Comparative micromorphology of nectariferous and nectarless labellar spurs in selected clades of subtribe Orchidinae (Orchidaceae)

Floral nectar spurs are widely considered to influence pollinator behaviour in orchids. Spurs of 21 orchid species selected from within four molecularly circumscribed clades of subtribe Orchidinae (based on Platanthera s.l., Gymnadenia-Dactylorhiza s.l., Anacamptis s.l., Orchis s.s.) were examined under light and scanning electron microscopes in order to estimate correlations between nectar production (categorized as absent, trace, reservoir), interior epidermal papillae (categorized as absent, short, medium, long) and epidermal cell striations (categorized as apparently absent, weak, moderate, strong). Closely related congeneric species scored similarly, but more divergent species showed less evidence of phylogenetic constraints. Nectar secretion was negatively correlated with striations and positively correlated with papillae, which were especially frequent and large in species producing substantial reservoirs of nectar. We speculate that the primary function of the papillae is conserving energy through nectar resorption and explain the presence of large papillae in a minority of deceit-pollinated species by arguing that the papillae improve pollination because they are a tactile expectation of pollinating insects. In contrast, the prominence of striations may be a 'spandrel', simply reflecting the thickness of the overlying cuticle. Developmentally, the spur is an invagination of the labellum; it is primarily vascularized by a single 'U'-shaped primary strand, with smaller strands present in some species. Several suggestions are made for developing further, more targeted research programmes. (C) 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160, 369-387.

The role of schizotypy and creativity in a group problem-solving task

The well-studied link between psychotic traits and creativity is a subject of much debate. The present study investigated the extent to which schizotypic personality traits - as measured by O-LIFE (Oxford-Liverpool Inventory of Feelings and Experiences) - equip healthy individuals to engage as groups in everyday tasks. From a sample of 69 students, eight groups of four participants - comprised of high, medium, or low-schizotypy individuals - were assembled to work as a team to complete a creative problem-solving task. Predictably, high scorers on the O-LIFE formulated a greater number of strategies to solve the task, indicative of creative divergent thinking. However, for task success (as measured by time taken to complete the problem) an inverted U shaped pattern emerged, whereby high and low-schizotypy groups were consistently faster than medium schizotypy groups. Intriguing data emerged concerning leadership within the groups, and other tangential findings relating to anxiety, competition and motivation were explored. These findings challenge the traditional cliche that psychotic personality traits are linearly related to creative performance, and suggest that the nature of the problem determines which thinking styles are optimally equipped to solve it. (C) 2009 Elsevier Ltd. All rights reserved.

Entrepreneurship and economic development in cities

Policy makers have identified the relationship between entrepreneurship and economic development. Yet, little is known about how this relationship varies over time in cities with different market sizes. This study examines the link between entrepreneurship and economic development using a panel of 127 European cities between 1994 and 2009. We found that the immediate economic development impact of new firm start-ups is positive for both small-/medium-size cities and large cities. The relationship is U-shaped for large cities, with the indirect effect taking 7 years, but the indirect effect does not occur in small-/medium-size cities. We offer useful information for policy makers, practitioners, and scholars.

The physiological and behavioural development of diving in Australian fur seal (Arctocephalus pusillus doriferus) pups

The physiological and behavioural development of diving was examined in Australian fur seal (Arctocephalus pusillus doriferus) pups to assess whether animals at weaning are capable of exploiting the same resources as adult females. Haematocrit, haemoglobin and myoglobin contents all increased throughout pup development though total body oxygen stores reached only 71% of adult female levels just prior to weaning. Oxygen storage components, however, did not develop at the same pace. Whereas blood oxygen stores had reached adult female levels by 9 months of age, muscle oxygen stores were slower to develop, reaching only 23% of adult levels by this age. Increases in diving behaviour corresponded to the physiological changes observed. Pups spent little time (<8%) in the water prior to moulting (age 1–2 months) whereas following the moult, they spent >27% of time in the water and made mid-water dives (maximum depth 35.7 ± 2.9 m) with durations of 0.35 ± 0.03 min. By 9 months (just prior to weaning), 30.5 ± 9.3% of all dives performed were U-shaped benthic dives (maximum depth 65.0 ± 6.0 m) with mean durations of 0.87 ± 0.25 min, significantly shorter than those of adult females. These results suggest that while Australian fur seal pups approaching the age of weaning are able to reach similar depths as adult females, they do not have the physiological capacity to remain at these depths for sufficient durations to exploit them to the same efficiency.

