cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Distributed Reinforcement Learning for Autonomous Driving
Creators: name: Huang, Zhe
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: subject: 80101 Adaptive Agents and Intelligent Robotics
subject: FOS: Computer and information sciences

description: Due to the complex and safety-critical nature of autonomous driving, recent works typically test their ideas on simulators designed for the very purpose of advancing self-driving research. Despite the convenience of modeling autonomous driving as a trajectory optimization problem, few of these methods resort to online reinforcement learning (RL) to address challenging driving scenarios. This is mainly because classic online RL algorithms are originally designed for toy problems such as Atari games, which are solvable within hours. In contrast, it may take weeks or months to get satisfactory results on self-driving tasks using these online RL methods as a consequence of the time-consuming simulation and the difficulty of the problem itself. Thus, a promising online RL pipeline for autonomous driving should be efficiency driven. In this thesis, we investigate the inefficiency of directly applying generic single-agent or distributed RL algorithms to CARLA self-driving pipelines due to the expensive simulation cost. We propose two asynchronous distributed RL methods, Multi-Parallel SAC (off-policy) and Multi-Parallel PPO (on-policy), dedicated to accelerating the online RL training on the CARLA simulator via a specialized distributed framework that establishes both inter-process and intra-process parallelization. We demonstrate that our distributed multi-agent RL algorithms achieve stateof-the-art performances on various CARLA self-driving tasks in much shorter and reasonable time.
(3844) James Sutherland
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.
Quantifying information transfer and mediation along causal pathways in complex systems
Creators: name: Runge, Jakob
Publisher: name: arXiv
Year: 2015
Subjects: subject: Methodology (stat.ME)
subject: Statistics Theory (math.ST)
subject: Other Statistics (stat.OT)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Measures of information transfer have become a popular approach to analyze interactions in complex systems such as the Earth or the human brain from measured time series. Recent work has focused on causal definitions of information transfer excluding effects of common drivers and indirect influences. While the former clearly constitutes a spurious causality, the aim of the present article is to develop measures quantifying different notions of the strength of information transfer along indirect causal paths, based on first reconstructing the multivariate causal network (\emph{Tigramite} approach). Another class of novel measures quantifies to what extent different intermediate processes on causal paths contribute to an interaction mechanism to determine pathways of causal information transfer. A rigorous mathematical framework allows for a clear information-theoretic interpretation that can also be related to the underlying dynamics as proven for certain classes of processes. Generally, however, estimates of information transfer remain hard to interpret for nonlinearly intertwined complex systems. But, if experiments or mathematical models are not available, measuring pathways of information transfer within the causal dependency structure allows at least for an abstraction of the dynamics. The measures are illustrated on a climatological example to disentangle pathways of atmospheric flow over Europe.
description: 20 pages, 6 figures
(3845) John Sutherland
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.
Experimental nutrition in the soft coral Alcyonium digitatum (Cnidaria: Octocorallia): removal rate of phytoplankton and zooplankton
Creators: name: MIGNÉ, Aline
name: DAVOULT, Dominique
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2002

description: The soft coral Alcyonium digitatum, a passive suspension feeder, is one of the three dominant species of the Dover
 Strait pebbles macrobenthic community (eastern English Channel). In order to study the exchanges between the water
 column and this community exposed to strong tidal currents, two sets of nutrition experiments were performed on the octo-
 coral. A mean removal rate of phytoplankton or zooplankton organisms was first calculated through experiments conducted
 in small enclosures, using cultures of diatoms Skeletonema costatum and of Artemia sp. nauplii. As the removal rate (± stan-
 dard deviation) of zooplankton (0.79 ± 0.48 mg C g-1 h-1) was much higher than the removal rate of phytoplankton (0.16 ±
 0.07 mg C g-1 h-1), Artemia sp. nauplii were used as feeding particles in the following experiments performed in a flume
 under a controlled flow. Three experiments are presented here under average condition of food availability and current speed.
 The mean removal rate was 0.64 ± 0.16 mg C g-1 h-1. These experiments clearly show the efficiency of this type of
approach to characterize the nutrition of this benthic species as a function of the nutritive particle flow. They allow an eva-
 luation of the transfer of organic carbon from the water column to the benthic population.
A Stochastic Multiscale Model that Explains the Segregation of Axonal Microtubules and Neurofilaments in Neurological Diseases
Creators: name: Xue, Chuan
name: Shtylla, Blerta
name: Brown, Anthony
Publisher: name: arXiv
Year: 2015
Subjects: subject: Cell Behavior (q-bio.CB)
subject: Biological Physics (physics.bio-ph)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The organization of the axonal cytoskeleton is a key determinant of the normal function of an axon, which is a long thin projection away from a neuron. Under normal conditions two axonal cytoskeletal polymers microtubules and neurofilaments align longitudinally in axons and are interspersed in axonal cross-sections. However, in many neurotoxic and neurodegenerative disorders, microtubules and neurofilaments segregate apart from each other, with microtubules and membranous organelles clustered centrally and neurofilaments displaced to the periphery. This striking segregation precedes abnormal and excessive neurofilament accumulation in these diseases, which in turn leads to focal axonal swellings. While neurofilament accumulation suggests the impairment of neurofilament transport along axons, the underlying mechanism of their segregation from microtubules remains poorly understood for over 30 years. To address this question, we developed a stochastic multiscale model for the cross-sectional distribution of microtubules and neurofilaments in axons. The model describes microtubules, neurofilaments and organelles as interacting particles in a 2D cross-section, and incorporates the stochastic interactions these particles through molecular motors. Simulations of the model demonstrate that organelles can pull nearby microtubules together, and in the absence of neurofilament transport, this mechanism gradually segregates microtubules from neurofilaments on a time scale of hours, similar to that observed in toxic neuropathies. This suggests that the microtubule-neurofilament segregation is simply a consequence of the selective impairment of neurofilament transport. The model generates the experimentally testable prediction that the rate and extent of segregation will be dependent on the sizes of the moving organelles as well as the density of their traffic.
Changes in the amounts of cytoskeletal proteins within the perikarya and axons of regenerating frog motoneurons
Creators: name: Sinicropi, D. V.
name: McIlwain, D. L.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1983

description: Changes in the amounts of tubulin, actin, and neurofilament polypeptides were found in regenerating motoneurons of grass frogs during the period of axonal elongation. Ventral roots 9 and 10 were transected unilaterally about 7 mm from the spinal cord. 35 d later, [3H]colchicine binding had decreased in the proximal stumps to approximately one-half of contralateral control values, well before the regenerating motor axons had reinnervated skeletal muscles of the hind limb. [3H]colchicine binding did not change significantly in the operated halves of the 9th and 10th spinal cord segments over a 75-d period. The relative amounts of actin, tubulin, and neurofilament polypeptides in the operated ventral roots were measured by quantitative densitometry of stained two-dimensional electrophoretic gels. Alpha-tubulin, beta-tubulin, and the 68,000 molecular weight subunit of neurofilaments (NF68) decreased within the transected ventral roots to 78%, 57%, and less than 15% of control values, respectively. The amount of actin increased to 132% of control values within the operated ventral roots, although this change was not statistically significant. Opposite changes were found within motoneuronal cell bodies isolated from the spinal cord. The relative amounts of alpha-tubulin, beta-tubulin and NF68 within axotomized perikarya increased, respectively, to 191%, 146%, and 144% of that in control perikarya isolated from the contralateral side of the spinal cord. Thus, the changes in NF68 and tubulin did not occur uniformly throughout the injured cells. The possible structural and functional consequences of these changes are discussed.
Variation of steroid concentrations during the reproductive cycle of the snail Osilinus articulatus in the Kerkennah Islands (Gulf of Gabes, Tunisia)
Creators: name: CHEOUR, Mohamed Karim
name: ELGHARSALLI, Refka
name: BENMESSAOUD, Rimel
name: ALOUI-BEJAOUI, Nejla
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2014

description: In this paper, the levels of Testosterone (T) and Estradiol-17β (E2) and their reciprocal ratios were determined in the ovaries and testes of the trochid model snail Osilinus articulatus by taking into account a putative relationship between the steroid levels and the reproductive cycle. Testosterone (T) and estradiol-17β (E2) were measured by radio- immunoassay (RIA) in the gonad/digestive gland of Osilinus articulatus. The reproductive cycle was also investigated. Osilinus articulatus were collected monthly from the Kerkennah Islands (southern Tunisia) from January to June 2009. The reproductive cycle was studied through the histological analysis of the gonads. Individuals showed a spawning period by the end of June for females, whilst males spawned in April. Steroids varied from 25.38 to 54.32 pg.g-1 wet mass for testosterone and from 18.97 to 76.28 pg.g-1 wet mass for estradiol-17β in females. However, for males, these steroids ranged from 21.73 to 87.23 pg.g-1 wet mass for testosterone and from 12.34 to 63.78 pg.g-1 wet mass for estradiol-17β. E2 concentrations were high at the beginning of gametogenesis for females. T concentrations increased during the spawning period. The aim of this study is to determine if E2 and T could play a role as endogenous modulators in the gametogenesis of Osilinus articulatus.
The role of the Aquarium of Rhodes (eastern Mediterranean Sea) on raising public awareness to marine invasions, with a note on the husbandry and trade of marine aliens
Creators: name: CORSINI-FOKA, Maria
name: KONDYLATOS, Gerasimos
name: SANTORINIOS, Elias
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2014

