bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential method for determining third-order derivative matrix of ray with respect to source ray variables at spherical boundary
Authors: Lin Psang Dain
Published: October 2020

The two most common optical boundaries in geometrical optics are the spherical and flat. The present group recently derived the third-order derivative matrix of a skew ray with respect to the source ray vector for a ray reflected/refracted at a flat boundary. The proposed method was based on a differential geometry approach, and hence had the advantages of an improved accuracy and the need to trace just one ray. In the present study, the method is extended to a ray incident on a spherical boundary. The derived matrix is used to explore the primary wavefront spherical aberration of an axis-symmetrical system. Its result is identical to that obtained from Zemax simulations. The estimation capability of the fifth-order Taylor series expansion of a ray is investigated by using the finite difference methods and the developed matrix. The proposed matrix can serve as a useful basis for determining the higher-order differential derivative matrices of a ray to explore higher-order ray or wavefront aberrations in future studies.
Experimental evaluation of the impact of the light source on the measurement of short-term average crosstalk in homogeneous single-mode multi-core fibers
Authors: Luís Ruben S. , Rademacher Georg , Puttnam Benjamin J. , Awaji Yoshinari , Furukawa Hideaki
Published: October 2020

This work compares the random time-varying crosstalk in homogeneous multi-core fibers measured using different types of light sources with linewidths ranging from 100 Hz to 2.5 MHz. We show that the frequency stability of the light source plays a significant role on the quality of short-term average crosstalk measurements with no observable impact from laser linewidth. We also compare the use of filtered amplified spontaneous emission noise and coherent light sources for crosstalk measurements. The former are shown to enable average crosstalk measurements in short time periods. In contrast, measurements using coherent light sources require long measurement periods to reach similar results.
Highly efficient thermo-optic tunable micro-ring resonator based on an LNOI platform
Authors: Liu Xiaoyue , Ying Pan , Zhong Xuming , Xu Jian , Han Ya , Yu Siyuan , Cai Xinlun
Published: October 2020

We demonstrate a high-efficiency thermo-optic (TO) tunable micro-ring
resonator in thin-film lithium niobate. Thermal insulation trenches
around the heated micro-ring resonator and the underlying silicon
substrate significantly reduce the heating power consumption and
improve the tuning efficiency. Compared to conventional TO devices
without thermal insulation trenches, the proposed device achieves a
full free spectral range wavelength shift with a 14.9 mW heating
power, corresponding to a thermal tuning efficiency of 53.7 pm/mW, a
more than 20-fold improvement of tuning efficiency. The approach
enables energy-efficient high-performance TO devices such as optical
switches, wavelength routers, and other reconfigurable photonic
devices.
Application of orthogonal fringe patterns in uniaxial microscopic 3D profilometry
Authors: Zhong Min , Cheng Ke , Chen Feng , Xiao Chao , Duan Peng , Li Min
Published: October 2020

This research presents a novel uniaxial microscopic 3D profilometry method with the application of orthogonal fringe patterns in a structured light system. Specifically, the projector alternately projects vertical and horizontal stripes, and subtraction of two adjacent shot images is applied to eliminate the influence of the background information. This method requires only one-tenth of our previous method in collection and data processing volume, but the accuracy can achieve almost the same as that method. We will describe the principle of this uniaxial microscopic 3D profilometry and demonstrate the accuracy of the proposed measurement framework by comparing it with the ten-step phase-shifting method and the Fourier transform method. It shows that approximately 5.22 µm root-mean-square (RMS) error with a depth range of 1100 µm can be achieved by the proposed approach.
Gastrointestinal parasite infection intensity and hematological parameters in South African communal indigenous goats in relation to anemia
Authors: Mpofu Takalani Judas , Nephawe Khathutshelo Agree , Mtileni Bohani
Published: October 2020

Aim: The study was conducted to determine the intensity of gastrointestinal parasite (GIP) infections and hematological parameters in South African communal indigenous goats in relation to anemia.

Materials and Methods: A total of 288 goats were randomly sampled in areas representing four agro-ecological zones. Fecal and blood samples were collected from the rectum and jugular vein, respectively, of each animal. The number of eggs per gram (EPG) and oocysts per gram (OPG) of feces and the hematological parameters were determined using the modified McMaster technique and a BC-2800Vet® automatic hematology analyzer, respectively. Data were analyzed using the repeated measures techniques of Minitab 17, modeling the covariance structure of the observed data.

Results: Based on EPG and OPG, goats in humid zone were significantly infected (p<0.05) with strongyles, Eimeria, Moniezia, and Trichuris spp. Hematological parameters of goats in arid and humid zone were lower (p<0.05) than those in semi-arid and dry sub-humid zone. GIP infection intensities were higher (p<0.05) in young animals than in adult and suckling goats. GIP infection intensity was similar between goat sexes, while hematological parameters were higher (p<0.05) in females. Higher (p<0.05) infection intensities for strongyles (302.90 EPG) and Eimeria (216.09 EPG) were observed in winter compared to summer (strongyles: 302.90, Eimeria: 216.09 EPG). Higher (p<0.05) values for the hematological parameters were observed during summer compared to that in winter.

