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1.
Stud Mycol ; 107: 149-249, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38600960

RESUMEN

Based on seven- and three-gene datasets, we discuss four alternative approaches for a reclassification of Fomitopsidaceae (Polyporales, Basidiomycota). After taking into account morphological diversity in the family, we argue in favour of distinguishing three genera only, viz. Anthoporia, Antrodia and Fomitopsis. Fomitopsis becomes a large genus with 128 accepted species, containing almost all former Fomitopsis spp. and most species formerly placed in Antrodia, Daedalea and Laccocephalum. Genera Buglossoporus, Cartilosoma, Daedalea, Melanoporia, Neolentiporus, alongside twenty others, are treated as synonyms of Fomitopsis. This generic scheme allows for morphologically distinct genera in Fomitopsidaceae, unlike other schemes we considered. We provide arguments for retaining Fomitopsis and suppressing earlier (Daedalea, Caloporus) or simultaneously published generic names (Piptoporus) considered here as its synonyms. Taxonomy of nine species complexes in the genus is revised based on ITS, ITS + TEF1, ITS + TEF1 + RPB1 and ITS + TEF1 + RPB2 datasets. In total, 17 species are described as new to science, 26 older species are reinstated and 26 currently accepted species names are relegated to synonymy. A condensed identification key for all accepted species in the genus is provided. Taxonomic novelties: New species: Fomitopsis algumicola Grebenc & Spirin, F. caseosa Vlasák & Spirin, F. cupressicola Vlasák, J. Vlasák Jr. & Spirin, F. derelicta Vlasák & Spirin, F. dollingeri Vlasák & Spirin, F. fissa Vlasák & Spirin, F. lapidosa Miettinen & Spirin, F. lignicolor Vlasák & Spirin, F. maculosa Miettinen & Spirin, F. pannucea Runnel & Spirin, F. perhiemata Viner & Spirin, F. purpurea Spirin & Ryvarden, F. retorrida Spirin & Kotiranta, F. solaris Rivoire, A.M. Ainsworth & Vlasák, F. tristis Miettinen & Spirin, F. tunicata Miettinen & Spirin, F. visenda Miettinen & Spirin. New combinations: Fomitopsis aculeata (Cooke) Spirin & Miettinen, F. aethalodes (Mont.) Spirin, F. alaskana (D.V. Baxter) Spirin & Vlasák, F. albidoides (A. David & Dequatre) Bernicchia & Vlasák, F. amygdalina (Berk. & Ravenel) Spirin & Vlasák, F. angusta (Spirin & Vlasák) Spirin & Vlasák, F. atypa (Lév.) Spirin & Vlasák, F. caespitosa (Murrill) Spirin & Miettinen, F. calcitrosa (Spirin & Miettinen) Spirin & Miettinen, F. circularis (B.K. Cui & Hai J. Li) Spirin, F. concentrica (G. Cunn.) M.D. Barrett, F. cyclopis (Miettinen & Spirin) Miettinen & Spirin, F. dickinsii (Berk. ex Cooke) Spirin, F. elevata (Corner) Spirin & Miettinen, F. eucalypti (Kalchbr.) Spirin, F. ferrea (Cooke) Spirin & Viner, F. flavimontis (Vlasák & Spirin) Vlasák & Spirin, F. foedata (Berk.) Spirin & Miettinen, F. gilvidula (Bres.) Spirin & Miettinen, F. glabricystidia (Ipulet & Ryvarden) Miettinen & Ryvarden, F. globispora (Ryvarden & Aime) Spirin, F. hartmannii (Cooke) M.D. Barrett & Spirin, F. hyalina (Spirin, Miettinen & Kotir.) Spirin & Miettinen, F. hypoxantha (Bres.) Spirin & Miettinen, F. incana (Lév.) Spirin & V. Malysheva, F. infirma (Renvall & Niemelä) Miettinen & Niemelä, F. juniperina (Murrill) Spirin & Vlasák, F. kuzyana (Pilát ex Pilát) Spirin & Vlasák, F. leioderma (Mont.) Spirin & Vlasak, F. leucaena (Y.C. Dai & Niemelä) Spirin & Miettinen, F. luzonensis (Murrill) Spirin & Miettinen, F. maculatissima (Lloyd) Spirin, F. madronae (Vlasák & Ryvarden) Vlasák & Ryvarden, F. malicola (Berk. & M.A. Curtis) Spirin, F. marchionica (Mont.) Spirin & Miettinen, F. marianii (Bres.) Spirin, Vlasák & Cartabia, F. mellita (Niemelä & Penttilä) Niemelä & Miettinen, F. microcarpa (B.K. Cui & Shun Liu) Spirin, F. micropora (B.K. Cui & Shun Liu) Spirin, F. modesta (Kuntze ex Fr.) Vlasák & Spirin, F. monomitica (Yuan Y. Chen) Spirin & Viner, F. morganii (Lloyd) Spirin & Vlasák, F. moritziana (Lév.) Spirin & Miettinen, F. neotropica (D.L. Lindner, Ryvarden & T.J. Baroni) Vlasák, F. nigra (Berk.) Spirin & Miettinen, F. nivosella (Murrill) Spirin & Vlasák, F. oboensis (Decock, Amalfi & Ryvarden) Spirin, F. oleracea (R.W. Davidson & Lombard) Spirin & Vlasák, F. philippinensis (Murrill) Spirin & Vlasák, F. primaeva (Renvall & Niemelä) Miettinen & Niemelä, F. psilodermea (Berk. & Mont.) Spirin & Vlasák, F. pulverulenta (Rivoire) Rivoire, F. pulvina (Pers.) Spirin & Vlasák, F. pulvinascens (Pilát ex Pilát) Niemelä & Miettinen, F. quercina (L.) Spirin & Miettinen, F. ramentacea (Berk. & Broome) Spirin & Vlasák, F. renehenticii (Rivoire, Trichies & Vlasák) Rivoire & Vlasák, F. roseofusca (Romell) Spirin & Vlasák, F. sagraeana (Mont.) Vlasák & Spirin, F. sandaliae (Bernicchia & Ryvarden) Bernicchia & Vlasák, F. sclerotina (Rodway) M.D. Barrett & Spirin, F. serialiformis (Kout & Vlasák) Vlasák, F. serialis (Fr.) Spirin & Runnel, F. serrata (Vlasák & Spirin) Vlasák & Spirin, F. squamosella (Bernicchia & Ryvarden) Bernicchia & Ryvarden, F. stereoides (Fr.) Spirin, F. subectypa (Murrill) Spirin & Vlasák, F. substratosa (Malençon) Spirin & Miettinen, F. tropica (B.K. Cui) Spirin, F. tumulosa (Cooke) M.D. Barrett & Spirin, F. tuvensis (Spirin, Vlasák & Kotir.) Spirin & Vlasák, F. uralensis (Pilát) Spirin & Miettinen, F. ussuriensis (Bondartsev & Ljub.) Spirin & Miettinen, F. variiformis (Peck) Vlasák & Spirin, F. yunnanensis (M.L. Han & Q. An) Spirin, Daedaleopsis candicans (P. Karst.) Spirin, Megasporoporia eutelea (Har. & Pat.) Spirin & Viner, Neofomitella hemitephra (Berk.) M.D. Barrett, Pseudophaeolus soloniensis (Dubois) Spirin & Rivoire, P. trichrous (Berk. & M.A. Curtis) Vlasák & Spirin. New synonyms: Antrodia bondartsevae Spirin, A. huangshanensis Y.C. Dai & B.K. Cui, A. taxa T.T. Chang & W.N. Chou, A. wangii Y.C. Dai & H.S. Yuan, Antrodiella subnigra Oba, Mossebo & Ryvarden, Antrodiopsis Audet, Boletus quercinus Schrad., Brunneoporus Audet, Buglossoporus Kotl. & Pouzar, Buglossoporus eucalypticola M.L. Han, B.K. Cui & Y.C. Dai, Caloporus P. Karst., Cartilosoma Kotlaba & Pouzar, Coriolus clemensiae Murrill, C. cuneatiformis Murrill, C. hollickii Murrill, C. parthenius Hariot & Pat., C. rubritinctus Murrill, Daedalea Pers., Daedalea allantoidea M.L. Han, B.K. Cui & Y.C. Dai, D. americana M.L. Han, Vlasák & B.K. Cui, D. radiata B.K. Cui & Hai J. Li, D. rajchenbergiana Kossmann & Drechsler-Santos, D. sinensis Lloyd, Daedalella B.K. Cui & Shun Liu, Dentiporus Audet, Flavidoporia Audet, Fomes subferreus Murrill, Fomitopsis cana B.K. Cui, Hai J. Li & M.L. Han, F. caribensis B.K. Cui & Shun Liu, F. cystidiata B.K. Cui & M.L. Han, F. ginkgonis B.K. Cui & Shun Liu, F. iberica Melo & Ryvarden, F. incarnata K.M. Kim, J.S. Lee & H.S. Jung, F. subfeei B.K. Cui & M.L. Han, F. subtropica B.K. Cui & Hai J. Li, Fragifomes B.K. Cui, M.L. Han & Y.C. Dai, Leptoporus epileucinus Pilát, Melanoporia Murrill, Neoantrodia Audet, Neolentiporus Rajchenb., Nigroporus macroporus Ryvarden & Iturr., Niveoporofomes B.K. Cui, M.L. Han & Y.C. Dai, Pilatoporus Kotl. & Pouzar, Piptoporus P. Karst., Polyporus aurora Ces., P. durescens Overh. ex J. Lowe, P. griseodurus Lloyd, Poria incarnata Pers., Pseudoantrodia B.K. Cui, Y.Y. Chen & Shun Liu, Pseudofomitopsis B.K. Cui & Shun Liu, Ranadivia Zmitr., Rhizoporia Audet, Rhodofomes Kotl. & Pouzar, Rhodofomitopsis B.K. Cui, M.L. Han & Y.C. Dai, Rhodofomitopsis pseudofeei B.K. Cui & Shun Liu, R. roseomagna Nogueira-Melo, A.M.S. Soares & Gibertoni, Rubellofomes B.K. Cui, M.L. Han & Y.C. Dai, Subantrodia Audet, Trametes fulvirubida Corner, T. lignea Murrill, T. lusor Corner, T. pseudodochmia Corner, T. subalutacea Bourdot & Galzin, T. supermodesta Ryvarden & Iturr., T. tuberculata Bres., Tyromyces multipapillatus Corner, T. ochraceivinosus Corner, T. palmarum Murrill, T. singularis Corner, T. squamosellus Núñez & Ryvarden, Ungulidaedalea B.K. Cui, M.L. Han & Y.C. Dai. Lectotypes: Hexagonia sulcata Berk., Polyporus castaneae Bourdot & Galzin, Poria incarnata Pers., Trametes subalutacea Bourdot & Galzin, Ungulina substratosa Malençon. Neotypes: Agaricus soloniensis Dubois, Boletus pulvinus Pers. Citation: Spirin V, Runnel K, Vlasák J, Viner I, Barrett MD, Ryvarden L, Bernicchia A, Rivoire B, Ainsworth AM, Grebenc T, Cartabia M, Niemelä T, Larsson K-H, Miettinen O (2024). The genus Fomitopsis (Polyporales, Basidiomycota) reconsidered. Studies in Mycology 107: 149-249. doi: 10.3114/sim.2024.107.03.