Dive behaviour, foraging locations and maternal-attendance patterns in Australian fur seals (Arctocephalus pusillus doriferus)

The dive behaviour, foraging locations, and colony-attendance patterns of female Australian fur seals (Arctocephalus pusillus doriferus) from Kanowna Island (39°10'S, 146°18'E) in Bass Strait, southeastern Australia, were determined throughout lactation during 1997–1999. Foraging-trip durations increased as lactation progressed, being shortest in summer (3.71 ± 0.24 days; mean ± 1 SE) and longest in winter (6.77 ± 0.57 days, P < 0.05), but maternal-attendance periods did not differ in duration (1.70 ± 0.10 days, P > 0.5). Individual mean attendance periods and trip durations were positively correlated (r² = 0.21, P < 0.005). Diving commenced shortly after seals left the colony (2.6 ± 0.4 h), was continuous for long periods (up to 36 h), occurred mostly during daylight hours, and lacked regular diel variation in depth. The majority of dives (78%) were typically U-shaped and reached depths corresponding to the prevailing depths in Bass Strait (65–85 m), indicating that these animals forage mostly on the benthos of the shallow continental shelf in this region. Such behaviour is unusual for fur seals but is reminiscent of that of some sea lion species. Mean dive durations varied between 2.0 and 3.7 min (maximum 8.9 min) and the theoretical aerobic dive limit (3.91–4.26 min) was exceeded on 17.3% of dives. Dive frequency (8.3 ± 0.6/h) and the proportion of time at sea spent diving (40.7 ± 2.1%) were weakly negatively related to the duration of the foraging trip (r²= 0.07, P < 0.004, and r² = 0.13, P < 0.0001, respectively). Data from at-sea locations showed that lactating females forage almost exclusively within Bass Strait during all seasons.

Traffic fatalities: does income inequity create an externality?

Responsible for 20 million severe injuries and/or deaths annually, few epidemics receive less attention than traffic accidents. Going beyond confirming an inverted U-shaped relationship between mean income and fatalities, we show theoretically that income inequality can positively affect fatalities in two ways. Each operates through heterogeneity between road users, and while the direct effect can be expected to evaporate with rising income, the indirect effect may prove to be an externality in that the relationship remains regardless of the level of income. Our model is supported by evidence from 79 countries between 1970 and 2000.

Height and construction costs of residential buildings in Hong Kong and Shanghai

A widely recognised theme of construction economics suggests that the cost of construction per square metre increases as building height rises. However, after many years, research conducted regarding the height and cost issue have established a classic relationship between those two, well known as a U-shaped curve. This paper describes the study of height-cost relationship of high-rise residential buildings in Shanghai and Hong Kong. Initial findings indicated that the curved relationships of height-cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The differences suggest that, Hong Kong contractors have more expertise in multi-storey and high-rise construction than contractors in Shanghai. The dissimilarities also imply that different sets of criteria should be applied in the judgement of height affects cost in different locations. Many factors could be contributors, such as the history and experience in constructing residential high-rise buildings, location, linkage and relationships to the neighbourhood provinces, design and construction regulations, and government policy on residential construction.

Entrepreneurship and economic growth : why is New Zealand an outlier? A preliminary analysis

The literature indicates that entrepreneurship and economic growth are closely and positively associated. For four years running, New Zealand has had the developed world’s highest rate of “Total Entry-Level Entrepreneurial Activity” (Acs et al. 2005; Frederick et al. 2004; Reynolds et al., 2004), yet it has slid to the lower ranks in the OECD in measures of economic development. At its level of entrepreneurial activity, New Zealand should have a higher level of economic development if it were to emulate other countries.

We make use of the Global Entrepreneurship Monitor data set, including nascent entrepreneurship rates for 45 countries over the 2000-2004 period as well as variables from standardised national statistics.

The paper uses two approaches. This research first finds evidence for “U-shaped curve” associating entrepreneurship with economic growth. It notes that New Zealand has the greatest deviation from this association compared to other developed countries with similar entrepreneurial rates (e.g. United States, Australia and Iceland). The second approach looks at nascent entrepreneurship as a function of non-economic conditions such as technology, demography, culture and institutions.

This short paper develops the hypotheses and carries out the “U-shaped curve” test. For the time being it leaves the factor analysis of non-economic conditions for another opportunity.

