Variation in habitat choice and delayed reproduction: Adaptive queuing strategies or individual quality differences?

In most species, some individuals delay reproduction or occupy inferior breeding positions. The queue hypothesis tries to explain both patterns by proposing that individuals strategically delay breeding (queue) to acquire better breeding or social positions. In 1995, Ens, Weissing, and Drent addressed evolutionarily stable queuing strategies in situations with habitat heterogeneity. However, their model did not consider the non - mutually exclusive individual quality hypothesis, which suggests that some individuals delay breeding or occupy inferior breeding positions because they are poor competitors. Here we extend their model with individual differences in competitive abilities, which are probably plentiful in nature. We show that including even the smallest competitive asymmetries will result in individuals using queuing strategies completely different from those in models that assume equal competitors. Subsequently, we investigate how well our models can explain settleme! nt patterns in the wild, using a long-term study on oystercatchers. This long-lived shorebird exhibits strong variation in age of first reproduction and territory quality. We show that only models that include competitive asymmetries can explain why oystercatchers' settlement patterns depend on natal origin. We conclude that predictions from queuing models are very sensitive to assumptions about competitive asymmetries, while detecting such differences in the wild is often problematic.

Optically activated ZnO/Sio2/Si cantilever beams

The photomechanical effect induced by periodically varying sub-bandgap illumination in thin ZnO films deposited on oxidized Si has been demonstrated for the first time. The efficiency of this effect is at least one order of magnitude higher as compared to the photothermal activation of Si. Thus it can be considered as a powerful optical drive for resonant sensors. A phenomenological model of the mechanisms involved in the process is proposed. The optomechanical effect can also be used as a complementary method in determination of the surface state parameters of ZnO films

Climwin: Climate Window Analysis

Contains functions to detect and visualise periods of climate sensitivity (climate windows) for a given biological response. Please see van de Pol et al. (2016) and Bailey and van de Pol (2016) for details. Climwin is designed for those interested in understanding the impacts of climate, particularly focussed on biological systems. When seeking to understand the effects of climate it is necessary to select a sampling period over which climate is recorded, a climate window. Often this choice is made arbitrarily, with many studies using seasonal values (e.g. spring temperature, winter precipitation). However, these climate windows may not be the most relevant for the biological system in question. If we fail to find a relationship between climate and the biological response it can be difficult to determine whether this is due to climate insensitivity in the biological response or if the choice of climate window is flawed. Rather than being required to make a single arbitrary choice of climate window, climwin allows users to test the effectiveness of a wide range of possible climate windows with the aim of identifying the most appropriate climate window for further use. climwin gives users the ability to visualise the results of their climate window analysis, using ggplot2, as a means to best interpret and understand the climate window results

Research methodology of grazing

Throughout Europe, grass is the main feed for dairy cattle. This report presents the main results of the first meeting of the European Grassland Federation (EGF) Working Group Grazing in Kiel on 29 August 2010. The theme of the meeting was "Research methodology of grazing". There were three sessions: - setting the scene; - modelling of grazing; and - field measurements

Maximising grazing in ruminant production systems: proceedings 6th Meeting EGF Working Group "Grazing" in Cork

This report presents the main outcomes of the sixth meeting of the EGF Working Group “Grazing” which was held in Cork, Ireland on 17 June 2018. The aim of the Working Group “Grazing” is to exchange knowledge on all aspects of grazing research and to provide a forum for networking. The theme of the meeting in Cork was “Maximising grazing in ruminant production systems”

Grazing in a high-tech world : Proceedings 5th meeting EGF Working Group "Grazing" in Trondheim

This report presents the main outcomes of the fifth meeting of the EGF Working Group “Grazing” which was held in Trondheim, Norway on 4 September 2016. The aim of the Working Group “Grazing” is to exchange knowledge on all aspects of grazing research and to provide a forum for networking. The theme of the meeting in Trondheim was “Grazing in a high-tech world

Having Fun in Learning Formal Specifications

There are many benefits in providing formal specifications for our software. However, teaching students to do this is not always easy as courses on formal methods are often experienced as dry by students. This paper presents a game called FormalZ that teachers can use to introduce some variation in their class. Students can have some fun in playing the game and, while doing so, also learn the basics of writing formal specifications in the form of pre- and post-conditions. Unlike existing software engineering themed education games such as Pex and Code Defenders, FormalZ takes the deep gamification approach where playing gets a more central role in order to generate more engagement. This short paper presents our work in progress: the first implementation of FormalZ along with the result of a preliminary users' evaluation. This implementation is functionally complete and tested, but the polishing of its user interface is still future work

