bluuebunny/crossref_metadata_2025 huggingface dataset:
Production losses five months after outbreak with a recombinant of two PRRSV vaccine strains in 13 Danish sow herds
Authors: Kristensen C. S. , Christiansen M. G. , Pedersen K. , Larsen L. E.
Published: October 2020

Background

In July 2019, a PRRSV-negative boar station was infected with a recombinant of two PRRSV vaccine strains, which subsequently spread to at least 36 herds that had received semen from the boar station. In the following months, all the infected herds reported reduced productivity. The aim of the present study was to evaluate the impact of the PRRS outbreak.

Results

Production data were collected from 13 of the herds. The average levels of farrowings/week, liveborns/litter, stillborns/litter, pre-weaning mortality and weaned pigs/litter were compared for the five-month period after infection and the preceding 7 months before infection with the new variant of PRRSV-1. Twelve herds experienced a decrease in farrowings/week (0.1–10.8% fewer farrowings/week), and all herds experienced fewer liveborns (0.8–4.8 fewer liveborns/litter) and more stillborns (0.6–2.6 more stillborns/litter). Pre-weaning mortality nearly doubled in half of the herds. Overall, the 13 herds were missing 2.4–6.5 pigs/litter at weaning during the 5 months after infection compared to the seven preceding months before infection.

Conclusion

In this study, the impact of this new PRRSV-1 variant on productivity exceeded that typically seen in Danish herds infected with PRRSV-1.
Determinant of emergency contraceptive practice among female university students in Ethiopia: systematic review and meta-analysis
Authors: Fikre Rekiku , Amare Belay , Tamiso Alemu , Alemayehu Akalewold
Published: October 2020

Introduction

Despite Ethiopia’s government’s commitment to alleviating unwanted pregnancy and unsafe abortion by increasing holistic reproductive health service accessibility, the rate of unwanted pregnancy among female students in the universities is distressing and becoming a multisectoral concern. Therefore, this systematic review aimed to assess the prevalence and determinant of emergency contraceptive practice among female university students in Ethiopia.

Result

The overall pooled prevalence of emergency contraceptive practice among female university students in Ethiopia was 34.5% [95% CI [20.8, 48.2%]. The pooled odds ratio showed that positive association between practice of emergency contraceptives with age of the students [OR, 0.19; 95% CI: 0.04, 0.98, P = 0.05] Previous contraceptive methods use [OR, 0.22; 95% CI: 0.12, 0.40, P = 0.0001], Marital status [OR, 0.09; 95% CI: 0.02, 0.40, P < 0.002] and knowledge [OR, 0.12; 95% CI: 0.04, 0.37, P < 0.0003].

Conclusion

The practice of emergency contraceptives among university female students was 34.5% and explained by knowledge, age, previous use of contraceptive methods and marital status.
Ideologies of Diplomacy
Authors: Wong Jane Yeang Chui
Published: October 2020

The publication in 2008 of John Watkins’s special issue for the Journal of Medieval and Early Modern Studies, “Toward a New Diplomatic History of Medieval and Early Modern Europe,” opened up the formal aspects of the ambassador’s office and official channels of diplomatic negotiation to a complex sociocultural landscape underlying the processes of diplomacy-in-the-making. The field of New Diplomatic History has since burgeoned. This current special issue hews closely to the cross-disciplinary nature of newer diplomatic history, and it responds to critical challenges that have recently emerged in scholarship, particularly the need to balance both breadth and depth of historical and cultural analysis. This volume considers how English institutional and sociocultural networks informed diplomatic practice in Elizabethan and Jacobean England, and how diplomatic thought, representation, and the forging of international relations were interpreted within various English communities. The collection takes special interest in how “ideologies of diplomacy” were formed, negotiated, and articulated within and beyond formal diplomatic spheres. Drawing on various elements of international relations theory, the essays address the ambiguous and contradictory elements of diplomatic reciprocity, explicating the tensions between diplomatic ambition and local governance.
Faction, Rhetoric, and Ideology
Authors: Coates Hannah
Published: October 2020

From his appointment as principal secretary to Elizabeth I in 1573, Sir Francis Walsingham was instrumental in every sphere of English diplomacy. He was particularly interested in maintaining friendly relations with Scotland, though this was complicated by his suspicions of individual Scots, especially the king, James VI, who embarked on his personal rule after the execution of the last regent in 1581. Walsingham’s keen interest in Anglo-Scottish diplomacy was partly occasioned by his office, but more importantly by his own concerns about the implications a weak or hostile Scotland would have for England. His extensive network of contacts among both English and Scottish diplomatic personnel enabled him to exert influence over this area of policy. Walsingham’s view of Scotland and his preferred policy drew him into conflict with other members of Elizabeth’s government, who espoused a different policy and outlook and had their own networks of influence. Using particularly the acrimonious falling out between Walsingham and another privy councillor, Lord Hunsdon, over Scottish policy in 1584, this essay analyzes the influence of personalities, political allegiances, and ideological factors on the formation and implementation of England’s Scottish policy.
Theological Polemics and James I’s Diplomacy, 1603–1617
Authors: Smuts R. Malcolm
Published: October 2020

