bluuebunny/crossref_metadata_2025 huggingface dataset:
Consequences of Adolescent Pregnancy: A Social, Medical, and Psychological Analysis
Authors: Bednarz Karolina , Basiaga Bartosz , Żądecka-Kobiałka Klaudia , Putra Anna , Marchaj Magdalena , Nowicka-Jasińska Monika , Frączyk Paweł , Bieniek-Zając Sara , Baczkowski Sebastian , Krawiec Klaudia
Published: April 2024

Introduction: Adolescent pregnancy remains a contentious issue despite improvements in quality of life and increased access to sexual education. The average age of first pregnancy has shifted due to financial instability among young people, leading to delayed pregnancies until financial stability is achieved. Teenage mothers face social stigma, and early sexual initiation not only increases the risk of pregnancy but also sexually transmitted infections (STIs). Often, adolescent pregnancies are unwanted, resulting in delayed medical consultation due to fear or ignorance.

Aim of the Study: This study aims to investigate the medical and social implications of adolescent pregnancy, emphasizing the importance of early sexual education and comprehensive healthcare support.

Description of the State of Knowledge: Adolescent pregnancy, defined as pregnancy between ages 10 and 19, is a global concern with millions of cases annually. It poses significant health risks, including premature birth, low birth weight, and intrauterine growth restriction. Socially, it affects educational attainment and financial stability, with adolescents from lower socioeconomic backgrounds facing greater challenges. Early sexual initiation and risky sexual behaviors further compound the issue, increasing the risk of STIs. Lack of comprehensive sexual education exacerbates these risks, highlighting the need for multidisciplinary support from healthcare professionals.

Conclusions: Adolescent pregnancy requires a holistic approach encompassing medical, social, and legal dimensions. Effective sexual education programs, involving gynecologists, pediatricians, and educators, are essential for prevention. Legal frameworks must protect adolescents and address issues of consent and sexual health. Additionally, access to comprehensive healthcare services, including prenatal care and contraception, is crucial for mitigating the adverse effects of adolescent pregnancy on both individuals and society.
EL ROL EDITORIAL. UNA MIRADA DE EQUIPO CON DIRECCIÓN ACADÉMICA Y PROFESIONAL
Authors: Montiel Espinosa Gisela
Published: April 2024

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APRENDER FUNCIONES COMO UN PROCESO DE MATEMATIZACIÓN PROGRESIVA: ESTUDIANTES DE SECUNDARIA ENFRENTADO UNA SECUENCIA DIDÁCTICA DE CAÍDA LIBRE
Authors: González-Polo Rosa Isela , Castañeda Apolo
Published: April 2024

Esta investigación analiza cómo los estudiantes de secundaria comprenden y desarrollan el concepto de función a través de una secuencia didáctica que utiliza la caída libre como fenómeno de estudio. Enmarcada en la Educación Matemática Realista, la secuencia promueve un aprendizaje activo y motiva la transición desde el conocimiento informal hacia el formal. La metodología comprende etapas de anticipación, experimentación, análisis mediante el software Tracker y formulación algebraica. Este diseño didáctico motiva a que los alumnos transiten desde una percepción intuitiva hacia una comprensión abstracta y general de las funciones. Los resultados destacan avances en la habilidad de los estudiantes para vincular distintas representaciones de funciones, gráficas, algebraicas, tabulares o descriptivas. El uso de la herramienta Tracker fue fundamental al apoyar la visualización y análisis de los datos. La investigación concluye que la matematización progresiva y el aprendizaje activo son útiles para una comprensión integral y versátil de las funciones.
TAREFAS DE APRENDIZAGEM PROFISSIONAL NA FORMAÇÃO DE PROFESSORES DE MATEMÁTICA
Authors: Nobrega Ferreira Miriam Criez , Alves da Silva Valdir , Messias Gonçalves Marcel , Jacques Ribeiro Alessandro
Published: April 2024

El artículo presenta los resultados de un estudio que tuvo como objetivo comprender cómo el diseño e implementación de una Tarea de Aprendizaje Profesional contribuyó a la identificación de conocimientos matemáticos y didácticos de los docentes de matemáticas en un proceso de formación. Se enmarca en una perspectiva cualitativo-interpretativa, en la que la recolección de datos provino de los audios de la planificación, el diseño, audios y videos de las discusiones en los subgrupos y la plenaria de la segunda reunión. Los resultados muestran que, a partir de la tarea de aprendizaje profesional planificada e implementada fue posible elevar el conocimiento de los docentes, además de mostrar la articulación entre los componentes de las Tareas de Aprendizaje Profesional.
INVESTIGANDO A PRÁTICA DO PROFESSOR NO ENSINO DE FRAÇÕES NUM CONTEXTO DE TRABALHO COLABORATIVO
Authors: Cardoso Paula , Mamede Ema
Published: April 2024

