Nerve Growth Factor and its association to osteoarthritis in the horse

Osteoarthritis is common in horses and is a cause of pain and compromised welfare. Osteoarthritis-associated pain in horses is currently diagnosed by subjective and objective measurements of joint pain; however, there is a need to develop methods for evaluation of the systemic osteoarthritic pain that has been recognised in other species. Nerve growth factor (NGF) is associated with pain and osteoarthritis in humans, dogs, cats and lab animals but little is known about NGF in the horse. The aim of this thesis was to determine the presence of NGF in the equine joint and circulation, and to investigate its connection to osteoarthritis-associated lameness. Serum and synovial fluid from lame horses with osteoarthritis were analysed by ELISA, and NGF levels were compared to those in sound horses. Cartilage and synovial membranes from osteoarthritic and healthy joints were analysed by immunohistochemistry for NGF and for the NGF receptors (TrkA and p75NTR). Chondrocyte lysates obtained from healthy and osteoarthritic cartilage were analysed by western blot and capillary simple western. On a group level, serum NGF was higher in horses with osteoarthritis-associated lameness than in sound horses. Joints with acute or chronic inflammation had higher mean synovial fluid NGF than healthy joints and the expression of NGF and NGF receptors was increased in osteoarthritic articular cartilage compared to healthy articular cartilage. NGF receptor expression in osteoarthritic synovial membranes was also increased with marked individual variation in the relative TrkA/p75NTR expression. Two NGF precursor forms, 40 and 45 kDa, could be identified in equine articular chondrocytes and these forms did not appear to change with inflammation.The results show that NGF is associated with osteoarthritis in the horse, in line with the findings in other species. The correlation between NGF and pain, individual variations in NGF receptor expression and the role of different precursor forms of NGF warrants further investigation

Nerve growth factor receptors in equine synovial membranes vary with osteoarthritic disease severity

Nerve growth factor (NGF) is a neurotrophin that has been implicated in pain signaling, apoptosis, inflammation and proliferation. The resultant effects depend on interaction with two different receptors; tyrosine kinase A (TrkA) and p75(NTR). NGF increases in synovial fluid from osteoarthritic joints, and monoclonal antibody therapy is trialed to treat osteoarthritis (OA)-related pain. Investigation of the complex and somewhat contradictory signaling pathways of NGF is conducted in neural research, but has not followed through to orthopaedic studies. The objectives of this study were to compare the expression of NGF receptors and the downstream regulator BAX in synovial membranes from joints in various stages of OA. The horse was used as a model. Synovial membranes were harvested from five healthy horses postmortem and from clinical cases with spontaneous OA undergoing arthroscopic surgery for lameness. Four horses with synovitis without gross cartilage changes, four horses with synovitis and cartilage damage, and four horses with synovitis and intracarpal fractures were included. Samples were investigated by immunohistochemistry and results showed that nuclear staining of TrkA, p75(NTR) and BAX increases in OA-associated synovitis. TrkA expression increased in early disease stages whereas increases in p75(NTR) were most prominent in later disease stages with cartilage damage and fibrosis. Clinical significance: Suppression of NGF may result in varied effects depending on different stages of the osteoarthritic disease process

Subsurface fluid injection and induced seismicity in southeast Saskatchewan

In order to mitigate CO2 emissions while continuing to use fossil fuels as an energy source, CO2 emissions from large point sources such as power stations can be captured and stored in suitable subsurface sedimentary formations. However, concerns have been raised that the injection of pressurized CO2 may alter the subsurface stress state, leading to the re-activation of faults and generating induced seismic activity. Southeast Saskatchewan has seen extensive oil and gas activity since the 1950s. This activity includes, in recent years, a boom in shale oil production entailing hydraulic fracturing. It is also home to two world-leading CCS projects, the Weyburn-Midale CO2 Monitoring and Storage Project, and the Boundary Dam/Aquistore Project. The aim of this paper is to assess whether any of the conventional oilfield operations, shale oil activity or CCS has caused induced seismicity in southeast Saskatchewan. We find that the region has a very low rate of natural seismicity, and that there is no evidence to suggest that any kind of oilfield activity has caused induced events. However, seismicity has been associated with potash mining activities in the region. It is not clear whether the potash mining-induced events are triggered by subsidence above the mined zones, or by re-injection of waste brines. It is of interest to compare the situation in southeast Saskatchewan with other areas that have seen substantial increases in the amount of injection-induced seismic activity. It is notable that in many areas that have seen injection-induced seismicity, fluid injection is into basal aquifers that are hydraulically connected to the crystalline Precambrian basement. In contrast, most oilfield activities in southeast Saskatchewan are in Carboniferous formations, while the only units to have experienced a net volume increase are of Cretaceous age. It is tentatively suggested that the lack of induced seismic activity is due to the fact that injection is hydraulically isolated from the basement rocks, although it is also possible that stress conditions in the region are less conducive to induced seismicity.</p