Conclusion: GIP infection intensity in the winter could be associated with hypochromic and normocytic anemia which likely to affects suckling goats while in the summer could be associated with normochromic and normocytic anemia which likely to affect young goats.

Keywords: hemoglobin concentration, mean corpuscular hemoglobin, packed cell volume, strongyles.
Migrant Workers Empowerment Through Vocational Education and Community-Based Learning: A Study Case of Indonesian in Taiwan
Authors: Yuniarto Paulus Rudolf
Published: October 2020

Based on the observation of Indonesian migrant workers vocational training programs and community-based learning activities in Taiwan, the training programs play a part in assisting migrant workers to improve their skill and develop self-capacity building, to facilitate knowledge transfer and offer guidelines on productive financial management to migrant workers, and to introduce and develop intercultural communication with locals. However, financial and material support from stakeholders (government and communities) to develop skills and building an institution that can bridge migrants and stakeholders are still underdeveloped. Various constraints ranged from the large number of migrants, voluntary absences, lack of material support, under-qualified teachers, limited business skill training, and limited networking are challenges that need to be addressed. In addition, vocational education/training curriculum are old fashioned and exclusive (segmented, only for active and bright worker). In the future development, it is vital to support more on community-based education/training programs and open access to a life skill education (knowledge) that can increase the worker’s self-esteem or self-transformation (a semblance of future carrier).
Immersing in Diverse Asian Migration
Authors: Utami Dian Wahyu
Published: October 2020

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Impact of Clinical Outcome Measures on Placebo Response Rates in Clinical Trials for Chronic Constipation: A Systematic Review and Meta-analysis
Authors: Chen Jie , Liu Xinghuang , Bai Tao , Hou Xiaohua
Published: October 2020

OBJECTIVES:

Chronic constipation (CC) is a recurrent functional bowel disorder worldwide. The purpose of this study is to examine its pooled placebo response rate and compare placebo response level in randomized controlled trials (RCTs) with different endpoint assessments.

METHODS:

PubMed, Cochrane Library, and Embase were electronically searched for therapeutic RCTs of CC with placebo control. Data extraction and assessment of risk of bias were performed independently by 2 reviewers. All the statistical calculation and analysis were performed using R 3.6.0. Our protocol has registered in PROSPERO with registration number: CRD42019121287.

RESULTS:

There were 46 studies included with 5,992 constipated patients allocated to the placebo arm in total. The pooled placebo response rate was 28.75% (95% confidence interval: 23.83%–33.67%) with significant heterogeneity among trials (

JOURNAL/cltg/04.03/01720094-202011000-00005/inline-formula1/v/2023-10-30T213709Z/r/image-tiff

= 93.6%). Treatment efficacy assessed using subjective improvement had a significantly higher placebo response rate than that assessed with improvement in complete (spontaneous) bowel movements or composite improvement (41.40% vs 18.31% or 20.35%, P < 0.001). According to the results of meta-regression, active treatment and endpoint assessment were most likely to lead to the huge heterogeneity among studies.

DISCUSSION:

Patients with CC have significant response level to placebo. Based on findings in this study, we do not recommend subjective improvement as endpoint while designing therapeutic RCTs for chronic constipated patients.
Investimentos e Comunidades Imaginadas de Futuros Professores de Inglês
Authors: Benitez Kadota Thais , Sanches Silva João Fábio
Published: October 2020

Questões relacionadas à construção identitária vem cada vez mais despertando interesse na comunidade acadêmica como um amplo campo de investigação. Nesta perspectiva, conceitos como investimento, identidades imaginadas e comunidades imaginadas são usados para ajudar a definir esse fenômeno composto por múltiplas camadas, chamado de identidade. A construção da identidade na pós-modernidade ocorre de modo contínuo e de forma aparentemente interminável, uma vez que o indivíduo se relaciona e pertence, ao mesmo tempo a diversos grupos e contextos sociais, que se integram e ajudam a formar a identidade do indivíduo. Embora não definida permanentemente, a identidade assumida por esse individuo afeta diretamente seu modo de ver o mundo e como ele deseja ser visto. A partir dos conceitos acima mencionados, o presente trabalho traz os resultados de um estudo qualitativo que teve por objetivo entender a construção da identidade de um grupo de futuros professores de inglês, enquanto aprendizes e usuários do referido idioma, e o impacto desta construção na sua prática docente ainda em formação. Os dados foram gerados a partir de um questionário aberto com alunos-professores de um curso de Letras Português/Inglês de uma universidade pública da cidade de Campo Grande. Os resultados sugerem que uma vez identificada relações entre comunidades imaginadas e identidades imaginadas no ambiente desses alunos-professores, seus investimentos e o desejo de se apropriar da língua geram impactos nas práticas da língua na formação destes alunos-professores. A compreensão destes conceitos ajudou a entender e construir suas identidades diante desse enredo de conflito e por vezes contraditórias.
Sim, meu Capitão!
Authors: Marcondes Valente Tiago
Published: October 2020

Texto literário
Understanding immersion in 2D platform-based online collaborative learning environments
Authors: Garcia Gibran , Jung Insung
Published: October 2020

