Search results for: highest posterior density (HPD) interval
Commenced in January 2007
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Edition: International
Paper Count: 8213

Search results for: highest posterior density (HPD) interval

2663 Optimization of the Drinking Water Treatment Process

Authors: M. Farhaoui, M. Derraz

Abstract:

Problem statement: In the water treatment processes, the coagulation and flocculation processes produce sludge according to the level of the water turbidity. The aluminum sulfate is the most common coagulant used in water treatment plants of Morocco as well as many countries. It is difficult to manage the sludge produced by the treatment plant. However, it can be used in the process to improve the quality of the treated water and reduce the aluminum sulfate dose. Approach: In this study, the effectiveness of sludge was evaluated at different turbidity levels (low, medium, and high turbidity) and coagulant dosage to find optimal operational conditions. The influence of settling time was also studied. A set of jar test experiments was conducted to find the sludge and aluminum sulfate dosages in order to improve the produced water quality for different turbidity levels. Results: Results demonstrated that using sludge produced by the treatment plant can improve the quality of the produced water and reduce the aluminum sulfate using. The aluminum sulfate dosage can be reduced from 40 to 50% according to the turbidity level (10, 20 and 40 NTU). Conclusions/Recommendations: Results show that sludge can be used in order to reduce the aluminum sulfate dosage and improve the quality of treated water. The highest turbidity removal efficiency is observed within 6 mg/l of aluminum sulfate and 35 mg/l of sludge in low turbidity, 20 mg/l of aluminum sulfate and 50 mg/l of sludge in medium turbidity and 20 mg/l of aluminum sulfate and 60 mg/l of sludge in high turbidity. The turbidity removal efficiency is 97.56%, 98.96% and 99.47% respectively for low, medium and high turbidity levels.

Keywords: coagulation process, coagulant dose, sludge, turbidity removal

Procedia PDF Downloads 328
2662 Kinetic and Removable of Amoxicillin Using Aliquat336 as a Carrier via a HFSLM

Authors: Teerapon Pirom, Ura Pancharoen

Abstract:

Amoxicillin is an antibiotic which is widely used to treat various infections in both human beings and animals. However, when amoxicillin is released into the environment, it is a major problem. Amoxicillin causes bacterial resistance to these drugs and failure of treatment with antibiotics. Liquid membrane is of great interest as a promising method for the separation and recovery of the target ions from aqueous solutions due to the use of carriers for the transport mechanism, resulting in highly selectivity and rapid transportation of the desired metal ions. The simultaneous processes of extraction and stripping in a single unit operation of liquid membrane system are very interesting. Therefore, it is practical to apply liquid membrane, particularly the HFSLM for industrial applications as HFSLM is proved to be a separation process with lower capital and operating costs, low energy and extractant with long life time, high selectivity and high fluxes compared with solid membranes. It is a simple design amenable to scaling up for industrial applications. The extraction and recovery for (Amoxicillin) through the hollow fiber supported liquid membrane (HFSLM) using aliquat336 as a carrier were explored with the experimental data. The important variables affecting on transport of amoxicillin viz. extractant concentration and operating time were investigated. The highest AMOX- extraction percentages of 85.35 and Amoxicillin stripping of 80.04 were achieved with the best condition at 6 mmol/L [aliquat336] and operating time 100 min. The extraction reaction order (n) and the extraction reaction rate constant (kf) were found to be 1.00 and 0.0344 min-1, respectively.

Keywords: aliquat336, amoxicillin, HFSLM, kinetic

Procedia PDF Downloads 272
2661 Fermented Unripe Plantain (Musa paradisiacal) Peel Meal as a Replacement for Maize in the Diet of Nile Tilapia (Oreochromis niloticus) Fingerlings

Authors: N. A. Bamidele, S. O. Obasa, I. O. Taiwo, I. Abdulraheem, O. C. Odebiyi, A. A. Adeoye, O. E. Babalola, O. V. Uzamere

Abstract:

A feeding trial was conducted to investigate the effect of fermented unripe plantain peel meal (FUP) on growth performance, nutrients digestibility and economic indices of production of Nile tilapia, Oreochromis niloticus fingerlings. Fingerlings (150) of Nile tilapia (1.70±0.1g) were stocked at 10 per plastic tank. Five iso-nitrogenous diets containing 40% crude protein in which maize meal was replaced by fermented unripe plantain peel meal at 0% (FUP0), 25% (FUP25), 50% (FUP50), 75% (FUP75) and 100% (FUP100) were formulated and prepared. The fingerlings were fed at 5% body weight per day for 56 days. There was no significant difference (p > 0.05) in all the growth parameters among the treatments. Feed conversion ratio of 1.35 in fish fed diet FUP25 was not significantly different (P > 0.05) from 1.42 of fish fed diet FUP0. Apparent protein digestibility of 86.94% in fish fed diet FUP100 was significantly higher (p < 0.05) than 70.37% in fish fed diet FUP0 while apparent carbohydrate of 88.34% in fish fed diet FUP0 was significantly different (p < 0.05) from 70.29% of FUP100. Red blood cell (4.30 ml/mm3) of fish fed diet FUP100 was not significantly different from 4.13 ml/mm3 of fish fed diet FUP50. The highest percentage profit of 88.85% in fish fed diet FUP100 was significantly higher than 66.68% in fish fed diet FUP0 while the profit index of 1.89 in fish fed diet FUP100 was significantly different from 1.67 in fish fed diet FUP0. Therefore, fermented unripe plantain peel meal can completely replace maize in the diet of O. niloticus fingerlings.

Keywords: fermentation, fish diets, plantain peel, tilapia

Procedia PDF Downloads 530
2660 Food Insecurity and Quality of Life among the Poor Elderly in South Korea

Authors: Jayoung Cho

Abstract:

Poverty has become a social problem in South Korea, given that seven out of ten elderly experience multidimensional poverty. As quality of life is a major social welfare measure of a society, verifying the major factors affecting the quality of life among the elderly in poverty can be used as baseline data for the promotion of welfare. This study aims to investigate the longitudinal relationships between food insecurity and quality of life among the elderly in poverty. In this study, panel regression analysis using 5-year longitudinal panel data were derived from Korea Welfare Panel Study (KWPS, 2011-2015) were used to identify the research question. A total of 1,327 elderly people aged 65 or older with less than 60% of median income was analyzed. The main results of the study are as follows; first, the level of quality of life of the poor elderly was on average of 5, and repeated the increase and decrease over time. Second, food insecurity and quality of life of the elderly in poverty had a longitudinal causal relationship. Furthermore, the statistical significance of food insecurity was the highest despite controlling for major variables affecting the quality of life among the poor elderly. Therefore, political and practical approaches are strongly suggested and considered regarding the food insecurity for the quality of life among the elderly in poverty. In practical intervention, it is necessary to pay attention to food insecurity when assessing the poor elderly. Also, there is a need to build a new delivery system that incorporates segmented health and nutrition-related services. This study has an academic significance in that it brought out the issue of food insecurity of the poor elderly and confirmed the longitudinal relationship between food insecurity and quality of life.

Keywords: food insecurity, longitudinal panel analysis, poor elderly, quality of life

Procedia PDF Downloads 233
2659 Soil Penetration Resistance and Water Content Spatial Distribution Following Different Tillage and Crop Rotation in a Chinese Mollisol

Authors: Xuewen Chen, Aizhen Liang, Xiaoping Zhang

Abstract:

To better understand the spatial variability of soil penetration resistance (SPR) and soil water content (SWC) induced by different tillage and crop rotation in a Mollisol of Northeast China, the soil was sampled from the tillage experiment which was established in Dehui County, Jilin Province, Northeast China, in 2001. Effect of no-tillage (NT), moldboard plow (MP) and ridge tillage (RT) under corn-soybean rotation (C-S) and continuous corn (C-C) system on SPR and SWC were compared with horizontal and vertical variations. The results showed that SPR and SWC spatially varied across the ridge. SPR in the rows was higher than inter-rows, especially in topsoil (2.5-15 cm) of NT and RT plots. SPR of MP changed in the trend with the curve-shaped ridge. In contrast to MP, NT, and RT resulted in average increment of 166.3% and 152.3% at a depth of 2.5-17.5 cm in the row positions, respectively. The mean SPR in topsoil in the rows means soil compaction is not the main factor limiting plant growth and crop yield. SPR in the row of RT soil was lower than NT at a depth of 2.5-12.5 cm. The SWC in NT and RT soil was highest in the inter-rows and least in the rows or shoulders, respectively. However, the lateral variation trend of MP was opposite to NT. From the profile view of SWC, MP was greater than NT and RT in 0-20 cm of the rows. SWC in RT soil was higher than NT in the row of 0-20 cm. Crop rotation did not have a marked impact on SPR and SWC. In addition to the tillage practices, the factor which affects SPR greatly was depth but not position. These two factors have significant effects on SWC. These results indicated that the adoption of RT was a more suitable conservation tillage practices than NT in the black soil of Northeast China.

Keywords: row, soil penetration resistance, spatial variability, tillage practice

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2658 Controlling Cocoa Pod Borer, Conopomorpha cramerella (Snell.) and Cost Analysis Production at Cacao Plantation

Authors: Alam Anshary, Flora Pasaru, Shahabuddin

Abstract:

The Cocoa Pod Borer (CPB), Conopomorpha cramerella (Snell.) is present on most of the larger cocoa producing islands in Indonesia. Various control measures CPB has been carried out by the farmers, but the results have not been effective. This study aims to determine the effect of application of Beauveria bassiana treatments and pruning technique to the control of CPB in the cocoa plantation people. Research using completely randomized design with 4 treatments and 3 replications, treatment consists of B.bassiana, Pruning, B. bassiana+pruning (Bb + Pr), as well as the control. The results showed that the percentage of PBK attack on cocoa pods in treatment (Bb + Pr) 3.50% the lowest compared to other treatments. CPB attack percentage in treatment B.bassiana 6.15%; pruning 8.75%, and 15.20% control. Results of the analysis of production estimates, the known treatments (Bb + Pr) have the highest production (1.95 tonnes / ha). The model results estimated production is Y= 0,20999 + 0,53968X1 + 0,34298X2+ 0,31410X3 + 0,35629X4 + 0,08345X5 + 0,29732X6. Farm production costs consist of fixed costs and variable costs, fixed costs are costs incurred by the farmer that the size does not affect the results, such as taxes and depreciation of production equipment. Variable costs are costs incurred by farmers who used up in one year cocoa farming activities. The cost of production in farming cocoa without integrated techniques control of CPB is Rp. 9.205.550 million/ha, while the cost of production with integrated techniques control is Rp. 6.666.050 million/ha.

Keywords: cacao, cocoa pod borer, pruning, Beauveria bassiana, production costs

Procedia PDF Downloads 278
2657 Creating Risk Maps on the Spatiotemporal Occurrence of Agricultural Insecticides in Sub-Saharan Africa

Authors: Chantal Hendriks, Harry Gibson, Anna Trett, Penny Hancock, Catherine Moyes

Abstract:

The use of modern inputs for crop protection, such as insecticides, is strongly underestimated in Sub-Saharan Africa. Several studies measured toxic concentrations of insecticides in fruits, vegetables and fish that were cultivated in Sub-Saharan Africa. The use of agricultural insecticides has impact on human and environmental health, but it also has the potential to impact on insecticide resistance in malaria transmitting mosquitos. To analyse associations between historic use of agricultural insecticides and the distribution of insecticide resistance through space and time, the use and environmental fate of agricultural insecticides needs to be mapped through the same time period. However, data on the use and environmental fate of agricultural insecticides in Africa are limited and therefore risk maps on the spatiotemporal occurrence of agricultural insecticides are created using environmental data. Environmental data on crop density and crop type were used to select the areas that most likely receive insecticides. These areas were verified by a literature review and expert knowledge. Pesticide fate models were compared to select most dominant processes that are involved in the environmental fate of insecticides and that can be mapped at a continental scale. The selected processes include: surface runoff, erosion, infiltration, volatilization and the storing and filtering capacity of soils. The processes indicate the risk for insecticide accumulation in soil, water, sediment and air. A compilation of all available data for traces of insecticides in the environment was used to validate the maps. The risk maps can result in space and time specific measures that reduce the risk of insecticide exposure to non-target organisms.

Keywords: crop protection, pesticide fate, tropics, insecticide resistance

Procedia PDF Downloads 138
2656 Identification and Understanding of Colloidal Destabilization Mechanisms in Geothermal Processes

Authors: Ines Raies, Eric Kohler, Marc Fleury, Béatrice Ledésert

Abstract:

In this work, the impact of clay minerals on the formation damage of sandstone reservoirs is studied to provide a better understanding of the problem of deep geothermal reservoir permeability reduction due to fine particle dispersion and migration. In some situations, despite the presence of filters in the geothermal loop at the surface, particles smaller than the filter size (<1 µm) may surprisingly generate significant permeability reduction affecting in the long term the overall performance of the geothermal system. Our study is carried out on cores from a Triassic reservoir in the Paris Basin (Feigneux, 60 km Northeast of Paris). Our goal is to first identify the clays responsible for clogging, a mineralogical characterization of these natural samples was carried out by coupling X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The results show that the studied stratigraphic interval contains mostly illite and chlorite particles. Moreover, the spatial arrangement of the clays in the rocks as well as the morphology and size of the particles, suggest that illite is more easily mobilized than chlorite by the flow in the pore network. Thus, based on these results, illite particles were prepared and used in core flooding in order to better understand the factors leading to the aggregation and deposition of this type of clay particles in geothermal reservoirs under various physicochemical and hydrodynamic conditions. First, the stability of illite suspensions under geothermal conditions has been investigated using different characterization techniques, including Dynamic Light Scattering (DLS) and Scanning Transmission Electron Microscopy (STEM). Various parameters such as the hydrodynamic radius (around 100 nm), the morphology and surface area of aggregates were measured. Then, core-flooding experiments were carried out using sand columns to mimic the permeability decline due to the injection of illite-containing fluids in sandstone reservoirs. In particular, the effects of ionic strength, temperature, particle concentration and flow rate of the injected fluid were investigated. When the ionic strength increases, a permeability decline of more than a factor of 2 could be observed for pore velocities representative of in-situ conditions. Further details of the retention of particles in the columns were obtained from Magnetic Resonance Imaging and X-ray Tomography techniques, showing that the particle deposition is nonuniform along the column. It is clearly shown that very fine particles as small as 100 nm can generate significant permeability reduction under specific conditions in high permeability porous media representative of the Triassic reservoirs of the Paris basin. These retention mechanisms are explained in the general framework of the DLVO theory

Keywords: geothermal energy, reinjection, clays, colloids, retention, porosity, permeability decline, clogging, characterization, XRD, SEM-EDS, STEM, DLS, NMR, core flooding experiments

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2655 Metallurgy of Friction Welding of Porous Stainless Steel-Solid Iron Billets

Authors: S. D. El Wakil

Abstract:

The research work reported here was aimed at investigating the feasibility of joining high-porosity stainless steel discs and wrought iron bars by friction welding. The sound friction-welded joints were then subjected to a metallurgical investigation and an analysis of failure resulting from tensile loading. Discs having 50 mm diameter and 10 mm thickness were produced by loose sintering of stainless steel powder at a temperature of 1350 oC in an argon atmosphere for one hour. Minor machining was then carried out to control the dimensions of the discs, and the density of each disc could then be determined. The level of porosity was calculated and was found to be about 40% in all of those discs. Solid wrought iron bars were also machined to facilitate tensile testing of the joints produced by friction welding. Using our previously gained experience, the porous stainless steel disc and the wrought iron tube were successfully friction welded. SEM was employed to examine the fracture surface after a tensile test of the joint in order to determine the type of failure. It revealed that the failure did not occur in the joint, but rather in the in the porous metal in the area adjacent to the joint. The load carrying capacity was actually determined by the strength of the porous metal and not by that of the welded joint. Macroscopic and microscopic metallographic examinations were also performed and showed that the welded joint involved a dense heat-affected zone where the porous metal underwent densification at elevated temperature, explaining and supporting the findings of the SEM study.

Keywords: fracture of friction-welded joints, metallurgy of friction welding, solid-porous structures, strength of joints

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2654 Drinking Water Quality of Lahore Pakistan: A Comparison of Quality of Drinking Water from Source and Distribution System

Authors: Zainab Abbas Soharwardi, Chunli Su, Fazeelat Tahira, Syed Zahid Aziz

Abstract:

The study monitors the quality of drinking water consumed by urban population of Lahore. A total of 50 drinking water samples (16 from source and 34 from distribution system) were examined for physical, chemical and bacteriological parameters. The parameters including pH, turbidity, electrical conductivity, total dissolved solids, total hardness, calcium, magnesium, total alkalinity, carbonate, sulphate, chloride, nitrite, fluoride, sodium and potassium were analyzed. Sixteen out of fifty samples showed high values of alkalinity compared to EPA standards and WHO guidelines. Twenty-eight samples were analyzed for heavy metals, chromium, iron, copper, zinc, cadmium and lead. Trace amounts of heavy metals were detected in some samples, however for most of the samples values were within the permissible limits although high concentration of zinc was detected in one sample collected from Mughal Pura area. Fifteen samples were analyzed for arsenic. The results were unsatisfactory; around 73% samples showed exceeding values of As. WHO has suggested permissible limits of arsenic < 0.01 ppm, whereas 27 % of samples have shown 0.05 ppm arsenic, which is five times greater than WHO highest permissible limits. All the samples were examined for E. coli bacteria. On the basis of bacteriological analysis, 42 % samples did not meet WHO guidelines and were unsafe for drinking.

Keywords: arsenic, heavy metals, ground water, Lahore

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2653 Effect of Size, Geometry and Tensile Strength of Fibers on the Flexure of Hooked Steel Fiber Reinforced Concrete

Authors: Chuchai Sujivorakul

Abstract:

This research focused on the study of various parameters of fiber itself affecting on the flexure of hooked steel fiber reinforced concrete (HSFRC). The size of HSFRC beams was 150x150 mm in cross section and 550 mm in length, and the flexural test was carried out in accordance with EN-14651 standard. The test result was the relationship between centre-point load and crack-mount opening displacement (CMOD) at the centre notch. Controlled concrete had a compressive strength of 42 MPa. The investigated variables related to the hooked fiber itself were: (a) 3 levels of aspect ratio of fibers (65, 80 and 100); (b) 2 different fiber lengths (35 mm and 60 mm); (c) 2 different tensile strength of fibers (1100 MPa and 1500 MPa); and (d) 3 different fiber-end geometries (3D 4D and 5D fibers). The 3D hooked fibers have two plastic hinges at both ends, while the 4D and 5D hooked fibers are the newly developed steel fibers by Bekaert, and they have three and four plastic hinges at both ends, respectively. The hooked steel fibers were used in concrete with three different fiber contents, i.e., 20 30 and 40 kg/m³. From the study, it was found that all variables did not seem to affect the flexural strength at limit of proportionality (LOP) of HSFRC. However, they affected the residual flexural tensile strength (fR,j). It was observed that an increase in fiber lengths and the tensile strength the fibers would significantly increase in the fR,j of HSFRC, while the aspect ratio of the fiber would slightly effect the fR,j of HSFRC. Moreover, it was found that using 5D fibers would better enhance the fR,j and flexural behavior of HSFRC than 3D and 4D fibers, because they gave highest mechanical anchorage effect created by their hooked-end geometry.

