Motorboat noise impacts parental behaviour and offspring survival in a reef fish

This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this record.Anthropogenic noise is a pollutant of international concern, with mounting evidence of disturbance and impacts on animal behaviour and physiology. However, empirical studies measuring survival consequences are rare. We use a field experiment to investigate how repeated motorboat-noise playback affects parental behaviour and offspring survival in the spiny chromis (Acanthochromis polyacanthus), a brooding coral reef fish. Repeated observations were made for 12 days at 38 natural nests with broods of young. Exposure to motorboat-noise playback compared to ambient-sound playback increased defensive acts, and reduced both feeding and offspring interactions by brood-guarding males. Anthropogenic noise did not affect the growth of developing offspring, but reduced the likelihood of offspring survival; while offspring survived at all 19 nests exposed to ambient-sound playback, six of the 19 nests exposed to motorboat-noise playback suffered complete brood mortality. Our study, providing field-based experimental evidence of the consequences of anthropogenic noise, suggests potential fitness consequences of this global pollutant.This work was supported by a NERC Knowledge Exchange Fellowship (for S.D.S.; NE/J500616/2), the UK Department for Environment Food and Rural Affairs (S.D.S. and A.N.R.; ME5207), funds from ARC Centre of Excellence for Coral Reef Studies (M.I.M; EI140100117), an EPSRC studentship and Subacoustech (S.L.N.)

Anthropogenic noise increases fish mortality by predation

PublishedNoise-generating human activities affect hearing, communication and movement in terrestrial and aquatic animals, but direct evidence for impacts on survival is rare. We examined effects of motorboat noise on post-settlement survival and physiology of a prey fish species and its performance when exposed to predators. Both playback of motorboat noise and direct disturbance by motorboats elevated metabolic rate in Ambon damselfish (Pomacentrus amboinensis), which when stressed by motorboat noise responded less often and less rapidly to simulated predatory strikes. Prey were captured more readily by their natural predator (dusky dottyback, Pseudochromis fuscus) during exposure to motorboat noise compared with ambient conditions, and more than twice as many prey were consumed by the predator in field experiments when motorboats were passing. Our study suggests that a common source of noise in the marine environment has the potential to impact fish demography, highlighting the need to include anthropogenic noise in management plans.This work was supported by a NERC Knowledge Exchange Fellowship (for S.D.S.), the UK Department for Environment Food and Rural Affairs (S.D.S. and A.N.R.), the ARC Centre of Excellence for Coral Reef Studies (M.I.M; EI140100117) and an EPSRC studentship (S.L.N.). NERC KE Fellowship (S.D.S.; NE/J500616/2

Dynamics of direct inter-pack encounters in endangered African wild dogs

Aggressive encounters may have important life history consequences due to the potential for injury and death, disease transmission, dispersal opportunities or exclusion from key areas of the home range. Despite this, little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters in detail. Here, we describe detailed spatial dynamics of inter-pack encounters in African wild dogs (Lycaon pictus), using data from custom-built high-resolution GPS collars in 11 free-ranging packs. On average, each pack encountered another pack approximately every 7 weeks and met each neighbour twice each year. Surprisingly, intruders were more likely to win encounters (winning 78.6% of encounters by remaining closer to the site in the short term). However, intruders did tend to move farther than residents toward their own range core in the short-term (1 h) post-encounter, and if this were used to indicate losing an encounter, then the majority (73.3%) of encounters were won by residents. Surprisingly, relative pack size had little effect on encounter outcome, and injuries were rare (<15% of encounters). These results highlight the difficulty of remotely scoring encounters involving mobile participants away from static defendable food resources. Although inter-pack range overlap was reduced following an encounter, encounter outcome did not seem to drive this, as both packs shifted their ranges post-encounter. Our results indicate that inter-pack encounters may be lower risk than previously suggested and do not appear to influence long-term movement and ranging

Increasing generality in machine learning through procedural content generation

Procedural Content Generation (PCG) refers to the practice, in videogames and other games, of generating content such as levels, quests, or characters algorithmically. Motivated by the need to make games replayable, as well as to reduce authoring burden, limit storage space requirements, and enable particular aesthetics, a large number of PCG methods have been devised by game developers. Additionally, researchers have explored adapting methods from machine learning, optimization, and constraint solving to PCG problems. Games have been widely used in AI research since the inception of the field, and in recent years have been used to develop and benchmark new machine learning algorithms. Through this practice, it has become more apparent that these algorithms are susceptible to overfitting. Often, an algorithm will not learn a general policy, but instead a policy that will only work for a particular version of a particular task with particular initial parameters. In response, researchers have begun exploring randomization of problem parameters to counteract such overfitting and to allow trained policies to more easily transfer from one environment to another, such as from a simulated robot to a robot in the real world. Here we review the large amount of existing work on PCG, which we believe has an important role to play in increasing the generality of machine learning methods. The main goal here is to present RL/AI with new tools from the PCG toolbox, and its secondary goal is to explain to game developers and researchers a way in which their work is relevant to AI research

A randomized controlled trial of mycophenolate mofetil in patients with IgA nephropathy [ISRCTN62574616]

BACKGROUND: IgAN is the most common type of glomerulonephritis in the world. Between 15 and 40 percent of adults and children diagnosed with IgAN eventually progress to ESRD. Despite the need for effective treatment strategies, very few RCTs for IgAN have been performed. The most effective therapies for IgAN appear to be corticosteroids, ACEi, and FOS that contain a high concentration of omega 3 fatty acids. While ACEi and FOS are generally well tolerated with minimal side effects, the use of high dose steroids over a long course of therapy is often associated with significant morbidity. OBJECTIVE OF THE STUDY: The objective of the study is to test the hypothesis that treatment with the immunosuppressive agent, MMF, will lead to significant and sustained improvement in urinary protein excretion in patients with IgAN who have been pre-treated (and continue to be treated) with ACE(i )and FOS compared to a placebo control group of patients receiving comparable doses of ACEi and FOS without MMF. DESIGN: After a three month treatment period with the ACEi, lisinopril and the FOS, Omacor(®), 100 (2 × 50) patients with IgAN and a urinary P/C ratio ≥ 0.6 (males) and ≥ 0.8 (females) and an estGFR ≥ 40 ml/min/1.73 m2 will be randomized to treatment with either MMF or placebo for one year. All patients will be followed off study drug for a second year, but will continue treatment with lisinopril and Omacor(® )for the two year duration of the study. The primary outcome measure of change in urine P/C ratio will be assessed at the end of years one and two

Cotranslational protein assembly imposes evolutionary constraints on homomeric proteins

Cotranslational protein folding can facilitate rapid formation of functional structures. However, it might also cause premature assembly of protein complexes, if two interacting nascent chains are in close proximity. By analyzing known protein structures, we show that homomeric protein contacts are enriched towards the C-termini of polypeptide chains across diverse proteomes. We hypothesize that this is the result of evolutionary constraints for folding to occur prior to assembly. Using high-throughput imaging of protein homomers in vivo in E. coli and engineered protein constructs with N- and C-terminal oligomerization domains, we show that, indeed, proteins with C-terminal homomeric interface residues consistently assemble more efficiently than those with N-terminal interface residues. Using in vivo, in vitro and in silico experiments, we identify features that govern successful assembly of homomers, which have implications for protein design and expression optimization