2,383 results match your criteria: "Mathematical Institute[Affiliation]"

Deflation is an efficient numerical technique for identifying new branches of steady state solutions to nonlinear partial differential equations. Here, we demonstrate how to extend deflation to discover new periodic orbits in nonlinear dynamical lattices. We employ our extension to identify discrete breathers, which are generic exponentially localized, time-periodic solutions of such lattices.

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Background: The aim was to determine whether salvage treatment with systemic antibiotics is a safe and effective strategy for Enterobacterales bloodstream infections (BSI) in pediatric oncology patients with a central venous catheter (CVC).

Methods: A retrospective study was performed on oncology and stem cell recipient patients with a CVC and blood culture with Enterobacterales , at the Princess Máxima Centre for Pediatric Oncology, Utrecht, the Netherlands. Analyses were performed for all BSI and for episodes meeting central line-associated bloodstream infection (CLABSI) criteria.

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Centrioles duplicate when a mother centriole gives birth to a daughter that grows from its side. Polo-like-kinase 4 (PLK4), the master regulator of centriole duplication, is recruited symmetrically around the mother centriole, but it then concentrates at a single focus that defines the daughter centriole assembly site. How PLK4 breaks symmetry is unclear.

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Vaccination compartmental epidemiological models for the delta and omicron SARS-CoV-2 variants.

Math Biosci

January 2024

Thermal Hydraulics & Multiphase Flow Laboratory, Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, N.C.S.R. "Demokritos", GR 15341, Agia Paraskevi, Greece.

We explore the inclusion of vaccination in compartmental epidemiological models concerning the delta and omicron variants of the SARS-CoV-2 virus that caused the COVID-19 pandemic. We expand on our earlier compartmental-model work by incorporating vaccinated populations. We present two classes of models that differ depending on the immunological properties of the variant.

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Mathematical methods for scaling from within-host to population-scale in infectious disease systems.

Epidemics

December 2023

Centre for Mathematical Biology, Department of Mathematical Sciences, University of Bath, Bath, BA2 7AY, United Kingdom.

Mathematical modellers model infectious disease dynamics at different scales. Within-host models represent the spread of pathogens inside an individual, whilst between-host models track transmission between individuals. However, pathogen dynamics at one scale affect those at another.

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Background: In this article, we attempt to demonstrate the superiority of the Bayesian approach over the frequentist approaches of the multiple linear regression model in identifying the influencing factors for the response variable.

Methods And Material: A survey was conducted among the 310 respondents from the Kathirkamam area in Puducherry. We have considered the response variable, body mass index (BMI), and the predictors such as age, weight, gender, nature of the job, and marital status of individuals were collected with the personal interview method.

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Euler characteristic curves and profiles: a stable shape invariant for big data problems.

Gigascience

December 2022

Dioscuri Centre in Topological Data Analysis, Mathematical Institute, Polish Academy of Sciences, Warsaw, 00-656, Poland.

Tools of topological data analysis provide stable summaries encapsulating the shape of the considered data. Persistent homology, the most standard and well-studied data summary, suffers a number of limitations; its computations are hard to distribute, and it is hard to generalize to multifiltrations and is computationally prohibitive for big datasets. In this article, we study the concept of Euler characteristics curves for 1-parameter filtrations and Euler characteristic profiles for multiparameter filtrations.

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Developmental time is a key life-history trait with large effects on Darwinian fitness. In many insects, developmental time is currently under strong selection to minimize ecological mismatches in seasonal timing induced by climate change. The genetic basis of responses to such selection, however, is poorly understood.

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A mathematical framework for the emergence of winners and losers in cell competition.

J Theor Biol

January 2024

Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK.

Cell competition is a process in multicellular organisms where cells interact with their neighbours to determine a "winner" or "loser" status. The loser cells are eliminated through programmed cell death, leaving only the winner cells to populate the tissue. Cell competition is context-dependent; the same cell type can win or lose depending on the cell type it is competing against.

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Modelling seasonality of Lassa fever incidences and vector dynamics in Nigeria.

PLoS Negl Trop Dis

November 2023

Zeeman Institute: SBIDER, School of Life Sciences and Mathematics Institute, University of Warwick, Coventry, United Kingdom.

Lassa fever (Lf) is a viral haemorrhagic disease endemic to West Africa and is caused by the Lassa mammarenavirus. The rodent Mastomys natalensis serves as the primary reservoir and its ecology and behaviour have been linked to the distinct spatial and temporal patterns in the incidence of Lf. Nigeria has experienced an unprecedented epidemic that lasted from January until April of 2018, which has been followed by subsequent epidemics of Lf in the same period every year since.

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Alpha-frequency feedback to early visual cortex orchestrates coherent naturalistic vision.

Sci Adv

November 2023

Mathematical Institute, Department of Mathematics and Computer Science, Physics, Geography, Justus-Liebig-Universität Gießen, Gießen 35392, Germany.

Article Synopsis
  • The brain creates clear visual experiences by combining sensory inputs spread across our visual field during naturalistic vision.
  • Researchers studied this integration process using EEG and fMRI while changing the coherence of videos shown to participants, discovering that different brain activities (gamma for incoherent and alpha for coherent stimuli) reflect this processing.
  • Their findings suggest that rhythmic activity in the brain's feedback mechanisms is crucial for building coherent visual perceptions, influencing how visual information is processed from early stages to higher-level analysis.
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Background: The authors developed a pain monitoring app offering educational information, and real-time health care professional feedback on clinically significant pain (>4 numeric rating scale [NRS]-11) for children with cancer to reduce pain at home.

Methods: This monocenter, nonblinded randomized controlled trial enrolled Dutch children (0-18 years old) receiving cancer treatment (≥3 months after diagnosis, ≥2 months treatment remaining). Children were randomly assigned to use the app or receive usual care (two parallel groups).

