Information propagation through quantum chains with fluctuating disorder

We investigate the propagation of information through one-dimensional quantum chains in fluctuating external fields. We find that information propagation is suppressed, but in a quite different way compared to the situation with static disorder. We study two settings: (i) a general model where an unobservable fluctuating field acts as a source of decoherence; (ii) the XX model with both observable and unobservable fluctuating fields. In the first setting we establish a noise threshold below which information can propagate ballistically and above which information is localised. In the second setting we find localisation for all levels of unobservable noise, whilst an observable field can yield diffusive propagation of information.Comment: 5 pages, 2 figure

Bounds on Information Propagation in Disordered Quantum Spin Chains

We investigate the propagation of information through the disordered XY model. We find, with a probability that increases with the size of the system, that all correlations, both classical and quantum, are suppressed outside of an effective lightcone whose radius grows at most polylogarithmically with |t|.Comment: 4 pages, pdflatex, 1 pdf figure. Corrected the bound for the localised propagator and quantified the probability it bound occur

The Carbon_h-Factor: Predicting Individuals' Research Impact at Early Stages of Their Career

Assessing an individual's research impact on the basis of a transparent algorithm is an important task for evaluation and comparison purposes. Besides simple but also inaccurate indices such as counting the mere number of publications or the accumulation of overall citations, and highly complex but also overwhelming full-range publication lists in their raw format, Hirsch (2005) introduced a single figure cleverly combining different approaches. The so-called h-index has undoubtedly become the standard in scientometrics of individuals' research impact (note: in the present paper I will always use the term “research impact” to describe the research performance as the logic of the paper is based on the h-index, which quantifies the specific “impact” of, e.g., researchers, but also because the genuine meaning of impact refers to quality as well). As the h-index reflects the number h of papers a researcher has published with at least h citations, the index is inherently positively biased towards senior level researchers. This might sometimes be problematic when predictive tools are needed for assessing young scientists' potential, especially when recruiting early career positions or equipping young scientists' labs. To be compatible with the standard h-index, the proposed index integrates the scientist's research age (Carbon_h-factor) into the h-index, thus reporting the average gain of h-index per year. Comprehensive calculations of the Carbon_h-factor were made for a broad variety of four research-disciplines (economics, neuroscience, physics and psychology) and for researchers performing on three high levels of research impact (substantial, outstanding and epochal) with ten researchers per category. For all research areas and output levels we obtained linear developments of the h-index demonstrating the validity of predicting one's later impact in terms of research impact already at an early stage of their career with the Carbon_h-factor being approx. 0.4, 0.8, and 1.5 for substantial, outstanding and epochal researchers, respectively

The Microphenotron: a robotic miniaturized plant phenotyping platform with diverse applications in chemical biology

Background Chemical genetics provides a powerful alternative to conventional genetics for understanding gene function. However, its application to plants has been limited by the lack of a technology that allows detailed phenotyping of whole-seedling development in the context of a high-throughput chemical screen. We have therefore sought to develop an automated micro-phenotyping platform that would allow both root and shoot development to be monitored under conditions where the phenotypic effects of large numbers of small molecules can be assessed. Results The ‘Microphenotron’ platform uses 96-well microtitre plates to deliver chemical treatments to seedlings of Arabidopsis thaliana L. and is based around four components: (a) the ‘Phytostrip’, a novel seedling growth device that enables chemical treatments to be combined with the automated capture of images of developing roots and shoots; (b) an illuminated robotic platform that uses a commercially available robotic manipulator to capture images of developing shoots and roots; (c) software to control the sequence of robotic movements and integrate these with the image capture process; (d) purpose-made image analysis software for automated extraction of quantitative phenotypic data. Imaging of each plate (representing 80 separate assays) takes 4 min and can easily be performed daily for time-course studies. As currently configured, the Microphenotron has a capacity of 54 microtitre plates in a growth room footprint of 2.1 m², giving a potential throughput of up to 4320 chemical treatments in a typical 10 days experiment. The Microphenotron has been validated by using it to screen a collection of 800 natural compounds for qualitative effects on root development and to perform a quantitative analysis of the effects of a range of concentrations of nitrate and ammonium on seedling development. Conclusions The Microphenotron is an automated screening platform that for the first time is able to combine large numbers of individual chemical treatments with a detailed analysis of whole-seedling development, and particularly root system development. The Microphenotron should provide a powerful new tool for chemical genetics and for wider chemical biology applications, including the development of natural and synthetic chemical products for improved agricultural sustainability