2.
Phys Rev Lett ; 124(19): 193001, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32469594

RESUMEN

Measurement of the ^{138}Ba^{+} ^{2}S_{1/2}-^{2}D_{5/2} clock transition frequency and D_{5/2} Landé g_{J} factor are reported. The clock transition frequency ν_{Ba^{+}}=170126432449333.31±(0.39)_{stat}±(0.29)_{sys} Hz, is obtained with accuracy limited by the frequency calibration of the maser used as a reference oscillator. The Landé g_{J} factor for the ^{2}D_{5/2} level is determined to be g_{D}=1.20036739(24), which is a 30-fold improvement on previous measurements. The g-factor measurements are corrected for an ac-magnetic field from trap-drive-induced currents in the electrodes, and data taken over a range of magnetic fields underscores the importance of accounting for this systematic.

3.
Phys Rev Lett ; 124(8): 083202, 2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-32167337

RESUMEN

We propose and experimentally demonstrate a scheme that realizes hyperfine averaging during a Ramsey interrogation of a clock transition. The method eliminates the need to average over multiple optical transitions, reduces the sensitivity of the clock to its environment, and reduces inhomogeneous broadening in a multi-ion clock. The method is compatible with autobalanced Ramsey spectroscopy, which facilitates the elimination of residual shifts due to imperfect implementation and ac stark shifts from the optical probe. We demonstrate the scheme using correlation spectroscopy of the ^{1}S_{0}↔^{3}D_{1} clock transition in a three-ion Lu^{+} clock. From the demonstration we are able to provide a measurement of the ^{3}D_{1} quadrupole moment, Θ(^{3}D_{1})=0.634(9)ea_{0}^{2}.

