Benthic Oxygen Consumption and Organic Matter Turnover in Organic-poor, Permeable Shelf Sands

The high permeability of sediments and strong near-bottom currents cause seawater to infiltrate the surface layers of Middle Atlantic Bight shelf deposits. In this study, sandy sediment cores from 11 to 12 m water depth were percolated with filtered seawater on shipboard. Sedimentary oxygen consumption (SOC) increased non-linearly with pore water flow, approaching maximum rates of 120 mmol m⁻² d⁻¹ (May 2001) or 75 mmol m⁻² d⁻¹(July 2001). The addition of acetate to the inflowing water promptly enhanced the release of dissolved inorganic carbon (DIC) from the cores. DIC production rates were a linear function of acetate concentration, ranging from 100 to 300 mmol m⁻² d⁻¹ without substrate addition to 572 mmol m⁻² d⁻¹ with 100 mM acetate. The sediments also hydrolyzed a glucose pseudopolymer, and the liberated glucose prompted an increase of SOC. Our results suggest that decomposition rates of organic matter in permeable sands can exceed those of fine-grained, organic-rich deposits, when water currents cause advective interstitial flow, supplying the subsurface microbial community with degradable material and electron acceptors. We conclude that the highly permeable sand beds of the Middle Atlantic Bight are responsive within minutes to hours and efficiently operate as biocatalytical filters.     

Complex kame belt morphology,stratigraphy and architecture

The development of glacier karst at the margins of melting ice sheets produces complex glaciofluvial sediment-landform assemblages that provide information on ice sheet downwasting processes. We present the first combined geomorphological, sedimentological and geophysical investigation of the Brampton Kame Belt, an important glaciofluvial depositional zone at the centre of the last British-Irish Ice Sheet. Ground-penetrating radar (GPR) data allow the broad scale internal architecture of ridges (eskers) and flat-topped hills (ice-walled lake plains) to be determined at four sites. In combination with sediment exposures, these provide information on lateral and vertical variations in accretion styles, depositional boundaries, and grain size changes. Building on existing work on the subject, we propose a refined model for the formation of ice-walled lake plains resulting from the evolution and collapse of major drainage axes into lakes as stable glacier karst develops during deglaciation. The internal structure of esker ridges demonstrates variations in sedimentation that can be linked to differences in ridge morphologies across the kame belt. This includes low energy flow conditions and multiple accretion phases identified within large S-N oriented esker ridges; and fluctuating water pressures, hyperconcentrated flows, and significant deformation within a fragmented SW–NE oriented esker ridge. In combination with updated geomorphological mapping, this work allows us to identify two main styles of drainage within the kame belt: (1) major drainage axes aligned broadly S-N that extend through the entire kame belt and collapsed into a chain of ice-walled lakes; and (2) a series of smaller, fragmented SW–NE aligned esker ridges that represent ice-marginal drainage as the ice sheet receded south-eastwards up the Vale of Eden. Our study demonstrates the importance of integrated geomorphological, sedimentological and geophysical investigations in order to understand complex and polyphase glaciofluvial sediment-landform assemblages. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.     

The effect of salinity on the development ofLoxothylacus panopaei larvae (Crustacea: Cirripedia: Rhizocephala)

The rhizocephalan barnacleLoxothylacus panopaei, which parasitizes the mud crabRhithropanopeus harrisii, releases its larvae as nauplii. The nauplii develop through four stages to the cypris stage; both larval forms are lecithotrophs. Parasitized crabs were acclimated in 10‰, 15‰, and 20‰ water during August and the development of releasedL. panopaei larvae was monitored in a range of salinities. After 48–60 h, the nauplii and cyprids in each experimental salinity were counted and the numbers used to calculate a developmental index. The range of salinities in which successful development to cyprids occurred (developmental index >70%) could be shifted as a consequence of the acclimating salinity.L. panopaei larvae can develop successfully over a 10–30‰ salinity range, indicating that settlement onto host crabs and virgin externae is likely to take place in nature within this range.     

SPATIAL DISTRIBUTION OF PRIMARY INDIVIDUALS

Primary individuals and the households that they head now compose a significant proportion of US households. This paper examines the regional and intraurban distribution of primary households. Macro-scale data from the 1960 and 1970 Censuses are used to examine the evolving regional patterns of primary individuals and households. Using intraurban data for the 1970's, the paper also examines the impact of recent rapid growth in the number of primary individuals on the spatial distribution of primary households within urban areas. Inferences are drawn with respect to the macro- and micro-scale distributions of primary individuals and households and the impact of continued growth of this subpopulation on urban form and population distribution.     

