A global analysis of bird plumage patterns reveals no association between habitat and camouflage

Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types—mottled (irregular), scales, bars and spots (regular)—and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species’ geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world’s birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world’s eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.This research was funded by an Entente Cordiale Scholarship to M.S., a Biotechnology and Biological Sciences Research Council studentship to K.L.A.M. and the Cambridge Overseas Trust to T-L.G

Shock structures in time averaged patterns for the Kuramoto-Sivashinsky equation

The Kuramoto-Sivashinsky equation with fixed boundary conditions is numerically studied. Shocklike structures appear in the time-averaged patterns for some parameter range of the boundary values. Effective diffusion constant is estimated from the relation of the width and the height of the shock structures.Comment: 6 pages, 7 figure

Emergence of Synchronous Oscillations in Neural Networks Excited by Noise

The presence of noise in non linear dynamical systems can play a constructive role, increasing the degree of order and coherence or evoking improvements in the performance of the system. An example of this positive influence in a biological system is the impulse transmission in neurons and the synchronization of a neural network. Integrating numerically the Fokker-Planck equation we show a self-induced synchronized oscillation. Such an oscillatory state appears in a neural network coupled with a feedback term, when this system is excited by noise and the noise strength is within a certain range.Comment: 12 pages, 18 figure

Abstract 13987: Underutilization of Oral Anticoagulant Therapy in At-Risk Patients With Atrial Fibrillation—Insights From a Multistate Healthcare System

Introduction: Oral anticoagulant (OAC) therapy significantly reduces the risk of thromboembolism among at-risk patients with atrial fibrillation (AF). Current guidelines provide strong support for an OAC in men and women with AF and CHA2DS2-VASc scores of \u3e2 and \u3e3, respectively. In spite of this, previous data has suggested that up to 40% of these patients are not treated in accordance with guideline recommendations. Hypothesis: We hypothesized that OAC therapy continues to remain significantly underutilized among at-risk patients with AF in real-world settings. Methods: We sought to evaluate the prevalence of OAC underuse and contributing factors in an ambulatory population of at-risk AF patients within a large multistate healthcare system. EHR and coding (ICD-10) data were used to identify patients with AF, calculate their CHA2DS2-VASc score, and define their current antithrombotic regimen. Demographics were assessed to allow for comparison between those receiving an OAC from those who were not. Chi square or Fisher exact tests were used to examine differences between groups. Results: Data was pulled from our EHR on 8/1/18, identifying 147,455 unique patients with AF, of which 102,728 (76.3%) had a CHA2DS2-VASc score \u3e2 (excluding female gender) (Table). Compared to those on an OAC, patients on antiplatelet therapy were more likely to have coronary artery disease, peripheral vascular disease, and prior MI (p Conclusions: In a contemporary, non-registry setting, OAC underuse remains substantial among at-risk patients with AF. Further investigation into tools that facilitate implementation of guideline-directed medical therapy is needed to limit preventable thromboembolic events in this population

Abstract 14012: Opportunities to Improve the Efficacy and Safety of Oral Anticoagulant Therapy in Atrial Fibrillation—Insights From a Multistate Healthcare System

Introduction: Vitamin K antagonists (VKAs) effectively reduce thromboembolic risk in atrial fibrillation (AF), but are limited by a narrow therapeutic window. Patients with reduced time in the therapeutic range (TTR) also face an increased risk of bleeding and ischemic events. Based in part on this, current guidelines give preference to direct-acting oral anticoagulants (DOACs) over VKAs in AF. Hypothesis: We hypothesized that DOACs are underutilized among those on oral anticoagulant therapy and that TTR remains suboptimal for large numbers of individuals on VKAs in real-world settings. Methods: We sought to evaluate a) the breakdown of OAC type and b) TTR for those on VKAs in an ambulatory population of at-risk AF patients within a large multistate healthcare system. EHR and coding (ICD-10) data were used to identify patients with AF, calculate their CHA2DS2-VASc score, and define their current antithrombotic regimen. For those on a VKA, TTR was assessed with the Rosendaal method and reported as mean values. Demographics were assessed to allow for comparison between those receiving a DOAC and a VKA, as well as, those with high (\u3e70%) vs. low ( Results: Data was pulled from our EHR on 8/1/18, identifying 147,455 unique patients with AF, of which 102,728 (76.3%) had a CHA2DS2-VASc score \u3e2 (excluding female gender). Among these at-risk patients, 61,698 (60.1%) were receiving an OAC, of which 47.8% were on a VKA and 52.2% were on a DOAC. The mean TTR was 56.3%, with 37.1%, 49.9% and 60.8% with TTRs \u3e70%, \u3e60%, and \u3e50%, respectively. Patients on a DOAC were more likely to be female and less likely to have heart failure, coronary artery disease, peripheral vascular disease, diabetes and renal disease (p70% were more likely to be male and less likely to have heart failure, diabetes, and renal disease (p Conclusions: In a contemporary, non-registry setting, VKAs continue to be used in nearly half of at-risk patients on an OAC for AF, with a suboptimal TTR in nearly two thirds. Further investigation is needed into tools that facilitate interchange from a VKA to a DOAC, particularly among those with a suboptimal TTR

United in Separation? Lozi Secessionism in Zambia and Namibia

Secessionism perseveres as a complex political phenomenon in Africa, yet often a more in-depth analysis is overshadowed by the aspirational simplicity of pursuing a new state. Using historical and contemporary approaches, this edited volume offers the most exhaustive collection of empirical studies of African secessionism to date. The respected expert contributors put salient and lesser known cases into comparative perspective, covering Biafra, Katanga, Eritrea and South Sudan alongside Barotseland, Cabinda, and the Comoros, among others. Suggesting that African secessionism can be understood through the categories of aspiration, grievance, performance, and disenchantment, the book's analytical framework promises to be a building block for future studies of the topic

Impaired Perinatal Growth and Longevity: A Life History Perspective

Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype is adaptively more appropriate to the anticipated environment. Thus, maternal and/or neonatally derived nutritional or endocrine cues suggesting a threatening environment may favour early growth and reproduction over investment in tissue reserve and repair capacity. These may directly affect longevity, as well as prioritise insulin resistance and capacity for fat storage, thereby increasing susceptibility to metabolic dysfunction and obesity. These shifts in developmental trajectory are associated with long-term expression changes in specific genes, some of which may be underpinned by epigenetic processes. This normative process of developmental plasticity may prove to be maladaptive in human environments in transition towards low extrinsic mortality and energy-dense nutrition, leading to the development of an inappropriate phenotype with decreased potential for longevity and/or increased susceptibility to metabolic disease

Forecasting confined spatiotemporal chaos with genetic algorithms

A technique to forecast spatiotemporal time series is presented. it uses a Proper Ortogonal or Karhunen-Lo\`{e}ve Decomposition to encode large spatiotemporal data sets in a few time-series, and Genetic Algorithms to efficiently extract dynamical rules from the data. The method works very well for confined systems displaying spatiotemporal chaos, as exemplified here by forecasting the evolution of the onedimensional complex Ginzburg-Landau equation in a finite domain.Comment: 4 pages, 5 figure