Axial Vector Z′Z' and Anomaly Cancellation

Whilst the prospect of new $Z'$ gauge bosons with only axial couplings to the Standard Model (SM) fermions is widely discussed, examples of anomaly-free renormalisable models are lacking in the literature. We look to remedy this by constructing several motivated examples. Specifically, we consider axial vectors which couple universally to all SM fermions, as well as those which are generation-specific, leptophilic, and leptophobic. Anomaly cancellation typically requires the presence of new coloured and charged chiral fermions, and we argue that in a large class of models masses of these new states are expected to be comparable to that of the axial vector. Finally, an axial vector mediator could provide a portal between SM and hidden sector states, and we also consider the possibility that the axial vector couples to dark matter. If the dark matter relic density is set due to freeze-out via the axial vector, this strongly constrains the parameter space.Comment: 28 pages, 8 figures. v2. published versio

Image segmentation using fuzzy LVQ clustering networks

In this note we formulate image segmentation as a clustering problem. Feature vectors extracted from a raw image are clustered into subregions, thereby segmenting the image. A fuzzy generalization of a Kohonen learning vector quantization (LVQ) which integrates the Fuzzy c-Means (FCM) model with the learning rate and updating strategies of the LVQ is used for this task. This network, which segments images in an unsupervised manner, is thus related to the FCM optimization problem. Numerical examples on photographic and magnetic resonance images are given to illustrate this approach to image segmentation

Renormalization of the neutrino mass matrix

The renormalization group equations for the general 2 by 2, complex, neutrino mass matrix are shown to have exact, analytic solutions. Simple formulas are given for the physical mixing angle, complex phase and mass ratio in terms of their initial values and the energy scales. We also establish a (complex) renormalization invariant relating these parameters. The qualitative features of the physical parameters' renormalization are clearly illustrated in vector field plots. In both the SM and MSSM, maximal mixing is a saddle point.Comment: 16 pages, 5 figure

Sun Simiao's academic thought and clinical study on acupuncture and moxibustion

孙思邈是唐代著名医学家，一生多种著作，其中以《备急千金要方》、《千金翼方》两部巨作对后世影响最大，广集唐朝之前与当代针灸之大成，并加入个人一生的临床经验与专业技能而成书，被誉为我国最早的一部临床医学百科全书，对后世医学的发展影响很深远。 本论文是经由深入《备急千金要方》、《千金翼方》两部巨作为主轴，研究探索 孙思邈针、灸学术特色，透析医籍文献中所记载与蕴含的针灸条文、临床选穴、临床应用、学术思想和具体的针法、灸法学术为研究方向，以总结与呈现孙思邈针灸学术、医学思想与临床应用的相对关系。 本论文研究主要共为五大部分： 第一部分是孙思邈针灸学术思想溯源研究，针对孙思邈针灸学术思想形成的时代...Sun Si-miao is a famous Medical expert of the Tang Dynasty, and wrote lots books in his life, among which 《Qian Jin Yao Fang》、《Qian Jin Yi Fang》two books are Collective greatly included the technology of Acupuncture and moxibustion during the period of before and after the Tang Dynasty, also within Sun’s personal clinical experience and skills to the Books,that also the most influence on the later...学位：医学硕士院系专业：医学院_针灸推拿学学号：2452014115465

Mrk 1419 - a new distance determination

Water vapor megamasers from the center of active galaxies provide a powerful tool to trace accretion disks at sub-parsec resolution and, through an entirely geometrical method, measure direct distances to galaxies up to 200 Mpc. The Megamaser Cosmology Project (MCP) is formed by a team of astronomers with the aim of identifying new maser systems, and mapping their emission at high angular resolution to determine their distance. Two types of observations are necessary to measure a distance: single-dish monitoring to measure the acceleration of gas in the disk, and sensitive VLBI imaging to measure the angular size of the disk, measure the rotation curve, and model radial displacement of the maser feature. The ultimate goal of the MCP is to make a precise measurement of H0 by measuring such distances to at least 10 maser galaxies in the Hubble flow. We present here the preliminary results from a new maser system, Mrk 1419. Through a model of the rotation from the systemic masers assuming a narrow ring, and combining these results with the acceleration measurement from the Green Bank Telescope, we determine a distance to Mrk 1419 of 81\pm10 Mpc. Given that the disk shows a significant warp that may not be entirely traced by our current observations, more sensitive observations and more sophisticated disk modeling will be essential to improve our distance estimation to this galaxy.Comment: 5 pages, 3 figures, to appear in the proceedings of IAU Symposium 287 "Cosmic Masers- from OH to Ho", in Stellenbosch, S

