cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Motion words selectively modulate direction discrimination sensitivity for threshold motion
Creators: name: Pavan, Andrea
name: Skujevskis, Maris
name: Baggio, Giosuè
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: spoken language, discrimination sensitivity, systems interaction, modular theory, embodied theory
subject: 150 Psychologie

description: Can speech selectively modulate the sensitivity of a sensory system so that, in the presence of a suitable linguistic context, the discrimination of certain perceptual features becomes more or less likely? In this study, participants heard upward or downward motion words followed by a single visual field of random dots moving upwards or downwards. The time interval between the onsets of the auditory and the visual stimuli was varied parametrically. Motion direction could be either discriminable (suprathreshold motion) or non-discriminable (threshold motion). Participants had to judge whether the dots were moving upward or downward. Results show a double dissociation between discrimination sensitivity (d') and reaction times depending on whether vertical motion was above or at threshold. With suprathreshold motion, responses were faster for congruent directions of words and dots, but sensitivity was equal across conditions. With threshold motion, sensitivity was higher for congruent directions of words and dots, but responses were equally fast across conditions. The observed differences in sensitivity and response times were largest when the dots appeared 450 ms after word onset, that is, consistently with electrophysiology, at the time the up/down semantics of the word had become available. These data suggest that word meanings can alter the balance between signal and noise within the visual system and affect the perception of low-level sensory features.
North American nurses' transnational relief efforts during the Armenian Genocide of 1915 -1923
Creators: name: Yacoubian, Hrag
Publisher: name: University of British Columbia
Year: 2017

description: During the Armenian Genocide of 1915-1923, nurses from the United States of America and Canada traveled to Turkey, Armenia and the surrounding region to render humanitarian assistance to the victims and survivors of the Turkish atrocities. Yet, there is inadequate knowledge on the important roles these nurses played and their experiences and motivations are not fully understood. This thesis aims to add new historical knowledge to existing literature about transnational and humanitarian relief work by North American nurses, to shed light on larger social trends and human experiences and to expand our historical understanding of the Armenian Genocide through their encounters with victims, refugees and orphans. This thesis explored the past editions of the American Journal of Nursing, the Canadian Nurse and The Globe from 1915 to1923. The findings revealed that North American nurses were significantly involved in humanitarian and relief efforts in very difficult circumstances during the Armenian Genocide. They were functioning under mostly secular organizations, such as the American Red Cross, and the Near East Relief, yet often they were significantly influenced by their Protestant Christian backgrounds. Despite the tremendous hardship encountered, many nurses chose to remain in Turkey and to serve those in need of their relief efforts. US and Canadian nurses worked together and in close proximity and their humanitarianism was transnational in nature. In addition to relief work, the nurses established nursing schools and hospitals, which served both as source of help and new resources for education and employment for Armenian survivors. The thesis concludes with recommendations for future studies involving documents to expand upon the beginning of the understanding North American nurses’ involvement and the meaning of transnational relationships during the Armenian Genocide.
Combined diffusion-weighted and functional magnetic resonance imaging reveals a temporal-occipital network involved in auditory-visual object processing
Creators: name: Beer, Anton Ludwig
name: Plank, Tina
name: Meyer, Georg
name: Greenlee, Mark W.
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: DWI, auditory cortex, extrastriate body area, fMRI, fiber tractography, multisensory processing, structural connectivity, superior temporal sulcus
subject: 150 Psychologie

description: Functional magnetic resonance imaging (MRI) showed that the superior temporal and occipital cortex are involved in multisensory integration. Probabilistic fiber tracking based on diffusion-weighted MRI suggests that multisensory processing is supported by white matter connections between auditory cortex and the temporal and occipital lobe. Here, we present a combined functional MRI and probabilistic fiber tracking study that reveals multisensory processing mechanisms that remained undetected by either technique alone. Ten healthy participants passively observed visually presented lip or body movements, heard speech or body action sounds, or were exposed to a combination of both. Bimodal stimulation engaged a temporal-occipital brain network including the multisensory superior temporal sulcus (msSTS), the lateral superior temporal gyrus (lSTG), and the extrastriate body area (EBA). A region-of-interest (ROI) analysis showed multisensory interactions (e.g., subadditive responses to bimodal compared to unimodal stimuli) in the msSTS, the lSTG, and the EBA region. Moreover, sounds elicited responses in the medial occipital cortex. Probabilistic tracking revealed white matter tracts between the auditory cortex and the medial occipital cortex, the inferior occipital cortex (IOC), and the superior temporal sulcus (STS). However, STS terminations of auditory cortex tracts showed limited overlap with the msSTS region. Instead, msSTS was connected to primary sensory regions via intermediate nodes in the temporal and occipital cortex. Similarly, the lSTG and EBA regions showed limited direct white matter connections but instead were connected via intermediate nodes. Our results suggest that multisensory processing in the STS is mediated by separate brain areas that form a distinct network in the lateral temporal and inferior occipital cortex.
Ballistic interferences in suspended graphene
Creators: name: Rickhaus, Peter
name: Maurand, Romain
name: Liu, Ming-Hao
name: Weiss, Markus
name: Richter, Klaus
name: Schönenberger, Christian
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: graphene
subject: 530 Physik

