A Model Behind the Standard Model

In spite of its many successes, the Standard Model makes many empirical assumptions in the Higgs and fermion sectors for which a deeper theoretical basis is sought. Starting from the usual gauge symmetry $u(1) \times su(2) \times su(3)$ plus the 3 assumptions: (A) scalar fields as vielbeins in internal symmetry space \cite{framevec}, (B) the ``confinement picture'' of symmetry breaking \cite{tHooft,Banovici}, (C) generations as ``dual'' to colour \cite{genmixdsm}, we are led to a scheme which offers: (I) a geometrical significance to scalar fields, (II) a theoretical criterion on what scalar fields are to be introduced, (III) a partial explanation of why $su(2)$ appears broken while $su(3)$ confines, (IV) baryon-lepton number (B - L) conservation, (V) the standard electroweak structure, (VI) a 3-valued generation index for leptons and quarks, and (VII) a dynamical system with all the essential features of an earlier phenomenological model \cite{genmixdsm} which gave a good description of the known mass and mixing patterns of quarks and leptons including neutrino oscillations. There are other implications the consistency of which with experiment, however, has not yet been systematically explored. A possible outcome is a whole new branch of particle spectroscopy from $su(2)$ confinement, potentially as rich in details as that of hadrons from colour confinement, which will be accessible to experiment at high energy.Comment: 66 pages, added new material on phenomenology, and some new reference

A Validity and Reliability Study of a Chinese Assessment Tool for Persons with Moderate to Severe Intellectual Disabilities

This study was designed to test the psychometric properties of the Chinese interRAI Intellectual Disability (ID) tool in a Chinese population with learning disabilities in Hong Kong. The Chinese interRAI ID was prepared based on the original interRAI ID which is a standardized, comprehensive instrument and is designed to evaluate the strengths, preferences, and needs of persons with all levels of ID living in various care settings. A sample of 100 people with moderate to severe intellectual disabilities was assessed with the Chinese interRAI ID and its criterion measures. The subscales of the interRAI ID, including the Cognitive Performance Scale, Depression Rating Scale, Aggressive Behavior Scale, Activities of Daily Living Hierarchy Scale, and Instrumental Activities of Daily Living Involvement Scale, had high internal consistency (Cronbach’s α = .66 to .87) and test–retest reliability (r = .96 to .99; κ = .68 to .81). Comparison of the interRAI ID scales with criterion measures supported concurrent and discriminant validity of these scales. The study results provide preliminary support for the Chinese interRAI ID as a reliable and valid tool for assessing Chinese individuals with learning disabilities in Hong Kong

Media and politics in Hong Kong: A decade after the handover

Hong Kong has been through numerous ups and downs in the ten years since the handover. The media have also undergone significant changes in relation to the larger social and political reconfigurations. While the press, driven by market forces and professional ideologies, has continued to provide timely information to the public and to monitor the behavior of power holders, the power center has employed various means to tame the media, and selfcensorship remains a haunting issue

Media and politics in Hong Kong: A decade after the handover

Hong Kong has been through numerous ups and downs in the ten years since the handover. The media have also undergone significant changes in relation to the larger social and political reconfigurations. While the press, driven by market forces and professional ideologies, has continued to provide timely information to the public and to monitor the behavior of power holders, the power center has employed various means to tame the media, and selfcensorship remains a haunting issue

The Sachs-Wolfe Effect: Gauge Independence and a General Expression

In this paper we address two points concerning the Sachs-Wolfe effect: (i) the gauge independence of the observable temperature anisotropy, and (ii) a gauge-invariant expression of the effect considering the most general situation of hydrodynamic perturbations. The first result follows because the gauge transformation of the temperature fluctuation at the observation event only contributes to the isotropic temperature change which, in practice, is absorbed into the definition of the background temperature. Thus, we proceed without fixing the gauge condition, and express the Sachs-Wolfe effect using the gauge-invariant variables.Comment: 5 pages, closer to published versio

Physiologically regulated transgenic ABCA1 does not reduce amyloid burden or amyloid‐beta peptide levels in vivo

J Lipid Res. 2007 Apr;48(4):914-23. Epub 2007 Jan 18. Physiologically regulated transgenic ABCA1 does not reduce amyloid burden or amyloid-beta peptide levels in vivo. Hirsch-Reinshagen V, Chan JY, Wilkinson A, Tanaka T, Fan J, Ou G, Maia LF, Singaraja RR, Hayden MR, Wellington CL. Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada. Abstract ABCA1-deficient mice have low levels of poorly lipidated apolipoprotein E (apoE) and exhibit increased amyloid load. To test whether excess ABCA1 protects from amyloid deposition, we crossed APP/PS1 mice to ABCA1 bacterial artificial chromosome (BAC) transgenic mice. Compared with wild-type animals, the ABCA1 BAC led to a 50% increase in cortical ABCA1 protein and a 15% increase in apoE abundance, demonstrating that this BAC supports modest ABCA1 overexpression in brain. However, this was observed only in animals that do not deposit amyloid. Comparison of ABCA1/APP/PS1 mice with APP/PS1 controls revealed no differences in levels of brain ABCA1 protein, amyloid, Abeta, or apoE, despite clear retention of ABCA1 overexpression in the livers of these animals. To further investigate ABCA1 expression in the amyloid-containing brain, we then compared ABCA1 mRNA and protein levels in young and aged cortex and cerebellum of APP/PS1 and ABCA1/APP/PS1 animals. Compared with APP/PS1 controls, aged ABCA1/APP/PS1 mice exhibited increased ABCA1 mRNA, but not protein, selectively in cortex. Additionally, ABCA1 mRNA levels were not increased before amyloid deposition but were induced only in the presence of extensive Abeta and amyloid levels. These data suggest that an induction of ABCA1 expression may be associated with late-stage Alzheimer's neuropathology. PMID: 17235115 [PubMed - indexed for MEDLINE