Towards Precision Supermassive Black Hole Masses using Megamaser Disks

Megamaser disks provide the most precise and accurate extragalactic supermassive black hole masses. Here we describe a search for megamasers in nearby galaxies using the Green Bank Telescope (GBT). We focus on galaxies where we believe that we can resolve the gravitational sphere of influence of the black hole and derive a stellar or gas dynamical measurement with optical or NIR observations. Since there are only a handful of super massive black holes (SMBH) that have direct black hole mass measurements from more than one method, even a single galaxy with a megamaser disk and a stellar dynamical black hole mass would provide necessary checks on the stellar dynamical methods. We targeted 87 objects from the Hobby-Eberly Telescope Massive Galaxy Survey, and detected no new maser disks. Most of the targeted objects are elliptical galaxies with typical stellar velocity dispersions of 250 km/s and distances within 130 Mpc. We discuss the implications of our non-detections, whether they imply a threshold X-ray luminosity required for masing, or possibly reflect the difficulty of maintaining a masing disk around much more massive (>10^8 Msun) black holes at low Eddington ratio. Given the power of maser disks at probing black hole accretion and demographics, we suggest that future maser searches should endeavour to remove remaining sample biases, in order to sort out the importance of these covariant effects.Comment: 9 pages, 5 figures, Apj, updated to match the accepted versio

Refining the M_BH-V_c scaling relation with HI rotation curves of water megamaser galaxies

Black hole - galaxy scaling relations provide information about the coevolution of supermassive black holes and their host galaxies. We compare the black hole mass - circular velocity (MBH - Vc) relation with the black hole mass - bulge stellar velocity dispersion (MBH - sigma) relation, to see whether the scaling relations can passively emerge from a large number of mergers, or require a physical mechanism, such as feedback from an active nucleus. We present VLA H I observations of five galaxies, including three water megamaser galaxies, to measure the circular velocity. Using twenty-two galaxies with dynamical MBH measurements and Vc measurements extending to large radius, our best-fit MBH - Vc relation, log MBH = alpha + beta log(Vc /200 km s^-1), yields alpha = 7.43+/-0.13, beta = 3.68+1.23/-1.20, and intrinsic scatter epsilon_int = 0.51+0.11/-0.09. The intrinsic scatter may well be higher than 0.51, as we take great care to ascribe conservatively large observational errors. We find comparable scatter in the MBH - sigma relations, epsilon_int = 0.48+0.10/-0.08, while pure merging scenarios would likely result in a tighter scaling with the dark halo (as traced by Vc) than baryonic (sigma) properties. Instead, feedback from the active nucleus may act on bulge scales to tighten the MBH - sigma relation with respect to the MBH - Vc relation, as observed.Comment: 27 pages, 15 figures, ApJ accepte

Modeling sediment movement in the turbidity maximum of an estuary

This research developed a two-dimensional, time-dependent numerical model to simulate the movement of water and suspended sediment in the turbidity maximum of an estuary. This model is a systematic sequence of mathematical procedures derived from the mass-balance equation and the equation of motion. Lateral integration is used to obtain two-dimensional equations; these equations are integrated with depth over the height of successive layers. Finite difference equations then are written for each layer and solved numerically using prescribed boundary conditions.https://scholarworks.wm.edu/book/1003/thumbnail.jp

Application of online CO2 monitoring to enable a better understanding of cell culture performance variation between GMP-scale and scaled-down bioreactors

Dissolved carbon dioxide (dCO2) or partial pressure of carbon dioxide (pCO2) is an important process parameter that may impact process performance (product titer and viability) and product quality attributes (such as glycosylation) during mammalian cell culture process in a bioreactor. The impact of altered level of pCO2 on the cell culture process may manifest itself upon process scale-up if the CO2 removal rate is not consistent between the development scale and the manufacturing scale. The pCO2 level during cell culture process is normally determined through offline measurement; however, the offset between online and offline pCO2 may conceal the true effect of pCO2 on the cell culture process. In this presentation, several studies using online pCO2 monitoring will be summarized and discussed, including 1) implementation of online pCO2 probe for measurement of actual pCO2 levels in a large scale bioreactor, 2) comparison of online and offline pCO2, 3) correlation between pH and pCO2, 4) estimation of CO2 stripping rate in large scale bioreactors, and 5) effect of sample handling on pCO2 level measurement. The key findings in this presentation are intended to establish biopharmaceutical manufacturing process knowledge, which is valuable for all partners in the cell culture manufacturing network