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Rhodopseudomonas palustris TIE‐1 grows photoautotrophically with Fe(II) as an electron donor and photoheterotrophically with a variety of organic substrates. However, it is unclear whether R. palustris TIE‐1 conducts Fe(II) oxidation in conditions where organic substrates and Fe(II) are available simultaneously. In addition, the effect of organic co‐substrates on Fe(II) oxidation rates or the identity of Fe(III) minerals formed is unknown. We incubated R. palustris TIE‐1 with 2 mM Fe(II), amended with 0.6 mM organic co‐substrate, and in the presence/absence of CO2. We found that in the absence of CO2, only the organic co‐substrates acetate, lactate and pyruvate, but not Fe(II), were consumed. When CO2 was present, Fe(II) and all organic substrates were consumed. Acetate, butyrate and pyruvate were consumed before Fe(II) oxidation commenced, whereas lactate and glucose were consumed at the same time as Fe(II) oxidation proceeded. Lactate, pyruvate and glucose increased the Fe(II) oxidation rate significantly (by up to threefold in the case of lactate). 57Fe Mössbauer spectroscopy revealed that short‐range ordered Fe(III) oxyhydroxides were formed under all conditions. This study demonstrates phototrophic Fe(II) oxidation proceeds even in the presence of organic compounds, and that the simultaneous oxidation of organic substrates can stimulate Fe(II) oxidation. [ABSTRACT FROM AUTHOR]

Laboratory‐based studies on microbial Fe(II) oxidation are commonly performed for 5–10 days in small volumes with high substrate concentrations, resulting in geochemical gradients and volumetric effects caused by sampling. We used a chemostat to enable uninterrupted supply of medium and investigated autotrophic nitrate‐reducing Fe(II)‐oxidizing culture KS for 24 days. We analysed Fe‐ and N‐speciation, cell‐mineral associations, and the identity of minerals. Results were compared to batch systems (50 and 700 mL—static/shaken). The Fe(II) oxidation rate was highest in the chemostat with 7.57 mM Fe(II) d−1, while the extent of oxidation was similar to the other experimental setups (average oxidation of 92% of all Fe(II)). Short‐range ordered Fe(III) phases, presumably ferrihydrite, precipitated and later goethite was detected in the chemostat. The 1 mM solid phase Fe(II) remained in the chemostat, up to 15 μM of reactive nitrite was measured, and 42% of visualized cells were partially or completely mineral‐encrusted, likely caused by abiotic oxidation of Fe(II) by nitrite. Despite (partial) encrustation, cells were still viable. Our results show that even with similar oxidation rates as in batch cultures, cultivating Fe(II)‐oxidizing microorganisms under continuous conditions reveals the importance of reactive nitrogen intermediates on Fe(II) oxidation, mineral formation and cell–mineral interactions. [ABSTRACT FROM AUTHOR]

Summary: It has been recently shown that magnetite nanoparticles (nanoFe3O4) can facilitate methanogenic syntrophy but the effect of magnetite on methanogenesis alone remains elusive. Here we show that aceticlastic methanogenesis by Methanosarcina mazei is accelerated by magnetite and is correlated with the redox cycling of structural Fe(II) and Fe(III) in the mineral. An enrichment and its closest pure culture relative, Ms. mazei zm‐15, both obtained from a natural wetland of the Tibetan plateau were tested in this experiment. The Fe(II) to Fe(III) ratios in magnetite, as measured by multiple approaches, show an initial increase in both the methanogenic cultures and the blank preparations containing no microbes. The Fe(II)/Fe(III) ratio then displays a distinct decline followed by an increase towards the end of incubation only in the enrichment and pure culture cultivations. This redox cycling of magnetite is in accordance with the stimulation of aceticlastic methanogenesis. Microscopic observation reveals the precipitation of nanoFe3O4 on methanogen cell surface. The genomic analysis predicts that in addition to electron transfer components essential for aceticlastic methanogenesis, Ms. mazei zm‐15 contains an outer‐surface multiheme c‐type cytochrome (MHC) and a few function‐unknown surface proteins that harbour monoheme motif. We hypothesize that the redox cycling of nanoFe3O4 delivers a positive influence via the MHC to the membrane electron transfer chain and hence promote the aceticlastic methanogenesis. [ABSTRACT FROM AUTHOR]

