Towards self-protecting ubiquitous systems : monitoring trust-based interactions

The requirement for spontaneous interaction in ubiquitous computing creates security issues over and above those present in other areas of computing, deeming traditional approaches ineffective. As a result, to support secure collaborations entities must implement self-protective measures. Trust management is a solution well suited to this task as reasoning about future interactions is based on the outcome of past ones. This requires monitoring of interactions as they take place. Such monitoring also allows us to take corrective action when interactions are proceeding unsatisfactorily. In this vein, we first present a trust-based model of interaction based on event structures. We then describe our ongoing work in the development of a monitor architecture which enables self-protective actions to be carried out at critical points during principal interaction. Finally, we discuss some potential directions for future work

Korsgaard on Reason and the Normativity of Rationality

Korsgaard (2009) argues, against Kolodny (2005) and Broome (2007), that rational requirements are in fact normative. In her view the normativity of rational requirements is a function of their constitutive role in the deliberative activity of reason. After surveying the treatment of this question in the relevant literature, I explain Korsgaard\u27s theory using pure constructivism as a framing device. I then argue that not only is her account of deliberative reason as an activity unsatisfactory (specifically, it fails to defeat the intuition that charges of boot-strapping are deeply problematic, and makes the adoption of reasons for belief from the deliberative perspective a function of an agent\u27s commitment to principles and not of her seeing the belief as true), but that she is unable to account for the normativity of rationality (because her theory is unable to provide an answer that avoids regress or is not trivial to her own “normative question” when it takes a rational requirement as its object)

A formal model of trust lifecycle management

The rapid development of collaborative environments over the internet has highlighted new concerns over security and trust in such global computing systems. The global computing infrastructure poses an issue of uncertainty about the potential collaborators. Reaching a trusting decision in such environments encompasses both risk and trust assessments. While much work has been done in terms of modelling trust, the investigation of the management of trust lifecycle issues with consideration of both trust and risk is less examined. Our previous work addressed the dynamic aspects of trust lifecycle with a consideration of trust formation, exploitation, and evolution. In this paper we provide an approach for formalizing these aspects. As part of the formalization of the trust lifecycle,we introduce a notion of attraction to model the effect of new pieces of evidence on our opinion. The formalization described in this paper constitutes the basis of ongoing work to investigate the properties of the model

Security models for trusting network appliances

A significant characteristic of pervasive computing is the need for secure interactions between highly mobile entities and the services in their environment. Moreover,these decentralised systems are also characterised by partial views over the state of the global environment, implying that we cannot guarantee verification of the properties of the mobile entity entering an unfamiliar domain. Secure in this context encompasses both the need for cryptographic security and the need for trust, on the part of both parties, that the interaction is functioning as expected. In this paper we make a broad assumption that trust and cryptographic security can be considered as orthogonal concerns (i.e. cryptographic measures do not ensure transmission of correct information). We assume the existence of reliable encryption techniques and focus on the characteristics of a model that supports the management of the trust relationships between two devices during ad-hoc interactions

Trust dynamics for collaborative global computing

Recent advances in networking technology have increased the potential for dynamic enterprise collaborations between an open set of entities on a global scale. The security of these collaborations is a major concern, and requires novel approaches suited to this new environment to be developed. Trust management appears to be a promising approach. Due to the dynamic nature of these collaborations,dynamism in the formation, evolution and exploitation of trust is essential. In this paper we explore the properties of trust dynamics in this context. Trust is formed and evolves according to personal experience and recommendations. The properties of trust dynamics are expressed through a formal model of trust. Specific examples, based on an e-purse application scenario are used to demonstrate these properties

Plane of nutrition before and after 6 months of age in Holstein-Friesian bulls: II. Effects on metabolic and reproductive endocrinology and identification of physiological markers of puberty and sexual maturation

peer-reviewedThe aim of this study was (1) to examine the effect of plane of nutrition during the first and second 6 mo of life on systemic concentrations of reproductive hormones and metabolites in Holstein-Friesian dairy bulls, and (2) to establish relationships with age at puberty and postpubertal semen production potential. Holstein-Friesian bull calves (n = 83) with a mean (standard deviation) age and body weight of 17 (4.4) d and 52 (6.2) kg, respectively, were assigned to a high or low plane of nutrition for the first 6 mo of life. At 24 wk of age, bulls were reassigned, within treatment, either to remain on the same diet or to switch to the opposite diet until puberty, resulting in 4 treatment groups: high-high, high-low, low-low, and low-high. Monthly blood samples were analyzed for metabolites (albumin, urea, total protein, β-hydroxybutyrate, glucose, nonesterified fatty acid, triglycerides and creatinine), insulin, insulin-like growth factor-1, leptin, adiponectin, FSH, and testosterone. A GnRH challenge was carried out at 16 and 32 wk of age (n = 9 bulls per treatment). Blood was collected at 15-min intervals for 165 min, with GnRH administered (0.05 mg/kg of body weight, i.v.) immediately after the third blood sample. Blood samples were subsequently analyzed for LH, FSH, and testosterone. Stepwise regression was used to detect growth and blood measurements to identify putative predictors of age at puberty and subsequent semen quality traits. Metabolic hormones and metabolites, in general, reflected metabolic status of bulls. Although FSH was unaffected by diet, it decreased with age both in monthly samples and following GnRH administration. Testosterone was greater in bulls on the high diet before and after 6 mo of age. Testosterone concentrations increased dramatically after 6 mo of age. Luteinizing hormone was unaffected by diet following GnRH administration but basal serum LH was greater in bulls on a high diet before 6 mo of age. In conclusion, the plane of nutrition offered before 6 mo of age influenced metabolic profiles, which are important for promoting GnRH pulsatility, in young bull

