The physics of baking: rheological and polymer molecular structure-function relationships in breadmaking

Molecular size and structure of the gluten polymers that make up the major structural components of wheat are related to their rheological properties via modern polymer rheology concepts. Interactions between polymer chain entanglements and branching are seen to be the key mechanisms determining the rheology of HMW polymers. Recent work confirms the observation that dynamic shear plateau modulus is essentially independent of variations in MW amongst wheat varieties of varying baking performance and is not related to variations in baking performance, and that it is not the size of the soluble glutenin polymers, but the structural and rheological properties of the insoluble polymer fraction that are mainly responsible for variations in baking performance. The rheological properties of gas cell walls in bread doughs are considered to be important in relation to their stability and gas retention during proof and baking, in particular their extensional strain hardening properties. Large deformation rheological properties of gas cell walls were measured using biaxial extension for a number of doughs of varying breadmaking quality at constant strain rate and elevated temperatures in the range 25oC to 60oC. Strain hardening and failure strain of cell walls were both seen to decrease with temperature, with cell walls in good breadmaking doughs remaining stable and retaining their strain hardening properties to higher temperatures (60oC), whilst the cell walls of poor breadmaking doughs became unstable at lower temperatures (45oC to 50oC) and had lower strain hardening. Strain hardening measured at 50oC gave good correlations with baking volume, with the best correlations achieved between those rheological measurements and baking tests which used similar mixing conditions. As predicted by the Considere failure criterion, a strain hardening value of 1 defines a region below which gas cell walls become unstable, and discriminates well between the baking quality of a range of commercial flour blends of varying quality. This indicates that the stability of gas cell walls during baking is strongly related to their strain hardening properties, and that extensional rheological measurements can be used as predictors of baking quality.

Effect of chymosin and salt reduction on the quality of ultrafiltrated white-salted cheese

This study demonstrated that both chymosin and salt-in-moisture (SM) were important factors for proteolysis in the manufacture of ultrafiltrated white-salted cheese, with significant effects on water-soluble nitrogen and nitrogen soluble in trichloroacetic acid. In contrast, the levels of free amino acids were not significantly affected by chymosin and salt treatments. The cheeses made using high levels of chymosin with low SM had lower levels of residual α(s1)- and β-casein at the end of ripening. On texture profile analysis, the hardness and fracturability of the cheeses significantly increased with SM and decreased during ripening. Increases in chymosin significantly contributed to the overall weakening of the structure throughout ripening. Bitter flavour was detected after 12 weeks in the cheese made with the higher chymosin level and lower SM, which could be the result of accumulation of γ-casein fractions. The sensory data indicated that the hedonic responses for low chymosin with low SM cheeses were good and acceptable in flavour, which may be due to the moderate levels of proteolysis products.

A model study of factors influencing projected changes in regional sea level over the 21st century

In addition to projected increases in global mean sea level over the 21st century, model simulations suggest there will also be changes in the regional distribution of sea level relative to the global mean. There is a considerable spread in the projected patterns of these changes by current models, as shown by the recent Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment (AR4). This spread has not reduced from that given by the Third Assessment models. Comparison with projections by ensembles of models based on a single structure supports an earlier suggestion that models of similar formulation give more similar patterns of sea level change. Analysing an AR4 ensemble of model projections under a business-as-usual scenario shows that steric changes (associated with subsurface ocean density changes) largely dominate the sea level pattern changes. The relative importance of subsurface temperature or salinity changes in contributing to this differs from region to region and, to an extent, from model-to-model. In general, thermosteric changes give the spatial variations in the Southern Ocean, halosteric changes dominate in the Arctic and strong compensation between thermosteric and halosteric changes characterises the Atlantic. The magnitude of sea level and component changes in the Atlantic appear to be linked to the amount of Atlantic meridional overturning circulation (MOC) weakening. When the MOC weakening is substantial, the Atlantic thermosteric patterns of change arise from a dominant role of ocean advective heat flux changes.

Energy at work: a measurement validation and linkage to unit effectiveness

We introduce the notion that the energy of individuals can manifest as a higher-level, collective construct. To this end, we conducted four independent studies to investigate the viability and importance of the collective energy construct as assessed by a new survey instrument—the productive energy measure (PEM). Study 1 (n = 2208) included exploratory and confirmatory factor analyses to explore the underlying factor structure of PEM. Study 2 (n = 660) cross-validated the same factor structure in an independent sample. In study 3, we administered the PEM to more than 5000 employees from 145 departments located in five countries. Results from measurement invariance, statistical aggregation, convergent, and discriminant-validity assessments offered additional support for the construct validity of PEM. In terms of predictive and incremental validity, the PEM was positively associated with three collective attitudes—units' commitment to goals, the organization, and overall satisfaction. In study 4, we explored the relationship between the productive energy of firms and their overall performance. Using data from 92 firms (n = 5939employees), we found a positive relationship between the PEM (aggregated to the firm level) and the performance of those firms. Copyright © 2011 John Wiley & Sons, Ltd.

