Views from the coalface: chemo-sensors, sensor networks and the semantic sensor web

Currently millions of sensors are being deployed in sensor networks across the world. These networks generate vast quantities of heterogeneous data across various levels of spatial and temporal granularity. Sensors range from single-point in situ sensors to remote satellite sensors which can cover the globe. The semantic sensor web in principle should allow for the unification of the web with the real-word. In this position paper, we discuss the major challenges to this unification from the perspective of sensor developers (especially chemo-sensors) and integrating sensors data in real-world deployments. These challenges include: (1) identifying the quality of the data; (2) heterogeneity of data sources and data transport methods; (3) integrating data streams from different sources and modalities (esp. contextual information), and (4) pushing intelligence to the sensor level

The histone fold domain of Cse4 is sufficient for CEN targeting and propagation of active centromeres in budding yeast

Centromere-specific H3-like proteins (CenH3s) are conserved across the eukaryotic kingdom and are required for packaging centromere DNA into a specialized chromatin structure required for kinetochore assembly. Cse4 is the CenH3 protein of the budding yeast Saccharomyces cerevisiae. Like all CenH3 proteins, Cse4 consists of a conserved histone fold domain (HFD) and a divergent N terminus (NT). The Cse4 NT contains an essential domain designated END (for essential N-terminal domain); deletion of END is lethal. To investigate the role of the Cse4 NT in centromere targeting, a series of deletion alleles (cse4DeltaNT) were analyzed. No part of the Cse4 NT was required to target mutant proteins to centromere DNA in the presence of functional Cse4. A Cse4 degron strain was used to examine targeting of a Cse4DeltaNT protein in the absence of wild-type Cse4. The END was not required for centromere targeting under these conditions, confirming that the HFD confers specificity of Cse4 centromere targeting. Surprisingly, overexpression of the HFD bypassed the requirement for the END altogether, and viable S. cerevisiae strains in which the cells express only the Cse4 HFD and six adjacent N-terminal amino acids (Cse4Delta129) were constructed. Despite the complete absence of the NT, mitotic chromosome loss in the cse4Delta129 strain increased only 6-fold compared to a 15-fold increase in strains overexpressing wild-type Cse4. Thus, when overexpressed, the Cse4 HFD is sufficient for centromere function in S. cerevisiae, and no posttranslational modification or interaction of the NT with other kinetochore component(s) is essential for accurate chromosome segregation in budding yeast

Combined organic biomarker and use-wear analyses of stone artefacts from Liang Bua, Flores, Indonesia

Organic biomarker and lithic use-wear analyses of archaeological implements manufactured and/or used by hominins in the past offers a means of assessing how prehistoric peoples utilised natural resources. Currently, most studies focus on one of these techniques, rather than using both in sequence. This study aims to assess the potential of combining both methods to analyse stone artefacts, using a set of 69 stones excavated from the cave site of Liang Bua (Flores, Indonesia). Prior to chemical analysis, an initial inspection of the artefacts revealed potential use-wear traces but no visible residues. Gas chromatography mass spectrometry (GC-MS) analysis, including the targeting of 86 lipids, terpenes, terpenoids, alkanes and their analogues, found compounds with plant or animal origin on 27 of the 69 stones. The artefacts were subsequently cleaned, and use-wear analysis identified traces of use on 43 artefacts. Use-wear analysis confirmed traces of use on 23 of the 27 artefacts with potential use-residues that were determined by GC-MS. The GC-MS results were broadly consistent with the functional classes identified in the later use-wear analysis. This inclusive approach for stone artefact analysis strengthens the identifications made through multiple lines of enquiry. There remain conflicts and uncertainties in specific cases, suggesting the need for further refinement and analyses of the relationships between use-wear and residues

Provider-initiated symptom screening for tuberculosis in Zimbabwe: diagnostic value and the effect of HIV status.

