cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Stochastic Dynamics of Filopodial Growth
Creators: name: Papoian, Garegin A.
name: Lan, Yueheng
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: A filopodium is a cytoplasmic projection, exquisitely built and regulated, which extends from the leading edge of the migrating cell, exploring the cell's neighborhood. Commonly, filopodia grow and retract after their initiation, exhibiting rich dynamical behaviors. We model the growth of a filopodium based on a stochastic description which incorporates mechanical, physical, and biochemical components. Our model provides a full stochastic treatment of the actin monomer diffusion and polymerization of each individual actin filament under stress of the fluctuating membrane. We investigated the length distribution of individual filaments in a growing filopodium and studied how it depends on various physical parameters. The distribution of filament lengths turned out to be narrow, which we explained by the negative feedback created by the membrane load and monomeric G-actin gradient. We also discovered that filopodial growth is strongly diminished upon increasing retrograde flow, suggesting that regulating the retrograde flow rate would be a highly efficient way to control filopodial extension dynamics. The filopodial length increases as the membrane fluctuations decrease, which we attributed to the unequal loading of the membrane force among individual filaments, which, in turn, results in larger average polymerization rates. We also observed significant diffusional noise of G-actin monomers, which leads to smaller G-actin flux along the filopodial tube compared with the prediction using the diffusion equation. Overall, partial cancellation of these two fluctuation effects allows a simple mean field model to rationalize most of our simulation results. However, fast fluctuations significantly renormalize the mean field model parameters. The biological significance of our filopodial model and avenues for future development are also discussed.
Actin-Myosin Viscoelastic Flow in the Keratocyte Lamellipod
Creators: name: Rubinstein, Boris
name: Jacobson, Ken
name: Mogilner, Alex
name: Fournier, Maxime F.
name: Verkhovsky, Alexander B.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: The lamellipod, the locomotory region of migratory cells, is shaped by the balance of protrusion and contraction. The latter is the result of myosin-generated centripetal flow of the viscoelastic actin network. Recently, quantitative flow data was obtained, yet there is no detailed theory explaining the flow in a realistic geometry. We introduce models of viscoelastic actin mechanics and myosin transport and solve the model equations numerically for the flat, fan-shaped lamellipodial domain of keratocytes. The solutions demonstrate that in the rapidly crawling cell, myosin concentrates at the rear boundary and pulls the actin network inward, so the centripetal actin flow is very slow at the front, and faster at the rear and at the sides. The computed flow and respective traction forces compare well with the experimental data. We also calculate the graded protrusion at the cell boundary necessary to maintain the cell shape and make a number of other testable predictions. We discuss model implications for the cell shape, speed, and bi-stability.
(101335) John Lewis
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Factor Xa Binding to Phosphatidylserine-Containing Membranes Produces an Inactive Membrane-Bound Dimer
Creators: name: Lentz, Barry R.
name: Weinreb, Gabriel E.
name: Majumder, Rinku
name: Koklic, Tilen
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Factor Xa (FXa) has a prominent role in amplifying both inflammation and the coagulation cascade. In the coagulation cascade, its main role is catalyzing the proteolytic activation of prothrombin to thrombin. Efficient proteolysis is well known to require phosphatidylserine (PS)-containing membranes that are provided by platelets in vivo. However, soluble, short-chain PS also triggers efficient proteolytic activity and formation of an inactive FXa dimer in solution. In this work, we ask whether PS-containing membranes also trigger formation of an inactive FXa dimer. We determined the proteolytic activity of human FXa toward human Pre2 as a substrate both at fixed membrane concentration (increasing FXa concentration) and at fixed FXa concentration (increasing membrane concentration). Neither of these experiments showed the expected behavior of an increase in activity as FXa bound to membranes, but instead suggested the existence of a membrane-bound inactive form of FXa. We found also that the fluorescence of fluorescein attached to FXa's active site serine was depolarized in a FXa concentration-dependent fashion in the presence of membranes. The fluorescence lifetime of FXa labeled in its active sites with a dansyl fluorophore showed a similar concentration dependence. We explained all these observations in terms of a quantitative model that takes into account dimerization of FXa after binding to a membrane, which yielded estimates of the FXa dimerization constant on a membrane as well as the kinetic constants of the dimer, showing that the dimer is effectively inactive.
