57,430 research outputs found
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Parapagurapseudopsis carinatus Brum 1973
No full textParapagurapseudopsis carinatus Brum, 1973 (Figs. 1–4) Brumia carinata Bäcescu, 1981 Parapagurapseudopsis carinata Guţu, 1998. Original description: Brum (1973): 3, fig. 3; 1974: 7–10, figs. 27–37. Material examined: 88 individuals. BRASIL, Bahia: MZUSP 16915, (1 preparatory, 1 immature female), Baía de Todos os Santos, Itaparica Island, V- 2004, St. 0 2, 13° 10.279´S – 38 ° 40.408´W, 27m; MZUSP 16916, (1 preparatory and 1 immature females), St. 0 3, 13° 10.803´S – 38 ° 43.546´W, 18m; MZUSP 16917, (1 preparatory female), St. 0 1, 13° 4.759´S – 38 ° 38.745´W, 16m; MZUSP 16918, (22 males; 5 immature females, 18 preparatory females; 4 females with eggs, 5 with embryos, 6 with empty marsupium; 15 juveniles), Baía de Todos os Santos, Guaibim beach, same date and col., St. 0 4, 13° 12.79´S – 38 ° 48.69´W, 18m; MZUSP 16919, (1 male, 3 immature female, 1 preparatory female, 1 female with empty marsupium,), St. 0 5, 13° 14.033´S – 38 ° 52.5´W, 15m. Female redescription. Body 1.7 mm long, cylindric (Fig. 1 a,b). Cephalothorax longer than broad; dorsal surface finely ornamented with discrete dorsodistal carina. Eye lobes present, without visual elements. Rostrum truncate, short, rounded. Epistome present. Pereon about 2.5 times the cephalothorax length, strong, indurate, with dorsal carina on all pereonites. First and sixth pereonites shortest; second and fifth pereonites a little shorter than the third and fourth ones. Pleon, as long as cephalothorax, with five short pleonites, decreasing in width, distally; pleonites with dorsal carina. Pleotelson (Fig. 1 a–d) longer than wide, almost equal to pleonites 3–5 length, apex finely serrate; two lateral spiniform projections subapically placed. Antenna 1 (Fig. 2 a) article 1 shorter than carapace length, 7 times as long as wide, both inner and outer margins with irregular spinous apophyses, intercalate for simple and plumose setae; distal spine on outer margin followed by a circumplumose setae near joint with article 2. Second peduncle article about 3.5 times shorter than the first, and the third one equal to the second article. Inner flagellum 4 -articulate; outer flagellum 7 -articulate, distal articles with aesthetascs. Antenna 2 (Fig. 2 b) with a very large inner expansion; article 2 with two great spiniform projections on inner and outer margins; outer margin with some acute and small processus; one medial simple seta on inner margin. Squama small, having one simple seta. Third article very short. Folowing two articles thin, each of them longer than the second article. Last three articles (measured together) about as long as fourth or third articles. Mandible (Fig. 2 c) with triarticulate palp; article 1 with serrate margin and three plumose setae; article 2 longer than the first or the third ones (Fig. 2 c 2); articles 2 and 3 with simple setae. Molar robust, without special features. Incisor of both mandibles and lacinia mobilis of the left mandible with four strong spines. Setiferous lobe with five setae, branched terminally. Labrum (Fig. 2 g) with fine hairs on lateral margin. Labium (Fig. 2 d) with broad and setulose area at outer margin, palp with fine lateral setules and two simple setae distally. Maxilla 1 (Fig. 2 f) with a biarticulate palp, ending in 4 subequal setae. Inner endite with a prominence on the middle of the outer side, fine hairs on lateral margins and five single sided pinnate setae apically situated. Outer endite long and narrow, lateral sides hairy, 11 spiniform setae on apical margin and two subterminal simple setae. Maxilla 2 (Fig. 2 e) with no special features; broad, having lobes with simple and with setulated setae, outer fixed lobe with two trifurcate and three pinnate setae. Maxilliped (Fig. 3 a) basis longer than wide with 4 plumose setae diagonally; palp of 4 articles, first article wider than long, with plumose seta at inner margin; second article broadest, larger at base, with 4 short plumose setae and several simple setae at inner margin; third and fourth articles equal in length with simple setae distally. Endite with with several kinds of setae and two coupling hooks. Epignath (Fig. 2 h) lobate with one simple seta distally. Cheliped (Fig. 4 c) with exopodite (broken off, not illustrated); basis globose; carpus 1.5 times the merus length. Propodus