157 research outputs found

    Mapping Digital Media: Malaysia

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    The Mapping Digital Media project examines the global opportunities and risks created by the transition from traditional to digital media. Covering 60 countries, the project examines how these changes affect the core democratic service that any media system should provide: news about political, economic, and social affairs.Malaysia has had a torrid relationship with digital. Mahathir Mohamad, the former Malaysian prime minister, fell in love with it in the 1990s when he launched the Multimedia Super Corridor, a sort of East Asian Silicon Valley, to develop the local information and communications technology industry.Two out of three Malaysians regularly use the internet (even though large areas of the East Malaysian states of Sabah and Sarawak, where nearly a fifth of the population lives, pose logistical challenges regarding infrastructure) and a third of the population have a 3G mobile subscription. Broadband household penetration in the capital, Kuala Lumpur, is 112 percent because many citizens have both fixed and mobile accounts. Nearly half the population is on Facebook with an average of 233 friends each, the greatest proportion in the world, all on social networks for an average nine hours a week. And they still seem to find enough time to watch television for three and a half hours a day and to listen to the radio for three hours.The outlook is for an expansion of internet and mobile-based platforms for news, comment, social networking, activism, and entertainment. However, a change of government is probably a prerequisite for the kinds of changes that would usher in greater diversity in broadcast and print, such as regulatory independence, repeal of the Printing Presses and Publications Act, and the dismantling of monopolies, rules on cross ownership, and political parties' ownership of media companies

    Broken-Symmetry States in Quantum Hall Superlattices

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    We argue that broken-symmetry states with either spatially diagonal or spatially off-diagonal order are likely in the quantum Hall regime, for clean multiple quantum well (MQW) systems with small layer separations. We find that for MQW systems, unlike bilayers, charge order tends to be favored over spontaneous interlayer coherence. We estimate the size of the interlayer tunneling amplitude needed to stabilize superlattice Bloch minibands by comparing the variational energies of interlayer-coherent superlattice miniband states with those of states with charge order and states with no broken symmetries. We predict that when coherent miniband ground states are stable, strong interlayer electronic correlations will strongly enhance the growth-direction tunneling conductance and promote the possibility of Bloch oscillations.Comment: 9 pages LaTeX, 4 figures EPS, to be published in PR

    Spontaneous coherence and the quantum Hall Effect in triple-layer electron systems

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    We investigate spontaneous interlayer phase coherence and the occurrence of the quantum Hall effect in triple-layer electron systems. Our work is based on a simple tight-binding model that greatly facilitates calculations and whose accuracy is verified by comparison with recent experiments. By calculating the ground state in an unrestricted Hartree-Fock approximation and the collective-mode spectrum in a time-dependent Hartree-Fock approximation, we construct a phase diagram delimiting regions in the parameter space of the model where the integer quantum Hall effect occurs in the absence of interlayer tunneling.Comment: To appear in Phys. Rev. B, 20 pages, 5 PostScript figures uuencoded with TeX fil

    Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for the Identification of Clinically Relevant Bacteria

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    Background: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) allows rapid and reliable identification of microorganisms, particularly clinically important pathogens. Methodology/Principal Findings: We compared the identification efficiency of MALDI-TOF MS with that of PhoenixH, APIH and 16S ribosomal DNA sequence analysis on 1,019 strains obtained from routine diagnostics. Further, we determined the agreement of MALDI-TOF MS identifications as compared to 16S gene sequencing for additional 545 strains belonging to species of Enterococcus, Gardnerella, Staphylococcus, and Streptococcus. For 94.7 % of the isolates MALDI-TOF MS results were identical with those obtained with conventional systems. 16S sequencing confirmed MALDI-TOF MS identification in 63 % of the discordant results. Agreement of identification of Gardnerella, Enterococcus, Streptococcus and Staphylococcus species between MALDI-TOF MS and traditional method was high (Crohn’s kappa values: 0.9 to 0.93). Conclusions/Significance: MALDI-TOF MS represents a rapid, reliable and cost-effective identification technique for clinically relevant bacteria

    Effectiveness of strategies to increase the validity of findings from association studies: size vs. replication

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    <p>Abstract</p> <p>Background</p> <p>The capacity of multiple comparisons to produce false positive findings in genetic association studies is abundantly clear. To address this issue, the concept of false positive report probability (FPRP) measures "the probability of no true association between a genetic variant and disease given a statistically significant finding". This concept involves the notion of prior probability of an association between a genetic variant and a disease, making it difficult to achieve acceptable levels for the FPRP when the prior probability is low. Increasing the sample size is of limited efficiency to improve the situation.</p> <p>Methods</p> <p>To further clarify this problem, the concept of true report probability (TRP) is introduced by analogy to the positive predictive value (PPV) of diagnostic testing. The approach is extended to consider the effects of replication studies. The formula for the TRP after k replication studies is mathematically derived and shown to be only dependent on prior probability, alpha, power, and number of replication studies.</p> <p>Results</p> <p>Case-control association studies are used to illustrate the TRP concept for replication strategies. Based on power considerations, a relationship is derived between TRP after k replication studies and sample size of each individual study. That relationship enables study designers optimization of study plans. Further, it is demonstrated that replication is efficient in increasing the TRP even in the case of low prior probability of an association and without requiring very large sample sizes for each individual study.</p> <p>Conclusions</p> <p>True report probability is a comprehensive and straightforward concept for assessing the validity of positive statistical testing results in association studies. By its extension to replication strategies it can be demonstrated in a transparent manner that replication is highly effective in distinguishing spurious from true associations. Based on the generalized TRP method for replication designs, optimal research strategy and sample size planning become possible.</p

