14 research outputs found
Population genetic analyses reveal distinct geographical blooms of the jellyfish Rhizostoma octopus (Scyphozoa)
High-resolution genetic analysis reveals extensive gene flow within the jellyfish Pelagia noctiluca (Scyphozoa) in the North Atlantic and Mediterranean Sea
12 pages, 5 figures, 3 tables, supporting Information http://onlinelibrary.wiley.com/doi/10.1111/bij.12654/suppinfoDespite the importance of gelatinous zooplankton as components of marine ecosystems, both ecologically and socio-economically, relatively little information is known about population persistence or connectivity in jellyfish. In the present study, we employed a combination of nuclear microsatellite markers and sequence data from the mitochondrial cytochrome oxidase I (COI) gene to determine levels and patterns of population genetic structuring in the holoplanktonic jellyfish Pelagia noctiluca across the northeast Atlantic Ocean and Mediterranean Sea. Our results indicate a high degree of connectivity in P. noctiluca, with little evidence of geographical structuring of genetic variation. A small but significant differentiation of Atlantic Ocean and Mediterranean stocks was detected based on the microsatellite data, but no evidence of differentiation was observed with the mtDNA, probably due to the higher power of the microsatellites to detect low levels of genetic structuring. Two clearly distinct groups of genotypes were observed within the mtDNA COI, which probably diverged in the early Pleistocene, but with no evidence of geographical structuring. Palaeodistribution modelling of P. noctiluca at the Last Glacial Maximum (LGM; c. 21 Kya) indicated large areas of suitable habitat south of the speciesâ current-day distribution, with little reduction in area. The congruent evidence for minimal genetic differentiation from the nuclear microsatellites and the mtDNA, coupled with the results of the palaeodistribution modelling, supports the idea of long-term population stability and connectivity, thus providing key insights into the population dynamics and demography of this important speciesFergal Glynnâs PhD was funded by the Department of Agriculture and Rural Development, Northern Ireland (DARDNI). Martin Lilley was funded by lâAgence Nationale de la Recherche projects âEcogelyâ ANR-10-PDOC-005-01 and âNanoDeconGelsâ ANR-12-EMMA-0008Peer Reviewe
A novel therapeutic approach encapsulating brain-derived neurotrophic factor in nanoparticles for treating sensorineural hearing loss.
There are approximately 688,000 adults in the UK with severe to profound sensorineural hearing loss. While many people who suffer from hearing loss benefit from the use of a conventional hearing aid, these devices are not effective in patients with profound sensorineural hearing loss. Spiral ganglion neurons (SGNs) are the target cells of the cochlear implant, a neural prosthesis designed to provide important auditory cues to profoundly deaf patients. The ongoing degeneration of SGNs that occurs following sensorineural hearing loss is therefore considered a limiting factor in cochlear implant efficacy. Exogenous application of neurotrophic factors prevents SGN degeneration and can enhance neurite outgrowth. Both the quantity and the quality of surviving SGNs appear to be important for the success of the cochlear implant. The addition of BDNF to the cochlear fluids can prevent degeneration of SGNs after sensory hair cells are lost in adult rodent cochleae. This neurotrophin has to be continuously delivered to maintain neuronal survival as they are rapidly cleared by the body's physiological mechanism. Current available methods of neurotrophin application are limited to delivery over a period of less than one month, and carry risks of wound infection and viral inoculation. Alternative methods of delivery are needed. We developed a biodegradable and biocompatible polyglutarnic acid particle which along with glycosaminglycan heparin, successfully sequestered BDNF. This BDNF was shown to be released in a biologically active form over a period of 70 days. Its biological activity was confirmed using the neuroblastoma cell line SHSY5Y. These particles were then successfully inserted into a deafened rat cochlea and improved SGN survival. This work has shown that the PGA-heparin particles are potential carriers for BDNF, for clinical application in an effort to improve patient outcome with profound sensorineural hearing loss. </p
Nasal foreign bodies in children: should they have a plain radiograph in the accident and emergency?
Objectives: Primary Objective: To determine the proportion of children with nasal foreign bodies who had button batteries as the foreign body.
