Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,233
result(s) for
"Squid"
Sort by:
Multiple observations of Bigfin Squid
One of the most remarkable groups of deep-sea squids is the Magnapinnidae, known for their large fins and strikingly long arm and tentacle filaments. Little is known of their biology and ecology as most specimens are damaged and juvenile, and in-situ sightings are sparse, numbering around a dozen globally. As part of a recent large-scale research programme in the Great Australian Bight, Remotely Operated Vehicles and a towed camera system were deployed in depths of 946-3258 m resulting in five Magnapinna sp. sightings. These represent the first records of Bigfin Squid in Australian waters, and more than double the known records from the southern hemisphere, bolstering a hypothesis of cosmopolitan distribution. As most previous observations have been of single Magnapinna squid these multiple sightings have been quite revealing, being found in close spatial and temporal proximity of each other. Morphological differences indicate each sighting is of an individual rather than multiple sightings of the same squid. In terms of morphology, previous in-situ measurements have been roughly based on nearby objects of known size, but this study used paired lasers visible on the body of a Magnapinna squid, providing a more accurate scaling of size. Squid of a juvenile size were also recorded and are confirmed to possess the long distal filaments which have thus far been mostly missing from specimens due to damage. We have described fine-scale habitat, in-situ colouration, and behavioural components including a horizontal example of the 'elbow' pose, and coiling of distal filaments: a behaviour not previously seen in squid. These sightings add to our knowledge of this elusive and intriguing genus, and reinforce the value of imagery as a tool in deep-sea squid research.
Journal Article
A New Generation of OPM for High Dynamic and Large Bandwidth MEG: The sup.4He OPMs—First Applications in Healthy Volunteers
MagnetoEncephaloGraphy (MEG) provides a measure of electrical activity in the brain at a millisecond time scale. From these signals, one can non-invasively derive the dynamics of brain activity. Conventional MEG systems (SQUID-MEG) use very low temperatures to achieve the necessary sensitivity. This leads to severe experimental and economical limitations. A new generation of MEG sensors is emerging: the optically pumped magnetometers (OPM). In OPM, an atomic gas enclosed in a glass cell is traversed by a laser beam whose modulation depends on the local magnetic field. MAG[sup.4]Health is developing OPMs using Helium gas ([sup.4]He-OPM). They operate at room temperature with a large dynamic range and a large frequency bandwidth and output natively a 3D vectorial measure of the magnetic field. In this study, five [sup.4]He-OPMs were compared to a classical SQUID-MEG system in a group of 18 volunteers to evaluate their experimental performances. Considering that the [sup.4]He-OPMs operate at real room temperature and can be placed directly on the head, our assumption was that [sup.4]He-OPMs would provide a reliable recording of physiological magnetic brain activity. Indeed, the results showed that the [sup.4]He-OPMs showed very similar results to the classical SQUID-MEG system by taking advantage of a shorter distance to the brain, despite having a lower sensitivity.
Journal Article
A Collagen Basketweave from the Giant Squid Mantle as a Robust Scaffold for Tissue Engineering
The growing applications of tissue engineering technologies warrant the search and development of biocompatible materials with an appropriate strength and elastic moduli. Here, we have extensively studied a collagenous membrane (GSCM) separated from the mantle of the Giant squid Dosidicus Gigas in order to test its potential applicability in regenerative medicine. To establish the composition and structure of the studied material, we analyzed the GSCM by a variety of techniques, including amino acid analysis, SDS-PAGE, and FTIR. It has been shown that collagen is a main component of the GSCM. The morphology study by different microscopic techniques from nano- to microscale revealed a peculiar packing of collagen fibers forming laminae oriented at 60–90 degrees in respect to each other, which, in turn, formed layers with the thickness of several microns (a basketweave motif). The macro- and micromechanical studies showed high values of the Young’s modulus and tensile strength. No significant cytotoxicity of the studied material was found by the cytotoxicity assay. Thus, the GSCM consists of a reinforced collagen network, has high mechanical characteristics, and is non-toxic, which makes it a good candidate for the creation of a scaffold material for tissue engineering.
Journal Article
On-scalp MEG sensor localization using magnetic dipole-like coils: A method for highly accurate co-registration
Source modelling in magnetoencephalography (MEG) requires precise co-registration of the sensor array and the anatomical structure of the measured individual’s head. In conventional MEG, the positions and orientations of the sensors relative to each other are fixed and known beforehand, requiring only localization of the head relative to the sensor array. Since the sensors in on-scalp MEG are positioned on the scalp, locations of the individual sensors depend on the subject’s head shape and size. The positions and orientations of on-scalp sensors must therefore be measured at every recording. This can be achieved by inverting conventional head localization, localizing the sensors relative to the head - rather than the other way around.
