351 research outputs found
Genome of the facultative scuticociliatosis pathogen Pseudocohnilembus persalinus provides insight into its virulence through horizontal gene transfer
This work is licensed under a Creative Commons Attribution 4.0 International License. The
images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ The attached file is the published version of the article
Coherent manipulation of nitrogen vacancy centers in 4H silicon carbide with resonant excitation
Silicon carbide (SiC) has become a key player in realization of scalable
quantum technologies due to its ability to host optically addressable spin
qubits and wafer-size samples. Here, we have demonstrated optically detected
magnetic resonance (ODMR) with resonant excitation, and clearly identified the
ground state energy levels of the NV centers in 4H-SiC. Coherent manipulation
of NV centers in SiC has been achieved with Rabi and Ramsey oscillations.
Finally, we show the successful generation and characterization of single
nitrogen vacancy (NV) center in SiC employing ion implantation. Our results are
highlighting the key role of NV centers in SiC as a potential candidate for
quantum information processing
Redefinition and Reassignment of the 18-cirri Genera Hemigastrostyla, Oxytricha, Urosomoida, and Actinotricha (Ciliophora, Hypotricha), and Description of One New Genus and Two New Species
The morphology, the infraciliature, and two stages of physiological reorganization of Hemigastrostyla elongata spec. nov.,isolated from the Yellow Sea near Qingdao (China), are described. The new species differs from the type H. stenocephala, inter alia, by the length of the dorsal bristles and the position of the pretransverse ventral cirri; from H. enigmatica by the number of caudal cirri; and from H. para-enigmatica spec. nov. – established for the H. enigmatica populations from the Yellow Sea – by the arrangement of the postoral ventral cirri and the cortical granulation. A key to the Hemigastrostyla species and some other 18-cirri hypotrichs is provided. Hemigastrostyla szaboi is fixed as type species of Heterooxytricha gen. nov. because the type population lacks the extra cirri which are characteristic for Hemigastrostyla. In addition, Oxytricha geleii is assigned to this new genus, whose species have, like many oxytrichids, 18 frontal-ventraltransverse cirri, but a Gonostomum dorsal kinety pattern. The old, large, and difficult genus Oxytricha is briefly reviewed, mainly on the basis of the dorsal kinety pattern. Very likely, only species with the Oxytricha pattern belong to this genus. Oxytricha marcili and O. pseudofurcata, which have the Urosomoida kinety pattern (i.e. kinety 3 fragmentation lacking), are transferred to Urosomoida which is, inter alia, defined by a more or less distinctly reduced number of ventral and transverse cirri. Some other Oxytricha species with this kinety pattern (O. islandica, O. lanceolata, O. pseudosimilis, O. setigera) are not transferred to Urosomoida, but preliminarily classified as incertae sedis in Oxytricha, because they have the full set of 18 cirri. The available molecular data on O. lanceolata indicate that this type of 18-cirri hypotrichs likely needs a genus of its own because O. lanceolata does not cluster with O. granulifera, type of this genus. The marine Actinotricha saltans, classified for a very long time in Oxytricha, seems to be a non-dorsomarginalian hypotrich according to molecular data, justifying the reactivation of the old genus Actinotricha. Oxytricha shii has a multiple dorsal kinety 3 fragmentation, three dorsomarginal rows, and the undulating membranes arranged in the Cyrtohymena pattern, strongly indicating that it is a member of the subgenus Cyrtohymena (Cyrtohymenides). This brief review is a further step to unravel the complicated systematics of the old, but still little-known genus Oxytricha. The following new combinations are made in this paper: Cyrtohymena (Cyrtohymenides) shii (Shi et al., 1997) comb. nov.; Heterooxytricha szaboi (Wilbert and Song, 2005) comb. nov.; Heterooxytricha geleii (Wilbert, 1986) comb. nov.; Urosomoida marcili (Paiva and Silva-Neto, 2004) comb. nov.; Urosomoida pseudofurcata (Berger, 1999) comb. nov
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Morphology and SSU rRNA Gene Sequences of Three Marine Ciliates from Yellow Sea, China, Including One New Species, Uronema heteromarinum nov. spec. (Ciliophora, Scuticociliatida)
The morphology, infraciliature, and silverline system of three marine scuticociliates, Uronema marinum Dujardin, 1841, U. heteromarinum nov. spec. and Pleuronema setigerum Calkins, 1902, isolated from coastal waters off Qingdao, China, were investigated using living observation and silver impregnation methods. Due to the great confusion in the species definition of the well-known species U. marinum, we have documented a detailed discussion/comparison and believe that most of the confusion is due to the fact that at least 2 closely-related sibling morphotypes exist which are often not recognized. Based on the data available, U. marinum is strictly defined as follows: marine Uronema ca. 30 × 10 μm in size, with truncated apical frontal plate and smooth pellicle, extrusomes inconspicuous, cytostome located equatorially, 12–14 somatic kineties and one contractile vacuole pore near posterior end of kinety 2. Uronema heteromarinum nov. spec. resembles U. marinum but can be distinguished morphologically by its notched pellicle with conspicuous extrusomes and reticulate ridges, the 15–16 somatic kineties, widely separated membranelle 1 and membranelle 2, as well as the subequatorially positioned cytostome. Based on the Qingdao population, an improved diagnosis for the poorly known Pleuronema setigerum is: marine slender oval-shaped form, in vivo about 40–50 × 15–20 μm; 3–5 preoral kineties and 14–22 somatic kineties; membranelle 1 and 3 three-rowed, and posterior end of M2a ring-like. The small subunit (SSU) rRNA gene for all three organisms were sequenced and analyzed with standard methods
- …
