Mostrando recursos 1 - 20 de 7.000

  1. Trouvaille: A Conversation About the Proofs of Maurice Blanchot’s L’Entretien Infini at Houghton Library

    McDonald, Christie; Morris, Leslie A.

  2. De L’ethnologie de L’échec au Collage des Arts

    McDonald, Christie
    Romance Languages and Literatures

  3. Which findings should be published?

    Alexander Frankel; Kasy, Maximilian
    Given a scarcity of journal space, what is the socially optimal rule for determining whether an empirical finding should be published? We show that if the goal of publication is to inform the public about a policy-relevant state of the world, then one should publish extreme results. For specific policy objectives, the optimal rule may take the form of a one- or two-sided test comparing the point estimate to the prior mean. Dynamic considerations may additionally justify the publication of precise null results. If one insists on a rule for which standard inference remains valid conditional on publication, however, the publication...

  4. A quick relaxation exercise for people with chronic obstructive pulmonary disease: explorative randomized controlled trial

    Volpato, Eleonora; Banfi, Paolo; Nicolini, Antonello; Pagnini, Francesco
    Background: People with Chronic Obstructive Pulmonary Disease (COPD) suffer from dyspnoea, which may be increased by anxiety. Previous studies suggest that relaxation techniques may have positive effects in pulmonary rehabilitation. The main aim of this study is to explore the clinical impact of a quick, one-session, relaxation training for people with COPD. Methods: In this perspective, 38 participants with COPD were recruited and randomly assigned to listen to a relaxing audio or to watch a neutral stimulus, during their routine exams. Participants were assessed for psychological and physiological variables, analysed through non-parametric tests. Results: Those who joined the relaxation training...

  5. Embryonic and postnatal neurogenesis produce functionally distinct subclasses of dopaminergic neuron

    Galliano, Elisa; Franzoni, Eleonora; Breton, Marine; Chand, Annisa N; Byrne, Darren J; Murthy, Venkatesh N; Grubb, Matthew S
    Most neurogenesis in the mammalian brain is completed embryonically, but in certain areas the production of neurons continues throughout postnatal life. The functional properties of mature postnatally generated neurons often match those of their embryonically produced counterparts. However, we show here that in the olfactory bulb (OB), embryonic and postnatal neurogenesis produce functionally distinct subpopulations of dopaminergic (DA) neurons. We define two subclasses of OB DA neuron by the presence or absence of a key subcellular specialisation: the axon initial segment (AIS). Large AIS-positive axon-bearing DA neurons are exclusively produced during early embryonic stages, leaving small anaxonic AIS-negative cells as...

  6. Compositional clustering in task structure learning

    Franklin, Nicholas T.; Frank, Michael J.
    Humans are remarkably adept at generalizing knowledge between experiences in a way that can be difficult for computers. Often, this entails generalizing constituent pieces of experiences that do not fully overlap, but nonetheless share useful similarities with, previously acquired knowledge. However, it is often unclear how knowledge gained in one context should generalize to another. Previous computational models and data suggest that rather than learning about each individual context, humans build latent abstract structures and learn to link these structures to arbitrary contexts, facilitating generalization. In these models, task structures that are more popular across contexts are more likely to...

  7. Critical role of climate change in plant selection and millet domestication in North China

    Yang, Xiaoyan; Wu, Wenxiang; Perry, Linda; Ma, Zhikun; Bar-Yosef, Ofer; Cohen, David J.; Zheng, Hongbo; Ge, Quansheng
    While North China is one of the earliest independent centers for cereal domestication in the world, the earliest stages of the long process of agricultural origins remain unclear. While only millets were eventually domesticated in early sedentary societies there, recent archaeobotanical evidence reported here indicates that grasses from the Paniceae (including millets) and Triticeae tribes were exploited together by foraging groups from the Last Glacial Maximum to the mid-Holocene. Here we explore how and why millets were selected for domestication while Triticeae were abandoned. We document the different exploitation and cultivation trajectories of the two tribes employing ancient starch data...

