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Parker S, Cramberg M, Scott A, Sopko S, Swords A, Taylor E, Young BA. On the spinal venous sinus of Alligator mississippiensis. Anat Rec (Hoboken) 2024; 307:2953-2965. [PMID: 38323749 DOI: 10.1002/ar.25403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 02/08/2024]
Abstract
The epidural space of the American alligator (Alligator mississippiensis) is largely filled by a continuous venous sinus. This venous sinus extends throughout the trunk and tail of the alligator, and is continuous with the dural sinuses surrounding the brain. Segmental spinal veins (sl) link the spinal venous sinus (vs) to the somatic and visceral venous drainage. Some of these sl, like the caudal head vein along the occipital plate of the skull, are enlarged, suggesting more functional linkage. No evidence of venous valves or external venous sphincters was found associated with the vs; the relative scarcity of smooth muscle in the venous wall of the sinus suggests limited physiological regulation. The proatlas (pr), which develops between the occipital plate and C1 in crocodylians, is shaped like a neural arch and is fused to the dorsal surface of the vs. The present study suggests that the pr may function to propel venous blood around the brain and spinal cord. The vs effectively encloses the spinal dura, creating a tube-within-a-tube system with the (smaller volume) spinal cerebrospinal fluid (CSF). Changes in venous blood pressure, as are likely during locomotion, would impact dural compliance and CSF pressure waves propagating along the spinal cord.
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Affiliation(s)
- Seth Parker
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Michael Cramberg
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Anchal Scott
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Stephanie Sopko
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Annelise Swords
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Ethan Taylor
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
| | - Bruce A Young
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, Missouri, USA
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2
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Benson DM, DeNardo DF. Effects of thermophily-relevant temperature variation and sex on digestive performance in pythons. Comp Biochem Physiol A Mol Integr Physiol 2024; 293:111636. [PMID: 38574988 DOI: 10.1016/j.cbpa.2024.111636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/01/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
Different physiological performances are often optimized at slightly varying temperatures, which can lead to ectotherms selecting higher body temperatures during certain physiological efforts (e.g., digestion, reproduction). Such thermophilic responses can lead to temperature-based tradeoffs between two physiological activities with differing optimal temperatures or between optimizing a physiological activity and water balance, as water loss is elevated at higher temperatures. For example, ectotherms will often select a higher body temperature after consuming a meal, but the extent to which body temperature is elevated after eating is affected by its hydric state. Despite this known hydration state-based suppression of thermophily associated with digestion, the impact of this reduced body temperature on digestion performance is unknown. Accordingly, we determined whether small, thermophily-relevant changes in body temperature impact digestive efficiency or passage time and whether sex influenced the extent of the effect. Eighteen (9 female and 9 male) Children's pythons (Antaresia childreni) each consumed a meal at three temperatures (29 °C, 30 °C, and 31 °C), and gut passage time and digestive efficiency were determined. We found that neither metric was affected by temperature over the range tested. However, digestive efficiency was significantly impacted by the interaction between sex and temperature with males having significantly lower digestive efficiency than females at 31 °C, but not 29 °C or 30 °C. Our results provide insight into the effects of temperature on digestive physiology across narrow temperature ranges as well as demonstrate a sex-based difference in digestive physiology.
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3
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Comparative transcriptome analysis provides novel insights into the molecular mechanism of the silver carp (Hypophthalmichthys molitrix) brain in response to hypoxia stress. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2022; 41:100951. [PMID: 34923202 DOI: 10.1016/j.cbd.2021.100951] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/06/2021] [Accepted: 12/08/2021] [Indexed: 02/05/2023]
Abstract
The brain of fish plays an important role in regulating growth and adapting to environmental changes. However, few studies have been performed to address the changes in gene expression profiles in fish brains under hypoxic stress. In the present study, silver carp (Hypophthalmichthys molitrix) were kept under hypoxic experimental conditions by using the method of natural oxygen consumption, which resulted in a significant decrease in malondialdehyde (MDA) and glutathione (GSH) content and superoxide dismutase (SOD) activity in the brain. In addition, RNA sequencing (RNA-Seq) was performed to analyze transcriptional regulation in the brains of silver carp under normoxia (control group), hypoxia, semi-asphyxia, and asphyxia conditions. The results of KEGG enrichment pathway analysis showed that the immune system, such as antigen processing and presentation, natural killer cell-mediated cytotoxicity, was enriched in the hypoxia group; the nervous system (e.g., "glutamatergic synapse"), signal transduction (e.g., "calcium signaling pathway"; "foxo signaling pathway"), and signaling molecules and interactions (e.g., "neuroactive ligand-receptor interaction") were enriched in the semi-asphyxia group; and signaling molecules and interactions (e.g., "neuroactive ligand-receptor interaction") were enriched in the asphyxia group. These results provide novel insights into the molecular regulatory mechanism of the fish brain coping with hypoxia stress.
