A first attempt to combine SysML requirements diagrams and B

This article describes a work-in-progress in the framework of a research project aiming at combining requirements engineering methods with formal methods. The main idea is to extend the SysML language with concepts of existing requirements engineering methods. In this article we present extensions to SysML with concepts from the goal model of the KAOS method and we give rules to derive a formal B specification from this goal model. The approach is then illustrated on a case study.     

Optimization of the operation of the anthropomorphic manipulator in a three-dimensional working space

This article presents the use of the particle swarm method to optimize the working cycle of an anthropomorphic manipulator. The working space contained stationary obstacles which made the working cycle difficult. Three objective functions were adopted in the study, concerning trajectory minimization, reduction of electricity consumption and multi-criteria optimization (minimization of both trajectory length and electricity consumption). The effects of selected parameters on the particle swarm optimization (PSO) algorithm and the results of the examinations were analysed.     

Computing Information in Neuronal Spikes

This paper provides new insights regarding the transfer of information between input signal and the output of neurons. Simulations of the Hodgkin-Huxley (HH) model combined with computational techniques are used to estimate this transfer of information. Our analysis shows that comparatively, mutual information (MI) between input signal and sodium flux is about two times that between input signal and output spikes during each spike within a millisecond-level time domain. This higher transfer of information provided by ionic fluxes extends the working frequency domain of neural cells beyond those accessible to information transfer within spikes alone.     

Global challenges in energy

Environmental and security concerns are stimulating global interest in hydrogen power, renewable energy, and advanced transportation technologies, but no significant movement away from oil and a carbon-based world economy is expected soon. Over the longer-term, however, a transition from fossil fuels to a non-carbon-based economy will likely occur, affecting the type of environment future generations may encounter. Key challenges will face the world's energy industry over the next few decades to ensure a smooth transition—challenges which will require government and industry solutions beginning as early as today. This paper identifies four critical challenges in energy and the choices which will have to be made on how best to confront growing pollution caused by fossil fuels and how to facilitate an eventual revolutionary-like transition to a non-carbon-based global economy.     

Boundary violations and personality traits among psychiatrists

OBJECTIVE: To demonstrate that sexual abuse of patients by psychiatrists can be due to a variety of contributors, which may include therapists' psychopathic and narcissistic personality styles. METHOD: Data from a prospective cohort of residents training in psychiatry were examined to evaluate the personality traits of 2 psychiatrists subsequently convicted of boundary violations. RESULTS: The 2 psychiatrists who lost their licenses were identifiable at the beginning of their residency training as individuals with significant character pathology. CONCLUSIONS: For some psychiatrists, repetitive sexual abuse of patients represents one aspect of an ongoing pattern of exploitative relationships. The professional and ethical implications of these findings as they relate to early identification for those at risk are considered.     

Review of the anatase to rutile phase transformation

Titanium dioxide, TiO₂, is an important photocatalytic material that exists as two main polymorphs, anatase and rutile. The presence of either or both of these phases impacts on the photocatalytic performance of the material. The present work reviews the anatase to rutile phase transformation. The synthesis and properties of anatase and rutile are examined, followed by a discussion of the thermodynamics of the phase transformation and the factors affecting its observation. A comprehensive analysis of the reported effects of dopants on the anatase to rutile phase transformation and the mechanisms by which these effects are brought about is presented in this review, yielding a plot of the cationic radius versus the valence characterised by a distinct boundary between inhibitors and promoters of the phase transformation. Further, the likely effects of dopant elements, including those for which experimental data are unavailable, on the phase transformation are deduced and presented on the basis of this analysis.     

The effect of food dry matter intake on endogenous ileal amino acid excretion determined under peptide alimentation in the 50 kg liveweight pig

The daily ileal excretion of amino acids was measured at different food dry matter intakes for the 50 kg liveweight pig under conditions of peptide alimentation. The experiment comprised two cross-over design trials each involving four pairs of entire male pigs fitted with simple T-cannulae at the terminal ileum and fed a hydrolysed casein semi-synthetic diet. Each pair of pigs received one of four sequences of food dry matter intake arranged in a Latin square design, namely 0.06, 0.08, 0.10 and 0.12 (Trial 1) and 0.05, 0.07, 0.09 and 0.11 (Trial 2) of metabolic body weight (W^0.75) day^?1. Each pig received the diet at its described level of intake for 8 days, with continuous 24 h collection of ileal digesta on the fifth and eighth days. Chromic oxide was included in the diet to permit correction of ileal flows to complete digesta collection. Pooled digesta from each pig at each level of dry matter intake were centrifuged and ultrafiltered and the high-molecular-weight fraction was analysed for amino acid and nitrogen contents. There were significant (P < 0.05) linear relationships between endogenous ileal amino acid, nitrogen and dry matter excretion (mg day^?1) and food dry matter intake (g day^?1) except for lysine, glutamic acid and phenylalanine which increased in a curvilinear manner (P < 0.05). The results indicate that dietary dry matter intake influences endogenous excretion from the ileum. The relationships, determined under physiological conditions, provide preliminary data on the magnitude of small intestinal amino acid loss in the young growing pig.     

Resin Acid Conversion with CYP105A1: An Enzyme with Potential for the Production of Pharmaceutically Relevant Diterpenoids

Cytochrome P450s are very versatile enzymes with great potential for biotechnological applications because of their ability to oxidize unactivated C? H bonds. CYP105A1 from Streptomyces griseolus was first described as a herbicide‐inducible sulfonylurea hydroxylase, but it is also able to convert other substrates such as vitamin D₃. To extend the substrate pool of this interesting enzyme further, we screened a small diterpenoid compound library and were able to show the conversion of several resin acids. Binding of abietic acid, dehydroabietic acid, and isopimaric acid to the active site was assayed, and V_max and K_m values were calculated. The products were analyzed by NMR spectroscopy and identified as 15‐hydroxyabietic acid, 15‐hydroxydehydroabietic acid, and 15,16‐epoxyisopimaric acid. As the observed products are difficult to obtain by chemical synthesis, CYP105A1 has proved to be a promising candidate for biotechnological applications that combine bioconversion and chemical synthesis to obtain functionalized resin acids.