bluuebunny/crossref_metadata_2025 huggingface dataset:
UWB quadruplet signal generation based on a DP–QPSK modulator and a delay-line filter
Authors: Du Cong , Liu Fangming , Li Xiang , Zhang Zhenguo , Dong Wei
Published: April 2020

A photonic ultra-wideband (UWB) quadruplet signal generation based on a
dual-polarization quadrature phase shift keying (DP–QPSK) modulator is
presented. A Gaussian sequence is split into four parts and input to
the four driving ports of the DP–QPSK. Through polarization rotation
and polarization combination, a pair of polarization-orthogonal,
polarity-reversed doublet signals are generated from the output of the
DP–QPSK modulator. Subsequently, they are injected into a balanced
photodetector (BPD) for further differentiation. After the heterodyne
detection, a UWB quadruplet signal can be obtained. In this system,
four electrical amplifiers are incorporated into the four electrical
driving paths to adjust the modulation indices of the DP–QPSK. To
attain the optimal spectral power efficiency (SPE), a relationship
among the SPE, pulse width, delay time, and the two main modulation
indices is created. Consequently, the optimal point is found with an
SPE of 53.46%. Then, several impairments brought by the nonideal
devices are considered in the simulation system. The distortion caused
by impairments is compensated by properly adjusting the devices. The
generated spectrum has a SPE of 53.38% and efficiently complies with
the Federal Communications Commission (FCC) mask without any
low-frequency components exceeding the FCC mask. In addition, on–off
keying and pulse position modulation are realized in the system.
Numerical study on the scattering property of porous polymer structures via supercritical CO2 microcellular foaming
Authors: Yu Shudong , Yu Jiadong , Chen Junchi , Ding Xinrui , Li Jiasheng , Rao Longshi , Tang Yong , Li Zongtao
Published: April 2020

Disordered porous polymer structures have gained tremendous attention
due to their wide applications in various fields. As a simple yet
versatile technique, supercritical

C
O

2

microcellular foaming has been
proposed to fabricate highly scattering porous polymer films, which
have been used to enhance the efficiency of quantum dots (QDs) films.
In the foaming process, numerous enclosed pores are generated, which
induce significant scattering, underpinning the efficiency enhancement
in optoelectronic devices. However, the scattering property of foamed
porous structures has still not been well investigated, and effective
guidelines for engineering the porous structures are still not
available. In this work, we use Mie scattering theory and ray-tracing
simulation to analyze the optical property of a single pore, pore
assembly, and porous film. Furthermore, it is demonstrated that the
scattering scheme in the porous QD films leads to a large enhancement
of excitation light absorption and QD emission extraction. It is
envisioned that our work will contribute to the engineering guidelines
of porous structures and boost the application of porous structures in
similar fields.
Use of embedded and patterned dichroic surfaces with reflective optical power to enable multiple optical paths in a micro-objective
Authors: Vega David , Sawyer Travis W. , Pham Nancy Y. , Barton Jennifer K.
Published: April 2020

We demonstrate the use of patterned dichroic surfaces with reflective optical power to create multiple optical paths in a single lens system. The application of these surfaces enables a micro-endoscope to accommodate multiple imaging technologies with only one optical system, making the packaging more compact and reliable. The optical paths are spectrally separated using different wavelengths for each path. The dichroic surfaces are designed such that the visible wavelengths transmit through the surfaces optically unaffected, but the near-infrared wavelengths are reflected in a telescope-like configuration with the curved dichroic surfaces providing reflective optical power. We demonstrate wide-field visible monochromatic imaging and microscopic near-infrared imaging using the same set of lenses. The on-axis measured resolution of the wide-field imaging configuration is approximately 14 µm, and the measured resolution of the microscopic imaging configuration is approximately 2 µm. Wide-field white-light imaging of an object is also demonstrated for a qualitative perspective on the imaging capabilities. Other configurations and applications in fields such as optical metrology are discussed to expand on the versatility of the demonstrated optical system.
Remitted photon path lengths in human skin: in-vivo measurement data
Authors: Lukinsone V. , Maslobojeva A. , Rubins U. , Kuzminskis M. , Osis M. , Spigulis J.
Published: April 2020

The remitted photon path lengths in human skin can be estimated by modelling; however, there are very few experimental data available to validate the simulations. This study exploited the photon time of flight method where picosecond laser pulses at seven wavelength bands in the spectral range 560-800 nm were launched into in-vivo forearm skin of 10 volunteers via an optical fiber. The pulses of back-scattered light were detected via another optical fiber placed at variable distance (1, 8, 12, 16 or 20 mm) from the input fiber, with subsequent analysis of their shapes for all 35 spectral-spatial combinations. Using a deconvolution algorithm, the distribution functions of remitted photon arrival times after infinitely narrow input pulse were calculated and transformed into distributions of skin-remitted photon path lengths. Nearly linear dependences of the remitted photon mean path length on inter-fiber distance were obtained for all wavelength bands, while the spectral dependences at fixed inter-fiber distances showed more complicated character, most probably due to absorption of the dermal hemoglobin.
ERON: an energy-efficient and elastic RF-optical architecture for mmWave 5G radio access networks
Authors: Lu Hongbo , Proietti Roberto , Liu Gengchen , Chen Xiaoliang , Yoo S. J. Ben
Published: April 2020