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4
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Parlin AF, Schaeffer PJ. Cardiovascular contributions and energetic costs of thermoregulation in ectothermic vertebrates. J Exp Biol 2022; 225:274253. [PMID: 35119074 DOI: 10.1242/jeb.243095] [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: 06/28/2021] [Accepted: 10/27/2021] [Indexed: 11/20/2022]
Abstract
Ectothermic vertebrates use a suite of physiological and behavioral mechanisms to thermoregulate, which result in various thermoregulatory strategies from thermoconformity to thermoregulation. Here, we present a novel synthesis of theoretical and empirical methods to determine cardiovascular contributions to heat transfer in free-living ectothermic vertebrates. We start by identifying the fundamental components of heat transfer and the cardiovascular mechanisms for physiological modulation of heat exchange, and then integrate these components into a single, integrative framework: the cardiovascular heat exchange framework (CHEF). We demonstrate that this framework can identify details of the thermoregulatory strategy in two turtle species, most notably the preponderance of instances where turtles use physiological mechanisms to avoid overheating, suggesting vulnerability to climate change. As modulated physiological contributions to heat flow incur a greater energy demand than relying on unmodulated passive heat transfer, we then asked whether we could characterize the energetic costs of thermoregulation. We measured field metabolic rate (FMR) in free-living turtles and used the CHEF to determine FMR while actively or passively thermoregulating. Comparing an individual's actual FMR to the rate calculated assuming absence of thermoregulation revealed that painted turtles, a partial thermoregulator, elevate their daily energy expenditure (DEE) by about 25%, while box turtles, a thermoconformer, have a DEE that is nearly unchanged as a result of thermoregulation. This integrative framework builds a new paradigm that provides a mechanism to explain correlations between energy demand and thermoregulatory strategy, quantifies the energetic costs of thermoregulation, and identifies the role of cardiovascular contributions to thermoregulation in free-living animals.
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Affiliation(s)
- Adam F Parlin
- Department of Biology, Miami University, Oxford, OH 45056, USA
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5
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Seasonal changes in steroid and thyroid hormone content in shed skins of the tegu lizard Salvator merianae. J Comp Physiol B 2021; 192:127-139. [PMID: 34379176 DOI: 10.1007/s00360-021-01397-3] [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: 01/10/2021] [Revised: 06/30/2021] [Accepted: 08/02/2021] [Indexed: 10/20/2022]
Abstract
Sampling blood for endocrine analysis from some species may not be practical or ethical. Quantification of hormones extracted from nontypical sample types, such as keratinized tissues, offers a less invasive alternative to the traditional collection and analysis of blood. Here, we aimed to validate assays by using parallelism and accuracy tests for quantification of testosterone, corticosterone, progesterone, and triiodothyronine (T3) in shed skins of tegu lizards. We assessed whether hormone content of sheds varied across one year similar to what was previously detected in plasma samples. In addition, we aimed to identify the phase relationship between hormone levels of shed skin and plasma levels obtained from the same animals. High frequency of shedding occurred during the active season for tegus (spring/summer), while shedding ceased during hibernation (winter). All hormones measured in shed skins exhibited seasonal changes in concentration. Levels of testosterone in shed skins of male tegus correlated positively with plasma testosterone levels, while corticosterone in both males and females exhibited an inverse relationship between sample types for the same month of collection. An inverse relationship was found when accounting for a lag time of 3 and 4 months between sheds and plasma testosterone. These results indicate that endocrine content of sheds may be confounded by factors (i.e., seasons, environmental temperature, thermoregulatory behavior, among others) that affect frequency of molting, skin blood perfusion, and therefore hormone transfer from the bloodstream and deposition in sheds of squamates.