Historians have typically represented James I as a king whose foreign policy was driven by a principled commitment to peace, religious reconciliation, and royal legitimacy that led him to avoid military engagement in confessional conflicts, notably the Thirty Years’ War. But his published writings on topics related to international politics and less formal pronouncements of principle in verbal discussions of European affairs have never received close contextual analysis. This essay examines how James deployed theoretical arguments in conducting diplomacy with other European states, especially France, in the period before the outbreak of the Thirty Years’ War. It argues that rather than basing policy decisions on principled convictions, he often deployed ideas strategically in efforts to justify and advance his own interests, and sometimes to mislead other statesmen about his true intentions. He did have some deep convictions, especially his abhorrence of theological justifications for rebellion and regicide, but even his efforts to combat such arguments were shaped by practical political calculations as well as purely theoretical concerns. Although he took ideas seriously, a closer examination of his record reveals him as a shrewd, flexible, and sometimes duplicitous royal politician, adept at fashioning high-minded justifications for self-interested maneuvers, rather than an idealistic scholar-statesman.
Παιδοπόλεις και περίθαλψη. Ιστορικοδημογραφική αποτύπωση του βιβλίου νοσηλείας των ετών 1950- 1954 της Παιδόπολης Ζηρού Πρέβεζας.
Authors: Αγάθος Στέφανος
Published: October 2020

Δε διατίθεται περίληψη / no abstract available
Estimation Method of the Didactic Complexity of the School Textbooks on Various Disciplines
Authors: Mayer Robert
Published: October 2020

The article discusses the problem of evaluating the differential didactic complexity (DDC) of educational texts, which characterizes the difficulty of their perception and assimilation by pupil. It is shown that DDC is determined by: 1) the density of semantic information, depending on the abstraction degree of the terms used and their presence in the pupil’s thesaurus; 2) the complexity level of mathematical, chemical and other formulas; 3) the structural complexity of the text, depending on the average length of its constituent words and sentences. Multiplying the DDC of the text by its volume, you can find the integral didactic complexity of the text. For the evaluation of the textbook DDC expert selects one page fragments of text randomly, identifies the key concepts, “measures” their average information content, determines the share of formulas and their average complexity. In this case, the classification of concepts according to the abstraction degree is used, which takes into account the occurrence of a particular word in the thesaurus of a preschool, fifth-grader, ninth-grader and school graduate. The structural complexity of the text is also taken into account, depending on the average length of words and sentences. The analysis of textbooks for school graduates has shown that the most difficult disciplines to understand are biology, physics, chemistry, mathematics. As a result of evaluating computer science textbooks for 3rd, 5th, 9th and 11th grades it was found that their semantic information density and differential semantic complexity monotonically increase from 5.3 to 8.1 and from 5.7 to 10.4 respectively.
Teacher of the Future: Monitoring of Scientific Potential College Teachers
Authors: Bychkov Anatoliy
Published: October 2020

In modern socio-economic conditions, advanced training of personnel, in particular mid-level specialists, as the leading subjects in the structure of effective production, becomes relevant. High-quality teaching activities in professional educational organizations (colleges) can be carried out by teachers who have developed scientific literacy, which largely determines the scientific potential of the teacher. The scientific potential of teachers can be improved by harmonizing the structure of the teacher's personality and the structure of his professional educational activities.
Computational Aspects of Bayesian Solution Estimators in Stochastic Optimization
Authors: Davarnia Danial , Kocuk Burak , Cornuéjols Gérard
Published: October 2020

We study a class of stochastic programs in which some of the elements in the objective function are random and their probability distribution has unknown parameters. The goal is to find a good estimate for the optimal solution of the stochastic program using data sampled from the distribution of the random elements. We investigate two common optimization criteria for evaluating the quality of a solution estimator—one based on the difference in objective values and the other based on the Euclidean distance between solutions. We use risk as the expected value of such criteria over the sample space. Under a Bayesian framework, where a prior distribution is assumed for the unknown parameters, two natural estimation-optimization strategies arise. A separate scheme first finds an estimator for the unknown parameters and then uses this estimator in the optimization problem. A joint scheme combines the estimation and optimization steps by directly adjusting the distribution in the stochastic program. We analyze the risk difference between the solutions obtained from these two schemes for several classes of stochastic programs and provide insight on the computational effort to solve these problems.
Infinite-Horizon Optimal Switching Regions for a Pair-Trading Strategy with Quadratic Risk Aversion Considering Simultaneous Multiple Switchings: A Viscosity Solution Approach
Authors: Suzuki Kiyoshi
Published: October 2020

