2,120 results match your criteria: "Niels Bohr Institute; University of Copenhagen ; Copenhagen[Affiliation]"

Structural evolution of maize starches with different amylose content during pasting and gelation as evidenced by Rapid Visco Analyser.

Food Chem

December 2024

Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Denmark. Electronic address:

Article Synopsis
  • The study investigated how different amylose content in maize starch affects its structure and viscosity during heating and gelation using a Rapid Visco Analyser.
  • At 50 °C, starch granules retained their shape and had low viscosity, but as temperature rose to 95 °C, their structures broke down, leading to swelling and increased viscosity.
  • The findings are the first to detail the structural changes in starch at multiple levels during gelatinization, highlighting that high amylose starch remains less viscous as it partially gelatinizes below its optimal temperature.
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Formation of human kinship structures depending on population size and cultural mutation rate.

Proc Natl Acad Sci U S A

August 2024

The Niels Bohr Institute, University of Copenhagen, Copenhagen 2100-DK, Denmark.

How does social complexity depend on population size and cultural transmission? Kinship structures in traditional societies provide a fundamental illustration, where cultural rules between clans determine people's marriage possibilities. Here, we propose a simple model of kinship interactions that considers kin and in-law cooperation and sexual rivalry. In this model, multiple societies compete.

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One hundred years of influenza A evolution.

Theor Popul Biol

October 2024

Department of Science and Environment, Roskilde University, Roskilde, Denmark. Electronic address:

Leveraging the simplicity of nucleotide mismatch distributions, we provide an intuitive window into the evolution of the human influenza A 'nonstructural' (NS) gene segment. In an analysis suggested by the eminent Danish biologist Freddy B. Christiansen, we illustrate the existence of a continuous genetic "backbone" of influenza A NS sequences, steadily increasing in nucleotide distance to the 1918 root over more than a century.

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Indistinguishability between photons is a key requirement for scalable photonic quantum technologies. We experimentally demonstrate that partly distinguishable single photons can be purified to reach near-unity indistinguishability by the process of quantum interference with ancillary photons followed by heralded detection of a subset of them. We report on the indistinguishability of the purified photons by interfering two purified photons and show improvements in the photon indistinguishability of 2.

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Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using 139  fb^{-1} of pp collision data at sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or Higgsino production decaying via standard model W, Z, or h bosons are combined to extend the mass reach to the produced supersymmetric particles by 30-100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% C.

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Article Synopsis
  • Microorganisms, like bacteria and viruses, can move through the air and mix with different habitats, which helps them share resources.
  • Scientists used a computer model to see how these air movements affect bacteria and their viruses, showing that while some species might die out locally, they can survive because they move to new places.
  • This air movement helps keep many different types of microbes alive together overall, even if they can't survive in the same spot.
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Vocal repertoire and individuality in the plains zebra ().

R Soc Open Sci

July 2024

Behavioural Ecology Group, Section for Ecology and Evolution, University of Copenhagen, Copenhagen, Denmark.

Acoustic signals are vital in animal communication, and quantifying them is fundamental for understanding animal behaviour and ecology. Vocalizations can be classified into acoustically and functionally or contextually distinct categories, but establishing these categories can be challenging. Newly developed methods, such as machine learning, can provide solutions for classification tasks.

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The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z ≈ 13 (refs. ). In addition, the discovery of many luminous galaxies at Cosmic Dawn (z > 10) has suggested that galaxies developed rapidly, in apparent tension with many standard models.

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Fresh Carrier for an Old Topical Local Anesthetic: Benzocaine in Nanostructured Lipid Carriers.

ACS Biomater Sci Eng

August 2024

Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), ZIP 13083-862 Campinas, São Paulo, Brazil.

Nanostructured lipid carriers (NLC) have emerged as innovative drug delivery systems, offering distinct advantages over other lipid-based carriers, such as liposomes and solid lipid nanoparticles. Benzocaine (BZC), the oldest topical local anesthetic in use, undergoes metabolism by pseudocholinesterase, leading to the formation of -aminobenzoic acid, a causative agent for allergic reactions associated with prolonged BZC usage. In order to mitigate adverse effects and enhance bioavailability, BZC was encapsulated within NLC.

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The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions.

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First Scan Search for Dark Photon Dark Matter with a Tunable Superconducting Radio-Frequency Cavity.

Phys Rev Lett

July 2024

School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China.

Article Synopsis
  • Dark photons are being researched as potential dark matter candidates, making their detection a major focus in several scientific fields.
  • The study involved using a specialized niobium superconducting radio-frequency cavity at very low temperatures to scan for dark photon signatures across a specific frequency range.
  • The experiment's high precision led to the most stringent limits on the interaction strength between dark photons and regular photons, indicating that the kinetic mixing coefficient ε is less than 2.2×10^{-16}.
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Flavor-dependent neutrino transport is described by a well-known kinetic equation for occupation-number matrices in flavor space. However, in the context of fast flavor conversion, we identify an unforeseen predicament: the pivotal self-induced exponential growth of small inhomogeneities strongly violates conservation of neutrino-neutrino refractive energy. We prove that it is traded with the huge reservoir of neutrino kinetic energy through gradients of neutrino flavor coherence (the off-diagonal piece of the flavor density matrix) and derive the missing gradient terms.

