Attention induced neural response trade-off in retinotopic cortex under load

The effects of perceptual load on visual cortex response to distractors are well established and various phenomena of ‘inattentional blindness’ associated with elimination of visual cortex response to unattended distractors, have been documented in tasks of high load. Here we tested an account for these effects in terms of a load-induced trade-off between target and distractor processing in retinotopic visual cortex. Participants were scanned using fMRI while performing a visual-search task and ignoring distractor checkerboards in the periphery. Retinotopic responses to target and distractors were assessed as a function of search load (comparing search set-sizes two, three and five). We found that increased load not only increased activity in frontoparietal network, but also had opposite effects on retinotopic responses to target and distractors. Target-related signals in areas V2–V3 linearly increased, while distractor response linearly decreased, with increased load. Critically, the slopes were equivalent for both load functions, thus demonstrating resource trade-off. Load effects were also found in displays with the same item number in the distractor hemisphere across different set sizes, thus ruling out local intrahemispheric interactions as the cause. Our findings provide new evidence for load theory proposals of attention resource sharing between target and distractor leading to inattentional blindness

Magnetic-film atom chip with 10 μ\mum period lattices of microtraps for quantum information science with Rydberg atoms

We describe the fabrication and construction of a setup for creating lattices of magnetic microtraps for ultracold atoms on an atom chip. The lattice is defined by lithographic patterning of a permanent magnetic film. Patterned magnetic-film atom chips enable a large variety of trapping geometries over a wide range of length scales. We demonstrate an atom chip with a lattice constant of 10 $\mu$m, suitable for experiments in quantum information science employing the interaction between atoms in highly-excited Rydberg energy levels. The active trapping region contains lattice regions with square and hexagonal symmetry, with the two regions joined at an interface. A structure of macroscopic wires, cut out of a silver foil, was mounted under the atom chip in order to load ultracold $^{87}$Rb atoms into the microtraps. We demonstrate loading of atoms into the square and hexagonal lattice sections simultaneously and show resolved imaging of individual lattice sites. Magnetic-film lattices on atom chips provide a versatile platform for experiments with ultracold atoms, in particular for quantum information science and quantum simulation.Comment: 7 pages, 7 figure

Prolonged diapause in the ectoparasite Carnus hemapterus (Diptera : Cyclorrhapha, Acalyptratae) -how frequent is it in parasites ?

S U M M A R Y Prolonged diapause is usually interpreted as an adaptation to unpredictable environmental conditions and resource availability. Many parasites usually face highly unpredictable environments, therefore prolonged diapause should be common among these organisms. Here we examine the occurrence and frequency of prolonged diapause in the ectoparasite Carnus hemapterus (Diptera : Cyclorrhapha, Acalyptratae). We found that the studied population is polymorphic with respect to diapause duration. Emergence of carnid flies after 2 and 3 wintering seasons was therefore detected in around 17% and 21 % of the samples respectively. The number of flies with prolonged diapause ranked 0 . 88-50 % with respect to the number of flies emerging during the first spring. Both the occurrence of prolonged diapause and the number of flies with a long life-cycle are related to the number of flies emerging during the first spring. The emergence pattern of flies with prolonged diapause was very similar to that observed for flies with a short cycle and occurred in synchrony with the occurrence of hosts. Prolonged diapause has been frequently reported in plant-feeding insects and in some host-parasitoid systems, but this is, to our knowledge, the second report ever on prolonged diapause in true parasites of animals. We discuss the reasons for the apparent rarity of prolonged diapause among these organisms

A semi-supervised approach for rapidly creating clinical biomarker phenotypes in the UK Biobank using different primary care EHR and clinical terminology systems

Objectives: The UK Biobank (UKB) is making primary care electronic health records (EHRs) for 500 000 participants available for COVID-19-related research. Data are extracted from four sources, recorded using five clinical terminologies and stored in different schemas. The aims of our research were to: (a) develop a semi-supervised approach for bootstrapping EHR phenotyping algorithms in UKB EHR, and (b) to evaluate our approach by implementing and evaluating phenotypes for 31 common biomarkers. Materials and Methods: We describe an algorithmic approach to phenotyping biomarkers in primary care EHR involving (a) bootstrapping definitions using existing phenotypes, (b) excluding generic, rare, or semantically distant terms, (c) forward-mapping terminology terms, (d) expert review, and (e) data extraction. We evaluated the phenotypes by assessing the ability to reproduce known epidemiological associations with all-cause mortality using Cox proportional hazards models. Results: We created and evaluated phenotyping algorithms for 31 biomarkers many of which are directly related to COVID-19 complications, for example diabetes, cardiovascular disease, respiratory disease. Our algorithm identified 1651 Read v2 and Clinical Terms Version 3 terms and automatically excluded 1228 terms. Clinical review excluded 103 terms and included 44 terms, resulting in 364 terms for data extraction (sensitivity 0.89, specificity 0.92). We extracted 38 190 682 events and identified 220 978 participants with at least one biomarker measured. Discussion and conclusion: Bootstrapping phenotyping algorithms from similar EHR can potentially address pre-existing methodological concerns that undermine the outputs of biomarker discovery pipelines and provide research-quality phenotyping algorithms