The Field Perturbation Theory of the Double Correlated Phase in High Temperature Superconductors

The Double-Correlated phase in HTSC, and its treatment by field perturbation theory, is established. In particular, we define the ground state, the quasi-particle excitations, and construct an appropriate field. We also derive the unperturbed Hamiltonian, and the propagators for the unperturbed state. Then we discuss the perturbation Hamiltonian, and show that the Hartree diagram is significant for both the pseudogap and the superconductive order parameter, and suggest that it yields the major contribution to these parameters.Comment: 23 pages Of MSWord in PDF format, 1 figur

Statistical mechanics of RNA folding: importance of alphabet size

We construct a minimalist model of RNA secondary-structure formation and use it to study the mapping from sequence to structure. There are strong, qualitative differences between two-letter and four or six-letter alphabets. With only two kinds of bases, there are many alternate folding configurations, yielding thermodynamically stable ground-states only for a small set of structures of high designability, i.e., total number of associated sequences. In contrast, sequences made from four bases, as found in nature, or six bases have far fewer competing folding configurations, resulting in a much greater average stability of the ground state.Comment: 7 figures; uses revtex

Client Service Receipt Inventory as a standardised tool for measurement of socio-economic costs in the rare genetic disease population (CSRI-Ra)

The measurement of costs is fundamental in healthcare decision-making, but it is often challenging. In particular, standardised methods have not been developed in the rare genetic disease population. A reliable and valid tool is critical for research to be locally meaningful yet internationally comparable. Herein, we sought to develop, contextualise, translate, and validate the Client Service Receipt Inventory for the RAre disease population (CSRI-Ra) to be used in cost-of-illness studies and economic evaluations for healthcare planning. Through expert panel discussions and focus group meetings involving 17 rare disease patients, carers, and healthcare and social care professionals from Hong Kong, we have developed the CSRI-Ra. Rounds of forward and backward translations were performed by bilingual researchers, and face validity and semantic equivalence were achieved through interviews and telephone communications with focus group participants and an additional of 13 healthcare professional and university students. Intra-class correlation coefficient (ICC) was used to assess criterion validity between CSRI-Ra and electronic patient record in a sample of 94 rare disease patients and carers, with overall ICC being 0.69 (95% CI 0.56–0.78), indicating moderate to good agreement. Following rounds of revision in the development, contextualisation, translation, and validation stages, the CSRI-Ra is ready for use in empirical research. The CSRI-Ra provides a sufficiently standardised yet adaptable method for collecting socio-economic data related to rare genetic diseases. This is important for near-term and long-term monitoring of the resource consequences of rare diseases, and it provides a tool for use in economic evaluations in the future, thereby helping to inform planning for efficient and effective healthcare. Adaptation of the CSRI-Ra to other populations would facilitate international research

The absence of ABCA1 decreases soluble ApoE levels but does not diminish amyloid deposition in two murine models of Alzheimer disease.

J Biol Chem. 2005 Dec 30;280(52):43243-56. Epub 2005 Oct 5. The absence of ABCA1 decreases soluble ApoE levels but does not diminish amyloid deposition in two murine models of Alzheimer disease. Hirsch-Reinshagen V, Maia LF, Burgess BL, Blain JF, Naus KE, McIsaac SA, Parkinson PF, Chan JY, Tansley GH, Hayden MR, Poirier J, Van Nostrand W, Wellington CL. Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia V4Z 5H5, Canada. Abstract ABCA1, a cholesterol transporter expressed in the brain, has been shown recently to be required to maintain normal apoE levels and lipidation in the central nervous system. In addition, ABCA1 has been reported to modulate beta-amyloid (Abeta) production in vitro. These observations raise the possibility that ABCA1 may play a role in the pathogenesis of Alzheimer disease. Here we report that the deficiency of ABCA1 does not affect soluble or guanidine-extractable Abeta levels in Tg-SwDI/B or amyloid precursor protein/presenilin 1 (APP/PS1) mice, but rather is associated with a dramatic reduction in soluble apoE levels in brain. Although this reduction in apoE was expected to reduce the amyloid burden in vivo, we observed that the parenchymal and vascular amyloid load was increased in Tg-SwDI/B animals and was not diminished in APP/PS1 mice. Furthermore, we observed an increase in the proportion of apoE retained in the insoluble fraction, particularly in the APP/PS1 model. These data suggested that ABCA1-mediated effects on apoE levels and lipidation influenced amyloidogenesis in vivo. PMID: 16207707 [PubMed - indexed for MEDLINE