242 research outputs found

    Partial delamination detection and quantification in composite laminates using Laser Doppler Vibrometer

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    Vibration based structural health monitoring techniques are widely used for detection and quantification of delamination in composite structures. In this work, non-contact vibration measurement technique namely Laser Doppler Vibrometer (LDV) is used for damage characterization of partial delamination in composite beams. The modal information such as natural frequencies and mode shapes of composite beam are obtained using LDV and validated with finite element models for comparison with the obtained experimental results. Mode shape based damage detection algorithms namely, fractal dimension approach is used for quantification of delamination in composite beams. In the present work, a modified generalized fractal dimension technique is proposed to locate delamination of different sizes and shapes in the composite beam. Different types of partial delamination like C-type, I-type in composite beam specimens were fabricated and experimentally studied usingLDV. The modified fractal dimension technique was then applied to the mode shapes results of the various partial delamination to quantify the damage. In addition, multiple delamination were introduced in composite plates and experiments were carried out using LDV. Modified fractal dimension technique was then applied to quantify the delamination in composite laminates

    Marine plastics from Norwegian west coast carry potentially virulent fish pathogens and opportunistic human pathogens harboring new variants of antibiotic resistance genes

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    To our best knowledge this is the first study characterizing fish pathogens isolated from marine plastics from the West coast of Norway for their potential for pathogenicity using whole genome sequencing. Marine plastic polymers identified as polyethylene, polyethylene/ethylene vinyl acetate copolymer and polypropylene, yielded a total of 37 bacterial isolates dominated by Pseudomonas spp. (70%). Six isolates representing either fish pathogens or opportunistic human pathogens were selected for whole genome sequencing (WGS). These included four isolates belonging to Aeromonas spp., one Acinetobacter beijerinckii isolate and one Morganella morganii isolate. Three Aeromonas salmonicida isolates were potentially virulent and carried virulence factors involved in attachment, type II and type VI secretion systems as well as toxins such as aerA/act, ahh1, ast, hlyA, rtxA and toxA. A. salmonicida and Acinetobacter beijerinckii carried new variants of antibiotic resistance genes (ARGs) such as β-lactamases and chloramphenicol acetyltransferase (catB), whereas Morganella morganii carried several clinically relevant ARGs. Our study shows that marine plastics carry not only potentially virulent fish pathogens but also multidrug resistant opportunistic human pathogens like M. morganii and may serve as vectors for transport of these pathogens in the marine environment.publishedVersio

    Utilizing Wild Cajanus platycarpus, a Tertiary Genepool Species for Enriching Variability in the Primary Genepool for Pigeonpea Improvement

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    The use of crop wild relatives in the breeding program has been well recognized to diversify the genetic base along with introgression of useful traits. Cajanus platycarpus (Benth.) Maesen, an annual wild relative belonging to the tertiary genepool of pigeonpea, possesses many useful traits such as early maturity, high protein content, photoperiod insensitivity, and pod borer tolerance for the genetic improvement of cultivated pigeonpea. Using this cross incompatible wild Cajanus species, an advanced backcross population was developed following the embryo rescue technique. In the present study, a prebreeding population consisting of 136 introgression lines (ILs) along with five popular varieties (used as checks) was evaluated for important agronomic traits during 2016 and 2017 rainy seasons and for grain nutrient content during 2016, 2017, and 2018 rainy seasons. Large genetic variation was observed for agronomic traits such as days to 50% flowering, number of pods per plant, pod weight per plant, grain yield per plant, and grain nutrients [protein content, grain iron (Fe), zinc (Zn), calcium (Ca), and magnesium (Mg)] in the pre-breeding population. Significant genotype × environment interaction was also observed for agronomic traits as well as grain nutrients indicating the sensitivity of these traits to the environments. No significant correlations were observed between grain yield and grain nutrients except grain Zn content which was negatively correlated with grain yield. Overall, 28 promising high-yielding ILs with high grain nutrient content were identified. These ILs, in particular, ICPP # 171012, 171004, 171102, 171087, 171006, and 171050 flowered significantly earlier than the popular mega variety, ICPL 87119 (Asha) and thus hold potential in developing new short-duration cultivars. The comprehensive multi-site assessment of these high-yielding, nutrient-rich accessions would be useful in identifying region-specific promising lines for direct release as cultivars. Moreover, these ILs are expected to replace the popular existing cultivars or for use as new and diverse sources of variations in hybridization programs for pigeonpea improvement

