76,214 research outputs found
Portrait of Amy Mack (Mrs Lancelot Harrison) [picture] /
No full textTitle from inscription on reverse.; Condition: Fair, glued to card.; Inscriptions: "Amy Mack (Mrs. Lancelot Harrison) author of 'A bush calendar', 'Bush days', etc. photo. J. S. P. Ramsay" --In ink on reverse
Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and Liquid Chromatography-Multiplexed Collision Induced Dissociation-Mass Spectrometry
No full textThermochemical pretreatment of cellulosic biomass improves cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yield information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEXTM)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides based on porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column (Prevail Carbohydrate ES) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) in both positive and negative modes. For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of accurate molecular and fragment masses of neutral oligosaccharids in a single analysis. These analyses directly revealed presence of glucans up to degree of polymerization (DP) 22 without side-chain modifications. Additionally, arabinoxylans with DP up to 6 were detected in the pretreated biomass samples (post-enzymatic digestion). All linkages between sugar units in glucans and arabinoxylans were identified to be p-1-4 linkages based on cross-ring fragment masses. Comprehensive profiling of soluble oligosaccharides also demonstrated that arabinoxylan acetylation was reduced by greater than 85% post-AFEXTM treatment.Published version: Vismeh, Ramin, Humpula, James F., Chundawat, Shishir P. S., Balan, Venkatesh, Dale, Bruce E. & Jones, A. Daniel. (2013). Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and LC-TOF MS. Carbohydrate Polymers 94(2), 791-799. http://dx.doi.org/10.1016/j.carbpol.2013.02.00
AIDS and endemic Kaposi's sarcoma development : comparison by histopathology, virology (HHV8/KSHV) and cytogenetics
No full textKaposi’s sarcoma (KS) is a highly and abnormally vascularized tumor-like lesion with spindle cells (SC) affecting the skin, lymphnodes and viscera which is found in four different clinico-epidemiological forms as Classic KS (CKS), Iatrogenic KS (IKS), Endemic KS (EKS) and AIDS-associated KS (AKS). All KS forms develop from early stages of patch/plaque to late, nodular tumors and are associated with Kaposi's sarcomaassociated herpesvirus or human herpesvirus-8 (KSHV/ HHV-8). HHV-8 is also associated with primary effusion lymphoma (PEL) and multicentric castleman's disease (MCD). Various studies favour an endothelial origin (CD34+) of the KS SC but whether of vascular (VEC) or lymphatic endothelial cell (LEC) origin has not been settled. The HHV-8 latency-associated nuclear antigen type 1 (LANA-1) protein is the most frequently expressed viral antigen in infected cells. KS is promoted by HIV infection mainly by the angiogenic and proinflammatory effects of HIV-Tat. Whether KS represents a predominantly monoclonal neoplastic cell proliferation or a hyperplastic, reactive polyclonal process is still controversial. Reports on cytogenetic and molecular genetic changes in KS are few indicating that initially KS may develop as a reactive polyclonal cell proliferation associated with chromosome instability, followed by clonal chromosome changes in later stages.In the present KS histopathological studies (paper I & V) by triple antibody immunofluorescence we observed that: (a) the frequency of LANA+/CD34+ cells increased from early patch to late KS nodular lesions; (b) 30- 40% of the CD34+ SC were LANA- in both early and late KS, suggesting a continuous recruitment of noninfected endothelial cell into the KS lesion; (c) LANA+/CD34- cells were more frequent in early as compared to late KS and most of them expressed LEC markers such as LYVE-1 and D2-40, suggesting that the resident LECs represent an early target of primary HHV-8 infection; (d) LANA+/CD34-/LYVE-1+ cells decreased from early (25%) to late (4%) KS suggesting a phenotype switch from LEC to VEC; (e) the frequency of proliferating cells (Ki67+) was higher in early as compared to late KS stages and no significant difference in cell proliferation was observed between nodular AKS and EKS, suggesting that the growth of the usually more aggressive AKS tumors may reflect a higher rate of SC progenitor recruitment as compared to the slower growing EKS lesions, consistent with the observed increase in non-proliferative SC during KS (AKS) evolution to nodular stage; (f) infiltrating lymphocytes were LANA negative, whereas some CD68+ monocyte-macrophase appeared to be LANA+.To validate our results from LANA immunostaining, we established and optimized a semi-quantitative PCR assay for HHV-8 detection in formalin-fixed paraffin-embedded KS biopsies (paper III) and two different protocols for DNA extraction were compared namely the Chelex 100 and Qia-gene kit method. Our result indicate a better performance for Chelex-extracted DNA in paraffin embedded archival biopsies. In late, nodular stage of both AKS and EKS the virus load per unit tissue actin (HHV-8/actin) is higher than in early stages (patch/plaque), which corroborates our findings from double immunostaining for LANA and CD34 of the same cases. Thus these PCR results by serial dilutions of HHV-8 DNA show a correlation between virus load and progressive stages of KS development i.e. the increase in LANA+ SC and does not indicate an increase in viral content of individual tumor cells.With quantitative real time PCR on sera (paper II), we found higher HHV8 DNA load in AKS compared to EKS, patch compared to nodular KS and males compared to females as well as a significantly higher serum viral DNA load in KS compared to non-KS patients’ sera.AKS patient sera studied by ELISA for HIV-Tat antibodies showed that patients with high HHV8-DNA level had no or low levels of anti-Tat antibodies while patients with very low HHV8-DNA levels had several fold higher anti-Tat IgG titers. Analysis of these KS sera for epitope specificity showed reactivity to various Tat epitopes but not to the transcriptional (functional) epitopes 46-60 (TAR-binding region). To determine cytogenetic changes during the development of KS as well as possible differences between AKS and EKS we studied 27 KS (10 nodular AKS, 8 patch AKS, 8 nodular EKS and 1 patch EKS) cases by laser microdissection, global amplification of DNA and comparative genomic hybridization (paper IV). Deletion of Chromosome Y was detected in 20 of 23 male KS and was the only chromosomal deletion observed in early (patch) KS biopsies. Late AKS and EKS apart from random aberrations also showed recurrent chromosomal deletions of chromosome 16, 17, Y and a gain of chromosome 21. The deletion of chromosome 16 and Y was confirmed by interphase FISH on paraffin embedded sections. EKS had higher number of chromosomal abnormalities than AKS.In summary KS SC apparently represents a mixed pool endothelial cells including cells from both VEC and LEC the later being a possible early target for HHV-8 infection. Non-infected CD34+ progenitor cells appears to be continuously recruited to the developing KS lesion and locally infected during the development of KS. Serum HHV-8 DNA load is higher in AKS compared to EKS and HIV-Tat titers were inversely correlated to HHV-8 DNA load in AKS patients. Increased number of recurrent and sporadic chromosomal abnormalities found mostly in a subset of late nodular KS cases may indicate the onset of a clonal cell population (sarcoma).List of scientific papersI. Pyakurel P, Massambu C, Castanos-Velez E, Ericsson S, Kaaya E, Biberfeld P, Heiden T (2004). Human herpesvirus 8/Kaposi sarcoma herpesvirus cell association during evolution of Kaposi sarcoma. J Acquir Immune Defic Syndr. 36(2): 678-83. https://doi.org/10.1097/00126334-200406010-00004 II. Massambu C, Pyakurel P, Kaaya E, Enbom M, Urassa W, Demirhan I, Loewer J, Linde A, Chandra A, Heiden T, Doerr HW, Chandra P, Biberfeld P (2003). Serum HHV8 DNA and Tat antibodies in Kaposis sarcoma patients with and without HIV-1 infection. Anticancer Res. 23(3B): 2389-95. https://pubmed.ncbi.nlm.nih.gov/12894519 III. Pak F, Pyakural P, Kokhaei P, Kaaya E, Akbar Pourfathollah A, Selinova G, Biberfeld P (2005). HHV-8/KSHV during development of Kaposis sarcoma: evaluation by PCR and immunohistochemistry. J Cutan Pathol. 32(1): 21-7. https://doi.org/10.1111/j.0303-6987.2005.00256.x IV. Pyakurel P, Montag U, Castanos-Velez E, Kaaya E, Christensson B, Biberfeld P, Schrock E, Heiden T (2005). Kaposis sarcoma: CGH ctogenetic analysis of microdissected early and late stage biopsies. [Manuscript]V. Pyakurel P, Pak F, Mwakigonja AR, Kaaya E, Heiden T, Biberfeld P (2005). Recruitment of Kaposis sarcoma spindle cells during tumor development. [Manuscript]</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Experimental study of thin film sensor networks for wind turbine blade damage detection
