2,376 research outputs found

    Individual skyrmion manipulation by local magnetic field gradients

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    Magnetic skyrmions are topologically protected spin textures, stabilised in systems with strong Dzyaloshinskii-Moriya interaction (DMI). Several studies have shown that electrical currents can move skyrmions efficiently through spin-orbit torques. While promising for technological applications, current-driven skyrmion motion is intrinsically collective and accompanied by undesired heating effects. Here we demonstrate a new approach to control individual skyrmion positions precisely, which relies on the magnetic interaction between sample and a magnetic force microscopy (MFM) probe. We investigate perpendicularly magnetised X/CoFeB/MgO multilayers, where for X = W or Pt the DMI is sufficiently strong to allow for skyrmion nucleation in an applied field. We show that these skyrmions can be manipulated individually through the local field gradient generated by the scanning MFM probe with an unprecedented level of accuracy. Furthermore, we show that the probe stray field can assist skyrmion nucleation. Our proof-of-concepts results pave the way towards achieving current-free skyrmion control

    Neuroprotective efficacy of nimesulide against hippocampal neuronal damage following transient forebrain ischemia

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    Cyclooxygenase-2 is involved in the inflammatory component of the ischemic cascade, playing an important role in the delayed progression of the brain damage. The present study evaluated the pharmacological effects of the selective cyclooxygenase-2 inhibitor nimesulide on delayed neuronal death of hippocampal CA1 neurons following transient global cerebral ischemia in gerbils. Administration of therapeutically relevant doses of nimesulide (3, 6 and 12 mg/kg; i.p.) 30 min before ischemia and at 6, 12, 24, 48 and 72 h after ischemia significantly (P<0.01) reduced hippocampal neuronal damage. Treatment with a single dose of nimesulide given 30 min before ischemia also resulted in a significant increase in the number of healthy neurons in the hippocampal CA1 sector 7 days after ischemia. Of interest is the finding that nimesulide rescued CA1 pyramidal neurons from ischemic death even when treatment was delayed until 24 h after ischemia (34+/-9% protection). Neuroprotective effect of nimesulide is still evident 30 days after the ischemic episode, providing the first experimental evidence that cyclooxygenase-2 inhibitors confer a long-lasting neuroprotection. Oral administration of nimesulide was also able to significantly reduce brain damage, suggesting that protective effects are independent of the route of administration. The present study confirms the ability of cyclooxygenase-2 inhibitors to reduce brain damage induced by cerebral ischemia and indicates that nimesulide can provide protection when administered for up to 24 h post-ischemia

    Modal Frustration and Periodicity Breaking in Artificial Spin Ice

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    Here, an artificial spin ice lattice is introduced that exhibits unique Ising and non-Ising behavior under specific field switching protocols because of the inclusion of coupled nanomagnets into the unit cell. In the Ising regime, a magnetic switching mechanism that generates a uni- or bimodal distribution of states dependent on the alignment of the field is demonstrated with respect to the lattice unit cell. In addition, a method for generating a plethora of randomly distributed energy states across the lattice, consisting of Ising and Landau states, is investigated through magnetic force microscopy and micromagnetic modeling. It is demonstrated that the dispersed energy distribution across the lattice is a result of the intrinsic design and can be finely tuned through control of the incident angle of a critical field. The present manuscript explores a complex frustrated environment beyond the 16-vertex Ising model for the development of novel logic-based technologies

    A Methodology to Sequence the Service Management Processes in IT Departments: Application to theTourism Industry

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    One of the key elements to consider in business management is the management of IT (In- formation Technology) departments by implementing processes as described in the ITIL (Information Technology Infrastructure Library) standard. This is particularly important in industries that are not directly related to ICT (Information and Communication Technologies), such as the tourism industry. In this paper, we present a methodology to sequence the implementation of the ITIL processes in any company to support its development. The methodology is based on an optimization algorithm and the information extracted from a survey. The optimal sequence is built from this information and from the information of the restrictions imposed by the company that implements the ITIL processes. We applied the methodology to a company in the tourism industry. The sequence obtained shows the need to implement operative processes (initial positions in the sequence), and afterwards strategic processes (final positions in the sequence). A comparison with other authors’ proposals shows differences in the order of processes proposed by this methodology. The main conclusion is that it is possible to use the information of companies to efficiently generate an optimal sequence of ITIL processes which enhances their management; this sequence is unique for every company that wants to implement ITIL in the tourism industry, and it is independent from the proposals of other authors who designed generic/non-optimal sequences.2021-2

    Cellular Senescence Is Immunogenic and Promotes Antitumor Immunity

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    Senescencia celular; Inmunidad antitumoralSenescència cel·lular; Immunitat antitumoralCellular senescence; Antitumor immunityCellular senescence is a stress response that activates innate immune cells, but little is known about its interplay with the adaptive immune system. Here, we show that senescent cells combine several features that render them highly efficient in activating dendritic cells (DC) and antigen-specific CD8 T cells. This includes the release of alarmins, activation of IFN signaling, enhanced MHC class I machinery, and presentation of senescence-associated self-peptides that can activate CD8 T cells. In the context of cancer, immunization with senescent cancer cells elicits strong antitumor protection mediated by DCs and CD8 T cells. Interestingly, this protection is superior to immunization with cancer cells undergoing immunogenic cell death. Finally, the induction of senescence in human primary cancer cells also augments their ability to activate autologous antigen-specific tumor-infiltrating CD8 lymphocytes. Our study indicates that senescent cancer cells can be exploited to develop efficient and protective CD8-dependent antitumor immune responses. Significance: Our study shows that senescent cells are endowed with a high immunogenic potential—superior to the gold standard of immunogenic cell death. We harness these properties of senescent cells to trigger efficient and protective CD8-dependent antitumor immune responses.We are grateful to Maria Isabel Muñoz for assistance with the animal protocols; to Kevin Kovalchik for help with data sharing; to Francesca Castoldi for help in total RNA extraction for B16F10 and IMR-90 cells; to Fredrik Fagerstrom-Billai, Susann Fält, Anastasios Damdimopoulos, and David Brodin at Bioinformatics and Expression Analysis Core Facility, Karolinska Institute (KI), for assistance in RNA-seq and analysis; to the IRB core facilities (Functional Genomics, Biostatistics/Bioinformatics and Histopathology); and to the PCB (Animal House) for general research support. I. Marin was the recipient of an FPI fellowship from the Spanish Ministry of Science (PRE2018-083381). O. Boix was the recipient of an FPI-AGAUR fellowship from the Generalitat de Catalunya. A. Garcia-Garijo was supported by a PERIS grant (SLT017/20/000131) from the Generalitat de Catalunya. J.A. López-Domínguez and M. Kovatcheva were supported by a fellowship from the Spanish Association Against Cancer (AECC). Work in the laboratory of E. Caron was funded by the Fonds de recherche du Québec – Santé (FRQS), the Cole Foundation, CHU Sainte-Justine, the Charles-Bruneau Foundation, the Canada Foundation for Innovation, the National Sciences and Engineering Research Council (#RGPIN-2020-05232), and the Canadian Institutes of Health Research (#174924). E. Garralda received funding from the Comprehensive Program of Cancer Immunotherapy and Immunology II (CAIMI-II) supported by the BBVA Foundation (grant 53/2021). The M. Abad lab received funding from the Spanish Ministry of Science and Innovation (RTI2018-102046-B-I00A and RTC-2017-6123-1) and the AECC (PRYCO211023SERR). M. Abad was the recipient of a Ramón y Cajal contract from the Spanish Ministry of Science and Innovation (RYC-2013-14747). A. Gros received funding from the Spanish Ministry of Science cofunded by the European Regional Development Fund (ERDF; RTC-2017-6123-1), from the Instituto de Salud Carlos III (MS15/00058), and from CAIMI-II (grant 53/2021) supported by the BBVA Foundation. The work in the laboratory of F. Pietrocola is supported by a KI Starting Grant, a Starting Grant from the Swedish Research Council (2019_02050_3), and grants from the Harald Jeanssons Foundation, the Loo and Hans Osterman Foundation, and Cancerfonden (21 1637 Pj). Work in the laboratory of M. Serrano was funded by the IRB and La Caixa Foundation, and by grants from the Spanish Ministry of Science cofunded by the European Regional Development Fund (SAF-2017-82613-R, RTC-2017-6123-1), the European Research Council (ERC-2014-AdG/669622), Secretaria d'Universitats i Recerca del Departament d'Empresa i Coneixement of Catalonia (Grup de Recerca consolidat 2017 SGR 282), and the AECC (PRYCO211023SERR). The publication costs of this article were defrayed in part by the payment of publication fees. Therefore, and solely to indicate this fact, this article is hereby marked “advertisement” in accordance with 18 USC section 1734