From kiwis to pad thai : why similar national framework conditions may lead to different entrepreneurial outcomes

Analyzing GEM 2005 data, we confirm that entrepreneurship and economic development form a U-shaped curve. We seek to understand New Zealand’s large deviation from the modeled curve by analyzing all countries’ deviations from the curve. We make recommendations that would move New Zealand toward the trend line and thus aid in increasing its level of economic development. Our findings more generally suggest how entrepreneurial policies should be designed differently, depending on the current level of economic development and a region’s short and long-term economic goals.

From kiwis to curry wurst : why similar national framework conditions may lead to different entrepreneurial outcomes

Analyzing GEM 2005 data, we confirm that entrepreneurship and economic development form a U-shaped curve. We seek to understand New Zealand’s large deviation from the modeled curve by analyzing all countries’ deviations from the curve. We make recommendations that would move New Zealand toward the trend line and thus aid in increasing its level of economic development. Our findings more generally suggest how entrepreneurial policies should be designed differently, depending on the current level of economic development and a region’s short and long-term economic goals.

The outlier phenomenon in entrepreneurship and economic growth : mollycoddling policies create New Zealand’s perfect storm

Analyzing GEM 2005 data, we confirm that entrepreneurship and economic development form a U-shaped curve. We seek to understand New Zealand’s large deviation from the modeled curve by factor-analyzing all countries’ deviations from the curve. We make recommendations that would move New Zealand toward the trend line and thus aid in increasing its level of economic development. Our findings indicate that measures that overprotect workers, spoil incentives, or indulge welfare passivity can stymie economic growth even in conditions of high entrepreneurial activity.

Height and construction costs of residential high-rise buildings in Shanghai

A widely recognized theme of construction economics suggests that the cost of construction per square meter increases as building height rises. However, over a number of years, research conducted regarding the height and cost issue has established a classic relationship between the two factors which can be represented by a U-shaped curve. This paper describes the study of the height-cost relationship of high-rise residential buildings in Shanghai in terms of the total construction cost and elemental costs while considering the context and commonality of buildings. This research was developed as an extension of the previous work, which examined data for buildings in Hong Kong. Initial findings indicate that the curves illustrating the relationships between height and cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The dissimilarities indicate that different sets of criteria should be applied in the judgment of height that affects cost in different locations. In terms of elemental costs, the findings suggest that there are differences in the way these costs react to changes in the building height.

Managerial share ownership and discretionary accruals in Australia : do independent and executive directors have different incentives?

We examine the relation between managerial share ownership (MSO) and discretionary accruals in Australia. We find a positive relation between MSO and discretionary accruals up to a certain level of MSO followed by a negative relation (inverse U-shaped). We suggest that these unique results are a result of certain Australian institutional features that are markedly different to those in the US and the UK and imply that the ownership-discretionary accruals relation is context specific with the wider corporate governance systems influencing the theorised incentive effects. We also posit that executive directors and independent directors have different ownership-discretionary accruals incentives and report results consistent with this proposition.

Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7 : Australian orthopaedic association national joint replacement registry

Background The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia.

Methods Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006–7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk.

Results Females accounted for 46.9% of the 642 primary THR performed during 2006–7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70–79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups.

Conclusions Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA.

Determinants of pregnancy, and induced and spontaneous abortion in a jointly determined framework: Evidence from a country wide district level household survey in India

This study provides evidence on the principal determinants of pregnancy and abortion in India using a large country-wide district-level data set (DLHS 2007). The paper provides an economic framework for the analysis of pregnancy and abortion. The study distinguishes between induced and spontaneous abortion and compares the effects of their determinants.

The results show that there are wide differences between induced and spontaneous abortions in terms of the sign and magnitude of the estimated effects of several of their determinants, most notably wealth, the woman’s age and her desire for children. The study makes a methodological contribution by proposing a trivariate probit estimation framework that recognizes the joint dependence of pregnancy and induced and spontaneous abortion, and provides evidence in support of this joint dependence.

The study reports an inverted U-shaped effect of a woman’s age on her pregnancy and both forms of abortion. The turning point in each case is quite robust to the estimation framework. A significant effect of contextual variables, at the village level, constructed from the individual responses, on a woman’s pregnancy is found. The effects are weaker in the case of induced abortion, and insignificant in the case of spontaneous abortion. The results are shown to be fairly robust. This paper extends the literature on the relation between son preference and fertility by examining the link between mother’s son preference and desire for more children with abortion rates.