Previous studies have revealed that when video gamers, or users of three-dimensional (3D) virtual worlds, display intense concentration coupled with an emotional engagement in their undertaking, they are affected by multisensory stimuli. This can lead to developing a feeling of detachment from the physical world, which, in turn, can lead to high levels of participation and engagement. Notwithstanding these results, it remains unclear as to whether students can experience the same kind of immersion in two-dimensional (2D) platform-based online collaborative learning spaces as has been achieved in video games and 3D worlds and, if they actually can, which features would lead to similar levels of increased engagement. This study is one of the first attempts to investigate the immersion experiences of students engaged in two 2D online collaborative learning platforms, one text-based and the other video-based. Data from eight students revealed that key features of immersion observed in video games and 3D worlds also appeared during the online collaborative activities but that the way such immersion was perceived by the students was greatly affected by the characteristics of the individual platform. When emotional engagement was considered, empathy was found to play an important role in the participants’ immersion experiences.

Implications for practice or policy:

Text-based platforms could be effective in motivating students to focus more on the postings, while video-based platforms may be more effective in generating empathy with others through observation of body language.

When selecting a communication platform for online collaboration, sensory stimuli of the platform should be carefully examined.

Empathy could be developed prior to an online collaborative activity so that students reflect on their thoughts and consider others’ feelings for a more immersive learning experience.
E-portfolio implementation: Examining learners’ perception of usefulness, self-directed learning process and value of learning
Authors: Song Boon Khing
Published: October 2020

Electronic portfolios (e-portfolios) have been widely used to help learners collect evidence of their learning, reflect on their evaluation, and promote self-directed learning. Through the introduction of an e-portfolio platform in a cluster of lessons in a module in a polytechnic in Singapore, this paper aimed to evaluate the effectiveness of the e-portfolio through the learners’ perceptions. A cross-sectional design using an online survey was employed with 226 students taking part in this study. There was high internal consistency among the survey items. Exploratory factor analysis suggested a 5-factor structure: (1) perceived usefulness (PU), (2) organisation (ORG), (3) collaboration (COL), (4) evaluation (EVA), and (5) perceived value of learning (PVL). In addition, confirmatory factor analysis verified that the proposed 5-factor solution was a good model fit. The final research instrument comprised 19 items. A further multiple regression analysis showed that all the independent variables, except for evaluation, were positive and significant predictors of learners’ PVL. Specifically, the ORG variable was the most influential predictor of PVL. In comparison, the PU variable was a relatively weaker predictor of PVL. The practical implications and further direction for research are discussed in the paper.

Implications for practice:

Curriculum designers could leverage on the use of Padlet as an e-portfolio as it has shown to be a promising tool in scaffolding students to practice self-directed learning.

Curriculum teams could increase learners’ perceived usefulness of e-portfolios by allowing learners to be familiarised with the tool in earlier phases of the curriculum.

Curriculum leaders may need to orchestrate carefully the technological, learning processes, and the affective aspects of learners to promote self-directed learning.
On Judge’s Trial Discourse in Chinese Courtroom from Goal-Driven Perspective
Authors: Zhang Qing
Published: October 2020

Any action has a certain goal, and the judge’s trial discourse is a system of goal with structure and level. Judges usually adopt some discourse strategies to achieve the goal of trial. Based on the court trial corpus collected by us, we find that judges often adopt purposeful discourse strategies to achieve the trial goal and discourse goal, such as question-and-answer strategy, power control strategy, presupposition strategy, repetition strategy and interruption strategy. Strategies actually refer to the means by which to achieve the goal of discourse. Because words are used to express and achieve the goal, the choice of means or strategies depends on the choice of the goal. From this perspective, we can see the relationship between strategy and goal. In a sense, strategy is rhetoric. The purpose of this paper is to study the discourse strategies adopted by judges in Chinese courts from the perspective of the goal principle.
Muzeum (nie)pamięci. Koń a Muzeum Powstania Warszawskiego
Authors: Lorenc Magdalena
Published: October 2020

Prezentowana od 2004 roku (nieprzerwanie od 2005 roku) wystawa stała w Muzeum Powstania Warszawskiego jest tekstem kultury – konstruktem niewolnym od władzy i polityki. Polityczność Muzeum nie przesądza jednak o jego wartości, a jedynie stanowi diagnozę rzeczywistości społecznej,w której kultura jest obszarem konfrontacji ideologicznej. Teza, że Muzeum jest uwikłane politycznie pod względem organizacyjnym i ideologicznym, nie jest deprecjonujące ani nobilitujące dla instytucji kultury. Wymaga jednak od Muzeum rezygnacji z roszczeń do neutralności, w sytuacji w której, decyzją swoich twórców, zajmuje ono w dyskursie określoną pozycję, czego przykładem jest pominięcie na ekspozycji historii zwierząt – ofiar wojny. Tymczasem nowa humanistyka oferuje nowemu muzeum (ale i tradycyjnemu) nurty, które demaskują twórcę narracji i demistyfikują jej obiektywny charakter. Pozwalają one zobaczyć i wyjaśnić powody pominięcia wojennej historii zwierząt w MPW, ale i wskazać, jak można i dlaczego powinno się inaczej o tych kwestiach myśleć, mówić i je pokazywać.
Między polityką kreowania a asertywnością. Polskie debaty o Europie na przykładzie europejskiego traktatu konstytucyjnego i wojny na Ukrainie
Authors: Karolewski Ireneusz Paweł , Mehlhausen Thomas
Published: October 2020

