Living with constraints - food quality effects on zooplankton

Copepods and daphniids exhibit different grazing patterns, which affect the seston size distribution. I have studied whether the grazing of one guild could be beneficial for the other guild. Daphniids grew faster on seston previous manipulated by copepods than on seston which was not manipulated. Seston manipulated by daphniids was a poor food source for Daphnia and thus, growth declined. When marine copepods were feeding on plankton previously manipulated by copepods their growth potential (RNA:DNA) decreased with increasing copepod densities. In the laboratory I studied the effect of fatty acids and phosphorus (P) on Daphnia magna life-history and stoichiometry. D. magna had low EPA saturation threshold for growth (0.04 µg EPA L-1) and high storage capacity. However for P, daphniids had high requirements but only small storage capacity. P storage could not be utilised, whereas EPA storage could compensate periods of poor food quality.Introduction 3 1 Resources and growth – general limitations 3 2 Food quality 4 3 The study organisms 9 4 Hypotheses 12 5 Thesis outline 13 Chapters I Differential impacts of copepods and cladocerans on lake seston, 17 and resulting effects on zooplankton growth II Impacts of copepods on marine seston, and resulting effects on 35 Calanus finmarchicus RNA:DNA ratios III Resource quality effects on life histories of Daphnia 54 IV Differential impacts of phosphorus and fatty acids on Daphnia 69 growth and reproduction V Discussion 91 Summary 98 Zusammenfassung 101 References 104 Acknowledgement 111 Curriculum vitae 112 Erklärung 11

Living Shorelines & Resilience in Southern California: A Summary of a Series of Workshops held as part of The Resilient Coastlines Project of Greater San Diego

In 2016, a series of workshops were held to discuss living shorelines in SouthernCalifornia. The workshops specifically focused on the unique benefits, challenges andopportunities for implementing living shorelines in the region, and the nexus betweennature-based solutions and ongoing local adaptation planning. Approximately 140participants partook in these dialogues, and some of the key themes that emergedinclude: Letting nature do the work for you Designing for the future Integrating nature into shoreline management projects Project goals distinguishing living shorelines Engineering and urban living shorelines Space constraints along urban coastlines Permitting pathways to support demonstration projects Living shorelines and phased sea level rise planning Designing with watersheds and sediment management in mind Exploring emerging commercial opportunities Public access and project success Planning for living shorelines alongside the community Sharing monitoring and best practices to ensure future success Citizen science and socio-ecological monitoringThe workshops provided the first ever opportunity for Southern California stakeholdersto outline what is unique about designing living shorelines in the context of SouthernCalifornia shorelines for state and federal entities

Computing Substrates and Life

Alive matter distinguishes itself from inanimate matter by actively maintaining a high degree of inhomogenous organisation. Information processing is quintessential to this capability. The present paper inquires into the degree to which the information processing aspect of living systems can be abstracted from the physical medium of its implementation. Information processing serving to sustain the complex organisation of a living system faces both the harsh reality of real-time requirements and severe constraints on energy and material that can be expended on the task. This issue is of interest for the potential scope of Artificial Life and its interaction with Synthetic Biology. It is pertinent also for information technology. With regard to the latter aspect, the use of a living cell in a robot control architecture is considered

Additional restrictions on quasi-exactly solvable systems

In this paper we discuss constraints on two-dimensional quantum-mechanical systems living in domains with boundaries. The constrains result from the requirement of hermicity of corresponding Hamiltonians. We construct new two-dimensional families of formally exactly solvable systems and applying such constraints show that in real the systems are quasi-exactly solvable at best. Nevertheless in the context of pseudo-Hermitian Hamiltonians some of the constructed families are exactly solvable.Comment: 11 pages, 3 figures, extended version of talk given at the International Workshop on Classical and Quantum Integrable Systems "CQIS-06", Protvino, Russia, January 23-26, 200

Monitoring and detection of agitation in dementia: towards real-time and big-data solutions

The changing demographic profile of the population has potentially challenging social, geopolitical, and financial consequences for individuals, families, the wider society, and governments globally. The demographic change will result in a rapidly growing elderly population with healthcare implications which importantly include Alzheimer type conditions (a leading cause of dementia). Dementia requires long term care to manage the negative behavioral symptoms which are primarily exhibited in terms of agitation and aggression as the condition develops. This paper considers the nature of dementia along with the issues and challenges implicit in its management. The Behavioral and Psychological Symptoms of Dementia (BPSD) are introduced with factors (precursors) to the onset of agitation and aggression. Independent living is considered, health monitoring and implementation in context-aware decision-support systems is discussed with consideration of data analytics. Implicit in health monitoring are technical and ethical constraints, we briefly consider these constraints with the ability to generalize to a range of medical conditions. We postulate that health monitoring offers exciting potential opportunities however the challenges lie in the effective realization of independent assisted living while meeting the ethical challenges, achieving this remains an open research question remains.Peer ReviewedPostprint (author's final draft

Superspace Formulation of 4D Higher Spin Gauge Theory

Interacting AdS_4 higher spin gauge theories with N \geq 1 supersymmetry so far have been formulated as constrained systems of differential forms living in a twistor extension of 4D spacetime. Here we formulate the minimal N=1 theory in superspace, leaving the internal twistor space intact. Remarkably, the superspace constraints have the same form as those defining the theory in ordinary spacetime. This construction generalizes straightforwardly to higher spin gauge theories N>1 supersymmetry.Comment: 24 p

Hsp-90 and the biology of nematodes

BACKGROUND: Hsp-90 from the free-living nematode Caenorhabditis elegans is unique in that it fails to bind to the specific Hsp-90 inhibitor, geldanamycin (GA). Here we surveyed 24 different free-living or parasitic nematodes with the aim of determining whether C. elegans Hsp-90 was the exception or the norm amongst the nematodes. We combined these data with codon evolution models in an attempt to identify whether hsp-90 from GA-binding and non-binding species has evolved under different evolutionary constraints.<BR/>RESULTS: We show that GA-binding is associated with life history: free-living nematodes and those parasitic species with free-living larval stages failed to bind GA. In contrast, obligate parasites and those worms in which the free-living stage in the environment is enclosed within a resistant egg, possess a GA-binding Hsp-90. We analysed Hsp-90 sequences from fifteen nematode species to determine whether nematode hsp-90s have undergone adaptive evolution that influences GA-binding. Our data provide evidence of rapid diversifying selection in the evolution of the hsp-90 gene along three separate lineages, and identified a number of residues showing significant evidence of adaptive evolution. However, we were unable to prove that the selection observed is correlated with the ability to bind geldanamycin or not.<BR/>CONCLUSION: Hsp-90 is a multi-functional protein and the rapid evolution of the hsp-90 gene presumably correlates with other key cellular functions. Factors other than primary amino acid sequence may influence the ability of Hsp-90 to bind to geldanamycin

Loop quantization of the Schwarzschild black hole

We quantize spherically symmetric vacuum gravity without gauge fixing the diffeomorphism constraint. Through a rescaling, we make the algebra of Hamiltonian constraints Abelian and therefore the constraint algebra is a true Lie algebra. This allows the completion of the Dirac quantization procedure using loop quantum gravity techniques. We can construct explicitly the exact solutions of the physical Hilbert space annihilated by all constraints. New observables living in the bulk appear at the quantum level (analogous to spin in quantum mechanics) that are not present at the classical level and are associated with the discrete nature of the spin network states of loop quantum gravity. The resulting quantum space-times resolve the singularity present in the classical theory inside black holes.Comment: 4 pages, Revtex, version to appear in Physical Review Letter