1
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Characterization of sinoatrial automaticity in Microcebus murinus to study the effect of aging on cardiac activity and the correlation with longevity. Sci Rep 2023; 13:3054. [PMID: 36810863 PMCID: PMC9944915 DOI: 10.1038/s41598-023-29723-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 02/09/2023] [Indexed: 02/24/2023] Open
Abstract
Microcebus murinus, or gray mouse lemur (GML), is one of the smallest primates known, with a size in between mice and rats. The small size, genetic proximity to humans and prolonged senescence, make this lemur an emerging model for neurodegenerative diseases. For the same reasons, it could help understand how aging affects cardiac activity. Here, we provide the first characterization of sinoatrial (SAN) pacemaker activity and of the effect of aging on GML heart rate (HR). According to GML size, its heartbeat and intrinsic pacemaker frequencies lie in between those of mice and rats. To sustain this fast automaticity the GML SAN expresses funny and Ca2+ currents (If, ICa,L and ICa,T) at densities similar to that of small rodents. SAN automaticity was also responsive to β-adrenergic and cholinergic pharmacological stimulation, showing a consequent shift in the localization of the origin of pacemaker activity. We found that aging causes decrease of basal HR and atrial remodeling in GML. We also estimated that, over 12 years of a lifetime, GML generates about 3 billion heartbeats, thus, as many as humans and three times more than rodents of equivalent size. In addition, we estimated that the high number of heartbeats per lifetime is a characteristic that distinguishes primates from rodents or other eutherian mammals, independently from body size. Thus, cardiac endurance could contribute to the exceptional longevity of GML and other primates, suggesting that GML's heart sustains a workload comparable to that of humans in a lifetime. In conclusion, despite the fast HR, GML replicates some of the cardiac deficiencies reported in old people, providing a suitable model to study heart rhythm impairment in aging. Moreover, we estimated that, along with humans and other primates, GML presents a remarkable cardiac longevity, enabling longer life span than other mammals of equivalent size.
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2
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City comfort: weaker metabolic response to changes in ambient temperature in urban red squirrels. Sci Rep 2023; 13:1393. [PMID: 36697502 PMCID: PMC9876937 DOI: 10.1038/s41598-023-28624-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
The ecophysiological responses of species to urbanisation reveal important information regarding the processes of successful urban colonization and biodiversity patterns in urban landscapes. Investigating these responses will also help uncover whether synurban species are indeed urban 'winners'. Yet we still lack basic knowledge about the physiological costs and overall energy budgets of most species living in urban habitats, especially for mammals. Within this context, we compared the energetic demands of Eurasian red squirrels (Sciurus vulgaris) from the core of an urban environment with those from a nearby forest. We measured oxygen consumption as a proxy for resting metabolic rate (RMR) of 20 wild individuals (13 urban, 7 forest), at naturally varying ambient temperature (Ta) in an outdoor-enclosure experiment. We found that the variation in RMR was best explained by the interaction between Ta and habitat, with a significant difference between populations. Urban squirrels showed a shallower response of metabolic rate to decreasing Ta than woodland squirrels. We suggest that this is likely a consequence of urban heat island effects, as well as widespread supplemental food abundance. Our results indicate energy savings for urban squirrels at cooler temperatures, yet with possible increased costs at higher temperatures compared to their woodland conspecifics. Thus, the changed patterns of metabolic regulation in urban individuals might not necessarily represent an overall advantage for urban squirrels, especially in view of increasing temperatures globally.