Artykuł analizuje fenomen polityzacji na przykładzie obrazów Europy w politycznym dyskursie Polski w latach 1990–2016. Autorzy wychodzą od fazowego modelu polskiej polityki europejskiej (adaptacja, kontestacja, kooperacja, suwerenizm) i argumentują, że zmiana wewnątrzpolitycznych relacji władzy w Polsce nie jest wystraczającym wyjaśnieniem dla dynamiki faz polskiej polityki europejskiej. Z tego względu analizie poddane są obrazy Europy, z którymi związane są różne potencjały polityzacyjne. Po przedstawieniu konceptualizacji obrazów Europy przeanalizowane zostaną dwa przypadki znajdujące się w fazach konfrontacji i suwerenizmu, które to wykazują duży stopień polaryzacji politycznej: debata o europejskim traktacie konstytucyjnym (2005) oraz polityka wschodnia w trakcie wojny na Ukrainie (2014). Analiza potwierdza, że w przypadku Polski głównymi podmiotami polityzacji pozostają partie polityczne. Poprzez silną polaryzację obrazów Europy na poziomie elit politycznych odzwierciedlane są z jednej strony zróżnicowane nastroje społeczne. Równocześnie, silna polaryzacja powoduje, że nawet w ramach jednej partii politycznej widoczna jest silna dynamika polityzacyjna, a obrazy Europy cechują się wysoką niestabilnością.
Azerbaijan – Kazakhstan relations: current situation and prospects
Authors: Huseynow Rusif
Published: October 2020

Azerbaijan and Kazakhstan should not be seen as two states which are close because of their Soviet past. In fact, the titular ethnic groups of Azerbaijan and Kazakhstan – Azerbaijanis and Kazakhs – come from a greater Turkic family. Azerbaijani-Kazakh brotherhood takes its roots from the very origins of the Turkic peoples that spread from the Altai Mountains and has been cemented by the Islamic factor. Maintaining maritime borders through the Caspian Sea, Azerbaijan and Kazakhstan are important nations for one another. Azerbaijan is seen as a bridge for Kazakhstan to access Turkey and Europe, while Kazakhstan offers Azerbaijan routes to Central Asia and China. The two countries attach great importance to their mutual relations, both bilateral and within various international organizations. These relations have only increased and not experienced any downturns or problems in the past 25 years. Kazakhstan recognized the territorial integrity of Azerbaijan, which is an important deal for Azerbaijan in its current conflict with neighboring Armenia. The countries even reached an agreement on the legal status of the Caspian Sea quite rapidly, while similar accords are still absent with other littoral countries. They are both interested in developing an East-West transport and energy corridor, enjoying a favorable geopolitical location that could serve as a bridge between the continents.
Political Participation and New Technologies of Communication in Spain
Authors: Luengo Óscar , Fernández-Garcia Belén
Published: October 2020

The consolidation of the Internet as not only a media outlet, but also a multifunctional platform, has put into question the traditional relationship between media and political participation. The latest political developments in Spain, such as the 15-M movement or the success of Podemos, show that new technologies increase the options for new and fresh ways of political activism. This study provides a diagnosis of the role played by new technologies of communication, particularly the Internet, in political activism in Spain. The results show a noteworthy dissemination of the Internet as a political information source, as well as a platform to participate in politics. In addition, the analysis suggests that online participation is a phenomenon more popular among young people, with high studies and located on the ideological left. This profile is similar to that of citizens who support the new political forces like Podemos and the different citizens’ movements which are demanding a reconfiguration of the democratic system in Spain.
THE CONCEPT OF ”SECURITY” IN ANNUAL SPEECHES OF THE REPUBLIC OF POLAND MINISTERS OF FOREIGN AFFAIRS AFTER 2001
Authors: Pochyły Piotr
Published: October 2020

After the WTC attacks in 2001, the international situation and security in the world has changed. The United States and its allies - including Poland – have started a war against global terrorism and got involved in the war in Afghanistan and Iraq. The economic crisis at the end of the first decade of the 21st century, the Arab Spring, the rise of the so-called Islamic State, the war in Ukraine and the refugee crisis have affected the state of security in Poland and in Europe. Since 2014 Poland’s foreign ministers have been forced to react to the most difficult geostrategic situation after 1989. The paper analyses the issue of security in the annual speeches of Poland’s foreign ministers. The research problem is the impact of the international situation on the contents of the ministers’ annual speeches in this regard.
IN PURSUIT OF BROAD AGREEMENTS IN THE FUTURE DEVELOPMENT OF THE DECLARATION ON THE RIGHT TO PEACE WITHIN THE UNITED NATIONS
Authors: Guillermet-Fernandez Christian , Puyana David Fernandez
Published: October 2020

