125,216 research outputs found
Data for "Measuring Light Absorption by Freshly Emitted Organic Aerosols: Optical Artifacts in Traditional Solvent Extraction-Based Methods"
No full textThe dataset was used to report optical artifacts in traditional solvent extraction based photometry techniques. Biomass fuels from different sources were combusted and the absorption coefficients obtained using solvent-extraction based techniques were compared to their particle-phase counterparts. Trends in the absorption coefficient bias were explored with (1) OC/TC ratios and (2) single scattering albedo (SSA). A linear trend with the OC/TC ratio and SSA was also observed for the biomass burning samples that were investigated. Obtained results and experimental methodology are detailed in the manuscript linked with this dataset
Structure Analysis Of Plant Lectin Domains
No full textLectins are multivalent carbohydrate binding proteins that specifically recognise diverse sugar structures and mediate a variety of biological processes, such as cell-cell and host-pathogen interactions, serum glycoprotein turnover and innate immune responses. Lectins have received considerable attention in recent years on account of their properties leading to wide use in research and biomedical applications. Seeds of leguminous plants are mainly rich sources of lectins, but lectins are also found in all classes and families of organisms. Legume lectins have similar tertiary structures, but exhibit a large variety of quaternary structures. The carbohydrate binding site in them is made up of four loops, the first three of which are highly conserved in all legume lectins. The fourth loop, which is variable, is implicated in conferring specificity. Legume lectins which share the same monosaccharide specificity often exhibit markedly different oligosaccharide specificities. This thesis primarily concerns with structure solution and analysis of lectins from the legume and β-prism II fold families using X-ray crystallography. Apart from having the property of specifically and reversibly binding to carbohydrates, lectins are also interesting models to study sequence-structure relationships, especially of how minor change in the sequence may bring about major changes in oligomerization and binding.
Chapter 1 gives an overview of different structural types of plant lectins and describes in detail, their carbohydrate binding features. The details of the various experimental procedures employed during the course of this research, are explained in Chapter 2.
Chapter 3 describes the crystal structure of a β-prism II fold lectin (RVL), from Remusatia vivipara, an epiphytic plant of traditional medicinal value, and analysis of its binding properties. This lectin was established to have distinct binding properties and has nematicidal activity against a root-knot nematode with the localization site identified as the high-mannose displaying gut-lining in the nematode. The crystal structure of RVL revealed a new quaternary association of this homodimeric lectin, different from those of reported β-prism II lectins. Functional studies on RVL showed that it fails to bind to simple mannose moieties yet showed agglutination with rabbit blood cells (which have mannose moieties on the surface) and some high mannose containing glycoproteins like mucin and asialofetuin. Further, ELISA and glycan array experiments indicated that RVL has high affinity to N-glycans like trimannose pentasaccharide such as in gp120, a capsid glycoprotein of HIV virus, necessary in virus-association with the host cell. The structural basis for this N-glycan binding was revealed through structure analysis and molecular modelling, and it was demonstrated that there are two distinct binding sites per monomer, making RVL a truly multivalent lectin. Evolutionary phylogeny revealed the divergence in the β-prism II fold proteins with regards to the number of sugar-binding regions per domain, oligomerization and specificity.
Chapter 4 deals with the structural studies on a galactose-specific legume lectin (DLL-II) from Dolichos lablab, a leguminous plant. The lectin was found to be a planar tetramer in the crystal structures of the native and ligand bound forms, as expected from our solution studies and phylogenetic analysis. The protein is a heterotetramer with subunits differing only in the presence or absence of a C-terminal helical region at the core of the tetramer. Due to the static disorder in all the crystals, the central helix could be oriented in either direction. Structure analysis of DLL-II proved to be an interesting endeavour as static disorder compounded with twinning in the crystal made the data processing and structure solution a challenging process. Subsequent structure and sequence alignments led to the identification of an adenine-binding pocket in the hydrophobic core of the tetramer. Based on this, DLL-II lectin was co-crystallized with adenine and the structure revealed the presence of adenine at the predicted binding site.
Chapter 5 describes the identification and analysis of potential plant lectins/lectin-like domains in the genome of Oryza sativa, using bioinformatics approaches. This project was initiated to study the occurrence of legume-lectin like domains (a predominant dicot feature) in O. sativa, which is a monocot. Later, a large scale genome analysis for all types of lectin domains was carried out through exhaustive PSI-BLAST, profile matching by HMMer, CDD and MulPSSM. The final validation was carried out by assessing the carbohydrate binding potential of the domain by examining the sugar binding sites. The primary interest in undertaking this work was to find the occurrence of association of these domains with other domains as in protein receptor kinases, where lectin is the receptor domain. Though primarily initiated as a bioinformatics project, further structural characterization was attempted by cloning, expression and purification of some of the annotated lectin proteins using prokaryotic expression systems. The protein expression was attained in reasonable amounts for a few of the annotated legume lectin homologs, however purification is yet to be achieved as the expressed proteins are insoluble.
A part of the results described in this thesis and the other related projects that the author was involved are reported in the following publications.