Este estudio tiene como objetivo comprender las prácticas de enseñanza de los docentes del 1er ciclo de Educación Básica al momento de introducir el concepto de fracciones a sus estudiantes. Se busca responder a las preguntas: 1) ¿Cómo introduce el docente el concepto de fracción a sus alumnos? 2) ¿Cómo explora el profesor la interpretación de fracciones en sus clases? 3) ¿Qué dificultades experimenta el docente al enseñar fracciones? Se adoptó una metodología cualitativa en un enfoque de estudio de caso para analizar seis clases observadas de un docente que participó de un programa de trabajo colaborativo, enfocado en la enseñanza de fracciones. Los resultados sugieren algunas debilidades en el conocimiento matemático y didáctico del profesor sobre fracciones, concretamente en la interpretación de las fracciones, su abordaje y articulación en las clases de matemáticas.
Superponer pasados: disputas simbólicas en torno a dispositivos de memoria en el espacio público de Santiago de Cali a mediados del siglo XX
Authors: Muñoz Burbano Carmen Cecilia
Published: April 2024

Este capítulo pretende analizar las disputas simbólicas que generaron, hacia mediados del siglo XX, algunos proyectos de estatuaria conmemorativa en el espacio público de Santiago de Cali (Colombia). Un acercamiento a los debates y las discusiones que suscitaron permite identificar un imaginario que busca privilegiar un referente a costa de olvidar o silenciar otros. Dichos debates tuvieron lugar en un momento clave de la historia de la ciudad, marcado por anhelos de progreso y modernidad. En este contexto, se han identificado cuatro proyectos: el primero hace referencia a un conjunto escultórico en homenaje a los sacerdotes franciscanos José Ignacio Ortiz, Pedro Herrera y José Joaquín Escobar; el segundo, a un obelisco para “honrar y perpetuar la memoria de los próceres caleños”; el tercero, a un monumento a las Américas, y, por último, a una gran placa conmemorativa a las Ciudades Confederadas. Las discusiones en torno a cada uno estos proyectos estuvieron entrecruzadas por un interés común: erigir como lugar de memoria a los próceres caleños que participaron en las gestas independentistas del siglo XIX y al contexto desde el cual actuaron, la Junta de Ciudades Confederadas o Ciudades Amigas, creada el 3 de julio de 1810 y conformada por Anserma, Buga, Cartago, Caloto, Toro y Cali.
Movilidad intergeneracional ocupacional: probabilidad de ascender a la formalidad en Colombia
Authors: Betancur Valencia Didier Santiago , Machado Cuéllar Jhan Marco , Huang Huang Sun Yin , Torres Gómez Edwin Esteban
Published: April 2024

El estatus laboral de los padres influye el futuro laboral de sus hijos y el resultado de esta interacción podría limitar la movilidad intergeneracional y profundizar las brechas de desigualdad en el mediano y en el largo plazo. Este capítulo procura determinar si los factores asociados con el estatus laboral de los padres afectan las condiciones ocupacionales de sus hijos. Para tal fin, se estima un modelo logit multinomial de cuatro categorías con el uso de datos de la Gran Encuesta Integrada de Hogares de 2010 y 2019. Además, se estudian aspectos relacionados con la edad, los años de escolaridad, el género, la composición y la ubicación del hogar. Los resultados muestran movilidad ocupacional relativa ascendente de los hijos hacia la formalidad para todos los estatus laborales del jefe de hogar, unido a una alta probabilidad de permanencia en el sector informal. Así mismo, se demuestra mayor movilidad ascendente para hombres, individuos con menores años de escolaridad y en hogares nucleares. Por último, se comparten los hallazgos geográficos consistentes en un patrón centro-periferia en la movilidad y diferencias marcadasentre las zonas urbanas y rurales.
Cambios normativos en el Sistema General de Seguridad Social en Salud y sus efectos en la informalidad laboral en Colombia
Authors: Camargo Yennifer Celin , Torres Gómez Edwin Esteban , López González Mauricio
Published: April 2024

El objetivo de este capítulo es examinar los efectos de las modificaciones en las tarifas de cotización al Sistema General de Seguridad Social en Salud sobre la informalidad laboral en Colombia, entre 2007 y 2008. Con este fin, se utilizan datos de la Gran Encuesta Integral de Hogares para calcular, con una modelación basada en la estructura de las ecuaciones de Mincer, la probabilidad de ser informal, antes y después de las reformas implementadas. Los resultados indican que estas reformas ocasionaron una disminución en la probabilidad media de ser informal para las mujeres y para los hombres con una remuneración mayor a 2.5 salarios mínimos mensuales legales vigentes; para los empleados domésticos, del 17.7 % y del 8.2 %, respectivamente; y para los trabajadores por cuenta propia, del 5.4 % para las mujeres y del 2.1 % para los hombres.
Descomposición histórica de los cambios en la informalidad laboral en Colombia: un análisis FAVAR
Authors: Gaona Gómez Ana María , Torres Gorrón Jhon Edwar , Sánchez Salazar Cristian Andrés , Torres Gómez Edwin Esteban , López González Mauricio
Published: April 2024

Entender la informalidad desde una perspectiva microeconómica ha sido el enfoque habitual. Este trabajo presenta una propuesta para entender la informalidad desde determinantes macroeconómicos por medio de la descomposición histórica de la tasa de informalidad en Colombia entre el 2007 y el 2021. Para ello, se aplican factores de autorregresión vectorial aumentada (favar, por la sigla inglesa de factors augmented vector autoregression) correspondientes con seis agregaciones denominadas fiscal, precios del mercado laboral, cantidades del mercado laboral, actividad económica, financiero y, por último, informalidad, como variable de interés. Los resultados muestran que, si bien la dinámica de la informalidad puede ser explicada por medio de variables macroeconómicas, aún queda una proporción importante de sus cambios que no se explicarían por estos fundamentales, y esto podría estar asociado a factores geográficos o de la toma de decisiones de los individuos, que no alcanzan a ser captados con el enfoque más agregado que se adopta.
Humanos, humanismos y humanidades: en busca de una educación prospectiva
Authors: Eslava Edgar
Published: April 2024

A partir de la revisión de algunas perspectivas clásicas del humanismo, en este capítulo se plantea una lectura contemporánea de las relaciones entre el significado que debe darse al concepto de humanidad y las tareas que tiene hoy en día la enseñanza de las humanidades como parte de la formación en ciudadanía. En ese orden de ideas, se afirma que, si se quieren defender las humanidades en el mundo de hoy, es fundamental que este tipo de disciplinas reubiquen una parte de su mirada en el futuro, a fin de enriquecer, pero sobre todo de complejizar la interpretación del problema, toda vez que la constante insistencia en la exploración acerca de las causas o la génesis de la crisis de las humanidades puede contribuir a la enajenación o, mejor, a la cesión del derecho a discutir y fijar nuestras necesidades, intereses, expectativas y proyectos. Esta labor, según la lectura planteada, no solo competería a la filosofía, sino al horizonte de las humanidades en general.
Effects of Audio-visual and Contextual Conditions on Auditory Word Recognition in Patients with Normal Pressure Hydrocephalus
Authors: Cho Yoo-Jung , Park Ki-Su , Kang Kyunghun , Ha Ji-Wan
Published: April 2024

Objectives: In this study, we compared performance on the auditory word recognition tasks between patients with normal pressure hydrocephalus (NPH) and healthy elderly adults (HE) under different visual, auditory, and contextual conditions to determine how these variables affect auditory comprehension with cognitive decline.Methods: We conducted a standardized comprehension assessment, Paradise Korean Western Aphasia Battery Revised (PK-WAB-R) and the auditory word recognition tasks on 30 patients with NPH and 30 HE. The auditory word recognition task was divided into noisy and quiet conditions (auditory variable), blurry and clean conditions (visual variable), and low- and high-context conditions (contextual variable).Results: Patients with NPH showed relatively good comprehension on the standardized comprehension test of PK-WAB-R. For the auditory word recognition tasks, there was a significant main effect of group, a significant within-group effect of auditory and contextual conditions, and significant interaction effects between auditory condition and group, auditory condition and contextual information, and auditory condition, contextual information, and group.Conclusion: This study confirmed that patients with NPH have difficulty processing auditory comprehension at the sentence level. In addition, the auditory word recognition performance in patients with NPH was significantly lower than HE, and that their difficulties may be more pronounced under certain conditions, such as noisy conditions and low contextual information.
The Effects of Prospective Memory Intervention on Language Ability and Activities of Daily Living in the Elderly with Alzheimer’s Disease
Authors: Hwang Eunji , Sung Jee Eun
Published: April 2024

Objectives: Alzheimer’s Disease (AD) is characterized by an early decline in memory and cognitive functions, leading to impairments in language abilities and difficulties in communication as the disease progresses. Therefore, the need for early diagnosis and intervention in AD is considered critical; and maintaining and improving Prospective Memory (PM) is reported to aid in enhancing complex cognitive functions. This study aimed to explore the changes observed before and after PM intervention using External Memory Aids (EMA) in elderly individuals with AD.Methods: This study was conducted with 7 elderly individuals with mild AD, over three weeks with 12 sessions, four times a week. The intervention was based on a protocol consisting of three stages using the Prospective Memory Task (PMT) developed for this research: 1) reading texts, 2) answering wh-questions, and 3) utilizing EMA.Results: Significant improvements were showed after the intervention in performance of intervention and non-intervention PMT, immediate recall of words and story, naming, and K-MMSE, indicating the generalized effects of the intervention. However, there were no significant improvements in delayed recall, verb fluency and Activities of Daily Living.Conclusion: The use of EMA in PM intervention appeared to positively impact the language abilities and overall cognitive functions of elderly AD patients, suggesting that the activated PM through the intervention could lead to improvements in general cognitive functions.
Supporting language skills post pandemic
Authors: Halls Christopher
Published: April 2024

In the first article in a three-part series, Dr Christopher Halls, head of Early Years at Dulwich Prep London, explores some of the sustained consequences of the pandemic and the national lockdowns on children's current attainment in early years.
Mitigation of Feed Horn Overlapping Condition for Multi-beam Parabolic Reflector Antenna
Authors: Fauzi Nur Faiqah , Rahman Nurul Huda Abd , Yamada Yoshihide , Awang Robi’atun Adayiah , Pasya Idnin
Published: April 2024

In designing a contoured beam for communication satellite services, a reflector antenna remains the most preferred option. Previously, a multi-beam technique employing many feed horns at optimal feed positions was proposed to obtain a precise contour beam for Malaysia. However, it has led to feed horn overlapping when the beams were arranged closely. Therefore, this issue of beam allocation and feed horn size shall be addressed. In this article, an analysis of the relationship between feed position and beam direction is analysed through the Beam Deviation Factor (BDF). As a result, a useful design chart was derived for no feed horn overlapping conditions, which determines beam separation and feed horn size at different values of F/D. A practical application showing the Peninsular Malaysia beam coverage was demonstrated to validate the derived correlation. As a result, five multi-beams have been successfully designed with no overlapping feed horns. Through simulation, an excellent contour beam for Peninsular Malaysia was justified, featuring low side lobes, narrow beam width and high gain.
Inductive Reactance Isolated Dynamic Seawater Monopole Antenna of High Efficiency
Authors: Li Lihua , Feng Shimin , Xiu Menglei
Published: April 2024

The dynamic-type seawater monopole antenna has the problem of direct connection between its radiation body and the seawater. This makes the radiation current flow into the seawater, which leads to low radiation efficiency. In this paper, a dynamic-type seawater monopole antenna of high efficiency is proposed using an inductive reactance isolated method. Based on this method, a dynamic seawater antenna of seawater inductance isolation structure is designed. According to its equivalent circuit diagram, the principle and design basis of isolation are analyzed. The FEKO software is then used to simulate the antenna’s radiation efficiency. In addition, the impacts of the radius of the seawater inductance, the number of turns of the seawater coil, the diameter of the seawater coil, and the average turn spacing on the efficiency of the antenna are studied. Moreover, the experimental verification shows that the radiation efficiency of the designed dynamic seawater antenna with inductive reactance isolation structure can be greater than 70%. The value of the received carrier power in the case of inductance isolation is higher by 10 dB compared with the case without isolation.
Why should I decide to engage? Polish medium-sized and large companies employees’ opinions about joining corporate volunteering and its benefits
Authors: Nowakowska Iwona , Duda Ewa , Szulawski Michał
Published: April 2024

Corporate volunteering, despite its benefits for the enterprises, supported people, and the volunteers themselves, is still not popular in Polish medium-sized and large companies. In this paper, we explore how people with/without experience in corporate volunteering perceive circumstances that would encourage them to join this activity, and the benefits of it to employers, beneficiaries, and themselves. Our insight may help to plan corporate volunteering programmes, especially for employers and nonprofit organisations collaborating with enterprises.
Who decides ‘what works’, and how does it get implemented? Insights from the UK’s new centre for implementing evidence in adult social care
Authors: Tawodzera Obert , Glasby Jon
Published: April 2024

The UK’s adult social care system faces severe challenges, including funding shortages, unmet needs and an overburdened workforce. Resultantly, there is a push for high-quality evidence in service enhancement and resource allocation. Using evidence to improve services is essential, but questions arise about best practices for identifying ‘what works’, integrating evidence into everyday practice and addressing resource constraints. Findings from a 2021 UK survey and consultative forums with stakeholders across adult social care underscore concerns about implementing evidence-based practices and highlight the need for increased collaboration to expand the evidence base. These findings shed light on stakeholders’ perspectives regarding factors shaping adult social care practices, opportunities for evidence to play a greater role, definitions of valid evidence and priorities for change. Improved communication and coordination within the sector are crucial to enhance evidence-based decision making, focus limited resources on proven strategies and shape a more effective, evidence-informed adult social care system.
In between lived life and a social policy agenda: the Global South social question from the inside (Brazil)
Authors: Georges Isabel , Araújo Filho Tarcísio Perdigão
Published: April 2024

This article aims to demonstrate how gender, class, and race are intertwined at the micro level, addressing the interaction of lived life and social policy, through biographical interviews, in Brazil. Less interested in the analysis of inequalities per se, this article focuses on the way black, elderly, poor, female heads of families, living in urban neighbourhoods, manage to subjectively resignify objective domination. The in-depth biographical approach reveals the (re)construction of their subjectivity, defining personal sacrifice as a form of protagonism (agency) and empowerment. This process of resignification occurs by exchanging the unit of experience they relate to, from the individual to the family unit. It engages with social policies (social assistance, public health, and social housing) implemented by the latest Labour Party’s term of office (2003–2016). These policies are based on the role of women as responsible for the family unit. The focus on subjectivity, in different Brazilian metropoles, challenges the production of conformed neoliberal selves, in this case of women, within a specific Global South context, marked by historically high levels of inequality and informal work, since the formal end of slavery.
A Madrid: 682 de Juan Ignacio Luca de Tena y la literatura fascista española: narración e ilustración al servicio de la propaganda
Authors: Iñiguez Egido Alain
Published: April 2024

El guion de cine A Madrid: 682 del escritor Juan Ignacio Luca de Tena reproduce algunos de los lugares comunes de la propaganda escrita por el bando sublevado durante la guerra civil española. No obstante, al margen de la tergiversación del relato histórico contrastado con respecto a algunos hechos —como ocurre con el asedio del Alcázar de Toledo—, llama la atención el medio por el cual Luca de Tena pergeña su texto. Así, la incorporación de ilustraciones del artista boliviano Arturo Reque Meruvia se estudia aquí como un medio adicional, muy significativo, de transmisión y consolidación de la propaganda franquista durante la guerra mediante el análisis de la función que desempeñan las ilustraciones en relación con el texto, intensificadoras de la estética grotesca presente en algunas escenas.
Extinción o supervivencia de las especies: hormigas, tataguas y mosquitos en la obra de Martha Luisa Hernández Cadenas
Authors: Timmer Nanne
Published: April 2024