Risky bodies: Public health, social marketing and the governance of obesity

The inclusion of obesity within public health rests on a proven and accepted biomedical link between body weight and health status. Drawing on the 2005 controversy over annual death rates attributable to obesity in the US, this paper contends that uncertainty as to the causal mechanisms linking body weight and health are undermining the development of effective obesity prevention policies. Consequently, this also weakens the justification of the inclusion of such policies within public health. This work draws on recent interest in ‘critical geographies of public health’ and the continued attention to the recursive relations between people and places in the context of health which may offer a useful theoretical viewpoint from which unpack such aetiological uncertainty. Without an agreed or universal risk from obesity, the paper argues that public health obesity prevention through social marketing should be geographical in outlook. The three examples of 5 a day, Jamie’s School Dinners and Sesame Street’s Cookie Monster are discussed to illustrate the effectiveness of communicating risk in a manner that allows intention to be effectively translated into risk-minimising behaviour within the dictates of locale.     

Identifying farmer attitudes towards genetically modified (GM) crops in Scotland: Are they pro- or anti-GM?

The GM debate in the European Union has been consistently presented as being conflictual and contentious, characterised as being polarised into those who are pro-GM and those who are anti-GM. This is largely based on the positions adopted by the public (consumers), non-governmental organisations (NGOs), and industry and corporate bodies. One group largely lacking from this debate is farmers, and yet their decisions about whether or not to cultivate GM crops will be crucial to the future of the technology in European agriculture. This paper reports findings from a study investigating farmers’ attitudes to GM crops in Scotland using Q methodology. Results reveal three discourses, one inclined to be positive towards the idea of GM and demonstrating an expectation of benefits, the second representing a more uncertain position, wary of the potential risks of the technology but likely to be reluctant adopters, and the third describing a group who demonstrate a somewhat fatalistic attitude towards the issue of GM technology adoption and impact. These findings contribute to the GM debate by elaborating the views of this important stakeholder group and suggest that they may be less profoundly pro- or anti-GM than other groups involved in the debate. This is significant if they represent the ‘middle ground’ between the biotechnology industry and the public.     

Inter‐annual variation in the topographic controls on catchment‐scale snow distribution in a maritime alpine catchment,New Zealand

Seasonal snow is a globally important water resource that contributes substantially to upland and lowland water resources. As such, there is a need to understand the controls on the spatial and temporal variation in snow distribution. This study meets this research need by investigating the topographic controls on snow depth distribution in the upper Jollie catchment in the Southern Alps of New Zealand. Furthermore, inter‐annual variation in the importance of the topographic controls is examined and linked to variation in the dominant synoptic‐scale weather patterns over a 4‐year period (2007–2010). Through the use of regression trees, the relative importance of the topographic controls on snow depth was shown to vary between the four study years. In particular, elevation explained the greatest amount of variance in 2007 and 2008 and east‐exposure explained the greatest variance in 2009 and 2010. The other wind exposure variables also had a large effect on the snow depth distribution in 2009 and 2010. Differences in the frequency and duration of synoptic weather patterns were physically consistent with the changing importance of these variables. In particular, a higher frequency of troughing events in 2009 and 2010 is thought to be associated with a reduced importance of elevation and greater influence of wind exposure on snow depth in these years. These findings demonstrate the importance of using multi‐year data sets, and of considering topographic and climatic influences, when attempting to model alpine snow distribution. Copyright © 2014 John Wiley & Sons, Ltd.     

Rethinking responsibility and care for a postcolonial world

Both responsibility and care have much to offer in thinking through the relationalities that make up a postcolonial world. Although contemporary political systems often posit responsibility and care within the context of individuated and autonomous selves, geographers have done much to relocate responsibility and care within narratives of interdependency - spatially and temporally. They have argued that both terms offer a route for thinking about ethical geographical relations between myriad places. In this article we take this project further, by looking at how the nature and shape of these relationships might be construed in a postcolonial world. We suggest that, through a more critical engagement with postcolonial thinking, any exploration of existing practices of responsibility and care will not only reveal the enormous potential of imagining these geographies as forms of existing and evolving relationalities, but will also lead us to interrogate the deployments of these terms in the context of past and present inequalities. We show that routing care and responsibility through postcolonial geographies moves us towards a more pragmatic responsiveness, one that involves a ‘care-full’ recognition of postcolonial interaction.     

Women, science and identity: interviews with female physical geographers

Summary Interviews with female physical geographers show that although the significance of gender in influencing a woman's position and identity in physical geography is contested, gender still remains an important social relation that structures the personal relations, institutional practices and material outcomes of academic physical geography.