Very few studies have explored the structure of optimal switching regimes. We extend the existing research on the infinite-horizon multiple-regime switching problem with an arbitrary number of switch options by replacing the linear running reward function with a quadratic function in the objective function. To make our analysis more rigorous, we establish the theoretical basis for the application of the simultaneous multiple-regime switches to the problem with the extended objective function, and provide the sufficient condition under which each certain separated region in the space includes, at most, one single connected optimal switching region, which determines the structure of the optimal switching regions, and we identify the structure of the optimal switching regions for the particular problem.
Sequential Product Development and Introduction by Cash-Constrained Start-Ups
Authors: Bhaskaran Sreekumar , Erzurumlu S. Sinan , Ramachandran Karthik
Published: October 2020

Problem definition: Firms developing novel and innovative products regularly face a canonical product development and introduction problem: introduce a proven and immediately available product or delay product introduction until the successful development of an advanced version. Academic/practical relevance: Limited access to resources for the development of an advanced version adds another wrinkle to this problem, particularly for cash-constrained start-ups. For such start-ups, the introduction of an on-hand product can generate additional funds to support the development of an advanced product. However, the lower performance of the on-hand product can negatively impact the perception of the firm’s future products and lower future profitability. Methodology: We study the trade-off between revenues that an on-hand product generates for research and development funding and the negative effect it has on future profits. We characterize the optimal introduction timing of the on-hand product as a function of the financial resource constraints, the interdependence between these sequential products and the cost of development. Results: We identify important differences between the optimal product introduction strategies of a start-up and an established firm. Specifically, although it is always optimal for an established firm to accelerate the launch of a better-quality on-hand product, a start-up might find it optimal to delay its launch. The impact of technological failure and different forms of learning on the optimal strategy of the start-up are also explored. We translate our analytical findings into a managerial framework and illustrate these results using examples from the pharmaceutical and medical devices industries.
On the Consistent Path Problem
Authors: Lozano Leonardo , Bergman David , Smith J. Cole
Published: October 2020

This paper studies a novel decomposition scheme, utilizing decision diagrams for modeling elements of a problem where typical linear relaxations fail to provide sufficiently tight bounds. Given a collection of decision diagrams, each representing a portion of the problem, together with linear inequalities modeling other portions of the problem, how can one efficiently optimize over such a representation? In this paper, we model the problem as a consistent path problem, where a path in each diagram has to be identified, all of which agree on the value assignments to variables. We establish complexity results and propose a branch-and-cut framework for solving the decomposition. Through application to binary cubic optimization and a variant of the market split problem, we show that the decomposition approach provides significant improvement gains over standard linear models.
Work-Family Programs and Nonwork Networks: Within-Group Inequality, Network Activation, and Labor Market Attachment
Authors: Ranganathan Aruna , Pedulla David S.
Published: October 2020

Organizations increasingly offer work-family programs to assist employees with balancing the competing demands of work and family life. Existing scholarship indicates that the consequences of work-family programs are heterogeneous across different socio-demographic groups, but limited research examines when and why workers within the same group may benefit differently from such programs. Understanding these differences may illuminate important mechanisms driving the effectiveness of work-family policies. We theorize that one key driver of within-group variation in the effectiveness of work-family programs is the extent to which workers’ nonwork social networks activate resources to support them. Specifically, we argue that workers whose nonwork networks are less likely to activate supportive resources will benefit more from organizational programs. We further posit that the status characteristics of workers’ dependents may shape the activation of resources among nonwork networks. Drawing on novel data from an Indian garment factory and a quasi-experimental research design, we examine how a work-family program, employer-sponsored childcare, affects the daily work attendance of a socio-demographically homogenous group of working mothers. We find that women whose nonwork networks are less likely to activate informal childcare support—specifically, women with daughters—benefit more from employer-sponsored childcare. Supplemental interview data supports our theoretical claims. We conclude by discussing the contributions of our argument to scholarship on work-family policies and social networks.
A Bucket Graph–Based Labeling Algorithm with Application to Vehicle Routing
Authors: Sadykov Ruslan , Uchoa Eduardo , Pessoa Artur
Published: October 2020

We consider the shortest path problem with resource constraints arising as a subproblem in state-of-the-art branch-cut-and-price algorithms for vehicle routing problems. We propose a variant of the bidirectional label-correcting algorithm in which the labels are stored and extended according to the so-called bucket graph. This organization of labels helps to significantly decrease the number of dominance checks and the running time of the algorithm. We also show how the forward/backward route symmetry can be exploited and how to eliminate arcs from the bucket graph using reduced costs. The proposed algorithm can be especially beneficial for vehicle routing instances with large vehicle capacity and/or with time window constraints. Computational experiments were performed on instances from the distance-constrained vehicle routing problem, including multidepot and site-dependent variants, on the vehicle routing problem with time windows, and on the “nightmare” instances of the heterogeneous fleet vehicle routing problem. Significant improvements over the best algorithms in the literature were achieved, and many instances could be solved for the first time.
Infiltration and Soil Water Distribution in Irrigation Furrows Treated with Polyacrylamide
Authors: Lentz Rick D. , Bautista Eduardo , Koehn Anita , Sojka Robert
Published: October 2020

Highlights

Control furrows with 1× inflow rates were compared with 3× advance inflows treated with 10 mg L-1 polymer (WSPAM).

