Physicochemical characterization of the PEG8000-Na2SO4 aqueous two-phase system

The polyethylene glycol-sodium sulfate aqueous two-phase system has been characterized at 23 °C. Tielines for the phase diagram were obtained experimentally. Phases in equilibrium were characterized by means of the solvatochromic parameters π*, α, and β, which provide a measurement of the polarity/polarizability and the H-bond donor and acceptor abilities, respectively. The ability of the phases to participate in hydrophobic interactions was characterized by means of the free energy of transfer of a methylene group between the conjugated phases, using the partition of a homologous series of dinitrophenylated amino acids. The results show the effect of the presence of polymer and salt in the aqueous phase, and a comparison of both phases with pure water is made.LSRE-PortoUniversidade Católica PortuguesaEscola Superior de Biotecnologia do PortoFundação para a Ciência e a Tecnologia (FCT

A combined experimental-theoretical study of the ligW-catalyzed decarboxylation of 5-carboxyvanillate in the metabolic pathway for lignin degradation

Although it is a member of the amidohydrolase superfamily, LigW catalyzes the nonoxidative decarboxylation of 5-carboxyvanillate to form vanillate in the metabolic pathway for bacterial lignin degradation. We now show that membrane inlet mass spectrometry (MIMS) can be used to measure transient CO₂ concentrations in real time, thereby permitting us to establish that C–C bond cleavage proceeds to give CO₂ rather than HCO₃^– as the initial product in the LigW-catalyzed reaction. Thus, incubation of LigW at pH 7.0 with the substrate 5-carboxyvanillate results in an initial burst of CO₂ formation that gradually decreases to an equilibrium value as CO₂ is nonenzymatically hydrated to HCO₃^–. The burst of CO₂ is completely eliminated with the simultaneous addition of substrate and excess carbonic anhydrase to the enzyme, demonstrating that CO₂ is the initial reaction product. This finding is fully consistent with the results of density functional theory calculations, which also provide support for a mechanism in which protonation of the C5 carbon takes place prior to C–C bond cleavage. The calculated barrier of 16.8 kcal/mol for the rate-limiting step, the formation of the C5-protonated intermediate, compares well with the observed <i>k</i>_cat value of 27 s^–1 for Sphingomonas paucimobilis LigW, which corresponds to an energy barrier of ∼16 kcal/mol. The MIMS-based strategy is superior to alternate methods of establishing whether CO₂ or HCO₃^– is the initial reaction product, such as the use of pH-dependent dyes to monitor very small changes in solution pH. Moreover, the MIMS-based assay is generally applicable to studies of all enzymes that produce and/or consume small-molecule, neutral gases

Labour supply and skills demands in fashion retailing

If, as Adam Smith once famously suggested, Britain was a nation of shopkeepers then it is now a nation of shopworkers. Retail is now a significant part of the UK economy, accounting for £256 billion in sales and one-third of all consumer spending (Skillsmart, 2007). It is the largest private sector employer in the UK, employing 3m workers, or 1 in 10 of the working population. For future job creation in the UK economy retail is also similarly prominent and the sector is expected to create a further 250,000 jobs to 2014 (Skillsmart, 2007). The centrality of retail to economic success and job creation is apparent in other advanced economies. For example, within the US, retail sales is the occupation with the largest projected job growth in the period 2004-2014 (Gatta et al., 2009) and in Australia retail accounts for 1 in 6 workers (Buchanan et al., 2003). Within the UK these workers are employed in approximately 290,000 businesses, encompassing large and small organizations and also a number of sub-sectors. This variance suggests that retail should not be regarded as homogenous in its labour demands. Hart et al. (2007) note how skill requirements and the types of workers employed may differ across the sector. This chapter further opens up this point, providing an analysis of the labour supply and skills demands for the sub-sectors of clothing, footwear and leather goods, which are described by Skillsmart (2007: 48) as being 'significant categories in UK retailing'

On the making and taking of professionalism in the further education workplace

This paper examines the changing nature of professional practice in English further education. At a time when neo-liberal reform has significantly impacted on this under-researched and over-market-tested sector, little is known about who its practitioners are and how they construct meaning in their work. Sociological interest in the field has tended to focus on further education practitioners as either the subjects of market and managerial reform or as creative agents operating within the contradictions of audit and inspection cultures. In challenging such dualism, which is reflective of wider sociological thinking, the paper examines the ways in which agency and structure combine to produce a more transformative conception of the further education professional. The approach contrasts with a prevailing policy discourse that seeks to re-professionalise and modernise further education practice without interrogating either the terms of its professionalism or the neo-liberal practices in which it resides

