556 research outputs found
Community Fisheries Management Handbook
This handbook is a unique product. It is the first "field guide" to community-based fisheries management focused specifically on fisheries, such as those of the Northwest Atlantic, that are already highly regulated by governmental authorities, with licensing and other requirements that limit access and effort. While a variety of resource materials are available on community-based natural resource management, almost all of these are written by practitioners working in the South (developing countries) and rely on case studies and techniques that have been tested in less industrialized tropical fisheries. Therefore, this handbook is one of the few publications about community-based management in 'Northern' fisheries.The need for this handbook was identified by participants working on an initiative on the Atlantic coast of Canada, "Turning the Tide: Communities Managing Fisheries Together" (www.turningthetide.ca). Turning the Tide works for improved fisheries management through community-based approaches, and through cooperative efforts among aboriginal and non-aboriginal communities. To that end, it has brought together fishermen and their communities to share information and ideas on community-based management, through events such as community forums and study tours. Participants recognized the need for a handbook on community-based fisheries management that is relevant to their own fisheries and that can be used as a tool to provide information and support for practitioners, as well as to document current practices and insights obtained, and to promote and raise public awareness about community-based fisheries management. The stories and insights in the handbook are those of Turning the Tide participants and their allies from around the Atlantic Region ā the Atlantic coast of Canada and the north-eastern North America-United States ā who shared this information during Turning the Tide activities, and in individual and group interviews, and who reviewed the materials used in producing this handbook. The various tools and ideas explored here are currently being applied in the region, and so the handbook demonstrates how community-based approaches to fisheries management are working today
Investigating the effect that disease-linked PLCĪ³2 variants have on enzymatic activity and exploring PLCĪ³2ās role within microglia cell function
Phospholipase C-gamma 2 (PLCĪ³2) is highly expressed in immune cells, such as microglia. PLCĪ³2 hydrolyses phosphatidylinositol 4,5-bisphosphate into inositol trisphosphate (IP3) and diacylglycerol. Variants of PLCĪ³2 have been described in several diseases, such as late onset Alzheimerās disease (LOAD), inflammatory bowel disease, as well as rare immune disorders, suggesting a key role for this enzyme in the regulation of immune cell function. To characterise the enzymatic activity of disease-linked PLCĪ³2 variants, an assay measuring inositol monophosphate (IP1), a downstream metabolite of IP3, was adapted and optimised. The S707Y, Ī845-848 and M1141K PLCĪ³2 variants, linked to a complex immune disorder, have strong hypermorphic activity, whereas the PLCĪ³2 V1103I variant shows a mild increase in PLC activity.
In the context of LOAD, microglia have been implicated as key mediators of disease pathophysiology. However, the role of PLCĪ³2 within microglia is still not fully understood. To address this issue, the hypermorphic PLCĪ³2 S707Y disease linked-variant was introduced into human inducible pluripotent stem cells (hiPSCs) to explore the role that strong gain-of-function PLCĪ³2 variants have within hiPSC-derived microglia. Based on the IP1 measurements, PLCĪ³2 S707Y hiPSC-derived microglia exhibited hypermorphic enzymatic activity under both basal and stimulated conditions, which in turn resulted in increased calcium flux. However, when challenged with apoptotic neuronal cells, a reduction in phagocytosis was observed. Additionally, secretion of IL-1Ī², IL-8 and TNF-Ī± was shown to be elevated in basal conditions. However, when challenged with lipopolysaccharide, PLCĪ³2 S707Y hiPSC-derived microglia exhibited a reduction in IL-10, IL-6 and TNF-Ī± secretion, likely due to decreased NF-ĪŗB activation and translocation. RNA sequencing of the PLCĪ³2 S707Y hiPSC-derived microglia revealed a downregulation of genes related to innate immunity and response. Therefore, this thesis demonstrates that despite the increase in PLCĪ³2 enzymatic activity, the PLCĪ³2 S707Y hiPSC-derived microglia display a loss of function for key microglial processes
Influence of inverse dynamics methods on the calculation of inter-segmental moments in vertical jumping and weightlifting
<p>Abstract</p> <p>Background</p> <p>A vast number of biomechanical studies have employed inverse dynamics methods to calculate inter-segmental moments during movement. Although all inverse dynamics methods are rooted in classical mechanics and thus theoretically the same, there exist a number of distinct computational methods. Recent research has demonstrated a key influence of the dynamics computation of the inverse dynamics method on the calculated moments, despite the theoretical equivalence of the methods. The purpose of this study was therefore to explore the influence of the choice of inverse dynamics on the calculation of inter-segmental moments.</p> <p>Methods</p> <p>An inverse dynamics analysis was performed to analyse vertical jumping and weightlifting movements using two distinct methods. The first method was the traditional inverse dynamics approach, in this study characterized as the 3 step method, where inter-segmental moments were calculated in the local coordinate system of each segment, thus requiring multiple coordinate system transformations. The second method (the 1 step method) was the recently proposed approach based on wrench notation that allows all calculations to be performed in the global coordinate system. In order to best compare the effect of the inverse dynamics computation a number of the key assumptions and methods were harmonized, in particular unit quaternions were used to parameterize rotation in both methods in order to standardize the kinematics.</p> <p>Results</p> <p>Mean peak inter-segmental moments calculated by the two methods were found to agree to 2 decimal places in all cases and were not significantly different (p > 0.05). Equally the normalized dispersions of the two methods were small.</p> <p>Conclusions</p> <p>In contrast to previously documented research the difference between the two methods was found to be negligible. This study demonstrates that the 1 and 3 step method are computationally equivalent and can thus be used interchangeably in musculoskeletal modelling technology. It is important that future work clarifies the influence of the other inverse dynamics methods on the calculation of inter-segmental moments. Equally future work is needed to explore the sensitivity of kinematics computations to the choice of rotation parameterization.</p
