bluuebunny/crossref_metadata_2025 huggingface dataset:
Describing student’s mathematical power: Do cognitive styles make any difference?
Authors: Fitriyani Harina , Setyawan Fariz , Hendroanto Aan , Istihapsari Vita
Published: April 2021

Mathematical competence refers to the skills of students in reasoning, connection, communication, representation, and problem-solving. Various researchers have massively discussed on how to foster mathematical competence. However, it is just a few of them comprehensively explain from the cognitive styles perspective. This research aims to measure the junior high school students’ mathematical competence based on their cognitive style.This research used a descriptive qualitative approach. There were 35 students took part in the mapping of cognitive styles using the Matching Familiar Figure Test and were then selected representative from the reflective and the impulsive cognitive style to have a further assessment of the mathematical competence using the mathematical competence test. The data analysis used the model of Milles and Huberman. The results showed that there was a difference mathematical competence between the subject having impulsive cognitive style and the one having reflective cognitive style. The percentage of mathematical competence of reflective subject was 69% while the impulsive subject was 56.89%. From all aspects of mathematical competence, the reflective subject tends better ability; for instance, the reflective subject has better ability than the impulsive subject on mathematical connection, mathematical reasoning, mathematical representation, and problem-solving.
Modern Roles of the Teacher of a Higher Educational Institution
Authors:   State Institution Luhansk Taras Shevchenko National University, Koteneva Iryna , Karlova Nadiia ,   State Institution Luhansk Taras Shevchenko National University
Published: April 2021

Article is devoted to consideration of questions of transformation of a modern role of the teacher of high school which changes and supplements a substantial basis of its professional competence and demands reconsideration and acceptance of new concepts. The role and the functions of the teacher connected with problems of education of youth in educational space of high school that promotes formation of communicative skills and social intelligence of competitors of higher education which of objects of influence become its subjects is characterised. It is defined that consulting preceptorship of group carries out adviser – the key subject of the socially-humanitarian influence which functions essentially differ from functions of the curator in traditional understanding. Socially-humanitarian functions and roles of adviser of groups of competitors of higher education are presented, socially-humanitarian directions and forms of its work. Status definition in educational process of an institution of higher education of student's advisers is proved, the purpose of their activity, the primary goals and functions. The conclusion, concerning modern development of the Ukrainian higher school, its European orientation which demands from teachers of performance of a certain number of roles – not as instructors and a source of knowledge and as couch, facilitator, the tutor, the moderator, the mentor and adviser of an individual educational trajectory of competitors of higher education is drawn.
Forms of interaction of higher educational institutions with territorial communities
Authors:   State Institution Luhansk Taras Shevchenko National University, Kravchenko Olena , Khrykov Yevhen ,   State Institution Luhansk Taras Shevchenko National University, Vasynova Nadiia ,   State Institution Luhansk Taras Shevchenko National University
Published: April 2021

The article raises the issue of interaction of higher education institutions with territorial communities in the conditions of decentralization. foreign experience of interaction of higher educational institutions with territorial communities are disclosed. The features of interaction of higher educational institutions with territorial communities in foreign countries are characterized. It has been established that the use of the positive foreign experience of interaction of higher educational institutions with territorial communities is promising for Ukraine. Ensuring cooperation between the university and local communities involves certain forms of interaction The authors identified the main forms of interaction between a higher education institution and territorial communities of the socio-economic development of territorial communities; of the cultural and sports life of the community; of Education; of cooperation of the university with local authorities; volunteer activity. Interaction of territorial communities and higher education institutions is the way of important changes in communities, educational institutions and society in general, which is the main advantage of business associations.
The Role of Educational and Cognitive Activities of Higher Education Applicants in Increasing the Competetiveness of Future Teachers
Authors:   SHEE ", Pshenichny Maksym ,   Donbas State Pedagogical University", Tsibulko Hryhorii ,   SHEE "Donbas State Pedagogical University", Musket Yulii ,   SHEE "Donbas State Pedagogical University"
Published: April 2021

Innovation and inventive activities related to the development of highly efficient equipment, technological equipment, tools, means of mechanization and automation, and improvement of production technology are important in accelerating the pace of scientific and technological progress. Innovative and inventive activities are carried out on the basis of design and technological knowledge and skills. The greater the amount of this knowledge and skills the manufacturer has, and the deeper they are, the greater its potential capabilities are. Providing such opportunities to specialists is carried out within the walls of the Institutions of Higer EducationWestern Military District, in the process of teaching them the basics of scientific research, the basics of technical creativity of design and modelling. So far educational the design and technological activity is the preparation for the corresponding production activity, then the question arises: what is the content of design and technological activity in the conditions of modern production and what professional requirements it puts forward. To answer these questions, you need to analyze the activities of the designer and technologist. This analysis was carried out by us on the basis of literary sources and personal experience. The conducted researches confirm the importance of the systematic process of organizing and using intersubject relations, the necessity and expediency of applying the system of methods of technical creativity to activate the educational and cognitive activities of students of technological faculties of higher pedagogical institutions.
Social and Psychological Training as a Means of Development of Communicative Abilities of Future Specialists in the Social Sphere
Authors:   SHEE ", Trubnik Inna ,   Donbas State Pedagogical University"
Published: April 2021

