Cost of reproduction in the Queensland fruit fly: Y-model versus lethal protein hypothesis

The trade-off between lifespan and reproduction is commonly explained by differential allocation of limited resources. Recent research has shown that the ratio of protein to carbohydrate (P : C) of a fly's diet mediates the lifespan–reproduction trade-off, with higher P : C diets increasing egg production but decreasing lifespan. To test whether this P : C effect is because of changing allocation strategies (Y-model hypothesis) or detrimental effects of protein ingestion on lifespan (lethal protein hypothesis), we measured lifespan and egg production in Queensland fruit flies varying in reproductive status (mated, virgin and sterilized females, virgin males) that were fed one of 18 diets varying in protein and carbohydrate amounts. The Y-model predicts that for sterilized females and for males, which require little protein for reproduction, there will be no effect of P : C ratio on lifespan; the lethal protein hypothesis predicts that the effect of P : C ratio should be similar in all groups. In support of the lethal protein hypothesis, and counter to the Y-model, the P : C ratio of the ingested diets had similar effects for all groups. We conclude that the trade-off between lifespan and reproduction is mediated by the detrimental side-effects of protein ingestion on lifespan.

Young adults and politics: investigating factors influencing voter decision making

Many parallels have been drawn between politics and marketing; however, the application of consumer behavior decision making to voter decision making is still an important research focus. Results from general elections around the world show that the turnout among young adults tends to be lower than in the general electorate, suggesting low interest and involvement in politics. This qualitative study investigated low-involvement decision making of young adult voters in Australia. Data were compiled from semistructured face-to-face interviews conducted with 29 young adults to explore their views, and NVivo software was used to assist with thematic analysis. Findings suggest that with low-involvement voter decision making, perceived knowledge and passive information seeking are important factors. Exposure to the media also plays an important role, and young voters rely more on traditional media such as newspapers and television than on social media for current political information.

Are vehicles 'mobile bird hides'?: A test of the hypothesis that 'cars cause less disturbance'

We tested the 'cars cause less disturbance' hypothesis by comparing the flight-initiation distance (FID) evoked by a car versus a single walker for 38 species of waterbird (n = 657 standardised approaches). For the 15 species where we had sample size adequate for statistical testing (n ≥ 5), we found that cars elicited shorter responses after controlling for starting distance. Within-species analyses revealed that this difference was significant in 8 of 15 species. Although mean FIDs for car approaches were always shorter than FIDs toward single walkers in the remaining species (7), the tests in those species lacked sufficient power to draw meaningful conclusions. Our results provide support for the hypothesis that birds respond to cars at shorter distances. The wide taxonomic breadth of species investigated suggests that this principle may be broadly applicable, at least in waterbirds. The results of this study and the FID estimates we present will allow development of meaningful stimulus-specific buffer zones to protect waterbirds from disturbance.

Cancer stem cells: a contentious hypothesis now moving forward

Cancer stem cells are a progressive concept to account for the cell biological nature of cancer. Despite the controversies regarding the cancer stem cell model, it has the potential to provide a foundation for new innovative treatment targeting the roots of cancer. The last two years have witnessed exceptional progress in cancer stem cell research, in particular on solid tumours, which holds promise for improved treatment outcomes. Here, we review recent advances in cancer stem cell research, discuss challenges in the field and explore future strategies and opportunities in cancer stem cell studies to overcome resistance to chemotherapy.

A factor analytical approach to the efficient futures market hypothesis

Most empirical evidence suggests that the efficient futures market hypothesis, henceforth referred to as EFMH, stating that spot and futures prices should cointegrate with a unit slope on futures prices, does not hold, a finding at odds with many theoretical models. This article argues that these results can be attributed in part to the low power of univariate tests, and that the use of panel data can generate more powerful tests. The current article can be seen as a step in this direction. In particular, a newly developed factor analytical approach is employed, which is very general and, in addition, free of the otherwise so common incidental parameters bias in the presence of fixed effects. The approach is applied to a large panel covering 17 commodities between March 1991 and August 2012. The evidence suggests that the EFMH cannot be rejected once the panel evidence has been taken into account. © 2014 Wiley Periodicals, Inc.

The efficient market hypothesis and corporate event waves: part 1

Efficient markets are commonly defined as ones that do not allow investors to earn above-average returns without accepting above-average risk. In a traditional framework, where investors are rational and there are no frictions, the efficient market hypothesis (EMH) states that a security's price reflects its fundamental value, which is the sum of its discounted expected future cash flows. Put simply, under the EMH, securities are "rightly priced." Through this study, the author finds that while the EMH has been widely accepted for decades among academics, practitioners and regulators still appear to be unconvinced. From a behavioral perspective, the author shows that human psychology and sentiment factors can account for some discrepancies in financial markets. He also finds evidence of limited arbitrage being risky and costly and, hence, impeding the ability of investors to take advantage of profitable opportunities. This study provides an extensive analysis of the critical discussions surrounding the EMH and deepens and strengthens the understanding of the EMH, as well as the arguments for and against.

The efficient market hypothesis and corporate event waves: part II

This article is the second of a two-part series on the efficient market hypothesis corporate event waves. The ideas of market efficiency, or rational theory, and the behavioral hypothesis have been extensively used to explain the modern phenomena of corporate event waves. Some studies investigate the patterns of corporate events from a behavioral finance perspective and suggest that corporate announcement waves are driven by investor sentiment. Baker and Wurgler examine equity market timing as an aspect of real corporate financial policy. Sentiment can also explain IPO waves. Post-announcement returns and IPO volume are positively correlated to firms' capital demands and the level of investor optimism. Helwge and Liang examine the IPO cycles from hot to cold markets from 1975 to 2000. Corporate e vent wave scan also be explained by the neoclassical efficiency hypothesis, proposing that business cycle fluctuations and economic conditions drive firms' decisions on financing transactions.