WSPAM reduced sediment loads in furrow streams by 89%, despite its 3× greater advance inflows.

WSPAM furrow advance times and infiltrated volumes were greater than predicted from increased inflows alone.

WSPAM enabled reduced upper-section infiltration and increased lower-section infiltration relative to control furrows.

Abstract. Few if any studies have measured the effects of water-soluble anionic polyacrylamide (WSPAM) on infiltration and soil water distribution in different segments of irrigation furrows. We conducted a four-year study on a silt loam soil with 1.5% slopes. Control furrows received no WSPAM and inflows were 15.1 L min-1, whereas WSPAM was applied using 10 mg L-1 a.i. to 45 L min-1 inflows during furrow advance. Despite its greater advance phase inflow rates, WSPAM application reduced sediment concentrations in furrow streams by an average of 89% relative to the control. A surface irrigation model, WinSRFR 5.1, was used to separate furrow inflow rate effects on infiltration from that of WSPAM. Relative to results predicted by simulation for the entire furrow, the polymer treatment: (1) increased advance time an average 1.4-fold, (2) increased advance-phase infiltrated volume 1.5-fold, and (3) increased infiltration volume at the common opportunity time 1.2-fold. Hence, these effects resulted from WSPAM and not from differences in treatment inflow rates. Treatment infiltration amounts varied markedly among irrigations and years, as did the intensity of WSPAM effects. These were attributed mainly to differences in infiltration opportunity time, but temporal differences in soil water content during furrow formation, irrigation water electrical conductivity, initial soil surface water content and water temperature, and the irrigation-long, furrow-stream mean sediment content also appear to have influenced infiltration rates. Although inconsistent, WSPAM increased net furrow infiltration in the lower section and reduced infiltration in the upper section relative to control furrows. This effect could not be explained by the greater inflow rate and shorter advance time of the WSPAM treatments and was attributed to spatially variable WSPAM effects on infiltration opportunity time and possibly irrigation water viscosity. The WSPAM management approach, while protecting against furrow erosion, may potentially provide a means of improving irrigation uniformity and reducing associated percolation water and nutrient losses. Keywords: Furrow advance, Irrigation, Irrigation uniformity, Polymers.
Una semana sin smartphone: usos, abuso y dependencia del teléfono móvil en jóvenes
Authors: González-Cortés Eugenia , Córdoba-Cabús Alba , Gómez Marisol
Published: October 2020

INTRODUCCIÓN. El 98% de la población española posee un teléfono móvil, siendo los jóvenes los que mejor se desenvuelven en este entorno. La tecnología ha transformado sus comunicaciones y las redes sociales son su canal preferente de información. La presente investigación examina: a) la percepción que los jóvenes tienen de su uso del teléfono móvil, b) el consumo que realizan del smartphone y c) su grado de dependencia del móvil a partir de una experiencia de desconexión digital. MÉTODO. El método planteado consta de técnicas cuantitativas y cualitativas. Primero se diseñó y aplicó un cuestionario para analizar la percepción que los jóvenes tienen de su empleo del teléfono móvil. El cuestionario se distribuyó entre jóvenes andaluces de 15 a 24 años (n=1068). De acuerdo con los resultados obtenidos, se procedió a la realización de un experimento de campo y un grupo de discusión para comprobar la dependencia real del dispositivo. En él participaron once estudiantes de la Universidad de Málaga, cuyos teléfonos móviles fueron monitorizados durante tres semanas. La desconexión durante una semana permitió observar las consecuencias sociales, informacionales y emocionales que provoca en este segmento poblacional una dieta digital de estas características. RESULTADOS. Los resultados evidencian que los jóvenes no pueden vivir sin su teléfono, y ponen de manifiesto cómo hacen un uso intensivo (4h/día) e irrefrenable del smartphone, principalmente para el seguimiento de redes sociales. Durante la desconexión, se han detectado sensaciones encontradas que irían desde la incomodidad, la desinformación y la dependencia hasta la liberación. DISCUSIÓN. Se concluye que tras la semana de privación los estudiantes, aun reconociendo el dominio que el móvil ejerce en su vida y la libertadque experimentaron de las aplicaciones, se sienten incapaces de controlar y rebajar de manera voluntaria su tiempo de consumo.
Infectivity and viability of dengue virus infected hepatocytes cocultured with peripheral blood mononuclear cells from a healthy subject
Authors: Tresnaningtyas Sekar Asri , Sjatha Fithriyah , Dewi Beti Ernawati
Published: October 2020

BACKGROUND Dengue virus (DENV) can infect and replicate in monocytes, resulting in antibody-dependent enhancement. The liver is the main target of DENV, and the infection mechanisms of DENV include direct cytopathic effects (CPEs) of the virus, mitochondrial dysfunction, and effect of cellular and humoral immune factors in the liver. This study was aimed to explore the infectivity of DENV and viability of human hepatocytes using Huh 7it-1 cells cocultured with peripheral blood mononuclear cells (PBMCs).

