Mapping and controlling molecular processes: The application of control theory and system identification algorithms to ASOPS and other fast pulse spectroscopies

Asynchronous Optical Sampling (ASOPS) [1,2] and frequency comb spectrometry [3] based on dual Ti:saphire resonators operated in a master/slave mode have the potential to improve signal to noise ratio in THz transient and IR sperctrometry. The multimode Brownian oscillator time-domain response function described by state-space models is a mathematically robust framework that can be used to describe the dispersive phenomena governed by Lorentzian, Debye and Drude responses. In addition, the optical properties of an arbitrary medium can be expressed as a linear combination of simple multimode Brownian oscillator functions. The suitability of a range of signal processing schemes adopted from the Systems Identification and Control Theory community for further processing the recorded THz transients in the time or frequency domain will be outlined [4,5]. Since a femtosecond duration pulse is capable of persistent excitation of the medium within which it propagates, such approach is perfectly justifiable. Several de-noising routines based on system identification will be shown. Furthermore, specifically developed apodization structures will be discussed. These are necessary because due to dispersion issues, the time-domain background and sample interferograms are non-symmetrical [6-8]. These procedures can lead to a more precise estimation of the complex insertion loss function. The algorithms are applicable to femtosecond spectroscopies across the EM spectrum. Finally, a methodology for femtosecond pulse shaping using genetic algorithms aiming to map and control molecular relaxation processes will be mentioned.

Pollination and other ecosystem services produced by mobile organisms: a conceptual framework for the effects of land-use change

Many ecosystem services are delivered by organisms that depend on habitats that are segregated spatially or temporally from the location where services are provided. Management of mobile organisms contributing to ecosystem services requires consideration not only of the local scale where services are delivered, but also the distribution of resources at the landscape scale, and the foraging ranges and dispersal movements of the mobile agents. We develop a conceptual model for exploring how one such mobile-agent-based ecosystem service (MABES), pollination, is affected by land-use change, and then generalize the model to other MABES. The model includes interactions and feedbacks among policies affecting land use, market forces and the biology of the organisms involved. Animal-mediated pollination contributes to the production of goods of value to humans such as crops; it also bolsters reproduction of wild plants on which other services or service-providing organisms depend. About one-third of crop production depends on animal pollinators, while 60-90% of plant species require an animal pollinator. The sensitivity of mobile organisms to ecological factors that operate across spatial scales makes the services provided by a given community of mobile agents highly contextual. Services vary, depending on the spatial and temporal distribution of resources surrounding the site, and on biotic interactions occurring locally, such as competition among pollinators for resources, and among plants for pollinators. The value of the resulting goods or services may feed back via market-based forces to influence land-use policies, which in turn influence land management practices that alter local habitat conditions and landscape structure. Developing conceptual models for MABES aids in identifying knowledge gaps, determining research priorities, and targeting interventions that can be applied in an adaptive management context.

In vitro biological activity of tannins from Acacia and other tree fruits: Correlations with colorimetric and gravimetric phenolic assays

This Study was designed to investigate impact of tannins on in vitro ruminal fermentation parameters as well as relationships between concentration and in vitro biological activity of tannins present in tree fruits. Dry and mature fruits of known phenolic content harvested from Acacia nilotica, A. erubescens, A. erioloba, A. sieberiana, Piliostigima thonningii and Dichrostachys cinerea tree species were fermented with rumen fluid in vitro with or without polyethylene glycol (PEG). Correlation between in vitro biological activity and phenolic concentration was determined. Polyethylene glycol inclusion increased Cumulative gas production from all fruit substrates. The largest Increase (225%) after 48 h incubation was observed in D. cinerea fruits while the least (12.7%) increase was observed in A. erubescens fruits. Organic matter degradability (48 h) was increased by PEG inclusion for all tree species except A. erubescens and P. thonningii. For D. cinerea fruits, colorimetric assays were poorly correlated to Increases In gas production due to PEG treatment. Ytterbium precipitable phenolics (YbPh) were also poorly correlated with response to PEG for A. erioloba and P. thonningii fruits. However, YbPh were strongly and positively correlated to the increase In Cumulative gas production due to PEG for A. erubescens and A. nilotica. Folin-Ciocalteau assayed phenolics (SPh) were not correlated to response to PEG in P. thonningii and A. sieberiana. It was Concluded that the PEG effect oil in vitro fermentation was closely related to some measures of phenolic concentration but the relationships varied with tree species.