Brief-Kopierbuch
Creators: name: Streckeisen-Caesar, Emanuel
Publisher: name: [s.n.]
Year: 1781

description: Darin: Hinten eingeklebter Registerband
description: Französisch
description: Verzeichnung=Description=Inventaire 2014 ISAD(G) / HAN Katalogisierungsregeln für Archivbestände Sebastian Preher
Functional and Structural Characterization of Factor Xa Dimer in Solution
Creators: name: Chattopadhyay, Rima
name: Majumder, Rinku
name: Lentz, Barry R.
name: Tomer, Kenneth B.
name: Sen, Shalmali
name: Iacob, Roxana
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Previous studies showed that binding of water-soluble phosphatidylserine (C6PS) to bovine factor Xa (FXa) leads to Ca2+-dependent dimerization in solution. We report the effects of Ca2+, C6PS, and dimerization on the activity and structure of human and bovine FXa. Both human and bovine dimers are 106- to 107-fold less active toward prothrombin than the monomer, with the decrease being attributed mainly to a substantial decrease in kcat. Dimerization appears not to block the active site, since amidolytic activity toward a synthetic substrate is largely unaffected. Circular dichroism reveals a substantial change in tertiary or quaternary structure with a concomitant decrease in α-helix upon dimerization. Mass spectrometry identifies a lysine (K270) in the catalytic domain that appears to be buried at the dimer interface and is part of a synthetic peptide sequence reported to interfere with factor Va (FVa) binding. C6PS binding exposes K351 (part of a reported FVa binding region), K242 (adjacent to the catalytic triad), and K420 (part of a substrate exosite). We interpret our results to mean that C6PS-induced dimerization produces substantial conformational changes or domain rearrangements such that structural data on PS-activated FXa is required to understand the structure of the FXa dimer or the FXa-FVa complex.
M&A Performance in Downturns : Evidence from the U.S. Banking Industry
Creators: name: Aegerter, Philip
Publisher: name: ZHAW Zürcher Hochschule für Angewandte Wissenschaften
Year: 2016
Subjects: 332: Finanzwirtschaft
658.1: Organisation und Finanzen

description: The topic of merger and acquisitions (M&A) has received wide attention in the management literature. To date, a vast majority of scholars conclude that, on average, M&A transactions tend to be value diminishing for acquirer shareholders. However, the thesis at hand unfolds a more differentiated story. The thesis investigates the influence of market cycles on M&A performance in the U.S. banking industry, obtained from firm-level data from January 2000 to December 2009. The research is based on a sample of 112 U.S. banks, each experiencing different market cycles during the observation period. The issue of M&A’s during challenging markets is becoming increasingly relevant, especially since financial crises have become a worldwide phenomenon in the last two decades. The central hypothesis advocates that M&A’s undertaken during downturns are of better quality and offer more value creation opportunities than those undertaken during booming markets. Moreover, it is predicted that method of payment, bidder experience and relative size are key moderators of M&A performance. Given the structure of the data, event study methodology, descriptive statistics, univariate analysis and hierarchical multiple linear regression analysis are applied to analyze the dataset. The results of the empirical analysis lend strong support to the core arguments of the thesis. Consistent with the results of prior studies, the findings indicate that most M&A transactions (58%) fail to add shareholder value. However, by creating subsamples that separate deals by market cycles, it is evident that transactions in downturns significantly outperform acquisitions in booming markets. In addition, M&A deals announced during upturns and paid with shares, as compared with cash, lead to significant value destruction for the acquirer shareholders. For the variable experience or relative size, no significant relationship is observed that alters the performance of M&A’s. Overall, the results of the study underscore the importance of incorporating the external environment into decisions regarding strategic adaptations. Strong evidence signifies that managers who are deliberately avoiding M&A deals in challenging markets may be missing an important strategic opportunity. Downturns can be an ideal time for companies to use M&A strategically to buy undervalued targets, consolidate markets and strengthen their competitive advantage.
