Mathematical Methods for the Multi-Criteria Optimization of Structure and Management of Energy Efficient Gas Supply Chains

While the problem of the optimal operation of gas networks has been the object of a large amount of research work, the inclusion of market mechanisms and environmental issues, leading to more complex models resulting in stochastic multiobjective optimization algorithms, has not been considered in its generality. The goal of this article is double: to identify the most general models and algorithms, capable of providing a complete decision support tool, and to show how simplified models can be obtained from them if the complexity of the network makes it necessary to reduce the computational burden.     

Expert Panel Workshop Consensus Statement on the Role of the Environment in the Development of Autoimmune Disease

Autoimmune diseases include 80 or more complex disorders characterized by self-reactive, pathologic immune responses in which genetic susceptibility is largely insufficient to determine disease onset. In September 2010, the National Institute of Environmental Health Sciences (NIEHS) organized an expert panel workshop to evaluate the role of environmental factors in autoimmune diseases, and the state of the science regarding relevant mechanisms, animal models, and human studies. The objective of the workshop was to analyze the existing data to identify conclusions that could be drawn regarding environmental exposures and autoimmunity and to identify critical knowledge gaps and areas of uncertainty for future study. This consensus document summarizes key findings from published workshop monographs on areas in which “confident” and “likely” assessments were made, with recommendations for further research. Transcribed notes and slides were reviewed to synthesize an overview on exposure assessment and questions addressed by interdisciplinary panels. Critical advances in the field of autoimmune disease research have been made in the past decade. Collaborative translational and interdisciplinary research is needed to elucidate the role of environmental factors in autoimmune diseases. A focus on exposure assessment methodology is needed to improve the effectiveness of human studies, and more experimental studies are needed to focus on causal mechanisms underlying observed associations of environmental factors with autoimmune disease in humans.     

Performance Analysis of Communication System with Nonlinear Power Amplifier

A communication system with nonlinear Power Amplifier (PA) is considered. The PA nonlinearity forces the designer of communication system to choose proper Back-Off, which influences three major parameters of the communication system: (i) power efficiency, (ii) Adjacent Channel Power Ratio (ACPR), and (iii) bit rate expressed by Mutual Information (MI). Having these three parameters, we propose to evaluate the performance of a communication system with nonlinear PA using the fact that ACPR is dictated by the regulator/communication standard. In what follows we propose to find power efficiency and MI as a function of ACPR. To illustrate the usefulness of the proposed method, the Solid State Power Amplifier (SSPA), and two linearized versions of SSPA are considered. The first version is a perfectly linearized PA using pre-distortion resulting with Soft Envelope Limiter (SEL), and the second is the Feed-Forward (FF) architecture based on SSPA. For each of the PAs ACPR, power efficiency and MI are found. While the analysis of SSPA and SEL is mainly based on the existing literature, the analysis of FF may be considered as a new contribution. From the results of the analysis it is concluded that linearization improves the overall performance of communication system. It is also shown that the pre-distortion method (SEL) shows better performance than FF.     

Fibred semantics for feature-based grammar logic

This paper gives a simple method for providing categorial brands of feature-based unification grammars with a model-theoretic semantics. The key idea is to apply the paradigm of fibred semantics (or layered logics, see Gabbay (1990)) in order to combine the two components of a feature-based grammar logic. We demonstrate the method for the augmentation of Lambek categorial grammar with Kasper/Rounds-style feature logic. These are combined by replacing (or annotating) atomic formulas of the first logic, i.e. the basic syntactic types, by formulas of the second. Modelling such a combined logic is less trivial than one might expect. The direct application of the fibred semantics method where a combined atomic formula like np (num: sg & pers: 3rd) denotes those strings which have the indicated property and the categorial operators denote the usual left- and right-residuals of these string sets, does not match the intuitive, unification-based proof theory. Unification implements a global bookkeeping with respect to a proof whereas the direct fibring method restricts its view to the atoms of the grammar logic. The solution is to interpret the (embedded) feature terms as global feature constraints while maintaining the same kind of fibred structures. For this adjusted semantics, the anticipated proof system is sound and complete.     

Pygmalion effects among outreach supervisors and tutors: Extending sex generalizability.

Students who supervised other students who tutored grade-school pupils in a university-based outreach program were randomly assigned to Pygmalion and control conditions. Experimental supervisors were told that their tutors were ideally qualified for their tutoring role; control supervisors were told nothing about their tutors' qualifications. A manipulation check revealed that the experimental supervisors expected more of their tutors. Analysis of variance of tutorial success measures confirmed the Pygmalion effect among supervisors of both sexes. No main effect or interaction involving either supervisor sex or tutor sex was significant. As predicted, the experimental supervisors also provided better leadership and the experimental tutors increased their self-efficacy. This was the first demonstration of the Pygmalion effect among women leading men. Pygmalion effects may be produced without regard for sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of saltgrass as a fodder crop for livestock

Farmland salinization due to unsustainable agricultural practices has become a worldwide problem. Salt‐resistant forage crops, introduced at the primary stages of land reclamation, can provide fodder for livestock, thus adding economic benefit to the process. Saltgrass (Distichlis spicata), a wild halophytic grass species distributed in salt marshes in America, is occasionally grazed by livestock and wild animals. In attempts to domesticate this species, we evaluated and ranked the fodder potential of groups of accessions from several sites in North and South America. Ash content never exceeded 110 g kg⁻¹, even when plants were grown with salty water. Crude protein content was variable and averaged 116 g kg⁻¹ of DM. Mean yield of metabolizable energy was 6.30 and 5.61 kJ g⁻¹ DM for sheep and goats, respectively. Organic matter digestibility (in vitro) was higher in sheep than in goats (506 g kg⁻¹ and 478 g kg⁻¹, respectively) for all saltgrass accessions. Differences in quality parameters were usually larger within than among groups of accession when sorted according to country of origin or ecosystem. Accessions from the South Atlantic coast of North America and from South America were superior in several parameters. South Atlantic coast accessions were relatively vigorous and were productive under saline conditions, as indicated by their relative growth rate (RGR) in small‐scale experiments. Six outstanding saltgrass accessions were chosen for further examination. The results of the present study indicate that saltgrass holds considerable promise for selection and suggest that efforts should continue to identify and characterize additional saltgrass ecotypes. Copyright © 2005 Society of Chemical Industry     

Observation of nanosecond laser induced fluorescence of in vitro seawater phytoplankton

Seawater has been irradiated using a train of 70 ns flashes from a 440 nm laser source. This wavelength is on resonance with the blue absorption peak of Chlorophyll pigment associated with the photosystem of in vitro phytoplankton. The resulting fluorescence at 685 nm is instantaneously recorded during each laser pulse using a streak camera. Delayed fluorescence is observed, yielding clues about initiation of the photosynthetic process on a nanosecond time scale. Further data processing allows for determination of the functional absorption cross section, found to be 0.0095 A(2), which is the first reporting of this number for in vitro phytoplankton. Unlike other flash-pump studies of Chlorophyll, using a LED or flashlamp-based sources, the short laser pulse used here does not reveal any pulse-to-pulse hysteresis (i.e., variable fluorescence), indicating that the laser pulses used here are not able to drive the photosynthetic process to completion. This is attributed to competition from a back reaction between the photoexcited photosystem II and the intermediate electron acceptor. The significance of this work as a new type of deployable ocean fluorimeter is discussed, and it is believed the apparatus will have applications in thin-layer phytoplankton research.