4.
Persoonia ; 44: 301-459, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33116344

RESUMEN

Novel species of fungi described in this study include those from various countries as follows: Antarctica, Cladosporium arenosum from marine sediment sand. Argentina, Kosmimatamyces alatophylus (incl. Kosmimatamyces gen. nov.) from soil. Australia, Aspergillus banksianus, Aspergillus kumbius, Aspergillus luteorubrus, Aspergillus malvicolor and Aspergillus nanangensis from soil, Erysiphe medicaginis from leaves of Medicago polymorpha, Hymenotorrendiella communis on leaf litter of Eucalyptus bicostata, Lactifluus albopicri and Lactifluus austropiperatus on soil, Macalpinomyces collinsiae on Eriachne benthamii, Marasmius vagus on soil, Microdochium dawsoniorum from leaves of Sporobolus natalensis, Neopestalotiopsis nebuloides from leaves of Sporobolus elongatus, Pestalotiopsis etonensis from leaves of Sporobolus jacquemontii, Phytophthora personensis from soil associated with dying Grevillea mccutcheonii. Brazil, Aspergillus oxumiae from soil, Calvatia baixaverdensis on soil, Geastrum calycicoriaceum on leaf litter, Greeneria kielmeyerae on leaf spots of Kielmeyera coriacea. Chile, Phytophthora aysenensis on collar rot and stem of Aristotelia chilensis. Croatia, Mollisia gibbospora on fallen branch of Fagus sylvatica. Czech Republic, Neosetophoma hnaniceana from Buxus sempervirens. Ecuador, Exophiala frigidotolerans from soil. Estonia, Elaphomyces bucholtzii in soil. France, Venturia paralias from leaves of Euphorbia paralias. India, Cortinarius balteatoindicus and Cortinarius ulkhagarhiensis on leaf litter. Indonesia, Hymenotorrendiella indonesiana on Eucalyptus urophylla leaf litter. Italy, Penicillium taurinense from indoor chestnut mill. Malaysia, Hemileucoglossum kelabitense on soil, Satchmopsis pini on dead needles of Pinus tecunumanii. Poland, Lecanicillium praecognitum on insects' frass. Portugal, Neodevriesia aestuarina from saline water. Republic of Korea, Gongronella namwonensis from freshwater. Russia, Candida pellucida from Exomias pellucidus, Heterocephalacria septentrionalis as endophyte from Cladonia rangiferina, Vishniacozyma phoenicis from dates fruit, Volvariella paludosa from swamp. Slovenia, Mallocybe crassivelata on soil. South Africa, Beltraniella podocarpi, Hamatocanthoscypha podocarpi, Coleophoma podocarpi and Nothoseiridium podocarpi (incl. Nothoseiridium gen. nov.) from leaves of Podocarpus latifolius, Gyrothrix encephalarti from leaves of Encephalartos sp., Paraphyton cutaneum from skin of human patient, Phacidiella alsophilae from leaves of Alsophila capensis, and Satchmopsis metrosideri on leaf litter of Metrosideros excelsa. Spain, Cladophialophora cabanerensis from soil, Cortinarius paezii on soil, Cylindrium magnoliae from leaves of Magnolia grandiflora, Trichophoma cylindrospora (incl. Trichophoma gen. nov.) from plant debris, Tuber alcaracense in calcareus soil, Tuber buendiae in calcareus soil. Thailand, Annulohypoxylon spougei on corticated wood, Poaceascoma filiforme from leaves of unknown Poaceae. UK, Dendrostoma luteum on branch lesions of Castanea sativa, Ypsilina buttingtonensis from heartwood of Quercus sp. Ukraine, Myrmecridium phragmiticola from leaves of Phragmites australis. USA, Absidia pararepens from air, Juncomyces californiensis (incl. Juncomyces gen. nov.) from leaves of Juncus effusus, Montagnula cylindrospora from a human skin sample, Muriphila oklahomaensis (incl. Muriphila gen. nov.) on outside wall of alcohol distillery, Neofabraea eucalyptorum from leaves of Eucalyptus macrandra, Diabolocovidia claustri (incl. Diabolocovidia gen. nov.) from leaves of Serenoa repens, Paecilomyces penicilliformis from air, Pseudopezicula betulae from leaves of leaf spots of Populus tremuloides. Vietnam, Diaporthe durionigena on branches of Durio zibethinus and Roridomyces pseudoirritans on rotten wood. Morphological and culture characteristics are supported by DNA barcodes.

