bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization study of metallic sub-wavelength gratings as the polarizer in infrared wavelengths
Authors: Yang Zongyao , Feng Bo , Lu Bingrui , Chen Yifang , Li Wenhao , Zhang Wei , Li Tao
Published: December 2019

Despite the polarimetric detection in the infrared wavelengths of 8–10 µm being of great importance and broad applications, there has been limited addressing of the grating-based polarizers in this band. One of the main issues lies in the process incompatibility between the conventional nanofabrication technique and the II-VI materials such as HgCdTe, so that the direct integration of polarizers with sensors still remains a big challenge. This paper reports our recent work on optimizing the grating structures, materials, and nanofabrication processes for enhancing both the transmittance and the extinction ratio of polarizers on Si and/or ZnSe wafers, using numerical simulations for the grating design and electron beam lithography for the nanoscale pattern generation. By utilizing the finite-difference time-domain method, both the transmittance and the extinction ratio are maximized by optimizing the grating geometric dimensions and the duty cycle for two different grating materials of Al and Au for comparison. Based on the designed structures, nanofabrications of sub-wavelength gratings in both Al and Au are carried out, and the processes are compared for achieving high polarization performance. Optical characterizations of the fabricated polarizers demonstrate that both high transmittance and extinction ratio can be achieved in feasible parameters and the nano-process developed in this work.
Coordinate calculation for direct shape measurement based on optical flow
Authors: Sun Ping , Dai Qing , Tang Yuxin , Lei Zhifang
Published: December 2019

A quite novel surface profilometry is proposed, which adopts a single optical grating projection setup with a small projection angle. The height distribution of the measured surface is retrieved by calculating the coordinates of the intersection between the projecting ray and the observing sight line. While the position of the observing point in the deformed fringe pattern can be detected by fringe optical flow. The relationship between optical flow and the height distribution of the tested surface is established. Simulations and some primary experiment results are completed to prove that the proposed method is feasible to measure a complex surface. The main advantage of the proposed method is obviously that the height distribution of the measured surface can be obtained directly without phase-to-height transformation.
Poles of the scattering matrix: an inverse method for designing photonic resonators
Authors: Slovick Brian , Matlin Erik
Published: December 2019

We develop and implement a new inverse computational framework for designing photonic elements with one or more high-Q scattering resonances. The approach relies on solving for the poles of the scattering matrix, which mathematically amounts to minimizing the determinant of the matrix representing the Fredholm integral operator of the electric field with respect to the permittivity profile of the scattering element. We apply the method to design subwavelength gradient-permittivity structures with multiple scattering resonances and quality factors as high as 800. We also find the spectral scattering cross sections are consistent with Fano lineshapes. The compact form and computational efficiency of our formalism suggest it can be an effective tool for designing Fano-resonant structures with multiple high-Q resonances for applications such as frequency mixing and conversion.
Classification of time-domain waveforms using a speckle-based optical reservoir computer
Authors: Paudel Uttam , Luengo-Kovac Marta , Pilawa Jacob , Shaw T. Justin , Valley George C.
Published: December 2019

Reservoir computing is a recurrent machine learning framework that expands the dimensionality of a problem by mapping an input signal into a higher-dimension reservoir space that can capture and predict features of complex, non-linear temporal dynamics. Here, we report on a bulk electro-optical demonstration of a reservoir computer using speckles generated by propagating a laser beam modulated with a spatial light modulator through a multimode waveguide. We demonstrate that the hardware can successfully perform a multivariate audio classification task performed using the Japanese vowel speakers public data set. We perform full wave optical calculations of this architecture implemented in a chip-scale platform using an SiO2 waveguide and demonstrate that it performs as well as a fully numerical implementation of reservoir computing. As all the optical components used in the experiment can be fabricated using a commercial photonic integrated circuit foundry, our result demonstrates a framework for building a scalable, chip-scale, reservoir computer capable of performing optical signal processing.
Terahertz diffractive structures for compact in-reflection inspection setup
Authors: Siemion A. , Komorowski P. , Surma M. , Ducin I. , Sobotka P. , Walczakowski M. , Czerwińska E.
Published: December 2019

Two diffractive optical elements are used to create a compact raster THz scanning setup in reflective configuration. The first one focuses the radiation into the small focal spot on the sample, while the second one collects reflected radiation and focuses it on the detector. To assure small size of the setup and large apertures of optical elements, structures work in the off-axis geometry. Thus, the focal spot is formed 100 mm after and 60 mm below the optical axis of the element, which measures 75 mm in diameter. The designed iterative algorithm allows further minimization of these values.
Dual frequency comb assisted analog-to-digital conversion
Authors: Deakin Callum , Liu Zhixin
Published: December 2019

Photonic analog to digital conversion offers promise to overcome the signal-to-noise ratio and sample rate trade-off in conventional analog to digital converters (ADCs), critical for modern digital communications and signal analysis. We propose using phase-stable dual frequency combs with a fixed frequency spacing offset to downconvert spectral slices of a broadband signal and enable high-resolution parallel digitization. To prove the concept of our proposed method, we demonstrate the detection of a 10 GHz subcarrier modulated (SCM) signal using 500 MHz bandwidth ADCs by optically converting the SCM signal to 10 1 GHz bandwidth signals that can be processed in parallel for full signal detection and reconstruction. Using sinusoidal-wave-based standard ADC testing, we demonstrate a spurious-free dynamic range of