large, broad with row of simple setae on dorsal margin of fixed finger. Pereopod 1 (Fig. 3 b) long and thin, approximately similar to the following ones, but a little shorter than the last three pereopods. Exopod absent. Coxa rounded. Basis slightly longer than merus, carpus and propodus together, ventral margin with sparce short setae, dorsal margin with one strong denticle and some short spiny projections. Merus shorter than the carpus or propodus. Carpus and propodus bearing 4–5 short cuspidate setae along ventral margin, an elongate seta distally on propodus; dactylus about 2.5 times longer than curved unguis. Pereopods 2 and 3 (Fig. 3 c,d) relatively similar to the preceding one, but a little smaller; the fourth pereopod smaller than the third one. Pereopods 4 to 6 (Fig. 3 e–g) subequal, fourth pereopod longer than others. Pereopod 4 carpus and propodus with cuspidate setae ventrally, last article with one pinnate and some simple setae distally. Pereopod 5 bearing a dense row of short spiniform setae at distal half. Pereopod 6 (Fig. 3 g) dactylus with a conspicuous protuberance larger than in preceding pereopods. Pleopod (Fig. 3 h) in five pairs, well developed in males and females, decreasing in size posteriorly. Protopod long with two articles, basal article nearly 14 times shorter, distal article with 2 long plumose setae. Endopod biarticulate with long plumose setae distally; exopod slightly longer than endopod bearing a short proximal and a long distal plumose seta. Uropod (Fig. 4 a) basal article about 2.7 times longer than wide; exopod triarticulate, endopod with 17 articles. Oostegites in 4 pairs. Description of the males. Body similar to the same of females. Chelipeds subequal. Propodus of the larger cheliped approximately of the same length as first four pereonites together; basis with dorsal margin serrate. Another cheliped about 2.5 times smaller than larger one. Exopod (Fig. 1 e. 1) triarticulate, with two plumose setae. Geographic distribution. BRASIL: Bahia. Habitat. Shallow waters, bottom with corals, algae, carbonate materials and/or rhodolites. Remarks. The right cheliped on young males was found to be larger than the left (Fig. 4 b 1, b 2), the opposite that occurs on adults (Fig. 1 e,f) as observed in two undamaged exemplars. This appendage is easily broken probably because of its great size when compared with the body length, or lost by autotomy. From all the examined specimens, only two males were found with chelipeds. Males without chelipeds were recognized by the presence of their genital cone. The number of antennal and uropodal articles in addition to pereopodal setation varies between individuals. In spite of the absence of the illustration of the cheliped in the original description (Brum, 1973) and the lack of cheliped in the type material we examined, the author stated that this appendix lacks an exopod. This statement was not confirmed through the examination of our material. Brum (1973) also described the rostrum of P. c a r i n a t u s as having a short tiny mesial spine. However, the species has a truncate rostrum and what can be observed in a dorsal view is the apex of the epistoma. Indeed, the epistoma was also named, in a wrong way, of pseudorostrum (Brum, 1973) and conic clypeus (Brum, 1974).Published as part of Santos, Kátia Christol Dos & Pires-Vanin, Ana Maria Setubal, 2006, Redescription of Parapagurapseudopsis carinatus (Tanaidacea: Apseudomorpha) and remarks about the male form, pp. 39-48 in Zootaxa 1363 on pages 41-47, DOI: 10.5281/zenodo.17472
Interacting Valence Holes In P -type Sige Quantum Disks In A Magnetic Field
No full textThe interaction of holes in p-type SiGe quantum disks in a magnetic field is studied. The holes are described by a Luttinger Hamiltonian, with parity replacing spin as a good quantum number. The interaction Hamiltonian separates into charge-charge and parity-parity parts. The effect of parity mediated hole-hole interactions is illustrated by numerical calculations of the energy and capacitance spectra for up to two holes in a quantum disk for parameters corresponding to a SiGe system.55231569415700Darnhuber, A.A., Stangl, J., Bauer, G., Lockwood, D.J., Noel, J.P., Wang, P.D., Sotomayor Torres, C.M., unpublishedAbstreiter, G., Schittenhelm, P., Engel, C., Silveira, E., Zrenner, A., Meertens, D., Jager, W., Proceedings of the 9th International Winterschool on New Developments