190 research outputs found

    Quantifying Privacy: A Novel Entropy-Based Measure of Disclosure Risk

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    It is well recognised that data mining and statistical analysis pose a serious treat to privacy. This is true for financial, medical, criminal and marketing research. Numerous techniques have been proposed to protect privacy, including restriction and data modification. Recently proposed privacy models such as differential privacy and k-anonymity received a lot of attention and for the latter there are now several improvements of the original scheme, each removing some security shortcomings of the previous one. However, the challenge lies in evaluating and comparing privacy provided by various techniques. In this paper we propose a novel entropy based security measure that can be applied to any generalisation, restriction or data modification technique. We use our measure to empirically evaluate and compare a few popular methods, namely query restriction, sampling and noise addition.Comment: 20 pages, 4 figure

    26. Chromosomal damage and survival of keratinocytes and fibroblasts after irradiation with 200 kV or 25 kV X-rays

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    A relative biological effectiveness of 1 is accepted for soft X-rays (25–30 kV), which are applied in diagnostic radiology (mammography). However, it has been shown that soft X-rays can be more effective in cell killing and chromosomal damage. The present study was initiated to define biological effects of low-energy X-rays in vitro. Experiments were performed with 25 kV X-rays and 200 kV reference X-rays on neonatal human keratinocytes (HEKn), and NIH/3T3 mouse fibroblasts. Cell survival was studied with graded doses in a clonogenic assay, chromosomal damage in a micronucleus (MN) assay. The surviving fraction at 2 Gy for keratinocytes was 46±5% after 200 kV and 33±11% after 25 kV X-rays. Linear-quadratic cell survival analysis yielded α=0.305±0.033 Gy-1 and β=0.048±0.011 Gy-2 for 200 kV and α=0.399±0.103 Gy-1 and β=0.048±0.054 Gy-2 for 25 kV. For 3T3 fibroblasts an SF2 of 53±3% after 200 kV and 61±18% after 25 kV was observed. Values of α=0.24±0.02 Gy-1 and β=0.022±0.002 Gy-2 for 200 kV and α=0.10±0.05 Gy-1 and β=0.070±0.010 Gy-2 for 25 kV were derived. In conclusion, keratinocyte survival was similar for both radiation qualities. For fibroblasts, a reduction in survival at higher doses was observed. Results from MN studies will be presented

    Environmental study of some metals on several aquatic macrophytes

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    Aquatic macrophytes can be used in the study of quality of water ecosystems and in monitoring of metals and other pollutants. This study was focused on assessment of metals accumulation in certain aquatic macrophytes (biomonitors), in comparison with water and sediment (abiotic monitors) of the lake. Concentrations of Fe, Mn, Cu and Pb were measured in water, sediment and plant samples, namely in stems and leaves of Bidens tripartitus L., Polygonum amphibium L., Lycopus europaeus L. and in roots, stems and leaves of two aquatic plants, Typha angustifolia L. and Typha latifolia L. The concentrations of all investigated metals were higher in sediment than in water. The mean concentrations of metals in macrophytes were sequenced: Fe > Mn > Cu > Pb. This study exhibited different metals concentration in aquatic plants, depending on the plant organ. The highest concentrations of Fe and Pb were recorded in root of T.latifolia L. As means of Mn and Cu, their concentrations were higher in stems and leaves of different investigated species. The application of macrophytes can be possible in finding of solutions for problems of protection, sanation and revitalization of different aquatic ecosystems.Key words: Aquatic macrophytes, metals (Fe, Mn, Cu and Pb), lake contamination

