Semantic role-based access control

In this thesis we propose two semantic ontological role-based access control (RBAC) reasoning processes. These processes infer user authorisations according to a set of role permission and denial assignments, together with user role assignments. The first process, SO-RBAC (Semantic Ontological Role-Based Access Control) uses OWL-DL to store the ontology, and SWRL to perform reasoning. It is based mainly on RBAC models previously described using Prolog. This demonstrates the feasibility of writing an RBAC model in OWL and performing reasoning inside it, but is still tied closely to descriptive logic concepts, and does not effectively exploit OWL features such as the class hierarchy. To fully exploit the capabilities of OWL, it was necessary to enhance the SO-RBAC model by programming it in OWL-Full. The resulting OWL-Full model, ESO-RBAC (Enhanced Semantic Ontological Role-Based Access Control), uses Jena for performing reasoning, and allows an object-oriented definition of roles and of data items. The definitions of roles as classes, and users as members of classes representing roles, allows user-role assignments to be defined in a way that is natural to OWL. All information relevant to determining authorisations is stored in the ontology. The resulting RBAC model is more flexible than models based on predicate logic and relational database systems. There are three motivations for this research. First, we found that relational database systems do not implement all of the features of RBAC that we modelled in Prolog. Furthermore, implementations of RBAC in database management systems is always vendor-specific, so the user is dependent on a particular vendor's procedures when granting permissions and denials. Second, Prolog and relational database systems cannot naturally represent hierarchical data, which is the backbone of any semantic representation of RBAC models. An RBAC model should be able to infer user authorisations from a hierarchy of both roles and data types, that is, determine permission or denial from not just the type of role (which may include sub-roles), but also the type of data (which may include sub-types). Third, OWL reasoner-enabled ontologies allow us to describe and manipulate the semantics of RBAC differently, and consequently to address the previous two problems efficiently. The contribution of this thesis is twofold. First, we propose semantic ontological reasoning processes, which are domain and implementation independent, and can be run from any distributed computing environment. This can be developed through integrated development environments such as NetBeans and using OWL APIs. Second, we have pioneered a way of exploiting OWL and its reasoners for the purpose of defining and manipulating the semantics of RBAC. Therefore, we automatically infer OWL concepts according to a specific stage that we define in our proposed reasoning processes. OWL ontologies are not static vocabularies of terms and constraints that define the semantics of RBAC. They are repositories of concepts that allow ad-hoc inference, with the ultimate goal in RBAC of granting permissions and denials

Notes on some distinctive points in the Pupae of West African mosquitos

n/

Guidelines for best practice in great ape tourism

Tourism based on the viewing of great apes is increasingly promoted as a means of generating revenue for range states, local communities, and the private sector (e.g. GRASP, 2006 ). This is despite known risks from tourism, including disease transmission, which have caused concern among conservationists and prompted the International Union for Conservation of Nature to publish guidelines on best practices for great ape tourism (Macfi e & Williamson, 2010 ). IUCN is one of the world's most respected authorities on species conservation, and brings together governments, UN agencies, and NGOs to conserve biodiversity and to ensure that any use of natural resources is equitable and ecologically sustainable

Compost Application Affects Metal Uptake in Plants Grown in Urban Garden Soils and Potential Human Health Risk

Purpose This study explores the effect of varying organic matter content on the potential human health risk of consuming vegetables grown in urban garden soils. Materials and methods Metal accumulation among edible tissues of green bean (Phaseolus vulgaris L.), lettuce (Lactuca sativa L.) and carrot (Daucus carota L.) was determined for plants grown in five urban garden soils amended with 0, 9, or 25% (v/v) compost. Potential risk to human health was assessed by calculating a bioconcentration factor and a hazard quotient. Results and discussion Overall, the consumption of lettuce and green bean pods grown in some urban gardens posed a potential human health risk due to unacceptably high concentrations of cadmium or lead. In many cases, compost amendment increased the accumulation of metals in the vegetables. Even in soils considered uncontaminated by current guidelines, some hazard quotients exceeded the threshold value of 1. The compost used in this study had a high fulvic acid to humic acid ratio, which may explain increased concentrations of metals in plants grown in compost-amended soils. Conclusions These results indicate a need to include soil characteristics, specifically organic matter quality, when setting threshold criteria for metal content of urban garden soils

Accumulation of Cadmium in Near-Isogenic Lines of Durum Wheat (Triticum Turgidum L. Var Durum): the Role of Transpiration

Concentrations of cadmium in the grain of durum wheat (Triticum turgidum L. var durum) are often above the internationally acceptable limit of 0.2 mg kg−1. Cultivars that vary in concentrations of cadmium in the grain have been identified but the physiology behind differential accumulation has not been determined. Three pairs of near-isogenic lines (isolines) of durum wheat that vary in aboveground cadmium accumulation (8982-TL ‘high’ and ‘low’, W9260-BC ‘high’ and ‘low’, and W9261-BG ‘high’ and ‘low’) were used to test the hypothesis that the greater amounts of cadmium in shoots of the ‘high’ isolines are correlated with greater volumes of water transpired. In general, cadmium content was positively correlated with transpiration only in the ‘low’ isolines. Although shoots of the ‘high’ isolines of W9260-BC and W9261-BG contained higher concentrations of cadmium than did their corresponding ‘low’ isolines, they did not transpire larger volumes of water. In addition, isolines of 8982-TL transpired less water than did the other pairs of isolines yet both ‘high’ and ‘low’ isolines of 8982-TL contained higher amounts of cadmium than did the other pairs. The difference between ‘high’ and ‘low’ isolines appears to be related to the relative contribution of transpiration to cadmium translocation to the shoot. Increased transpiration was associated with increased cadmium content in the ‘low’ isolines but in the ‘high’ isolines increased cadmium in the shoot occurred independently of the volume of water transpired