METHODS Huh 7it-1 cells were infected with dengue virus serotype-2 (DENV-2) New Guinea C strain at multiplicity of infection of 0.5 and 1 FFU/cell, and cocultured in vitro with and without adherent PBMCs. The infectivity of DENV was assessed by immunoperoxidase staining. The viability of Huh 7it-1 cells was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT, a tetrazole) assay and trypan blue staining. Data were statistically analyzed by ShapiroWilk and analysis of variance for normality significances.

RESULTS The result showed that addition of PBMCs to DENV-2 infected Huh 7it-1 cells decreased the infectivity of DENV (1537%). DENV-2 infection decreased the viability of Huh 7it-1 cells (15.520.8%). Despite the decrease in infectivity of DENV, the addition of PBMCs increased the Huh 7it-1 cells viability (4.510.2%).

CONCLUSIONS Addition of PBMCs to Huh 7it-1 cells that are infected with DENV-2 decreased the infectivity of DENV and increased Huh 7it-1 cells viability.
β-endorphin response to aerobic and anaerobic exercises in Wistar male rats
Authors: Flora Rostika , Zulkarnain Mohammad , Sukirno
Published: October 2020

BACKGROUND Physical exercise is strongly associated with the release of β-endorphin. It is assumed that the type and intensity of physical exercise contributes to the release of β-endorphin. This study aimed to compare levels of β-endorphin in brain tissue in response to aerobic and anaerobic physical exercise. METHODS This study was an experimental laboratory study using 35 male Wistar rats divided into one control group and two physical exercise treatment groups: aerobic and anaerobic. Physical exercise was conducted on an animal treadmill running at aspeed of 20 m/min for 30 min of aerobic exercise and 35 m/min with 1-min intervals every 5 min for 20 min for anaerobic exercises. Each aerobic and anaerobic exercise group was furtherly classified into three subgroups (1×/week, 3×/week, and 7×/week). β-endorphin levels were determined using enzyme-linked immunosorbent assay. The data were analyzed using independent t-test and one-way analysis of variance. RESULTS The highest mean of β-endorphin level was found in the weekly exercise (54.45 [1.41] pg/ml) of aerobic exercise group and daily exercise (70.50 [11.67] pg/ml) of anaerobic exercise group. Mean of β-endorphin level in control group was 33.34 (3.54) pg/ml. A significant increased of β-endorphin mean level (p<0.001) was found in all aerobic and anaerobic exercise groups except the aerobic exercise 7×/week group(37.37 [6.30] pg/ml) compared to control. CONCLUSIONS Both aerobic and anaerobic physical exercise conducted for 6 weeks could increase the level of β-endorphin in brain tissue.
Retraction: Periodic acid-Schiff and alcian blue immunohistochemistry to detect mucin in mucinous breast carcinoma
Authors: Rustamadji Primariadewi , Wibowo Jason , Murtani Belinda , Magdalena Christy
Published: October 2020

[This retracts the article DOI: 10.13181/mji.oa.192768]
Investigation of a highly compact intracavity actively Q-switched cascade diamond Raman laser
Authors: Yang Haolin , Chen Yue , Ding Kaili , Jia Fuqiang , Li Kang , Copner Nigel , Davies Antony
Published: October 2020

A laser diode (LD) pumped intracavity chemical vapor deposition (CVD) diamond cascade Raman laser is reported here. By rotating a Brewster plate (BP) in the laser resonator, the Raman laser with tunable output coupling rate is achieved. The highly compact diamond laser emitted 1240 nm and 1485 nm Stokes light simultaneously via optimization of the pumping direction. The slope efficiency of the intracavity diamond laser is improved by optimizing the output coupling rate and adjusting the repetition rate of the 1064 nm fundamental laser. Ultimately, the maximum slope efficiency of the first Stokes light (1240 nm) is 16.8%, and the corresponding output power is about 0.6 W. The maximum peak power is 2.5 kW when the power of 808 nm LD is 34.7 W.
Breadth-first piston diagnosing approach for segmented mirrors through supervised learning of multiple-wavelength images
Authors: Hui Mei , Li Weiqian , Wu Yong , Liu Ming , Dong Liquan , Kong Lingqin , Zhao Yuejin
Published: October 2020

Piston diagnosing approaches for segmented mirrors via machine-learning have shown great success. However, they are inevitably challenged with

2

π

ambiguity, and the accuracy is usually influenced by the location and number of submirrors. A piston diagnosing approach for segmented mirrors, which employs the breadth-first search (BFS) algorithm and supervised learning strategies of multi-wavelength images, is investigated. An original kind of object-independent and normalized dataset is generated by the in-focal and defocused images at different wavelengths. Additionally, the segmented mirrors are divided into several sub-models of binary tree and are traversed through the BFS algorithm. Furthermore, two deep image-based convolutional neural networks are constructed for predicting the ranges and values of piston aberrations. Finally, simulations are performed, and the accuracy is independent of the location and number of submirrors. The Pearson correlation coefficients for test sets are above 0.99, and the average root mean square error of segmented mirrors is approximately

