The global anaerobic regulator Anr, is involved in cell attachment and aggregation influencing the first stages of biofilm development in Pseudomonas extremaustralis

Pseudomonas extremaustralis is a versatile Antarctic bacterium, able to grow under microaerobic and anaerobic conditions and is related to several non-pathogenic Pseudomonads. Here we report on the role of the global anaerobic regulator Anr, in the early steps of P. extremaustralis biofilm development. We found that the anr mutant was reduced in its ability to attach, to form aggregates and to display twitching motility but presented higher swimming motility than the wild type. In addition, microscopy revealed that the wild type biofilm contained more biomass and was thicker, but were less rough than that of the anr mutant. In silico analysis of the P. extremaustralis genome for Anr-like binding sites led to the identification of two biofilm-related genes as potential targets of this regulator. When measured using Quantitative Real Time PCR, we found that the anr mutant expressed lower levels of pilG , which encodes a component of Type IV pili and has been previously implicated in cellular adhesion. Levels of morA, involved in signal transduction and flagella development, were also lower in the mutant. Our data suggest that under low oxygen conditions, such as those encountered in biofilms, Anr differentially regulates aggregation and motility thus affecting the first stages of biofilm formation.Fil: Tribelli, Paula Maria. Consejo Nacional de Invest.cientif.y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Quimica Biologica de la Facultad de Cs. Exactas y Naturales;Fil: Hay, Anthony.Fil: Lopez, Nancy Irene. Consejo Nacional de Invest.cientif.y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Quimica Biologica de la Facultad de Cs. Exactas y Naturales

Trade in Mesopotamia from the early dynastic period to the early Achaemenid period with emphasis on the finance of such trade

This dissertation considered trade and trade finance in Mesopotamia over a period of 2000 years commencing with Sumeria and ending with Achaemenid Persia, taking in Ur III and Assyria. A range of financial instruments was selected together with important business transactions, for instance, agricultural finance, specifically the brewing industry and the working capital requirements of merchants and money lenders. The role of women in private enterprise was examined, including their role in retail finance. The great estates of temple and palace had a substantial impact on finance and trade throughout the periods. Their interaction with merchants and money lenders was important to the study. I used reductionism to facilitate analysis of complex products highlighting the essentials of finance namely, borrowing, lending and return. The study concludes that, during the era under consideration, the evolution and enhancement of the financial instruments and products developed in self-generated, incremental and progressive steps.Biblical and Ancient StudiesM.A. (Ancient Near East Studies

Do Interactions Between Gut Ecology and Environmental Chemicals Contribute to Obesity and Diabetes?

Background: Gut microbiota are important factors in obesity and diabetes, yet little is known about their role in the toxicodynamics of environmental chemicals, including those recently found to be obesogenic and diabetogenic

Investigating the causes of low birth weight in contrasting ovine paradigms.

Intrauterine growth restriction (IUGR) still accounts for a large incidence of infant mortality and morbidity worldwide. Many of the circulatory and transport properties of the sheep placenta are similar to those of the human placenta and as such, the pregnant sheep offers an excellent model in which to study the development of IUGR. Two natural models of ovine IUGR are those of hyperthermic exposure during pregnancy, and adolescent overfeeding, also during pregnancy. Both models yield significantly reduced placental weights and an asymmetrically growth-restricted fetus, and display altered maternal hormone concentrations, indicative of an impaired trophoblast capacity. Additionally, impaired placental angiogenesis and uteroplacental blood flow appears to be an early defect in both the hyperthermic and adolescent paradigms. The effects of these alterations in placental functional development appear to be irreversible. IUGR fetuses are both hypoxic and hypoglycaemic, and have reduced insulin and insulin-like growth factor-1 (IGF-1), and elevated concentrations of lactate. However, fetal utilization of oxygen and glucose, on a weight basis, remain constant compared with control pregnancies. Maintained utilization of these substrates, in a substrate-deficient environment, suggests increased sensitivities to metabolic signals, which may play a role in the development of metabolic diseases in later adult life

Temperature and humidity within a mobile barchan sand dune, implications for microbial survival

International audienc

Defining childhood severe falciparum malaria for intervention studies.