May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk

Genome-wide coancestry reveals details of ancient and recent male-driven reticulation in baboons

[INTRODUCTION] As a widespread but comparatively young clade of six parapatric species, the baboons (Papio sp.) exemplify a frequently observed pattern of mammalian diversity. In particular, they provide analogs for the population structure of the multibranched prehuman lineage that occupied a similar geographic range before the hegemony of “modern” humans, Homo sapiens. Despite phenotypic and genetic differences, interspecies hybridization has been described between baboons at several locations, and population relationships based on mitochondrial DNA (mtDNA) do not correspond with relationships based on phenotype. These previous studies captured the broad outlines of baboon population genetic structure and evolutionary history but necessarily used data that were limited in genomic and geographical coverage and therefore could not adequately document inter- and intrapopulation variation. In this study, we analyzed whole-genome sequences of 225 baboons representing all six species and 19 geographic sites, with 18 local populations represented by multiple individuals.[RATIONALE] Recent studies have identified several mammalian species groups in which genetically distinct lineages have hybridized to generate complex reticulate phylogenies. Baboons provide a valuable context for studying processes generating such population and phylogenetic complexity because extant parapatric species form hybrid zones in several regions of Africa, allowing for direct observation of ongoing introgression. Furthermore, prior studies of nuclear and mtDNA and phenotypic diversity have demonstrated gene flow among differentiated lineages but were unable to develop the detailed picture of process and history that is now possible using whole-genome sequences and modern computational methods. To address these questions, we designed a study that would provide a more fine-grained picture of recent and ancient genetic reticulation by comparing phenotypes and autosomal, X and Y chromosomal, and mtDNA sequences, along with polymorphic insertions of repetitive elements across multiple baboon populations.[RESULTS] Using deep whole-genome sequence data from 225 baboons representing multiple populations, we identified several previously unknown geographic sites of gene flow between genetically distinct populations. We report that yellow baboons (P. cynocephalus) from western Tanzania are the first nonhuman primate found to have received genetic input from three distinct lineages. We compared the ancestry shared among individuals, estimated separately from the X chromosome and autosomes, to distinguish shared ancestry due to ancestral population relationships from coancestry as a result of recent male-biased immigration and gene flow. This reveals directionality and sex bias of recent gene flow in several locations. Analyses of population differences within species quantified different degrees of interspecies introgression among populations with an essentially identical phenotype.[CONCLUSION] The population genetic structure and history of introgression among baboon lineages are even more complex than predicted from observed phenotypic diversity and prior studies of limited genetic data. Single populations can carry genetic contributions from more than two ancestral sources. Populations that appear homogeneous on the basis of observable phenotype can display different levels of interspecies introgression. The evolutionary dynamics and current structure of baboon population diversity indicate that other mammals displaying differentiated and geographically separate species may also have more-complex histories than anticipated. This may also be true for the morphologically defined hominin taxa from the past 4 million years.This work was funded by “la Caixa” Foundation (ID 100010434), fellowship code LCF/BQ/PR19/11700002 (M.K.); the Vienna Science and Technology Fund (WWTF) (10.47379/VRG20001) (M.K.); German Research Foundation grants FI707/9-1, KN1097/3-1/3-1, KN1097/4-1, ZI548/5-1, and RO3055/2-1 (J.F., S.K., D.Z., and C.R.); Novo Nordisk Foundation grant 0058553 (E.F.S. and K.M.); R01 GM59290 (M.A.B.); and internal funding from Baylor College of Medicine (J.R.). T.M.B. is supported by funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant 864203), PID2021-126004NB-100 (MICIIN/FEDER, UE) and Secretaria d'Universitats i Recerca and CERCA Programme del Departament d'Economia i Coneixement de la Generalitat de Catalunya (GRC 2021 SGR 00177).Peer reviewe

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead