247 research outputs found

    Elemental Composition Analysis of Soil Samples from Bayelsa State in the Niger Delta Region of Nigeria

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    This study analysis the elemental composition and concentration of elements in the soils of the study area to ascertain degree of elemental enhancement in the soil resulting from anthropogenic activities with possible soil contamination, human health and environmental detriment. The study area was divided into eight grids and two soil samples per grid from over burden to a depth of 900mm was collected randomly in each grid. The samples were prepared using standard methods and analyzed with a linear accelerator. The number of detectable elements and their quantitative information was extracted from the elemental spectral signatures. . The result showed a high concentration value in some elements in the soil samples above values of elemental concentrations in soils from other reported studied region. In addition, Aluminium, Strontium, Barium, Gallium etc also showed an extremely high value in their concentration that exceeds the world wide mean range upper limit values in crustal soil study published. The study indicates some degree of potential contamination and therefore necessitate a regular periodic monitoring study to reduce potential health detriment to humans and the environment to as low as reasonably possible

    Presentation and Preliminary Results of DROÏD Project: Development of a Distributed Optical Fibre Dosimeter

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    International audienceABSTRACT DROÏD project is intended to develop a distributed optical fibre dosimeter based on Radiation-Induced Attenua-tion (RIA). The RIA will be measured by a high resolution Optical Time Domain Reflectometry (OTDR) technique that allows to locate the irradiated fibre section. The first part of the project focuses on designing a high radiation sensitive fibre. As a preliminary work, the attenu-ation of several fibres with various compositions has been recorded in situ during and after irradiation. The experimental setup and RIA values are presented and discussed. Several dopants and their combinations have been identified as a good starting point to design a highly radiation sensitive fibre

    Spatial Distribution of Radiometric and Dosimetric Parameters in Soil Samples from Selected Areas in Bayelsa State, Nigeria

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    Radiation from radioactive materials/radionuclides in the environment enhanced by anthropogenic activities is presently of a great concern globally. The objective of this study is to determine the radiometric and dosimetric parameters from soil samples collected randomly from the study area of Bayelsa State, Nigeria. The samples were prepared using standard methods and analyzed with a high resolution Hyperpure Germanium Detector configuration (HPGe). The results showed the clay samples to have higher activity concentration to the sands samples with activity concentration of clay samples ranging between 68.99±9.05 –189, 42±21.11Bq/kg and the sand samples with activity concentration range of 17.95±5.87 – 38.59±7.43Bq/kg. The activity concentration spatial distribution map in clay lithologies showed 2 peak values trending north-west, while the sand lithology showed a single peak central distribution. The result also showed the values of the absorbed doses with the 8 clay samples values ranging between 59.09 - 155.25nGy/h and sand samples values between 17.90 – 33.92nGy/h. The spatial distribution of the dose showed 2 peak central distribution in clay samples and north-east trending distribution of high peak values for samples with sand lithologies.  In addition, the results showed an effective absorbed dose of range of 0.235-0.0616mSv/y for samples with clay lithology and 0.0071-0.0135mSv/y for samples with sand lithology The activity concentration of all the samples studied are below the 1000Bq/kg international reference limit  for Radium 226, Thorium 232, uranium 238 and 10,000Bq/kg for potassium 40. The absorbed dose rate and annual effective absorbed dose are also below the international reference limits published by ICRP, 2007 and UNSCEAR, 2000 publications. Also, effective activity maximum limit of 370Bq/kg for input raw materials for public building is not exceeded

    The evaluation of cartilage differentiations using transforming growth factor beta3 alone and with combination of bone morphogenetic protein-6 on adult stem cells

