6 results on '"Archer, Matthew"'
Search Results
2. Digital extraction: Blockchain traceability in mineral supply chains.
- Author
-
Calvão, Filipe and Archer, Matthew
- Subjects
- *
SUPPLY chains , *POLITICAL geography , *BLOCKCHAINS , *MINERALS , *POLITICAL ecology , *TERRITORIAL waters - Abstract
Digital data — including technologically-mediated data generated by blockchain-enabled traceability — is performing an increasingly integral role in extractive operations, but scarce attention has been paid to the structuring effect of these digital technologies or the socio-economic spatiality of data-driven mining operations. Drawing on extensive qualitative research (interviews, participant observation, and two sets of survey data among actors relevant to these mineral supply chains), this article advances the notion of "digital extraction" to describe the collection, analysis, and instrumentalization of digital data generated under the banner of blockchain-based due diligence, chain of custody certifications, and various transparency mechanisms, situated alongside and in support of mineral extraction. The article mobilizes concepts from political geography and political ecology to argue that digital technologies of traceability in extractive processes potentially create new forms of control and exclusion or exacerbate existing social, political, and territorial dispossession through asymmetric relations of power and knowledge in mineral supply chains. Despite industry efforts to make mineral supply chains more sustainable by resorting to digital certification and traceability, the strategic uses of uncertainty, ignorance, and ambiguity undergirding blockchain-enabled traceability systems fail to challenge existing inequalities in resource use and access or fulfill the promise of transparency and accountability. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
3. An assessment of the East Australian Current as a renewable energy resource.
- Author
-
Schaeffer, Amandine, Archer, Matthew R., Baumard, Quentin, Roughan, Moninya, and Kerry, Colette
- Subjects
- *
RENEWABLE energy sources , *KINETIC energy , *RADAR altimetry , *POWER resources , *OCEAN currents , *MEANDERING rivers - Abstract
Ocean currents are an energy resource that could be harnessed to increase renewable energy yields and reduce humanity's dependence on fossil fuels. The first challenge is to identify regions of significant kinetic energy flux that are a viable distance from the shore for the extraction and transport of energy. Western boundary currents (WBCs) have been identified as the most promising resource in this regard due to their strong current speeds (typically 1–2 m s−1). However, such a resource is by necessity regional, so each prospective region requires thorough investigation. While global studies of WBCs (including the East Australian Current, hereafter the EAC) have been conducted using numerical models, they have coarse resolutions and often underestimate kinetic energy, which is the specific resource that needs accurate assessment. Here we address this knowledge gap, using a range of current velocity observations from moorings, high frequency radar and satellite altimetry to investigate the potential of the EAC as a future renewable energy resource, at various latitudes along the east Australian coast. Finally, in combination with a high-resolution data assimilating model, we propose the optimal location for future energy extraction opportunities with relatively high hydrokinetic flux (average of ~ 500 W m−2 at 50 m depth), constant direction and suitable location (25 km from shore in 400 m seawater depth). • First assessment of the East Australian Current (EAC) as a renewable energy resource • Observations reveal high variability in the extractable power due to EAC meandering. • High-resolution modelling allows the identification of an optimal extraction location. • Mean extractable power per device could reach 167 kW, extractable 74% of the time [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
4. A survey on computational intelligence approaches for predictive modeling in prostate cancer.
- Author
-
Cosma, Georgina, Brown, David, Archer, Matthew, Khan, Masood, and Graham Pockley, A.
- Subjects
- *
COMPUTATIONAL intelligence , *ARTIFICIAL intelligence , *PROSTATE cancer , *DATA analysis , *BIG data - Abstract
Predictive modeling in medicine involves the development of computational models which are capable of analysing large amounts of data in order to predict healthcare outcomes for individual patients. Computational intelligence approaches are suitable when the data to be modelled are too complex for conventional statistical techniques to process quickly and efficiently. These advanced approaches are based on mathematical models that have been especially developed for dealing with the uncertainty and imprecision which is typically found in clinical and biological datasets. This paper provides a survey of recent work on computational intelligence approaches that have been applied to prostate cancer predictive modeling, and considers the challenges which need to be addressed. In particular, the paper considers a broad definition of computational intelligence which includes metaheuristic optimisation algorithms (also known as nature inspired algorithms), Artificial Neural Networks, Deep Learning, Fuzzy based approaches, and hybrids of these, as well as Bayesian based approaches, and Markov models. Metaheuristic optimisation approaches, such as the Ant Colony Optimisation, Particle Swarm Optimisation, and Artificial Immune Network have been utilised for optimising the performance of prostate cancer predictive models, and the suitability of these approaches are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
5. Sedation-Associated Medications at Dementia Diagnosis, Their Receptor Activity, and Associations With Adverse Outcomes in a Large Clinical Cohort.
- Author
-
Mbazira, Agnes, Bishara, Delia, Perera, Gayan, Rawlins, Elizabeth, Webb, Silas, Archer, Matthew, Balasundaram, Bharathi, Shetty, Hitesh, Tsamakis, Konstantinos, Taylor, David, Sauer, Justin, Stewart, Robert, and Mueller, Christoph
- Subjects
- *
DRUG side effects , *COGNITION disorder risk factors , *STRUCTURAL equation modeling , *ANESTHESIA , *PSYCHIATRIC drugs , *TIME , *MORTALITY , *MULTIVARIATE analysis , *RETROSPECTIVE studies , *MENTAL health , *HEALTH status indicators , *REGRESSION analysis , *DEMENTIA patients , *RISK assessment , *HOSPITAL care , *LONGITUDINAL method , *PROPORTIONAL hazards models - Abstract
We aimed to investigate whether sedative medications are associated with adverse outcomes in people with dementia, and whether specific characteristics of these medications predict a higher risk of harm. Retrospective cohort study. 15,210 patients diagnosed with dementia between 2008 and 2017 in South London. From recorded medications at dementia diagnosis, we ascertained those with drowsiness listed as a side effect (termed "sedative" hereafter) and subdivided them by frequency and strength of sedation, receptor profile, half-life, and whether they were psychotropics. Multivariable Cox regression models were applied to determine risk of mortality and emergency hospitalization, and generalized estimating equations to investigate cognitive decline. Final models were adjusted for 19 potential confounders, including measures of physical and mental health, functioning, and central anticholinergic burden. At diagnosis, 70.4% of patients with dementia were receiving at least 1 sedative medication. Median survival time was 4.0 years and median time to first hospitalization 1.4 years. After controlling for potential confounders, receipt of any sedative medication at dementia diagnosis was associated with accelerated cognitive decline and a higher hospitalization risk, but only medications with a cautionary warning yielded an increased mortality hazard. Medications acting through γ-aminobutyric acid agonism, psychotropic sedatives, and those with a short half-life were associated with a higher risk of mortality. γ-aminobutyric acid agonists, N -methyl- d -aspartate receptor antagonists, and nonpsychotropic sedatives were associated with an increased hospitalization risk. α 1 antagonist, antihistamines, N -methyl- d -aspartate receptor antagonists, psychotropic sedatives, and those with the shortest or longest half-life were associated with accelerated cognitive decline. Receipt of any sedative agent was associated with hospitalization and accelerated cognitive decline. Differences in hazard appear to exist between frequency and strength of sedation, receptor profiles, half-life, and prescribing indication. These differences should be taken into consideration in medication reviews at the time of dementia diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Revisiting the circulation of the East Australian Current: Its path, separation, and eddy field.
- Author
-
Oke, Peter R., Roughan, Moninya, Cetina-Heredia, Paulina, Pilo, Gabriela S., Ridgway, Kenneth R., Rykova, Tatiana, Archer, Matthew R., Coleman, Richard C., Kerry, Colette G., Rocha, Carlos, Schaeffer, Amandine, and Vitarelli, Eduardo
- Subjects
- *
EDDIES , *MESOSCALE eddies , *VERTICAL motion , *OCEAN dynamics , *CONTINENTAL shelf - Abstract
• We present challenge the traditional view of the EAC system and offer a new interpretation. • The EAC is a meandering stream that feeds a field of eddies. • We show that the Tasman Front and EAC Extension are rarely seen as distinct features.distinct, identifiable. • We summarise publishedworks on the EAC's path, separation, and eddy field. The traditional view of the East Australian Current (EAC), as depicted in many schematics, is of a continuous boundary current that flows along the shelf off eastern Australia, between approximately 18°S and about 32.5°S, where it separates from the coast and continues either towards New Zealand, along the Tasman Front; or towards Tasmania, as the EAC Extension. Additionally, it is widely recognised that eddies are prevalent in the EAC region – particularly south of the EAC separation. We revisit this long-standing paradigm and suggest that the EAC is perhaps better viewed as a continuous, meandering stream, flowing adjacent to the coast that "feeds" a field of mesoscale eddies. Observations show that EAC eddies are prevalent over a broad region of the western Tasman Sea, as far north as 25°S, typically with maximum intensity between 30 and 35°S. At any instant in time the EAC jet is usually evident as a poleward stream adjacent to the continental shelf edge. Other commonly accepted components of the EAC System, including the Tasman Front and EAC Extension, are rarely seen as distinct, identifiable features. Rather, these features are evident only in time-mean fields, when the eddy-variability is filtered out. It is also common for the EAC to be spatially discontinuous – due to the presence of eddies – often with multiple short streams that sometimes separate and re-attach to the coast. Recognition of the EAC as an eddy-dominated current system has seen many recent studies focus on various aspects of eddies in the EAC System, providing new insights into mesoscale ocean dynamics. Recent studies of individual eddies have shown that the circulation within eddies, including tilting and vertical motion, is more complex than previously understood. A summary of these studies, along with a review of the EAC System, particularly its path, separation, and eddy field is presented here. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.