    Desarrollo y validación de un método por cromatografía líquida de alta resolución para la estimación de esomeprazol en forma de dosificación a granel y en tableta

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    Introduction: An accurate, simple, precise, rapid, economic and reproducible reverse-phase high-performance liquid chromatography method was developed and validated for the estimation of Esomeprazole (ESO) in bulk and tablet dosage form. Method: The separation was carried out on Finepak SIL C18T-5 column (250 × 4.6 mm, 5.0 µm i. d.) using potassium dihydrogen phosphate buffer (0.025M): ACN (20:80 v/v) and at a flow rate of 1.0 mL/min. using UV detector at 302 nm with a run time of 10 min. The method was validated for accuracy for linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ) and robustness. Results: The standard calibration curve was linear with R2 = 0.995. LOD and LOQ obtained for esomeprazole were 0.0001 and 0.0004 µg/mL respectively. The method was found robust for possible changes. Results of analysis of other parameters were also tested and validated as per ICH guidelines and recovery studies confirmed the accuracy of the proposed method. validation studies showed that the developed HPLC method is simple, reproducible, rapid, precise and reliable. The high recovery and low relative standard deviation confirm the suitability of the developed method for the determination of esomeprazole in the tablet dosage form. Conclusion: This method may be used as a more convenient and efficient option for the analysis of esomeprazole to establish the quality of the substance during routine analysis with consistent and reproducible results.Introducción: Se desarrolló y validó un método de cromatografía líquida de alta resolución de fase reversa exacto, simple, preciso, rápido, económico y reproducible para la estimación de esomeprazol (ESO) en forma de dosificación a granel y en tabletas. Método: La separación se llevó a cabo en columna Finepak SIL C18T-5 (250 × 4,6 mm; 5,0 µm i.d.) utilizando tampón fosfato dihidrógeno de potasio (0,025 M): ACN (20:80 v/v) y a un caudal de 1,0 ml/min. utilizando un detector UV a 302 nm con un tiempo de ejecución de 10 min. El método fue validado para exactitud de linealidad, exactitud, precisión, límite de detección (LOD), límite de cuantificación (LOQ) y robustez. Resultados: La curva de calibración estándar fue lineal con R2 = 0,995. El LOD y el LOQ obtenidos para esomeprazol fueron 0,0001 y 0,0004 µg/mL respectivamente. El método se encontró robusto para posibles cambios. Los resultados del análisis de otros parámetros también se probaron y validaron según las pautas de ICH y los estudios de recuperación confirmaron la precisión del método propuesto. Los estudios de validación mostraron que el método HPLC desarrollado es simple, reproducible, rápido, preciso y confiable. La alta recuperación y la baja desviación estándar relativa confirman la idoneidad del método desarrollado para la determinación de esomeprazol en forma de dosificación en tabletas. Conclusión: Este método puede ser utilizado como una opción más conveniente y eficiente para el análisis de esomeprazol para establecer la calidad de la sustancia durante el análisis de rutina con resultados consistentes y reproducibles

    Evaluation of the effect of solar radiations on the growth of potential water borne and food borne pathogens during solar eclipse

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    On new moon day when Moon passes between Earth and Sun solar eclipse can be seen from Earth. Although solar eclipse is a fascinating astronomical event, even in today’s fast, modern and civilized life, people have not been able to go away with superstitious beliefs related to outer space activity behind solar eclipse. These misbelieves eventually lead to great socio-economic losses due to discarding of cooked food and drinking water that was exposed to the eclipse directly or indirectly. So considering these misbelieves a study was conducted to see possible biological effects of solar radiations during solar eclipse on bacteria responsible for water borne and food borne diseases. E. coli, S. aureus, B. subtilis, S. typhi, which are known water and food borne pathogens, were exposed to solar radiations throughout the eclipse period. The effect of these radiations on the survival and growth rate of these organisms was assessed by suitable method and compared with that on control day. When such comparison was made, it indicated that there was no statistically significant effect of solar eclipse on the survival and the growth rate of these organisms. Hence, we insist dumping the cooked food or drinking water after solar eclipse should be avoided