OBJECTIVE: To assess the diagnostic value of provider-initiated symptom screening for tuberculosis (TB) and how HIV status affects it. METHODS: We performed a secondary analysis of randomly selected participants in a community-based TB-HIV prevalence survey in Harare, Zimbabwe. All completed a five-symptom questionnaire and underwent sputum TB culture and HIV testing. We calculated the sensitivity, specificity, and positive and negative predictive values of various symptoms and used regression analysis to investigate the relationship between symptoms and TB disease. FINDINGS: We found one or more symptoms of TB in 21.2% of 1858 HIV-positive (HIV+) and 9.9% of 7121 HIV-negative (HIV-) participants (P or = 2 weeks' duration, any symptom and a positive sputum culture had sensitivities of 48%, 81% and 65%, respectively; in HIV- participants, the sensitivities were 45%, 71% and 74%, respectively. Symptoms had a similar sensitivity and specificity in HIV+ and HIV- participants, but in HIV+ participants they had a higher positive and a lower negative predictive value. CONCLUSION: Even smear-positive TB may be missed by provider-initiated symptom screening, especially in HIV+ individuals. Symptom screening is useful for ruling out TB, but better TB diagnostics are urgently needed for resource-poor settings

Immunization with the C-domain of α-toxin prevents lethal infection, localizes tissue injury, and promotes host response to challenge with Clostridium perfringens

© 2004 by the Infectious Diseases Society of America. All rights reserved.Clostridium perfringens gas gangrene is characterized by rapid tissue destruction, impaired host response, and, often, death. Phospholipase C (α-toxin) is the virulence factor most responsible for these pathologies. The present study investigated the efficacy of active immunization with the C-terminal domain of α-toxin (Cpa247–370) in a murine model of gas gangrene. Primary end points of the study were survival, progression of infection, and tissue perfusion. Secondary end points, which were based on findings of histologic evaluation of tissues, included the extent of tissue destruction and microvascular thrombosis, as well as the magnitude of the tissue inflammatory response. Survival among C-domain–immunized animals was significantly greater than that among sham-immunized control animals. Furthermore, immunization with the C-domain localized the infection and prevented ischemia of the feet. Histopathologic findings demonstrated limited muscle necrosis, reduced microvascular thrombosis, and enhanced granulocytic influx in C-domain–immunized mice. We conclude that immunization with the C-domain of phospholipase C is a viable strategy for the prevention of morbidity and mortality associated with C. perfringens gas gangrene

The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effect of dose and time since intervention exposure.

BACKGROUND: Despite recent decreases in HIV incidence in many sub-Saharan African countries, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term evaluation in 2007/8 found that the intervention improved knowledge, attitudes to sex and some reported risk behaviours, but not HIV or HSV2 prevalence. The aim of this paper was to assess the differential impact of the intervention according to gender, age, marital status, number of years of exposure and time since last exposure to the intervention. METHODS: In 2007, a cross-sectional survey was conducted in the 20 trial communities among 13,814 young people (15-30 yrs) who had attended intervention or comparison schools between 1999 and 2002. Outcomes for which the intervention had an impact in 2001 or 2007 were included in this subgroup analysis. Data were analysed using cluster-level methods for stratified cluster-randomised trials, using interaction tests to determine if intervention impact differed by subgroup. RESULTS: Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect-modifiers emerged. Impact on pregnancy knowledge and reported attitudes to sex increased with years of exposure to high-quality intervention. CONCLUSIONS: The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. This suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza. TRIAL REGISTRATION: ClinicalTrials.gov NCT00248469

Improving ART programme retention and viral suppression are key to maximising impact of treatment as prevention - a modelling study.

BACKGROUND: UNAIDS calls for fewer than 500,000 new HIV infections/year by 2020, with treatment-as-prevention being a key part of their strategy for achieving the target. A better understanding of the contribution to transmission of people at different stages of the care pathway can help focus intervention services at populations where they may have the greatest effect. We investigate this using Uganda as a case study. METHODS: An individual-based HIV/ART model was fitted using history matching. 100 model fits were generated to account for uncertainties in sexual behaviour, HIV epidemiology, and ART coverage up to 2015 in Uganda. A number of different ART scale-up intervention scenarios were simulated between 2016 and 2030. The incidence and proportion of transmission over time from people with primary infection, post-primary ART-naïve infection, and people currently or previously on ART was calculated. RESULTS: In all scenarios, the proportion of transmission by ART-naïve people decreases, from 70% (61%-79%) in 2015 to between 23% (15%-40%) and 47% (35%-61%) in 2030. The proportion of transmission by people on ART increases from 7.8% (3.5%-13%) to between 14% (7.0%-24%) and 38% (21%-55%). The proportion of transmission by ART dropouts increases from 22% (15%-33%) to between 31% (23%-43%) and 56% (43%-70%). CONCLUSIONS: People who are currently or previously on ART are likely to play an increasingly large role in transmission as ART coverage increases in Uganda. Improving retention on ART, and ensuring that people on ART remain virally suppressed, will be key in reducing HIV incidence in Uganda