scholarly journals Chronic, sublethal effects of high temperatures will cause severe declines in southern African arid-zone birds during the 21st century

2019 ◽  
Vol 116 (28) ◽  
pp. 14065-14070 ◽  
Author(s):  
Shannon R. Conradie ◽  
Stephan M. Woodborne ◽  
Susan J. Cunningham ◽  
Andrew E. McKechnie
Keyword(s):  
Body Mass ◽  
21St Century ◽  
Sublethal Effects ◽  
Heat Waves ◽  
Arid Zone ◽  
Heat Exposure ◽  
Fitness Costs ◽  
Breeding Failure ◽  
Hot Weather ◽  
Using Data

Birds inhabiting hot, arid regions are among the terrestrial organisms most vulnerable to climate change. The potential for increasingly frequent and intense heat waves to cause lethal dehydration and hyperthermia is well documented, but the consequences of sublethal fitness costs associated with chronic exposure to sustained hot weather remain unclear. Using data for species occurring in southern Africa’s Kalahari Desert, we mapped exposure to acute lethal risks and chronic sublethal fitness costs under past, present, and future climates. For inactive birds in shaded microsites, the risks of lethal dehydration and hyperthermia will remain low during the 21st century. In contrast, exposure to conditions associated with chronic, sublethal costs related to progressive body mass loss, reduced nestling growth rates, or increased breeding failure will expand dramatically. For example, by the 2080s the region will experience 10–20 consecutive days per year on which Southern Pied Babblers (Turdoides bicolor) will lose ∼4% of body mass per day, conditions under which this species’ persistence will be extremely unlikely. Similarly, exposure to air temperature maxima associated with delayed fledging, reduced fledgling size, and breeding failure will increase several-fold in Southern Yellow-billed Hornbills (Tockus leucomelas) and Southern Fiscals (Lanius collaris). Our analysis reveals that sublethal costs of chronic heat exposure are likely to drive large declines in avian diversity in the southern African arid zone by the end of the century.

scholarly journals Heat and dehydration induced oxidative damage and antioxidant defenses following incubator heat stress and a simulated heat wave in wild caught four-striped field mice Rhabdomys dilectus

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242279
Author(s):  
Paul J. Jacobs ◽  
M. K. Oosthuizen ◽  
C. Mitchell ◽  
Jonathan D. Blount ◽  
Nigel C. Bennett
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Heat Stress ◽  
Oxidative Damage ◽  
Heat Wave ◽  
Body Mass ◽  
Heat Waves ◽  
Heat Exposure ◽  
Field Mice ◽  
The Brain

Heat waves are known for their disastrous mass die-off effects due to dehydration and cell damage, but little is known about the non-lethal consequences of surviving severe heat exposure. Severe heat exposure can cause oxidative stress which can have negative consequences on animal cognition, reproduction and life expectancy. We investigated the current oxidative stress experienced by a mesic mouse species, the four striped field mouse, Rhabdomys dilectus through a heat wave simulation with ad lib water and a more severe temperature exposure with minimal water. Wild four striped field mice were caught between 2017 and 2019. We predicted that wild four striped field mice in the heat wave simulation would show less susceptibility to oxidative stress as compared to a more severe heat stress which is likely to occur in the future. Oxidative stress was determined in the liver, kidney and brain using malondialdehyde (MDA) and protein carbonyl (PC) as markers for oxidative damage, and superoxide dismutase (SOD) and total antioxidant capacity (TAC) as markers of antioxidant defense. Incubator heat stress was brought about by increasing the body temperatures of animals to 39–40.8°C for 6 hours. A heat wave (one hot day, followed by a 3-day heatwave) was simulated by using temperature cycle that wild four striped field mice would experience in their local habitat (determined through weather station data using temperature and humidity), with maximal ambient temperature of 39°C. The liver and kidney demonstrated no changes in the simulated heat wave, but the liver had significantly higher SOD activity and the kidney had significantly higher lipid peroxidation in the incubator experiment. Dehydration significantly contributed to the increase of these markers, as is evident from the decrease in body mass after the experiment. The brain only showed significantly higher lipid peroxidation following the simulated heat wave with no significant changes following the incubator experiment. The significant increase in lipid peroxidation was not correlated to body mass after the experiment. The magnitude and duration of heat stress, in conjunction with dehydration, played a critical role in the oxidative stress experienced by each tissue, with the results demonstrating the importance of measuring multiple tissues to determine the physiological state of an animal. Current heat waves in this species have the potential of causing oxidative stress in the brain with future heat waves to possibly stress the kidney and liver depending on the hydration state of animals.