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Clarac F, Scheyer TM, Desojo JB, Cerda IA, Sanchez S. The evolution of dermal shield vascularization in Testudinata and Pseudosuchia: phylogenetic constraints versus ecophysiological adaptations. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190132. [PMID: 31928197 PMCID: PMC7017437 DOI: 10.1098/rstb.2019.0132] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2019] [Indexed: 01/18/2023] Open
Abstract
Studies on living turtles have demonstrated that shells are involved in the resistance to hypoxia during apnea via bone acidosis buffering; a process which is complemented with cutaneous respiration, transpharyngeal and cloacal gas exchanges in the soft-shell turtles. Bone acidosis buffering during apnea has also been identified in crocodylian osteoderms, which are also known to employ heat transfer when basking. Although diverse, many of these functions rely on one common trait: the vascularization of the dermal shield. Here, we test whether the above ecophysiological functions played an adaptive role in the evolutionary transitions between land and aquatic environments in both Pseudosuchia and Testudinata. To do so, we measured the bone porosity as a proxy for vascular density in a set of dermal plates before performing phylogenetic comparative analyses. For both lineages, the dermal plate porosity obviously varies depending on the animal lifestyle, but these variations prove to be highly driven by phylogenetic relationships. We argue that the complexity of multi-functional roles of the post-cranial dermal skeleton in both Pseudosuchia and Testudinata probably is the reason for a lack of obvious physiological signal, and we discuss the role of the dermal shield vascularization in the evolution of these groups. This article is part of the theme issue 'Vertebrate palaeophysiology'.
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Affiliation(s)
- François Clarac
- Department of Organismal Biology, Subdepartment of Evolution and Development, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
| | - Torsten M. Scheyer
- Paleontological Institute and Museum, University of Zurich, Karl Schmid-Strasse 4, 8006 Zurich, Switzerland
| | - Julia B. Desojo
- CONICET, División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n°, B1900FWA La Plata, Argentina
| | - Ignacio A. Cerda
- CONICET, Argentina y Instituto de Investigacion en Paleobiología y Geología, Universidad Nacional de Río Negro, Museo Carlos Ameghino, Belgrano 1700, Paraje Pichi Ruca (predio Marabunta), 8300 Cipolletti, Río Negro, Argentina
| | - Sophie Sanchez
- Department of Organismal Biology, Subdepartment of Evolution and Development, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS-40220, 38043 Grenoble Cedex, France
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7
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Filogonio R, Wang T, Abe AS, Leite CA. Cooling and Warming Rates are Unaffected by Autonomic Vascular Control in the South American Rattlesnake (Crotalus durissus). SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2019. [DOI: 10.2994/sajh-d-18-00013.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Renato Filogonio
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Augusto S. Abe
- Department of Zoology, State University of São Paulo, Rio Claro, SP, Brazil
| | - Cléo A.C. Leite
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP, Brazil
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8
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The crocodylian skull and osteoderms: A functional exaptation to ectothermy? ZOOLOGY 2018; 132:31-40. [PMID: 30736927 DOI: 10.1016/j.zool.2018.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 12/08/2018] [Accepted: 12/11/2018] [Indexed: 10/27/2022]
Abstract
The crocodylians are ectothermic semi-aquatic vertebrates which are assessed to have evolved from endothermic terrestrial forms during the Mesozoic. Such a physiological transition should have involved modifications in their cardio-vascular system allowing to increase the heat transfers with the surrounding environment by growing a peripheral vascularization which would be mainly located in the dermal skeleton: the dermatocranium and the osteoderms. In order to assess the implication of these anatomical regions in thermal exchanges, we have recorded the temperature above a set of representative skin areas in order to draw comparisons between the skull, the osteoderms, and the rest of the body parts which present either none or residual dermal ossification. We computed the data after the specimens were successively laid in different stereotyped environmental conditions which involved significant variations in the environmental temperature. Our results show that the osteoderms collect the external heat during the basking periods as they become significantly warmer than the surrounding skin; they further release the heat into the core of the organism as they turn out to be colder than the surrounding skin after a significant cooling period. In disregard of the environmental temperature variations, the skull table (which encloses the braincase) remains warmer than the rest of the cranial regions and shows less temperature variations than the osteoderms; a result which has lead us to think that the braincase temperature is monitored and controlled by a thermoregulatory system. Therefore, as hypothesized by previous authors regarding the ectothermic diapsids, we assume that the crocodylian skull possesses shunting blood pathways which tend to maintain both the braincase and the main sensory organs at the nearest to the optimal physiological temperature depending on the external temperature variations. Concerning the skin vascularization, the study of an albino Alligator mississippiensis specimen permitted to observe the repartition of the superficial blood vessels by transparency through the skin. We thus testify that the skin which covers either the skull or the osteoderms is more vascularized than the skin which does not present any subjacent dermal ossification. We consequently deduce that the significant contrast in the thermal behavior between the dermal skeleton and the rest of the body is indeed correlated with a difference in the relative degree of skin vascularization. This last assessment confirms that the development of the dermal skeleton should have played a functional role in the crocodylian transition from endothermy to ectothermy through the set-up of a peripheral vessel network.