Risk factors against bovine respiratory diseade in suckling calves from Argentina

An observacional cross-sectional study was performed to determine the risk factors associated to the main viral agents of the bovine respiratory disease: bovine herpesvirus type 1 (HVB1), bovine viral diarrhoea virus (VDVB), bovine respiratory syncytial virus (VRSB) and parainfluenza 3 virus (VPI3). Blood samples from dairy calves in the provinces of Cordova and Santa Fe (Argentina) were obtained, and an epidemiological ques-tionnaire was filled. Antibodies against studied viruses were detected by commercial ELISA kits. A total of 852 blood samples from 55 dairy operations were obtained between years 2000 and 2002. Four epidemiologic logistic regression models were performed. We found significant associations between infection and variables related to the age of the calf, the season, the size population, the vaccinations, the feeding or the breeding system, among many others.Se ha realizado un estudio epidemiológico observacional de tipo transversal para conocer los factores que actúan sobre la seropositividad de los principales agentes víricos del síndrome respiratorio bovino: el herpesvirus bovino tipo 1 (HVB1), el virus de la diarrea vírica bovina (VDVB), el virus respiratorio sincitial bovino (VRSB) y el virus de la parainfluenza 3 (VPI3). Se tomaron muestras de sangre de terneros procedentes de explotaciones lecheras situadas en las provincias argentinas de Córdoba y Santa Fé, y se cumplimentaron cuestionarios epide-miológicos. Los análisis serológicos se realizaron mediante la técnica ELISA. En total se tomaron muestras de sangre de 852 terneros procedentes de 55 explotaciones entre los años 2000 y 2002. Se realizaron cuatro modelos epidemiológicos mediante regresión logística, uno por cada virus donde, entre otras, aparecen variables asociadas a la infección relacionadas con la edad del ternero, la estación del año, el número de animales, la alimentación, las vacunaciones o el sistema de crianza

From SLA to vendor-neutral metrics: An intelligent knowledge-based approach for multi-cloud SLA-based broker

Cloud computing has been consolidated as a support for the vast majority of current and emerging technologies. However, there are some barriers that prevent the exploitation of the full potential of this technology. First, the major cloud providers currently put the onus of implementing the mechanisms that ensure compliance with the desired service levels on cloud consumers. However, consumers do not have the required expertise. Since each cloud provider exports a different set of low-level metrics, the strategies defined to ensure compliance with the established service-level agreement (SLA) are bound to a particular cloud provider. This fosters provider lock-in and prevents consumers from benefiting from the advantages of multi-cloud environments. This paper presents a solution to the problem of automatically translating SLAs into objectives expressed as metrics that can be measured across multiple cloud providers. First, we propose an intelligent knowledge-based system capable of automatically translating high-level SLAs defined by cloud consumers into a set of conditions expressed as vendor-neutral metrics, providing feedback to cloud consumers (intelligent tutoring system). Secondly, we present the set of vendor-neutral metrics and explain how they can be measured for the different cloud providers. Finally, we report a validation based on two use cases (IaaS and PaaS) in a multi-cloud environment formed by leading cloud providers. This evaluation has demonstrated that, thanks to the complementarity of the two solutions, cloud consumers can automatically and transparently exploit the multi-cloud in many application domains, as endorsed by the cloud experts consulted in the course of this study.2020-2

Good exemplars of natural scene categories elicit clearer patterns than bad exemplars but not greater BOLD activity

