535 research outputs found
A requirements engineering framework for developing COTS GIS applications : a thesis presented in partial fulfilment of the requirements for the degree of Master of Information Science in Information Systems at Massey University
There has been an increase in recent years in the number of Geographic Information System (GIS) applications being developed for stakeholders using Commercial Off-The-Shelf (COTS) software. There are a lack of guidelines in both industry and the literature on how to acquire user requirements for the development of GIS applications in this COTS software environment. This study investigates process activities in order to build a framework to address these inadequacies. The construction of the framework incorporates requirements engineering and COTS software evaluation and selection process activities from the Information Systems (IS) area. The framework is used to explore three issues related to developing GIS applications and used to determine whether: 1) a life cycle model is used to guide the gathering and analysing of requirements when developing GIS applications, 2) standard IS requirements processes can be used for developing GIS solutions, and 3) standard IS COTS software acquisition processes can be used for developing GIS solutions. Case studies were used to analyse current practices in the GIS industry and to validate the usefulness of these activities in the framework. The results of this investigation suggest that RE practices associated with the COTS paradigm within the IS arena are suitable for developing GIS applications based on user requirements
Post-polypectomy surveillance colonoscopy: In whom and when?
Introduction
Post-polypectomy surveillance by colonoscopy is recommended in national and international guidelines. While colonoscopy is the gold standard colorectal investigation, it carries a risk of adverse events as well as being inconvenient and often uncomfortable for the patient.
It is established that population screening reduces mortality from colorectal cancer (CRC). The effect of post-polypectomy surveillance, however, is less clear. An increasing number of colonoscopies are being performed worldwide for both symptoms and screening. The adenoma detection rate at colonoscopy is also increasing with improved technology and training against the backdrop of an ageing population. As a result, an increasing number of individuals are entering post-polypectomy surveillance.
Aims & Objectives
The aim of the analysis was to evaluate the findings of post-polypectomy surveillance within the English Bowel Cancer Screening Programme (BCSP). This was done by assessing linked data from the BCSP database and the National Cancer Registration and Analysis Service (NCRAS). Objectives were:
1. To document surveillance pathways among the intermediate and high risk groups.
2. To determine the risk factors (adenoma and person-specific) at screening which predict the outcome of initial surveillance.
3. To determine the adenoma, advanced adenoma (AA) and CRC yield at initial surveillance of each colonoscopy surveillance cohort (and subcategories within each cohort) within the BCSP.
Methods
Data on individuals participating in the BCSP is entered prospectively onto the screening programme’s relational database, BCSS. BCSS was interrogated for individuals who had attended for post-polypectomy surveillance at any time from the start of the programme in 2006 until the end of 2016. In addition, linked data on CRCs diagnosed in this cohort were obtained from NCRAS.
Two separate analyses were performed. The first focussed on the detection of any AA (size ≥10mm or ≥25% villous or high-grade dysplasia) at the first surveillance attended by an individual. A separate analysis was performed with a diagnosis of CRC as the primary outcome.
Results
Of individuals with high risk findings at baseline colonoscopy, 12.3% of those attending first surveillance were found to have AA, 48.0% non-advanced adenoma, 39.1% no adenoma, and 0.5% CRC.
In the case of individuals with intermediate risk findings at baseline, of those attending first surveillance, 8.0% were found to have AA, 35.3% non-advanced adenoma, 56.1% no adenoma, and 0.4% CRC. In those categorised as intermediate risk based on the finding of a single adenoma (≥10mm) at baseline, 6.3% of those attending first surveillance were found to have AA and 0.3% CRC.
The most significant factor increasing the risk of AA at first surveillance was a higher total number of adenomas at baseline colonoscopy.
Conclusions
The rates of AA and CRC at first surveillance are relatively low and were found to be higher in the high risk group compared to intermediate risk. Those individuals categorised as intermediate risk based on a single adenoma (≥10mm) at baseline, had a particularly low rate of AA and CRC at first surveillance.