This paper proposes an elastic RF-optical networking (ERON) architecture solution for millimeter wave (mmWave) 5G radio access networks. The ERON architecture achieves energy efficiency and throughput elasticity using photonic-enhanced multibeam mmWave spatial multiplexing capability at the radio units. The centralization of the hardware resources and the converged management of the RF and optical resources in the data units offer high resource pooling gain. A numerical study on the energy efficiency of ERON’s photonic-enabled mmWave 5G system reveals that ERON is 5× more energy efficient than both conventional digital and hybrid RF beam-forming implementations. We also conducted a user mobility-aware network resources study, and the results show a 10 dB network resource pooling gain when compared to classic radio access network implementations.
Ranging performance model considering the pulse pileup effect for PMT-based photon-counting lidars
Authors: Zhang Zhiyu , Ma Yue , Li Song , Zhao Pufan , Xiang Yuyan , Liu Xinyuan , Zhang Wenhao
Published: April 2020

Currently, the ranging performance model for a photomultiplier tube (PMT)-based photon-counting lidar assumes the dead time is a fixed value for simplicity. This assumption introduces a bias in evaluating the ranging performance for a given PMT-based lidar because the dead time of PMTs is actually changeably caused by the pulse pileup effect. In this paper, the changeable dead time is calculated by a new empirical equation based on the Monte Carlo simulation. The empirical equation of the dead time is then used to derive the ranging performance model for PMT-based PC lidar systems. The proposed model is verified by an experimental lidar system equipped with a PMT and utilized to quantitatively analyze the influence of factors, such as the noise rate, discrimination threshold, signal intensity, and receiving pulse width. The result indicates that the receiving pulse width has a major influence, and when it exceeds 10 ns, the pulse pileup effect will introduce biases of more than 5 cm if the conventional model (ignoring the pulse pileup effect) is used. For a spaceborne lidar at an altitude of several hundred kilometers, the receiving pulse width will be significantly stretched when lasers illuminate on sloping surfaces, e.g., for a sloping surface larger than 2 degrees, so the effect of pulse pileup effect will have to be taken into consideration.
Deep learning–enhanced fluorescence microscopy via degeneration decoupling
Authors: Liu Jiahao , Huang Xiaoshuai , Chen Liangyi , Tan Shan
Published: April 2020

Deep learning–based reconstruction has emerged as an effective tool in fluorescence microscopy, with the potential to resolve diffraction-limited structures. However, most deep-learning reconstruction methods employed an end-to-end strategy, which ignored physical laws in the imaging process and made the preparation of training data highly challenging as well. In this study, we have proposed a novel deconvolution algorithm based on an imaging model, deep-learning priors and the alternating direction method of multipliers. This scheme decouples the reconstruction into two separate sub-problems, one for deblurring and one for restraining noise and artifacts. As a result of the decoupling, we are able to introduce deep-learning image priors and a variance stabilizing transform against targeted image degeneration due to the low photon budget. Deep-learning priors are learned from the general image dataset, in which biological images do not have to be involved, and are more powerful than hand-designed ones. Moreover, the use of the imaging model ensures high fidelity and generalization. Experiments on various kinds of measurement data show that the proposed algorithm outperforms existing state-of-the-art deconvolution algorithms in resolution enhancement and generalization.
Correlation between turbulence-impacted optical signals collected via a pair of adjacent spatial-mode receivers
Authors: Chen Chunyi , Yang Huamin
Published: April 2020

Optical spatial-mode reception has a physical nature quite different from that of the traditional optical power-in-the-bucket (PIB) reception. The former belongs to coherent reception scheme while the latter pertains to incoherent reception scheme. Under weak-turbulence conditions, the statistical correlation between turbulence-impacted optical signals collected by a pair of adjacent spatial-mode receivers is mathematically formulated in terms of a new theoretical framework that takes into account the distinctive nature of the spatial-mode reception. The aperture Fresnel number, coherence Fresnel number, separation Fresnel number and mode Fresnel number are identified as fundamental determinative parameters in evaluation of the correlation coefficient. With the help of the obtained formulations, two analytical asymptotic formulae for the correlation coefficient are further derived under the conditions that the aperture Fresnel number is much smaller than the coherence Fresnel number and separation Fresnel number, respectively. Despite the use of asymptotic approximations in the theoretical derivation, it is found that the two asymptotic formulae indeed have utility in many situations of practical interest to us. Furthermore, Monte-Carlo-simulation-based calculations are carried out to examine the accuracy of employing the two asymptotic formulae to approximate the correlation coefficient. It is shown that the ranges of applicability of these two asymptotic formulae are mainly determined by the coherence Fresnel number and the ratio of the separation Fresnel number to the aperture Fresnel number, basically irrespective of the mode Fresnel number.
Confocal Bragg ptychography for bulk specimens: a numerical demonstration
Authors: Pedersen Anders Filsøe , Chamard Virginie , Poulsen Henning Friis
Published: April 2020