1) Purification, characterization and molecular cloning of a monocot mannose-binding lectin from Remusatia vivipara with nematicidal activity Bhat GG, Shetty KN, Nagre NN, Neekhra VV, Lingaraju S, Bhat RS, Inamdar SR, Suguna K, Swamy BM. 2010. Glycoconjugate J. 27(3):309-320
2) Modification of the sugar specificity of a plant lectin: structural studies on a point mutant of Erythrina corallodendron lectin Thamotharan S, Karthikeyan T, Kulkarni KA, Shetty KN, Surolia A, Vijayan M & Suguna K. 2011. Acta Crystallographica D 67(3):218-227
3) Crystal structure of a β-prism II lectin from Remusatia vivipara Shetty KN, Bhat GG, Inamdar SR, Swamy BM, Suguna K. 2012. Glycobiology 22(1): 56-69.
4) Structure of a galactose binding lectin from Dolichos lablab
Shetty KN, Lavanyalatha V, Rao RN, SivaKumar N & Suguna K (Under review)
5) Occurrence of lectin-like domains: Oryza sativa genome analysis. Shetty KN & Suguna K. (Manuscript in preparation
Problems in computer security
No full textAuerbach, R.L.; Kerbel, N.; Megraw, M.; Osburn, R.; Shetty, S.; Hoffman, J.. (1998). Problems in computer security. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3251
sj-docx-1-han-10.1177_15589447211064365 – Supplemental material for Prescription Opioids and Patient-Reported Outcomes and Satisfaction After Carpal Tunnel Release Surgery
No full textSupplemental material, sj-docx-1-han-10.1177_15589447211064365 for Prescription Opioids and Patient-Reported Outcomes and Satisfaction After Carpal Tunnel Release Surgery by Pragna N. Shetty, Kavya K. Sanghavi, Mihriye Mete and Aviram M. Giladi in HAND</p
sj-docx-2-han-10.1177_15589447211064365 – Supplemental material for Prescription Opioids and Patient-Reported Outcomes and Satisfaction After Carpal Tunnel Release Surgery
No full textSupplemental material, sj-docx-2-han-10.1177_15589447211064365 for Prescription Opioids and Patient-Reported Outcomes and Satisfaction After Carpal Tunnel Release Surgery by Pragna N. Shetty, Kavya K. Sanghavi, Mihriye Mete and Aviram M. Giladi in HAND</p
Ossifying fibromyxoid tumour of the sphenoid sinus
No full textIntroduction: Ossifying fibromyxoid tumour is a recently described, rare but morphologically distinctive soft tissue neoplasm characterised by a combination of myxoid and/or fibrous stroma with areas of ossification. Although most authors postulate a neuroectodermal origin for this peculiar tumour, there is no agreement in the literature regarding its histopathogenesis. To our knowledge, this is the first reported case of ossifying fibromyxoid tumour involving the sphenoid sinus.Histological findings: Tumour of low cell density, composed of small, spindle-shaped or stellate cells with small, irregular nuclei set in a fibromyxoid stroma.Management: Following discussion at the skull base multidisciplinary team meeting, a combined surgical team including an otorhinolaryngologist and a neurosurgeon carried out resection of the lesion, using an endoscopic transnasal approach, followed by reconstruction of the defect.Conclusions: An awareness of the distinctive histopathological features of ossifying fibromyxoid tumour, and of its clinical effects, is crucial to establishing a definitive diagnosis and thereby instituting appropriate management. This case report also reinforces the evolving role of the endoscopic transnasal approach in the management of inflammatory and neoplastic disease involving the skull base. This is increasingly being made possible by close collaboration between multiple surgical specialties, including otorhinolaryngology and neurosurgery.<br/
Energy requirements of adults.
No full textOBJECTIVES: To describe issues related to energy requirements of free living adults and discuss the importance of basal metabolic rate (BMR) and their relationships to total energy expenditure (TEE ) and physical activity level (PAL, derived as TEE/BMR) and to determine the influence of body weight, height, age and sex. DESIGN: Based on a review of the literature, this paper examines the variability in BMR due to methodology, ethnicity, migration and adaptation (both metabolic and behavioural) due to changes in nutritional status. Collates and compiles data on measurements of TEE in free living healthy adults, to arrive at limits and to compare TEE of populations with different life-styles. RESULTS AND CONCLUSIONS: The constancy of BMR and its validity as a reliable predictor of TEE in adults as well as the validity of PAL as an index of TEE adjusted for BMR and thus its use to categorise the physical activity pattern and lifestyle of an individual was confirmed. The limits of human daily energy expenditure at around 1.2 x BMR and 4.5 x BMR based on measurements made in free living adults have been reported in the literature. A large and robust database now exists of energy expenditure measurements obtained by the doubly labelled water method in the scientific literature and the data shows that, in general, levels of energy expenditure are similar to the recommendations for energy requirements adopted by FAO/WHO/UNU (1985). The review also confirms that metabolic adaptation to energy restriction is not an important factor that needs to be considered when recommending energy requirements for adults in developing countries
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
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