Monitoring bull kelp (Nereocystis leutkeana) remotely at high resolutions

Bull kelp (Nereocystis leutkeana) is a foundational seaweed in nearshore, marine systems, traditionally supporting economically important fisheries, extracting nutrients in its vicinity, and sequestering carbon and transporting it great distances to subsidize shallow and deep-sea environments. Bull kelp is also a culturally important species for some indigenous peoples along the northeastern Pacific coastline and provides a harvestable product with growing demand. Global trends in kelp distribution show patterns of decline, and the immense loss of northern California bull kelp forests in response to climatic changes have highlighted the need for alternative sources of kelp, both for the product itself, as well as the environmental benefits it provides. Seaweed aquaculture has been a growing industry nationwide and Humboldt Bay has two of the first open-water, commercial kelp farms in California growing bull kelp. In both natural and farmed settings, the need for consistent, accurate monitoring is critical for timely management interventions when populations are observed to be declining, and to reduce long-term costs for California farmers, who already have immense permitting expenses to overcome. Fortunately, low-cost and high-resolution remote monitoring technologies are available through unoccupied aircraft vehicles (or UAVs). The goal of this project was to evaluate the use of UAVs to monitor the growth of bull kelp in farms in Humboldt Bay, and nearby, wild populations along the coast in Trinidad. The second chapter also aims to use the National Agricultural Imaging Program (NAIP) imagery to detect kelp at high resolutions and, combined with recent surveys from UAV, build a time-series of kelp change through the past nine years. I tested various classification methodologies and identified some to be relatively successful in farm settings and others better suited for coastal settings. In terms of accuracy, the classifications were deemed reliable in detecting the presence of bull kelp but varying tidal heights across surveys presented a confounding factor in kelp measured at both the farm and the coast. Generally, detecting kelp from NAIP imagery was found to be more accurate than from drone imagery (91% versus 86% overall accuracy, respectively) in Trinidad. Findings from Chapter 2 indicate that the kelp detection accuracy may be improved with higher altitude UAV surveys, but overall, the results showed success in the usage of UAV and NAIP imagery to monitor the presence and distribution of bull kelp

Some aspects of gyroscope stability and dynamic response

The thesis describes the results of some investigations into the causes of instability in free gimbal-mounted gyroscopes. Considerable use has been made of analogue and digital computation to isolate the effects of various types of reaction forces which may occur in the spin axis bearings, and the effect of rotor asymmetry is also considered. Rotor asymmetry and variation of radial stiffness in the spin axis bearings were both found to give rise to I inear differential equations with periodic coefficients, and an analytical procedure of general applicability has been developed for obtaining the width of the unstable zones and the degree of instability at the parametric resonances. This procedure gives excellent agreement with the results of direct computer solution of the equations of motion. Slackness in the spin axis bearings of a gyroscope did not appear, per se, to produce instability. It may do so, however, as a secondary effect since forces which otherwise would be negligible become significant when other restraints on shaft displacement are removed. Tangential forces in the spin axis bearings in either direction were found to produce instability but different modes of vibration were excited according to the direction of the forces. The effect of cage accelerations in the spin axis bearings has been considered and has been shown to be small. Likewise, transverse couples which arise due to non uniformity of the motor magnetic field when the rotor tilts relative to the stator, have been shown to be negligible. Shaft and bearing compliance has also been considered, mainly from the point of view of natural frequency and frequency response to externally applied torques. Bearing eccentricity has been shown to cause a forced nutation at the frequency of rotation of the ball cage, giving rise to a simple resonance if this frequency should coincide with a natural frequency of the gyro. Experimental work has been carried out with a view to establishing the nature of the dynamic forces and deflections in the spin axis bearings. Because these are of such small amplitude and of such a complex waveform, analysis of the experimental results has proved difficult. Sinusoidal forcing of a casing containing a gyro rotor in order to obtain the frequency response of the shaft and bearing deflections was moderately successful while the rotor was stationary but no readings were possible with the rotor running because of a seemingly random variation in the response

The Metal-Enriched Outer Disk of NGC 2915

We present optical emission-line spectra for outlying HII regions in the extended neutral gas disk surrounding the blue compact dwarf galaxy NGC 2915. Using a combination of strong-line R23 and direct oxygen abundance measurements, we report a flat, possibly increasing, metallicity gradient out to 1.2 times the Holmberg radius. We find the outer-disk of NGC 2915 to be enriched to a metallicity of 0.4 Z_solar. An analysis of the metal yields shows that the outer disk of NGC 2915 is overabundant for its gas fraction, while the central star-foming core is similarly under-abundant for its gas fraction. Star formation rates derived from very deep ~14 ks GALEX FUV exposures indicate that the low-level of star formation observed at large radii is not sufficient to have produced the measured oxygen abundances at these galactocentric distances. We consider 3 plausible mechanisms that may explain the metal-enriched outer gaseous disk of NGC 2915: radial redistribution of centrally generated metals, strong galactic winds with subsequent fallback, and galaxy accretion. Our results have implications for the physical origin of the mass-metallicity relation for gas-rich dwarf galaxies.Comment: 11 pages, 4 figures, accepted to ApJ April 8th, 201

Smart Cities: Towards a New Citizenship Regime? A Discourse Analysis of the British Smart City Standard

Growing practice interest in smart cities has led to calls for a less technology-oriented and more citizen-centric approach. In response, this articles investigates the citizenship mode promulgated by the smart city standard of the British Standards Institution. The analysis uses the concept of citizenship regime and a mixture of quantitative and qualitative methods to discern key discursive frames defining the smart city and the particular citizenship dimensions brought into play. The results confirm an explicit citizenship rationale guiding the smart city (standard), although this displays some substantive shortcomings and contradictions. The article concludes with recommendations for both further theory and practice development

