Hit-and-run trophallaxis of small hive beetles

Some parasites of social insects are able to exploit the exchange of food between nestmates via trophallaxis, because they are chemically disguised as nestmates. However, a few parasites succeed in trophallactic solicitation although they are attacked by workers. The underlying mechanisms are not well understood. The small hive beetle (=SHB), Aethina tumida, is such a parasite of honey bee, Apis mellifera, colonies and is able to induce trophallaxis. Here, we investigate whether SHB trophallactic solicitation is innate and affected by sex and experience. We quantified characteristics of the trophallactic solicitation in SHBs from laboratory-reared individuals that were either bee-naïve or had 5 days experience. The data clearly show that SHB trophallactic solicitation is innate and further suggest that it can be influenced by both experience and sex. Inexperienced SHB males begged more often than any of the other groups had longer breaks than their experienced counterparts and a longer soliciting duration than both experienced SHB males and females, suggesting that they start rather slowly and gain more from experience. Successful experienced females and males were not significantly different from each other in relation to successful trophallactic interactions, but had a significantly shorter soliciting duration compared to all other groups, except successful inexperienced females. Trophallactic solicitation success, feeding duration and begging duration were not significantly affected by either SHB sex or experience, supporting the notion that these behaviors are important for survival in host colonies. Overall, success seems to be governed by quality rather than quantity of interactions, thereby probably limiting both SHB energy investment and chance of injury (<1%). Trophallactic solicitation by SHBs is a singular example for an alternative strategy to exploit insect societies without requiring chemical disguise. Hit-and-run trophallaxis is an attractive test system to get an insight into trophallaxis in the social insects

Social Waves in Giant Honeybees Repel Hornets

Giant honeybees (Apis dorsata) nest in the open and have evolved a plethora of defence behaviors. Against predatory wasps, including hornets, they display highly coordinated Mexican wave-like cascades termed ‘shimmering’. Shimmering starts at distinct spots on the nest surface and then spreads across the nest within a split second whereby hundreds of individual bees flip their abdomens upwards. However, so far it is not known whether prey and predator interact and if shimmering has anti-predatory significance. This article reports on the complex spatial and temporal patterns of interaction between Giant honeybee and hornet exemplified in 450 filmed episodes of two A. dorsata colonies and hornets (Vespa sp.). Detailed frame-by-frame analysis showed that shimmering elicits an avoidance response from the hornets showing a strong temporal correlation with the time course of shimmering. In turn, the strength and the rate of the bees' shimmering are modulated by the hornets' flight speed and proximity. The findings suggest that shimmering creates a ‘shelter zone’ of around 50 cm that prevents predatory wasps from foraging bees directly from the nest surface. Thus shimmering appears to be a key defence strategy that supports the Giant honeybees' open-nesting life-style

Ultrafast Light and Electrons: Imaging the Invisible

In this chapter, the evolutionary and revolutionary developments of microscopic imaging are overviewed with focus on ultrashort light and electrons pulses; for simplicity, we shall use the term “ultrafast” for both. From Alhazen’s camera obscura, to Hooke and van Leeuwenhoek’s optical micrography, and on to three- and four-dimensional (4D) electron microscopy, the developments over a millennium have transformed humans’ scope of visualization. The changes in the length and time scales involved are unimaginable, beginning with the visible shadows of candles at the centimeter and second scales, and ending with invisible atoms with space and time dimensions of sub-nanometer and femtosecond, respectively. With these advances it has become possible to determine the structures of matter and to observe their elementary dynamics as they fold and unfold in real time, providing the means for visualizing materials behavior and biological function, with the aim of understanding emergent phenomena in complex systems. Both light and light-generated electrons are now at the forefront of femtosecond and attosecond science and technology, and the scope of applications has reached beyond the nuclear motion as electron dynamics become accessible

Tales of the unexpected: the selection of British party leaders since 1963

Jeremy Corbyn’s election as Leader of the Labour Party in 2015 stunned observers and practitioners of British politics alike. In this article, we first outline a theoretical framework that purports to explain why political parties operating in parliamentary systems choose the leaders they do. We then examine 32 leadership successions involving five major British parties since 1963, and note that many of these were unexpected, in that they were triggered by unforeseen circumstances, such as the sudden death or resignation of the incumbent. Examining each party in turn, we briefly explain why the winners won and identify at least eight cases (a quarter of our sample) where a candidate widely expected to prevail at the outset was ultimately defeated by a ‘dark horse’, ‘second favourite’ or even ‘rank outsider’. Of these, Corbyn’s election in 2015 was the most unexpected and, consistent with the findings of studies of party leadership conventions in other parliamentary systems, namely Canada and Spain, suggests that ideological and policy concerns are sometimes more important than considerations of party unity and electability, especially when a leadership contest is dominated by party activists

Physiologically Based Pharmacokinetic Modelling of Cytochrome P450 2C9-Related Tolbutamide Drug Interactions with Sulfaphenazole and Tasisulam

Background and Objectives: Cytochrome P450 2C9 (CYP2C9) is involved in the biotransformation of many commonly used drugs, and significant drug interactions have been reported for CYP2C9 substrates. Previously published physiologically based pharmacokinetic (PBPK) models of tolbutamide are based on an assumption that its metabolic clearance is exclusively through CYP2C9; however, many studies indicate that CYP2C9 metabolism is only responsible for 80–90% of the total clearance. Therefore, these models are not useful for predicting the magnitude of CYP2C9 drug–drug interactions (DDIs). This paper describes the development and verification of SimCYP-based PBPK models that accurately describe the human pharmacokinetics of tolbutamide when dosed alone or in combination with the CYP2C9 inhibitors sulfaphenazole and tasisulam. Methods: A PBPK model was optimized in SimCYP for tolbutamide as a CYP2C9 substrate, based on published in vitro and clinical data. This model was verified to replicate the magnitude of DDI reported with sulfaphenazole and was further applied to simulate the DDI with tasisulam, a small molecule investigated for the treatment of cancer. A clinical study (CT registration # NCT01185548) was conducted in patients with cancer to assess the pharmacokinetic interaction of tasisulum with tolbutamide. A PBPK model was built for tasisulam, and the clinical study design was replicated using the optimized tolbutamide model. Results: The optimized tolbutamide model accurately predicted the magnitude of tolbutamide AUC increase (5.3–6.2-fold) reported for sulfaphenazole. Furthermore, the PBPK simulations in a healthy volunteer population adequately predicted the increase in plasma exposure of tolbutamide in patients with cancer (predicted AUC ratio = 4.7–5.4; measured mean AUC ratio = 5.7). Conclusions: This optimized tolbutamide PBPK model was verified with two strong CYP2C9 inhibitors and can be applied to the prediction of CYP2C9 interactions for novel inhibitors. Furthermore, this work highlights the utility of mechanistic models in navigating the challenges in conducting clinical pharmacology studies in cancer patients

Is there a need for conservation of Honeybees in Africa?

Honeybees are native to Africa and Europe but have been spread worldwide as the basis for an apicultural industry. To date, large and diverse wild populations only remain in Africa. On this continent the beekeeping industry is relatively undeveloped and relies on trapping swarms from wild populations to constitute the managed stocks. Bee breeding is seldom practiced. The situation is therefore different from that of Europe or North America where wild or feral honeybees have almost disappeared and this distinction is important when assessing the conservation status of African honeybees. While African honeybees appear to be more resistant to major diseases, the history of honeybee populations worldwide suggests that their conservation is a necessity. After analyzing the threats to which honeybees are exposed in Africa, we argue that preventive conservation measures are required to maintain the present favorable situation and avoid the declines in populations experienced elsewhere