En el imaginario literario de Martha Luisa Hernández Cadenas (La Habana, 1991) aparecen insectos por varios lugares. En Días de hormigas el rastro de las hormigas indica una dirección de vida y libertad en medio de un paisaje de devastación, paisaje que vuelve también en Extintos. Aquí no vuelan mariposas (2018), mientras que en La puta y el hurón (2020) los mosquitos formulan una resistencia al orden violento y patriarcal. En este artículo estudiaré el papel de los insectos en la obra de esta joven escritora y performer cubana. Argumento que, a pesar de los escenarios de derrumbes y ruinas, construye también una idea de futuro y de comunidad. Con la ayuda de Rosi Braidotti, propongo que en el devenir insecto y en el devenir mujer se entrelazan lo abyecto, lo liminal y un estar fuera del tiempo que permite articular formas de resiliencia. Mediante las alianzas entre los «infraseres», en el volverse molécula y en el hacerse imperceptible, sostengo que el devenir insecto funciona como un modo de resistir y disentir.
Radial basis point interpolation for strain field calculation in digital image correlation
Authors: Du Jiayi , Zhao Jian , Liu Jiahui , Zhao Dong
Published: April 2024

In order to extract smooth and accurate strain fields from the noisy displacement
fields obtained by digital image correlation (DIC), a point
interpolation meshless (PIM) method with a radial basis function (RBF)
is introduced for full-field strain calculation, which overcomes the
problems of slow calculation speed and unstable matrix inverse
calculation of the element-free Galerkin method (EFG). The radial
basis point interpolation method (RPIM) with three different radial
basis functions and the moving least squares (MLS) and pointwise least
squares (PLS) methods are compared by analyzing and validating the
strain fields with high-strain gradients in simulation experiments.
The results indicate that the RPIM is nearly 80% more computationally
efficient than the MLS method when a larger support domain is used,
and the efficiency of the RPIM is nearly 26% higher than that of the
MLS method when a smaller support domain is used; the strain
calculation accuracy is slightly lower than that of the MLS method by
0.3–0.5%, but the stability of the calculation is significantly
improved. In contrast with the PLS method, which is easily affected by
the noise and the size of the strain calculation window, the RPIM is
insensitive to the displacement noise and the size of the support
domain and can obtain a similar calculation accuracy. The RPIM with
multiquadric (MQ) radial basis functions performs well in balancing
the computational accuracy and efficiency and is insensitive to shape
parameters. The application cases show that the method can effectively
compute the strain field at the crack tip, validating its
applicability to the study of the plastic region at the crack tip. In
conclusion, the proposed RPIM-based method provides an accurate,
practical, and robust approach for full-field strain measurements.
Fractioned-pattern radiation mapping, Part I: modeling
Authors: Valencia Estrada Juan Camilo , Garcia-Marquez Jorge , Etienne Romain
Published: April 2024

Here, we present a technique that predicts the radiation’s distribution in any optical system. It is based on decomposing the emitting source power by assigning a fraction of the total power to each emitted ray. All kinds of power losses in the rays’ optical paths are considered. Fractioned radiation patterns are created in the last optical system surface, each associated with a single ray. We refer to fractioned patterns as those that conform to a whole radiating pattern. Thus, the irradiance of the completely illuminated surface is calculated by adding the optical system’s fractioned radiation maps. This method is non-zero étendue. The result presented here allows for predicting the radiation patterns accurately with a handful of equations and can help design any image and non-image-forming optical systems.
Investigation of zero-phonon line characteristics in ensemble nitrogen-vacancy centers at 1.6 K–300 K
Authors: Zhang Zhenrong , Wen Huan Fei , Gao Ziheng , Liu Yanjie , Cao Bo , Guo Hao , Li Zhonghao , Ma Zongmin , Li Xin , Tang Jun , Liu Jun
Published: April 2024

The ensemble of nitrogen-vacancy (NV) centers is widely used in quantum information transmission, high-precision magnetic field, and temperature sensing due to their advantages of long-lived state and the ability to be pumped by optical cycling. In this study, we investigate the zero-phonon line behavior of the two charge states of NV centers by measuring the photoluminescence of the NV center at 1.6 K-300 K. The results demonstrate a positional redshift, an increase in line width, and a decrease in fluorescence intensity for the ZPL of NV0 and NV- as the temperature increased. In the range of 10 K to 140 K, the peak shift with high concentrations of NV- revealed an anomaly of bandgap reforming. The peak position undergoes a blueshift and then a redshift as temperature increases. Furthermore, the transformation between NV0 and NV- with temperature changes has been obtained in diamonds with different nitrogen concentrations. This study explored the ZPL characteristics of NV centers in various temperatures, and the findings are significant for the development of high-resolution temperature sensing and high-precision magnetic field sensing in ensemble NV centers.
Improving the rising edge of the temporal contrast of PHELIX by spatial conditioning in an unfolded stretcher
Authors: Roeder Simon , Zobus Yannik , Major Zsuzsanna , Bagnoud Vincent
Published: April 2024

We showcase a new, unfolded stretcher setup at the PHELIX facility that incorporates a beam expander for spatial conditioning of the rising edge in the temporal contrast. With this purely optical technique we are able to improve the rising-edge contrast from 10-6 achieved with the standard, folded stretcher at PHELIX to 5.7⋅10−10±0.2⋅10−10 at −30 ps. By comparing between measurements and model predictions based on spectral-phase and -amplitude effects, we are able to determine limiting factors at PHELIX. Those indicate that the achieved improvement is sufficient to make other limiting factors, like the compressor, visible in the rising edge.
Enhancing the performance of AlGaN-based DUV-LEDs with multifocal laser stealth dicing
Authors: Shen Meng-Chun , Chen Jinlan , Tseng Ming-Chun , Lai Shouqiang , Zhang Zhening , Zheng Lijie , Lin Su-Hui , Peng Kang-Wei , Chen Zhong , Wu Tingzhu
Published: April 2024

