Dehalogenation of polychlorinated biphenyls and polybrominated diphenyl ethers using a hybrid bioinorganic catalyst

The environmentally prevalent polybrominated diphenyl ether (PBDE) #47 and polychlorinated biphenyls (PCBs) #28 and #118 were challenged for 24 hours with a novel biomass-supported Pd catalyst (BioPd0). Analysis of the products via GC/MS revealed the BioPd0 to cause the challenged compounds to undergo stepwise dehalogenation with preferential loss of the least sterically hindered halogen atom. A mass balance for PCB #28 showed that it is degraded to three dichlorobiphenyls (33.9 %), two monochlorobiphenyls (12 %), and biphenyl (30.7 %). The remaining mass was starting material. In contrast, while PCB #118 underwent degradation to yield five tetra- and five trichlorinated biphenyls; no less chlorinated products or biphenyl were detected, and the total mass of degraded products was 0.3 %. Although the BioPd0 material was developed for treatment of PCBs, a mass balance for PBDE #47 showed that the biocatalyst could prove a useful method for treatment of PBDEs. Specifically, 10 % of PBDE # 47 was converted to identifiable lower brominated congeners, predominantly the tribrominated BDE 17, and the dibrominated BDE 4, 75 % remained intact, while 15 % of the starting mass was unaccounted for

Austerity, ageing and the financialisation of pensions policy in the UK

This article offers a detailed analysis of the recent history of pensions policy in the United Kingdom, culminating in two apparent ‘revolutions’ in policy now underway: the introduction of ‘automatic enrolment’ into private pensions, and proposals for a new ‘single-tier’ state pension. These reforms are considered exemplary of the ‘financialisation’ of UK welfare provision – typified in pensions policy by the notion that individuals must take personal responsibility for their own long-term financial security, and engage intimately with the financial services industry to do so. As such, the reforms represent the continuation of pensions policy between the Labour and coalition governments, despite the coalition government’s novel rhetorical commitment to austerity. In fact, the pensions revolutions will actually cost the state significantly more than current arrangements, yet the importance of fears about population ageing means that the government is both able to marshal the imagery of austerity to justify financialisation, but is also required to partly conceal the increased expenditure this requires. The article shows therefore how the financialisation agenda in pensions policy was evident before the financial crisis, but has evolved to both take advantage, and mitigate the constraints, of a post-crisis political climate

Assessment of Arthrobacter viscosus as reactive medium for forming permeable reactive biobarrier applied to PAHs remediation

Polycyclic aromatic hydrocarbons (PAHs) are significant environmental contaminants as they are present naturally as well as anthropogenically in soil, air and water. In spite of their low solubility, PAHs are spread to the environment, and they are present in surface water, industrial effluent or groundwater. Amongst all remediation technologies for treating groundwater contaminated with PAHs, the use of a permeable reactive biobarrier (PRBB) appears to be the most cost-effective, energy efficient, and environmentally sound approach. In this technology, the microorganisms are used as reactive medium to degrade or stabilize the contaminants. The main limits of this approach are that the microorganisms or consortium used for forming the PRBB should show adequate characteristics. They must be retained in the barrier-forming biofilm, and they should also have degradative ability for the target pollutants. The aim of the present work is to evaluate the viability of Arthrobacter viscosus as bioreactive medium for forming PRBB. Initially, the ability of A. viscosus to remove PAHs, benzo[a]anthracene 100 μM and phenanthrene 100 μM was evaluated operating in a batch bench-scale bioreactor. In both cases, total benzo[a]anthracene and phenanthrene removals were obtained after 7 and 3 days, respectively. Furthermore, the viability of the microorganisms was evaluated in the presence of chromium in a continuous mode. As a final point, the adhesion of A. viscosus to sepiolite forming a bioreactive material to build PRBB was demonstrated. In view of the attained results, it can be concluded that A. viscosus could be a suitable microorganism to form a bioreactive medium for PAHs remediation.This work has been supported by the Spanish Ministry of Economy and Competitiveness and FEDER Funds (Project CTM 2011-25389). Marta Pazos received financial support under the Ramon y Cajal programme and Marta Cobas under the final project master grant "Campus do Mar Knowledge in depth"

Social work for critical peace: A comparative approach to understanding social work and political conflict

This paper uses a case study approach to explore issues of social work policy and practice in three sites of political conflict in Europe: Northern Ireland; Bosnia and Herzegovina; and Cyprus. It begins with a review of the international literature on social work and political conflict and then discusses the strengths and limitations in engaging with comparative case study approaches. The authors explain how they view the writing of the paper as an intellectual encounter that helped establish the beginning stages of their comparative analysis. This starts with an analysis of the existing knowledge base about the three case studies that each share similar patterns of colonial histories, political and community conflict and the social work response. The second part of the paper extends this analysis to a critique of the impact of neo-liberal social and economic policies that often adversely impact upon the role of social workers in resolving conflict and building peace. The paper concludes with an appeal for social work to rediscover its rights-based role in working with victims and survivors of political conflict, what the authors describe as: ‘social work for critical peace’

Automated Force Volume Image Processing for Biological Samples

Atomic force microscopy (AFM) has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature) which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image

Bacterial Surface Appendages Strongly Impact Nanomechanical and Electrokinetic Properties of Escherichia coli Cells Subjected to Osmotic Stress

The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM) and electrokinetics (electrophoresis). Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus). From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700–900 kPa and ∼100–300 kPa respectively). Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the intimate relationship between structure/flexibility and charge of bacterial envelope and propensity of bacterium and surface appendages to contract under hypertonic conditions