Interaction of pesticides with p-glycoprotein and other ABC proteins: A survey of the possible importance to insecticide, herbicide and fungicide resistance

P-glycoproteins (p-gps) are ubiquitous membrane proteins from the ABC (ATP-binding cassette) family. They have been found in many animals, bacteria, plants and fungi and are extremely important in regulating a wide range of xenobiotics including pesticides. P-gps have been linked to xenobiotic resistance, most famously in resistance to cancer drug treatments. Their wide substrate range has led to what is known as "multidrug resistance", where resistance developed to one type of xenobiotic gives resistance to a different classes of xenobiotic. P-gps are a major contributor to drug resistance in mammalian tumours and infections of protozoan parasites such as Plasmodium and Leishmania. There is a growing body of literature suggesting that p-gps, and other ABC proteins, are important in regulating pesticide toxicity and represent potential control failure through the development of pesticide resistance, in both agricultural and medical pests. At the same time, aspects of their biochemistry offer new hope in pest control, in particular in furthering our understanding of toxicity and offering insights into how we can improve control without recourse to new chemical discovery. (c) 2008 Elsevier Inc. All rights reserved.

The effect of free Ca2+ on the heat stability and other characteristics of low-heat skim milk powder

Low-heat skim milk powder (SMP), reconstituted to 25% total solids, was found to have poor heat stability. This could be improved by reducing the free Ca2+ concentration to 1.14 mm, or lower, by the addition of either Amberlite IR-120 ion-exchange resin in its sodium form or tri-sodium citrate in skim milk prior to evaporation and spray drying. Reduction in Ca2+ concentration was accompanied by increases in pH, particle size, and kinematic viscosity, and by a reduction in zeta-potential and changes in colour. In-container sterilisation of the reconstituted powder increased particle size, zeta-potential, kinematic viscosity and a* and b* values. However. Ca2+ concentration, pH and whiteness decreased. This study elucidated the importance of Ca2+ concentration and pH on heat stability of low-heat SMP, suggesting that Ca2+ concentration and pH in bulk milk are useful indicators for ensuring that spray dried milk powder has good heat stability. (C) 2009 Elsevier Ltd. All rights reserved.

A comparison of the relative toxicity of bone meal and other P sources used as remedial treatments to the earthworm Eisenia fetida

It has been suggested that sources of P could be used to remediate metal-contaminated soil. The toxicity of four potential P sources, potassium hydrogen phosphate (PHP), triple superphosphate (TSP), rock phosphate (RP) and raw bone meal (RBM) to Eisenia fetida was determined. The concentration of P that is statistically likely to kill 50% of the population (LC50) for PHP, TSP and RBM was determined in OECD acute toxicity tests. 14 day LC50s expressed as bulk P concentration lay in the range 3319–4272 mg kg−1 for PHP, 3107–3590 mg kg−1 for TSP and 1782–2196 mg kg−1 for RBM (ranges present the 95% confidence intervals). For PHP and TSP mortality was significantly impacted by the electrical conductivity of the treated soils. No consistent relationship existed between mortality and electrical conductivity, soil pH and available (Olsen) P across the PHP, TSP and RBM amendment types. In RP toxicity tests mortality was low and it was not possible to determine a LC50 value. Incineration of bone meal at temperatures between 200 and 300 ◦C, pre-washing the bone meal, co-amendment with 5% green waste compost and delaying introduction of earthworms after bone meal amendments by 21 days or more led to significant reductions in the bone meal toxicity. These results are consistent with the toxicity being associated with the release and/or degradation of a soluble organic component present in raw bone meal. Bone meal can be used as an earthworm-friendly remedial amendment in metal-contaminated soils but initial additions may have a negative effect on any earthworms surviving in the contaminated soil before the organic component in the bone meal degrades in the soil.

