Interactions between macrofaunal epiphytes and their host algae

Open Multiagent Systems, in which heterogeneous agents interact with each other and organize themselves into Virtual Organizations, demand infrastructures supporting these features. In these systems, dynamic and complex interactions between agents may arise. Interaction Protocols allow the definition of communication patterns. However in open systems, dynamic and complex interactions may also require these patterns be modified at execution time. We propose a support for modelling complex, concurrent and dynamic interactions between agents in terms of conversations. Conversations between agents follow predefined Interaction Protocols that can be dynamically modified without restarting the system. This support is provided at agent level and is integrated into the Magentix Multiagent Platform.

Indirect Mutualism: Variations on a Theme by Stephen Levine

Building upon the rich legacies of bioacoustics and animal communication, soundscape ecology represents a new perspective through which ecologists can use the acoustic properties of ecosystems to understand the complex interactions of organisms, geophysical dynamics, and human activities. In this paper, we focus on the potential benefits of a soundscape approach for enhancing ornithological research and of ornithological perspectives for advancing the nascent field of soundscape ecology. We first summarize 4 major grounding principles of soundscape ecology in relation to avian ecology, evolution, and behavior. We then propose 3 research objectives that we envision as future directions for soundscape ecology: development of (1) soundscape metrics and interpretation, (2) understanding of soundscape drivers, and (3) soundscape-based disturbance indicators. Ornithological contributions can help advance the field of soundscape ecology to obtain these research objectives across various spatial, tempora...

Taxonomy, molecular phylogeny, and ultrastructural morphology of Olpidiopsis porphyrae sp. nov. ( Oomycetes, straminipiles), a unicellular obligate endoparasite of Bangia and Porphyra spp. ( Bangiales, Rhodophyta)

Resilience to fire and climate seasonality drive the temporal dynamics of ant-plant interactions in a fire-prone ecosystem

G protein-gated inwardly rectifying potassium (GIRK) channels control neuronal excitability in the brain and are implicated in several different neurological diseases. The anionic phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) is an essential cofactor for GIRK channel gating, but the precise mechanism by which PIP2 opens GIRK channels remains poorly understood. Previous structural studies have revealed several highly conserved, positively charged residues in the "tether helix" (C-linker) that interact with the negatively charged PIP2 However, these crystal structures of neuronal GIRK channels in complex with PIP2 provide only snapshots of PIP2's interaction with the channel and thus lack details about the gating transitions triggered by PIP2 binding. Here, our functional studies reveal that one of these conserved basic residues in GIRK2, Lys200 (6'K), supports a complex and dynamic interaction with PIP2 When Lys200 is mutated to an uncharged amino acid, it activates the channel by enhancing the interaction with PIP2 Atomistic molecular dynamic simulations of neuronal GIRK2 with the same 6' substitution reveal an open GIRK2 channel with PIP2 molecules adopting novel positions. This dynamic interaction with PIP2 may explain the intrinsic low open probability of GIRK channels and the mechanism underlying activation by G protein Gβγ subunits and ethanol.

This article draws attention to language choice and language use of Austrian bi- and multilingual school children. We explore some implications of their linguistic practices with regard to social inclusion in an Austrian educational school setting. Pursuing a Dynamic Systems and Complexity Theory approach, we hypothesise that before language users actually use a language within a certain context, they have to evaluate the respective communicative situation by taking multiple contextual factors into consideration, meaning language users choose to use, or not to use, a language based on the socio-contextual information at hand. We consider these contextual factors to be most relevant as they provide the basis on which speakers can actually make use of a certain language within a given context. By drawing on examples of empirical data obtained through a language background survey, we examine some of the complex and dynamic interactions of contextual parameters influencing language choice and language use in the formal educational setting of classroom instruction. Based on the results of this study, we display a selection of the dynamic and complex interactions of pupils’ language use in one specific context as well as their language preferences and how these relate to social inclusion.

Is feedback control effective for ecosystem-based fisheries management?

Over past decade, there has been a tremendous increase in the number of pulmonary clinics dedicated to diagnosing and treating primary sleep disorders. An important contributing factor to this phenomenal expansion of the field of sleep medicine is the recognition of the need to better understand the effects of sleep on respiratory control, since it is during sleep that potentially harmful apneas or hypopneas occur in apparently normal individuals. Previous studies have shown that sleep onset leads to a reduction in metabolic rate and the baseline level of ventilation, and an elevation of circulatory delay and average Paco2 [1],[2]. These changes work together with the accompanying depression of upper airway muscle tone and chemoresponsiveness to alter the operating set-point of the respiratory control system. In the light stages of sleep, the decrease in damping may be large enough to offset the reduction in controller gain leading to a system that is more susceptible to oscillation[3],[4],[5]. Under conditions of high loop gain, spontaneous oscillations in ventilation can develop as a result of feedback instability [6]. Alternatively, because of decreased damping, continual random excitation from a variety of sources, including influences from other physiological control systems, can also produce significant periodic and nonperiodic variability in breathing 7. A number of studies have reported a close association between ventilatory oscillations and fluctuations in sleep states[8],[9],[10]. These observations suggest a third possibility: that respiratory variability during sleep may be due to primary fluctuations in state[11]. It is likely, however, that more than one of the above three mechanisms are at play in any given instance of sleep-disordered breathing (SDB). Moreover, it is probably reasonable to expect that there will be considerable interplay among the multiple factors and that these relationships will likely be complex and dynamic. Physical intuition and conventional physiological methodology are not the best tools for unraveling the mechanisms underlying such complex interactions. Under these circumstances, the rigorous framework provided by a quantitative dynamic model becomes not only useful but, as one could argue, necessary. The theoretical study of Khoo et al.[12] represented a starting point for this kind of model-based approach. However, a number of assumptions were made that did not have firm empirical bases. In this chapter, we consider potential extensions of the model, incorporating data that have been obtained in recent experimental studies. While the specific goal of this study is to enhance our current understanding of the control of breathing during sleep, an equally important objective is to highlight the utility of modeling as a means for hypothesis testing as well as a tool for extracting relevant information from highly variable and dynamic data.

A multi-material ALE model for investigating impact dynamics of pile-soil systems

Bone is now regarded to be a key regulator of a number of metabolic processes, in addition to the regulation of mineral metabolism. However, our understanding of complex bone metabolic interactions at a systems level remains rudimentary. in vitro molecular biology and bioinformatics approaches have frequently been used to understand the mechanistic changes underlying disease at the cell level, however, these approaches lack the capability to interrogate dynamic multi-bone metabolic interactions in vivo. Here we present a novel and integrative approach to understand complex bone metabolic interactions in vivo using total-body positron emission tomography (PET) network analysis of murine 18F-FDG scans, as a biomarker of glucose metabolism in bones. In this report we show that different bones within the skeleton have a unique glucose metabolism and form a complex metabolic network, which could not be identified using single tissue simplistic PET standard uptake values analysis. The application of our approach could reveal new physiological and pathological tissue interactions beyond skeletal metabolism, due to PET radiotracers diversity and the advent of clinical total-body PET systems.

This paper innovatively extends existing practice-theoretical mobility research by examining biographical aspects of people’s everyday mobility that capture and reflect their social relations. Drawing on nine qualitative interviews with couples who live in/near Vienna without a private car, the paper demonstrates the promising potential of retrospective forms of social research for uncovering the dynamics of mobility practices across the life course. It conceptualises individuals as inherently social and mutually interconnected mobility practitioners whose complex and dynamic interactions with others make up more or less mobile households and families. The paper thus treats social relations as a major connector between the constitutive social and material elements of (mobility) practices, making an explicitly relational contribution to current practice-theoretical debates in mobility research.

How do laypeople perceive uncertainties about environmental health risks? How do risk-related cognitions and emotions influence these uncertainties, and what roles do sociodemographic and contextual factors, risk judgments, and information exposures play? This study explores these questions using secondary analyses of survey data. Results suggest that uncertainty reflects individual-level emotions and cognitions, but may also be shaped by a variety of social and contextual factors. Emotions (worry and anger) are strongly associated with perceived uncertainty, and perceived lack of knowledge and perceived likelihood of becoming ill are weakly associated with it. Several demographic variables, information exposures, and risk judgment variables affect perceived uncertainty indirectly, primarily through perceived knowledge and emotions. These findings raise a variety of questions about the complex and dynamic interactions among risk contexts, socioeconomic factors, communication processes, perceived knowledge, emotions, and perceived uncertainties about risks.

Recent research has drawn upon the social determinants of health (SDH) framework to attempt to systematize the relationship between social enterprise and health. In this article, we adopt a realist evaluation approach to conceptualize social enterprises, and work integration social enterprises in particular, as 'complex interventions' that necessarily produce differential health outcomes for their beneficiaries, communities and staff. Drawing upon the findings from four social enterprises involving a range of methods including 93 semi-structured interviews with employees, managers and enterprise partners, together with participant observation, we demonstrate that these health outcomes are influenced by a limitless mix of complex and dynamic interactions between systems, settings, spaces, relationships and organizational and personal factors that cannot be distilled by questions of causality and attribution found in controlled trial designs. Given the increased policy focus on the potential of social enterprises to affect the SDH, this article seeks to respond to evidence gaps about the mechanisms and contexts through which social enterprises promote or constrain health outcomes, and thereby provide greater clarity about how research evidence can be used to support the social enterprise sector and policy development more broadly.

Claudette M. Williams has undertaken a most needed critical work on the politics of color in Spanish Caribbean literature. The preface delineates the strategy: "to explore the complex and dynamic interaction between ideological contexts, on the one hand, and cultural projects, on the other" (x). The literature of Cuba (the most prevalent), Puerto Rico, and, to a lesser extent, the Dominican Republic, provide the examples. Most come from the lyrical tradition and a few from the narrative. The time period comprises the beginning of the nineteenth century to the 1970s. Her analysis incorporates canonical authors (e.g., Nicolás Guillén, [End Page 200] Luis Palés, Nancy Morejón, and Rosario Ferré) alongside lesser-known figures. This juxtaposition provides a more complex vision of the intricacies that race contributes to Caribbean societies.