108,545 research outputs found

    The Effects of Air and Underwater Blast on Composite Sandwich Panels and Tubular Laminate Structures

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    The resistance of glass-fibre reinforced polymer (GFRP) sandwich panels and laminate tubes to blast in air and underwater environments has been studied. Procedures for monitoring the structural response of such materials during blast events have been devised. High-speed photography was employed during the air-blast loading of GFRP sandwich panels, in conjunction with digital image correlation (DIC), to monitor the deformation of these structures under shock loading. Failure mechanisms have been revealed by using DIC and confirmed in post-test sectioning. Strain gauges were used to monitor the structural response of similar sandwich materials and GFRP tubular laminates during underwater shocks. The effect of the backing medium (air or water) of the target facing the shock has been identified during these studies. Mechanisms of failure have been established such as core crushing, skin/core cracking, delamination and fibre breakage. Strain gauge data supported the mechanisms for such damage. These studies were part of a research programme sponsored by the Office of Naval Research (ONR) investigating blast loading of composite naval structures. The full-scale experimental results presented here will aid and assist in the development of analytical and computational models. Furthermore, it highlights the importance of support and boundary conditions with regards to blast resistant design

    Evaluando los niveles tróficos de dos tiburones oceánicos del Océano Pacífico suroriental

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    Indexación: Web of ScienceStable isotope analyses for shortfin mako (Isurus oxyrinchus) and blue sharks (Prionace glauca) were conducted to assess their trophic position in two periods of time (before 1980 and after 2000) in the Southeastern Pacific waters (SEP). Both sharks showed that their trophic position decreased over time (P < 0.05). Many factors could be involved in this change such as dietary shifts, prey availability, or indirect fishing effects in SEP waters.RESUMEN. Para evaluar los niveles tróficos de los tiburones marrajo (Isurus oxyrinchus) y azulejo (Prionace glauca) en dos períodos de tiempo (previo a 1980 y posterior al 2000) en aguas del Pacífico suroriental (SEP), se realizaron análisis de isótopos estables. Ambos tiburones mostraron un descenso del nivel trófico en el tiempo (P < 0,05). Varios son los factores que pueden estar involucrados en este evento, como los cambios dietarios, la disponibilidad de las presas o los efectos indirectos de la pesquería en aguas del Pacífico suroriental.http://www.lajar.cl/pdf/imar/v44n2/Art%C3%ADculo_44_2_25.pd

    The effect of chemotherapeutic agents on telomere length maintenance in breast cancer cell lines

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    Copyright @ 2014 the authors. This article is made available through the Brunel Open Access Publishing Fund. It is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Mammalian telomeric DNA consists of tandem repeats of the sequence TTAGGG associated with a specialized set of proteins, known collectively as Shelterin. These telosomal proteins protect the ends of chromosomes against end-to-end fusion and degradation. Short telomeres in breast cancer cells confer telomere dysfunction and this can be related to Shelterin proteins and their level of expression in breast cancer cell lines. This study investigates whether expression of Shelterin and Shelterin-associated proteins are altered, and influence the protection and maintenance of telomeres, in breast cancer cells. 5-aza-2'-deoxycytidine (5-aza-CdR) and trichostatin A (TSA) were used in an attempt to reactivate the expression of silenced genes. Our studies have shown that Shelterin and Shelterin-associated genes were down-regulated in breast cancer cell lines; this may be due to epigenetic modification of DNA as the promoter region of POT1 was found to be partially methylated. Shelterin genes expression was up-regulated upon treatment of 21NT breast cancer cells with 5-aza-CdR and TSA. The telomere length of treated 21NT cells was measured by q-PCR showed an increase in telomere length at different time points. Our studies have shown that down-regulation of Shelterin genes is partially due to methylation in some epithelial breast cancer cell lines. Removal of epigenetic silencing results in up-regulation of Shelterin and Shelterin-associated genes which can then lead to telomere length elongation and stability

    Estrogen Binding Protein Activity in Morris Hepatoma 7777 Compared With Normal Rat Liver