0.01
λ

. This technique allows the piston error between segmented mirrors to be measured without

2

π

ambiguity. Moreover, it can be used for data collected by a real setup. Furthermore, it can be applied to segmented mirrors with different numbers of submirrors based on the sub-model of a binary tree.
Benchmarking background oriented schlieren against interferometric measurement using open source tools
Authors: Kaganovich D. , Johnson L. A. , Mamonau A. A. , Hafizi B.
Published: October 2020

Gas flow from an under-expanding jet nozzle is measured using
synchronized background oriented schlieren and interferometry
diagnostics. The gas density distribution is obtained from a shift
vector field of the background oriented schlieren and compared to the
interferometric data. The comparison makes use of a simple calibration
routine and open source Python recipes.
Sub-40  fs pulses at 1.8  µm and MHz repetition rates by chirp-assisted Raman scattering in hydrogen-filled hollow-core fiber
Authors: Loranger Sébastien , Russell Philip St. J. , Novoa David
Published: October 2020

The possibility to perform time-resolved spectroscopic studies in the molecular fingerprinting region or extending the cutoff wavelength of high-harmonic generation has recently boosted the development of efficient mid-infrared (mid-IR) ultrafast lasers. In particular, fiber lasers based on active media such as thulium or holmium are a very active area of research since they are robust, compact, and can operate at high repetition rates. These systems, however, are still complex, are unable to deliver pulses shorter than 100 fs, and are not yet as mature as their near-infrared counterparts. Here, we report the generation of sub-40 fs pulses at 1.8 µm, with quantum efficiencies of 50% and without the need for post-compression, in hydrogen-filled, hollow-core photonic crystal fiber pumped by a commercial high-repetition-rate 300 fs fiber laser at 1030 nm. This is achieved by pressure-tuning the dispersion and avoiding Raman gain suppression by adjusting the chirp of the pump pulses and the proportion of higher-order modes launched into the fiber. The system is optimized using a physical model that incorporates the main linear and nonlinear contributions to the optical response. The approach is average power-scalable, permits adjustment of the pulse shape, and can potentially allow access to much longer wavelengths.
Virtual optics and sensing of the retrieved complex field in the back focal plane using a constrained defocus algorithm
Authors: Shen Mengqi , Chow Terry W. K. , Shen Hong , Somekh Michael G.
Published: October 2020

The reflected back focal plane from a microscope objective is known to provide excellent information of material properties and can be used to analyze the generation of surface plasmons and surface waves in a localized region. Most analysis has concentrated on direct measurement of the reflected intensity in the back focal plane. By accessing the phase information, we show that examination in the back focal plane becomes considerably more powerful allowing the reconstructed field to be filtered, propagated and analyzed in different domains. Moreover, the phase often gives a superior measurement that is far easier to use in the assessment of the sample, an example of such cases is examined in the present paper. We discuss how the modified defocus phase retrieval algorithm has the potential for real time measurements with parallel image acquisition since only three images are needed for reliable retrieval of arbitrary distributions.
Upconversion detection of 1.25 Gb/s mid-infrared telecommunications using a silicon avalanche photodiode
Authors: Gray Alan C. , Berry Sam A. , Carpenter Lewis G. , Gates James C. , Gawith Corin B. E. , Smith Peter G. R.
Published: October 2020

With an ever-increasing interest in secure and reliable free-space optical communication, upconversion detectors enabled through nonlinear optical processes are an attractive route to transmitting data as a mid-infrared signal. This spectral region is known to have a higher transmissivity through the atmosphere. In this work, we present an upconversion scheme for detection in the silicon absorption band using magnesium-oxide doped periodically poled lithium niobate to generate 21 mW of a 3.4 µm signal from commercial laser sources using a difference frequency generation process. Following a further nonlinear frequency conversion, via sum-frequency generation, the resulting signal at 809 nm is detected. We achieve >50 µW of signal and bit error rates of 10−7 from a single-pass nonlinear conversion for both the transmitter and receiver systems without the need for additional optical amplifiers at the receiving end. The error rates due to potentially reduced laser powers at the receiver end are investigated and laser noise transfer through our system is discussed.
Graphene/α-In2Se3 heterostructure for ultrafast nonlinear optical applications
Authors: Wang Lizhen , Li Jialin , Cui Yudong , Li Yujie , Zhang Duoduo , Ma Yaoguang , Zhu Haiming , Tan Dezhi , Liu Xueming , Wang Pan , Guo Xin , Li Linjun , Tong Limin
Published: October 2020