A microfluidic chip based model for the study of full thickness human intestinal tissue using dual flow

© 2016 Author(s). The study of inflammatory bowel disease, including Ulcerative Colitis and Crohn's Disease, has relied largely upon the use of animal or cell culture models; neither of which can represent all aspects of the human pathophysiology. Presented herein is a dual flow microfluidic device which holds full thickness human intestinal tissue in a known orientation. The luminal and serosal sides are independently perfused ex vivo with nutrients with simultaneous waste removal for up to 72 h. The microfluidic device maintains the viability and integrity of the tissue as demonstrated through Haematoxylin & Eosin staining, immunohistochemistry and release of lactate dehydrogenase. In addition, the inflammatory state remains in the tissue after perfusion on the device as determined by measuring calprotectin levels. It is anticipated that this human model will be extremely useful for studying the biology and tes ting novel interventions in diseased tissue

Production of Organic Acids and Adsorption of Cd on Roots of Durum Wheat (Triticum turgidum L. var. durum)

A number of isolines of durum wheat (Triticum turgidum var durum) differ in their translocation of Cd. In the field, the high isolines accumulate twice the Cd in leaves and grain when compared to the low isolines. The hypothesis that differential accumulation of Cd is associated with differential production of organic acids was tested by measuring Cd content in tissues, Cd partitioning within the root, and organic acids in tissues. In solution culture, the high and low isolines of W9261-BG did not differ in any of the variables measured. Within W9260-BC, the low isoline had half the Cd in its shoot, 30% more tightly-bound Cd in the root and higher concentrations of fumaric, malic, and succinic acids in the root compared to the high isoline. Differential Cd accumulation may be linked to differential adsorption and retention of Cd in the roots of the low Cd-accumulating isolines, possibly via chelation with organic acids

Localization and Chemical Speciation of Cadmium in the Roots of Barley and Lettuce

Plants have the potential to accumulate toxic amounts of cadmium (Cd), and understanding how and where Cd is stored in plants is important for ensuring food safety. Previous experiments have determined that a greater amount of Cd is translocated into the leaves of lettuce (Lactuca sativa) as compared to barley leaves (Hordeum vulgare). Preferential retention of Cd in root of barley would explain this difference. Hence, the purpose of this study was to determine the localization and coordination environment of Cd (i.e., the ligands to which Cd was bound) in the different root tissues of lettuce and barley using histochemical staining, electron microscopy and micro X-ray spectroscopy. Retention of Cd in barley roots could be explained by accumulation of Cd at the endodermis, comparatively higher amounts of Cd sequestered in the symplast of cortical cells and binding to xylem cell walls. Increased translocation of Cd to lettuce shoots seemed to be due to a less effective barrier at the endodermis and less sequestration of Cd in the cortex. Regardless of the tissue type, most of the Cd2+ was bound to S ligands in the roots of barley, possibly reflecting accumulation of Cd–phytochelatin and Cd–S molecules in the vacuoles. In lettuce roots, Cd was more evenly distributed among ligands containing S, O and NO3 groups, which is indicative of proportionately more Cd binding to the cell walls, relative to barley. These results will be useful in uncovering the mechanisms of differential Cd-tolerance and sequestration in lettuce and barley

Adam Smith and Colonialism

In the context of debates about liberalism and colonialism, the arguments of Adam Smith have been taken as illustrative of an important line of anti-colonial liberal thought. The reading of Smith presented here challenges this interpretation. It argues that Smith’s opposition to colonial rule derived largely from its impact on the metropole, rather than on its impact on the conquered and colonised; that Smith recognised colonialism had brought ‘improvement’ in conquered territories and that Smith struggled to balance recognition of moral diversity with a universal moral framework and a commitment to a particular interpretation of progress through history. These arguments have a wider significance as they point towards some of the issues at stake in liberal anti-colonial arguments more generally

Feasibility of a novel exercise prehabilitation programme in patients scheduled for elective colorectal surgery: a feasibility randomised controlled trial

© 2019, The Author(s). Background and objectives: To investigate the feasibility of delivering a functional exercise-based prehabilitation intervention and its effects on postoperative length of hospital stay, preoperative physical functioning and health-related quality of life in elective colorectal surgery. Materials and methods: In this randomised controlled feasibility trial, 22 elective colorectal surgery patients were randomly assigned to exercise prehabilitation (n = 11) or standard care (n = 11). Feasibility of delivering the intervention was assessed based on recruitment and compliance to the intervention. Impact on postoperative length of hospital stay and complications, preoperative physical functioning (timed up and go test, five times sit to stand, stair climb test, handgrip dynamometry and 6-min walk test) and health-related quality of life were also assessed. Results: Over 42% of patients (84/198) screened were deemed ineligible for prehabilitation due to insufficient time existing prior to scheduled surgery. Of those who were eligible, approximately 18% consented to the trial. Median length of hospital stay was 8 [range 6–27] and 10 [range 5–12] days respectively for the standard care and prehabilitation groups. Patterns towards preoperative improvements for the timed up and go test, stair climb test and 6-min walk test were observed for all participants receiving prehabilitation but not standard care. Conclusions: Despite prehabilitation appearing to convey positive benefits on physical functioning, short surgical wait times and patient engagement represent major obstacles to implementing exercise prehabilitation programmes in colorectal cancer patients