The effect of power stretchers on occupational injury rates in an urban emergency medical services system

BACKGROUND

To examine occupational injury rates in a dual-response emergency medical services (EMS) system before and after implementation of a power-lift stretcher system.

METHODS

The seasonally-adjusted occupational injury rate was estimated relative to medical call volume (per 1000 calls) and workers (per 100 FTEs) from 2009 to 2019, and stratified by severity (lost-time, healthcare only), role (EMS, FIRE) and type (patient-handling). Power-lift stretchers were adopted between 2013 and 2015. Preinjury versus postinjury rates were compared using binomial tests. Interrupted time series (ITS) analysis was used to estimate the trend and change in injuries related to patient-handling, with occupational illnesses serving as control.

RESULTS

Binomial tests revealed varied results, with reductions in the injury rate per 1000 calls (-14.0%) and increases in the rate per 100 FTEs (+14.1%); rates also differed by EMS role and injury severity. ITS analysis demonstrated substantial reductions in patient-handling injuries following implementation of power-lift stretchers, both in the injury rate per 1000 calls (-50.4%) and per 100 FTEs (-46.6%), specifically among individuals deployed on the ambulance. Injury rates were slightly elevated during the winter months (+0.8 per 100 FTEs) and lower during spring (-0.5 per 100 FTEs).

CONCLUSIONS

These results support the implementation of power-lift stretchers for injury prevention in EMS systems and demonstrate advantages of ITS analysis when data span long preintervention and postintervention periods.

Hibernating female big brown bats (Eptesicus fuscus) adjust huddling and drinking behaviour, but not arousal frequency, in response to low humidity

Many mammals hibernate during winter, reducing energy expenditure via bouts of torpor. The majority of a hibernator's energy reserves are used to fuel brief, but costly, arousals from torpor. Although arousals likely serve multiple functions, an important one is to restore water stores depleted during torpor. Many hibernating bat species require high humidity, presumably to reduce torpid water loss, but big brown bats (Eptesicus fuscus) appear tolerant of a wide humidity range. We tested the hypothesis that hibernating female E. fuscus use behavioural flexibility during torpor and arousals to maintain water balance and reduce energy expenditure. We predicted: (1) E. fuscus hibernating in dry conditions would exhibit more compact huddles during torpor and drink more frequently than bats in high humidity conditions; and (2) the frequency and duration of torpor bouts and arousals, and thus total loss of body mass would not differ between bats in the two environments. We housed hibernating E. fuscus in temperature- and humidity-controlled incubators at 50% or 98% relative humidity (8°C, 110 days). Bats in the dry environment maintained a more compact huddle during torpor and drank more frequently during arousals. Bats in the two environments had a similar number of arousals, but arousal duration was shorter in the dry environment. However, total loss of body mass over hibernation did not differ between treatments, indicating that the two groups used similar amounts of energy. Our results suggest that behavioural flexibility allows hibernating E. fuscus to maintain water balance and reduce energy costs across a wide range of hibernation humidities.

Chalcogen-substituted carbenes: a density functional study of structure, stability, and donor ability

Chalcogen-substituted carbenes are examined computationally using density functional theory. Several approaches are used to assess the stability and reactivity of chalcogenazol-2-ylidene carbenes (NEHCs; E = O, S, Se, Te). The known unsaturated species 1,3-dimethylimidazol-2-ylidene is studied at the same level of theory as the NEHC molecules, as a reference. Electronic structures, stability towards dimerization, and ligand properties are discussed. The results highlight the NEHCs as potentially valuable ancillary ligands for stabilizing low-valent metals or paramagnetic main group molecules. A simple, effective computational method for evaluating σ donor ability and π acidity of carbenes is presented.

'A change of heart': Indigenous perspectives from the Onjisay Aki Summit on climate change

In June 2017, the Turtle Lodge Indigenous knowledge centre convened the Onjisay Aki International Climate Summit, an unparalleled opportunity for cross-cultural dialogue on climate change with environmental leaders and Indigenous Knowledge Keepers from 14 Nations around the world. In collaboration with Turtle Lodge, the Prairie Climate Centre was invited to support the documentation and communication of knowledge shared at the Summit. This process of Indigenous-led community-based research took an inter-epistemological approach, using roundtable discussions within a ceremonial context and collaborative written and video methods. The Summit brought forward an understanding of climate change as a symptom of a much larger problem with how colonialism has altered the human condition. The Knowledge Keepers suggested that, in order to effectively address climate change, humanity needs a shift in values and behaviours that ground our collective existence in a balanced relationship with the natural world and its laws. They emphasized that their diverse knowledges and traditions can provide inspiration and guidance for this cultural shift. This underscores the need for a new approach to engaging with Indigenous knowledge in climate research, which acknowledges it not only as a source of environmental observations, but a wealth of values, philosophies, and worldviews which can inform and guide action and research more broadly. In this light, Onjisay Aki makes significant contributions to the literature on Indigenous knowledge on climate change in Canada and internationally, as well as the ways in which this knowledge is gathered, documented, and shared through the leadership of the Knowledge Keepers.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10584-021-03000-8.

Lower Nitrogen Availability Enhances Resistance to Whiteflies in Tomato

Soil nitrogen (N) supplementation via fertilizers may increase crop yields substantially. However, by increasing tissue N content, added N can make plants more attractive to herbivores, effectively reducing their resistance to herbivores (ability to avoid herbivore damage). In turn, greater pest infestation may cause more severe reductions in fruit production than a moderate N scarcity. In this study, we tested whether lower N supplementation results in greater resistance to whiteflies and lower fruit production in four tomato varieties. We assessed the effects of N availability on tolerance to herbivores (degree to which fitness is affected by damage) and tested for the long-hypothesized trade-off between resistance and tolerance. Plants grown at half of an agronomically recommended amount of N had greater resistance without a significant drop in fruit production. Tomato varieties differed in resistance and tolerance to whiteflies, and showed a clear trade-off between these modes of defense. Root:shoot ratios were greater at lower N, but had no clear relation to tolerance. We estimated that the economic benefit of decreasing N addition almost fully compensates for losses due to lower tomato production. Additionally, lower fertilization rates would contribute to reduce environmental costs of large-scale use of agrochemicals.

SuperCam Calibration Targets: Design and Development

SuperCam is a highly integrated remote-sensing instrumental suite for NASA's Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and Infrared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and evaluate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental conditions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system.