19 research outputs found
Genetic diversity analysis in the Hypericum perforatum populations in the Kashmir valley by using inter-simple sequence repeats (ISSR) markers
Assessment of genetic variability among the Hypericum perforatum populations is critical to the development of effective conservation strategies in the Kashmir valley. To obtain accurate estimates of genetic diversity among and within populations of H. perforatum, inter-simple sequence repeats (ISSR) markers were used. The study was aimed to check, whether ISSR fingerprinting may be a useful tool for studying genetic variations among H. perforatum populations in the Kashmir valley (India). A total of 15 ISSR primers were tested with the 20 genotypes of H. perforatum. The ten informative primers were selected and used to evaluate the degree of polymorphism and genetic relationships within and among all the H. perforatum populations. ISSR of 20 genotypes analysis yielded 98 fragments that could be scored, of which 71 were polymorphic, with an average of 7.1 polymorphic fragments per primer. Number of amplified fragments varied in size from 150 to 1650 bp. Percentage of polymorphism ranged from 60% to a maximum of 100%. Resolving power ranged from a minimum of 7.7 to a maximum of 14.3. Shannon indexes ranges from 0.166 to 0.389 with an average of 0.198 and Nei’s genetic diversity (h) ranges from 6.98 to 9.8. Estimated value of gene flow (Nm = 0.579) indicated that there was limited gene flow among the populations. The genetic diversity (Ht) within the population of 0.245 was clearly higher than that of among population genetic diversity (Hs= 0.115), indicating an out-crossing predominance in the studied populations. Analysis of molecular variance by ISSR markers indicated that over half of the total variation in the studied populations (58%) could be accounted for by differences among the 8 divisions, with a further 42% being accounted for by the variation among populations within a division.The dendrogram grouping the populations by unweighted pair-group method with arithmeticaverages (UPGMA) method revealed eight main clusters. In conclusion, combined analysis of ISSR markers and hypericin content is an optimal approach for further progress and breeding programs.Keywords: Hypericum perforatum (St. John's Wort), inter-simple sequence repeats (ISSR) markers, unweighted pair-group method with arithmetic averages (UPGMA), Nei’s genetic diversityAfrican Journal of Biotechnology, Vol. 13(1), pp. 18-31, 1 January, 201
A Novel Structural Assessment Technique to Prevent Damaged FRP-Wrapped Concrete Bridge Piers from Collapse
Repairing deteriorated concrete bridge piers using externally wrapped fiber reinforced polymer (FRP) composites have been proven as an effective approach. This technique has also been applied to low-rise building structures. Failures in FRP-wrapped concrete structures may occur by flexural failures of critical sections or by debonding of FRP plate from the concrete substrate. Debonding in the FRP/adhesive/concrete interface region may cause a significant decrease in member capacity leading to a premature failure of the system. In this chapter, a novel structural assessment technique aiming at inspecting the near-surface FRP debonding and concrete cracking of damaged FRP-wrapped concrete bridge piers to prevent the structures from collapse is presented. In the first part of this chapter, failure mechanisms of FRP-wrapped concrete systems are briefly discussed. The second part of this chapter introduces a novel structural assessment technique in which far-field airborne radar is applied. In this development, emphasis is placed on inspection of debonding in glass FRP (GFRP)-wrapped concrete cylinders, while the technique is also applicable to beams and slabs with bonded GFRP composites. Physical radar measurements on laboratory specimens with structural damages were conducted and used for validating the technique. Processed experimental measurements have shown promising results for the future application of the technique. Finally, research findings and issues are summarized.National Science Foundation (U.S.) (Grant CMS-0324607)Lincoln Laborator
Comparison of Expression Profiles in Ovarian Epithelium In Vivo and Ovarian Cancer Identifies Novel Candidate Genes Involved in Disease Pathogenesis
Molecular events leading to epithelial ovarian cancer are poorly understood but
ovulatory hormones and a high number of life-time ovulations with concomitant
proliferation, apoptosis, and inflammation, increases risk. We identified genes
that are regulated during the estrous cycle in murine ovarian surface epithelium
and analysed these profiles to identify genes dysregulated in human ovarian
cancer, using publically available datasets. We identified 338 genes that are
regulated in murine ovarian surface epithelium during the estrous cycle and
dysregulated in ovarian cancer. Six of seven candidates selected for
immunohistochemical validation were expressed in serous ovarian cancer,
inclusion cysts, ovarian surface epithelium and in fallopian tube epithelium.
Most were overexpressed in ovarian cancer compared with ovarian surface
epithelium and/or inclusion cysts (EpCAM, EZH2, BIRC5) although BIRC5 and EZH2
were expressed as highly in fallopian tube epithelium as in ovarian cancer. We
prioritised the 338 genes for those likely to be important for ovarian cancer
development by in silico analyses of copy number aberration and
mutation using publically available datasets and identified genes with
established roles in ovarian cancer as well as novel genes for which we have
evidence for involvement in ovarian cancer. Chromosome segregation emerged as an
important process in which genes from our list of 338 were over-represented
including two (BUB1, NCAPD2) for which there
is evidence of amplification and mutation. NUAK2, upregulated in ovarian surface
epithelium in proestrus and predicted to have a driver mutation in ovarian
cancer, was examined in a larger cohort of serous ovarian cancer where patients
with lower NUAK2 expression had shorter overall survival. In conclusion,
defining genes that are activated in normal epithelium in the course of
ovulation that are also dysregulated in cancer has identified a number of
pathways and novel candidate genes that may contribute to the development of
ovarian cancer
Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host
BACKGROUND: Gene expression profiles of bacteria in their natural hosts can provide novel insight into the host-pathogen interactions and molecular determinants of bacterial infections. In the present study, the transcriptional profile of the porcine lung pathogen Actinobacillus pleuropneumoniae was monitored during the acute phase of infection in its natural host. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial expression profiles of A. pleuropneumoniae isolated from lung lesions of 25 infected pigs were compared in samples taken 6, 12, 24 and 48 hours post experimental challenge. Within 6 hours, focal, fibrino hemorrhagic lesions could be observed in the pig lungs, indicating that A. pleuropneumoniae had managed to establish itself successfully in the host. We identified 237 differentially regulated genes likely to encode functions required by the bacteria for colonization and survival in the host. This group was dominated by genes involved in various aspects of energy metabolism, especially anaerobic respiration and carbohydrate metabolism. Remodeling of the bacterial envelope and modifications of posttranslational processing of proteins also appeared to be of importance during early infection. The results suggested that A. pleuropneumoniae is using various strategies to increase its fitness, such as applying Na+ pumps as an alternative way of gaining energy. Furthermore, the transcriptional data provided potential clues as to how A. pleuropneumoniae is able to circumvent host immune factors and survive within the hostile environment of host macrophages. This persistence within macrophages may be related to urease activity, mobilization of various stress responses and active evasion of the host defenses by cell surface sialylation. CONCLUSIONS/SIGNIFICANCE: The data presented here highlight the importance of metabolic adjustments to host conditions as virulence factors of infecting microorganisms and help to provide insight into the mechanisms behind the efficient colonization and persistence of A. pleuropneumoniae during acute disease