422 research outputs found
Relativization in Dà gáárè and its typological implications: Left-headed but internally-headed
This article examines in detail the syntax of relativization in Dà gáárè, a Mabia (Oti-Volta) language of the Gur branch in the Niger-Congo family. The main aims of our investigation are twofold. The first is to describe a cluster of typologically interesting syntactic features of relativization in Dà gáárè in the light of the fact that no detailed description exists in the literature. The second is to demonstrate that relative clauses in Dà gáárè are head-internal relative clauses (HIRCs), even though they are, on the surface, postnominal relative clauses, like those in English. Thus, they are not of the in-situ type of HIRC that is well known in the literature. We call this type of relative clause a left-headed HIRC. This type of relativization has rarely been noticed cross-linguistically in the previous literature and therefore is of considerable significance for general linguistics, linguistic typology, as well as theoretical linguistics. Evidence comes from coordination in possessor relativization and PP relativization. Our discovery shows that Universal Grammar allows left-headed HIRCs as an option in addition to the more familiar types: in-situ HIRCs and head-external relative clauses (HERCs). © 2009 Elsevier B.V. All rights reserved.postprin
Dynamics of a deformable self-propelled particle under external forcing
We investigate dynamics of a self-propelled deformable particle under
external field in two dimensions based on the model equations for the center of
mass and a tensor variable characterizing deformations. We consider two kinds
of external force. One is a gravitational-like force which enters additively in
the time-evolution equation for the center of mass. The other is an
electric-like force supposing that a dipole moment is induced in the particle.
This force is added to the equation for the deformation tensor. It is shown
that a rich variety of dynamics appears by changing the strength of the forces
and the migration velocity of self-propelled particle
Modulation of MUC1 mucin as an escape mechanism of breast cancer cells from autologous cytotoxic T-lymphocytes
MUC1 mucin is known to serve as a target molecule in the killing of breast cancer cells by cytotoxic T-lymphocytes (CTLs). We searched for a possible mechanism allowing tumour cells to escape from autologous CTLs. When the killing of breast cancer cells by autologous lymphocytes was examined in 26 patients with breast cancer, significant tumour cell lysis was observed in 8 patients, whereas virtually no autologous tumour cell lysis was detected in as many as 18 patients. In the patients who showed negligible tumour cell lysis, the autologous tumour cells expressed MUC1-related antigenic epitopes much more weakly than the tumour cells in the patients who exhibited strong cytotoxicity (significant statistically at P< 0.0005–0.0045), suggesting that the unresponsiveness of cancer cells to CTLs observed in these patients was mainly due to loss of MUC1 expression or modulation of its antigenicity. A breast cancer cell line, NZK-1, established from one of the cytotoxicity-negative patients, did not express MUC1 and was resistant to killing by CTLs, while control breast cancer cell lines expressing MUC-1 were readily killed by CTLs. Transfection of NZK-1 cells with MUC1 cDNA induced significant lysis by autologous T-lymphocytes. These results supported the importance of MUC1 mucin in autologous anti-tumour immunity, but suggested that the major escape mechanism of tumour cells from autologous T-lymphocytes is the loss and/or modulation of MUC1 antigenicity on tumour cells, which would limit the effectiveness of possible immunotherapy designed to target the MUC1 mucin. © 2001 Cancer Research Campaign http://www.bjcancer.co
MicroRNA-125b regulates the expression of aggrecanase-1 (ADAMTS-4) in human osteoarthritic chondrocytes
INTRODUCTION: Increased expression of aggrecanase-1 (ADAMTS-4) has emerged as an important factor in osteoarthritis (OA) and other joint diseases. This study aimed to determine whether the expression of ADAMTS-4 in human chondrocytes is regulated by miRNA. METHODS: MiRNA targets were identified using bioinformatics. Chondrocytes were isolated from knee cartilage and treated with interleukin-1 beta (IL-1β). Gene expression was quantified using TaqMan assays and protein production was determined by immunoblotting. Luciferase reporter assay was used to verify interaction between miRNA and target messenger RNA (mRNA). RESULTS: In silico analysis predicted putative target sequence of miR-125b on ADAMTS-4. MiR-125b was expressed in both normal and OA chondrocytes, with significantly lower expression in OA chondrocytes than in normal chondrocytes. Furthermore, IL-1β-induced upregulation of ADAMTS-4 was suppressed by overexpression of miR-125b in human OA chondrocytes. In the luciferase reporter assay, mutation of the putative miR-125b binding site in the ADAMTS-4 3'UTR abrogated the suppressive effect of miR125. CONCLUSIONS: Our results indicate that miR-125b plays an important role in regulating the expression of ADAMTS-4 in human chondrocytes and this identifies miR-125b as a novel therapeutic target in OA
Effects of radiation damage caused by proton irradiation on Multi-Pixel Photon Counters (MPPCs)
We have investigated the effects caused by proton-induced radiation damage on
Multi-Pixel Photon Counter (MPPC), a pixelized photon detector developed by
Hamamatsu Photonics. The leakage current of irradiated MPPC samples linearly
increases with total irradiated doses due to radiation damage, which is not
completely recovered even after a year from the irradiation. No significant
change has been observed in the gains at least up to 8.0 Gy (
n/mm in 1 MeV neutron equivalent fluence, ). The device has
completely lost its photon-counting capability due to baseline fluctuations and
noise pile-up after 21 Gy irradiation ( n/mm in ), which might be problematic for some applications, such as ring-imaging
Cherenkov detectors. We have found that the pulse-height resolution has been
slightly deteriorated after 42 Gy irradiation ( n/mm in
), where the measured sample has been illuminated with a few
hundred photons. This effect should be considered in the case of
energy-measurement applications.Comment: 18 pages, 10 figure
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