Functional colloids from a lignin-rich bioresidue and their application

This thesis details the extraction and characterisation of a lignin-rich bioresidue from cocoa bean shell (CBS), the formation of particles using antisolvent precipitation, and applications in emulsions and microfluidics. A co-product of the food industry, there is an estimated 600 kt of CBS produced annually. Lignin, an aromatic component of CBS, is of interest to researchers aiming to develop analogues to current consumer goods from sustainable feedstocks, and as a natural source of aromatics has properties of interest such as hydrophobicity and anti-microbial effects. Lignin liberation from biomass typically involves depolymerisation by processes such as bleaching, often produced as a byproduct of commercial processes such as the Kraft paper pulping process termed Kraft lignin, however, this research uses mild acid assisted ethanol extraction. The bioresidue characteristics and co-products were characterised using analysis techniques such as FTIR and GCMS, identifying the presence of molecular surfactant, termed lipid. The extracted bioresidue which contained the lipid fraction (CBS-LC) was processed further to remove molecular surfactant, generating a second ‘lipid removed’ extract (CBS-LR). It was found that hydrodynamic flow-focusing microfluidics was unsuitable for a proposed desorption approach to antisolvent precipitation in water. An alternative continuous process for colloidal lignin-rich particle (CLP) production was generated by setting up a coaxial jet mixing device (CJM). By varying processing conditions to explore the effect of Reynolds number and volumetric flow rate ratio, non-aggregating particles were precipitated with average diameters between 150 and 600 nm. The aqueous dispersions were stable with respect to particle size for at least 14 days, for both types of extract. The impact of both lipid and co-extractives from the crude bioresidue was assessed by use of CLPs as Pickering particles in emulsion studies. It was found that the emulsions containing crude CLPs were less efficient at stabilising a 1 in 10 sunflower oil-in-water emulsion than Kraft lignin analogues. This was theorised to be the result of the presence of co-extracted molecular surfactant, which may have had a competitive adsorption effect with the CLPs at the oil and water interface. The lipid fraction of the CBS extract was removed, and the resultant change in measured contact angle offered an indication that the CLP surface properties varied from hydrophobic to hydrophilic. It was also found that lignin-rich CLPs could be transferred from aqueous to non-aqueous dispersion in the presence of a molecular surfactant. The application of the aqueous and non-aqueous CLP dispersions as a particle dispersion for ghost particle velocimetry (GPV) was explored, motivated by the fact that non aqueous tracer particle systems for GPV have not yet been reported. GPV is a technique for flow field imaging introduced in the last 10 years, allowing development of real-time quantification of flow fields in the focal plane and different cross-sections of a microfluidic channel using particles with a diameter of < 200 nm. This is currently achieved using a polystyrene based particle dispersion in the aqueous phase, and by demonstrating that lignin-rich CLPs can equally quantify flow fields, there potential to substitute these, which is an example of waste valorisation and environmentally sustainable substitution of a material. Application examples of this novel particle system were found not only to agree with theoretical flow velocity values but were able to quantify flow simultaneously in static and dynamic flow systems in both aqueous and non-aqueous phases. Whilst this thesis has demonstrated the ability to visualise and quantify flow fields using CLPs, the systems presented contain molecular surfactant in each instance. This thesis contributes to the understanding of extraction and utilisation of lignin-rich bioresidue from CBS, highlighting its potential for use as a source of colloidal particles. Combining the spectroscopic techniques with characterisations such as contact angle offer insights into how particle behaviour is impacted by composition, paving the way for future advancements in creating dispersed particle systems with potential applicability in flow field imaging. Additionally, the first example of non-aggregating colloidal tracer particles in a non-aqueous system offers great potential for imaging not only the velocity of non-aqueous systems in confined channels, but formation of droplets; an area of significant interest in chemical micro-reactor systems. To advance research in this area, it is recommended that initial work on the interactions between lignin and co-extracted surfactants are developed with respect to non-aqueous phase dispersions. Furthermore, there is an opportunity to explore the variation of the wetting characteristics of CLPs by employing novel solvent-antisolvent pairings. This would enable greater variation in the polarity of solvents in which CLPs can be dispersed. . In combining modified wettability with the adjustable particle diameter in a CJM, CLPs tailorable in both diameter and wettability may be produced, which could substitute a variety of current food-grade Pickering stabilisers