We report on a new X-ray imaging method, which generalizes Bragg ptychography to 3D mapping of embedded crystalline volumes within thick specimens. The sample is probed by a pencil X-ray beam. The diffracted beam is magnified by an objective and passes through a slit in the image plane to be monitored by a 2D detector in the far-field of the image plane. The dimensions of the incoming beam and the slit opening define a confocal Bragg volume. Scanning the sample with respect to this probe volume, an iterative oversampling routine is used to reconstruct the shape and projected displacement field of extended internal volumes. This routine takes into account the pupil function and known aberrations of the lens. We demonstrate the method by a numerical study of a 3.5 µm grain comprising a wall of edge dislocations. With a probe volume of ∼0.12 µm3 and a compound refractive lens with a numerical aperture of 0.49×10−3 as the objective, the dislocations are fully resolved with a displacement sensitivity of ∼10 pm. The spatial resolution is 26×27×123 nm3 (rms), with the poor resolution along the optical axis being limited by the probe size. With a four times larger numerical aperture, the resolution becomes 16×8×123 nm3 (rms). The lens aberrations are found to be not critical.
Biases from incorrect reflectance convolution
Authors: Burggraaff Olivier
Published: April 2020

Reflectance, a crucial earth observation variable, is converted from hyperspectral to multispectral through convolution. This is done to combine time series, validate instruments, and apply retrieval algorithms. However, convolution is often done incorrectly, with reflectance itself convolved rather than the underlying (ir)radiances. Here, the resulting error is quantified for simulated and real multispectral instruments, using 18 radiometric data sets (N = 1799 spectra). Biases up to 5% are found, the exact value depending on the spectrum and band response. This significantly affects extended time series and instrument validation, and is similar in magnitude to errors seen in previous validation studies. Post-hoc correction is impossible, but correctly convolving (ir)radiances prevents this error entirely. This requires publication of original data alongside reflectance.
High-resolution imaging system with an annular aperture of coded phase masks for endoscopic applications
Authors: Dubey Nitin , Rosen Joseph , Gannot Israel
Published: April 2020

Partial aperture imaging is a combination of two different techniques; coded aperture imaging and imaging through an aperture that is only a part of the complete disk, commonly used as the aperture of most imaging systems. In the present study, the partial aperture is a ring where the imaging through this aperture resolves small details of the observed scene similarly to the full disk aperture with the same diameter. However, unlike the full aperture, the annular aperture enables using the inner area of the ring for other applications. In this study, we consider the implementation of this special aperture in medical imaging instruments, such as endoscopes, for imaging internal cavities in general and of the human body in particular. By using this annular aperture, it is possible to transfer through the internal open circle of the ring other elements such as surgical tools, fibers and illumination devices. In the proposed configuration, light originated from a source point passes through an annular coded aperture and creates a sparse, randomly distributed, intensity dot pattern on the camera plane. A combination of the dot patterns, each one recorded only once, is used as the point spread hologram of the imaging system. The image is reconstructed digitally by cross correlation between the object intensity response and the point spread hologram.
Dual-controlled broadband terahertz absorber based on graphene and Dirac semimetal
Authors: Xiong Han , Ji Qing , Bashir Tahir , Yang Fan
Published: April 2020

We proposed a dual-controlled broadband terahertz (THz) absorber based on graphene and Dirac semimetal. Calculated results show that the absorptance over 90% is achieved in the frequency range of 4.79-8.99 THz for both transverse electric (TE) and transverse magnetic (TM) polarizations. Benefiting from the advantage of the dielectric constant of these materials varying with chemical doping or gate voltage, the simulation results exhibit that the absorbance bandwidth can be controlled independently or jointly by varying the Fermi energy of the graphene or Dirac semimetal patterns instead of redesigning the absorbers. Impedance matching theory was introduced to analyze the absorption spectra changing with EF. The bandwidth and absorptivity of the proposed absorber are almost independent of changing the incident angle θ up to 35° and 40° for TE and TM modes, respectively. It works well even at a larger incident angle. Because of the symmetry of the structure, this designed absorber is polarization insensitive and almost the same absorptivity for both polarizations. Furthermore, the physical mechanisms were further disclosed by the electric field distributions. The proposed broadband and dual-controlled absorber may have potential applications in various fields of high-performance terahertz devices.
Dual-toroidal dipole excitation on permittivity-asymmetric dielectric metasurfaces
Authors: Liu Xingguang , Li Junqing , Zhang Qiang , Wang Yixiao
Published: April 2020

Magnetic and electric toroidal dipoles possess interesting properties differing from traditional electric and magnetic dipoles. In order to generate both the magnetic and electric toroidal dipoles simultaneously in one single structure, a permittivity-asymmetric dielectric metasurface is proposed, which is composed of clusters of four high-index dielectric nano-disks with asymmetric permittivity distribution. These two types of toroidal dipole responses can be separately observed at different spectral positions. This study reveals that symmetry-breaking in a broad sense is crucial for exciting toroidal responses, and the proposed metasurface points to a unique routine of exciting and enhancing the toroidal responses, which may be used to realize efficient light–matter interaction in the area of meta-optics.
ErAs:In(Al)GaAs photoconductor-based time domain system with 4.5  THz single shot bandwidth and emitted terahertz power of 164  µW
Authors: Nandi Uttam , Dutzi Katja , Deninger Anselm , Lu Hong , Norman Justin , Gossard Arthur C. , Vieweg Nico , Preu Sascha
Published: April 2020

