USAP-DC

{"dp_type": "Dataset", "free_text": "Aerobic"}

[{"awards": "1853377 Shero, Michelle; 0838937 Costa, Daniel; 0838892 Burns, Jennifer", "bounds_geometry": ["POLYGON((-180 -72,-179.8 -72,-179.6 -72,-179.4 -72,-179.2 -72,-179 -72,-178.8 -72,-178.6 -72,-178.4 -72,-178.2 -72,-178 -72,-178 -72.7,-178 -73.4,-178 -74.1,-178 -74.8,-178 -75.5,-178 -76.2,-178 -76.9,-178 -77.6,-178 -78.3,-178 -79,-178.2 -79,-178.4 -79,-178.6 -79,-178.8 -79,-179 -79,-179.2 -79,-179.4 -79,-179.6 -79,-179.8 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.3,162 -77.6,162 -76.9,162 -76.2,162 -75.5,162 -74.8,162 -74.1,162 -73.4,162 -72.7,162 -72,163.8 -72,165.6 -72,167.4 -72,169.2 -72,171 -72,172.8 -72,174.6 -72,176.4 -72,178.2 -72,-180 -72))"], "date_created": "Fri, 20 Sep 2024 00:00:00 GMT", "description": "Diel vertical migrations (DVM) have been well-documented across numerous taxa, with prey descend through the water column during daylight hours to avoid visual predators and feed at the surface at night. However, the ability of marine mammals such as Weddell seals (Leptonychotes weddellii) to follow prey to depths is likely constrained by limited breath-hold capacities and the physiological consequences of pushing aerobic thresholds. In particular, dives that exceed the aerobic dive limit require exponentially longer surface recuperation times to clear lactate byproducts from circulation. This is time that the animals then cannot spend foraging. In this study, we assess the circadian organization of the Weddell seal\u0027s dive efforts and when animals make their longest/deepest (most \u0027extreme\u0027) dives that far exceed aerobic thresholds. Sixty-two adult Weddell seals were instrumented with satellite linked relay loggers in the Ross Sea to collect behavioral information across the austral winter. Daily activities are likely to shift across the year in a highly-seasonal polar environment, and through this \u0027natural experiment\u0027 we test how free-ranging seals alter foraging behavior during Polar Day and Night (continuous light, LL and dark, DD, respectively) and varying light/dark (LD) cycling across the year.", "east": -178.0, "geometry": ["POINT(172 -75.5)"], "keywords": "Aerobic; Antarctica; Cryosphere; Weddell Seal", "locations": "Antarctica; Antarctica", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Shero, Michelle", "project_titles": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals; Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea", "projects": [{"proj_uid": "p0000661", "repository": "USAP-DC", "title": "Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea"}, {"proj_uid": "p0010369", "repository": "USAP-DC", "title": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Weddell seal dive behavior and rhythmicity from 2010-2012 in the Ross Sea", "uid": "601835", "west": 162.0}, {"awards": "1744999 Todgham, Anne", "bounds_geometry": null, "date_created": "Wed, 07 Feb 2024 00:00:00 GMT", "description": "In this study we examined aerobic metabolic capacity in three species, Trematomus bernacchii, T. pennellii and T. newnesi, and between two life stages, juvenile and adult, by assessing mitochondrial function of permeabilized cardiac fibers.", "east": null, "geometry": null, "keywords": "Antarctica; McMurdo Sound", "locations": "Antarctica; McMurdo Sound", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Todgham, Anne; Mandic, Milica; Frazier, Amanda; Naslund, Andrew", "project_titles": "Interacting Stressors: Metabolic Capacity to Acclimate under Ocean Warming and CO2- Acidification in Early Developmental Stages of Antarctic Fishes", "projects": [{"proj_uid": "p0010241", "repository": "USAP-DC", "title": "Interacting Stressors: Metabolic Capacity to Acclimate under Ocean Warming and CO2- Acidification in Early Developmental Stages of Antarctic Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A comparative and ontogenetic examination of mitochondrial function in Antarctic notothenioid species", "uid": "601766", "west": null}, {"awards": "1246463 Burns, Jennifer", "bounds_geometry": ["POLYGON((162 -75,162.6 -75,163.2 -75,163.8 -75,164.4 -75,165 -75,165.6 -75,166.2 -75,166.8 -75,167.4 -75,168 -75,168 -75.4,168 -75.8,168 -76.2,168 -76.6,168 -77,168 -77.4,168 -77.8,168 -78.2,168 -78.6,168 -79,167.4 -79,166.8 -79,166.2 -79,165.6 -79,165 -79,164.4 -79,163.8 -79,163.2 -79,162.6 -79,162 -79,162 -78.6,162 -78.2,162 -77.8,162 -77.4,162 -77,162 -76.6,162 -76.2,162 -75.8,162 -75.4,162 -75))"], "date_created": "Tue, 05 Jul 2022 00:00:00 GMT", "description": "The profound impacts that maternal provisioning of finite energy resources has on offspring survival have been extensively studied across mammals. However, in addition to calories, we tested whether high hemoprotein concentrations in diving mammals necessitates exceptional female-to-pup iron transfer. To answer this question adult female Weddell seals (Leptonychotes weddellii) were handled across the austral summer. This included post-partum females during lactation and post-weaning. To demonstrate that any observed changes in iron dynamics were due to lactation, equivalent skip-breeding females (i.e., that did not produce a pup) were also handled. We measured numerous indices of iron mobilization (ferritin, serum iron, total-iron-binding-capacity, transferrin saturation, milk iron concentration), hemoprotein concentrations, and oxygen stores.", "east": 168.0, "geometry": ["POINT(165 -77)"], "keywords": "Aerobic; Antarctica; Dive Capacity; Iron; McMurdo Sound; Weddell Seal", "locations": "Antarctica; McMurdo Sound", "north": -75.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Shero, Michelle", "project_titles": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals; The Cost of A New Fur Coat: Interactions between Molt and Reproduction in Weddell Seals", "projects": [{"proj_uid": "p0000229", "repository": "USAP-DC", "title": "The Cost of A New Fur Coat: Interactions between Molt and Reproduction in Weddell Seals"}, {"proj_uid": "p0010369", "repository": "USAP-DC", "title": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Weddell seal iron dynamics and oxygen stores across lactation", "uid": "601587", "west": 162.0}, {"awards": "1341663 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "Studies in temperate fishes provide evidence that cardiac mitochondrial function and the capacity to fuel cardiac work contribute to thermal tolerance. Here, we tested the hypothesis that decreased cardiac aerobic metabolic capacity contributes to the lower thermal tolerance of the haemoglobinless Antarctic icefish, Chaenocephalus aceratus, compared with that of the red-blooded Antarctic species, Notothenia coriiceps. Maximal activities of citrate synthase (CS) and lactate dehydrogenase (LDH), respiration rates of isolated mitochondria, adenylate levels and changes in mitochondrial protein expression were quantified from hearts of animals held at ambient temperature or exposed to their critical thermal maximum (CTmax). Compared with C. aceratus, activity of CS, ATP concentration and energy charge were higher in hearts of N. coriiceps at ambient temperature and CTmax While state 3 mitochondrial respiration rates were not impaired by exposure to CTmax in either species, state 4 rates, indicative of proton leakage, increased following exposure to CTmax in C. aceratus but not N. coriiceps The interactive effect of temperature and species resulted in an increase in antioxidants and aerobic metabolic enzymes in N. coriiceps but not in C. aceratus Together, our results support the hypothesis that the lower aerobic metabolic capacity of C. aceratus hearts contributes to its low thermal tolerance. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Cardiac metabolism in Antarctic fishes in response to an acute increase in temperature", "uid": "601405", "west": null}, {"awards": "1341663 O\u0027Brien, Kristin; 1341602 Crockett, Elizabeth", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "The ability of Antarctic notothenioid fishes to mount a robust molecular response to hypoxia is largely unknown. The transcription factor, hypoxia-inducible factor-1 (HIF-1), a heterodimer of HIF-1\u03b1 and HIF-1\u03b2 subunits, is the master regulator of oxygen homeostasis in most metazoans. We sought to determine if, in the hearts of Antarctic notothenioids, HIF-1 is