bluuebunny/crossref_metadata_2025 huggingface dataset:
Corruption-Robust Exploration in Episodic Reinforcement Learning
Authors: Lykouris Thodoris , Simchowitz Max , Slivkins Aleksandrs , Sun Wen
Published: May 2024

We initiate the study of episodic reinforcement learning (RL) under adversarial corruptions in both the rewards and the transition probabilities of the underlying system, extending recent results for the special case of multiarmed bandits. We provide a framework that modifies the aggressive exploration enjoyed by existing reinforcement learning approaches based on optimism in the face of uncertainty by complementing them with principles from action elimination. Importantly, our framework circumvents the major challenges posed by naively applying action elimination in the RL setting, as formalized by a lower bound we demonstrate. Our framework yields efficient algorithms that (a) attain near-optimal regret in the absence of corruptions and (b) adapt to unknown levels of corruption, enjoying regret guarantees that degrade gracefully in the total corruption encountered. To showcase the generality of our approach, we derive results for both tabular settings (where states and actions are finite) and linear Markov decision process settings (where the dynamics and rewards admit a linear underlying representation). Notably, our work provides the first sublinear regret guarantee that accommodates any deviation from purely independent and identically distributed transitions in the bandit-feedback model for episodic reinforcement learning.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/moor.2021.0202 .
Sons da resistência:
Authors: Eleutério de Oliveira Gleicivânia , Nara Maria Forte Diogo Rocha
Published: May 2024

O presente estudo se propôs a investigar os desafios enfrentados por mulheres capoeiristas em sua busca por destaque e reconhecimento no contexto da capoeira, uma manifestação cultural afro-brasileira intrinsecamente imersa em dinâmicas socioculturais permeadas por conflitos de gênero. Utilizando abordagem de pesquisa de campo e adotando fundamentos conceituais e metodológicos da etnografia dialógica, o artigo explora especificamente contribuições da musicalidade da capoeira para o processo de emancipação dessas mulheres. O questionamento central orientador do estudo é direcionado para a compreensão de como a musicalidade na capoeira desempenha papel significativo no processo de emancipação das mulheres capoeiristas. A análise se desenvolve no contexto do coletivo Mulheres de Luanda, buscando promover um espaço reflexivo que propicie visibilidade e protagonismo feminino. Essa iniciativa visa criar um ambiente propício para o compartilhamento de experiências, a escuta atenta e a condução de debates fundamentais para a valorização das narrativas apresentadas pelas mulheres capoeiristas. Os resultados obtidos durante a pesquisa de campo revelam a persistência de preconceitos em relação à participação feminina na capoeira, destacando a existência de relações de poder que permeiam diversos aspectos, como o corpo, o jogo e a musicalidade dentro das rodas. Além disso, são identificadas barreiras que a própria capoeira e seus agentes precisam superar para integrar, de maneira mais efetiva, as mulheres nessa prática.
Conciliação entre educação e maternidade:
Authors: Gonçalves da Fonseca Rosilaine , Ribeiro Andrade Eliane
Published: May 2024

O presente artigo busca discutir, com base em resultados de pesquisa, como mulheres mães conciliam estudos e maternidade na vida cotidiana. Apresenta-se como objetivo principal entender como constroem estratégias, os suportes e apoios que têm permitido a elas ampliar a escolaridade. No que tange à metodologia, a pesquisa recorre a abordagem quantitativa, elaborando e aplicando extenso questionários e articulando os resultados com e observação de campo. O estudo empírico efetivou-se no conjunto de favelas da Maré, situado no Rio de Janeiro, com mães estudantes da educação de jovens e adultos (EJA). Os resultados mostraram que Trabalho é uma categoria em destaque na relação entre estudos e maternidade, sobretudo entre as mais pobres, moradoras de favela, pretas e pardas, tendo em vista que é considerado fator prioritário, principalmente nos casos em que a mulher é a única ou a principal responsável pelo sustento da casa. Ficou evidente, que nas suas trajetórias os afazeres domésticos e os cuidados dos filhos são considerados, na maioria das vezes, tarefas exclusivas das mulheres, condição que acaba distanciando muitas delas da escolarização. Nesse contexto, a EJA aparece como o “campo de possibilidade”. Assim, o estudo transita pelo debate que aproxima gênero dos campos da educação, trabalho e demais intersecções, buscando levantar elementos capazes de fornecer subsídios para a construção de políticas públicas, que consolide o direito à educação para todas as mulheres, como prevê a Constituição Federal.
Direito à educação, educação ao longo da vida e educação de jovens e adultos:
Authors: Elesbão Duarte Filho José , Pontes Costa Renato
Published: May 2024