Superlattice structures of In(Al)GaAs with localized ErAs trap centers feature excellent material properties for terahertz (THz) generation and detection. The carrier lifetime of these materials as emitter and receiver has been measured as 1.76 ps and 0.39 ps, respectively. Packaged photoconductors driven by a 1550 nm, 90 fs commercial Toptica “TeraFlash pro” system feature a 4.5 THz single shot bandwidth with more than 60 dB dynamic range. The emitted THz power of the ErAs:In(Al)GaAs emitter versus laser power has been recorded with a pyroelectric detector calibrated by the Physikalisch Technische Bundesanstalt (PTB). The maximum power was 164 µW at a laser power of 42 mW and a bias of 200 V.
High-speed 1D Raman analyzer for temperature and major species measurements in a combustion environment
Authors: Yang Chaobo , Tang Hao , Magnotti Gaetano
Published: April 2020

In this Letter, we demonstrate a 5 kHz 1D Raman instrument for temporally and spatially resolved quantitative measurements of temperature and all the major species (

N

2

,

O

2

,

H

2

, and

H

2

O

) concentration in

H

2

-air flames. The major constituents of the system are a pulse-burst laser operated at 5 kHz and four back-illuminated CCD cameras operated in subframe burst-gating mode. The use of CCD cameras allows achieving a high sampling rate with no compromise on instrument precision, but it requires one camera for each species of interest. A cascade of dichroic mirrors and bandpass filters spectrally separates the Raman signal associated with each of the four species and directs it to a separate camera. Measurements in a well-characterized

H

2

-air premixed flat flame show that the system has precision comparable with the low-speed Raman system. The measuring uncertainty of the species mole fraction ranges between 1% (

N

2

) and

3

∼

4
%

(

O

2

in lean flames). Measurements in laminar and turbulent

H

2

/

N

2

jet flames show good agreement with the theoretical prediction. By measuring all species simultaneously, important combustion quantities such as the mixture fraction are also derived.
Multiplexed polarized hypodermic Raman needle probe for biostructural analysis of articular cartilage
Authors: Jensen Magnus , Horgan Conor C. , Vercauteren Tom , Albro Michael B. , Bergholt Mads S.
Published: April 2020

In this Letter, we report a multiplexed polarized hypodermic Raman needle probe for the biostructural analysis of articular cartilage. Using a custom-developed needle probe with a sapphire ball lens, we measure polarized Raman spectra of cartilage. By imaging two polarizations simultaneously on the charge-coupled device (CCD) and binning them separately, we capture both biochemical and structural tissue information in real time. Here, we demonstrate that polarized Raman spectroscopy can distinguish between different collagen fibril alignment orientations in a cartilage explant model system, supporting its capacity for diagnosing the hallmark collagen alignment changes occurring in the early stages of osteoarthritis (OA). Accordingly, this work shows that needle-based polarized Raman spectroscopy has great potential for the monitoring and diagnosis of early OA.
Team 10’s discourse and Madrid architecture of the second phase of modernity
Authors: Guerrero Salvador
Published: April 2020

Madrid architects of the 20th century had little inclination, if any, to be gregarious. Remember their token presence in the first International Congresses of Modern Architecture (CIAM), a presence which had altogether vanished by the time of the fourth CIAM conference, which took place aboard the S.S. Patris. The only Spaniards we find in Athens in the summer of 1933 are Raimon Torres Clavé, Josep Lluís Sert, Antonio Bonet Castellana, Josep Torres Clavé, and Cristófol Alzamora. There is no sign of architects from Madrid. So who explained Madrid as a functional city?
2nd Reuse of Modernist Buildings Workshop
Authors: Moniz Gonçalo Canto , Providência Paulo , Melenhorst Michel
Published: April 2020

After the 1st RMB Student Workshop 2017 in the region of Marl (Germany), the 2nd edition worked in Coimbra, a historical university city in the centre of Portugal. In April 2018, the Reuse of Modernist Buildings (RMB) project, financed by ERASMUS+, organized the 2nd RMB Workshop to rethink the urban areas developed according to the De Groer Urban Plan of 1940.
Verified Interval Enclosure Techniques for Robust Gain Scheduling Controllers
Authors: Kersten Julia , Rauh Andreas , Aschemann Harald
Published: April 2020

In real-life applications, dynamic systems are often subject to uncertainty due to model simplifications, measurement inaccuracy or approximation errors which can be mapped to specific parameters. Uncertainty in dynamic systems can come either in stochastic forms or as interval representations, when they are considered as bounded as it will be done in this paper. The main idea, here, is to find a joint approach for an interval-based gain scheduling controller while simultaneously reducing overestimation by enclosing state intervals with the least amount of conservativity. The robust and/ or optimal control design is realized using linear matrix inequalities (LMIs) to find an efficient solution and aims at a guaranteed stabilization of the system dynamics over a predefined time horizon. Since the resulting system is assumed to be asymptotically stable, a temporal reduction of the widths of intervals representing worst-case bounds of the system states at a specific point of time should occur. However, for commonly used approaches in the computation of interval enclosures those interval widths seemingly blow up due to the wrapping effect in many cases. To avoid this, we provide two interval enclosure techniques --- an exploitation of cooperativity and an exponential approach --- and discuss their applicability taking into account two real-life applications, a high-bay rack feeder and an inverse pendulum.
Interval Predictors for a Class of Uncertain Discrete-Time Systems
Authors: Meslem Nacim , Martinez John
Published: April 2020