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We study phase equilibria in a minimal model of charge-regulated polymer solutions. Our model consists of a single polymer species whose charge state arises from protonation-deprotonation processes in the presence of a dissolved acid, whose anions serve as screening counterions. We explicitly account for variability in the polymers' charge states.

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Single cell spatial analysis reveals inflammatory foci of immature neutrophil and CD8 T cells in COVID-19 lungs.

Nat Commun

November 2023

MRC Translational Immunology Discovery Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.

Single cell spatial interrogation of the immune-structural interactions in COVID -19 lungs is challenging, mainly because of the marked cellular infiltrate and architecturally distorted microstructure. To address this, we develop a suite of mathematical tools to search for statistically significant co-locations amongst immune and structural cells identified using 37-plex imaging mass cytometry. This unbiased method reveals a cellular map interleaved with an inflammatory network of immature neutrophils, cytotoxic CD8 T cells, megakaryocytes and monocytes co-located with regenerating alveolar progenitors and endothelium.

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We examine the buckling shape and critical compression of confined inhomogeneous composite sheets lying on a liquid foundation. The buckling modes are controlled by the bending stiffness of the sheet, the density of the substrate, and the size and the spatially dependent elastic coefficients of the sheet. We solve the beam equation describing the mechanical equilibrium of a sheet when its bending stiffness varies parallel to the direction of confinement.

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In this work, we theoretically explore how litter decomposition processes and soil-borne pathogens contribute to negative plant-soil feedbacks, in particular in transient and stable spatial organisation of tropical forest trees and seedlings known as Janzen-Connell distributions. By considering soil-borne pathogens and autotoxicity both separately and in combination in a phenomenological model, we can study how both factors may affect transient dynamics and emerging Janzen-Connell distributions. We also identify parameter regimes associated with different long-term behaviours.

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Emergent Worldsheet for the AdS Virasoro-Shapiro Amplitude.

Phys Rev Lett

October 2023

Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom.

We construct a representation for the first anti-de Sitter curvature correction to the Virasoro-Shapiro amplitude, as an integral over the Riemann sphere. The integrand is that of the Virasoro-Shapiro amplitude in flat space, with the extra insertion of a linear combination of single-valued multiple polylogarithms of weight three. The integral representation implies an elegant, manifestly single-valued representation for the Wilson coefficients of the low-energy expansion.

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The rise in health care costs, caused by older and more complex patient populations, requires Population Health Management approaches including risk stratification. With risk stratification, patients are assigned individual risk scores based on medical records. These patient stratifications focus on future high costs and expensive care utilization such as hospitalization, for which different models exist.

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Free Field Realisation of the Chiral Universal Centraliser.

Ann Henri Poincare

May 2023

Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG UK.

In the TQFT formalism of Moore-Tachikawa for describing Higgs branches of theories of class , the space associated to the unpunctured sphere in type is the universal centraliser , where . In more physical terms, this space arises as the Coulomb branch of pure gauge theory in three dimensions with gauge group , the Langlands dual. In the analogous formalism for describing chiral algebras of class , the vertex algebra associated to the sphere has been dubbed the .

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Your place or mine? The neural dynamics of personally familiar scene recognition suggests category independent familiarity encoding.

Cereb Cortex

December 2023

Department of Biological Psychology and Cognitive Neurosciences, Institute of Psychology, Friedrich Schiller University Jena, Leutragraben 1, D-07743 Jena, Thüringen, Germany.

Recognizing a stimulus as familiar is an important capacity in our everyday life. Recent investigation of visual processes has led to important insights into the nature of the neural representations of familiarity for human faces. Still, little is known about how familiarity affects the neural dynamics of non-face stimulus processing.

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In the recent JAVELIN Bladder 100 phase 3 trial, avelumab plus best supportive care significantly prolonged overall survival relative to best supportive care alone as first-line maintenance therapy following first-line platinum-based chemotherapy in patients with advanced urothelial cancer (aUC). Discovering biomarkers using genomic profiling to understand potential patient heterogeneity is essential to help improve patient care with precision medicine. For the JAVELIN Bladder 100 trial, it is unclear which variable selection methods can most reliably identify biomarkers to inform patient care because the dataset is characterized by high collinearity and low signal.

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Context: During treatment, children with acute lymphoblastic leukemia (ALL) receive high doses dexamethasone, which induce acute side effects.

Objective: To determine the influence of a 5-day dexamethasone course on changes in leptin, fat mass, BMI, hunger, sleep, and fatigue and to explore associations between these changes.

Methods: Pediatric ALL patients were included during maintenance treatment.

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Moduli spaces of compact RCD(0,N)-structures.

Math Ann

October 2022

University of Oxford, Mathematical Institute, Radcliffe Observatory, Andrew Wiles Building, Woodstock Rd, OX2 6GG Oxford, UK.

The goal of the paper is to set the foundations and prove some topological results about moduli spaces of non-smooth metric measure structures with non-negative Ricci curvature in a synthetic sense (via optimal transport) on a compact topological space; more precisely, we study moduli spaces of -structures. First, we relate the convergence of -structures on a space to the associated lifts' equivariant convergence on the universal cover. Then we construct the Albanese and soul maps, which reflect how structures on the universal cover split, and we prove their continuity.

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Objective: To elucidate which markers of ultra-processing (MUP) and their combinations are best suited to detect ultra-processed food (UPF).

Design: The study was based on the 206 food and 32 beverage items of the Oxford WebQ which encompass all major foods consumed in the UK. For each Oxford WebQ question, ingredient lists of up to ten matching different commercial products ( 2146) were researched online using data from the two market leaders of groceries in the UK sorted by relevance (Tesco) and by top sellers (Sainsbury's), respectively.

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