activated and functional in response to either an acute heat stress or hypoxia. The red-blooded Notothenia coriiceps and the hemoglobinless icefish, Chaenocephalus aceratus, were exposed to their critical thermal maximum (CTMAX) or hypoxia (5.0 \u00b1 0.3 mg of O2 L-1) for 2 h. Additionally, N. coriiceps was exposed to 2.3 \u00b1 0.3 mg of O2 L-1 for 12 h, and red-blooded Gobionotothen gibberifrons was exposed to both levels of hypoxia. Levels of HIF-1\u03b1 were quantified in nuclei isolated from heart ventricles using western blotting. Transcript levels of genes involved in anaerobic metabolism, and known to be regulated by HIF-1, were quantified by real-time PCR, and lactate levels were measured in heart ventricles. Protein levels of HIF-1\u03b1 increase in nuclei of hearts of N. coriiceps and C. aceratus in response to exposure to CTMAX and in hearts of N. coriiceps exposed to severe hypoxia, yet mRNA levels of anaerobic metabolic genes do not increase in any species, nor do lactate levels increase, suggesting that HIF-1 does not stimulate metabolic remodeling in hearts of notothenioids under these conditions. Together, these data suggest that Antarctic notothenioids may be vulnerable to hypoxic events, which are likely to increase with climate warming. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctic Peninsula; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Hypoxia response of hearts of Antarctic fishes", "uid": "601406", "west": null}, {"awards": "1043740 Lenczewski, Melissa", "bounds_geometry": ["POLYGON((165 -77.5,165.3 -77.5,165.6 -77.5,165.9 -77.5,166.2 -77.5,166.5 -77.5,166.8 -77.5,167.1 -77.5,167.4 -77.5,167.7 -77.5,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,168 -78.1,168 -78.2,168 -78.3,168 -78.4,168 -78.5,167.7 -78.5,167.4 -78.5,167.1 -78.5,166.8 -78.5,166.5 -78.5,166.2 -78.5,165.9 -78.5,165.6 -78.5,165.3 -78.5,165 -78.5,165 -78.4,165 -78.3,165 -78.2,165 -78.1,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "The PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research.\nThis proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research.\n", "east": 168.0, "geometry": ["POINT(166.5 -78)"], "keywords": "Andrill; Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:rock; Chemistry:Rock; Drilling Fluid; Geochemistry; McMurdo; Ross Sea; Sediment Core", "locations": "McMurdo; Antarctica; Ross Sea", "north": -77.5, "nsf_funding_programs": null, "persons": "Lenczewski, Melissa", "project_titles": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "projects": [{"proj_uid": "p0000468", "repository": "USAP-DC", "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.5, "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "uid": "600129", "west": 165.0}, {"awards": "0944220 Ponganis, Paul", "bounds_geometry": ["POLYGON((-160 -68,-159 -68,-158 -68,-157 -68,-156 -68,-155 -68,-154 -68,-153 -68,-152 -68,-151 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-151 -78,-152 -78,-153 -78,-154 -78,-155 -78,-156 -78,-157 -78,-158 -78,-159 -78,-160 -78,-160 -77,-160 -76,-160 -75,-160 -74,-160 -73,-160 -72,-160 -71,-160 -70,-160 -69,-160 -68))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Emperor penguins (Aptenodytes forsteri) and leopard seals (Hydrurga leptonyx) are iconic, top predators in Antarctica. Understanding their physiological ecology is essential to the assessment of their adaptability to the threats of climate change, pollution, and overfishing. The proposed research has multipronged objectives. Prior results suggest that Emperor penguins have flexible (vs. static) aerobic dive limits (ADL) that vary with the type of dive, and that the role of heart rate in utilization of oxygen stores also varies with dive type. A series of physiological measurements are proposed with backpack electrocardiogram recorders, that will allow further delineation of patterns and interrelationships among heart rate, dive behavior, and oxygen stores. Importantly, the research will be done on free diving emperors, and not individuals confined to a dive hole, thereby providing a more genuine measure of diving physiology and behavior. A separate objective is to examine foraging behavior of leopard seals, using a backpack digital camera and time depth recorder. Leopard seal behavior and prey intake is poorly quantified, but known to be significant. Accordingly the research is somewhat exploratory but will provide important baseline data. Finally, the P.I. proposes to continue long term overflight censuses of Emperor penguin colonies in the Ross Sea. Broader impacts include collaboration with National Geographic television, graduate student training, and development of sedation techniques for leopard seals.