This work presents set-valued algorithms to compute tight interval predictions of the state trajectories for a certain class of uncertain dynamical systems. Based on interval analysis and the analytic expression of the state response of discrete-time linear systems, non-conservative numerical schemes are proposed. Moreover, under some stability conditions, the convergence of the width of the predicted state enclosures is proved. The performance of the proposed set-valued algorithms are illustrated through two numerical examples and the results are compared to that obtained with an other method selected from the literature.
Reliable Bounding Zones and Inconsistency Measures for GPS Positioning using Geometrical Constraints
Authors: Dbouk Hani , Schön Steffen
Published: April 2020

Reliable confidence domains for Global Navigation Satellite System (GNSS) positioning and inconsistency measures of the observations are of great importance for any navigation system, especially for safety critical applications. In this work, deterministic error bounds are introduced in form of intervals to assess remaining observation errors. The intervals can be computed based on expert knowledge or based on a sensitivity analysis of the measurement correction process. Using convex optimization, bounding zones are computed for GPS positioning using the geometrical constraints imposed by the observation intervals. The bounding zone is a convex polytope, where exploiting only the navigation geometry, confidence domain is computed in form of zonotope. We show that the relative volume between the polytopes and the zonotope is an inconsistency measures. Small polytope volume indicates bad consistency of the observations. In extreme cases empty sets are obtained which indicates large outliers. We determine the observation intervals via sensitivity analysis of the Klobuchar ionospheric model and Saastamoinen tropospheric model. The remaining errors are treated as white noise. We explain how the shape and the volume of the polytope are related to the positioning geometry. We show that this assignment has to be interpreted with care. Furthermore, we propose a new concept of Minimum Detectable Biases (MDB). Taking GPS data from simulations and real experiments, a comparison analysis between the proposed deterministic bounding method and the classical least-squares adjustment has been conduct in terms of accuracy and reliability. This helps validating that our proposed deterministic bound methods shows high internal and external reliability compared to the probabilistic approaches and that it provides rigorous inconsistency measures.
Reliable Visual Analytics, a Prerequisite for Outcome Assessment of Engineering Systems
Authors: Luther Wolfram , Auer Ekaterina , Weyers Benjamin
Published: April 2020

Various evaluation approaches exist for multi-purpose visual analytics (VA) frameworks. They are based on empirical studies in information visualization or on community activities, for example, VA Science and Technology Challenge (2006-2014) created as a community evaluation resource to 'decide upon the right metrics to use, and the appropriate implementation of those metrics including datasets and evaluators'. In this paper, we propose to use evaluated VA environments for computer-based processes or systems with the main goal of aligning user plans, system models and software results. For this purpose, trust in VA outcome should be established, which can be done by following the (meta-)design principles of a human-centered verification and validation assessment and also in dependence on users' task models and interaction styles, since the possibility to work with the visualization interactively is an integral part of VA. To define reliable VA, we point out various dimensions of reliability along with their quality criteria, requirements, attributes and metrics. Several software packages are used to illustrate the concepts.
Aportes da ecologia política para a construção de uma educação ambiental de base comunitária no contexto latino-americano: narrando a experiência de um Curso de Extensão Universitária
Authors: Sánchez Celso , Salgado Stephanie Di Chiara , De Oliveira Sônia Terezinha
Published: April 2020

Este trabalho pretende trazer aportes para consolidação de uma Educação Ambiental (EA) de Base Comunitária, que vem sendo formulada a partir dos acúmulos de pesquisa do Grupo de Estudos em Educação Ambiental desde el Sur (GEASur), através do diálogo entre o campo da EA Crítica em articulação com a Ecologia Política Latino-Americana e a Educação Popular. Para tal, iremos descrever e discutir a experiência de um curso de extensão oferecido pela Universidade Federal do Estado do Rio de Janeiro (UNIRIO), através do GEASur, que ocorreu de 2017 a 2019, em três edições. Para tanto, refletiremos também sobre o papel da extensão universitária na formação de educadores e ativistas socioambientais críticos, com a intenção de responder às demandas da educação ambiental em territórios que enfrentam conflitos ambientais.
Filmowe wcielenia Krzysztofa Kamila Baczyńskiego
Authors: Szpulak Andrzej
Published: April 2020

Szpulak Andrzej, Filmowe wcielenia Krzysztofa Kamila Baczyńskiego [Film Incarnations of Krzysztof Kamil Baczyński]. „Przestrzenie Teorii” 32. Poznań 2019, Adam Mickiewicz University Press, pp. 301–322. ISSN 1644-6763. DOI 10.14746/pt.2019.32.16.