Keywords: hooked steel fibers, fiber reinforced concrete, EN-14651, flexural test

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2652 Analyzing the Impact of Migration on HIV and AIDS Incidence Cases in Malaysia

Authors: Ofosuhene O. Apenteng, Noor Azina Ismail

Abstract:

The human immunodeficiency virus (HIV) that causes acquired immune deficiency syndrome (AIDS) remains a global cause of morbidity and mortality. It has caused panic since its emergence. Relationships between migration and HIV/AIDS have become complex. In the absence of prospectively designed studies, dynamic mathematical models that take into account the migration movement which will give very useful information. We have explored the utility of mathematical models in understanding transmission dynamics of HIV and AIDS and in assessing the magnitude of how migration has impact on the disease. The model was calibrated to HIV and AIDS incidence data from Malaysia Ministry of Health from the period of 1986 to 2011 using Bayesian analysis with combination of Markov chain Monte Carlo method (MCMC) approach to estimate the model parameters. From the estimated parameters, the estimated basic reproduction number was 22.5812. The rate at which the susceptible individual moved to HIV compartment has the highest sensitivity value which is more significant as compared to the remaining parameters. Thus, the disease becomes unstable. This is a big concern and not good indicator from the public health point of view since the aim is to stabilize the epidemic at the disease-free equilibrium. However, these results suggest that the government as a policy maker should make further efforts to curb illegal activities performed by migrants. It is shown that our models reflect considerably the dynamic behavior of the HIV/AIDS epidemic in Malaysia and eventually could be used strategically for other countries.

Keywords: epidemic model, reproduction number, HIV, MCMC, parameter estimation

Procedia PDF Downloads 362
2651 Eco-Environmental Vulnerability Evaluation in Mountain Regions Using Remote Sensing and Geographical Information System: A Case Study of Pasol Gad Watershed of Garhwal Himalaya, India

Authors: Suresh Kumar Bandooni, Mirana Laishram

Abstract:

The Mid Himalaya of Garhwal Himalaya in Uttarakhand (India) has a complex Physiographic features withdiversified climatic conditions and therefore it is suspect to environmental vulnerability. Thenatural disasters and also anthropogenic activities accelerate the rate of environmental vulnerability. To analyse the environmental vulnerability, we have used geoinformatics technologies and numerical models and it is adoptedby using Spatial Principal Component Analysis (SPCA). The model consist of many factors such as slope, landuse/landcover, soil, forest fire risk, landslide susceptibility zone, human population density and vegetation index. From this model, the environmental vulnerability integrated index (EVSI) is calculated for Pasol Gad Watershed of Garhwal Himalaya for the years 1987, 2000, and 2013 and the Vulnerability is classified into five levelsi.e. Very low, low, medium, high and very highby means of cluster principle. The resultsforeco-environmental vulnerability distribution in study area shows that medium, high and very high levels are dominating in the area and it is mainly caused by the anthropogenic activities and natural disasters. Therefore, proper management forconservation of resources is utmost necessity of present century. It is strongly believed that participation at community level along with social worker, institutions and Non-governmental organization (NGOs) have become a must to conserve and protect the environment.

Keywords: eco-environment vulnerability, spatial principal component analysis, remote sensing, geographic information system, institutions, Himalaya

Procedia PDF Downloads 254
2650 Comparison of the Cyclic Fatigue Resistance of Endoart Gold, Endoart Blue, Protaper Universal, and Protaper Gold Files at Body Temperature

Authors: Ayhan Eymirli, Sila N. Usta

Abstract:

The aim of this study is the comparison of the cyclic fatigue resistance of EndoArt Gold (EAG, Inci Dental, Istanbul, Turkey), EndoArt Blue (EAB, Inci Dental, Istanbul, Turkey), ProTaper Universal (PTU, Dentsply Tulsa Dental Specialties), and ProTaper Gold (PTG, Dentsply Tulsa Dental Specialties) files at body temperature. Twelve instruments of each EAG, EAB, PTU, PTG file system were included in this study. All selected files were rotated in the artificial canals, which have a 60° angle and a 5-mm radius of curvature until fracture occurred. The time to fracture (Ttf) was measured in seconds by a chronometer in the control panel that presents in the cyclic fatigue testing device when a fracture was detected visually and/or audibly. The lengths of the fractured fragments (FL) were also measured with a digital microcaliper. The data of Ttf and FL were analyzed using Kruskal-Wallis, one-way ANOVA and post hoc Bonferroni tests at the 5% significance level. There was a statistically significant difference among the file systems (p < 0.05). EAB had the statistically highest fatigue resistance, and PTU had the statistically lowest fatigue resistance (p < 0.05). PTG system had a statistically higher FL means than EAB and PTU file systems (p < 0.05). EAB had the greatest cyclic fatigue resistance amongst the other file systems. It can be stated that heat treatments may be a factor that increases fatigue resistance.

Keywords: cyclic fatigue resistance, Endo art blue, Endo art gold, pro taper gold, pro taper universal

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2649 Distribution of Phospholipids, Cholesterol and Carotenoids in Two-Solvent System during Egg Yolk Oil Solvent Extraction

Authors: Aleksandrs Kovalcuks, Mara Duma

Abstract:

Egg yolk oil is a concentrated source of egg bioactive compounds, such as fat-soluble vitamins, phospholipids, cholesterol, carotenoids and others. To extract lipids and other fat-soluble nutrients from liquid egg yolk, a two-step extraction process involving polar (ethanol) and non-polar (hexane) solvents were used. This extraction technique was based on egg yolk bioactive compounds polarities, where non-polar compound was extracted into non-polar hexane, but polar in to polar alcohol/water phase. But many egg yolk bioactive compounds are not strongly polar or non-polar. Egg yolk phospholipids, cholesterol and pigments are amphipatic (have both polar and non-polar regions) and their behavior in ethanol/hexane solvent system is not clear. The aim of this study was to clarify the behavior of phospholipids, cholesterol and carotenoids during extraction of egg yolk oil with ethanol and hexane and determine the loss of these compounds in egg yolk oil. Egg yolks and egg yolk oil were analyzed for phospholipids (phosphatidylcholine (PC) and phosphatidylethanolamine (PE)), cholesterol and carotenoids (lutein, zeaxanthin, canthaxanthin and β-carotene) content using GC-FID and HPLC methods. PC and PE are polar lipids and were extracted into polar ethanol phase. Concentration of PC in ethanol was 97.89% and PE 99.81% from total egg yolk phospholipids. Due to cholesterol’s partial extraction into ethanol, cholesterol content in egg yolk oil was reduced in comparison to its total content presented in egg yolk lipids. The highest amount of lutein and zeaxanthin was concentrated in ethanol extract. The opposite situation was observed with canthaxanthin and β-carotene, which became the main pigments of egg yolk oil.

Keywords: cholesterol, egg yolk oil, lutein, phospholipids, solvent extraction

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2648 Assessment of Hemostatic Activity of the Aqueous Extract of Leaves of Marrubium vulgare L.: A Mediterranean Lamiaceae Algeria

Authors: Nabil Ghedadba, Abdessemed Samira, Leila Hambaba, Sidi Mohamed Ould Mokhtar, Nassima Fercha, Houas Bousselsela

Abstract:

The overall objective of this study was to evaluate in vitro the hemostatic activity of secondary metabolites (polyphenols, flavonoids, and tannins) of Marrubium vulgare leaves, aromatic plant widely used in traditional medicine for the treatment of asthma, cough, diabetes (by its effect on the pancreas to secrete insulin), heart disease, fever has a high efficiency as against inflammation. Qualitative analysis of the aqueous extract (AQE) by thin layer chromatography revealed the presence of quercetin, kaempferol and rutin. Quantification of total phenols by Folin Ciocalteu method and flavonoids by AlCl3 method gave high values with AQE: 175±0.80 mg GAE per 100g of the dry matter, 23.86±0.36 mg QE per 100g of dry matter. Moreover, the assay of condensed tannins by the vanillin method showed that AQE contains the highest value: 16.55±0.03 mg e-catechin per 100 g of dry matter. Assessment of hemostatic activity by the plasma recalcification method (time of Howell) has allowed us to discover the surprising dose dependent anticoagulant effect of AQE lyophilized from leaves of M. vulgare. A positive linear correlation between the two parameters studied: the content of condensed tannins and hemostatic activity (r=0.96) were used to highlight a possible role of these compounds that are potent vasoconstrictor activity in hemostatic. From these results we can see that Marrubium vulgre could be used for the treatment of health.

Keywords: Marrubium vulgare L., aqueous extract, phenolic compounds dosing, hemostatic activity, condensed tannins

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2647 Effect of Phosphorus and Potassium Nutrition on Growth, Yield and Minerals Accumulation of Two Soybean Cultivars Differing in Phytate Contents

Authors: Taliman Nisar Ahmad, Hirofume Saneoka

Abstract:

A pot experiment was conducted to investigate the effect of phosphorus (P) and potassium (K) nutrition on grain yield, phytic acid and grain quality of high-phytate (Akimaro) and low-phytate line. Phosphorus and potassium were applied as; P₁ (20 kg ha⁻¹) and P₂ (100 kg ha⁻¹), same as K₁ (20 kg ha⁻¹) and K₂ (100 kg ha⁻¹), respectively. Low-phytate soybean had the highest grain yield, and 75% increase was observed compared to the high-phytate under same treatments. Highly significant differences of seed phytate P were observed in both cultivars, and the phytate P in high-phytate was found 39% higher than low-phytate, whereas no significant differences observed in response to P and K treatment. Percentage of phytate P from total P in seeds was 28 to 35% in low-phytate and 72 to 81% in high-phytate in different treatments. The lipid content in low-phytate was found lowered compared to that of high-phytate. Crude protein in grains was also found significantly higher in PK combined. No significant difference was observed in seed calcium (Ca), magnesium (Mg), and Zinc (Zn) in different treatments, but high-phytate showed 87% increase in seed Ca and 76% of Mg compared to low-phytate; however, low-phytate showed 82% increase in Zn content over high-phytate. The result illustrates that low-phytate soybean achieved higher grain yield and grain Pi in response to increased P and K nutrition. To achieve higher yield and quality seeds from the low-phytate soybean, it is recommended that proper phosphorus and potassium nutrition to be applied suggested in this study.

Keywords: phytic acid, low-phytate soybean, high-phytate soybean, P and K nutrition, protein content, soybean

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2646 Binary Metal Oxide Catalysts for Low-Temperature Catalytic Oxidation of HCHO in Air

Authors: Hanjie Xie, Raphael Semiat, Ziyi Zhong

Abstract:

It is well known that many oxidation reactions in nature are closely related to the origin and life activities. One of the features of these natural reactions is that they can proceed under mild conditions employing the oxidant of molecular oxygen (O₂) in the air and enzymes as catalysts. Catalysis is also a necessary part of life for human beings, as many chemical and pharmaceutical industrial processes need to use catalysts. However, most heterogeneous catalytic reactions must be run at high operational reaction temperatures and pressures. It is not strange that, in recent years, research interest has been redirected to green catalysis, e.g., trying to run catalytic reactions under relatively mild conditions as much as possible, which needs to employ green solvents, green oxidants such O₂, particularly air, and novel catalysts. This work reports the efficient binary Fe-Mn metal oxide catalysts for low-temperature formaldehyde (HCHO) oxidation, a toxic pollutant in the air, particularly in indoor environments. We prepared a series of nanosized FeMn oxide catalysts and found that when the molar ratio of Fe/Mn = 1:1, the catalyst exhibited the highest catalytic activity. At room temperature, we realized the complete oxidation of HCHO on this catalyst for 20 h with a high GHSV of 150 L g⁻¹ h⁻¹. After a systematic investigation of the catalyst structure and the reaction, we identified the reaction intermediates, including dioxymethylene, formate, carbonate, etc. It is found that the oxygen vacancies and the derived active oxygen species contributed to this high-low-temperature catalytic activity. These findings deepen the understanding of the catalysis of these binary Fe-Mn metal oxide catalysts.