In this study, AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) processed via standard laser dicing (SLD) and multifocal laser stealth dicing (MFLSD) were investigated. Adopting the MFLSD technology would generate a roughing surface rather than the V-shaped grooves on the sidewall of 508 × 508 µm2 DUV-LEDs, which would reduce the forward operating voltage and increase the wall-plug efficiency, light output power, and far-field radiation patterns of these devices. In addition, the wavelength shift, far-field patterns, and light-tracing simulation results of the DUV-LEDs processed with SLD and MFLSD were clearly demonstrated and analyzed. Accordingly, it was observed that the MFLSD process provided more possibilities for photon escape to increase the light extraction efficiency (LEE) of DUV-LEDs, thus decreased the wavelength-redshift and junction temperature in DUV-LEDs. These results provide a reference for advanced nano-processing practices implemented during the fabrication of semiconductor devices.
Augmented reality display with high eyebox uniformity over the full field of view based on a random mask grating
Authors: Wu Yuanjun , Pan Cheng , Lu Changtai , Zhang Yinxin , Zhang Lin , Huang Zhanhua
Published: April 2024

Ensuring uniform illuminance in waveguide-based augmented reality (AR) display devices is crucial for providing an immersive and comfortable visual experience. However, there is a lack of a straightforward and efficient design method available to achieve illuminance uniformity over the full field of view. To address this issue, we propose a novel design that utilizes random mask gratings (RMGs) as the folding grating and the out-coupling grating. Unlike traditional approaches that modify the grating structure, we control the diffraction efficiency distribution by adjusting the filling factor of the mask while keeping the grating structure unchanged in one RMG. The grating structures are designed and optimized based on rigorous coupled wave analysis and particle swarm optimization. The feasibility of our method is verified by the simulation results in Lighttools. In the FOV range of 20°×15°, the eyebox uniformities of all fields are greater than 0.78, which can provide a good visual experience for users.
Proton energy enhancement by optimizing a laser pulse profile
Authors: Liu Yuanyuan , Zhang Xiaomei , Shen Baifei , Zheng Xiaolong , Xing Jinlong , Kong Fanqiu
Published: April 2024

Based on current laboratory laser parameters and the low density target that is induced by the inevitable prepulse, we propose what we believe to be a new scheme to enhance the proton energy by employing a laser pulse with two different peak intensities. Initially, the lower-intensity peak of the laser pulse P1, irradiates the low-density plasma target induced by the prepulse to form a significantly denser plasma target. Such a compressed high-density target is critical for supporting the subsequent main pulse P2 with higher peak intensity to drive proton acceleration. As an example, particle-in-cell (PIC) simulations reveal that when using a circularly polarized (CP) flat-top P1 with a peak intensity of approximately 1.71 × 10 19 W/cm2, full-width at half-maximum(FWHM) duration of 325 fs and a CP P2 with a peak intensity of 1.54 × 10 22 W/cm2, FWHM duration of 26.5 fs, and focal spot radius of 4 µm successively acting on a target with an initial density of 8nc, protons with cut-off energy of 940 MeV can be obtained from the cascaded acceleration scheme. Compared with the case without P1, the cutoff energy increased by 340 MeV. Owing to the intervention of P1, this scheme overcomes the limitation of laser contrast and is more feasible to be implemented experimentally.
Octave-spanning supercontinuum generation in a CMOS-compatible thin Si3N4 waveguide coated with highly nonlinear TeO2
Authors: Mbonde Hamidu M. , Singh Neetesh , Segat Frare Bruno L. , Sinobad Milan , Ahmadi Pooya Torab , Hashemi Batoul , Bonneville Dawson B. , Mascher Peter , Kärtner Franz X. , Bradley Jonathan D. B.
Published: April 2024

Supercontinuum generation (SCG) is an important nonlinear optical process enabling broadband light sources for many applications, for which silicon nitride (Si3N4) has emerged as a leading on-chip platform. To achieve suitable group velocity dispersion and high confinement for broadband SCG the Si3N4 waveguide layer used is typically thick (>∼700 nm), which can lead to high stress and cracks unless specialized processing steps are used. Here, we report on efficient octave-spanning SCG in a thinner moderate-confinement 400-nm Si3N4 platform using a highly nonlinear tellurium oxide (TeO2) coating. An octave supercontinuum spanning from 0.89 to 2.11 µm is achieved at a low peak power of 258 W using a 100-fs laser centered at 1565 nm. Our numerical simulations agree well with the experimental results giving a nonlinear parameter of 2.5 ± 0.5 W−1m−1, an increase by a factor of 2.5, when coating the Si3N4 waveguide with a TeO2 film. This work demonstrates highly efficient SCG via effective dispersion engineering and an enhanced nonlinearity in CMOS-compatible hybrid TeO2–Si3N4 waveguides and a promising route to monolithically integrated nonlinear, linear, and active functionalities on a single silicon photonic chip.
Amplification-free GW-level, 150 W, 14 MHz, and 8 fs thin-disk laser based on compression in multipass cells
Authors: Goncharov Semyon , Fritsch Kilian , Pronin Oleg
Published: April 2024