(101334) Daisy Blanche Leigh
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
(101333) Emmeline May Leigh
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Operapaedia
Creators: name: Kopanakis, Dimitrios
Publisher: name: CQUniversity
Year: 2023
Subjects: Organisation of information and knowledge resources
Performing arts not elsewhere classified

description: This project is concerned with identifying and investigating a problem faced by students undertaking studies in opera, namely, readily available performance related materials for students of opera to consult when preparing for a performance. The purpose of this project is to develop an internet-based resource containing a range of information about operas, musical scores and their interpretation, opera recordings, opera literature, opera composers, opera performers, and opera companies as a solution to this problem. The Project uses aspects of opera interpretation and opera libretti as a theoretical framework. In order to accomplish these outcomes, this project demonstrates that no single source of information that is presently available in print or electronic form is comprehensive, reliable and convenient enough to provide opera students with information necessary for use in a production. The Project highlights the need for an electronic resource that is comprehensive for opera students. The analysis of the usability of website research literature indicates that successful electronic resources embody the principles of: "24/7", 'anywhere', 'anytime' access; ease-of-access, user-friendly website design; and resources relevant to the specific enquiry of the user in their design. The Project leads to the conclusion that no single source of information is comprehensive enough for an opera student to acquire, process and assimilate all of the information necessary for use in a production. The overarching product of the project is a design and guidelines for the development of an internet-based resource aimed at eliminating the lack of performance related materials in the field of opera study. I call this resource Operapaedia.
Electroweak interacting dark matter with a singlet scalar portal
Creators: name: Chiang, Cheng-Wei
name: Senaha, Eibun
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate an electroweak interacting dark matter (DM) model in which the DM is the neutral component of the SU$(2)_L$ triplet fermion that couples to the standard model (SM) Higgs sector via an SM singlet Higgs boson. In this setup, the DM can have a CP-violating coupling to the singlet Higgs boson at the renormalizable level. As long as the nonzero Higgs portal coupling (singlet-doublet Higgs boson mixing) exists, we can probe CP violation of the DM via the electric dipole moment of the electron. Assuming the $\mathcal{O}(1)$ CP-violating phase in magnitude, we investigate the relationship between the electron EDM and the singlet-like Higgs boson mass and coupling. It is found that for moderate values of the Higgs portal couplings, current experimental EDM bound is not able to exclude the wide parameter space due to a cancellation mechanism at work. We also study the spin-independent cross section of the DM in this model. It is found that although a similar cancellation mechanism may diminish the leading-order correction, as often occurs in the ordinary Higgs portal DM scenarios, the residual higher-order effects leave an $\mathcal{O}(10^{-47})~{\rm cm}^2$ correction in the cancellation region. It is shown that our benchmark scenarios would be fully tested by combining all future experiments of the electron EDM, DM direct detection and Higgs physics.
description: 17 pages, 6 figures. v2: references added; v3: references added, version to appear in Phys.Lett.B
Slit Mask Integral Field Units for the Southern African Large Telescope
Creators: name: Chattopadhyay, Sabyasachi
name: Bershady, Matthew A.
name: Wolf, Marsha J.
name: Smith, Michael P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Two fibre integral field units (IFU) are being built in the SAAO fibre-lab for the Robert Stobie Spectrograph's visible arm and the future red arm. Each IFU sits in its own slit-mask cassette and is referred to as a slit-mask IFU (SMI). They will be available some time in 2022. The smaller, 200 micron fibre IFU has 309 X 0.9 arcsec diameter spatial elements covering an elongated hexagonal footprint of 18 X 23 arcsec. The larger, 400 micron fibre IFU has 178 X 1.8 arcsec diameter spatial elements covering an on-sky area of 21 X 44 arcsec. In both cases there are two groups of 13 fibres offset by roughly 50 arcsec on either side of the primary array to sample sky. The 1.8 and 0.9 arcsec spatial resolution SMIs provide median spectral resolution of 1200 and 2400 respectively at H alpha wavelengths in the low resolution mode covering 320 to 740 nm bandpass. At a higher grating angle the SMI will deliver spectral resolution up to 5000 and 10000 with 400 and 200 micron core fibre respectively. A future red-arm will extend the simultaneous wavelength coverage up to 900 nm at a median resolution of 3000/6000 for the same flavors of IFUs. SMIs are inserted in the same fashion as the existing longslit cassettes at the SALT focal plane. Prismatic fold mirrors direct the focal plane into the fibre IFU and then back into the RSS collimator after the fibres are routed 180 deg within the cassette and formatted into a pseudo-slit. Fold prisms ensure that the spectrograph collimator continues to see the same focal plane. In this paper we describe the design, fabrication, assembly and characterization of Slit Mask IFUs.