Summary: Iron is the most abundant redox‐active metal in the Earth's crust. The one electron transfer between the two most common redox states, Fe(II) and Fe(III), plays a role in a huge range of environmental processes from mineral formation and dissolution to contaminant remediation and global biogeochemical cycling. It has been appreciated for more than a century that microorganisms can harness the energy of this Fe redox transformation for their metabolic benefit. However, this is most widely understood for anaerobic Fe(III)‐reducing or aerobic and microaerophilic Fe(II)‐oxidizing bacteria. Only in the past few decades have we come to appreciate that bacteria also play a role in the anaerobic oxidation of ferrous iron, Fe(II), and thus can act to form Fe(III) minerals in anoxic settings. Since this discovery, our understanding of the ecology of these organisms, their mechanisms of Fe(II) oxidation and their role in environmental processes has been increasing rapidly. In this article, we bring these new discoveries together to review the current knowledge on these environmentally important bacteria, and reveal knowledge gaps for future research. [ABSTRACT FROM AUTHOR]

Abstract: As a consequence of Earth's surface oxygenation, ocean geochemistry changed from ferruginous (iron(II)‐rich) into more complex ferro‐euxinic (iron(II)‐sulphide‐rich) conditions during the Paleoproterozoic. This transition must have had profound implications for the Proterozoic microbial community that existed within the ocean water and bottom sediment; in particular, iron‐oxidizing bacteria likely had to compete with emerging sulphur‐metabolizers. However, the nature of their coexistence and interaction remains speculative. Here, we present geochemical and microbiological data from the Arvadi Spring in the eastern Swiss Alps, a modern model habitat for ferro‐euxinic transition zones in late Archean and Proterozoic oceans during high‐oxygen intervals, which enables us to reconstruct the microbial community structure in respective settings for this geological era. The spring water is oxygen‐saturated but still contains relatively elevated concentrations of dissolved iron(II) (17.2 ± 2.8 μM) and sulphide (2.5 ± 0.2 μM) with simultaneously high concentrations of sulphate (8.3 ± 0.04 mM). Solids consisting of quartz, calcite, dolomite and iron(III) oxyhydroxide minerals as well as sulphur‐containing particles, presumably elemental S0, cover the spring sediment. Cultivation‐based most probable number counts revealed microaerophilic iron(II)‐oxidizers and sulphide‐oxidizers to represent the largest fraction of iron‐ and sulphur‐metabolizers in the spring, coexisting with less abundant iron(III)‐reducers, sulphate‐reducers and phototrophic and nitrate‐reducing iron(II)‐oxidizers. 16S rRNA gene 454 pyrosequencing showed sulphide‐oxidizing Thiothrix species to be the dominating genus, supporting the results from our cultivation‐based assessment. Collectively, our results suggest that anaerobic and microaerophilic iron‐ and sulphur‐metabolizers could have coexisted in oxygenated ferro‐sulphidic transition zones of late Archean and Proterozoic oceans, where they would have sustained continuous cycling of iron and sulphur compounds. [ABSTRACT FROM AUTHOR]

The article discusses the trends and developments in the use of microbiology to treat metalloid arsenic (As) and heavy metal cadmium (Cd) from drinking water, which are often associated with agricultural soils and, mining and other industrial activities that led to groundwater contamination. Topics include considerations for direct microbial bioremediation, indirect microbial bioremediation, and the use of Microbacterium lacticum to oxidize As sorbed to activated charcoal or alumina.

Coastal marine sediments contain varying concentrations of iron, oxygen, nitrate and organic carbon. It is unknown how organic carbon content influences the activity of nitrate-reducing and phototrophic Fe(II)-oxidizers and microbial Fe-redox cycling in such sediments. Therefore, microcosms were prepared with two coastal marine sediments (Kalø Vig and Norsminde Fjord at Aarhus Bay, Denmark) varying in TOC from 0.4 to 3.0 wt%. The microcosms were incubated under light/dark conditions with/without addition of nitrate and/or Fe(II). Although most probable number (MPN) counts of phototrophic Fe(II)-oxidizers were five times lower in the low-TOC sediment, phototrophic Fe(II) oxidation rates were higher compared with the high-TOC sediment. Fe(III)-amended microcosms showed that this lower net Fe(II) oxidation in the high-TOC sediment is caused by concurrent bacterial Fe(III) reduction. In contrast, MPN counts of nitrate-reducing Fe(II)-oxidizers and net rates of nitrate-reducing Fe(II) oxidation were comparable in low- and high-TOC sediments. However, the ratio of nitratereduced:iron(II)oxidized was higher in the high-TOC sediment, suggesting that a part of the nitrate was reduced by mixotrophic nitrate-reducing Fe(II)-oxidizers and chemoorganoheterotrophic nitrate-reducers. Our results demonstrate that dynamic microbial Fe cycling occurs in these sediments and that the extent of Fe cycling is dependent on organic carbon content. [ABSTRACT FROM AUTHOR]

