Tests for attraction to prey and predator avoidance by chemical cues in spiders of the beech forest floor

Spiders leave draglines, faeces and other secretions behind when traveling through their microhabitat. The presence of these secretions may unintentionally inform other animals, prey as well as predators, about a recent and possible current predation risk or food availability. For a wolf spider, other spiders including smaller conspecifics, form a substantial part of their prey, and larger wolf spiders, again including conspecifics, are potential predators. We tested two hypotheses: that large wolf spiders may locate patches of potential spider prey through the presence of silk threads and/or other secretions; and that prey spiders may use secretions from large wolf spiders to avoid patches with high predation risk. We used large (subadult or adult) Pardosa saltans to provide predator cues and mixed dwarf spiders or small (juvenile) P. saltans to provide prey cues. Subadult wolf spiders were significantly attracted to litter contaminated by dwarf spiders or small conspecifics after 6 hours but no longer after 24 hours. In contrast, neither dwarf spiders nor small P. saltans showed significant avoidance of substrate contaminated by adult P. saltans. However, small P. saltans showed different activity patterns on the two substrates. The results indicate that wolf spiders are able to increase the efficiency of foraging by searching preferentially in patches with the presence of intraguild prey. The lack of a clear patch selection response of the prey in spite of a modified activity pattern may possibly be associated with the vertical stratification of the beech litter habitat: the reduced volume of spaces in the deeper layers could make downward rather than horizontal movement a fast and safe tactic against a large predator that cannot enter these spaces

Cumulant expansions for atmospheric flows

The equations governing atmospheric flows are nonlinear. Consequently, the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifest itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can capture the growth of the convective boundary layer even if it does not capture important turbulent transport terms. Second, we study the evolution of two-dimensional large-scale waves representing waves in Earth's upper atmosphere. We demonstrate that a cumulant expansion truncated at second order (CE2) can capture the evolution of such waves and their nonlinear interaction with the mean flow in some circumstances, for example, when the wave amplitude is small enough or the planetary rotation rate is large enough. However, CE2 fails to capture the flow evolution when nonlinear eddy--eddy interactions in surf zones become important. Higher-order closures can capture these missing interactions. The results point to new ways in which the dynamics of turbulent boundary layers may be represented in climate models, and they illustrate different classes of nonlinear processes that can control wave dissipation and momentum fluxes in the troposphere.Comment: 43 pages, 10 figures, accepted for publication in the New Journal of Physic

Social innovation and sustainability; how to disentangle the buzzword and its application in the field of agriculture and rural development

Social innovation is often appointed as an essential part of agricultural and rural innovation. Everybody seems to agree that social innovation is important but what exactly is meant by the term remains often unclear. This paper aims at clarifying the meaning and significance of the concept by going back to its root in innovation science and policy. It appoints three main interpretations of social innovation, referring to the social mechanism of innovation, the social responsibility of innovation and the need for innovating society. Studying its application in the field of agriculture and rural development reveals that social innovation is rarely referred to when agriculture as a singular economic activity is concerned, but prominently present in discussions about rural development. Here social innovation may be referred to when identifying society’s need for more sustainable production methods, the necessity for collaboration and social learning, and the scope of change needed for revitalising (rural) society. Often, however, social innovation is presented as a tangle of interdependent processes and beneficial outcomes. Its fuzziness contributes to its discursive power in discussions about agricultural politics and the significance of sustainability, but also hides the valued-loadedness of social innovation. As a result its critical potential becomes neutralised. For gaining more insight in how to more effectively support social innovation, it is important to disentangle the social innovation jumble, to unravel the diverse interrelations and to explore and monitor its functioning and contribution to processes of social change and renewal

Functional connectivity profile of the human inferior frontal junction: involvement in a cognitive control network

