60 research outputs found

    T-cell number and subtype influence the disease course of primary chronic lymphocytic leukaemia xenografts in alymphoid mice.

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    Chronic lymphocytic leukaemia (CLL) cells require microenvironmental support for their proliferation. This can be recapitulated in highly immunocompromised hosts in the presence of T cells and other supporting cells. Current primary CLL xenograft models suffer from limited duration of tumour cell engraftment coupled with gradual T-cell outgrowth. Thus, a greater understanding of the interaction between CLL and T cells could improve their utility. In this study, using two distinct mouse xenograft models, we investigated whether xenografts recapitulate CLL biology, including natural environmental interactions with B-cell receptors and T cells, and whether manipulation of autologous T cells can expand the duration of CLL engraftment. We observed that primary CLL xenografts recapitulated both the tumour phenotype and T-cell repertoire observed in patients and that engraftment was significantly shorter for progressive tumours. A reduction in the number of patient T cells that were injected into the mice to 2-5% of the initial number or specific depletion of CD8+ cells extended the limited xenograft duration of progressive cases to that characteristic of indolent disease. We conclude that manipulation of T cells can enhance current CLL xenograft models and thus expand their utility for investigation of tumour biology and pre-clinical drug assessment

    The Planck-LFI flight model composite waveguides

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    The Low Frequency Instrument on board the PLANCK satellite is designed to give the most accurate map ever of the CMB anisotropy of the whole sky over a broad frequency band spanning 27 to 77 GHz. It is made of an array of 22 pseudo-correlation radiometers, composed of 11 actively cooled (20 K) Front End Modules (FEMs), and 11 Back End Modules (BEMs) at 300K. The connection between the two parts is made with rectangular Wave Guides. Considerations of different nature (thermal, electromagnetic and mechanical), imposed stringent requirements on the WGs characteristics and drove their design. From the thermal point of view, the WG should guarantee good insulation between the FEM and the BEM sections to avoid overloading the cryocooler. On the other hand it is essential that the signals do not undergo excessive attenuation through the WG. Finally, given the different positions of the FEM modules behind the focal surface and the mechanical constraints given by the surrounding structures, different mechanical designs were necessary. A composite configuration of Stainless Steel and Copper was selected to satisfy all the requirements. Given the complex shape and the considerable length (about 1.5-2 m), manufacturing and testing the WGs was a challenge. This work deals with the development of the LFI WGs, including the choice of the final configuration and of the fabrication process. It also describes the testing procedure adopted to fully characterize these components from the electromagnetic point of view and the space qualification process they underwent. Results obtained during the test campaign are reported and compared with the stringent requirements. The performance of the LFI WGs is in line with requirements, and the WGs were successfully space qualified.Comment: this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins

    Measurement of the ratio B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) and the time-integrated CP asymmetry in D0->pi+pi-pi0

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    We report a high-statistics measurement of the relative branching fraction B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) using a 532 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured value of the relative branching fraction is B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) = (10.12 +/- 0.04(stat) +/- 0.18(syst))x10^{-2} which has an accuracy comparable to the world average. We also present a measurement of the time-integrated CP asymmetry in D0->pi+pi-pi0 decay. The result, A_{CP} = (0.43 +/- 1.30)%, shows no significant CP violation.Comment: 15 pages, 11 figures, submitted to Physics Letters

    Search for the Xb and other hidden-beauty states in the π+π−ϒ(1S) channel at ATLAS

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    This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges of 10.05–10.31 GeV and 10.40–11.00 GeV, in the channel Xb→π+π−ϒ(1S)(→Ό+Ό−), using 16.2 fb−1 of pp   collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the ϒ(2S), at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(13DJ), , and states also reveal no significant signals

    Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

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    The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

    The 'six-eyed' stomatopod

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    Stomatopods (mantis shrimps) possess one of the most complex visual systems in the animal kingdom. Each eye is capable of monocular distance judgement, colour vision involving eight or more primary channels and polarisation vision. This involves a series of eye movements unique among the crustaceans. Furthermore, each eye usually acts almost entirely independently of the other. Colour, in particular, seems to be important to stomatopods. Many live in spectrally diverse tropical coral reef habitats and possess coloured markings which are used in communication between and within species

    Polarization signals in the marine environment

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    Although natural light sources produce depolarized light, partially linearly polarized light is naturally abundant in the scenes animals view, being produced by scattering in air or water or by reflection from shiny surfaces. Many species of animals are sensitive to light's polarization, and use this sensitivity to orient themselves using polarization patterns in the atmosphere or underwater. A few animal species have been shown to take this polarization sensitivity to another level of sophistication, seeing the world as a polarization image, analogous to the color images humans and other animals view. This sensory capacity has been incorporated into biological signals by a smaller assortment of species, who use patterns of polarization on their bodies to communicate with conspecific animals. In other words, they use polarization patterns for tasks similar to those for which other animals use biologically produced color patterns. Polarization signals are particularly useful in marine environments, where the spectrum of incident light is variable and unpredictable. Here, cephalopod mollusks (octopuses, squids, and cuttlefish) and stomatopod crustaceans (mantis shrimps) have developed striking patterns of polarization used in communication
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