bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of wither application of an analogue of pig appeasing pheromone on encounters between unfamiliar mini-pigs
Authors: Marcet-Rius Míriam , Mendonça Tiago , Pageat Patrick , Arroub Sana , Bienboire-Frosini Cécile , Chabaud Camille , Teruel Eva , Cozzi Alessandro
Published: December 2022

Background

The practice of mixing unfamiliar pigs on farms is common but results in fighting, welfare problems and performance issues. Pigs have different ways of resolving social conflicts, including aggressive and affiliative behaviours. Synthetic appeasing pheromones have demonstrated many positive effects in animal husbandry and are regularly used by breeders to improve animal welfare and performance. The aim of the study was to investigate the effect of a new method of applying pig appeasing-pheromone (PAP) to the withers in an experimental model of pig mixing to determine whether PAP reduced aggression and fighting, increased prosocial behaviours, and improved behavioural and physiological indicators of welfare.

Results

PAP reduced fighting between mini-pigs (df = 1; F = 13.47;P = 0.001; mixed logistic regression). Even if not significant, agonistic behaviours tended to be reduced when the treatment was applied (df = 1; F = 4.14;P = 0.058; mixed logistic regression). Likewise, mini-pigs seemed to be scored as not aggressive at all (df = 1; F = 3.61;P = 0.070; GLMM) and to be less aggressive toward the other pig than when placebo was applied. Concerning the latency of the first contact without aggression, a significant effect was found between the PAP and placebo groups (df = 1;χ2 = 4.74;P = 0.0295; Cox model). Moreover, even if not significant, the treated mini-pigs seemed to spent more time looking at each other (df = 1; F = 3.59;P = 0.071; GLMM) and immobile and/or ground sniffing (df = 1; F = 3.18;P = 0.088; GLMM) than those that received placebo. No significant difference was found between groups for salivary cortisol concentration (df = 1; F = 0.10;P = 0.752; GLMM), but variances between groups were heterogeneous at every time. No significant difference was found between groups regarding alpha-amylase activity (df = 1; F = 0.25;P = 0.621; GLMM), but variances between groups were heterogeneous at T0, T1 and T3. These results indicate that the variability (dispersion) within each group was lower when PAP was applied than when the placebo was applied.

Conclusions

The new method of applying PAP improved welfare of mini-pigs (as models of domestic pigs) by reducing fighting, among other interesting results. PAP seems thus a promising biomimetic tool to enhance animal welfare in pig production systems.
Advances in surface modifications of the silicone breast implant and impact on its biocompatibility and biointegration
Authors: Foroushani Fatemeh Tavakoli , Dzobo Kevin , Khumalo Nonhlanhla P , Mora Vanessa Zamora , de Mezerville Roberto , Bayat Ardeshir
Published: December 2022

Silicone breast implants are commonly used for cosmetic and oncologic surgical indications owing to their inertness and being nontoxic. However, complications including capsular contracture and anaplastic large cell lymphoma have been associated with certain breast implant surfaces over time. Novel implant surfaces and modifications of existing ones can directly impact cell-surface interactions and enhance biocompatibility and integration. The extent of foreign body response induced by breast implants influence implant success and integration into the body. This review highlights recent advances in breast implant surface technologies including modifications of implant surface topography and chemistry and effects on protein adsorption, and cell adhesion. A comprehensive online literature search was performed for relevant articles using the following keywords silicone breast implants, foreign body response, cell adhesion, protein adsorption, and cell-surface interaction. Properties of silicone breast implants impacting cell-material interactions including surface roughness, wettability, and stiffness, are discussed. Recent studies highlighting both silicone implant surface activation strategies and modifications to enhance biocompatibility in order to prevent capsular contracture formation and development of anaplastic large cell lymphoma are presented. Overall, breast implant surface modifications are being extensively investigated in order to improve implant biocompatibility to cater for increased demand for both cosmetic and oncologic surgeries.
Subarachnoid hemorrhage triggers neuroinflammation of the entire cerebral cortex, leading to neuronal cell death
Authors: Yamada Hiroki , Kase Yoshitaka , Okano Yuji , Kim Doyoon , Goto Maraku , Takahashi Satoshi , Okano Hideyuki , Toda Masahiro
Published: December 2022

Background

Subarachnoid hemorrhage (SAH) is a fatal disease, with early brain injury (EBI) occurring within 72 h of SAH injury contributes to its poor prognosis. EBI is a complicated phenomenon involving multiple mechanisms. Although neuroinflammation has been shown to be important prognosis factor of EBI, whether neuroinflammation spreads throughout the cerebrum and the extent of its depth in the cerebral cortex remain unknown. Knowing how inflammation spreads throughout the cerebrum is also important to determine if anti-inflammatory agents are a future therapeutic strategy for EBI.

Methods

In this study, we induced SAH in mice by injecting hematoma into prechiasmatic cistern and created models of mild to severe SAH. In sections of the mouse cerebrum, we investigated neuroinflammation and neuronal cell death in the cortex distal to the hematoma injection site, from anterior to posterior region 24 h after SAH injury.

Results

Neuroinflammation caused by SAH spread to all layers of the cerebral cortex from the anterior to the posterior part of the cerebrum via the invasion of activated microglia, and neuronal cell death increased in correlation with neuroinflammation. This trend increased with the severity of the disease.