5.
Phys Rev Lett ; 123(6): 063201, 2019 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-31491162

RESUMEN

We demonstrate precision measurement and control of inhomogeneous broadening in a multi-ion clock consisting of three ^{176}Lu^{+} ions. Microwave spectroscopy between hyperfine states in the ^{3}D_{1} level is used to characterize differential systematic shifts between ions, most notably those associated with the electric quadrupole moment. By appropriate alignment of the magnetic field, we demonstrate suppression of these effects to the ∼10^{-17} level relative to the ^{1}S_{0}↔^{3}D_{1} optical transition frequency. Correlation spectroscopy on the optical transition demonstrates the feasibility of a 10-s Ramsey interrogation in the three ion configuration with a corresponding projection noise limited stability of σ(τ)=8.2×10^{-17}/sqrt[τ].

6.
Phys Rev Lett ; 119(21): 213601, 2017 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-29219405

RESUMEN

We propose a method for engineering spin dynamics in ensembles of integer-spin atoms confined within a high-finesse optical cavity. Our proposal uses cavity-assisted Raman transitions to engineer a Dicke model for integer-spin atoms, which, in a dispersive limit, reduces to effective atom-atom interactions within the ensemble. This scheme offers a promising and flexible new avenue for the exploration of a wide range of spinor many-body physics. As an example of this, we present results showing that this method can be used to generate spin-nematic squeezing in an ensemble of spin-1 atoms. With realistic parameters, the scheme should enable substantial squeezing on time scales much shorter than current experiments with spin-1 Bose-Einstein condensates.

7.
Phys Rev Lett ; 117(16): 160802, 2016 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-27792388

RESUMEN

We show that it is possible to significantly reduce rank 2 tensor shifts of a clock transition by operating at a judiciously chosen magnetic-field-insensitive point. In some cases shifts are almost completely eliminated making the transition an effective J=0 to J=0 candidate. This significantly improves the feasibility of a recent proposal for clock operation with large ion crystals. For such multi-ion clocks, geometric constraints and selection rules naturally divide clock operation into two categories based on the orientation of the magnetic field. We discuss the limitations imposed on each type and how calibrations might be carried out for clock operation.

8.
Persoonia ; 31: 188-296, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24761043

RESUMEN

Novel species of microfungi described in the present study include the following from South Africa: Camarosporium aloes, Phaeococcomyces aloes and Phoma aloes from Aloe, C. psoraleae, Diaporthe psoraleae and D. psoraleae-pinnatae from Psoralea, Colletotrichum euphorbiae from Euphorbia, Coniothyrium prosopidis and Peyronellaea prosopidis from Prosopis, Diaporthe cassines from Cassine, D. diospyricola from Diospyros, Diaporthe maytenicola from Maytenus, Harknessia proteae from Protea, Neofusicoccum ursorum and N. cryptoaustrale from Eucalyptus, Ochrocladosporium adansoniae from Adansonia, Pilidium pseudoconcavum from Greyia radlkoferi, Stagonospora pseudopaludosa from Phragmites and Toxicocladosporium ficiniae from Ficinia. Several species were also described from Thailand, namely: Chaetopsina pini and C. pinicola from Pinus spp., Myrmecridium thailandicum from reed litter, Passalora pseudotithoniae from Tithonia, Pallidocercospora ventilago from Ventilago, Pyricularia bothriochloae from Bothriochloa and Sphaerulina rhododendricola from Rhododendron. Novelties from Spain include Cladophialophora multiseptata, Knufia tsunedae and Pleuroascus rectipilus from soil and Cyphellophora catalaunica from river sediments. Species from the USA include Bipolaris drechsleri from Microstegium, Calonectria blephiliae from Blephilia, Kellermania macrospora (epitype) and K. pseudoyuccigena from Yucca. Three new species are described from Mexico, namely Neophaeosphaeria agaves and K. agaves from Agave and Phytophthora ipomoeae from Ipomoea. Other African species include Calonectria mossambicensis from Eucalyptus (Mozambique), Harzia cameroonensis from an unknown creeper (Cameroon), Mastigosporella anisophylleae from Anisophyllea (Zambia) and Teratosphaeria terminaliae from Terminalia (Zimbabwe). Species from Europe include Auxarthron longisporum from forest soil (Portugal), Discosia pseudoartocreas from Tilia (Austria), Paraconiothyrium polonense and P. lycopodinum from Lycopodium (Poland) and Stachybotrys oleronensis from Iris (France). Two species of Chrysosporium are described from Antarctica, namely C. magnasporum and C. oceanitesii. Finally, Licea xanthospora is described from Australia, Hypochnicium huinayensis from Chile and Custingophora blanchettei from Uruguay. Novel genera of Ascomycetes include Neomycosphaerella from Pseudopentameris macrantha (South Africa), and Paramycosphaerella from Brachystegia sp. (Zimbabwe). Novel hyphomycete genera include Pseudocatenomycopsis from Rothmannia (Zambia), Neopseudocercospora from Terminalia (Zambia) and Neodeightoniella from Phragmites (South Africa), while Dimorphiopsis from Brachystegia (Zambia) represents a novel coelomycetous genus. Furthermore, Alanphillipsia is introduced as a new genus in the Botryosphaeriaceae with four species, A. aloes, A. aloeigena and A. aloetica from Aloe spp. and A. euphorbiae from Euphorbia sp. (South Africa). A new combination is also proposed for Brachysporium torulosum (Deightoniella black tip of banana) as Corynespora torulosa. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

