149 research outputs found
Supersymmetric Grand Unified Models without Adjoint Higgs Fields
We discuss two classes of supersymmetric grand unified theories based on
extended gauge groups and . Effective adjoint fields of each gauge group SO(10) are argued to be
formed from combining two Higgs fields in fundamental representation of the
extended gauge groups, one obtaining its VEV along the diagonal
direction and the other acquiring its VEV along the diagonal or its subgroup direction. Thus experimentally acceptable fermion mass
matrices, such as Georgi-Jarlskog ansatz, with successful GUT mass relations
can be constructed in these theories.Comment: 23 pages, 1 figure and 3 table
Models of Dynamical Supersymmetry Breaking from a SU(2k+3) Model
We investigate three classes of supersymmetric models which can be obtained
by breaking the chiral SU(2k+3) gauge theories with one antisymmetric tensor
and 2k-1 antifundamentals. For N=3, the chiral SU(2k)SU(3)U(1)
theories break supersym metry by the quantum deformations of the moduli spaces
in the strong SU(2k) gauge coupling limit. For N=2, it is the generalization of
the SU(5)U(2)U(1) model mentioned in the literature.
Supersymmetry is broken by carefully choosing the q uark-antiquark-doublet
Yukawa couplings in this model. For N=1, this becomes the well-known model
discussed in the literature.Comment: 13 pages, modifications to the sections two and thre
Tracking and Following Algorithms of Mobile Robots for Service Activities in Dynamic Environments
By providing the capability of following a human target in an appropriate manner, the robot can assist people in various ways under different environments. One of the main difficulties when performing human tracking and following is the occlusion problem caused by static as well as dynamic obstacles. The aim of the paper is to tackle the occlusion problem by planning a robotic trajectory of maximizing target visibility and following the moving target. Initially, a laser range finder is used to detect the human target and then robustly track the target using the Kalman filter. Afterward, a human following algorithm based on a look-ahead algorithm, DWA*, is implemented to pursue the target while avoiding any static or dynamic obstacles. Fundamental experiments have been extensively tested to evaluate robot maneuvers and several field tests are conducted in more complex environments such as student cafeteria, computer center, and university library.</span
The role of cytochrome c oxidase subunit Va in non-small cell lung carcinoma cells: association with migration, invasion and prediction of distant metastasis
BACKGROUND: Lung cancer is one of the most lethal malignancies worldwide, but useful biomarkers of lung cancer are still insufficient. The aim of this study is to identify some membrane-bound protein(s) associated with migration and invasion in human non-small cell lung cancer (NSCLC) cells. METHODS: We classified four NSCLC cell lines into high and low migration/invasion groups by Transwell and Matrigel assays. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), we identified 10 membrane-associated proteins being significantly overexpressed in the high migration/invasion group. The expression of the target protein in the four NSCLC cell lines was then confirmed by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunostaining. RNA interference technique was applied to observe the influence of the target protein on migration and invasion. Gelatin zymography was also performed to evaluate the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Expression condition of the target protein on surgical specimens was further examined by immunohistochemical staining and the clinicopathologic data were analyzed. RESULTS: We identified a mitochondria-bound protein cytochrome c oxidase subunit Va (COX Va) because of its abundant presence found exclusively in tumorous areas. We also demonstrated that migration and invasion of NSCLC cells decreased substantially after knocking down COX Va by siRNA. Meanwhile, we found a positive correlation between COX Va expression, Bcl-2 expression and activities of MMP-2 and MMP-9 in NSCLC cells. Immunohistochemical staining of surgically resected lung adenocarcinomas in 250 consecutive patients revealed that strong COX Va expression was found in 54.8% (137/250) of patients and correlated positively with the status of lymph node metastasis (P = 0.032). Furthermore, strong COX Va expression was associated with the presence of distant metastasis (P = 0.033). CONCLUSIONS: Our current study showed that COX Va may play a role in migration and invasion of NSCLC cells and can be used as a biomarker to predict aggressiveness of NSCLC
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