17 research outputs found
Experiments on synthetic dimensions in photonics
The first and introductory section of the dissertation presents the working principle of a one- and two-dimensional photonic mesh lattice based on the time-multiplexing technique. The basis of a random walk interrelated to the corresponding light and quantum walk is comprehensively discussed as well. The second part of the dissertation consists of three experiments on a one-dimensional photonic mesh lattice. Firstly, the Kapitza-based guiding light project models the Kapitza potential as a continuous Pauli-Schrödinger-like equation and presents an experimental observation of light localization when the transverse modulation is bell-shaped but with a vanishing average along the propagation direction. Secondly, the optical thermodynamics project experimentally demonstrates for the first time that any given initial modal occupancy reaches thermal equilibrium by following a Rayleigh-Jeans distribution when propagates through a multimodal photonic mesh lattice with weak nonlinearity. Remarkably, the final modal occupancy possesses a unique temperature and chemical potential that have nothing to do with the actual thermal environment. Finally, the quantum interference project discusses an experimental all-optical architecture based on a coupled-fiber loop for generating and processing time-bin entangled single-photon pairs. Besides, it shows coincidence-to-accidental ratio and quantum interference measurements relying on the phase modulation of those time bins. The third part of the dissertation comprises two experiments on a two-dimensional photonic mesh lattice. The first project discusses the experimental realization of a two-dimensional mesh lattice employing short- and long-range interaction. To some extent, the second project presents a nonconservative system based on a two-dimensional photonic mesh lattice exploiting parity-time (PT) symmetry
GHz-Pulsed Source of Entangled Photons for Reconfigurable Quantum Networks
Entanglement is a universal resource in quantum networks, yet entangled
photon sources are typically custom-made for a specific use case. Versatility,
both in terms of state modulation and tunability of the temporal properties of
the photons, is the key to flexible network architectures and cryptographic
primitives that go beyond quantum key distribution. Here, we report on a
flexible source design that produces high-quality entanglement in
continuous-wave and GHz-rate-pulsed operation modes. Utilizing off-the-shelf
optical components, our approach uses a fiber-based Sagnac loop to generate
polarization-entangled photons at telecom wavelength with high efficiency and
fidelities above 0.99. Phase modulation up to GHz before entangled state
generation is also possible for fast entangled state switching. We show phase
modulation at 100 MHz with an average fidelity of 0.95. Furthermore, the source
60 nm spectral bandwidth is entirely compatible with fully reconfigurable
wavelength-multiplexed quantum networks.Comment: 10 pages, 5 figure
The impact of the COVID-19 pandemic on dental trauma attendance: a systematic review and meta-analysis
This systematic review and meta-analysis aimed to analyze the impact of the COVID-19 pandemic on dental trauma patient attendance. The study was registered in the PROSPERO system, using the CRD42021288398 protocol. Searching was performed in PubMed, Scopus, Web of Science, Embase, Lilacs, and OpenGrey databases, using the following keywords: âTooth injuries,â âDental trauma,â âTraumatic Dental injury,â and âCOVID-19". We included observational studies evaluating dental trauma in the context of the COVID-19 pandemic. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Cross-Sectional Studies. Meta-analysis was performed in RevMan 5.4 software with Odds Ratios as a pooled measure of effect, with a 95% confidence interval, and using random-effects modeling. After applying the eligibility criteria, 32 studies were included for qualitative analysis, in which 10 were used to assess the frequency of dental trauma diagnoses in dental emergencies. Despite the decrease of visits during COVID-19, the analysis revealed no difference between the pandemic and pre-pandemic periods. Regarding the type of dental trauma, two of the studies revealed no differences for the periods before and during the pandemic. This study revealed that the COVID-19 pandemic has not impacted the frequency or type of dental trauma compared to previous periods
Dementia in Latin America : paving the way towards a regional action plan
Regional challenges faced by Latin American and Caribbean countries (LACs) to fight dementia, such as heterogeneity, diversity, political instabilities, and socioeconomic disparities, can be addressed more effectively grounded in a collaborative setting based on the open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking and translational research) and align them to current global strategies to translate regional knowledge into actions with transformative power. Then, by characterizing genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions and mapping these to the above challenges, we provide the basic mosaics of knowledge that will pave the way towards a KtAF. We describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF
The impact of the COVID-19 pandemic on dental trauma attendance: a systematic review and meta-analysis
Abstract This systematic review and meta-analysis aimed to analyze the impact of the COVID-19 pandemic on dental trauma patient attendance. The study was registered in the PROSPERO system, using the CRD42021288398 protocol. Searching was performed in PubMed, Scopus, Web of Science, Embase, Lilacs, and OpenGrey databases, using the following keywords: âTooth injuries,â âDental trauma,â âTraumatic Dental injury,â and âCOVID-19". We included observational studies evaluating dental trauma in the context of the COVID-19 pandemic. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Cross-Sectional Studies. Meta-analysis was performed in RevMan 5.4 software with Odds Ratios as a pooled measure of effect, with a 95% confidence interval, and using random-effects modeling. After applying the eligibility criteria, 32 studies were included for qualitative analysis, in which 10 were used to assess the frequency of dental trauma diagnoses in dental emergencies. Despite the decrease of visits during COVID-19, the analysis revealed no difference between the pandemic and pre-pandemic periods. Regarding the type of dental trauma, two of the studies revealed no differences for the periods before and during the pandemic. This study revealed that the COVID-19 pandemic has not impacted the frequency or type of dental trauma compared to previous periods.</div
Dismantling Brazil's science threatens global biodiversity heritage
In the middle of a political and fiscal crisis, the Brazilian government is applying successive budget cuts, including in science funding. Recent cuts radically affect research programs on biodiversity that are crucial components for the design and monitoring of public policies for nature conservation and sustainable development. We analyze the consequences of such cuts on the Research Program on Biodiversity (PPBio), the largest biodiversity research network in Brazil (626 researchers, nine networks in all Brazilian biomes). Brazil holds a substantial part of the world's biodiversity and of tropical forests that play a significant role for regional and global climate stability. If underfunding is maintained, the dismantling of the Brazilian PPBio will have consequences that go beyond biodiversity knowledge itself but affect society as a whole. Brazil will likely fail to reach the National Targets for Biodiversity 2011â2020, and it will be difficult to fulfill the restoration target of the Brazilian NDC and to advance with the sustainable development goals. © 2017 Associação Brasileira de CiĂȘncia EcolĂłgica e Conservaçã
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Dementia in Latin America: Paving the way toward a regional action plan.
Across Latin American and Caribbean countries (LACs), the fight against dementia faces pressing challenges, such as heterogeneity, diversity, political instability, and socioeconomic disparities. These can be addressed more effectively in a collaborative setting that fosters open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking, and translational research) and align them to current global strategies to translate regional knowledge into transformative actions. Then we characterize key sources of complexity (genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions), map them to the above challenges, and provide the basic mosaics of knowledge toward a KtAF. Finally, we describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF