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Ionic currents in intimal cultured synoviocytes from the rabbit
No full textHyaluronan, a joint lubricant and regulator of synovial fluid content, is secreted by fibroblast-like synoviocytes lining the joint cavity, and secretion is greatly stimulated by Ca2+-dependent protein kinase C. This study aimed to define synoviocyte membrane currents and channels that may influence synoviocyte Ca2+ dynamics. Resting membrane potential ranged from −30 mV to −66 mV (mean −45 ± 8.60 mV, n = 40). Input resistance ranged from 0.54 GΩ to 2.6 GΩ (mean 1.28 ± 0.57 GΩ; ν = 33). Cell capacitance averaged 97.97 ± 5.93 pF. Voltage clamp using Cs+ pipette solution yielded a transient inward current that disappeared in Ca2+-free solutions and was blocked by 1 μM nifedipine, indicating an L-type calcium current. The current was increased fourfold by the calcium channel activator FPL 64176 (300 nM). Using K+ pipette solution, depolarizing steps positive to −40 mV evoked an outward current that showed kinetics and voltage dependence of activation and inactivation typical of the delayed rectifier potassium current. This was blocked by the nonspecific delayed rectifier blocker 4-aminopyridine. The synoviocytes expressed mRNA for four Kv1 subtypes (Kv1.1, Kv1.4, Kv1.5, and Kv1.6). Correolide (1 μM), margatoxin (100 nM), and α-dendrotoxin block these Kv1 subtypes, and all of these drugs significantly reduced synoviocyte outward current. The current was blocked most effectively by 50 nM κ-dendrotoxin, which is specific for channels containing a Kv1.1 subunit, indicating that Kv1.1 is critical, either as a homomultimeric channel or as a component of a heteromultimeric Kv1 channel. When 50 nM κ-dendrotoxin was added to current-clamped synoviocytes, the cells depolarized by >20 mV and this was accompanied by an increase in intracellular calcium concentration. Similarly, depolarization of the cells with high external potassium solution caused an increase in intracellular calcium, and this effect was greatly reduced by 1 μM nifedipine. In conclusion, fibroblast-like synoviocytes cultured from the inner synovium of the rabbit exhibit voltage-dependent inward and outward currents, including Ca2+ currents. They thus express ion channels regulating membrane Ca2+ permeability and electrochemical gradient. Since Ca2+-dependent kinases are major regulators of synovial hyaluronan secretion, the synoviocyte ion channels are likely to be important in the regulation of hyaluronan secretion
Air Source Heat Pump Performance in an Irish Climate - 1 Year Monitoring Study
No full textAir source heat pumps can use ambient outdoor air as their heat source to efficiently provide space heat and hot water to buildings. Ireland's maritime climate can be suitable for air source heat pumps, that are appropriately installed, in domestic and commercial buildings for heat provision. This study assesses the measured performance an IGEN Ochsner GMLW 19 air source heat pump on the east coast of Ireland for one year. The study was carried by the Centre for Renewable Energy at Dundalk Institute of Technology (CREDIT
Geophysical Surveys to assist the INSTAR Boyne Landscapes Project at the Brú na Bóinne World Heritage Site, County Meath, Ireland
Get PDFHistorically aerial photography, and latterly LiDAR, have been used to identify and map new sites in the Brú na Bóinne World Heritage Site (WHS), an internationally significant archaeological landscape known for its Neolithic passage tombs, other monuments and megalithic art. The landscape is largely composed of the floodplain and terraces of the River Boyne which are farmed in a combination of pasture and tillage crops. The INSTAR (Irish National Strategic Archaeological Research) Boyne Landscapes Project is a response to some of the key issues to be addressed in the research strategy published in the Brú na Bóinne WHS Research Framework (Smyth, 2009). Key issues to be addressed where geophysical survey can be of assistance include:
• Reconstruction and modelling the palaeoenvironment and landscape development
• Establishing the nature and extent of later prehistoric activity
• Understanding the structural sequence and phasing of the passage tombs
• Investigating the sequence of monuments between Newgrange Passage Tomb and the River Boyne
• Integrating monuments and landscapes
• Understanding land-use change
• Investigating the archaeology of the River Boyne
The project is developing an integrated and comprehensive landscape archaeological model for the Boyne Valley, with a focus on linking changing land use and environment to the known landscape of ancient monuments and settlement. The project has aimed to collate all available landscape and environmental data into a GIS database for modelling purposes, and to use this database to identify zones of likely change in the natural and cultural landscapes. Ground-truthing of specific zones of the river system against the model developed from the GIS database is being carried out, and then integrated into the GIS, providing a comprehensive dataset for and model of landscape and river history in the Boyne Valley.
Ground-truthing involves a combination geophysical survey and coring to obtain material for sedimentological and geochemical analysis and for radiocarbon dating. Surveyed zones include previously identified sites as well as areas with high archaeological potential based on landscape analysis using LiDAR. The preliminary results from low topographic profile site LP1 identified during the current project using LiDAR are presented here. LP1 is located on the north bank of the River Boyne on the first terrace above the floodplain. The feature has a diameter of approximately 100m and lies close to a standing stone (Site D). The site was initially investigated by magnetic gradiometry on a 1m x 0.25m grid.