The magnetic moments of magnetite nanoparticles are dramatically enhanced through the addition of zinc in a microbiologically driven synthesis procedure. The particles are produced through the reduction of Fe(III)-compounds containing Zn(II) by the iron reducing bacterium Geobacter sulfurreducens. Results indicate a significant increase in the saturation magnetization by over 50% compared to magnetite at both room and low temperatures for relatively minor quantities of zinc substitution. A maximum saturation magnetization of nearly 100 emu g−1 of sample is measured at room temperature. Analysis of the cation site ordering reveals a complex dependence on the Zn content, with the combined effect of Zn substitution of Fe3+ ions on tetrahedral sites, together with Fe2+ cation oxidation, leading to the observed magnetization enhancement for low Zn doping levels. The improved magnetic properties give superior performance in MRI applications with an MRI contrast enhancement among the largest values reported, being more than 5 times larger than a commercial contrast agent (Feridex) measured under identical conditions. The synthesis technique applied here involves an environmentally benign route and offers the potential to tune the magnetic properties of magnetic nanoparticles, with increased overall magnetization desirable for many different commercial applications. [ABSTRACT FROM AUTHOR]

This study compared summer stream temperature between two years in the Star Creek catchment, Alberta, a headwater basin on the eastern slopes of the Canadian Rocky Mountains. Star Creek is a subsurface water dominated stream, which represents important habitat for native salmonid species. Hydrometeorological data from May to September of 2010 and 2011 accompanied by stream energy budget calculations were used to describe the drivers of stream temperature in this small forested stream. Mean, maximum, and minimum weekly stream temperatures were lower from May to August and higher in September 2011 compared to 2010. Weekly range in stream temperature was also different between years with a higher range in 2010. Inter-annual stream temperature variation was attributed discharge differences between years, shown to be primarily governed by catchment-scale moisture conditions. This study demonstrates that both meteorological and hydrological processes must be considered in order to understand stream temperature response to changing environmental conditions in mountainous regions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The rate of climatic change over western North America (WNA) is quantified for 485 climate stations for the period 1950-2005. Additionally, six stations with quality long-term records were selected and analysed for the period 1906-2005. The indicators used were developed by the World Meteorological Organization (WMO) and the World Climate Research Program's Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). From the 27 core indices, 4 temperature-based and 4 precipitation-based indicators were selected for in-depth analysis. The 8 million km2 study area is comprised of the 22 contiguous US states and 4 Canadian provinces west of the Mississippi River and Great Lakes. The results were divided into six general regions for interpretation and presentation. GIS interpolation of station-specific statistical output was completed to further aid in the identification of spatially coherent trends across WNA. Mean slopes were calculated over the whole study area, and by region, for each index, and then tested to determine if they were significantly different from zero. Results of the study show statistically significant historical climate trends across the study area. As expected in a region as geographically diverse as WNA, results differed between, and within, regions. Overall, temperature-based indicators showed a general warming trend over the entire study area, with the greatest increases along the North American Cordillera. The trends in precipitation-based indicators were more varied. General trends indicate moderately increasing precipitation volume and intensity over much of WNA. The strongest precipitation trends were found in areas with climate largely controlled by air masses originating over the Gulf of Mexico. Copyright © 2011 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

The article discusses various reports published within the issue related to the social ecology of community corrections, including a research on Maryland's Proactive Community Supervision model, an essay highlighting the important features of the Maryland program and an argument over the application of community-level performance measure by community corrections agencies.

