Micro-geographic risk factors for malarial infection.

BACKGROUND: Knowledge of geography is integral to the study of insect-borne infectious disease such as malaria. This study was designed to evaluate whether geographic parameters are associated with malarial infection in the East Sepik province of Papua New Guinea (PNG), a remote area where malaria is a major cause of morbidity and mortality. METHODS: A global positioning system (GPS) unit was used at each village to collect elevation, latitude and longitude data. Concurrently, a sketch map of each village was generated and the villages were sub-divided into regions of roughly equal populations. Blood samples were taken from subjects in each region using filter paper collection. The samples were later processed using nested PCR for qualitative determination of malarial infection. The area was mapped using the GPS-information and overlaid with prevalence data. Data tables were examined using traditional chi square statistical techniques. A logistic regression analysis was then used to determine the significance of geographic risk factors including, elevation, distance from administrative centre and village of residence. RESULTS: Three hundred and thirty-two samples were included (24% of the total estimated population). Ninety-six were positive, yielding a prevalence of 29%. Chi square testing within each village found a non-random distribution of cases across sub-regions (p < 0.05). Multivariate logistic regression techniques suggested malarial infection changed with elevation (OR = 0.64 per 10 m, p < 0.05) and distance from administrative centre (OR = 1.3 per 100 m, p < 0.05). CONCLUSION: These results suggest that malarial infection is significantly and independently associated with lower elevation and greater distance from administrative centre in a rural area in PNG. This type of analysis can provide information that may be used to target specific areas in developing countries for malaria prevention and treatment

Performance analysis of the doubly-linked list protocol family for distributed shared memory systems

The 2nd International Conference on Algorithms and Architectures for Parallel Processing, Singapore, 11-13 June 1996The doubly-linked list (DLL) protocol provides a memory efficient, scalable, high-performance and yet easy to implement method to maintain memory coherence in distributed shared memory (DSM) systems. In this paper, the performance analysis of the DLL family of protocols is presented. Theoretically, the DLL protocol with stable owners has the shortest remote memory access latency among the DLL protocol family. According to the simulated performance evaluation, the DLL-S protocol is 65.7% faster than the DDM algorithm for the linear equation solver; and is 16.5% faster for the matrix multiplier. From the trend of the performance figures, it is predicted that the improvement in performance due to the DLL-S protocol will be considerably greater when a larger number of processors are used, indicating that the DLL-S protocol is also the most scalable of the protocols tested.published_or_final_versio

Cyclic ADP ribose is a novel regulator of intracellular Ca 2+ oscillations in human bone marrow mesenchymal stem cells

Bone marrow mesenchymal stem cells (MSCs) are a promising cell source for regenerative medicine. However, the cellular biology of these cells is not fully understood. The present study characterizes the cyclic ADP-ribose (cADPR)-mediated Ca 2+ signals in human MSCs and finds that externally applied cADPR can increase the frequency of spontaneous intracellular Ca 2+ (Ca 2+ i) oscillations. The increase was abrogated by a specific cADPR antagonist or an inositol trisphosphate receptor (IP3R) inhibitor, but not by ryanodine. In addition, the cADPR-induced increase of Ca 2+ i oscillation frequency was prevented by inhibitors of nucleoside transporter or by inhibitors of the transient receptor potential cation melastatin-2 (TRPM2) channel. RT-PCR revealed mRNAs for the nucleoside transporters, concentrative nucleoside transporters 1/2 and equilibrative nucleoside transporters 1/3, IP3R1/2/3 and the TRPM2 channel, but not those for ryanodine receptors and CD38 in human MSCs. Knockdown of the TRPM2 channel by specific short interference RNA abolished the effect of cADPR on the Ca 2+ i oscillation frequency, and prevented the stimulation of proliferation by cADPR. Moreover, cADPR remarkably increased phosphorylated extracellular-signal-regulated kinases 1/2 (ERK1/2), but not Akt or p38 mitogen-activated protein kinase (MAPK). However, cADPR had no effect on adipogenesis or osteogenesis in human MSCs. Our results indicate that cADPR is a novel regulator of Ca 2+ i oscillations in human MSCs. It permeates the cell membrane through the nucleoside transporters and increases Ca 2+ oscillationviaactivation of the TRPM2 channel, resulting in enhanced phosphorylation of ERK1/2 and, thereby, stimulation of human MSC proliferation. This study delineates an alternate signalling pathway of cADPR that is distinct from its well-established role of serving as a Ca 2+ messenger for mobilizing the internal Ca 2+ stores. Whether cADPR can be used clinically for stimulating marrow function in patients with marrow disorders remains to be further studied. © 2011 The Authors © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.postprin

Increases in absenteeism among health care workers in Hong Kong during influenza epidemics, 2004–2009

