Nectar resource diversity organises flower-visitor community structure

Communities of nectar-producing plants show high spatio-temporal variation in the patterns of volume and concentration presentation. We illustrate a novel approach for quantifying nectar reward structures in complex communities, demonstrating that nectar resource diversity (defined as the variety of nectar volume-concentration combinations available) may be a fundamental factor organising nectarivore communities. In a series of diverse bee and entomophilous flower communities in Israel, our measure of nectar resource diversity alone explains the majority of variation in bee species richness, while other nectar variables (volume, concentration, energy value, and water content) have little predictive value per se. The new measure of nectar resource diversity is highly correlated with floral species richness and particularly with the species richness of annuals, yet it is additive in its effect on bee diversity. We conclude that relying solely upon measurements of mean nectar volume and mean nectar concentration overlooks a key characteristic of community-level reward structure, nectar resource diversity, so that previous studies may have failed to identify an important determinant of flower-visitor community structure.

Why was urban overcrowding much more severe in Scotland than in the rest of the British Isles? Evidence from the first (1904) official household expenditure survey

This article presents an analysis of British urban working-class housing conditions in 1904, using a rediscovered survey. We investigate overcrowding and find major regional differences. Scottish households in the survey were more overcrowded despite being less poor. Investigating the causes of this overcrowding, we find little support for supply-side theories or for the idea that the Scottish households in our survey experienced particularly great variations in income, causing them to commit to overly modest accommodation. We present evidence that is consistent with idea that particularly tough Scottish tenancy and local tax laws caused excess overcrowding. We also provide evidence that Scottish workers had a relatively high preference for food, rather than housing, expenditure, which can be at least partly attributed to their inheritance of more communal patterns of urban living.

Rental depreciation and capital expenditure in the UK commercial real estate market, 1993–2009

This paper identifies the long-term rental depreciation rates for UK commercial properties and rates of capital expenditure incurred to offset depreciation over the same period. It starts by reviewing the economic depreciation literature and the rationale for adopting a longitudinal method of measurement, before discussing the data used and results. Data from 1993 to 2009 were sourced from Investment Property Databank and CB Richard Ellis real estate consultants. This is used to compare the change in values of new buildings in different locations with the change in values of individual properties in those locations. The analysis is conducted using observations on 742 assets drawn from all major segments of the commercial real estate market. Overall rental depreciation and capital expenditure rates are similar to those in other recent UK studies. Depreciation rates are 0.8% pa for offices, 0.5% pa for industrial properties and 0.3% pa for standard retail properties. These results hide interesting variations at a segment level, notably in retail where location often dominates value rather than the building. The majority of properties had little (if any) money spent on them over the last 16 years, but those subject to higher rates of expenditure were found to have lower depreciation rates.

Habitual energy expenditure modifies the association between NOS3 gene polymorphisms and blood pressue

BACKGROUND: The endothelial nitric-oxide synthase (NOS3) gene encodes the enzyme (eNOS) that synthesizes the molecule nitric oxide, which facilitates endothelium-dependent vasodilation in response to physical activity. Thus, energy expenditure may modify the association between the genetic variation at NOS3 and blood pressure. METHODS: To test this hypothesis, we genotyped 11 NOS3 polymorphisms, capturing all common variations, in 726 men and women from the Medical Research Council (MRC) Ely Study (age (mean +/- s.d.): 55 +/- 10 years, body mass index: 26.4 +/- 4.1 kg/m(2)). Habitual/non-resting energy expenditure (NREE) was assessed via individually calibrated heart rate monitoring over 4 days. RESULTS: The intronic variant, IVS25+15 [G-->A], was significantly associated with blood pressure; GG homozygotes had significantly lower levels of diastolic blood pressure (DBP) (-2.8 mm Hg; P = 0.016) and systolic blood pressure (SBP) (-1.9 mm Hg; P = 0.018) than A-allele carriers. The interaction between NREE and IVS25+15 was also significant for both DBP (P = 0.006) and SBP (P = 0.026), in such a way that the effect of the GG-genotype on blood pressure was stronger in individuals with higher NREE (DBP: -4.9 mm Hg, P = 0.02. SBP: -3.8 mm Hg, P= 0.03 for the third tertile). Similar results were observed when the outcome was dichotomously defined as hypertension. CONCLUSIONS: In summary, the NOS3 IVS25+15 is directly associated with blood pressure and hypertension in white Europeans. However, the associations are most evident in the individuals with the highest NREE. These results need further replication and have to be ideally tested in a trial before being informative for targeted disease prevention. Eventually, the selection of individuals for lifestyle intervention programs could be guided by knowledge of genotype.

Examining Visitor Attitudes and Motivations at a Space Science Centre

The H.R. MacMillan Space Centre is a multi-faceted organization whose mission is to educate, inspire and evoke a sense of wonder about the universe, our planet and space exploration. As a popular, Vancouver science centre, it faces the same range of challenges and issues as other major attractions: how does the Space Centre maintain a healthy public attendance in an increasingly competitive market where visitors continue to be presented with an increasingly rich range of choices for their leisure spending and entertainment dollars?This front-end study investigated visitor attitudes, thoughts and preconceptions on the topic of space and astronomy. It also examined visitors’ motivations for coming to a space science centre. Useful insights were obtained which will be applied to improve future programme content and exhibit development.

Important Parameters in Designing and Presenting Exhibits and Planetarium Programs in Science Centers : A Visitor-Based Framework

This dissertation proposes an initial framework for designing and presenting exhibits in science centers and to recommend methods for improving the educational role of planetariums in science centers.