    Characterization and identification of annual wild Cicer species for seed protein and mineral concentrations for chickpea improvement

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    Developing nutrient-rich crop cultivars is the most economic strategy to combat malnutrition resulting from protein and mineral deficiencies. Chickpea (Cicer arietinum L.) is an important staple grain legume source of good quality dietary protein around the world, particularly in southern Asia, northern Africa, and the Middle East. In the present investigation, the genetic variability for protein and mineral concentrations was studied in 41 accessions of cultivated chickpea and eight annual wild Cicer species of primary, secondary, and tertiary gene pool. Large variability was observed between and within Cicer species for seed protein, Fe, Zn, Cu, Mn, Ca, and Mg concentration with high heritability. C. chorassanicum (Bunge) Popov was found to be the most promising species for high seed protein and Ca; C. judaicum Boiss. for high seed Fe, Cu. and Mg; C. yamashiatae Kitam. for high seed Zn and Fe; and C. pinnatifidum Jaub. & Spach for high seed Mn concentrations. All the wild Cicer accessions except ICC20190 (C. echinospermum P. H. Davis) had high concentration of at least one or more seed nutrients. Wild Cicer accessions such as ICC17141 (C. chorassanicum), ICC17269 and ICC17303 (both C. pinnatifidum), ICC17261 and ICC17262 (C. reticulatum), ICC20236 (C. chorassanicum), and ICC17117 and ICC17281 (C. yamashitae) were found promising for multiple seed nutrients. As C. reticulatum Ladiz. and C. echinospremum accessions are crossable with cultivated chickpea, promising C. reticulatum accessions identified in the present study can be used in crossing program for developing new nutrient-rich chickpea cultivars

    Seawater from Bergen harbor is a reservoir of conjugative multidrug-resistance plasmids carrying genes for virulence

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    Aquatic environments play important roles in the dissemination of clinically-relevant antibiotic resistance genes (ARGs) and pathogens. Limited knowledge exists about the prevalence of clinically-relevant acquired resistance genes in the marine environment, especially in Norway. The aim of the current study was to investigate the presence of and characterize self-transmissible resistance plasmids from Bergen harbor seawater, with exogenous-plasmid capture, using a green fluorescent protein (GFP)-tagged Escherichia coli strain as a recipient. We obtained transconjugants resistant against ampicillin and cefotaxime from four of the 13 samples processed. Nine transconjugants, selected on the basis of antibiotic sensitivity patterns, were sequenced, using Illumina MiSeq and Oxford Nanopore MinION platforms. Ten different plasmids (ranging from 35 kb to 136 kb) belonging to incompatibility groups IncFII/IncFIB/Col156, IncFII, IncI1 and IncB/O/K/Z were detected among these transconjugants. Plasmid p1A1 (IncFII/IncFIB/Col156, 135.7 kb) carried resistance genes blaTEM-1, dfrA17, sul1, sul2, tet(A), mph(A), aadA5, aph(3″)-Ib and aph(6)-Id, conferring resistance against six different classes of antibiotics. Plasmid p1A4 carried blaCTX-M-55, lnu(F), aadA17 and aac(3)-IId. Cephalosporinase blaCMY-2 was detected on plasmids captured from an area impacted by wastewater from a local marine aquarium. Along with ARGs, some plasmids also carried virulence factors, such as enterotoxins, adhesion factors and siderophores. Our study demonstrates the presence of clinically-important multidrug-resistance conjugative plasmids in seawater from Bergen harbor, which have the potential to be transferred to human microbiota. The results highlight the need for surveillance of antibiotic resistance in the environment, as suggested by the World Health Organization, especially in low prevalence settings like Norway.publishedVersio
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