65 research outputs found

    Body density and diving gas volume of the northern bottlenose whale (Hyperoodon ampullatus)

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    Funding for fieldwork and data analysis was provided by the Strategic Environmental Research and Development Program (SERDP), project RC-2337Diving lung volume and tissue density, reflecting lipid store volume, are important physiological parameters that have only been estimated for a few breath-hold diving species. We fitted 12 northern bottlenose whales with data loggers that recorded depth, 3-axis acceleration and speed either with a fly-wheel or from change of depth corrected by pitch angle.We fitted measured values of the change in speed during 5 s descent and ascent glides to a hydrodynamic model of drag and buoyancy forces using a Bayesian estimation framework. The resulting estimate of diving gas volume was 27.4±4.2 (95% credible interval, CI) ml kg−1, closely matching the measured lung capacity of the species. Dive-by-dive variation in gas volume did not correlate with dive depth or duration. Estimated body densities of individuals ranged from 1028.4 to 1033.9 kg m−3 at the sea surface, indicating overall negative tissue buoyancy of this species in seawater. Body density estimates were highly precise with ±95% CI ranging from 0.1to 0.4 kg m−3, which would equate to a precision of <0.5% of lipid content based upon extrapolation from the elephant seal. Six whales tagged near Jan Mayen (Norway, 71°N) had lower body density and were closer to neutral buoyancy than six whales tagged in the Gully (Nova Scotia, Canada, 44°N), a difference that was consistent with the amount of gliding observed during ascent versus descent phases in these animals. Implementation of this approach using longer duration tags could be used to track longitudinal changes in body density and lipid store body condition of free-ranging cetaceans.Publisher PDFPeer reviewe

    High resting metabolic rates with low thermal dependence induce active dives in overwintering Pacific juvenile loggerhead turtles

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    UTokyo FOCUS Articles掲載「三陸のウミガメは寒冷地仕様 高い休止代謝速度と低い温度依存性によって冬季でも活動性を維持」https://www.u-tokyo.ac.jp/focus/ja/articles/a_00627.htmlUTokyo FOCUS Articles "Cold never bothered me anyway Pacific sea turtles\u27 metabolisms stay active over winter" https://www.u-tokyo.ac.jp/focus/en/articles/z0508_00003.htm

    High diving metabolic rate indicated by high-speed transit to depth in negatively buoyant long-finned pilot whales

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    The US Office of Naval Research and Strategic Environmental Research and Development Program (SERDP) supported the fieldwork as a part of the 3S study collaboration. This study was also supported by the program Bio-Logging Science of the University of Tokyo (UTBLS).To maximize foraging duration at depth, diving mammals are expected to use the lowest cost optimal speed during descent and ascent transit and to minimize the cost of transport by achieving neutral buoyancy. Here, we outfitted 18 deep-diving long-finned pilot whales with multi-sensor data loggers and found indications that their diving strategy is associated with higher costs than those of other deep-diving toothed whales. Theoretical models predict that optimal speed is proportional to (basal metabolic rate/drag)1/3 and therefore to body mass0.05. The transit speed of tagged animals (2.7±0.3 m s−1) was substantially higher than the optimal speed predicted from body mass (1.4–1.7 m s−1). According to the theoretical models, this choice of high transit speed, given a similar drag coefficient (median, 0.0035) to that in other cetaceans, indicated greater basal metabolic costs during diving than for other cetaceans. This could explain the comparatively short duration (8.9±1.5 min) of their deep dives (maximum depth, 444±85 m). Hydrodynamic gliding models indicated negative buoyancy of tissue body density (1038.8± 1.6 kg m–3, ±95% credible interval, CI) and similar diving gas volume (34.6±0.6 ml kg−1, ±95% CI) to those in other deep-diving toothed whales. High diving metabolic rate and costly negative buoyancy imply a ‘spend more, gain more’ strategy of long-finned pilot whales, differing from that in other deep-diving toothed whales, which limits the costs of locomotion during foraging. We also found that net buoyancy affected the optimal speed: high transit speeds gradually decreased during ascent as the whales approached neutral buoyancy owing to gas expansion.Publisher PDFPeer reviewe

    Alternative to Rituximab Therapy for a Patient with Ankylosing Spondylitis Who Was Unable to Continue Anti-TNF Therapy

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    We herein present a case of a 38-year-old man who had bamboo spine and severe sacroiliitis and who was diagnosed with ankylosing spondylitis (AS). Infliximab (IFX) markedly improved the axial symptom but was discontinued due to the side effect of peripheral neuropathy. Switching from IFX to etanercept worsened the side effect. Rituximab (RTX) administration elicited a good response without side effects. RTX might be a suitable option for AS therapy when TNF inhibitors are difficult to use

    Preventative Effect of a Flavonoid, Enzymatically Modified Isoquercitrin on Ocular Symptoms of Japanese Cedar Pollinosis

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    ABSTRACTBackgroundFlavonoids are nutrients that exert anti-allergic effects. We investigated the preventative effect of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve the symptoms of Japanese cedar pollinosis.MethodsIn a parallel-group, double-blind placebo-controlled study design, 24 subjects with Japanese cedar pollinosis took 100 mg EMIQ or a placebo for 8 weeks, starting 4 weeks prior to the onset of pollen release. Subjective symptoms, ADL scores and the usage of drugs were recorded daily, and the QOL score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum levels of IgE and flavonoids.ResultsDuring the entire study period, ocular symptom + medication score for the EMIQ group was significantly lower (p < 0.05) than that of the placebo group. When limited to the period, ocular symptom scores (p < 0.05, weeks 5–6), and ocular congestion scores (p < 0.05, weeks 5–6) for the EMIQ group was significantly lower than that for the placebo group while other scores for the EMIQ group, such as ocular itching scores (p = 0.09, weeks 4–5), lacrimation scores (p = 0.07, weeks 5–6), and ocular congestion scores (p = 0.06, weeks 45), all tended to be lower. However no significant differences were found in nasal symptoms between the two groups. Serum concentrations of IgE were not significantly downregulated but the serum concentrations of quercetin and its derivatives were elevated significantly by the intake of EMIQ.ConclusionsIntake of the quercetin glycoside EMIQ proved to be effective for the relief of ocular symptoms caused by Japanese cedar pollinosis

    Risk Factors for Chronic Damage Accumulation Across Different Onset Eras in Systemic Lupus Erythematosus: A Cross-sectional Analysis of a Lupus Registry of Nationwide Institutions (LUNA)

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    Chronic damage accumulation affects not only mortality but also quality of life in patients with systemic lupus erythematosus (SLE). Risk factors for chronic damage were explored in SLE through different onset eras. Two hundred forty-five patients at Okayama University Hospital and Showa University Hospital were divided into three groups based on the onset era: a past-onset group (onset before 1995; n=83), middle-onset group (1996-2009; n=88), and recent-onset group (after 2010; n=74). The mean Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score as an index of chronic damage was 1.93, 1.24, and 0.53 in the past-, middle-, and recent-onset groups, respectively. In the pastonset group, the total SDI score was significantly associated with glucocorticoid monotherapy by linear regression analysis (β-coefficient [β]=0.63; 95% confidence interval [CI], 0.21-1.05) and C-reactive protein levels (β=0.67; 95% CI, 0.27-1.07). In the middle-onset group, the total SDI score was significantly associated with the SLE Disease Activity Index at registration (β=0.09; 95% CI, 0.03-0.12). Reducing the accumulation of chronic damage in SLE patients might be possible with the concomitant use of immunosuppressants and tight control of disease activity

    Latitudinal cline in the foraging dichotomy of loggerhead sea turtles reveals the importance of East China Sea for priority conservation

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    Special Issue: Biological traits, geographic distributions and species conservation in aquatic ecosystems[Aim]Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. [Location]North Pacific Ocean. [Methods]We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). [Results]Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. [Main conclusions]The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection

    Body density of humpback whales (Megaptera novaengliae) in feeding aggregations estimated from hydrodynamic gliding performance

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    This study was funded by Strategic Environmental Research and Development Program (https://www.serdp-estcp.org; grant number RC-2337). In addition, the study was partly supported by Core Research for Evolutional Science and Technology by Japan Science and Technology Agency (http://www.jst.go.jp/kisoken/crest/en/index.html, grant number JPMJCR1685) and Bilateral Open Partnership Joint Research Projects by Japan Society for the Promotion of Science (http://www.jsps.go.jp/english/e-bilat/index.html; no specific grant number).Many baleen whales undertake annual fasting and feeding cycles, resulting in substantial changes in their body condition, an important factor affecting fitness. As a measure of lipid-store body condition, tissue density of a few deep diving marine mammals has been estimated using a hydrodynamic glide model of drag and buoyancy forces. Here, we applied the method to shallow-diving humpback whales (Megaptera novaeangliae) in North Atlantic and Antarctic feeding aggregations. High-resolution 3-axis acceleration, depth and speed data were collected from 24 whales. Measured values of acceleration during 5 s glides were fitted to a hydrodynamic glide model to estimate unknown parameters (tissue density, drag term and diving gas volume) in a Bayesian framework. Estimated species-average tissue density (1031.6 ± 2.1 kg m-3, ±95% credible interval) indicates that humpback whale tissue is typically negatively buoyant although there was a large inter-individual variation ranging from 1025.2 to 1043.1 kg m-3. The precision of the individual estimates was substantially finer than the variation across different individual whales, demonstrating a progressive decrease in tissue density throughout the feeding season and comparably high lipid-store in pregnant females. The drag term (CDAm-1) was estimated to be relatively high, indicating a large effect of lift-related induced drag for humpback whales. Our results show that tissue density of shallow diving baleen whales can be estimated using the hydrodynamic gliding model, although cross-validation with other techniques is an essential next step. This method for estimating body condition is likely to be broadly applicable across a range of aquatic animals and environments.Publisher PDFPeer reviewe

