803 research outputs found

    Bacterial Ligands Generated in a Phagosome Are Targets of the Cytosolic Innate Immune System

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    Macrophages are permissive hosts to intracellular pathogens, but upon activation become microbiocidal effectors of innate and cell-mediated immunity. How the fate of internalized microorganisms is monitored by macrophages, and how that information is integrated to stimulate specific immune responses is not understood. Activation of macrophages with interferon (IFN)–γ leads to rapid killing and degradation of Listeria monocytogenes in a phagosome, thus preventing escape of bacteria to the cytosol. Here, we show that activated macrophages induce a specific gene expression program to L. monocytogenes degraded in the phago-lysosome. In addition to activation of Toll-like receptor (TLR) signaling pathways, degraded bacteria also activated a TLR-independent transcriptional response that was similar to the response induced by cytosolic L. monocytogenes. More specifically, degraded bacteria induced a TLR-independent IFN-ÎČ response that was previously shown to be specific to cytosolic bacteria and not to intact bacteria localized to the phagosome. This response required the generation of bacterial ligands in the phago-lysosome and was largely dependent on nucleotide-binding oligomerization domain 2 (NOD2), a cytosolic receptor known to respond to bacterial peptidoglycan fragments. The NOD2-dependent response to degraded bacteria required the phagosomal membrane potential and the activity of lysosomal proteases. The NOD2-dependent IFN-ÎČ production resulted from synergism with other cytosolic microbial sensors. This study supports the hypothesis that in activated macrophages, cytosolic innate immune receptors are activated by bacterial ligands generated in the phagosome and transported to the cytosol

    Design of laminated structures using piezoelectric materials

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    Composite structures incorporating piezoelectric sensors and actuators are increasingly becoming important due to the offer of potential benefits in a wide range of engineering applications such as vibration and noise supression, shape control and precisition positioning. This paper presents a finit element formulation based on classical laminated plate theory for laminated structures with integrated piezoelectric layers or patches, acting as actuators. The finite element model is a single layer triangular nonconforming plate/shell element with 18 degrees of freedom for the generalized displacements, and one electrical potential degree of freedom for each piezsoelectric elementlayer or patch, witch are surface bonded on the laminate. An optimization of the patches position is performed to maximize the piezoelectric actuators efficiency as well as, the electric potential distribuition is search to reach the specified structure transverse displacement distribuition (shape control). A gradient based algorithm is used for this purpose. The model is applied in the optimization of illustrative laminated plate cases, and the results are presented and discussed

    Shape control of laminated panels using piezoelectric actuators

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    This paper presents a finite element formulation based on the classical laminated plate theory for laminated structures with integrated piezoelectric layers or patches, acting as actuators.The finite element model is a single layer trinaguular nonconforming plate/shell element with 18 degrees of fredom for the generalized displacements, and one electrical potential degree of freedom for each piezoelectric element elemenet layer or patch. An optimization of the patches position is perfomed to maximize the piezoelectric actuators efficiency as well as,the electric potential distribution is serach to reach the specified strusctura transverse displacement distribution is search to reach the specified structures trsnsverse displacement distribution (shape control). A gradient based algorithm is used for this purpose.Results are presented and discussed

    Language and anxiety: an ethnographic study of international postgraduate students

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    This paper presents some findings from an ethnographic study of international postgraduate students at a university in the South of England, which involved interviews and participant observation over a twelve-month academic year. One of the major themes that emerged from this research was students’ anxiety over their level of English language. Although all students entered their course with a minimum level of IELTS 6, the majority felt disadvantaged by particularly poor spoken English, and suffered feelings of anxiety, shame and inferiority. Low self-confidence meant that they felt ill-equipped to engage in class discussion and in social interaction which used English as the medium of communication. A common reaction to stress caused by language problems was to retreat into monoethnic communication with students from the same country, further inhibiting progress in language. Whilst some linguistic progress was made by nearly all students during the academic sojourn, the anxiety suffered by students in the initial stage must not be underestimated, and appropriate support systems must be put in place to alleviate their distress

    Data-based analysis of speech and gesture: the Bielefeld Speech and Gesture Alignment corpus (SaGA) and its applications

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    LĂŒcking A, Bergmann K, Hahn F, Kopp S, Rieser H. Data-based analysis of speech and gesture: the Bielefeld Speech and Gesture Alignment corpus (SaGA) and its applications. Journal on Multimodal User Interfaces. 2013;7(1-2):5-18.Communicating face-to-face, interlocutors frequently produce multimodal meaning packages consisting of speech and accompanying gestures. We discuss a systematically annotated speech and gesture corpus consisting of 25 route-and-landmark-description dialogues, the Bielefeld Speech and Gesture Alignment corpus (SaGA), collected in experimental face-to-face settings. We first describe the primary and secondary data of the corpus and its reliability assessment. Then we go into some of the projects carried out using SaGA demonstrating the wide range of its usability: on the empirical side, there is work on gesture typology, individual and contextual parameters influencing gesture production and gestures’ functions for dialogue structure. Speech-gesture interfaces have been established extending unification-based grammars. In addition, the development of a computational model of speech-gesture alignment and its implementation constitutes a research line we focus on

    Substantially improved pharmacokinetics of recombinant human butyrylcholinesterase by fusion to human serum albumin