\n", "east": -150.0, "geometry": ["POINT(-155 -73)"], "keywords": "Antarctica; Biota; Electrocardiogram; Penguin; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -68.0, "nsf_funding_programs": null, "persons": "Ponganis, Paul", "project_titles": "The Physiological Ecology of Two Antarctic Icons: Emperor Penguins and Leopard Seals", "projects": [{"proj_uid": "p0000349", "repository": "USAP-DC", "title": "The Physiological Ecology of Two Antarctic Icons: Emperor Penguins and Leopard Seals"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "The Physiological Ecology of Two Antarctic Icons: Emperor Penguins and Leopard Seals", "uid": "600113", "west": -160.0}, {"awards": "0437887 Sidell, Bruce", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "The polar ocean presently surrounding Antarctica is the coldest, most thermally stable marine environment on earth. Because oxygen solubility in seawater is inversely proportional to temperature, the cold Antarctic seas are an exceptionally oxygen-rich aquatic habitat. Eight families of a single perciform suborder, the Notothenioidei, dominate the present fish fauna surrounding Antarctica. Notothenioids account for approximately 35% of fish species and 90% of fish biomass south of the Antarctic Polar Front. Radiation of closely related notothenioid species thus has occurred rapidly and under a very unusual set of conditions: relative oceanographic isolation from other faunas due to circumpolar currents and deep ocean trenches surrounding the continent, chronically, severely cold water temperatures, very high oxygen availability, very low levels of niche competition in a Southern Ocean depauperate of species subsequent to a dramatic crash in species diversity of fishes that occurred sometime between the mid-Tertiary and present. These features make Antarctic notothenioid fishes an uniquely attractive group for the study of physiological and biochemical adaptations to cold body temperature. Few distinctive features of Antarctic fishes are as unique as the pattern of expression of oxygen-binding proteins in one notothenioid family, the Channichthyidae (Antarctic icefishes). All channichthyid icefishes lack the circulating oxygen-binding protein, hemoglobin (Hb); the intracellular oxygen-binding protein, myoglobin (Mb) is not uniformly expressed in species of this family. Both proteins are normally considered essential for adequate delivery of oxygen to aerobically poised tissues of animals. To compensate for the absence of Hb, icefishes have developed large hearts, rapidly circulate a large blood volume and possess elaborate vasculature of larger lumenal diameter than is seen in red-blooded fishes. Loss of Mb expression in oxidative muscles correlates with dramatic elevation in density of mitochondria within the cell, although each individual organelle is less densely packed with respiratory proteins. Within the framework of oxygen movement, the adaptive significance of greater vascular density and mitochondrial populations is understandable but mechanisms underlying development of these characteristics remain unknown. The answer may lie in another major function of both Hb and Mb, degradation of the ubiquitous bioactive compound, nitric oxide (NO). The research will test the hypothesis that loss of hemoprotein expression in icefishes has resulted in an increase in levels of NO that mediate modification of vascular systems and expansion of mitochondrial populations in oxidative tissues. The objectives of the proposal are to quantify the vascular density of retinas in +Hb and -Hb notothenioid species, to characterize NOS isoforms and catalytic activity in retina and cardiac muscle of Antarctic notothenioid fishes, to evaluate level of expression of downstream factors implicat ed in angiogenesis (in retinal tissue) and mitochondrial biogenesis (in cardiac muscle), and to determine whether inhibition of NOS in vivo results in regression of angiogenic and mitochondrial biogenic responses in icefishes. Broader impacts range from basic biology, through training of young scientists, to enhanced understanding of clinically relevant biomedical processes.