Social and psychological training as a kind of active training can be used in the training of specialists in the social sphere. It is aimed at increasing of psychological culture of communication which is one of components of the professional activity of social workers and social security specialists (specialties such as 231 «Social work», 232 «Social security»). The author outlines the factors of the efficient conduct of the training work, the basic principles of training sessions’ formations, the general rules of training participants’ behavior. The article substantiates the need to develop the communicative abilities of future social workers at the stage of professional training in a higher education institution (within the framework of studying the discipline «Social and communicative development of personality»), defines the content and methods, offers guidelines for conducting trainings and the topics of training sessions. The analysis of the results of experimental work proves the effectiveness of using social and psychological training as a means of developing the communicative abilities of future specialists in the social sphere, confirms the activity and interest of students in trainings participation.
Some Aspects of Professional Training of Future Teachers of Physical Culture for the Formation of Social Health of Primary School Students
Authors:   State Institution Luhansk Taras Shevchenko National University, Babich Viacheslav
Published: April 2021

The article is devoted to the problem of professional training of future physical education teachers to the formation of social health of primary school students. It is noted, that today the concept of «social health of primary school students» remains almost unexplored, needs to develop the content and structure of social health of students of this age period. It is revealed, that the formation of social health involves the mastery of the student's knowledge, skills and necessary experiencein the context of interaction with the micro-, meso- and macro-environment, leading a healthy lifestyle, etc. It is noted, that the formation of social health should begin with the first grades in general secondary education. Significant potentialin the above contexthas an educational subject «Physical culture». It is emphasized, that at present the modernization of the process of training future physical education teachers is a particularly important problem, in particular on the mastery of the latter necessary arsenal, knowledge, skills, abilities and the minimum necessary in the context of the formation of social health of primary school students. It is determined that in the conditions of education reform there is an urgent need to develop pedagogical conditions for professional training of future physical education teachers for the formation of social health of primary school students, correction of the content of professional disciplines, as well as improving the forms, methods and technologies of training future physical education teachers in the above context.
The Determination of the Essence of the Readiness of Officers to Carry Out Language Training in Military Units of National Guard of Ukraine
Authors:   National Academy of the National Guard of Ukraine, Honchar Volodymyr
Published: April 2021

The urgency of the article is due to the stable European integration aspirations of Ukraine, the participation of military formations of Ukraine in particular the National Guard of Ukraine in international cooperation, so the organization of language training in military units in modern conditions should become an integral part of professional development and training of officers in general. An analysis of scientific sources on the readiness of officers to conduct language training in military units of both the NGU and the Armed Forces revealed that this problem has not been studied and needs additional attention. The essence of the of the readiness of officers to carry out language training in the military units of NGU is revealed – this is the quality that is formed as a result of a set of measures for the formation of professional readiness for service and pedagogical activity which is formed by purposeful pedagogical influence for the formation of psychological readiness and the necessary competencies.
Prácticas de ocio y tiempo libre de los adolescentes en Galicia: análisis y reflexiones en clave socioeducativa
Authors: De Valenzuela Bandín Ángela L. , Martínez García Rubén , Escobar Arias Diana Morela
Published: April 2021

INTRODUCCIÓN. Desde hace décadas diversos estudios han revelado el potencial del tiempo de ocio para el desarrollo personal y social. Un tiempo que, no en pocas ocasiones, queda relegado a un segundo plano en detrimento de otros considerados socialmente prioritarios. El objetivo de este trabajo es identificar las actividades de ocio que practican los estudiantes gallegos de Educación Secundaria Obligatoria (ESO), tanto entre semana como en fines de semana, y analizar la influencia del nivel de estudios de los progenitores en las actividades lúdicas que los adolescentes más realizan. MÉTODO. La metodología es de corte cuantitativo. Se ha aplicado un cuestionario elaborado ad hoc al alumnado de 1.º a 4.º de la ESO de centros educativos públicos y privados/concertados de Galicia, obteniendo 1.890 cuestionarios válidos. RESULTADOS. El ocio digital, ver la televisión y practicar deporte son las actividades que los adolescentes practican en mayormedida. Contrariamente, participar en asociaciones y voluntariado, así como asistir a actos culturalesson las actividades menos practicadas. En general, se evidencia que los adolescentes dedican más tiempo al ocio los fines de semana. En cuanto a la influencia del nivel de estudios de los progenitores, se constata que cuanto más alto es su nivel académico, menos tiempo dedican sus hijos/as al ocio digital y más al deporte y a la actividad física. Esta misma tendencia se observa en la lectura, actividad de ocio estudiada por su relación con el capital cultural. DISCUSIÓN. En líneas generales, los datos obtenidos coinciden con la literatura existente. Así, se presentan datos de otras investigaciones que reafirman, y en algún caso contradicen, estos resultados. En conclusión, la educación del ocio tiene un papel clave a la hora de alfabetizar el ocio de los adolescentes a fin de que transiten de la mera ocupación del tiempo libre al desarrollo de experienciasde ocio valiosas.
Routine group and save screening prior to emergency laparoscopic surgery
Authors: Alyacoubi S , Taj T , Raza I
Published: April 2021

Introduction

Two group and save (G&S) samples are routinely collected from patients undergoing diagnostic laparoscopy and/or emergency appendicectomy. We aimed to identify the necessity of this practice by looking at the perioperative transfusion rates.