description: The low-energy electronic excitations in graphene are described by massless Dirac fermions that have a linear dispersion relation. Taking advantage of this ‘optics-like’ electron dynamics, generic optical elements like lenses and wave guides have been proposed for electrons in graphene. Tuning of these elements relies on the ability to adjust the carrier concentration in defined areas. However, the combination of ballistic transport and complex gating remains challenging. Here we report on the fabrication and characterization of suspended graphene p–n junctions. By local gating, resonant cavities can be defined, leading to complex Fabry–Pérot interferences. The observed conductance oscillations account for quantum interference of electrons propagating ballistically over distances exceeding 1 μm. Visibility of the interferences is demonstrated to be enhanced by Klein collimation at the p–n interface. This finding paves the way to more complex gate-controlled ballistic graphene devices and brings electron optics in graphene closer to reality.
Theory of carrier density in multigated doped graphene sheets with quantum correction
Creators: name: Liu, Ming-Hao
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: 530 Physik

description: The quantum capacitance model is applied to obtain an exact solution for the space-resolved carrier density in a multigated doped graphene sheet at zero temperature, with quantum correction arising from the finite electron capacity of the graphene itself taken into account. The exact solution is demonstrated to be equivalent to the self-consistent Poisson-Dirac iteration method by showing an illustrative example, where multiple gates with irregular shapes and a nonuniform dopant concentration are considered. The solution therefore provides a fast and accurate way to compute spatially varying carrier density, on-site electric potential energy, as well as quantum capacitance for bulk graphene, allowing for any kind of gating geometry with any number of gates and any types of intrinsic doping.
Utility of Oblique Sagittal Reformatted and Three-dimensional Surface Reconstruction Computed Tomography in Foraminal Stenosis Decompression
Creators: name: Oshina, Masahito
name: Oshima, Yasushi
name: Tanaka, Sakae
name: Tan, Lee A.
name: Li, Xudong Josh
name: Tuchman, Alexander
name: Riew, K. Daniel
Publisher: name: Columbia University
Year: 2018
Subjects: Tomography
Nervous system--Diseases
Diagnostic imaging
Spinal canal--Stenosis
Cervix uteri--Diseases

description: Determining the responsible level of cervical radiculopathy can be difficult. Because asymptomatic findings are common in cervical radiculopathy, diagnoses based on imaging studies can be inaccurate. Therefore, we investigated whether the application of oblique sagittal reformatted computed tomography (oblique sagittal CT) and three-dimensional surface reconstruction CT (3DCT) affects surgical plans for patients with cervical foraminal stenosis and whether it assists diagnosis of foraminal stenosis. Accordingly, four reviewers, with office notes, observed the CT and magnetic resonance imaging (MRI) images of 18 patients undergoing surgical treatment for cervical radiculopathy. After reviewing the MRI and sagittal, coronal, and axial CT images, the reviewers recorded the operation to be performed; they examined oblique sagittal CT and 3DCT images of the same patients and noted any differences from their surgical plans. Consequently, we analyzed these changes in the decompressed foramina in the surgical plan; mean percent change in the plan was 18.1%. Inter-rater reliability improved from κ - 0.194 to κ - 0.240. Therefore, the addition of oblique and 3DCT images improves inter-rater reliability owing to changes in a part of decompressed foramina. The addition of oblique sagittal CT and 3DCT is helpful in evaluating the foramen and planning surgical treatment of cervical radiculopathy.
Massive Gravity: Exorcising the Ghost
Creators: name: Alberte, Lasma
name: Chamseddine, Ali H.
name: Mukhanov, Viatcheslav
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider Higgs massive gravity [1,2] and investigate whether a nonlinear ghost in this theory can be avoided. We show that although the theory considered in [10,11] is ghost free in the decoupling limit, the ghost nevertheless reappears in the fourth order away from the decoupling limit. We also demonstrate that there is no direct relation between the value of the Vainshtein scale and the existence of nonlinear ghost. We discuss how massive gravity should be modified to avoid the appearance of the ghost.
description: 16 pages
Extending in vitro conditioning in Aplysia to analyze operant and classical processes in the same preparation
Creators: name: Brembs, Björn
name: Baxter, D. A.
name: Byrne, J. H.
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 590 Tiere (Zoologie)

description: Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in Aplysia are helping to narrow the gap in the level of understanding between operant and classical conditioning, and have raised the possibility of studying the neuronal processes underlying the interaction of operant and classical components in a relatively complex learning task. In the present study, we describe a first step toward realizing this goal, by developing a single in vitro preparation in which both operant and classical conditioning can be studied concurrently. The new paradigm reproduced previously published results, even under more conservative and homogenous selection criteria and tonic stimulation regime. Moreover, the observed learning was resistant to delay, shortening, and signaling of reinforcement.
Candidate protein markers for radiation biodosimetry in the hematopoietically humanized mouse model
Creators: name: Lee, Younghyun
name: Pujol Canadell, Monica
name: Shuryak, Igor
name: Perrier, Jay R.
name: Taveras, Maria
name: Patel, Purvi
name: Koller, Antonius
name: Smilenov, Lubomir B.
name: Brenner, David J.
name: Chen, Emily I.
name: Turner, Helen C.
Publisher: name: Columbia University
Year: 2018
Subjects: Hematopoietic system
Radiation--Physiological effect
Proteins--Effect of radiation on

