Pre-copulatory reproductive behaviours are preserved in Drosophila melanogaster infected with bacteria

Reproduction and immunity are crucial traits that determine an animal’s fitness. Terminal investment hypothesis predicts that reproductive investment should increase in the face of a mortality risk caused by infection. However, due to competitive allocation of energetic resources, individuals fighting infections are expected to decrease reproductive efforts. While there is evidence for both hypotheses, the factors that determine the choice between these strategies are poorly understood. Here, we assess the impact of bacterial infection on pre-copulatory behaviours in the fruit fly Drosophila melanogaster. We found that male flies infected with six different bacteria, including pathogenic and non-pathogenic strains, show no significant differences in courtship intensity and mating success. Similarly, bacterial infections did not affect sexual receptivity in female flies. Our data suggest that pre-copulatory reproductive behaviours remain preserved in infected animals, despite the huge metabolic cost of infection.

Perceived Loudness Sensitivity Influenced by Brightness in Urban Forests: A Comparison When Eyes Were Opened and Closed

Soundscape plays a positive, health-related role in urban forests, and there is a competitive allocation of cognitive resources between soundscapes and lightscapes. This study aimed to explore the relationship between perceived loudness sensitivity and brightness in urban forests through eye opening and closure. Questionnaires and measuring equipment were used to gather soundscape and lightscape information at 44 observation sites in urban forested areas. Diurnal variations, Pearson’s correlations, and formula derivations were then used to analyze the relationship between perception sensitivity and how perceived loudness sensitivity was influenced by lightscape. Our results suggested that soundscape variation plays a role in audio–visual perception in urban forests. Our findings also showed a gap in perception sensitivity between loudness and brightness, which conducted two opposite conditions bounded by 1.24 dBA. Furthermore, we found that the effect of brightness on perceived loudness sensitivity was limited if variations of brightness were sequential and weak. This can facilitate the understanding of individual perception to soundscape and lightscape in urban forests when proposing suitable design plans.

A weapons–testes trade-off in males is amplified in female traits

Sexually selected weapons are assumed to trade off with traits related to ejaculates, such as testes. However, remarkably little is known about what governs resource allocation and why trade-offs are found in some cases and not others. Often-used models depict competitive allocation occurring within the functional grouping of traits (e.g. reproduction); however, other factors including tissue expense and developmental timing may influence allocation. Experimental comparisons of investment across the sexes have the potential to illuminate allocation rules, because the sexes do not always use traits for the same functions. Here, we capitalize upon a species where females have weapons–testes homologues. We report that a documented trade-off in investment between hind-limb weapons and testes in leaf-footed cactus bugs, Narnia femorata , is even more pronounced in female hind limbs and ovaries. Female hind limbs in this species do not share the clear reproductive function of male hind limbs; therefore, this trade-off spans trait functional groups. Such patterns of investment suggest that future studies of reproductive trade-offs should consider factors such as tissue expense and developmental timing.

Multiple Lenders, Strategic Default, and Covenants

We study capital markets in which investors compete by designing financial contracts to control an entrepreneur’s ability to side trade and default on multiple loans. We show that covenants may have anticompetitive effects: in particular, they prevent investors from providing additional funds and reduce the entrepreneur’s investment capacity. As a result, a large number of inefficient allocations is supported at equilibrium. We propose a subsidy mechanism similar to guarantee funds in financial markets that efficiently controls the entrepreneur’s side trading and sustains the competitive allocation as the unique equilibrium one. (JEL D21, D82, D86, G21, G32)

Trade and growth in a model of allocative inefficiency

The empirical evidence on the causal relationship between international trade and economic growth is inconclusive. While some studies show that trade leads to growth, others have pointed to a reverse causation. In this paper, we develop a model of international trade and productivity growth in the presence of a misallocation of resources. Misallocation in a country arises as a result of lobbying by firms to establish barriers to the competitive allocation of labor. Misallocation prevents the country from exploiting its technological comparative advantage and leads to a reduction in the volume of trade in the absence of any explicit trade barriers. In the model, whether barriers diminish or worsen with productivity growth depends on the extent of the initial resource misallocation. If the initial resource misallocation is not severe, then productivity growth leads to diminishing barriers and vice versa. In either case, productivity growth strengthens the comparative advantage over time and therefore increases the volume of trade.

Architectural research and its enemies

Like the Research Assessment Exercise (RAE) that preceded it, the UK government's proposed Research Excellence Framework (REF) is a means of allocating funding in higher education to support research. As with any method for the competitive allocation of funds it creates winners and losers and inevitably generates a lot of emotion among those rewarded or penalised. More specifically, the ‘winners’ tend to approve of the method of allocation and the ‘losers’ denigrate it as biased against their activities and generally unfair. An extraordinary press campaign has been consistently waged against research assessment and its methods by those involved in architectural education, which I will track over a decade and a half. What follows will question whether this campaign demonstrates the sophistication and superior judgment of those who have gone into print, or conversely whether its mixture of misinformation and disinformation reveals not just disenchantment and prejudice, but a naivety and a depth of ignorance about the fundamentals of research that is deeply damaging to the credibility of architecture as a research-based discipline. With the recent consultation process towards a new cycle of research assessment, the REF, getting under way, I aim to draw attention to the risk of repeating past mistakes.