Methods

Data were obtained from our electronic theatre system for all patients who underwent emergency laparoscopic surgery (specifically diagnostic laparoscopy and/or laparoscopic appendicectomy) between January 2017 and December 2018. Records were reviewed for the number of G&S samples sent and perioperative transfusion rates.

Results

A total of 451 patients were included in the study. The numbers of procedures performed in 2017 and 2018 were 202 (44.8%) and 249 (55.2%), respectively. The total number of samples sent was 930. Only 786 (84.5%) samples were processed and the rest were rejected for various reasons. Of the 451 patients included in the study, 308 (68.3%) had two G&S samples sent, whereas 41 patients (9.1%) had only one G&S sample sent. Fifty-six (12.4%) and 20 (4.4%) patients had three and four G&S samples sent, respectively. Only two patients required transfusion perioperatively (0.4%), and the indication in both was irrelevant to the primary operation.

Conclusions

These results demonstrate a near-zero transfusion rate in this patient cohort. Omitting G&S is safe and potentially saves time and resources.
The role of simulation in training breast surgeons: a systematic review
Authors: Kankam HKN , Lenti L , Razai MS , Hourston GJM , Khatib M
Published: April 2021

Background

As surgical education has evolved, most curricula have favoured a competency-based approach over traditional apprenticeship models. Surgical simulation can be a useful aide in the training of both oncological and reconstructive breast surgery trainees. This review investigates the extent to which simulation of breast surgery procedures has been validated as a training tool.

Methods

A comprehensive literature search for studies evaluating the objective validity of breast surgery simulators was performed, using MEDLINE, EMBASE and the Cochrane Library databases. Studies assessing construct, concurrent or predictive validity were included, as well as those demonstrating skill acquisition.

Findings

The initial literature search returned 1,625 hits, with only five articles meeting the inclusion criteria. Simulators were designed to train procedures such as breast augmentation, lesion biopsy and excision. Of these, breast biopsy was the most simulated procedure (three studies). Two studies evaluated animal models, two evaluated synthetic models and one study assessed both a synthetic and animal model. Construct validity was confirmed in two studies, concurrent validity in one study and a learning curve demonstrated in another study. No association between experience and performance was seen in the remaining study. The quality of the evidence presented in each article was low due to numerous limitations. Despite the abundance of breast surgery simulators created for trainees, few have been objectively validated and they only cover a narrow range of breast procedures. Although early results are promising, further studies are required before routine use of simulators is considered in breast surgery curricula.
El cine como herramienta didáctica en la escuela inclusiva
Authors: Mujika Joxe , Gaintza Zuriñe
Published: April 2021

El presente estudio se desarrolla en el marco de la escuela inclusiva y presenta los resultados de una experiencia innovadora del uso del cine para la asignatura de Educación Plástica, Visual y Audiovisual. El objetivo del estudio es informar y sensibilizar al alumnado sin discapacidad de la realidad y las necesidades que el alumnado con discapacidad visual (AcDv) presenta y, de esta forma, desarrollar actitudes positivas hacia dicho colectivo. Para medir la actitud, se administra un cuestionario con escala Likert a 31 adolescentes de 1º de la Educación Secundaria Obligatoria antes y después de la intervención. La intervención se desarrolla a lo largo de 4 horas y el núcleo de esta consiste en la proyección de una escena cinematográfica privando al alumnado del sentido de la vista y la posterior elaboración de un storyboard. Los resultados muestran que el alumnado presenta diferencias significativas en la actitud, tanto las chicas como los chicos mejoran la actitud hacia el AcDv. Con ello, se concluye que tanto la información proporcionada como el uso del cine con privación visual y la realización del storyboard aumentan el conocimiento y la sensibilidad hacia el AcDv y generan cambios de actitud hacia dicho colectivo.
Libro: Teatro en la educación (España, 1970-2018)
Authors: Navarro-Amorós Antoni
Published: April 2021