    26. Chromosomal damage and survival of keratinocytes and fibroblasts after irradiation with 200 kV or 25 kV X-rays

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    A relative biological effectiveness of 1 is accepted for soft X-rays (25–30 kV), which are applied in diagnostic radiology (mammography). However, it has been shown that soft X-rays can be more effective in cell killing and chromosomal damage. The present study was initiated to define biological effects of low-energy X-rays in vitro. Experiments were performed with 25 kV X-rays and 200 kV reference X-rays on neonatal human keratinocytes (HEKn), and NIH/3T3 mouse fibroblasts. Cell survival was studied with graded doses in a clonogenic assay, chromosomal damage in a micronucleus (MN) assay. The surviving fraction at 2 Gy for keratinocytes was 46±5% after 200 kV and 33±11% after 25 kV X-rays. Linear-quadratic cell survival analysis yielded α=0.305±0.033 Gy-1 and β=0.048±0.011 Gy-2 for 200 kV and α=0.399±0.103 Gy-1 and β=0.048±0.054 Gy-2 for 25 kV. For 3T3 fibroblasts an SF2 of 53±3% after 200 kV and 61±18% after 25 kV was observed. Values of α=0.24±0.02 Gy-1 and β=0.022±0.002 Gy-2 for 200 kV and α=0.10±0.05 Gy-1 and β=0.070±0.010 Gy-2 for 25 kV were derived. In conclusion, keratinocyte survival was similar for both radiation qualities. For fibroblasts, a reduction in survival at higher doses was observed. Results from MN studies will be presented

    Uticaj mineralne ishrane na prinos ozime pšenice (Triticum aestivum L.)

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    Investigations were carried out during the 2006/2007 year on stationary field trial, the Center for Small Grains in Kragujevac. The objective of this study was to investigate the influence of mineral nutrition on the yield of winter wheat varieties (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). For these investigations were conducted two experiments (N1-80 kg ha-1 and N2-120 kg ha-1). Analysis of variance indicates very significant effects of cultivar on the grain yield, 1000-grain weight and test weight. Analysis of variance for the impact of nitrogen rates (N1 and N2) on investigated traits was found that doses of nitrogen in combination with NPK fertilizers significantly affected only on grain yield.Istraživanja su izvedena tokom 2006/2007. godine na stacionarnom poljskom ogledu, Centra za strna žita u Kragujevcu. Cilj ovog istraživanja je bio da se ispita uticaj mineralne ishrane na prinos ozime pšenice sorte (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). Za ova istraživanja su izvedena dva ogleda (N1-80 kg ha-1 i N2-120 kg ha-1). Analizaom varijanse je utvrđen vrlo visoko značajan uticaj sorte na prinos, masu 1000 zrna i hektolitarsku masu. Analizom varijanse za uticaj doze azota (N1 i N2) na ispitivane osobine utvrđeno je da su doze azota u kombinaciji sa NPK đubrivima značajno uticale samo na prinos zrna

    Sol-gel as a Method to Tailor the Magnetic Properties of Co1+yAl2-yO4

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    The magnetic properties of mesoscopic materials are modified by size and surface effects. We present a sol-gel method used to tailor these effects, and illustrate it on Co1+yAl2-yO4 spinel. Nanocomposites made of spinel oxide Co1+yAl2-yO4 particles dispersed in an amorphous SiO2 matrix were synthesized. Samples with various mass fractions -x of Co1+yAl2-yO4 in composite, ranging from predominantly SiO2 (x = 10 wt%) to predominantly spinel (x = 95 wt%), and with various Co concentrations in spinel y were studied. The spinel grain sizes were below 100 nm with a large size distribution, for samples with predominant spinel phase. Those samples showed Curie-Weiss paramagnetic behavior with antiferromagnetically interacting Co ions (theta approximate to -100 K). The grain sizes of spinel stays confined in 100 nm range even in the spinel samples diluted with as low as 5 wt% concentration of amorphous SiO2. For the samples with predominant SiO2 the crystalline nanoparticles are well separated and of size of around 100 nm, but with presence of much smaller spinel nanoparticles of about 10 nm. The magnetic properties of the samples with predominant silica phase showed complex behavior, spin-glass magnetic freezing at the lowest temperatures and lower absolute value of theta and consequently lower exchange constant

    Understanding of interaction (subgroup) analysis in clinical trials

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    Background: When the treatment effect on the outcome of interest is influenced by a baseline/demographic factor, investigators say that an interaction is present. In randomized clinical trials (RCTs), this type of analysis is typically referred to as subgroup analysis. Although interaction (or subgroup) analyses are usually stated as a secondary study objective, it is not uncommon that these results lead to changes in treatment protocols or even modify public health policies. Nonetheless, recent reviews have indicated that their proper assessment, interpretation and reporting remain challenging. Results: Therefore, this article provides an overview of these challenges, to help investigators find the best strategy for application of interaction analyses on binary outcomes in RCTs. Specifically, we discuss the key points of formal interaction testing, including the estimation of both additive and multiplicative interaction effects. We also provide recommendations that, if adhered to, could increase the clarity and the completeness of reports of RCTs. Conclusion: Altogether, this article provides a brief non-statistical guide for clinical investigators on how to perform, interpret and report interaction (subgroup) analyses in RCTs

