Non Abelian Geometrical Tachyon

We investigate the dynamics of a pair of coincident D5 branes in the background of $k$ NS5 branes. It has been proposed by Kutasov that the system with a single probing D-brane moving radially in this background is dual to the tachyonic DBI action for a non-BPS Dp brane. We extend this proposal to the non-abelian case and find that the duality still holds provided one promotes the radial direction to a matrix valued field associated with a non-abelian geometric tachyon and a particular parametrization for the transverse scalar fields is chosen. The equations of motion of a pair of coincident D5 branes moving in the NS5 background are determined. Analytic and numerical solutions for the pair are found in certain simplified cases in which the U(2) symmetry is broken to $U(1) \times U(1)$ corresponding to a small transverse separation of the pair. For certain range of parameters these solutions describe periodic motion of the centre of mass of the pair 'bouncing off' a finite sized throat whose minimum size is limited by the D5 branes separation.Comment: 18 pages, 2 figures, PdfLatex: references added.accepted for publication in JHE

Regulation and Function of Activity-Dependent Homer in Synaptic Plasticity

Alterations in synaptic signaling and plasticity occur during the refinement of neural circuits over the course of development and the adult processes of learning and memory. Synaptic plasticity requires the rearrangement of protein complexes in the postsynaptic density (PSD), trafficking of receptors and ion channels and the synthesis of new proteins. Activity-induced short Homer proteins, Homer1a and Ania-3, are recruited to active excitatory synapses, where they act as dominant negative regulators of constitutively expressed, longer Homer isoforms. The expression of Homer1a and Ania-3 initiates critical processes of PSD remodeling, the modulation of glutamate receptor-mediated functions, and the regulation of calcium signaling. Together, available data support the view that Homer1a and Ania-3 are responsible for the selective, transient destabilization of postsynaptic signaling complexes to facilitate plasticity of the excitatory synapse. The interruption of activity-dependent Homer proteins disrupts disease-relevant processes and leads to memory impairments, reflecting their likely contribution to neurological disorders

Rescue of long-term memory after reconsolidation blockade

Memory reconsolidation is considered to be the process whereby stored memories become labile on recall, allowing updating. Blocking the restabilization of a memory during reconsolidation is held to result in a permanent amnesia. The targeted knockdown of either Zif268 or Arc levels in the brain, and inhibition of protein synthesis, after a brief recall results in a non-recoverable retrograde amnesia, known as reconsolidation blockade. These experimental manipulations are seen as key proof for the existence of reconsolidation. However, here we demonstrate that despite disrupting the molecular correlates of reconsolidation in the hippocampus, rodents are still able to recover contextual memories. Our results challenge the view that reconsolidation is a separate memory process and instead suggest that the molecular events activated initially at recall act to constrain premature extinction

A FATAL CASE OF BILATERAL INTERSTITIAL PNEUMONIA (BLIP): INTERFERON ALPHA 2 A INDUCED.

  Adult T-cell leukemia/lymphoma (ATLL) is a rare lymph proliferative disorder of mature CD4 T-cells caused by the human T-lymph tropic type 1 (HTLV 1) of retrovirus family. Combination of zidovudine and interferon Alfa combination is one of most commonly used regimen. Many drugs are implicated in causing interstitial lung disease. Hence, we report a case of interferon Alfa-induced bilateral interstitial pneumonia in a 32-year-old female patient diagnosed with ATLL with HTLV 1 positivity

Hippocampal Regulation of Postsynaptic Density Homer1 by Associative Learning

Genes involved in synaptic plasticity, particularly genes encoding postsynaptic density proteins, have been recurrently linked to psychiatric disorders including schizophrenia and autism. Postsynaptic density Homer1 proteins contribute to synaptic plasticity through the competing actions of short and long isoforms. The activity-induced expression of shortHomer1isoforms,Homer1aandAnia-3, is thought to be related to processes of learning and memory. However, the precise regulation ofHomer1aandAnia-3with different components of learning has not been investigated. Here, we used in situ hybridization to quantify short and longHomer1expression in the hippocampus following consolidation, retrieval, and extinction of associative fear memory, using contextual fear conditioning in rats.Homer1aandAnia-3, but not longHomer1, were regulated by contextual fear learning or novelty detection, although their precise patterns of expression in hippocampal subregions were dependent on the isoform. We also show for the first time that the two short Homer1 isoforms are regulated after the retrieval and extinction of contextual fear memory, albeit with distinct temporal and spatial profiles. These findings support a role of activity-induced Homer1 isoforms in learning and memory processes in discrete hippocampal subregions and suggest that Homer1a and Ania-3 may play separable roles in synaptic plasticity.</jats:p