O presente artigo versa sobre direito à educação, à luz da educação de jovens e adultos (EJA) analisada a partir da ideia de educação e aprendizagem ao longo da vida. A Educação, em suas dimensões histórica, cultural e sociopolítica, é entendida como direito humano inalienável. Considerando o momento político dos últimos dez anos, marcado pelo encolhimento da modalidade e por retrocessos no campo das políticas públicas, o texto se propõe a discutir analiticamente conceitos já conhecidos no campo da EJA, entendendo a necessidade de sua reafirmação em tempos de reconstrução de direitos. As reflexões apontadas englobam a heterogeneidade dos sujeitos, a diversidade de demandas que atravessam a EJA e a noção de educação ao longo da vida enquanto uma prática social que articula conhecimentos, saberes e experiências de vida dos educandos. A análise fundamenta-se em autores diversos e tem um foco no pensamento freiriano. Conclui-se ratificando o entendimento de que a EJA se investe de um caráter inerente à educação enquanto aprendizagem ao longo da vida, não divorciado da dimensão social, individual e coletiva de aprendizagem. Denota, pois, um processo de aprendizagem que é permanente e precisa ter como horizonte a retomada da reflexão sobre essas temáticas nas instâncias de formação de educadores e na construção de políticas públicas.
EL DERECHO A LA EDUCACIÓN DE MUJERES
Authors: Cotta Carrizo Carla Betsabé , Tosolini Mariana Alejandra , Delprato María Fernanda
Published: May 2024

El artículo propone reflexiones para pensar el derecho a la educación desde la perspectiva de mujeres de escasa escolaridad recuperando la experiencia de una escuela de jóvenes y adultos en la ciudad de Córdoba, Argentina. A partir de un enfoque socio-antropológico e interseccional sostiene que las mujeres, como colectivo, están expuestas a diversas desigualdades donde convergen intersecciones de categorías que concluyen en exclusiones. Como respuesta a las mismas emergen estrategias de resistencias. 
Se lleva a cabo el análisis con dos líneas de reflexiones, la primera tensiona el derecho a la educación desde lo que expresan las legislaciones con las subordinaciones cotidianas que atraviesan estas mujeres. La segunda, propone el  vínculo con la escuela como estrategia de resistencia, en el marco de la participación en un movimiento social que construye condiciones para la permanencia y sostenimiento de las trayectorias escolares. Al mismo tiempo, surgen saberes necesarios para la participación en la organización vinculados con la lectura y escritura que también fortalecen el vínculo con la escuela. 
Como reflexiones finales se propone pensar el lugar de las políticas educativas y de inclusión cuando se trata del derecho a la educación de mujeres de escasa escolaridad, a partir de recuperar las resistencias, saberes y derechos que construyen desde sus inserciones en el movimiento social.  
Palabras claves: mujeres; educación;derecho; identidades letradas.
Política de educação e currículo
Authors: De Oliveira Elizângela Farias , Dumara Ruiz Silveira Nadia , Victor de Oliveira Ozerina
Published: May 2024

Este artigo problematiza a relação entre políticas de educação, currículo, envelhecimento e trabalho envolvendo indivíduos adultos 50+. O objetivo é analisar concepções de política de educação e de currículo da educação não formal nos processos de subjetivação de pessoas da faixa etária de 50+, em situação de trabalho. O processo investigativo pautou-se na abordagem qualitativa, tendo como procedimentos metodológicos estudos bibliográficos, análise de documentos e pesquisa de campo com realização de entrevistas, tendo como sujeitos pessoas com 50+. Os resultados das análises revelam fragilidades na articulação entre políticas públicas e diversidade etária, em uma perspectiva de direitos humanos e justiça social, frente à imposição de um padrão de produtividade. As reflexões e interpretações realizadas estimulam novas investigações frente aos desafios que se colocam à construção de políticas públicas e de currículo na perspectiva da conquista de direitos e da justiça social, considerando o processo de envelhecimento.
Reflexão sobre a formação do docente para a EJA
Authors: Cicci Romero Márcia , dos Santos Sônia Maria
Published: May 2024

Este artigo tem como foco refletir sobre o papel da formação do docente para a educação de jovens e adultos (EJA) nas campanhas de alfabetização. Como a EJA se torna modalidade de ensino somente em 1996, por meio da LDB, a formação de professores para essa área não era prioridade. As companhas de alfabetização no Brasil tiveram seu início na década de 1940 e mesmo nas décadas posteriores, muitos governantes, continuaram a acreditar que o Brasil poderia erradicar o analfabetismo por meio de campanhas e programas de alfabetização. Segundo as referências documentais e bibliográficas que nos subsidiaram, a campanha mais cara e com pouco sucesso, foi o MOBRAL, que durou aproximadamente dez anos. Em seguida tivemos a Fundação Educar. Nos anos 1990 tivemos surgiram vários programas para erradicação do analfabetismo nos municípios brasileiros, o mais estudado foi o Programa Alfabetização Solidária, que tinha muita semelhança com as campanhas anteriores. A campanha mais recente foi a Brasil Alfabetizado, que não evoluiu nada em relação aos docentes e as concepções de leitura e escrita. Para esses programas e campanhas qualquer ser humano pode alfabetizar, não havendo necessidade de habilitação em nenhuma licenciatura. Nossos resultados apontaram que apesar de ter existido várias campanhas e programas de alfabetização na história da educação de jovens e adultos, podemos afirmar que não houve preocupação com a formação inicial e continuada dos professores de EJA, e esta quando se dava, acontecia de forma rasa, para ensinar pessoas leigas e estudantes da graduação para atuar nos projetos.
Educação física e educação de jovens, adultos e idosos:
Authors: Bemvenuto Vitória da Silva , Dalmonte Malacarne José Augusto , Marins Nogueira Peil Luciana
Published: May 2024

