A case study using lightweight formalism to review an information system specification

This paper presents an approach using derivation of a formal model to review the diagram‐and‐text specification of an information system specification, based on concepts from the formal and structured integrated method, SAZ. Extraction of the formal model is outlined, and the approach is illustrated with a simplified extract from an industrial trial. Some empirical findings from the trial, which reviewed a pre‐existing commercial specification, are presented, and the general applicability of the review approach is discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Understanding how people process health information: A comparison of tailored and nontailored weight-loss materials.

Health information tailored to meet individuals' unique needs has been shown to be more effective than generic information in promoting risk-reducing behavior changes. To explore mechanisms underlying tailoring's effectiveness, this study randomly assigned 198 overweight adults to receive weight-loss materials that were either (a) tailored to the individual, (b) in an American Heart Association (AHA) brochure, or (c) AHA-content formatted to look like tailored materials. Participants who received tailored materials had more positive thoughts about the materials, positive personal connections to the materials, positive self-assessment thoughts, and positive thoughts indicating behavioral intention than those who received either of the untailored materials. The tailoring of health information can significantly improve the chances the information will be thoughtfully considered and can stimulate prebehavioral changes such as self-assessment and intention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the factors controlling the mechanical properties of nanotube films

We have studied the mechanical and morphological properties of carbon nanotube films prepared from tubes produced by a range of commercial suppliers. We find significant correlations between mechanical parameters (modulus, strength, toughness and ductility) and morphological parameters (porosity and bundle diameter). Both strength and toughness scale linearly with the number of inter-bundle junctions per unit volume as calculated from the porosity and bundle size. Applying a simple model, we can use this data to find the average force and energy required to break a junction to be ∼113 pN and 0.7 eV, respectively. This latter value agrees well with the value of 0.9 eV estimated from the nanotube surface energy, indicating that adjacent bundles are bound predominately by van der Waals interactions.     

Actions of Esomeprazole on the Maternal Vasculature in Lean and Obese Pregnant Mice with Impaired Nitric Oxide Synthesis: A Model of Preeclampsia

Preeclampsia is a devastating, multisystem disorder of pregnancy. It has no cure except delivery, which if premature can impart significant neonatal morbidity. Efforts to repurpose pregnancy-safe therapeutics for the treatment of preeclampsia have led to the assessment of the proton pump inhibitor, esomeprazole. Preclinically, esomeprazole reduced placental secretion of anti-angiogenic sFlt-1, improved endothelial dysfunction, promoted vasorelaxation, and reduced maternal hypertension in a mouse model. Our understanding of the precise mechanisms through which esomeprazole works to reduce endothelial dysfunction and enhance vasoreactivity is limited. Evidence from earlier studies suggested esomeprazole might work via the nitric oxide pathway, upregulating endothelial nitric oxide synthase (eNOS). Here, we investigated the effect of esomeprazole in a mouse model of L-NAME-induced hypertension (decreased eNOS activity). We further antagonised the model by addition of diet-induced obesity, which is relevant to both preeclampsia and the nitric oxide pathway. Esomeprazole did not decrease blood pressure in this model, nor were there any alterations in vasoreactivity or changes in foetal outcomes in lean mice. We observed similar findings in the obese mouse cohort, except esomeprazole treatment enhanced ex vivo acetylcholine-induced vasorelaxation. As acetylcholine induces nitric oxide production, these findings hint at a function for esomeprazole in the nitric oxide pathway.     

An Empirical Study of Analogy-based Software Effort Estimation

Conventional approaches to software cost estimation have focused on algorithmic cost models, where an estimate of effort is calculated from one or more numerical inputs via a mathematical model. Analogy-based estimation has recently emerged as a promising approach, with comparable accuracy to algorithmic methods in some studies, and it is potentially easier to understand and apply. The current study compares several methods of analogy-based software effort estimation with each other and also with a simple linear regression model. The results show that people are better than tools at selecting analogues for the data set used in this study. Estimates based on their selections, with a linear size adjustment to the analogue's effort value, proved more accurate than estimates based on analogues selected by tools, and also more accurate than estimates based on the simple regression model.     