description: After a radiological incident, there is an urgent need for fast and reliable bioassays to identify radiation-exposed individuals within the first week post exposure. This study aimed to identify candidate radiation-responsive protein biomarkers in human lymphocytes in vivo using humanized NOD scid gamma (Hu-NSG) mouse model. Three days after X-irradiation (0–2 Gy, 88 cGy/min), human CD45+ lymphocytes were collected from the Hu-NSG mouse spleen and quantitative changes in the proteome of the human lymphocytes were analysed by mass spectrometry. Forty-six proteins were differentially expressed in response to radiation exposure. FDXR, BAX, DDB2 and ACTN1 proteins were shown to have dose-dependent response with a fold change greater than 2. When these proteins were used to estimate radiation dose by linear regression, the combination of FDXR, ACTN1 and DDB2 showed the lowest mean absolute errors (≤0.13 Gy) and highest coefficients of determination (R2 = 0.96). Biomarker validation studies were performed in human lymphocytes 3 days after irradiation in vivo and in vitro. In conclusion, this is the first study to identify radiation-induced human protein signatures in vivo using the humanized mouse model and develop a protein panel which could be used for the rapid assessment of absorbed dose 3 days after radiation exposure.
Novel Magnetic Chiral Structures and Unusual Temperature Hysteresis in the Metallic Helimagnet MnP
Creators: name: Yamazaki, Teruo
name: Tabata, Yoshikazu
name: Waki, Takeshi
name: Sato, Taku J
name: Matsuura, Masato
name: Ohoyama, Kenji
name: Yokoyama, Makoto
name: Nakamura, Hiroyuki
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have reinvestigated the magnetic properties of the classical metallic helimagnet MnP by magnetization and neutron scattering experiments. Our neutron scattering results indicate that the previously reported magnetic structure in the low-temperature (LT) helimagnetic phase (T < 47K) should be modified to an alternately tilted helimagnetic structure pro- duced by the Dzyaloshinsky-Moriya interaction. In the intermediate temperature (IT) range between the LT helimagnetic phase and the high-temperature (HT) ferromagnetic phase along the c-axis, 47K < T < 282K, we have found a weak ferromagnetic behavior along the b-axis. Surprisingly, the IT weak ferromagnetic phase has two different states, namely, the large magnetization (LM) and small magnetization (SM) states. The SM state emerges with cooling from the paramagnetic phase above 292 K via the HT ferromagnetic phase and LM state emerges with warming from the LT helimagnetic phase. The weak ferromagnetism along the b-axis and the unusual temperature hysteresis in the IT phase can be understood by assuming a spontaneous formation of the stripe structure consisting of alternately arranged HT ferromagnetic and LT helimagnetic domains.
description: 18 pages, 9 figures
title: Faire ou ne pas faire ses devoirs :
title: pratiques et perceptions d’élèves de voie générale en fin de scolarité obligatoire
titleType: Subtitle
title: Faire ou ne pas faire ses devoirs :
titleType: AlternativeTitle
Creators: name: Piguet, Jérôme
name: Cheseaux, Julien
Publisher: name: Unknown
Year: 0
Subjects: subject: élèves
subject: devoirs
subject: tensions
subject: coronavirus
subject: autorégulation
subject: différenciation

description: Les devoirs sont une pratique scolaire traditionnelle et universelle. Leur bien-fondé est un sujet de débat dans notre société mais également dans nos classes de voie générale. Enseignants d’élèves de 11ème Harmos, nous constatons tous les jours les problèmes liés à la gestion des devoirs, véritable source de tensions. C’est pourquoi nous avons choisi ce sujet, cette étude devant nous aider à améliorer cette situation. Il était intéressant de savoir dans quelle mesure les recommandations des scientifiques sont en adéquation avec les dires et ressentis de nos élèves et comment elles pourraient être appliquées. Pour cela il fallait connaître et comprendre les élèves et leurs pratiques. Nous avons donc décidé de les interviewer en organisant six entretiens semi-directifs. Pour chacun d’entre eux, des portraits ont été réalisés, accompagnés d’une analyse thématique. Quelques semaines après nos entretiens est survenue la crise du Coronavirus et la mise en place de l’école à distance. Les devoirs ont alors pris une place prépondérante. Cette expérience est venue ajouter de riches observations à notre travail. Cette crise allait-elle exacerber les comportements habituels de nos élèves ? Pourquoi certains élèves effectuent leurs devoirs et d’autres les copient, les bâclent ou ne les font pas ? Cette étude a mis en évidence la grande disparité qui peut exister entre élèves d’une même classe : différences de pratiques, de compétences intellectuelles, inégalités d’environnements familiaux, de capacités d’autorégulation. Cette diversité, aussi riche soit-elle humainement parlant, complique la question des devoirs. Nous verrons néanmoins comment ce travail nous aura finalement permis de pointer du doigt certaines pratiques enseignantes à éviter, et d’autres à adopter, dans les modalités liées aux devoirs.
The 59 Sound : A fictional historiography of the TISH poetry movement
Creators: name: Mash, C. A.
Publisher: name: University of British Columbia
Year: 2018

