The Anatomy and Facets of Dynamic Policies

Information flow policies are often dynamic; the security concerns of a program will typically change during execution to reflect security-relevant events. A key challenge is how to best specify, and give proper meaning to, such dynamic policies. A large number of approaches exist that tackle that challenge, each yielding some important, but unconnected, insight. In this work we synthesise existing knowledge on dynamic policies, with an aim to establish a common terminology, best practices, and frameworks for reasoning about them. We introduce the concept of facets to illuminate subtleties in the semantics of policies, and closely examine the anatomy of policies and the expressiveness of policy specification mechanisms. We further explore the relation between dynamic policies and the concept of declassification.Comment: Technical Report of publication under the same name in Computer Security Foundations (CSF) 201

District heating as a flexibility service: Challenges in sector coupling for increased solar and wind power production in Sweden

With expanding solar and wind power production, the topic of flexibility services attracts increased attention in the Swedish energy system. In this context, the potentials in using thermal storage capacities in district heating (DH) systems have been brought forward, primarily by academic scholars. Using a ‘grounded’ approach, this study investigates if professionals assigned to Swedish DH companies and electricity distribution system operators utilise, or plan to utilise, DH systems as flexibility services for the electricity grid. Original data was collected through semi-structured interviews, held with fourteen individuals affiliated to different actors in the Swedish energy system. These individuals were identified as being experts, or practically engaged, in using DH utilities as flexibility services for the electricity grid. The findings show that although technologies for coupling between DH systems and the electricity grid are already in place, initiatives for using DH systems as flexibility services for the electricity system are rare in Sweden. Coupling challenges stem from ownership and operation legislation frameworks, marginal incentives and a widespread focus on firm benefits rather than energy systems benefits. Identified initiatives for using DH systems for flexibility services are primarily run on a local scale, designed and propelled by small groups of engaged individuals

Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density

Background: Low bone mineral density (BMD) may constitute an underestimated comorbidity in schizophrenia patients undergoing long-term antipsychotic treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are antidiabetic drugs, which may also affect bone turnover.Methods: In planned secondary analyses of a 3 months, double-blind, randomized, placebo-controlled trial (n = 45), we explored effects of the GLP-1 receptor agonist exenatide 2 mg once-weekly (n = 23), or placebo (n = 22) on bone turnover markers (BTMs) and BMD in chronic, obese, antipsychotic-treated patients with schizophrenia spectrum disorder. Baseline BTMs were compared to sex- and age-adjusted reference values from a Danish population cohort, and T- and Z-scores were calculated for BMD.Results: In women (n = 24), all baseline BTM measurements of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX) were within reference values. In men (n = 21), 5% displayed lower PINP and 14% displayed lower CTX. One patient displayed BMD Z-score Conclusions: Sex- and age-adjusted measures of bone status in chronic, obese, antipsychotic-treated patients appeared comparable to the reference population. Subtle changes in bone markers during 3 months exenatide treatment may suggest beneficial effects of GLP-1 receptor agonists on bone status in antipsychotic-treated patients, and further studies should consider the potential influence of prolactin.</p

Effect of GLP-1 Receptor Agonist Treatment on Body weight in Obese Antipsychotic-treated Patients with Schizophrenia:a Randomized, Placebo-controlled Trial Byline

AIMS: Schizophrenia is associated with cardiovascular co‐morbidity and a reduced life‐expectancy of up to 20 years. Antipsychotics are dopamine D(2) receptor antagonists and are the standard of medical care in schizophrenia, but the drugs are associated with severe metabolic side effects such as obesity and diabetes. Glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) are registered for treatment of both obesity and type 2 diabetes. We investigated metabolic effects of the GLP‐1RA, exenatide once‐weekly, in non‐diabetic, antipsychotic‐treated, obese patients with schizophrenia. MATERIAL AND METHODS: Antipsychotic‐treated, obese, non‐diabetic, schizophrenia spectrum patients were randomized to double‐blinded adjunctive treatment with once‐weekly subcutaneous exenatide (n = 23) or placebo (n = 22) injections for 3 months. The primary outcome was loss of body weight after treatment and repeated measures analysis of variance was used as statistical analysis. RESULTS: Between March 2013 and June 2015, 40 patients completed the trial. At baseline, mean body weight was 118.3 ± 16.0 kg in the exenatide group and 111.7 ± 18.0 kg in the placebo group, with no group differences ( P = .23). The exenatide and placebo groups experienced significant ( P = .004), however similar ( P = .98), weight losses of 2.24 ± 3.3 and 2.23 ± 4.4 kg, respectively, after 3 months of treatment. CONCLUSIONS: Treatment with exenatide once‐weekly did not promote weight loss in obese, antipsychotic‐treated patients with schizophrenia compared to placebo. Our results could suggest that the body weight‐lowering effect of GLP‐1RAs involves dopaminergic signaling, but blockade of other receptor systems may also play a role. Nevertheless, anti‐obesity regimens effective in the general population may not be readily implemented in antipsychotic‐treated patients with schizophrenia

Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density

Background: Low bone mineral density (BMD) may constitute an underestimated comorbidity in schizophrenia patients undergoing long-term antipsychotic treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are antidiabetic drugs, which may also affect bone turnover.Methods: In planned secondary analyses of a 3 months, double-blind, randomized, placebo-controlled trial (n = 45), we explored effects of the GLP-1 receptor agonist exenatide 2 mg once-weekly (n = 23), or placebo (n = 22) on bone turnover markers (BTMs) and BMD in chronic, obese, antipsychotic-treated patients with schizophrenia spectrum disorder. Baseline BTMs were compared to sex- and age-adjusted reference values from a Danish population cohort, and T- and Z-scores were calculated for BMD.Results: In women (n = 24), all baseline BTM measurements of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX) were within reference values. In men (n = 21), 5% displayed lower PINP and 14% displayed lower CTX. One patient displayed BMD Z-score &lt; −2, and 23% of patients (17% of women and 29% of men) displayed −2.5 &lt; T-scores &lt; –1 indicating osteopenia, but none had osteoporosis. After treatment, PINP decreased at trend level significance (P = 0.05), and body mass index BMD increased for L2–L4 (P = 0.016). No changes in bone markers were significant after correction for mean prolactin levels.Conclusions: Sex- and age-adjusted measures of bone status in chronic, obese, antipsychotic-treated patients appeared comparable to the reference population. Subtle changes in bone markers during 3 months exenatide treatment may suggest beneficial effects of GLP-1 receptor agonists on bone status in antipsychotic-treated patients, and further studies should consider the potential influence of prolactin

Programming Language Design - Issues in Web Programming and Security

This thesis consists of two separate parts. Both concernprogramming language design, the first in the domain ofweb programming and the other for security.The first part consists of two papers, both discussingvarious aspects of how to extend the general purposeprogramming language Haskell to make it serve as aspecialized scripting language for writing dynamicweb pages. The first paper in this area concerns one specifictheoretic aspect of this extension, namely how to extendHaskell with regular expression pattern matching. We discusssyntax, typing and semantics for regular expression patterns,and show an implementation of the system in Haskell.In the second paper we give an overview of HaskellServer Pages, an extension of Haskell for writing dynamicweb pages. Then we go on to discuss how to implementthe runtime system of this language by using on-requestcompilation and dynamic loading of pages into a runningserver application.The second part of the thesis concerns security, and in particularlanguage-based information flow security. We show acalculus, based on $\lambda$-calculus with references,that allows dynamic changes to the flow policies of aprogram during execution. We also give a type systemfor the calculus that tracks valid flows, and a semantics.To prove that our type system is sound, we define anon-interference-like semantic security property andprove that it is implied by the type system using abisimulation-style proof.Our aim with the calculus is to provide a core calculusthat can be used to explain properties of other systems.To establish it as such, we also show how to encode variousother similar systems in our calculus

Rational Points on Cubic Surfaces

Let k be an algebraic number field and F(x_0, x_1, x_2, x_3) a non-singular cubic form with coefficients in k. Suppose that the projective cubic k-surface X ae P k given by F = 0 contains three coplanar lines defined over k, and let U(k) be the set of k-points on X which does not lie on any line on X. We show that the number of points in U(k), with height at most B, is OF;&quot; (B ) for any &amp;epsilon; &gt; 0