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9
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Hamilton MT, Finger JW, Elsey RM, Mastromonaco GF, Tuberville TD. Corticosterone in American alligator (Alligator mississippiensis) tail scutes: Evaluating the feasibility of using unconventional samples for investigating environmental stressors. Gen Comp Endocrinol 2018; 268:7-13. [PMID: 30031024 DOI: 10.1016/j.ygcen.2018.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/23/2018] [Accepted: 07/13/2018] [Indexed: 12/31/2022]
Abstract
Baseline plasma corticosterone (CORT) concentrations have been widely used to investigate the effects of stressors in wild and captive crocodilians. However, collecting baseline plasma CORT samples from wild crocodilians may be particularly difficult due to the capture and handling protocols used for large individuals. Thus, it may prove beneficial to use recently modified techniques for extracting CORT deposited in keratinized and non-keratinized tissues to better quantify the effects of long-term stress in crocodilians. In this study, we investigated the feasibility of using American alligator (Alligator mississippiensis) tail scute tissues to quantify CORT by collecting blood and tail scutes from 40 alligators before and after a short-term handling stressor. The objective of the current study was to better understand CORT deposition in crocodilian scutes and whether short-term increases in CORT could be detected. We found that CORT can be reliably extracted from alligator scute tissue and quantified using a commercially available enzyme immunoassay. However, there was a significant increase in scute CORT concentrations following an alligator being exposed to a short-term stressor (p = 0.017), although the magnitude of change was less than observed in plasma samples from the same individuals (p = 0.002). Furthermore, our results indicate that there was a significant effect of body condition on an alligator's post-stressor CORT concentration (p = 0.02). While our study is among the first to experimentally examine the usefulness of tissue CORT in crocodilians, a combination of field and laboratory experiments are needed to better understand deposition rates of CORT in scute tissues and to further validate the usefulness of tissue glucocorticoids for evaluating the effects of stress.
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Affiliation(s)
- Matthew T Hamilton
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA.
| | - John W Finger
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Ruth M Elsey
- Louisiana Department of Wildlife and Fisheries, Rockefeller Wildlife Refuge, Grand Chenier, LA 70643, USA
| | | | - Tracey D Tuberville
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
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10
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Clarac F, De Buffrénil V, Cubo J, Quilhac A. Vascularization in Ornamented Osteoderms: Physiological Implications in Ectothermy and Amphibious Lifestyle in the Crocodylomorphs? Anat Rec (Hoboken) 2017; 301:175-183. [PMID: 29024422 DOI: 10.1002/ar.23695] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/20/2017] [Accepted: 08/07/2017] [Indexed: 11/10/2022]
Abstract
Vascularization in the core of crocodylian osteoderms, and in their superficial pits has been hypothesized to be a key feature involved in physiological thermoregulation and/or acidosis buffering during anoxia (apnea). However, up to now, there have been no quantitative data showing that the inner, or superficial, blood supply of the osteoderms is greater than that occurring in neighboring dermal tissues. We provide such data: our results clearly indicate that the vascular networks in both the osteoderms and the pits forming their superficial ornamentation are denser than in the overlying dermis. These results support previous physiological assumptions and indicate that vascularization in pseudosuchian (crocodylians and close relatives) ornamented osteoderms could be part of a broad eco-physiological adaptation towards ectothermy and aquatic ambush predation acquired by the crocodylomorphs during their post-Triassic evolution. Moreover, regressions demonstrate that the number of enclosed vessels is correlated with the sectional area of the cavities housing them (superficial pits and inner cavities). These regressions can be used to infer the degree of vascularization on dry and fossilized osteoderms and thus document the evolution of the putative function of the osteoderms in the Pseudosuchia. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:175-183, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- F Clarac
- Sorbonne Universités, UPMC Université Paris 06, CNRS, Institut des Sciences de la Terre Paris (ISTeP), Paris, F-75005, France.,Département Histoire de la Terre, Museum National d'Histoire Naturelle, UMR 7207 (CR2P), Sorbonne Universités, MNHN/CNRS/UPMC, F-75231, France
| | - V De Buffrénil
- Département Histoire de la Terre, Museum National d'Histoire Naturelle, UMR 7207 (CR2P), Sorbonne Universités, MNHN/CNRS/UPMC, F-75231, France
| | - J Cubo
- Sorbonne Universités, UPMC Université Paris 06, CNRS, Institut des Sciences de la Terre Paris (ISTeP), Paris, F-75005, France