A largely intolerable combination of two mainly unconnected texts: 1. Description of the Barefoot in the Head event, at BHQU, NY, 12/11/09; 2. Fictioning and the End

An evaluation of the 'Barefoot in the Head' performance event, I co-curated with Alun Rowlands and Mark Beasley, at Bruce High Quality Foundation University, New York, as part of Performa 09 New York, 12 November 2009 - an examination of my own performance and the other performances occurring simultaneously at the event.

Development and validation of a qPCR-based method for quantifying Shiga toxin-encoding and other lambdoid bacteriophages

P>To address whether seasonal variability exists among Shiga toxin-encoding bacteriophage (Stx phage) numbers on a cattle farm, conventional plaque assay was performed on water samples collected over a 17 month period. Distinct seasonal variation in bacteriophage numbers was evident, peaking between June and August. Removal of cattle from the pasture precipitated a reduction in bacteriophage numbers, and during the winter months, no bacteriophage infecting Escherichia coli were detected, a surprising occurrence considering that 1031 tailed-bacteriophages are estimated to populate the globe. To address this discrepancy a culture-independent method based on quantitative PCR was developed. Primers targeting the Q gene and stx genes were designed that accurately and discriminately quantified artificial mixed lambdoid bacteriophage populations. Application of these primer sets to water samples possessing no detectable phages by plaque assay, demonstrated that the number of lambdoid bacteriophage ranged from 4.7 x 104 to 6.5 x 106 ml-1, with one in 103 free lambdoid bacteriophages carrying a Shiga toxin operon (stx). Specific molecular biological tools and discriminatory gene targets have enabled virus populations in the natural environment to be enumerated and similar strategies could replace existing propagation-dependent techniques, which grossly underestimate the abundance of viral entities.

Economists are not dismal, the world is not a Petri dish and other reasons for optimism

One of the recurrent themes in the debate around how to ensure global food security concerns the capacity of the planet to support its growing population. Neo-Malthusian thinking suggests that we are in a situation in which further expansion of the population cannot be supported and that the population checks, with their dismal consequences envisaged by Malthus, will lead to a new era of stagnant incomes and population. More sophisticated models of the link between population and income are less gloomy however. They see population growth as an integral component of the economic growth which is necessary to ensure that the poorest achieve food security. An undue focus on the difficulties of meeting the demands of the increasing population risks damaging this growth. Instead, attention should be focused on ensuring that the conditions to ensure that economic growth accompanies population growth are in place.

Dynamical properties of S-gap shifts and other shift spaces

We study the dynamical properties of certain shift spaces. To help study these properties we introduce two new classes of shifts, namely boundedly supermultiplicative (BSM) shifts and balanced shifts. It turns out that any almost specified shift is both BSM and balanced, and any balanced shift is BSM. However, as we will demonstrate, there are examples of shifts which are BSM but not balanced. We also study the measure theoretic properties of balanced shifts. We show that a shift space admits a Gibbs state if and only if it is balanced. Restricting ourselves to S-gap shifts, we relate certain dynamical properties of an S-gap shift to combinatorial properties from expansions in non-integer bases. This identification allows us to use the machinery from expansions in non-integer bases to give straightforward constructions of S -gap shifts with certain desirable properties. We show that for any q∈(0,1) there is an S-gap shift which has the specification property and entropy q . We also use this identification to address the question, for a given q∈(0,1), how many S-gap shifts exist with entropy q? For certain exceptional values of q there is a unique S-gap shift with this entropy.