In this study we present a practical method for localizing sensors using magnetic dipole-like coils attached to the subject’s head. We implement and evaluate the method in a set of on-scalp MEG recordings using a 7-channel on-scalp MEG system based on high critical temperature superconducting quantum interference devices (high-Tc SQUIDs). The method allows individually localizing the sensor positions, orientations, and responsivities with high accuracy using only a short averaging time (≤ 2 mm, < 3° and < 3%, respectively, with 1-s averaging), enabling continuous sensor localization. Calibrating and jointly localizing the sensor array can further improve the accuracy of position and orientation (< 1 mm and < 1°, respectively, with 1-s coil recordings).
We demonstrate source localization of on-scalp recorded somatosensory evoked activity based on co-registration with our method. Equivalent current dipole fits of the evoked responses corresponded well (within 4.2 mm) with those based on a commercial, whole-head MEG system.
•We present and test a method that enables accurate co-registration in on-scalp MEG.•The method uses an array of dipole-like coils to localize individual or small groups of magnetometers.•We localized sensors individually with position errors below 2 mm and orientation errors below 3° with 1-s coil recordings.•We demonstrate source localization of N20m activity in a human subject using the method for co-registration.
Journal Article
Two new pygmy squids, Idiosepius kijimuna n. sp. and Kodama jujutsu n. gen., n. sp. (Cephalopoda: Idiosepiidae) from the Ryukyu Islands, Japan
Two new pygmy squid from the Ryukyu archipelago, Japan, are described: Kodama jujutsu, n. gen., n. sp. and Idiosepius kijimuna, n. sp. They differ from all other nominal species in a combination of traits, including the number of tentacular club suckers, shape of the funnel-mantle locking-cartilage, modification of the male hectocotylus and the structure of the gladius and nuchal-locking cartilage, in addition to mitochondrial DNA markers (12S, 16S and COI). They are both known from Okinawa Island and there is some overlap in their distributions. In a molecular phylogeny that includes all nominal Idiosepiidae, Kodama jujutsu, n. gen., n. sp. is sister taxon to a clade containing Xipholeptos Reid & Strugnell, 2018 and Idiosepius Steenstrup, 1881. Xipholeptos and Idiosepius are sister taxa. Idiosepius spp. now includes seven nominal species. In addition, aspects of the behaviour of the new species are described.
Journal Article
Effect of Squid Cartilage Chitosan Molecular Structure on the Properties of Its Monofilament as an Absorbable Surgical Suture
Suture is an important part of surgery, and wounds closing after surgery remains a challenge for postoperative care. Currently, silk, linen fiber, and cotton are available in the market as non-absorbable suture biomaterials. So, there is an urgent need to develop a novel suture with advantageous characteristics compared to the ones available on the market. In present study, a series of ultra-high molecular weight chitosan with different DD and MV were prepared from squid cartilage by alkaline treatment and ultrasonic degradation. The corresponding chitosan monofilaments were prepared by a wet spinning process and were characterized as sutures. The effects of the DD and MV of chitosan on the properties of its monofilament were studied, including surface morphology, mechanical property, swelling ratio, ash content, in vitro enzymatic degradation, and in vitro cytotoxicity. According to the results, AS-85 was chosen to be the best suitable as an absorbable surgical suture, which was spun from squid cartilage chitosan with DD~85% and MV~1.2 × 106. The outcome of the present study might derive tremendous possibilities for the utilization of squid cartilage β-chitin for biomedical applications.
Journal Article
Environmental influence on life-history traits in male squid Uroteuthis edulis with alternative reproductive tactics
Squid are characterized by flexible life-history traits (LHTs) that change in response to changing oceanic parameters. Male alternative reproductive tactics (ARTs), characterized by large-sized ‘consorts’ versus small-sized ‘sneakers’, are commonly observed in loliginid species. This study reports on LHTs flexibility in male squids displaying ARTs. LHTs of consorts and sneakers in Uroteuthis edulis, including body size, age, growth rate and gonado-somatic energy allocation, were compared among seasonal and geographical groups from Japan and Taiwan. The ratio of consorts to sneakers was highest in the group spawning in the ‘Japan-warm’ season (June–November), followed by that of the ‘Japan-cold’ season (December–May), and lowest in Taiwan (spring and autumn). LHTs were compared among cohorts separated by hatching season and catch location (Jwarm, Jcold and Taiwan cohorts). Mean body size of consorts showed no difference among cohorts, although Taiwan consorts were relatively younger than Japan consorts. Mean size and age of sneakers decreased with increased water temperature at hatching. Growth rates of consorts and sneakers were slightly different among cohorts, in accordance with differences of statolith increment widths during their early life stage (50–150 days). Growth rates of both consorts and sneakers were highest in the Taiwan cohort, followed by the Jwarm cohort, with the Jcold cohort lowest. Sneakers invested more both in mantle and gonadal weights than consorts in all cohorts. Gonado-somatic energy allocation patterns of consorts and sneakers were consistent at different temperatures. LHTs of U. edulis consorts and sneakers were strongly influenced by temperature, with higher flexibility in sneakers than consorts.
Journal Article