scholarly journals Avian mortality risk during heat waves will increase greatly in arid Australia during the 21st century

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Shannon R Conradie ◽  
Stephan M Woodborne ◽  
Blair O Wolf ◽  
Anaïs Pessato ◽  
Mylene M Mariette ◽  
...  
Keyword(s):  
21St Century ◽  
Mortality Risk ◽  
Heat Waves ◽  
Arid Zone ◽  
Climate Change Scenarios ◽  
Arid Environments ◽  
Zebra Finches ◽  
Tolerance Limits ◽  
Water Losses ◽  
Evaporative Water

Abstract Intense heat waves are occurring more frequently, with concomitant increases in the risk of catastrophic avian mortality events via lethal dehydration or hyperthermia. We quantified the risks of lethal hyperthermia and dehydration for 10 Australian arid-zone avifauna species during the 21st century, by synthesizing thermal physiology data on evaporative water losses and heat tolerance limits. We evaluated risks of lethal hyperthermia or exceedance of dehydration tolerance limits in the absence of drinking during the hottest part of the day under recent climatic conditions, compared to those predicted for the end of this century across Australia. Increases in mortality risk via lethal dehydration and hyperthermia vary among the species modelled here but will generally increase greatly, particularly in smaller species (~10–42 g) and those inhabiting the far western parts of the continent. By 2100 CE, zebra finches’ potential exposure to acute lethal dehydration risk will reach ~ 100 d y−1 in the far northwest of Australia and will exceed 20 d y−1 over > 50% of this species’ current range. Risks of dehydration and hyperthermia will remain much lower for large non-passerines such as crested pigeons. Risks of lethal hyperthermia will also increase substantially for smaller species, particularly if they are forced to visit exposed water sources at very high air temperatures to avoid dehydration. An analysis of atlas data for zebra finches suggests that population declines associated with very hot conditions are already occurring in the hottest areas. Our findings suggest that the likelihood of persistence within current species ranges, and the potential for range shifts, will become increasingly constrained by temperature and access to drinking water. Our model adds to an increasing body of literature suggesting that arid environments globally will experience considerable losses of avifauna and biodiversity under unmitigated climate change scenarios.

scholarly journals The impact of late-career job loss and genetic risk on body mass index: Evidence from variance polygenic scores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lauren L. Schmitz ◽  
Julia Goodwin ◽  
Jiacheng Miao ◽  
Qiongshi Lu ◽  
Dalton Conley
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Complex Traits ◽  
Job Loss ◽  
Past Research ◽  
Long Term Effects ◽  
Polygenic Scores ◽  
Show Evidence ◽  
Using Data ◽  
The Impact

AbstractUnemployment shocks from the COVID-19 pandemic have reignited concerns over the long-term effects of job loss on population health. Past research has highlighted the corrosive effects of unemployment on health and health behaviors. This study examines whether the effects of job loss on changes in body mass index (BMI) are moderated by genetic predisposition using data from the U.S. Health and Retirement Study (HRS). To improve detection of gene-by-environment (G × E) interplay, we interacted layoffs from business closures—a plausibly exogenous environmental exposure—with whole-genome polygenic scores (PGSs) that capture genetic contributions to both the population mean (mPGS) and variance (vPGS) of BMI. Results show evidence of genetic moderation using a vPGS (as opposed to an mPGS) and indicate genome-wide summary measures of phenotypic plasticity may further our understanding of how environmental stimuli modify the distribution of complex traits in a population.

scholarly journals Heat Exposure and Youth Migration in Central America and the Caribbean

