Coral resistance to natural and anthropogenic disturbances

The effects of natural (upwelling, tsunami) and human induced (eutrophication, overfishing, bomb fishing) disturbances to corals were investigated in highly diverse reefs of SE Asia. Firstly, coral recruitment patterns and their contribution to reef recovery and secondly, the corals metabolic flexibility in various environments were investigated. In addition, the bacterial community structure in biofilms was assessed in relation to environmental changes. In summary, the investigated coral reefs seem to be very dynamic visible in recruitment patterns and bacterial community structure being highly responsive to seasonal changes and being able to support reef recovery in most cases. The widely distributed coral species P. lutea and S. subseriata feature a highly flexible metabolism allowing their distribution even to environmental extremes. However, these corals belong to the minority as indicated by the loss of coral diversity in strongly polluted reefs, but it also shows a high interspecific variability, which provides high diversity reefs with a certain buffer capacity to environmental changes

Designed-in security for cyber-physical systems

An expert from academia, one from a cyber-physical system (CPS) provider, and one from an end asset owner and user offer their different perspectives on the meaning and challenges of 'designed-in security.' The academic highlights foundational issues and talks about emerging technology that can help us design and implement secure software in CPSs. The vendor's view includes components of the academic view but emphasizes the secure system development process and the standards that the system must satisfy. The user issues a call to action and offers ideas that will ensure progress

Amalgamation of real zero polynomials

With this article, we hope to launch the investigation of what we call the real zero amalgamation problem. Whenever a polynomial arises from another polynomial by substituting zero for some of its variables, we call the second polynomial an extension of the first one. The real zero amalgamation problem asks when two (multivariate real) polynomials have a common extension (called amalgam) that is a real zero polynomial. We show that the obvious necessary conditions are not sufficient. Our counterexample is derived in several steps from a counterexample to amalgamation of matroids by Poljak and Turz\'ik. On the positive side, we show that even a degree-preserving amalgamation is possible in three very special cases with three completely different techniques. Finally, we conjecture that amalgamation is always possible in the case of two shared variables. The analogue in matroid theory is true by another work of Poljak and Turz\'ik. This would imply a very weak form of the Generalized Lax Conjecture.Comment: 24 page

Effects of Eutrophication, Seasonality and Macrofouling on the Diversity of Bacterial Biofilms in Equatorial Coral Reefs

Biofilms play an important role as a settlement cue for invertebrate larvae and significantly contribute to the nutrient turnover in aquatic ecosystems. Nevertheless, little is known about how biofilm community structure generally responds to environmental changes. This study aimed to identify patterns of bacterial dynamics in coral reef biofilms in response to associated macrofouling community structure, microhabitat (exposed vs. sheltered), seasonality, and eutrophication. Settlement tiles were deployed at four reefs along a cross-shelf eutrophication gradient and were exchanged every 4 months over 20 months. The fouling community composition on the tiles was recorded and the bacterial community structure was assessed with the community fingerprinting technique Automated Ribosomal Intergenic Spacer Analysis (ARISA). Bacterial operational taxonomic unit (OTU) number was higher on exposed tiles, where the fouling community was homogenous and algae-dominated, than in sheltered habitats, which were occupied by a variety of filter feeders. Furthermore, OTU number was also highest in eutrophied near-shore reefs, while seasonal variations in community structure were most pronounced in the oligotrophic mid-shelf reef. In contrast, the macrofouling community structure did not change significantly with seasons. Changes in bacterial community patterns were mostly affected by microhabitat, seasonal and anthropogenically derived changes in nutrient availability, and to a lesser extent by changes in the macrofouling community structure. Path analysis revealed a complex interplay of various environmental and biological factors explaining the spatial and temporal variations in bacterial biofilm communities under natural conditions

Rhythmische Allianzen

Der Titel dieser Arbeit, Rhythmische Allianzen, verweist bereits auf die Ambivalenz des Verhältnisses, in dem die zwei Parameter des Films, Bild und Ton, zueinander stehen – einerseits haben sie alle Freiheiten, sich in verschiedene Richtungen zu bewegen und miteinander zu interagieren, andererseits bleiben sie immer aneinander gebunden, so weit sie sich auch voneinander entfernen mögen. Ziel meiner Arbeit ist es, am Beispiel ausgewählter Filme von Robert Nelson, Jean-Marie Straub/Danièle Huillet und Mauricio Kagel die Bedeutung des Verhältnisses von Bild und Ton für das Kino herauszustellen, die für das Verständnis seines künstlerischen Potenzials essenziell ist.The title of this thesis, Rhythmic Alliances, refers to the ambivalent relationship between sound and image—the two parameters of film. In modern cinema they are free to move in different directions and to interact in innumerous ways. At the same time they remain tied to each other. The term alliance contains the possibility of collaboration and therefore represents a positive definition of this interdependency. I analyze three different filmmakers and their particular experimental practices of connecting sounds and images. Robert Nelson (b. 1930)—American artist and filmmaker—re-evaluates the sound-image relationship ironically and loosens its boundaries. French filmmakers Jean-Marie Straub (b. 1933) and Danièle Huillet (1936-2006) oppose visual landscape and speech in their advanced sound films. Finally, Mauricio Kagel (1931-2008), a Cologne-based composer from Argentina, transfers the musical figure of counterpoint to the sound-image relationship