Este ensaio deriva de uma pesquisa desenvolvida em um curso de especialização de uma universidade pública brasileira. Ao longo do texto refletimos sobre a educação de jovens, adultos e idosos e a educação física, na contemporaneidade, pensando-as como direitos garantidos, respeitados e inegociáveis, apostando na possibilidade poética e política de torná-las outras coisas, como nos ensina a Didática da invenção, de Manoel de Barros. O organizamos em quatro momentos escolares: a entrada, a chamada, a aula e a saída. Espaços-tempos para ensaiarmos possibilidades para transpor a hegemonia dominante, encontrando na educação, ambiência propícia para a emancipação dos estudantes, se aliando através da pesquisa com ações-teorias que visibilizam os/as sujeitos/as envolvidos/as na/com a educação de jovens e adultos (EJA). Gente que elabora suas juventudes e senioridades em conjunto, no chão da escola, no cotidiano. Assim, apostamos na experiência de um fazer acadêmico implicado com pessoas de conhecimentos aprendidos e criados ao longo de suas existências.
Compondo currículos nômades nos cotidianos escolares da educação de jovens e adultos
Authors: Fonseca Daniele , Delboni Tânia Mara
Published: May 2024

Este artigo é parte de uma pesquisa em andamento com turmas do segundo segmento da educação de jovens e adultos (EJA) de uma escola pública da rede municipal que aposta na composição de currículos nômades constituídos nos movimentos de corpos coletivos nos cotidianos escolares. Problematiza como as macro/micropolíticas engendram currículos nômades, configurando linhas de fuga nos cotidianos escolares da EJA. Objetiva cartografar os processos de composições curriculares que ocorrem nos encontros coletivos e nos espaços de ensino-aprendizagem, como outros modos possíveis de ser e estar na educação. Entende-se que a cartografia, como metodologia de pesquisa, requer o acompanhamento com olhar sensível do cartógrafo aos deslocamentos traçados nas composições de mapas abertos, passíveis de rasuras e mudanças de percurso. As ferramentas teórico-conceituais apresentadas têm como intercessores teóricos Deleuze, Guattari, Rolnik, Gallo e Foucault, para problematizar os conceitos de macro/micropolítica entendidos como forças indissociáveis em constante relação na educação; currículos nômades como linhas de fuga a outros fazeres possíveis; e heterotopias como o espaço do fora, os espaços dessacralizados de aprendizagens nas composições curriculares com a EJA. Como conclusão parcial, aponta os movimentos que constituem currículos nômades como insurgências tecidas nos encontros, nos afetos e afecções de corpos coletivos que potencializam a vida dos cotidianos escolares da EJA.
Is it right to talk about patient safety rights?
Authors: Tingle John , Eggleton Angela
Published: May 2024

John Tingle, Lecturer in Law, Birmingham Law School, University of Birmingham and Angela Eggleton, Teaching Fellow, Birmingham Law School, University of Birmingham, discuss some reports on patient rights
Managing severe anaemia with a blood transfusion in a suspected IMHA case
Authors: Huitson Kelly
Published: May 2024

This article discusses a challenging case from initial presentation, stabilisation and treatment to relapse. The case had an inconclusive diagnosis and differentials of hemangiosarcoma or immune-mediated haemolytic anaemia. The case progression included intensive medical management and a whole-blood transfusion with an excellent outcome. The patient, Patch (8-year-old male neutered Jack Russell Terrier), presented with history of lethargy and sudden onset of inappetence. Clinical symptoms alongside a MPCV 19%, RBC 0.25, haemoglobin 63, high platelets and borderline basophils.
How young people can shape environmental policy in urban spaces
Authors: Sloam James , Henn Matt
Published: May 2024

Younger generations have become increasingly disillusioned with mainstream democratic politics in established democracies. Although young people are interested in politics and engage in many issue-based forms of participation, it is hard for them to realise the fruits of their labour at the national level. Local democracy may provide a better opportunity for engaging effectively in the issues that affect young people’s everyday lives. This article examines how Public Value approaches work in practice for young people whose voices are usually excluded from the policy-making process. The research adopted a complex large-scale multi-stage qualitative design, that involved focus groups and interviews with young people and local civic leaders from across London. It used participatory research with young Londoners from traditionally marginalised groups. The research revealed that, although policy makers face important structural challenges, such as the concentration of power and resources in Westminster, they have the potential to move beyond tokenistic engagement with young people. In particular, the results showed how civic and local authorities can build efficacy and trust through initiatives that provide opportunities for deliberation and the co-creation of public policy. In this way, the article makes a clear contribution to our understanding of the role of young people in environmentalism and their democratic value.
‘They would throw you into a room…’: a study of abandonment and ethical loneliness in an Italian prison during the pandemic
Authors: Maculan Alessandro
Published: May 2024

