Intrinsic noise and two-dimensional maps: Quasicycles, quasiperiodicity, and chaos

We develop a formalism to describe the discrete-time dynamics of systems containing an arbitrary number of interacting species. The individual-based model, which forms our starting point, is described by a Markov chain, which in the limit of large system sizes is shown to be very well-approximated by a Fokker-Planck-like equation, or equivalently by a set of stochastic difference equations. This formalism is applied to the specific case of two species: one predator species and its prey species. Quasi-cycles --- stochastic cycles sustained and amplified by the demographic noise --- previously found in continuous-time predator-prey models are shown to exist, and their behavior predicted from a linear noise analysis is shown to be in very good agreement with simulations. The effects of the noise on other attractors in the corresponding deterministic map, such as periodic cycles, quasiperiodicity and chaos, are also investigated.Comment: 21 pages, 12 figure

Suppressing escape events in maps of the unit interval with demographic noise

We explore the properties of discrete-time stochastic processes with a bounded state space, whose deterministic limit is given by a map of the unit interval. We find that, in the mesoscopic description of the system, the large jumps between successive iterates of the process can result in probability leaking out of the unit interval, despite the fact that the noise is multiplicative and vanishes at the boundaries. By including higher-order terms in the mesoscopic expansion, we are able to capture the non-Gaussian nature of the noise distribution near the boundaries, but this does not preclude the possibility of a trajectory leaving the interval. We propose a number of prescriptions for treating these escape events, and we compare the results with those obtained for the metastable behavior of the microscopic model, where escape events are not possible. We find that, rather than truncating the noise distribution, censoring this distribution to prevent escape events leads to results which are more consistent with the microscopic model. The addition of higher moments to the noise distribution does not increase the accuracy of the final results, and it can be replaced by the simpler Gaussian noise.Comment: 14 pages, 13 figure

Taxonomic revision of the genus Sarcosphaera (Ascomycota: Pezizales) in Europe and North America revealed unexpected diversity.

Sarcosphaera (Ascomycota: Pezizales) is a genus of rare spring fungi, currently encompassing a single species, S. coronaria, which is red-listed in many European countries. The genus is characterized by large bright-colored fruit-bodies and high arsenic content. This study investigates the genetic diversity across Europe and North America. Using integrated molecular techniques, including ITS and 28S rDNA sequencing, we aimed to resolve the taxonomic ambiguities and assess their arsenic hyperaccumulation capabilities, a rare trait among fungi. We identified the presence of two species in the Western Palearctic (S. coronaria, S. crassa) and at least 12 additional lineages in North America, indicating a more complex taxonomic structure than previously recognized. To consolidate the taxonomy and nomenclature of these fungi, we selected reference specimens for S. coronaria and S. crassa and discussed their morphological and ecological differences. Two genera, Caulocarpa (C. montana) and Hydnotryopsis (H. setchellii), a genus comprising hypogeous fungi, are newly placed in the genus Sarcosphaera. Sarcosphaera is thus another genus where the rapid evolution of hypogeous forms from their above-ground ancestors took place. Furthermore, two new Sarcosphaera species, S. columbiana and S. pacifica, are described from the Pacific Northwest. Investigation of arsenic content of Sarcosphaera species revealed that arsenic mass fractions in ascocarps vary significantly between species and even within species across different geographical locations. Our findings have important implications for the taxonomy and conservation of the S. coronaria species complex and also point to future directions for further research in the taxonomy, geomycology, and toxicology of this group of fungi

Symptomatic and Subclinical Infection with Rotavirus P[8]G9, Rural Ecuador

Prevalence of this genotype is increasing

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

De-Novo Assembly and Analysis of the Heterozygous Triploid Genome of the Wine Spoilage Yeast Dekkera bruxellensis AWRI1499

Despite its industrial importance, the yeast species Dekkera (Brettanomyces) bruxellensis has remained poorly understood at the genetic level. In this study we describe whole genome sequencing and analysis for a prevalent wine spoilage strain, AWRI1499. The 12.7 Mb assembly, consisting of 324 contigs in 99 scaffolds (super-contigs) at 26-fold coverage, exhibits a relatively high density of single nucleotide polymorphisms (SNPs). Haplotype sampling for 1.2% of open reading frames suggested that the D. bruxellensis AWRI1499 genome is comprised of a moderately heterozygous diploid genome, in combination with a divergent haploid genome. Gene content analysis revealed enrichment in membrane proteins, particularly transporters, along with oxidoreductase enzymes. Availability of this assembly and annotation provides a resource for further investigation of genomic organization in this species, and functional characterization of genes that may confer important phenotypic traits