Reconciling model and information uncertainty in development appraisal

This paper investigates the effect of choices of model structure and scale in development viability appraisal. The paper addresses two questions concerning the application of development appraisal techniques to viability modelling within the UK planning system. The first relates to the extent to which, given intrinsic input uncertainty, the choice of model structure significantly affects model outputs. The second concerns the extent to which, given intrinsic input uncertainty, the level of model complexity significantly affects model outputs. Monte Carlo simulation procedures are applied to a hypothetical development scheme in order to measure the effects of model aggregation and structure on model output variance. It is concluded that, given the particular scheme modelled and unavoidably subjective assumptions of input variance, simple and simplistic models may produce similar outputs to more robust and disaggregated models.

The interplay of secondary Hg⋯S, Hg⋯N and Hg⋯π bonding interactions in supramolecular structures of phenylmercury(ii) dithiocarbamates

Three new phenylmercury(II) and one mercury(II) dithiocarbamate complexes viz. PhHg S2CN(PyCH2) Bz (1), PhHg S2CN(PyCH2)CH3 (2), PhHg S2CN(Bz)CH3 (3), and [Hg (NCS2(PyCH2)Bz)(2)] (4) (Py = pyridine; Bz = benzyl) have been synthesized and characterized by elemental analyses, IR, electronic absorption, H-1 and C-13 NMR spectroscopy. The crystal structures of 1, 2 and 3 showed a linear S-Hg-C core at the centre of the molecule, in which the metal atom is bound to the sulfur atom of the dithiocarbamate ligand and a carbon atom of the aromatic ring. In contrast the crystal structure of 4 showed a linear S-Hg-S core at the Hg(II) centre of the molecule. Weak intermolecular Hg center dot center dot center dot N (Py) interactions link molecules into a linear chain in the case of 1, whereas chains of dimers are formed in 2 through intermolecular Hg center dot center dot center dot N (Py) and Hg center dot center dot center dot S interactions. 3 forms a conventional face-to-edge dimeric structure through intermolecular Hg center dot center dot center dot S secondary bonding and 4 forms a linear chain of dimers through face-to-face Hg center dot center dot center dot S secondary bonding. In order to elucidate the nature of these secondary bonding interactions and the electronic absorption spectra of the complexes, ab initio quantum chemical calculations at the MP2 level and density functional theory calculations were carried out for 1-3. Complexes 1 and 2 exhibited photoluminescent properties in the solid state as well as in the solution phase. Studies indicate that Hg center dot center dot center dot S interactions decrease and Hg center dot center dot center dot N interactions increase the chances of photoluminescence in the solid phase

Interaction of anthocyanins with human serum albumin: influence of pH and chemical structure on binding

The affinity of anthocyanins for human serum albumin (HSA) was determined by a fluorescence quenching method. The effects of pH and structure of anthocyanins on the binding constants were studied. The constants for binding of anthocyanins to HSA ranged from 1.08 x 10^5 M-1 to 13.16 x 10^5 M-1. A hydrophobic effect at acidic pH was shown by the relatively high positive entropy values under the conditions studied. Electrostatic interactions including hydrogen bonding contributed to the binding at pH 7.4. The effect of structure of anthocyanins on the affinity was pH dependent, particularly the effect of additional hydroxyl substituents. Hydroxyl substituents and glycosylation of anthocyanins decreased the affinity for binding to HSA at lower pH (especially pH 4), but increased the strength of binding at pH 7.4. In contrast, methylation of a hydroxyl group enhanced the binding at acidic pH, while this substitution reduced the strength of binding at pH 7.4. This paper has shown that changes in anthocyanin structure or reductions in pH, which may occur in the region of inflammatory sites, have an effect of the binding of anthocyanins to HSA.