in Solid State Physics (1996) Semicond. Sci. Technol., 11, p. 1521. , Mauterndorf, 1996Zaslavsky, A., Milkove, K.R., Lee, Y.H., Ferland, B., Sedgwick, T.O., (1995) Appl. Phys. Lett., 67, p. 3921Zaslavsky, A., Smith III, T.P., Grutzmacher, D.A., Lin, S.Y., Sedgwick, T.O., Syphers, D.A., (1993) Phys. Rev. B, 48, p. 15112Liu, H.C., Landheer, P., Buchanan, M., Houghton, D.C., (1989) Appl. Phys. Lett., 52, p. 1809Arafa, M., Fay, P., Ismail, K., Chu, J.O., Meyerson, B.S., Adesida, I., (1996) IEEE Electron Device Lett., 17, p. 124Houghton, D.C., Aers, G.C., Eric Yang, S.R., Wang, E., Rowell, N.L., (1995) Phys. Rev. Lett., 75, p. 866Ashoori, R.C., Stormer, H.L., Weiner, J.S., Pfeiffer, L.N., Baldwin, K.W., West, K.W., (1993) Phys. Rev. Lett., 71, p. 613Su, B., Goldman, V.J., Cunningham, I.E., (1992) Science, 255, p. 313Hansen, W., Smith III, T.P., Lee, K.Y., Brum, J.A., Knoedler, C.M., Hong, J.M., Kern, O.P., (1989) Phys. Rev. Lett., 62, p. 2168Drexler, H., Leonard, D., Hansen, W., Kotthaus, J.P., Petroff, P.M., (1994) Phys. Rev. Lett., 73, p. 2252Vahala, K.J., Sercel, P.C., (1990) Phys. Rev. Lett., 65, p. 239Sercel, P.C., Vahala, K.J., (1990) Phys. Rev. B, 42, p. 3690Broido, D.A., Cros, A., Rössler, U., (1992) Phys. Rev. B, 45, p. 11395Darnhofer, T., Rössler, U., Broido, D.A., (1995) Phys. Rev. B, 52, p. 14376Darnhofer, T., (1996) Phys. Rev. B, 53, p. 13631Pedersen, F.B., Chang, Y.-C., (1996) Phys. Rev. B, 53, p. 1507Kastner, M., (1993) Phys. Today, 46, p. 24Chakraborty, T., (1992) Comments Condens. Matter Phys., 16, p. 35Palacios, J.J., Hawrylak, P., (1995) Phys. Rev. B, 51, p. 1769MacDonald, A.H., Platzman, P.M., Boebinger, G.S., (1990) Phys. Rev. Lett., 65, p. 775Marzin, J.-Y., Gerard, J.-M., Voisin, P., Brum, J.A., (1990) Semiconductor and Semimetals, 32, p. 56. , Strained-Layer Superlattices: Physics, edited by T.P. Pearsall, Academic Press, New YorkLuttinger, J.M., Kohn, W., (1955) Phys. Rev., 97, p. 869Luttinger, J.M., (1956) Phys. Rev., 102, p. 1030Broido, D., Sham, L.J., (1985) Phys. Rev. B, 31, p. 888Wagner, M., Merkt, U., Chaplik, A.V., (1992) Phys. Rev. B, 45, p. 1951Maksym, P.A., Chakraborty, T., (1992) Phys. Rev. B, 45, p. 1947Bryant, G.W., (1987) Phys. Rev. Lett., 59, p. 1140Pfannkuche, D., Gerhardts, R., (1991) Phys. Rev. B, 44, p. 13132Hawrylak, P., (1993) Phys. Rev. Lett., 71, p. 334
Valence Band Anti-crossing In Gaas/algaas Quantum Wells Under Tensile Biaxial Strain
No full textWe present here the study of the effects of the biaxial tensile strain on the optical properties in GaAs/AlGaAs quantum wells using low-temperature photoluminescence and photoluminescence excitation techniques. We used a pressure cell that permits to apply a biaxial tensile strain on an epitaxial film up to ∼ 0.3 % (for GaAs). The strain was determined by the energy shift of the excitonic recombination of the own GaAs buffer layer of the sample. The results of the optical measurements show clear the strain effects on the light and heavy hole excitons transitions and also show their anti-crossing. This new results show that this system is appropriated to study optical properties involving resonant phenomena in semiconductor quantum wells. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.13547550Tudury, H.A.P., Nakaema, M.K.K., Iikawa, F., Brum, J.A., Ribeiro, E., Carvalho Jr., W., Bernussi, A.A., Gobbi, A.L., (2001) Phys. Rev. B, 64, p. 153301Thewald, M.L.W., Harrison, D.A., Heinhart, C.F., Wok, J.A., (1997) Phys. Rev. Lett., 79, p. 269Iikawa, F., Cerdeira, F., Vazquez-Lopes, C., Motisuke, P., Sacilotti, M.A., Masut, R.A., Roth, A.P., (1988) Phys. Rev. B, 38, p. 8473Landoldt-Börnstein, (1982) Numerical Data and Functional Relationships in Science and Technology, III-17A, p. 218. , edited by O. Madelung Springer-Verlag, Berlin, New SeriesMichler, P., Hangleiter, A., Moritz, A., Fuchs, G., Härle, V., Scholz, F., (1993) Phys. Rev. B, 48, p. 11991Gershoni, D., Vandenberg, J.M., Hamm, R.A., Temkin, H., Panish, M.B., (1987) Phys. Rev. B, 36, p. 1320Triques, A.L.C., Brum, J.A., (1994) Proc. of 22nd International Conference on the Physics of Semiconductors, 2, p. 1328. , Vancouver, edited by D. J. Lockwood World Scientifi
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Convective–reactive nucleosynthesis of K, Sc, Cl and p-process isotopes in O–C shell mergers