    Developing textile entrepreneurial inclination model by integrating experts mining and ISM-MICMAC

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    The Indian textile industry is lacking in an entrepreneurial inclination of a skilled young generation; because of this, the industry is facing a challenge to achieve sustainable development and growth. To overcome this problem, the goal of this work is to build an entrepreneurial inclination model in the context of the textile industry. For achieving this goal, a combined approach of an extensive literature review and experts mining has been used to establish the entrepreneurial inclination factors in phased of the study. In the second phase, an Interpretive Structural Modelling (ISM) with Matrice d'Impacts Croisés Multiplication Appliqués à un Classement (MICMAC) has been applied to build a structural model and to find the driving force factors and dependence power. The results show that effective entrepreneurship courses, institutional policy, training and internship, institutional corporation and the involvement of institutional heads play a very significant role in encouraging youth towards entrepreneurship. The outcomes of the study can help both the government and academic institutes to draw up effective policy and develop an entrepreneurial culture which can help to create more entrepreneurs in the textile field.N

    A qualitative meta-synthesis of interpersonal violence prevention programs focused on males

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    Exceptionally high levels of interpersonal violence have triggered a call by many experts for the need to determine effective ways to address the onset and effects of exposure to interpersonal violence. The specific aim of this study was to identify and draw on existing promising practices to make a more informed decision on strategies to develop a contextually relevant intervention that focused on the promotion of positive forms of masculinity to create safety and peace. This study used a qualitative meta-synthesis (QMS) technique to integrate and interpret findings from various intervention studies that focused on males and/or gender. An in-depth literature search yielded a total of 827 papers that met the search criteria. After removal of duplicates, abstract review, and review of the full texts, the subsequent sample for this meta-synthesis included 12 intervention programs and 23 studies. This QMS revealed the value of a comprehensive approach, using multiple strategies, employing participatory and interactive methods, and promoting social mobilization to address interpersonal violence. The promotion of positive forms of masculinity as an interpersonal violence prevention strategy is a much-needed, relatively untapped approach to generating safety and peace for both males and females

    Mortality After Pediatric Arterial Ischemic Stroke

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    OBJECTIVES: Cerebrovascular disease is among the top 10 causes of death in US children, but risk factors for mortality are poorly understood. Within an international registry, we identify predictors of in-hospital mortality after pediatric arterial ischemic stroke (AIS). METHODS: Neonates (0-28 days) and children (29 days- < 19 years) with AIS were enrolled from January 2003 to July 2014 in a multinational stroke registry. Death during hospitalization and cause of death were ascertained from medical records. Logistic regression was used to analyze associations between risk factors and in-hospital mortality. RESULTS: Fourteen of 915 neonates (1.5%) and 70 of 2273 children (3.1%) died during hospitalization. Of 48 cases with reported causes of death, 31 (64.6%) were strokerelated, with remaining deaths attributed to medical disease. In multivariable analysis, congenital heart disease (odds ratio [OR]: 3.88; 95% confidence interval [CI] : 1.23-12.29; P = .021), posterior plus anterior circulation stroke (OR: 5.36; 95% CI: 1.70-16.85; P = .004), and stroke presentation without seizures (OR: 3.95; 95% CI: 1.26-12.37; P = .019) were associated with in-hospital mortality for neonates. Hispanic ethnicity (OR: 3.12; 95% CI: 1.56-6.24; P = .001), congenital heart disease (OR: 3.14; 95% CI: 1.75-5.61; P < .001), and posterior plus anterior circulation stroke (OR: 2.71; 95% CI: 1.40-5.25; P = .003) were associated with in-hospital mortality for children. CONCLUSIONS: In-hospital mortality occurred in 2.6% of pediatric AIS cases. Most deaths were attributable to stroke. Risk factors for in-hospital mortality included congenital heart disease and posterior plus anterior circulation stroke. Presentation without seizures and Hispanic ethnicity were also associated with mortality for neonates and children, respectively. Awareness and study of risk factors for mortality represent opportunities to increase survival
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