Browsing by Department "University of Cambridge"

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  • How can airborne transmission of COVID-19 indoors be minimised?
    (2020-09) Morawska, Lidia; Tang, Julian W.; Bahnfleth, William; Bluyssen, Philomena M.; Boerstra, Atze; Buonanno, Giorgio; Cao, Junji; Dancer, Stephanie; Floto, Andres; Franchimon, Francesco; Haworth, Charles; Hogeling, Jaap; Isaxon, Christina; Jimenez, Jose L.; Kurnitski, Jarek; Li, Yuguo; Loomans, Marcel; Marks, Guy; Marr, Linsey C.; Mazzarella, Livio; Melikov, Arsen Krikor; Miller, Shelly; Milton, Donald K.; Nazaroff, William; Nielsen, Peter V.; Noakes, Catherine; Peccia, Jordan; Querol, Xavier; Sekhar, Chandra; Seppänen, Olli; Tanabe, Shin ichi; Tellier, Raymond; Tham, Kwok Wai; Wargocki, Pawel; Wierzbicka, Aneta; Yao, Maosheng
     Letter
    During the rapid rise in COVID-19 illnesses and deaths globally, and notwithstanding recommended precautions, questions are voiced about routes of transmission for this pandemic disease. Inhaling small airborne droplets is probable as a third route of infection, in addition to more widely recognized transmission via larger respiratory droplets and direct contact with infected people or contaminated surfaces. While uncertainties remain regarding the relative contributions of the different transmission pathways, we argue that existing evidence is sufficiently strong to warrant engineering controls targeting airborne transmission as part of an overall strategy to limit infection risk indoors. Appropriate building engineering controls include sufficient and effective ventilation, possibly enhanced by particle filtration and air disinfection, avoiding air recirculation and avoiding overcrowding. Often, such measures can be easily implemented and without much cost, but if only they are recognised as significant in contributing to infection control goals. We believe that the use of engineering controls in public buildings, including hospitals, shops, offices, schools, kindergartens, libraries, restaurants, cruise ships, elevators, conference rooms or public transport, in parallel with effective application of other controls (including isolation and quarantine, social distancing and hand hygiene), would be an additional important measure globally to reduce the likelihood of transmission and thereby protect healthcare workers, patients and the general public.
  • Planck 2015 results
    (2016-10-01) Ade, P. A R; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Battye, R.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J. P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J. F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R. R.; Chiang, H. C.; Chluba, J.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P L; Combet, C.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; De Bernardis, P.; De Rosa, A.; De Zotti, G.; Delabrouille, J.; Désert, F. X.; Di Valentino, E.; Dickinson, C.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Farhang, M.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Gerbino, M.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Giusarma, E.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hamann, J.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J. M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Maciás-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marchini, A.; Maris, M.; Martin, P. G.; Martinelli, M.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mcgehee, P.; Meinhold, P. R.; Melchiorri, A.; Melin, J. B.; Mendes, L.; Mennella, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschênes, M. A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J. L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rouillé D'orfeuil, B.; Rowan-Robinson, M.; Rubinõ-Martín, J. A.; Rusholme, B.; Said, N.; Salvatelli, V.; Salvati, L.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Serra, P.; Shellard, E. P S; Spencer, L. D.; Spinelli, M.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A. S.; Sygnet, J. F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Väliviita, J.; Van Tent, F.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; White, M.; White, S. D M; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper presents cosmological results based on full-mission Planck observations of temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation. Our results are in very good agreement with the 2013 analysis of the Planck nominal-mission temperature data, but with increased precision. The temperature and polarization power spectra are consistent with the standard spatially-flat 6-parameter ΛCDM cosmology with a power-law spectrum of adiabatic scalar perturbations (denoted "base ΛCDM" in this paper). From the Planck temperature data combined with Planck lensing, for this cosmology we find a Hubble constant, H0 = (67.8 ± 0.9) km s-1Mpc-1, a matter density parameter Ωm = 0.308 ± 0.012, and a tilted scalar spectral index with ns = 0.968 ± 0.006, consistent with the 2013 analysis. Note that in this abstract we quote 68% confidence limits on measured parameters and 95% upper limits on other parameters. We present the first results of polarization measurements with the Low FrequencyInstrument at large angular scales. Combined with the Planck temperature and lensing data, these measurements give a reionization optical depth of τ = 0.066 ± 0.016, corresponding to a reionization redshift of \hbox{$z-{\rm re}=8.8{+1.7}-{-1.4}$}. These results are consistent with those from WMAP polarization measurements cleaned for dust emission using 353-GHz polarization maps from the High Frequency Instrument. We find no evidence for any departure from base ΛCDM in the neutrino sector of the theory; for example, combining Planck observations with other astrophysical data we find Neff = 3.15 ± 0.23 for the effective number of relativistic degrees of freedom, consistent with the value Neff = 3.046 of the Standard Model of particle physics. The sum of neutrino masses is constrained to â'mν < 0.23 eV. The spatial curvature of our Universe is found to be very close to zero, with | ΩK | < 0.005. Adding a tensor component as a single-parameter extension to base ΛCDM we find an upper limit on the tensor-to-scalar ratio of r0.002< 0.11, consistent with the Planck 2013 results and consistent with the B-mode polarization constraints from a joint analysis of BICEP2, Keck Array, and Planck (BKP) data. Adding the BKP B-mode data to our analysis leads to a tighter constraint of r0.002 < 0.09 and disfavours inflationarymodels with a V(φ) φ2 potential. The addition of Planck polarization data leads to strong constraints on deviations from a purely adiabatic spectrum of fluctuations. We find no evidence for any contribution from isocurvature perturbations or from cosmic defects. Combining Planck data with other astrophysical data, including Type Ia supernovae, the equation of state of dark energy is constrained to w =-1.006 ± 0.045, consistent with the expected value for a cosmological constant. The standard big bang nucleosynthesis predictions for the helium and deuterium abundances for the best-fit Planck base ΛCDM cosmology are in excellent agreement with observations. We also constraints on annihilating dark matter and onpossible deviations from the standard recombination history. In neither case do we find no evidence for new physics. The Planck results for base ΛCDM are in good agreement with baryon acoustic oscillation data and with the JLA sample of Type Ia supernovae. However, as in the 2013 analysis, the amplitude of the fluctuation spectrum is found to be higher than inferred from some analyses of rich cluster counts and weak gravitational lensing. We show that these tensions cannot easily be resolved with simple modifications of the base ΛCDM cosmology. Apart from these tensions, the base ΛCDM cosmology provides an excellent description of the Planck CMB observations and many other astrophysical data sets.
