Broad-scale analysis of fish community data suggests critical need to support regional connectivity of coral reefs

Connectivity is vital for the biodiversity and functioning of marine ecosystems. It is known to be important for coral reefs, but the scales at which connectivity effects matter—and, correspondingly, the scales at which management responses are needed—are poorly understood in marine systems. We used 23 years of fish monitoring data collected from ~50 different coral reefs by the Australian Institute of Marine Science, together with a range of geographic data layers (including the Allen Coral Atlas) and additional network analysis, to explore the balance of local and regional influence on fish communities. Variance partitioning indicated that 42% of the variance in fish community composition could be explained by regional effects or their interaction with coarse-grained local influences (habitat). The variance explained by regional influences was divided evenly between measures that capture location on environmental gradients (e.g., proximity to coastal shelf, latitude) and cross-scale centrality measures of reef location within a broader reef network. A total of 11% of variance could be directly or indirectly attributed to management. Our results provide clear evidence that management and restoration of reefs across the globe must consider both local and regional influences on reef-associated organisms and highlight the potential benefits of improving connectivity in human-dominated coastal seascapes

Terahertz single pixel imaging based on a Nipkow disk

We describe a terahertz single pixel imaging system based on a Nipkow disk. Nipkow disks have been used for fast scanning imaging systems since the first experimental television was invented in 1926. In our work, a Nipkow disk with 24 scanning lines was used to provide an axial resolution of 2 mm/pixel. We also show that by implementing a microscanning technique the axial resolution can be further improved to 0.5 mm/pixel. Imaging of several objects was demonstrated to show that this simple scanning system is promising for fast and/or real time terahertz imaging applications

A terahertz polarization insensitive dual band metamaterial absorber

Metamaterial absorbers have attracted considerable attention for applications in the terahertz range. In this Letter, we report the design, fabrication, and characterization of a terahertz dual band metamaterial absorber that shows two distinct absorption peaks with high absorption. By manipulating the periodic patterned structures as well as the dielectric layer thickness of the metal–dielectric–metal structure, significantly high absorption can be obtained at specific resonance frequencies. Finite-difference time-domain modeling is used to design the structure of the absorber. The fabricated devices have been characterized using a Fourier transform IR spectrometer. The experimental results show two distinct absorption peaks at 2.7 and 5.2 THz, which are in good agreement with the simulation. The absorption magnitudes at 2.7 and 5.2 THz are 0.68 and 0.74, respectively

Spectral Modeling of SNe Ia Near Maximum Light: Probing the Characteristics of Hydro Models

We have performed detailed NLTE spectral synthesis modeling of 2 types of 1-D hydro models: the very highly parameterized deflagration model W7, and two delayed detonation models. We find that overall both models do about equally well at fitting well observed SNe Ia near to maximum light. However, the Si II 6150 feature of W7 is systematically too fast, whereas for the delayed detonation models it is also somewhat too fast, but significantly better than that of W7. We find that a parameterized mixed model does the best job of reproducing the Si II 6150 line near maximum light and we study the differences in the models that lead to better fits to normal SNe Ia. We discuss what is required of a hydro model to fit the spectra of observed SNe Ia near maximum light.Comment: 29 pages, 14 figures, ApJ, in pres

Quantifying spatial resilience

1. Anthropogenic stressors affect the ecosystems upon which humanity relies. In some cases when resilience is exceeded, relatively small linear changes in stressors can cause relatively abrupt and nonlinear changes in ecosystems. 2. Ecological regime shifts occur when resilience is exceeded and ecosystems enter a new local equilibrium that differs in its structure and function from the previous state. Ecological resilience, the amount of disturbance that a system can withstand before it shifts into an alternative stability domain, is an important framework for understanding and managing ecological systems subject to collapse and reorganization. 3. Recently, interest in the influence of spatial characteristics of landscapes on resilience has increased. Understanding how spatial structure and variation in relevant variables in landscapes affects resilience to disturbance will assist with resilience quantification, and with local and regional management. 4. Synthesis and applications. We review the history and current status of spatial resilience in the research literature, expand upon existing literature to develop a more operational definition of spatial resilience, introduce additional elements of a spatial analytical approach to understanding resilience, present a framework for resilience operationalization and provide an overview of critical knowledge and technology gaps that should be addressed for the advancement of spatial resilience theory and its applications to management and conservation