Drawing on prisoners’ accounts, this article explores how mitigation strategies adopted to contain the spread of the virus in prison shaped their everyday prison life. The article, using Stauffer’s concept of ethical loneliness, sheds light on the different ways in which a sense of abandonment was experienced by 26 detained individuals interviewed in a prison in Northern Italy, with a focus on the role of the State regarding the measures implemented (and not implemented) and, on an everyday basis, those of the prison staff. Participants’ narratives tell us how, even during the dramatic emergency of the pandemic, prisoners were conceived as stigmatised and otherised individuals where the issue of security, far from being understood in terms of health protection, continued to take on repressive connotations.
Cross-correlation technique for phase error correction in reflection mode terahertz time-domain spectroscopy
Authors: Koalla Rajesh , Chaudhary Anil Kumar
Published: May 2024

Terahertz time-domain spectroscopy in reflection mode geometry provides valuable
surface and subsurface information, making it suitable for a layer
analysis, coating, and non-destructive testing applications. The
exchanging of the sample and reference’s position introduces a phase
error when the position or alignment of the sample is not precisely
maintained during measurements. This micrometer order of pitch error (Δx) between the reference and the sample
could lead to an inherent error in the phase spectrum of the sample.
In the present work, a novel approach, to the best of our knowledge,
based on the cross-correlation with an envelope technique, has been
demonstrated to reduce the uncertainty in the phase and reveal the
hidden characteristic features of the given sample in THz TDS
spectroscopy. In conjunction with experimental verification, we have
employed a finite element analysis in COMSOL Multiphysics to simulate
a misplacement error between a lossy dielectric medium (n=1.2 to 3.0 and k=0 to 0.9) and a reference. We have
investigated the impact of varying properties of the lossy dielectric
medium on delay measurements using a cross-correlation with an
envelope analysis. We illustrated and demonstrated the advantage of
our approach by measuring the optical properties of Teflon, quartz,
and RDX by correcting the misalignment of the 15.75, 17.55, and
20.70 µm ranges, respectively.
Long-range fiber-based laser Doppler vibrometer using Faraday rotator for polarization-rotation compensation
Authors: Arahira Shin , Fujii Akihiro
Published: May 2024

In this paper, we report a method for extending distance of an optical fiber-based laser Doppler vibrometer system. This method uses a Faraday rotator (FR) to compensate polarization rotation in an installed long-range optical fiber. The construction of the proposed system is simple and achieved only by adding the FR to the sensing head unit, leading to stable and highly reliable vibration measurement even by using a long-range optical fiber exceeding kilometer. Experiments by using 100-m and 10-km long standard single mode fibers with emulated polarization rotation verified advantages of the proposed method; the system performances retained almost the same values even when the polarization state of reflected light was randomly rotated in installed optical fibers.
Exceptional point proximity-driven mode-locking in coupled microresonators
Authors: Imamura Riku , Fujii Shun , Nakashima Ayata , Tanabe Takasumi
Published: May 2024

We show theoretically and numerically that mode-locking is feasible with a coupled-cavity system with gain and loss, notably, without any natural saturable absorber. We highlight that in the vicinity of the exceptional point, system Q exhibits substantial modulation even with minor refractive index changes and a minimal Kerr effect contribution. Leveraging this unique behavior, we propose an unprecedented approach wherein the lossy auxiliary cavity functions as an efficient artificial saturable absorber, thus facilitating mode-locking. This approach is not only novel, but also presents considerable advantages over conventional systems where both gain and saturable absorption are contained within a single microcavity. These benefits include reduced operational power and ease of post-adjustment, achievable through the manipulation of the coupling strength between the two microcavities.
Dynamical encircling of multiple exceptional points in anti-PT symmetry system
Authors: Wang Lei , Liu Ni , Wu Chaohua , Chen Gang
Published: May 2024

Exceptional points (EPs) in non-Hermitian systems have turned out to be at the origin of many intriguing effects with no counterparts in Hermitian cases. A typically interesting behavior is the chiral mode switching by dynamically winding the EP. Most encircling protocols focus on the two-state or parity-time (PT) symmetry systems. Here, we propose and investigate the dynamical encircling of multiple EPs in an anti-PT-symmetric system, which is constructed based on a one-dimensional lattice with staggered lossy modulation. We reveal that dynamically encircling the multiple EPs results in the chiral dynamics via multiple non-Hermiticity-induced nonadiabatic transitions, where the output state is always on the lowest-loss energy sheet. Compared with the PT-symmetric systems that require complicated variation of the gain/loss rate or on-site potentials, our system only requires modulations of the couplings which can be readily realized in various experimental platforms. Our scheme provides a route to study non-Hermitian physics by engineering the EPs and implement novel photonic devices with unconventional functions.
Single image Fourier ring correlation
Authors: Rieger Bernd , Droste Isabel , Gerritsma Fabian , ten Brink Tip , Stallinga Sjoerd
Published: May 2024

We address resolution assessment for (light super-resolution) microscopy imaging. In modalities where imaging is not diffraction limited, correlation between two noise independent images is the standard way to infer the resolution. Here we take away the need for two noise independent images by computationally splitting one image acquisition into two noise independent realizations. This procedure generates two Poisson noise distributed images if the input is Poissonian distributed. As most modern cameras are shot-noise limited this procedure is directly applicable. However, also in the presence of readout noise we can compute the resolution faithfully via a correction factor. We evaluate our method on simulations and experimental data of widefield microscopy, STED microscopy, rescan confocal microscopy, image scanning microscopy, conventional confocal microscopy, and transmission electron microscopy. In all situations we find that using one image instead of two results in the same computed image resolution.
Photonics-assisted integrated sensing and communication with ranging resolution improvement by multiple signal classification
Authors: Peng Lanfeng , Yin Mingzhu , Zou Dongdong , Yang Nan , Xiao Yaoqiang , Li Fan
Published: May 2024

The combination of orthogonal frequency-division multiplexing (OFDM) with photonics-assisted millimeter-wave (MMW) technology serves as an effective solution for realizing integrated sensing and communication (ISAC) systems. In this paper, we experimentally demonstrate a low-cost and simple photonics-assisted OFDM ISAC system using intensity modulation and envelope detection. Nonlinear distortion in the communication function of this ISAC system is compensated using decision feedback frequency domain Volterra nonlinear equalization (DF-FD-VNLE). Furthermore, the multiple signal classification (MUSIC) algorithm, implemented through subspace decomposition, is employed to enhance the low ranging resolution in radar function with limited waveform bandwidth. Experimental results indicate that the DF-FD-VNLE can achieve a 1.8 dB receiver sensitivity improvement at the hard-decision forward error correction (HD-FEC) threshold for the 4 Gbps OFDM signal over 1 m wireless transmission compared to linear equalization and 0.9 dB receiver sensitivity compared to conventional frequency domain Volterra nonlinear equalization (FD-VNLE). By utilizing the MUSIC algorithm, the radar performance is significantly improved compared to fast Fourier transform (FFT), resulting in an enhancement from 15 cm to 1 cm for single target detection and from 21 cm to 10 cm for dual target detection. Additionally, there is a significant improvement in PSLR by 18.6 dB.
Miura-ori based reconfigurable multilayer absorber for high-efficiency wide-angle absorption
Authors: Zhu Zhibiao , Li Yongfeng , Qin Ze , Jiang Lixin , Wang Wenjie , Chen Hongya , Wang Jiafu , Zheng Lin , Qu Shaobo
Published: May 2024

Radar stealth structures that can achieve high-efficiency wide-angle absorption are key components of future military equipment. However, it is difficult for both planar and three-dimensional (3D) absorbers to achieve efficient absorption in a large incidence angle range. The multilayer reconfigurable absorber component based on Miura origami provides a unique solution. First, the multilayer origami absorber is parameterized in the simulation software. Each origami structure is covered with resistive films that fit the panels. Geometric constraints are satisfied among the multilayer structures. They support reconfigurability in the range of continuous states (as opposed to discrete states), which is conducive to finding the folded state with a more efficient absorption rate within the frequency band. Secondly, the designed structure does not require a specialized mechanically supported multilayer origami absorber. In addition, the equivalent analogue circuit method is used to analyze the efficient absorption of multilayer origami under oblique incidence. Finally, our proposed absorber satisfies the requirements of multiple absorption metrics: broadband, high efficiency, wide incidence angle, and polarization insensitivity. As the validation, we simulated and fabricated a double-layer origami absorber. Our proposed origami absorber can maintain an absorption rate of more than 90% for both transverse electric (TE) and transverse magnetic (TM) polarizations in the operating frequency band (5-20 GHz) over a wide range of incidence angles (0°-70°). When the incidence angle qinc = 40°, the double-layer origami absorber (q1 = 90°, α1 = 60°, and a2 = 75°) can achieve at least 10 dB reflection reduction of -18 dB and -20 dB in TE and TM modes, respectively. The proposed origami absorber provides a reference for the design of other absorbers.
Adaptive multi-band modulation for robust and low-complexity faster-than-Nyquist non-orthogonal FDM IM-DD systems
Authors: Song Peiji , Hu Zhouyi , Liu Yuan , Dai Yizhan , Gao Chao , Chan Chun-kit
Published: May 2024

Faster-than-Nyquist non-orthogonal frequency-division multiplexing (FTN-NOFDM) has been shown to have good robustness against the steep frequency roll-off in a bandwidth-limited optical communication system. Among various FTN-NOFDM techniques, the non-orthogonal matrix precoding (NOM-p) based FTN has relatively high compatibility, which can easily utilize the existing advanced digital signal processing (DSP) techniques in the conventional OFDM. In this work, we propose what we believe to be a novel FTN-NOFDM scheme with adaptive multi-band modulation. By dividing the single-band NOM-p into multiple-band NOM-p, the proposed scheme is able to assign different quadrature amplitude modulation (QAM) levels to different sub-bands, leading to better utilization of the low-pass-like channel as well as reduced computational complexity. The impacts of sub-band number and bandwidth compression factor on the bit-error-rate (BER) performance and complexity are experimentally analyzed in a 32.23-Gb/s and 20-km intensity modulation-direct detection (IM-DD) optical transmission system. Results show that the proposed scheme with a proper sub-band number can lower the BER and greatly reduce the complexity compared to the conventional single-band scheme.
Hybrid fiber-based time synchronization and vibration detection system
Authors: Dai Hongfei , Song Dongqi , Li Wenlin , Wang Guan , Pang Zhongwang , Li Chunyi , Wang Bo
Published: May 2024