| | - A Quilhac
- Sorbonne Universités, UPMC Université Paris 06, CNRS, Institut des Sciences de la Terre Paris (ISTeP), Paris, F-75005, France
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11
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Porter WR, Sedlmayr JC, Witmer LM. Vascular patterns in the heads of crocodilians: blood vessels and sites of thermal exchange. J Anat 2016; 229:800-824. [PMID: 27677246 DOI: 10.1111/joa.12539] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2016] [Indexed: 11/27/2022] Open
Abstract
Extant crocodilians are a highly apomorphic archosaur clade that is ectothermic, yet often achieve large body sizes that can be subject to higher heat loads. Therefore, the anatomical and physiological roles that blood vessels play in crocodilian thermoregulation need further investigation to better understand how crocodilians establish and maintain cephalic temperatures and regulate neurosensory tissue temperatures during basking and normal activities. The cephalic vascular anatomy of extant crocodilians, particularly American alligator (Alligator mississippiensis) was investigated using a differential-contrast, dual-vascular injection technique and high resolution X-ray micro-computed tomography (μCT). Blood vessels were digitally isolated to create representations of vascular pathways. The specimens were then dissected to confirm CT results. Sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in evaporative cooling and cephalic thermoregulation in other diapsids. Blood vessels to and from sites of thermal exchange were studied to detect conserved vascular patterns and to assess their ability to deliver cooled blood to neurosensory tissues. Within the orbital region, both the arteries and veins demonstrated consistent branching patterns, with the supraorbital, infraorbital, and ophthalmotemporal vessels supplying and draining the orbit. The venous drainage of the orbital region showed connections to the dural sinuses via the orbital veins and cavernous sinus. The palatal region demonstrated a vast plexus that comprised both arteries and veins. The most direct route of venous drainage of the palatal plexus was through the palatomaxillary veins, essentially bypassing neurosensory tissues. Anastomotic connections with the nasal region, however, may provide an alternative route for palatal venous blood to reach neurosensory tissues. The nasal region in crocodilians is probably the most prominent site of thermal exchange, as it offers a substantial surface area and is completely surrounded by blood vessels. The venous drainage routes from the nasal region offer routes directly to the dural venous sinuses and the orbit, offering evidence of the potential to directly affect neurosensory tissue temperatures. The evolutionary history of crocodilians is complex, with large-bodied, terrestrial, and possibly endothermic taxa that may have had to deal with thermal loads that likely provided the anatomical building-blocks for such an extensive vascularization of sites of thermal exchange. A clear understanding of the physiological abilities and the role of blood vessels in the thermoregulation of crocodilians neurosensory tissues is not available but vascular anatomical patterns of crocodilian sites of thermal exchange indicate possible physiological abilities that may be more sophisticated than in other extant diapsids.
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Affiliation(s)
- William Ruger Porter
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, OH, USA
| | - Jayc C Sedlmayr
- Department of Cell Biology and Anatomy, Louisiana State University Heath Sciences Center, New Orleans, LA, USA
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, OH, USA
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12
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Braga VHDS, Armelin VA, Teixeira MT, Abe AS, Rantin FT, Florindo LH. The Effects of Feeding on Cardiac Control of the Broad-Nosed Caiman (Caiman latirostris): The Role of the Autonomic Nervous System and NANC Factors. ACTA ACUST UNITED AC 2016; 325:524-531. [DOI: 10.1002/jez.2036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/06/2016] [Accepted: 08/05/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Victor Hugo Da Silva Braga
- Department of Zoology and Botany; São Paulo State University (UNESP); São José do Rio Preto São Paulo Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
| | - Vinicius Araújo Armelin
- Department of Zoology and Botany; São Paulo State University (UNESP); São José do Rio Preto São Paulo Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
| | - Mariana Teodoro Teixeira
- Department of Zoology and Botany; São Paulo State University (UNESP); São José do Rio Preto São Paulo Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
| | - Augusto Shinya Abe
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
- Department of Zoology; São Paulo State University (UNESP); Rio Claro São Paulo Brazil
- Aquaculture Center (CAUNESP); São Paulo State University (UNESP); Jaboticabal São Paulo Brazil
| | - Francisco Tadeu Rantin
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
- Department of Physiological Sciences; Federal University of São Carlos (UFSCar); São Carlos, São Paulo Brazil
