830 research outputs found
A search for energy deposition by neutrinos in matter
An exploratory search for an anomalous energy deposition by neutrinos in a
germanium crystal was performed in the CERN high energy neutrino beam. No
signal was found and a limit is set at a level of about 10^-12 of the normal
dE/dx for a minimum ionizing particle.Comment: 7 pages, 3 figures Paper accepted by Physics Letters B on March 4th,
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Rediscovery and reclassification of the dipteran taxon Nothomicrodon Wheeler, an exclusive endoparasitoid of gyne ant larvae
The myrmecophile larva of the dipteran taxon Nothomicrodon Wheeler is rediscovered, almost a century after its original description and unique report. The systematic position of this dipteran has remained enigmatic due to the absence of reared imagos to confirm indentity. We also failed to rear imagos, but we scrutinized entire nests of the Brazilian arboreal dolichoderine ant Azteca chartifex which, combined with morphological and molecular studies, enabled us to establish beyond doubt that Nothomicrodon belongs to the Phoridae (Insecta: Diptera), not the Syrphidae where it was first placed, and that the species we studied is an endoparasitoid of the larvae of A. chartifex, exclusively attacking sexual female (gyne) larvae. Northomicrodon parasitism can exert high fitness costs to a host colony. Our discovery adds one more case to the growing number of phorid taxa known to parasitize ant larvae and suggests that many others remain to be discovered. Our findings and literature review confirm that the Phoridae is the only taxon known that parasitizes both adults and the immature stages of different castes of ants, thus threatening ants on all fronts.Peer reviewe
Angular Power Spectrum Estimation of Cosmic Ray Anisotropies with Full or Partial Sky Coverage
We study the angular power spectrum estimate in order to search for large
scale anisotropies in the arrival directions distribution of the highest-energy
cosmic rays. We show that this estimate can be performed even in the case of
partial sky coverage and validated over the full sky under the assumption that
the observed fluctuations are statistically spatial stationary. If this
hypothesis - which can be tested directly on the data - is not satisfied, it
would prove, of course, that the cosmic ray sky is non isotropic but also that
the power spectrum is not an appropriate tool to represent its anisotropies,
whatever the sky coverage available. We apply the method to simulations of the
Pierre Auger Observatory, reconstructing an input power spectrum with the
Southern site only and with both Northern and Southern ones. Finally, we show
the improvement that a full-sky observatory brings to test an isotropic
distribution, and we discuss the sensitivity of the Pierre Auger Observatory to
large scale anisotropies.Comment: 16 pages, 6 figures, version accepted for publication by JCA
Mesothelial cells: A cellular surrogate for tissue engineering of corneal endothelium
[Purpose]: To evaluate whether mouse adipose tissue mesothelial cells (ATMCs) share morphologic and biochemical characteristics with mouse corneal endothelial cells (CECs) and to evaluate their capacity to adhere to the decellularized basal membrane of human anterior lens capsules (HALCs) as a potential tissue-engineered surrogate for corneal endothelium replacement. [Methods]: Adipose tissue mesothelial cells were isolated from the visceral adipose tissue of adult mice, and their expression of several corneal endothelium markers was determined with quantitative RT-PCR, immunofluorescence, and Western blotting. Adipose tissue mesothelial cells were cultured in a mesothelial retaining phenotype medium (MRPM) and further seeded and cultured on top of the decellularized basal membrane of HALCs. ATMC-HALC composites were evaluated by optical microscopy, immunofluorescence, and transmission electron microscopy. [Results]: Mesothelial retaining phenotype medium-cultured ATMCs express the corneal endothelium markers COL4A2, COL8A2, SLC4A4, CAR2, sodium- and potassium-dependent adenosine triphosphatase (Na+/K+-ATPase), b-catenin, zona occludens-1, and N-cadherin in a pattern similar to that in mouse CECs. Furthermore, ATMCs displayed strong adhesion capacity onto the basal membrane of HALCs and formed a confluent monolayer within 72 hours of culture in MRPM. Ultrastructural morphologic and marker characteristics displayed by ATMC monolayer on HALCs clearly indicated that ATMCs retained their original phenotype of squamous epithelial-like cells. [Conclusions]: Corneal epithelial cells and ATMCs share morphologic (structural) and marker (functional) similarities. The ATMCs adhered and formed structures mimicking focal adhesion complexes with the HALC basal membrane. Monolayer structure and achieved density of ATMCs support the proposal to use adult human mesothelial cells (MCs) as a possible surrogate for damaged corneal endothelium.Supported by Fondos FEDER, Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía (Grant PI-0022/2008),
INNPACTO Program (INP-2011-1615-900000), and SUDOE Program-BIOREG
(Intereg SOE3/P1/E750); Consejer´ıa de Innovación
Ciencia y Empresa, Junta de Andalucía (Grant CTS-6505); Ministry of Science and Innovation (Red TerCel-FEDER Grant RD12/0019/
0028); Instituto de Salud Carlos III Grant PI10/00964); the Ministry of Health and Consumer Affairs Advanced Therapies Program
Grant TRA-120 (BS); and Corporación Tecnológica de Andalucía CTA (NBT). CIBERDEM is an initiative of the Instituto de Salud Carlos III.Peer Reviewe
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