Keywords: oxygen vacancy, catalytic oxidation, binary transition oxide, formaldehyde

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2645 Activation of Spermidine/Spermine N1-Acetyltransferase 1 (SSAT-1) as Biomarker in Breast Cancer

Authors: Rubina Ghani, Sehrish Zia, Afifa Fatima Rafique, Shaista Emad

Abstract:

Background: Cancer is a leading cause of death worldwide, with breast cancer being the most common cancer in women. Pakistan has the highest rate of breast cancer cases among Asian countries. Early and accurate diagnosis is crucial for treatment outcomes and quality of life. Method: It is a case-control study with a sample size of 150. There were 100 suspected cancer cases, 25 healthy controls, and 25 diagnosed cancer cases. To analyze SSAT-1 mRNA expression in whole blood, Zymo Research Quick-RNA Miniprep and Innu SCRIPT—One Step RT-PCR Syber Green kits were used. Patients were divided into three groups: 100 suspected cancer cases, 25 controls, and 25 confirmed breast cancer cases. Result: The total mRNA was isolated, and the expression of SSAT-1 was measured using RT-qPCR. The threshold cycle (Ct) values were used to determine the amount of each mRNA. Ct values were then calculated by taking the difference between the CtSSAT-1 and Ct GAPDH, and further Ct values were calculated with the median absolute deviation for all the samples within the same experimental group. Samples that did not correlate with the results were taken as outliers and excluded from the analysis. The relative fold change is shown as 2^-Ct values. Suspected cases showed a maximum fold change of 32.24, with a control fold change of 1.31. Conclusion: The study reveals an overexpression of SSAT-1 in breast cancer. Furthermore, we can use SSAT-1 as a diagnostic, prognostic, and therapeutic marker for early diagnosis of cancer.

Keywords: breast cancer, spermidine/spermine, qPCR, mRNA

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2644 A Survey on General Health Status of Paddy Field Workers in Mazandaran Province Using the GHQ-28 Questionnaire

Authors: Sharifirad M., Poursaeed A., Lashgarara F., Mirdamadi S. M.

Abstract:

Introduction: Paddy farming has been reported as one of the most important causes of non-fatal injuries and occupational accidents among farmers. The ignorance of the health of farmers can cause harm to farmers and lead to disability. As a result, these health consequences can result in less exploitation and economic growth in households. Therefore, this study aimed to determine the general health status of paddy field workers in Mazandaran province, Iran. Materials & Methods: This cross-sectional descriptive study evaluated 384 paddy farmers in Mazandaran province, Iran, who were selected using stratified random sampling. The required data were collected using the standard questionnaire of GHQ-28 with four domains of somaticsymptoms, anxiety and insomnia, social dysfunction, and symptoms of depression. The obtained data were then analyzed using SPSS software (version 25) through Spearman, Kendall, Mann-Whitney, and Kruskal-Wallis tests. Findings: The highest number of participants in this study was in the age group of 50-59 years, with a mean age of 46.9 years. According to the results, the total general health score was obtained at 64.3% for the subjects. Moreover, the scores of four areas of general health were determined at 91.1% (depression symptoms), 73.4% (social dysfunction), 48.7% (anxiety symptoms and insomnia), and 47.1% (somatic symptoms) in descending order. Discussions& Conclusions: The general health of the studied population was not in a good range. In addition, the most observed disorder in the general health of paddy farmers was related to the symptoms of depression, followed by somatic symptoms.

Keywords: general-health, mazandaran, paddyfield

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2643 Critical Thinking Index of College Students

Authors: Helen Frialde-Dupale

Abstract:

Critical thinking Index (CTI) of 150 third year college students from five State Colleges and Universities (SUCs) in Region I were determined. Only students with Grade Point Average (GPA) of at least 2.0 from four general classification of degree courses, namely: Education, Arts and Sciences, Engineering and Agriculture were included. Specific problem No.1 dealt with the profile variables, namely: age, sex, degree course, monthly family income, number of siblings, high school graduated from, grade point average, personality type, highest educational attainment of parents, and occupation of parents. Problem No. 2 determined the critical thinking index among the respondents. Problem No. 3 investigated whether or not there are significant differences in the critical thinking index among the respondents across the profile variables. While problem No.4 determined whether or not there are significant relationship between the critical thinking index and selected profile variables, namely: age, monthly family income, number of siblings, and grade point average of the respondents. Finally, on problem No. 5, the critical thinking instrument which obtained the lowest rates, were used as basis for outlining an intervention program for enhancing critical thinking index (CTI) of students. The following null hypotheses were tested at 0.05 level of significance: there are no significant differences in the critical thinking index of the third college students across the profile variables; there are no significant relationships between the critical thinking index of the respondents and selected variables, namely: age, monthly family income, number of siblings, and grade point average.

Keywords: attitude as critical thinker, critical thinking applied, critical thinking index, self-perception as critical thinker

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2642 Political Economy of Social Movements: The Influence of Capitalism on the Emergence of the Feminist Movement in Ukraine

Authors: Nadiya Didyk

Abstract:

This thesis deals with the unique history of the emergence of the Ukrainian feminist movement. Ukrainian feminism is still in its making, so the field is under-investigated in general. Nevertheless, the perspective of political economy and the enabling and constraining effects of capitalist dynamics are almost absent from the research on the emergence and the development of the feminist movement in Ukraine. This research was inspired by Hetland and Goodwin’s approach and an attempt to test their approach on the case of the Ukrainian feminist movement. Hetland and Goodwin claim that many scholars tend to neglect political economy from analysis of feminism as a new social movements, namely because such movement are not about class or materialist concerns, and thus have no discernible connection to capitalism. Both scholars, however, point out that there at least four ways in which capitalism has been of high importance for any social movement. Accordingly, the following issues are analysed in this paper: capitalism as the facilitator of the emergence and development of Ukrainian feminism; the influence of class balance in society on the formation of the Ukrainian feminist movement, and the ways in which class divisions within the movement shape its goals and strategies. This paper also focuses on the role of capitalist institutions and free wage labour expansion in shaping collective feminist identities and solidarities. Specific attention is paid to the representativeness of women in the highest echelons in business and politics under the capitalist systems. This study shows that there is a significant hole in the literature regarding the feminist movement in Ukraine and aims to motivate further detailed research.

Keywords: feminism, hetland, goodwin, new soical movements, political economy

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2641 An Estimating Equation for Survival Data with a Possibly Time-Varying Covariates under a Semiparametric Transformation Models

Authors: Yemane Hailu Fissuh, Zhongzhan Zhang

Abstract:

An estimating equation technique is an alternative method of the widely used maximum likelihood methods, which enables us to ease some complexity due to the complex characteristics of time-varying covariates. In the situations, when both the time-varying covariates and left-truncation are considered in the model, the maximum likelihood estimation procedures become much more burdensome and complex. To ease the complexity, in this study, the modified estimating equations those have been given high attention and considerations in many researchers under semiparametric transformation model was proposed. The purpose of this article was to develop the modified estimating equation under flexible and general class of semiparametric transformation models for left-truncated and right censored survival data with time-varying covariates. Besides the commonly applied Cox proportional hazards model, such kind of problems can be also analyzed with a general class of semiparametric transformation models to estimate the effect of treatment given possibly time-varying covariates on the survival time. The consistency and asymptotic properties of the estimators were intuitively derived via the expectation-maximization (EM) algorithm. The characteristics of the estimators in the finite sample performance for the proposed model were illustrated via simulation studies and Stanford heart transplant real data examples. To sum up the study, the bias for covariates has been adjusted by estimating density function for the truncation time variable. Then the effect of possibly time-varying covariates was evaluated in some special semiparametric transformation models.