(101332) Manuel Ignacia Vincente Mendicta
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Kinetics of the Multistep Rupture of Fibrin ‘A-a’ Polymerization Interactions Measured Using Atomic Force Microscopy
Creators: name: Akhremitchev, Boris B.
name: Gorkun, Oleg V.
name: Averett, Laurel E.
name: Schoenfisch, Mark H.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Fibrin, the structural scaffold of blood clots, spontaneously polymerizes through the formation of ‘A-a’ knob-hole bonds. When subjected to external force, the dissociation of this bond is accompanied by two to four abrupt changes in molecular dimension observable as rupture events in a force curve. Herein, the configuration, molecular extension, and kinetic parameters of each rupture event are examined. The increases in contour length indicate that the D region of fibrinogen can lengthen by ∼50% of the length of a fibrin monomer before rupture of the ‘A-a’ interaction. The dependence of the dissociation rate on applied force was obtained using probability distributions of rupture forces collected at different pull-off velocities. These distributions were fit using a model in which the effects of the shape of the binding potential are used to quantify the kinetic parameters of forced dissociation. We found that the weak initial rupture (i.e., event 1) was not well approximated by these models. The ruptured bonds comprising the strongest ruptures, events 2 and 3, had kinetic parameters similar to those commonly found for the mechanical unfolding of globular proteins. The bonds ruptured in event 4 were well described by these analyses, but were more loosely bound than the bonds in events 2 and 3. We propose that the first event represents the rupture of an unknown interaction parallel to the ‘A-a’ bond, events 2 and 3 represent unfolding of structures in the D region of fibrinogen, and event 4 is the rupture of the ‘A-a’ knob-hole bond weakened by prior structural unfolding. Comparison of the activation energy obtained via force spectroscopy measurements with the thermodynamic free energy of ‘A-a’ bond dissociation indicates that the ‘A-a’ bond may be more resistant to rupture by applied force than to rupture by thermal dissociation.
(101331) Sarah Louise Heaton
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Molecular Model of a Cell Plasma Membrane With an Asymmetric Multicomponent Composition: Water Permeation and Ion Effects
Creators: name: Jungwirth, Pavel
name: Berkowitz, Max L.
name: Vácha, Robert
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: We present molecular dynamics simulations of a multicomponent, asymmetric bilayer in mixed aqueous solutions of sodium and potassium chloride. Because of the geometry of the system, there are two aqueous solution regions in our simulations: one mimics the intracellular region, and one mimics the extracellular region. Ion-specific effects are evident at the membrane/aqueous solution interface. Namely, at equal concentrations of sodium and potassium, sodium ions are more strongly adsorbed to carbonyl groups of the lipid headgroups. A significant concentration excess of potassium is needed for this ion to overwhelm the sodium abundance at the membrane. Ion-membrane interactions also lead to concentration-dependent and cation-specific behavior of the electrostatic potential in the intracellular region because of the negative charge on the inner leaflet. In addition, water permeation across the membrane was observed on a timescale of ∼100 ns. This study represents a step toward the modeling of realistic biological membranes at physiological conditions in intracellular and extracellular environments.
(101330) Emily Jane Harris
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Sparse Attentive Memory Network for Click-through Rate Prediction with Long Sequences
Creators: name: Lin, Qianying
name: Zhou, Wen-Ji
name: Wang, Yanshi
name: Da, Qing
name: Chen, Qing-Guo
name: Wang, Bing
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Sequential recommendation predicts users' next behaviors with their historical interactions. Recommending with longer sequences improves recommendation accuracy and increases the degree of personalization. As sequences get longer, existing works have not yet addressed the following two main challenges. Firstly, modeling long-range intra-sequence dependency is difficult with increasing sequence lengths. Secondly, it requires efficient memory and computational speeds. In this paper, we propose a Sparse Attentive Memory (SAM) network for long sequential user behavior modeling. SAM supports efficient training and real-time inference for user behavior sequences with lengths on the scale of thousands. In SAM, we model the target item as the query and the long sequence as the knowledge database, where the former continuously elicits relevant information from the latter. SAM simultaneously models target-sequence dependencies and long-range intra-sequence dependencies with O(L) complexity and O(1) number of sequential updates, which can only be achieved by the self-attention mechanism with O(L^2) complexity. Extensive empirical results demonstrate that our proposed solution is effective not only in long user behavior modeling but also on short sequences modeling. Implemented on sequences of length 1000, SAM is successfully deployed on one of the largest international E-commerce platforms. This inference time is within 30ms, with a substantial 7.30% click-through rate improvement for the online A/B test. To the best of our knowledge, it is the first end-to-end long user sequence modeling framework that models intra-sequence and target-sequence dependencies with the aforementioned degree of efficiency and successfully deployed on a large-scale real-time industrial recommender system.