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3
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Marsden GE, Schoeman MC, Vosloo D. Rewarming rates of seven insectivorous bat species along an altitudinal gradient in South Africa. J Therm Biol 2022; 110:103341. [DOI: 10.1016/j.jtherbio.2022.103341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 08/11/2022] [Accepted: 09/20/2022] [Indexed: 10/14/2022]
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4
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Petrullo L, Delaney D, Boutin S, McAdam AG, Lane JE, Boonstra R, Palme R, Dantzer B. The glucocorticoid response to environmental change is not specific to agents of natural selection in wild red squirrels. Horm Behav 2022; 146:105262. [PMID: 36191397 DOI: 10.1016/j.yhbeh.2022.105262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/30/2022] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Evolutionary endocrinology aims to understand how natural selection shapes endocrine systems and the degree to which endocrine systems themselves can induce phenotypic responses to environmental changes. Such responses may be specialized in that they reflect past selection for responsiveness only to those ecological factors that ultimately influence natural selection. Alternatively, endocrine responses may be broad and generalized, allowing organisms to cope with a variety of environmental changes simultaneously. Here, we empirically tested whether the endocrine response of female North American red squirrels (Tamiasciurus hudsonicus) was specialized or generalized. We first quantified the direction and magnitude of natural selection acting on three female life history traits (parturition date, litter size, offspring postnatal growth rate) during 32 years of fluctuations in four potential ecological agents of selection (food availability, conspecific density, predator abundance, and temperature). Only three of the four variables (food, density, and predators) affected patterns of natural selection on female life history traits. We then quantified fecal glucocorticoid metabolites (FGMs) across 7 years and found that all four environmental variables, regardless of their effects on patterns of selection, were associated with glucocorticoid production. Our results provide support for a generalized, rather than specific, glucocorticoid response to environmental change that can integrate across multiple co-occurring environmental stressors.
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Affiliation(s)
- Lauren Petrullo
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA.
| | - David Delaney
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Andrew G McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, Centre for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, ON M1C 1A6, Canada
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterina ̈rplatz 1, Vienna 1210, Austria
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48108, USA
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5
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Behavioural adjustments of predators and prey to wind speed in the boreal forest. Oecologia 2022; 200:349-358. [PMID: 36175692 DOI: 10.1007/s00442-022-05266-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/19/2022] [Indexed: 10/14/2022]
Abstract
Wind speed can have multifaceted effects on organisms including altering thermoregulation, locomotion, and sensory reception. While forest cover can substantially reduce wind speed at ground level, it is not known if animals living in forests show any behavioural responses to changes in wind speed. Here, we explored how three boreal forest mammals, a predator and two prey, altered their behaviour in response to average daily wind speeds during winter. We collected accelerometer data to determine wind speed effects on activity patterns and kill rates of free-ranging red squirrels (n = 144), snowshoe hares (n = 101), and Canada lynx (n = 27) in Kluane, Yukon from 2015 to 2018. All 3 species responded to increasing wind speeds by changing the time they were active, but effects were strongest in hares, which reduced daily activity by 25%, and lynx, which increased daily activity by 25%. Lynx also increased the number of feeding events by 40% on windy days. These results highlight that wind speed is an important abiotic variable that can affect behaviour, even in forested environments.
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6
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Maloney CM, Careau V. Individual variation in heat substitution: is activity in the cold energetically cheaper for some individuals than others? J Exp Biol 2022; 225:276466. [PMID: 36036801 DOI: 10.1242/jeb.244186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 08/25/2022] [Indexed: 11/20/2022]
Abstract
In many endotherms, a potentially important yet often overlooked mechanism to save energy is the use of the heat generated by active skeletal muscles to replace heat that would have been generated by thermogenesis (i.e., "activity-thermoregulatory heat substitution"). While substitution has been documented numerous times, the extent of individual variation in substitution has never been quantified. Here, we used a home-cage respirometry system to repeatedly measure substitution through the concomitant monitoring of metabolic rate (MR) and locomotor activity in 46 female white-footed mice (Peromyscus leucopus). A total of 117 measures of substitution were taken by quantifying the difference in the slope of the relationship between MR and locomotor activity speed at two different ambient temperatures. Consistency repeatability (±se) of substitution was 0.313±0.131 - hence, about a third of the variation in substitution occurs at the among-individual level. Body length and heart mass were positively correlated with substitution whereas surface area was negatively correlated with substitution. These two sub-organismal traits accounted for the majority of the among-individual variation (i.e., individual differences in substitution were not significant after accounting for these traits). Overall, our results imply that the energetic cost of activity below the thermoneutral zone is consistently cheaper from some individuals than others, and that the energy saved from substitution might be available to invest in fitness-enhancing activities.