>

45

d
B

and signal-to-noise-and-distortion of

>

20

d
B

, limited by the receiver front-end design.
Mode-locked and tunable fiber laser at the 3.5  µm band using frequency-shifted feedback
Authors: Henderson-Sapir Ori , Bawden Nathaniel , Majewski Matthew R. , Woodward Robert I. , Ottaway David J. , Jackson Stuart D.
Published: December 2019

We report on a mid-infrared mode-locked fiber laser that uses an acousto-optic tunable filter to achieve frequency-shifted feedback pulse generation with frequency tuning over a 215 nm range. The laser operates on the 3.5 µm transition in erbium-doped zirconium fluoride-based fiber and utilizes the dual-wavelength pumping scheme. Stable, self-starting mode locking with a minimum pulse duration of 53 ps was measured using a two-photon absorption autocorrelator. The longest wavelength demonstrated was 3612 nm, and the maximum average powers achieved were 50 and 167 mW in fundamental and multi-pulse mode-locking regimes, respectively. To the best of our knowledge, this is the longest wavelength rare-earth-doped mode-locked fiber laser demonstrated. The broad tunability promises potential uses for environmental sensing applications.
Silica-based photonic crystal fiber for the generation of broad band UV radiation
Authors: Perret S. , Poudel C. , Ghosh A. N. , Fanjoux G. , Provino L. , Taunay T. , Monteville A. , Landais D. , Kaminski C. F. , Dudley J. M. , Sylvestre T.
Published: December 2019

We report a small-core UV-grade silica multimode photonic crystal fiber for nonlinear frequency conversion in the ultraviolet spectral region. The fiber has been fabricated using F110 UV-Grade glass from Heraeus, which features excellent transmission and low solarization in the UV window. Pumping the fiber core at 355 nm with picosecond laser pulses, we observe the appearance of parametric sidebands in several spatial modes up to 380 nm. We modelled this process using intermodal phase-matching conditions and obtained excellent agreement between calculations and the measured data. We further report frequency conversion pumping into the fiber microstructured cladding where broadband cascaded Raman scattering spanning up to 391 nm is observed. These results represent a significant step towards the efficient and stable generation of UV supercontinuum spectra in an all-silica fiber platform.
High-Q surface electromagnetic wave resonance excitation in magnetophotonic crystals for supersensitive detection of weak light absorption in the near-infrared
Authors: Borovkova O. V. , Ignatyeva D. O. , Sekatskii S. K. , Karabchevsky A. , Belotelov V. I.
Published: December 2019

The mid-infrared spectrum can be recorded from almost any material, making mid-infrared spectroscopy an extremely important and widely used sample characterization and analysis technique. However, sensitive photoconductive detectors operate primarily in the near-infrared (NIR), but not in the mid-infrared, making the NIR more favorable for accurate spectral analysis. Although the absorption cross section of vibrational modes in the NIR is orders of magnitude smaller compared to the fundamental vibrations in the mid-infrared, different concepts have been proposed to increase the detectability of weak molecular transitions overtones. Yet, the contribution of magnetophotonic structures in the NIR absorption effect has never been explored so far. Here we propose high-Q magnetophotonic structures for a supersensitive detection of weak absorption resonances in the NIR. We analyze the contributions of both magnetic and nonmagnetic photonic crystal configurations to the detection of weak molecular transitions overtones. Our results constitute an important step towards the development of highly sensitive spectroscopic tools based on high-Q magnetophotonic sensors.
Fe3O4 nanoparticles as a saturable absorber for a tunable Q-switched dysprosium laser around 3  μm
Authors: Yang Jian , Hu Jiyi , Luo Hongyu , Li Jianfeng , Liu Jishu , Li Xiaohui , Liu Yong
Published: December 2019

We demonstrate for the first time to our knowledge the use of

Fe

3

O

4

nanoparticles for

Q

-switching a tunable mid-infrared (Mid-IR)

Dy

3
+

-doped ZBLAN fiber laser around 3 μm. The

Q

-switcher was fabricated by depositing the prepared

Fe

3

O

4

nanoparticles solution onto an Au mirror. Its nonlinear optical response was characterized using a mode locked

Ho

3
+

/

Pr

3
+

-codoped ZBLAN fiber laser at 2.87 μm, and showed a modulation depth of 11.9% as well as a saturation intensity of

1.44
  
MW
/

cm

2

. Inserting the device into a tunable

Dy

3
+

-doped ZBLAN fiber laser, stable

Q

-switched pulses within the tunable range of 2812.4–3031.6 nm were obtained. When tuning the wavelength to 2931.2 nm, a maximum

Q

-switching output power of 111.0 mW was achieved with a repetition rate of 123.0 kHz and a pulse width of 1.25 μs. The corresponding pulse energy was 0.90 μJ. This demonstration suggests that

Fe

3

O

4

nanoparticles are a promising broadband saturable absorption material for mid-infrared operation.
Cute babies: How imagery and representation shape our collective beliefs
Authors: Kienke Chris
Published: December 2019

Images about race, class and gender deeply affect our beliefs about what American values are and who gets to share and who does not get to share in those values. The continuing discussions about these issues filtered through social media, film and television in the United States is
a dialogue that demands visual rendering. Realizing the depth of this conditioning is the first step. Critical next steps are examining which images are made available to the public and how to work with students who are developing their own voice.
Locating visual arts education in a post-liberal arts landscape
Authors: Swift Jason
Published: December 2019