We propose a hybrid fiber-based time synchronization and vibration detection system. The vibration is detected by exploring the idle light of the time synchronization system, i.e., the Rayleigh backscattering of the timing pulse disseminated in the fiber link. The addition of a sensing function does not affect the performance of time synchronization. In the multiuser experimental demonstration, time deviation results are 3.6 ps at τ = 1 s and 1.4 ps at τ = 104 s on the 40-km fiber link. Meanwhile, the hybrid system can accurately detect and locate vibrations occurring on the link. This method enables multiple functions of the optical fiber network without occupying extra optical channels. Moreover, it gives a possible solution for enhancing the security of the time synchronization network through vibration detection.
Self-illuminated third-harmonic image upconversion
Authors: Torregrosa Adrián J. , Rico María Luisa , Capmany Juan
Published: May 2024

We demonstrate third-harmonic upconversion imaging to visualize real time infrared images in the visible with standard CCD or CMOS silicon-based cameras operating at room temperature. Different from the usual sum-frequency mixing image upconversion, our third-harmonic image upconversion approach does not require an auxiliary IR source to illuminate a target. The upconversion system uses a passively Q-switched Nd3+:YVO4 laser operating at 1342 nm with two intracavity KTP crystals, obtaining a 447 nm upconverted image by a cascaded process where an upconverted image at 671 nm is also obtained as an intermediate step.
Dual-grating single-shot pump-probe technique
Authors: Tianchen Yu , Yang Junyi , Li Zhongguo , Wu Xingzhi , fang yu , Yang Yong , SONG Ying-lin
Published: May 2024

A simple and effective single-shot pump-probe technique is reported. Using only two commercial gratings, a large time window of ~ 95.58 ps is spatially encoded in a single probe pulse, and single-shot time-resolved measurements are implemented. The time window exceeds the maximum reported values for single-shot pump-probe techniques using the echelon or angle beam encoding strategy. The phase difference problem in the echelon encoding strategies is also eliminated and a customized echelon is not needed in this technique. The measurements of the ultrafast dynamics of ZnSe at a wavelength of 650 nm verify the effectiveness of this technique.
Full-field amplitude speckle decorrelation angiography
Authors: Mansutti Giulia , Villiger Martin , Bouma Brett , Uribe-Patarroyo Néstor
Published: May 2024

We propose a new simple and cost-effective optical imaging technique, full-field amplitude speckle decorrelation angiography (FASDA), that can be implemented with cameras with conventional frame rates, does not require raster scanning, and is capable of classifying vessels into superficial and deep.
The proposed imaging technique is based on the simultaneous evaluation of two metrics: the blood flow index, a contrast-based metric used in laser speckle contrast imaging, and the adaptive speckle decorrelation index (ASDI), a new metric that we defined based on the second-order autocorrelation function that considers the limited speckle modulation that occurs in partially-coherent imaging.
We demonstrate excellent delineation of superficial vessels in skin nevi using ASDI and deeper vessels using BFI, providing a powerful new tool for the imaging of microvasculature with significantly lower hardware complexity than other optical imaging techniques.
Symmetric silicon microring resonator optical crossbar array for accelerated inference and training in deep learning
Authors: Tang Rui , Ohno Shuhei , Tanizawa Ken , Ikeda Kazuhiro , Okano Makoto , Toprasertpong Kasidit , Takagi Shinichi , Takenaka Mitsuru
Published: May 2024

Photonic integrated circuits are emerging as a promising platform for accelerating matrix multiplications in deep learning, leveraging the inherent parallel nature of light. Although various schemes have been proposed and demonstrated to realize such photonic matrix accelerators, the in situ training of artificial neural networks using photonic accelerators remains challenging due to the difficulty of direct on-chip backpropagation on a photonic chip. In this work, we propose a silicon microring resonator (MRR) optical crossbar array with a symmetric structure that allows for simple on-chip backpropagation, potentially enabling the acceleration of both the inference and training phases of deep learning. We demonstrate a 4×4 circuit on a Si-on-insulator platform and use it to perform inference tasks of a simple neural network for classifying iris flowers, achieving a classification accuracy of 93.3%. Subsequently, we train the neural network using simulated on-chip backpropagation and achieve an accuracy of 91.1% in the same inference task after training. Furthermore, we simulate a convolutional neural network for handwritten digit recognition, using a 9×9 MRR crossbar array to perform the convolution operations. This work contributes to the realization of compact and energy-efficient photonic accelerators for deep learning.
Quantifying trapping stability of optical tweezers with an external flow
Authors: Xu Feng , Yu Yarong , Liu Yang , Chang Yao , Jiao Wenxiang , Wang Lin , Ho Hopui , Wu Bei , Xu Fei , Lu Yanqing , Pang Yuanjie , Wang Guanghui
Published: May 2024