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    In our quest to standardize our formula for a clinical trial, transforming growth factor-beta3 (TGF-β3) alone and in combination with bone morphogenetic protein-6 (BMP-6) were evaluated for their effectiveness in cartilage differentiation. Bone Marrow Stem Cells (BMSCs) and Adipose Derived Stem Cells (ADSCs) were induced to chondrogenic lineage using two different media. Native chondrocytes served as positive control. ADSCs and BMSCs proved multipotency by tri-lineage differentiations. ADSC has significantly higher growth kinetics compare to Chondrocyte only p ≤ 0.05. Using TGF-β3 alone, BMSC revealed higher expressions for hyaline cartilage genes compare to ADSCs. Chondrocyte has significantly higher early chondrogenic markers expression to ADSCs and BMSCs, while BMSCs was only higher to ADSC at chondroadherin, p ≤ 0.0001. On mature chondrogenic markers, chondrocytes were significantly higher to ADSCs and BMSCs for aggrecan, collagen IX, sry (sex determining region y)-box9, collagen II and fibromodullin; and only to ADSC for collagen XI. BMSC was higher to ADSC for aggrecan and collagen IX, p ≤ 0.0001. The combination of TGF-β3 + BMP-6 revealed increased gene expressions on both BMSCs and ADSCs for early and mature chondrogenic markers, but no significance difference. For dedifferentiation markers, ADSC was significantly higher to chondrocyte for collagen I. Glycosaminoglycan evaluations with both formulas revealed that chondrocytes were significantly higher to ADSCs and BMSCs, but none was significant to each other, p ≤ 0.0001. Combination of 10 ng TGF-β3 with 10 ng of BMP-6 enhanced chondrogenic potentials of BMSCs and ADSCs compare to TGF-β3 alone. This could be the ideal cocktail for either cell’s chondrogenic induction

    Structural Bootstrapping - A Novel, Generative Mechanism for Faster and More Efficient Acquisition of Action-Knowledge

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    eISSN: 1943-0612Humans, but also robots, learn to improve their behavior. Without existing knowledge, learning either needs to be explorative and, thus, slow or-to be more efficient-it needs to rely on supervision, which may not always be available. However, once some knowledge base exists an agent can make use of it to improve learning efficiency and speed. This happens for our children at the age of around three when they very quickly begin to assimilate new information by making guided guesses how this fits to their prior knowledge. This is a very efficient generative learning mechanism in the sense that the existing knowledge is generalized into as-yet unexplored, novel domains. So far generative learning has not been employed for robots and robot learning remains to be a slow and tedious process. The goal of the current study is to devise for the first time a general framework for a generative process that will improve learning and which can be applied at all different levels of the robot's cognitive architecture. To this end, we introduce the concept of structural bootstrapping-borrowed and modified from child language acquisition-to define a probabilistic process that uses existing knowledge together with new observations to supplement our robot's data-base with missing information about planning-, object-, as well as, action-relevant entities. In a kitchen scenario, we use the example of making batter by pouring and mixing two components and show that the agent can efficiently acquire new knowledge about planning operators, objects as well as required motor pattern for stirring by structural bootstrapping. Some benchmarks are shown, too, that demonstrate how structural bootstrapping improves performanceTaikomosios informatikos katedraVytauto Didžiojo universiteta

    Coping style and health-related quality of life in caregivers of epilepsy patients

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    Epilepsy has a significant impact on health-related quality of life (HRQOL) of patients and personal coping style is an important determinant. Less is known about home caregivers. This study investigates HRQOL and coping style of both patients and caregivers and their interaction. Epilepsy patients attending the outpatient clinic of the University Medical Centre in Utrecht and their caregivers were sent EQ5D and RAND-36 questionnaires. The Utrecht Coping List was used to chart personal coping styles. HRQOL scores of patients and caregivers were compared to the general Dutch population. The association between patient and caregiver HRQOL scores was calculated. A stepwise backward multivariate linear regression analysis was used to explain variances in caregiver HRQOL. Eighty-six couples (49%) returned all questionnaires. Caregiver HRQOL scores were comparable to the general Dutch population (EQ5D: 0.88–0.88; p = 0.90, RAND-36 MCS: −2 points; p = 0.16), while patients HRQOL scores were lower (EQ5D: 0.79; p < 0.01, RAND-36 MCS −10 points; p < 0.01). However, on several specific domains, associations between patient and caregiver HRQOL scores within couples were found. Passive coping style explained 50% of variation in HRQOL scores of caregivers. As a group, caregivers of epilepsy patients have normal HRQOL, but there are significant associations between patient and caregiver HRQOL scores. Improving caregiver HRQOL through interventions on coping style might benefit patients as well. Recognizing personal coping styles of both patient and caregiver should be part of a patient-oriented approach in treatment

    Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT)

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    The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 μg.g -1 , and ranged from 1.06 μg.g -1 for the triploid Nanica (Cavendish group) to 19.24 μg.g -1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 μg.g -1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank
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