description: Much has been written about the Tish poetry movement in Vancouver in the 1950s and 60s, yet currently no major historiographic study on the group exists. This project takes an interdisciplinary approach, working at the nexus of English, history, and creative writing, and takes the form of a critical thesis and accompanying novella in order to contribute to existing historiography on Tish. The two parts of this project are located within the historical discourses of narrativism and constructivism, and the narrative traditions of historiographic metafiction and neo-historical fiction. By identifying the major gaps, silences, and erasures in the received Tish historical narrative, the critical section works with the accompanying novella to attempt to address those limitations through the use of a historical narrative.
The biology of psychology ‘Simple’ conditioning?
Creators: name: Colomb, J.
name: Brembs, Björn
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: insect, flight, choice, decisionmaking, spontaneity, behavior, memory
subject: 590 Tiere (Zoologie)

description: Operant (instrumental) and classical (Pavlovian) conditioning are taught as the simplest forms of associative learning. Recent research in several invertebrate model systems has now accumulated evidence that the dichotomy is not as simple as it seemed. During operant learning in the fruit fly Drosophila, at least two genetically distinct learning systems interact dynamically. Inspired by analogous results in three other research fields, we propose to term one of these systems world-learning (assigning value to sensory stimuli) and the other self-learning (assigning value to a specific action or movement). During the goal-directed phase of operant learning, world-learning inhibits self-learning (in Drosophila via the mushroom-body neuropil), to allow for flexible generalization. Extended training overcomes this inhibition in a phase transition akin to habit formation in vertebrates, allowing self-learning to transform spontaneous actions to habitual responses. In part, these insights were achieved by reducing operant experiments beyond the traditional set-ups (i.e., ‘pure’ operant learning) and using modern, molecular and/or genetic model systems.
Operant Reward Learning in Aplysia: Neuronal Correlates and Mechanisms
Creators: name: Brembs, Björn
name: Lorenzetti, F. D.
name: Reyes, F. D.
name: Baxter, D. A.
name: Byrne, J. H.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 590 Tiere (Zoologie)

description: Operant conditioning is a form of associative learning through which an animal learns about the consequences of its behavior. Here, we report an appetitive operant conditioning procedure inAplysia that induces long-term memory. Biophysical changes that accompanied the memory were found in an identified neuron (cell B51) that is considered critical for the expression of behavior that was rewarded. Similar cellular changes in B51 were produced by contingent reinforcement of B51 with dopamine in a single-cell analog of the operant procedure. These findings allow for the detailed analysis of the cellular and molecular processes underlying operant conditioning.
Usp9X Regulates Cell Death in Malignant Peripheral Nerve Sheath Tumors
Creators: name: Bianchetti, Elena
name: Bates, S.J.
name: Carroll, Steven L.
name: Siegelin, Markus D.
name: Roth, Kevin A.
Publisher: name: Columbia University
Year: 2018
Subjects: Myelin sheath
Neurofibromatosis
Nervous system--Tumors
Cell death
Cancer

description: Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of death in neurofibromatosis type 1 (NF1) patients. Current treatment modalities have been largely unsuccessful in improving MPNST patient survival, making the identification of new therapeutic targets urgent. In this study, we found that interference with Usp9X, a deubiquitinating enzyme which is overexpressed in nervous system tumors, or Mcl-1, an anti-apoptotic member of the Bcl-2 family whose degradation is regulated by Usp9X, causes rapid death in human MPNST cell lines. Although both Usp9X and Mcl-1 knockdown elicited some features of apoptosis, broad spectrum caspase inhibition was ineffective in preventing knockdown-induced MPNST cell death suggesting that caspase-independent death pathways were also activated. Ultrastructural examination of MPNST cells following either Usp9X interference or pharmacological inhibition showed extensive cytoplasmic vacuolization and swelling of endoplasmic reticulum (ER) and mitochondria most consistent with paraptotic cell death. Finally, the Usp9X pharmacological inhibitor WP1130 significantly reduced human MPNST growth and induced tumor cell death in an in vivo xenograft model. In total, these findings indicate that Usp9X and Mcl-1 play significant roles in maintaining human MPNST cell viability and that pharmacological inhibition of Usp9X deubiquitinase activity could be a therapeutic target for MPNST treatment.
Transfer Matrix for Partially Quenched QCD
Creators: name: Bernard, Claude
name: Golterman, Maarten
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We construct the transfer matrix for the ghost sector of partially quenched QCD. This transfer matrix is not hermitian, but we show that it is still bounded. We thus expect that all euclidean correlation functions will decay exponentially with distance (up to possible powers), and demonstrate that this is indeed the case for free ghost quarks.
description: 7 pages, contribution to Lattice 2010
title: Narramus, ou comment apprendre à un élève autiste à comprendre un album de littérature jeunesse
title: Narramus, ou comment apprendre à un élève autiste à comprendre un album de littérature jeunesse
titleType: AlternativeTitle
Creators: name: Isoz, Annick
Publisher: name: Unknown
Year: 0
Subjects: subject: Trouble du spectre de l’autisme (TSA)
subject: Compréhension
subject: Album de littérature jeunesse
subject: Narramus
subject: Lecture partagée
subject: Enseignement explicite