Optical tweezers (OTs) can immobilize and manipulate objects with sizes that span between nano- and micro-meter scales. The manipulating ability of OTs is traditionally characterized by stability factor (S), which can only indicate an empirical “hit-or-miss” process. Additionally, the current quantitative models for trapping stability rarely consider the influence of external flow. In this paper, a comprehensive analysis to quantify the optical trapping stability in a perturbed asymmetric potential well is presented from the perspective of statistics, especially for weak trapping scenarios. Our analytical formulation takes experimentally measurable parameters including particle size, optical power, and spot width as inputs and precisely outputs a statistically relevant mean trapping time. Importantly, this formulation takes into account general and realistic cases including fluidic flow velocity and other perturbations. To verify the model, a back-focal-plane-interferometer-monitored trapping experiment in a flow is set up and the statistical characteristics of trapping time demonstrate good agreement with theoretical predictions. In total, the model quantitatively reveals the effects of external disturbance on trapping time, which will find applications where optical trapping stability is challenged by external perturbations in weak trapping conditions.
Diverse task-driven modeling of macaque V4 reveals functional specialization towards semantic tasks
Authors: Cadena Santiago A. , Willeke Konstantin F. , Restivo Kelli , Denfield George , Sinz Fabian H. , Bethge Matthias , Tolias Andreas S. , Ecker Alexander S.
Published: May 2024

Responses to natural stimuli in area V4—a mid-level area of the visual ventral stream—are well predicted by features from convolutional neural networks (CNNs) trained on image classification. This result has been taken as evidence for the functional role of V4 in object classification. However, we currently do not know if and to what extent V4 plays a role in solving other computational objectives. Here, we investigated normative accounts of V4 (and V1 for comparison) by predicting macaque single-neuron responses to natural images from the representations extracted by 23 CNNs trained on different computer vision tasks including semantic, geometric, 2D, and 3D types of tasks. We found that V4 was best predicted by semantic classification features and exhibited high task selectivity, while the choice of task was less consequential to V1 performance. Consistent with traditional characterizations of V4 function that show its high-dimensional tuning to various 2D and 3D stimulus directions, we found that diverse non-semantic tasks explained aspects of V4 function that are not captured by individual semantic tasks. Nevertheless, jointly considering the features of a pair of semantic classification tasks was sufficient to yield one of our top V4 models, solidifying V4’s main functional role in semantic processing and suggesting that V4’s selectivity to 2D or 3D stimulus properties found by electrophysiologists can result from semantic functional goals.
Transferable deep generative modeling of intrinsically disordered protein conformations
Authors: Janson Giacomo , Feig Michael
Published: May 2024

Intrinsically disordered proteins have dynamic structures through which they play key biological roles. The elucidation of their conformational ensembles is a challenging problem requiring an integrated use of computational and experimental methods. Molecular simulations are a valuable computational strategy for constructing structural ensembles of disordered proteins but are highly resource-intensive. Recently, machine learning approaches based on deep generative models that learn from simulation data have emerged as an efficient alternative for generating structural ensembles. However, such methods currently suffer from limited transferability when modeling sequences and conformations absent in the training data. Here, we develop a novel generative model that achieves high levels of transferability for intrinsically disordered protein ensembles. The approach, named idpSAM, is a latent diffusion model based on transformer neural networks. It combines an autoencoder to learn a representation of protein geometry and a diffusion model to sample novel conformations in the encoded space. IdpSAM was trained on a large dataset of simulations of disordered protein regions performed with the ABSINTH implicit solvent model. Thanks to the expressiveness of its neural networks and its training stability, idpSAM faithfully captures 3D structural ensembles of test sequences with no similarity in the training set. Our study also demonstrates the potential for generating full conformational ensembles from datasets with limited sampling and underscores the importance of training set size for generalization. We believe that idpSAM represents a significant progress in transferable protein ensemble modeling through machine learning.
Extreme heat & public perception in Portland, Oregon: Evidence of a compounding vulnerability effect for climate hazards
Authors: Suldovsky Brianne , Baer Kramer Molly , Fink Jonathan
Published: May 2024

Extreme heat events are a global public health threat, and the frequency of these events are projected to increase significantly in the coming decades. Responding to extreme heat requires that municipalities communicate with public audiences. Generally speaking, risk communication and public engagement efforts are more effective when they are responsive to current risk perception trends. This social scientific study examines extreme heat risk perceptions, emergency response needs, and level of trust in first responders among residents of the Portland (OR) Metro Area. Using quantitative survey data, it demonstrates the compounding influence of three previously identified vulnerability indicators–poverty, disability, and race–on public perception surrounding extreme heat and environmental emergencies. Results show these vulnerability indicators have a significant compounding effect on public perception, such that an increased number of vulnerability indicators is associated with greater anticipated harm from extreme heat, higher anticipated need in the event of an environmental emergency, and lower trust in first responders. Firefighters and medical providers were the most trusted first responders across all vulnerability groups. Guidelines for public engagement and recommendations for future social scientific research are discussed.
Addressing 6 challenges in generative AI for digital health: A scoping review
Authors: Templin Tara , Perez Monika W. , Sylvia Sean , Leek Jeff , Sinnott-Armstrong Nasa
Published: May 2024

Generative artificial intelligence (AI) can exhibit biases, compromise data privacy, misinterpret prompts that are adversarial attacks, and produce hallucinations. Despite the potential of generative AI for many applications in digital health, practitioners must understand these tools and their limitations. This scoping review pays particular attention to the challenges with generative AI technologies in medical settings and surveys potential solutions. Using PubMed, we identified a total of 120 articles published by March 2024, which reference and evaluate generative AI in medicine, from which we synthesized themes and suggestions for future work. After first discussing general background on generative AI, we focus on collecting and presenting 6 challenges key for digital health practitioners and specific measures that can be taken to mitigate these challenges. Overall, bias, privacy, hallucination, and regulatory compliance were frequently considered, while other concerns around generative AI, such as overreliance on text models, adversarial misprompting, and jailbreaking, are not commonly evaluated in the current literature.
Using routinely collected clinical data for circadian medicine: A review of opportunities and challenges
Authors: Kervezee Laura , Dashti Hassan S. , Pilz Luísa K. , Skarke Carsten , Ruben Marc D.
Published: May 2024