description: A total of 33 alien species collected from the wild, has been listed among the displays of the public Aquarium of Rhodes (Greece), mainly since 2000. The essential contribution of the Aquarium to document the intensification of marine alien species introduction, disseminate knowledge and increase public awareness on the ecological and socio- economic risks linked to biological invasions is underlined. The diffusion of aliens in other eastern Mediterranean Aquaria is reported. The potential use of these organisms in the aquarium trade and its eventual effects on marine ecosystems are discussed. Details on collection and aquarium maintenance conditions are also provided.
Reproductive parameters and seasonal variation in fatty acid composition of Atherina boyeri s. str. and A. lagunae populations from open sea, lagoon and island coasts of Tunisia
Creators: name: BOURIGA, Nawzet
name: MILI, Sami
name: ENNOURI, Rym
name: QUIGNARD, Jean-Pierre
name: TRABELSI, Monia
name: FAURE, Eric
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2014

description: Growth, reproductive properties and variations in total lipids and fatty acids of sand smelt (Atherina boyeri s.str. and Atherina lagunae) caught from Kerkennah Islands; Bizerta Lagoon and Open Sea in Tunisia were studied by sampling carried out between March 2009 and February 2010 to elucidate the importance of these components during sexual maturation. A total of 1411 fish was examined. The proportion of males was significantly lower than females. The length- weight relationship of islands sand smelts (A. lagunae) showed a negative allometry. However, it was positive for fishes from Bizerta Lagoon (A. lagunae) and Open Sea (A. boyeri s.str.). The reproductive season, evaluated from the gonado - somatic index, extended from April to July for both A. lagunae populations of lagoon and islands and from March to July for sea population. The total lipid and fatty acid content of the investigated fishes showed significant seasonal variations. Atherina lagunae populations from Kerkennah Islands and Bizerta Lagoon have the highest fat content during the late spring-summer period. Major fatty acids of this species are C14:0, C16:0, C18:0, C16:1n-7, C18:1n-9, C20:5n-3, C22:5n- 3 and C22:6n-3. Alternatively, A. boyeri s. str. silversides from open sea showed the highest fat concentrations during the late winter-spring period. The n-3/n-6 ratio fatty acids ratio of sand smelt can be significantly influenced by spawning and season. It was concluded that these two Atherina species are a healthy item in the human diet during period when balanced n-3/n-6 ratios and EPA and DHA levels are considered.
Visualization of the exocytosis/endocytosis secretory cycle in cultured adrenal chromaffin cells
Creators: name: Wilson, S. P.
name: Phillips, J. H.
name: Burridge, K.
name: Kirshner, N.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1983

description: Cultured bovine adrenal medullary chromaffin cells were stimulated to secrete catecholamines by addition of veratridine or nicotine. The formation of an exocytotic pit exposes a major secretory granule membrane antigen, the enzyme dopamine beta-hydroxylase, to the external medium. By including antiserum to this enzyme in the medium, we were able to visualize sites of exocytosis by decoration of bound antibody using a fluorescent second antibody. Internalization of this antibody- antigen complex was then followed in chase experiments: approximately half the surface complex was internalized in 15-30 min. In other experiments, secretion was triggered in the absence of antiserum, and surface enzyme was revealed by binding antibodies at various times after secretion had been halted by an antagonist. Surface patches of antigen remained discrete from the bulk of the plasma membrane for at least 30 min, although a substantial proportion of the antigen was internalized within this time. Cell surface concanavalin A receptors were internalized at a roughly similar rate, suggesting that mechanisms may be similar. After internalization, chromaffin granule membranes fused to larger structures, possibly lysosomes, and were transported over a few hours to the perinuclear region of the cell.
Ultrastructural localization of the Mr 43,000 protein and the acetylcholine receptor in Torpedo postsynaptic membranes using monoclonal antibodies
Creators: name: Wray, B. E.
name: Froehner, S. C.
name: Sealock, R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1984

description: Four mouse monoclonal antibodies (mabs) were shown by immunoblotting procedures to recognize the major, basic, membrane-bound Mr 43,000 protein (43K protein) of acetylcholine receptor-rich postsynaptic membranes from Torpedo nobiliana . These mabs and a mab against an extracellular determinant on the acetylcholine receptor were used to localize the two proteins in electroplax (Torpedo californica) and on unsealed postsynaptic membrane fragments at the ultrastructural level. Bound mabs were revealed with a rabbit anti-mouse Ig serum and protein A-colloidal gold. The anti-43K mabs bound only to the cytoplasmic surface of the postsynaptic membrane. The distributions of the receptor and the 43K protein along the membrane were found to be coextensive. Distances between the membrane center and gold particles were very similar for anti-receptor and anti-43K mabs (29 +/- 7 nm and 26 to 29 +/- 7 to 10 nm, respectively). These results show that the 43K protein is a receptor-specific protein having a restricted spatial relationship to the membrane. They thus support models in which the 43K protein is associated with the cytoplasmic domains of the receptor molecule.
Platelet-derived growth factor-induced alterations in vinculin and actin distribution in BALB/c-3T3 cells
Creators: name: Pledger, W. J.
name: Herman, B.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1985

description: Exposure of BALB/c-3T3 cells (clone A31) to platelet-derived growth factor (PDGF) results in a rapid time- and dose-dependent alteration in the distribution of vinculin and actin. PDGF treatment (6-50 ng/ml) causes vinculin to disappear from adhesion plaques (within 2.5 min after PDGF exposure) and is followed by an accumulation of vinculin in punctate spots in the perinuclear region of the cell. This alteration in vinculin distribution is followed by a disruption of actin- containing stress fibers (within 5 to 10 min after PDGF exposure). Vinculin reappears in adhesion plaques by 60 min after PDGF addition while stress fiber staining is nondetectable at this time. PDGF treatment had no effect on talin, vimentin, or microtubule distribution in BALB/c-3T3 cells; in addition, exposure of cells to 5% platelet-poor plasma (PPP), 0.1% PPP, 30 ng/ml epidermal growth factor (EGF), 30 ng/ml somatomedin C, or 10 microM insulin also had no effect on vinculin or actin distribution. Other competence-inducing factors (fibroblast growth factor, calcium phosphate, and choleragen) and tumor growth factor produced similar alterations in vinculin and actin distribution as did PDGF, though not to the same extent. PDGF treatment of cells for 60 min followed by exposure to EGF (0.1-30 ng/ml for as long as 8 h after PDGF removal), or 5% PPP resulted in the nontransient disappearance of vinculin staining within 10 min after EGF or PPP additions; PDGF followed by 0.1% PPP or 10 microM insulin had no effect. Treatment of cells with low doses of PDGF (3.25 ng/ml), which did not affect vinculin or actin organization in cells, followed by EGF (10 ng/ml), resulted in the disappearance of vinculin staining in adhesion plaques, thus demonstrating the synergistic nature of PDGF and EGF. These data suggest that PDGF-induced competence and stimulation of cell growth in quiescent fibroblasts are associated with specific rapid alterations in the cellular organization of vinculin and actin.
(3839) James Wilson Mann
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.
Ultrastructural study of spermatogenesis in Marphysa sanguinea (Montagu, 1815) (Annelida, Polychaeta, Eunicida) from the Lagoon of Tunis
Creators: name: ELBARHOUMI, Monia
name: SCAPS, Patrick
name: ZGHAL, Fathia
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2014

description: Light microscopy and transmission electron microscopy (TEM) were used to describe spermatogenesis and the morphology of mature sperm in Marphysa sanguinea from the Lagoon of Tunis. No well-defined testis occurs in M. sanguinea and the male germ cells are released into the coelom from a few specialized regions of the peritoneum. Spermatogonia undergo mitotic divisions without complete cytokinesis, resulting in the formation of spermatogonial clusters referred as morulae. Each cluster contains 40 to 100 cells. Clusters break up at the end of the meiotic prophase and spermatocytes then continue to develop in groups of 2 or 4 cells. Both spermatogonia and early spermatocytes are charac- terized by a wide nucleus and scarce cytoplasm containing numerous free ribosomes, many endoplasmic reticulum cisternae and Golgi complexes. The acrosomal vesicle proceeds from coalescence of dense proacrosmal granules. At the end of spermatogenesis, mature spermatozoa float freely in the coelom. The mature spermatozoon of M. sanguinea is morphologically simple and corresponds to the ect-aquasperm type as defined by Jamieson & Rouse (1989). It measures about 6 µm (including the flagellum) in length and 1.3 µm in width. It appears to have an elongated nucleus, a cap-like round acrosome, a short mid-piece with 5-6 mitochondria and a single long flagellum with a basic 9 x 2 + 2 axoneme.
Increment entropy as a measure of complexity for time series
Creators: name: Liu, Xiaofeng
name: Jiang, Aimin
name: Xu, Ning
name: Xue, Jianru
Publisher: name: arXiv
Year: 2015
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Entropy has been a common index to quantify the complexity of time series in a variety of fields. Here, we introduce increment entropy to measure the complexity of time series in which each increment is mapped into a word of two letters, one letter corresponding to direction and the other corresponding to magnitude. The Shannon entropy of the words is termed as increment entropy (IncrEn). Simulations on synthetic data and tests on epileptic EEG signals have demonstrated its ability of detecting the abrupt change, regardless of energetic (e.g. spikes or bursts) or structural changes. The computation of IncrEn does not make any assumption on time series and it can be applicable to arbitrary real-world data.
description: 12pages,7figure,2 tables
Economic Growth Benefits more from Population Health than Foreign Direct Investment: Evidence from Tanzania
Creators: name: Byaro, Mwoya
name: Mgale, Yohana
name: Mafwolo, Gemma
name: Byaro, Mwoya
name: Mgale, Yohana
name: Mafwolo, Gemma
Publisher: name: Unknown
Year: 2022
Subjects: subject: International Development
subject: FDI
subject: population health
subject: economic growth
subject: ARDL

description: This paper uses annual secondary data for the period 1990-2019 to establish and compare the contributions of population life expectancy and foreign direct investment (FDI) on economic growth, controlled for inflation and exports of goods and services in Tanzania. It applies autoregressive distributed lag (ARDL) model as an estimation technique. The findings show that, FDI and export of goods and services have no significant impact on economic growth in the short run. Only life expectancy shows a positive and significant effect on economic growth in the short run. The long run findings show that FDI inflows have no significant impact on economic growth. However, population life expectancy and exports of goods and services all show positive and significant impact on economic growth in the long run. The magnitude of population life expectancy on economic growth is greater than that of FDI inflows or exports, meaning that economic growth benefits more from population health. We suggest the government to implement policies that improve population health such as expanding access to priority public health interventions (i.e. increase health facilities, better nutrition, medical care and other universal health coverage) to boost longevity, and with it, the economy. Overall, we conclude that investments in health should be prioritized because high levels of population health are associated with high levels of economic growth (i.e. income).
Analysis of the treadmilling model during metaphase of mitosis using fluorescence redistribution after photobleaching
Creators: name: Wadsworth, P.
name: Salmon, E. D.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1986

description: One recent hypothesis for the mechanism of chromosome movement during mitosis predicts that a continual, uniform, poleward flow or "treadmilling" of microtubules occurs within the half-spindle between the chromosomes and the poles during mitosis (Margolis, R. L., and L. Wilson, 1981, Nature (Lond.), 293:705-711). We have tested this treadmilling hypothesis using fluorescent analog cytochemistry and measurements of fluorescence redistribution after photobleaching to examine microtubule behavior during metaphase of mitosis. Mitotic BSC 1 mammalian tissue culture cells or newt lung epithelial cells were microinjected with brain tubulin labeled with 5-(4,6-dichlorotriazin-2- yl) amino fluorescein (DTAF) to provide a fluorescent tracer of the endogenous tubulin pool. Using a laser microbeam, fluorescence in the half-spindle was photobleached in either a narrow 1.6 micron wide bar pattern across the half-spingle or in a circular area of 2.8 or 4.5 micron diameter. Fluorescence recovery in the spindle fibers, measured using video microscopy or photometric techniques, occurs as bleached DTAF-tubulin subunits within the microtubules are exchanged for unbleached DTAF-tubulin in the cytosol by steady-state microtubule assembly-disassembly pathways. Recovery of 75% of the bleached fluorescence follows first-order kinetics and has an average half-time of 37 sec, at 31-33 degrees C. No translocation of the bleached bar region could be detected during fluorescence recovery, and the rate of recovery was independent of the size of the bleached spot. These results reveal that, for 75% of the half-spindle microtubules, FRAP does not occur by a synchronous treadmilling mechanism.
Local structure of current fluctuations in diffusive systems beyond one dimension
Creators: name: Villavicencio-Sanchez, Rodrigo
name: Harris, Rosemary J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In order to illuminate the properties of current fluctuations in more than one dimension, we use a lattice-based Markov process driven into a non-equilibrium steady state. Specifically, we perform a detailed study of the particle current fluctuations in a two-dimensional zero-range process with open boundary conditions and probe the influence of the underlying geometry by comparing results from a square and a triangular lattice. Moreover, we examine the structure of local currents corresponding to a given global current fluctuation and comment on the role of spatial inhomogeneities for the discrepancies observed in testing some recent fluctuation symmetries.
description: 18 pages, 7 figures
(3842) Janet Hogart Mann
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.
Spectral flow of exterior Landau-Robin hamiltonians
Creators: name: Goffeng, Magnus
name: Schrohe, Elmar
Publisher: name: arXiv
Year: 2015
Subjects: subject: Spectral Theory (math.SP)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We study the spectral flow of Landau-Robin hamiltonians in the exterior of a compact domain with smooth boundary. This provides a method to study the spectrum of the exterior Landau-Robin hamiltonian's dependence on the choice of Robin data, even explaining the heuristics of how the spectrum of the Robin problem asymptotically tends to the spectrum of the Dirichlet problem. The main technical result concerns the continuous dependence of Landau-Robin hamiltonians on the Robin data in the gap topology. The problem can be localized to the compact boundary where the asymptotic behavior of the spectral flow in some special cases can be described.
description: 22 pages
Expression of the Ca2+-binding protein, parvalbumin, during embryonic development of the frog, Xenopus laevis
Creators: name: Kay, B. K.
name: Shah, A. J.
name: Halstead, W. E.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1987

description: A cDNA segment encoding the Ca2+-binding protein, parvalbumin, was isolated with the use of antibodies, from a lambda gtll expression library of Xenopus laevis tadpole poly(A)+ RNAs. The bacterially expressed beta-galactosidase-parvalbumin fusion protein of one lambda recombinant shows high affinity 45Ca2+ binding. The sequence of the tadpole parvalbumin is highly similar to previously characterized beta- parvalbumins of other organisms. Data from protein and RNA blotting experiments demonstrate that parvalbumin is absent in oocytes, eggs, and early staged embryos, and only becomes expressed during embryogenesis at the time of myogenesis. The protein can be detected in individual developing muscle cells and in muscle fibers of tadpole tail muscles. A simple method is also described for the isolation of neural tube-notochord-somite complexes from Xenopus embryos.
Determinants of the Perceived Quality of Malaria Diagnostic Services in Dar es Salaam, Tanzania
Creators: name: Osoro, Otieno
name: Osoro, Otieno
Publisher: name: Unknown
Year: 2022
Subjects: subject: Health Economics and Policy
subject: healthcare quality
subject: logit
subject: malaria
subject: Tanzania

description: This study explores the determinants of perceived quality of malaria diagnostic services in Dar es Salaam, Tanzania using a logit model. The study uses exit interview data from 600 people who had tested for malaria in 30 health facilities in Dar es Salaam in the year 2020. The estimated results show that age of diagnosticians, type of response to suspected malaria illness, and time of testing for malaria influence perceived quality of malaria diagnostic services. Perception of malaria diagnostic services differ significantly by gender with males being influenced by reliability factors while females are influenced more by accessibility factors. Furthermore, youth were more likely to have a lower perception of quality of malaria diagnostic services. The policy implications are threefold. First, enhancing awareness of importance of testing prior to taking medication via coordinated health education initiatives. Second, emphasis of in-service training to maintain competence of diagnosticians is strongly advocated. Third, perpetual monitoring of diagnostician work hours in order to maintain productivity is required.
Selective excision of the centromere chromatin complex from Saccharomyces cerevisiae
Creators: name: Kenna, M.
name: Amaya, E.
name: Bloom, K.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1988

description: We have taken advantage of the known structural parameters associated with centromere DNA in vivo to construct a CEN fragment that can be selectively excised from the chromatin DNA with restriction endonucleases. CEN3 DNA is organized in chromatin such that a 220-250- bp region encompassing the elements of centromere homology is resistant to nuclease digestion. Restriction enzyme linkers encoding the Bam HI- recognition site were ligated to a 289 base pair DNA segment that spans the 220-250-bp protected core (Bloom et al., 1984). Replacement of this CEN3-Bam HI linker cassette into a chromosome or plasmid results in formation of a complete structural and functional centromeric unit. A centromere core complex that retains its protected chromatin conformation can be selectively excised from intact nuclei by restriction with the enzyme Bam HI. The centromeric protein-DNA complex is therefore not dependent upon the intact torsional constrains on linear chromosomes for its structural integrity. Isolation of this complex provides a novel approach to characterizing authentic centromeric proteins bound to DNA in their native state.
(3840) Alexander Mann
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.
(3841) William Crichton Mann
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.
An interaction between alpha-actinin and the beta 1 integrin subunit in vitro
Creators: name: Pavalko, Fredrick M.
name: Otey, Carol A.
name: Burridge, Keith
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1990