2017 ◽  
Vol 107 (5) ◽  
pp. 446-450 ◽  
Author(s):  
Javier Baez ◽  
German Caruso ◽  
Valerie Mueller ◽  
Chiyu Niu
Keyword(s):  
Central America ◽  
Heat Waves ◽  
Heat Exposure ◽  
Temperature Data ◽  
Urban Centers ◽  
Standard Deviation Increase ◽  
Heat Effects ◽  
Triple Difference ◽  
The Caribbean ◽  
Youth Migration

We employ a triple difference-in-difference approach, using censuses and georeferenced temperature data, to quantify heat effects on internal migration in Central America and the Caribbean. A 1-standard deviation increase in heat would affect the lives of 7,314 and 1,578 unskilled young women and men. The effect is smaller than observed in response to droughts and hurricanes but could increase with climate change. Interestingly, youth facing heat waves are more likely to move to urban centers than when exposed to disasters endemic to the region. Research identifying the implications of these choices and interventions available to minimize distress migration is warranted.

scholarly journals Comparison of built environment adaptations to heat exposure and mortality during hot weather, West Midlands region, UK

2018 ◽  
Vol 111 ◽  
pp. 287-294 ◽  
Author(s):  
Jonathon Taylor ◽  
Paul Wilkinson ◽  
Roberto Picetti ◽  
Phil Symonds ◽  
Clare Heaviside ◽  
...  
Keyword(s):  
Built Environment ◽  
Heat Exposure ◽  
West Midlands ◽  
Hot Weather

54 Body Mass Index vs Weight-for-Length in Infancy and Cardiometabolic Outcomes at Age 8-10 Years

2021 ◽  
Vol 26 (Supplement_1) ◽  
pp. e39-e39
Author(s):  
Jean-Baptiste Roberge ◽  
Soren Harnois-Leblanc ◽  
Vanessa McNealis ◽  
Andraea van Hulst ◽  
Tracie A Barnett ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Predictive Ability ◽  
Subject Area ◽  
Overweight And Obesity ◽  
Growth Monitoring ◽  
Linear Regression Models ◽  
Eta Squared ◽  
Z Scores ◽  
Using Data

Abstract Primary Subject area Public Health and Preventive Medicine Background The WHO provides body mass index (BMI) curves for infants 0 to < 2 years old, but how these compare to the recommended method (weight-for-length [WFL]) in predicting later adiposity and cardiometabolic measures is uncertain. Objectives Our project aimed to: 1) confirm that WFL and BMI in infancy are associated with adiposity and cardiometabolic measures at 8-10 years old; and 2) compare the predictive ability of the two methods. We hypothesized that both methods would perform similarly. Design/Methods WFL and BMI Z-scores (zWFL and zBMI) at 6, 12, and 18 months of age were computed using data extracted from health booklets, used among participants in a prospective cohort study investigating the natural history of obesity and cardiovascular risk in youth (n = 464). Outcome measures at 8-10 years included adiposity, lipid profile, blood pressure, and insulin dynamics. The relationships between zWFL, zBMI, and each outcome were estimated using multivariable linear regression models. Outcome prediction at 8-10 years was compared between the two methods, using eta-squared and Lin’s concordance correlation. Results zWFL and zBMI were associated with all measures of adiposity at 8-10 years. Associations with other cardiometabolic measures were less consistent. For both zWFL and zBMI across infancy, eta-squared were highly similar and the Lin’s coefficients were markedly high (> 0.991) for all outcomes. Conclusion zBMI measured in infants appeared to be equivalent to zWFL for predicting adiposity and cardiometabolic measures in childhood. This lends support to the sole use of zBMI for growth monitoring and screening of overweight and obesity from birth to 18 years.

scholarly journals Using naturalistic incubation temperatures to demonstrate how variation in the timing and continuity of heat wave exposure influences phenotype