The text concerns two film biographies of Krzysztof Kamil Baczyński, an outstanding and legendary poet of the Second World War killed in 1944 during the Warsaw Uprising. The films Fourth Day by Ludmiła Niedbalska (1984) and Baczyński by Konrad Piwowarski (2013) were subject to a comparative analysis. It covered genaelogical issues, the poet’s biography and a presentation of his work. The analysis shows the extreme difference in creative concepts, and thus the various possibilities that the biographical film faces.
Dissociation of Unit Activity and Gamma Oscillations during Vocalization in Primate Auditory Cortex
Authors: Tsunada Joji , Eliades Steven J.
Published: April 2020

Vocal production is a sensory-motor process in which auditory self-monitoring is used to ensure accurate communication. During vocal production, the auditory cortex of both humans and animals is suppressed, a phenomenon that plays an important role in self-monitoring and vocal motor control. However, the underlying neural mechanisms of this vocalization-induced suppression are unknown. γ-band oscillations (>25 Hz) have been implicated a variety of cortical functions and are thought to arise from activity of local inhibitory interneurons, but have not been studied during vocal production. We therefore examined γ-band activity in the auditory cortex of vocalizing marmoset monkeys, of either sex, and found that γ responses increased during vocal production. This increase in γ contrasts with simultaneously recorded suppression of single-unit and multiunit responses. Recorded vocal γ oscillations exhibited two separable components: a vocalization-specific nonsynchronized (“induced”) response correlating with vocal suppression, and a synchronized (“evoked”) response that was also present during passive sound playback. These results provide evidence for the role of cortical γ oscillations during inhibitory processing. Furthermore, the two distinct components of the γ response suggest possible mechanisms for vocalization-induced suppression, and may correspond to the sensory-motor integration of top-down and bottom-up inputs to the auditory cortex during vocal production.

SIGNIFICANCE STATEMENTVocal communication is important to both humans and animals. In order to ensure accurate information transmission, we must monitor our own vocal output. Surprisingly, spiking activity in the auditory cortex is suppressed during vocal production yet maintains sensitivity to the sound of our own voice (“feedback”). The mechanisms of this vocalization-induced suppression are unknown. Here we show that auditory cortical γ oscillations, which reflect interneuron activity, are actually increased during vocal production, the opposite response of that seen in spiking units. We discuss these results with proposed functions of γ activity during inhibitory sensory processing and coordination of different brain regions, suggesting a role in sensory-motor integration.
Comparison of Short and Mid-Term Mortality and Morbidity in Patients With Severe Aortic Stenosis (Intermediate/High Risk) Who Underwent Transcatheter Aortic Valve Replacement and Surgical Aortic Valve Replacement
Authors: Yesiltas Mehmet Ali , Haberal İsmail , Kuserli Yusuf , Yildiz Ahmet , Koyuncu Ahmet Ozan , Özsoy Sadiye Deniz
Published: April 2020

Treatment protocols for severe aortic valve stenosis include surgical aortic valve replacement (SAVR), balloon valvuloplasty, transcatheter aortic valve replacement (TAVR), and medical  treatment. Because the success rates are getting higher with both SAVR and TAVR, making the right treatment decision is important.
This study retrospectively shows the short- (1 month) and mid-term (6 months) mortality and morbidity rate differences between 2 groups of patients, who arrived to our hospital from January 2014 through October 2018. The first group consists of 54 patients who underwent mid-high risk SAVR operations at Istanbul University-Cerrahpasa, Institute of Cardiology, Department of Cardiovascular Surgery. The second group consists of 57 patients who underwent TAVR at the Cardiology Department.
Preoperative evaluation showed that the mean age of the SAVR group (71.5 years) was higher than the TAVR group (80 years). Also, the history of previous cardiac valve replacement surgery significantly was higher in the SAVR group than the TAVR group (P = .028). There were no significant differences between the remaining preoperative tests and diagnostic procedures.
Of the patients who underwent SAVR, 3.7% experienced postoperative cardiac arrhythmias, while the 17.5% of patients from the TAVR group experienced cardiac arrhythmias after the procedure. This difference between the groups were statistically significant. Mortality rate was 9.3% in the SAVR group and 5.3% in the TAVR group. The mortality rate was not statistically different between the groups. There was no significant difference between the groups in the means of neurological incidents. The TAVR group had more vascular complications (17.9% to none) and pacemaker implantations (21.4% to 1.9%).
Minor or major bleeding was the most common reason for admission to the hospital after SAVR. Seven out of 10 patients experienced bleeding. Aortic regurgitation was more common in the TAVR group at the first and sixth month following the procedure. Ratios between the gradient values were higher in the SAVR group (P < .001). Peak gradient values at the sixth month following the procedure were lower than the values of the first month (P < .040).
Aortic regurgitation symptoms increased with patients at the mid-term follow-up appointment. To prevent the vascular complications in the TAVR group, preoperative peripheral vascular examination thoroughly should be performed. Considering that bleeding disorders are the main reason the SAVR group arrived to the hospital, INR values should closely be monitored. There seems to be no mortality difference between the groups at the six-month follow up, but studies should continue with more patients and long-term results.
An NCBP3-Domain Protein Mediates Meiotic Silencing by Unpaired DNA
Authors: Boone Erin C , Xiao Hua , Vierling Michael M , Decker Logan M , Sy Victor T , Kennedy Rana F , Bonham Marilyn A , Schmitz Shannon F , John Annie M , Hammond Thomas M , Shiu Patrick K T
Published: April 2020

