15 research outputs found
Agent based modelling of the dry bulk shipping sector
This thesis presents an agent based model of the dry bulk shipping sector. The model is highly disaggregated, representing all voyages and cargoes transported through to 2050, including approximately 500 shippers and 750 shipowners with a total fleet of greater than 1000 vessels. In multiple projection scenarios, 2700 trade flows are modelled. The purpose of the approach is to identify a high fidelity representation of the system to gain a greater understanding of how aggregate level properties, for example total fuel consumption, are generated from individual company based decisions such as when to transport cargo, what vessels to use, and what technology to invest in. Contracts of affreightment, the spot market and time charter market are represented within the model to create, where possible, a realistic representation of actual contractual conditions. The model is deployed to investigate the impact of climate change on the sector. Specifically, it investigated: physical impacts of climate change through the opening of Arctic sea routes; changing demand for commodities due to climate change and projected evolution of the global economy; changing fuel prices due to external projected changes in the shipping sector, and; effects of mitigation of climate change through carbon pricing and minimum standards on vessel efficiency. A key finding from the work is that endogeneous changes in the shipping system, through for example shipper preferences, create greater variability than those driven by external factors. This variability is reflected in the number of vessels in each of the size categories, the technology uptaken and the strategic approach of shippers in transporting their cargo. There remains a strong coupling of transport supply and emissions, with the regulations tested and available technology not resulting in significant improvements in energy efficiency. On the modelling of the dry bulk shipping system, clear computational and scope limits were identified. On computational limits, the system is constrained such that parallelisation is limited leading to long runtimes. To understand the effects of agents choices, the modelling of the individual voyages is necessary leading to large degrees of freedom. In addition, the work has highlighted the need for more validation data of greater granularity
A multi-wavelength discriminating sensor with a wireless mote interface for aquatic pollution monitoring
peer-reviewedThe system presented in this paper demonstrates how a novel fibre optic based sensing platform, capable of detecting minute changes in the level of impurity in a liquid, can be incorporated onto a Mote based platform enabling real time monitoring of a body of water. How these features can be used to detect a representative sample of chlorophyll within a aquatic environment, will be demonstrated. Systems currently deployed worldwide include satellite mapping technology and high cost water monitoring platforms. Growing international emphasis on the management of water quality is giving rise to an expansion of the international market for novel robust, miniaturized, intelligent water monitoring systems capable of measuring local environmentally detrimental events such as localised small scale chemical pollution.PUBLISHEDpeer-reviewe
Attenuated CSF-1R signalling drives cerebrovascular pathology
Cerebrovascular pathologies occur in up to 80% of cases of Alzheimer's disease; however, the underlying mechanisms that lead to perivascular pathology and accompanying blood-brain barrier (BBB) disruption are still not fully understood. We have identified previously unreported mutations in colony stimulating factor-1 receptor (CSF-1R) in an ultra-rare autosomal dominant condition termed adult-onset leucoencephalopathy with axonal spheroids and pigmented glia (ALSP). Cerebrovascular pathologies such as cerebral amyloid angiopathy (CAA) and perivascular p-Tau were some of the primary neuropathological features of this condition. We have identified two families with different dominant acting alleles with variants located in the kinase region of the CSF-1R gene, which confer a lack of kinase activity and signalling. The protein product of this gene acts as the receptor for 2 cognate ligands, namely colony stimulating factor-1 (CSF-1) and interleukin-34 (IL-34). Here, we show that depletion in CSF-1R signalling induces BBB disruption and decreases the phagocytic capacity of peripheral macrophages but not microglia. CSF-1R signalling appears to be critical for macrophage and microglial activation, and macrophage localisation to amyloid appears reduced following the induction of Csf-1r heterozygosity in macrophages. Finally, we show that endothelial/microglial crosstalk and concomitant attenuation of CSF-1R signalling causes re-modelling of BBB-associated tight junctions and suggest that regulating BBB integrity and systemic macrophage recruitment to the brain may be therapeutically relevant in ALSP and other Alzheimer's-like dementias
Multi-directional dynamic model for traumatic brain injury detection
Traumatic brain injury (TBI) is a complex injury that is hard to predict and
diagnose, with many studies focused on associating head kinematics to brain
injury risk. Recently, there has been a push towards using computationally
expensive finite element (FE) models of the brain to create tissue deformation
metrics of brain injury. Here, we developed a 3 degree-of-freedom
lumped-parameter brain model, built based on the measured natural frequencies
of a FE brain model simulated with live human impact data, to be used to
rapidly estimate peak brain strains experienced during head rotational
accelerations. On our dataset, the simplified model correlates with peak
principal FE strain by an R2 of 0.80. Further, coronal and axial model
displacement correlated with fiber-oriented peak strain in the corpus callosum
with an R2 of 0.77. Using the maximum displacement predicted by our brain
model, we propose an injury criteria and compare it against a number of
existing rotational and translational kinematic injury metrics on a dataset of
head kinematics from 27 clinically diagnosed injuries and 887 non-injuries. We
found that our proposed metric performed comparably to peak angular
acceleration, linear acceleration, and angular velocity in classifying injury
and non-injury events. Metrics which separated time traces into their
directional components had improved deviance to those which combined components
into a single time trace magnitude. Our brain model can be used in future work
as a computationally efficient alternative to FE models for classifying
injuries over a wide range of loading conditions.Comment: 10 figures, 3 table
Assessment of the antithrombotic properties of polar lipids of beer and brewing industry by-products.