Conclusions

Neuroinflammation caused by SAH had spread throughout the cerebrum, causing neuronal cell death. Considering that the cerebral cortex is responsible for long-term memory and movement, suppressing neuroinflammation in all layers of the cerebral cortex may improve the prognosis of patients with SAH.
Transportability Methods for Time-to-Event Outcomes: Application in Adjuvant Colon Cancer Trials
Authors: Zuo Shuozhi , Josey Kevin P. , Raghavan Sridharan , Yang Fan , Juaréz-Colunga Elizabeth , Ghosh Debashis
Published: December 2022

PURPOSE

Differences in the benefits of treatment on 5-year overall survival have been observed in 12 randomized phase III colon cancer adjuvant clinical trials from the ACCENT group. We investigated the reasons for these differences by incorporating the distribution of the observed covariates from each trial.

MATERIALS AND METHODS

We applied state-of-the-art transportability methods on the basis of causal inference, and compared them with a conventional meta-analysis approach to predict the treatment effect for the target population. Prediction errors were defined to evaluate whether the identifiability conditions necessary for causal inference were satisfied among the 12 trials, and to measure the performance of each method.

RESULTS

In the one-trial-at-a-time transportability analysis, the ranks of prediction errors for the target population were mostly consistent with the discrepancy in treatment effects among the 12 trials across the three models. The overall prediction errors between the leave-one-trial-out transportability method and the conventional individual participant data meta-analysis approach were very similar, and more than 40% lower than the overall prediction errors from the one-trial-at-a-time transportability method.

CONCLUSION

The discrepancy in treatment effects among the 12 trials is unlikely to arise from the choice of model specification or distribution of observed covariates but from the distribution of unobserved covariates or study-level features. The ability to quantify heterogeneity among the 12 trials was greatly reduced in both the leave-one-trial-out transportability method and the conventional meta-analysis approach compared with the one-trial-at-a-time transportability method.
On the derivation of the generalized Langevin equation and the fluctuation-dissipation theorem
Authors: Vroylandt Hadrien
Published: December 2022

The generalized Langevin equation is widely used to model the effective dynamics of chemical, soft or biological systems. It is used to describe the evolution of a small number of collective variables, and is derived using the projection operator formalism. However, the validity of the derivation of the generalized Langevin equation in systems featuring non-linear potential of mean force is presently questioned. In this paper, we rigorously derive, using a two-projection operator formalism, the usual form of the generalized Langevin equation with non-linear potential of mean force and constant memory kernel. We show that the usual fluctuation-dissipation theorem is violated and a modified version should be considered. We also illustrate this violation on a numerical example.
Serum Thyrotropin and Triiodothyronine Levels in Levothyroxine-treated Patients
Authors: Ettleson Matthew D , Prieto Wesley H , Russo Pedro S T , de Sa Jose , Wan Wen , Laiteerapong Neda , Maciel Rui M B , Bianco Antonio C
Published: December 2022

Context

Small adjustments in levothyroxine (LT4) dose do not appear to provide clinical benefit despite changes in thyrotropin (TSH) levels within the reference range. We hypothesize that the accompanying changes in serum total triiodothyronine (T3) levels do not reflect the magnitude of the changes in serum TSH.

Objective

This work aims to characterize the relationships of serum free thyroxine (FT4) vs T3, FT4 vs TSH, and FT4 vs the T3/FT4 ratio.

Methods

This cross-sectional, observational study comprised 9850 participants aged 18 years and older treated with LT4 from a large clinical database from January 1, 2009, to December 31, 2019. Patients had been treated with LT4, subdivided by serum FT4 level. Main outcome measures included model fitting of the relationships between serum FT4 vs TSH, FT4 vs T3, and FT4 vs T3/FT4. Mean and median values of TSH, T3, and T3/FT4 were calculated.

Results

The relationships T3 vs FT4 and TSH vs FT4 were both complex and best represented by distinct, segmented regression models. Increasing FT4 levels were linearly associated with T3 levels until an inflection point at an FT4 level of 0.7 ng/dL, after which a flattening of the slope was observed following a convex quadratic curve. In contrast, increasing FT4 levels were associated with steep declines in TSH following 2 negative sigmoid curves. The FT4 vs T3/FT4 relationship was fit to an asymptotic regression curve supporting less T4 to T3 activation at higher FT4 levels.

Conclusion

In LT4-treated patients, the relationships between serum FT4 vs TSH and FT4 vs T3 across a range of FT4 levels are disproportionate. As a result, dose changes in LT4 that robustly modify serum FT4 and TSH values may only minimally affect serum T3 levels and result in no significant clinical benefit.
Religious Distinctions
Authors: Balboni Philip
Published: December 2022

This essay works to clarify Edward Said’s writings on religion, criticism, and the secular, arguing that this clarification has serious implications not only for Said’s project of “secular criticism” but also for understanding the workings of what he called the “critical consciousness” within a “purely secular view of reality.” The essay holds that there are not one but two concepts of the religious operative in Said’s work and maintains that most commentators on Said have ignored the second concept and have therefore misconstrued secular criticism’s relationship to what it nominates as religious. By reexamining Said’s writings on religion, criticism, and the secular, as well as his early studies of modern literature, this essay contends that a secular criticism aware of its commitment to both concepts of the religious allows for a more nuanced and powerful account of the manner in which such criticism can call itself secular. It suggests, furthermore, that this account not only clarifies the workings of Said’s own critical consciousness but also provides a likewise more nuanced view of the “method” or “rationality” such a consciousness deploys in making sense of human life, ingenuity, and history.
Under Construction
Authors: Nancy Jean-Luc
Published: December 2022