Recommending cut scores with a subset of items: An empirical illustration

Many testing programs face the practical challenge of having limited resources to conduct comprehensive standard setting studies. Some researchers have suggested that replicating a group’s recommended cut score on a full-length test may be possible by using a subset of the items. However, these studies were based on simulated data. This study describes a standard setting application using two independent panels providing judgments on a 300-item licensure test. Specifically, one panel provided judgments on all 300 items; whereas the second panel made judgments on a randomly-selected subset of 150 items. Both panels also participated in an alternate standard setting method to evaluate panel comparability. Results suggest caution for practitioners considering using subsets of items for standard setting studies. Accessed 7,224 times on https://pareonline.net from May 11, 2010 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Alien Registration- Gerrow, Ada (Fort Fairfield, Aroostook County)

https://digitalmaine.com/alien_docs/35653/thumbnail.jp

Lignin recovery from cocoa bean shell using microwave-assisted extraction and deep eutectic solvents

Lignin is the second most abundant natural polymer after cellulose, and valorisation of lignin-rich streams has attracted increasing attention recently. This paper presents a novel and sustainable method to recover lignin from Cocoa Bean Shells (CBS) using Deep Eutectic Solvents (DES) and microwaves. A DES containing p-toluenesulfonic acid, choline chloride and glycerol (2:1:1 M ratio) was selected based on its dielectric properties. Under 200 W microwave power, the optimum yield of 95.5 % lignin was achieved at 130 °C and 30 min. DES-extracted lignin exhibited unique structural characteristics including larger particle sizes (242.5 µm D50 size), structural diversity (410.4 µm D90-D10 size) and H/G sub-unit ratio (71.9 %) compared with commercial Kraft lignin (77.2 µm, 157.9 µm and 0.1 % respectively), indicating the potential of DES in the modification and upgrading of lignin for novel value-added products

Unveiling the role of plasticity rules in reservoir computing

Reservoir Computing (RC) is an appealing approach in Machine Learning that combines the high computational capabilities of Recurrent Neural Networks with a fast and easy training method. Likewise, successful implementation of neuro-inspired plasticity rules into RC artificial networks has boosted the performance of the original models. In this manuscript, we analyze the role that plasticity rules play on the changes that lead to a better performance of RC. To this end, we implement synaptic and non-synaptic plasticity rules in a paradigmatic example of RC model: the Echo State Network. Testing on nonlinear time series prediction tasks, we show evidence that improved performance in all plastic models are linked to a decrease of the pair-wise correlations in the reservoir, as well as a significant increase of individual neurons ability to separate similar inputs in their activity space. Here we provide new insights on this observed improvement through the study of different stages on the plastic learning. From the perspective of the reservoir dynamics, optimal performance is found to occur close to the so-called edge of instability. Our results also show that it is possible to combine different forms of plasticity (namely synaptic and non-synaptic rules) to further improve the performance on prediction tasks, obtaining better results than those achieved with single-plasticity models

The Lantern, 2023-2024

God, worship, and damnation in the font of my body • The Men in My Life • Vagabond Fishermen • Unfinished Elegy • Big Game • Bitters • On the Ferris Wheel • Ruffling Feathers • Haunted House • Dragon in the Pond • Saint Sebastian • The Last Supper • The Perfect Babka • Session • Sunrise • Dish Dog • A Love Letter to Hands • In Memoriam: Mary Lobo \u2715 • Champagne • Resting Place • Balance • An Arboreal Requiem • Moving Forward • Bye-Bye Beach Days • Portofino • The Moth on My Dashboard • Golden Ash • New Chapters, Old Books • Visions of a Tired Receptionist • If It Ends • Salt-Lined Sidewalks • Poetry Can Be Anything • Happy Birthday • Overlooked • Dead Water • Daylight • Morn • The Last of the Bulgarians • To the Infamous • Loneliest Boy in the World • Barn on Fire • Mustang • Rhea • At Fault • Magic Circle • Thursday Afternoon • That Beautiful Blue • Post-Roe Lullaby • A Redefinition of Childhood • Frankenstein\u27s Monster • Eyes • Of Fields and Forests • A Toast to the End of My Life • Water Buffalo • Harvest Season • A Child of Cain Threw a Can Across the Room • To Be the Fairest of Them All • Chaoshttps://digitalcommons.ursinus.edu/lantern/1192/thumbnail.jp

