1,718 research outputs found

    Fermion Generations and Mixing from Dualized Standard Model

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    We review a possible solution to the fermion generation puzzle based on a nonabelian generalization of electric--magnetic duality derived some years ago. This nonabelian duality implies the existence of another SU(3) symmetry dual to colour, which is necessarily broken when colour is confined and so can play the role of the ``horizontal'' symmetry for fermion generations. When thus identified, dual colour then predicts 3 and only 3 fermion generations, besides suggesting a special Higgs mechanism for breaking the generation symmetry. A phenomenological model with a Higgs potential and a Yukawa coupling constructed on these premises is shown to explain immediately all the salient qualitative features of the fermion mass hierarchy and mixing pattern, excepting for the moment CP-violation. Calculations already carried out to 1-loop order is shown to give with only 3 adjustable parameters the following quantities all to within present experimental error: all 9 CKM matrix elements Vrs|V_{rs}| for quarks, the neutrino oscillation angles or the MNS lepton mixing matrix elements Uμ3,Ue3|U_{\mu 3}|, |U_{e 3}|, and the mass ratios mc/mt,ms/mb,mμ/mτm_c/m_t, m_s/m_b, m_\mu/m_\tau. The special feature of this model crucial for deriving the above results is a fermion mass matrix which changes its orientation (rotates) in generation space with changing energy scale, a feature which is shown to have direct empirical support.Comment: updated version of course of lectures given at the 42nd Cracow School of Theoretical Physics, 2002, Polan

    A functional description of the Buffered Telemetry Demodulator (BTD)

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    This article gives a functional description of the buffered telemetry demodulator (BTD), which operates on recorded digital samples to extract the symbols from the received signal. The key advantages of the BTD are as follows: (1) its ability to reprocess the signal to reduce acquisition time; (2) its ability to use future information about the signal and to perform smoothing on past samples; and (3) its minimum transmission bandwidth requirement as each sub carrier harmonic is processed individually. The first application of the BTD would be the Galileo S-band contingency mission, where the signal is so weak that reprocessing to reduce the acquisition time is crucial. Moreover, in the event of employing antenna arraying with full spectrum combining, only the sub carrier harmonics need to be transmitted between sites, resulting in significant reduction in data rate transmission requirements. Software implementation of the BTD is described for various general-purpose computers

    Designing signaling environments to steer transcriptional diversity in neural progenitor cell populations

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    Stem cell populations within developing embryos are diverse, composed of many different subpopulations of cells with varying developmental potential. The structure of stem cell populations in cell culture remains poorly understood and presents a barrier to differentiating stem cells for therapeutic applications. In this paper we develop a framework for controlling the architecture of stem cell populations in cell culture using high-throughput single cell mRNA-seq and computational analysis. We find that the transcriptional diversity of neural stem cell populations collapses in cell culture. Cell populations are depleted of committed neuron progenitor cells and become dominated by a single pre-astrocytic cell population. By analyzing the response of neural stem cell populations to forty distinct signaling conditions, we demonstrate that signaling environments can restructure cell populations by modulating the relative abundance of pre-astrocyte and pre-neuron subpopulations according to a simple linear code. One specific combination of BMP4, EGF, and FGF2 ligands switches the default population balance such that 70% of cells correspond to the committed neurons. Our work demonstrates that single-cell RNA-seq can be applied to modulate the diversity of in vitro stem cell populations providing a new strategy for population-level stem cell control

    A Solution of the Strong CP Problem Transforming the theta-angle to the KM CP-violating Phase

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    It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta-angle term in the QCD action of topological origin can be eliminated by chiral transformations, while giving still nonzero masses to all quarks. Instead, the effects of such transformations get transmitted by the rotation to the CKM matrix as the KM phase giving, for θ\theta of order unity, a Jarlskog invariant typically of order 10510^{-5} as experimentally observed. Strong and weak CP violations appear then as just two facets of the same phenomenon.Comment: 14 pages, 2 figure

    The evaluation of partial binocular overlap on car maneuverability: A pilot study

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    An engineering approach to enlarge the helmet mounted display (HMD) field of view (FOV) and maintain resolution and weight by partially overlapping the binocular FOV has received renewed interest among human factors scientists. It is evident, based on the brief literature review, that any panoramic display with a binocular overlap, less than a minimum amount, annoys the viewer, degrades performance, and elicits undesirable behavior. The major finding is that across the 60 deg conditions, subjects moved their heads a greater distance (by about 5 degs on each side) than in the 180 deg condition, presumably to compensate for the lack of FOV. It is quite clear that the study, based on simple car maneuverability and two subjects, reveals differences in FOV, but nothing significant between binocular overlap levels and configurations. This tentatively indicates that some tradeoffs of binocular vision for a larger overall display FOV are acceptable