We report an amplification-free thin-disk laser system delivering 0.9 GW peak power. The 120 fs pulses, at 14 MHz, centered around 1 µm, containing 12.8 µJ delivered by a thin-disk oscillator, were compressed by factor 15 down to 8.0 fs with 148 W average output power and overall 82% efficiency. Additionally, we showed that even a sub-two-cycle operation with 6.2 fs can be reached with this technology. The system will be a crucial part of the XUV frequency comb being developed and a unique high-repetition rate driver for attosecond pulse generation.
Optical skyrmion laser using a wedged output coupler
Authors: Kerridge-Johns William R. , Rao A. Srinivasa , Omatsu Takashige
Published: April 2024

Optical skyrmions are a recently demonstrated topological state of light that promise a rich set of physics and applications, in particular, material manipulation. In this work, we demonstrate a method to generate these states from a laser, which has an intermediate bimeron state, providing a route to compact, high power, and low cost skyrmion research and applications. We use a praseodymium gain medium to make red (640 nm) and orange (607 nm) Bloch-, Néel-, and anti-skyrmions, with a route to the other visible emission bands of the gain medium. This approach uses a wedged optic as the key component, which could be easily adapted to other laser gain media and laser cavity configurations, and other exotic topological states.
Safety awareness and adaptation strategies of Nigerian construction workers in extreme heat conditions
Authors: Moda Haruna Musa , Zailani Mahmud Bello , Rangarajan Ravi , Hickey Pauline , Abubakar Mu’awiya , Maina Joy , Makarfi Yahaya Ibrahim
Published: April 2024

The nature of most construction activities exposes workers to health and safety risks associated with extreme hot weather conditions especially within developing countries in the global south. Considering the magnitude of health and safety risks associated with extreme heat exposure and the prevailing safety culture, and attitude among workers that impede adaptation to safe work practices under extreme heat conditions, it is imperative that serious attention is given to workplace climate change impact on construction workers. The current study provides empirical evidence on safety awareness and practices among Nigerian construction workers, those often exposed to extreme hot weather conditions. A structured questionnaire was used to elicit data from 576 respondents using random sampling technique and the data was analysed using descriptive and inferential statistical tools. As part of the study outcome, 57.3% of the respondents raised concerns regarding the non-availability of potable water source on sites, which directly impacts their level of fluid intake while working in extreme heat conditions. To improve safety and enhance productivity, construction organisations need to prioritise workers’ safety through the implementation of sustainable adaptive strategies that include the development of early warning systems related to heat stress at work, development of tailored intervention and adaptive measures and enhancement of heat stress awareness among workers. The study provides evidence on the impact of heat stress among construction workers and the need to improve safety awareness and mitigation against climate change driven extreme heat conditions especially among workers in tropical countries.
Child, family and household characteristics associated with physical activity in Samoan children aged 3–8 years: A cross-sectional study
Authors: Warmath Clara R. , Choy Courtney C. , McGarvey Stephen T. , Sherar Lauren B. , Duckham Rachel L. , Soti-Ulberg Christina , Naseri Take , Reupena Muagututia S. , Wang Dongqing , Hawley Nicola L.
Published: April 2024

Physical activity is a key component of many obesity prevention strategies. The aim of this analysis was to identify child, family, and household characteristics associated with parent-reported physical activity in Samoan children aged 3–8 years. Children (n = 445; 51.2% female, mean age 5.4 years) were part of an ongoing, mixed-longitudinal study of child growth, development, and wellbeing (the Ola Tuputupua’e cohort). Bivariate analyses and multivariate generalized linear regressions were conducted to investigate the relationship of child, family, and household characteristics with physical activity level, measured using the Netherlands Physical Activity Questionnaire (NPAQ). Children were classified as being ‘highly active’ if they had NPAQ scores in the 75th percentile or above. Among the n = 111 children classified as ‘highly active’, n = 67 (60.4%) were boys. After adjusting for child, family, and household-level characteristics, hours of child sleep per night was the only variable significantly associated with odds of being highly active. Compared to children who slept less than 9 hours at night, those who slept 10–10.99 hours (OR: 5.97, 95% CI: 2.14–18.13) and 11+ hours (OR: 25.75, 95% CI: 8.14–90.12) had higher odds of being ‘highly active’. Future research should examine the mechanisms driving the relationship between nighttime sleep and physical activity among Samoan children. Intervening on sleep duration and quality may improve physical activity and, in turn, obesity risk in this setting.
Treatment seeking behaviour and associated factors among adults with high blood pressure from three selected states in Nigeria
Authors: Bamgboye Eniola , Ayoyemi Abiola , Salawu Mobolaji Modinat , Akinyemi Joshua Odunayo , Ogah Okechukwu Samuel , Uja Uzoamaka Alice , Jalo Rabiu Ibrahim , Oyewole Oyediran , Sani Mahmoud , Ajayi IkeOluwapo Oyeneye
Published: April 2024