This article explores the current climate and location of visual arts at post-secondary institutions in a growing post-liberal arts climate in the United States. It discusses the future of visual and liberal arts education in a socio-political climate that appears to value career-ready
degrees and profit over scholarship and the cerebral, emotive and visceral importance of education and the arts. The history of conservative efforts to remake post-secondary education and government efforts to defund it are discussed, providing context for the shift to a post-liberal arts
landscape. A growing divide and class separation are investigated as an outcome of the efforts made to de-liberalize colleges and universities and defund educational assistance programmes, potentially placing it in the hands of the upper class and out of the hands of the middle and lower classes.
Corruption and Economic Growth: The Case of Portugal
Authors: Bação Pedro , Gaspar Inês , Simões Marta
Published: December 2019

In this paper we investigate the impact of corruption on economic growth in Portugal over the period 1980-2018. The empirical approach makes use of a VAR model inspired by the standard Cobb-Douglas aggregate production function. The VAR model includes the capital stock, hours worked, total factor productivity and the corruption perceptions index (CPI) of Transparency International. The CPI combines several sources of information on the level of corruption in each country. The scale of this index goes from 0, the highest level of corruption, to 10, the lowest level. The magnitude of the estimated effect of corruption on economic growth in the unrestricted VAR model is large (and positive), but statistically not significantly different from zero. However, the results from the estimation of a structural VAR model with economically plausible long-run restrictions indicate modest gains from reducing corruption.
Are CO2 emissions converging in the European Union? Policy implications
Authors: Morales-Lage Rafael , Bengochea-Morancho Aurelia , Martínez-Zarzoso Immaculada
Published: December 2019

This paper focuses on the process of convergence in per capita CO2 emissions that would occur if the measures taken by the European Union to meet the Kyoto Protocol commitments had been effective. We apply a time series and cross-sectional analysis to test for the existence of convergence among countries and for different economic sectors. The sample covers data for the 28 member countries from 1960 to 2012. The results show weak absolute convergence across countries but clear evidence of conditional convergence, with GDP, the weight of industrial sector and the use of renewable energies being the main drivers of divergence. Concerning sectors, there is an increase of emissions in the agricultural sector, but a reduction in the industrial and energy sectors. Different patterns arise in the energy subsectors where manufacturing and electricity notably reduced their emissions while the transport sector increased them in all countries.
Entrevista a Raúl Zibechi: “Los movimientos sociales son los únicos que pueden impedir la barbarización a la que nos conduce el sistema capitalista”
Authors: Català Oltra Lluís , Copete Fernández José María
Published: December 2019

Entrevista a Raúl Zibechi: “Los movimientos sociales son los únicos que pueden impedir la barbarización a la que nos conduce el sistema capitalista”.
Los estudios reglados de comunicación en las universidades del ranking de Shangai. Propuestas para una epistemología de las ciencias de la comunicación
Authors: Marzal-Felici Javier , Soler-Campillo Maria , Rodríguez-Serrano Aaron
Published: December 2019

El presente artículo propone una reflexión crítica sobre el estatuto y naturaleza de los estudios de comunicación en el contexto académico español. En primer lugar, se examina la situación de los estudios de comunicación, que las autoridades académicas españolas han establecido unívocamente en la rama de “ciencias sociales y jurídicas”, más concretamente en el ámbito de las ciencias sociales. En segundo lugar, se aborda el estudio de la ubicación de los estudios de comunicación en las primeras 40 universidades del ranking de Shangai. Para ello, se han estudiado los planes de estudio (grado y postgrado) y la disposición estructural de sus facultades tanto en el campo de la comunicación audiovisual como del periodismo. Los resultados demuestran que, frente a lo que comúnmente se da por sentado, nuestras titulaciones se suelen encontrar mucho más cerca de centros vinculados explícitamente con las “humanidades”. Del mismo modo, mostramos cómo el número de universidades que apuestan por la comunicación es notablemente alto (80% del núcleo del ránking). Finalmente, se debate la posibilidad de definir una nueva epistemología de las ciencias de la comunicación, que asuma su carácter interdisciplinar, esto es, como espacio disciplinar en el que concurren saberes humanísticos y de las ciencias sociales.
Media Multitasking and geographical affiliation: an exploratory study
Authors: Barbosa Cláudia , Pedro Luís
Published: December 2019

Multitasking, especially involving media, has become a constant in our daily lives, increasingly promoted by technological developments on ever-developing personal equipment. Media multitasking has frequently been studied from the perspectives of both gender and age, so as to determine who multitasks more or better: men or women, adults or younger people. There are, however, fewer studies on how origin, cultural or geographical background can affect the tendency to media multitask. This paper will attempt to analyse a possible link between geographical affiliation, media use and the tendency to multitask of a group of 36 researchers of different nationalities, working in the same research institute. Differences in the use of several media and global media-use values have been recorded, with Europe presenting the lowest media use - less than half of the values of the highest cluster (Latin America). SMS is the least prevalent media, with Computer-based applications and web-surfing constituting the most prevalent media in most clusters. The European cluster also presents the lowest multitasking values, while the West African cluster registers the highest index.
Reformas legales y su efecto sobre las rupturas matrimoniales
Authors: Becerril Ruiz Diego , Jiménez Cabello José
Published: December 2019