    Glycoprotein nonmetastatic melanoma protein B: A key mediator and an emerging therapeutic target in autoimmune diseases

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    The glycoprotein nonmetastatic melanoma protein B (GPNMB, also known as osteoactivin) is highly expressed in many cell types and regulates the homeostasis in various tissues. In different physiological contexts, it functions as a melanosome- associated protein, membrane- bound surface receptor, soluble ligand, or adhesion molecule. Therefore, GPNMB is involved in cell differentiation, migration, inflammation, metabolism, and neuroprotection. Because of its various involvement in different physiological conditions, GPNMB has been implicated in many diseases, including cancer, neurological disorders, and more recently immune- mediated diseases. This review summarizes the regulation and function of GPNMB in normal physiology, and discusses the involvement of GPNMB in disease conditions with a particular focus on its potential role and therapeutic implications in autoimmunity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155959/1/fsb220630.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155959/2/fsb220630_am.pd

    On the Corner Elements of the CKM and PMNS Matrices

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    Recent experiments show that the top-right corner element (Ue3U_{e3}) of the PMNS, like that (VubV_{ub}) of the CKM, matrix is small but nonzero, and suggest further via unitarity that it is smaller than the bottom-left corner element (Uτ1U_{\tau 1}), again as in the CKM case (Vub<VtdV_{ub} < V_{td}). An attempt in explaining these facts would seem an excellent test for any model of the mixing phenomenon. Here, it is shown that if to the assumption of a universal rank-one mass matrix, long favoured by phenomenologists, one adds that this matrix rotates with scale, then it follows that (A) by inputting the mass ratios mc/mt,ms/mb,mμ/mτm_c/m_t, m_s/m_b, m_\mu/m_\tau, and m2/m3m_2/m_3, (i) the corner elements are small but nonzero, (ii) Vub<VtdV_{ub} < V_{td}, Ue3<Uτ1U_{e 3} < U_{\tau 1}, (iii) estimates result for the ratios Vub/VtdV_{ub}/V_{td} and Ue3/Uτ1U_{e 3}/U_{\tau 1}, and (B) by inputting further the experimental values of Vus,VtbV_{us}, V_{tb} and Ue2,Uμ3U_{e2},U_{\mu 3}, (iv) estimates result for the values of the corner elements themselves. All the inequalities and estimates obtained are consistent with present data to within expectation for the approximations made.Comment: 9 pages, 2 figures, updated with new experimental data and more detail

    New Angle on the Strong CP and Chiral Symmetry Problems from a Rotating Mass Matrix

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    It is shown that when the mass matrix changes in orientation (rotates) in generation space for changing energy scale, then the masses of the lower generations are not given just by its eigenvalues. In particular, these masses need not be zero even when the eigenvalues are zero. In that case, the strong CP problem can be avoided by removing the unwanted θ\theta term by a chiral transformation in no contradiction with the nonvanishing quark masses experimentally observed. Similarly, a rotating mass matrix may shed new light on the problem of chiral symmetry breaking. That the fermion mass matrix may so rotate with scale has been suggested before as a possible explanation for up-down fermion mixing and fermion mass hierarchy, giving results in good agreement with experiment.Comment: 14 page

    Web-based Remote Sensing Applications and Java Tools for Environmental Monitoring

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    This paper introduces a web-based remote sensing application which can provide advanced image comparison and processing functions for natural habitat conservation and environmental monitoring. This project is one of several NASA Affiliated Research Center (ARC) projects being developed at San Diego State University in response to NASA\u27s Earth Science Enterprise (ESE) Focus Area program. This project utilized Java programming and commercial Internet Map Server technology to provide integrated web-based analytical capabilities to regional government agencies and park services. A prototype website (http://map.sdsu.edu/arc) was established to demonstrate the on-line analytical functions and potential operational applications for environmental monitoring and habitat managers. The web-based prototype was tested and evaluated by several user groups, including park rangers, graduate students, and GIS professionals. Users\u27 feedback indicated that the Java-based tools and Internet Map Servers can provide a flexible way to access both remote sensing data and geospatial analytical tools for environmental monitoring tasks
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