Inferring the structure of the solar corona and inner heliosphere during the Maunder minimum using global thermodynamic magnetohydrodynamic simulations

Observations of the Sun’s corona during the space era have led to a picture of relatively constant, but cyclically varying solar output and structure. Longer-term, more indirect measurements, such as from 10Be, coupled by other albeit less reliable contemporaneous reports, however, suggest periods of significant departure from this standard. The Maunder Minimum was one such epoch where: (1) sunspots effectively disappeared for long intervals during a 70 yr period; (2) eclipse observations suggested the distinct lack of a visible K-corona but possible appearance of the F-corona; (3) reports of aurora were notably reduced; and (4) cosmic ray intensities at Earth were inferred to be substantially higher. Using a global thermodynamic MHD model, we have constructed a range of possible coronal configurations for the Maunder Minimum period and compared their predictions with these limited observational constraints. We conclude that the most likely state of the corona during—at least—the later portion of the Maunder Minimum was not merely that of the 2008/2009 solar minimum, as has been suggested recently, but rather a state devoid of any large-scale structure, driven by a photospheric field composed of only ephemeral regions, and likely substantially reduced in strength. Moreover, we suggest that the Sun evolved from a 2008/2009-like configuration at the start of the Maunder Minimum toward an ephemeral-only configuration by the end of it, supporting a prediction that we may be on the cusp of a new grand solar minimum.

Disorder prediction methods, their applicability to different protein targets and their usefulness for guiding experimental studies

The role and function of a given protein is dependent on its structure. In recent years, however, numerous studies have highlighted the importance of unstructured, or disordered regions in governing a protein’s function. Disordered proteins have been found to play important roles in pivotal cellular functions, such as DNA binding and signalling cascades. Studying proteins with extended disordered regions is often problematic as they can be challenging to express, purify and crystallise. This means that interpretable experimental data on protein disorder is hard to generate. As a result, predictive computational tools have been developed with the aim of predicting the level and location of disorder within a protein. Currently, over 60 prediction servers exist, utilizing different methods for classifying disorder and different training sets. Here we review several good performing, publicly available prediction methods, comparing their application and discussing how disorder prediction servers can be used to aid the experimental solution of protein structure. The use of disorder prediction methods allows us to adopt a more targeted approach to experimental studies by accurately identifying the boundaries of ordered protein domains so that they may be investigated separately, thereby increasing the likelihood of their successful experimental solution.

Thiol and Sulfenic Acid Oxidation of AhpE, the One-Cysteine Peroxiredoxin from Mycobacterium tuberculosis: Kinetics, Acidity Constants, and Conformational Dynamics

Drug resistance and virulence of Mycobacterium tuberculosis are partially related to the pathogen`s antioxidant systems. Peroxide detoxification in this bacterium is achieved by the heme-containing catalase peroxidase and different two-cysteine peroxiredoxins. M. tuberculosis genome also codifies for a putative one-cysteine peroxiredoxin, alkyl hydroperoxide reductase E (MtAhpE). Its expression was previously demonstrated at a transcriptional level, and the crystallographic structure of the recombinant protein was resolved under reduced and oxidized states. Herein, we report that the conformation of MtAhpE changed depending on its single cysteine redox state, as reflected by different tryptophan fluorescence properties and changes in quaternary structure. Dynamics of fluorescence changes, complemented by competition kinetic assays, were used to perform protein functional studies. MtAhE reduced peroxynitrite 2 orders of magnitude faster than hydrogen peroxide (1.9 x 10(7) M(-1) s(-1) vs 8.2 x 10(4) M(-1) s(-1) at pH 7.4 and 25 degrees C, respectively). The latter also caused cysteine overoxidation to sulfinic acid, but at much slower rate constant (40 M(-1) s(-1)). The pK(a) of the thiol in the reduced enzyme was 5.2, more than one unit lower than that of the sulfenic acid in the oxidized enzyme. The pH profile of hydrogen peroxide-mediated thiol and sulfenic acid oxidations indicated thiolate and sulfenate as the reacting species. The formation of sulfenic acid as well as the catalytic peroxidase activity of MtAhpE was demonstrated using the artificial reducing substrate thionitrobenzoate. Taken together, our results indicate that MtAhpE is a relevant component in the antioxidant repertoire of M. tuberculosis probably involved in peroxide and specially peroxynitrite detoxification.