  8. Quantifying ecological impacts of mass extinctions with network analysis of fossil communities

    Muscente, A. D.; Prabhu, Anirudh; Zhong, Hao; Eleish, Ahmed; Meyer, Michael B.; Fox, Peter; Hazen, Robert M.; Knoll, Andrew H.
    Mass extinctions documented by the fossil record provide critical benchmarks for assessing changes through time in biodiversity and ecology. Efforts to compare biotic crises of the past and present, however, encounter difficulty because taxonomic and ecological changes are decoupled, and although various metrics exist for describing taxonomic turnover, no methods have yet been proposed to quantify the ecological impacts of extinction events. To address this issue, we apply a network-based approach to exploring the evolution of marine animal communities over the Phanerozoic Eon. Network analysis of fossil co-occurrence data enables us to identify nonrandom associations of interrelated paleocommunities. These associations,...

  9. Budding-like division of all-aqueous emulsion droplets modulated by networks of protein nanofibrils

    Song, Yang; Michaels, Thomas C. T.; Ma, Qingming; Liu, Zhou; Yuan, Hao; Takayama, Shuichi; Knowles, Tuomas P. J.; Shum, Ho Cheung
    Networks of natural protein nanofibrils, such as cytoskeletal filaments, control the shape and the division of cells, yet mimicking this functionality in a synthetic setting has proved challenging. Here, we demonstrate that artificial networks of protein nanofibrils can induce controlled deformation and division of all-aqueous emulsion droplets with budding-like morphologies. We show that this process is driven by the difference in the immersional wetting energy of the nanofibril network, and that both the size and the number of the daughter droplets formed during division can be controlled by modulating the fibril concentration and the chemical properties of the fibril network....

  10. Macrophage-mediated delivery of light activated nitric oxide prodrugs with spatial, temporal and concentration control† †Electronic supplementary information (ESI) available: Includes detailed experimental details plus 10 additional figures. See DOI: 10.1039/c8sc00015h

    Evans, Michael A.; Huang, Po-Ju; Iwamoto, Yuji; Ibsen, Kelly N.; Chan, Emory M.; Hitomi, Yutaka; Ford, Peter C.; Mitragotri, Samir
    Nitric oxide (NO) holds great promise as a treatment for cancer hypoxia, if its concentration and localization can be precisely controlled. Here, we report a “Trojan Horse” strategy to provide the necessary spatial, temporal, and dosage control of such drug-delivery therapies at targeted tissues. Described is a unique package consisting of (1) a manganese–nitrosyl complex, which is a photoactivated NO-releasing moiety (photoNORM), plus Nd3+-doped upconverting nanoparticles (Nd-UCNPs) incorporated into (2) biodegradable polymer microparticles that are taken up by (3) bone-marrow derived murine macrophages. Both the photoNORM [Mn(NO)dpaqNO2]BPh4(dpaqNO2 = 2-[N,N-bis(pyridin-2-yl-methyl)]-amino-N′-5-nitro-quinolin-8-yl-acetamido) and the Nd-UCNPs are activated by tissue-penetrating near-infrared (NIR) light at...

  11. Identifying key descriptors in surface binding: interplay of surface anchoring and intermolecular interactions for carboxylates on Au(110)† †Electronic supplementary information (ESI) available: Supporting experimental methods and supporting discussion are included in the supplementary information. See DOI: 10.1039/c7sc05313d

    O'Connor, Christopher R.; Hiebel, Fanny; Chen, Wei; Kaxiras, Efthimios; Madix, Robert J.; Friend, Cynthia M.
    The relative stability of carboxylates on Au(110) was investigated as part of a comprehensive study of adsorbate binding on Group IB metals that can be used to predict and understand how to control reactivity in heterogeneous catalysis. The binding efficacy of carboxylates is only weakly dependent on alkyl chain length for relatively short-chain molecules, as demonstrated using quantitative temperature-programmed reaction spectroscopy. Corresponding density functional theory (DFT) calculations demonstrated that the bidentate anchoring geometry is rigid and restricts the amount of additional stabilization through adsorbate-surface van der Waals (vdW) interactions which control stability for alkoxides. A combination of scanning tunneling microscopy...