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Affiliation(s)
- Caroline M Maloney
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Vincent Careau
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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7
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Zhang VY, Gagorik CN, Brenner LJ, Boser CL, Theimer TC, Buck CL. Interspecific Asymmetries in Behavioral Plasticity Drive Seasonal Patterns of Temporal Niche Partitioning in an Island Carnivore Community. Integr Comp Biol 2022; 62:998-1011. [PMID: 35803500 DOI: 10.1093/icb/icac113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/08/2022] [Accepted: 06/30/2022] [Indexed: 11/12/2022] Open
Abstract
Animals vary considerably in the amount of behavioral plasticity they exhibit in daily activity timing and temporal niche switching. It is not well understood how environmental factors drive changes in temporal activity or how interspecific differences in the plasticity of activity timing ultimately manifest in free-living animals. Here, we investigated the temporal structure and organization of activity patterns of two insular mammalian carnivores living in sympatry, the island fox (Urocyon littoralis) and island spotted skunk (Spilogale gracilis amphiala). Using collar-mounted accelerometers, we assessed the plasticity of behavioral activity rhythms in foxes and skunks by investigating how environmental factors drive the distribution of locomotor activity across the day and year, and subsequently examined the dynamics of temporal niche overlap between the two species. We documented that foxes express phenotypic plasticity in daily activity timing across the year, ranging from nocturnal to diurnal to crepuscular rhythms depending on individual and time of year. Most notably, foxes increased the proportion of daytime activity as seasonal temperatures decreased. Overall, activity patterns of foxes were consistent with the circadian thermoenergetics hypothesis, which posits that animals that switch their patterns of activity do so to coincide with the most energetically favorable time of day. In contrast to foxes, skunks exhibited little behavioral plasticity, appearing strictly nocturnal across the year. While the duration of skunk activity bouts increased with the duration of night, timing of activity onset and offset extended into daytime hours during summer when the duration of darkness was shortest. Analysis of temporal niche overlap between foxes and skunks suggested that niche overlap was highest during summer and lowest during winter and was dictated primarily by temporal niche switching in foxes, rather than skunks. Collectively, our results highlight how interspecific asymmetries in behavioral plasticity drive dynamic patterns of temporal niche overlap within an island carnivore community.
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Affiliation(s)
- Victor Y Zhang
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | | | | | | | - Tad C Theimer
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
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8
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Apprehending the Effect of Internet of Things (IoT) Enables Big Data Processing through Multinetwork in Supporting High-Quality Food Products to Reduce Breast Cancer. J FOOD QUALITY 2022. [DOI: 10.1155/2022/2275517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Medical science in recent times has witnessed the large implications of AI-based IoT approaches that made the clinical process easier than before. However, effective IoT technologies can connect as well as exchange necessary clinical data with other healthcare systems and devices conducted across the vast Internet facilities. With the help of IoT-enabled big data processing technologies, physicians can measure accurate weight, blood pressure, and daily symptoms related to spreading breast cancer cases across the globe. Utilizing IoT is essential for providing proper medical assistance, treatment, and detection at the initial stages within the healthcare environment regulated by the facilities of the Internet of Things. The implementation of IoT-based big data processes food products for supporting the detection and prevention of breast cancer. The study supports in making a critical analysis on the role of IoT in the big data mainly in cancer detection and increasing the quality of food products. The study’s main scope is to employ IoT-enabled big data processing to aid in the identification of breast cancer. However, the research is mainly focused on studying the assistance offered to healthcare professionals and others in identifying the disease effectively. The overall research study is going to investigate the role of IoT in the early detection of breast cancer symptoms. A total of 20 women were studied and certain factors have been identified which are the early symptoms of breast cancer and can potentially cause breast cancer. These include age, family history, breast density, and breast temperature (independent variables). A dependent variable has been selected: probability of breast cancer occurrence. After that, linear regression analysis has been carried out to understand how the independent variables impact the dependent variable. Findings showed that age, family history of cancer, breast density, and breast temperature are some measurable factors for breast cancer detection. The work contributes to a critical investigation of the function of IoT in big data, specifically in cancer detection and improving food product quality. Age acceleration increases the risk of breast cancer development; breast temperature increases slightly during cancer formation, and breast density has a positive impact on cancer development. Lastly, this study has provided a future scope of using IoT in cancer detection and prevention.
