Mobility and removal of nitrate in heterogeneous Eocene aquifers

n a study of the principles of lateral and vertical nitrate mobility and removal in unconfined heterogeneous fine sandy Eocene aquifers by long-term observation, no significant nitrate reduction could be observed over short distances (90 m) in the lateral flow direction. Decreasing oxygen contents and limited flow velocity in a downward direction (caused by clay lenses and layers) resulted in a more efficient but incomplete nitrate removal with increasing depth. Chemo-organotrophic and chemo-lithotrophic denitrification coexist in the aquifers. Recharge input of organic matter and the reactivity of sedimentary organic sources, as well as the amounts of pyrite and Fe2+-bearing minerals, control which microbiologically catalysed process finally occurs. Sharp boundaries between different redox zones do not exist due to locally changing availability of organic and inorganic electron donors used for nitrate reduction. Furthermore, preferential flow paths result in a wide spread occurrence of low concentrations of nitrate below the main denitrification zone

Service Offshoring and Firm Employment

Major technological advances have recently spurred a new wave of offshoring in services, which used to be non-tradable. Should service workers in developed countries worry about their jobs? Trade theory has given a nuanced answer to this question, suggesting that efficiency gains from offshoring may counteract direct job losses, which leaves the predicted net effect ambiguous. This paper investigates the employment effects of service offshoring in a newly combined and exceptionally detailed panel dataset, covering almost the entire universe of German firms’ service imports over the years 2002-2013. It exploits firm-specific export supply shocks by partner countries and service types as an instrumental variable to find that service offshoring has increased firm employment. In line with the canonical trade in tasks model, the employment gains are greater in firms with higher initial levels of service offshoring

Herding History: Law and the Transformation of Collective Subjectivities in the Dairyspheres of Ukraine

In response to the limitations of socialism and capitalism in meeting basic needs, this article explores the alternative version of modernity offered in post-Soviet Ukraine and its agriculture. Tracing a century of fundamental transformations through the story of milk, it finds a history that troubles universalized framings of indigeneity and colonialism. This article argues that under socialism milk became a product of collectivized effort and a reservoir of household resilience; and then, with post-Soviet disintegration of some forms of collective life and emergence of others, that milk has come to delineate spheres of both collective action and individual striving. This research finds in Ukrainian farming communities a tale of two privatizations, one concentrating wealth and the other, distributing it in more equalizing ways. In the dispersed structure that results, much Ukrainian milk production avoids some of the more environmentally harmful forms for which the contemporary milk economy is famous elsewhere. This study reveals the pragmatic play of gender dynamics within legal disputes and social transformation. Though now enmeshed in global economic networks and policy agendas, milk has remained the ground of specific social networks; this article shows the resilience of intimate relationships between dairy cows and their keepers and the political strength, untapped nationally but salient locally, of dairy maids

Patterns of Product Development Interactions

Development of complex products and large systems is a highly interactive social process involving hundreds of people designing thousands of interrelated components and making millions of coupled decisions. Nevertheless, in the research summarized by this paper, we have created methods to study the development process, identify its underlying structures, and critique its operation. In this article, we introduce three views of product development complexity: a process view, a product view, and an organization view. We are able to learn about the complex social phenomenon of product development by studying the patterns of interaction across the decomposed elements within each view. We also compare the alignment of the interaction patterns between the product, process, and organization domains. We then propose metrics of product development complexity by studying and comparing these interaction patterns. Finally, we develop hypotheses regarding the patterns of product development interactions, which will be helpful to guide future research.Singapore-MIT Alliance (SMA