The Lantern, 2022-2023

The Genie and the Scotsman • Taxi Driver Savior Complex • Midnight Waltz • Eulogy of Caution • Don\u27t cry over spilled milk!! • I am the spider • The Lamb • The Witch and the Shepherd • Nostalgia • In the Summer I Want Light • I Am (Not) • Thanatophobia • We\u27re not children anymore • Hamlet\u27s Fool • Lemon • the last two people in the world • Amongst Chaos (what captivated me) • How About Now, Billy Joel • Bug Trap • Spring, Musser Hall, Room 219 • Time\u27s Denial • A Song of History • A Haiku for You • Hello! My Name Is: • Toilet Humor • Waterfalls • Communion • Shift • Mama Told Me Not To Waste My Life • Writer\u27s Block • Sharp-Tongued Women • Off Trail • Paper Bag Town • Serenity • Landscape of Ursinus Courtyard • Image #07, Affinist designer • Love Birds • Discount Narnia • False Security • Stripes and Illusions • The Burning of Ophelia • Molly\u27s Folly • The Son of Bethany • Meta • Little Blue Sailboats • Grease Trap • Hitchhiking With My Eyes Closed • The Donna of Our Time • The Magic of Cooking • The Closing Shift • A Baptism of Teeth • Dear Beloved • How Kansas Got to Chicago • Anywhere, if you look hard enoughhttps://digitalcommons.ursinus.edu/lantern/1191/thumbnail.jp

Estimation of the number of synapses in the hippocampus and brain-wide by volume electron microscopy and genetic labeling

Determining the number of synapses that are present in different brain regions is crucial to understand brain connectivity as a whole. Membrane-associated guanylate kinases (MAGUKs) are a family of scaffolding proteins that are expressed in excitatory glutamatergic synapses. We used genetic labeling of two of these proteins (PSD95 and SAP102), and Spinning Disc confocal Microscopy (SDM), to estimate the number of fluorescent puncta in the CA1 area of the hippocampus. We also used FIB-SEM, a three-dimensional electron microscopy technique, to calculate the actual numbers of synapses in the same area. We then estimated the ratio between the three-dimensional densities obtained with FIB-SEM (synapses/µm) and the bi-dimensional densities obtained with SDM (puncta/100 µm). Given that it is impractical to use FIB-SEM brain-wide, we used previously available SDM data from other brain regions and we applied this ratio as a conversion factor to estimate the minimum density of synapses in those regions. We found the highest densities of synapses in the isocortex, olfactory areas, hippocampal formation and cortical subplate. Low densities were found in the pallidum, hypothalamus, brainstem and cerebellum. Finally, the striatum and thalamus showed a wide range of synapse densities.This work was supported by grants from the following entities: the Spanish “Ministerio de Ciencia, Innovación y Universidades” (Grant PGC2018-094307-B-I00 and the Cajal Blue Brain Project [C080020-09; the Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland]; the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No. 785907 (Human Brain Project, SGA2); the Wellcome Trust (Technology Development Grant 202932); and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (695568 SYNNOVATE). L.T.-R. is a recipient of grants from the EMBO Long-term fellowship 2016–2018 and the IBRO-PERC InEurope grants programme

Secreted factors as synaptic organizers

A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic differentiation. Many of these factors appear to function at both the neuromuscular junction and in the central nervous system, although the specific function of the molecules differs between the two. Here we review secreted molecules that organize the synaptic compartments and discuss how these molecules shape synaptic development, focusing on mammalian in vivo systems. Their critical role in shaping a functional neural circuit is underscored by their possible link to a wide range of neurological and psychiatric disorders both in animal models and by mutations identified in human patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79160/1/j.1460-9568.2010.07338.x.pd

Concerted action of zinc and ProSAP/Shank in synaptogenesis and synapse maturation

ProSAP/Shank are scaffolding proteins that localize to the postsynaptic density (PSD). This study shows that Zn2+ ions directly regulate the localization and recruitment of Shank/ProSAP1/2 to PSDs to facilitate synapse formation and maturation