In the filamentous fungus Neurospora crassa, genes unpaired during meiosis are silenced by a process known as meiotic silencing by unpaired DNA (MSUD). MSUD utilizes common RNA interference (RNAi) proteins, such as Dicer and Argonaute, to target homologous mRNAs for silencing. Previously, we demonstrated that nuclear cap-binding proteins NCBP1 and NCBP2 are involved in MSUD. We report here that SAD-8, a protein similar to human NCBP3, also mediates silencing. Although SAD-8 is not essential for either vegetative or sexual development, it is required for MSUD. SAD-8 localizes predominantly in the nucleus and interacts with both NCBP1 and NCBP2. Similar to NCBP1 and NCBP2, SAD-8 interacts with a component (Argonaute) of the perinuclear meiotic silencing complex (MSC), further implicating the involvement of cap-binding proteins in silencing.
On Negative Heritability and Negative Estimates of Heritability
Authors: Steinsaltz David , Dahl Andy , Wachter Kenneth W
Published: April 2020

We consider the problem of interpreting negative maximum likelihood estimates of heritability that sometimes arise from popular statistical models of additive genetic variation. These may result from random noise acting on estimates of genuinely positive heritability, but we argue that they may also arise from misspecification of the standard additive mechanism that is supposed to justify the statistical procedure. Researchers should be open to the possibility that negative heritability estimates could reflect a real physical feature of the biological process from which the data were sampled.
Educational Use of Digital Video in the Context of Practical Work in Dentistry Prospective Evaluation Survey of the Optimal Duration of Educational Films by Second-Year Students of Dentistry in Rabat
Authors: Regragui Anissa , Abdedine Ahmed , Merzouk Nadia , Benfdil Faïza
Published: April 2020

The transmission of knowledge is a critical step that requires dedication and logistic assets to achieve the desired objective.Among these advantages is the online launch of educational films on the university's platform which aims at the improvement of understanding by students, and the information provided during practical work. For this, we have made three videos on the implementation of shaped clasps, while fixing the duration of the films successively at 8min50, 5min05, and 3min30. The videos were evaluated by the entire class through a questionnaire distributed to students who were present in the practical work training session. The biostatistical analysis revealed the preference to be for the 8min50 video with an initial viewing percentage of 59.3%. At a second and another viewing, preference was successively in favor of the 5min05 video (54.5%) and that of 3min 30 (43.4%). Furthermore, the students’ favorite videos were those with a time interval of 10 to 20 minutes (46.9%) for upcoming educational materials.
Educando con el cuerpo y desde este: Cultura, cuerpo y reeducación corporal
Authors: Tur-Porres Gisselle , Ires-Correa Washington
Published: April 2020

Este artículo invita a la reflexión sobre procesos educativos mediados por el cuerpo. Se presenta una experiencia docente en Ecuador, con la población universitaria de educación inicial de la Universidad Nacional de Educación. Su objetivo fue incluir el cuerpo en el accionar educativo, acercar a las personas participantes al concepto y vivencia de reeducar el cuerpo, para la generación de competencias profesionales desde un enfoque de prevención e inclusión. La experiencia se analiza desde la relación cultura, cuerpo y reeducación corporal. Se desarrollan técnicas corporales en el aula, que permiten la observación, la escucha y la comunicación (verbal y no verbal) en el proceso educativo, dando voz al cuerpo de las personas participantes. Además, se aplican cuestionarios para realizar diagnóstico, análisis y evaluación de la experiencia pedagógica. Los resultados indican que la aplicación de técnicas corporales en el aula permite, a la población estudiantil, innovar e incluir el cuerpo en sus prácticas educativas. Esto favorece el trabajo autónomo y de equipo, la reflexión de la práctica educativa, y la inclusión del cuerpo en los procesos de enseñanza-aprendizaje.
Los videojuegos en la educación: Beneficios y perjuicios
Authors: Núñez-Barriopedro Estela , Sanz-Gomez Yeray , Ravina-Ripoll Rafael
Published: April 2020

Desde el ámbito de la educación, se plantea un cambio de paradigma hacia un proceso enseñanza-aprendizaje más innovador. Concretamente, incluyendo en las aulas videojuegos como recurso docente con la finalidad de conseguir una educación de calidad más entretenida, eficaz y motivadora para el estudiantado. El objetivo principal de esta investigación es analizar si existen diferencias significativas entre las personas consumidoras de videojuegos sobre los beneficios o perjuicios que estos aportan especialmente en educación o si, por el contrario, existe una opinión generalizada positiva o negativa sobre la influencia de los videojuegos en el comportamiento de las personas usuarias. Para el análisis de las perspectivas de los videojuegos se ha llevado a cabo un estudio exploratorio, seguido de un estudio correlacional mediante encuesta donde se ha empleado el análisis clúster y el análisis factorial de correspondencia. En este estudio participaron 400 personas del conjunto nacional de España con edades comprendidas entre los 11 y 64 años. Entre los resultados obtenidos se destaca la creación de varios grupos de personas con diferencias significativas en sus actitudes sobre los videojuegos, en unos casos muy positivas y en otros, algo más conservadoras. Estos resultados permiten concluir que la opinión de las personas consumidoras acerca de cómo los videojuegos pueden influir en el desarrollo personal son más positivas, abriendo las puertas a un uso en la educación y en otros sectores.
La investigación en la disciplina de la orientación: procesos de formación desde la percepción estudiantil
Authors: Artavia-Aguilar Cindy Vanessa , Campos-Hernández Luis Roberto
Published: April 2020