Background Clinical trials of interventions designed to prevent severe falciparum malaria in children require a clear endpoint. The internationally accepted definition of severe malaria is sensitive, and appropriate for clinical purposes. However, this definition includes individuals with severe nonmalarial disease and coincident parasitaemia, so may lack specificity in vaccine trials. Although there is no “gold standard” individual test for severe malaria, malaria-attributable fractions (MAFs) can be estimated among groups of children using a logistic model, which we use to test the suitability of various case definitions as trial endpoints. Methods and Findings A total of 4,583 blood samples were taken from well children in cross-sectional surveys and from 1,361 children admitted to a Kenyan District hospital with severe disease. Among children under 2 y old with severe disease and over 2,500 parasites per microliter of blood, the MAFs were above 85% in moderate- and low-transmission areas, but only 61% in a high-transmission area. HIV and malnutrition were not associated with reduced MAFs, but gastroenteritis with severe dehydration (defined by reduced skin turgor), lower respiratory tract infection (clinician's final diagnosis), meningitis (on cerebrospinal fluid [CSF] examination), and bacteraemia were associated with reduced MAFs. The overall MAF was 85% (95% confidence interval [CI] 83.8%–86.1%) without excluding these conditions, 89% (95% CI 88.4%–90.2%) after exclusions, and 95% (95% CI 94.0%–95.5%) when a threshold of 2,500 parasites/μl was also applied. Applying a threshold and exclusion criteria reduced sensitivity to 80% (95% CI 77%–83%). Conclusions The specificity of a case definition for severe malaria is improved by applying a parasite density threshold and by excluding children with meningitis, lower respiratory tract infection (clinician's diagnosis), bacteraemia, and gastroenteritis with severe dehydration, but not by excluding children with HIV or malnutrition

Blended electrospinning with human liver extracellular matrix for engineering new hepatic microenvironments

Abstract Tissue engineering of a transplantable liver could provide an alternative to donor livers for transplant, solving the problem of escalating donor shortages. One of the challenges for tissue engineers is the extracellular matrix (ECM); a finely controlled in vivo niche which supports hepatocytes. Polymers and decellularized tissue scaffolds each provide some of the necessary biological cues for hepatocytes, however, neither alone has proved sufficient. Enhancing microenvironments using bioactive molecules allows researchers to create more appropriate niches for hepatocytes. We combined decellularized human liver tissue with electrospun polymers to produce a niche for hepatocytes and compared the human liver ECM to its individual components; Collagen I, Laminin-521 and Fibronectin. The resulting scaffolds were validated using THLE-3 hepatocytes. Immunohistochemistry confirmed retention of proteins in the scaffolds. Mechanical testing demonstrated significant increases in the Young’s Modulus of the decellularized ECM scaffold; providing significantly stiffer environments for hepatocytes. Each scaffold maintained hepatocyte growth, albumin production and influenced expression of key hepatic genes, with the decellularized ECM scaffolds exerting an influence which is not recapitulated by individual ECM components. Blended protein:polymer scaffolds provide a viable, translatable niche for hepatocytes and offers a solution to current obstacles in disease modelling and liver tissue engineering

Reorienting the Treasury, Reorienting British Capitalism

In its dual role as both the ‘economics ministry’ and the ‘finance ministry’, HM Treasury sits at the apex of the British state, and indeed the British political economy. This role has received a great deal of critical attention in the wake of the 2008/09 recession and subsequent imposition of ‘austerity’ by the Conservative-Liberal Democrat coalition government, continued by the Conservative majority government; for example, it is currently being reviewed by former Head of the UK Civil Service, Lord Kerslake, on behalf of the Labour Party. In this Brief, we consider previous attempts to challenge the Treasury’s pre-eminence within government over economic policy, and suggest that the Treasury should be accepted as the dominant economics ministry with political capital and effort spent on reforming its role, responsibilities and mandate. Creating an alternative economics department within government – a ‘beefed up’ business department – will have only a limited impact. The Brief also sets out how and why a ‘developmental’ approach to the Treasury should be considered and outlines the need for a new growth model and how the Treasury can oversee its development and functioning, before suggesting a new approach for the Treasury to economic stability and regulation

Vertical structure of surface gravity waves propagating over a sloping sea bed: theory and field measurements

[1] Theoretical predictions of the vertical structure of wave motion over a sloping seabed are compared with field observations close to the bed in the nearshore zone. Of particular interest is the effect of the local slope on the magnitude and phase of the vertical velocity. Field measurements of near-bed velocity profiles on a 2°bed slope were obtained using a coherent Doppler profiler. The surface elevation was measured by a colocated, upward looking, acoustic sounder. Results are presented from two intervals of different wave energy levels during a storm event: for wave height/water depth ratios smaller than 0.3 and for Ursell numbers smaller than 0.6. The local comparisons of magnitude and phase between the vertical velocity and surface elevation measurements are in good agreement with linear theory for a sloping bed, but differ greatly from that for a horizontal bottom, especially in the lower water column. The sloping bottom, however, has little effect on the horizontal velocity. Linear theory appears to adequately describe the transfer function between the surface elevation and the near-bed velocities, not only at the peak frequencies but also at their harmonics. However, in relatively shallow water the local transformations of free and forced waves at the harmonic frequencies are indistinguishable in the lower water column. Therefore, given surface elevation measurements at a particular location (which reflect the integrated effects of nonlinearities associated with wave shoaling), the vertical structure of the third moments of velocity fields estimated from linear theory is in reasonable agreement with the observations. Both theory and observations show that the skewness and asymmetry of the vertical velocity are subject to significant bottom slope effects, whereas those of horizontal velocity are not. Citation: Zou, Q., A. E. Hay, and A. J. Bowen, Vertical structure of surface gravity waves propagating over a sloping seabed: Theory and field measurements