Jean-Luc Nancy published four times in Qui Parle during his lifetime: once in 1987, once in 1989, and twice in 2017. “Under Construction: Interventions” marks the first English translation of his first publication in this journal, in its second-ever issue. In this short piece, written five years after his groundbreaking La communauté désoeuvrée, Nancy takes up the question of teaching and its inherent entwinement, as he argues, with “the work of thought.” Teaching is here understood much like Nancy’s community: not as what stems from collaboration but as comprising a series of mimetic displacements, reproductions, gestures. Teaching thus magnifies the possibilities at “the limit of sense.” As Nancy puts it: the reconfiguration of those listening students will continue its reach where a teacher’s mastery has reached its finitude. Amid contemporary conversations about collaborative learning and pedagogical missions, Nancy’s brief missive offers a compelling intervention—an alternative model to that of master and pupil—but envisions a classroom community built on layers of displacement.
Nancy’s Prophetic Voice
Authors: James Ian
Published: December 2022

This article gives a personal recollection of discussions with Jean-Luc Nancy and offers a reflection on these together with a philosophical analysis of texts written by him that were published in 2020 in the volume La peau fragile du monde (The Fragile Skin of the World). It engages with Nancy’s novel understanding of prophecy to understand his own writing as a form of “prophetic voice” receptive to the emergence of the present and its opening onto the future. A meditation on time, the loss of history, and on the need to be receptive to what comes to us as the real and from the real, the article outlines Nancy’s singular, generous, and open praxis and ethos of thought.
Αυτοαξιολόγηση σχολικής μονάδας: Απόψεις διευθυντών/ριών πρωτοβάθμιας εκπαίδευσης
Authors: Κολοσίδου Σοφία , Κακανά Δόμνα
Published: December 2022

Τις τελευταίες δεκαετίες έχει παρατηρηθεί στο εξωτερικό αλλά και στην Ελλάδα αυξημένο ενδιαφέρον από ακαδημαϊκούς και πολιτικούς κύκλους για την αξιολόγηση, εσωτερική και εξωτερική, των σχολικών μονάδων. Σκοπός της παρούσας έρευνας είναι η ανάδειξη των απόψεων διευθυντών/ριών δημοτικής ως προς την έννοια της αξιολόγησης και το πρόσφατο νομοσχέδιο για το πλαίσιο της αυτοαξιολόγησης σχολικών μονάδων (ΦΕΚ 111/Α/2020). Το δείγμα της ποιοτικής έρευνας αποτέλεσαν 12 διευθυντές/ριες δημοτικών σχολείων της Δυτικής Θεσσαλονίκης. Ως ερευνητικό εργαλείο αξιοποιήθηκε η ημι-δομημένη συνέντευξη και ως ερευνητική τεχνική η υβριδική θεματική ανάλυση. Από τα αποτελέσματα προέκυψε πως, ενώ όλα τα στελέχη τάχθηκαν υπέρ της αξιολόγησης ως έννοιας, παρόλα αυτά άσκησαν κριτική στο πλαίσιό της, χαρακτηρίζοντας την άκαιρη και ανεφάρμοστη λόγω κορωνοϊού, γραφειοκρατική και δυσνόητη. Η πλειοψηφία υποστήριξε πως οι προτεινόμενοι δείκτες καλύπτουν τις ανάγκες της αυτοαξιολόγησης, ενώ υπήρξαν στελέχη που εστίασαν σε αστοχίες και παραλείψεις των δεικτών. Επίσης τα μισά σχεδόν στελέχη ανέφεραν φόβους και ανησυχίες που συνδέονται με τον τρόπο υλοποίησης της αυτοαξιολόγησης. Συμπεραίνουμε πως ένα αξιοσημείωτο ποσοστό στελεχών αντιμετωπίζει σκεπτικά ως και αρνητικά την υλοποίηση της αυτοαξιολόγησης. Ενδεχομένως η ενημέρωση και η επιμόρφωσή τους από τους υπεύθυνους κρατικούς φορείς να ήταν σύντομη και να μην κατάφερε να καλύψει επαρκώς τις απορίες και τις ανησυχίες τους επί του θέματος.
Ειδωλολατρική πλάνη ή πρόδρομος του χριστιανισμού;
Authors: Κονάρης Μιχάλης
Published: December 2022