    Global Analysis of Circulating Immune Cells by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

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    Background: MALDI-TOF mass spectrometry is currently used in microbiological diagnosis to characterize bacterial populations. Our aim was to determine whether this technique could be applied to intact eukaryotic cells, and in particular, to cells involved in the immune response. Methodology/Principal Findings: A comparison of frozen monocytes, T lymphocytes and polymorphonuclear leukocytes revealed specific peak profiles. We also found that twenty cell types had specific profiles, permitting the establishment of a cell database. The circulating immune cells, namely monocytes, T lymphocytes and polymorphonuclear cells, were distinct from tissue immune cells such as monocyte-derived macrophages and dendritic cells. In addition, MALDI-TOF mass spectrometry was valuable to easily identify the signatures of monocytes and T lymphocytes in peripheral mononuclear cells. Conclusions/Significance: This method was rapid and easy to perform, and unlike flow cytometry, it did not require any additional components such as specific antibodies. The MALDI-TOF mass spectrometry approach could be extended t

    Differentiation of Gram-Negative Bacterial Aerosol Exposure Using Detected Markers in Bronchial-Alveolar Lavage Fluid

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    The identification of biosignatures of aerosol exposure to pathogens has the potential to provide useful diagnostic information. In particular, markers of exposure to different types of respiratory pathogens may yield diverse sets of markers that can be used to differentiate exposure. We examine a mouse model of aerosol exposure to known Gram negative bacterial pathogens, Francisella tularensis novicida and Pseudomonas aeruginosa. Mice were subjected to either a pathogen or control exposure and bronchial alveolar lavage fluid (BALF) was collected at four and twenty four hours post exposure. Small protein and peptide markers within the BALF were detected by matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and analyzed using both exploratory and predictive data analysis methods; principle component analysis and degree of association. The markers detected were successfully used to accurately identify the four hour exposed samples from the control samples. This report demonstrates the potential for small protein and peptide marker profiles to identify aerosol exposure in a short post-exposure time frame

    Critical review of immediate implant loading

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    Background : Implant dentistry has become successful with the discovery of the biological properties of titanium. In the original protocol, studies have advocated a 2-stage surgical protocol for load-free and submerged healing to ensure predictable osseointegration. However, the discomfort, inconvenience, and anxiety associated with waiting period remains a challenge to both patients and clinicians. Hence, loading implant right after placement was attempted and has gained popularity among clinicians. Issues/questions related to this approach remain unanswered. Therefore, it is the purpose of this review article to (1) review and analyze critically the current available literature in the field of immediate implant loading and (2) discuss, based on scientific evidence, factors that may influence this treatment modality. Material and Methods : Literature published over the past 20 years was selected and reviewed. Findings from these studies were discussed and summarized in the tables. The advantages and disadvantages associated with immediate implant loading were analyzed. Factors that may influence the success of immediate implant loading, including patient selection, type of bone quality, required implant length, micro- and macrostructure of the implant, surgical skill, need for achieving primary stability/control of occlusal force, and prosthesis guidelines, were thoroughly reviewed and discussed. Results and Conclusion : Various studies have demonstrated the feasibility and predictability of this technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are primarily based on short-term results and long-term follow-ups are still scarce in this field. Nonetheless, from available literature, it may be concluded that anatomic locations, implant designs, and restricted prosthetic guidelines are key to ensure successful outcomes. Future studies, preferably randomized, prospective longitudinal studies, are certainly needed before this approach can be widely used. To cite this article: Gapski R, Wang H-L, Mascarenhas P, Lang NP. Critical review of immediate implant loading. Clin. Oral Impl. Res , 14 , 2003; 515–527Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73058/1/j.1600-0501.2003.00950.x.pd

    Visualization and Curve-Parameter Estimation Strategies for Efficient Exploration of Phenotype Microarray Kinetics

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    The Phenotype MicroArray (OmniLog® PM) system is able to simultaneously capture a large number of phenotypes by recording an organism's respiration over time on distinct substrates. This technique targets the object of natural selection itself, the phenotype, whereas previously addressed '-omics' techniques merely study components that finally contribute to it. The recording of respiration over time, however, adds a longitudinal dimension to the data. To optimally exploit this information, it must be extracted from the shapes of the recorded curves and displayed in analogy to conventional growth curves.The free software environment R was explored for both visualizing and fitting of PM respiration curves. Approaches using either a model fit (and commonly applied growth models) or a smoothing spline were evaluated. Their reliability in inferring curve parameters and confidence intervals was compared to the native OmniLog® PM analysis software. We consider the post-processing of the estimated parameters, the optimal classification of curve shapes and the detection of significant differences between them, as well as practically relevant questions such as detecting the impact of cultivation times and the minimum required number of experimental repeats.We provide a comprehensive framework for data visualization and parameter estimation according to user choices. A flexible graphical representation strategy for displaying the results is proposed, including 95% confidence intervals for the estimated parameters. The spline approach is less prone to irregular curve shapes than fitting any of the considered models or using the native PM software for calculating both point estimates and confidence intervals. These can serve as a starting point for the automated post-processing of PM data, providing much more information than the strict dichotomization into positive and negative reactions. Our results form the basis for a freely available R package for the analysis of PM data
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