description: Les élèves qui présentent un trouble du spectre autistique (TSA) rencontrent souvent des difficultés à comprendre les albums de littérature jeunesse qui leur sont lus en classe. Les moments de lecture sont peu structurés, le sens des albums se construit à partir du texte et de l’image qui ne racontent pas toujours la même chose, les élèves manquent de vocabulaire et de connaissances sur les univers de référence des albums lus, ils ont de la peine à identifier les idées principales, à les organiser, à tisser des liens entre les informations, ou encore à accéder aux pensées et aux motivation des personnages. Or, comprendre des textes est l’une des compétences clé de la réussite scolaire. Ce mémoire cherche donc à proposer des pistes pour aider un élève avec TSA. intégré dans une classe de 2P, à participer activement aux moments de lecture et à accéder au sens des albums qui sont lus en classe. Pour cela, j’ai testé l’utilisation de Narramus, un outil conçu par Cèbe et Goigoux (2017), destiné à apprendre aux élèves de maternelle à comprendre des textes pour ensuite les raconter. Si cet outil ne s’adresse pas a priori spécifiquement à des élèves avec TSA, certaines de ses caractéristiques m’ont semblé pouvoir répondre à leurs besoins, comme le caractère structuré et répétitif des activités ou l’enseignement explicite et systématique des compétences nécessaires à la compréhension. J’ai ainsi voulu tester si l’utilisation de Narramus permettait à un élève avec TSA d’accéder à la compréhension des textes, aussi bien que ses camarades. Les résultats sont très encourageants et donnent des pistes concrètes aux enseignants de classe ordinaire, qui souhaitent adapter leurs pratiques pour favoriser les apprentissages des élèves avec TSA qu’ils accueillent dans leurs classes.
Anomalous Heat Diffusion
Creators: name: Liu, Sha
name: Hänggi, Peter
name: Li, Nianbei
name: Ren, Jie
name: Li, Baowen
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Consider anomalous energy spread in solid phases, i.e., $MSD= \int (x -{\langle x \rangle}_E)^2 ρ_E(x,t)dx \propto t^β$, as induced by a small initial excess energy perturbation distribution $ρ_{E}(x,t=0)$ away from equilibrium. The associated total thermal equilibrium heat flux autocorrelation function $C_{JJ}(t)$ is shown to obey rigorously the intriguing relation, $d^2 MSD/dt^2 = 2C_{JJ}(t)/(k_BT^2c)$, where $c$ is the specific volumetric heat capacity. Its integral assumes a time-local Helfand-moment relation; i.e. $ dMSD/dt|_{t=t_s} = 2/(k_BT^2c)\int_0^{t_s} C_{JJ}(s)ds$, where the chosen cut-off time $t_s$ is determined by the maximal signal velocity for heat transfer. Given the premise that the averaged nonequilibrium heat flux is governed by an anomalous heat conductivity, energy diffusion scaling determines a corresponding anomalous thermal conductivity scaling behaviour.
Context generalization and occasion setting in Drosophila visual learning
Creators: name: Brembs, Björn
name: Wiener, J.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 590 Tiere (Zoologie)

description: In a permanently changing environment, it is by no means an easy task to distinguish potentially important events from negligible ones. Yet, to survive, every animal has to continuously face that challenge. How does the brain accomplish this feat? Building on previous work in Drosophila melanogaster visual learning, we have developed an experimental methodology in which combinations of visual stimuli (colors and patterns) can be arranged such that the same stimuli can either be directly predictive, indirectly predictive, or nonpredictive of punishment. Varying this relationship, we found that wild-type flies can establish different memory templates for the same contextual color cues. The colors can either leave no trace in the pattern memory template, leading to context-independent pattern memory (context generalization), or be learned as a higher-order cue indicating the nature of the pattern-heat contingency leading to context-dependent memory (occasion setting) or serve as a conditioned stimulus predicting the punishment directly (simple conditioning). In transgenic flies with compromised mushroom-body function, the sensitivity to these subtle variations is altered. Our methodology constitutes a new concept for designing learning experiments. Our findings suggest that the insect mushroom bodies stabilize visual memories against context changes and are not required for cognition-like higher-order learning.
Dynamic phasor modeling of type 3 wind turbine generators for large-scale power system transient stability studies
Creators: name: Choi, Wonbae
Publisher: name: University of British Columbia
Year: 2017