No full text© 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. We address the deficiency of odd-Z elements P, Cl, K and Sc in Galactic chemical evolution models through an investigation of the nucleosynthesis of interacting convective O and C shells in massive stars. 3D hydrodynamic simulations of O-shell convection with moderate C-ingestion rates show no dramatic deviation from spherical symmetry. We derive a spherically averaged diffusion coefficient for 1D nucleosynthesis simulations, which show that such convective-reactive ingestion events can be a production site for P, Cl, K and Sc. An entrainment rate of 10-3M⊙s-1features overproduction factors OPs≈ 7. Full O-C shell mergers in our 1D stellar evolution massive star models have overproduction factors OPm> 1 dex but for such cases 3D hydrodynamic simulations suggest deviations from spherical symmetry. γ - process species can be produced with overproduction factors of OPm> 1 dex, for example, for130, 132Ba. Using the uncertain prediction of the 15M⊙, Z = 0.02 massive star model (OPm≈ 15) as representative for merger or entrainment convective-reactive events involving O- and C-burning shells, and assume that such events occur in more than 50 per cent of all stars, our chemical evolution models reproduce the observed Galactic trends of the odd-Z elements
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Acute Ethanol Administration Rapidly Increases Phosphorylation of Conventional Protein Kinase C in Specific Mammalian Brain Regions in Vivo
No full textBackground
Protein kinase C (PKC) is a family of isoenzymes that regulate a variety of functions in the central nervous system including neurotransmitter release, ion channel activity, and cell differentiation. Growing evidence suggests that specific isoforms of PKC influence a variety of behavioral, biochemical, and physiological effects of ethanol in mammals. The purpose of this study was to determine whether acute ethanol exposure alters phosphorylation of conventional PKC isoforms at a threonine 674 (p-cPKC) site in the hydrophobic domain of the kinase, which is required for its catalytic activity.
Methods
Male rats were administered a dose range of ethanol (0, 0.5, 1, or 2 g/kg, intragastric) and brain tissue was removed 10 minutes later for evaluation of changes in p-cPKC expression using immunohistochemistry and Western blot methods.
Results
Immunohistochemical data show that the highest dose of ethanol (2 g/kg) rapidly increases p-cPKC immunoreactivity specifically in the nucleus accumbens (core and shell), lateral septum, and hippocampus (CA3 and dentate gyrus). Western blot analysis further showed that ethanol (2 g/kg) increased p-cPKC expression in the P2 membrane fraction of tissue from the nucleus accumbens and hippocampus. Although p-cPKC was expressed in numerous other brain regions, including the caudate nucleus, amygdala, and cortex, no changes were observed in response to acute ethanol. Total PKC? immunoreactivity was surveyed throughout the brain and showed no change following acute ethanol injection
Temperature-driven global sea-level variability in the Common Era
No full textWe assess the relationship between temperature and global sea-level (GSL) variability over the Common Era through a statistical metaanalysis of proxy relative sea-level reconstructions and tide-gauge data. GSL rose at 0.1 ± 0.1 mm/y (2σ) over 0–700 CE. A GSL fall of 0.2 ± 0.2 mm/y over 1000–1400 CE is associated with ∼0.2 °C global mean cooling. A significant GSL acceleration began in the 19th century and yielded a 20th century rise that is extremely likely (probability P≥0.95) faster than during any of the previous 27 centuries. A semiempirical model calibrated against the GSL reconstruction indicates that, in the absence of anthropogenic climate change, it is extremely likely (P=0.95) that 20th century GSL would have risen by less than 51% of the observed 13.8±1.5 cm. The new semiempirical model largely reconciles previous differences between semiempirical 21st century GSL projections and the process model-based projections summarized in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report.This article is available Open Access at the Link to published version: http://dx.doi.org/10.1016/j.emospa.2016.02.006Also available as related resources: Supporting Information (PDF), Dataset S1 (PDF), Dataset S2 (Excel), Dataset S3 (Excel).Peer reviewe
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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