Improving the collaboration between architects and energy consultants through design-integrated early BIM-tools

There is a lack of optimization of buildings towards energy performance in early design stages in practice. Interviews with architects and energy consultants showed that one reason is the inefficient communication between these two groups. This paper investigates how a design-integrated early-BIM tool can improve the relation between architects and energy consultants to support an optimization process in early design stages and facilitate issuing energy performance certificates. Two case studies show that the early-BIM tool provides meaningful results for the architects involved and can reduce the input time for energy consultants by 50%. Furthermore, the simple 3D model functions as boundary object between the two groups and supports the collaboration

Pedometry and 'peer support' in older Chinese adults: a 12-month cluster randomised controlled trial

Session - Exercise/RehabilitationResearch Dissemination ReportsThere is a need to increase physical activity to attenuate age-related morbidity. This 12-month factorial design cluster trial randomized 399 volunteers from 24 centres to buddy peer support, pedometry, or control group. Data were anaysed using last-observation carried-forward and intention-to-treat methods. Compared to the controls, participants in the pedometry group increased their levels of physical activity energy expenditure significantly, as did those in the buddy group. As recorded by the International Physical Activity Questionnaire [IPAQ], the respective increases amounted to 1820 (95% confidence interval [CI], 1360-2290) and 1260 (95% CI, 780-17 460) metabolic equivalent of task (MET).min.wk-1. The buddy group also had significantly improved aerobic fitness after adjustment for body weight (12%; 95% CI, 4-21%), but this did not attain significance in the pedometry group (7%; 95% CI, -1 to 15%). Our results suggest that recourse to pedometers and the buddy peer support system is simple means of increasing physical activity in older subjects.published_or_final_versio

Association of a genetic polymorphism in the gene encoding fibrinogen beta chain with hypertension in Hong Kong Chinese

published_or_final_versionThe 15th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16, suppl. 1, p. 51, abstract no. 8

Mendelian randomisation analysis suggests that plasma interleukin-6 is raised in hypertension but does not cause its development

Introduction: Interleukin-6 (IL-6) plays a central role in inflammation and insulin resistance as well as atherogenesis. We investigated the associations of plasma IL-6 and its genetic variants with hypertension in both cross-sectional and prospective study designs. Methods: Plasma IL-6 was measured in 648 normotensive and 294 hypertensive subjects from the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS-2) in 2000-2004 and three tagging SNPs in the IL-6 gene (IL6) were genotyped. Among subjects normotensive in CRISPS-2, 515 subjects were followed up in CRISPS-3 in 2005- 2008 and 100 of them had developed hypertension. Results: Plasma IL-6 correlated with systolic blood pressure (r=0.128, P<0.001), pulse pressure (r=0.144, P<0.001), and mean arterial pressure (r=0.086, P=0.008). Hypertensive subjects have significantly higher plasma IL-6 level after adjusting for age and sex (geometric mean [95% CI]=0.60 [0.54-0.65] vs 0.47 [0.44-0.50] pg/mL, P=0.021). In stepwise logistic regression, plasma IL-6 was associated with hypertension in women (P=0.004), but not in men. The SNP rs1800796 was associated with plasma IL-6 (beta= –0.098, P=0.002) in stepwise linear regression. However, this SNP was not associated with hypertension or blood pressure. Among subjects normotensive in CRISPS-2, plasma IL-6 was not associated with the development of hypertension in CRISPS-3. Conclusion: Elevated plasma IL-6 is associated with hypertension, especially in women. Plasma IL-6 is influenced by the SNP rs1800796. However, this SNP is not associated with hypertension, suggesting that hypertension is caused by other factors that elevate plasma IL-6. Acknowledgement: This study was funded by Hong Kong Research Grant Council grants (HKU7229/01M and HKU7626/07M) and the Sun Chieh Yeh Heart Foundation.published_or_final_versio