En este libro, Tomás Motos hace un estudio sobre lo que conocemos como Teatro en la Educación en España desde 1970 a 2018.  Este movimiento y metodología teatral, cuyos orígenes se remontan a algunos proyectos de trabajo conjunto entre actores y profesores llevados a cabo en Coventry (Reino Unido) en 1965, consiste, en esencia, en el uso de las técnicas teatrales para educar. El Teatro en la educación, con el tiempo, se ha ido convirtiendo en un término paraguas que ha ido cambiando de nombre a lo largo del periodo que abarca el estudio de este libro. Así han aparecido nomenclaturas como expresión dinámica, expresión dramática, teatro infantil, teatro juvenil, dramatización, taller de teatro, etc.La labor principal del autor, miembro de la Academia de Artes Escénicas de España y director del Máster en Teatro Aplicado (Universidad de Valencia) ha sido sistematizar la pedagogía teatral, sentar las bases epistemológicas del teatro en la educación y formar especialistas en teatro aplicado. Y con este libro busca poner al servicio de los especialistas y de los que se inician qué se ha hecho en la España contemporánea sobre Teatro en la Educación.
Pensamiento geográfico y educación ciudadana en Chile. Una mirada desde la educación geográfica.
Authors: Llancavil Llancavil Daniel , González Quitulef Hernán
Published: April 2021

La reciente reforma curricular del sistema escolar chileno, en los dos últimos niveles de Educación Secundaria, significó el surgimiento de la asignatura Educación Ciudadana. Uno de los enfoques de esta evidencia su vinculación con educación geográfica al considerar que la política y el ejercicio ciudadano se expresan en el espacio y que este, a su vez, es generador de limitantes y oportunidades para los ciudadanos. Por lo anterior, los objetivos de este artículo son analizar los aportes de la educación geográfica a la educación ciudadana y evaluar las posibilidades que ofrece esta relación para la formación de un pensamiento geográfico en estudiantes de Educación Secundaria en Chile. A partir de la revisión bibliográfica, es posible concluir que la educación geográfica contribuye a la educación ciudadana y que ambas tributan a formar ciudadanos responsables dotados de habilidades y actitudes que les permiten vincularse de manera activa y favorable con su espacio geográfico. Asimismo, contribuye a que los estudiantes puedan constituirse como ciudadanos territoriales que piensan geográficamente, capaces de reconocer y enfrentar problemas y conflictos socioespaciales desde la empatía, el respeto y la tolerancia.
Proyecto de innovación docente en geografía y educación ambiental para estudiantes con trastorno del espectro autista
Authors: Jerez García Óscar , Vera Díaz Claudia
Published: April 2021

Proponemos el diseño de un programa de Educación Ambiental (EA) para estudiantes con Trastorno del Espectro Autista (TEA) a través de actividades con Scratch e impartidas gracias a las Tecnologías de la Información y la Comunicación (TIC). El objetivo principal es diseñar y crear un material multimedia para mejorar el proceso de enseñanza-aprendizaje de estudiantes con TEA y contribuir a su formación para conocer la problemática actual en relación con el medio ambiente, actuar de forma responsable y respetar y cuidar la naturaleza. La metodología de este proyecto de innovación docente consta de cuatro partes (planteamiento inicial, marco teórico, metodología y diseño) que corresponden con las fases necesarias para diseñar el material. Se han analizado los resultados de unas encuestas orientadas a evaluar los conocimientos, intereses y actitudes sobre la problemática ambiental. A partir de estos resultados, se ha diseñado y desarrollado un recurso didáctico ajustado a la realidad socioambiental contextualizándola en un centro de educación especial de Ciudad Real, pero extrapolable a cualquier centro educativo. La situación que ha provocado el estado de alarma sanitaria en España, unido al interés de los estudiantes con TEA por los dispositivos electrónicos y las TIC, ha motivado la planificación de esta propuesta de intervención educativa resuelta con el diseño de material didáctico acorde al contexto.
The aesthetics of green guerrilla. From activism to fine art
Authors: Gralińska-Toborek Agnieszka
Published: April 2021

Los movimientos de base: - los activismos asociados con la ecologización de las ciudades, la recuperación de tierras baldías, el establecimiento de jardines comunitarios, la mejora de la calidad de vida en lugares industrializados a través de intervenciones menores basadas en la naturaleza, así como la protección y salvaguardia de los restos de la naturaleza dentro de las ciudades- lo que en este artículo llamo guerrilla verde.Quiero demostrar cómo crecen estos movimientos de base a pequeña escala; cómo sus acciones conducen a soluciones oficiales; cómo se institucionalizan y, a veces, se comercializan. Sin embargo, sobre todo, al vincularlas con las tendencias estéticas medioambientales yparticipativas, quiero indicar sus aspectos estéticos y el hecho de que con frecuencia llevan las señas del arte.
Heterodyne photothermal spectroscopy of methane near 1651 nm inside hollow-core fiber using a bismuth-doped fiber amplifier
Authors: Gomolka Grzegorz , Krajewska Monika , Khegai Aleksandr M. , Alyshev Sergey V. , Lobanov Aleksey S. , Firstov Sergei V. , Pysz Dariusz , Stepniewski Grzegorz , Buczynski Ryszard , Klimczak Mariusz , Nikodem Michal
Published: April 2021

