1,711 research outputs found
Classical resolution of black hole singularities via wormholes
In certain extensions of General Relativity, wormholes generated by
spherically symmetric electric fields can resolve black hole singularities
without necessarily removing curvature divergences. This is shown by studying
geodesic completeness, the behavior of time-like congruences going through the
divergent region, and by means of scattering of waves off the wormhole. This
provides an example of the logical independence between curvature divergences
and space-time singularities, concepts very often identified with each other in
the literature.ns of curvature divergences in the context of space-time
singularities.Comment: 6 pages, 4 figures; several improvements in main body and abstract;
final version to appear in Eur. Phys. J.
ICT tools for tackling bullying in schools: an analysis and opportunities
[EN] Bullying is defined as the act of repeatedly and intentionally causing harm to another person who feels
helpless (i.e., the victim) against the perpetrator or group of perpetrators. These series of acts of physical
and/or psychological violence have been reported to cause a negative impact on the victim on several
aspects of his/her well-being and daily life. Recently, multidisciplinary research teams have noticed the
potential of ICT tools as catalysts for fighting bullying in schools. A range of ICT-based tools such as elearning systems, intelligent tutoring systems, gamified applications, analytics, or even artificial
intelligence have been proposed as technological assets against bullying. In this paper, we identify,
categorize, and analyse the use of these ICT tools against bullying under a wide range of criteria such
as their role (e.g., prevention, mitigation, detection, etc.), the potential investment that is required, the
target age of users, and strengths and weaknesses of each tool. Then, we discuss on potential areas
of expansion for the use of ICT tools in the fight bullying, and we identify new potential areas of research.This work has been partially funded by the Generalitat Valenciana (GV/2019/012).Alberola Oltra, JM.; Sanchez-Anguix, V.; Soto-González, MD.; Molines Borrás, S.; Monfort Torres, G.; DÃaz Novillo, S. (2020). ICT tools for tackling bullying in schools: an analysis and opportunities. IATED. 4662-4667. https://doi.org/10.21125/inted.2020.1289S4662466
Exacerbated inflammatory signaling underlies aberrant response to BMP9 in pulmonary arterial hypertension lung endothelial cells
Imbalanced transforming growth factor beta (TGFβ) and bone morphogenetic protein (BMP) signaling are postulated to favor a pathological pulmonary endothelial cell (EC) phenotype in pulmonary arterial hypertension (PAH). BMP9 is shown to reinstate BMP receptor type-II (BMPR2) levels and thereby mitigate hemodynamic and vascular abnormalities in several animal models of pulmonary hypertension (PH). Yet, responses of the pulmonary endothelium of PAH patients to BMP9 are unknown. Therefore, we treated primary PAH patient-derived and healthy pulmonary ECs with BMP9 and observed that stimulation induces transient transcriptional signaling associated with the process of endothelial-to-mesenchymal transition (EndMT). However, solely PAH pulmonary ECs showed signs of a mesenchymal trans-differentiation characterized by a loss of VE-cadherin, induction of transgelin (SM22α), and reorganization of the cytoskeleton. In the PAH cells, a prolonged EndMT signaling was found accompanied by sustained elevation of pro-inflammatory, pro-hypoxic, and pro-apoptotic signaling. Herein we identified interleukin-6 (IL6)-dependent signaling to be the central mediator required for the BMP9-induced phenotypic change in PAH pulmonary ECs. Furthermore, we were able to target the BMP9-induced EndMT process by an IL6 capturing antibody that normalized autocrine IL6 levels, prevented mesenchymal transformation, and maintained a functional EC phenotype in PAH pulmonary ECs. In conclusion, our results show that the BMP9-induced aberrant EndMT in PAH pulmonary ECs is dependent on exacerbated pro-inflammatory signaling mediated through IL6
Beaming into the Rat World: Enabling Real-Time Interaction between Rat and Human Each at Their Own Scale
Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human’s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale
First measurement of the CP-violating phase in B0s→J/ψ( → e+e−)ϕ decays
A flavour-tagged time-dependent angular analysis of B0 s → J/ψφ decays is presented where the J/ψ meson is reconstructed through its decay to an e +e − pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1 . The CP-violating phase and lifetime parameters of the B0 s system are measured to be φs = 0.00 ± 0.28 ± 0.05 rad, ∆Γs = 0.115 ± 0.045 ± 0.011 ps−1 and Γs = 0.608 ± 0.018 ± 0.011 ps−1 where the first uncertainty is statistical and the second systematic. This is the first time that CP-violating parameters are measured in the B0 s → J/ψφ decay with an e +e − pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions
Clinical practice guidelines of the European Association for Endoscopic Surgery (EAES) on bariatric surgery: update 2020 endorsed by IFSO-EC, EASO and ESPCOP
Background:
Surgery for obesity and metabolic diseases has been evolved in the light of new scientific evidence, long-term outcomes and accumulated experience. EAES has sponsored an update of previous guidelines on bariatric surgery.
Methods:
A multidisciplinary group of bariatric surgeons, obesity physicians, nutritional experts, psychologists, anesthetists and a patient representative comprised the guideline development panel. Development and reporting conformed to GRADE guidelines and AGREE II standards.
Results:
Systematic review of databases, record selection, data extraction and synthesis, evidence appraisal and evidence-to-decision frameworks were developed for 42 key questions in the domains Indication; Preoperative work-up; Perioperative management; Non-bypass, bypass and one-anastomosis procedures; Revisional surgery; Postoperative care; and Investigational procedures. A total of 36 recommendations and position statements were formed through a modified Delphi procedure.
Conclusion:
This document summarizes the latest evidence on bariatric surgery through state-of-the art guideline development, aiming to facilitate evidence-based clinical decisions
Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: long-term follow up of a multicenter randomized controlled clinical trial (phase I/II)
Background: Mesenchymal stromal cells (MSCs) are a promising option to treat knee osteoarthritis (OA). Their safety
and usefulness have been reported in several short-term clinical trials but less information is available on the longterm efects of MSC in patients with osteoarthritis. We have evaluated patients included in our previous randomized
clinical trial (CMM-ART, NCT02123368) to determine their long-term clinical efect.
Materials: A phase I/II multicenter randomized clinical trial with active control was conducted between 2012 and
2014. Thirty patients diagnosed with knee OA were randomly assigned to Control group, intraarticularly administered
hyaluronic acid alone, or to two treatment groups, hyaluronic acid together with 10×106
or 100×106
cultured autol‑
ogous bone marrow-derived MSCs (BM-MSCs), and followed up for 12 months. After a follow up of 4 years adverse
efects and clinical evolution, assessed using VAS and WOMAC scorings are reported.
Results: No adverse efects were reported after BM-MSCs administration or during the follow-up. BM-MSCs-adminis‑
tered patients improved according to VAS, median value (IQR) for Control, Low-dose and High-dose groups changed
from 5 (3, 7), 7 (5, 8) and 6 (4, 8) to 7 (6, 7), 2 (2, 5) and 3 (3, 4), respectively at the end of follow up (Low-dose vs Control
group, p=0.01; High-dose vs Control group, p=0.004). Patients receiving BM-MSCs also improved clinically accord‑
ing to WOMAC. Control group showed an increase median value of 4 points (−11;10) while Low-dose and Highdose groups exhibited values of −18 (−28;−9) and −10 (−21;−3) points, respectively (Low-dose vs Control group
p=0.043). No clinical diferences between the BM-MSCs receiving groups were found.
Conclusions: Single intraarticular injection of in vitro expanded autologous BM-MSCs is a safe and feasible proce‑
dure that results in long-term clinical and functional improvement of knee OA
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