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Biota; Oceans; Pot; Sample/collection Description; Sample/Collection Description; Southern Ocean; Trawl", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Sidell, Bruce", "project_titles": "Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis.", "projects": [{"proj_uid": "p0000527", "repository": "USAP-DC", "title": "Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis", "uid": "600039", "west": -180.0}, {"awards": "0538594 Ponganis, Paul", "bounds_geometry": ["POLYGON((165.983 -77.683,166.0164 -77.683,166.0498 -77.683,166.0832 -77.683,166.1166 -77.683,166.15 -77.683,166.1834 -77.683,166.2168 -77.683,166.2502 -77.683,166.2836 -77.683,166.317 -77.683,166.317 -77.6897,166.317 -77.6964,166.317 -77.7031,166.317 -77.7098,166.317 -77.7165,166.317 -77.7232,166.317 -77.7299,166.317 -77.7366,166.317 -77.7433,166.317 -77.75,166.2836 -77.75,166.2502 -77.75,166.2168 -77.75,166.1834 -77.75,166.15 -77.75,166.1166 -77.75,166.0832 -77.75,166.0498 -77.75,166.0164 -77.75,165.983 -77.75,165.983 -77.7433,165.983 -77.7366,165.983 -77.7299,165.983 -77.7232,165.983 -77.7165,165.983 -77.7098,165.983 -77.7031,165.983 -77.6964,165.983 -77.6897,165.983 -77.683))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "The research will examine blood and muscle oxygen store depletion in relation to the documented aerobic dive limit (ADL, onset of post-dive blood lactate accumulation) in diving of emperor penguins. The intellectual merits of this proposal involve its evaluation of the physiological basis of the ADL concept. The ADL is probably the most commonly-used, but rarely measured, factor to interpret and model the behavior and foraging ecology of diving animals. Based on prior studies, and on recent investigations of respiratory and blood oxygen depletion during dives of emperor penguins, it is hypothesized that the ADL is a result of the depletion of myoglobin (Mb)-bound oxygen and increased glycolysis in the primary locomotory muscles. This project will accurately define the physiological mechanisms underlying the ADL through 1) evaluation of the rate and magnitude of muscle oxygen depletion during dives in relation to the previously measured ADL, 2) characterization of the hemoglobin-oxygen dissociation curve in blood of emperor penguins and comparison of that curve to those of other diving and non-diving species, 3) application of the emperor hemoglogin-oxygen dissociation curve to previously collected oxygen and hemoglobin data in order to estimate the rate and magnitude of blood oxygen depletion during dives, and 4) measurement of muscle phosphoocreatine and glycogen concentrations in order to estimate their potential contributions to muscle energy metabolism during diving. The project also continues the census and monitoring of the emperor colonies in the Ross Sea, which is especially important in light of both fisheries activity and the movement of iceberg B15-A. Broader impacts of the project include: 1) technological development of microprocessor-based, \u0027backpack\u0027 near-infrared spectrophotometer, which will be applicable not only to other species, but also to other fields (i.e., exercise physiology), 2) collaboration with the Department of Anesthesia at the U.S. Naval Hospital in San Diego in the training of anesthesia residents in research techniques, 3) the training and thesis research of two graduate students in these techniques and in Antarctic field research, and 4) a better understanding of the ADL concept and its use in the fields of diving behavior and physiology. In addition the annual census of emperor penguin colonies in the Ross Sea, in