We present laser-based methane detection near 1651 nm inside an antiresonant hollow-core fiber (HCF) using photothermal spectroscopy (PTS). A bismuth-doped fiber amplifier capable of delivering up to more than 160 mW at 1651 nm is used to boost the PTS signal amplitude. The design of the system is described, and the impact of various experimental parameters (such as pump source modulation frequency, modulation amplitude, and optical power) on signal amplitude and signal-to-noise ratio is analyzed. Comparison with similar PTS/HCF-based systems is presented. With 1.3 m long HCF and a fiber amplifier for signal enhancement, this technique is capable of detecting methane at single parts-per-million levels, which makes this robust in-fiber sensing approach promising also for industrial applications such as, e.g., natural gas leak detection.
Image reconstruction with the chaotic fiber laser in scattering media
Authors: Li Jia , Yang Ling Zhen , Ding Wei Jie , Zhan Mao Xuan , Fan Lin Lin , Wang Juan Fen , Shang Hui Feng , Ti Gang
Published: April 2021

The reconstruction of the size, position, optical properties, and structure of the object in scattering media was realized with a chaotic fiber laser. The light from the chaotic fiber laser was split into two parts. One part was used as the detection signal to detect the object, and the other was used as the reference signal; then, the two signals were cross correlated. The attenuation of light in scattering media was attributed to scattering and absorption. The theoretical model of the peak value of cross correlation of the chaotic signals as projection data were established by the attenuation law, and the filtered back-projection algorithms were used to realize the image reconstruction. The mean squared error, the normalized mean squared error, the peak signal-to-noise ratio, and the structural similarity index of the reconstructed image were analyzed. The results show that the high resolution of the reconstructed image benefits from the high signal-to-noise ratio with the chaotic fiber laser based on a delta-like cross-correlation function.
Curved waveguides in silicon written by a shaped laser beam
Authors: Wang Xinya , Yu Xiaoming , Berg Matthew J. , Chen Pingping , Lacroix Brice , Fathpour Sasan , Lei Shuting
Published: April 2021

We demonstrate, for the first time, the direct writing of curved optical waveguides in monocrystalline silicon with curve radii from 2 mm to 6 cm. The bending loss of the curved waveguides is measured and a good agreement with theoretical values is found. Raman spectroscopy measurements suggest the formation of inhomogeneous amorphous and polycrystalline phases in the laser-modified region. This direct laser-writing method may advance fabrication capabilities for integrated 3D silicon photonic devices.
Double-sided optical coating of strongly curved glass by atomic layer deposition
Authors: Gao Ling-Shan , Cai Qing-Yuan , Hu Er-Tao , Zhou Jing , Li Yao-Peng , Luo Hai-Han , Liu Bao-Jian , Zheng Yu-Xiang , Liu Ding-Quan
Published: April 2021

A reaction chamber of atomic layer deposition (ALD) was developed for simultaneous coating on the inner and outer surfaces of a large-size and strongly curved glass bowl. The inner surface ALD process was in a showerhead reaction mode and the outer surface ALD process was in a cross-flow reaction mode. Blue reflection (BR) film of 400 nm wavelength and broadband antireflection (BBAR) film of 400-700 nm wavelength were coated on different glass bowls by ALD. The spectral uniformity of both coated bowls was studied. The measured spectra at multiple positions of the glass bowl with the BBAR coating show better spectral uniformity along the circumference than the depth. The spectral deviation is mainly caused by the non-uniformity of the film on the outer surface (<±3%), and the film on the inner surface has good uniformity along both the circumference and the depth (<±0.7%). The growth rate of the outer film was reduced by 10% on average compared to that of the inner film due to the different gas flow mode.
Anomalous circular photogalvanic effect in p-GaAs
Authors: Wu Jing , Hao Hui ming , Liu Yu , Zhang Yang , Zeng Xiao lin , Zhu Shen bo , Niu Zhi chuan , Ni Hai qiao , Chen Yong hai
Published: April 2021

The anomalous circular photogalvanic effect (ACPGE) is observed in p-GaAs with a thickness of 2 μm at room temperature, in which circularly polarized light is used to inject spin-polarized carriers and the spin diffusion can generate a macroscopic detectable charge current due to the inverse spin Hall effect. The normalized ACPGE signals show first increasing and then decreasing with increasing the doping concentration. The role of the doping impurities is discussed by both extrinsic and intrinsic models, and both can well explain the variation of ACPGE with the doping concentration.
Twin curvilinear vortex beams
Authors: Wang Zhuang , Yuan Zheng , Gao Yuan , Yan Wenxiang , Liang Chunjuan , Ren Zhi-Cheng , Wang Xi-Lin , Ding Jianping , Wang Hui-Tian
Published: April 2021

