The power of suburbia

IT IS A COMMONLY held belief that a compact city is a more energy-efficient city. In Auckland, like many other cities, this has become enshrined in policy. Compact housing is believed to have a lower surface to volume ratio and will therefore lose less heat. The low-density urban form of suburbia is also believed to be energy inefficient because of high oil-dependent private transport use. At face value, compact houses and urban forms appear to be the solution for a sustainable Auckland. But while these beliefs may be true for now, consider the future when: ●the climate will be warmer ●emerging technologies will replace the internal combustion engine ●harvesting energy from rooftop photovoltaics will be cheaper than the grid. Should we be designing buildings and cities for the present or for future conditions

Measuring the solar potential of a city and its implications on energy policy

This research investigates the maximum potential energy that can be made available by efficiently installing PV systems on buildings throughout a city, from the central business district (CBD) out to low density suburbs. The purpose of this is to evaluate the contribution that electricity from PVs can make to reduce the electricity load of a city, supply the needs of a mixture of building types, reduce peak electricity demand and contribute towards the charging of electric vehicles (EVs). A sample of the main urban building types have been taken and reassembled into a representative typical cross-section of a city. The application of PVs for all the building types is investigated and then the potential electricity distribution is evaluated for different urban densities and dispersion patterns. This research is concerned not only with how individual buildings may gain from distributed generation (DG) but, more importantly, how a city as a whole may benefit. The results indicate that low dense suburbia is not only the most efficient collector of solar energy but that enough excess electricity can be generated to power daily transport needs of suburbia and also contribute to peak daytime electrical loads in the city centre. This challenges conventional thinking that suburbia is energy inefficient. While a compact city may be more efficient for the internal combustion engine vehicles, a dispersed city is more efficient when DG solar power is the main energy source and EVs are the means of transport

Diversity and evolution of fruits in Cuscuta (dodders; Convolvulaceae)

Cuscuta (dodder) is a genus of roughly 200 species of obligate stem parasites with sub-cosmopolitan distribution. The fruit, generally regarded as a capsule, has a thin pericarp containing one to four seeds and opening at the base (circumscissile dehiscence; DE), or remaining closed (indehiscent; IN). IN has evolved multiple times in Cuscuta from DE, and is most common in the North American clades of subgenus Grammica. In addition, some species produce fruits that open irregularly. Characteristics pertaining to the fruits of Cuscuta are important as their seeds contribute most to their distribution and prevalence across the globe, and their reduced vegetative organs limit the morphological variation available for species’ identification. In this thesis, I examined the structural mechanism behind DE to elucidate fruit types and their evolution. I surveyed fruit morphological traits to determine their systematic significance and functional correlations with dehiscence/indehiscence. Finally, I explored the putative evolutionary advantage(s) of fruit indehiscence by examining distribution, floatability, germination, and infructescence architecture. Pericarp structure revealed three distinct fruit types: DE fruits with an abscission zone (AZ), IN fruits with a uniform pericarp, and fruits that dehisce irregularly via the thinning of endocarp cell walls (IrA). IN fruits that break open irregularly (IrB) may also be an evolutionary fruit trait and were considered as such. Most qualitative fruit traits were polymorphic and their evolution involved multiple transitions to each state. Differences in quantitative traits were not consistent among fruit types, however IrB fruit species generally have a large interstylar aperture and large fruits with more seeds. IrB fruit species have a larger geographical range and more northern latitudinal limit than DE fruit species, and their infructescences slightly more compact than IN fruit species; which along with fruit traits may contribute to their irregular dehiscence. Capsules of C. gronovii were capable of floating for at least one week longer than their seeds. Seeds of C. gronovii exhibit a delayed germination when not removed from their IN fruits; a strategy known as bet-hedging. These results suggest that the evolution of IN in Cuscuta has provided certain species with heterodiaspory, and enhanced their dispersal and germination strategies

Shaping Sustainability in Classroom Curricula in Singapore: Educators and Students as Collaborative Change Agents