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9
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Menzies A, Studd EK, Seguin JL, Derbyshire RE, Murray D, Boutin S, Humphries MM. Activity, heart rate, and energy expenditure of a cold-climate mesocarnivore, the Canada lynx. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2021-0142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The energetic consequences of body size, behaviour, and fine-scale environmental variation remain understudied, particularly among free-ranging carnivores, due to logistical and methodological challenges of studying them in the field. Here, we present novel activity, heart rate, and metabolic data on free-ranging Canada lynx (Lynx canadensis Kerr, 1792) to a) investigate intraspecific patterns of energy expenditure, particularly how they relate to body size, environmental conditions, and activity variation, and b) position lynx - a cold-climate, mesocarnivore - within interspecific allometries of carnivore energetics. Lynx demonstrated limited behavioural and metabolic responses to environmental conditions, despite extreme cold and moderate snow depths during our study, but marked body size patterns with larger lynx having higher activity and lower resting heart rate than smaller lynx. Compared to similar-sized carnivores, lynx were less active and had lower heart rate, likely due to their ambush hunting style, but higher energy expenditure, likely due to their cold-climate existence and access to abundant prey. Overall, lynx were more similar to other ambush hunters than to sympatric cold-climate species and mesocarnivores. Our data provide insight into the relative importance of abiotic and biotic drivers of carnivore energetics and the ways in which predators maintain energy balance in variable environments.
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Affiliation(s)
- Allyson Menzies
- University of Guelph School of Environmental Sciences, 170218, Guelph, Ontario, Canada, N1G 2W1
| | | | - Jacob Luc Seguin
- Wildlife Conservation Society Canada, Thunder Bay, Ontario, Canada
| | - Rachael Elizabeth Derbyshire
- Trent University, Biology, DNA B 108.8, 1600 West Bank Drive, Peterborough, Ontario, Canada, K9L 0G2,
- 204-180 Edingburgh St.Peterborough, Ontario, Canada, K9H 3E2,
| | - D.L. Murray
- Departments of Biology and Environmental, Studies, Trent University, Peterborough, Ontario, Canada, K9J 7B8
| | - Stan Boutin
- University of Alberta, Department of Biological Sciences, Cw405 Biological Sciences, Edmonton, Alberta, Canada, T6G 2E9
| | - Murray M Humphries
- McGill University, Natural Resource Sciences, 21111 Lakeshore, Ste-Ane-de-Bellevue, Quebec, Canada, H9X 3V9
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10
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Wild TA, Wikelski M, Tyndel S, Alarcón‐Nieto G, Klump BC, Aplin LM, Meboldt M, Williams HJ. Internet on animals: Wi‐Fi‐enabled devices provide a solution for big data transmission in biologging. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13798] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Timm A. Wild
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
- Department of Biology University of Konstanz Konstanz Germany
- Product Development Group Zurich (pd z) ETH Zürich Zürich Switzerland
| | - Martin Wikelski
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
- Department of Biology University of Konstanz Konstanz Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Konstanz Germany
| | - Stephen Tyndel
- Cognitive and Cultural Ecology Research Group Max Planck Institute of Animal Behavior Radolfzell Germany
| | - Gustavo Alarcón‐Nieto
- Cognitive and Cultural Ecology Research Group Max Planck Institute of Animal Behavior Radolfzell Germany
| | - Barbara C. Klump
- Cognitive and Cultural Ecology Research Group Max Planck Institute of Animal Behavior Radolfzell Germany
| | - Lucy M. Aplin
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Konstanz Germany
- Cognitive and Cultural Ecology Research Group Max Planck Institute of Animal Behavior Radolfzell Germany
| | - Mirko Meboldt
- Product Development Group Zurich (pd z) ETH Zürich Zürich Switzerland
| | - Hannah J. Williams
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
- Department of Biology University of Konstanz Konstanz Germany
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Murugan K, Subramaniam J, Rajaganesh R, Panneerselvam C, Amuthavalli P, Vasanthakumaran M, Jayashanthini S, Dinesh D, Anitha J, Wang L, Hwang JS, Dahms HU, Mudigonda S, Aziz AT. Efficacy and side effects of bio-fabricated sardine fish scale silver nanoparticles against malarial vector Anopheles stephensi. Sci Rep 2021; 11:19567. [PMID: 34599250 PMCID: PMC8486798 DOI: 10.1038/s41598-021-98899-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/20/2021] [Indexed: 02/08/2023] Open
Abstract
