5,802 research outputs found
An endemic Taenia from South America: validation of T. talicei Dollfus, 1960 (Cestoda: Taeniidae) with characterization of metacestodes and adults
Taenia talicei is redescribed based on new data from polycephalic, fimbriocercus and cysticercus metacestodes found in Ctenomys spp. (Rodentia: Ctenomyidae) from Argentina. Strobilate adult specimens, derived from experimental infections in domestic dogs, are described for the first time. Identity of the adult and metacestodes stages is based on the number of rostellar hooks (44â50 hooks in 2 rows), their dimensions (large hooks= 232â242; small= 150â187) and shape. Taenia talicei is distinguished from those species that occur naturally in Neotropical Felidae and from those cosmopolitan species that circulate in synanthropic cycles with rodents (or lagomorphs) and domestic hosts such as cats and dogs in South America based on the structure of the metacestode, dimensions and numbers of rostellar hooks and a suite of specific characters of the genital system in strobilate adults. This species is the first that can be considered endemic to South America. Origins of an endemic Taenia species or taeniid assemblages in South America would have relationships to either North American or Eurasian placental carnivores. In these instances, the expansion of Taenia may have resulted from geographic colonization of South America, radiation in both felids (and canids), and host switching by tapeworms to caviomorphs, prior to the emergence of the Panamanian Isthmus. Taenia talicei is capable of development in domestic dogs, and metacestodes in species of Ctenomys were found in urban or semi-urban environments. These factors may establish a role for synanthropic cycles linked to definitive hosts including dogs and cats as a route for exposure of humans to infection by this taeniid.Fil: Rossin, Maria Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de BiologĂa. Laboratorio de ParasitologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de BiologĂa. Laboratorio de ParasitologĂa; ArgentinaFil: Hoberg, Eric P.. United States Department of Agriculture. Agricultural Research Service; Argentin
The Microchannel X-ray Telescope for the Gamma-Ray Burst mission SVOM
We present the Microchannel X-ray Telescope, a new light and compact
focussing telescope that will be flying on the Sino-French SVOM mission
dedicated to Gamma-Ray Burst science. The MXT design is based on the coupling
of square pore micro-channel plates with a low noise pnCCD. MXT will provide an
effective area of about 50 cmsq, and its point spread function is expected to
be better than 3.7 arc min (FWHM) on axis. The estimated sensitivity is
adequate to detect all the afterglows of the SVOM GRBs, and to localize them to
better then 60 arc sec after five minutes of observation.Comment: 12 pages, 8 figures, to be published in SPIE Astronomical Telescopes
+ Instrumentation, Montreal, June 201
Semi-kinematic mount of the FIREBALL large optics
In the context of the NASA CNES FIREBALL balloon borne experiment, we present the design of a semi-kinematic mount to hold the 1 meter class mirrors of this mission. To maintain these large optics in a reasonable mass and price budgets we choose thin ULE mirrors with a thickness over diameter ratio of 1/16. Such thin mirrors require a multi support mount to reduce self weight deflection. Classical multi support mount used for ground based telescope would not survive the level of shock observed in a balloon experiment either at parachute opening or landing. To firmly maintain these mirrors in several points without noticeably deforming them we investigated the design of a two stages semi-kinematic mount composed of 24 monopods. We present the detailed design of this innovative mirror mount, the finite element modeling with the deduced optical wavefront deformation. During the FIREBALL integration and flight campaign in July 2007 at CSBF, we confirmed the validity of the mechanical concept by obtaining an image quality well within the required specifications. Variants of this approach are potentially applicable to large thin mirrors on ground-based observatories
Tetrazine-Triggered Release of Carboxylic-Acid-Containing Molecules for Activation of an Anti-inflammatory Drug.