Calcification, photosynthesis and nutritional status of the hermatypic coral Porites lutea: contrasting case studies from Indonesia and Thailand

In situ incubation experiments, complemented by tissue analyses, were conducted with the coral Porites lutea at four sites featuring contrasting environmental conditions: two shallow (3m) reefs in Spermonde Archi-pelago (Indonesia) subjected to coastal pollution (Lae Lae, LL) and oligotrophic waters (Bonebatang, BBA), respectively; a deep (20m, KR-D) and a shallow (7m, KR-S) reef at off-shore Ko Racha (KR) in the Andaman Sea (Thailand) subjected to pulsed upwelling. Mean tem-perature varied only little (29-30°C). While most tis-sue parameters responded to light and nutrient changes as ex-pected, metabolic rates revealed surprising patterns: 3-fold elevated calcification occurred at KR-S compared to all other sites despite reduced gross photosynthesis. Fur-ther-more, equal photosynthesis occurred in 7 and 20m depth at KR, despite a 5-fold reduction in light intensity, which could not be solely ascribed to photo-acclimation processes, such as increased cell-specific chlorophyll a in 20m depth. These findings support the notion of a highly flexible species and indicate that this might partly be ascribed to a strong variation in the internal turnover of oxygen and nutrients between coral host and zooxanthellae, meaning a strong variation in the rates of energy ac-quisition. Those differences are particularly difficult to determine in situ, but require greater attention in the future in order to enhance our understanding of metabolic pro-cesses and acclimatization abilities

On the signal contribution function with respect to different norms

The signal contribution function (SCF) in multivariate curve resolution evaluates signal portions of specific components either in absolute or in relative form related to the integrated signal of all components. In 1999, Gemperline used the summed signal data, and in 2001, Tauler worked with the square-summed relative signal in order to determine the profiles that minimize, respectively maximize, the signal contribution. These profiles approximate the bands of all feasible profiles. Here, Gemperline's approach using the entrywise 1-matrix norm is proved to provide accurate bounds for two-component systems. This revives the approach of summed mass or absorption values with its potentially better chemical interpretability.Fil: Neymeyr, Klaus. Universität Rostock; Alemania. Leibniz-Institut für Katalyse; AlemaniaFil: Sawall, Mathias. Universität Rostock; AlemaniaFil: Olivieri, Alejandro Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; Argentin

On the avoidance of crossing of singular values in the evolving factor analysis

Evolving factor analysis (EFA) investigates the evolution of the singular values of matrices formed by a series of measured spectra, typically, resulting from the spectral observation of an ongoing chemical process. In the original EFA, the logarithms of the singular values are plotted for submatrices that include an increasing number of spectra. A typical observation in these plots is that pairs of trajectories of the singular values are on a collision course, but finally, the curves seem to repel each other and then run in different directions. For parameter-dependent square matrices, such a behaviour is known for the eigenvalues under the keyword of an avoidance of crossing. Here, we adjust the explanation of this avoidance of crossing to the curves of singular values of EFA. Further, a condition is studied that breaks this avoidance of crossing. We demonstrate that the understanding of this noncrossing allows us to design model data sets with a predictable crossing behaviour. © 2020 John Wiley & Sons, Ltd

Discrete Pulses of Cooler Deep Water Can Decelerate Coral Bleaching During Thermal Stress: Implications for Artificial Upwelling During Heat Stress Events

Global warming is considered to be the most severe threat to coral reefs globally, which makes it important for scientists to develop novel strategies that mitigate the impact of warming on corals and associated habitats. Artificial upwelling of cooler deep water to the surface layer may be a possible mitigation/management tool. In this study, we investigated the effect of simulated artificial upwelling with deep water off Bermuda collected at 50 m (24°C) and 100 m (20°C) on coral symbiont biology of 3 coral species (Montastrea cavernosa, Porites astreoides, and Pseudodiploria strigosa) in a temperature stress experiment. The following treatments were applied over a period of 3 weeks: (i) control at 28°C (ii) heat at 31°C, (iii) heat at 31°C+ deep water from 50 m depth, and (iv) heat at 31°C+ deep water from 100 m depth. Artificial upwelling was simulated over a period of 25 min on a daily basis resulting in a reduction of temperature for 2 h per day and the following degree-heating-weeks: 5.7°C-weeks for ii, 4.6°C-weeks for iii and 4.2°C-weeks for iv. Comparative analysis of photosynthetic rate, chlorophyll-a concentration and zooxanthellae density revealed a reduction of heat stress responses in artificial upwelling treatments in 2 of the 3 investigated species, and a stronger positive effect of 100-m water than 50-m water. These results indicate that artificial upwelling could be an effective strategy to mitigate coral bleaching during heat stress events allowing corals to adjust to increasing temperatures more gradually. It will still be necessary to further explore the ecological benefits as well as potential ecosystem impacts associated with different artificial upwelling scenarios to carefully implement an effective in situ artificial upwelling strategy in coral reefs