Energy consumption at the state level: the unit root null hypothesis from Australia

In this paper, our goal is to examine the unit root null hypothesis in energy consumption for Australian states and territory. We consider sectoral energy consumption for Australia and its six states and one territory using time series data for the period 1973-2007. This is the first study that does this. Generally, except for some cases in South Australia, we find strong support that shocks to energy consumption have a temporary effect on energy consumption in Australia. © 2009 Elsevier Ltd. All rights reserved.

Is the efficient market hypothesis day-of-the-week dependent? Evidence from the banking sector

In this article, we propose a new hypothesis: that the efficient market hypothesis is day-of-the-week-dependent. We apply the test to firms belonging to the banking sector and listed on the NYSE. We find significant evidence that the efficient market hypothesis is day-of-the-week-dependent. Overall, for only 62% of firms, the unit root null hypothesis is rejected on all the five trading days. We also discover that when investors do not account for unit root properties in devising trading strategies, they obtain spurious profits.

Evaluating young adult voter decision-making involvement within a compulsory political system

Purpose - This study aims to specifically focus on the lower-involvement young adult voters within the Australian compulsory voting context. It explores voters’ political decision-making by considering the influence of the consumer behaviour theory of involvement. Design/methodology/approach - A thematic analysis was conducted to analyse the interviews within the two research questions: information seeking and decision-making. Findings - Key themes within information seeking are the reach of the information available, the frequency of the information presented, the creativity of the message and one-way versus two-way communication. Key themes within evaluation are promise keeping/trust, achievements or performance and policies. Lower-involvement decision-making has the potential to be a habitual, limited evaluation decision. However, issues of trust, performance and policies may encourage evaluation, thereby reducing the chances of habitually voting for the same party as before. Practical implications - This new area of research has implications for the application of marketing for organisations and political marketing theory. Considering voting decision-making as a lower-involvement decision has implications for assisting the creation and adaptation of strategies to focus on this group of the population. Originality/value - The compulsory voting environment creates a unique situation to study lower-involvement decision-making, as these young adults are less likely to opt out of the voting process. Previous research in political marketing has not specifically explored the application of involvement to young adult voting within a compulsory voting environment.

Habitat switching by Bewick's swans: Maximization of average long-term energy gain?

1. In a system where depletion drives a habitat shift, the hypothesis was tested that animals switch habitat as soon as the average daily net energy intake (or gain) drops below that attainable in the alternative habitat.

2. The study was performed in the Lauwersmeer area. Upon arrival during the autumn migration, Bewick's swans first feed on below-ground tubers of fennel pondweed on the lake, but subsequently switched to feeding on harvest remains in sugar beet fields.

3. The daily energy intake was estimated by multiplying the average time spent foraging per day with the instantaneous energy intake rate while foraging. In the case of pondweed feeding, the latter was estimated from the functional response and the depletion of tuber biomass. In the case of beet feeding, it was estimated from dropping production rate. Gross energy intake was converted to metabolizable energy intake using the assimilation as determined in digestion trials. The daily energy expenditure was estimated by the time-energy budget method. Energetic costs were determined using heart rate.

4. The daily gain of pondweed feeding at the median date of the habitat switch (i.e. when 50% of the swans had switched) was compared with that of beet feeding. The daily gain of beet feeding was calculated for two strategies depending on the night activity on the lake: additional pondweed feeding (mixed feeding) or sleeping (pure beet feeding).

5. The majority of the swans switched when the daily gain they could achieve by staying on the pondweed bed fell just below the average daily gain of pure beet feeders. However, mixed feeders would attain an average daily gain considerably above that of pondweed feeders. A sensitivity analysis showed that this result was robust.

6. We therefore reject the hypothesis that the habitat switch by swans can be explained by simple long-term energy rate maximization. State-dependency, predation risk, and protein requirements are put forward as explanations for the delay in habitat switch.

The contact hypothesis in urban china: the perspective of minority-status migrant workers

This study is the first to test Allport's (1954) contact hypothesis from the perspective of a minority group in China. Employing a sample of off-farm migrant workers in urban China, results indicate a positive effect on self-reported attitudes of intergroup friendship contact between migrant and local workers; and positive effects on self-reported behavioral interaction between migrants and urban locals of both intergroup friendship and intergroup nonfriendship contact. © 2011 Urban Affairs Association.

Panel cointegration tests of the sustainability hypothesis in rich OECD countries

This study reexamines the sustainability hypothesis by testing whether government revenues and expenditures for eight rich OECD countries between 1977Q1 and 2005Q4 are cointegrated. For this purpose, a nonstationary panel data approach is adopted, which is general enough to permit for cross-country dependence as well as structural breaks representing major shifts in fiscal policy. In contrast to many earlier studies, the results reported in this study suggest that the sustainability hypothesis cannot be rejected. © 2010 Taylor & Francis.

Estimating cointegrated panels with common factors and the forward rate unbiasedness hypothesis

This article proposes a bias-adjusted estimator for use in cointegrated panel regressions when the errors are cross-sectionally correlated through an unknown common factor structure. The asymptotic distribution of the new estimator is derived and is examined in small samples using Monte Carlo simulations. For the estimation of the number of factors, several information-based criteria are considered. The simulation results suggest that the new estimator performs well in comparison to existing ones. In our empirical application, we provide new evidence suggesting that the forward rate unbiasedness hypothesis cannot be rejected. © The Author 2007.