description: Published as a conference paper at the 31st ACM International Conference on Information and Knowledge Management, CIKM 2022
Molecular Renormalization Group Coarse-Graining of Polymer Chains: Application to Double-Stranded DNA
Creators: name: Papoian, Garegin A.
name: Savelyev, Alexey
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Coarse-graining of atomistic force fields allows us to investigate complex biological problems, occurring at long timescales and large length scales. In this work, we have developed an accurate coarse-grained model for double-stranded DNA chain, derived systematically from atomistic simulations. Our approach is based on matching correlators obtained from atomistic and coarse-grained simulations, for observables that explicitly enter the coarse-grained Hamiltonian. We show that this requirement leads to equivalency of the corresponding partition functions, resulting in a one-step renormalization. Compared to prior works exploiting similar ideas, the main novelty of this work is the introduction of a highly compact set of Hamiltonian basis functions, based on molecular interaction potentials. We demonstrate that such compactification allows us to reproduce many-body effects, generated by one-step renormalization, at low computational cost. In addition, compact Hamiltonians greatly increase the likelihood of finding unique solutions for the coarse-grained force-field parameter values. By successfully applying our molecular renormalization group coarse-graining technique to double-stranded DNA, we solved, for the first time, a long-standing problem in coarse-graining polymer systems, namely, how to accurately capture the correlations among various polymeric degrees of freedom. Excellent agreement is found among atomistic and coarse-grained distribution functions for various structural observables, including those not included in the Hamiltonian. We also suggest higher-order generalization of this method, which may allow capturing more subtle correlations in biopolymer dynamics.
Primordial black holes as a novel probe of primordial gravitational waves
Creators: name: Nakama, Tomohiro
name: Suyama, Teruaki
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We propose a novel method to probe primordial gravitational waves by means of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations on comoving scales much smaller than those relevant to Cosmic Microwave Background is very large, it induces scalar perturbations due to second-order effects substantially. If the amplitude of resultant scalar perturbations becomes too large, then PBHs are overproduced to a level that is inconsistent with a variety of existing observations constraining their abundance. This leads to upper bounds on the amplitude of initial tensor perturbations on super-horizon scales. These upper bounds from PBHs are compared with other existing bounds.
description: 6 pages, part of discussion modified
Iterated Hardy-type inequalities involving suprema
Creators: name: Gogatishvili, Amiran
name: Mustafayev, Rza
Publisher: name: arXiv
Year: 2015
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: Primary 26D10, Secondary 26D15

description: In this paper the complete solution of the restricted inequalities for supremal operators are given. The boundedness of the composition of supremal operators with the Hardy and Copson operators in weighted Lebesgue spaces are characterized.
description: 18 pages. arXiv admin note: text overlap with arXiv:1503.04079
Predicting student performance using sequence classification with time-based windows
Creators: name: Deeva, Galina
name: De Smedt, Johannes
name: Saint-Pierre, Cecilia
name: Weber, Richard
name: De Weerdt, Jochen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: A growing number of universities worldwide use various forms of online and blended learning as part of their academic curricula. Furthermore, the recent changes caused by the COVID-19 pandemic have led to a drastic increase in importance and ubiquity of online education. Among the major advantages of e-learning is not only improving students' learning experience and widening their educational prospects, but also an opportunity to gain insights into students' learning processes with learning analytics. This study contributes to the topic of improving and understanding e-learning processes in the following ways. First, we demonstrate that accurate predictive models can be built based on sequential patterns derived from students' behavioral data, which are able to identify underperforming students early in the course. Second, we investigate the specificity-generalizability trade-off in building such predictive models by investigating whether predictive models should be built for every course individually based on course-specific sequential patterns, or across several courses based on more general behavioral patterns. Finally, we present a methodology for capturing temporal aspects in behavioral data and analyze its influence on the predictive performance of the models. The results of our improved sequence classification technique are capable to predict student performance with high levels of accuracy, reaching 90 percent for course-specific models.
