Biogeography and potential factors regulating shallow subtidal reef communities in the western Indian Ocean

Includes bibliographical references (p. 209-274).The biogeography and ecology of benthic shallow subtidal reef communities in the western Indian Ocean is poorly known, particularly in north-eastern South Africa and southern Mozambique. This thesis uses quantitative information to resolve biogeographic patterns, define reef community types, elucidate potential abiotic determinants of community composition, and evaluate whether subsidies of riverine-derived particulate organic matter (POM) support filter-feeder biomass and drive biogeographic patterns. A large-scale biogeographic analysis was conducted using quantitative biomass data derived from 55 shallow subtidal reefs spanning five countries in the western Indian Ocean. Two statistically distinct marine provinces, Tropical Indo-West Pacific and Subtropical Natal, were recognised by differences in community composition and separated by a biogeographic break in the vicinity of Cape Vidal, South Africa. The biogeographic break took the form of a transitional or overlap area corresponding in location to the Delagoa Bioregion, one of three bioregions also revealed by post-hoc analyses. Significant differences in total average biomass and trophic structure were evident among bioregions, with a number of inter-bioregional trends in trophic groups being apparent. In total, 12 reef community types were recognised, based on similarity profile permutation tests. Most reefs in the Subtropical Natal Bioregion were dominated by a community type characterised by a high biomass of the filter-feeding ascidian Pyura stolonifera and various species of articulated coralline algae. In the Delagoa Overlap Bioregion, a comparatively high diversity of community types was defined, many dominated by algal turf, P. stoloniferaand various Alcyonacea and Scleractinia. Further north, P. stolonifera diminished and the contributions of Scleractinia, especially Porites spp., Pocilloporaspp. and Galaxea spp. increased. Many of these community types are not represented within protected area networks, particularly those in southern Mozambique. When the biomass data were correlated with nine abiotic variables, likely determinants of community composition emerged at both inter- and intra-regional scales. Sea surface temperature, significant wave height, chlorophyll-a and suspended inorganic sediment were the variables highly correlated with community composition and therefore most likely to drive biogeographic differences. Within each bioregion, different sets of abiotic variables were found to be important in driving community differences among sites, including turbidity, chlorophyll-a, reef susceptibility to sand inundation, reef heterogeneity and sea surface temperature. Striking differences in the oceanographic conditions of bioregions were evident, especially between Subtropical Natal and Delagoa Overlap bioregions. In particular, the strong influence of wave height emerged as a novel and unexpected correlate at a biogeographic scale. These differences initiated a trophic study conducted in the Subtropical Natal Bioregion, aimed at determining the importance of riverine-derived POM subsidies in supporting the high filter-feeder biomass in this bioregion. Using carbon, nitrogen and sulphur isotopes and a three-source Bayesian mixing model to calculate proportional contributions, I determined that marine-derived POM formed the bulk of the diets of four species of filter-feeders, but the assimilation of riverine-derived POM was nevertheless notable, ranging from 8 to 33 %. I concluded that riverine POM is likely to play an important but secondary role to factors such as increased levels of turbidity and productivity in explaining the high filter-feeder biomass in the Subtropical Natal Bioregion. These findings provide the first evidence of riverine-inshore-pelagic coupling in filterfeeder communities in this bioregion, and throw light on the factors linked to large-scale biogeographic patterns

Low-frequency gravitational-wave science with eLISA/NGO

We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from 0.1 mHz to 1 Hz), detecting and characterizing a broad variety of systems and events throughout the Universe, including the coalescences of massive black holes brought together by galaxy mergers; the inspirals of stellar-mass black holes and compact stars into central galactic black holes; several millions of ultracompact binaries, both detached and mass transferring, in the Galaxy; and possibly unforeseen sources such as the relic gravitational-wave radiation from the early Universe. eLISA's high signal-to-noise measurements will provide new insight into the structure and history of the Universe, and they will test general relativity in its strong-field dynamical regime.Comment: 20 pages, 8 figures, proceedings of the 9th Amaldi Conference on Gravitational Waves. Final journal version. For a longer exposition of the eLISA science case, see http://arxiv.org/abs/1201.362

The Mock LISA Data Challenges: from Challenge 3 to Challenge 4

The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in Apr 2008, which demonstrated the positive recovery of signals from chirping Galactic binaries, from spinning supermassive--black-hole binaries (with optimal SNRs between ~ 10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Omega_gw(f) ~ 10^-11, slightly below the LISA instrument noise.Comment: 12 pages, 2 figures, proceedings of the 8th Edoardo Amaldi Conference on Gravitational Waves, New York, June 21-26, 200

Low-Frequency Gravitational-Wave Science with eLISA/ NGO

We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from 0.1 mHz to 1 Hz), detecting and characterizing a broad variety of systems and events throughout the Universe, including the coalescences of massive black holes brought together by galaxy mergers; the inspirals of stellar-mass black holes and compact stars into central galactic black holes; several millions of ultracompact binaries, both detached and mass transferring, in the Galaxy; and possibly unforeseen sources such as the relic gravitational-wave radiation from the early Universe. eLISA's high signal-to-noise measurements will provide new insight into the structure and history of the Universe, and they will test general relativity in its strong-field dynamical regime