    Northern bottlenose whales in a pristine environment respond strongly to close and distant navy sonar signals

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    The research described in this paper was supported by US Office of Naval Research (ONR grants N00014-15-1-2533 and N00014-16-1-3059), US Strategic Environmental Research and Development Program (SERDP award RC-2337), the French Ministry of Defence (DGA) and the Netherlands Ministry of Defence. P.L.T. acknowledges support from the MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland; supported by the Scottish Funding Council, grant reference HR09011, and contributing institutions). All relevant data and scripts are within the paper and its electronic supplementary material, or available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.fc5c0s4Impact assessments for sonar operations typically use received sound levels to predict behavioural disturbance in marine mammals. However, there are indications that cetaceans may learn to associate exposures from distant sound sources with lower perceived risk. To investigate the roles of source distance and received level in an area without frequent sonar activity, we conducted multi-scale controlled exposure experiments (n = 3) with 12 northern bottlenose whales near Jan Mayen, Norway. Animals were tagged with high-resolution archival tags (n = 1 per experiment) or medium-resolution satellite tags (n = 9 in total) and subsequently exposed to sonar. We also deployed bottom-moored recorders to acoustically monitor for whales in the exposed area. Tagged whales initiated avoidance of the sound source over a wide range of distances (0.8–28 km), with responses characteristic of beaked whales. Both onset and intensity of response were better predicted by received sound pressure level (SPL) than by source distance. Avoidance threshold SPLs estimated for each whale ranged from 117–126 dB re 1 µPa, comparable to those of other tagged beaked whales. In this pristine underwater acoustic environment, we found no indication that the source distances tested in our experiments modulated the behavioural effects of sonar, as has been suggested for locations where whales are frequently exposed to sonar.Publisher PDFPeer reviewe

    Ocean observations in support of studies and forecasts of tropical and extratropical cyclones

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Domingues, R., Kuwano-Yoshida, A., Chardon-Maldonado, P., Todd, R. E., Halliwell, G., Kim, H., Lin, I., Sato, K., Narazaki, T., Shay, L. K., Miles, T., Glenn, S., Zhang, J. A., Jayne, S. R., Centurioni, L., Le Henaff, M., Foltz, G. R., Bringas, F., Ali, M. M., DiMarco, S. F., Hosoda, S., Fukuoka, T., LaCour, B., Mehra, A., Sanabia, E. R., Gyakum, J. R., Dong, J., Knaff, J. A., & Goni, G. Ocean observations in support of studies and forecasts of tropical and extratropical cyclones. Frontiers in Marine Science, 6, (2019): 446, doi:10.3389/fmars.2019.00446.Over the past decade, measurements from the climate-oriented ocean observing system have been key to advancing the understanding of extreme weather events that originate and intensify over the ocean, such as tropical cyclones (TCs) and extratropical bomb cyclones (ECs). In order to foster further advancements to predict and better understand these extreme weather events, a need for a dedicated observing system component specifically to support studies and forecasts of TCs and ECs has been identified, but such a system has not yet been implemented. New technologies, pilot networks, targeted deployments of instruments, and state-of-the art coupled numerical models have enabled advances in research and forecast capabilities and illustrate a potential framework for future development. Here, applications and key results made possible by the different ocean observing efforts in support of studies and forecasts of TCs and ECs, as well as recent advances in observing technologies and strategies are reviewed. Then a vision and specific recommendations for the next decade are discussed.This study was supported by the National Oceanic and Atmospheric Administration and JSPS KAKENHI (Grant Numbers: JP17K19093, JP16K12591, and JP16H01846)
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