30 research outputs found
Investigation of Natural Effective Gamma Dose Rates case study: Ardabil Province in Iran
Gamma rays pose enough energy to form charged particles and adversely affect human health. Since, the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardabil province from 2009 to 2010. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed dose for Ardabil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSvh-1, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardabil province was estimated to be 1.73 (1.35-2.39) mSv, which is on average 2 times higher than the world population weighted average
A framework for increasing the value of predictive data-driven models by enriching problem domain characterization with novel features
The need to leverage knowledge through data mining has driven enterprises in a demand for more data. However, there is a gap between the availability of data and the application of extracted knowledge for improving decision support. In fact, more data do not necessarily imply better predictive data-driven marketing models, since it is often the case that the problem domain requires a deeper characterization. Aiming at such characterization, we propose a framework drawn on three feature selection strategies, where the goal is to unveil novel features that can effectively increase the value of data by providing a richer characterization of the problem domain. Such strategies involve encompassing context (e.g., social and economic variables), evaluating past history, and disaggregate the main problem into smaller but interesting subproblems. The framework is evaluated through an empirical analysis for a real bank telemarketing application, with the results proving the benefits of such approach, as the area under the receiver operating characteristic curve increased with each stage, improving previous model in terms of predictive performance.The work of P. Cortez was supported by FCT within the Project Scope
UID/CEC/00319/2013. The authors would like to thank the anonymous reviewers
for their helpful comments.info:eu-repo/semantics/publishedVersio
Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?
peer reviewedBackground
Aboveground, plants release volatile organic compounds (VOCs) that act as chemical
signals between neighbouring plants. It is now well documented that VOCs emitted by
the roots in the plant rhizosphere also play important ecological roles in the soil
ecosystem, notably in plant defence because they are involved in interactions between
plants, phytophagous pests and organisms of the third trophic level. The roles played
by root-emitted VOCs in between- and within-plant signalling, however, are still poorly
documented in the scientific literature.
Scope
Given that (1) plants release volatile cues mediating plant-plant interactions
aboveground, (2) roots can detect the chemical signals originating from their
neighbours, and (3) roots release VOCs involved in biotic interactions belowground,
the aim of this paper is to discuss the roles of VOCs in between- and within-plant
signalling belowground. We also highlight the technical challenges associated with the
analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated
root-root interactions.
Conclusions
We conclude that root-root interactions mediated by volatile cues deserve more
research attention and that both the analytical tools and methods developed to study
the ecological roles played by VOCs in interplant signalling aboveground can be
adapted to focus on the roles played by root-emitted VOCs in between- and within-plant
signalling
Comparison of diagnostic accuracy of serologic test with histology for Helicobacter pylori in diabetic patients with dyspepsia
Background: Helicobacter pylori infection is a major cause of gastric diseases in humans that its rapid, simple and low cost diagnosis is important. Diabetes mellitus increases the risk of Helicobacter pylori infection.
Objective: The aim of this study was to compare diagnostic accuracy of serologic test with histology for Helicobacter Pylori in diabetic patients with dyspepsia.
Methods: This analytical study was conducted on 183 diabetic patients with dyspepsia referred to Imam Hossain hospital of Shahroud in 2014. All patients underwent endoscopy. Standard biopsy was performed as gold standard which included six gastric and duodenal samples. Simultaneously, blood samples were taken for serologic test. The presence of Helicobacter pylori was examined using Giemsa staining in histological study. Anti-Helicobacter pylori IgG was measured using ELISA in serological study. Sensitivity, specificity, and positive and negative predictive values were calculated. Data were analyzed using Chi-square test.
Findings: Of 183, 104 patients (57.1%) were positive for Helicobacter pylori in serological study and 151 patients (82.5%) were positive in histological study. The sensitivity, specificity, positive predictive value and negative predictive value of serologic test for diagnosis of Helicobacter pylori were 64.2%, 78.1%, 93.3%, and 31.6%, respectively. IgG cut point for diagnosis of Helicobacter pylori was set to be 1.4 (sensitivity: 92.4% and specificity: 75.3%).
Conclusion: The serologic test can be used as screening test for Helicobacter pylori in diabetic patients with regards to relatively high sensitivity and specificity as well as its simplicity, rapidity, and low price