429 research outputs found
It's all about timing : an electrophysiological examination of feedback-based learning with immediate and delayed feedback
Feedback regarding an individual's action can occur immediately or with a temporal delay. Processing of feedback that varies in its delivery time is proposed to engage different brain mechanisms. fMRI data implicate the striatum in the processing of immediate feedback, and the medial temporal lobe (MTL) in the processing of delayed feedback. The present study offers an electrophysiological examination of feedback processing in the context of timing, by studying the effects of feedback timing on the feedback-related negativity (FRN), a product of the midbrain dopamine system, and elucidating whether the N170 ERP component could capture MTL activation associated with the processing of delayed feedback. Participants completed a word-object paired association learning task; they received feedback 500 ms (immediate feedback condition) following a button press during the learning of two sets of 14 items, and at a delay of 6500 ms (delayed feedback condition) during the learning of the other two sets. The results indicated that while learning outcomes did not differ under the two timing conditions, Event Related Potential (ERPs) pointed to differential activation of the examined ERP components. FRN amplitude was found to be larger following the immediate feedback condition when compared with the delayed feedback condition, and sensitive to valence and learning only under the immediate feedback condition. Additionally, the amplitude of the N170 was found larger following the delayed feedback condition when compared with the immediate feedback condition. Taken together, the findings of the present study support the contention that the processing of delayed feedback involves a shift away from midbrain dopamine activation to the recruitment of the MTL
Giant radiation heat transfer through the micron gaps
Near-field heat transfer between two closely spaced radiating media can
exceed in orders radiation through the interface of a single black body. This
effect is caused by exponentially decaying (evanescent) waves which form the
photon tunnel between two transparent boundaries. However, in the mid-infrared
range it holds when the gap between two media is as small as few tens of
nanometers. We propose a new paradigm of the radiation heat transfer which
makes possible the strong photon tunneling for micron thick gaps. For it the
air gap between two media should be modified, so that evanescent waves are
transformed inside it into propagating ones. This modification is achievable
using a metamaterial so that the direct thermal conductance through the
metamaterial is practically absent and the photovoltaic conversion of the
transferred heat is not altered by the metamaterial.Comment: 4 pages, 3 figure
The Prevalence of Burnout and Musculoskeletal Disorders in Physician Associates Students
Physician Associate, formerly known as Physician Assistant, (PA) is a growing occupation that originated in the 1960s. Previous research focused on the prevalence of musculoskeletal disorders and burnout in nursing, nursing students, PA, and ubiquitously assumed among many healthcare professionals; however, burnout and musculoskeletal disorders are under-researched in PA students. PURPOSE: To investigate the prevalence of burnout and musculoskeletal disorders in Physician Associate students. METHODS: This study was conducted at a private university in Florida. Twelve PA students participated in the study, nine females and three males (mean age 26.3 ± 1.8 years; mean height 166.6 ± 7.6 cm; mean weight 67.9 ± 14.0 kg). Eleven PA students were in their fifth clinical rotation and one in their sixth. Maslach Burnout Inventory Human Services Survey for Medical Personnel (MBI) and the Canadian Medical History Checklist: Symptoms Survey for Work-Related Musculoskeletal Disorders (WMSDs) were used. In the MBI questionnaire, burnout was quantified by three subcomponents: emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (PA). The WMSDs questionnaire measured the degree of acute pain in the neck, shoulder, elbow, wrist, hand, upper back, lower back, and foot. Participants filled out the two questionnaires in one session and the data were collected and analyzed. RESULTS: In the MBI survey, 84% of participants reported high to moderate EE (67% high, 17% moderate, and 17% low); 58.3% of participants reported high to moderate DP (33.3% high, 25% moderate, and 41.7% low); 66.6% of participants reported high to moderate PA (33.3% high, 33.3% moderate, and 33.3% low). In the WMSDs questionnaire, 75% of participants reported having pain or discomfort, in the last year, caused by their job that lasted two days or more in the neck, shoulder, and upper back, whereas 58% reported lower back pain or discomfort. Out of all participants reporting pain or discomfort, several participants reported that pain worsened while working, 67.7% reported for the neck; 44.4% for the shoulder; 67.7% for the upper back; and 57.1% for lower back pain. CONCLUSION: The results of the questionnaires indicated a high prevalence of burnout and musculoskeletal disorders in PA students. Physician Associate programs should include educational content emphasizing techniques to minimize burnout and reduce the prevalence of musculoskeletal disorders. Further research is needed to identify the influence of physical activity and relaxation techniques on burnout levels and the prevalence of musculoskeletal disorders in PA students
INO80 and Îł-H2AX Interaction Links ATP-Dependent Chromatin Remodeling to DNA Damage Repair