Στις αρχές του 19ου αιώνα σφοδρές αντιπαραθέσεις έλαβαν χώρα στις ΗΠΑ γύρω από τη θέση που θα πρέπει να κατέχει η αρχαία ελληνική γραμματεία στην αμερικανική εκπαίδευση. Οι υποστηρικτές της διδασκαλίας της τόνιζαν ότι τα θεμέλια του δυτικού πολιτισμού ανάγονταν στην αρχαία Ελλάδα· οι επικριτές της, από την άλλη, στηλίτευαν την πλάνη της ειδωλολατρικής και πολυθεϊστικής θρησκείας των αρχαίων Ελλήνων και ισχυρίζονταν ότι τα λογοτεχνικά και καλλιτεχνικά έργα που ενέπνευσε δεν είχαν θέση στην παιδεία ενός χριστιανικού έθνους. Κατέκριναν ιδίως την αρχαία ελληνική μυθολογία, της οποίας τις αναφορές σε πράξεις βίας και ερωτικού περιεχομένου τις θεωρούσαν ως πηγές διαφθοράς. Ανταπαντώντας στις αιτιάσεις τους, οι αμερικανοί κλασικοί φιλόλογοι της εποχής επιχειρηματολογούσαν υποστηρίζοντας ότι η αρχαία ελληνική θρησκεία και μυθολογία όχι μόνο δεν αποτελούσαν κίνδυνο για τα χρηστά ήθη, αλλά εμπεριείχαν αντιθέτως έναν πυρήνα υψηλών θρησκευτικών και ηθικών αρχών οι οποίες προοικονομούσαν τον χριστιανισμό. Στο παρόν άρθρο εξετάζονται αυτές οι αντικρουόμενες προσεγγίσεις και αποτιμήσεις της αρχαίας ελληνικής θρησκείας και μυθολογίας στην αμερικανική ιστοριογραφία του 19ου αιώνα, δίνοντας έμφαση στον ρόλο που διαδραμάτισαν στις διενέξεις υπέρ και κατά της κλασικής παιδείας και στη χριστιανοκεντρική οπτική τόσο των υπερασπιστών όσο και των πολέμιών τους.
Computer Modeling and 3D Printing in Reconstructive Surgery of Skull Bone Defects
Authors: Stupak V.V. , Mishinov S.V. , Koporushko N.A.
Published: December 2022

Краниопластика – вторая после трепанации выполненная нейрохирургическая операция в истории – и сегодня не теряет своей актуальности, несмотря на развитие цивилизации и совершенствование медицинской науки. Тенденции персонализированной медицины сформировали свою нишу в нейрохирургии, которая в первую очередь включила в себя реконструктивные вмешательства, направленные на восстановление утраченных структур черепа. Каждая подобная операция является уникальной, поскольку не существует двух абсолютно идентичных больных с одинаковыми дефектами костей черепа. Развитие компьютерного трёхмерного моделирования нашло своё применение в разрезе проектирования индивидуальных имплантатов: так, процесс создания трёхмерной модели черепа, равно как и создания имплантата, перекочевал в виртуальную среду. После создания имплантата в компьютерной программе его можно воссоздать с помощью трёхмерной печати, которая на сегодняшний день уже крепко укоренилась в парадигме современного медицинского производства. В работе освещена проблема современной реконструктивной нейрохирургии, и представлен опыт оперативных вмешательств с применением индивидуальных имплантатов, полученных путем прямого лазерного спекания порошка титанового сплава на установках промышленного аддитивного производства.
Mastering Professional Terminology and Developing Conceptual Apparatus in Preparing Pre-Service Language Teachers for Professional Communication
Authors: Guschina Yu. , Korenev A. , Perevertkina M.
Published: December 2022

The article is devoted to the difficulties in mastering professional terminology in pre-service language teachers’ education. The aim of the article is to consider this problem in the context of professional communication. Critical analysis of research literature, monitoring and observation of the educational process, as well as diagnostic and final testing in Russian and English were used as research methods. The results of diagnostic testing showed the difficulties of graduate students in defining terms from the field of education and language pedagogy. The results of the final tests clearly indicate the effectiveness of the course described in the article in terms of mastering professional terminology. The scientific novelty in this case consists not only in singling out graduate students who are undergoing academic adaptation into a separate group, but also in considering various aspects of the formation of professionally oriented lexical competence in future language teachers. The practical significance lies both in the possibility of using the course described in the article in other universities, and in the possibility of compiling similar courses on its basis for other profiles and areas of education.
The Role of Communication Factors in the Development of Students’ Presentation Skills
Authors: Baranova O. , Voskresenskaya I. , Lanina M. , Kurukalova E.
Published: December 2022

The article discusses the importance of mastering presentation skills by students as one of the forms of communication. The authors highlight the fact that the need to possess these skills to achieve a competitive advantage of a professional worker of the new time is of crucial importance. The authors aimed to analyze a wide range of mistakes made by students in public speeches of various types and suggest ways to overcome them. The communicative-pragmatic factor was chosen as the basic evaluation criterion. Special attention is paid to translation. When studying the problem, the authors were guided by their own experience of working with students in getting them prepared to various types of scientific conferences and competitions. A conclusion is made on importance of developing in students of self-awareness, which will provide conscious approach and control at all levels of discourse generation: cognitive, linguistic, paralinguistic and psychological.
Does Social Influence Change with Other Information Sources? A Large-Scale Randomized Experiment in Medical Crowdfunding
Authors: Hur Yun Young , Jin Fujie , Li Xitong , Cheng Yuan , Hu Yu Jeffrey
Published: December 2022

We examine how social influence interacts with other information sources to affect user behaviors in the context of medical crowdfunding. We conduct a large-scale randomized field experiment on a leading medical crowdfunding platform, showing friends’ donation information to donors in the treatment group and not showing such information in the control group, and examine how the likelihood to donate differs. In addition, we conduct a survey on Amazon Mechanical Turk to evaluate the informational value of different case attributes in conveying the patients’ need for help to donors. We find that for cases containing attributes with high informational value (e.g., minor patient, severe conditions), social influence is insignificant. In contrast, for cases lacking attributes with high informational value, social influence significantly increases donors’ likelihood to donate. Overall, our results show that the impact of social influence depends on the informational value of other information sources, suggesting that the social influence in our context is primarily informational. Our findings indicate that rather than generating an entrenchment effect, where cases with attributes of high informational value attract disproportionate benefits, social influence can increase donation likelihood to cases that lack such attributes, promoting more equal access to resources overall.