Versatile Horizontal Force Probe for Mechanical Tests on Pipette-Held Cells, Particles, and Membrane Capsules
Creators: name: Dayton, Paul A.
name: Heinrich, Volkmar
name: Xie, Hongtao
name: Ounkomol, Chawin
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: We present a multipurpose nanomechanical force probe that combines a sideways-mounted elastic cantilever and an optical-lever detection module with automated micropipette manipulation. It allows us to apply and measure compression, stretching, adhesion, and dissociation forces in the horizontal direction while providing a “side view” of ongoing experiments. The integrated micropipette setup facilitates the easy manipulation and mechanical interrogation of individual cells, functionalized particles, and synthetic membrane capsules. Pipette-held test objects are translated perpendicularly to and from the stationary cantilever, eliminating the need to attach them to a carrier surface and substantially reducing unwanted hydrodynamic coupling effects. Moreover, the test objects can be brought into contact with the cantilever anywhere along its length, which considerably enlarges the range of forces that can be applied with a single cantilever. Advantages of this instrument are demonstrated in example measurements of single-cell compression, membrane-tether extrusion, oligonucleotide stretching, and extraction of individual lipids from surfactant-monolayer surfaces of microbubbles.
Study of B, Bs mesons using heavy quark effective theory
Creators: name: Gandhi, Keval
name: Rai, Ajay Kumar
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Inspired by the lower statistical information in the bottom {\bf sector, in this paper, we} calculate the masses and the strong decays of excited $B$ and $B_s$ mesons in the framework of heavy quark effective theory (HQET). Using an effective chiral Lagrangian approach based on heavy quark spin-flavor and light quark chiral symmetry, we explore the flavor independent parameters $Δ_F^{(c)} = Δ_F^{(b)}$ and $λ_F^{(c)} = λ_F^{(b)}$ to calculate the masses of experimentally unknown bottom mesons. Our predictions are consistent with the available experimental results and other theoretical studies. Their strong decay to the ground state bottom mesons plus light pseudoscalar mesons is calculated in terms of the square of the couplings $g_H$, $g_S$, $g_T$, $g_X$, $g_Y$, and $g_R$. The weighted average value of the couplings $g_H$, $g_S$ and $g_T$ {\bf is} obtained in the charm sector [Phys. Rev. D \textbf{86}, 054024 (2012)] by fitting the calculated decay widths with experimental measurements, which will be used in the present study to analyze the strong decays of excited open bottom mesons. Moreover, the ratio of the decay rates is also predicted, which can be countered with future experimental data.
description: 13 pages Accepted for publication in EPJC
Initial state and thermalization in the Color Glass Condensate framework
Creators: name: Gelis, F.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In this review, I present the description of the early stages of heavy ion collisions at high energy in the Color Glass Condensate framework, from the pre-collision high energy nuclear wavefunction to the point where hydrodynamics may start becoming applicable.
description: Review to appear in QGP5, 64 pages, 67 figures
Design of Active Transport Must Be Highly Intricate: A Possible Role of Myosin and Ena/VASP for G-Actin Transport in Filopodia
Creators: name: Papoian, Garegin A.
name: Zhuravlev, Pavel I.
name: Der, Bryan S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Recent modeling of filopodia—the actin-based cell organelles employed for sensing and motility—reveals that one of the key limiting factors of filopodial length is diffusional transport of G-actin monomers to the polymerizing barbed ends. We have explored the possibility of active transport of G-actin by myosin motors, which would be an expected biological response to overcome the limitation of a diffusion-based process. We found that in a straightforward implementation of active transport the increase in length was unimpressive, ≤30%, due to sequestering of G-actin by freely diffusing motors. However, artificially removing motor sequestration reactions led to approximately threefold increases in filopodial length, with the transport being mainly limited by the motors failing to detach from the filaments near the tip, clogging the cooperative conveyer belt dynamics. Making motors sterically transparent led to a qualitative change of the dynamics to a different regime of steady growth without a stationary length. Having identified sequestration and clogging as ubiquitous constraints to motor-driven transport, we devised and tested a speculative means to sidestep these limitations in filopodia by employing cross-linking and putative scaffolding roles of Ena/VASP proteins. We conclude that a naïve design of molecular-motor-based active transport would almost always be inefficient—an intricately organized kinetic scheme, with finely tuned rate constants, is required to achieve high-flux transport.