Modularity and robustness of bone networks

Cortical bones, essential for mechanical support and structure in many animals, involve a large number of canals organized in intricate fashion. By using state-of-the art image analysis and computer graphics, the 3D reconstruction of a whole bone (phalange) of a young chicken was obtained and represented in terms of a complex network where each canal was associated to an edge and every confluence of three or more canals yielded a respective node. The representation of the bone canal structure as a complex network has allowed several methods to be applied in order to characterize and analyze the canal system organization and the robustness. First, the distribution of the node degrees (i.e. the number of canals connected to each node) confirmed previous indications that bone canal networks follow a power law, and therefore present some highly connected nodes (hubs). The bone network was also found to be partitioned into communities or modules, i.e. groups of nodes which are more intensely connected to one another than with the rest of the network. We verified that each community exhibited distinct topological properties that are possibly linked with their specific function. In order to better understand the organization of the bone network, its resilience to two types of failures (random attack and cascaded failures) was also quantified comparatively to randomized and regular counterparts. The results indicate that the modular structure improves the robustness of the bone network when compared to a regular network with the same average degree and number of nodes. The effects of disease processes (e. g., osteoporosis) and mutations in genes (e.g., BMP4) that occur at the molecular level can now be investigated at the mesoscopic level by using network based approaches.

Göra illa för att hjälpa eller hjälpa till att göra illa? : Arbetslösas reservationslöner, jobbchanser och återanställningsinkomster

Hurting to help or helping to hurt? The reservation wages of unemployed, job chances and reemployment incomes in Sweden Economic incentives and their impact on the job search behaviour of the unemployed have been a central focus in the academic and political debate in Sweden. A key concept has been the reservation wages of the unemployed, the lowest income at which an unemployed person would be willing to accept a job offer. Unemployment benefit systems have been argued to raise and maintain reservation wages at high levels that lower job chances. This has been supported by a large number of international studies. From this perspective lower reservation wages would function as protection against long term unemployment and the scarring effects associated with it. High reservation wages might however, based on the same behavioural assumptions, have a human capital preserving effect. The possibility to hold out for the right job should reduce human capital losses compared to accepting the first available job offer. In this article we use Swedish longitudinal micro data combining interview and register data in order to investigate three central aspects reservation wages in a Swedish context: factors influencing the setting of reservation wages, the effect of reservation wage on job chances and the impact of reservation wages on reemployment incomes. Our findings show that benefit level and pre-unemployment position in the wage structure are central factors for setting the reservation wage. The effects of reservation wages were however not the expected. No effects were found on job chances, while a strong positive effect was found on reemployment income. This together indicates that high reservation wages have a human capital preserving effect in Sweden.

Escolariedade, salários e empregabilidade: implicações no mercado de empregos do Rio de Janeiro

The high degree of flexibility has been pointed as one of the outstanding characteristics of the Brazilian job market. Employability is being a frequent discussion issue among the professionals of the human resources area. The Human Capital Theory and the contemporary discussion concerning Employability argue the relationship of the educational practice and of the production practice in a capitalist economical-social structure as a whole. The education consequences in the individuals' life are reflected in several ways, direct and indirectly. Our objective is to evaluate, with statistics methods, and in that universe of consequences, the explanatory events of the relationships between education-wage and education¿job. The main reason of this work is to evaluate the relationship between education, wage and Employability from a structural model perspective, seeking to compare and to contrast two effective theories: the one from the human capital and other from the Employability. To make this analysis, a database of individuals that are working at the formal work market in the Rio de Janeiro Metropolitan Area, had been used. The results showed the education importance on the wage level, as well as, on the Employability factor, whose values and highest taxes correspond to the individuals graduated on the university.

Macroeconomic policy and poverty in Brazil

O Brasil é um país onde os 50% mais pobres se apropriam aproximadamente de 10% da renda agregada, e os 10% mais ricos detêm quase 50% deste mesmo. O colorário desse alto grau de desigualdade é que se uma pessoa está somente preocupada em maximizar o nível de GPD, a função de bem–estar social implícita adotada devota parte do seu peso ao bem-estar de 10% da população. Em outras palavras, a concentração brasileira de renda cria uma anomalia dentro da perspectiva de agente representativo implícito na análise macroeconômica aonde as pessoas valem aquilo que ganham. A análise da pobreza inverte esse peso estrutural da população, estipulando zero de peso para o segmento não pobre da sociedade e atribuindo pesos aos indivíduos que aumentam com suas necessidades insatisfeitas. Esse projeto estuda as conexões entre a evolução macroeconômica Brasileira recente e da pobreza. A análise é dividida em duas partes: A primeira parte descreve a evolução da pobreza brasileira e seus principais determinantes macroeconômicos durante os últimos 15 anos. A segunda parte tira proveito das mudanças da pobreza e desigualdades medidas durante o período 1993-96 para estudar seus principais determinantes macroeconômicos. Dado a maior importância do Plano Real, uma especial atenção foi dada a análise dos impactos da desinflação no nível e na distribuição de renda e a possível sinergia entre essas duas dimensões de determinação da pobreza. A terceira parte do projeto decompõe as mudanças dos diversos índices de pobreza através dos diferentes grupos dado pelas características dos chefes de família (i.e.; sexo, anos de estudo, raça, classe trabalhadora, setores de atividades, região, densidade populacional). Depois essa decomposição é avançada um passo desatrelando as mudanças nessa diferentes células de pobreza em termos de suas respectivas mudanças em termos de desigualdade da renda per capita. Esse perfil de pobreza ajuda a mapear as diferentes fontes de mudança da pobreza na análise histórica e fornece consistência interna para os exercícios de análises contra-factuais.