| | - Luiz Henrique Florindo
- Department of Zoology and Botany; São Paulo State University (UNESP); São José do Rio Preto São Paulo Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq); São Paulo Brazil
- Aquaculture Center (CAUNESP); São Paulo State University (UNESP); Jaboticabal São Paulo Brazil
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13
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Kolomeyets NL, Roshchevskaya IM. The electrical resistivity of a segment of the tail, lungs, liver, and intercostal muscles of the grass snake during in vivo cooling. Biophysics (Nagoya-shi) 2016. [DOI: 10.1134/s0006350916050110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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14
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Clarac F, Souter T, Cornette R, Cubo J, de Buffrénil V. A quantitative assessment of bone area increase due to ornamentation in the Crocodylia. J Morphol 2015; 276:1183-92. [DOI: 10.1002/jmor.20408] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/16/2015] [Accepted: 04/30/2015] [Indexed: 11/05/2022]
Affiliation(s)
- François Clarac
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), UPMC Univ Paris 06, UMR 7193, Institut Des Sciences De La Terre Paris (ISTeP); 4 Place Jussieu, BC 19 Paris F-75005 France
- CNRS, UMR 7193, Institut Des Sciences De La Terre Paris (ISTeP); 4 Place Jussieu, BC 19 Paris F-75005 France
- Département Histoire De La Terre; Museum National D'histoire Naturelle, UMR 7207 (CR2P), Sorbonne Universités, Muséum National d'Histoire Naturelle (MNHN)/CNRS/UPMC; Bâtiment De Géologie Paris Cedex 05 F-75231 France
| | - Thibaud Souter
- Plateforme De Morphométrie Du MNHN -UMS 2700 Outils Et Méthodes De La Systématique Intégrative; 55 Rue Buffon Paris 75005 France
| | - Raphaël Cornette
- Institut De Systématique, Evolution, Biodiversité, ISYEB, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National D'histoire Naturelle, Sorbonne Universités; 57 Rue Cuvier 75005 Paris France
| | - Jorge Cubo
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), UPMC Univ Paris 06, UMR 7193, Institut Des Sciences De La Terre Paris (ISTeP); 4 Place Jussieu, BC 19 Paris F-75005 France
- CNRS, UMR 7193, Institut Des Sciences De La Terre Paris (ISTeP); 4 Place Jussieu, BC 19 Paris F-75005 France
| | - Vivian de Buffrénil
- Département Histoire De La Terre; Museum National D'histoire Naturelle, UMR 7207 (CR2P), Sorbonne Universités, Muséum National d'Histoire Naturelle (MNHN)/CNRS/UPMC; Bâtiment De Géologie Paris Cedex 05 F-75231 France
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15
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Filogonio R, Taylor EW, Carreira LB, Leite GS, Abe AS, Leite CA. Systemic Blood Flow Relations in Conscious South American Rattlesnakes. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2014. [DOI: 10.2994/sajh-d-14-00012.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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16
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Seebacher F, Tallis JA, James RS. The cost of muscle power production: muscle oxygen consumption per unit work increases at low temperatures in Xenopus laevis. ACTA ACUST UNITED AC 2014; 217:1940-5. [PMID: 24625645 DOI: 10.1242/jeb.101147] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Metabolic energy (ATP) supply to muscle is essential to support activity and behaviour. It is expected, therefore, that there is strong selection to maximise muscle power output for a given rate of ATP use. However, the viscosity and stiffness of muscle increases with a decrease in temperature, which means that more ATP may be required to achieve a given work output. Here, we tested the hypothesis that ATP use increases at lower temperatures for a given power output in Xenopus laevis. To account for temperature variation at different time scales, we considered the interaction between acclimation for 4 weeks (to 15 or 25°C) and acute exposure to these temperatures. Cold-acclimated frogs had greater sprint speed at 15°C than warm-acclimated animals. However, acclimation temperature did not affect isolated gastrocnemius muscle biomechanics. Isolated muscle produced greater tetanus force, and faster isometric force generation and relaxation, and generated more work loop power at 25°C than at 15°C acute test temperature. Oxygen consumption of isolated muscle at rest did not change with test temperature, but oxygen consumption while muscle was performing work was significantly higher at 15°C than at 25°C, regardless of acclimation conditions. Muscle therefore consumed significantly more oxygen at 15°C for a given work output than at 25°C, and plastic responses did not modify this thermodynamic effect. The metabolic cost of muscle performance and activity therefore increased with a decrease in temperature. To maintain activity across a range of temperature, animals must increase ATP production or face an allocation trade-off at lower temperatures. Our data demonstrate the potential energetic benefits of warming up muscle before activity, which is seen in diverse groups of animals such as bees, which warm flight muscle before take-off, and humans performing warm ups before exercise.