Imaging Fabry-Perot Spectroscopy of NGC 5775: Kinematics of the Diffuse Ionized Gas Halo

We present imaging Fabry-Perot observations of Halpha emission in the nearly edge-on spiral galaxy NGC 5775. We have derived a rotation curve and a radial density profile along the major axis by examining position-velocity (PV) diagrams from the Fabry-Perot data cube as well as a CO 2-1 data cube from the literature. PV diagrams constructed parallel to the major axis are used to examine changes in azimuthal velocity as a function of height above the midplane. The results of this analysis reveal the presence of a vertical gradient in azimuthal velocity. The magnitude of this gradient is approximately 1 km/s/arcsec, or about 8 km/s/kpc, though a higher value of the gradient may be appropriate in localized regions of the halo. The evidence for an azimuthal velocity gradient is much stronger for the approaching half of the galaxy, although earlier slit spectra are consistent with a gradient on both sides. There is evidence for an outward radial redistribution of gas in the halo. The form of the rotation curve may also change with height, but this is not certain. We compare these results with those of an entirely ballistic model of a disk-halo flow. The model predicts a vertical gradient in azimuthal velocity which is shallower than the observed gradient, indicating that an additional mechanism is required to further slow the rotation speeds in the halo.Comment: 18 pages, 18 figures. Uses emulateapj.cls. Accepted for publication in Ap

Galactic and Magellanic Evolution with the SKA

As we strive to understand how galaxies evolve it is crucial that we resolve physical processes and test emerging theories in nearby systems that we can observe in great detail. Our own Galaxy, the Milky Way, and the nearby Magellanic Clouds provide unique windows into the evolution of galaxies, each with its own metallicity and star formation rate. These laboratories allow us to study with more detail than anywhere else in the Universe how galaxies acquire fresh gas to fuel their continuing star formation, how they exchange gas with the surrounding intergalactic medium, and turn warm, diffuse gas into molecular clouds and ultimately stars. The $\lambda$21-cm line of atomic hydrogen (HI) is an excellent tracer of these physical processes. With the SKA we will finally have the combination of surface brightness sensitivity, point source sensitivity and angular resolution to transform our understanding of the evolution of gas in the Milky Way, all the way from the halo down to the formation of individual molecular clouds.Comment: 25 pages, from "Advancing Astrophysics with the Square Kilometre Array", to appear in Proceedings of Scienc

Product Service System Innovation in the Smart City

Product service systems (PSS) may usefully form part of the mix of innovations necessary to move society toward more sustainable futures. However, despite such potential, PSS implementation is highly uneven and limited. Drawing on an alternate socio-technical perspective of innovation, this paper provides fresh insights, on among other things the role of context in PSS innovation, to address this issue. Case study research is presented focusing on a use orientated PSS in an urban environment: the Copenhagen city bike scheme. The paper shows that PSS innovation is a situated complex process, shaped by actors and knowledge from other locales. It argues that further research is needed to investigate how actors interests shape PSS innovation. It recommends that institutional spaces should be provided in governance landscapes associated with urban environments to enable legitimate PSS concepts to co-evolve in light of locally articulated sustainability principles and priorities

An intellectual disability syndrome with single nucleotide variants in <i>O-GlcNAc Transferase</i>

Contains fulltext : 220584.pdf (Publisher’s version ) (Open Access)Intellectual disability (ID) is a neurodevelopmental condition that affects ~1% of the world population. In total 5-10% of ID cases are due to variants in genes located on the X chromosome. Recently, variants in OGT have been shown to co-segregate with X-linked intellectual disability (XLID) in multiple families. OGT encodes O-GlcNAc transferase (OGT), an essential enzyme that catalyses O-linked glycosylation with β-N-acetylglucosamine (O-GlcNAc) on serine/threonine residues of thousands of nuclear and cytosolic proteins. In this review, we compile the work from the last few years that clearly delineates a new syndromic form of ID, which we propose to classify as a novel Congenital Disorder of Glycosylation (OGT-CDG). We discuss potential hypotheses for the underpinning molecular mechanism(s) that provide impetus for future research studies geared towards informed interventions

Open Education and the emancipation of academic labour

I have previously argued that open education is a liberal project with a focus on the freedom of things rather than the freedom of people (Winn, Joss. 2012. “Open Education: From the Freedom of Things to the Freedom of People.” In Towards Teaching in Public: Reshaping the Modern University, edited by Michael Neary, Howard Stevenson, and Les Bell, 133– 147. London: Continuum). Furthermore, I have argued that despite an implicit critique of private property with its emphasis on ‘the commons’, the literature on open education offers no corresponding critique of academic labour (Neary, Mike, and Joss Winn. 2012. “Open Education: Common(s), Commonism and the New Common Wealth.” Ephemera: Theory & Politics in Organization 12 (4): 406–422). In this paper, I develop my critical position that an emancipatory form of education must work towards the emancipation of teachers and students from labour, the dynamic, social, creative source of value in capitalism. In making this argument, I first establish the fundamental characteristics of academic labour. I then offer a ‘form-analytic’ critique of open access, followed by a corresponding critique of its legal form. Finally, I critically discuss the potential of ‘open cooperatives’ as a transitional organisational form for the production of knowledge through which social relations become ‘transparent in their simplicity’ (Marx, Karl. 1976. Capital, Vol. 1. London: Penguin Classics, 172)