The microseismic response at the In Salah Carbon Capture and Storage (CCS) site

AbstractIn 2004, injection of carbon dioxide (CO2) to be stored at depth began at the In Salah Carbon Capture and Storage (CCS) site and a pilot microseismic monitoring array was installed in 2009. The In Salah project presents an unusual dataset since it is the first major non-Enhanced Oil Recovery (EOR) CCS project to be monitored for microseismicity. This paper outlines an extensive seismological study using a range of techniques, relying mainly on data from a single three-component geophone. Important information is derived from the data, such as event locations, event magnitudes and fracture characteristics, that could be used in real-time to regulate the geomechanical response of a site to CO2 injection. The event rate closely follows the CO2 injection rate, with a total of 9506 seismic events detected. The locations for a carefully selected subset of events are estimated to occur at or below the injection interval, thereby ruling out fault or fracture activation caused by CO2 migration at shallow depths. A very small number of events (11) with less well-constrained locations may have occurred above the injection interval. However, there is no microseismic evidence that these events are correlated with CO2 injection and we suggest they are caused by stress transfer rather than CO2 migration into the caprock. The observed maximum moment magnitude, Mw=1.7, is consistent with estimated fracture dimensions at the injection depth. Fracture orientation estimated using shear-wave splitting analysis is approximately NW-SE, in agreement with fracture orientations inferred from logging data. During periods of high injection rates the degree of anisotropy increases slightly and then falls back to original values when injection rates fall. This implies the CO2 is opening pre-existing fractures which then close as pressure decreases.This an important proof-of-concept study that proves the value of microseismic monitoring of CCS projects, even with a limited array. We thus recommend that microseismic monitoring arrays are installed prior to CO2 injection at future CCS sites to enhance our understanding by making baseline and comparative studies possible. This would also provide real-time monitoring of the geomechanical response to injection, allowing operators to modify injection parameters and to help ensure the safe operation of a project

Music, Identity, and Community

This chapter discusses the role of music in the imagination of self, community, and nation. It includes topics such as Tibetan pop music, ‘anti-extremism’ campaigns in Xinjiang, Cantopop in Hong Kong, and contemporary revivals of ‘red songs’

The expression of nerve growth factor in healthy and inflamed equine chondrocytes analysed by capillary western immunoassay

Nerve Growth Factor (NGF) is a signalling molecule for pain and inflammation. NGF is increased in synovial fluid from osteoarthritic humans and animals, compared to healthy controls. Monoclonal antibody therapy directed against NGF has been approved to treat pain in osteoarthritic dogs but despite many years of trialling, therapy has not been approved for human use. One reason for this is that adverse reactions with rapidly progressing osteoarthritis has occurred in some individuals. More detailed knowledge of NGF expression in joints is needed. In this study, capillary-based Simple Western was used to analyse NGF in cultured equine chondrocytes. Chondrocytes were collected post mortem from three macroscopically healthy intercarpal joints and three intercarpal joints with mild osteoarthritic changes. The chondrocytes were expanded to passage one and seeded in chondrogenic medium to maintain the phenotype. On day four, cells were either stimulated with LPS or kept untreated in medium. All cells were harvested on day five. Wes analysis of lysates did not show mature NGF but two proforms, 40 and 45 kDa, were identified. Results were confirmed with western blot. The same proforms were expressed in chondrocytes from healthy and osteoarthritic joints. Acute inflammation induced by LPS stimulation did not change the forms of expressed NGF. Capillary Simple Western offers a sensitive and sample -sparing alternative to traditional western blot. However, confirmation of peaks is imperative in order to avoid misinterpretation of findings. In addition, in this case the method did not offer the possibility of quantification advertised by the manufacturers