A study carried out in the Oldman River watershed in southern Alberta, Canada, to delineate potential surface water pollution sources revealed that the use of conventional raster-based digital elevation models (DEMs) and flow-direction algorithms resulted in the delineation of incorrect watershed boundaries. The inaccuracies resulted from the resolution of the available DEM, which is too coarse to represent the presence of anthropogenically modified terrain features, such as roads, ditches and canals, which can significantly alter overland flow paths. This observation prompted the development of the computer model RIDEM (Rural Infrastructure Digital Elevation Model). By incorporating ancillary data to refine anthropogenically modified overland flow paths into the grid-based watershed delineation process, the scale of runoff flow paths created with RIDEM is reduced below the scale defined by the representation of terrain with the DEM. RIDEM also resolves the inability of grid-based flow-direction algorithms to account for the split-flow patterns that occur in irrigated landscapes. The model outputs include a corrected flow-direction matrix, gross watershed boundaries, and road-induced dead drainages. The watershed areas derived with RIDEM differed by up to 49% from watersheds derived using a conventional DEM with a 20 m grid cell size. However, results of watershed boundaries could not be verified, because highly accurate watershed boundaries do not exist for our study area. [ABSTRACT FROM AUTHOR]

The article focuses on divergent perspectives on the role of the treatment in the adult corrections system. If short-term reduction in recidivism is the outcome, then it certainly makes sense to consider targeting high-risk offenders for residential treatment. Policy makers and program directors want to know how program completion rates vary by risk level, given the costs of program failure, for individuals, families, communities, and program integrity. For many, overall program completion rates are one measure of a program's success with a difficult population. A similar, risk-driven strategy can also be used at the point of release from prison, but some obvious implementation problems must be considered. The most comprehensive reviews of research support the notion that treatment can change offender behavior. A short-term prison management strategy, such as recreation, should never replace the provision of treatment programs. Perhaps more important, research suggests that informal social controls are more effective than formal social controls, at both the individual and the community level. Ultimately, the choice of crime control policies should reflect the recognition of the inexorable link between individual and community change.

Books reviewed: Perry Schmidt–Leukel (ed.), Buddhist Perceptions of Jesus: Papers of the Third Conference of the European Network of Buddhist–Christian Studies (St Ottilien 1999) David Jobling, Tina Pippin, Ronald Schleifer (eds), The Postmodern Bible Reader Mark D. Chapman, Ernst Troeltsch and Liberal Theology: Religion and Cultural Synthesis in Wilhelmine Germany Stephen J. Hunt, Religion in Western Society James J. Buckley and David S. Yeago (eds), Knowing the Triune God: The Work of the Spirit in the Practices of the Church Miroslav Volf and Dorothy C. Bass (eds), Practicing Theology: Beliefs and Practices in Christian Life Dan R. Stiver, Theology After Ricoeur: New Directions in Hermeneutical Theology T. J. Gorringe, The Education of Desire: Towards a Theology of the Senses Anthony Harvey, By What Authority? George Guiver (ed.), Priests in a People‘s Church Sarah Coakley, Powers and Submissions: Spirituality, Philosophy and Gender Robert McKim, Religious Ambiguity and Religious Diversity Kenneth Leech, Through our Long Exile: Contextual Theology and the Urban Experience David N. Power, ‘The Word of the Lord’: Liturgy’s Use of Scripture Owen Hardwicke, Living Beyond Conformity: An Experience of Ministry and Priesthood. [ABSTRACT FROM AUTHOR]

BSTRACT: In southern Alberta, as elsewhere, pressures on limited water supplies are increasing. Not surprisingly, a great deal of attention has been focused on irrigated agriculture, which accounts for the largest share of water consumed in the region. In order to meet broadly accepted water conservation goals, some commentators have suggested that irrigation water use should be metered and that irrigators should be charged based on the amount of water used. An alternative proposal would have water management authorities rely upon the perceived adaptability of irrigators. This paper offers a perspective on the willingness of irrigators to conserve water. Based on a survey of 183 irrigation farmers conducted over the summer and early fall of 1998, we found that irrigators are generally aware of the need to conserve water and soil moisture, and that a variety of water conserving strategies were being employed. Water saving technologies specific to irrigation agriculture were less widely adopted. The findings suggest that there is considerable potential to reduce the amount of water consumed by the irrigation sector through increased efficiency, but that change will be limited if current economic circumstances and institutional arrangements persist. [ABSTRACT FROM AUTHOR]