description: A number of cytoskeletal-associated proteins that are concentrated in focal contacts, namely alpha-actinin, vinculin, talin, and integrin, have been shown to interact in vitro such that they suggest a potential link between actin filaments and the membrane. Because some of these interactions are of low affinity, we suspect the additional linkages also exist. Therefore, we have used a synthetic peptide corresponding to the cytoplasmic domain of beta 1 integrin and affinity chromatography to identify additional integrin-binding proteins. Here we report our finding of an interaction between the cytoplasmic domain of beta 1 integrin and the actin-binding protein alpha-actinin. Beta 1- integrin cytoplasmic domain peptide columns bound several proteins from Triton extracts of chicken embryo fibroblasts. One protein at approximately 100 kD was identified by immunoblot analysis as alpha- actinin. Solid phase binding assays indicated that alpha-actinin bound specifically and directly to the beta 1 peptide with relatively high affinity. Using purified heterodimeric chicken smooth muscle integrin (a beta 1 integrin) or the platelet integrin glycoprotein IIb/IIIa complex (a beta 3 integrin), binding of alpha-actinin was also observed in similar solid phase assays, albeit with a lower affinity than was seen using the beta 1 peptide. alpha-Actinin also bound specifically to phospholipid vesicles into which glycoprotein IIb/IIIa had been incorporated. These results lead us to suggest that this integrin-alpha- actinin linkage may contribute to the attachment of actin filaments to the membrane in certain locations.
Predicting Grades
Creators: name: Meier, Yannick
name: Xu, Jie
name: Atan, Onur
name: van der Schaar, Mihaela
Publisher: name: arXiv
Year: 2015
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: To increase efficacy in traditional classroom courses as well as in Massive Open Online Courses (MOOCs), automated systems supporting the instructor are needed. One important problem is to automatically detect students that are going to do poorly in a course early enough to be able to take remedial actions. Existing grade prediction systems focus on maximizing the accuracy of the prediction while overseeing the importance of issuing timely and personalized predictions. This paper proposes an algorithm that predicts the final grade of each student in a class. It issues a prediction for each student individually, when the expected accuracy of the prediction is sufficient. The algorithm learns online what is the optimal prediction and time to issue a prediction based on past history of students' performance in a course. We derive a confidence estimate for the prediction accuracy and demonstrate the performance of our algorithm on a dataset obtained based on the performance of approximately 700 UCLA undergraduate students who have taken an introductory digital signal processing over the past 7 years. We demonstrate that for 85% of the students we can predict with 76% accuracy whether they are going do well or poorly in the class after the 4th course week. Using data obtained from a pilot course, our methodology suggests that it is effective to perform early in-class assessments such as quizzes, which result in timely performance prediction for each student, thereby enabling timely interventions by the instructor (at the student or class level) when necessary.
description: 15 pages, 15 figures
Comparative behavior of membrane protein-antibody complexes on motile fibroblasts: implications for a mechanism of capping
Creators: name: Jacobson, K.
name: Holifield, B. F.
name: Ishihara, A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1990

description: A characteristic feature of fibroblast locomotory activity is the rearward transport across the leading lamella of various materials used to mark the cell surface. The two processes most frequently invoked as explanations for this transport phenomenon, called capping, are (a) retrograde membrane flow arising from directed membrane insertion and (b) rearward cortical cytoskeletal flow arising from cytoskeletal assembly and contraction. The retrograde lipid flow hypothesis, the most current form of the membrane flow scheme, makes explicit predictions about the movement of membrane proteins subjected to the postulated rearward lipid flow. Several of these predictions were tested by comparing the behavior of four membrane proteins, Pgp-1, Thy- 1, H-2, and influenza HA0, identified by fluorescent antibodies. With the exception of Pgp-1, these proteins were uniformly distributed under nonaggregated conditions but were capped when aggregated into patches. In contrast, Pgp-1 was capped in similar time frames in both nonaggregated and aggregated states where the lateral diffusion coefficients were very different. Furthermore, the capping behavior of two tagged membrane proteins was markedly different yet both had similar diffusion coefficients. The results from these tests disprove the bulk membrane flow hypothesis and are at odds with explicit predictions of the retrograde lipid flow hypothesis for the mechanism of capping. This work, therefore, supports the alternative cytoskeletal- based mechanism for driving capping. Requirements for coupling cytoskeletal movement to membrane components are discussed.
Poleward force at the kinetochore in metaphase depends on the number of kinetochore microtubules
Creators: name: Salmon, E. D.
name: Hays, T. S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1990

description: To examine the dependence of poleward force at a kinetochore on the number of kinetochore microtubules (kMTs), we altered the normal balance in the number of microtubules at opposing homologous kinetochores in meiosis I grasshopper spermatocytes at metaphase with a focused laser microbeam. Observations were made with light and electron microscopy. Irradiations that partially damaged one homologous kinetochore caused the bivalent chromosome to shift to a new equilibrium position closer to the pole to which the unirradiated kinetochore was tethered; the greater the dose of irradiation, the farther the chromosome moved. The number of kMTs on the irradiated kinetochore decreased with severity of irradiation, while the number of kMTs on the unirradiated kinetochore remained constant and independent of chromosome-to-pole distance. Assuming a balance of forces on the chromosome at congression equilibrium, our results demonstrate that the net poleward force on a chromosome depends on the number of kMTs and the distance from the pole. In contrast, the velocity of chromosome movement showed little dependence on the number of kMTs. Possible mechanisms which explain the relationship between the poleward force at a kinetochore, the number of kinetochore microtubules, and the lengths of the kinetochore fibers at congression equilibrium include a "traction fiber model" in which poleward force producers are distributed along the length of the kinetochore fibers, or a "kinetochore motor-polar ejection model" in which force producers located at or near the kinetochore pull the chromosomes poleward along the kMTs and against an ejection force that is produced by the polar microtubule array and increases in strength toward the pole.
Ionic strength of the intermembrane space of intact mitochondria as estimated with fluorescein-BSA delivered by low pH fusion
Creators: name: Cortese, J. D.
name: Hackenbrock, C. R.
name: Voglino, A. L.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1991

description: The electrostatic interactions of cytochrome c with its redox partners and membrane lipids, as well as other protein interactions and biochemical reactions, may be modulated by the ionic strength of the intermembrane space of the mitochondrion. FITC-BSA was used to determine the relative value of the mitochondrial intermembrane ionic strength with respect to bulk medium external to the mitochondrial outer membrane. FITC-BSA exhibited an ionic strength-dependent fluorescence change with an affinity in the mM range as opposed to its pH sensitivity in the microM range. A controlled, low pH-induced membrane fusion procedure was developed to transfer FITC-BSA encapsulated in asolectin liposomes, to the intermembrane space of intact mitochondria. The fusion procedure did not significantly affect mitochondrial ultrastructure, electron transport, or respiratory control ratios. The extent of fusion of liposomes with the mitochondrial outer membrane was monitored by fluorescence dequenching assays using a membrane fluorescent probe (octadecylrhodamine B) and the soluble FITC-BSA fluorescent probe, which report membrane and contents mixing, respectively. Assays were consistent with a rapid, low pH-induced vesicle-outer membrane fusion and delivery of FITC-BSA into the intermembrane space. Similar affinities for the ionic strength- dependent change in fluorescence were found for bulk medium, soluble (9.8 +/- 0.8 mM) and intermembrane space-entrapped FITC-BSA (10.2 +/- 0.6 mM). FITC-BSA consistently reported an ionic strength in the intermembrane space of the functionally and structurally intact mitochondria within +/- 20% of the external bulk solution. These findings reveal that the intermembrane ionic strength changes as does the external ionic strength and suggest that cytochrome c interactions, as well as other protein interactions and biochemical reactions, proceed in the intermembrane space of mitochondria in the intact cell at physiological ionic strength, i.e., 100-150 mM.
Anomalous compliance and early yielding of nanoporous gold
Creators: name: Ngô, Bao-Nam Dinh
name: Stukowski, Alexander
name: Mameka, Nadiia
name: Markmann, Jürgen
name: Albe, Karsten
name: Weissmüller, Jörg
Publisher: name: arXiv
Year: 2015
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a study of the elastic and plastic behavior of nanoporous gold in compression, focusing on molecular dynamics simulation and inspecting experimental data for verification. Both approaches agree on an anomalously high elastic compliance in the early stages of deformation, along with a quasi immediate onset of plastic yielding even at the smallest load. Already before the first loading, the material undergoes spontaneous plastic deformation under the action of the capillary forces, requiring no external load. Plastic deformation under compressive load is accompanied by dislocation storage and dislocation interaction, along with strong strain hardening. Dislocation-starvation scenarios are not supported by our results. The stiffness increases during deformation, but never approaches the prediction by the relevant Gibson-Ashby scaling law. Microstructural disorder affects the plastic deformation behavior and surface excess elasticity might modify elastic response, yet we relate the anomalous compliance and the immediate yield onset to an atomistic origin: the large surface-induced prestress induces elastic shear that brings some regions in the material close to the shear instability of the generalized stacking fault energy curve. These regions are elastically highly compliant and plastically weak.