DAS dataset suitable for microseismic and ANI analysis

Deliverable 1.2 concerns a DAS dataset suitable for microseismic and ambient noise interferometry (ANI). For this deliverable the DAS field dataset of FORGE is recommended. FORGE is the Frontier Organization For Research in Geothermal Energy, and is a field laboratory for developing an enhanced geothermal system in hot crystalline rock situated near the town of Milford in Utah, USA (https://utahforge.com/). The FORGE team is led by Joe Moore of Utah (and funded by the US Department of Energy) and is credited for this dataset. The dataset is completely open access, but obviously attribution would be appreciated in any publications. The FORGE dataset applies for deliverable 1.2, because it provides downhole DAS and geophone recordings of microseismic events, and covers approximately two weeks of continuous DAS recordings that can be used to test the potential of DAS for the ANI method. In addition to the FORGE dataset, various other DAS datasets have recently become publicly available that are recommended to consider as well for further work in task 1.3 and associated tasks, since they can be valuable in addressing different research aspects of the application of DAS. Table 1.1 gives a summary of the different open access datasets considered for this deliverable. This table also shows whether the datasets are suitable to be used for microseismic and ANI analysis. With this application in mind for deliverable 1.2, and when compared against alternative datasets (see Table 1.1), the FORGE dataset is considered to be especially relevant for this deliverable, since it provides both microseismic event data and continuous DAS recordings from a borehole configuration spanning a relatively long duration (17 days). The borehole configuration is preferable for the purpose of detecting micro-seismicity since it allows measurements close to the reservoir and therefore able to detect weaker events compared to a trenched deployment at the surface. FORGE concerns an enhanced geothermal system and in this setting the mechanism driving seismicity is different compared to the case of CO2 injection and storage (DIGIMON). However, the performance of the DAS cable with respect to detected seismicity is expected to be similar for the case of monitoring CO2 injection and storage as in a geothermal setting and therefore the FORGE dataset is expected to be suited for this purpose

DAS field dataset to compare technologies and deployment scenarios

This report describes a Distributed Acoustic Sensor (DAS) dataset acquired by DigiMon partners at the Containment and Monitoring Institute’s (CaMI) Field Research Station (FRS), Canada, between 6th to 10th September 2021. The field dataset contributes to the Deliverable D1.1 of the DigiMon project (DAS field dataset to compare technologies and deployment scenarios), which supports tasks 1.2 and 1.3 of the project. The objective of the DigiMon project is to develop an early-warning system for Carbon Capture and Storage (CCS), which utilises a broad range of sensor technologies including DAS. While the system is primarily focused on CCS projects located in shallow offshore environment of the North Sea, it is also intended to be adaptable to onshore settings. Some of the key areas that the systems will monitor include the movement of the plume within the reservoir, well integrity, and CO2 leakage into the overburden. A combination of both active and passive seismic methods will be deployed to track the movement of CO2, for example seismic reflection to image seismic velocity changes and microseismics to capture fault activation. Acquiring seismic surveys using DAS is highly novel and offers cost-effective approach which can significantly increase the spatial resolution of the survey data; however, it has had limited use in the operational environment with several technical challenges still needing to be resolved, such as the transfer function of DAS. CaMi FRS was selected as a field test location as the site has been specifically established to advance the development of monitoring technologies and protocols for CCS operations. At CaMi FRS, several different monitoring arrays have been installed which are directly applicable to DigiMon. This includes a 5km loop of DAS optical fibre, located with a 1.1 km surface trench and two observation wells, an array of surface and borehole geophone nodes, and 6 broadband seismometers operating by the University of Bristol. This monitoring infrastructure has been primarily installed to monitor CO2 injections into the Basal Belly River sandstone formation at approximately 300m below ground level. Injection of CO2 began at FRS in 2019 and during this time microseismic events have been recorded, albeit at shallower levels than the injection point. The site therefore provides a potential DAS dataset which contains both active and passive measurements for the DigiMon project. The abundance of instrumentation including DAS, geophones, and broadband seismometers provides a unique chance to test the capacity of these instruments for C02 storage monitoring