España ha registrado, durante las últimas décadas, las transformaciones más significativas relacionadas con las rupturas matrimoniales. Desde la reaparición de la posibilidad legal de ruptura, hasta sustanciales reformas en época más reciente, relacionadas con la Ley 15/2005. Este proceso ha sucedido sin un análisis de la incidencia de las reformas legales sobre la propia evolución de las rupturas, que es el objetivo principal de este trabajo. Utilizando los datos disponibles en el Consejo General del Poder Judicial (CGPJ) y el Instituto Nacional de Estadística (INE) se analizan las tendencias de las rupturas. Se concluye que las variaciones en las rupturas se han producido, en gran medida, de forma ajena a la introducción de reformas legales, si bien es cierto que las reformas tienen una incidencia relevante, aunque temporal.
Movimiento FabLab: diseño de investigación mediante métodos mixtos
Authors: García Ruiz María Elena , Lena Acebo Francisco Javier
Published: December 2019

Los laboratorios de fabricación digital (FabLab) son una realidad que presenta nuevas oportunidades a los usuarios y consumidores de convertirse en diseñadores y creadores de objetos de uso cotidiano. Concebidos en el MIT a principios de este siglo, como entornos de desarrollo de proyectos con componentes digitales han sufrido un crecimiento espectacular en los últimos años. El movimiento FabLab, en parte debido a su juventud y a cierto alejamiento de los circuitos académicos al estar más relacionado con la cultura Maker y el movimiento Open-Source, ha sido poco estudiado formalmente. El presente trabajo plantea un acercamiento a dicho movimiento mediante el uso de una metodología mixta que permite identificar las dimensiones relevantes en este movimiento y definir las preguntas de investigación a las que dar respuesta en posteriores investigaciones.
Discursos y prácticas del Buen Convivir en un contexto de post-violencia en Michoacán (México)
Authors: González de la Fuente Íñigo , Paleta Pérez Guillermo
Published: December 2019

El objetivo principal del artículo es analizar el complejo proceso a través del cual el paradigma del Buen Convivir cobra significado en el contexto de post-violencia en Tancítaro, Michoacán, México. A nivel metodológico, utilizamos información registrada en campo durante los años 2016 y 2017, tanto del análisis de contenido en varios documentos públicos, como de la observación y las entrevistas en profundidad realizadas. A modo de conclusión, los autores señalamos el Buen Vivir como una construcción social. Y esto significa exactamente que su conceptualización ha de estar sujeta a las circunstancias sociales e históricas de cada contexto local.
Digital transformation and egovernment. For a research agenda on the Liguria Region
Authors: Raffini Luca , Giampellegrini Pietro Paolo , Pirni Andrea
Published: December 2019

The contribution analysis the effects of digital transformation, provides a critical assessment of the policies on e-government in Europe and in Italy, and draft a research agenda focused on Liguria Region. The article moves from the need to conduct research aimed at analyzing the change in the relations between subject and institution in contemporary western societies. The article, focusing on official documents, explores the strategies of digital transformation adopted by the EU. Liguria is a case study of interest because, starting from the 2016-2018 Digital Strategic Program, has adopted a strong focus on the principles of Open Government and an explicit decision to invest in specific digital services for citizens and businesses.
Presentación: España y el final de la Guerra Fría
Authors: López Zapico Misael Arturo , Treglia Emanuele
Published: December 2019

El 9 de noviembre de 1989 caía el Muro de Berlín, encaminando al “corto siglo XX” hacia su final. Con ocasión del trigésimo aniversario de aquel trascendental acontecimiento, el presente monográfico explora cómo fue observado y recibido desde España el final de la Guerra Fría, trazando un panorama de la forma en la que este país interaccionó con la cambiante realidad de su entorno en un momento clave para la apertura española a la esfera internacional. Los cinco artículos que componen el dossier emplean múltiples enfoques y atienden a distintos niveles. Se presta atención a las relaciones bilaterales entretejidas por España con Estados Unidos y a la actuación exterior de los gobiernos de Felipe González en Latinoamérica y el área mediterránea. Además, se analizan tanto las actividades propagandísticas realizadas por la URSS en España durante la perestroika, como las actitudes adoptadas por los comunistas españoles hacia la caída del bloque soviético y la consecuente configuración de un nuevo orden mundial en la Posguerra Fría. Se pretende así arrojar nueva luz no solo sobre la historia de las relaciones internacionales de España sino, más en general, sobre la historia política del país ibérico durante los años ochenta y primeros noventa.
Reseñas de libros
Authors: Pasado y Memoria Revista
Published: December 2019