  12. Changes in Pain Perception following Psychotherapy: The Mediating Role of Psychological Components

    Zanini, Susanna; Voltolini, Alessandra; Gragnano, Gaia; Fumagalli, Emilia; Pagnini, Francesco
    Chronic pain is frequently associated with significant psychological issues, such as depression or anxiety. Psychological treatments, such as psychotherapy, can often alleviate both psychological and pain symptoms. However, there is limited research about the association between psychological symptoms and perceived pain in the context of psychotherapeutic interventions. We conducted a retrospective study that analyzed, in a hospital context, how changes in psychological functioning and well-being were associated with pain reduction. Thirty-seven records of patients with chronic pain attending psychotherapy in a public hospital were included. All patients were assessed before psychotherapy, as well as after 6 and 10 months, with...

  13. Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) Study: Reverse Transcription-Polymerase Chain Reaction and Cataract Surgery Outcomes of Ebola Survivors in Sierra Leone☆

    Shantha, Jessica G.; Mattia, John G.; Goba, Augustine; Barnes, Kayla G.; Ebrahim, Faiqa K.; Kraft, Colleen S.; Hayek, Brent R.; Hartnett, Jessica N.; Shaffer, Jeffrey G.; Schieffelin, John S.; Sandi, John D.; Momoh, Mambu; Jalloh, Simbirie; Grant, Donald S.; Dierberg, Kerry; Chang, Joyce; Mishra, Sharmistha; Chan, Adrienne K.; Fowler, Rob; O'Dempsey, Tim; Kaluma, Erick; Hendricks, Taylor; Reiners, Roger; Reiners, Melanie; Gess, Lowell A.; ONeill, Kwame; Kamara, Sarian; Wurie, Alie; Mansaray, Mohamed; Acharya, Nisha R.; Liu, William J.; Bavari, Sina; Palacios, Gustavo; Teshome, Moges; Crozier, Ian; Farmer, Paul E.; Uyeki, Timothy M.; Bausch, Daniel G.; Garry, Robert F.; Vandy, Matthew J.; Yeh, Steven
    Background: Ebola virus disease (EVD) survivors are at risk for uveitis during convalescence. Vision loss has been observed following uveitis due to cataracts. Since Ebola virus (EBOV) may persist in the ocular fluid of EVD survivors for an unknown duration, there are questions about the safety and feasibility of vision restorative cataract surgery in EVD survivors. Methods: We conducted a cross-sectional study of EVD survivors anticipating cataract surgery and patients with active uveitis to evaluate EBOV RNA persistence in ocular fluid, as well as vision outcomes post cataract surgery. Patients with aqueous humor that tested negative for EBOV RNA were...

  14. Contributions of Reward Sensitivity to Ventral Striatum Activity Across Adolescence and Early Adulthood

    Schreuders, Elisabeth; Braams, Barbara R.; Blankenstein, Neeltje E.; Peper, Jiska S.; Güroğlu, Berna; Crone, Eveline A.
    It was examined how ventral striatum responses to rewards develop across adolescence and early adulthood and how individual differences in state‐ and trait‐level reward sensitivity are related to these changes. Participants (aged 8–29 years) were tested across three waves separated by 2 years (693 functional MRI scans) in an accelerated longitudinal design. The results confirmed an adolescent peak in reward‐related ventral striatum, specifically nucleus accumbens, activity. In early to mid‐adolescence, increases in reward activation were related to trait‐level reward drive. In mid‐adolescence to early adulthood decreases in reward activation were related to decreases in state‐level hedonic reward pleasure. This study...

  15. Disequilibrium of fire-prone forests sets the stage for a rapid decline in conifer dominance during the 21st century

    Serra-Diaz, Josep M.; Maxwell, Charles; Lucash, Melissa S.; Scheller, Robert M.; Laflower, Danelle M.; Miller, Adam D.; Tepley, Alan J.; Epstein, Howard E.; Anderson-Teixeira, Kristina J.; Thompson, Jonathan R.
    The impacts of climatic changes on forests may appear gradually on time scales of years to centuries due to the long generation times of trees. Consequently, current forest extent may not reflect current climatic patterns. In contrast with these lagged responses, abrupt transitions in forests under climate change may occur in environments where alternative vegetation states are influenced by disturbances, such as fire. The Klamath forest landscape (northern California and southwest Oregon, USA) is currently dominated by high biomass, biodiverse temperate coniferous forests, but climate change could disrupt the mechanisms promoting forest stability (e.g. growth, regeneration and fire tolerance). Using...