These findings support the hypothesis that the incidence of AA and CRC are low at post-polypectomy surveillance colonoscopy. The particularly low yield in the subgroup with a single adenoma at baseline suggests that surveillance is not be needed in this group and may not be necessary for the intermediate risk cohort as a whole
Tensions in relation: How peer support is experienced and received in a hepatitis C treatment intervention.
Peer support and involvement is recognised as a vital component of hepatitis C (HCV) treatment provision for marginalised populations, such as people who inject drugs (PWID). Developments in HCV treatments enable increased provision in community settings - expanding the possibilities for meaningful peer involvement in HCV treatment plans. To date, HCV peer support has generally been viewed as a positive intervention, with little critical reflection on the ways social structures, policies, health and drug services and social identity impact on how peer support is experienced and received.
We report on the qualitative component of a UK-based intervention designed to increase HCV diagnosis and treatment in primary care and drug treatment settings. Data were collected between 2014 and 2016. Pre-intervention, a total of 35 PWID clients took part in nine in-depth interviews and four focus groups. In addition, 22 drug services and intervention providers took part in two focus groups and nine interviews. Post-intervention, one focus group and eight interviews were conducted with 13 PWID clients, and four focus groups and ten interviews were conducted with 26 drug services and intervention providers. Our data generation and thematic analysis focused on the peer education and buddy support component of the intervention.
Participants had common expectations of the peer role (to 'just be there') and its occupants' attributes (empathy, trustworthy, etc.). However, in practice, peers faced constraints on realising these expectations. A 'recovery' dominated drug treatment ethos in the UK appeared to influence the selection of 'recovery champions' as peers for the intervention. This created tensions in relations with clients, particularly when risk-adverse discourses were internalised by the peers. Peers were poorly integrated and supported within the service, affecting opportunities to relate and build trust with clients. Thus, the scope for peer support to impact on the nature and extent of clients' testing and treatment for HCV was limited.
The efficacy of peer involvement can be constrained by organisational structures and boundaries - especially regarding who is deemed to be 'a peer'. Peer programmes take time and care to implement and weave into wider recovery and harm reduction frameworks
A proposed method of grading malaria chemoprevention efficacy
The efficacy and effectiveness of antimalarial drugs are threatened by increasing levels of resistance and therefore require continuous monitoring. Chemoprevention is increasingly deployed as a malaria control measure, but there are no generally accepted methods of assessment. We propose a simple method of grading the parasitological response to chemoprevention (focusing on seasonal malaria chemoprevention) that is based on pharmacometric assessment
Geodesics in Transitive Graphs
AbstractLetPbe a double ray in an infinite graphX, and letdanddPdenote the distance functions inXand inPrespectively. One callsPageodesicifd(x, y)=dP(x, y), for all verticesxandyinP. We give situations when every edge of a graph belongs to a geodesic or a half-geodesic. Furthermore, we show the existence of geodesics in infinite locally-finite transitive graphs with polynomial growth which are left invariant (set-wise) under “translating” automorphisms. As the main result, we show that an infinite, locally-finite, transitive, 1-ended graph with polynomial growth is planar if and only if the complement of every geodesic has exactly two infinite components
Embedding Digraphs on Orientable Surfaces
AbstractWe consider a notion of embedding digraphs on orientable surfaces, applicable to digraphs in which the indegree equals the outdegree for every vertex, i.e., Eulerian digraphs. This idea has been considered before in the context of compatible Euler tours or orthogonal A-trails by Andersen and by Bouchet. This prior work has mostly been limited to embeddings of Eulerian digraphs on predetermined surfaces and to digraphs with underlying graphs of maximum degree at most 4. In this paper, a foundation is laid for the study of all Eulerian digraph embeddings. Results are proved which are analogous to those fundamental to the theory of undirected graph embeddings, such as Duke's theorem [5], and an infinite family of digraphs which demonstrates that the genus range for an embeddable digraph can be any nonnegative integer given. We show that it is possible to have genus range equal to one, with arbitrarily large minimum genus, unlike in the undirected case. The difference between the minimum genera of a digraph and its underlying graph is considered, as is the difference between the maximum genera. We say that a digraph is upper-embeddable if it can be embedded with two or three regions and prove that every regular tournament is upper-embeddable
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