Contiene: SUÁREZ CORTINA, Manuel, Los caballeros de la razón. Cultura institucionista y democracia parlamentaria en la España liberal, Genueve Ediciones, 2019, 375 pp. / Sergio Sánchez Collantes; SANTIÑO, Santiago, Pascual de Gayangos. Erudición y cosmopolitismo en la España del XIX, Pamplona, Urgoiti Editores, 2018, 608 pp. / Rafael Fernández-Sirvent; VILA, Santi, De quan el liberalisme era pecat. Fèlix Sardà i Salvany, reaccionari i innovador. Pròleg de Jordi Amat. Barcelona, Viena Edicions, 2018, 291 pp. / Antonio Moliner Prada; BLASCO HERRANZ, Inmaculada (ed.), Mujeres, hombres y catolicismo en la España contemporánea. Nuevas visiones desde la historia, Valencia, Tirant Humanidades, 2018, 276 pp. / Verónica García Martín; OLIVIER COMPAGNON, Camille Foulard, Guillemette Martin y María Inés Tato (coords.). La Gran Guerra en América Latina. Una historia conectada. México, CEMCA, 2018, 492 pp. / Agustín Daniel Desiderato; JIMÉNEZ REDONDO, Juan Carlos, Franco y Salazar. La respuesta dictatorial a los desafíos de un mundo en cambio, 1936-1968, Madrid, Sílex Universidad, 2019, 242 pp. / José Antonio Abreu Colombri; ROSAS, Fernando, Salazar e os fascismos, Lisboa, Tinta da China, 2019, 305 pp. / Nelson Jorge De Castro Araújo; VALERO GÓMEZ, Sergio y GARCÍA CARRIÓN, Marta (eds.), Desde la capital de la República. Nuevas perspectivas y estudios sobre la Guerra Civil española, Valencia, Publicaciones de la Universitat de València, 2019, 416 pp. / Juan Boris Ruiz Núñez; PAYÁ LÓPEZ, Pedro (ed.), Desde las cenizas de Auschwitz. Historia, memoria, educación, Granada, Comares, 2019, 325 pp. / Sergio Vaquero Martínez; FERNÁNDEZ, Eider de Dios, Sirvienta, empleada, trabajadora del hogar. Género, clase e identidad en el franquismo y la transición a través del servicio doméstico, Málaga, UMA editorial, 2019. / Sonia García Galán; BORJA, Jordi. Bandera Roja. 1968-1974. Del maig del 68 a l’inici de la transició, Barcelona, Edicions 62, 2018, 133 pp. / Samuel Calatayud Sempere; BEORLEGUI, David, Transición y melancolía. La experiencia del desencanto en el País Vasco (1976-1986), Madrid, Postmetrópolis Editorial, 2017, 353 pp. / Nicolás Buckley.
Efecto de la masoterapia sobre la ictericia neonatal: revisión sistemática
Authors: Molina Díaz Ainhoa , Ávila-Alzate Jennihe Alejandra , Gómez Martín de Vidales Nazaret
Published: December 2019

Objetivo: Identificar, evaluar y sintetizar la mayor evidencia disponible sobre el efecto del masaje en la ictericia en neonatos a término tratados o no con fototerapia. Método: Se desarrolló una revisión siguiendo la declaración PRISMA. Para ello se realizóuna exhaustiva búsqueda sistemática en las bases de datos PubMed, Cuiden, Scopus, Scielo y Cnki de los artículos publicados entre enero del 2009 y junio del 2018. Los estudios seleccionados fueron sometidos a una evaluación de la calidad metodológica mediante la escala PEDro. Resultados: Un total de 10 trabajos cumplían los criterios inclusión y fueron incorporados a la revisión. Estos presentaban una calidad metodológica moderada (xˉ=7,3). Los diferentes estudios mostraban un incremento de la frecuencia defecatoria y una disminución de los niveles de bilirrubina en el grupo intervención. En los pacientes tratados con fototerapia, la duración de la hiperbilirrubinemia era menor en el grupo experimental. Según los autores se podía justificar por un aumento de la actividad gastrointestinal debido a una estimulación vagal gracias al masaje.Conclusión: A pesar de la escasa evidencia existente, la masoterapia se establece como una herramienta eficaz, segura y económica para la prevención y tratamiento de niveles elevados de bilirrubina en neonatos a término.
Pulse Width Modulation of Three Phase Inverters Based on Linear Programming
Authors: Komrska Tomáš , Glasberger Tomáš
Published: December 2019

Traditional three-phase voltage-source inverters supplied by constant dc-link voltage usually utilize the space vector PWM to achieve maximum output voltage. This paper deals with optimization of inverter leg voltages using linear programming method. System definition is based on the relationship between the known voltage vector, which is demanded by an upper control loop and the unknown leg voltages which enter the carrier-based PWM block as modulation signals. A slack variable is introduced to the system as minimization objective, defining border for all leg voltages. Optimization procedure minimizes leg voltage maxima, and thus, the maximum utilization of the dc-link voltage is ensured. The theoretical assumptions have been verified by simulations as well as by experiments on laboratory prototype.
The «cut-off point» of vitamin D: a method of suppressing excessive secretion of PTH
Authors: Suplotova Liudmila A. , Avdeeva Valeria A. , Pigarova Ekaterina A. , Rozhinskaya Liudmila Ya.
Published: December 2019

BACKGROUND: The subject of discussion is the issue of the separation point, which determines sufficient levels of vitamin D for bone health. When determining the adequate reference range of vitamin D, researchers are mainly guided by the results of research, where the level of 25(OH)D is determined, at which the PTH level decreases and reaches a plateau.
AIM: To establish the cut-off point of vitamin D by suppressing excessive secretion of PTH.
MATERIALS AND METHODS: Observational, single-site, single-stage, selective, uncontrolled study of the search for vitamin D levels by the effect on PTH secretion in residents of Tyumen region was conducted (n = 176). All selected study participants determined the level of 25(OH)D and PTH in serum. The calculation of the cut-off point was carried out using the method of searching for changes in the correlation dependence of PTH on the level of vitamin D, followed by verification of the data obtained using ROC analysis.
RESULTS: A mathematical analysis of the dependence of 25(OH)D and PTH showed the cut-off point of vitamin D, equal to 23.6 ng/ml.
CONCLUSION: The cut-off point of 23.6 ng/ml is optimal for suppressing excessive PTH secretion. The data obtained may be an incentive for further working out the cut-off point of vitamin D for the Russian population and can be used to clarify the classification of deficiency, insufficiency and optimal levels of vitamin D for the population of the Russian Federation.
Multiple effects of bariatric surgery on human biochemical status
Authors: Sushentseva Natalya N. , Apalko Svetlana V. , Vasiliev Evgeny V. , Gladyshev Dmitrii V. , Vrublevskaya Stanislava N. , Salukhov Vladimir V. , Sarana Andrey M. , Scherbak Sergey G.
Published: December 2019