THE ROLE OF SPATIAL FORMS IN EDUCATION: INNOVATIONS FOR 21ST CENTURY EDUCATION
Creators: name: Xusanboyeva Zulfizarxon Xayrulla qizi
Publisher: name: Zenodo
Year: 2023

description: This article explores the evolving role of spatial forms in education, focusing on the integration of innovative teaching methods to enhance 21st-century learning experiences. In an era marked by technological advancements and changing pedagogical paradigms, educational spaces are undergoing a transformation. The article delves into how spatial design, technology, and interactive classrooms are being leveraged to create active learning environments that promote student engagement and pedagogical innovation. As educators and institutions adapt to meet the demands of the future, understanding the significance of spatial forms in education becomes crucial.
Evidence that αC Region Is Origin of Low Modulus, High Extensibility, and Strain Stiffening in Fibrin Fibers
Creators: name: Hudson, Nathan E.
name: Ping, Lifang
name: Lord, Susan T.
name: Falvo, Michael R.
name: O'Brien III, E. Timothy
name: Superfine, Richard
name: Houser, John R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Fibrin fibers form the structural scaffold of blood clots and perform the mechanical task of stemming blood flow. Several decades of investigation of fibrin fiber networks using macroscopic techniques have revealed remarkable mechanical properties. More recently, the microscopic origins of fibrin's mechanics have been probed through direct measurements on single fibrin fibers and individual fibrinogen molecules. Using a nanomanipulation system, we investigated the mechanical properties of individual fibrin fibers. The fibers were stretched with the atomic force microscope, and stress-versus-strain data was collected for fibers formed with and without ligation by the activated transglutaminase factor XIII (FXIIIa). We observed that ligation with FXIIIa nearly doubled the stiffness of the fibers. The stress-versus-strain behavior indicates that fibrin fibers exhibit properties similar to other elastomeric biopolymers. We propose a mechanical model that fits our observed force extension data, is consistent with the results of the ligation data, and suggests that the large observed extensibility in fibrin fibers is mediated by the natively unfolded regions of the molecule. Although some models attribute fibrin's force-versus-extension behavior to unfolding of structured regions within the monomer, our analysis argues that these models are inconsistent with the measured extensibility and elastic modulus.
Effective Theory of Squeezed Correlation Functions
Creators: name: Mirbabayi, Mehrdad
name: Simonović, Marko
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Various inflationary scenarios can often be distinguished from one another by looking at the squeezed limit behavior of correlation functions. Therefore, it is useful to have a framework designed to study this limit in a more systematic and efficient way. We propose using an expansion in terms of weakly coupled super-horizon degrees of freedom, which is argued to generically exist in a near de Sitter space-time. The modes have a simple factorized form which leads to factorization of the squeezed-limit correlation functions with power-law behavior in $k_{\rm long}/k_{\rm short}$. This approach reproduces the known results in single-, quasi-single-, and multi-field inflationary models. However, it is applicable even if, unlike the above examples, the additional degrees of freedom are not weakly coupled at sub-horizon scales. Stronger results are derived in two-field (or sufficiently symmetric multi-field) inflationary models. We discuss the observability of the non-Gaussian 3-point function in the large-scale structure surveys, and argue that the squeezed limit behavior has a higher detectability chance than equilateral behavior when it scales as $(k_{\rm long}/k_{\rm short})^Δ$ with $Δ<1$ -- where local non-Gaussianity corresponds to $Δ=0$.
description: 19+6 pages
ESM video captions and PCA table from Paternal care regulates the timing, synchrony and success of hatching in a coral reef fish
Creators: name: Majoris, John E.
name: Francisco, Fritz A.
name: Burns, Corinne M.
name: Brandl, Simon J.
name: Warkentin, Karen M.
name: Buston, Peter M.
Publisher: name: The Royal Society
Year: 2022
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Developmental Biology
subject: 60801 Animal Behaviour

description: ESM video captions and PCA results table.