AbstractWhile the role of ATP-dependent chromatin remodeling in transcription is well established, a link between chromatin remodeling and DNA repair has remained elusive. We have found that the evolutionarily conserved INO80 chromatin remodeling complex directly participates in the repair of a double-strand break (DSB) in yeast. The INO80 complex is recruited to a HO endonuclease-induced DSB through a specific interaction with the DNA damage-induced phosphorylated histone H2A (Îł-H2AX). This interaction requires Nhp10, an HMG-like subunit of the INO80 complex. The loss of Nhp10 or Îł-H2AX results in reduced INO80 recruitment to the DSB. Finally, components of the INO80 complex show synthetic genetic interactions with the RAD52 DNA repair pathway, the main pathway for DSB repair in yeast. Our findings reveal a new role of ATP-dependent chromatin remodeling in nuclear processes and suggest that an ATP-dependent chromatin remodeling complex can read a DNA repair histone code
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Multimedia delivery in the future internet
The term âNetworked Mediaâ implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizensâ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications âon the moveâ, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
A Transgenic Model Reveals the Role of Klotho in Pancreatic Cancer Development and Paves the Way for New Klotho-Based Therapy
Klotho; CĂ ncer de pĂ ncrees; Supressor del tumorKlotho; CĂĄncer de pĂĄncreas; Supresor de tumorKlotho; Pancreatic cancer; Tumor suppressorKlotho is an anti-aging transmembrane protein, which can be shed and can function as a hormone. Accumulating data indicate that klotho is a tumor suppressor in a wide array of malignancies, and designate the subdomain KL1 as the active region of the protein towards this activity. We aimed to study the role of klotho as a tumor suppressor in pancreatic ductal adenocarcinoma (PDAC). Bioinformatics analyses of The Cancer Genome Atlas (TCGA) datasets revealed a correlation between the survival of PDAC patients, levels of klotho expression, and DNA methylation, and demonstrated a unique hypermethylation pattern of klotho in pancreatic tumors. The in vivo effects of klotho and KL1 were examined using three mouse models. Employing a novel genetic model, combining pancreatic klotho knockdown with a mutation in Kras, the lack of klotho contributed to PDAC generation and decreased mousece survival. In a xenograft model, administration of viral particles carrying sKL, a spliced klotho isoform containing the KL1 domain, inhibited pancreatic tumors. Lastly, treatment with soluble sKL prolonged survival of Pdx1-Cre; KrasG12D/+;Trp53R172H/+ (KPC) mice, a model known to recapitulate human PDAC. In conclusion, this study provides evidence that klotho is a tumor suppressor in PDAC. Furthermore, these data suggest that the levels of klotho expression and DNA methylation could have prognostic value in PDAC patients, and that administration of exogenous sKL may serve as a novel therapeutic strategy to treat PDAC.This project was funded by the The Sami and Tova Sagol Foundation for the Study of Aging, the Margaret Stultz foundation for Pancreatic Cancer Research, the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Ministerio de Ciencia e InnovaciĂłn âProyectos I+D+I 2019, to M.C., (grant number PID2019-104034RB-I00) and by the TASMC excellence fund. to I.W
Stationary solutions of the one-dimensional nonlinear Schroedinger equation: II. Case of attractive nonlinearity
All stationary solutions to the one-dimensional nonlinear Schroedinger
equation under box or periodic boundary conditions are presented in analytic
form for the case of attractive nonlinearity. A companion paper has treated the
repulsive case. Our solutions take the form of bounded, quantized, stationary
trains of bright solitons. Among them are two uniquely nonlinear classes of
nodeless solutions, whose properties and physical meaning are discussed in
detail. The full set of symmetry-breaking stationary states are described by
the character tables from the theory of point groups. We make
experimental predictions for the Bose-Einstein condensate and show that, though
these are the analog of some of the simplest problems in linear quantum
mechanics, nonlinearity introduces new and surprising phenomena.Comment: 11 pages, 9 figures -- revised versio
Exact closed form analytical solutions for vibrating cavities
For one-dimensional vibrating cavity systems appearing in the standard
illustration of the dynamical Casimir effect, we propose an approach to the
construction of exact closed-form solutions. As new results, we obtain
solutions that are given for arbitrary frequencies, amplitudes and time
regions. In a broad range of parameters, a vibrating cavity model exhibits the
general property of exponential instability. Marginal behavior of the system
manifests in a power-like growth of radiated energy.Comment: 17 pages, 7 figure
Stability of stationary states in the cubic nonlinear Schroedinger equation: applications to the Bose-Einstein condensate
The stability properties and perturbation-induced dynamics of the full set of
stationary states of the nonlinear Schroedinger equation are investigated
numerically in two physical contexts: periodic solutions on a ring and
confinement by a harmonic potential. Our comprehensive studies emphasize
physical interpretations useful to experimentalists. Perturbation by stochastic
white noise, phase engineering, and higher order nonlinearity are considered.
We treat both attractive and repulsive nonlinearity and illustrate the
soliton-train nature of the stationary states.Comment: 9 pages, 11 figure
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