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Context: In residential landscapes, people acknowledge and manage larger, conventionally attractive plants differently than smaller, less conspicuous ones, possibly leading to a divergence in basic ecological patterns such as diversity-area relationships. Objectives: We tested for divergences between lawn and non-lawn plants, and compared perceived and actual species richness in residential yards. We hypothesized that: (1) homeowner perception of plant species richness is more related to the actual species richness of non-lawn plants than lawn plants, and (2) alpha diversity will increase more rapidly, and beta diversity will decrease less rapidly for non-lawn plants than lawn plants with increasing spatial scale. Methods: We recorded all plant species in four 5 × 5 m plots in the front and back yards of 30 residences within four neighborhoods of Gainesville, Florida, United States (N = 238 plots). We also surveyed residents regarding perceived plant species richness in their yards. Results: We detected 386 non-lawn and 140 lawn species. Perceived plant species richness was positively related to non-lawn species richness and negatively related to lawn species richness, suggesting perception of species richness largely reflected that of non-lawn plants. Alpha diversity increased more rapidly, while beta diversity decreased less rapidly, for non-lawn plants than lawn plants with increasing spatial scale, although lawns had more species within individual yards. Conclusions: Findings revealed a divergence in diversity-area relationships between different plant groups in residential landscapes. We should consider the ecological implications of unrecognized plant diversity, particularly in residential lawns, where management often strives to limit plant species richness. [ABSTRACT FROM AUTHOR]

Simulations of binary black hole systems using the Spectral Einstein Code (SpEC) are done on a computational domain that excises the regions inside the black holes. It is imperative that the excision boundaries are outflow boundaries with respect to the hyperbolic evolution equations used in the simulation. We employ a time-dependent mapping between the fixed computational frame and the inertial frame through which the black holes move. The time-dependent parameters of the mapping are adjusted throughout the simulation by a feedback control system in order to follow the motion of the black holes, to adjust the shape and size of the excision surfaces so that they remain outflow boundaries, and to prevent large distortions of the grid. We describe in detail the mappings and control systems that we use. We show how these techniques have been essential in the evolution of binary black hole systems with extreme configurations, such as large spin magnitudes and high mass ratios, especially during the merger, when apparent horizons are highly distorted and the computational domain becomes compressed. The techniques introduced here may be useful in other applications of partial differential equations that involve time-dependent mappings. [ABSTRACT FROM AUTHOR]

Purpose – This paper seeks to describe a protocol to estimate annual community energy consumption baselines for single-family detached homes in the Gainesville Regional Utility service area of Alachua County, Florida, USA. Further, it details methods using these baselines to make direct comparisons of individual households' energy consumption and evaluate the energy impacts of three prescriptive demand side management (DSM) programs. Design/methodology/approach – To improve estimates of energy savings, the paper proposes using a "micro" scale multivariate regression methodology based on a census of utility and property appraiser household data. Findings – Results suggest that traditional analysis approaches are likely to overestimate savings significantly and that the annual community baseline technique provides more consistent estimates of energy savings than most commonly used methods. Practical implications – This type of analysis could provide a tool that utilities can use to more accurately and cost effectively measure DSM savings. This could result in reduced energy demand related to streamlined program setup and management. Originality/value – The proposed methodology is unique in that it defines a new household-level energy consumption baseline measure that we think is a more appropriate performance measure, uses a census of publicly available data for the population of interest, merging metered utility data with property appraiser data, and works upward to construct a simple model for evaluating household-level energy consumption. The critical element that distinguishes our proposed energy performance measures is that they are calculated and interpreted using annual, population-level, comparison-group baselines that effectively normalize for community energy consumption patterns in any given year. [ABSTRACT FROM AUTHOR]