Force Generation and Dynamics of Individual Cilia under External Loading
Creators: name: O'Brien, E. Timothy
name: Estes, Ashley
name: Hill, David B.
name: Superfine, R.
name: Davis, C. William
name: Swaminathan, Vinay
name: Cribb, Jeremy
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Motile cilia are unique multimotor systems that display coordination and periodicity while imparting forces to biological fluids. They play important roles in normal physiology, and ciliopathies are implicated in a growing number of human diseases. In this work we measure the response of individual human airway cilia to calibrated forces transmitted via spot-labeled magnetic microbeads. Cilia respond to applied forces by 1), a reduction in beat amplitude (up to an 85% reduction by 160–170 pN of force); 2), a decreased tip velocity proportionate to applied force; and 3), no significant change in beat frequency. Tip velocity reduction occurred in each beat direction, independently of the direction of applied force, indicating that the cilium is “driven” in both directions at all times. By applying a quasistatic force model, we deduce that axoneme stiffness is dominated by the rigidity of the microtubules, and that cilia can exert 62 ± 18 pN of force at the tip via the generation of 5.6 ± 1.6 pN/dynein head.
Formation of primordial supermassive stars by burst accretion
Creators: name: Sakurai, Y.
name: Hosokawa, T.
name: Yoshida, N.
name: Yorke, H. W.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A promising formation channel of SMBHs at redshift 6 is the so-called DC model, which posits that a massive seed BH forms through gravitational collapse of a $\sim 10^5~M_\odot$ SMS. We study the evolution of such a SMS growing by rapid mass accretion. In particular, we examine the impact of time-dependent mass accretion of repeating burst and quiescent phases that are expected to occur with a self-gravitating circumstellar disk. We show that the stellar evolution with such episodic accretion differs qualitatively from that expected with a constant accretion rate, even if the mean accretion rate is the same. Unlike the case of constant mass accretion, whereby the star expands roughly following $R_* \simeq 2.6 \times 10^3 R_\odot (M_*/100~M_\odot)^{1/2}$, the protostar can substantially contract during the quiescent phases between accretion bursts. The stellar effective temperature and ionizing photon emissivity increase accordingly as the star contracts, which can cause strong ionizing feedback and halt the mass accretion onto the star. With a fixed duration of the quiescent phase $Δt_{\rm q}$, such contraction occurs in early evolutionary phases, i.e. for $M_* \lesssim 10^3~M_\odot$ with $Δt_{\rm q} \simeq 10^3$ yr. For later epochs and larger masses but the same $Δt_{\rm q}$, contraction is negligible even during quiescent phases. With larger quiescent times $Δt_{\rm q}$, however, the star continues to contract during quiescent phases even for the higher stellar masses. We show that such behavior is well understood by comparing the interval time and the thermal relaxation time for a bloated surface layer. We conclude that the UV radiative feedback becomes effective if the quiescent phase associated by the burst accretion is longer than $\sim 10^3$ yr, which is possible in an accretion disk forming in the direct collapse model.
description: 10 pages, 7 figures, submitted to MNRAS
(101329) John Purser
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Internal Binding of Halogenated Phenols in Dehaloperoxidase-Hemoglobin Inhibits Peroxidase Function
Creators: name: Howes, Barry D.
name: Nicoletti, Francesco P.
name: Thompson, Matthew K.
name: Serrano, Vesna De
name: Davis, Michael F.
name: Smulevich, Giulietta
name: Franzen, Stefan
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Dehaloperoxidase (DHP) from the annelid Amphitrite ornata is a catalytically active hemoglobin-peroxidase that possesses a unique internal binding cavity in the distal pocket above the heme. The previously published crystal structure of DHP shows 4-iodophenol bound internally. This led to the proposal that the internal binding site is the active site for phenol oxidation. However, the native substrate for DHP is 2,4,6-tribromophenol, and all attempts to bind 2,4,6-tribromophenol in the internal site under physiological conditions have failed. Herein, we show that the binding of 4-halophenols in the internal pocket inhibits enzymatic function. Furthermore, we demonstrate that DHP has a unique two-site competitive binding mechanism in which the internal and external binding sites communicate through two conformations of the distal histidine of the enzyme, resulting in nonclassical competitive inhibition. The same distal histidine conformations involved in DHP function regulate oxygen binding and release during transport and storage by hemoglobins and myoglobins. This work provides further support for the hypothesis that DHP possesses an external binding site for substrate oxidation, as is typical for the peroxidase family of enzymes.