conjunction with the continued evaluation of previously developed remote cameras to monitor colony status, will form the basis of a new educational web site, and allow development of an educational outreach program to school children through SeaWorld of San Diego.", "east": 166.317, "geometry": ["POINT(166.15 -77.7165)"], "keywords": "Antarctica; Biota; Oceans; Penguin; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -77.683, "nsf_funding_programs": null, "persons": "Ponganis, Paul", "project_titles": "The Aerobic Dive Limit: Oxygen Transport and Depletion in Emperor Penguins", "projects": [{"proj_uid": "p0000535", "repository": "USAP-DC", "title": "The Aerobic Dive Limit: Oxygen Transport and Depletion in Emperor Penguins"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.75, "title": "The Aerobic Dive Limit: Oxygen Transport and Depletion in Emperor Penguins", "uid": "600057", "west": 165.983}, {"awards": "0634682 Kanatous, Shane", "bounds_geometry": ["POLYGON((160 -77,160.7 -77,161.4 -77,162.1 -77,162.8 -77,163.5 -77,164.2 -77,164.9 -77,165.6 -77,166.3 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.3 -78,165.6 -78,164.9 -78,164.2 -78,163.5 -78,162.8 -78,162.1 -78,161.4 -78,160.7 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "During the past three decades, intensive field studies have revealed much about the behavior, physiology, life history, and population dynamics of the Weddell seal (Leptonychotes weddelli) population of McMurdo Sound, Antarctica. These animals are marine predators that are highly adapted for an aquatic life in shore-fast and pack ice habitats. They must locate and capture sparsely distributed under the ice. Most of what is known about their diving behavior is based on studies of adult animals with little known about the development or the genetic controls of diving behavior of young animals. The goal of this project is to examine the temporal development of aerobic capacity, lipid metabolism and oxygen stores in the skeletal muscles of young Weddell seals and to determine which aspects of the cellular environment are important in the regulation of these adaptations during maturation. This project builds on past results to investigate the molecular controls that underlie the development of these adaptations. The first objective is to further characterize the ontogenetic changes in muscle aerobic capacity, lipid metabolism and myoglobin concentration and distribution using enzymatic, immuno-histochemical and myoglobin assays in newly weaned, subadult, and adult seals. The second objective is to determine the molecular controls that regulate these changes in aerobic capacity, fiber type distribution and myoglobin in skeletal muscles during maturation. Through subtractive hybridization and subsequent analysis, differences in mRNA populations in the swimming muscles of the different age classes of Weddell seals will be determined. These techniques will allow for the identification of the proteins and transcription factors that influence the ontogenetic changes in myoglobin concentration, fiber type distribution and aerobic capacity. These results will increase our understanding of both the ontogeny and molecular mechanisms by which young seals acquire the physiological capabilities to make deep (up to 700 m) and long aerobic dives (ca 20 min). This study will advance knowledge of the molecular regulation for the adaptations that enable active skeletal muscle to function under hypoxic conditions; this has a broader application for human medicine especially in regards to cardiac and pulmonary disease. Additional broader impacts include the participation of underrepresented scientists and a continuation of a website in collaboration with the Science Teachers Access to Resources at Southwestern University (STARS Program) which involves weekly updates about research efforts during the field season, weekly questions/answer session involving students and teachers, and updates on research results throughout the year.", "east": 167.0, "geometry": ["POINT(163.5 -77.5)"], "keywords": "Antarctica; Biota; Oceans; Seals; Sea Surface; Southern Ocean", "locations": "Sea Surface; Southern