Sequence analysis of the cupin gene family in Synechocystis PCC6803

The recently described cupin superfamily of proteins includes the germin and germinlike proteins, of which the cereal oxalate oxidase is the best characterized. This superfamily also includes seed storage proteins, in addition to several microbial enzymes and proteins with unknown function. All these proteins are characterized by the conservation of two central motifs, usually containing two or three histidine residues presumed to be involved with metal binding in the catalytic active site. The present study on the coding regions of Synechocystis PCC6803 identifies a previously unknown group of 12 related cupins, each containing the characteristic two-motif signature. This group comprises 11 single-domain proteins, ranging in length from 104 to 289 residues, and includes two phosphomannose isomerases and two epimerases involved in cell wall synthesis, a member of the pirin group of nuclear proteins, a possible transcriptional regulator, and a close relative-of a cytochrome c551 from Rhodococcus. Additionally, there is a duplicated, two-domain protein that has close similarity to an oxalate decarboxylase from the fungus Collybia velutipes and that is a putative progenitor of the storage proteins of land plants

Algebras for parameterised monads

Parameterised monads have the same relationship to adjunctions with parameters as monads do to adjunctions. In this paper, we investigate algebras for parameterised monads. We identify the Eilenberg-Moore category of algebras for parameterised monads and prove a generalisation of Beck’s theorem characterising this category. We demonstrate an application of this theory to the semantics of type and effect systems

A Model to Estimate Sediment Yield from Field-Sized Areas: Development of Model

A tool for evaluating sediment yield from field-sized areas is needed for planning management practices to control sediment yield. We developed a reasonably simple simulation model which incorporates fundamental principles of erosion, deposition, and sediment transport mechanics. The model summarizes the state-of-the-art in erosion and sediment yield modeling with appropriate simplifications required to couple the governing equations. Limited testing showed that the procedures developed here give improved estimates over the Universal Soil Loss Equation. Specific components of the model were tested using experimental data from overland flow, erodible channel, and impoundment studies. These results suggest that the model produces reasonable estimates of erosion, sediment transport, and deposition under a variety of circumstances common to field-scale areas. Alternative management practices such as conservation tillage, terracing, and contouring can be evaluated separately or in combination to determine their influence on sediment yield. Given a particular location with specified characteristics for climate, soils, topography, and crops, the model provides a means of evaluating alternative management practices to suit a particular farming operation

Transferring management practices to China: a Bourdieusian critique of ethnocentricity

This paper provides a critique of the emergent theories of human resource management in China with a view to generating new theoretical insights with particular reference to Pierre Bourdieu's social theory. It reassesses the relevance of the orthodox critique of ethnocentricity and the coherence of approaches embedded in Chinese culture. With reference to six case studies of the largest retail firms, we identify two key challenges: the reliance on headquarter human resource practices that reflect an ethnocentric ethos, i.e. country-of-origin bias, and the failure to empower local managers and the problems this creates for managers expected to implement ethnocentric practices. We examine how Bourdieu's social theory sheds light on the processes by which these firms realise their strategic objectives through the complicity of local managers whose scope for resistance is constrained by the use of normative control and in part through attractive remuneration and career prospects that generate Bourdieusian capital for these managers. We conclude with some suggestions for further research

Optimal modelling and experimentation for the improved sustainability of microfluidic chemical technology design

Optimization of the dynamics and control of chemical processes holds the promise of improved sustainability for chemical technology by minimizing resource wastage. Anecdotally, chemical plant may be substantially over designed, say by 35-50%, due to designers taking account of uncertainties by providing greater flexibility. Once the plant is commissioned, techniques of nonlinear dynamics analysis can be used by process systems engineers to recoup some of this overdesign by optimization of the plant operation through tighter control. At the design stage, coupling the experimentation with data assimilation into the model, whilst using the partially informed, semi-empirical model to predict from parametric sensitivity studies which experiments to run should optimally improve the model. This approach has been demonstrated for optimal experimentation, but limited to a differential algebraic model of the process. Typically, such models for online monitoring have been limited to low dimensions. Recently it has been demonstrated that inverse methods such as data assimilation can be applied to PDE systems with algebraic constraints, a substantially more complicated parameter estimation using finite element multiphysics modelling. Parametric sensitivity can be used from such semi-empirical models to predict the optimum placement of sensors to be used to collect data that optimally informs the model for a microfluidic sensor system. This coupled optimum modelling and experiment procedure is ambitious in the scale of the modelling problem, as well as in the scale of the application - a microfluidic device. In general, microfluidic devices are sufficiently easy to fabricate, control, and monitor that they form an ideal platform for developing high dimensional spatio-temporal models for simultaneously coupling with experimentation. As chemical microreactors already promise low raw materials wastage through tight control of reagent contacting, improved design techniques should be able to augment optimal control systems to achieve very low resource wastage. In this paper, we discuss how the paradigm for optimal modelling and experimentation should be developed and foreshadow the exploitation of this methodology for the development of chemical microreactors and microfluidic sensors for online monitoring of chemical processes. Improvement in both of these areas bodes to improve the sustainability of chemical processes through innovative technology. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved

Limit on the fermion masses in technicolor models

Recently it has been pointed out that no limits can be put on the scale of fermion mass generation $(M)$ in technicolor models, because the relation between the fermion masses $(m_f)$ and $M$ depends on the dimensionality of the interaction responsible for generating the fermion mass. Depending on this dimensionality it may happens that $m_f$ does not depend on $M$ at all. We show that exactly in this case $m_f$ may reach its largest value, which is almost saturated by the top quark mass. We make few comments on the question of how large can be a dynamically generated fermion mass.Comment: 5 pages, 1 figure, RevTeX

Attention mechanisms in the CHREST cognitive architecture

In this paper, we describe the attention mechanisms in CHREST, a computational architecture of human visual expertise. CHREST organises information acquired by direct experience from the world in the form of chunks. These chunks are searched for, and verified, by a unique set of heuristics, comprising the attention mechanism. We explain how the attention mechanism combines bottom-up and top-down heuristics from internal and external sources of information. We describe some experimental evidence demonstrating the correspondence of CHREST’s perceptual mechanisms with those of human subjects. Finally, we discuss how visual attention can play an important role in actions carried out by human experts in domains such as chess

The fifth dimension as an analogue computer for strong interactions at the LHC

We present a mechanism to get S ~ 0 or even negative, without bringing into play the SM fermion sector. This mechanism can be applied to a wide range of 5D models, including composite Higgs and Higgsless models. As a realization of the mechanism we introduce a simple model, although the effect on S does not rely on the underlying dynamics generating the background. Models that include this mechanism enjoy the following features: weakly-coupled light resonances (as light as 600 GeV) and degenerate or inverted resonance spectrum.Comment: JHEP version. References adde

A Topological Study of Contextuality and Modality in Quantum Mechanics

Kochen-Specker theorem rules out the non-contextual assignment of values to physical magnitudes. Here we enrich the usual orthomodular structure of quantum mechanical propositions with modal operators. This enlargement allows to refer consistently to actual and possible properties of the system. By means of a topological argument, more precisely in terms of the existence of sections of sheaves, we give an extended version of Kochen-Specker theorem over this new structure. This allows us to prove that contextuality remains a central feature even in the enriched propositional system.Comment: 10 pages, no figures, submitted to I. J. Th. Phy