Effects of H2S addition on hydrogen ignition behind reflected shock waves: Experiments and modeling

Hydrogen sulfide is a common impurity that can greatly change the combustion properties of fuels, even when present in small concentrations. However, the combustion chemistry of H₂S is still poorly understood, and this lack of understanding subsequently leads to difficulties in the design of emission-control and energy-production processes. During this study, ignition delay times were measured behind reflected shock waves for mixtures of 1% H₂/1% O₂ diluted in Ar and doped with various concentration of H₂S (100, 400, and 1600 ppm) over large pressure (around 1.6, 13, and 33 atm) and temperature (1045–1860 K) ranges. Results typically showed a significant increase in the ignition delay time due to the addition of H₂S, in some cases by a factor of 4 or more over the baseline mixtures with no H₂S. The magnitude of the increase is highly dependent on the temperature and pressure. A detailed chemical kinetics model was developed using recent, up-to-date detailed-kinetics mechanisms from the literature and by changing a few reaction rates within their reported error factor. This updated model predicts well the experimental data obtained during this study and from the shock-tube literature. However, flow reactor data from the literature were poorly predicted when H₂S was a reactant. This study highlights the need for a better estimation of several reaction rates to better predict H₂S oxidation chemistry and its effect on fuel combustion. Using the kinetics model for sensitivity analyses, it was determined that the decrease in reactivity in the presence of H₂S is because H₂S initially reacts before the H₂ fuel does, mainly through the reaction H₂S + H ? SH + H₂, thus taking H atoms away from the main branching reaction H + O₂ ? OH + O and inhibiting the ignition process.     

Islet Regeneration: Endogenous and Exogenous Approaches

Both type 1 and type 2 diabetes are characterized by a progressive loss of beta cell mass that contributes to impaired glucose homeostasis. Although an optimal treatment option would be to simply replace the lost cells, it is now well established that unlike many other organs, the adult pancreas has limited regenerative potential. For this reason, significant research efforts are focusing on methods to induce beta cell proliferation (replication of existing beta cells), promote beta cell formation from alternative endogenous cell sources (neogenesis), and/or generate beta cells from pluripotent stem cells. In this article, we will review (i) endogenous mechanisms of beta cell regeneration during steady state, stress and disease; (ii) efforts to stimulate endogenous regeneration and transdifferentiation; and (iii) exogenous methods of beta cell generation and transplantation.     

OPUS的挂钩

OPUS是一个专门从事手袋挂钩的品牌。那些挂钩可以安全地摆在桌角,用于悬挂手袋。即不占桌椅的空间,又可以解放双手去做其事情。位于台北的OPUS是其品牌全球唯一的一家实体经营店,店面是由台北本土的年轻团队Paradox Studio担任设计。空间围绕这"多功能性"展开,既可用于会议,也可像零售店一样出售产品。     

The Discovery of Potent Nonstructural Protein 5A (NS5A) Inhibitors with a Unique Resistance Profile—Part 2

In ongoing studies towards novel hepatitis C virus (HCV) therapeutics, inhibitors of nonstructural protein 5A (NS5A) were evaluated. Specifically, starting from previously reported lead compounds, peripheral substitution patterns of a series of biaryl‐linked pyrrolidine NS5A replication complex inhibitors were probed and structure–activity relationships were elucidated. Using molecular modelling and a supercritical fluid chromatographic (SFC) technique, intramolecular H‐bonding and peripheral functional group topology were evaluated as key determinants of activity and membrane permeability. The novel compounds exhibited retained potency as compared with the lead compounds, and also showed promising results against a panel of resistance viruses. Together, the results of the study take us a step closer towards understanding the potency of daclatasvir, a clinical candidate upon which the compounds were based, and to designing improved analogues as second‐generation antiviral agents targeting NS5A.