76,180 research outputs found
Bio-optical properties of the cyanobacterium <i>Nodularia spumigena</i>
Get PDFIn the last century, an increasing number of extreme weather events have been
experienced across the globe. These events have also been linked to changes
in water quality, especially due to heavy rains, flooding, or droughts. In
terms of blue economic activities, harmful algal bloom events can pose a major
threat, especially when they become widespread and last for several days. We
present and discuss advanced measurements of a bloom dominated by the
cyanobacterium Nodularia spumigena conducted by hyperspectral optical technologies via
experiments of opportunity. Absorption coefficients, absorbance and
fluorescence were measured in the laboratory, and these data are available at
https://doi.org/10.4121/21610995.v1
(Wollschläger et al., 2022), https://doi.org/10.4121/21822051.v1 (Miranda et al., 2023)
and https://doi.org/10.4121/21904632.v1 (Miranda and
Garaba, 2023). Data used to derive the above-water reflectance are available
from https://doi.org/10.4121/21814977.v1 (Garaba,
2023) and https://doi.org/10.4121/21814773.v1
(Garaba and Albinus, 2023). Additionally, hyperspectral
fluorescence measurements of the dissolved compounds in the water were carried out.
These hyperspectral measurements were conducted over a wide spectrum (200–2500 nm). Diagnostic optical features were determined using robust
statistical techniques. Water clarity was inferred from Secchi disc
measurements (https://doi.org/10.1594/PANGAEA.951239,
Garaba and Albinus, 2022). Identification of the cyanobacterium
was completed via visual analysis under a microscope. Full sequences of the 16S rRNA and rbcL genes were
obtained, revealing a very strong match to
N. spumigena; these data are available via GenBank: https://www.ncbi.nlm.nih.gov/nuccore/OP918142/
(Garaba and Bonthond, 2022b) and https://www.ncbi.nlm.nih.gov/nuccore/OP925098
(Garaba and Bonthond, 2022a). The chlorophyll-a
and phycocyanin levels determined are available from https://doi.org/10.4121/21792665.v1 (Rohde et al., 2023).
Our experiments of opportunity echo the importance of sustainable,
simplified, coordinated and continuous water quality monitoring as a way to
thrive with respect to the targets set in the United Nations Sustainable Development Goals (e.g. 6, 11, 12 and 14) or the European Union Framework Directives (e.g. the Water Framework Directive and
Marine Strategy Framework Directive).</p
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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDFDamage 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
Get PDFCharm 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
- …