This study investigated the in vitro antithrombotic properties of the lipids extracted from malted grain (MG), brewer’s spent grain (BSG), raw hops (RWHP), spent hops (SPHP), wort, and beer. Total lipids (TL) were extracted according to the Bligh & Dyer method and further separated into total polar lipid (TPL) and total neutral lipid (TNL) using a modified counter-current distribution method. The TPL of the beer was further fractionated by TLC and isolated bands were extracted. The antithrombotic activities of the TL, TPL and TNL of the MG, BSG, RWHP and SPHP were analysed in vitro for their ability to inhibit platelet-activating factor (PAF) induced aggregation in human platelets. Seven bands extracted by preparative TLC of the beer TPL were also tested for the ability to inhibit PAF induced platelet aggregation. This study demonstrated that the TPL extracts were the most bioactive with the exception of BSG as the TL displayed potent antithrombotic activity. The wort and beer TPL displayed the most potent inhibitory activity against PAF induced platelet aggregation. However, the beer TPL possessed the strongest inhibitory activity against PAF with the lowest IC50 value (7.8 ± 3.9 μg) and it was noted that fermentation of the wort increased the antithrombotic activity, which may warrant further investigation. The TLC bands 2 and 3 of the beer TPL exhibited potent inhibitory activity against PAF, which may be due to the presence of phenolic compounds. The fatty acid composition of the TPL extracts of all samples were analysed by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis of the TPL found that the wort and beer shared similar fatty acid compositions. The findings of this study provide new information into the effect of fermentation on the fatty acid composition and antithrombotic properties of beer. Further structural and functional studies are required to identify the exact compounds responsible for the observed biological activity of the TPL extracts
A multi-wavelength discriminating sensor with a wireless mote interface for aquatic pollution monitoring
The system presented in this paper demonstrates how a novel fibre optic based sensing platform, capable of detecting minute changes in the level of impurity in a liquid, can be incorporated onto a Mote based platform enabling real time monitoring of a body of water. How these features can be used to detect a representative sample of chlorophyll within a aquatic environment, will be demonstrated. Systems currently deployed worldwide include satellite mapping technology and high cost water monitoring platforms. Growing international emphasis on the management of water quality is giving rise to an expansion of the international market for novel robust, miniaturized, intelligent water monitoring systems capable of measuring local environmentally detrimental events such as localised small scale chemical pollution
Bioprospecting for antithrombotic polar lipids from salmon, herring, and boarfish by-products
Marine polar lipids (PLs) have exhibited promising cardioprotection. In this study,
marine by-products such as salmon heads (SHs), their brain, eyes and main optic nerves (SBEON),and head-remnants after SBEON removal (RemSH), as well as herring fillets (HFs), herring heads(HHs) and minced boarfish (MB), were evaluated as potential sustainable sources of such bioactive PLs.The antithrombotic bioactivities of PLs derived from these marine by-products were assessed for the first time in human platelets against platelet-activating factor (PAF), thrombin, collagen, and adenosine diphosphate (ADP), while their fatty acid composition was evaluated by gas chromatography–mass
spectrometry (GC-MS). PLs from all marine by-products tested possess strong antithrombotic activities against aggregation of human platelets induced by all platelet agonists tested. RemSH, SBEON, HHs, HFs, and MB exhibited strong anti-PAF e ects, similar to those previously reported for salmon fillets. PLs from MB had the strongest anti-collagen e ects and PLs from SHs and SBEON were the most active against thrombin and ADP. PLs from HHs had similar antithrombotic e ects with those from
HFs in all agonists. RemSH was less active in all agonists, suggesting that SBEON is the main source of bioactive PLs in SHs. All PLs were rich in omega-3 polyunsaturated fatty acids (!3PUFA), such as docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) acid, with favourable low values of the !6/!3 ratio. Salmon, herring, and boarfish by-products are rich sources of bioactive marine PLs with potent antithrombotic and cardioprotective properties
A multidirectional two-tube method for chemical pleurodesis could improve distribution of the sclerosing agent within the pleural cavity - A pilot study.