description: The wind power penetration has been increasing significantly, and this trend is likely to continue. As wind power penetration levels increase, interconnecting large-scale wind power plants (WPPs) into the existing power system has become a critical issue. Therefore, appropriate wind turbine generator models are required to conduct transient stability (TS) studies. While it is possible to construct detailed and accurate models of manufacturer-specific wind turbine generators in electromagnetic transient (EMT) simulators, such models are not suitable for large-scale transient stability studies due to their high computational complexity. The Western Electricity Coordinating Council (WECC) Renewable Energy Modeling Task Force (REMTF) is working towards developing generic wind turbine generator models that would be applicable for a range of general purpose system-level studies. However, such the generic models are typically over-simplified and not able to predict some of the phenomena, e.g. the unbalanced disturbance which is easily captured by the EMT simulations. In this research, a numerically-efficient model for the doubly-fed induction generator (DFIG) is developed that can predict steady state, balanced and unbalanced disturbances, and is sufficiently generic. The new DFIG model is based on the dynamic-phasor (DP) based machine models, which have been recently developed for the EMT simulators and can work with fairly large time-steps (up to several milliseconds) approaching that of the TS program solution. The WPP models have been implemented in MATLAB/Simulink® to assess the improved accuracy and computational efficiency. The new DP-based DFIG model is tested in a single machine infinite bus case and a two-area four-machine network to validate the model’s responses to balanced and unbalanced conditions of the grid. The accuracy of new DFIG model is shown to be significantly better compared to traditional TS models, which is achieved at a slightly increased computational cost. The result of this research will provide more accurate dynamic phasor based models of WPP for TS analysis. Since TS programs are widely used by utilities over the world, the new DP-based DFIG model will contribute to more reliable and accurate studies. This, in turn, will enable more reliable integration of large-scale WPPs into the existing and expanding power grids.
Performance of Deep Learning Architectures and Transfer Learning for Detecting Glaucomatous Optic Neuropathy in Fundus Photographs
Creators: name: Christopher, Mark
name: Belghith, Akram
name: Bowd, Christopher
name: Proudfoot, James A.
name: Goldbaum, Michael H.
name: Weinreb, Robert N.
name: Girkin, Christopher A.
name: Liebmann, Jeffrey M.
name: Zangwill, Linda M.
Publisher: name: Columbia University
Year: 2018
Subjects: Glaucoma--Diagnosis
Fundus oculi
Diagnostic imaging
Machine learning

description: The ability of deep learning architectures to identify glaucomatous optic neuropathy (GON) in fundus photographs was evaluated. A large database of fundus photographs (n = 14,822) from a racially and ethnically diverse group of individuals (over 33% of African descent) was evaluated by expert reviewers and classified as GON or healthy. Several deep learning architectures and the impact of transfer learning were evaluated. The best performing model achieved an overall area under receiver operating characteristic (AUC) of 0.91 in distinguishing GON eyes from healthy eyes. It also achieved an AUC of 0.97 for identifying GON eyes with moderate-to-severe functional loss and 0.89 for GON eyes with mild functional loss. A sensitivity of 88% at a set 95% specificity was achieved in detecting moderate-to-severe GON. In all cases, transfer improved performance and reduced training time. Model visualizations indicate that these deep learning models relied on, in part, anatomical features in the inferior and superior regions of the optic disc, areas commonly used by clinicians to diagnose GON. The results suggest that deep learning-based assessment of fundus images could be useful in clinical decision support systems and in the automation of large-scale glaucoma detection and screening programs.
Variability in coral-reconstructed sea surface salinity between the northern and southern Lombok Strait linked to East Asian winter monsoon mean state reversals.
Creators: name: Murty, Sujata
name: Goodkin, Nathalie
name: Wiguna, A. A.
name: Gordon, Arnold L.
Publisher: name: Columbia University
Year: 2018
Subjects: Paleoceanography
Paleoclimatology
Monsoons
Salinity

description: The Indonesian throughflow (ITF) impacts heat and buoyancy transport from the Pacific Ocean to the Indian Ocean, influencing air-sea heat exchange and Indo-Pacific climate. Nearly 80% of the total 15 sverdrups (1 Sv = 106m3/s) of ITF water moves through the Makassar Strait in the western Indonesian seas, with ~20% of total ITF transport subsequently entering the Indian Ocean through the Lombok Strait. During the East Asian winter monsoon (EAWM), buoyant South China Sea (SCS) waters obstruct southward surface ITF transport in the Makassar Strait, likely impacting surface variability throughout the Lombok Strait. Here we present two subannually resolved, multicentury records of coral-reconstructed sea surface salinity (SSS) from the northern (110 years) and southern Lombok Strait (193 years). Differences in boreal winter (January–March) SSS variability between the two sites suggest the influence of multiple source waters. Instrumental and reconstructed temperature-salinity (T-S) relationships indicate that SCS surface waters dominate the northern Lombok Strait, while Indian Ocean surface waters instead dominate the southern Lombok Strait before 1960. These dissimilarities are likely due to changes in monsoon-driven surface water advection. At the northern site, the EAWM consistently influences SSS variability. The EAWM influence at the southern site, however, reverses in direction (inverse to direct) coincidentally with a transition from a positive (strong) to negative (weak) EAWM state in 1960. Our records collectively reveal that changes in the strength and state of the EAWM impact Lombok Strait surface water circulation, likely interacting with southward ITF transport and thus Indo-Pacific climate.
Variability in Makassar Strait heat flux and its effect on the eastern tropical Indian Ocean
Creators: name: Gruenburg, Laura Kristen
name: Gordon, Arnold L.
Publisher: name: Columbia University
Year: 2018
Subjects: subject: Environmental sciences
subject: Oceanography
subject: FOS: Earth and related environmental sciences
subject: Heat flux
subject: Ocean temperature