War and peace perpetually alternate and peace is always seen as an endless project, even a dream, to be realised in brotherhood by everyone all over the earth. Present generations should ensure that both they and future generations learn to live together in peace with the highest aspiration of sparing future generations the scourge of war. The UN Charter is the most solemn pact of peace in history, which lays down on the necessary basic principles for an enduring peace. Recently, in the context of the joint effort in the recognition of the high importance of practicing tolerance, dialogue, cooperation and solidarity among all human beings, peoples and nations, the General Assembly has raised the voice of victims to strongly condemn war and to openly reiterate their inalienable right to enjoy peace such that all human rights are promoted and protected and development is fully realized. The aim is to present activities of the General Assembly focused on the adoption of the Declaration on the right to peace.
PRZEGLĄD STRATEGICZNY BEZPIECZEŃSTWA PAŃSTW EUROPEJSKICH
Authors: Magiera Maciej , Donaj Łukasz
Published: October 2020

Treścią publikacji jest dokonanie przeglądu strategicznego bezpieczeństwa europejskiego państw europejskich w 2016 roku, i stworzenie – na wzór metody „scenariuszy międzynarodowych” – prognoz krótko-, średnio- oraz długoterminowych. Autorzy zajęli się zarówno wydarzeniami mającymi charakter konfliktów zbrojnych (w tym także tzw. „zamrożonymi konfliktami”), a także problemem nasilających się aktów terrorystycznych. Zwrócono także uwagę na kwestię kryzysu imigracyjnego, powodującego zarówno wzrost nastrojów radykalnych, ale będącego również „źródłem” przemytu osób (w tym terrorystów) oraz towarów (w tym broni, wykorzystywanej następnie w zamachach).
TEORIA SZARYCH SYSTEMÓW A PROGNOZOWANIE W NAUKACH SPOŁECZNYCH. PRZYCZYNEK DO DYSKUSJI
Authors: Donaj Łukasz
Published: October 2020

Treścią publikacji jest przedstawienie wybranych problemów prognozowania w naukach społecznych. W artykule skoncentrowano się na teorii szarych systemów. Zwrócono także szczególną uwagę na kwestię komplikacji wynikających ze złożoności takich systemów, jak system polityczny, a w konsekwencji na niedostatki tradycyjnych metod badawczych – takich jak chociażby metoda analizy systemowej. Celem publikacji jest zasygnalizowanie możliwości wykorzystania tak zdawałoby się egzotycznej dla „politologów” metodologii szarych systemów oraz modelowania rozmytego do prognozowania zjawisk politycznych.
Traumatic Brain Injury Diminishes Feedforward Activation of Parvalbumin-Expressing Interneurons in the Dentate Gyrus
Authors: Folweiler Kaitlin A. , Xiong Guoxiang , Best Kaitlin M. , Metheny Hannah E. , Nah Gabriel , Cohen Akiva S.
Published: October 2020

Traumatic brain injury (TBI) is associated with aberrant network hyperexcitability in the dentate gyrus (DG). GABAAergic parvalbumin-expressing interneurons (PV-INs) in the DG regulate network excitability with strong, perisomatic inhibition, although the posttraumatic effects on PV-IN function after TBI are not well understood. In this study, we investigated physiological alterations in PV-INs one week after mild lateral fluid percussion injury (LFPI) in mice. PV-IN cell loss was observed in the dentate hilus after LFPI, with surviving PV-INs showing no change in intrinsic membrane properties. Whole-cell voltage clamp recordings in PV-INs revealed alterations in both EPSCs and IPSCs (EPSCs/IPSCs). Evoked EPSCs (eEPSCs) in PV-INs from perforant path electrical stimulation were diminished after injury but could be recovered with application of a GABAA-receptor antagonist. Furthermore, current-clamp recordings using minimal perforant path stimulation demonstrated a decrease in evoked PV-IN action potentials (APs) after LFPI, which could be restored by blocking GABAAergic inhibition. Together, these findings suggest that injury alters synaptic input onto PV-INs, resulting in a net inhibitory effect that reduces feedforward PV-IN activation in the DG. Decreased PV-IN activation suggests a potential mechanism of DG network hyperexcitability contributing to hippocampal dysfunction after TBI.
Complementary Effects of Adaptation and Gain Control on Sound Encoding in Primary Auditory Cortex
Authors: Pennington Jacob R. , David Stephen V.
Published: October 2020

An important step toward understanding how the brain represents complex natural sounds is to develop accurate models of auditory coding by single neurons. A commonly used model is the linear-nonlinear spectro-temporal receptive field (STRF; LN model). The LN model accounts for many features of auditory tuning, but it cannot account for long-lasting effects of sensory context on sound-evoked activity. Two mechanisms that may support these contextual effects are short-term plasticity (STP) and contrast-dependent gain control (GC), which have inspired expanded versions of the LN model. Both models improve performance over the LN model, but they have never been compared directly. Thus, it is unclear whether they account for distinct processes or describe one phenomenon in different ways. To address this question, we recorded activity of neurons in primary auditory cortex (A1) of awake ferrets during presentation of natural sounds. We then fit models incorporating one nonlinear mechanism (GC or STP) or both (GC+STP) using this single dataset, and measured the correlation between the models’ predictions and the recorded neural activity. Both the STP and GC models performed significantly better than the LN model, but the GC+STP model outperformed both individual models. We also quantified the equivalence of STP and GC model predictions and found only modest similarity. Consistent results were observed for a dataset collected in clean and noisy acoustic contexts. These results establish general methods for evaluating the equivalence of arbitrarily complex encoding models and suggest that the STP and GC models describe complementary processes in the auditory system.
Normocalcaemic hyperparathyroidism and primary hyperparathyroidism: least significant change for adjusted serum calcium
Authors: Schini Marian , Jacques Richard , Oakes Eleanor , Peel Nicola , Walsh Jennifer S , Eastell Richard
Published: October 2020