Mosquitoes are a great menace for humankind since they transmit pathogenic organisms causing Malaria, Dengue, Chikungunya, Elephantiasis and Japanese encephalitis. There is an urgent need to discover new and novel biological tools to mitigate mosquito-borne diseases. To develop bioinsecticides through newly developed nanotechnology is another option in the present research scenario. In this study we synthesize and characterize sardine fish scales with silver nitrate by adopting various instrumental techniques such as UV- and FTIR-spectroscopy, energy-dispersive X-ray (EDAX), X-ray diffraction analyses (XRD) and scanning electron microscopy (SEM). Toxicity bioassays were conducted with young developmental stages of mosquito vectors. Significant mortality appeared after different life stages of mosquito vectors (young larval and pupal instars were exposed to the nanomaterials). LC50 values were 13.261 ppm for young first instar larvae and 32.182 ppm for pupae. Feeding and predatory potential of G. affinis, before and after exposure to nanoparticles against mosquito larval (I & II) instars of the mosquitoes showed promising results in laboratory experiments. Feeding potential of mosquito fish without nanoparticle treatment was 79.7% and 70.55% for the first and second instar larval populations respectively. At the nanoparticle-exposed situation the predatory efficiency of mosquitofish was 94.15% and 84.3%, respectively. Antioxidant enzymes like (SOD), (CAT), and (LPO) were estimated in the gill region of sardine fish in control and experimental waters. A significant reduction of egg hatchability was evident after nanoparticle application. It became evident from this study that the nano-fabricated materials provide suitable tools to control the malaria vector Anopheles stephensi in the aquatic phase of its life cycle. This finding suggests an effective novel approach to mosquito control.
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Affiliation(s)
- Kadarkarai Murugan
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
| | - Jayapal Subramaniam
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Rajapandian Rajaganesh
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | | | - Pandiyan Amuthavalli
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | | | - Sudalaimani Jayashanthini
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Devakumar Dinesh
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Jaganathan Anitha
- Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Jiang-Shiou Hwang
- Institute of Marine Biology, National Taiwan Ocean University, Keelung, 20224, Taiwan.
- Center of Excellence for Ocean Engineering, National Taiwan Ocean University, Keelung, 20224, Taiwan.
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 20224, Taiwan.
| | - Hans-Uwe Dahms
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, 80424, Taiwan
- Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung City, 807, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung City, 804, Taiwan
| | - Sunaina Mudigonda
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, 80424, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung City, 807, Taiwan
| | - Al Thabiani Aziz
- Department of Biology, Faculty of Science, University of Tabuk, Tabuk, 71491, Saudi Arabia
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12
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Heterothermy as a mechanism to offset energetic costs of environmental and homeostatic perturbations. Sci Rep 2021; 11:19038. [PMID: 34561468 PMCID: PMC8463709 DOI: 10.1038/s41598-021-96828-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022] Open
Abstract
Environmental and biotic pressures impose homeostatic costs on all organisms. The energetic costs of maintaining high body temperatures (Tb) render endotherms sensitive to pressures that increase foraging costs. In response, some mammals become more heterothermic to conserve energy. We measured Tb in banner-tailed kangaroo rats (Dipodomys spectabilis) to test and disentangle the effects of air temperature and moonlight (a proxy for predation risk) on thermoregulatory homeostasis. We further perturbed homeostasis in some animals with chronic corticosterone (CORT) via silastic implants. Heterothermy increased across summer, consistent with the predicted effect of lunar illumination (and predation), and in the direction opposite to the predicted effect of environmental temperatures. The effect of lunar illumination was also evident within nights as animals maintained low Tb when the moon was above the horizon. The pattern was accentuated in CORT-treated animals, suggesting they adopted an even further heightened risk-avoidance strategy that might impose reduced foraging and energy intake. Still, CORT-treatment did not affect body condition over the entire study, indicating kangaroo rats offset decreases in energy intake through energy savings associated with heterothermy. Environmental conditions receive the most attention in studies of thermoregulatory homeostasis, but we demonstrated here that biotic factors can be more important and should be considered in future studies.
