The Renormalization-Group Method Applied to Asymptotic Analysis of Vector Fields

The renormalization group method of Goldenfeld, Oono and their collaborators is applied to asymptotic analysis of vector fields. The method is formulated on the basis of the theory of envelopes, as was done for scalar fields. This formulation actually completes the discussion of the previous work for scalar equations. It is shown in a generic way that the method applied to equations with a bifurcation leads to the Landau-Stuart and the (time-dependent) Ginzburg-Landau equations. It is confirmed that this method is actually a powerful theory for the reduction of the dynamics as the reductive perturbation method is. Some examples for ordinary diferential equations, such as the forced Duffing, the Lotka-Volterra and the Lorenz equations, are worked out in this method: The time evolution of the solution of the Lotka-Volterra equation is explicitly given, while the center manifolds of the Lorenz equation are constructed in a simple way in the RG method.Comment: The revised version of RYUTHP 96/1. Submitted to Prog. Theor. Phys. (Kyoto) in Feb., 1996. 28 pages. LATEX. No figure

Flow cytometric evaluation of red blood cells transformed with variable amounts of synthetic A and B glycolipids

Background: According to national guidelines or directives, monoclonal ABO reagents may be required to detect Ax and B weak subgroup red blood cells (RBCs). Many routine laboratories do not have access to naturallyoccurring ABO subgroups that can be used as weak controls for these reagents. Group O RBCs modified with synthetic analogs of blood group A and/or B glycolipids (KODE technology) to mimic weak ABO subgroups could be used for quality control purposes. Aim: Extensive serological testing of KODE RBCs has previously been performed. An extended evaluation of KODE RBCs using flow cytometry was performed to explore the correlation between the concentrations of synthetic glycolipids and A/B site density of the resulting RBCs. The aim of this study was to examine if KODE RBCs mimic the distinct flow cytometric patterns of naturally-occurring ABO subgroups. Material and Methods: KODE RBCs were prepared according to a previously decribed procedure [Frame et al., Transfusion 2007; 47: 876–82]. RBCs were modified with 15 different concentrations of synthetic glycolipids, ranging from 1 mg/mL to 60 ng/mL for KODE-A and 5 mg/mL to 0.3 lg/mL for KODE-B. The concentration was decreased by doubling dilution steps. Sensitive and specific flow cytometry [Hult & Olsson. Transfusion 2006; 9S: 32A] was used to characterize and semiquantify the synthetic A and B antigen levels on RBCs. Relevant control RBCs (A1, A2, Ax, B, Bweak and O) were included in each run. For both KODE-A and KODE-B RBCs, repeat samples were produced for four selected concentrations and all KODE batches were tested in triplicate. Results: Flow cytometric testing of KODE RBCs modified with high concentrations of synthetic glycolipids revealed a uniform and even distribution of antigens in the cell population as shown by a single narrow peak in the FACS histograms. When lower concentrations were used, peaks tended to broaden to a pattern found in Ax and most B subgroups indicating a more variable antigen site density on the cells in the population. The concentrations of synthetic glycolipids that produced KODE cells that resembled the naturally-occurring subgroup control RBCs used in this study are ~2–4 lg/mL for KODE-A and ~10 lg/mL for KODEB. Repeat testing demonstrated good correlation between flow cytometric runs. Discussion and Conclusion: Using very low amounts of synthetic glycolipids, KODE-A and KODE-B RBCs can be made to mimic Ax and Bweak subgroup control RBCs, respectively, according to this flow cytometry method. With higher concentrations of synthetic glycolipids, the KODE RBCs demonstrated a more uniform and even distribution of antigens among the cells. This is in contrast to naturally-occurring subgroups in which some cells express almost no A or B antigen whilst others have close to normal levels. The reason for this is unknown. KODE RBCs obviously lack A carrying glycoproteins but it is not fully understood to what extent glycolipid versus glycoprotein epitopes contribute to the phenotype of weak subgroups. This study indicates that KODE RBCs with weak expression of A and/or B antigen have characteristics compatible with use as quality controls for monoclonal ABO reagents and could be a valuable addition in the serological laboratory

FAK acts as a suppressor of RTK-MAP kinase signalling in Drosophila melanogaster epithelia and human cancer cells