9.
Opt Express ; 20(19): 21379-84, 2012 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-23037261

RESUMEN

We present precision measurements of the hyperfine intervals in the 5D3/2 manifold of a single trapped Barium ion, ¹³7Ba⁺. Measurements of the hyperfine intervals are made between mF = 0 sublevels over a range of magnetic fields allowing us to interpolate to the zero field values with an accuracy below a few Hz, an improvement on previous measurements by three orders of magnitude. Our results, in conjunction with theoretical calculations, provide a 30-fold reduction in the uncertainty of the magnetic dipole (A) and electric quadrupole (B) hyperfine constants. In addition, we obtain the magnetic octupole constant (C) with an accuracy below 0.1Hz. This gives a subsequent determination of the nuclear magnetic octupole moment, Ω, with an uncertainty of 1% limited almost completely by the accuracy of theoretical calculations. This constitutes the first observation of the octupole moment in ¹³7Ba⁺ and the most accurately determined octupole moment to date.

10.
Phys Rev Lett ; 109(15): 153002, 2012 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-23102304

RESUMEN

We make a detailed experimental study of the threshold for the self-organization of thermal 87Rb atoms coupled to a high-finesse cavity over a range of atom numbers and cavity detunings. We investigate the difference between probing with a traveling wave and a retroreflected lattice. These two scenarios lead to qualitatively different behavior in terms of the response of the system as a function of cavity detuning with respect to the probe. In both cases, we confirm a N(-1) scaling of the threshold with atom number.

11.
Nature ; 432(7017): 602-5, 2004 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-15577904

RESUMEN

Scalable quantum computation and communication require error control to protect quantum information against unavoidable noise. Quantum error correction protects information stored in two-level quantum systems (qubits) by rectifying errors with operations conditioned on the measurement outcomes. Error-correction protocols have been implemented in nuclear magnetic resonance experiments, but the inherent limitations of this technique prevent its application to quantum information processing. Here we experimentally demonstrate quantum error correction using three beryllium atomic-ion qubits confined to a linear, multi-zone trap. An encoded one-qubit state is protected against spin-flip errors by means of a three-qubit quantum error-correcting code. A primary ion qubit is prepared in an initial state, which is then encoded into an entangled state of three physical qubits (the primary and two ancilla qubits). Errors are induced simultaneously in all qubits at various rates. The encoded state is decoded back to the primary ion one-qubit state, making error information available on the ancilla ions, which are separated from the primary ion and measured. Finally, the primary qubit state is corrected on the basis of the ancillae measurement outcome. We verify error correction by comparing the corrected final state to the uncorrected state and to the initial state. In principle, the approach enables a quantum state to be maintained by means of repeated error correction, an important step towards scalable fault-tolerant quantum computation using trapped ions.

