43,486 research outputs found
The abnormal spindle protein is required for germ cell mitosis and oocyte differentiation during Drosophila oogenesis
No full textIn this study, we present evidence that the asp function is required in oogenesis for germline cell divisions as well as for cyst polarity and oocyte differentiation. Consistent with previously described roles in spindle organization during Drosophila meiosis and mitosis, asp mutation leads to severe defects in spindle microtubule organization within the germarium. The mitotic spindles of the mutant cystocytes are composed by wavy microtubules and have abnormal poles that often lack g-tubulin. The fusome structure is also compromised. In the absence of asp function, the cystocyte divisions fail resulting in egg chamber with fewer than 16 germ cells. Moreover, the microtubule network within the developing germline cysts may assemble incorrectly in turn affecting the microtubule based transport of the specific determinants that is required during mid-oogenesis for the oocyte differentiation progra
Painting of Robbins & Kelly flight
No full textCaption: "Star-Telegram artist's conception of historic refueling of 'Fort Worth' during record endurance flight of Reg L. Robbins and Jim Kelly, May 19-26, 1929," cover of Fort Worth Star-Telegram and Sunday Record Magazine Sectio
Decomposition, Condensation Defects, and Fusion
No full textIn this paper we outline the application of decomposition to condensation defects and their fusion rules. Briefly, a condensation defect is obtained by gauging a higher-form symmetry along a submanifold, and so there is a natural interplay with notions of decomposition, the statement that d-dimensional quantum field theories with global (Formula presented.) -form symmetries are equivalent to disjoint unions of other quantum field theories. We will also construct new (sometimes non-invertible) defects, and compute their fusion products, again utilizing decomposition. An important role will be played in all these analyses by theta angles for gauged higher-form symmetries, which can be used to select individual universes in a decomposition
Dr. R. L. Robbins.
No full textEditors: Aug. 1859-July 1865, J. D. White, J. H. McQuillen, G. J. Ziegler.--Aug. 1865-Dec. 1871, J. H. McQuillen, G. J. Ziegler.--Jan. 1872-May 1891, J. W. White.--July 1891-Apr. 1930, E. C. Kirk (with L. P. Anthony, Dec. 1917-Apr. 1930).--May 1930-Dec. 1936, L. P. Anthony.Vols. 1-13 are called "new series."Merged in Jan. 1937 with: Journal of the American Dental Association, ISSN 1048-6364, to form: Journal of the American Dental Association and dental cosmos, ISSN 0375-8451
Half-Integer Point Defects in the Q-Tensor Theory of Nematic Liquid Crystals
No full textWe investigate prototypical profiles of point defects in two-dimensional liquid crystals within the framework of Landau–de Gennes theory. Using boundary conditions characteristic of defects of index k/2, we find a critical point of the Landau–de Gennes energy that is characterised by a system of ordinary differential equations. In the deep nematic regime, b2 small, we prove that this critical point is the unique global minimiser of the Landau–de Gennes energy. For the case b2=0, we investigate in greater detail the regime of vanishing elastic constant L→0, where we obtain three explicit point defect profiles, including the global minimiser
Ixodes murreleti Cooley and Kohls 1945
No full text152. Ixodes murreleti Cooley and Kohls, 1945. A Nearctic species known only to parasitize Charadriiformes: Alcidae. M: unknown F: Cooley and Kohls (1945) N: unknown L: unknown Redescription F: Guzmán-Cornejo and Robbins (2010)Published as part of Guglielmone, Alberto A., Petney, Trevor N. & Robbins, Richard G., 2020, Ixodidae (Acari: Ixodoidea): descriptions and redescriptions of all known species from 1758 to December 31, 2019, pp. 1-322 in Zootaxa 4871 (1) on page 49, DOI: 10.11646/zootaxa.4871.1.1, http://zenodo.org/record/442334
Does Stellate cause meiotic drive in Drosophila melanogaster?.
No full textDrosophila melanogaster males deficient for the crystal (cry) locus of the Y chromosome that carry between 15 and 60 copies of the X-linked Stellate (Ste) gene are semisterile, have elevated levels of nondisjunction, produce distorted sperm genotype ratios (meiotic drive), and evince hyperactive transcription of Ste in the testes. Ste seems to be the active element in this system, and it has been proposed that the ancestral Ste gene was "selfish" and increased in frequency because it caused meiotic drive. This hypothetical evolutionary history is based on the idea that Ste overexpression, and not the lack of cry, causes the meiotic drive of cry(-) males. To test whether this is true, we have constructed a Ste-deleted X chromosome and examined the phenotype of Ste(-)/cry(-) males. If hyperactivity of Ste were necessary for the transmission defects seen in cry(-) males, cry(-) males completely deficient for Ste would be normal. Although it is impossible to construct a completely Ste(-) genotype, we find that Ste(-)/cry(-) males have exactly the same phenotype as Ste(+)/cry(-) males. The deletion of all X chromosome Ste copies not only does not eliminate meiotic drive and nondisjunction, but it also does not even reduce them below the levels produced when the X carries 15 copies of Ste
Ixodes tancitarius Cooley and Kohls 1942
No full text226. Ixodes tancitarius Cooley and Kohls, 1942b. A Nearctic and Neotropical species whose female has been found on Rodentia: Cricetidae. Ixodes tancitarius is a very rare parasite of humans, with a single record treated as provisionally valid by Guglielmone and Robbins (2018). M: unknown F: Cooley and Kohls (1942b) N: unknown L: unknown Redescriptions F: Cooley and Kohls (1945), Guzmán-Cornejo and Robbins (2010)Published as part of Guglielmone, Alberto A., Petney, Trevor N. & Robbins, Richard G., 2020, Ixodidae (Acari: Ixodoidea): descriptions and redescriptions of all known species from 1758 to December 31, 2019, pp. 1-322 in Zootaxa 4871 (1) on page 70, DOI: 10.11646/zootaxa.4871.1.1, http://zenodo.org/record/442334
Ixodes guatemalensis Kohls 1956
No full text95. Ixodes guatemalensis Kohls, 1956a. A Neotropical species whose adults (mostly females) have been found on Rodentia: Cricetidae and Sciuridae, Carnivora: Mustelidae, and Soricomoprha: Soricidae. There are no records of Ixodes guatemalensis causing human parasitism. M: Keirans and Eckerlin (2005) F: Kohls (1956a) N: unknown L: unknown Redescriptions M: Guzmán-Cornejo and Robbins (2010) F: Keirans and Eckerlin (2005), Guzmán-Cornejo and Robbins (2010)Published as part of Guglielmone, Alberto A., Petney, Trevor N. & Robbins, Richard G., 2020, Ixodidae (Acari: Ixodoidea): descriptions and redescriptions of all known species from 1758 to December 31, 2019, pp. 1-322 in Zootaxa 4871 (1) on page 33, DOI: 10.11646/zootaxa.4871.1.1, http://zenodo.org/record/442334
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
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