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Affiliation(s)
- Frank Seebacher
- School of Biological Sciences A08, University of Sydney, Sydney NSW 2006, Australia
| | - Jason A Tallis
- Department of Biomolecular and Sport Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK
| | - Rob S James
- Department of Biomolecular and Sport Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK
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17
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Role of brain nitric oxide in the cardiovascular control of bullfrogs. Comp Biochem Physiol A Mol Integr Physiol 2013; 165:263-71. [DOI: 10.1016/j.cbpa.2013.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 11/23/2022]
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18
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Tattersall GJ, Sinclair BJ, Withers PC, Fields PA, Seebacher F, Cooper CE, Maloney SK. Coping with Thermal Challenges: Physiological Adaptations to Environmental Temperatures. Compr Physiol 2012; 2:2151-202. [DOI: 10.1002/cphy.c110055] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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19
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Seebacher F, Franklin CE. Physiology of invasion: cane toads are constrained by thermal effects on physiological mechanisms that support locomotor performance. ACTA ACUST UNITED AC 2011; 214:1437-44. [PMID: 21490252 DOI: 10.1242/jeb.053124] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Understanding the mechanisms that constrain the invasiveness of introduced animals is essential for managing invasions and for predicting their limits. In most vertebrate species, the capacity for invasion relies upon the physiological systems that support locomotion, and oxygen transport and metabolism may become limiting as environmental temperatures increase as predicted by the oxygen limitation hypothesis. Here we test the oxygen limitation hypothesis and propose the alternative hypothesis that within-individual plasticity will compensate for thermal variation. We show that during exercise in the invasive cane toad (Rhinella marina) oxygen transport by the cardiovascular system was maximised in warm-acclimated toads at high (30°C) temperatures, and that oxygen content of arterial blood was not affected by temperature. Resting oxygen consumption remained stable across a 10°C temperature range (20-30°C) when toads were allowed to acclimate, so that there was no increase in resting oxygen demand that could lead to a decrease in aerobic scope at high temperatures. Additionally, temperature acclimation had no effect on arterial-venous differences in oxygen partial pressures. Toads relied more on glycolytic ATP production at low temperatures to support locomotor activity. Mitochondrial capacities (citrate synthase and cytochrome c oxidase activities) were greatest at warmer temperatures. Interestingly, the metabolic cost of exercise increased at low temperatures. In contradiction to predictions by the oxygen limitation hypothesis, aerobic performance was not limited by high temperatures. On the contrary, the relatively slow advance of cane toads to cooler climates can be explained by the constraints of low temperatures on the physiological systems supporting locomotion. It is likely that human-induced global warming will facilitate invasions of environments that are currently too cool to support cane toads.
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Affiliation(s)
- Frank Seebacher
- Integrative Physiology, School of Biological Sciences A08, University of Sydney, NSW 2006, Australia.
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20
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Gräns A, Olsson C, Pitsillides K, Nelson HE, Cech JJ, Axelsson M. Effects of feeding on thermoregulatory behaviours and gut blood flow in white sturgeon (Acipenser transmontanus) using biotelemetry in combination with standard techniques. ACTA ACUST UNITED AC 2010; 213:3198-206. [PMID: 20802122 DOI: 10.1242/jeb.043570] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of thermoregulatory behaviours on gut blood flow in white sturgeon Acipenser transmontanus before and after feeding was studied using a blood flow biotelemetry system in combination with a temperature preference chamber. This is the first study to look at cardiovascular responses to feeding in white sturgeon, and also the first time behavioural tests in fish have been combined with recordings of cardiac output, heart rate, cardiac stroke volume and gut blood flow. The results showed strong correlations between gut blood flow and temperature choice after feeding (R(2)=0.88+/-0.03, 6-8 h postprandially and R(2)=0.89+/-0.04, 8-10 h postprandially) but not prior to feeding (R(2)=0.11+/-0.05). Feeding did not affect the actual temperature preference (18.4+/-0.7 degrees C before feeding, 18.1+/-0.7 degrees C, 6-8 h postprandially and 17.5+/-0.5 degrees C, 8-10 h postprandially). Fish instrumented with a blood flow biotelemetry device, and allowed to move freely in the water, had a significantly lower resting heart rate (37.3+/-0.26 beats min(-1)) compared with the control group that was traditionally instrumented with transit-time blood flow probes and kept in a confined area in accordance with the standard procedure (43.2+/-2.1 beats min(-1)). This study shows, for the first time in fish, the correlation between body temperature and gut blood flow during behavioural thermoregulation.