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A mega-electron volt emission line in the spectrum of a gamma-ray burst.

Science

July 2024

Osservatorio Astronomico di Brera, Istituto Nazionale di Astrofisica, Merate 23807, Italy.

A long gamma-ray burst (GRB) is observed when the collapse of a massive star produces an ultrarelativistic outflow pointed toward Earth. Gamma-ray spectra of long GRBs are smooth, typically modeled by joint power-law segments describing a continuum, with no detected spectral lines. We report a significant (>6σ) narrow emission feature at ~10 mega-electron volts (MeV) in the spectrum of the bright GRB 221009A.

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Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on the nightside and that molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum of the hot Jupiter WASP-43b measured from 5 μm to 12 μm with the JWST's Mid-Infrared Instrument.

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The extremophile bacterium Deinococcus radiodurans is characterized by its ability to survive and sustain its activity at high levels of radiation and is considered an organism that might survive in extraterrestrial environments. In the present work, we studied the combined effects of temperature and chlorine-containing salts, with focus on perchlorate salts which have been detected at high concentrations in Martian regolith, on D. radiodurans activity (CO production rates) and viability after incubation in liquid cultures for up to 30 days.

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Geometric confinement and topological constraints present promising means of controlling active materials. By combining analytical arguments derived from the Born-Oppenheimer approximation with numerical simulations, we investigate the simultaneous impact of confinement together with curvature singularity by characterizing the dynamics of an active nematic on a cone. Here, the Born-Oppenheimer approximation means that textures can follow defect positions rapidly on the timescales of interest.

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Article Synopsis
  • Transmission spectroscopy has been an essential method for studying exoplanet atmospheres, but recent studies question the assumption that the atmosphere is uniform, particularly for heated gas giants like WASP-39 b.
  • Using the James Webb Space Telescope, researchers detected differences in the morning and evening transmission spectra of WASP-39 b, finding that the evening spectra had significantly larger transit depths compared to the morning ones.
  • The findings suggest that the evening terminator is hotter and possibly clearer than the morning terminator, leading to implications about atmospheric circulation and cloud formation on the exoplanet.
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Article Synopsis
  • * The measurements utilized both semileptonic and hadronic decays of top quarks, along with events focused on single top quark production in the electroweak t channel.
  • * The combined result for the top quark mass is 172.52 GeV, with a reduced total uncertainty of 0.33 GeV, showcasing an improvement of 31% over previous measurements.
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Applying the quantum field theoretic perturbiner approach to Einstein gravity, we compute the metric of a Schwarzschild black hole order by order in perturbation theory. Using recursion, this calculation can be carried out in de Donder gauge to all orders in Newton's constant. The result is a geometric series which is convergent outside a disk of finite radius, and it agrees within its region of convergence with the known de Donder gauge metric of a Schwarzschild black hole.

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T-even bacteriophages are known to employ lysis inhibition (LIN), where the lysis of an infected host is delayed in response to secondary adsorptions. Upon the eventual burst of the host, significantly more phage progenies are released. Here, we analysed the competitive advantage of LIN using a mathematical model.

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Filopodia: integrating cellular functions with theoretical models.

Trends Cell Biol

July 2024

Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø, Denmark. Electronic address:

Filopodia, widely distributed on cell surfaces, are distinguished by their dynamic extensions, playing pivotal roles in a myriad of biological processes. Their functions span from mechanosensing and guidance to cell-cell communication during cellular organization in the early embryo. Filopodia have significant roles in pathogenic processes, such as cancer invasion and viral dissemination.

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We investigate the boundary between chemotaxis driven by spatial estimation of gradients and chemotaxis driven by temporal estimation. While it is well known that spatial chemotaxis becomes disadvantageous for small organisms at high noise levels, it is unclear whether there is a discontinuous switch of optimal strategies or a continuous transition exists. Here, we employ deep reinforcement learning to study the possible integration of spatial and temporal information in an a priori unconstrained manner.

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SARS-CoV-2 induces delayed type-I/III interferon production, allowing it to escape the early innate immune response. The delay has been attributed to a deficiency in the ability of cells to sense viral replication upon infection, which in turn hampers activation of the antiviral state in bystander cells. Here, we introduce a cellular automaton model to investigate the spatiotemporal spreading of viral infection as a function of virus and host-dependent parameters.

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Three approaches for determining the thermodynamic stability of irreversible processes are described in generalized formulations. The simplest is the Gibbs-Duhem theory, specialized to irreversible trajectories, which uses the concept of virtual displacement in the reverse direction. Its only drawback is that even a trajectory leading to an explosion is identified as a thermodynamically stable motion.

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The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z ≈ 10.2 (ref. ).

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