Este artículo surge ante la necesidad de sistematizar las experiencias vividas, reflexiones y discusiones en torno a los procesos de formación investigativa en la carrera de Orientación de la Universidad Nacional, desde la perspectiva estudiantil. Con este fin, se plantea el objetivo de indagar los requerimientos laborales en el área de investigación, así como si la estrategia pedagógica empleada en esta materia es aplicable al quehacer profesional. El estudio es cuantitativo con alcance exploratorio; en este, se les solicitó a 15 estudiantes del curso Metodología de investigación de la licenciatura en Orientación en los años: 2014, 2015, 2016 y 2017 que realizaran un análisis de fortalezas, oportunidades, debilidades y amenazas (FODA) a este eje curricular, para recoger información en la categoría “percepción de la formación académica en investigación”, y completaran un cuestionario con preguntas abiertas y semi-estructuradas, en las categorías “características de una persona orientadora-investigadora” y “aplicabilidad de la investigación en el quehacer profesional”. Dentro de las principales conclusiones, destaca la trascendencia de la investigación en la vida profesional de la persona Orientadora, y la importancia de la integralidad de estos procesos en todo el quehacer profesional y de formación académica.
Modelos de gestión pedagógica: Factores de participación, cambio e innovación en centros educativos costarricenses
Authors: Chen-Quesada Evelyn , Cerdas-Montano Virginia , Rosabal-Vitoria Satya
Published: April 2020

El estudio presenta los resultados de investigación derivados del proyecto de extensión Modelos de gestión pedagógica (MGP), realizado con centros educativos públicos de las provincias de Heredia, Alajuela y San José, bajo la responsabilidad de la División de Educación para el Trabajo (DET), del Centro de Investigación en Docencia y Educación (CIDE) de la Universidad Nacional, Costa Rica (UNA). El objetivo es analizar la influencia del desarrollo de los modelos de gestión pedagógica en los centros educativos participantes, entre el 2005 al 2013, en el ámbito educativo costarricense; así como determinar la relación entre las variables: participación y cambio y la categoría; innovación y su efecto sobre el colectivo docente y administrativo. Esta investigación utiliza un método mixto (Creswell, 2009), porque es abordada desde un enfoque cuantitativo y cualitativo. Lo cualitativo se estudia desde lo fenomenológico, al reflexionar sobre el sentido y significado que aporta el grupo de participantes al proceso de MGP, en relación con las innovaciones metodológicas en el aula, espacios colectivos y organización administrativa. Mientras que el enfoque cuantitativo se realiza con un diseño ex post facto y transversal, porque responde a la percepción del colectivo participante, explora elementos y factores que influyen en la participación y la actitud, frente al cambio en el desarrollo de los MGP. El grupo de estudio está compuesto por 72 participantes del proyecto, 78,6% docentes y 21, 4% personal directivo. Entre los principales resultados se destacan que la participación y cambio son necesarios para avanzar hacia modelos pedagógicos más acordes con la realidad institucional. Los MGP contribuyen a la innovación metodológica y son producto de un trabajo participativo y colaborativo, pensado desde las necesidades e intereses de los contextos educativos. La principal implicación de la investigación es brindar a personal académico e investigador un referente basado en evidencia que pueda ser consultado en futuros estudios en materia de calidad de la gestión pedagógica en centros educativos costarricenses.
El enfoque por competencias y su relevancia en la actualidad: Consideraciones desde la orientación ocupacional en contextos educativos
Authors: Ramírez-Díaz Jose Laurian
Published: April 2020

El enfoque por competencias se ha planteado como una de las propuestas contemporáneas para articular los procesos de formación con el mercado de trabajo. Sin una posición epistemológica específica, el concepto de competencias ha evolucionado en las últimas décadas hasta alcanzar una relevancia internacional destacada en la actualidad. Así mismo, con la consideración de constructos teóricos tales como la ocupación y empleabilidad, el enfoque por competencias ha ampliado su consideración hacia ámbitos variados y amplios entre los cuales se destacan los educativos, con planteamientos que le defienden y retractan. Este ensayo plantea una revisión teórica de los modelos más destacados del enfoque por competencias, así como de la relación que tienen con la orientación ocupacional y sus modelos de intervención, con el objetivo de que profesionales en la disciplina consideren sus aportes para el desarrollo de los procesos que realizan en distintos contextos, especialmente los educativos.
La lectura en voz alta y la escenificación: Un camino hacia la comprensión de la narrativa
Authors: Leyva-Ortiz Jesús Alberto , Vaca-Morales María Azareel
Published: April 2020

El presente artículo expone los resultados obtenidos de una propuesta didáctica-literaria que fomentó y representó una herramienta exitosa para la comprensión lectora y con ella aportó experiencias a la enseñanza de la literatura. Consistió en vincular la lectura individual con la lectura en voz alta y la escenificación de la novela La tregua, del autor Mario Benedetti, como estrategia para el acercamiento de la obra. Este proyecto se aplicó en el nivel superior con el personal docente en formación de la Benemérita y Centenaria Escuela Normal del Estado de San Luis Potosí con la participación directa de 32 estudiantes y 8 personas catedráticas en un periodo de diez meses. Los hallazgos consideran una muestra de 81 personas, 40 de ellas como el total de sujetos colaboradores activos y el resto público asistente; y expone datos cualitativos y cuantitativos sobre la importancia y necesidad de la propuesta, hasta la profundización y comprensión de la obra con datos relevantes sobre la eficiencia alcanzada; confiamos en esta contribución que ponemos a su consideración.