2,014 research outputs found
Identification of a novel titin-cap/telethonin mutation in a Portuguese family with hypertrophic cardiomyopathy
INTRODUCTION AND OBJECTIVES: Hypertrophic cardiomyopathy (HCM) is a genetically and phenotypically heterogeneous disease; there is still a large proportion of patients with no identified disease-causing mutation. Although the majority of mutations are found in the MYH7 and MYBPC3 genes, mutations in Z-disk-associated proteins have also been linked to HCM. METHODS: We assessed a small family with HCM based on family history, physical examination, 12-lead ECG, echocardiogram and magnetic resonance imaging. After exclusion of mutations in eleven HCM disease genes, we performed direct sequencing of the TCAP gene encoding the Z-disk protein titin-cap (also known as telethonin). RESULTS: We present a novel TCAP mutation in a small family affected by HCM. The identified p.C57W mutation showed a very low population frequency, as well as high conservation across species. All of the bioinformatic prediction tools used considered this mutation to be damaging/deleterious. Family members were screened for this new mutation and a co-segregation pattern was detected. Both affected members of this family presented with late-onset HCM, moderate asymmetric left ventricular hypertrophy, atrial fibrillation and heart failure with preserved ejection fraction and low risk of sudden cardiac death. CONCLUSIONS: We present evidence supporting the classification of the TCAP p.C57W mutation, encoding the Z-disk protein titin-cap/telethonin as a new likely pathogenic variant of hypertrophic cardiomyopathy, with a specific phenotype in the family under analysis
Analysis of transition forms towards more ecologically-oriented farming: the case of organic farming and integrated crop protection
Interdisciplinary approaches developed concerning the conversion to organic farming show that the types of conversion trajectories can be differentiated on the basis of the progression of crop protection changes within a larger framework where relationships to other “objects” are transformed – the soil, products, rotations, work organisation, marketing, social networks and knowledge acquisition. In the case of integrated plant production, the extent of changes depends on the degree of recomposition of agronomic practices. This transition implies major knowledge acquisition that relies on the support and contribution of advisors and on the group dynamics that develop within a group of farmers. Transitions towards integrated crop protection are, by their nature, more reversible and therefore more fragile than the conversion to organic farming. This is due to the fact that they are not stabilised by a certification or by the market, and analysis shows that their sustainability is linked in part to their integration within a group dynamics
The Equation of State and the Hugoniot of Laser Shock-Compressed Deuterium
The equation of state and the shock Hugoniot of deuterium are calculated
using a first-principles approach, for the conditions of the recent shock
experiments. We use density functional theory within a classical mapping of the
quantum fluids [ Phys. Rev. Letters, {\bf 84}, 959 (2000) ]. The calculated
Hugoniot is close to the Path-Integral Monte Carlo (PIMC) result. We also
consider the {\it quasi-equilibrium} two-temperature case where the Deuterons
are hotter than the electrons; the resulting quasi-equilibrium Hugoniot mimics
the laser-shock data. The increased compressibility arises from hot
pairs occuring close to the zero of the electron chemical potential.Comment: Four pages; One Revtex manuscript, two postscipt figures; submitted
to PR
KNAPSACK PROBLEMS WITH SETUPS
RÉSUMÉ : We consider two variants of knapsack problems with setups arising as subproblems in a DantzigWolfe decomposition approach to more complex combinatorial optimization problems. In the multiple-class binary knapsack problem with setups, items are partitioned into classes whose use implies a setup cost and associated capacity consumption. Item weights are assumed to be a multiple of their class weight. The total weight of selected items and setups is bounded. The objective is to maximize the difference between the profits of selected items and the fixed costs incurred for setting-up classes. In the continuous knapsack problems with setups, each class holds a single item and a fraction of an item can be selected while incurring a full setup. The paper shows the extent to which classical results for the knapsack problem can be generalized to these variants. In particular, an extension of the branch-and-bound algorithm of Horowitz and Sahni is developed for problems with positive setup costs. Our direct approach is compared experimentally with the approach proposed in the literature consisting in converting the problem into a multiple choice knapsack with pseudo-polynomial size
Minimal work principle: proof and counterexamples
The minimal work principle states that work done on a thermally isolated
equilibrium system is minimal for adiabatically slow (reversible) realization
of a given process. This principle, one of the formulations of the second law,
is studied here for finite (possibly large) quantum systems interacting with
macroscopic sources of work. It is shown to be valid as long as the adiabatic
energy levels do not cross. If level crossing does occur, counter examples are
discussed, showing that the minimal work principle can be violated and that
optimal processes are neither adiabatically slow nor reversible. The results
are corroborated by an exactly solvable model.Comment: 13 pages, revtex, 2 eps figure
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