Non-linear, cata-Condensed, Polycyclic Aromatic Hydrocarbon Materials: A Generic Approach and Physical Properties
A generic approach to the regiospecific synthesis of halogenated polycyclic aromatics is made possible by the one- or two-directional benzannulation reactions of readily available (ortho-allylaryl)trichloroacetates (the āBHQā reaction). Palladium-catalysed cross-coupling reactions of the so-formed haloaromatics enable the synthesis of functionalised polycyclic aromatic hydrocarbons (PAHs) with surgical precision. Overall, this new methodology enables the facile mining of chemical space in search of new electronic functional materials
Lower-extremity musculoskeletal geometry affects the calculation of patellofemoral forces in vertical jumping and weightlifting
The calculation of the patellofemoral joint contact force using three-dimensional (3D) modelling techniques requires a description of the musculoskeletal geometry of the lower limb. In this study, the influence of the complexity of the muscle model was studied by considering two different muscle models, the Delp and Horsman models. Both models were used to calculate the patellofemoral force during standing, vertical jumping, and Olympic-style weightlifting. The patellofemoral forces predicted by the Horsman model were markedly lower than those predicted by the Delp model in all activities and represented more realistic values when compared with previous work. This was found to be a result of a lower level of redundancy in the Delp model, which forced a higher level of muscular activation in order to allow a viable solution. The higher level of complexity in the Horsman model resulted in a greater degree of redundancy and consequently lower activation and patellofemoral forces. The results of this work demonstrate that a well-posed muscle model must have an adequate degree of complexity to create a sufficient independence, variability, and number of moment arms in order to ensure adequate redundancy of the force-sharing problem such that muscle forces are not overstated. (Author's abstract
The development of a segment-based musculoskeletal model of the lower limb: Introducing FreeBody
Traditional approaches to the biomechanical analysis of movement are joint-based; that is the mechanics of the body are described in terms of the forces and moments acting at the joints, and that muscular forces are considered to create moments about the joints. We have recently shown that segment-based approaches, where the mechanics of the body are described by considering the effect of the muscle, ligament and joint contact forces on the segments themselves, can also prove insightful. We have also previously described a simultaneous, optimization-based, musculoskeletal model of the lower limb. However, this prior model incorporates both joint- and segment-based assumptions. The purpose of this study was therefore to develop an entirely segment-based model of the lower limb and to compare its performance to our previous work. The segment-based model was used to estimate the muscle forces found during vertical jumping, which were in turn compared with the muscular activations that have been found in vertical jumping, by using a Geersā metric to quantify the magnitude and phase errors. The segment-based model was shown to have a similar ability to estimate muscle forces as a model based upon our previous work. In the future, we will evaluate the ability of the segment-based model to be used to provide results with clinical relevance, and compare its performance to joint-based approaches. The segment-based model described in this article is publicly available as a GUIbasedMATLAB _ application and in the original source code (at www.msksoftware.org.uk)
Alumni Online Plus: An Online Community for Professional Networking
This paper describes the functional specifications for an online community to facilitate networking and professional development among the current, former, and future students of the School of Information and Library Science ("SILS") at UNC Chapel Hill. A literature review, surveys conducted on behalf of SILS in the summer and fall of 2002, and a survey conducted in conjunction with this paper in January of 2003 were used to inform the design of the community. In this paper, the evidence supporting a need to create more services for students and alumni is demonstrated, the literature supporting the creation of online communities is examined, and a design for the system is proposed
An Optimization-Based Simultaneous Approach to the Determination of Muscular, Ligamentous, and Joint Contact Forces Provides Insight into Musculoligamentous Interaction
Typical inverse dynamics approaches to the calculation of muscle, ligament, and joint contact forces are based on a step-wise solution of the equations of motion. This approach is therefore limited in its ability to provide insight as to the muscular, ligamentous, and articular interactions that create joint stability. In this study, a new musculoskeletal model of the lower limb is described, in which the equations of motion describing the force and moment equilibrium at the joints of the lower limb are solved simultaneously using optimization techniques. The new model was employed to analyze vertical jumping using a variety of different optimization cost functions and the results were compared to more traditional approaches. The new model was able to find a solution with lower muscular force upper bounds due to the ability of the ligaments to contribute to moment equilibrium at the ankle and knee joints. Equally, the new model produced lower joint contact forces than traditional approaches for cases which also included a consideration as to ligament or joint contact forces within the cost function. This study demonstrates the possibility of solving the inverse dynamic equations of motion simultaneously using contemporary technology, and further suggests that this might be important due to the complementary function of the muscles and ligaments in creating joint stability
MODELLING SCAPULAR BIOMECHANICS TO ENHANCE INTERPRETATION OF KINEMATICS AND PERFORMANCE DATA IN ROWING
Rowing involves repetitive, high intensity loading on the glenohumeral joint. Shoulder pain is associated with muscle weakness and imbalance, resulting in long-lasting overuse injuries. The goal of this study was to explore three-dimensional shoulder biomechanics during rowing to identify parameters that influence technique. Eleven athletes had their movement recorded by motion capture while using an instrumented ergometer. Kinetics and kinematics drove a computational model which output joint and muscle forces across the shoulder. Results suggest that subtle muscular changes identified by the model can be sensitively mapped to performance variables. When evaluated alongside ergometer-derived power metrics, biomechanics parameters can provide athletes and coaches a fuller picture of performance potential, injury risk, and training program efficacy
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