is to estimate the prevalence and incidence in LMICs of secondary lymphedema related to cancer and/or its treatment(s) and identify risk factors. METHOD:A systematic review and meta-analysis was conducted. Medline, EMBASE and CINAHL were searched in June 2019 for peer-reviewed articles that assessed prevalence and/or incidence of cancer-related lymphedema in LMICs. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies. Estimates of pooled prevalence and incidence estimates were calculated with 95% confidence intervals (CI), with sub-group analyses grouping studies according to: country of origin, study design, risk of bias, setting, treatment, and lymphedema site and measurement. Heterogeneity was measured using X2 and I2, with interpretation guided by the Cochrane Handbook for Systematic Reviews. RESULTS:Of 8766 articles, 36 were included. Most reported on arm lymphedema secondary to breast cancer treatment (n = 31), with the remainder reporting on leg lymphedema following gynecological cancer treatment (n = 5). Arm lymphedema was mostly measured by arm circumference (n = 16/31 studies), and leg lymphedema through self-report (n = 3/5 studies). Eight studies used more than one lymphedema measurement. Only two studies that measured prevalence of leg lymphedema could be included in a meta-analysis (pooled prevalence =10.0, 95% CI 7.0-13.0, I2 = 0%). The pooled prevalence of arm lymphedema was 27%, with considerable heterogeneity (95% CI 20.0-34.0, I2 = 94.69%, n = 13 studies). The pooled incidence for arm lymphedema was 21%, also with considerable heterogeneity (95% CI 15.0-26.0, I2 = 95.29%, n = 11 studies). There was evidence that higher body mass index (> 25) was associated with increased risk of arm lymphedema (OR: 1.98, 95% CI 1.45-2.70, I2 = 84.0%, P < 0.0001, n = 4 studies). CONCLUSION:Better understanding the factors that contribute to variability in cancer-related arm lymphedema in LMICs is an important first step to developing targeted interventions to improve quality of life. Standardising measurement of lymphedema globally and better reporting would enable comparison within the context of information about cancer treatments and lymphedema care

Increasing dominance of large lianas in Amazonian forests

Ecological orthodoxy suggests that old-growth forests should be close to dynamic equilibrium, but this view has been challenged by recent findings that neotropical forests are accumulating carbon and biomass, possibly in response to the increasing atmospheric concentrations of carbon dioxide. However, it is unclear whether the recent increase in tree biomass has been accompanied by a shift in community composition. Such changes could reduce or enhance the carbon storage potential of old-growth forests in the long term. Here we show that non-fragmented Amazon forests are experiencing a concerted increase in the density, basal area and mean size of woody climbing plants (lianas). Over the last two decades of the twentieth century the dominance of large lianas relative to trees has increased by 1.7–4.6% a year. Lianas enhance tree mortality and suppress tree growth, so their rapid increase implies that the tropical terrestrial carbon sink may shut down sooner than current models suggest. Predictions of future tropical carbon fluxes will need to account for the changing composition and dynamics of supposedly undisturbed forests

A facile method for bright, colour-tunable light-emitting diodes based on Ga-doped ZnO nanorods

© 2018 IOP Publishing Ltd. Bottom-up fabrication of nanowire-based devices is highly attractive for oxide photonic devices because of high light extraction efficiency; however, unsatisfactory electrical injection into ZnO and poor carrier transport properties of nanowires severely limit their practical applications. Here, we demonstrate that ZnO nanorods doped with Ga donors by in situ dopant incorporation during vapour-solid growth exhibit superior optoelectronic properties that exceed those currently synthesised by chemical vapour deposition, and accordingly can be electrically integrated into Si-based photonic devices. Significantly, the doping method was found to improve the nanorod quality by decreasing the concentration of point defects. Light-emitting diodes (LEDs) fabricated from the Ga-doped ZnO nanorod/p-Si heterojunction display bright and colour-tunable electroluminescence (EL). These nanorod LEDs possess a dramatically enhanced performance and an order of magnitude higher EL compared with equivalent devices fabricated with undoped nanorods. These results point to an effective route for large-scale fabrication of conductive, single-crystalline ZnO nanorods for photonic and optoelectronic applications