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    Estrogen binding protein activities were determined in the cytosol from adult male Buffalo rat liver and Morris hepatoma 7777. Estrogen receptors were prepared using the protamine sulfate precipitation technique of Chamness. The ability of various unlabeled steroids competing with [3H]estradiol was examined to establish the binding specificity. Estradiol binding in Morris hepatoma 7777 cytosol was greatly decreased compared with that present in hepatic cytosol prepared from normal rat liver. The receptor concentration expressed as femtomoles per milligram of cytoplasmic protein was 31.1 ± 2.9 SD for normal rat liver and 0.41 ± 0.88 SD for the hepatoma. Gel filtration chromatography revealed the presence of an estrogen binder in hepatoma cytosol which was not present in either normal liver or in the protamine sulfate precipitates of hepatoma cytosol. The molecular weight, binding specificity, and precipitation of this protein by specific antiserum suggests that it is α-fetoprotein. © 1984, American Gastroenterological Association. All rights reserved

    Litter Size and Lamb Survivability of Batur Sheep in Upland Areas of Banjarnegara Regency, Indonesia

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    . The objective of the current study was to find out the litter size and lamb survivability of Batur sheep, and also to identify the effects of ewe parities on litter size and lamb survivability; and the effects of birth type on lamb survivability of Batur sheep. The study was conducted at the Batur sheep Farming Group in the upland areas of Banjarnegara regency, Central Java province of Indonesia. Data from 311 records of lambing of Batur sheep at the village breeding centre for Batur sheep were analyzed. Least squares procedure by the General Linear Model was used to identify the effect of parity on litter size at birth and at weaning. Preweaning survivability was analyzed using the Chi-squares. Results showed that average litter size at birth and at weaning, and lambs survivability till weaning were 1.55±0.03 and 1.36±0.03 lambs; and 88.42%, respectively. Litter size at weaning and lambs survivability was significantly different among ewe parities, and increased by advancing ewes parities. Its indicating that age of ewe was important factor for the success in early stage for producing lamb. Survivability of single lamb (93.62%) was significantly higher that twins (84.11%). Increased care for twins by providing proper management might lead to a recognizable increase in lamb survival and flock productivity of Batur sheep

    Litter Size and Lamb Survivability of Batur Sheep in Upland Areas of Banjarnegara Regency, Indonesia

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    Abstract. The objective of the current study was to find out the litter size and lamb survivability of Batur sheep, and also to identify the effects of ewe parities on litter size and lamb survivability; and the effects of birth type on lamb survivability of Batur sheep. The study was conducted at the Batur sheep Farming Group in the upland areas of Banjarnegara regency, Central Java province of  Indonesia.   Data from 311 records of lambing of Batur sheep at the village breeding centre for Batur sheep were analyzed. Least squares procedure by the General Linear Model was used to identify the effect of parity on litter size at birth and at weaning. Preweaning survivability was analyzed using the Chi-squares. Results showed that average litter size at birth and at weaning, and lambs survivability till weaning were 1.55±0.03 and 1.36±0.03 lambs; and 88.42%, respectively. Litter size at weaning and lambs survivability was significantly different among ewe parities, and increased by advancing ewes parities. Its indicating that age of ewe was important factor for the success in early stage for producing lamb. Survivability of single lamb (93.62%) was significantly higher that twins (84.11%). Increased care for twins by providing proper management might lead to a recognizable increase in lamb survival and flock productivity of Batur sheep.Key words: Batur sheep, litter size, lamb survivability, parity, preweaningAnimal Production 13(3):166-172 (2011

    Local three-nucleon interaction from chiral effective field theory

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    The three-nucleon (NNN) interaction derived within the chiral effective field theory at the next-to-next-to-leading order (N2LO) is regulated with a function depending on the magnitude of the momentum transfer. The regulated NNN interaction is then local in the coordinate space, which is advantages for some many-body techniques. Matrix elements of the local chiral NNN interaction are evaluated in a three-nucleon basis. Using the ab initio no-core shell model (NCSM) the NNN matrix elements are employed in 3H and 4He bound-state calculations.Comment: 17 pages, 9 figure

    Universal properties of thermal and electrical conductivity of gauge theory plasmas from holography

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    We propose that for conformal field theories admitting gravity duals, the thermal conductivity is fixed by the central charges in a universal manner. Though we do not have a proof as yet, we have checked our proposal against several examples. This proposal, if correct, allows us to express electrical conductivity in terms of thermodynamical quantities even in the presence of chemical potential.Comment: 13 pages, appendix added, close to journal versio
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