Beneficial effect of bariatric surgery is expressed not only in reducing body weight, but also in improving the functioning of the body as a whole. On the one hand, numerous studies devoted to the investigations of specific mechanisms of the influence of bariatric surgery on the general condition of an organism testify to the enormous interest of scientists in this problem. On the other hand, the range of changes is so vast that it covers almost all physiological and biochemical processes. The most noticeable response to bariatric surgery is from the digestive (including the composition of the microbiota), immune (reducing the level of systemic and local inflammation), cardiovascular (reducing the risks of atherosclerosis and other diseases) systems. Partial or complete compensation of type 2 diabetes mellitus and metabolic syndrome also occurs. Among the variety of data, there is insufficient research on only standard biomarkers: leptin, C-reactive protein, interleukin 6, etc. A detailed study of the profiles of both circulating biomarkers and local ones is necessary. At the same time, it is obligate to continue to accumulate evidence on the positive effect of bariatric surgery, since this type of surgical intervention has come into practice relatively recently. Unfortunately, at the present time in Russia bariatric surgery is not an affordable and popular treatment for morbid obesity (MO). Nevertheless, it is extremely important to change the current situation, since bariatric treatment is an optimal and effective solution to socially significant diseases such as MO or type 2 diabetes mellitus.
Vitamin D binding protein polymorphysm in patients with acute coronary syndrome in kaliningrad region
Authors: Bogachev Robert S. , Kozel Anastasia Y. , Litvinova Larisa S. , Mikhailova Larisa V. , Shytova Elena S. , Ankudоvich Vitaly B. , Mordvintsev Vladislav V. , Dobrynina Ulyana A.
Published: December 2019

BACKGROUND: Vitamin D binding protein is a main vitamin D carrier in serum. It also has an impact on macrophagial function. Role of vitamin D and macrophages in the pathogenesis of atherosclerosis is scientifically proven but there is lack of data on vitamin D binding protein in this regard.
AIMS: To evaluate the vitamin D binding protein polymorphism in patients with acute coronary syndrome without diabetes mellitus, autoimmune diseases and malignant tumors. Determine correlation, if there is, between vitamin D binding protein allele and features of acute coronary syndrome among this patient group.
MATERIALS AND METHODS: It is a cross-sectional observational study. Study subjects are patients with acute coronary syndrome. Exclusion criteria are the presence of diabetes mellitus, autoimmune diseases and malignant tumors. In all participants were evaluated: predisposing factors for heart diseases, CBC, biochemical blood test, troponin, coronarography, echocardiography. The study lasted for 5 months from November 2017 until March 2018. Primary end point assessment of vitamin D binding protein polymorphysm in this group of patients with acute coronary syndrome by means of vitamin D binding protein gene sequencing. 50 patients were enrolled into this study who were urgently admitted to hospital and diagnosed with acute coronary syndrome. Among them 36 males and 14 females. Mean age was 60 (55;66) years. All participants were sequenced for single nucleotide polymorphysm in VDBP p.T436K (rs4588) and P.432E (rs7041).
RESULTS: Gene polymorphysms of interest were found in 43 patients among 50 enrolled. Haplotype Gc1s/2 (rs7041G-rs4588A) was found in 7 (14%) patients, Gc2 (rs7041T-rs4588A) in 9 (18%) patients, Gc1s (rs7041G-rs4588C) in 20 (40%) patients, Gc1f (rs7041T-rs4588C) in 14 (28%). Coronarography showed that coronary artery occlusions obstructing more than 50% of vessel lumen was found in 16 patients; obstruction greater than 90% was seen in 8 patients; total occlusion in 4 patients.
CONCLUSIONS: In patient group with acute coronary syndrome prevalence of vitamin D binding protein gene polymorphysm was high in 86% of participants. The features of Gc2 haplotype were higher frequency of recurrent myocardial infarction and total coronary artery occlusion, as well as tendency to decreased serum vitamin D3 (25(OH)D) levels.
Ovarian reserve in women with obesity
Authors: Grigoryan Olga R. , Mikheev Robert K. , Andreeva Elena N. , Dedov Ivan I.
Published: December 2019