12.
Nature ; 429(6993): 737-9, 2004 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-15201904

RESUMEN

Quantum teleportation provides a means to transport quantum information efficiently from one location to another, without the physical transfer of the associated quantum-information carrier. This is achieved by using the non-local correlations of previously distributed, entangled quantum bits (qubits). Teleportation is expected to play an integral role in quantum communication and quantum computation. Previous experimental demonstrations have been implemented with optical systems that used both discrete and continuous variables, and with liquid-state nuclear magnetic resonance. Here we report unconditional teleportation of massive particle qubits using atomic (9Be+) ions confined in a segmented ion trap, which aids individual qubit addressing. We achieve an average fidelity of 78 per cent, which exceeds the fidelity of any protocol that does not use entanglement. This demonstration is also important because it incorporates most of the techniques necessary for scalable quantum information processing in an ion-trap system.

13.
Nat Commun ; 9(1): 1650, 2018 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-29695720

RESUMEN

The accuracy of state-of-the-art atomic clocks is derived from the insensitivity of narrow optical atomic resonances to environmental perturbations. Two such resonances in singly ionized lutetium have been identified with potentially lower sensitivities compared to other clock candidates. Here we report measurement of the most significant unknown atomic property of both transitions, the static differential scalar polarizability. From this, the fractional blackbody radiation shift for one of the transitions is found to be -1.36(9) × 10-18 at 300 K, the lowest of any established optical atomic clock. In consideration of leading systematic effects common to all ion clocks, both transitions compare favorably to the most accurate ion-based clocks reported to date. This work firmly establishes Lu+ as a promising candidate for a future generation of more accurate optical atomic clocks.

14.
Biochim Biophys Acta ; 600(2): 270-90, 1980 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-6250594

RESUMEN

Changes in membrane and macromolecular fluidity which may accompany the differentiation processes of sporulation and germination in Bacillus megaterium K.M. are examined by electron spin and nuclear magnetic resonance spectroscopy. No change in membrane lipid fluidity is observed in isolated forespores up to stage VI. Between stage VI and release of mature spores, the ESR spectrum of doxylstearic acid spin labels becomes polycrystalline. This change in spectral fluidity is completely reversed during germination and is paralleled by the rapid release of Ca2+ from the spore. NMR studies also show that the mature spore has reduced macromolecular mobility and an increased nonexchangeable water pool compared with vegetative cells.


Asunto(s)
Bacillus megaterium/fisiología , Fluidez de la Membrana , Calcio/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Espectroscopía de Resonancia Magnética , Marcadores de Spin , Esporas Bacterianas/fisiología , Termodinámica
15.
Nat Commun ; 6: 6896, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25898253

RESUMEN

The pursuit of better atomic clocks has advanced many research areas, providing better quantum state control, new insights in quantum science, tighter limits on fundamental constant variation and improved tests of relativity. The record for the best stability and accuracy is currently held by optical lattice clocks. Here we take an important step towards realizing the full potential of a many-particle clock with a state-of-the-art stable laser. Our (87)Sr optical lattice clock now achieves fractional stability of 2.2 × 10(-16) at 1 s. With this improved stability, we perform a new accuracy evaluation of our clock, reducing many systematic uncertainties that limited our previous measurements, such as those in the lattice ac Stark shift, the atoms' thermal environment and the atomic response to room-temperature blackbody radiation. Our combined measurements have reduced the total uncertainty of the JILA Sr clock to 2.1 × 10(-18) in fractional frequency units.

16.
Gene ; 197(1-2): 375-8, 1997 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-9332388

RESUMEN

Recent data have shown that distinct DNA sequence elements direct the germination and sugar responses of the cucumber (Cucumis sativus, L.) malate synthase (Ms) gene (Sarah et al. (1996) Mol. Gen. Genet., 250, 153-161). Such information is, however, lacking for the isocitrate lyase (Icl) gene which is coordinately regulated with Ms. Deletions from the 5' end of the Icl promoter were therefore created specifically to address this question. Analysis of expression in seeds of transgenic Nicotiana plumbaginifolia plants showed that whereas a promoter sequence of 2.9 kilobases (kb) produced a normal germination response, deletion to -1568 base pairs (bp) dramatically reduced this response. Examination of the sugar response employed a transgenic cucumber root system. In this case, the 2900 bp and 1568 bp promoters both gave a strong sugar response, but further deletion to -1367 bp eliminated the response. Therefore, the germination and sugar responses of the Icl gene require distinct cis-acting elements, located respectively upstream and downstream of -1568 bp. This observation is consistent with distinct signal transduction systems regulating gene expression in each case.