    Current Status of the Insecticide Resistance in Aedes aegypti (Diptera: Culicidae) from Mexico

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    The mosquito Aedes aegypti (Diptera: Culicidae) is the primary vector of dengue in Mexico and lately virus Chikungunya, although Aedes albopictus is widely distributed; its role in both diseases’ transmission has not been confirmed. The control of mosquitoes in Mexico includes source reduction consisting in the elimination of containers that are favorable sites for oviposition and development of the aquatic stage. The use of insecticides is to control larvae and adulticides as outdoor ultra-low volume applications and indoor residual spray and more recently impregnated materials. The health department regulates the use of insecticides, and such regulations are revised and adapted over time. Since 1999, the vector control regulations gave preference to the use of pyrethroids, a permethrin-based formulation to control adult forms. This insecticide was used as the only adulticide in Mexico for more than 10 years. The consequences of this actions have evolved in a widespread and strong resistance to other insecticides, mainly pyrethroids. We include in this revision evidence of resistance reported in Ae. aegypti in Mexico

    RNase H2, mutated in Aicardi-Goutières syndrome, promotes LINE-1 retrotransposition

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    Long INterspersed Element class 1 (LINE-1) elements are a type of abundant retrotransposons active in mammalian genomes. An average human genome contains ~100 retrotransposition-competent LINE-1s, whose activity is influenced by the combined action of cellular repressors and activators. TREX1, SAMHD1 and ADAR1 are known LINE-1 repressors and when mutated cause the autoinflammatory disorder Aicardi-Goutières syndrome (AGS). Mutations in RNase H2 are the most common cause of AGS, and its activity was proposed to similarly control LINE-1 retrotransposition. It has therefore been suggested that increased LINE-1 activity may be the cause of aberrant innate immune activation in AGS. Here, we establish that, contrary to expectations, RNase H2 is required for efficient LINE-1 retrotransposition. As RNase H1 overexpression partially rescues the defect in RNase H2 null cells, we propose a model in which RNase H2 degrades the LINE-1 RNA after reverse transcription, allowing retrotransposition to be completed. This also explains how LINE-1 elements can retrotranspose efficiently without their own RNase H activity. Our findings appear to be at odds with LINE-1-derived nucleic acids driving autoinflammation in AGS.M.B.-G. is funded by a “Formacion Profesorado Universitario” (FPU) PhD fellowship from the Government of Spain (MINECO, Ref FPU15/03294), and this paper is part of her thesis project (“Epigenetic control of the mobility of a human retrotransposon”). R.V.-A. is funded by a PFIS Fellowship from the Government of Spain (ISCiii, FI16/00413). O.M. is funded by an EMBO Long-Term Fellowship (ALTF 7-2015), the European Commission FP7 (Marie Curie Actions, LTFCOFUND2013, GA-2013-609409) and the Swiss National Science Foundation (P2ZHP3_158709). S.R.H. is funded by the Government of Spain (MINECO, RYC-2016-21395 and SAF2015-71589-P). A.P.J’s laboratory is supported by the UK Medical Research Council (MRC University Unit grant U127527202). J.L.G.P’s laboratory is supported by CICEFEDER- P12-CTS-2256, Plan Nacional de I+D+I 2008-2011 and 2013-2016 (FISFEDER- PI14/02152), PCIN-2014-115-ERA-NET NEURON II, the European Research Council (ERC-Consolidator ERC-STG-2012-233764), by an International Early Career Scientist grant from the Howard Hughes Medical Institute (IECS-55007420), by The Wellcome Trust-University of Edinburgh Institutional Strategic Support Fund (ISFF2) and by a private donation from Ms Francisca Serrano (Trading y Bolsa para Torpes, Granada, Spain)

    Neural plasticity of the uterus : New targets for endometrial cancer?