Ocean; Antarctica", "north": -77.0, "nsf_funding_programs": null, "persons": "Lyons, W. Berry; Kanatous, Shane", "project_titles": "The Molecular Signals that Regulate the Ontogeny of Aerobic Capacity, Lipid Metabolism and Elevated Myoglobin Concentrations in the Skeletal Muscles of Weddell Seals", "projects": [{"proj_uid": "p0000536", "repository": "USAP-DC", "title": "The Molecular Signals that Regulate the Ontogeny of Aerobic Capacity, Lipid Metabolism and Elevated Myoglobin Concentrations in the Skeletal Muscles of Weddell Seals"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "The Molecular Signals that Regulate the Ontogeny of Aerobic Capacity, Lipid Metabolism and Elevated Myoglobin Concentrations in the Skeletal Muscles of Weddell Seals", "uid": "600063", "west": 160.0}, {"awards": "0229638 Ponganis, Paul", "bounds_geometry": ["POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))"], "date_created": "Tue, 01 Jan 2008 00:00:00 GMT", "description": "The emperor penguin, Aptenodytes forsteri, is the premier avian diver and a top predator in the Antarctic ecosystem. The routine occurrence of 500-m diver during foraging trips to sea is both a physiological and behavior enigma. The objectives of this project address how and why emperors dive as deep and long as they do. The project examines four major topics in the diving biology of emperor penguins: pressure tolerance, oxygen store management, end-organ tolerance of diving hypoxemia/ischemia, and deep-dive foraging behavior. These subjects are relevant to the role of the emperor as a top predator in the Antarctic ecosystem, and to critical concepts in diving physiology, including decompression sickness, nitrogen narcosis, shallow water blackout, hypoxemic tolerance, and extension of aerobic dive time. The following hypotheses will be tested: 1) Prevention of nitrogen narcosis and decompression sickness in emperor penguins is achieved by inhibition of pulmonary gas exchange at depth. 2) Shallow water black out does not occur because of greater cerebral hypoxemic tolerance, and, in deep dives, because of resumption of pulmonary gas exchange during final ascent. 3) The rate of depletion of the blood oxygen store is a function of depth of dive and heart rate. 4) The aerobic dive limit (ADL) reflects the onset of lactate accumulation in locomotory muscle, not total depletion of all oxygen stores. 5) Elevation of tissue antioxidant capacity and free-radical scavenging enzyme activities protect against the routine ischemia/reperfusion which occur during diving. 6) During deep dives, the Antarctic silverfish, Pleuorogramma antarcticum, is the primary prey item for emperors. In addition to evaluation of the hypotheses below, the project has broader impacts in several areas such as partnership with foreign and national institutes and organizations (e.g., the National Institute of Polar Research of Japan, Centro de Investigacioines del Noroeste of Mexico, National Geographic, the University of Texas Southwestern Medical Center, and Sea World). Participation in National Geographic television documentaries will provide unique educational opportunities for the general public; development of state-of-the-art technology (e.g., blood oxygen electrode recorders, blood samplers, and miniaturized digital cameras) will lay the groundwork for future research by this group and others; and the effects of the B15 iceberg on breeding success of emperor penguins will continue to be evaluated with population censuses during planned fieldwork at several Ross Sea emperor penguin colonies.", "east": 167.0, "geometry": ["POINT(165 -77.5)"], "keywords": "Antarctica; Biota; Oceans; Penguin; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -77.0, "nsf_funding_programs": null, "persons": "Ponganis, Paul", "project_titles": "Diving Physiology and Behavior of Emperor Penguins", "projects": [{"proj_uid": "p0000239", "repository": "USAP-DC", "title": "Diving Physiology and Behavior of Emperor Penguins"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Diving Physiology and Behavior of Emperor Penguins", "uid": "600031", "west": 163.0}]

View results on map Help on results map