Differences in the perception of interest representation: a comparision of Brasília and Brussels lobbying activity

The research topic of this paper is focused on the analysis of how trade associations perceive lobbying in Brussels and in Brasília. The analysis will be centered on business associations located in Brasília and Brussels as the two core centers of decision-making and as an attraction for the lobbying practice. The underlying principles behind the comparison between Brussels and Brasilia are two. Firstof all because the European Union and Brazil have maintained diplomatic relations since 1960. Through these relations they have built up close historical, cultural, economic and political ties. Their bilateral political relations culminated in 2007 with the establishment of a Strategic Partnership (EEAS website,n.d.). Over the years, Brazil has become a key interlocutor for the EU and it is the most important market for the EU in Latin America (European Commission, 2007). Taking into account the relations between EU and Brazil, this research could contribute to the reciprocal knowledge about the perception of lobby in the respective systems and the importance of the non-market strategy when conducting business. Second both EU and Brazilian systems have a multi-level governance structure: 28 Member States in the EU and 26 Member States in Brazil; in both systems there are three main institutions targeted by lobbying practice. The objective is to compare how differences in the institutional environments affect the perception and practice of lobbying, where institutions are defined as ‘‘regulative, normative, and cognitive structures and activities that provide stability and meaning to social behavior’’ (Peng et al., 2009). Brussels, the self-proclaimed "Capital of Europe”, is the headquarters of the European Union and has one of the highest concentrations of political power in the world. Four of the seven Institutions of the European Union are based in Brussels: the European Parliament, the European Council, the Council and the European Commission (EU website, n.d.). As the power of the EU institutions has grown, Brussels has become a magnet for lobbyists, with the latest estimates ranging from between 15,000 and 30,000 professionals representing companies, industry sectors, farmers, civil society groups, unions etc. (Burson Marsteller, 2013). Brasília is the capital of Brazil and the seat of government of the Federal District and the three branches of the federal government of Brazilian legislative, executive and judiciary. The 4 city also hosts 124 foreign embassies. The presence of the formal representations of companies and trade associations in Brasília is very limited, but the governmental interests remain there and the professionals dealing with government affairs commute there. In the European Union, Brussels has established a Transparency Register that allows the interactions between the European institutions and citizen’s associations, NGOs, businesses, trade and professional organizations, trade unions and think tanks. The register provides citizens with a direct and single access to information about who is engaged in This process is important for the quality of democracy, and for its capacity to deliver adequate policies, matching activities aimed at influencing the EU decision-making process, which interests are being pursued and what level of resources are invested in these activities (Celgene, n.d). It offers a single code of conduct, binding all organizations and self-employed individuals who accept to “play by the rules” in full respect of ethical principles (EC website, n.d). A complaints and sanctions mechanism ensures the enforcement of the rules and addresses suspected breaches of the code. In Brazil, there is no specific legislation regulating lobbying. The National Congress is currently discussing dozens of bills that address regulation of lobbying and the action of interest groups (De Aragão, 2012), but none of them has been enacted for the moment. This work will focus on class lobbying (Oliveira, 2004), which refers to the performance of the federation of national labour or industrial unions, like CNI (National Industry Confederation) in Brazil and the European Banking Federation (EBF) in Brussels. Their performance aims to influence the Executive and Legislative branches in order to defend the interests of their affiliates. When representing unions and federations, class entities cover a wide range of different and, more often than not, conflicting interests. That is why they are limited to defending the consensual and majority interest of their affiliates (Oliveira, 2004). The basic assumption of this work is that institutions matter (Peng et al, 2009) and that the trade associations and their affiliates, when doing business, have to take into account the institutional and regulatory framework where they do business.