Rheagogies: modelling non-trophic effects in food webs

In a food web, nutrients flow via trophic links. For this reason, trophic interactions have a fundamental character due to the principle of mass conservation. To further comply with this principle, we consider a food web model that includes nutrient cycling. Non-trophic effects amongst species of the food web are modelled as interaction modifications, i.e., a functional change in the trophic interaction between two species caused by a third species (a three-party interaction that we call ‘‘rheagogy’’).We also consider that the ecological communities modelled by the food webs result from an assembly process that involves colonisations and extinctions. We find that two distinct classes of ecological communities must be distinguished: (a) ‘‘superefficient’’ communities, in which almost all available nutrients are incorporated into the biomass and (b) ‘‘sub-efficient’’ ones, in which a large proportion of nutrients is not fixed by living organisms. We show that rheagogies (that model non-trophic interactions) are crucial: the larger the effects of rheagogies, the easier the construction of super-efficient communities. These communities are characterized by positive rheagogies, meaning that a certain proportion of mutualistic interactions is necessary. Systems with few or weak rheagogies are less likely to use available abiotic resources efficiently. Although richness (i.e., number of species) is also positively related to efficient nutrient use, its importance is much smaller than that of rheagogies

Factors affecting quality in mutton and beef with special reference to the proportions of muscle, fat, and bone

On the basis of measurements taken at Smithfield Fatstock Show between 1921 and 1932 the subject is discussed under the following heads: mutton: quality as af fected by the proportions of muscle, fat and bone in the carcase; marbling; beef: factors influencing carcase proportions, the texture and tenderness of meat, the colour of meat, the colour of fat, the firmness of fat, the amount of intramuscular fat in the meat and factors influencing the flavour of meat and fat.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentation PDF-Format.Includes bibliographical referencesab201

A catalog of stream processing optimizations

Cataloged from PDF version of article.Various research communities have independently arrived at stream processing as a programming model for efficient and parallel computing. These communities include digital signal processing, databases, operating systems, and complex event processing. Since each community faces applications with challenging performance requirements, each of them has developed some of the same optimizations, but often with conflicting terminology and unstated assumptions. This article presents a survey of optimizations for stream processing. It is aimed both at users who need to understand and guide the system's optimizer and at implementers who need to make engineering tradeoffs. To consolidate terminology, this article is organized as a catalog, in a style similar to catalogs of design patterns or refactorings. To make assumptions explicit and help understand tradeoffs, each optimization is presented with its safety constraints (when does it preserve correctness?) and a profitability experiment (when does it improve performance?). We hope that this survey will help future streaming system builders to stand on the shoulders of giants from not just their own community. © 2014 ACM

Myosin isoenzymes in human hypertrophic hearts. Shift in atrial myosin heavy chains and in ventricular myosin light chains

The myosin light chain complement and proteolytic peptide patterns of myosin heavy chains were studied by two-dimensional and one-dimensional electrophoretic techniques respectively, in a total of 57 samples from ventricular and atrial tissues of normal and hypertrophied human hearts. Hypertrophies were classified haemodynamically as due to pressure-overload and volume-overload. In addition to the occurrence of ventricular light chains in hypertrophied atria we also observed the atrial light chain-1 (ALC-1) in hypertrophied ventricular tissues. On average over 6% of total light-chain-1 comprised ALC-1 in pressure-overloaded ventricles and around 3% in volume-overloaded ventricles. In single cases of pressure-overload ALC-1 amounted up to over 20% of total light chain-1. With regard to the myosin heavy chains limited digestion by two different proteinases produced over 200 clearly resoluble peptides. The absence of any detectable differences in the peptide patterns between myosin heavy chains from normal and hypertrophic tissues of left or right ventricle is in line with the findings of J. J. Schier and R. S. Adelstein (J Clin Invest 1982; 69: 816-825). In atrial tissues however, reproducible qualitative differences in the peptide patterns indicated that during hypertrophy a different type of myosin heavy chains becomes expressed. No differences were seen between the myosin heavy chains from normal left and right atri

River: an intermediate language for stream processing

Summary This paper presents both a calculus for stream processing, named Brooklet, and its realization as an intermediate language, named River. Because River is based on Brooklet, it has a formal semantics that enables reasoning about the correctness of source translations and optimizations. River builds on Brooklet by addressing the real-world details that the calculus elides. We evaluated our system by implementing front-ends for three streaming languages, and three important optimizations, and a back-end for the System S distributed streaming runtime. Overall, we significantly lower the barrier to entry for new stream-processing languages and thus grow the ecosystem of this crucial style of programming. Copyright © 2015 John Wiley & Sons, Ltd

From a calculus to an execution environment for stream processing

At one level, this paper is about River, a virtual execution environment for stream processing. Stream processing is a paradigm well-suited for many modern data processing systems that ingest high-volume data streams from the real world, such as audio/video streaming, high-frequency trading, and security monitoring. One attractive property of stream processing is that it lends itself to parallelization on multicores, and even to distribution on clusters when extreme scale is required. Stream processing has been co-evolved by several communities, leading to diverse languages with similar core concepts. Providing a common execution environment reduces language development effort and increases portability. We designed River as a practical realization of Brooklet, a calculus for stream processing. So at another level, this paper is about a journey from theory (the calculus) to practice (the execution environment). The challenge is that, by definition, a calculus abstracts away all but the most central concepts. Hence, there are several research questions in concretizing the missing parts, not to mention a significant engineering effort in implementing them. But the effort is well worth it, because using a calculus as a foundation yields clear semantics and proven correctness results. Copyright © 2012 ACM

Early results after mitral valvuloplasty for pure mitral regurgitation

In this study we present the results of 105 consecutive patients with pure mitral regurgitation who underwent surgical treatment. In all patients mitral regurgitation was associated with mitral valve prolapse: 54 patients underwent mitral valvuloplasty and 51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-up criteria at one year after surgery. After mitral valvuloplasty, NYH A decreased from 2.7±0.8 to 1.1±0.7 (P<0.01) and workload capacity increased from 65±28% to 96±25% (P<0.001); left endsystolic atrial dimension and enddiastolic dimension decreased from 6.2±0.8 to 4.8±1.2 cm (P<0.001) and from 7.2±1.3 to 5.9±0.8 cm (P<0.01); ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographic improvement was significant but less remarkable than after valvuloplasty; ventricular contraction fraction fell from 39±7% to 29±8% in contrast to patients undergoing mitral valvuloplasty in whom no significant change occurred. Complications were rare in both groups though only a minority of patients undergoing mitral valvuloplasty received anticoagulants. We conclude that mitral valvuloplasty in patients with pure mitral regurgitation associated with mitral valve prolapse gives excellent results, particularly regarding left ventricular function when compared with the patients after mitral valve replacemen

A catalog of stream processing optimizations

Various research communities have independently arrived at stream processing as a programming model for efficient and parallel computing. These communities include digital signal processing, databases, operating systems, and complex event processing. Since each community faces applications with challenging performance requirements, each of them has developed some of the same optimizations, but often with conflicting terminology and unstated assumptions. This article presents a survey of optimizations for stream processing. It is aimed both at users who need to understand and guide the system's optimizer and at implementers who need to make engineering tradeoffs. To consolidate terminology, this article is organized as a catalog, in a style similar to catalogs of design patterns or refactorings. To make assumptions explicit and help understand tradeoffs, each optimization is presented with its safety constraints (when does it preserve correctness?) and a profitability experiment (when does it improve performance?). We hope that this survey will help future streaming system builders to stand on the shoulders of giants from not just their own community. © 2014 ACM