Background: The human inferior frontal junction area (IFJ) is critically involved in three main component processes of cognitive control (working memory, task switching and inhibitory control). As it overlaps with several areas in established anatomical labeling schemes, it is considered to be underreported as a functionally distinct location in the neuroimaging literature. While recent studies explicitly focused on the IFJ´s anatomical organization and functional role as a single brain area, it is usually not explicitly denominated in studies on cognitive networks. However based on few analyses in small datasets constrained by specific a priori assumptions on its functional specialization, the IFJ has been postulated to be part of a cognitive control network. Goal of this meta-analysis was to establish the IFJ’s connectivity profile on a high formal level of evidence by aggregating published implicit knowledge about its co-activations. We applied meta-analytical connectivity modeling (MACM) based on the activation likelihood estimation (ALE) method without specific assumptions regarding functional specialization on 180 (reporting left IFJ activity) and 131 (right IFJ) published functional neuroimaging experiments derived from the BrainMap database. This method is based on coordinates in stereotaxic space, not on anatomical descriptors. Results: The IFJ is significantly co-activated with areas in the dorsolateral and ventrolateral prefrontal cortex, anterior insula, medial frontal gyrus / pre-SMA, posterior parietal cortex, occipitotemporal junction / cerebellum, thalamus and putamen as well as language and motor areas. Results are corroborated by an independent resting-state fMRI analysis. Conclusions: These results support the assumption that the IFJ is part of a previously described cognitive control network. They also highlight the involvement of subcortical structures in this system. A direct line is drawn from works on the functional significance of brain activity located at the IFJ and its anatomical definition to published results related to distributed cognitive brain systems. The IFJ is therefore introduced as a convenient starting point to investigate the cognitive control network in further studies

Young Muslims’ religious identities in relation to places beyond the UK:a qualitative map-making technique in Newcastle upon Tyne

Transnational relations can play an important role in young people’s identity negotiations and transitions to adulthood. In this article, we explore how young British-born Muslims construct and contest their religious identities and experience their changing religious identities from their lateteens until their early-twenties. We analyse how places beyond the UK shape their religious beliefs and identities in Newcastle upon Tyne in the North East of England, and present a methodological tool to understand young people’s complex and changing (religious) identities and spatialities. We draw on in-depth interviews–including map-making methods–with a small number of young Muslims living in Newcastle upon Tyne whose parents migrated from Pakistan or Bangladesh. This article contributes to youth geographies, by illustrating that when the participants begin to negotiate ‘being Muslim’ more independently, the spatial orientation of their religious identities starts to change as well. We show that the changing meaning and importance of the places beyond the UK should be understood in relation to other spatial notions when explaining religious identity negotiations of young people. Moreover, the paper provides a methodological contribution in demonstrating how map-making can help to examine young people’s identities and changing relationships to places in a transnational context

Analysis of cysteine-containing proteins using precolumn derivatization with N-(2-ferroceneethyl)maleimide and liquid chromatography/electrochemistry/mass spectrometry

N-(2-Ferroceneethyl)maleimide (FEM) is introduced as an electroactive derivatizing agent for thiol functionalities in proteins. Using appropriate reaction conditions, the derivatization is completed within five minutes and no unspecific labeling of free amino functions is observed. Liquid chromatography/electrochemistry/mass spectrometry was used to detect the reaction products. The reagent is a useful tool for determining the number of free thiol groups or the total number of free and disulfide-bound thiol groups in proteins. The electrochemical cell provides additional information, because the increase in mass spectrometric response upon electrochemical oxidation of the neutral ferrocene to the charged ferrocinium groups is monitored. The method was successfully applied to the analysis of native proteins and their tryptic digests

Kriterien zur Auswahl konnektionistischer Verfahren für betriebliche Probleme

In einem von der Deutschen Forschungsgemeinschaft geförderten Forschungsvorhaben werden die Anwendbarkeit und die Qualität konnektionistischer Lösungsansätze für betriebswirtschaftliche Problemstellungen untersucht. Neben der Konzeption und Realisierung spezifischer Anwendungen stellt die Bereitstellung von Hilfsmitteln, die eine Zuordnung konnektionistischer Verfahren zu betrieblichen Problemen und umgekehrt erlauben, einen Arbeitsschwerpunkt dar. Zu diesem Zweck wird ein Ansatz zur Abbildung betrieblicher Problemstellungen auf neuronale Netze auf Basis einer mehrstufigen Klassifikation erarbeitet und beschrieben. Die Klassifikationskriterien werden gebräuchlichen Kategorisierungen betrieblicher Problemstellungen und neuronaler Netze entnommen. Zusätzlich werden in einer projektbegleitenden Literaturrecherche bereits existierende Anwendungen neuronaler Netzwerke analysiert und die Ergebnisse der Analyse zur Evaluierung der gewählten Kategorisierung herangezogen.<br/