description: The heat flux anomaly (HFa) within Makassar Strait, Indonesia, is investigated using observed velocity time series and El Niño-Southern Oscillation (ENSO)- scaled temperature profiles. Direct measurements of velocity from 40 m to 740 m depth were recorded during 2004–2011 and 2013–2017 during the International Nusantara STratification ANd Transport (INSTANT) and Monitoring Indonesian Throughflow (MITF) programs. The velocity profile is thermocline-intensified, with a velocity maximum near 100 m depth. In situ temperature measurements during 2004–2006 and ship-based CTD profiles collected during these two monitoring campaigns were combined with all available World Ocean Database CTD, ocean station, mechanical bathythermograph, and expendable bathythermograph data collected within Makassar Strait since 1950 to create representative temperature profiles for positive, negative, and neutral phases of ENSO. The Makassar velocity profile displays a stronger (weaker), shallower (deeper) velocity maximum, and a deeper (shallower) thermocline during La Niña (El Niño). Southward Makassar HFa increases rapidly from 2006 to 2008, with a peak of 0.13 PW in 2008 and 2009. Afterward, Makassar HFa slowly decreases to a minimum of −0.25 PW (less southward) during 2015, after which southward heat flux begins to climb again. Variability in depth-integrated volume transport from the surface to 740 m depth explains 57% of HFa variance. However, the total volume transport does not reflect the relative contributions of the warm upper and cool lower layers. Changes in the depth-dependent velocity profile explain 72% of HFa variance, whereas temperature profile variability explains only 28%. The impact of Makassar HFa variability on the Indian Ocean is assessed through comparison with the heat content anomaly (HCa) in an eastern tropical Indian Ocean box (ETIO; 101.5°E–105.5°E, and 9.5°S–15.5°S) using gridded Argo data. The ETIO HCa follows a similar pattern (R = 0.83) when lagged 30 months behind the Makassar HFa. Although well correlated, a notable discrepancy between the two time series is present in the ETIO in 2012/2013, possibly owing to a shift of the ITF from the dominant South Equatorial Current pathway to a southward Leeuwin track.
Remarks on the Bottcher-Wenzel Inequality
Creators: name: Lu, Zhiqin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Rings and Algebras (math.RA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: In 2005, Böttcher and Wenzel raised the conjecture that if $X,Y$ are real square matrices, then $||XY-YX||^2\leq 2||X||^2||Y||^2$, where $||\cdot||$ is the Frobenius norm. Various proofs of this conjecture were found in the last few years by several authors. We here give another proof. This proof is highly conceptual and requires minimal computation. We also briefly discuss related inequalities, in particular, the classical Chern-do Camo-Kobayashi inequality.
description: Journal reference added
Automorphisms of the Torelli complex for the one-holed genus two surface
Creators: name: Kida, Yoshikata
name: Yamagata, Saeko
Publisher: name: arXiv
Year: 2010
Subjects: subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 20E36, 20F38

description: Let S be a connected, compact and orientable surface of genus two having exactly one boundary component. We study automorphisms of the Torelli complex for S, and describe any isomorphism between finite index subgroups of the Torelli group for S. More generally, we study superinjective maps from the Torelli complex for S into itself, and show that any finite index subgroup of the Torelli group for S is co-Hopfian.
description: 28 pages, 21 figures. Proof was largely modified because some hexagons had been overlooked (v3), Figures added and exposition improved (v4)
R^2 Dark Matter
Creators: name: Cembranos, Jose A. R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: There is a non-trivial four-derivative extension of the gravitational spectrum that is free of ghosts and phenomenologically viable. It is the so called $R^2$-gravity since it is defined by the only addition of a term proportional to the square of the scalar curvature. Just the presence of this term does not improve the ultraviolet behaviour of Einstein gravity but introduces one additional scalar degree of freedom that can account for the dark matter of our Universe.
description: 6 pages, 1 figure, to appear in the Proceedings of the sixth International Workshop on the Dark Side of the Universe (DSU2010) Leon, Guanajuato, Mexico 1-6 June 2010
Open Source Tracking and Analysis of Adult Drosophila Locomotion in Buridan’s Paradigm with and without Visual Targets
Creators: name: Colomb, J.
name: Reiter, L.
name: Blaszkiewicz, J.
name: Wessnitzer, J.
name: Brembs, Björn
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 590 Tiere (Zoologie)

