Maskless etching of silicon using patterned microdischarges

Microdischarges in flexible copper-polyimide structures with hole diameters of 200 µm have been used as stencil masks to pattern bare silicon in CF4/Ar chemistry. The discharges were operated at 20 Torr using the substrate as the cathode, achieving etch rates greater than 7 µm/min. Optical emission spectroscopy provides evidence of excited fluorine atoms. The etch profiles show a peculiar shape attributed to plasma expansion into the etched void. Forming discharges in multiple hole and line shapes permits direct pattern transfer in silicon and could be an alternative to ultrasonic milling and laser drilling

Managing organizational change by using soft systems thinking in action research projects

Purpose – This paper aims to show how systems thinking can be incorporated in action research (AR) interventions to successfully implement organizational change. The two case studies described in this paper would be useful to managers who want to implement change in their own organizations. Design/methodology/approach – Both projects used AR as the methodology due to its flexible, responsive and emergent nature. In one project, there was a deliberate attempt to incorporate soft systems thinking whereas in the other project soft systems thinking was used as a sensemaking process while carrying out AR. As an added benefit both approaches have resulted in successful completion of doctoral research. Findings – Soft systems methodology (SSM) and AR can both help in addressing illstructured problems faced by managers, in collaboration with stakeholders using questioning and reflection. Both lead to an increased understanding about the problem situation. The difference is that SSM uses a more structured approach while AR is emergent in its application. SSM practitioners advocate that action researchers would benefit by declaring in advance an intellectual framework to guide their research. This has the additional benefit of overcoming obstacles in an academic environment where research processes are still governed based on traditional research methods. Practical implications – The ideas presented in the paper could be particularly useful to a practicebased discipline such as project management where research into its practice is in demand. Originality/value – This paper would be useful to managers interested in a rigorous methodology to implement organizational change in addressing business problems. It demonstrates ways of combining SSM and AR, resulting in a powerful research tool to carry out rigorous research. © 2009, Emerald Group Publishing Limite

Gut immune dysfunction through impaired innate pattern recognition receptor expression and gut microbiota dysbiosis in chronic SIV infection.

HIV targets the gut mucosa early in infection, causing immune and epithelial barrier dysfunction and disease progression. However, gut mucosal sensing and innate immune signaling through mucosal pattern recognition receptors (PRRs) during HIV infection and disease progression are not well defined. Using the simian immunodeficiency virus (SIV)-infected rhesus macaque model of AIDS, we found a robust increase in PRRs and inflammatory cytokine gene expression during the acute SIV infection in both peripheral blood and gut mucosa, coinciding with viral replication. PRR expression remained elevated in peripheral blood following the transition to chronic SIV infection. In contrast, massive dampening of PRR expression was detected in the gut mucosa, despite the presence of detectable viral loads. Exceptionally, expression of Toll-like receptor 4 (TLR4) and TLR8 was downmodulated and diverged from expression patterns for most other TLRs in the gut. Decreased mucosal PRR expression was associated with increased abundance of several pathogenic bacterial taxa, including Pasteurellaceae members, Aggregatibacter and Actinobacillus, and Mycoplasmataceae family. Early antiretroviral therapy led to viral suppression but only partial maintenance of gut PRRs and cytokine gene expression. In summary, SIV infection dampens mucosal innate immunity through PRR dysregulation and may promote immune activation, gut microbiota changes, and ineffective viral clearance

Sequence fingerprints distinguish erroneous from correct predictions of Intrinsically Disordered Protein Regions

More than sixty prediction methods for intrinsically disordered proteins (IDPs) have been developed over the years, many of which are accessible on the world-wide web. Nearly, all of these predictors give balanced accuracies in the ~65% to ~80% range. Since predictors are not perfect, further studies are required to uncover the role of amino acid residues in native IDP as compared to predicted IDP regions. In the present work, we make use of sequences of 100% predicted IDP regions, false positive disorder predictions, and experimentally determined IDP regions to distinguish the characteristics of native versus predicted IDP regions. A higher occurrence of asparagine is observed in sequences of native IDP regions but not in sequences of false positive predictions of IDP regions. The occurrences of certain combinations of amino acids at the pentapeptide level provide a distinguishing feature in the IDPs with respect to globular proteins. The distinguishing features presented in this paper provide insights into the sequence fingerprints of amino acid residues in experimentally-determined as compared to predicted IDP regions. These observations and additional work along these lines should enable the development of improvements in the accuracy of disorder prediction algorithm