Texture controls on the size distribution and properties of nano- and small microaggreates in soil

Soil microaggregates (SMA) with a size of <250 µm are one of the key factors influencing soil properties of ecological and structural relevance. In order to better understand their role in soil ecosystems, a quantitative understanding about the building units (BU) is necessary. The BU (divided into small SMA (<20 µm) and nanoparticles (NP, <220 nm)) where analyzed to quantify their size distribution and chemical composition. This approach will help to evaluate the properties of BU required for SMA formation.Soils with different clay contents of a Luvisol site (Scheyern, Germany) were fractionated into SMA and NP by wet sieving and pressure filtration. The differentiation between free and occluded BU was carried out by mechanical disaggregation using ultrasonic treatment. The size distribution of small SMA was analyzed with a XPT particle analyzer, while the abundance and chemical composition of NP were analyzed by field flow fractionation (AF4) coupled to a UV detector and ICP-MS.According to the mass distribution of the macroaggregate (8 mm-250 µm), large and small SMA fractions, the soils could be grouped into low (15, 18 and 19%) and high (28 and 30%) clay content. The proportion of occluded small and large SMA was increased with clay content. Interestingly the free small SMA proportion was constant and independent from clay content. Also the particle size distribution (PSD) of free small SMA did not correlate with clay content. The similar PSD of free and occluded small SMA was interpreted as a pool of potential BU for the formation of new aggregates. The NP showed three different size fractions. The evaluation of the elements Al, Si and Fe in these size fractions revealed different mass ratios and gave an insight into the composition of free and occluded NP

Bodenmüdigkeit und Stickstoffdynamik im Wurzelraum von Apfel im Erwerbsanbau

Die Nachbaukrankheit im Apfelanbau (Apple Replant Disease, ARD) besitzt eine hohe ökologische und ökonomische Relevanz, da der Nachbau oft über einen Zeitraum von 30 Jahren betroffen ist. Aus diesem Grund wird im Rahmen des BonaRes-Programms der Ordiamur-Verbund zu diesem Thema gefördert. Die Betrachtung von Nährstoffkreisläufen im Boden, insbesondere der Prozesse in der Rhizosphäre, ist zum Verständnis und zur Überwindung dieser Krankheit unabdingbar. Wir betrachten hier den N-Kreislauf in einem Topfexperiment mit 15N-Düngerapplikation, sowie auf der Pflanze-Bodenskala in einer Obstplantage (Meckenheim, Deutschland). Das 15N-Düngeexperiment wurde für ARD-Böden, jungfräuliche und behandelte Böden durchgeführt. Es gibt erste Hinweise darauf, dass Stickstoff im Gesamtbodenmaterial von ARD-Böden angereichert und immobilisiert wird. In der mikroskaligen Betrachtung (Gradienten von der Wurzel in den Boden) konnten wir erste Effekte von ARD-Behandlung auf den C- und N-Kreislauf durch Veränderung der Stabilisotopenverhältnisse beobachten. In Zukunft wird der Grad der ARD und der veränderten C- und N-Kreisläufe mit räumlichen Bodeneigenschaftenkarten korreliert. Hinweis der Autoren: Die Zuordnung zu einem Thema ist variabel- ggf. passt auch Kommission IV; K IV u. K I. Zu begrüßen wäre die Einordnung gemeinsam mit anderen ORDIAMUR-Projektpartnern (AG Vetterlein, AG Guggenberger

BMW – Mastering the Crises with “New Efficiency?”

Purpose Make a contribution on company business models and typical reactions to economic crises. Design/methodology/approach Media-analysis-based case study. Findings Crisis is handled through drawing on a strategy deriving from the typical features of the company; through the crisis these features are even intensified. Research limitations/implications Multinational companies are complex and only transparent to a small degree; the empirical data therefore rests on a database with articles. Social implications Social implications can be seen at the BMW as a functioning example for social partnership as a form of economic embeddedness at the societal level

Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al

Economic crisis and youth unemployment: Comparing Greece and Ireland

Both Greece and Ireland have long suffered high youth unemployment rates and have been pressured to restructure their employment and social systems under the European Employment Strategy. Problems were aggravated by the harsh conditions imposed by the Troika following bail-outs. Yet there was significant divergence in youth employment outcomes between Greece and Ireland despite a convergence of policies. In Ireland, tighter conditionality of benefits and stronger ‘activation’ were already on the agenda of the social actors, so their implementation was not forcefully contested. In Greece, the lack of effective social protection made it difficult for successive governments to build support for flexibilization, and the escalating insecurity of young Greeks and their families gave rise to social unrest and political instability. This contrast leads to a reappraisal of the convergence–divergence debat

Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales