204 research outputs found
Neuroanatomical Structure of the Spinner Dolphin (Stenella longirostris orientalis) Brain From Magnetic Resonance Images
High-resolution magnetic resonance (MR) images of the brain of an adult spinner dolphin (Stenella longirostris orientalis) were acquired in the coronal plane at 55 antero-posterior levels. From these scans a computergenerated set of resectioned virtual images in the two remaining orthogonal planes was constructed with the use of the VoxelView and VoxelMath (Vital Images, Inc.) programs. Neuroanatomical structures were labeled in all three planes, providing the first labeled anatomical description of the spinner dolphin brain
Evidence for Infanticide in Bottlenose Dolphins of the Western North Atlantic
Nine bottlenose dolphin (Tursiops truncatus) calves that stranded in Virginia in 1996 and 1997 died of severe blunt-force trauma. Injuries were concentrated on the head and chest and multiple rib fractures, lung lacerations, and soft tissue contusions were prominent. Skeletal and/or soft tissue trauma occurred bilaterally in all of the calves. One had a bite wound across the left mandible that exhibited deep punctures consistent with the tooth placement in an adult bottlenose dolphin. The lesions were not compatible with predation, boat strike, fisheries interactions, rough-surf injury, or blast injury. However, they were similar to traumatic injuries described in stranded bottlenose dolphin calves and harbor porpoises (Phocoena phocoena) in Great Britain attributed to violent dolphin interactions. The evidence suggests that violent dolphin behavior was the cause of the trauma in the nine calves reported here and that infanticide occurs in bottlenose dolphins of the western North Atlantic
Fecal glucocorticoids and anthropogenic injury and mortality in North Atlantic right whales Eubalaena glacialis
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Endangered Species Research 34 (2017): 417-429, doi:10.3354/esr00866.As human impacts on marine ecosystems escalate, there is increasing interest in quantifying sub-lethal physiological and pathological responses of marine mammals. Glucocorticoid hormones are commonly used to assess stress responses to anthropogenic factors in wildlife. While obtaining blood samples to measure circulating hormones is not currently feasible for free-swimming large whales, immunoassay of fecal glucocorticoid metabolites (fGCs) has been validated for North Atlantic right whales Eubalaena glacialis (NARW). Using a general linear model, we compared fGC concentrations in right whales chronically entangled in fishing gear (n = 6) or live-stranded (n = 1), with right whales quickly killed by vessels (n = 5) and healthy right whales (n = 113) to characterize fGC responses to acute vs. chronic stressors. fGCs in entangled whales (mean ± SE: 1856.4 ± 1644.9 ng g-1) and the stranded whale (5740.7 ng g-1) were significantly higher than in whales killed by vessels (46.2 ± 19.2 ng g-1) and healthy whales (51.7 ± 8.7 ng g-1). Paired feces and serum collected from the live-stranded right whale provided comparison of fGCs in 2 matrices in a chronically stressed whale. Serum cortisol and corticosterone in this whale (50.0 and 29.0 ng ml-1, respectively) were much higher than values reported in other cetaceans, in concordance with extremely elevated fGCs. Meaningful patterns in fGC concentration related to acute vs. chronic impacts persisted despite potential for bacterial degradation of hormone metabolites in dead whales. These results provide biological validation for using fGCs as a biomarker of chronic stress in NARWs.This
research was funded by the NOAA/NMFS, Office of Naval
Research Marine Mammals and Biology Program, Northeast
Consortium, Island Foundation, Irving Oil, NEAq Internal
Research Fund, Prescott Grant NA08NMF4390590, and
NOAA CINAR Cooperative Agreement NA09OAR4320129
A comparative analysis of marine mammal tracheas