Flavonoids Influence Monocytic GTPase Activity and Are Protective in Experimental Allergic Encephalitis

In the chronic disabling disease multiple sclerosis (MS), migration of monocytes across the blood-brain barrier is a crucial step in the formation of new lesions in the central nervous system (CNS). Infiltrating monocyte-derived macrophages secrete inflammatory mediators such as oxygen radicals, which contribute to axonal demyelination and damage, resulting in neurological deficits. Flavonoids are compounds occurring naturally in food, which scavenge oxygen radicals and have antiinflammatory properties. To investigate whether they might suppress clinical symptoms in MS, we treated rats sensitized for acute and chronic experimental allergic encephalomyelitis, an experimental model of MS, with flavonoids. We demonstrated that the flavonoid luteolin substantially suppressed clinical symptoms and prevented relapse when administered either before or after disease onset. Luteolin treatment resulted in reduced inflammation and axonal damage in the CNS by preventing monocyte migration across the brain endothelium. Luteolin influenced migration by modulating the activity of Rho GTPases, signal transducers involved in transendothelial migration. Oral administration of luteolin also significantly reduced clinical symptoms

Serotonergic Drugs Inhibit Chikungunya Virus Infection at Different Stages of the Cell Entry Pathway

Chikungunya virus (CHIKV) is an important reemerging human pathogen transmitted by mosquitoes. The virus causes an acute febrile illness, chikungunya fever, which is characterized by headache, rash, and debilitating (poly)arthralgia that can reside for months to years after infection. Currently, effective antiviral therapies and vaccines are lacking. Due to the high morbidity and economic burden in the countries affected by CHIKV, there is a strong need for new strategies to inhibit CHIKV replication. The serotonergic drug 5-nonyloxytryptamine (5-NT) was previously identified as a potential host-directed inhibitor for CHIKV infection. In this study, we determined the mechanism of action by which the serotonin receptor agonist 5-NT controls CHIKV infection. Using time-of-addition and entry bypass assays, we found that 5-NT predominantly inhibits CHIKV in the early phases of the replication cycle, at a step prior to RNA translation and genome replication. Intriguingly, however, no effect was seen during virus-cell binding, internalization, membrane fusion and genomic RNA (gRNA) release into the cell cytosol. In addition, we show that the serotonin receptor antagonist methiothepin mesylate (MM) also has antiviral properties toward CHIKV and specifically interferes with the cell entry process and/or membrane fusion. Taken together, pharmacological targeting of 5-HT receptors may represent a potent way to limit viral spread and disease severity. IMPORTANCE The rapid spread of mosquito-borne viral diseases in humans puts a huge economic burden on developing countries. For many of these infections, including those caused by chikungunya virus (CHIKV), there are no specific treatment possibilities to alleviate disease symptoms. Understanding the virus-host interactions that are involved in the viral replication cycle is imperative for the rational design of therapeutic strategies. In this study, we discovered an antiviral compound, elucidated its mechanism of action, and propose serotonergic drugs as potential host-directed antivirals for CHIKV

GANGs: Generative Adversarial Network Games

Generative Adversarial Networks (GAN) have become one of the most successful frameworks for unsupervised generative modeling. As GANs are difficult to train much research has focused on this. However, very little of this research has directly exploited game-theoretic techniques. We introduce Generative Adversarial Network Games (GANGs), which explicitly model a finite zero-sum game between a generator ($G$) and classifier ($C$) that use mixed strategies. The size of these games precludes exact solution methods, therefore we define resource-bounded best responses (RBBRs), and a resource-bounded Nash Equilibrium (RB-NE) as a pair of mixed strategies such that neither $G$ or $C$ can find a better RBBR. The RB-NE solution concept is richer than the notion of `local Nash equilibria' in that it captures not only failures of escaping local optima of gradient descent, but applies to any approximate best response computations, including methods with random restarts. To validate our approach, we solve GANGs with the Parallel Nash Memory algorithm, which provably monotonically converges to an RB-NE. We compare our results to standard GAN setups, and demonstrate that our method deals well with typical GAN problems such as mode collapse, partial mode coverage and forgetting