We report on a novel curvilinear optical vortex beam named twin curvilinear vortex beams (TCVBs) with intensity and phase distribution along a pair of two- or three-dimensional curves, both of which share the same shape and the same topological charge. The TCVBs also possess the character of perfect optical vortex, namely having a size independent of topological charge. We theoretically demonstrate that a TCVB rather than a single-curve vortex beam can be created by the Fourier transform of a cylindrically polarized beam. The behavior of TCVBs generated through our method is investigated by simulation and experiment, including interference experiments for identifying the vortex property of the TCVBs. The TCVBs may find applications in optical tweezers, such as trapping low refractive index particles in the dark region between two curves and driving them moving along the curvilinear trajectory.
Microwave photonic radar system with ultra-flexible frequency-domain tunability
Authors: Wang Anle , Zheng Daikun , Du Shirui , Zhang Jin , Du Pengfei , Zhu Yong , Cong Wenshan , Luo Xiong , Wang Yalan , Dai Yitang
Published: April 2021

Both effective detection demand against diversified development of flight targets and remote sensing providing identifiable and fine target information all call for microwave radar system with flexible and ultra-wideband frequency-domain ability to provide more high-resolution and multi-source information. A microwave photonic radar system with theoretically full-band and ultra-wideband working ability is presented and experimentally demonstrated. An optical frequency operation module is employed in the transmitter to break the frequency-domain limitation on the emitted radar signal, while two types of optical mixing structures are switched to provide the ability to receive target echoes at any frequency band. In the experiments, high-SNR optical frequency operation and subsequent waveform generation at each normal radar band, that is from HF to Ka, are carried out. Good linearity and coherence of the generated waveforms are also demonstrated. Then, multi-band system-level detection experiments are completed to show the full-band working ability. Centimeter-scale or even sub-centimeter-scale resolution are realized at different bands, which identifies the proposed system can handle target detection with flexible performance and support acquiring rich target information at different frequency bands in future.
Reconfigurable magnetic near-field distributions based on the coding metasurfaces in MHz band
Authors: Li Guo , Guo Zhiwei , Ren Jie , Sun Yong , Jiang Haitao , Li Yunhui , Chen Hong
Published: April 2021

Magnetic near-field control has attracted extensive attention and have a wide range of applications in filters, sensors, and energy-transfer devices. Coding metamaterial has the convenience of miniaturization and integration, which not only provides a bridge between physics and information science, but also exploits a whole new perspective for magnetic near-field control. In this work, we theoretically propose and experimentally verify that the coding metasurface can realize the reconfigurable magnetic near-field distributions. By adjusting the digital voltage signals which drive the resonant units of metasurface, capacitance of the resonator can be dynamically controlled, thus the dynamic modulation of magnetic near-field distribution can be achieved. Specially, this magnetic near-field control can be explained with the help of coupled mode theory and coherent superposition method. Moreover, simulated annealing algorithm is employed to determine working frequency of the whole modulation system, which can avoid time-consuming frequency scanning process. The experimental results are in good agreement with the calculated results. This work reveals the significant potential of coding metasurface for the experimental study of the magnetic near-field control and promotes the use of metasurface for numerous integrated functional devices.
Gigahertz-bandwidth optical memory in Pr3+:Y2SiO5
Authors: Nicolle M. , Becker J. N. , Weinzetl C. , Walmsley I. A. , Ledingham P. M.
Published: April 2021

We experimentally study a broadband implementation of the atomic frequency comb (AFC) rephasing protocol with a cryogenically cooled

P
r

3
+

:

Y

2

S
i
O

5

crystal. To allow for storage of broadband pulses, we explore a novel, to the best of our knowledge, regime where the input photonic bandwidth closely matches the inhomogeneous broadening of the material

(
∼
5

G
H
z

)

, thereby significantly exceeding the hyperfine ground and excited state splitting

(
∼
10

M
H
z

)

. Through an investigation of different AFC preparation parameters, we measure a maximum efficiency of 10% after a rephasing time of 12.5 ns. With a suboptimal AFC, we witness up to 12 rephased temporal modes.
Secure key distribution based on bidirectional Michelson interferometers
Authors: Song Qiuheng , Lai Xin , Chen Yongchao , Peng Hekuo , Guo Jiachen , Wu Hongyan , Jia Bo
Published: April 2021

A scheme based on bidirectional Michelson interferometers to distribute secret keys through the phase of light wave is proposed and demonstrated. The structure uses two optical cable transmission schemes, lasers of short coherent length, random phase drift, polarization random disturbance, and vibration positioning technology to ensure the safe transmission of the secret key. The feasibility of 80 km secret key transmission is verified by experiments. When the secret key is transmitted at the frequency of 200 kHz, the bit error rate is less than 0.3%, and the disturbance positioning accuracy is within

±

100

m

.
High-temperature reliable quantum-dot lasers on Si with misfit and threading dislocation filters
Authors: Shang Chen , Hughes Eamonn , Wan Yating , Dumont Mario , Koscica Rosalyn , Selvidge Jennifer , Herrick Robert , Gossard Arthur C. , Mukherjee Kunal , Bowers John E.
Published: April 2021

Direct epitaxial growth of III-V light sources on Si photonic chips is promising to realize low-cost and high-functionality photonic integrated circuits. Historically, high temperature reliability of such devices has been the major roadblock due to crystalline defects from heteroepitaxy. Here, by reducing the threading dislocation densities to