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Trondrud LM, Pigeon G, Albon S, Arnold W, Evans AL, Irvine RJ, Król E, Ropstad E, Stien A, Veiberg V, Speakman JR, Loe LE. Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200215. [PMID: 34176322 PMCID: PMC8237166 DOI: 10.1098/rstb.2020.0215] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2021] [Indexed: 02/02/2023] Open
Abstract
Seasonal energetic challenges may constrain an animal's ability to respond to changing individual and environmental conditions. Here, we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer (Rangifer tarandus platyrhynchus), a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females, we recorded heart rate, subcutaneous temperature and activity using biologgers. Mean heart rate more than doubled from winter to summer. Typical drivers of energy expenditure, such as reproduction and activity, explained a relatively limited amount of variation (2-6% in winter and 16-24% in summer) compared to seasonality, which explained 75% of annual variation in heart rate. The relationship between heart rate and subcutaneous temperature depended on individual state via body mass, age and reproductive status, and the results suggested that peripheral heterothermy is an important pathway of energy management in both winter and summer. While the seasonal plasticity in energetics makes Svalbard reindeer well-adapted to their highly seasonal environment, intraseasonal constraints on modulation of their heart rate may limit their ability to respond to severe environmental change. This study emphasizes the importance of encompassing individual state and seasonal context when studying energetics in free-living animals. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.
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Affiliation(s)
- L. Monica Trondrud
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Gabriel Pigeon
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, Québec, Canada, J1 K 2R1
| | - Steve Albon
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Walter Arnold
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstr. 1, 1160 Vienna, Austria
| | - Alina L. Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, 2418 Elverum, Norway
| | - R. Justin Irvine
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
- Frankfurt Zoological Society, PO Box 100003, South Africa Street, Addis Ababa, Ethiopia
| | - Elżbieta Król
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Erik Ropstad
- Faculty of Veterinary Science, Norwegian University of Life Sciences, PO Box 8146, NO-0033 Oslo, Norway
| | - Audun Stien
- Department of Arctic and Marine Biology, The Arctic University of Norway, PO Box 6050 Langnes, NO-9037 Tromsø, Norway
| | - Vebjørn Veiberg
- Norwegian Institute for Nature Research, PO Box 5685 Torgarden, NO-7485 Trondheim, Norway
| | - John R. Speakman
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
- CAS Center of Excellence in Animal Evolution and Genetics, Kunming 650223, People's Republic of China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Leif Egil Loe
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
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14
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Linek N, Volkmer T, Shipley JR, Twining CW, Zúñiga D, Wikelski M, Partecke J. A songbird adjusts its heart rate and body temperature in response to season and fluctuating daily conditions. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200213. [PMID: 34121457 PMCID: PMC8200648 DOI: 10.1098/rstb.2020.0213] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2021] [Indexed: 12/11/2022] Open
Abstract
In a seasonal world, organisms are continuously adjusting physiological processes relative to local environmental conditions. Owing to their limited heat and fat storage capacities, small animals, such as songbirds, must rapidly modulate their metabolism in response to weather extremes and changing seasons to ensure survival. As a consequence of previous technical limitations, most of our existing knowledge about how animals respond to changing environmental conditions comes from laboratory studies or field studies over short temporal scales. Here, we expanded beyond previous studies by outfitting 71 free-ranging Eurasian blackbirds (Turdus merula) with novel heart rate and body temperature loggers coupled with radio transmitters, and followed individuals in the wild from autumn to spring. Across seasons, blackbirds thermoconformed at night, i.e. their body temperature decreased with decreasing ambient temperature, but not so during daytime. By contrast, during all seasons blackbirds increased their heart rate when ambient temperatures became colder. However, the temperature setpoint at which heart rate was increased differed between seasons and between day and night. In our study, blackbirds showed an overall seasonal reduction in mean heart rate of 108 beats min-1 (21%) as well as a 1.2°C decrease in nighttime body temperature. Episodes of hypometabolism during cold periods likely allow the birds to save energy and, thus, help offset the increased energetic costs during the winter when also confronted with lower resource availability. Our data highlight that, similar to larger non-hibernating mammals and birds, small passerine birds such as Eurasian blackbirds not only adjust their heart rate and body temperature on daily timescales, but also exhibit pronounced seasonal changes in both that are modulated by local environmental conditions such as temperature. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