  • Simultaneous investigation of the liquid transport and swelling performance during tablet disintegration
    (2020-06-30) Al-Sharabi, Mohammed; Markl, Daniel; Mudley, Theona; Bawuah, Prince; Karttunen, Anssi Pekka; Ridgway, Cathy; Gane, Patrick; Ketolainen, Jarkko; Peiponen, Kai Erik; Rades, Thomas; Zeitler, J. Axel
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Fast disintegrating tablets have commonly been used for fast oral drug delivery to patients with swallowing difficulties. The different characteristics of the pore structure of such formulations influence the liquid transport through the tablet and hence affect the disintegration time and the release of the drug in the body. In this work, terahertz time-domain spectroscopy and terahertz pulsed imaging were used as promising analytical techniques to quantitatively analyse the impact of the structural properties on the liquid uptake and swelling rates upon contact with the dissolution medium. Both the impact of porosity and formulation were investigated for theophylline and paracetamol based tablets. The drug substances were either formulated with functionalised calcium carbonate (FCC) with porosities of 45% and 60% or with microcrystalline cellulose (MCC) with porosities of 10% and 25%. The terahertz results reveal that the rate of liquid uptake is clearly influenced by the porosity of the tablets with a faster liquid transport observed for tablets with higher porosity, indicating that the samples exhibit structural similarity in respect to pore connectivity and pore size distribution characteristics in respect to permeability. The swelling of the FCC based tablets is fully controlled by the amount of disintegrant, whereas the liquid uptake is driven by the FCC material and the interparticle pores created during compaction. The MCC based formulations are more complex as the MCC significantly contributes to the overall tablet swelling. An increase in swelling with increasing porosity is observed in these tablets, which indicates that such formulations are performance-limited by their ability to take up liquid. Investigating the effect of the microstructure characteristics on the liquid transport and swelling kinetics is of great importance for reaching the next level of understanding of the drug delivery, and, depending on the surface nature of the pore carrier function, in turn controlling the performance of the drug mainly in respect to dissolution in the body.
  • Unveiling the diversity of scholarly debate on living labs
    (2020-12) Greve, Katharina; Leminen, Seppo; Vita, Riccardo D.E.; Westerlund, Mika
     A2 Katsausartikkeli tieteellisessä aikakauslehdessä
    Living labs (LLs) are becoming an increasingly popular approach to engage in open innovation. Although applications and influence of LLs have grown rapidly over the last decade, the landscape of LL research remains largely unclear and underexplored. Hence, there is an urgent need to develop a consolidated understanding of this research field and to detect the potential areas of fragmentation and isolation. Through a systematic review of the scholarly literature on LLs, this study applies bibliometric methods on a dataset of 411 journal articles. The results of this study reveal the diverse and fragmented nature of the LL field, with contributions spanning across different disciplines and application domains. Despite such fragmentation, some clusters of scholars and publications are identified as well as influential contributions. Given the nascent state of the literature, the role of special issues in shaping the evolution of the LL debate is prominent. This study provides a map to practitioners to investigate and learn from the application of LLs in diverse fields. This aspect is particularly important in light of the current COVID-19 pandemic, which stresses the key role of open and collaborative approaches to innovation, making the use of LLs increasingly relevant for governments, companies, public organisations and individuals.
  • Voltage-driven displacement of magnetic vortex cores
    (2020-10-21) Ghidini, M.; Pellicelli, R.; Mansell, R.; Pesquera, D.; Nair, B.; Moya, X.; Farokhipoor, S.; Maccherozzi, F.; Barnes, C. H.W.; Cowburn, R. P.; Dhesi, S. S.; Mathur, N. D.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Magnetic vortex cores in polycrystalline Ni discs underwent non-volatile displacements due to voltage-driven ferroelectric domain switching in single-crystal BaTiO3. This behaviour was observed using photoemission electron microscopy to image both the ferromagnetism and ferroelectricity, while varying in-plane sample orientation. The resulting vector maps of disc magnetization match well with micromagnetic simulations, which show that the vortex core is translated by the transit of a ferroelectric domain wall, and thus the inhomogeneous strain with which it is associated. The non-volatility is attributed to pinning inside the discs. Voltage-driven displacement of magnetic vortex cores is novel, and opens the way for studying voltage-driven vortex dynamics.