Introduction

The least significant change (LSC) is a term used in individuals in order to evaluate whether one measurement has changed significantly from the previous one. It is widely used when assessing bone mineral density (BMD) scans. To the best of our knowledge, there no such estimate available in the literature for patients with disorders of calcium metabolism. Our aim was to provide an estimate of the least significant change for albumin-adjusted calcium in patients with normocalcaemic hyperparathyroidism (NPHPT) and primary hyperparathyroidism (PHPT).

Methods

We used the within-subject standard deviatio calculated in a population of NPHPT and PHPT patients and multiplied it by 2.77.

Results

The LSC for NPHPT and PHPT were found to be 0.25 and 0.24 mmol/L, respectively (1.00 and 0.96 mg/dL). In clinical practice, the value of 0.25 mmol/L could be used.

Discussion

The least significant change given, could be used in two ways in these patients. First, it gives a range to which values are expected. This can provide some reassurance for the patient and the physician in cases of intermittent hypercalcaemia. Moreover, it can be a marker of whether an individual has an actual significant change of his calcium after parathyroid surgery.
Body mass index rather than the phenotype impacts precocious ultrasound cardiovascular risk markers in polycystic ovary syndrome
Authors: Pandurevic Srdjan , Bergamaschi Luca , Pizzi Carmine , Patton Laura , Rucci Paola , Corzani Francesca , Cecchetti Carolina , Pelusi Carla , Altieri Paola , Vicennati Valentina , Di Dalmazi Guido , Fanelli Flaminia , Macut Djuro , Pagotto Uberto , Gambineri Alessandra
Published: October 2020

Objective

Research into cardiovascular disease (CV) prevention has demonstrated a variety of ultrasound (US) markers predicting risk in the general population but which have been scarcely used for polycystic ovary syndrome (PCOS). Obesity is a major factor contributing to CV disease in the general population, and it is highly prevalent in PCOS. However, it is still unclear how much risk is attributable to hyperandrogenism. This study evaluates the most promising US CV risk markers in PCOS and compares them between different PCOS phenotypes and BMI values.

Design

Women fulfilling the Rotterdam criteria for PCOS were recruited from our outpatient clinic for this cross-sectional study.

Methods

Participants (n = 102) aged 38.9 ± 7.4 years were stratified into the four PCOS phenotypes and the three BMI classes (normal-weight, overweight, obese). They were assessed for clinical and biochemical parameters together with the following US markers: coronary intima-media thickness (cIMT), flow-mediated vascular dilation (FMD), nitroglycerine-induced dilation (NTG), and epicardial fat thickness (EFT).

Results

There was no statistical difference among the four phenotypes in terms of cIMT, FMD, NTG or EFT, however all the US parameters except NTG showed significant differences among the three BMI classes. Adjusting for confounding factors in multiple regression analyses, EFT retained the greatest direct correlation with BMI and cIMT remained directly correlated but to a lesser degree.

Conclusions

This study showed that obesity rather than the hyperandrogenic phenotype negatively impacts precocious US CV risk markers in PCOS. In addition, EFT showed the strongest association with BMI, highlighting its potential for estimating CV risk in PCOS.
Diagnóstico y reestructuración pedagógica en la enseñanza de programación de computadores en Ingeniería de Sistemas
Authors: Ramírez Prada Paulo César , Ortiz Beltrán Ariel Orlando , Lobo Quintero Rene Alejandro
Published: October 2020

La forma tradicional de enseñar programación ha resultado ser ineficiente a la hora de motivar a las nuevas generaciones de ingenieros para encontrar su camino profesional. En la Universidad Autónoma de Bucaramanga se tomó la decisión de crear una estrategia para resolver este problema, con el objetivo de mejorar las métricas de desempeño sobre los alumnos y profesores, así como orientar el currículo hacia las tendencias específicas de la disciplina (apps, IoT, web, IA y videojuegos) y, por último, hacer una revisión de las herramientas, plataformas y lenguajes de programación que estaban en tendencia a nivel mundial para incluirlos en el plan docente en conjunto con una metodología de gamificación experimental diseñada por los mismos docentes. Como resultado, las calificaciones generales mejoraron, las tasas de deserción disminuyeron y la población estudiantil en general aumentó.
Análisis del componente de formación humanística dado a los oficiales de la Policía Nacional de Colombia entre 2010 y 2019 y su incidencia en la consolidación de un profesional íntegro con vocación de servicio
Authors: Fajardo Pascagaza Ernesto , Céspedes Prieto Nubia Edith , Cervantes Estrada Luis Carlos , Mahecha Sánchez Sara Juliana , Morales Viveros Erick Sebastián , Viasús De Antonio Jonathan Alexander
Published: October 2020