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    Altres ajuts: European Regional Development Fund (FEDER); FMMA grant (AP166942017); European Social Fund (ESF 'Investing in Your Future').Endometrial carcinoma is the most common gynecological malignancy in Western countries and is expected to increase in the following years because of the high index of obesity in the population. Recently, neural signaling has been recognized as part of the tumor microenvironment, playing an active role in tumor progression and invasion of different solid tumor types. The uterus stands out for the physiological plasticity of its peripheral nerves due to cyclic remodeling brought on by estrogen and progesterone hormones throughout the reproductive cycle. Therefore, a precise understanding of nerve-cancer crosstalk and the contribution of the organ-intrinsic neuroplasticity, mediated by estrogen and progesterone, of the uterine is urgently needed. The development of new and innovative medicines for patients with endometrial cancer would increase their quality of life and health. This review compiles information on the architecture and function of autonomous uterine neural innervations and the influence of hormone-dependent nerves in normal uterus and tumor progression. It also explores new therapeutic possibilities for endometrial cancer using these endocrine and neural advantages

    Shoc2/Sur8 protein regulates neurite outgrowth

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    This is an openaccess article distributed under the terms of the Creative Commons Attribution License.-- et al.The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.GL, TG and LMD were recipients of fellowships from the Ministerio de Educación y Ciencia (MEC) (to GL, TG), and Fondo de Investigaciones Sanitarias (FIS) (to LMD). LSR held a postdoctoral research contract from CIBERNED. This work was supported by FIS grant (PI10/00815) to JLO; CIBERNED to MC; SAF2008-01951, Comunidad Autónoma de Madrid (CAM) SSAL-0202-2006-01 and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) to TI; FIS grant PI12/00775 and ISCIII-RETIC (Red Temática de Investigación Cooperativa en Cáncer) RD12/0036/0027 from the Instituto de Salud Carlos III to PSG; and FIS grants (PI09/0562 and PI13/00703), ISCIIIRETIC (RD06/0020/0003 and RD12/0036/0021), and the Spanish Association Against Cancer (AECC) to JMR.Peer Reviewe

    Propuesta estratégica de mejora en la implementación de los estándares mínimos del Sistema de Gestión de la Seguridad Y Salud en el Trabajo (SG-SST) en la empresa Distribuidores Asociados S.A.S. para el segundo semestre del 2019 y principios del 2020

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    La principal finalidad que se tiene con la realización del presente trabajo, es la investigación, el análisis de la información e implementación del programa del Sistema de Gestión de Salud y Seguridad en el trabajo en la empresa DISTRIBUIDORES ASOCIADOS S.A.S. Es una compañía cuidadosa de la salud y seguridad de sus empleados, razón por la cual ha cumplido con la implementación del SG-SST y aunque se ha avanzado bastante en su despliegue, también es cierto, que la calificación de los estándares contemplados por la norma, arroja un resultado del 80.5%., encontrando en el análisis de la matriz, puntos susceptibles de acciones de mejora. Para el alcance del objetivo pretendido, el trabajado se desarrollará en el análisis de cinco (5) capítulos, así: Capítulo I, identificación del problema; Capítulo II, marco teórico y Legal, Capítulo III, Metodología investigación cualitativa, Capítulo IV, Resultados y Capítulo V, Plan de mejora.La principal finalidad que se tiene con la realización del presente trabajo, es la investigación, el análisis de la información e implementación del programa del Sistema de Gestión de Salud y Seguridad en el trabajo en la empresa DISTRIBUIDORES ASOCIADOS S.A.S. Es una compañía cuidadosa de la salud y seguridad de sus empleados, razón por la cual ha cumplido con la implementación del SG-SST y aunque se ha avanzado bastante en su despliegue, también es cierto, que la calificación de los estándares contemplados por la norma, arroja un resultado del 80.5%., encontrando en el análisis de la matriz, puntos susceptibles de acciones de mejora. Para el alcance del objetivo pretendido, el trabajado se desarrollará en el análisis de cinco (5) capítulos, así: Capítulo I, identificación del problema; Capítulo II, marco teórico y Legal, Capítulo III, Metodología investigación cualitativa, Capítulo IV, Resultados y Capítulo V, Plan de mejora
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