2,702 research outputs found
The glia response after peripheral nerve injury: A comparison between Schwann cells and olfactory ensheathing cells and their uses for neural regenerative therapies
The peripheral nervous system (PNS) exhibits a much larger capacity for regeneration than the central nervous system (CNS). One reason for this difference is the difference in glial cell types between the two systems. PNS glia respond rapidly to nerve injury by clearing debris from the injury site, supplying essential growth factors and providing structural support; all of which enhances neuronal regeneration. Thus, transplantation of glial cells from the PNS is a very promising therapy for injuries to both the PNS and the CNS. There are two key types of PNS glia: olfactory ensheathing cells (OECs), which populate the olfactory nerve, and Schwann cells (SCs), which are present in the rest of the PNS. These two glial types share many similar morphological and functional characteristics but also exhibit key differences. The olfactory nerve is constantly turning over throughout life, which means OECs are continuously stimulating neural regeneration, whilst SCs only promote regeneration after direct injury to the PNS. This review presents a comparison between these two PNS systems in respect to normal physiology, developmental anatomy, glial functions and their responses to injury. A thorough understanding of the mechanisms and differences between the two systems is crucial for the development of future therapies using transplantation of peripheral glia to treat neural injuries and/or disease.Griffith Health, School of Nursing and MidwiferyFull Tex
Algorithms for detecting dependencies and rigid subsystems for CAD
Geometric constraint systems underly popular Computer Aided Design soft-
ware. Automated approaches for detecting dependencies in a design are critical
for developing robust solvers and providing informative user feedback, and we
provide algorithms for two types of dependencies. First, we give a pebble game
algorithm for detecting generic dependencies. Then, we focus on identifying the
"special positions" of a design in which generically independent constraints
become dependent. We present combinatorial algorithms for identifying subgraphs
associated to factors of a particular polynomial, whose vanishing indicates a
special position and resulting dependency. Further factoring in the Grassmann-
Cayley algebra may allow a geometric interpretation giving conditions (e.g.,
"these two lines being parallel cause a dependency") determining the special
position.Comment: 37 pages, 14 figures (v2 is an expanded version of an AGD'14 abstract
based on v1
Recommended from our members
Global perspectives and translations of consuming clothing waste in the present
The mass consumption of clothing has resulted in collection charities such as Oxfam exporting unwanted second hand clothing to markets in the Sub-Saharan region. This is a trade that is seen as supporting sustainable solutions to unwanted clothing but offers ‘both opportunity’ and ‘danger’ to local communities (Haggblade, 2007). The research explores the second hand clothing trade in Ghana, which evidences this danger and challenges the notion of opportunity.
The second hand clothing market whilst benefitting local communities in Africa has also impacted upon local textile production. From our conversations around these issues, a collaborative project idea emerged entitled ‘Return to Sender’. The project aims to highlight and challenge the effects of the second hand clothing market upon local heritage in Africa. A shared perspective through global design stories can encourage designers to understand the consequences of design but at the time same enable them to have the power to impact and drive change of consumer habits. The current and future perspectives of purchasing clothing and re-use is explored, regarding how this could then influence and change the global second hand clothing markets.
This paper also explores the potential of sustainable outcomes through focusing design in the present, rather than the future. In order to understand a global world we need to see the world as it is to solve the problems and in turn prevent problems in the future. We need an approach that is not engrained into a system but something that promotes creativity and openness to change
Human visceral nociception: findings from translational studies in human tissue.
Peripheral sensitization of nociceptors during disease has long been recognized as a leading cause of inflammatory pain. However, a growing body of data generated over the last decade has led to the increased understanding that peripheral sensitization is also an important mechanism driving abdominal pain in highly prevalent functional bowel disorders, in particular, irritable bowel syndrome (IBS). As such, the development of drugs that target pain-sensing nerves innervating the bowel has the potential to be a successful analgesic strategy for the treatment of abdominal pain in both organic and functional gastrointestinal diseases. Despite the success of recent peripherally restricted approaches for the treatment of IBS, not all drugs that have shown efficacy in animal models of visceral pain have reduced pain end points in clinical trials of IBS patients, suggesting innate differences in the mechanisms of pain processing between rodents and humans and, in particular, how we model disease states. To address this gap in our understanding of peripheral nociception from the viscera and the body in general, several groups have developed experimental systems to study nociception in isolated human tissue and neurons, the findings of which we discuss in this review. Studies of human tissue identify a repertoire of human primary afferent subtypes comparable to rodent models including a nociceptor population, the targeting of which will shape future analgesic development efforts. Detailed mechanistic studies in human sensory neurons combined with unbiased RNA-sequencing approaches have revealed fundamental differences in not only receptor/channel expression but also peripheral pain pathways.Non
Isometric exercise-induced hemodynamic load strongly predicts left ventricular mass in hypertension
C
Recommended from our members
Clothing sustainability and upcycling in Ghana
The aim of this paper is to assess opportunities for the upcycling of waste clothing through design workshops held in Accra, Ghana. An upcycling approach to clothing longevity examines how garments can be re-designed and resold in a new form. Significant amounts of surplus and second-hand clothing from the developed world and large producer nations, for example China, are distributed to Africa and sold in local markets at affordable prices. The research was conducted into upcycling waste clothing from the market by five groups of fashion design students at Accra Technical University (ATU). A participatory research design was applied to the project and the initial briefing to design groups confirmed the concept of upcycling and the design parameters. Each group defined a design theme, made a selection of clothes and accessories in the Accra market and returned to the university to conceptualise and re-create clothes and accessories. The project culminated in presentations of finished garments modelled by the students. It addressed the disposal stage of the circular economy model of clothing sustainability by providing new knowledge of how waste clothing, readily available in a developing country’s market can be sourced and creatively re-designed into new garments and accessories
Olfactory ensheathing glia are required for embryonic olfactory axon targeting and the migration of gonadotropin-releasing hormone neurons.
Kallmann's syndrome is caused by the failure of olfactory axons and gonadotropin-releasing hormone (GnRH) neurons to enter the embryonic forebrain, resulting in anosmia and sterility. Sox10 mutations have been associated with Kallmann's syndrome phenotypes, but their effect on olfactory system development is unknown. We recently showed that Sox10 is expressed by neural crest-derived olfactory ensheathing cells (OECs). Here, we demonstrate that in homozygous Sox10(lacZ/lacZ) mouse embryos, OEC differentiation is disrupted; olfactory axons accumulate in the ventromedial olfactory nerve layer and fewer olfactory receptor neurons express the maturation marker OMP (most likely owing to the failure of axonal targeting). Furthermore, GnRH neurons clump together in the periphery and a smaller proportion enters the forebrain. Our data suggest that human Sox10 mutations cause Kallmann's syndrome by disrupting the differentiation of OECs, which promote embryonic olfactory axon targeting and hence olfactory receptor neuron maturation, and GnRH neuron migration to the forebrain.This work was supported by the Wellcome Trust [grant 091555 to C.V.H.B. and P.B.], a Griffith University Encouragement Research grant to J.A.S., and Deutsche Forschungsgemeinschaft [grant We1326/9 to M.W.].This is the final version of the article. It was first available from The Company of Biologists via http://dx.doi.org/10.1242/bio.2013524
- …