Objetivo: analizar cómo la formación ofrecida a los oficiales de la Policía Nacional en Colombia entre 2010 y 2019 ha incidido en la labor profesional, particularmente en la consolidación de un profesional íntegro con vocación de servicio, orientado a mejorar la percepción de los colombianos frente a la imagen de la institución. Método: se desarrolló una metodología mixta con la que se generará una directriz eficaz para la dimensión del proyecto de investigación con cinco fases que enmarcan todo el contenido. Resultados: se obtuvo la apreciación de los expertos tanto sobre el manejo del talento humano y su formación policial, como sobre su servicio de policía. De igual manera, se logró realizar una encuesta a una muestra representativa de los cursos 101 a 105 de oficiales, que fue planteada a partir de los lineamientos de humanismo previstos en la institución desde el 2010. Discusión y conclusión: el aporte significativo es la integración de todos los componentes que enmarcan un ideal profesional de policía, orientado a su formación como líder de los nuevos cambios sociales; dicha magnitud referencia una vez más que el humanismo en la Policía Nacional enmarca profesionales íntegros y con vocación hacia la comunidad colombiana, confirmado por los resultados obtenidos en el trabajo investigativo.
Cultivating Well-being: Young People and Food Gardens in Tanna, Vanuatu
Authors: Mitchell Jean , Niras Joan , Niefeu Lesbeth
Published: October 2020

Gardens in Vanuatu, an archipelago in the SW Pacific, materialize the multiple relationships between land, humans, and the more-than-human world that facilitate self-reliance, and wellbeing. This paper analyzes a collaborative project (2016-18) undertaken on the Island of Tanna in Vanuatu. A project for and with youth and their communities, it aimed to train young people to do basic research on customary food gardens and to document Indigenous customary knowledge, practices, and customary stories about food and gardens. The project started after a catastrophic cyclone destroyed gardens and infrastructure, rendering the self-sufficient islanders dependent on food aid at a time of rising rates of non-communicable diseases (NCDs). There is also concern about the declining interest in traditional knowledge among youth. With about 60% of the population under 30 years of age, this paper argues that youth are critical actors in ensuring the continuity of customary knowledge and practices that are essential for food sovereignty, the maintenance of social relations and wellbeing, all of which are embedded in relational ecologies of care.
Verification of a hydrodynamic model of a liquid-propellant rocket engine’s cavitating pumps using experimental and theoretical pump transfer matrices
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Dolgopolov S.I.
Published: October 2020

Cavities at the pump inlet may lead to inadmissible cavitation self-oscillations in the feed system of liquid-propellant rocket engines (LPREs) and to POGO instability if the oscillation frequency of the liquid is close to that of the rocket structure. Because of this, it is important to prevent both cavitation and POGO oscillations as early as at the engine and rocket design stage. This calls for a reliable mathematical model of the dynamics of LPRE cavitating pumps. In this paper, a hydrodynamic model of LPRE cavitating pumps is verified using theoretical and experimental transfer matrices of cavitating pumps. The experimental transfer matrix was borrowed from Brennen, Meissner, Lo, and Hoffman’s work because it features the least spread of values among the matrices reported in the literature. The theoretical matrix was borrowed from Pilpenko and Kvasha’s work where is was constructed for a cavitating pump as a distributed-parameter system. Four versions of the hydrodynamic model of LPRE cavitating pumps are verified, and six possible model coefficients are considered. Only one coefficient, namely, the liquid inertance at the cavity location, takes a physically meaningless negative value, which makes its use impossible. The verification results show that a four-coefficient model of cavitating pipe dynamics adequately describes cavitation effects in LPRE pumps over the frequency range up to 200 Hz. The four coefficients are the cavitation elasticity, the cavitation resistance, the cavity-caused disturbance transfer delay time, and the cavity time constant or the cavitation resistance distribution coefficient.
Global trends in the development of low-orbit space systems for optoelectronic Earth observation
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Volosheniuk O.L.
Published: October 2020

The aim of this work is to identify the global trends in the use of low-orbit spacecraft constellations, which have a number of substantial advantages in Earth remote sensing (ERS). Much attention is given to the construction of large constellations of single- and different-type spacecraft by foreign companies and operators, such as Digital Globe, Planet Labs, Black Sky, Satellogic S.A. etc., and to the plans of deployment of constellations of this type in the USA, China, Japan, Canada, Europe, and other countries. The characteristics of the various, mainly commercial, low-orbit constellations of optoelectronic Earth observation spacecraft put into orbit over the past five years are considered. It is shown that low-orbit spacecraft constellations can be used to good advantage in the solution of numerous socio-economic problems, such as geodesy and cartography, urban development, transport infrastructure, crop estimate, environmental monitoring, health monitoring, etc., and new problems aimed at prompt continuous monitoring of various objects. The paper presents a comparative analysis of the technical implementations and ways of achievement of the main target spacecraft characteristics, such as information performance, capture range, revisit time, geodetic connection accuracy, imaging immediacy, and the possibility of stereo and video imaging by satellite constellations. It is shown that the construction of large low-orbit constellations is a new trend in the world astronautics, which requires systematic methods for their design and control. The results obtained allows one to make recommendations on the design of low-orbit constellations of home ERS spacecraft, in particular on the development of orbit determination models and algorithms and spacecraft dynamics models.
Effect of the location of a gas flow control element in an ejector unit on the flow pattern
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Ihnatev O.D. , Shevelova H.M. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Published: October 2020