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    <p>Abstract</p> <p>Background</p> <p>Human butyrylcholinesterase (huBChE) has been shown to be an effective antidote against multiple LD<sub>50 </sub>of organophosphorus compounds. A prerequisite for such use of huBChE is a prolonged circulatory half-life. This study was undertaken to produce recombinant huBChE fused to human serum albumin (hSA) and characterize the fusion protein.</p> <p>Results</p> <p>Secretion level of the fusion protein produced <it>in vitro </it>in BHK cells was ~30 mg/liter. Transgenic mice and goats generated with the fusion constructs expressed in their milk a bioactive protein at concentrations of 0.04–1.1 g/liter. BChE activity gel staining and a size exclusion chromatography (SEC)-HPLC revealed that the fusion protein consisted of predominant dimers and some monomers. The protein was confirmed to have expected molecular mass of ~150 kDa by Western blot. The purified fusion protein produced <it>in vitro </it>was injected intravenously into juvenile pigs for pharmacokinetic study. Analysis of a series of blood samples using the Ellman assay revealed a substantial enhancement of the plasma half-life of the fusion protein (~32 h) when compared with a transgenically produced huBChE preparation containing >70% tetramer (~3 h). <it>In vitro </it>nerve agent binding and inhibition experiments indicated that the fusion protein in the milk of transgenic mice had similar inhibition characteristics compared to human plasma BChE against the nerve agents tested.</p> <p>Conclusion</p> <p>Both the pharmacokinetic study and the <it>in vitro </it>nerve agent binding and inhibition assay suggested that a fusion protein retaining both properties of huBChE and hSA is produced <it>in vitro </it>and <it>in vivo</it>. The production of the fusion protein in the milk of transgenic goats provided further evidence that sufficient quantities of BChE/hSA can be produced to serve as a cost-effective and reliable source of BChE for prophylaxis and post-exposure treatment.</p

    Social gradients in self-reported health and well-being among adults aged 50 and over in Pune District, India

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    Background: India&#146;s older population is projected to increase up to 96 million by 2011 with older people accounting for 18% of its population by 2051. The Study on Global Ageing and Adult Health aims to improve empirical understanding of health and well-being of older adults in developing countries. Objectives: To examine age and socio-economic changes on a range of key domains in self-reported health and well-being amongst older adults. Design: A cross-sectional survey of 5,430 adults aged 50 and over using a shortened version of the SAGE questionnaire to assess self-reported assessments (scales of 1&#x2013;5) of performance, function, disability, quality of life and well-being. Self-reported responses were calibrated using anchoring vignettes in eight key domains of mobility, self-care, pain, cognition, interpersonal relationships, sleep/energy, affect, and vision. WHO Disability Assessment Schedule Index and WHO health scores were calculated to examine for associations with socio-demographic variables. Results: Disability in all domains increased with increasing age and decreasing levels of education. Females and the oldest old without a living spouse reported poorer health status and greater disability across all domains. Performance and functionality self-reports were similar across all SES quintiles. Self-reports on quality of life were not significantly influenced by socio-demographic variables. Discussion: The study provides standardised and comparable self-rated health data using anchoring vignettes in an older population. Though expectations of good health, function and performance decrease with age, self-reports of disability severity significantly increased with age, more so if female, if uneducated and living without a spouse. However, the presence or absence of spouse did not significantly alter quality of life self-reports, suggesting a possible protective effect provided by traditional joint family structures in India, where older people are social if not financial assets for their children

    In Vivo Comparison of Two Human Norovirus Surrogates for Testing Ethanol-Based Handrubs: The Mouse Chasing the Cat!

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    Human noroviruses (HuNoV), a major cause of acute gastroenteritis worldwide, cannot be readily cultured in the lab. Therefore, a feline calicivirus (FCV) is often used as its surrogate to, among other things, test alcohol-based handrubs (ABHR). The more recent laboratory culture of a mouse norovirus (MNV) provides an alternative. While MNV is closer to HuNoV in several respects, to date, no comparative testing of FCV and MNV survival and inactivation on human hands has been performed. This study was designed to address the knowledge gap. The rates of loss in viability during drying on hands were −1.91 and −1.65% per minute for FCV and MNV, respectively. When the contaminated skin was exposed for 20 s to either a commercial ABHR with 62% (v/v) ethanol or to 75% (v/v) ethanol in water, FCV infectivity was reduced by <1 log10 while that of MNV by nearly 2.8 log10. Extending the contact time to 30 s reduced the FCV titer by almost 2 log10 by both test substances and that of MNV by >3.5 log10 by the commercial ABHR while 75% ethanol did not show any noticeable improvement in activity as compared to the 20 s contact. An 80% (v/v) aqueous solution of ethanol gave only a 1.75 log10 reduction in MNV activity after 20 s. The results show significant differences in the ethanol susceptibility of FCV and MNV in contact times relevant to field use of ABHR and also that 62% ethanol was a more effective virucide than either 75% or 80% ethanol. These findings indicate the need for a review of the continuing use of FCV as a surrogate for HuNoV

    African Rice (Oryza glaberrima Steud.): Lost Crop of the Enslaved Africans Discovered in Suriname1

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    African Rice (Oryza glaberrimaSteud.): Lost Crop of the Enslaved Africans Discovered in Suriname. African rice (Oryza glaberrima Steud.) was introduced to the Americas during the slave trade years and grown by enslaved Africans for decades before mechanical milling devices facilitated the shift towards Asian rice (O. sativa L.). Literature suggests that African rice is still grown in Guyana and French Guiana, but the most recent herbarium voucher dates from 1938. In this paper, evidence is presented that O. glaberrima is still grown by Saramaccan Maroons both for food and ritual uses. Saramaccan informants claim their forefathers collected their first “black rice” from a mysterious wild rice swamp and cultivated these seeds afterwards. Unmilled spikelets (grains with their husk still attached) are sold in small quantities for ancestor offerings, and even exported to the Netherlands to be used by Maroon immigrants. Little is known of the evolution of O. glaberrima, before and after domestication. Therefore, more research is needed on the different varieties of rice and other “lost crops” grown by these descendants of enslaved Africans who escaped from plantations in the 17th and 18th centuries and maintained much of their African cultural heritage in the deep rainforest
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