647 research outputs found

    Topology driven g-factor tuning in type-II quantum dots

    Get PDF
    We investigate how the voltage control of the exciton lateral dipole moment induces a transition from singly to doubly connected topology in type-II In As/Ga Asx Sb1−x quantum dots. The latter causes visible Aharonov-Bohm oscillations and a change of the exciton g factor, which are modulated by the applied bias. The results are explained in the frame of realistic →k⋅ →p and effective Hamiltonian models and could open a venue for new spin quantum memories beyond the In As/Ga As realm

    Voltage tuning of exciton topology and g-factor in type-II InAs/GaAsSb quantum dots

    Get PDF
    Trabajo presentado en la DPG Conference - Geometry and Topology Controlled Nanoarchitectures, celebrada en Berlín (alemania), del 11 al 16 de marzo de 2018Peer reviewe

    Type-II Quantum Dots with Topology Driven g-factor tunability

    Get PDF
    Trabajo presentado en el ICSNN2018: 20th International Conference on Superlattices Nanostructures and Nanodevices, celebrado en Madrid del 23 al 27 de julio de 2018Peer reviewe

    Stress related epigenetic changes may explain opportunistic success in biological invasions in Antipode mussels

    Get PDF
    Different environmental factors could induce epigenetic changes, which are likely involved in the biological invasion process. Some of these factors are driven by humans as, for example, the pollution and deliberate or accidental introductions and others are due to natural conditions such as salinity. In this study, we have analysed the relationship between different stress factors: time in the new location, pollution and salinity with the methylation changes that could be involved in the invasive species tolerance to new environments. For this purpose, we have analysed two different mussels’ species, reciprocally introduced in antipode areas: the Mediterranean blue mussel Mytilus galloprovincialis and the New Zealand pygmy mussel Xenostrobus securis, widely recognized invaders outside their native distribution ranges. The demetylathion was higher in more stressed population, supporting the idea of epigenetic is involved in plasticity process. These results can open a new management protocols, using the epigenetic signals as potential pollution monitoring tool. We could use these epigenetic marks to recognise the invasive status in a population and determine potential biopollutants

    Anthropocene and "development" : intertwined trajectories since the beginning of the Great Acceleration = Antropoceno e "desenvolvimento" : trajetórias entrelaçadas desde o começo da Grande Aceleração

    Get PDF
    Objectives: We aim to propose the thesis that the trajectories of the Anthropocene and the current mainstream understandings of development are intertwined from the beginning. It means that the Anthropocene and the “development” are coetaneous: the implementation of development policies for the so-considered underdeveloped regions started to happen at the same time of what is known as The Great Acceleration of production, consumption and environmental degradation in a global level. Method: In this conceptual paper, we adopt a decolonial critique as an analytical lens and argue that different geopolitical positions may be necessary for approaching the issue of the Anthropocene from epistemological reflections that can include the cultural and political context of the production and reproduction of local knowledge. Results: Our theoretical argumentation sheds light on the role of Global North and South relations in shaping the environmental crisis. Latin America (LA) exemplifies the modus operandi of the intertwinement of the practical effects of development policies and the environmental consequences underlying the Anthropocene, in which natural resources are over-explored to satisfy export-oriented trade, from the South toward the North. LA is not only a propitious context to show the validity of our thesis, but also the source of alternatives to such developmental model. Conclusion: The emphasis on development as a cause of the Anthropocene supports The Great Acceleration thesis. The proposition of the name Developmentocene comes from the thesis that development and Anthropocene are coetaneous, the intertwinement of both resulting in the very definition of the new epoch.Objetivo: Buscamos propor a tese de que as trajetórias do Antropoceno e o entendimento atualmente dominante sobre desenvolvimento estão entrelaçadas desde o começo. Isso implica que o Antropoceno e o “desenvolvimento” são coetâneos: a implementação de políticas de desenvolvimento em regiões tidas como subdesenvolvidas começou a acontecer ao mesmo tempo em que teve início A Grande Aceleração da produção, do consumo e da degradação ambiental em nível global. Método: Neste artigo conceitual, nós adotamos a crítica decolonial como lente analítica e argumentamos a necessidade de diferentes posições geopolíticas para abordar a questão do Antropoceno a partir de reflexões epistemológicas que possam incluir o contexto cultural e político de produção e reprodução do conhecimento. Resultados: Nossa argumentação teórica enaltece as relações entre o Norte e o Sul Global no delineamento da crise ambiental. A América Latina (AL) exemplifica o modus operandi do entrelaçamento entre os efeitos práticos das políticas de desenvolvimento e as consequências ambientais subjacentes ao Antropoceno, em que os recursos naturais são explorados além dos limites para satisfazer o comércio para exportações, desde o Sul para o Norte. Nesse quadro, a AL não é apenas um contexto propício para mostrar a validade da nossa tese, mas também a fonte de alternativas a esse modelo de desenvolvimento. Conclusão: A ênfase no desenvolvimento como causa do Antropoceno apoia a tese da Grande Aceleração. A proposição do nome Desenvolvimentoceno advém da tese de que o desenvolvimento e o Antropoceno são coetâneos e que o entrelaçamento de ambos resulta na própria definição da nova época