  16. Cadherins Interact With Synaptic Organizers to Promote Synaptic Differentiation

    Yamagata, Masahito; Duan, Xin; Sanes, Joshua R.
    Classical cadherins, a set of ~20 related recognition and signaling molecules, have been implicated in many aspects of neural development, including the formation and remodeling of synapses. Mechanisms underlying some of these steps have been studied by expressing N-cadherin (cdh2), a Type 1 cadherin, in heterologous cells, but analysis is complicated because widely used lines express cdh2 endogenously. We used CRISPR-mediated gene editing to generate a Human embryonic kidney (HEK)293 variant lacking Cdh2, then compared the behavior of rodent cortical and hippocampal neurons co-cultured with parental, cdh2 mutant and cdh2-rescued 293 lines. The comparison demonstrated that Cdh2 promotes neurite branching...

  17. The brown anole dewlap revisited: do predation pressure, sexual selection, and species recognition shape among-population signal diversity?

    Baeckens, Simon; Driessens, Tess; Van Damme, Raoul
    Animal signalling structures are amongst the most variable characteristics, as they are subjected to a diversity of selection pressures. A well-known example of a diverse signalling system in the animal kingdom is the dewlap of Anolis lizards. Dewlap characteristics can vary remarkably among and within species, and also between sexes. Although a considerable amount of studies have attempted to disentangle the functional significance of the staggering dewlap diversity in Anolis, the underlying evolutionary processes remain elusive. In this study, we focus on the contribution of biotic selective pressures in shaping geographic variation in dewlap design (size, colour, and pattern) and...

  18. Contrasting patterns of Andean diversification among three diverse clades of Neotropical clearwing butterflies

    Chazot, Nicolas; De‐Silva, Donna Lisa; Willmott, Keith R.; Freitas, André V. L.; Lamas, Gerardo; Mallet, James; Giraldo, Carlos E.; Uribe, Sandra; Elias, Marianne
    Abstract The Neotropical region is the most biodiverse on Earth, in a large part due to the highly diverse tropical Andean biota. The Andes are a potentially important driver of diversification within the mountains and for neighboring regions. We compared the role of the Andes in diversification among three subtribes of Ithomiini butterflies endemic to the Neotropics, Dircennina, Oleriina, and Godyridina. The diversification patterns of Godyridina have been studied previously. Here, we generate the first time‐calibrated phylogeny for the largest ithomiine subtribe, Dircennina, and we reanalyze a published phylogeny of Oleriina to test different biogeographic scenarios involving the Andes within...

  19. Competition Elicits more Physical Affiliation between Male than Female Friends

    Benenson, Joyce F.; White, Maxwell M.; Pandiani, Delfina Martinez; Hillyer, Lindsay J.; Kantor, Sera; Markovits, Henry; Wrangham, Richard W.
    Across species, cooperative alliances must withstand internal tensions. The mechanisms by which allies respond to competing against one another have been studied extensively in non-human animals, but much less so in humans. In non-human species, affiliative physical contact and close proximity immediately following a contest are utilized to define reconciliation between opponents. The proportion of conflicts that are reconciled however differs markedly by species and sex. The purpose of this study was to examine whether, like many other social species, humans utilize physical contact and close proximity following a competition between friends, and if so, whether one sex is more...

  20. Effective Network Size Predicted From Simulations of Pathogen Outbreaks Through Social Networks Provides a Novel Measure of Structure-Standardized Group Size

    McCabe, Collin M.; Nunn, Charles L.
    The transmission of infectious disease through a population is often modeled assuming that interactions occur randomly in groups, with all individuals potentially interacting with all other individuals at an equal rate. However, it is well known that pairs of individuals vary in their degree of contact. Here, we propose a measure to account for such heterogeneity: effective network size (ENS), which refers to the size of a maximally complete network (i.e., unstructured, where all individuals interact with all others equally) that corresponds to the outbreak characteristics of a given heterogeneous, structured network. We simulated susceptible-infected (SI) and susceptible-infected-recovered (SIR) models...

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