Quasi-classical Lie algebras and their contractions

After classifying indecomposable quasi-classical Lie algebras in low dimension, and showing the existence of non-reductive stable quasi-classical Lie algebras, we focus on the problem of obtaining sufficient conditions for a quasi-classical Lie algebras to be the contraction of another quasi-classical algebra. It is illustrated how this allows to recover the Yang-Mills equations of a contraction by a limiting process, and how the contractions of an algebra may generate a parameterized families of Lagrangians for pairwise non-isomorphic Lie algebras.Comment: 17 pages, 2 Table

Manual for judging Oregon soils

Published September 1984. A more recent revision exists. Information within this publication may be outdated. Please check for up-to-date titles in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo

Performance over professional learning and the complexity puzzle: lesson observation in England’s further education sector

Attempts to measure the quality of teaching and learning have resulted in an overreliance on quantitative performance data and the normalisation of a set of reductionist practices in England’s further education sector in recent years. Focusing on lesson observation as an illustrative example and drawing on data from a national study, this article examines the application of observation and its impact on further education teachers’ practice. In viewing lesson observation through a complexity theory lens and contextualising it against the wider neoliberal backdrop of the marketisation of education, we seek to critique the inadequacies of current reductionist approaches to teacher evaluation, whilst simultaneously opening up a debate regarding the consequences of seeing classrooms as complex adaptive systems. In focusing on performative models of lesson observation in particular, the article exposes what we perceive as some of the epistemological and methodological shortcomings of neoliberalism in practice, but also offers an alternative way forward in dealing with the contested practice of evaluating the quality of teaching and learning

Follicular fluid high density lipoprotein-associated micronutrient levels are associated with embryo fragmentation during IVF

To investigate whether follicular fluid lipid-soluble micronutrients are associated with embryo morphology parameters during IVF. Follicle fluid and oocytes were obtained prospectively from 81 women. Embryo morphology parameters were used as surrogate markers of oocyte health. HDL lipids and lipid-soluble micronutrients were analyzed by high-pressure liquid chromatography. Non-parametric bi-variate analysis and multivariable ordinal logistic regression models were employed to examine associations between biochemical and embryo morphology parameters. Follicular fluid HDL cholesterol (r = −0.47, p &lt; 0.01), α-tocopherol (r = −0.41, p &lt; 0.01), δ-tocopherol (r = −0.38, p &lt; 0.05) and β-cryptoxanthine (r = −0.42, p &lt; 0.01) are negatively correlated with embryo fragmentation. Ordinal logistic regression models indicate that a 0.1 μmol/L increase in β-cryptoxanthine, adjusted for γ-tocopherol, is associated with a 75% decrease in the cumulative odds of higher embryo fragmentation (p = 0.010). Follicular fluid HDL micronutrients may play an important role in the development of the human oocyte as evident by embryo fragmentation during IVF

Less is more: possibility and necessity as centres of gravity in a usage-based classification of core modals in Polish

In this paper we present the results of an empirical study into the cognitive reality of existing classifications of modality using Polish data. We analyzed random samples of 250 independent observations for the 7 most frequent modal words (móc, można, musieć, należy, powinien, trzeba, wolno), extracted from the Polish national corpus. Observations were annotated for modal type according to a number of classifications, including van der Auwera and Plungian (1998), as well as for morphological, syntactic and semantic properties using the Behavioral Profiling approach (Divjak and Gries 2006). Multiple correspondence analysis and (polytomous) regression models were used to determine how well modal type and usage align. These corpus-based findings were validated experimentally. In a forced choice task, naive native speakers were exposed to definitions and prototypical examples of modal types or functions, then labeled a number of authentic corpus sentences accordingly. In the sorting task, naive native speakers sorted authentic corpus sentences into semantically coherent groups. We discuss the results of our empirical study as well as the issues involved in building usage-based accounts on traditional linguistic classifications

A new form of Saturn's magnetopause using a dynamic pressure balance model, based on in situ, multi‐instrument Cassini measurements

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95429/1/jgra19967.pd