Nanostructures Technology, Research, and Applications

Contains reports on seventeen research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-0001Joint Services Electronics Program Grant DAAH04-95-1-0038Semiconductor Research Corporation Contract 94-MJ-550National Science Foundation Grant ECS 94-07078U.S. Army Research Office Contract DAAL03-92-G-0291Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-92-K-0021National Aeronautics and Space Administration Contract NAS8-36748National Aeronautics and Space Administration Grant NAGW-2003IBM Corporation Contract 1622U.S. Army Research Office Grant DAAH04-94-G-0377U.S. Air Force - Office of Scientific Research Grant F-49-620-92-J-006

Systemic Inhibition of NF-κB Activation Protects from Silicosis

Background: Silicosis is a complex lung disease for which no successful treatment is available and therefore lung transplantation is a potential alternative. Tumor necrosis factor alpha (TNFα) plays a central role in the pathogenesis of silicosis. TNFα signaling is mediated by the transcription factor, Nuclear Factor (NF)-κB, which regulates genes controlling several physiological processes including the innate immune responses, cell death, and inflammation. Therefore, inhibition of NF-κB activation represents a potential therapeutic strategy for silicosis. Methods/Findings: In the present work we evaluated the lung transplant database (May 1986-July 2007) at the University of Pittsburgh to study the efficacy of lung transplantation in patients with silicosis (n = 11). We contrasted the overall survival and rate of graft rejection in these patients to that of patients with idiopathic pulmonary fibrosis (IPF, n = 79) that was selected as a control group because survival benefit of lung transplantation has been identified for these patients. At the time of lung transplantation, we found the lungs of silica-exposed subjects to contain multiple foci of inflammatory cells and silicotic nodules with proximal TNFα expressing macrophage and NF-κB activation in epithelial cells. Patients with silicosis had poor survival (median survival 2.4 yr; confidence interval (CI): 0.16-7.88 yr) compared to IPF patients (5.3 yr; CI: 2.8-15 yr; p = 0.07), and experienced early rejection of their lung grafts (0.9 yr; CI: 0.22-0.9 yr) following lung transplantation (2.4 yr; CI:1.5-3.6 yr; p<0.05). Using a mouse experimental model in which the endotracheal instillation of silica reproduces the silica-induced lung injury observed in humans we found that systemic inhibition of NF-κB activation with a pharmacologic inhibitor (BAY 11-7085) of IκBα phosphorylation decreased silica-induced inflammation and collagen deposition. In contrast, transgenic mice expressing a dominant negative IκBα mutant protein under the control of epithelial cell specific promoters demonstrate enhanced apoptosis and collagen deposition in their lungs in response to silica. Conclusions: Although limited by its size, our data support that patients with silicosis appear to have poor outcome following lung transplantation. Experimental data indicate that while the systemic inhibition of NF-κB protects from silica-induced lung injury, epithelial cell specific NF-κB inhibition appears to aggravate the outcome of experimental silicosis. © 2009 Di Giuseppe et al

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

The Neutrophil's Eye-View: Inference and Visualisation of the Chemoattractant Field Driving Cell Chemotaxis In Vivo

As we begin to understand the signals that drive chemotaxis in vivo, it is becoming clear that there is a complex interplay of chemotactic factors, which changes over time as the inflammatory response evolves. New animal models such as transgenic lines of zebrafish, which are near transparent and where the neutrophils express a green fluorescent protein, have the potential to greatly increase our understanding of the chemotactic process under conditions of wounding and infection from video microscopy data. Measurement of the chemoattractants over space (and their evolution over time) is a key objective for understanding the signals driving neutrophil chemotaxis. However, it is not possible to measure and visualise the most important contributors to in vivo chemotaxis, and in fact the understanding of the main contributors at any particular time is incomplete. The key insight that we make in this investigation is that the neutrophils themselves are sensing the underlying field that is driving their action and we can use the observations of neutrophil movement to infer the hidden net chemoattractant field by use of a novel computational framework. We apply the methodology to multiple in vivo neutrophil recruitment data sets to demonstrate this new technique and find that the method provides consistent estimates of the chemoattractant field across the majority of experiments. The framework that we derive represents an important new methodology for cell biologists investigating the signalling processes driving cell chemotaxis, which we label the neutrophils eye-view of the chemoattractant field

Nanostructures Technology, Research, and Applications

Contains reports on twenty research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-0001Semiconductor Research Corporation Contract 94-MJ-550U.S. Army Research Office Grant DAAL03-92-G-0291Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-92-K-0021National Science Foundation Grant ECS 90-16437National Science Foundation Grant ECS 90-16737IBM Corporation Contract 1622U.S. Air Force - Office of Scientific Research Grant F-49-62-92-J-0064National Science Foundation Grant DMR 87-19217National Science Foundation Grant DMR 90-22933National Aeronautics and Space Administration Contract NAS8-3674