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 217 (2014): 1154-1166, doi:10.1242/âjeb.093146.In 1940, Scholander suggested that stiffened upper airways remained open and received air from highly compressible alveoli during marine mammal diving. There are little data available on the structural and functional adaptations of the marine mammal respiratory system. The aim of this research was to investigate the anatomical (gross) and structural (compliance) characteristics of excised marine mammal tracheas. Here we defined different types of tracheal structures, categorizing pinniped tracheas by varying degrees of continuity of cartilage (categories 1-4) and cetacean tracheas by varying compliance values (categories 5A and 5B). Some tracheas fell into more than one category, along their length, for example, the harbor seal (Phoca vitulina) demonstrated complete rings cranially, and as the trachea progressed caudally tracheal rings changed morphology. Dolphins and porpoises had less stiff, more compliant spiraling rings while beaked whales had very stiff, less compliant spiraling rings. The pressure-volume (P-V) relationships of isolated tracheas from different species were measured to assess structural differences between species. These findings lend evidence for pressure-induced collapse and re-inflation of lungs, perhaps influencing variability in dive depth or ventilation rates of the species investigated.This project was supported by a grant from the Office of Naval Research (award number N00014-10-1-0059).2014-12-0
Anatomy and Three-Dimensional Reconstructions of the Brain of a Bottlenose Dolphin (Tursiops truncatus) From Magnetic Resonance Images
Cetacean (dolphin, whale, and porpoise) brains are among the least studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Magnetic resonance imaging offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Furthermore, internal structures can be analyzed in their precise anatomic positions, which is difficult to accomplish after the spatial distortions often accompanying histological processing. In this study, images of the brain of an adult bottlenose dolphin, Tursiops truncatus, were scanned in the coronal plane at 148 antero-posterior levels. From these scans a computer-generated three-dimensional model was constructed using the programs Voxel-View and VoxelMath (Vital Images, Inc.). This model, wherein details of internal and external morphology are represented in three-dimensional space, was then resectioned in orthogonal planes to produce corresponding series of virtual sections in the horizontal and sagittal planes. Sections in all three planes display the sizes and positions of major neuroanatomical features such as the arrangement of cortical lobes and subcortical structures such as the inferior and superior colliculi, and demonstrate the utility of MRI for neuroanatomical investigations of dolphin brains
Entanglements of North Atlantic right whales increase as their distribution shifts in response to climate change: The need for a new management paradigm [poster]
Presented at 2019: World Marine Mammal Science Conference, Barcelona, Spain, December 9-12, 2019.Detection rate of severely injured or entangled NARWs began to increase around 2004 - 2007.We thank the North Atlantic Right Whale Consortium for data curation and dissemination, and the Atlantic Large Whale Disentanglement Network for entanglement sighting information
First Meeting
The transcription of this meeting was published in the Review and Herald, June 6, 1946, page 12.
After singing the hymn âNearer, My God to Thee,â General Conference President J. L. McElhany opens the 45th General Conference Session. The Congregation sings hymn 664, the same hymn used at the opening of the 1st General Conference Session. W. A. Spicer gives prayer. The A Cappella Choir of Washington Missionary College, under the leadership of Minnie Iverson Wood, sings Holy Lord God. J. L. McElhany and Secretary E. D. Dick proceed with business. J. L. McElhany give an address. Secretary E. D. Dick presents greetings from those who were unable to attend including: Elder C. H. Watson, Sydney, Australia; Dr. Hoiberg, Senior Specialist of Evangelical Affairs; A. Minck, President of the Central European Division; Russian Division officials Grigorieff (President), Galladsheff (Secretary), and Melnik (Treasurer). Dick reads a letter from Brother D. Drinhaus, representing the eleven missionaries who were serving in the Dutch East Indies and were taken to an internment camp in Dehra Dun near the Himalayan Mountains almost 7 years ago. He also presents greetings from E. A. Moon (Southern Africa Division); the Zambesi Union Committee; S. G. Maxwell (Superintendent of Southeast African Union); E. R. Osmunson (Superintendent of South India Union Mission; brother Manley, (Superintendent of Burma Mission), M. J. Sorensen (Ethiopia), and Elder Cartwell (China). A letter of response to the messages is pesented. Announcements precede closing hymn 255, âHow Firm a Foundation.â F. M. Wilcox gives prayer