Bridging the Gap between Micro and Nanotechnology: Using Lab-on-a-Chip to enable Nanosensors for Genomics, Proteomics and Diagnostic Screening

Abstract. The growing need for accurate and fast methods of DNA and protein determination in the post human genome era has generated considerable interest in the development of new microfluidic analytical platforms, fabricated using methods adapted from the semi-conductor industry. These methods have resulted in the development of the Lab-on-a-Chip concept, a technology which often involves having a miniaturised biochip (as an analytical device), with rather larger instrumentation associated with the control of the associated sensors and of fluidics. This talk will explore the development of new Lab-ona-Chip platforms for DNA, protein and cell screening, using microfluidics as a packaging technology in order to enable advances in nanoscale science to be implemented in a Lab-on-a-Chip format. The talk will also show how system on a chip methods can be integrated with Lab-on-a-Chip devices to create remote and distributed intelligent sensors, which can be used in a variety of diagnostic applications, including for example chemical sensing within the GI tract

Single-chip, mid-infrared array for room temperature video rate imaging

The need for energy efficiency and lower emissions from industrial plants and infrastructures is driving research into novel sensor technologies, especially those that allow observing and measuring greenhouse gases, such as CO2CO2. CO2CO2 emissions can be captured using mid-infrared imagers, but at present, these are based on hybrid technologies that need expensive manufacturing and require cooling. The high price tag prevents a wider diffusion of mid-infrared imagers and hence their use for many low-cost and large-volume applications. Here we report a monolithic III-V technology that integrates GaAs transistors with an InSb photodiode array. The monolithic material system reduces costs and provides an excellent platform for the sensor system-on-chip. We present a focal plane array imaging technology operating at room temperature in the 3–6 μm wavelength range that will address the need for identification and measurement of a range of industrially important gases.ESPRC 58833, ESPRC 6672

Factor VIII companion diagnostic for haemophilia

Haemophilia is predominantly an inherited disorder that impairs the body’s ability to make blood clots, a process needed to stop bleeding. The condition of this disease is complex to manage, but many patients do so through home therapy and often only see their core multidisciplinary healthcare team annually. There is an increasing need for patients to be able to monitor their condition efficiently at home while staying connected with their healthcare team. As a consequence, a low-cost handheld self-monitoring solution for clotting factor is required. Here we have demonstrated a suitable one-step Factor VIII companion diagnostic sensing approach based on a chromogenic assay for haemophilia A. The results show comparable performance to the gold standard method. Our approach is able to deliver accurate cost-effective results in under 5 min from undiluted human plasma. It has the potential to be able to reduce the human and monetary costs of over- or under-medication for haemophiliacs

Piecewise Linear Models for the Quasiperiodic Transition to Chaos

We formulate and study analytically and computationally two families of piecewise linear degree one circle maps. These families offer the rare advantage of being non-trivial but essentially solvable models for the phenomenon of mode-locking and the quasi-periodic transition to chaos. For instance, for these families, we obtain complete solutions to several questions still largely unanswered for families of smooth circle maps. Our main results describe (1) the sets of maps in these families having some prescribed rotation interval; (2) the boundaries between zero and positive topological entropy and between zero length and non-zero length rotation interval; and (3) the structure and bifurcations of the attractors in one of these families. We discuss the interpretation of these maps as low-order spline approximations to the classic ``sine-circle'' map and examine more generally the implications of our results for the case of smooth circle maps. We also mention a possible connection to recent experiments on models of a driven Josephson junction.Comment: 75 pages, plain TeX, 47 figures (available on request