History: Olivia Liu Sheng, Senior Editor; Yuliang (Oliver) Yao, Associate Editor.

Supplemental Material: The online appendices are available at https://doi.org/10.1287/isre.2022.1189 .
Vital pulp therapy: the past, present and future
Authors: El-Ma'aita Ahmad M , Qualtrough Alison JE , Darcey James , Hunter Mark J
Published: December 2022

Vital pulp therapy (VPT) aims to preserve pulpal sensation. Historically VPT was considered a treatment option for deciduous teeth or young immature permanent teeth. Carious pulp exposure in permanent mature teeth was considered a contraindication for VPT and warranted root canal treatment (RCT). Recently, VPT has been used for management of carious pulp exposures in mature permanent teeth, with good outcomes, even in the presence of clinical signs and symptoms suggestive of irreversible pulpitis. VPT is a simple and conservative alternative to root canal treatment in a few clinical situations. It is imperative that dentists understand its indications and techniques.

CPD/Clinical Relevance: The reader should understand the evidence-based changes in approach to VPT and the future direction of this treatment modality.
Assessment of Ecological Conditions and Potential of Pastures, Meadows and Steppes Landscapes of Georgia
Authors: Elizbarashvili Nodar , Grigolia Lado , Sandodze Gela
Published: December 2022

The natural diversity of Georgia is outstanding in the world. This is particularly true with the subtropical and moderate belts of the country presenting over seventy natural landscapes, from humid subtropical or light semiarid forests through moist and Alpine landscapes. Such a variety is the result of several factors, with the following ones being most important: geographical location (location along the border of the tropical and moderate belts), effect of the Black Sea (which never freezes), altitudinal zoning (up to 5200 ml) and several-thousand-year-long history of the economic use of the territory.

The highly diverse landscapes of Georgia complicate the study of the geographical-ecological (geo-ecological) properties of the country. Among such properties, horizontal and vertical structure of landscapes, energy and substance transformation in the landscape (functioning), forms and scales of influence on the landscapes, landscape stability and function, and landscape condition and potential have a particular importance.

The condition of landscapes is determined by the forms and scales of external influence. The character of influence can be considered by the ability of self-regeneration of the landscape structure. It is admitted that if the impact applies to the biologic components only, the landscape preserves the self-generation ability. The self-regeneration mechanism is impossible to maintain if: 1. the influence coincides with or stimulates (increases) the negative natural processes; 2. The basic landscape creator component or relief and climate is under the impact; 3. One ecosystem is changed by another equivalent one.

Potential of landscapes is a spatial-and-time category ensuing from the natural properties of the landscapes, results of anthropogenic impact and kinds and trends of the territory use. In some cases, they attribute the landscape potential to the terms of landscape comfort and quantitative indicators of the landscape structure and components, what gives a too general view of the landscape potential.

Condition and potential of landscapes are important issues of territorial planning, eventually determining the forms of use, protection and sustainable development of pastures, meadows and steep landscapes.

The article evaluates the ecological condition and potential of those landscapes (ecosystems - pastures, meadows and steppes) of Georgia, which are greatly influenced by both human economic activity and climate change trends.
Stofnunareðli framhaldsskóla í faraldurskreppu. Ný reynsla og breytt umboð skólastjórnenda
Authors: Ragnarsdóttir Guðrún , Jónasson Jón Torfi
Published: December 2022

Á vormánuðum 2020 hóf COVID-19 innreið sína. Í kjölfarið var öll staðbundin kennsla í framhaldsskólum færð í fjarkennslu út vorönnina og um haustið breyttist fyrirkomulag skólastarfs ítrekað í takt við síbreytilegar sóttvarnareglur. Markmið þessarar rannsóknar er að öðlast skilning á verkefnum og aðstæðum skólastjórnenda, skólameistara og aðstoðarskólameistara, og samskiptum þeirra við ýmsa hagaðila úr ytra og innra umhverfi framhaldsskólanna á fyrsta ári faraldursins. Jafnframt er leitast við að skoða hvernig niðurstöðurnar speglast í nýstofnanakenningum (e. neo-institutional theories). Leitað var eftir reynslu skólastjórnenda við mjög breyttar aðstæður og breytt umboð þeirra til aðgerða. Byggt var á blandaðri rannsóknaraðferð. Stuðst var við gögn úr tveimur spurningalistakönnunum frá Menntavísindastofnun sem náði til framhaldsskólastigsins alls og sex viðtöl við skólameistara og aðstoðarskólameistara úr þremur framhaldsskólum. Vissir þættir starfsins losnuðu úr viðjum stofnanaramma framhaldsskólans, afstofnanavæddust (e. deinstitutionalised) og breyttust mikið í faraldrinum á meðan áherslur aðila úr ytra umhverfi skóla styrktu stofnanaumgjörð skólanna og drógu úr umboði skólastjórnenda til áhrifa. Rannsóknin staðfestir fyrri niðurstöður um að í sumum tilvikum sé eðlilegt að túlka viðbrögð skólastjórnenda sem viðbrögð stjórnenda skipulagsheilda (e. organizational leadership) og í öðrum tilfellum sem stjórnenda stofnana (e. institutional leadership). Samskiptaform milli ólíkra aðila breyttust og verkefni og verkaskipting þróuðust eftir því sem á leið. Samhliða auknu ákalli kennara um kennslufræðilegan stuðning tóku stjórnendur forystu um vissa tæknilega þætti. Þeir fóru þó ekki út fyrir það umboð sem þeir töldu sig hafa og virtu faglegt sjálfstæði kennara. Mikið álag var á skólastjórnendum og gjá myndaðist á milli starfsfólks að mati viðmælenda, einkum í upphafi faraldursins, sem aftur ýtti undir einangrun í starfi skólastjórnenda. Niðurstöðurnar vekja athygli á eðli skóla sem stofnana annars vegar og skipulagsheilda hins vegar og vekja upp áleitnar spurningar, m.a. um álag, verkaskiptingu og umboð stjórnenda til aðgerða. Þá dregur rannsóknin fram veikleika í samskiptum á milli ólíkra hópa í faraldrinum.
Dynamic range expansion of spatial light modulators based on a module-nπ method
Authors: Zhou Xing , Jia Shuhai , Lin Zihan , Zhang Huajian , Wang Longning , Yu Hongqiang , Zhang Yunlong
Published: December 2022

