A Data Cube Extraction Pipeline for a Coronagraphic Integral Field Spectrograph

Project 1640 is a high contrast near-infrared instrument probing the vicinities of nearby stars through the unique combination of an integral field spectrograph with a Lyot coronagraph and a high-order adaptive optics system. The extraordinary data reduction demands, similar those which several new exoplanet imaging instruments will face in the near future, have been met by the novel software algorithms described herein. The Project 1640 Data Cube Extraction Pipeline (PCXP) automates the translation of 3.8*10^4 closely packed, coarsely sampled spectra to a data cube. We implement a robust empirical model of the spectrograph focal plane geometry to register the detector image at sub-pixel precision, and map the cube extraction. We demonstrate our ability to accurately retrieve source spectra based on an observation of Saturn's moon Titan.Comment: 35 pages, 15 figures; accepted for publication in PAS

An evidence-based method for targeting an abusive head trauma prevention media campaign and its evaluation

BACKGROUND: A triple-dose abusive head trauma (AHT) prevention program (Period of PURPLE Crying) was implemented. The third dose consisted of an education media campaign. The study objectives were to describe the qualitative and spatial methods developed to target AHT prevention and to evaluate this campaign. METHODS: A questionnaire on the level of importance of factors, rated on a 7-point Likert scale, was distributed to a panel of experts to determine the best advertising locations. Ranked factors were used to create weights for statistical modeling and mapping within a Geographic Information Systems to determine optimal ad locations. The media campaign was evaluated via a telephone survey of randomly selected households. RESULTS: The survey found locations of new families, high population density, and high percentage of lone parents to be the most important factors for selecting billboard sites. Spatial analysis revealed six areas that ranked highest in our factors. Five billboards, four media posters, and six transit shelters were selected for our advertisements. A population-based telephone survey revealed that 23% of respondents knew the campaign. Nearly half (42%) heard the radio public service announcements, and 9% saw billboards. CONCLUSION: Extending primary prevention efforts to the public helps to create a cultural change in the way inconsolable crying, the trigger for AHT, is viewed. With the use of ranked factors and Geographic Information Systems, geographic locations with high visibility and specific risk factors for AHTwere identified for targeting the campaign, facilitating the likelihood that our message was reaching the population in greatest need

Social Media and Well-being: A Methodological Perspective

Due to the methodological challenges inherent in studying social media use (SMU), as well as the methodological choices that have shaped research into the effects of SMU on well-being, clear conclusions regarding relationships between SMU and well-being remain elusive. We provide a review of five methodological developments poised to provide increased understanding in this domain: (1) increased use of longitudinal and experimental designs; (2) the adoption of behavioural (rather than self-report) measures of SMU; (3) focusing on more nuanced aspects of SMU; (4) embracing effect heterogeneity; and (5) the use of formal modelling and machine learning. We focus on how these advances stand to bring us closer to understanding relations between SMU and well-being, as well as the challenges associated with these developments

In-Lecture Media Use and Academic Performance: Investigating Demographic and Intentional Moderators

The growing prevalence of continuous media use among university students in lecture environments has potential for detrimental effects. In this study we investigate the relationships between in-lecture media use and academic performance. Previous studies have shown that students frequently engage with digital media whilst in university lectures. Moreover, multitasking imposes cognitive costs detrimental to learning and task execution. We propose, accordingly, that the constant distractions created by digital media, interrupt the thought and communication processes of students during lectures and, subsequently, obstruct their ability to learn. To test this proposition we conducted a survey-based empirical investigation of digital media use and academic performance among undergraduate university students. A significant negative correlation was found between the number of in-lecture media use instances and academic performance. Furthermore, this effect was found to be pervasive independent of individual demographic factors and the intention with which a medium was used

Constraining mass ratio and extinction in the FU Orionis binary system with infrared integral field spectroscopy

We report low resolution near infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0.5" south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J and H band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low resolution near infrared spectrum in conjunction with 10.2 micron interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, A_V =8-12, with an effective temperature of ~ 4000-6500 K . Finally we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary syste

How well do large-scale models reproduce regional hydrological extremes in Europe?

This paper presents a new methodology for assessing the ability of gridded hydrological models to reproduce large-scale hydrological high and low flow events (as a proxy for hydrological extremes) as described by catalogues of historical droughts [using the regional deficiency index (RDI)] and high flows [regional flood index (RFI)] previously derived from river flow measurements across Europe. Using the same methods, total runoff simulated by three global hydrological models from the Water Model Intercomparison Project (WaterMIP) [Joint U.K. Land Environment Simulator (JULES), Water Global Assessment and Prognosis (WaterGAP), and Max Planck Institute Hydrological Model (MPI-HM)] run with the same meteorological input (watch forcing data) at the same spatial 0.58 grid was used to calculate simulated RDI and RFI for the period 1963-2001 in the same European regions, directly comparable with the observed catalogues. Observed and simulated RDI and RFI time series were compared using three performance measures: the relative mean error, the ratio between the standard deviation of simulated over observed series, and the Spearman correlation coefficient. Results show that all models can broadly reproduce the spatiotemporal evolution of hydrological extremes in Europe to varying degrees. JULES tends to produce prolonged, highly spatially coherent events for both high and low flows, with events developing more slowly and reaching and sustaining greater spatial coherence than observed-this could be due to runoff being dominated by slow-responding subsurface flow. In contrast, MPI-HM shows very high variability in the simulated RDI and RFI time series and a more rapid onset of extreme events than observed, in particular for regions with significant water storage capacity-this could be due to possible underrepresentation of infiltration and groundwater storage, with soil saturation reached too quickly. WaterGAP shares some of the issues of variability with MPIHM- also attributed to insufficient soil storage capacity and surplus effective precipitation being generated as surface runoff-and some strong spatial coherence of simulated events with JULES, but neither of these are dominant. Of the three global models considered here, WaterGAP is arguably best suited to reproduce most regional characteristics of large-scale high and low flow events in Europe. Some systematic weaknesses emerge in all models, in particular for high flows, which could be a product of poor spatial resolution of the input climate data (e.g., where extreme precipitation is driven by local convective storms) or topography. Overall, this study has demonstrated that RDI and RFI are powerful tools that can be used to assess how well large-scale hydrological models reproduce large-scale hydrological extremes-an exercise rarely undertaken in model intercomparisons. © 2011 American Meteorological Society

Career success across the globe: Insights from the 5C project

The Cross-Cultural Collaboration on Contemporary Careers (5C Project) conducted in-depth, longitudinal qualitative research into what career success means to people in a diverse range of countries; specifically: Australia, Austria, Belgium, Brazil, Canada, China, Colombia, Costa Rica, Finland, France, Germany, Greece, India, Israel, Italy, Japan, Korea, Malaysia, Mexico, Netherlands, Nigeria, Norway, Philippines, Portugal, Russian Federation, Serbia, Slovakia, Slovenia, South Africa, Spain, Thailand, Turkey, UK, and USA. This paper presents the seven major meanings of career success that emerged across these diverse global cultures and thus may be deemed relevant all around the world. These are financial security (being able to consistently provide the basic necessities for living), financial achievement (steadily making more money, wealth, incentives, and perks), learning and development (via continuous informal learning on the job and/or formal training and education), work-life-balance (between work and non-work, relationships, activities and interests), positive relationships (as signified by, for instance, enjoying working with people who you respect and admire), positive impact (by helping others in one’s immediate social environment and/or leaving some sort of legacy to a community, or society more broadly), and entrepreneurship founding one’s own enterprise or being able to invent and develop one’s own projects within the work context). We describe examples of each from different cultures and offer practical implications of these meanings for the primary stakeholders of career research: individuals, organizations, as well as counselors, coaches and consultants

Working in a post Covid-19 world : towards a conceptual framework for distributed work

CITATION: Henry, M. S., Le Roux, D. B. & Parry, D. A. 2019. Working in a post Covid-19 world : towards a conceptual framework for distributed work. South African Journal of Business Management, 52(1):a2155, doi:10.4102/sajbm.v52i1.2155.The original publication is available at https://sajbm.orgPurpose: Against the backdrop of the increased prevalence of telework practices as a result of Covid-19, the purpose of the present article is to address the conceptual confusion, overlap and ambiguity characterising much of the published literature in this domain through the development of an integrated conceptual framework describing distributed work practices at various levels of organisations. Design/methodology/approach: To develop the framework, a collection of definitions for distributed work concepts were systematically selected and reviewed. These concepts include telework, remote work, distributed work and virtual work, as well as telecommuting, virtual teams, virtual organisations and distributed organisations. The reviewed definitions were systematically analysed to elicit the key principles underlying each concept, and then integrated to produce the conceptual framework. Findings: Our analysis suggests that virtuality and distributedness can be defined as distinct continua which, when combined, can be used to describe particular work settings. Additionally, we identify four factors which impact organisational policy in terms of virtuality and distributedness: interdependence of tasks, nature of work, technological environment and temporal distance. Practical implications: The framework offers managers a foundation for establishing distributed work policies and determining policy implications. Additionally, researchers conducting empirical investigations of distributed work practices can utilise the framework to differentiate between and describe particular work settings. Originality/value: The conceptual integration of virtuality, distributedness and organisational levels present a novel and important development. As organisations adapt to the effects of the Covid-19 pandemic, the framework we propose serves as a useful artefact to support and inform their decision making.https://sajbm.org/index.php/sajbm/article/view/2155Publisher's versio

A New High Contrast Imaging Program at Palomar Observatory

We describe a new instrument that forms the core of a long-term high contrast imaging program at the 200-inch Hale Telescope at Palomar Observatory. The primary scientific thrust is to obtain images and low-resolution spectroscopy of brown dwarfs and young Jovian mass exoplanets in the vicinity of stars within 50 parsecs of the Sun. The instrument is a microlens-based integral field spectrograph integrated with a diffraction limited, apodized-pupil Lyot coronagraph, mounted behind the Palomar adaptive optics system. The spectrograph obtains imaging in 23 channels across the J and H bands (1.06 - 1.78 microns). In addition to obtaining spectra, this wavelength resolution allows suppression of the chromatically dependent speckle noise, which we describe. We have recently installed a novel internal wave front calibration system that will provide continuous updates to the AO system every 0.5 - 1.0 minutes by sensing the wave front within the coronagraph. The Palomar AO system is undergoing an upgrade to a much higher-order AO system ("PALM-3000"): a 3388-actuator tweeter deformable mirror working together with the existing 241-actuator mirror. This system will allow correction with subapertures as small as 8cm at the telescope pupil using natural guide stars. The coronagraph alone has achieved an initial dynamic range in the H-band of 2 X 10^-4 at 1 arcsecond, without speckle noise suppression. We demonstrate that spectral speckle suppression is providing a factor of 10-20 improvement over this bringing our current contrast at an arcsecond to ~2 X 10^-5. This system is the first of a new generation of apodized pupil coronagraphs combined with high-order adaptive optics and integral field spectrographs (e.g. GPI, SPHERE, HiCIAO), and we anticipate this instrument will make a lasting contribution to high contrast imaging in the Northern Hemisphere for years.Comment: Accepted to PASP: 12 pages, 12 figure