Receptor Tyrosine Kinases (RTKs) and Focal Adhesion Kinase (FAK) regulate multiple signalling pathways, including mitogen-activated protein (MAP) kinase pathway. FAK interacts with several RTKs but little is known about how FAK regulates their downstream signalling. Here we investigated how FAK regulates signalling resulting from the overexpression of the RTKs RET and EGFR. FAK suppressed RTKs signalling in Drosophila melanogaster epithelia by impairing MAPK pathway. This regulation was also observed in MDA-MB-231 human breast cancer cells, suggesting it is a conserved phenomenon in humans. Mechanistically, FAK reduced receptor recycling into the plasma membrane, which resulted in lower MAPK activation. Conversely, increasing the membrane pool of the receptor increased MAPK pathway signalling. FAK is widely considered as a therapeutic target in cancer biology; however, it also has tumour suppressor properties in some contexts. Therefore, the FAK-mediated negative regulation of RTK/MAPK signalling described here may have potential implications in the designing of therapy strategies for RTK-driven tumours

Preventive medical care in remote Aboriginal communities in the Northern Territory: a follow-up study of the impact of clinical guidelines, computerised recall and reminder systems, and audit and feedback

Background Interventions to improve delivery of preventive medical services have been shown to be effective in North America and the UK. However, there are few studies of the extent to which the impact of such interventions has been sustained, or of the impact of such interventions in disadvantaged populations or remote settings. This paper describes the trends in delivery of preventive medical services following a multifaceted intervention in remote community health centres in the Northern Territory of Australia. Methods The intervention comprised the development and dissemination of best practice guidelines supported by an electronic client register, recall and reminder systems and associated staff training, and audit and feedback. Clinical records in seven community health centres were audited at regular intervals against best practice guidelines over a period of three years, with feedback of audit findings to health centre staff and management. Results Levels of service delivery varied between services and between communities. There was an initial improvement in service levels for most services following the intervention, but improvements were in general not fully sustained over the three year period. Conclusions Improvements in service delivery are consistent with the international experience, although baseline and follow-up levels are in many cases higher than reported for comparable studies in North America and the UK. Sustainability of improvements may be achieved by institutionalisation of relevant work practices and enhanced health centre capacity

Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity

The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (nu_x) 8B solar neutrino flux without assumptions about the energy dependence of the nu_e survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27 (stat) +/- 0.38 (syst) x10^6 cm^{-2}s^{-1}, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Delta m^{2} = 7.1^{+1.2}_{-0.6}x10^{-5} ev^2 and theta = 32.5^{+2.4}_{-2.3} degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.Comment: Submitted to Phys. Rev. Let

Phosphorylated c-Src in the nucleus is associated with improved patient outcome in ER-positive breast cancer

Elevated c-Src protein expression has been shown in breast cancer and <i>in vitro</i> evidence suggests a role in endocrine resistance. To investigate whether c-Src is involved in endocrine resistance, we examined the expression of both total and activated c-Src in human breast cancer specimens from a cohort of oestrogen receptor (ER)-positive tamoxifen-treated breast cancer patients. Tissue microarray technology was employed to analyse 262 tumour specimens taken before tamoxifen treatment. Immunohistochemistry using total c-Src and activated c-Src antibodies was performed. Kaplan–Meier survival curves were constructed and log-rank test were performed. High level of nuclear activated Src was significantly associated with improved overall survival (<i>P</i>=0.047) and lower recurrence rates on tamoxifen (<i>P</i>=0.02). Improved patient outcome was only seen with activated Src in the nucleus. Nuclear activated Src expression was significantly associated with node-negative disease and a lower NPI (<i>P</i><0.05). On subgroup analysis, only ER-positive/progesterone receptor (PgR)-positive tumours were associated with improved survival (<i>P</i>=0.004). This shows that c-Src activity is increased in breast cancer and that activated Src within the nucleus of ER-positive tumours predicts an improved outcome. In ER/PgR-positive disease, activated Src kinase does not appear to be involved in <i>de novo</i> endocrine resistance. Further study is required in ER-negative breast cancer as this may represent a cohort in which it is associated with poor outcome

Community professionals' management of client care : a mixed-methods systematic review

This is the final draft, after peer-review, of a manuscript published in Journal of Health Services Research & Policy. The definitive version, detailed above, is available online at www.rsmjournals.com.Peer reviewedPostprin

Projective dynamics and first integrals

We present the theory of tensors with Young tableau symmetry as an efficient computational tool in dealing with the polynomial first integrals of a natural system in classical mechanics. We relate a special kind of such first integrals, already studied by Lundmark, to Beltrami's theorem about projectively flat Riemannian manifolds. We set the ground for a new and simple theory of the integrable systems having only quadratic first integrals. This theory begins with two centered quadrics related by central projection, each quadric being a model of a space of constant curvature. Finally, we present an extension of these models to the case of degenerate quadratic forms.Comment: 39 pages, 2 figure