It is known that the cumbersome

2

π

correction is needed in the traditional module-

2

π

method (i.e., the phase wrapping method) due to the

2

π

deviation of the phase modulation depth of spatial light modulators (SLMs). To avoid the cumbersome

2

π

correction in the module-

2

π

method, this paper proposes a module-

n

π

method, and it can directly utilize any full-field phase modulation depth. First, for a Gaussian phase with a phase depth of 30 rad, wrapped by the module-

3.6

π

, it is reconstructed with the root-mean-square (RMS) values of its phase response are

0.1006

λ

(for the Twyman–Green interferometer) and

0.1101

λ

(for the Shack–Hartmann wavefront sensor method), respectively, which proves that the monitoring accuracy is relatively consistent. Subsequently, some comparative experiments based on the traditional module-

2

π

are performed. The experimental results show that the RMS values of its phase response are

0.8886

λ

(for a modulation depth of 11.3 rad) and

0.2261

λ

(for a modulation depth of 6.28 rad), respectively. All the results have proved that the SLM with a phase modulation depth exceeding

2

π

(e.g., 11.3 rad) has more prominent advantages. More specifically, increasing the SLM’s phase modulation depth can effectively reduce the fringe orders of the wrapped patterns generated by the module-

n

π

method. With the further reduction of the fringe orders, the influence of the fly-back zone error on the wavefront phase modulation is reduced, that is, the modulation accuracy is improved (the RMS values are reduced from

0.2261

λ

to

0.1006

λ

). Different from the traditional module-

2

π

method, there is no need to consider the problems of the SLMs’ over modulation or the insufficient modulation in the module-

n

π

method. Furthermore, it avoids the cumbersome

2

π

correction process, which will make the use of the SLM more convenient.
Double-function enhancement algorithm for low-illumination images based on retinex theory
Authors: Chen Liwei , Liu Yanyan , Li Guoning , Hong Jintao , Li Jin , Peng Jiantao
Published: December 2022

In order to solve the problems of noise amplification and excessive enhancement caused by low contrast and uneven illumination in the process of low-illumination image enhancement, a high-quality image enhancement algorithm is proposed in this paper. First, the total-variation model is used to obtain the smoothed V- and S-channel images, and the adaptive gamma transform is used to enhance the details of the smoothed V-channel image. Then, on this basis, the improved multi-scale retinex algorithms based on the logarithmic function and on the hyperbolic tangent function, respectively, are used to obtain different V-channel enhanced images, and the two images are fused according to the local intensity amplitude of the images. Finally, the three-dimensional gamma function is used to correct the fused image, and then adjust the image saturation. A lightness-order-error (LOE) approach is used to measure the naturalness of the enhanced image. The experimental results show that compared with other classical algorithms, the LOE value of the proposed algorithm can be reduced by 79.95% at most. Compared with other state-of-the-art algorithms, the LOE value can be reduced by 53.43% at most. Compared with some algorithms based on deep learning, the LOE value can be reduced by 52.13% at most. The algorithm proposed in this paper can effectively reduce image noise, retain image details, avoid excessive image enhancement, and obtain a better visual effect while ensuring the enhancement effect.
Perfectly conducting cylinder covered by two layers of dielectric separated by an infinitely thin impedance layer: multiple suppression of the scattered field harmonics (rigorous approach)
Authors: Shestopalov Yury , Matekovits Ladislau
Published: December 2022

We propose and develop a novel rigorous technique that enables one to obtain the explicit numerical values of parameters at which several lowest-order harmonics of the scattered field are suppressed. This provides partial cloaking of the object, a perfectly conducting cylinder of circular cross section covered by two layers of dielectric separated by an infinitely thin impedance layer, a two-layer impedance Goubau line (GL). The developed approach is a rigorous method that enables one to obtain in the closed form (and without numerical calculations) the values of parameters providing the cloaking effect, achieved particularly in terms of the suppression of several scattered field harmonics and variation of the sheet impedance. This issue constitutes the novelty of the accomplished study. The elaborated technique could be applied to validate the results obtained by commercial solvers with virtually no limitations on the parameter ranges, i.e., use it as a benchmark. The determination of the cloaking parameters is straightforward and does not require computations. We perform comprehensive visualization and analysis of the achieved partial cloaking. The developed parameter-continuation technique enables one to increase the number of the suppressed scattered-field harmonics by appropriate choice of the impedance. The method can be extended to any dielectric-layered impedance structures possessing circular or planar symmetry.
Miniaturized infrared spectrometer based on the tunable graphene plasmonic filter
Authors: Dong Jiduo , Tang Linlong , Wei Binbin , Bai Xiangxing , Zang Qing , Zhang Hao , Liu Chunheng , Shi Haofei , Liu Yang , Lu Yueguang
Published: December 2022