Introduction: Malignant pleural effusion (MPE) affects approximately 200,000 people in the United States per annum. Chemical pleurodesis is a recommended first line treatment in the management of MPE, however, success rates as low as 43% has been reported. A bedside chemical pleurodesis can cost up to 5 billion in the US alone. This study aims to assess the distribution of the talc slurry within the pleural space using human cadaveric models and to determine the force required to push the talc slurry though a 14 Fr chest tube.Materials and methods: The force required to administer the talc slurry through a 14 Fr chest tube was tested using a Zwick/Roelle Z005 mechanical tester, using a porcine thoracic biomodel. Talc slurry distribution within the pleural cavity was assessed by direct visualisation following administration to the human cadaveric models using single and multidirectional two-tube methods.Results: Maximum force required to push the talc slurry through a 14 Fr chest tube was 11.36 N ± 2.79 N. Distribution of the talc slurry within the pleural cavity was found to be poor with a single tube method. Multidirectional two-tube method of administration showed more even distribution.Conclusion: The experimental multidirectional two-tube method results in wider distribution of the talc slurry within the pleural cavity and could further improve success rate of the talc pleurodesis.</div
Optical fibre multi-parameter sensing with secure cloud based signal capture and processing
Recent advancements in cloud computing technologies in the context of optical and optical fibre based systems are reported. The proliferation of real time and multi-channel based sensor systems represents significant growth in data volume. This coupled with a growing need for security presents many challenges and presents a huge opportunity for an evolutionary step in the widespread application of these sensing technologies. A tiered infrastmctural system approach is adopted that is designed to facilitate the delivery of Optical Fibre based "SENsing as a Service-SENaaS". Within this infrastructure, novel optical sensing platforms, deployed within different environments, are interfaced with a Cloud-based backbone infrastructure which facilitates the secure collection, storage and analysis of real-time data. Feedback systems, which harness this data to affect a change within the monitored location/environment/condition, are also discussed. The cloud based system presented here can also be used with chemical and physical sensors that require real-time data analysis, processing and feedback
The in vitro antithrombotic properties of ale, lager, and stout beers
The in vitro antithrombotic properties of polar lipid microconstituents of three Irish beers (ale, larger, and stout) have been assessed against platelet-activating factor-induced platelet aggregation. Total lipid (TL) extracts were obtained using the Bligh and Dyer method and each beer was separated into the organic phase and hydromethanolic phase. The total polar lipid (TPL) and total neutral lipid (TNL) fractions of the organic phase and hydromethanolic phase of each beer were obtained using a counter-current distribution. The TL, TNL, and TPL extracts of each phase of each beer were measured for their capacity to inhibit platelet-activating factor-induced platelet aggregation. The low IC50 values obtained suggest that all three beers contain potent polar lipids that can inhibit platelet-activating factor-induced platelet aggregation. The fatty acid composition of the organic phase TPL extracts were measured using gas chromatography-mass spectrometry. The organic phase total polar lipid extracts were further fractionated using thin-layer chromatography (TLC) and the antithrombotic bioactivities of these TLC bands were measured. This data suggested that the TLC bands corresponding to phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and cardiolipin were the most active phospholipids in the total polar lipids of the organic phase. These promising results indicate that beer consumption may provide antithrombotic effects