BACKGROUND: One of the consequences of obesity for the female body is a decrease in fertility. It is shown that impaired reproductive function in obese patients can be associated, in particular, with a decrease in ovarian reserve.
AIMS: To evaluate the ovarian reserve function in female patients of reproductive age with different classes of obesity in comparison with women without obesity.
MATERIALS AND METHODS: This study evaluated 320 caucasian women, age 20-30 years, without obesity (BMI30, n=80) and with obesity WHO class I-III (n=80 per class). Anthropometrics, serum concentrations of anti-Mullerian hormone (AMH), inhibin B, follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, and testosterone were compared on the 2-3 day of menstrual cycle as ovarian volume and antral follicle count (AFC).
RESULTS: We reveal statistically significant difference in following parameters in normal BMI women in comparison with obesity women: AMH, testosterone, ovarian volume and AFC. Moreover, we reveal significant difference between patients with different WHO class of obesity. But even in class III obesity parameters remained within reference ranges.
CONCLUSIONS: Ovarian reserve function parameters progressively decrease with increase of obesity class in subjects, but ovarian reserve parameters were in normal reference range even in class III obese patients. Further large randomized multicenter studies are required to find influence of obesity in relation to ethnicity and other factors to ovarian reserve function.
Análise espacial da produtividade do café na região Sudeste do Brasil: 1990-2015
Authors: Cardozo Daniela Peres , Schaab Luana Las , Parré José Luiz
Published: December 2019

O objetivo deste artigo é analisar a evolução da produtividade média do setor cafeeiro da região sudeste nos anos de quinquênio de 1990 a 2015. Para tanto, analisouse a dinâmica espacial, a formação de clusters e, por fim, verificou-se a incidência de convergência na produtividade média do café. A metodologia utilizada é a análise exploratória de dados espaciais e a econometria espacial. Os resultados indicam que existe autocorrelação espacial global positiva. Houve convergência em todos os subperíodos analisados, dado que o valor do coeficiente estimado foi negativo e significativo. Assim, os resultados corroboram a hipótese de convergência espacial, indicando que a produção de café nas microrregiões menos produtivas cresceu a umataxa maior do que nas microrregiões mais produtivas.
Consumo e distinção social: abordagens convergentes sobre o caso da moda e vestuário em Veblen e Sahlins
Authors: Guedes Sebastião Neto Ribeiro , Jerônimo Rodrigo Constantino , Siqueira Álvaro Martins , Da Silva Thiago Cordeiro
Published: December 2019

O presente artigo busca comparar e examinar as similaridades entre as abordagens heterodoxas sobre o consumo de acordo com a Escola Econômica Institucional Original, a Sociologia Econômica e a Antropologia Econômica. Dessa forma, o texto dá atenção especial às análises de Thorstein Veblen e Marshall Sahlinspara o caso do consumo de moda e vestimenta nos Estados Unidos. O artigo debate que a observação do caso de consumo de vestimenta, assim como suas ideias resultantes oferecem uma ligação entre Veblen na Economia e Sahlins na Antropologia, unindo ambos às ideias da Sociologia Econômica de distinção social em Bourdieu. O texto também debate que, apesar de escreverem em diferentes épocas, contextos e por meiode escolas de pensamento distintas, ambos os autores rejeitam os pressupostos neoclássicos de consumo baseados na maximização da utilidade. Em vez disso, apresentam esse assunto como uma questão de determinação cultural e de influências dos hábitos sociais imersos em propósitos não-maximizadores, puramente motivados pela busca de distinção social e demonstração de poder simbólico, questionando aracionalidade das decisões econômicas dos agentes.
Editorial v.34 n.1 a.2019
Authors: Botelho Marisa dos Reis Azevedo , Benzaquen Perosa Bruno
Published: December 2019

Editorial v.34 n.1 a.2019
Reflexiones y percepciones sobre la evaluación automatizada del discurso escrito
Authors: Benítez Ricardo Alberto
Published: December 2019

Este artículo presenta reflexiones y percepciones acerca de un potencial problema en la enseñanza y aprendizaje de la escritura en el ámbito escolar y universitario: su evaluación con instrumentos computarizados. El conflicto entre esta evaluación y la realizada por humanos puede constituir motivo de debate y análisis, como ya lo es en Estados Unidos. Allí, varios experimentos han intentado automatizar las evaluaciones de composiciones escritas. Sin embargo, los resultados han sido insatisfactorios desde el punto de vista tanto de los investigadores como de los estudiantes, a cuyos productos escritos se les ha aplicado dicha evaluación. Este artículo, por tanto, surge de la inquietud por indagar las percepciones de estudiantes universitarios acerca de su disposición a recibir retroalimentación y evaluación de sus composiciones escritas a través de un instrumento automatizado. Para recabar esta información, se les solicitó que contestaran en línea si estarían dispuestos o no a someter la evaluación de sus trabajos escritos a una computadora con la posibilidad de agregar comentarios. Las respuestas y los comentarios fueron categorizados como positivos,negativos e indecisos. Las negativas obtuvieron la mayoría, seguidas de las positivas y las indecisas. Se concluye que faltan estudios de mayor envergadura que exploren las percepciones tanto de estudiantes como de profesores de producción escrita para obtener resultados más consistentes y que las instituciones que decidan
La conexión en el discurso oral de estudiantes secundarios: limitaciones y desafíos
Authors: Osorio Jorge , Henríquez Marisol , Cisternas Irsa
Published: December 2019

El presente artículo tiene como objetivo caracterizar la función de conexión de un grupo de estudiantes de segundo ciclo de enseñanza media, a partir del repertorio de conectores utilizados en una tarea de renarración. La muestra estuvo conformada por 15 escolares chilenos, que cursaban 3° y 4° medio en un establecimiento diurno particular subvencionado de la comuna de Florida, región del Biobío. Los resultados señalan que los relatos: i) en su mayoría, tienen marcadores de inicio y cierre; ii) contienen un repertorio limitado de conectores; y iii) se evidencia una sobreabundancia del conector subespecificado (y). Esto último permite concluir que el desarrollo de la competencia narrativa oral aún requiere de diseños explícitos, sistemáticos y progresivos que permitan a los escolares ampliar su repertorio activo de conectores en contexto narrativo.
Anleitung für die ,,Große Transformation“
Authors: Sachs Wolfgang
Published: December 2019

Die Situation ist klar: Die Menschheit braucht die sozial-ökologische Wende, damit ihre Existenz auf der Erde langfristig gesichert bleibt. Auch der Weg dorthin ist vorgezeichnet, wir müssen ihn nur gehen. Ein Buch mit knappen Argumenten und in Thesen zugespitzt ‐ es
ist ein Appell an Politik und Gesellschaft, für einen radikalen Wandel des Wirtschaftssystems einzutreten.
Wachsen oder weichen!? Eine Analyse der agrarstrukturellen Debatte im Kontext der EU-Agrarpolitik nach 2020
Authors: Nowack Wiebke , Schmid Julia C. , Grethe Harald
Published: December 2019

Die Zahl landwirtschaftlicher Betriebe in Deutschland und Europa nimmt ab und ihre durchschnittliche Größe zu. Besteht Anlass für eine stärkere Unterstützung kleinerer Betriebe? Agrarpolitische Interessensgruppen deuten den Größenstrukturwandel unterschiedlich
und ziehen verschiedene politische Schlussfolgerungen.Structural changes in agriculture are frequently considered problematic. Concerns are expressed about the declining number of farms and the growth of the farms that remain. A structuring content analysis of 50 position papers on the
post-2020 Common Agricultural Policy (CAP) reform shows that the development of agricultural-sized structures is interpreted as a problem of both equity and multifunctionality. The respective positionings overlap when it comes to the principle of performance equity and comes together around
the goal of maintaining as many (small) farms as possible. It is either assumed that small enterprises would benefit if subsidies were tied to the provision of public goods, or that promoting the existence of small farms would automatically lead to their provision. Existing studies can only
partially prove or refute such connections. What remains is the need for public negotiations regarding the societal functions which agriculture should assume, and with what priority.
A comparative analysis of chemistry curriculum for lower secondary education in the Czech Republic, Poland, Slovenia and Estonia
Authors: Stratilová Urválková Eva , Teplá Milada , Janoušková Svatava
Published: December 2019

This article presents an analysis based on the principles of (international) comparativepedagogy focusing on the study of the similarities and differences in subject-specific competences,educational content, and teaching strategies and methods. The analysis focuseson the field of chemistry, specifically the intended curriculum of the abovementioned countries for the level of lower secondary education. Three parameters were monitored and compared: the number of hours allocated for the teaching of chemistry, of all science subjects from the 6th to 9th grades, the educational content of the subject of chemistry and the teaching strategies discussed and/or recommended for the teaching of natural sciences. Analysis has shown that chemistry is taught for the same length of time, but chemistry topics in Slovenia and Estonia are also taught within the subject Natural Sciences in the 7th grade. The expected outcomes are comparable in all countries, but Czech outcomes are grouped into broad topic areas with few outcomes. The expected outcomes from other countries are specified in much more detail. The recommended teaching methods are most closely described in the Slovenian curriculum, which also contains extensive didactic recommendations for individual subjects.
Editorial
Authors: Janoušková Svatava
Published: December 2019

Introduction to the articles of this special issue.
Survival outcomes of low-risk and intermediate-risk stage IB1 cervical cancer patients
Authors: Vanichtantikul Asama , Tantbirojn Patou , Manchana Tarinee
Published: December 2019

Background

Survival for patients with early stage cervical cancer without any high-risk factors treated with radical hysterectomy is excellent. However, there are few data on the survival outcomes for low-risk and intermediate-risk early stage cervical cancer patients.

Objective

To determine survival outcomes and prognostic factors of low-risk and intermediate-risk stage IB1 cervical cancer patients.

Methods

Stage IB1 cervical cancer patients with radical hysterectomy and pelvic lymphadenectomy were retrospectively reviewed. Patients with positive pelvic nodes, parametrial involvement, and positive margin who are classified as high-risk patients were excluded. Patients with squamous cell carcinoma or grade 1–2 adenocarcinoma, tumor size less than 2 cm, no lymphovascular space invasion (LVSI), and depth of stromal invasion (DSI) less than 10 mm were defined as low-risk patients. Survival was evaluated using the Kaplan–Meier method and compared by the log-rank test. Multivariate analysis was performed using Cox proportional-hazards regression.

Results

There were 82 (42.3%) low-risk patients and 112 (57.7%) intermediate-risk patients. More patients in intermediate risk received adjuvant treatment (3.6% and 14.3%, P = 0.07). Three (3.6%) low-risk patients and 18 (16.1%) intermediate-risk patients had recurrent disease (P = 0.004). At median follow-up of 86 months, 1.2% of low-risk patients and 8.9% of intermediate-risk had cancer-related deaths (P = 0.02). Low-risk patients had significantly better 5-year disease-free survival (98.2% vs 91.1%, P = 0.01) and estimated 5-year overall survival (98.5% vs 91.1%, P = 0.01). DSI more than 10 mm and presence of LVSI were significantly associated with recurrence. However, LVSI was an independent prognostic factor.

Conclusion

Stage IB1 cervical cancer patients had excellent survival. Low-risk patients had significantly better survival. Presence of LVSI was an independent prognostic factor.