Miniaturization of a conventional spectrometer is challenging because of the tradeoffs of size, cost, signal-to-noise ratio, and spectral resolution, etc. Here, a new type of miniaturized infrared spectrometer based on the integration of tunable graphene plasmonic filters and infrared detectors is proposed. The transmittance spectrum of a graphene plasmonic filter can be tuned by varying the Fermi energy of the graphene, allowing light incident on the graphene plasmonic filter to be dynamically modulated in a way that encodes its spectral information in the receiving infrared detector. The incident spectrum can then be reconstructed by using decoding algorithms such as ridge regression and neural networks. The factors that influence spectrometer performance are investigated in detail. It is found that the graphene carrier mobility and the signal-to-noise ratio are two key parameters in determining the resolution and precision of the spectrum reconstruction. The mechanism behind our observations can be well understood in the framework of the Wiener deconvolution theory. Moreover, a hybrid decoding (or recovery) algorithm that combines ridge regression and a neural network is proposed that demonstrates a better spectral recovery performance than either the ridge regression or a deep neural network alone, being able to achieve a sub-hundred nanometer spectral resolution across the 8∼14 µm wavelength range. The size of the proposed spectrometer is comparable to a microchip and has the potential to be integrated within portable devices for infrared spectral imaging applications.
Gapless tuning of quantum cascade laser frequency combs with external cavity optical feedback
Authors: Teng Chu C. , Westberg Jonas , Wysocki Gerard
Published: December 2022

We present the operation of quantum cascade laser frequency combs in an external cavity configuration. Experimental observations show dependence of comb repetition rate and optical spectrum on the external cavity length. The low phase-noise comb regime is extended to a broader range of bias currents, enabling gapless frequency tuning of the comb modes. Dual-comb measurements also confirm improved comb stability in the presence of unwanted optical feedback when operating in an external cavity configuration. These observations indicate that aside from the continuing efforts to assure low and uniform dispersion characteristics of quantum cascade laser frequency combs, the proposed simple approach of adding a broadband external cavity can significantly enhance operation of sub-optimal devices for spectroscopic applications.
Optical memory for arbitrary perfect Poincaré states in an atomic ensemble
Authors: Zeng Lei , Ye Ying-Hao , Dong Ming−Xin , Zhang Wei-Hang , Li En-Ze , Li Da-Chuang , Ding Dong-Sheng , Shi Bao-Sen
Published: December 2022

Inherent spin angular momentum (SAM) and orbital angular momentum (OAM), which manifest as polarization and spatial degrees of freedom (DOFs) of photons, hold a promise of large capability for applications in classical and quantum information processing. To enable these photonic spin and orbital dynamic properties strongly coupled with each other, Poincaré states have been proposed and offer advantages in data multiplexing, information encryption, precision metrology, and quantum memory. However, since the transverse size of Laguerre–Gaussian beams strongly depends on their topological charge numbers | l |, it is difficult to store asymmetric Poincaré states due to the significantly different light–matter interaction for distinct spatial modes. Here, we experimentally realize the storage of perfect Poincaré states with arbitrary OAM quanta using the perfect optical vortex, in which 121 arbitrarily selected perfect Poincaré states have been stored with high fidelity. The reported work has great prospects in optical communication and quantum networks for dramatically increased encoding flexibility of information.
High-gain single-frequency Tm3+-doped ZBLAN fiber amplifier at 2.33 μm
Authors: Li Xuanxi , Zhu Xiran , Yang LinYong , Cui Yulong , Zhou Zhiyue , Wang Meng , Wang Zefeng
Published: December 2022

We report here, to the best of our knowledge, the first high-gain, single-frequency Tm3+-doped fiber amplifier operating at the 2.3-μm band with conventional ground-state pumping transition (3H6→3H4) at 793 nm. The gain fiber is an 8.5-m-long ZBLAN fiber with a Tm3+ doping concentration of 3 mol.%, and the seed is a single-frequency distributed feedback diode laser operated at 2331.9 nm. A gain up to 24.1 dB is generated for ∼14 W of launched pump power with the maximum output power of 246 mW. The competitive 3F4 →3H6 laser transition at ∼2 µm is also investigated, and the prospects for further power scaling are discussed.
Fractal superconducting nanowire single-photon detectors working in dual bands and their applications in free-space and underwater hybrid LIDAR
Authors: Zou Kai , Hao Zifan , Feng Yifan , Meng Yun , Hu Nan , Steinhauer Stephan , Gyger Samuel , Zwiller Val , Hu Xiaolong
Published: December 2022

We demonstrate a fiber-coupled fractal superconducting nanowire single-photon detector (SNSPD) system with minimum polarization dependence of detection efficiency. Its system detection efficiency (SDE) was maximized at the wavelength of 1540 nm, which was measured to be 91 ± 4%; furthermore, we observed the second local maximum of SDE at the wavelength of 520 nm, which was measured to be 61 ± 2%. This dual-band feature of SDE was due to the enhancement of the optical absorptance by two longitudinal resonance modes of the micro-cavity. By using high SDE with minimum polarization dependence in these two bands, we implemented a hybrid LIDAR for imaging the remote objects in free space and under water.
Improved reference-frame-independent quantum key distribution: erratum
Authors: Zhu Jian-Rong , Wang Rong , Zhang Chun-Mei
Published: December 2022