Climate change is a global crisis, and in Singapore, a low-lying city-state, its geography makes it susceptible to extreme weather events and zoonotic diseases. Singapore\u27s alignment with global commitments like the United Nations Agenda for Sustainable Development is elevated by its presence as a leader in urban sustainability. Using a mixed-methods approach, this paper explores sustainability as a classroom concept and educators\u27 role in translating curriculum standards into learning that informs, educates, and empowers students to become agents of change. Sharing these perspectives will help develop collaborative learning programs that center educators and students, improving understanding of this important field

Measuring 14 elemental abundances with R=1,800 LAMOST spectra

The LAMOST survey has acquired low-resolution spectra (R=1,800) for 5 million stars across the Milky Way, far more than any current stellar survey at a corresponding or higher spectral resolution. It is often assumed that only very few elemental abundances can be measured from such low-resolution spectra, limiting their utility for Galactic archaeology studies. However, Ting et al. (2017) used ab initio models to argue that low-resolution spectra should enable precision measurements of many elemental abundances, at least in theory. Here we verify this claim in practice by measuring the relative abundances of 14 elements from LAMOST spectra with a precision of $\lesssim$ 0.1 dex for objects with ${\rm S/N}_{\rm LAMOST}$ > 30 (per pixel). We employ a spectral modeling method in which a data-driven model is combined with priors that the model gradient spectra should resemble ab initio spectral models. This approach assures that the data-driven abundance determinations draw on physically sensible features in the spectrum in their predictions and do not just exploit astrophysical correlations among abundances. Our analysis is constrained to the number of elemental abundances measured in the APOGEE survey, which is the source of the training labels. Obtaining high quality/resolution spectra for a subset of LAMOST stars to measure more elemental abundances as training labels and then applying this method to the full LAMOST catalog will provide a sample with more than 20 elemental abundances that is an order of magnitude larger than current high-resolution surveys, substantially increasing the sample size for Galactic archaeology.Comment: 6 pages, 3 figures, ApJ (Accepted for publication- 2017 October 9

Zaremba problem with degenerate weights

We establish Zaremba problem for Laplacian and $p$-Laplacian with degenerate weights when the Dirichlet condition is only imposed in a set of positive weighted capacity. We prove weighted Sobolev-Poincar\'{e} inequality with sharp scaling-invariant constants involving weighted capacity. Then we show higher integrability of the gradient of the solution (Meyers estimate) with minimal conditions on the part of the boundary where the Dirichlet condition is assumed. Our results are new both for the linear $p=2$ and nonlinear case and include problems with the weight not only as a measure but also as a multiplier of the gradient of the solution

Defining scalable cell culture processes for Biosimilar candidates

Biosimilar process development is technically challenging compared to novel drug development due to the need to achieve comparable product quality attributes (PQAs) as the brand product. Cell culture process development plays a critical role in modulating PQAs such as sialic acid and glycans. PQA modulation is challenging because often times the change of one PQA may affect other PQAs and/or titer. This poster describes Momenta’s systematic approach to developing scalable cell culture processes for biosimilar candidates while achieving sufficiently high titer and comparable sialylation and N-glycan profiles. In addition to conventional methods of screening media and feeds and optimizing process operating parameters to modulate PQAs, we introduced different process levers such as trace metals and nucleotide sugar precursors into our basal medium and feeds based on our scientific understanding of the molecule of the brand product and the metabolic and enzymatic activities in the cell. With the synergetic approach of media and feeds screening, process operating parameter optimization and process lever addition, in one case study we were able to increase sialic acid levels by about 25% while decreasing a key N-glycan peak by about 5%, achieving comparable PQA profiles as the brand product. In another case study, we successfully increased sialic acid by about 25% while increasing titer by about 50%. Both processes have been successfully scaled up from bench top bioreactors to single-use 250L and 2000L bioreactors

Is Fashion Universal? : Towards a Sociology of Proto-Fashion

Peer reviewe