Development of paediatric quality of inpatient care indicators for low-income countries - A Delphi study

BACKGROUND: Indicators of quality of care for children in hospitals in low-income countries have been proposed, but information on their perceived validity and acceptability is lacking. METHODS: Potential indicators representing structural and process aspects of care for six common conditions were selected from existing, largely qualitative WHO assessment tools and guidelines. We employed the Delphi technique, which combines expert opinion and existing scientific information, to assess their perceived validity and acceptability. Panels of experts, one representing an international panel and one a national (Kenyan) panel, were asked to rate the indicators over 3 rounds and 2 rounds respectively according to a variety of attributes. RESULTS: Based on a pre-specified consensus criteria most of the indicators presented to the experts were accepted: 112/137(82%) and 94/133(71%) for the international and local panels respectively. For the other indicators there was no consensus; none were rejected. Most indicators were rated highly on link to outcomes, reliability, relevance, actionability and priority but rated more poorly on feasibility of data collection under routine conditions. There was moderate to substantial agreement between the two panels of experts. CONCLUSIONS: This Delphi study provided evidence for the perceived usefulness of most of a set of measures of quality of hospital care for children proposed for use in low-income countries. However, both international and local experts expressed concerns that data for many process-based indicators may not currently be available. The feasibility of widespread quality assessment and responsiveness of indicators to intervention should be examined as part of continued efforts to improve approaches to informative hospital quality assessment

Project PISA: Phosphorus Influence on Steel Ageing

The integrity of the pressure vessel is vital to the safe operation of a nuclear reactor. It is therefore necessary to monitor or predict the changes in the reactor pressure vessel (RPV) material during operation. Exposure to irradiation (or elevated temperatures) causes the segregation of phosphorus to internal grain boundaries in RPV steels. This, in turn, encourages brittle intergranular failure of the material. The PISA project had the objective of reducing the uncertainties associated with the impact of this failure mechanism on the properties of the RPV, both during service and at the end-of-life. This report presents the experimental results on the segregation of P and C during irradiation and thermal treatments, and the associated mechanical property changes, generated within PISA. The new data cover a range of bulk P levels, irradiation temperatures and fluences, steel types and product forms. In all cases only modest increases of P level on the grain boundary have been observed in commercial steels. Segregation is higher in pre-strained than in unstrained material. In addition a model for P segregation under irradiation has been developed, and shown to be capable of fitting the experimentally observed changes in P level after irradiation. Significant insight into the development of the microstructure under irradiation has thereby been obtained. Overall, the data and modelling together indicated that relatively small amounts of segregation are likely to occur under most reactor operational conditions in homogeneous commercial steels, and an (unexpectedly) small amount of additional embrittlement likely to derive from this process during reactor service.JRC.F.4-Nuclear design safet

Effect of early calf-hood nutrition on the transcriptomic profile of subcutaneous adipose tissue in Holstein-Friesian bulls

peer-reviewedBackground: Adipose tissue is a major endocrine organ and is thought to play a central role in the metabolic control of reproductive function in cattle. Plane of nutrition during early life has been shown to influence the timing of puberty in both male and female cattle, though the exact biological mechanisms involved are currently unknown. The aim of this study was to investigate the effect of early calf-hood nutrition on the transcriptomic profile of subcutaneous adipose tissue in Holstein-Friesian bulls to identify possible downstream effects on reproductive physiology. Results: Holstein-Friesian bull calves with a mean (±S.D.) age and bodyweight of 19 (±8.2) days and 47.5 (±5.3) kg, respectively, were assigned to either a high (n = 10) or low (n = 10) plane of nutrition. Calves were fed in order to achieve an overall growth rate of 1.08 and 0.57 kg/day for the high and low plane of nutrition treatments, respectively. At 126 days of age, the bulls were euthanized, subcutaneous adipose tissue samples were harvested and RNAseq analysis was performed. There were 674 genes differentially expressed in adipose tissue of calves on the low compared with the high plane of nutrition (P 2.0). High plane of nutrition positively altered the expression of genes across an array of putative biological processes but the most dominant cellular processes affected were cellular energy production and branched chain amino acid degradation. A high plane of nutrition caused upregulation of genes such as leptin (LEP) and adiponectin (ADIPOQ), which are known to directly affect reproductive function. Conclusions: These results provide an insight into the effect of augmenting the plane of nutrition of Holstein-Friesian bull calves in the prepubertal period on the transcriptome of adipose tissue

The effect of temperature on bubble lattice formation in copper under in situ He ion irradiation

In situ ion irradiation in a transmission electron microscope was used to investigate the effects of temperature on radiation-induced bubble lattice formation in Cu by low energy (12 keV) helium ions. Bubble lattices were observed to form between − 100 and 100 °C, but at 200 °C lattice formation was impeded by continued growth and agglomeration of bubbles. Both nucleation of bubbles, and to a lesser extent bubble lattice formation, are observed at lower fluences as temperature increases, which we suggest is due to increased point defect mobility. Previous work on point defect concentrations in irradiated copper is considered when interpreting these results