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Affiliation(s)
- A Gräns
- Department of Zoology, University of Gothenburg, SE-405 30 Göteborg, Sweden.
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21
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Cramp RL, De Vries I, Gary Anderson W, Franklin CE. Hormone-dependent dissociation of blood flow and secretion rate in the lingual salt glands of the estuarine crocodile, Crocodylus porosus. J Comp Physiol B 2010; 180:825-34. [DOI: 10.1007/s00360-010-0464-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 02/23/2010] [Accepted: 02/24/2010] [Indexed: 12/01/2022]
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22
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Seebacher F. Responses to temperature variation: integration of thermoregulation and metabolism in vertebrates. J Exp Biol 2009; 212:2885-91. [DOI: 10.1242/jeb.024430] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SUMMARY
Many vertebrates regulate their body temperature in response to thermal variability of the environment. Endotherms maintain relatively stable body temperatures by adjusting metabolic heat production in response to varying environmental heat loads. Although most ectotherms do not display adaptive thermogenesis, they do acclimate cellular metabolism to compensate for environmental temperature variation. The components of the thermoregulatory systems in endotherms and ectotherms are evolutionarily conserved, and I suggest that metabolic acclimation in ectotherms relies on the same regulatory pathways as adaptive thermogenesis in endotherms. Both groups rely on transient receptor potential ion channels to sense environmental temperatures. Thermosensory (afferent) information is relayed to the hypothalamus, which initiates a sympathetic efferent response. Cardiovascular responses to heat are similar in ectothermic crocodiles and in mammals, and are mediated by the autonomic nervous system in both cases. The sympathetic nervous system also modulates cellular metabolism by inducing expression of the transcriptional regulator peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α), which interacts with a range of transcription factors that control glycolysis, fatty acid oxidation, gluconeogenesis, mitochondrial biogenesis and bioenergetics, and metabolic rate. PGC-1α is best known from mammalian model species but there is increasing evidence that it is also instrumental in non-mammalian vertebrates. Hence, endothermic adaptive thermogenesis may result from the same regulatory pathways as ectothermic metabolic acclimation, and both could be considered as adaptive metabolic responses to temperature variation.
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Affiliation(s)
- Frank Seebacher
- Integrative Physiology, School of Biological Sciences A08, University of Sydney, NSW 2006, Australia
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23
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Rutskina IM, Litvinov NA, Roshchevskaya IM, Roshchevskii MP. Temperature adaptation of the heart in the grass snake (Natrix natrix L.), common European viper (Vipera berus L.), and steppe viper (Vipera renardi Christoph) (Reptilia: Squamata: Serpentes). RUSS J ECOL+ 2009. [DOI: 10.1134/s1067413609050026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Merchant M, Monroe C, Falconi R. Dipeptidyl peptidase IV activity in the blood of the American alligator (Alligator mississippiensis). Comp Biochem Physiol B Biochem Mol Biol 2009; 154:341-5. [PMID: 19665574 DOI: 10.1016/j.cbpb.2009.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/08/2009] [Accepted: 07/30/2009] [Indexed: 11/27/2022]
Abstract
Dipeptidyl peptidase IV (DPP4) enzyme activity, associated with cell surface and soluble CD26, was measured in alligator plasma and whole blood. DPP4 activity was higher in whole blood than in the plasma, presumably due to the inclusion of both membrane-bound CD26 on the surface of T-cells and sCD26 in the plasma. The plasma DPP4 activity was measured within 5 min after the addition of the substrate, and maximal accumulation of product was reached at 120 min. Alligator whole blood DPP4 activity peaked at 120 min. In addition, the DPP4 activity in both plasma and whole blood was temperature-dependent, with moderate activities at lower temperatures (5-20 degrees C) and peak activity at 40 degrees C. Alligator plasma DPP4 displayed classical Michaelis-Menten kinetics, with a V(max) value of 267+/-9 nmol/min, and a K(m) of 21.1+/-1.9 microM, while these values were 286+/-14 nmol/min and 57.1+/-3.7 microM, respectively, for whole blood. The proteolytic activity was inhibited in a concentration-dependent manner by a specific DPP4 inhibitor, diprotin A, which indicates that the activity is probably due to the presence of DPP4. The significance of the presence of this activity in alligator blood is still unknown.
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Affiliation(s)
- Mark Merchant
- Department of Chemistry, McNeese State University, Lake Charles, LA 70609, USA.
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