2020 ◽  
Vol 287 (1932) ◽  
pp. 20200992 ◽  
Author(s):  
Anthony T. Breitenbach ◽  
Amanda W. Carter ◽  
Ryan T. Paitz ◽  
Rachel M. Bowden
Keyword(s):  
Heat Wave ◽  
Time Course ◽  
Heat Waves ◽  
Heat Exposure ◽  
Effect Of Temperature ◽  
Similar Time ◽  
Expression Of Genes ◽  
Short Period ◽  
The Face ◽  
Temperature Exposure

Most organisms are exposed to bouts of warm temperatures during development, yet we know little about how variation in the timing and continuity of heat exposure influences biological processes. If heat waves increase in frequency and duration as predicted, it is necessary to understand how these bouts could affect thermally sensitive species, including reptiles with temperature-dependent sex determination (TSD). In a multi-year study using fluctuating temperatures, we exposed Trachemys scripta embryos to cooler, male-producing temperatures interspersed with warmer, female-producing temperatures (heat waves) that varied in either timing during development or continuity and then analysed resulting sex ratios. We also quantified the expression of genes involved in testis differentiation ( Dmrt1 ) and ovary differentiation ( Cyp19A1 ) to determine how heat wave continuity affects the expression of genes involved in sexual differentiation. Heat waves applied during the middle of development produced significantly more females compared to heat waves that occurred just 7 days before or after this window, and even short gaps in the continuity of a heat wave decreased the production of females. Continuous heat exposure resulted in increased Cyp19A1 expression while discontinuous heat exposure failed to increase expression in either gene over a similar time course. We report that even small differences in the timing and continuity of heat waves can result in drastically different phenotypic outcomes. This strong effect of temperature occurred despite the fact that embryos were exposed to the same number of warm days during a short period of time, which highlights the need to study temperature effects under more ecologically relevant conditions where temperatures may be elevated for only a few days at a time. In the face of a changing climate, the finding that subtle shifts in temperature exposure result in substantial effects on embryonic development becomes even more critical.

Changing Gears in the Assessment Cycle

2022 ◽  
pp. 157-182
Author(s):  
Ben Seipel ◽  
Paul Bailey ◽  
Rachel Teasdale
Keyword(s):  
21St Century ◽  
Culturally Responsive ◽  
Assessment Tools ◽  
Assessment Framework ◽  
Comprehensive University ◽  
21St Century Learners ◽  
Using Data ◽  
Postsecondary Educators ◽  
Improve Student Learning ◽  
Careful Assessment

There is an ongoing need to prepare postsecondary educators to use not only 21st century assessment tools but also 21st andragogy/pedagogy that meets the needs of all 21st century learners. This chapter reviews those issues, reviews different aspects and approaches to assessment, and proposes an encompassing assessment framework for culturally responsive, authentic, reflective, ethical, formative, universal, and learner-focused (CAREFUL) assessment. The chapter contextualizes these approaches in faculty development (FDEV) to help “change gears” using data from a FDEV opportunity at a midsized, comprehensive university. The chapter provides several examples of CAREFUL assessment and a discussion of how FDEV can improve student learning and experiences.

Physiological and morphological effects of climate change

2019 ◽  
pp. 120-133 ◽  
Author(s):  
Andrew E. McKechnie
Keyword(s):  
Climate Change ◽  
Body Mass ◽  
High Temperatures ◽  
Arid Zone ◽  
Future Research ◽  
Long Term Effects ◽  
Adaptation To Climate Change ◽  
Heat Events

The direct impacts of higher temperatures on birds are manifested over timescales ranging from minutes and hours to years and decades. Over short timescales, acute exposure to high temperatures can lead to hyperthermia or dehydration, which among arid-zone species occasionally causes catastrophic mortality events. Over intermediate timescales of days to weeks, high temperatures can have chronic sub-lethal effects via body mass loss or reduced nestling growth rates, negatively affecting sev eral fitness components. Long-term effects of warming manifested over years to decades involve declining body mass or changes in appendage size. Key directions for future research include elucidating the role of phenotypic plasticity and epigenetic processes in avian adaptation to climate change, examining the role of stress pathways in mediating responses to heat events, and understanding the consequences of higher temperatures for species that traverse hot regions while migrating.

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