    H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia

    Get PDF
    We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522

    Adjuvant interferon gamma in patients with pulmonary atypical Mycobacteriosis: A randomized, double-blind, placebo-controlled study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>High antibiotic resistance is described in atypical Mycobacteriosis, mainly by <it>Mycobacterium avium </it>complex (MAC).</p> <p>Methods</p> <p>A randomized, double-blind, placebo-controlled clinical trial was carried out in two hospitals to evaluate the effect of interferon (IFN) gamma as immunoadjuvant to chemotherapy on patients with atypical mycobacteria lung disease. Patients received placebo or 1 × 10<sup>6 </sup>IU recombinant human IFN gamma intramuscularly, daily for one month and then three times per week up to 6 months as adjuvant to daily oral azithromycin, ciprofloxacin, ethambutol and rifampin. Sputum samples collection for direct smear observation and culture as well as clinical and thorax radiography assessments were done during treatment and one year after. Cytokines and oxidative stress determinations were carried out in peripheral blood before and after treatment.</p> <p>Results</p> <p>Eighteen patients were included in the IFN group and 14 received placebo. Groups were homogeneous at entry; average age was 60 years, 75% men, 84% white; MAC infection prevailed (94%). At the end of treatment, 72% of patients treated with IFN gamma were evaluated as complete responders, but only 36% in the placebo group. The difference was maintained during follow-up. A more rapid complete response was obtained in the IFN group (5 months before), with a significantly earlier improvement in respiratory symptoms and pulmonary lesions reduction. Disease-related deaths were 35.7% of the patients in the placebo group and only 11.1% in the IFN group. Three patients in the IFN group normalized their globular sedimentation rate values. Although differences in bacteriology were not significant during the treatment period, some patients in the placebo group converted again to positive during follow-up. Significant increments in serum TGF-beta and advanced oxidation protein products were observed in the placebo group but not among IFN receiving patients. Treatments were well tolerated. Flu-like symptoms predominated in the IFN gamma group. No severe events were recorded.</p> <p>Conclusion</p> <p>These data suggest that IFN gamma is useful and well tolerated as adjuvant therapy in patients with pulmonary atypical Mycobacteriosis, predominantly MAC. Further wider clinical trials are encouraged.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN70900209.</p

    Searches for lepton-flavour-violating decays of the Higgs boson into eτ and μτ in \sqrt{s} = 13 TeV pp collisions with the ATLAS detector

    Get PDF
    Abstract This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy s s \sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Leptonic (τ → ℓνℓντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, B B \mathcal{B} (H → eτ) < 0.20% (0.12%) and B B \mathcal{B} (H → μτ ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → μτ signals. The best-fit branching ratio difference, B B \mathcal{B} (H → μτ) → B B \mathcal{B} (H → eτ), measured with the Symmetry method in the channel where the τ-lepton decays to leptons, is (0.25 ± 0.10)%, compatible with a value of zero within 2.5σ

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH &lt; 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 &lt; κλ &lt; 6.9 and −0.5 &lt; κ2V &lt; 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Evidence of off-shell Higgs boson production from ZZ leptonic decay channels and constraints on its total width with the ATLAS detector

    Get PDF
    This Letter reports on a search for off-shell production of the Higgs boson using 139 fb(-1) of pp collision data at root s = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. The signature is a pair of Z bosons, with contributions from both the production and subsequent decay of a virtual Higgs boson and the interference of that process with other processes. The two observable final states are ZZ -&gt; 4l and Z Z -&gt; 2l2 nu with l = e or mu. In the ZZ -&gt; 4l final state, a dense Neural Network is used to enhance analysis sensitivity with respect to matrix element-based discrimination. The background-only hypothesis is rejected with an observed (expected) significance of 3.3 (2.2) standard deviations, representing experimental evidence for off-shell Higgs boson production. Assuming that no new particles enter the production of the virtual Higgs boson, its total width can be deduced from the measurement of its off-shell production cross-section. The measured total width of the Higgs boson is 4.5(-2.5)(+3.3) MeV, and the observed (expected) upper limit on the total width is found to be 10.5 (10.9) MeV at 95% confidence level. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
    corecore