Keywords: EM algorithm, estimating equation, semiparametric transformation models, time-to-event outcomes, time varying covariate

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2640 Graphene Based Materials as Novel Membranes for Water Desalination and Boron Separation

Authors: Francesca Risplendi, Li-Chiang Lin, Jeffrey C. Grossman, Giancarlo Cicero

Abstract:

Desalination is one of the most employed approaches to supply water in the context of a rapidly growing global water shortage. However, the most popular water filtration method available is the reverse osmosis (RO) technique, still suffers from important drawbacks, such as a large energy demands and high process costs. In addition some serious limitations have been recently discovered, among them, the boron problem seems to have a critical meaning. Boron has been found to have a dual effect on the living systems on Earth and the difference between boron deficiency and boron toxicity levels is quite small. The aim of this project is to develop a new generation of RO membranes based on porous graphene or reduced graphene oxide (rGO) able to remove salts from seawater and to reduce boron concentrations in the permeate to the level that meets the drinking or process water requirements, by means of a theoretical approach based on density functional theory and classical molecular dynamics. Computer simulations have been employed to investigate the relationship between the atomic structure of nanoporous graphene or rGO monolayer and its membrane properties in RO applications (i.e. water permeability and resilience at RO pressures). In addition, an emphasis has been given to multilayer nanoporous rGO and rGO flakes based membranes. By means of non-equilibrium MD simulations, we investigated the water transport mechanism permeating through such multilayer membrane focusing on the effect of slit widths and sheet geometries. These simulations allowed us to establish the implications of these graphene based materials as promising membrane properties for desalination plants and as boron filtration.

Keywords: boron filtration, desalination, graphene membrane, reduced graphene oxide membrane

Procedia PDF Downloads 295
2639 Hygrothermal Performance of Sheep Wool in Cold and Humid Climates

Authors: Yuchen Chen, Dehong Li, Bin Li, Denis Rodrigue, Xiaodong (Alice) Wang

Abstract:

When selecting insulation materials, not only should their thermal efficiency be considered, but also their impact on the environment. Compared to conventional insulation materials, bio-based materials not only have comparable thermal performance, but they also have a lower embodied energy. Sheep wool has the advantages of low negative health impact, high fire resistance, eco-friendliness, and high moisture resistance. However, studies on applying sheep wool insulation in cold and humid climates are still insufficient. The purpose of this study is to simulate the hygrothermal performance of sheep wool insulation for the Quebec City climate, as well as analyze the mold growth risks. The results show that a sheep wool wall has better thermal performance than a reference wall and that both meet the minimum requirements of the Quebec Code for the thermal performance of above-ground walls. The total water content indicates that the sheep wool wall can reach dynamic equilibrium in the Quebec climate and can dry out. At the same time, a delay of almost four months in the maximum total water content indicates that the sheep wool wall has high moisture absorption compared to the reference wall. The hygrothermal profiles show that the sheathing-insulation interface of both walls is at the highest risk for condensation. When the interior surface gypsum was replaced by stucco, the mold index significantly dropped.

Keywords: sheep wool, water content, hygrothermal performance, mould growth risk

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2638 Failure of Agriculture Soil following the Passage of Tractors

Authors: Anis Eloud, Sayed Chehaibi

Abstract:

Compaction of agricultural soils as a result of the passage of heavy machinery on the fields is a problem that affects many agronomists and farmers since it results in a loss of yield of most crops. To remedy this, and raise the overall future of the food security challenge, we must study and understand the process of soil degradation. The present review is devoted to understanding the effect of repeated passages on agricultural land. The experiments were performed on a plot of the area of the ESIER, characterized by a clay texture in order to quantify the soil compaction caused by the wheels of the tractor during repeated passages on agricultural land. The test tractor CASE type puissance 110 hp and 5470 kg total mass of 3500 kg including the two rear axles and 1970 kg on the front axle. The state of soil compaction has been characterized by measuring its resistance to penetration by means of a penetrometer and direct manual reading, the density and permeability of the soil. Soil moisture was taken jointly. The measurements are made in the initial state before passing the tractor and after each pass varies from 1 to 7 on the track wheel inflated to 1.5 bar for the rear wheel and broke water to the level of valve and 4 bar for the front wheels. The passages are spaced to the average of one week. The results show that the passage of wheels on a farm tilled soil leads to compaction and the latter increases with the number of passages, especially for the upper 15 cm depth horizons. The first passage is characterized by the greatest effect. However, the effect of other passages do not follow a definite law for the complex behavior of granular media and the history of labor and the constraints it suffers from its formation.

Keywords: wheel traffic, tractor, soil compaction, wheel

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2637 Development of Electrospun Membranes with Defined Polyethylene Collagen and Oxide Architectures Reinforced with Medium and High Intensity Statins

Authors: S. Jaramillo, Y. Montoya, W. Agudelo, J. Bustamante

Abstract:

Cardiovascular diseases (CVD) are related to affectations of the heart and blood vessels, within these are pathologies such as coronary or peripheral heart disease, caused by the narrowing of the vessel wall (atherosclerosis), which is related to the accumulation of Low-Density Lipoproteins (LDL) in the arterial walls that leads to a progressive reduction of the lumen of the vessel and alterations in blood perfusion. Currently, the main therapeutic strategy for this type of alteration is drug treatment with statins, which inhibit the enzyme 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase), responsible for modulating the rate of cholesterol production and other isoprenoids in the mevalonate pathway. This enzyme induces the expression of LDL receptors in the liver, increasing their number on the surface of liver cells, reducing the plasma concentration of cholesterol. On the other hand, when the blood vessel presents stenosis, a surgical procedure with vascular implants is indicated, which are used to restore circulation in the arterial or venous bed. Among the materials used for the development of vascular implants are Dacron® and Teflon®, which perform the function of re-waterproofing the circulatory circuit, but due to their low biocompatibility, they do not have the ability to promote remodeling and tissue regeneration processes. Based on this, the present research proposes the development of a hydrolyzed collagen and polyethylene oxide electrospun membrane reinforced with medium and high-intensity statins, so that in future research it can favor tissue remodeling processes from its microarchitecture.