The gradiometry results partially map the northern part of LP1 where there appear to be two parallel curving ditches with the southerly ditch forming part of LP1. The remaining part of the topographic anomaly does not have a strong magnetic expression. This may be due to the nature of the sediments on the lower part of the sloping terrace and/or agricultural activity. There are two previously unrecognised features at the south and at the east of the survey area. The southern feature is
presently interpreted as a sinuous ditch. The eastern feature is a circular ditch some 15m in diameter possibly enclosed by a ring of pits giving an overall diameter of some 30m.
In order to investigate the sediments and the sub-surface structure of LP1 an N-S ERT transect was carried out using a Wenner array with 2m electrode or ‘a’ spacing.
There is an approx. 10m height variation between the lower ground in the south and the higher ground in the north of the pseudosection. There are two main features seen in the pseudosection with a higher resistivity ‘lens’ lying in the lower ground and low resistivity material forming the higher ground. There is an intermittent, thin lower resistivity veneer of variable thickness lying on the ‘lens’. The ‘lens’ could be comprised of sands and gravels which have been laid down by the river in a bowl or hollow which itself has been exploited to form an enclosure. The features in the ERT section provide targets to be investigated by coring in order to investigate the relationship between LP1 and the riverine landscape.
The poster presents results from a series of sites currently being investigated in the Brú na Bóinne World Heritage Site.
Bibliography
Smyth, J. (2009). Brú na Bóinne World Heritage Site Research Framework. The Heritage Council : Kilkenny
Implementation of a Hybrid Low Overhead Assessment Method for Medical Device Software Development
No full textThe need for software is increasingly growing in the medical device industry. Even though the primary concern of medical device software development is safety, medical device software development organisations are also concerned with time and budget overruns, plus ensuring that the customer requirements are fulfilled. At present the medical device software industry lacks strategies to combine adhering to mandatory regulatory guidelines with increasing the quality of the software developed. Software process improvement (SPI) assists software development organizations to increase their software quality, and assessments are an integral part of this process. Unfortunately, software process assessments are often expensive and time consuming. Additionally, they often provide companies with a long list of issues without providing realistic suggestions. The goal of this paper is to describe the implementation of a new low-overhead hybrid assessment method that has been designed specifically for medical device software development organisations wishing to improve their software development practices. This assessment method combines the SPI models of the Capability Maturity Model Integration (CMMI) and ISO/IEC 15504-5 with medical device software development regulations
Rho-associated kinase plays a role in rabbit urethral smooth muscle contraction, but not via enhanced myosin light chain phosphorylation
No full textThe involvement of Rho-associated kinase (ROK) in activation of rabbit urethral smooth muscle contraction was investigated by examining the effects of two structurally distinct inhibitors of ROK, Y27632 and H1152, on the contractile response to electric field stimulation (EFS), membrane depolarization with KCl, and α 1 -adrenoceptor stimulation with phenylephrine. Both compounds inhibited contractions elicited by all three stimuli. The protein kinase C inhibitor, GF109203X, on the other hand, had no effect. Urethral smooth muscle strips were analysed for phosphorylation of three potential direct or indirect substrates of ROK: (i) myosin regulatory light chains (LC 20 ) at S19; (ii) the myosin targeting subunit of myosin light chain phosphatase, MYPT1, at T697 and T855; and (iii) cofilin at S3. The following results were obtained: (i) under resting tension, LC 20 was phosphorylated to 0.65 ± 0.02 mol P i /mol LC 20 (n = 21) at S19; (ii) LC 20 phosphorylation did not change in response to KCl or phenylephrine; (iii) ROK inhibition had no effect on LC 20 phosphorylation in the absence or presence of contractile stimuli; (iv) under resting conditions, MYPT1 was partially phosphorylated at T697 and T855 and cofilin at S3; (v) phosphorylation of MYPT1 and cofilin was unaffected by KCl or phenylephrine; and (vi) KCl- and phenylephrine-induced contraction-relaxation cycles did not correlate with actin polymerization-depolymerization. We conclude that ROK plays an important role in urethral smooth muscle contraction, but not via inhibition of MLCP or polymerization of actin
Boyne Valley Landscapes Project Phase III Final Report 2010
No full textThis report details the third phase of research of the Boyne Valley Landscape Project which has seen Irish National Strategic Archaeological Research (INSTAR) funding from 2008 to 2010. The overarching aims of the project are to produce an integrated, comprehensive landscape archaeological model of the evolution of the Boyne catchment, and so develop an environmentally-contextualised understanding of a key part of Ireland's archaeological heritage
Creating Software Process Capability/Maturity Models
No full textA seeming multitude of software process capability/maturity models (SPCMMs) have emerged, and many software engineers have had to worry about compliance with them at one time or another. Although using SPCMMs is a well-established practice, the ways they're used can vary widely. At best, they can pull together vast bodies of knowledge about good software practices-the hard-won expertise of many engineers-into a form that's easier to work with. At worst, they're misused as "processes for process' sake," in which conforming to the model stifles opportunities for innovation and tailoring. If software engineers had better knowledge about how SPCMMs are developed and the basis of their recommendations, they might be able to interpret and use them to optimize their benefits. We therefore studied these issues in a systematic literature review and follow-on questionnaire
Comparison of the antimicrobial activity of Ulmo honey from Chile and Manuka honey against methicillin-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa
No full textHoney has previously been shown to have wound healing and antimicrobial properties, but this is dependent on the type of honey, geographical location and flower from which the final product is derived. We tested the antimicrobial activity of a Chilean honey made by Apis mellifera (honeybee) originating from the Ulmo tree (Eucryphia cordifolia), against selected strains of bacteria