In addition to its use for the study of biomolecules in living systems, bioorthogonal chemistry has emerged as a promising strategy to enable protein or drug activation in a spatially and temporally controlled manner. This study demonstrates the application of a bioorthogonal inverse electron-demand Diels-Alder (iEDDA) reaction to cleave trans-cyclooctene (TCO) and vinyl protecting groups from carboxylic acid-containing molecules. The tetrazine-mediated decaging reaction proceeded under biocompatible conditions with fast reaction kinetics (<2â
min). The anti-inflammatory activity of ketoprofen was successfully reinstated after decaging of the nontoxic TCOprodrug in live macrophages. Overall, this work expands the scope of functional groups and the application of decaging reactions to a new class of drugs
Longitudinal spin transport in diluted magnetic semiconductor superlattices: the effect of the giant Zeeman splitting
Longitudinal spin transport in diluted magnetic semiconductor superlattices
is investigated theoretically. The longitudinal magnetoconductivity (MC) in
such systems exhibits an oscillating behavior as function of an external
magnetic field. In the weak magnetic field region the giant Zeeman splitting
plays a dominant role which leads to a large negative magnetoconductivity. In
the strong magnetic field region the MC exhibits deep dips with increasing
magnetic field. The oscillating behavior is attributed to the interplay between
the discrete Landau levels and the Fermi surface. The decrease of the MC at low
magnetic field is caused by the exchange interaction between the electron
in the conduction band and the magnetic ions.Comment: 6 pages, 9 figures, submitted to Phys. Rev.
Transglutaminase Type 2 Regulates ER-Mitochondria Contact Sites by Interacting with GRP75
Transglutaminase type 2 (TG2) is a multifunctional enzyme that plays a key role in mitochondria homeostasis under stressful cellular conditions. TG2 interactome analysis reveals an enzyme interaction with GRP75 (glucose-regulated protein 75). GRP75 localizes in mitochondria-associated membranes (MAMs) and acts as a bridging molecule between the two organelles by assembling the IP3R-GRP75-VDAC complex, which is involved in the transport of Ca2+ from the endoplasmic reticulum (ER) to mitochondria. We demonstrate that the TG2 and GRP75 interaction occurs in MAMs. The absence of the TG2-GRP75 interaction leads to an increase of the interaction between IP3R-3 and GRP75; a decrease of the number of ER-mitochondria contact sites; an impairment of the ER-mitochondrial Ca2+ flux; and an altered profile of the MAM proteome. These findings indicate TG2 is a key regulatory element of the MAMs
An evaluation of metal removal during wastewater treatment: The potential to achieve more stringent final effluent standards
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Taylor & Francis.Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible requirements for the removal of copper my be challenging
The silicon micro-strip detector plane for the LOFT/Wide Field Monitor
The main objective of the Wide Field Monitor (WFM) on the LOFT mission is to
provide unambiguous detection of the high-energy sources in a large field of
view, in order to support science operations of the LOFT primary instrument,
the LAD. The monitor will also provide by itself a large number of results on
the timing and spectral behaviour of hundreds of galactic compact objects,
Active Galactic Nuclei and Gamma-Ray Bursts. The WFM is based on the coded
aperture concept where a position sensitive detector records the shadow of a
mask projected by the celestial sources. The proposed WFM detector plane, based
on Double Sided micro-Strip Silicon Detectors (DSSD), will allow proper
2-dimensional recording of the projected shadows. Indeed the positioning of the
photon interaction in the detector with equivalent fine resolution in both
directions insures the best imaging capability compatible with the allocated
budgets for this telescope on LOFT. We will describe here the overall
configuration of this 2D-WFM and the design and characteristics of the DSSD
detector plane including its imaging and spectral performances. We will also
present a number of simulated results discussing the advantages that this
configuration offers to LOFT. A DSSD-based WFM will in particular reduce
significantly the source confusion experienced by the WFM in crowded regions of
the sky like the Galactic Center and will in general increase the observatory
science capability of the mission.Comment: Proceedings of SPIE, Vol. 8443, Paper No. 8443-89, 201
Mechanical design report of the barrel liquid argon presampler
The note describes the mechanical design of the Atlas barrel presampler and its evolution since the publication of thecalorimeter TDR in December 9
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