Within the range of images that we might categorize as a “beach”, for example, some will be more representative of that category than others. We used ‘good’ and ‘bad’ exemplars of six natural scene categories to confirm that human categorization is sensitive to this manipulation and explore whether brain regions previously implicated in natural scene categorization show a similar sensitivity to how well an image exemplifies a category. Participants were more accurate and faster at categorizing good exemplars of natural scenes. A classifier trained to discriminate patterns of fMRI activity associated with the viewing of our scene categories showed higher decoding accuracy for good than bad exemplars of a category in the PPA, RSC and V1. A univariate analysis, however, revealed that there was either no difference in overall BOLD signal evoked by good and bad scenes (in RSC and V1) or the signal was actually higher for bad scenes (in PPA), suggesting that good exemplars produce a qualitatively, rather than quantitatively, better pattern of activity for categorizing natural scenes. Overall, our results provide further evidence that V1, RSC and the PPA contain information relevant for natural scene categorization. Finally, image statistic analysis shows that good images in our categories produce a more discernible average image and are more similar to each other. These results are consistent with both low-level models of scene category and models in which the category is built around a prototype

Parabolic stable surfaces with constant mean curvature

We prove that if u is a bounded smooth function in the kernel of a nonnegative Schrodinger operator $-L=-(\Delta +q)$ on a parabolic Riemannian manifold M, then u is either identically zero or it has no zeros on M, and the linear space of such functions is 1-dimensional. We obtain consequences for orientable, complete stable surfaces with constant mean curvature $H\in\mathbb{R}$ in homogeneous spaces $\mathbb{E}(\kappa,\tau)$ with four dimensional isometry group. For instance, if M is an orientable, parabolic, complete immersed surface with constant mean curvature H in $\mathbb{H}^2\times\mathbb{R}$, then $|H|\leq 1/2$ and if equality holds, then M is either an entire graph or a vertical horocylinder.Comment: 15 pages, 1 figure. Minor changes have been incorporated (exchange finite capacity by parabolicity, and simplify the proof of Theorem 1)

RSV-specific airway resident memory CD8+ T cells and differential disease severity after experimental human infection

In animal models, resident memory CD8+ T (Trm) cells assist in respiratory virus elimination but their importance in man has not been determined. Here, using experimental human respiratory syncytial virus (RSV) infection, we investigate systemic and local virus-specific CD8+ T cell responses in adult volunteers. Having defined the immunodominance hierarchy, we analyze phenotype and function longitudinally in blood and by serial bronchoscopy. Despite rapid clinical recovery, we note surprisingly extensive lower airway inflammation with persistent viral antigen and cellular infiltrates. Pulmonary virus-specific CD8+ T cells display a CD69+CD103+ Trm phenotype and accumulate to strikingly high frequencies into convalescence without continued proliferation. These are more highly differentiated but express fewer cytotoxicity markers than in blood, but their abundance prior to infection correlates with protection from more severe disease

Rhinovirus induction of fractalkine (CX3CL1) in airway and peripheral blood mononuclear cells in asthma

Rhinovirus infection is associated with the majority of asthma exacerbations. The role of fractalkine in anti-viral (type 1) and pathogenic (type 2) responses to rhinovirus infection in allergic asthma is unknown. To determine whether (1) fractalkine is produced in airway cells and in peripheral blood leucocytes, (2) rhinovirus infection increases production of fractalkine and (3) levels of fractalkine differ in asthmatic compared to non-asthmatic subjects. Fractalkine protein and mRNA levels were measured in bronchoalveolar lavage (BAL) cells and peripheral blood mononuclear cells (PBMCs) from non-asthmatic controls (n = 15) and mild allergic asthmatic (n = 15) subjects. Protein levels of fractalkine were also measured in macrophages polarised ex vivo to give M1 (type 1) and M2 (type 2) macrophages and in BAL fluid obtained from mild (n = 11) and moderate (n = 14) allergic asthmatic and non-asthmatic control (n = 10) subjects pre and post in vivo rhinovirus infection. BAL cells produced significantly greater levels of fractalkine than PBMCs. Rhinovirus infection increased production of fractalkine by BAL cells from non-asthmatic controls (P<0.01) and in M1-polarised macrophages (P<0.05), but not in BAL cells from mild asthmatics or in M2 polarised macrophages. Rhinovirus induced fractalkine in PBMCs from asthmatic (P<0.001) and healthy control subjects (P<0.05). Trends towards induction of fractalkine in moderate asthmatic subjects during in vivo rhinovirus infection failed to reach statistical significance. Fractalkine may be involved in both immunopathological and anti-viral immune responses to rhinovirus infection. Further investigation into how fractalkine is regulated across different cell types and into the effect of stimulation including rhinovirus infection is warranted to better understand the precise role of this unique dual adhesion factor and chemokine in immune cell recruitment