1,810 research outputs found

    Multi-Lifespan Information System Design

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    Contemporary information ecosystems evolve at lightening speed. Last year’s cutting edge innovations are this year’s standard fare and next year’s relics. An information innovation can be implemented, made available through the Internet, and appropriated within 24 hours. Yet, significant societal problems engage much longer timeframes. In 2010 Friedman and Nathan pointed to a fundamental disconnect between mainstream design thinking and these longer-term problems. To address this disconnect, they proposed a multi-lifespan information system design framing. This workshop builds on previous work by the organizers and others to: (1) elaborate and identify new opportunities and challenges in taking up multi-lifespan information system design problems, and (2) generate critical and constructive discussions for further development of multi- lifespan information system design thinking.

    Effects of Low-Level Artificial Light at Night on Kentucky Bluegrass and Introduced Herbivore

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    Increasing evidence suggests that artificial light at night (ALAN) can negatively impact organisms. However, most studies examine the impacts of ALAN on a single species or under high levels of artificial light that are infrequent or unrealistic in urban environments. We currently have little information on how low levels of artificial light emanating from urban skyglow affect plants and their interactions with herbivores. We examined how low levels of ALAN affect grass and insects, including growth rate, photosynthesis, and stomatal conductance in grass, and foraging behavior and survival in crickets. We compared growth and leaf-level gas exchange of Kentucky Bluegrass (Poa pratensis) under low-levels of ALAN (0.3 lux) and starlight conditions (night light at 0.001 lux). Furthermore, each light treatment was divided into treatments with and without house crickets (Acheta domesticus). Without crickets present, bluegrass grown under artificial light at night for three weeks grew taller than plants grown under natural night light levels. Once crickets were introduced at the end of week three, grass height decreased resulting in no measurable effects of light treatment. There were no measurable differences in grass physiology among treatments. Our results indicate that low levels of light resulting from skyglow affect plant growth initially. However, with herbivory, ALAN effects on grass may be inconsequential. Gaining an understanding of how ALAN affects plant-insect interactions is critical to predicting ecological and evolutionary consequences of anthropogenic disturbance

    Spectroscopy of Isolated Prebiotic Nucleobases

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    We use multiphoton ionization and double resonance spectroscopy to study the excited state dynamics of biologically relevant molecules as well as prebiotic nucleobases, isolated in the gas phase. Molecules that are biologically relevant to life today tend to exhibit short excited state lifetimes compared to similar but non-biologically relevant analogs. The mechanism is internal conversion, which may help protect the biologically active molecules from UV damage. This process is governed by conical intersections that depend very strongly on molecular structure. Therefore we have studied purines and pyrimidines with systematic variations of structure, including substitutions, tautomeric forms, and cluster structures that represent different base pair binding motifs. These structural variations also include possible alternate base pairs that may shed light on prebiotic chemistry. With this in mind we have begun to probe the ultrafast dynamics of molecules that exhibit very short excited states and search for evidence of internal conversions

    Collections Of Trauma: Exploring Generative Frictions

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    Through this paper we identify systemic challenges that face efforts to ethically steward collections of trauma in a conflict-ridden world. Our scholarly reflections are grounded in the context of a centre being created to hold materials related to Canada’s ongoing Truth and Reconciliation Commission. We report on initial discussions with those involved in the Centre’s development and our ongoing review of court documents and media accounts related to the Centre. We call attention to the amalgamation of socio-technical, political, and legal structures that influence the actions of those managing collections of trauma. We highlight how those involved in the Centre’s development (including the researchers) are participants in and descendants of Canada’s legacy of colonizing initiatives. We identify generative frictions related to issues of conflict, plurality, agency, and distrust that underlie the design and management of collections of trauma. These reflections guide our ongoing investigation.ye

    Safety Recommendations for Evaluation and Surgery of the Head and Neck During the COVID-19 Pandemic

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    Importance The rapidly expanding novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged the medical community to an unprecedented degree. Physicians and health care workers are at added risk of exposure and infection during the course of patient care. Because of the rapid spread of this disease through respiratory droplets, health care workers who come in close contact with the upper aerodigestive tract during diagnostic and therapeutic procedures, such as otolaryngologists–head and neck surgeons, are particularly at risk. A set of safety recommendations was created based on a review of the literature and communications with physicians with firsthand knowledge of safety procedures during the COVID-19 pandemic. Observations A high number of health care workers were infected during the first phase of the pandemic in the city of Wuhan, China. Subsequently, by adopting strict safety precautions, other regions were able to achieve high levels of safety for health care workers without jeopardizing the care of patients. The most common procedures related to the examination and treatment of upper aerodigestive tract diseases were reviewed. Each category was reviewed based on the potential risk imposed to health care workers. Specific recommendations were made based on the literature, when available, or consensus best practices. Specific safety recommendations were made for performing tracheostomy in patients with COVID-19. Conclusions and Relevance Preserving a highly skilled health care workforce is a top priority for any community and health care system. Based on the experience of health care systems in Asia and Europe, by following strict safety guidelines, the risk of exposure and infection of health care workers could be greatly reduced while providing high levels of care. The provided recommendations, which may evolve over time, could be used as broad guidance for all health care workers who are involved in the care of patients with COVID-19

    Evaluating the validity and applicable domain of the toxic load model: Impact of concentration vs. time profile on inhalation lethality of hydrogen cyanide

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    The ten Berge model (or ‘‘toxic load’’ model) is often used to estimate the acute toxicity for varying combinations of inhaled concentration and duration. Expressed as Cn X t = toxic load (TL), TLs are assumed constant for various combinations of concentration (C) and time (t). Experimental data in a recent acute inhalation study of rats exposed to time-varying concentrations of hydrogen cyanide (HCN) supported the validity of the toxic load model except under very brief, discontinuous, high concentration exposures. In the present investigation, experiments were conducted to extend the evaluation of the applicable domain of the model for acute lethality of HCN in the rat (cumulative exposure range of 2900–11,000 ppm min). The lethality of HCN over very short (\u3c5 min) durations of high concentrations did not conform to the toxic load model. A value of n = 1.57 was determined for uninterrupted exposures P5 min. For 30-min exposures, the presence or absence of a gap between two exposure pulses of different concentrations, the relative duration, relative height, and the ordering of the pulses (low then high, vs. high then low) did not appear to have a meaningful impact on the toxic load required for median lethality

    Fighting the flinch : experimentally induced compassion makes a difference in healthcare providers

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    Objectives: Although healthcare providers are required to sustain care in difficult circumstances, some patients challenge this principle. Evoking compassion seems likely to be helpful in such situations. This research aimed to evaluate whether inducing compassion in healthcare providers might mitigate disengagement with patients who have challenging presenting features such as those with disgusting symptoms and/or are to blame for their own health problems. Design: An online experimental study with clinical healthcare providers. Methods: Medical students (n=219) and qualified healthcare professionals (n=108) took part in an online experiment. Participants were randomised to view a slideshow of either neutral images (control) or compassion-inducing images (compassion condition) and were then presented with a series of patient vignettes where presenting problems systematically varied on patient responsibility and disgusting symptoms. Engagement was assessed by asking participants how caring they felt, how much they would want to help, how challenging it would be, and whether they would wear a mask. Results: Participants reported less engagement with patients who were responsible for their illness and who presented with disgusting symptoms. Induced compassion offset disengagement and qualified health professionals were more caring and willing to help patients than medical students. The compassion induction eliminated some differences between experienced and trainee clinicians. Conclusions: This research demonstrates that disgust and patient responsibility impacts clinical engagement and that medical students are more impacted by such scenarios than qualified health providers. Inducing compassion may help to mitigate these differences and further investigation into strategies that foster engagement with difficult patients is warranted

    Locally Contingent and Community-Dependent: Tools and Technologies for Indigenous Language Mobilization

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    2021. Jennifer Carpenter, Annie Guerin, Michelle Kaczmarek, Gerry Lawson, Kim Lawson, Lisa P. Nathan and Mark Turin. “Locally Contingent and Community-Dependent: Tools and Technologies for Indigenous Language Mobilization.” In Indigenous Languages and the Promise of Archives, edited by Adrianna Link, Abigail Shelton, and Patrick Spero, 125–55. Lincoln: University of Nebraska Press

    Design and Construction of Absorption Cells for Precision Radial Velocities in the K Band using Methane Isotopologues

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    We present a method to optimize absorption cells for precise wavelength calibration in the near-infrared. We apply it to design and optimize methane isotopologue cells for precision radial velocity measurements in the K band. We also describe the construction and installation of two such cells for the CSHELL spectrograph at NASA's IRTF. We have obtained their high-resolution laboratory spectra, which we can then use in precision radial velocity measurements and which can also have other applications. In terms of obtainable RV precision methane should out-perform other proposed cells, such as the ammonia cell (14^{14}NH3_{3}) recently demonstrated on CRIRES/VLT. The laboratory spectra of Ammonia and the Methane cells show strong absorption features in the H band that could also be exploited for precision Doppler measurements. We present spectra and preliminary radial velocity measurements obtained during our first-light run. These initial results show that a precision down to 20-30 m s−1^{-1} can be obtained using a wavelength interval of only 5 nm in the K band and S/N∌\sim150. This supports the prediction that a precision down to a few m s−1^{-1} can be achieved on late M dwarfs using the new generation of NIR spectrographs, thus enabling the detection of terrestrial planets in their habitable zones. Doppler measurements in the NIR can also be used to mitigate the radial velocity jitter due to stellar activity enabling more efficient surveys on young active stars.Comment: accepted PASP, Apr 2012 (in press). Preprint version with 36 pages, 9 Figures, 2 Table
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