Severity: Warning
Message: fopen(/var/lib/php/sessions/ci_sessionn9k36qsiumoa9pek4vtn8ut5c32a747r): Failed to open stream: No space left on device
Filename: drivers/Session_files_driver.php
Line Number: 177
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)
Filename: Session/Session.php
Line Number: 137
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
We have discovered features of the nuchal joint in the squid, , that are unique compared with moveable joints in other animals. The joint's function is unclear but it allows the head to glide toward and away from the mantle. The head glides along the joint with ease yet disarticulating the joint perpendicular to the axis of movement requires considerable force. After disarticulation, the joint components can be repositioned and full function restored immediately. Thus, an unknown attachment mechanism prevents the joint from being disarticulated yet permits gliding. We show that the joint was formed by the articulation of the nuchal cartilage and a heretofore-undescribed organ that we named the nuchal 'joint pad'. The joint pad is composed predominantly of muscle, connective tissue and cartilage organized into two distinct regions: a ventral cartilaginous layer and a dorsal muscular layer. Disarticulating the nuchal joint at a displacement rate of 5 mm s required 1.5 times greater stress (i.e. force per unit area) than at 1 mm s The force required to disarticulate the joint increased with nuchal cartilage area and with nuchal cartilage length The stress required to shear the nuchal joint was nearly three orders of magnitude lower than that required to disarticulate the joint. Stimulation of the joint pad dorso-ventral musculature resulted in significantly greater shear force required to move the joint (=0.004). Perforating the nuchal cartilage decreased the stress required to disarticulate the joint to nearly zero. The results support the hypothesis that suction is the attachment mechanism.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1242/jeb.211227 | DOI Listing |
Forensic Sci Med Pathol
December 2024
Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13 Hangkong Road, Wuhan, 430030, People's Republic of China.
Unlabelled: In forensic practice, spinal cord injury (SCI) resulting in death has rarely been reported. Here, we present the case of a 65-year-old woman who on admission was conscious without dyspnea or dysphagia. Physical examination revealed two sharp objects penetrating the neck: a pair of scissors lodged in the neck on the right side of the thyroid cartilage and a knife embedded in the nuchal region accompanied by minor seepage of bloody exudate.
View Article and Find Full Text PDFMicrosc Res Tech
April 2022
Department of Histology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
In Sohag City, 400 samples were collected from different food markets of different meat products from two companies with high and low prices (e.g., minced meat, kofta sausage, beef burger, and luncheon meat) for determining food fraud.
View Article and Find Full Text PDFJ Anat
November 2021
Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Present-day crocodylians exhibit a remarkably akinetic skull with a highly modified braincase. We present a comprehensive description of the neurocranial osteology of extant crocodylians, with notes on the development of individual skeletal elements and a discussion of the terminology used for this project. The quadrate is rigidly fixed by multiple contacts with most braincase elements.
View Article and Find Full Text PDFZootaxa
October 2020
Tohoku National Fisheries Research Institute, Japan Fisheries Research and Education Agency, National Research and Development Agency, 25-259 Shimomekurakubo, Same, Hachinohe, Aomori 031-0841, Japan.
A new species of softnose skate (Arhynchobatidae), Bathyraja sexoculata Misawa, Orlov, Orlova, Gordeev and Ishihara is described on the basis of five specimens collected from off the east coast of Simushir Island, Kuril Islands, located in the western North Pacific. The specimens conformed to the genus Bathyraja by having the anteriormost pectoral-fin skeleton almost reaching the snout tip, and a slender unsegmented rostral cartilage. Within Bathyraja, the new species belongs to the subgenus Arctoraja (currently with four valid species) due to the relatively short tail (79-86% of disc width), high count of predorsal caudal vertebrae (more than 86), and large strong nuchal and scapular thorns.
View Article and Find Full Text PDFJ Exp Biol
January 2020
Department of Biology, Franklin & Marshall College, PO Box 3003, Lancaster, PA 17604-3003, USA
We have discovered features of the nuchal joint in the squid, , that are unique compared with moveable joints in other animals. The joint's function is unclear but it allows the head to glide toward and away from the mantle. The head glides along the joint with ease yet disarticulating the joint perpendicular to the axis of movement requires considerable force.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!