A wealth of data is available from electronic health records (EHR) that are collected as part of routine clinical care in hospitals worldwide. These rich, longitudinal data offer an attractive object of study for the field of circadian medicine, which aims to translate knowledge of circadian rhythms to improve patient health. This narrative review aims to discuss opportunities for EHR in studies of circadian medicine, highlight the methodological challenges, and provide recommendations for using these data to advance the field. In the existing literature, we find that data collected in real-world clinical settings have the potential to shed light on key questions in circadian medicine, including how 24-hour rhythms in clinical features are associated with—or even predictive of—health outcomes, whether the effect of medication or other clinical activities depend on time of day, and how circadian rhythms in physiology may influence clinical reference ranges or sampling protocols. However, optimal use of EHR to advance circadian medicine requires careful consideration of the limitations and sources of bias that are inherent to these data sources. In particular, time of day influences almost every interaction between a patient and the healthcare system, creating operational 24-hour patterns in the data that have little or nothing to do with biology. Addressing these challenges could help to expand the evidence base for the use of EHR in the field of circadian medicine.
Developing content for a virtual reality scenario that motivates quit attempts in adult smokers: A focus group study with art-based methods
Authors: Okpako Tosan , Kale Dimitra , Perski Olga , Brown Jamie
Published: May 2024

Virtual reality (VR) could be used to deliver messages to smokers that encourages them to attempt quitting. For a VR smoking cessation intervention to be effective, the target population must find the content engaging, relevant, inoffensive, and compelling. Informed by health behaviour theory and narrative transportation theory, this study used focus groups combined with art-based methods (participant sketches) to inform the development of VR content that will appropriately address smokers’ beliefs about quitting smoking. Data were analysed using reflexive thematic analysis. Four in-person focus groups (N = 21) were held between July and August 2023. Just under half the sample were from an ethnic minority (42.8%) and women (42.9%), and the mean age was 33.6 years (standard deviation = 15.9). More than half the sample had a low motivation to quit (61.0%). We developed six themes concerning: the VR content suggested by participants, the rationale behind it, its technological execution and potential widescale implementation. Many participants downplayed the health consequences of smoking, prioritising the immediate rewards of smoking over quitting’s long-term benefits. Therefore, participants suggested content set in the future, showing the benefits of cessation or the negative consequences of continued smoking. Family members were recommended as supporting VR characters to increase the contents’ emotional salience. Participants also suggested graphic content that would trigger anxiety about smoking, suggesting that fear appeals were welcome. Participants wanted a truly novel intervention- not a leaflet about smoking statistics presented through VR. Participants suggested healthcare locations (e.g., doctors’ offices) for implementation, as home ownership of VR headsets is low. Also, this would make the VR appear more legitimate as a health intervention (rather than casual entertainment) and could complement in-person advice. Future research will refine the participant-generated ideas with experts in VR design and smoking cessation.
An exploration of multi-level factors affecting routine linkage to HIV care in Zambia’s PEPFAR-supported treatment program in the treat all era
Authors: Chipungu Jenala , Smith Helene , Mwamba Chanda , Haambokoma Mwiza , Sharma Anjali , Savory Theodora , Musheke Maurice , Pry Jake , Bolton Carolyn , Sikazwe Izukanji , Herce Michael E.
Published: May 2024

Multiple steps from HIV diagnosis to treatment initiation and confirmed engagement with the health system are required for people living with HIV to establish full linkage to care in the modern treat all era. We undertook a qualitative study to gain an in-depth understanding of the impeding and enabling factors at each step of this linkage pathway. In-depth interviews were conducted with fifty-eight people living with HIV recruited from ten routine HIV care settings supported by the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) in Lusaka, Zambia. Using a semi-structured interview guide informed by an established conceptual framework for linkage to care, questions explored the reasons behind late, missed, and early linkage into HIV treatment, as well as factors influencing the decision to silently transfer to a different clinic after an HIV diagnosis. We identified previously established and intersecting barriers of internal and external HIV-related stigma, concerns about ART side effects, substance use, uncertainties for the future, and a perceived lack of partner and social support that impeded linkage to care at every step of the linkage pathway. However, we also uncovered newer themes specific to the current test and treat era related to the rapidity of ART initiation and insufficient patient-centered post-test counseling that appeared to exacerbate these well-known barriers, including callous health workers and limited time to process a new HIV diagnosis before treatment. Long travel distance to the clinic where they were diagnosed was the most common reason for silently transferring to another clinic for treatment. On the other hand, individual resilience, quality counseling, patient-centered health workers, and a supportive and empathetic social network mitigated these barriers. These findings highlight potential areas for strengthening linkage to care and addressing early treatment interruption and silent transfer in the test and treat era in Zambia.