No full textDamage detection of wind turbine blades is difficult due to their complex geometry and large size, for which large deployment of sensing systems is typically not economical. A solution is to develop and deploy dedicated sensor networks fabricated from inexpensive materials and electronics. The authors have recently developed a novel skin-type strain gauge for measuring strain over very large surfaces. The skin, a type of large-area electronics, is constituted from a network of soft elastomeric capacitors. The sensing system is analogous to a biological skin, where local strain can be monitored over a global area. In this paper, we propose the utilization of a dense network of soft elastomeric capacitors to detect, localize, and quantify damage on wind turbine blades. We also leverage mature off the shelf technologies, in particular resistive strain gauges, to augment such dense sensor network with high accuracy data at key locations, therefore constituting a hybrid dense sensor network. The proposed hybrid dense sensor network is installed inside a wind turbine blade 1:25 scale model, and tested in a wind tunnel to simulate an operational environment. Results demonstrate the ability of the hybrid dense sensor network to detect, localize, and quantify damage.</p
Prompt charm production in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV
No full textCharm production at the LHC in pp collisions at s√=7 TeV is studied with the LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, D+s→ϕ(K−K+)π+, Λ+c→pK−π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0<pT<8 GeV/c and 2.0<y<4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above pT-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives
σ(cc¯)pT<8 GeV/c,2.0<y<4.5=1419±12(stat)±116(syst)±65(frag) μb,
where the uncertainties are statistical, systematic, and due to the fragmentation functions
Probing the nature of AFEX-pretreated corn stover derived decomposition products that inhibit cellulase activity
No full textSequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24–28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60–65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34–43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44–56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69–70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.Published version: Humpula, James F., Uppugundla, Nirmal, Vismeh, Ramin, Sousa, Leonardo, Chundawat, Shishir P. S., Jones, A. Daniel, Balan, Venkatesh, Dale, Bruce E. & Cheh, Albert M. (2014). Probing the nature of AFEX-retreated corn stover derived decomposition products that inhibit cellulase activity. Bioresource Technology 152, 38-45. http://dx.doi.org/10.1016/j.biortech.2013.10.08
Neo-Simulation and Gaming Toward Active Learning
No full textThis book provides tips to teachers for moving toward active learning by using simulation and gaming. The book is a rare reference for teachers who wish to initiate active learning by applying many real experiences from world experts in simulation and gaming. This cumulative wisdom comes from cutting-edge trials reported at the 49th International Simulation and Gaming Association’s annual conference in Thailand 9–13 July 2018. The importance of changing teachers’ one-way lecture approach to that of active learning has been commonly understood for several decades and has been promoted especially in recent years in Asian universities. Simulation and gaming meets the requirements of such teaching programs, especially for active learning, but there are few books or references on how to gamify a lecture. This book serves as a guide to facilitate that change. The author recognizes the duty to provide readers with fixed directions toward simulation and gaming in the next generation, which have still not been fully elucidated. Developing a simulation and gaming culture and making it sustainable in the next decade are the purpose of this book
Newton's Laws
No full textAuthored and curated by David P. Stern, this series of web pages, part of "From Stargazers to Starships," describes Newton's three laws of motion and the two concepts on which they are based, force and inertia. The author breaks down the page in this fashion: the concept of force, motion against outside resistance, and motion with significant resistance. The author also provides additional links for further study on the life of Issac Newton. A lesson plan for instructors is also provided
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