∼

1

×

1

0

6

c

m

−
2

and efficiently removing misfit dislocations above and below the active region, 1.3 µm InAs quantum-dot lasers directly grown on industry standard on-axis Si (001) show record-breaking reliability at 80°C. The hero device shows minimum degradation after more than 1200 h of constant current stress. Statistical analysis shows an extrapolated lifetime of over 22 years for the median devices, bringing these devices one big step closer to real world applications.
All-optical pulse peak power stabilization and its impact in phase-OTDR vibration detection
Authors: Vanus Benoit , Baker Chams , Chen Liang , Bao Xiaoyi
Published: April 2021

We present an all-optical technique for the stabilization of laser power using the nonlinear Kerr effect and experimentally demonstrate improvement of vibration recovery in direct-detection phase-sensitive optical time domain reflectometry (Φ-OTDR). A pulsed or continuous wave optical signal impressed with a sinusoidal modulation generates sidebands while experiencing self-phase modulation in a nonlinear medium which can be utilized to stabilize the peak power of the signal. By adjusting the peak power at the entrance of the Kerr medium, the signal created at the first order sideband exhibits reduced peak power fluctuations and can be extracted using a band-pass filter. Experimental results show that the generated pulses with stabilized peak power improve vibration detection in a Φ-OTDR with a direct-detection scheme. This technique can be combined with other performance enhancement techniques to allow for the detection of weak signals, and reduces the need of an optoelectronic-based power control loop on a fiber laser.
VolPy: Automated and scalable analysis pipelines for voltage imaging datasets
Authors: Cai Changjia , Friedrich Johannes , Singh Amrita , Eybposh M. Hossein , Pnevmatikakis Eftychios A. , Podgorski Kaspar , Giovannucci Andrea
Published: April 2021

Voltage imaging enables monitoring neural activity at sub-millisecond and sub-cellular scale, unlocking the study of subthreshold activity, synchrony, and network dynamics with unprecedented spatio-temporal resolution. However, high data rates (>800MB/s) and low signal-to-noise ratios create bottlenecks for analyzing such datasets. Here we present VolPy, an automated and scalable pipeline to pre-process voltage imaging datasets. VolPy features motion correction, memory mapping, automated segmentation, denoising and spike extraction, all built on a highly parallelizable, modular, and extensible framework optimized for memory and speed. To aid automated segmentation, we introduce a corpus of 24 manually annotated datasets from different preparations, brain areas and voltage indicators. We benchmark VolPy against ground truth segmentation, simulations and electrophysiology recordings, and we compare its performance with existing algorithms in detecting spikes. Our results indicate that VolPy’s performance in spike extraction and scalability are state-of-the-art.
The gut virome of healthy children during the first year of life is diverse and dynamic
Authors: Taboada Blanca , Morán Patricia , Serrano-Vázquez Angélica , Iša Pavel , Rojas-Velázquez Liliana , Pérez-Juárez Horacio , López Susana , Torres Javier , Ximenez Cecilia , Arias Carlos F.
Published: April 2021

In this work, we determined the diversity and dynamics of the gut virome of infants during the first year of life. Fecal samples were collected monthly, from birth to one year of age, from three healthy children living in a semi-rural village in Mexico. Most of the viral reads were classified into six families of bacteriophages including five dsDNA virus families of the orderCaudovirales, withSiphoviridaeandPodoviridaebeing the most abundant. Eukaryotic viruses were detected as early as two weeks after birth and remained present all along the first year of life. Thirty-four different eukaryotic virus families were found, where eight of these families accounted for 98% of all eukaryotic viral reads:Anelloviridae,Astroviridae,Caliciviridae,Genomoviridae,Parvoviridae,Picornaviridae,Reoviridaeand the plant-infecting viruses of theVirgaviridaefamily. Some viruses in these families are known human pathogens, and it is surprising that they were found during the first year of life in infants without gastrointestinal symptoms. The eukaryotic virus species richness found in this work was higher than that observed in previous studies; on average between 7 and 24 virus species were identified per sample. The richness and abundance of the eukaryotic virome significantly increased during the second semester of life, probably because of an increased environmental exposure of infants with age. Our findings suggest an early and permanent contact of infants with a diverse array of bacteriophages and eukaryotic viruses, whose composition changes over time. The bacteriophages and eukaryotic viruses found in these children could represent a metastable virome, whose potential influence on the development of the infant’s immune system or on the health of the infants later in life, remains to be investigated.
Rewarding behavior with a sweet food strengthens its valuation
Authors: Bauer Jan M. , Schröder Marina , Vecchi Martina , Bake Tina , Dickson Suzanne L. , Belot Michèle
Published: April 2021