Keywords: atherosclerosis, medium and high-intensity statins, microarchitecture, electrospun membrane

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2636 Foodborne Pathogens in Different Types of Milk: From the Microbiome to Risk Assessment

Authors: Pasquali Frederique, Manfreda Chiara, Crippa Cecilia, Indio Valentina, Ianieri Adriana, De Cesare Alessandra

Abstract:

Microbiological hazards can be transmitted to humans through milk. In this study, we compared the microbiome composition and presence of foodborne pathogens in organic milk (n=6), organic hay milk (n=6), standard milk (n=6) and high-quality milk (n=6). The milk samples were collected during six samplings between December 2022 to January 2023 and between April and May 2024 to take into account seasonal variations. The 24 milk samples were submitted to DNA extraction and library preparation before shotgun sequencing on the Illumina HiScan™ SQ System platform. The total sequencing output was 600 GB. In all the milk samples, the phyla with the highest relative abundances were Pseudomonadota, Bacillota, Ascomycota, Actinomycetota and Apicomplexa, while the most represented genera were Pseudomonas, Streptococcus, Geotrichum, Acinetobacter and Babesia. The alpha and beta diversity indexes showed a clear separation between the microbiome of high-quality milk and those of the other milk types. Moreover, in the high-quality milk, the relative abundance of Staphylococcus (4.4%), Campylobacter (4.5%), Bacillus (2.5%), Enterococcus (2.4%), Klebsiella (1.3%) and Escherichia (0 .7%) was significantly higher in comparison to other types of milk. On the contrary, the relative abundance of Geotrichum (0.5%) was significantly lower. The microbiome results collected in this study showed significant differences in terms of the relative abundance of bacteria genera, including foodborne pathogen species. These results should be incorporated into risk assessment models tailored to different types of milk.

Keywords: raw milk, foodborne pathogens, microbiome, risk assessment

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2635 Preparation, Characterization, and in-Vitro Drug Release Study of Methotrexate-Loaded Hydroxyapatite-Sodium Alginate Nanocomposites

Authors: Friday G. Okibe, Edit B. Agbaji, Victor O. Ajibola, Christain C. Onoyima

Abstract:

Controlled drug delivery systems reduce dose-dependent toxicity associated with potent drugs, including anticancer drugs. In this research, hydroxyapatite (HA) and hydroxyapatite-sodium alginate nanocomposites (HASA) were successfully prepared and characterized using Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The FTIR result showed absorption peaks characteristics of pure hydroxyapatite (HA), and also confirmed the chemical interaction between hydroxyapatite and sodium alginate in the formation of the composite. Image analysis from SEM revealed nano-sized hydroxyapatite and hydroxyapatite-sodium alginate nanocomposites with irregular morphologies. Particle size increased with the formation of the nanocomposites relative to pure hydroxyapatite, with no significant change in particles morphologies. Drug loading and in-vitro drug release study were carried out using synthetic body fluid as the release medium, at pH 7.4 and 37 °C and under perfect sink conditions. The result shows that drug loading is highest for pure hydroxyapatite and decreased with increasing quantity of sodium alginate. However, the release study revealed that HASA-5%wt and HASA-20%wt presented better release profile than pure hydroxyapatite, while HASA-33%wt and HASA-50%wt have poor release profiles. This shows that Methotrexate-loaded hydroxyapatite-sodium alginate if prepared under optimal conditions is a potential carrier for effective delivery of Methotrexate.

Keywords: drug-delivery, hydroxyapatite, methotrexate, nanocomposites, sodium alginate

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2634 Valorization of Surveillance Data and Assessment of the Sensitivity of a Surveillance System for an Infectious Disease Using a Capture-Recapture Model

Authors: Jean-Philippe Amat, Timothée Vergne, Aymeric Hans, Bénédicte Ferry, Pascal Hendrikx, Jackie Tapprest, Barbara Dufour, Agnès Leblond

Abstract:

The surveillance of infectious diseases is necessary to describe their occurrence and help the planning, implementation and evaluation of risk mitigation activities. However, the exact number of detected cases may remain unknown whether surveillance is based on serological tests because identifying seroconversion may be difficult. Moreover, incomplete detection of cases or outbreaks is a recurrent issue in the field of disease surveillance. This study addresses these two issues. Using a viral animal disease as an example (equine viral arteritis), the goals were to establish suitable rules for identifying seroconversion in order to estimate the number of cases and outbreaks detected by a surveillance system in France between 2006 and 2013, and to assess the sensitivity of this system by estimating the total number of outbreaks that occurred during this period (including unreported outbreaks) using a capture-recapture model. Data from horses which exhibited at least one positive result in serology using viral neutralization test between 2006 and 2013 were used for analysis (n=1,645). Data consisted of the annual antibody titers and the location of the subjects (towns). A consensus among multidisciplinary experts (specialists in the disease and its laboratory diagnosis, epidemiologists) was reached to consider seroconversion as a change in antibody titer from negative to at least 32 or as a three-fold or greater increase. The number of seroconversions was counted for each town and modeled using a unilist zero-truncated binomial (ZTB) capture-recapture model with R software. The binomial denominator was the number of horses tested in each infected town. Using the defined rules, 239 cases located in 177 towns (outbreaks) were identified from 2006 to 2013. Subsequently, the sensitivity of the surveillance system was estimated as the ratio of the number of detected outbreaks to the total number of outbreaks that occurred (including unreported outbreaks) estimated using the ZTB model. The total number of outbreaks was estimated at 215 (95% credible interval CrI95%: 195-249) and the surveillance sensitivity at 82% (CrI95%: 71-91). The rules proposed for identifying seroconversion may serve future research. Such rules, adjusted to the local environment, could conceivably be applied in other countries with surveillance programs dedicated to this disease. More generally, defining ad hoc algorithms for interpreting the antibody titer could be useful regarding other human and animal diseases and zoonosis when there is a lack of accurate information in the literature about the serological response in naturally infected subjects. This study shows how capture-recapture methods may help to estimate the sensitivity of an imperfect surveillance system and to valorize surveillance data. The sensitivity of the surveillance system of equine viral arteritis is relatively high and supports its relevance to prevent the disease spreading.

Keywords: Bayesian inference, capture-recapture, epidemiology, equine viral arteritis, infectious disease, seroconversion, surveillance

Procedia PDF Downloads 292