Declarative Specification

Deriving formal specifications from informal requirements is extremely difficult since one has to overcome the conceptual gap between an application domain and the domain of formal specification methods. To reduce this gap we introduce application-specific specification languages, i.e., graphical and textual notations that can be unambiguously mapped to formal specifications in a logic language. We describe a number of realised approaches based on this idea, and evaluate them with respect to their domain specificity vs. generalit

Wind tunnel investigations at transonic Mach numbers

Investigation utilizes static and fluctuating pressure measurements and oil flow visualization techniques to analyze perturbed flow environments of three-dimensional protuberances and the surrounding structure. Significant findings are given

Deciphering The Hindu Growth Epic

India’s investment rate has increased fourfold since 1950 and is now nearly 40% of GDP. Many studies have suggested that this rising investment rate is the most significant component of India’s growth acceleration. I assess these hypotheses using the neoclassical growth model decomposition method. Unlike other methods based on this model, such as Hall and Jones (QJE 1999), the method used in this paper does not rely on the assumption of steady state. I find that the rise in investment rates since the 1970s explains only 30% of India’s growth over that period. I conclude that, notwithstanding the high investment rates, the main source of India’s growth acceleration is the modest upward trend in productivity growth since the 1970s.Economic Growth, India, Growth Accounting, Investment, Productivity

On the origins of Mendelian disease genes in man: the impact of gene duplication

Over 3,000 human diseases are known to be linked to heritable genetic variation, mapping to over 1,700 unique genes. Dating of the evolutionary age of these disease-associated genes has suggested that they have a tendency to be ancient, specifically coming into existence with early metazoa. The approach taken by past studies, however, assumes that the age of a disease is the same as the age of its common ancestor, ignoring the fundamental contribution of duplication events in the evolution of new genes and function. Here, we date both the common ancestor and the duplication history of known human disease-associated genes. We find that the majority of disease genes (80%) are genes that have been duplicated in their evolutionary history. Periods for which there are more disease-associated genes, for example, at the origins of bony vertebrates, are explained by the emergence of more genes at that time, and the majority of these are duplicates inferred to have arisen by whole-genome duplication. These relationships are similar for different disease types and the disease-associated gene's cellular function. This indicates that the emergence of duplication-associated diseases has been ongoing and approximately constant (relative to the retention of duplicate genes) throughout the evolution of life. This continued until approximately 390 Ma from which time relatively fewer novel genes came into existence on the human lineage, let alone disease genes. For single-copy genes associated with disease, we find that the numbers of disease genes decreases with recency. For the majority of duplicates, the disease-associated mutation is associated with just one of the duplicate copies. A universal explanation for heritable disease is, thus, that it is merely a by-product of the evolutionary process; the evolution of new genes (de novo or by duplication) results in the potential for new diseases to emerge

About the relationship between the zooplankton and fluctuating water levels of Lago Camaleão, a Central Amazonian várzea lake

A two-year study of the composition and abundance of the zooplankton was conducted in an Amazonian vãrzea lake, Lago Camaleão. Rotifers were dominant in terms of both species numbers and density. The extremely low standing-stock observed during the high water period is attributed to prevailing poor oxygen conditions and, during extreme floods, current. The species associations of rotifers also reflect the flooding regime and its consequences

Satellite retrieval system

A satellite retrieval system with first and second pairs of coacting parallel bars are separately mounted in spaced parallel planes on the front of a spacecraft. The bars of one pair are at right angles to bars of the other pair, and together the two pairs of bars effect a variable aperture adapted to close around a rod extending from a second spacecraft to effect the capture of the latter

Optimizing the Extraction of Procyanidins Oligomers through Decamer

The extraction of procyanidins from a food is influenced by food matrix, extraction solvent, sample particle size, sample to solvent ratio, as well as other factors. Many of these parameters can easily be controlled in a laboratory to improve or target the extraction of low or high molecular weight oligomers. As various oligomers have differing biological and functional qualities, preferred extraction of one group of oligomers may be a desired target. In the following study, we describe the influence of solvent polarity and composition, solvent-solute ratio and particle size on the extraction of procyanidin oligomers monomer through decamer. The solvents evaluated included dimethyl sulfoxide (DMSO), acetone and methanol