Sub-second periodicity in a fast radio burst

Fast radio bursts (FRBs) are millisecond-duration flashes of radio waves that are visible at distances of billions of light-years. The nature of their progenitors and their emission mechanism remain open astrophysical questions. Here we report the detection of the multi-component FRB 20191221A and the identification of a periodic separation of 216.8(1) ms between its components with a significance of 6.5 sigmas. The long (~3 s) duration and nine or more components forming the pulse profile make this source an outlier in the FRB population. Such short periodicity provides strong evidence for a neutron-star origin of the event. Moreover, our detection favours emission arising from the neutron-star magnetosphere, as opposed to emission regions located further away from the star, as predicted by some models.Comment: Updated to conform to the accepted versio

Evolution in Australasian Mangrove Forests: Multilocus Phylogenetic Analysis of the Gerygone Warblers (Aves: Acanthizidae)

The mangrove forests of Australasia have many endemic bird species but their evolution and radiation in those habitats has been little studied. One genus with several mangrove specialist species is Gerygone (Passeriformes: Acanthizidae). The phylogeny of the Acanthizidae is reasonably well understood but limited taxon sampling for Gerygone has constrained understanding of its evolution and historical biogeography in mangroves. Here we report on a phylogenetic analysis of Gerygone based on comprehensive taxon sampling and a multilocus dataset of thirteen loci spread across the avian genome (eleven nuclear and two mitochondrial loci). Since Gerygone includes three species restricted to Australia's coastal mangrove forests, we particularly sought to understand the biogeography of their evolution in that ecosystem. Analyses of individual loci, as well as of a concatenated dataset drawn from previous molecular studies indicates that the genus as currently defined is not monophyletic, and that the Grey Gerygone (G. cinerea) from New Guinea should be transferred to the genus Acanthiza. The multilocus approach has permitted the nuanced view of the group's evolution into mangrove ecosystems having occurred on multiple occasions, in three non-overlapping time frames, most likely first by the G. magnirostris lineage, and subsequently followed by those of G. tenebrosa and G. levigaster

Challenges and opportunities in the design and construction of a GIS-based emission inventory infrastructure for the Niger Delta region of Nigeria

© 2017, Springer-Verlag Berlin Heidelberg. Environmental monitoring in middle- and low-income countries is hampered by many factors which include enactment and enforcement of legislations; deficiencies in environmental data reporting and documentation; inconsistent, incomplete and unverifiable data; a lack of access to data; and technical expertise. This paper describes the processes undertaken and the major challenges encountered in the construction of the first Niger Delta Emission Inventory (NDEI) for criteria air pollutants and CO2 released from the anthropogenic activities in the region. This study focused on using publicly available government and research data. The NDEI has been designed to provide a Geographic Information System-based component of an air quality and carbon management framework. The NDEI infrastructure was designed and constructed at 1-, 10- and 20-km grid resolutions for point, line and area sources using industry standard processes and emission factors derived from activities similar to those in the Niger Delta. Due to inadequate, incomplete, potentially inaccurate and unavailable data, the infrastructure was populated with data based on a series of best possible assumptions for key emission sources. This produces outputs with variable levels of certainty, which also highlights the critical challenges in the estimation of emissions from a developing country. However, the infrastructure is functional and has the ability to produce spatially resolved emission estimates

Heritage: A phase III safety and efficacy trial of the proposed trastuzumab biosimilar Myl-1401O versus Herceptin

Background: Trastuzumab has revolutionized treatment of HER2+ breast cancer. Globally accessible alternatives are a critical need. We evaluated Myl-1401O, a proposed trastuzumab biosimilar, as treatment for HER2+ metastatic breast cancer (MBC), based on physicochemical analyses, nonclinical, pharmacokinetic and pharmacodynamic studies*. Methods: Heritage is a double-blind, randomized clinical trial designed to evaluate comparative efficacy and safety of Myl-1401O vs Herceptin. Eligible patients (pts) had ..