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WIJAM: a mobile collaborative improvisation platform under Master-players Paradigm

Music jamming is an extremely difficult task for musical novices. Trying to extend this meaningful and highly enjoyable activity to a larger recipient group, we present WIJAM, a mobile application for an ad-hoc group of musical novices to perform improvisation along with a music master. In this master-players' paradigm, the master offers a music backing, orchestrates the musical flow, and gives feedbacks to the players; the players improvise by tapping and sketching on their smartphones. We argue that this paradigm can be a significant contribution to the possibility of music playing by a group of novices with no instrumental training leading to decent musical results.published_or_final_versio

Asymmetric-detection time-stretch optical microscopy (ATOM) for high-contrast and high-speed microfluidic cellular imaging

High-throughput cellular imaging is acclaimed as captivating yet challenging in biomedical diagnostics. We have demonstrated a new imaging modality, asymmetric-detection time-stretch optical microscopy (ATOM), by incorporating a simple detection scheme which is a further advancement in time-stretch microscopy - a viable solution to achieve high-speed and high-throughput cellular imaging. Through the asymmetric-detection scheme in ATOM, the time-stretch image contrast is enhanced through accessing to the phase-gradient information. With the operation in the 1 μm wavelength range, we demonstrate high-resolution and high-contrast cellular imaging in ultrafast microfluidic flow (up to 10 m/s) by ATOM - achieving an imaging throughput equivalent to 100,000 cells/sec. © 2014 SPIE.published_or_final_versio

A Smart Card-Based Electronic School Absenteeism System for Influenza-Like Illness Surveillance in Hong Kong: Design, Implementation, and Feasibility Assessment

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A randomised controlled study comparing the efficacy of once-daily triple therapy with twice-daily triple therapy in the eradication of Helicobacter pylori

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Meta-Analyst: software for meta-analysis of binary, continuous and diagnostic data

<p>Abstract</p> <p>Background</p> <p>Meta-analysis is increasingly used as a key source of evidence synthesis to inform clinical practice. The theory and statistical foundations of meta-analysis continually evolve, providing solutions to many new and challenging problems. In practice, most meta-analyses are performed in general statistical packages or dedicated meta-analysis programs.</p> <p>Results</p> <p>Herein, we introduce Meta-Analyst, a novel, powerful, intuitive, and free meta-analysis program for the meta-analysis of a variety of problems. Meta-Analyst is implemented in C# atop of the Microsoft .NET framework, and features a graphical user interface. The software performs several meta-analysis and meta-regression models for binary and continuous outcomes, as well as analyses for diagnostic and prognostic test studies in the frequentist and Bayesian frameworks. Moreover, Meta-Analyst includes a flexible tool to edit and customize generated meta-analysis graphs (e.g., forest plots) and provides output in many formats (images, Adobe PDF, Microsoft Word-ready RTF). The software architecture employed allows for rapid changes to be made to either the Graphical User Interface (GUI) or to the analytic modules.</p> <p>We verified the numerical precision of Meta-Analyst by comparing its output with that from standard meta-analysis routines in Stata over a large database of 11,803 meta-analyses of binary outcome data, and 6,881 meta-analyses of continuous outcome data from the Cochrane Library of Systematic Reviews. Results from analyses of diagnostic and prognostic test studies have been verified in a limited number of meta-analyses versus MetaDisc and MetaTest. Bayesian statistical analyses use the OpenBUGS calculation engine (and are thus as accurate as the standalone OpenBUGS software).</p> <p>Conclusion</p> <p>We have developed and validated a new program for conducting meta-analyses that combines the advantages of existing software for this task.</p

Interferometric time-stretch microscopy for ultrafast quantitative cellular and tissue imaging at 1 μm

Quantitative phase imaging (QPI) has been proven to be a powerful tool for label-free characterization of biological specimens. However, the imaging speed, largely limited by the image sensor technology, impedes its utility in applications where high-throughput screening and efficient big-data analysis are mandated. We here demonstrate interferometric time-stretch (iTS) microscopy for delivering ultrafast quantitative phase cellular and tissue imaging at an imaging line-scan rate >20 MHz-orders-of-magnitude faster than conventional QPI. Enabling an efficient time-stretch operation in the 1-mum wavelength window, we present an iTS microscope system for practical ultrafast QPI of fixed cells and tissue sections, as well as ultrafast flowing cells (at a flow speed of up to 8 ms). To the best of our knowledge, this is the first time that time-stretch imaging could reveal quantitative morphological information of cells and tissues with nanometer precision. As many parameters can be further extracted from the phase and can serve as the intrinsic biomarkers for disease diagnosis, iTS microscopy could find its niche in high-throughput and high-content cellular assays (e.g., imaging flow cytometry) as well as tissue refractometric imaging (e.g., whole-slide imaging for digital pathology).published_or_final_versio