Two-dimensional (2D) heterostructure materials have attracted increasing attention in ultrafast nonlinear optical applications due to their intriguing properties. Here, we fabricate a graphene/α-In2Se3 heterostructure by dropping α-In2Se3 dispersion onto the surface of few-layered graphene film and investigate its nonlinear optical responses. We show that the graphene/α-In2Se3 heterostructure has combined advantages of ultrafast relaxation (τ1 ∼ 78 fs, τ2 ∼ 14 ps) and a large effective nonlinear absorption coefficient (βeff ∼ −1.2 × 104 cm/GW) with relatively large modulation depth. We have further integrated the heterostructure into an erbium-doped fiber laser for mode-locked pulse generation. These results indicate that graphene/α-In2Se3 heterostructures are a promising 2D material for ultrafast nonlinear optical applications.
CURRICULUM AND IDENTITY ITS IMPACTS ON THE SCHOOL CONTEXT IN GOIÁS: POINTS AND COUNTERPOINTS
Authors: Purificação Marcelo Máximo , Catarino Elisângela Maura , Teixeira Maria Filomena Rodrigues , Santana Lousana de Jesus , Abdalla Cláudia de Souza , Alves Angélica Ferreira
Published: October 2020

Abstract: One of the biggest challenges of contemporary education is to work with diversity, and identity plurality in school spaces, spaces in which relationships are often marked by tensions, conflicts, due to the asymmetries of power that permeate them and cause the construction of hierarchy, processes of subordination, (re) affirm prejudices, discrimination and violence in relation to certain social actors. It is a text of bibliographic review, in a qualitative approach, approaching the theoretical aspect of Cultural Studies. Keywords: Culture. Curriculum. Differences. Cultural Studies
Genetic dissimilarity between biofortified lettuce genotypes for leaf carotenoid levels
Authors: De Sousa Luciana Alves , Maciel Gabriel Mascarenhas , Juliatti Fernando Cezar , Beloti Igor Forigo , Siquieroli Ana Carolina Silva , Clemente Andressa Alves
Published: October 2020

Lettuce is the main leafy vegetable, presenting the highest consumption and economic importance in the world. In the recent decades, concerns about vitamin A deficiency have led Brazilian researchers to develop cultivars with higher levels of carotenoids provitamin A. Therefore the experiment aimed to verify the genetic dissimilarity of biofortified lettuce genotypes, investigating the correlation between agronomic characteristics and the potential for use to increase the carotenoid content in future breeding programs. Ninety one genotypes were evaluated, with 86 lettuce strains from hybridization between cultivars Pira 72 versus Uberlândia 10000 (rich in carotenoids) followed by three successive self-fertilizations and 5 commercial cultivars (Grand Rapids; UFU MC BIOFORT1; Pira 72; Uberlândia 10000 and Robusta).During the course of the trial, were evaluated characteristics as chlorophyll content of the leaves, plant diameter, stem diameter and the number of leaves per plant were counted. Genetic diversity was represented by a dendrogram that was obtained using the hierarchical method of UPGMA and the optimization method of Tocher. There is genetic divergence between the lettuce genotypes analyzed, and the carotenoid content character contributed most significantly to the divergence between the evaluated genotypes. The UFU215#12 genotypes; UFU215#14; UFU215#2; UFU 215#1; UFU215#4; UFU199#3 and UFU199#2 have good agronomic characteristics and high levels of carotenoids, being promising to continue the biofortified lettuce breeding program, aiming to obtain new cultivars rich in carotenoids pro vitamin A.
A educação popular na “Roda da Saúde”
Authors: Costa Márcia Barros da , Pereira Amanda Vargas , Cezário Felippe de Oliveira
Published: October 2020

Há tempos homens e mulheres participam de encontros e compartilham pensamentos e saberes. A cantiga “Vinde, Vinde”, é de domínio popular e muito interpretada pelos artistas das regiões Norte e Nordeste. É possível, através dessa cantiga, relembrar a infância, as histórias contadas pelos mais velhos, quando a noite chegava, e refletir sobre identidades e memórias. “Somos seres com história, construímos nossa identidade através de um processo que mescla as experiências vividas no ambiente e as nossas vivências interiores”. E foi possível recriá-la através da experiência em Educação Popular em Saúde, intitulada Roda da Saúde. A Equipe de Vigilância Ambiental em Saúde da Secretaria de Estadual de Saúde do Rio de Janeiro formada por Agentes de Combate as Endemias e um grupo de mulheres do Município de Queimados, Baixada Fluminense reuniam-se semanalmente. De mãos dadas, em roda, entoando cantigas e recontando histórias para sentir o mundo. A experiência Roda da Saúde foi realizada em janeiro de 2014; mês em que o sol e a chuva preparam sabiamente um clima tropical e muito propício para a proliferação do mosquito Aedes aegypti. A experiência Roda da Saúde foi baseada na Educação Popular em Saúde como concepção metodológica para as ações em comunidade.
No mar brasileiro agitado pela COVID-19, não estamos todos no mesmo barco
Authors: Souza e Souza Luís Paulo , Souza Antônia Gonçalves de
Published: October 2020

A pandemia da COVID-19 é a pior crise sanitária do século. Inicialmente, parecia consenso que o SARS-CoV-2 não escolhia classe, raça ou região, espalhando-se rapidamente de um corpo para o outro, contudo, as maneiras como os corpos estão dispostos no mundo variam a partir de marcadores sociais de desigualdades. No Brasil, a doença colocou em destaques importantes iniquidades já existentes, que seguiram seu curso com a pandemia (com alguns agravamentos); e, neste artigo, discutem-se algumas delas. Avaliando as medidas para contenção do vírus, ao mesmo tempo que visam proteger um determinado segmento da sociedade, deixam outros completamente desprotegidos, destacando-se os que não têm acesso à internet; desempregados; trabalhadores informais; os pretos e pardos; os de menor renda e escolaridade; os que residem no Norte e Nordeste. A pandemia no Brasil tem classe social, raça, cor e região; e, nesse mar agitado por ela, algumas pessoas estão em navios com serviços all inclusive, outras em lanchas, uma parte em barcos a remo, e outros tantos atravessando a nado. O país precisa pensar sobre qual projeto usar para enfrentamento da pandemia: seria um projeto que olha para as vulnerabilidades ou será o que segue em curso - deixando morrer uma parte da população, principalmente, a mais pobre? Além dos desafios da doença, o país ainda vivencia o impasse de ter um comandante do navio despreparado, cuja postura é claramente anticientífica e negacionista, deixando o navio à deriva. Discutir os princípios do Sistema Único de Saúde – SUS se faz importante, para garantir que sejam legitimados neste momento. A adoção de políticas públicas para superação das desigualdades é urgente, com forte participação social, possibilitando que esses grupos estejam mais fortalecidos para encararem desafios futuros; dando, no mínimo, condições mais dignas para atravessarem outros mares ou tempestades - caso sobrevivam ao mar revolto da COVID-19.
The Coextensive Circumstance- Parachordoma
Authors: Bajaj Anubha
Published: October 2020

Parachordoma is an extremely exceptional, peripherally situated soft tissue neoplasm arising at non axial locations. Also designated as soft tissue “myoepithelioma” or “mixed tumour”, the tumefaction histologically simulates a chordoma of axial skeleton and was referred to as “central chordoma” emerging within non- axial sites. Nevertheless, a distinctive immune profile categorises the lesion as a unique entity.
Between Aura and Access: Artefactuality, Institutionality, and the Allure of the Archival
Authors: Sommer Tim
Published: October 2020

This article analyses narratives inspired by the institutional emergence of the literary archive. It focuses in particular on what historian Arlette Farge has described as the “allure of the archives”: the elusive immediacy of encounters with artefactual remnants of the past. Key to this experience is what has often been described as the ability of archival objects to conjure up the presence of their creators – a process that at the same time paradoxically depends on the uniqueness and fundamental ‘unapproachability’ of the artefact. Through regulating and restricting access to documents, the archive thus maintains their distance and simultaneously makes them available for acts of reverential consumption. Focusing on such forms of gatekeeping and consecration, the article reads Henry James’s novella “The Aspern Papers” (1888) and Martha Cooley’s novelThe Archivist(1998) to enquire how the literary archive – both as an idea and as an institution – has shaped ways of thinking about the relationship between physical absence and auratic presence.
Words, Wares, Names: Dave the Potter as American Archive
Authors: Chaney Michael A.
Published: October 2020

This article introduces readers to the enslaved African American crafter, David Drake, otherwise known as “Dave the Potter”, who incised poetry, signatures, dates, and sayings onto the stoneware ceramic jugs and plantation storage pots he made (from the 1830 s to the 1860s). In view of the concept of an archive, Dave the Potter’s works are significant as they are made up of writing and plastic arts, words and material. They not only record what has been thought through writing, they also perform through material languages of handles, spouts, bases, rims, etc. disruptions of the conventional functioning of the archive. If, as Derrida and others have argued, an archive confuses the content of cultural artefacts with the invested right of those housing an archive to interpret its content, then Dave the Potter’s incised jars perform this contradiction on their very surfaces, in their very design and construction, showing how the place or site of memory is also a house of hidden hermeneutic rights to remember.
From Parchment to Podcast: The Collaborative Process of Building and Unlocking an Archive
Authors: Oertel Kristen T. , Harvey Renee , Folsom Diana
Published: October 2020

This project began with a deceptively simple question: “Were there runaway slaves in Indian Territory in the 1830 s and 40s?” The answer was complicated and relied upon the combined expertise of historians, archivists, curators, and collectors. This article describes how collaborative research, performed at the Helmerich Center for American Research at the Gilcrease Museum in Tulsa, Oklahoma, uncovered a long-neglected piece of history in Indian Territory. The collections, which contain diverse sources such as manuscripts written on parchment, archaeological artefacts, original art, and more recently, digitised documents, images, and videos, shape the way scholars answer their questions. Although scholarly research may appear to be an independent endeavour – the professor mining sources at a desk or writing alone on a computer – the reality, especially in the twenty-first century, is much different. What shows up on the page and, now, what results in a podcast, is rooted in a shared journey, beginning with an archivist or curator collecting and cataloguing materials and ending in cyberspace.
Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument
Authors: Cardman Ryan , Gonçalves Luís F. , Sapiro Rachel E. , Raithel Georg , Anderson David A.
Published: October 2020

We present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution ofλRF/2${\lambda }_{RF}/2$with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.