description: Background Insects have been among the most widely used model systems for studying the control of locomotion by nervous systems. In Drosophila, we implemented a simple test for locomotion: in Buridan's paradigm, flies walk back and forth between two inaccessible visual targets [1]. Until today, the lack of easily accessible tools for tracking the fly position and analyzing its trajectory has probably contributed to the slow acceptance of Buridan's paradigm. Methodology/Principal Findings We present here a package of open source software designed to track a single animal walking in a homogenous environment (Buritrack) and to analyze its trajectory. The Centroid Trajectory Analysis (CeTrAn) software is coded in the open source statistics project R. It extracts eleven metrics and includes correlation analyses and a Principal Components Analysis (PCA). It was designed to be easily customized to personal requirements. In combination with inexpensive hardware, these tools can readily be used for teaching and research purposes. We demonstrate the capabilities of our package by measuring the locomotor behavior of adult Drosophila melanogaster (whose wings were clipped), either in the presence or in the absence of visual targets, and comparing the latter to different computer-generated data. The analysis of the trajectories confirms that flies are centrophobic and shows that inaccessible visual targets can alter the orientation of the flies without changing their overall patterns of activity. Conclusions/Significance Using computer generated data, the analysis software was tested, and chance values for some metrics (as well as chance value for their correlation) were set. Our results prompt the hypothesis that fixation behavior is observed only if negative phototaxis can overcome the propensity of the flies to avoid the center of the platform. Together with our companion paper, we provide new tools to promote Open Science as well as the collection and analysis of digital behavioral data.
Investigating the Causes of Increased Twentieth-Century Fall Precipitation over the Southeastern United States
Creators: name: Bishop, Daniel Alexander
name: Williams, A. Park
name: Seager, Richard
name: Fiore, Arlene M.
name: Cook, Benjamin I.
name: Mankin, Justin S.
name: Singh, Deepti
name: Smerdon, Jason E.
name: Rao, Mukund Palat
Publisher: name: Columbia University
Year: 2019
Subjects: Mass transfer
Atmospheric circulation
Climatic changes
Precipitation (Meteorology)
Precipitation variability
Climatology

description: Much of the eastern United States experienced increased precipitation over the twentieth century. Characterizing these trends and their causes is critical for assessing future hydroclimate risks. Here, U.S. precipitation trends are analyzed for 1895–2016, revealing that fall precipitation in the southeastern region north of the Gulf of Mexico (SE-Gulf) increased by nearly 40%, primarily increasing after the mid-1900s. Because fall is the climatological dry season in the SE-Gulf and precipitation in other seasons changed insignificantly, the seasonal precipitation cycle diminished substantially. The increase in SE-Gulf fall precipitation was caused by increased southerly moisture transport from the Gulf of Mexico, which was almost entirely driven by stronger winds associated with enhanced anticyclonic circulation west of the North Atlantic subtropical high (NASH) and not by increases in specific humidity. Atmospheric models forced by observed SSTs and fully coupled models forced by historical anthropogenic forcing do not robustly simulate twentieth-century fall wetting in the SE-Gulf. SST-forced atmospheric models do simulate an intensified anticyclonic low-level circulation around the NASH, but the modeled intensification occurred farther west than observed. CMIP5 analyses suggest an increased likelihood of positive SE-Gulf fall precipitation trends given historical and future GHG forcing. Nevertheless, individual model simulations (both SST forced and fully coupled) only very rarely produce the observed magnitude of the SE-Gulf fall precipitation trend. Further research into model representation of the western ridge of the fall NASH is needed, which will help us to better predict whether twentieth-century increases in SE-Gulf fall precipitation will persist into the future.
Flexibility in a single behavioral variable of Drosophila
Creators: name: Heisenberg, M.
name: Wolf, R.
name: Brembs, Björn
Publisher: name: Universität Regensburg
Year: 2001
Subjects: subject: 590 Tiere (Zoologie)

description: The flexibility of behavior is so rich, and its components are so exquisitely interwoven, that one may be well advised to turn to an isolated behavioral module for study. Gill withdrawal inAplysia, the proboscis extension reflex in the honeybee, and lid closure in mammals are such examples. We have chosen yawing, a single component of flight orientation in Drosophila melanogaster, for this approach. A specialty of this preparation is that the behavioral output can be reduced beyond the single module by one further step. It can be studied in tethered animals in which all turns are blocked while the differentially beating wings still provide the momentum. These intended yaw turns are measured by a torque meter to which the fly is hooked. The fly is held horizontally as if cruising at high speed. The head is glued to the thorax. It can bend its abdomen, extend its proboscis, and move its legs but cannot shift its direction of gaze or its orientation in space. Evidently, a fly hardly ever encounters this bizarre situation in the wild. We describe here the flexibility in this single behavioral variable. It provides insights into the relation between classical and operant conditioning, the processing of and interactions between the conditioned visual stimuli, early visual memory, visual pattern recognition, selective attention, and several other experience-dependent properties of visual orientation behavior. We start with a brief summary of visual flight control at the torque meter.