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Affiliation(s)
- Nils Linek
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Tamara Volkmer
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - J Ryan Shipley
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Cornelia W Twining
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Limnological Institute, University of Konstanz, Konstanz, Germany
| | - Daniel Zúñiga
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Martin Wikelski
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Jesko Partecke
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
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15
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Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter. Proc Natl Acad Sci U S A 2021; 118:2100707118. [PMID: 34282012 DOI: 10.1073/pnas.2100707118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Qinghai-Tibetan Plateau, with low precipitation, low oxygen partial pressure, and temperatures routinely dropping below -30 °C in winter, presents several physiological challenges to its fauna. Yet it is home to many endemic mammalian species, including the plateau pika (Ochotona curzoniae). How these small animals that are incapable of hibernation survive the winter is an enigma. Measurements of daily energy expenditure (DEE) using the doubly labeled water method show that pikas suppress their DEE during winter. At the same body weight, pikas in winter expend 29.7% less than in summer, despite ambient temperatures being approximately 25 °C lower. Combined with resting metabolic rates (RMRs), this gives them an exceptionally low metabolic scope in winter (DEE/RMRt = 1.60 ± 0.30; RMRt is resting metabolic rate at thermoneutrality). Using implanted body temperature loggers and filming in the wild, we show that this is achieved by reducing body temperature and physical activity. Thyroid hormone (T3 and T4) measurements indicate this metabolic suppression is probably mediated via the thyroid axis. Winter activity was lower at sites where domestic yak (Bos grunniens) densities were higher. Pikas supplement their food intake at these sites by eating yak feces, demonstrated by direct observation, identification of yak DNA in pika stomach contents, and greater convergence in the yak/pika microbiotas in winter. This interspecific coprophagy allows pikas to thrive where yak are abundant and partially explains why pika densities are higher where domestic yak, their supposed direct competitors for food, are more abundant.
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16
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Nespolo RF, Mejías C, Espinoza A, Quintero-Galvis J, Rezende EL, Fontúrbel FE, Bozinovic F. Heterothermy as the Norm, Homeothermy as the Exception: Variable Torpor Patterns in the South American Marsupial Monito del Monte ( Dromiciops gliroides). Front Physiol 2021; 12:682394. [PMID: 34322034 PMCID: PMC8311349 DOI: 10.3389/fphys.2021.682394] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/11/2021] [Indexed: 12/30/2022] Open
Abstract
Hibernation (i.e., multiday torpor) is considered an adaptive strategy of mammals to face seasonal environmental challenges such as food, cold, and/or water shortage. It has been considered functionally different from daily torpor, a physiological strategy to cope with unpredictable environments. However, recent studies have shown large variability in patterns of hibernation and daily torpor ("heterothermic responses"), especially in species from tropical and subtropical regions. The arboreal marsupial "monito del monte" (Dromiciops gliroides) is the last living representative of the order Microbiotheria and is known to express both short torpor episodes and also multiday torpor depending on environmental conditions. However, only limited laboratory experiments have documented these patterns in D. gliroides. Here, we combined laboratory and field experiments to characterize the heterothermic responses in this marsupial at extreme temperatures. We used intraperitoneal data loggers and simultaneous measurement of ambient and body temperatures (T A and T B, respectively) for analyzing variations in the thermal differential, in active and torpid animals. We also explored how this differential was affected by environmental variables (T A, natural photoperiod changes, food availability, and body mass changes), using mixed-effects generalized linear models. Our results suggest that: (1) individuals express short bouts of torpor, independently of T A and even during the reproductive period; (2) seasonal torpor also occurs in D. gliroides, with a maximum bout duration of 5 days and a mean defended T B of 3.6 ± 0.9°C (one individual controlled T B at 0.09°C, at sub-freezing T A); (3) the best model explaining torpor occurrence (Akaike information criteria weight = 0.59) discarded all predictor variables except for photoperiod and a photoperiod by food interaction. Altogether, these results confirm that this marsupial expresses a dynamic form of torpor that progresses from short torpor to hibernation as daylength shortens. These data add to a growing body of evidence characterizing tropical and sub-tropical heterothermy as a form of opportunistic torpor, expressed as daily or seasonal torpor depending on environmental conditions.