Myoglobin concentration and oxygen stores in different functional muscle groups from three small cetacean species
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Arregui, M., Singleton, E. M., Saavedra, P., Pabst, D. A., Moore, M. J., Sierra, E., Rivero, M. A., CĂąmara, N., Niemeyer, M., Fahlman, A., McLellan, W. A., & Bernaldo de QuirĂłs, Y. Myoglobin concentration and oxygen stores in different functional muscle groups from three small cetacean species. Animals, 11(2), (2021): 451, https://doi.org/10.3390/ani11020451.Compared with terrestrial mammals, marine mammals possess increased muscle myoglobin concentrations (Mb concentration, g Mb · 100gâ1 muscle), enhancing their onboard oxygen (O2) stores and their aerobic dive limit. Although myoglobin is not homogeneously distributed, cetacean muscle O2 stores have been often determined by measuring Mb concentration from a single muscle sample (longissimus dorsi) and multiplying that value by the animalâs locomotor muscle or total muscle mass. This study serves to determine the accuracy of previous cetacean muscle O2 stores calculations. For that, body muscles from three delphinid species: Delphinus delphis, Stenella coeruleoalba, and Stenella frontalis, were dissected and weighed. Mb concentration was calculated from six muscles/muscle groups (epaxial, hypaxial and rectus abdominis; mastohumeralis; sternohyoideus; and dorsal scalenus), each representative of different functional groups (locomotion powering swimming, pectoral fin movement, feeding and respiration, respectively). Results demonstrated that the Mb concentration was heterogeneously distributed, being significantly higher in locomotor muscles. Locomotor muscles were the major contributors to total muscle O2 stores (mean 92.8%) due to their high Mb concentration and large muscle masses. Compared to this method, previous studies assuming homogenous Mb concentration distribution likely underestimated total muscle O2 stores by 10% when only considering locomotor muscles and overestimated them by 13% when total muscle mass was considered.This research was funded by the US Office of Naval Research N00014-13-1-0773, the Subprograma de Biodiversidad del Ministerio de EconomĂa y Competitividad del Gobierno de España (MINECO CGL 2012-39681 and CGL2015-71498-P) and the Canary Islands Government, which has funded and provided support to the stranding network. M.A. is funded by the University Professor Formation fellowship from the Spanish Ministry of Education, and Y.B.d.Q. is funded by a postdoctoral fellowship from the University of Las Palmas de Gran Canaria
A regioselectively 1, 1',3 ,3'-tetrazincated ferrocene complex displaying core and peripheral reactivity
Regioselective 1,1âČ,3,3âČ-tetrazincation [C-H to C-Zn(tBu)] of ferrocene has been achieved by reaction of a fourfold excess of di-t-butylzinc (tBu2Zn) with sodium 2,2,6,6-tetramethylpiperidide (NaTMP) in hexane solution manifested in the trimetallic iron-sodium-zinc complex [Na4(TMP)4Zn4(tBu)4{(C5H3)2Fe}], 1. X-ray crystallographic studies supported by DFT modelling reveal the structure to be an open inverse crown in which two [Na(TMP)Zn(tBu)Na(TMP)Zn(tBu)]2+ cationic units surround a {(C5H3)2Fe}4- tetraanion. Detailed C6D6 NMR studies have assigned the plethora of 1H and 13C chemical shifts of this complex. It exists in a major form in which capping and bridging TMP groups interchange, as well as a minor form that appears to be an intermediate in this complicated exchange phenomenon. Investigation of 1 has uncovered two distinct reactivities. Two of its peripheral t-butyl carbanions formally deprotonate toluene at the lateral methyl group to generate benzyl ligands that replace these carbanions in [Na4(TMP)4Zn4(tBu)2(CH2Ph)2{(C5H3)2Fe}], 2, which retains its tetrazincated ferrocenyl core. Benzyl-Na Ï-arene interactions are a notable feature of 2. In contrast, reaction with pyridine affords the crystalline product {[Na·4py][Zn(pyâ)2(tBu)·py]}â, 3, where py is neutral pyridine (C5H5N) and pyâ is the anion (4-C5H4N), a rare example of pyridine deprotonated/metallated at the 4-position. This ferrocene-free complex appears to be a product of core reactivity in that the core-positioned ferrocenyl anions of 1, in company with TMP anions, have formally deprotonated the heterocycle
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