Asunto(s)
Cucumis sativus/genética , Regulación de la Expresión Génica de las Plantas/genética , Isocitratoliasa/genética , Regiones Promotoras Genéticas/genética , Cucumis sativus/enzimología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas/genética , Germinación , Plantas Modificadas Genéticamente , Plantas Tóxicas , Eliminación de Secuencia , Sacarosa/farmacología , Nicotiana/genética
17.
Nutr Metab ; 22(1): 51-7, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-619314

RESUMEN

Weanling rats were fed a semipurified diet based on 10% casein and 1,500 ppm potassium cyanide. The diet was supplemented with varying levels of DL-methionine and/or potassium sulfate such that all diets were iso-sulfurous except for the basal which had no additional sulfur. The animals were fed for 2 weeks after which half of the rats in all groups except the basal were used in a radioactive study. Urine was collected and analyzed for thiocyanate. Animals which received labeled methionine were more efficient in producing labeled thiocyanate than those which received labeled sodium sulfate, although the latter did contribute to the detoxification of cyanide. Increases due to additional methionine were larger for weight gain, feed consumption, and urinary and plasma thiocyanate than with supplemental sulfate.


Asunto(s)
Biotransformación , Cianuros/metabolismo , Inactivación Metabólica , Metionina/metabolismo , Sulfatos/metabolismo , Animales , Peso Corporal , Caseínas/administración & dosificación , Cianuros/administración & dosificación , Masculino , Metionina/administración & dosificación , Ratas , Sulfatos/administración & dosificación , Radioisótopos de Azufre , Tiocianatos/orina
18.
IEEE Trans Biomed Eng ; 46(3): 331-9, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10097468

RESUMEN

We have developed an extrinsic Fabry-Perot interferometer (EFPI) to measure displacements of microscopic, living organelles in the inner ear. The EFPI is an optical phase-shifted instrument that can be used to measure nanometer displacements. The instrument transmits a coherent light signal to the end of a single glass optical fiber where the measurement is made. As the coherent light reaches the end of the fiber, part of this incident signal is reflected off the internal face of the fiber end (reference reflection) and part is transmitted through the end of the fiber. This transmitted light travels a short distance and is reflected off the surface whose displacement is to be measured (the target). This sensing reflection then reenters the fiber where it interferes with the reference reflection. The resulting interference signal then travels up the same optical fiber to a detector, where it is converted into a voltage that can be read from an oscilloscope. When the target moves, the phase relation between reference and sensing reflections changes, and the detector receives a modulated signal proportional to the target movement. Reflections of as little as 1% at both the sensor tip and target surfaces produce good results with this system. We use the EFPI in conjunction with fine glass whiskers to measure the stiffness (force per unit deflection) of stereociliary bundles on hair cells of the inner ear. The forces generated are in the tenths of picoNewton range and the displacements are tens of nanometers. Here we describe the EFPI and its development as a method for measuring displacements of microscopic organelles in a fluid medium. We also report experiments to validate the accuracy of the EFPI output and preliminary measurements of ciliary bundle stiffness in the posterior semicircular canal.


Asunto(s)
Células Ciliadas Auditivas/citología , Células Ciliadas Auditivas/fisiología , Interferometría/instrumentación , Animales , Calibración , Elasticidad , Diseño de Equipo , Tecnología de Fibra Óptica , Interferometría/métodos , Microscopía de Interferencia/métodos , Modelos Biológicos , Fibras Ópticas , Procesamiento de Señales Asistido por Computador , Tortugas
19.
J Plast Reconstr Aesthet Surg ; 64(12): 1689-92, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21600862

RESUMEN

Iatrogenic femoral nerve injury is an uncommon but recognised complication of abdominal and gynaecological surgery. There have been several reported cases following colorectal surgery which specifically report transient femoral nerve neuropathies with variable but often full recovery. To our knowledge, this is the first documented case of femoral nerve reconstruction after iatrogenic resection during right hemicolectomy. We present a case report of complete femoral nerve transection following abdominal surgery and discuss our management.


Asunto(s)
Colectomía/efectos adversos , Nervio Femoral/cirugía , Neuropatía Femoral/cirugía , Complicaciones Intraoperatorias/cirugía , Procedimientos de Cirugía Plástica/métodos , Enfermedades del Ciego/cirugía , Desbridamiento , Neuropatía Femoral/etiología , Adhesivo de Tejido de Fibrina/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Adhesivos Tisulares
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