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Affiliation(s)
- Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Carlos Mejías
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Angelo Espinoza
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Julián Quintero-Galvis
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Enrico L. Rezende
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Francisco Bozinovic
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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17
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Studd EK, Bates AE, Bramburger AJ, Fernandes T, Hayden B, Henry HAL, Humphries MM, Martin R, McMeans BC, Moise ERD, O'Sullivan AM, Sharma S, Sinclair BJ, Sutton AO, Templer PH, Cooke SJ. Nine Maxims for the Ecology of Cold-Climate Winters. Bioscience 2021. [DOI: 10.1093/biosci/biab032] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Frozen winters define life at high latitudes and altitudes. However, recent, rapid changes in winter conditions have highlighted our relatively poor understanding of ecosystem function in winter relative to other seasons. Winter ecological processes can affect reproduction, growth, survival, and fitness, whereas processes that occur during other seasons, such as summer production, mediate how organisms fare in winter. As interest grows in winter ecology, there is a need to clearly provide a thought-provoking framework for defining winter and the pathways through which it affects organisms. In the present article, we present nine maxims (concise expressions of a fundamentally held principle or truth) for winter ecology, drawing from the perspectives of scientists with diverse expertise. We describe winter as being frozen, cold, dark, snowy, less productive, variable, and deadly. Therefore, the implications of winter impacts on wildlife are striking for resource managers and conservation practitioners. Our final, overarching maxim, “winter is changing,” is a call to action to address the need for immediate study of the ecological implications of rapidly changing winters.
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Affiliation(s)
- Emily K Studd
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Amanda E Bates
- Department of Ocean Sciences at Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Andrew J Bramburger
- Department of Ocean Sciences at Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Timothy Fernandes
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Brian Hayden
- Canadian Rivers Institute, Biology Department, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Hugh A L Henry
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Murray M Humphries
- Department of Natural Resource Sciences, Macdonald Campus, McGill University, Ste-Anne-de-Bellevue, Québec, Canada
| | - Rosemary Martin
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Bailey C McMeans
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Eric R D Moise
- Natural Resources Canada's Canadian Forest Service, Corner Brook, Newfoundland, Canada
| | - Antóin M O'Sullivan
- Canadian Rivers Institute, Biology Department, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Sapna Sharma
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Brent J Sinclair
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Alex O Sutton
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Pamela H Templer
- Department of Biology, Boston University, Boston, Massachusetts, United States
| | - Steven J Cooke
- Department of Biology and the Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
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18
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Abstract
Temperature is an important environmental factor governing the ability of organisms to grow, survive and reproduce. Thermal performance curves (TPCs), with some caveats, are useful for charting the relationship between body temperature and some measure of performance in ectotherms, and provide a standardized set of characteristics for interspecific comparisons. Endotherms, however, have a more complicated relationship with environmental temperature, as endothermy leads to a decoupling of body temperature from external temperature through use of metabolic heat production, large changes in insulation and variable rates of evaporative heat loss. This has impeded our ability to model endothermic performance in relation to environmental temperature as well as to readily compare performance between species. In this Commentary, we compare the strengths and weaknesses of potential TPC analogues (including other useful proxies for linking performance to temperature) in endotherms and suggest several ways forward in the comparative ecophysiology of endotherms. Our goal is to provide a common language with which ecologists and physiologists can evaluate the effects of temperature on performance. Key directions for improving our understanding of endotherm thermoregulatory physiology include a comparative approach to the study of the level and precision of body temperature, measuring performance directly over a range of body temperatures and building comprehensive mechanistic models of endotherm responses to environmental temperatures. We believe the answer to the question posed in the title could be 'yes', but only if 'performance' is well defined and understood in relation to body temperature variation, and the costs and benefits of endothermy are specifically modelled.
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Affiliation(s)
| | - Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
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19
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Green JA. Assessing the functional significance of metabolism and activity in niche diversification. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Jonathan A. Green
- School of Environmental Sciences University of Liverpool Liverpool UK
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