Secondary Objective: To describe the clinical care and outcome of those children with a button battery foreign body.
Methods: A retrospective review of all children presenting to the accident and emergency room with a nasal foreign body or unilateral nasal discharge during a 6-month period was assessed.
Results: Forty-four children were included. The most common object found was a plastic bead (27%), followed by foam, paper, or tissue fragments (23%); food matter represented 15%. A button battery was found in 3 patients (7%); other foreign bodies included stones, buttons, crayons, erasers, and a pellet. Thiry-six (82%) had their foreign body removed without anesthetic and 8 (18%) required a general anesthetic. All 3 children with a button battery went undiagnosed until examination in the operating theater. Because there was no previous indication of the presence of a button battery in the 3 children, the removal of the foreign body under general anesthesia was scheduled for the following day.
Conclusions: The removal of the button batteries would have been expedited had a plain radiograph been obtained, possibly resulting in less morbidity for our patients. We recommend a plain radiograph in all children presenting with a nonvisible foreign body or unilateral nasal discharge
Upper airway obstruction in infectious mononucleosis
Patients with infectious mononucleosis caused by the EpsteinâBarr virus frequently present to the accident and emergency department. The most common presenting symptoms are fever, fatigue, odynophagia and malaise. Although significant airway compromise is rare and occurs in an estimated 1â3.5% of cases, it may present as a potentially life-threatening situation demanding immediate intervention. We present two such cases and discuss their management
High-resolution genetic analysis reveals extensive gene flow within the jellyfishpelagia noctiluca(scyphozoa) in the north atlantic and mediterranean sea
Additive Manufacture of Composite Soft Pneumatic Actuators
This article presents a direct additive manufacturing method for composite material soft pneumatic actuators that are capable of performing a range of programmable motions. Commonly, molding is the method used to manufacture soft fluidic actuators. This is material, labor, and time intensive and lacks the design freedom to produce custom actuators efficiently. This article proposes an alternative semiautomated method of designing and manufacturing composite soft actuators. An affordable, open-source, desktop three-dimensional (3D) printer was modified into a four-axis, combined, fused deposition modeling, and paste extrusion printer. A Grasshopper 3D algorithm was devised to implement custom actuator designs according to user inputs, resulting in a G-code print file. Bending, contracting, and twisting motion actuators were parametrically designed and subsequently additively manufactured from silicone and thermoplastic elastomer (TPE) materials. Experimental testing was completed on these actuators along with their constitutive materials. Finite element models were created to simulate the actuator's kinematic performance. Having a platform method to digitally configure and directly additively manufacture custom-motion, composite soft actuators has the potential to accelerate the development of more intricate designs and lead to potential impacts in a range of areas, including in-clinic personalization of soft assistive devices and patient-specific biomedical devices.European Commission - European Regional Development FundScience Foundation Irelan
High-resolution genetic analysis reveals extensive gene flow within the jellyfishpelagia noctiluca(scyphozoa) in the north atlantic and mediterranean sea
Ipsilateral cochlear implantation after cochlear nerve preserving vestibular schwannoma surgery in patients with neurofibromatosis type 2
The Royal College of Surgeons multidisciplinary guidelines on elective tracheostomy insertion in COVID-19 ventilated patients
Background: The current COVID-19 pandemic has placed enormous strain on healthcare systems worldwide. Understanding of COVID-19 is rapidly evolving. Pneumonia associated with COVID-19 may lead to respiratory failure requiring mechanical ventilation. The rise in patients requiring mechanical ventilation may lead to an increase in tracheostomies being performed in patients with COVID-19. Performing tracheostomy in patients with active SARS-CoV-2 infection poses a number of challenges.
Methods: These guidelines were written following multidisciplinary agreement between Otolaryngology, Head and Neck Surgery, Respiratory Medicine and the Department of Anaesthetics and Critical Care Medicine in the Royal College of Surgeons in Ireland. A literature review was performed and a guideline for elective tracheostomy insertion in patients with COVID-19 proposed.
Conclusion: The decision to perform tracheostomy in patients with COVID-19 should be undertaken by senior members of the multidisciplinary team. Steps should be taken to minimise risks to healthcare workers.</p