335 research outputs found

    Institutional assessment for climate change adaptation, Didahara, Borena, southern Ethiopia

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    Physical characterization of cellulosic fibres from Sesbania grandiflora stem

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    In the present investigation, the morphology and the porosity of the Sesbania grandiflora fibre has been studied by SEMin order to understand their effects on the capillary structure and the hygroscopic behavior. The physical properties, such astensile strength, elongation, density, fineness, morphological structure, water absorption coefficient and thermo-gravimetricanalysis, have been examined. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) are used to identify thecrystalline index and chemical groups present in the fibre. It has been found that this new vegetable material has a very lowbulk density and a highest water absorption capacity. FTIR and X-ray analyses have proved that these fibres are rich incellulosic content with crystallinity index of 51% cellulose content of 70.75 wt %, density of 1.4738 g/cc, and tensilestrength of 365-11100 Mpa. The results show that Sesbania grandiflora fibres have comparable fibre strength, elongationand cellulose content to jute, hemp, ramie, Phoenicx sp, okra and Prosopis juliflora. The new fibre has better crystallinityindex than banana, bagasse and sponge gourd and hence can be utilized for technical textiles application

    Physical characterization of cellulosic fibres from Sesbania grandiflora stem

    Get PDF
    437-441In the present investigation, the morphology and the porosity of the Sesbania grandiflora fibre has been studied by SEM in order to understand their effects on the capillary structure and the hygroscopic behavior. The physical properties, such as tensile strength, elongation, density, fineness, morphological structure, water absorption coefficient and thermo-gravimetric analysis, have been examined. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) are used to identify the crystalline index and chemical groups present in the fibre. It has been found that this new vegetable material has a very low bulk density and a highest water absorption capacity. FTIR and X-ray analyses have proved that these fibres are rich in cellulosic content with crystallinity index of 51% cellulose content of 70.75 wt %, density of 1.4738 g/cc, and tensile strength of 365-11100 Mpa. The results show that Sesbania grandiflora fibres have comparable fibre strength, elongation and cellulose content to jute, hemp, ramie, Phoenicx sp, okra and Prosopis juliflora. The new fibre has better crystallinity index than banana, bagasse and sponge gourd and hence can be utilized for technical textiles application

    Transcriptome analysis in switchgrass discloses ecotype difference in photosynthetic efficiency

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    Citation: Serba, D. D., Uppalapati, S. R., Krom, N., Mukherjee, S., Tang, Y. H., Mysore, K. S., & Saha, M. C. (2016). Transcriptome analysis in switchgrass discloses ecotype difference in photosynthetic efficiency. Bmc Genomics, 17, 14. doi:10.1186/s12864-016-3377-8Background: Switchgrass, a warm-season perennial grass studied as a potential dedicated biofuel feedstock, is classified into two main taxa - lowland and upland ecotypes - that differ in morphology and habitat of adaptation. But there is limited information on their inherent molecular variations. Results: Transcriptome analysis by RNA-sequencing (RNA-Seq) was conducted for lowland and upland ecotypes to document their gene expression variations. Mapping of transcriptome to the reference genome (Panicum virgatum v1. 1) revealed that the lowland and upland ecotypes differ substantially in sets of genes transcribed as well as levels of expression. Differential gene expression analysis exhibited that transcripts related to photosynthesis efficiency and development and photosystem reaction center subunits were upregulated in lowlands compared to upland genotype. On the other hand, catalase isozymes, helix-loop-helix, late embryogenesis abundant group I, photosulfokinases, and S-adenosyl methionine synthase gene transcripts were upregulated in the upland compared to the lowlands. At >= 100x coverage and >= 5% minor allele frequency, a total of 25,894 and 16,979 single nucleotide polymorphism (SNP) markers were discovered for VS16 (upland ecotype) and K5 (lowland ecotype) against the reference genome. The allele combination of the SNPs revealed that the transition mutations are more prevalent than the transversion mutations. Conclusions: The gene ontology (GO) analysis of the transcriptome indicated lowland ecotype had significantly higher representation for cellular components associated with photosynthesis machinery controlling carbon fixation. In addition, using the transcriptome data, SNP markers were detected, which were distributed throughout the genome. The differentially expressed genes and SNP markers detected in this study would be useful resources for traits mapping and gene transfer across ecotypes in switchgrass breeding for increased biomass yield for biofuel conversion

    Dsg2 Upregulation as a Rescue Mechanism in Pemphigus

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    In pemphigus vulgaris (PV), autoantibodies directed against the desmosomal cadherin desmoglein (Dsg) 3 cause loss of intercellular adhesion. It is known that Dsg3 interactions are directly inhibited by autoantibody binding and that Dsg2 is upregulated in epidermis of PV patients. Here, we investigated whether heterophilic Dsg2-Dsg3 interactions occur and would modulate PV pathogenesis. Dsg2 was upregulated in PV patients’ biopsies and in a human ex vivo pemphigus skin model. Immunoprecipitation and cell-free atomic force microscopy (AFM) experiments demonstrated heterophilic Dsg2-Dsg3 interactions. Similarly, in Dsg3-deficient keratinocytes with severely disturbed intercellular adhesion Dsg2 was upregulated in the desmosome containing fraction. AFM revealed that Dsg2-Dsg3 heterophilic interactions showed binding frequency, strength, Ca2+-dependency and catch-bond behavior comparable to homophilic Dsg3-Dsg3 or homophilic Dsg2-Dsg2 interactions. However, heterophilic Dsg2-Dsg3 interactions had a longer lifetime compared to homophilic Dsg2-Dsg2 interactions and PV autoantibody-induced direct inhibition was significantly less pronounced for heterophilic Dsg2-Dsg3 interactions compared to homophilic Dsg3 interactions. In contrast, a monoclonal anti-Dsg2 inhibitory antibody reduced heterophilic Dsg2-Dsg3 and homophilic Dsg2-Dsg2 binding to the same degree and further impaired intercellular adhesion in Dsg3-deficient keratinocytes. Taken together, the data demonstrate that Dsg2 undergoes heterophilic interactions with Dsg3, which may attenuate autoantibody-induced loss of keratinocyte adhesion in pemphigus

    Role of ADAM10 and ADAM17 in the Regulation of Keratinocyte Adhesion in Pemphigus Vulgaris

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    The severe autoimmune blistering disease Pemphigus vulgaris (PV) is mainly caused by autoantibodies (IgG) against desmoglein (Dsg) 3 and Dsg1. The mechanisms leading to the development of blisters are not fully understood, but intracellular signaling seems to play an important role. Sheddases ADAM10 and ADAM17 are involved in the turnover of the desmosomal cadherin Dsg2 and ADAM10 has been shown to contribute to acantholysis in a murine pemphigus model. In the present study, we further examined the role of ADAM10 and ADAM17 both in keratinocyte adhesion and in the pathogenesis of PV. First, we found that inhibition of ADAM10 enhanced adhesion of primary human keratinocytes but not of immortalized keratinocytes. In dissociation assays, inhibition of ADAM10 shifted keratinocyte adhesion towards a hyperadhesive state. However, ADAM inhibition did neither modulate protein levels of Dsg1 and Dsg3 nor activation of EGFR at Y1068 and Y845. In primary human keratinocytes, inhibition of ADAM10, but not ADAM17, reduced loss of cell adhesion and fragmentation of Dsg1 and Dsg3 immunostaining in response to a PV1-IgG from a mucocutaneous PV patient. Similarly, inhibition of ADAM10 in dissociation assay decreased fragmentation of primary keratinocytes induced by a monoclonal antibody against Dsg3 and by PV-IgG from two other patients both suffering from mucosal PV. However, such protective effect was not observed in both cultured cells and ex vivo disease models, when another mucocutaneous PV4-IgG containing more Dsg1 autoantibodies was used. Taken together, ADAM10 modulates both hyperadhesion and PV-IgG-induced loss of cell adhesion dependent on the autoantibody profile
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