Sweet foods are commonly used as rewards for desirable behavior, specifically among children. This study examines whether such practice may contribute to reinforce the valuation of these foods. Two experiments were conducted, one with children, the other with rats. The first study, conducted with first graders (n = 214), shows that children who receive a food reward for performing a cognitive task subsequently value the food more compared to a control group who received the same food without performing any task. The second study, conducted on rats (n = 64), shows that rewarding with food also translates into higher calorie intake over a 24-hour period. These results suggest that the common practice of rewarding children with calorie-dense sweet foods is a plausible contributing factor to obesity and might therefore be ill advised.
Recreationist willingness to pay for aquatic invasive species management
Authors: Levers Lucia R. , Pradhananga Amit K.
Published: April 2021

We estimated willingness to pay for local aquatic invasive species lake management in the form of a daily lake access fee by conducting summer lake surveys in Minnesota, USA. Similar pairs of lakes with differing infestations of zebra mussels, Dreissena polymorpha, and starry stonewort, Nitellopsis obtuse, were used as study sites to infer how being at an infested lake vs. being at an uninfested lake and different local species would impact responses. We also examined recreationists’ visit motivation, and aquatic invasive species perceived risk, knowledge, and awareness of problem. We estimated mean willingness to pay about nine to ten dollars per day, which did not differ significantly by lake. Additionally, perceived risk, awareness of problem, and visit motivation were significant in predicting willingness to pay, which could have important ramifications for aquatic invasive species management.
Archaeological science meets Māori knowledge to model pre-Columbian sweet potato (Ipomoea batatas) dispersal to Polynesia’s southernmost habitable margins
Authors: Barber Ian G. , Higham Thomas F. G.
Published: April 2021

Most scholars of the subject consider that a pre-Columbian transpacific transfer accounts for the historical role of American sweet potato Ipomoea batatas as the kūmara staple of Indigenous New Zealand/Aotearoa Māori in cooler southwestern Polynesia. Archaeologists have recorded evidence of ancient Polynesian I. batatas cultivation from warmer parts of generally temperate-climate Aotearoa, while assuming that the archipelago’s traditional Murihiku region in southern South Island/Te Waipounamu was too cold to grow and store live Polynesian crops, including relatively hardy kūmara. However, archaeological pits in the form of seasonal Māori kūmara stores (rua kūmara) have been discovered unexpectedly at Pūrākaunui on eastern Murihuku’s Otago coast, over 200 km south of the current Polynesian limit of record for premodern I. batatas production. Secure pit deposits that incorporate starch granules with I. batatas characteristics are radiocarbon-dated within the decadal range 1430–1460 CE at 95% probability in a Bayesian age model, about 150 years after Polynesians first settled Te Waipounamu. These archaeological data become relevant to a body of Māori oral history accounts and traditional knowledge (mātauranga) concerning southern kūmara, incorporating names, memories, landscape features and seemingly enigmatic references to an ancient Murihiku crop presence. Selected components of this lore are interpreted through comparative exegesis for correlation with archaeological science results in testable models of change. In a transfer and adaptation model, crop stores if not seasonal production technologies also were introduced from a warmer, agricultural Aotearoa region into dune microclimates of 15th-century coastal Otago to mitigate megafaunal loss, and perhaps to support Polynesia’s southernmost residential chiefdom in its earliest phase. A crop loss model proposes that cooler seasonal temperatures of the post-1450 Little Ice Age and (or) political change constrained kūmara supply and storage options in Murihiku. The loss model allows for the disappearance of kūmara largely, but not entirely, as a traditional Otago crop presence in Māori social memory.
Learning about COVID-19-related stigma, quarantine and isolation experiences in Finland
Authors: Lohiniva Anna-Leena , Dub Timothee , Hagberg Lotta , Nohynek Hanna
Published: April 2021

Background

The COVID-19 pandemic has intensely changed the everyday lives of people worldwide. This study explores the forms and outcomes of coronavirus and COVID-19-related social stigma and the experiences of people who were home quarantined or isolated in Finland during the spring 2020. The findings of this study can be used to improve support for those quarantined or isolated and to develop strategies to reduce the stigma associated with coronavirus and COVID-19.

Methods

The study is based on qualitative one-to-one interviews with households with at least two members and at least one PCR confirmed COVID-19 case. Recruitment took place via website or SMS messages sent to PCR confirmed cases in the capital area of Helsinki. Sampling was based on maximum variation to acquire different types of respondents. The framework of health stigma was used to develop question guides and analyze stigma. Quarantine and isolation experiences were explored through open-ended questions. The analysis was based on thematic analysis.

Results

The study included 64 participants from 24 households. Perceived stigma among respondents was driven by fear and blame for infection, and it manifested in various ways leading to a reluctance to disclose their coronavirus status to others. Self-stigma developed from conflicting information and advice about coronavirus and COVID-19 led to difficulties interacting with others outside of the house and reluctance to meet people after quarantine and isolation. Quarantine and isolation experiences included uncertainty, health concerns, and boredom. Communication with others in similar situations was perceived vital, whereas discussions with family members about worries and fears related to coronavirus and COVID-19 was not preferred.

Conclusions

This study shed light on the lives of those quarantined or isolated at home and provided a set of operational recommendations to minimize coronavirus and COVID-19-associated stigma and to reduce challenges faced by those in quarantine or isolation.