This article is devoted to a numerical simulation of the flow in a jet mill ejector equipped with a gas flow control element. This element is a channel wherefrom an additional gas flow enters the accelerating tube of the ejector. The gas flows in the mill ejector are controlled using the energy of additional gas flows, thus increasing the velocity of the main flow at the outlet of the ejector accelerating tube and producing a protective layer around the tube walls to prevent their wear. At the same time, there is no substantiation for the choice of optimal control parameters, a methodology, or scientific methods for gas flow control in the ejector channels. The purpose of this work is to investigate the effect of the location of the gas flow control element on gas-dynamic ejector performance and the flow pattern in the ejector channels. A numerical study was carried out using the Ansys Fluent software package and the SST k-? turbulence model. In the course of the study, the pressure of the additional gas flow and the distance from the accelerating tube inlet to the energy carrier supply channel were varied. The angle of the additional gas flow was 20 ?. The numerical simulation gave flow patterns in the ejector as a function of the location of the gas flow control element. Streamlines of the additional gas flow were constructed. The article presents the average flow velocity at the accelerating tube outlet and the energy carrier flow rate as a function of the pressure of the additional flow of the energy carrier and the location of the gas flow control element and the maximum values of the average outlet velocity for given pressure ranges. The article substantiates the choice of the gas flow control parameters that maximize the velocity of the mixed flow at the accelerating tube outlet at a minimum gas flow rate. The results may be used in improving material processing technologies.
Transient dynamic response of a nanocomposite conical shell with a ring stiff-ener under the action of an impact load
Authors:   A. Pidgorny Institute of Mechanical Engineering Problems, Avramov K.V. , Sakhno N.H. ,   National Technical University “Kharkiv Polytechnic Institute” Ministry of Education and Science of Ukraine, Uspensky B.V. ,   A. Pidgorny Institute of Mechanical Engineering Problems
Published: October 2020

This work is devoted to the study of transient processes occurring in a nanocomposite shell with a ring stiffener under the action of an impact load. Nanocomposites are promising new materials for the aerospace industry. However, the analysis of dynamic processes in nanocomposite structures requires the development of new methods due to the anisotropic, functional-gradient nature of these materials. The problem is further complicated if a composed structure is to be analyzed. This paper proposes a model of deformation of a functionally graded composite conical shell reinforced with carbon nanotubes with an isotropic ring stiffener. The deformation of the functionally graded nanocomposite conical shell is described by Reddy’s high-order shear theory, and the deformation of the ring stiffener is described by the Euler–Bernoulli hypotheses. The Rayleigh–Ritz method is used to study the natural vibrations of the composite structure. The main variables are the displacements and angles of rotation of the conical shell. A mathematical model of the transient response of the structure under the action of an impact load is obtained in the form of a linear dynamic system in generalized coordinates. To obtain this system, the prescribed form method is used. Numerical studies of the free dynamics and transient response of a nanocomposite conical shell with an isotropic ring stiffener of rectangular section under the action of an impact load were carried out. The results of the numerical modeling of the transient process in the shell showed a close agreement with the results of finite element modeling in the ANSYS package. The effect of the ring stiffener on the amplitudes of the transient response of the nanocomposite shell is investigated. It is shown that the ring-stiffener significantly reduces the amplitude of the transient response of the composite conical shell when it is subjected to an impact load. The proposed method and the conclusions drawn may be used in the aerospace industry in the design of nanocomposite units for multistage launch vehicles.
Increasing the 18-100 freight-car truck shear stiffness
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Pasichnyk S.S. , Bezrukavyi N.V. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Published: October 2020

Although a large number of truck models have been put into service on the 1520 mm gage railways over the past ten years, the problem of an insufficient shear stiffness of a freight car truck still remains topical. This problem is a consequence of attempts to keep a sufficient degree of unification of new truck models with the 18-100 truck because this greatly simplifies the introduction of new trucks and allows one to make the best use of the existing maintenance and repair infrastructure. However, this also results in that new designs inherit many drawbacks of the 18-100 truck. One of its critical drawbacks is a low connectedness in a horizontal plane, which reduces the critical speed and increases truck component wear. A solution to this problem may be an auxiliary stiffening frame. This paper presents a new design of an auxiliary stiffening frame for the 18-100 truck. The design increases the truck shear stiffness, thus improving freight car dynamic performance and service life. Mathematical simulation, oscillation theory, and elasticity theory methods were used to design an auxiliary stiffening frame installable between the 18-100 truck side frames without any significant changes in the freight car basic design. The physical and mechanical properties of the auxiliary stiffening frame’s structural materials were selected. Loads on the auxiliary stiffening frame were determined and then used in the calculation of the stresses that develop therein in motion. It was found that the proposed auxiliary stiffening frame with resilient polyurethane inserts increases the truck shear stiffness by 0.5 MN/m. The proposed improved design of the 18-100 truck increases its shear stiffness, improves freight car dynamic and operational performance, and reduces truck component wear. Besides, the auxiliary stiffening frame is simple in design. Because of this, its introduction will bring considerable economic benefits.