Management of hypertension is challenging in multi-cultural and multi-ethnic sub-Saharan African countries like Nigeria. This diversity calls for multi-dimensional interventional approaches for hypertension control. This study assessed the treatment seeking behaviour and associated factors among adults with high blood pressure from three ethnic groups in Nigeria. A cross-sectional study was conducted among 762 adults with high blood pressure from three purposively selected States representing the three main tribes in Nigeria. Using a multistage stratified sampling technique, five communities were selected from two Local Government Areas (LGAs) stratified into urban and rural LGAs in each State. All consenting respondents in each community were consecutively screened for hypertension and recruited. A pretested interviewer-administered questionnaire was used to obtain information on socio-demographic characteristics, treatment seeking behaviour and factors affecting their choice. Data were summarized using descriptive statistics. Relationship between individual, health-related factors and treatment seeking behaviour, as well as the predictors were assessed using a binary logistic regression. at p<0.05 Participants’ mean age was 55.4 ± 16.6 years, 63.0% were females and most were Igbo speaking (39.9%). About half (368, 48.3%) were unaware of their status. Of those aware, most (58.9%) went to hospital upon diagnosis of hypertension while some sought advice from health care professionals (28.5%) mostly Hausas, others either went to chemists (6.2%) or did nothing (5.1%), predominantly Yorubas. Significant predictors of orthodox treatment seeking practices for hypertension were female gender [(AOR = 2.60; 95%CI (1.18–5.71)], availability of medicine and personnel [(AOR = 8.7; 95%CI (4.15–18.3)] and perceived good quality of care [(AOR = 4.88; 95%CI (1.81–13.1)]. Orthodox treatment was the common choice among adults with high blood pressure. To further encourage patronage of orthodox treatment, the health facilities should be adequately equipped with medications and trained personnel to improve the quality of care. Targeted education on continuous practice of orthodox treatment is recommended.
Assessment of sewer connectivity in the United States and its implications for equity in wastewater-based epidemiology
Authors: Yu QinQin , Olesen Scott W. , Duvallet Claire , Grad Yonatan H.
Published: April 2024

Wastewater-based epidemiology is a promising public health tool that can yield a more representative view of the population than case reporting. However, only about 80% of the U.S. population is connected to public sewers, and the characteristics of populations missed by wastewater-based epidemiology are unclear. To address this gap, we used publicly available datasets to assess sewer connectivity in the U.S. by location, demographic groups, and economic groups. Data from the U.S. Census’ American Housing Survey revealed that sewer connectivity was lower than average when the head of household was American Indian and Alaskan Native, White, non-Hispanic, older, and for larger households and those with higher income, but smaller geographic scales revealed local variations from this national connectivity pattern. For example, data from the U.S. Environmental Protection Agency showed that sewer connectivity was positively correlated with income in Minnesota, Florida, and California. Data from the U.S. Census’ American Community Survey and Environmental Protection Agency also revealed geographic areas with low sewer connectivity, such as Alaska, the Navajo Nation, Minnesota, Michigan, and Florida. However, with the exception of the U.S. Census data, there were inconsistencies across datasets. Using mathematical modeling to assess the impact of wastewater sampling inequities on inferences about epidemic trajectory at a local scale, we found that in some situations, even weak connections between communities may allow wastewater monitoring in one community to serve as a reliable proxy for an interacting community with no wastewater monitoring, when cases are widespread. A systematic, rigorous assessment of sewer connectivity will be important for ensuring an equitable and informed implementation of wastewater-based epidemiology as a public health monitoring system.
Edge Artificial Intelligence (AI) for real-time automatic quantification of filariasis in mobile microscopy
Authors: Lin Lin , Dacal Elena , Díez Nuria , Carmona Claudia , Martin Ramirez Alexandra , Barón Argos Lourdes , Bermejo-Peláez David , Caballero Carla , Cuadrado Daniel , Darias-Plasencia Oscar , García-Villena Jaime , Bakardjiev Alexander , Postigo Maria , Recalde-Jaramillo Ethan , Flores-Chavez Maria , Santos Andrés , Ledesma-Carbayo María Jesús , Rubio José M. , Luengo-Oroz Miguel
Published: April 2024

Filariasis, a neglected tropical disease caused by roundworms, is a significant public health concern in many tropical countries. Microscopic examination of blood samples can detect and differentiate parasite species, but it is time consuming and requires expert microscopists, a resource that is not always available. In this context, artificial intelligence (AI) can assist in the diagnosis of this disease by automatically detecting and differentiating microfilariae. In line with the target product profile for lymphatic filariasis as defined by the World Health Organization, we developed an edge AI system running on a smartphone whose camera is aligned with the ocular of an optical microscope that detects and differentiates filarias species in real time without the internet connection. Our object detection algorithm that uses the Single-Shot Detection (SSD) MobileNet V2 detection model was developed with 115 cases, 85 cases with 1903 fields of view and 3342 labels for model training, and 30 cases with 484 fields of view and 873 labels for model validation before clinical validation, is able to detect microfilariae at 10x magnification and distinguishes four species of them at 40x magnification: Loa loa, Mansonella perstans, Wuchereria bancrofti, and Brugia malayi. We validated our augmented microscopy system in the clinical environment by replicating the diagnostic workflow encompassed examinations at 10x and 40x with the assistance of the AI models analyzing 18 samples with the AI running on a middle range smartphone. It achieved an overall precision of 94.14%, recall of 91.90% and F1 score of 93.01% for the screening algorithm and 95.46%, 97.81% and 96.62% for the species differentiation algorithm respectively. This innovative solution has the potential to support filariasis diagnosis and monitoring, particularly in resource-limited settings where access to expert technicians and laboratory equipment is scarce.