We present an erratum to our Letter [Opt. Lett. 47, 4219 (2022)10.1364/OL.470558]. This erratum corrects the error results of Figs. 2 and 4 due to the error in the simulation code. The corrections have no influence on the conclusions of the original Letter.
Multiband metamaterial emitters for infrared and laser compatible stealth with thermal management based on dissipative dielectrics
Authors: Yu Kun , Zhang Wei , Qian Mengdan , Shen Peng , Liu Yufang
Published: December 2022

The modulation of thermal radiation in the infrared region is a highly anticipated method to achieve infrared sensing and camouflage. Here, a multiband metamaterial emitter based on the

Al
/

SiO

2

/
Al

nanosandwich structure is proposed to provide new ideas for effective infrared and laser-compatible camouflage. By virtue of the intrinsic absorption and magnetic resonance property of lossy materials, the thermal radiation in the infrared region can be rationally modulated. The fabricated samples generally present low emissivity (

ε

3
–
5
 
μm

=
0.21

,

ε

8
–
14
 
μm

=
0.19

) in the atmospheric windows to evade infrared detection as well as high emissivity (

ε

5
–
8
 
μm

=
0.43

) in the undetected band for energy dissipation. Additionally, the laser camouflage is also realized by introducing a strong absorption at 10.6 μm through the nonlocalized plasmon resonance of the

SiO

2

layer. Moreover, the fabricated emitter shows promising prospects in thermal management due to the good radiative cooling property that is comparable to the metallic Al material. This work demonstrates a multiband emitter based on the metasurface structure with compatible infrared-laser camouflage as well as radiative cooling properties, which is expected to pave new routes for the design of thermal radiation devices.
Two distinct lipid transporters together regulate invasive filamentous growth in the human fungal pathogen Candida albicans
Authors: Basante-Bedoya Miguel A. , Bogliolo Stéphanie , Garcia-Rodas Rocio , Zaragoza Oscar , Arkowitz Robert A. , Bassilana Martine
Published: December 2022

Flippases transport lipids across the membrane bilayer to generate and maintain asymmetry. The human fungal pathogenCandida albicanshas 5 flippases, including Drs2, which is critical for filamentous growth and phosphatidylserine (PS) distribution. Furthermore, adrs2deletion mutant is hypersensitive to the antifungal drug fluconazole and copper ions. We show here that such a flippase mutant also has an altered distribution of phosphatidylinositol 4-phosphate [PI(4)P] and ergosterol. Analyses of additional lipid transporters,i.e. the flippases Dnf1-3, and all the oxysterol binding protein (Osh) family lipid transfer proteins,i.e. Osh2-4 and Osh7, indicate that they are not critical for filamentous growth. However, deletion of Osh4 alone, which exchanges PI(4)P for sterol, in adrs2mutant can bypass the requirement for this flippase in invasive filamentous growth. In addition, deletion of the lipid phosphatase Sac1, which dephosphorylates PI(4)P, in adrs2mutant results in a synthetic growth defect, suggesting that Drs2 and Sac1 function in parallel pathways. Together, our results indicate that a balance between the activities of two putative lipid transporters regulates invasive filamentous growth,viaPI(4)P. In contrast, deletion ofOSH4indrs2does not restore growth on fluconazole, nor on papuamide A, a toxin that binds PS in the outer leaflet of the plasma membrane, suggesting that Drs2 has additional role(s) in plasma membrane organization, independent of Osh4. As we show thatC.albicansDrs2 localizes to different structures, including the Spitzenkörper, we investigated if a specific localization of Drs2 is critical for different functions, using a synthetic physical interaction approach to restrict/stabilize Drs2 at the Spitzenkörper. Our results suggest that the localization of Drs2 at the plasma membrane is critical forC.albicansgrowth on fluconazole and papuamide A, but not for invasive filamentous growth.
Design and experiments of an automatic depth-adjusting double screw trencher and fertiliserning
Authors: Zhan Caixue , Ding Wenqin , Han Yu , Jiang Qinghai , Zhao Ying , Zhao Liang , Song Zhiyu
Published: December 2022

In response to the problems of low fertilizer application efficiency, poor operation quality, and uneven application of fertilizer by domestic tea garden trenching and fertilizing machines, an automatic depth-adjusting double screw trenching and fertilizing machine was designed. The machine uses a double spiral furrowing and fertilizer application method, which can complete the integrated operation of furrowing, fertilizer application, and mulching at one time. The key components of the machine such as the screw-type fertilizer discharger, trenching, and fertilizer application mechanism are designed using theoretical analysis, and the trenching depth is automatically adjusted through the hydraulic control system to maintain a consistent depth. A single-factor test and a quadratic regression rotary orthogonal test were conducted to select the diameter of the spiral fertilizer discharger, the rotational speed of the spiral fertilizer discharger, and the rotational speed of the trenching and fertilizer application mechanisms. Based on these tests, the fertilizer application performance of the fertilizer machine was evaluated, and a mathematical model of the fertilizer application volume and coefficient of variation was established. The influence of the test factors on the coefficient of variation was also analyzed. In the study, 58.36 and 480.35 r/min were found to be the optimal rotational speeds for spiral fertilizer discharge and trenching and fertilizer application, respectively, while 88.90 mm was found to be the optimal diameter for spiral fertilizer discharge. The coefficient of variation for the spiral fertilizer discharge was 3.95%, which meets the tea plantation’s fertilizer application requirements.